An apparatus and a method for mitigating interference between uplink signals of a user equipment in a mobile communication system are provided. The apparatus includes a frequency regulator for, when fast movement of a user equipment is confirmed, changing a transmit frequency by calculating a frequency offset compensation value which compensates for a frequency required for a transmit frequency band.

1. Field of the Invention
The present invention relates generally to an apparatus and a method for controlling an uplink frequency in a mobile communication system. More particularly, the present invention relates to an apparatus and a method for controlling a frequency to mitigate interference between uplink signals of a user equipment in a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) mobile communication system.
2. Description of the Related Art
Multimedia systems of the future need to meet demands for fast transmission of high-capacity data, and an increasing demand for wireless communication. Recently, research has been conducted relating to a transmission scheme that allows for high-speed data transmission with high frequency utilization. To transmit high-speed data of a short symbol period, a wide transmission band is required and a frequency selective fading, caused by Inter-Symbol Interference (ISI) or multi-path interference of a radio channel, should be overcome. Multi-carrier techniques transmit data using multiple carriers by extending the symbol period. An Orthogonal Frequency Division Multiplexing (OFDM) scheme, which is one of the multi-carrier techniques, features high frequency utilization by overlapping orthogonal frequency bands of the subcarriers, and fast modulation and demodulation using the multiple carriers through Inverse Fast Fourier Transform (IFFT) and Fast Fourier Transform (FFT). The OFDM scheme can achieve the simple equalization with one tap per subcarrier in the frequency domain by sustaining the orthogonality of the subcarriers using a guard interval longer than a delay spread of the signal of the multi-path channel.
An Orthogonal Frequency Division Multiple Access (OFDMA) transmission scheme sends data using multiple carriers. The multi-carrier maintains a minimum frequency spacing (subcarrier spacing) and thus utilizes the entire frequency band with efficiency.
However, the OFDMA transmission scheme, which is very sensitive to a frequency offset, suffers from Inter-Carrier Interference (ICI) caused by some frequency offset.
To mitigate the interference of the frequency offset, a general mobile communication system adopts a frequency control method using an oscillator and a frequency control method using a numerically controlled oscillator.
FIG. 1 depicts the frequency control method of a static channel in the general mobile communication system.
When a base station transmits a DownLink (DL) signal using a Radio Frequency (RF) center frequency of fRF—BS—DL in FIG. 1, the spectrum is generated as shown in (a).
Next, provided that a frequency offset ΔfRx—UE is generated in consideration of an oscillator variation between the user equipment and the base station while an antenna of the user equipment receives a receive signal in (b), the user equipment receives the receive signal over the RF center frequency fRF—UE—DL as shown in (c). When the user equipment compensates for the frequency offset using an Automatic Frequency Controller (AFC), the signal is received with the transmit and receive frequencies matched as shown in (d).
Meanwhile, UpLink (UL) data of the user equipment is transmitted using a transmit frequency fRF—UE—DL of the frequency spacing fRF—UE—DL−fRF—UE—UL as shown in (e). The base station can receive the signal compensated by the AFC of the user equipment as shown in (f) and (g).
FIG. 2 depicts the frequency control method of a mobile channel in the general mobile communication system.
When the base station transmits a DL signal using the RF center frequency fRF—BS—DL in FIG. 2, the spectrum is generated as shown in (a). Doppler frequency offset generated when the user equipment moves around causes the reception spectrum as shown in (b).
Accordingly, the difference between the RF receive frequency and the RF transmit frequency of the user equipment produces the frequency offset Δfdoppler—DL+Δfosc which combines the Doppler frequency offset and the offset of the transmit and receive frequencies as shown in (c).
Next, when the AFC of the user equipment compensates the frequency offset, the user equipment receives the receive signal of (d).
Meanwhile, the data transmission from the user equipment to the base station uses a transmit frequency fRF—UE—UL with the frequency spacing fRF—UE—DL−fRF—UE—UL as shown in (e). The signal received at the base station suffers the Doppler frequency Δfdoppler—DL as shown in (f).
When the user equipment and the base station use the multi-path channel under the same condition, the Doppler frequency of the base station faces the same direction as the Doppler frequency of the user equipment as shown in (f).
This problem arises when the user equipment moves at a low speed, rather than at a high speed. Hence, a receiver of the base station is subject to the additional frequency offset.
FIG. 3 depicts the signal received at the base station in the general mobile communication system.
When a plurality of user equipments accesses the base station at the same time, the user equipments suffer from the Doppler frequency according to their different channel environments. The signals of the fast moving user equipments and the signals of the slow moving user equipments of FIG. 3 cause the ICI in the uplink of the multi-access scheme, such as OFDMA, and thus degrade the reception performance.

Apparatus and method for controlling frequency in mobile communication system


An LED CoB structure with the combination use of blue and red LED dies is used to achieve warm white light, with good quantum conversion efficiency at a reasonably low cost. Both the red and blue LED dies are fabricated on transparent substrates. The current density of the LED dies is designed to match the different degradation rate of each type of LED die. The methods used to achieve high efficiency include adjusting the power, wavelength, and/or position of the dies.

Current light emitting device (LED) Chip-On-Board (CoB) architectures generate white light through the combination of blue LED dies and phosphors. To achieve warm white light, red phosphors are usually added to convert part of the blue light emitted from blue LED die into red light. The quantum conversion efficiency of red phosphors is usually low and the cost of red phosphors is high.

This patent is subject to a terminal disclaimer.

High efficiency chip-on-board light-emitting diode


The invention relates to a method for preventing or attenuating one or more complications of intracerebral haemorrhage (ICH), the method comprising: (i) selecting an ICH patient who exhibits one or more of the following characteristics: age≦70, baseline ICH volume≦60 mL, baseline IVH volume≦5 mL, and elapsed time since onset of symptoms of less than about 2.5 hours; and (ii) administering to said patient in need thereof an effective amount of a first coagulation agent comprising Factor VIIa or a Factor VIIa equivalent.

Haemostasis is a complex physiological process which ultimately results in the arrest of bleeding. This is dependent on the proper function of three main components: blood vessels (especially the endothelial lining), coagulation factors, and platelets. Once a haemostatic plug is formed, the timely activation of the fibrinolytic system is equally important to prevent further unnecessary haemostatic activation. Any malfunction of this system (due to a reduced number, or molecular dysfunction, of the haemostatic components or increased activation of the fibrinolytic components) may lead to clinical bleeding such as, e.g., haemorrhagic diathesis of varying severity.
In most physiological situations, haemostasis is triggered by the interaction of circulating activated coagulation factor VII (FVIIa) with tissue factor (TF) subsequent to exposure of TF at the site of an injury. Endogenous FVIIa becomes proteolytically active only after forming a complex with TF. Normally, TF is expressed in the deep layers of the vessel wall and is exposed following injury. This ensures a highly localized activation of coagulation and prevents disseminated coagulation. TF also seems to exist in a non-active form, so-called encrypted TF. The regulation of encrypted versus active TF is still unknown.
Intracerebral haemorrhage (ICH) is a neurological condition that occurs spontaneous and results in blood collecting in the intraparenchymal brain tissue. Blood may further collect in the brain ventricles (intraventricular haemorrhage (IVH)). The results of an ICH have been demonstrated to result in significant morbidity and mortality. In recent years ICH has been shown to increase in volume in the hours following the initial insult. This occurs in from approximately 38% (Brott et al., 1997) to 73% (Davis, et al. 2006) of patients suffering from ICH. The reason for the increase is unclear, but it is thought to be either through a continuous oozing of the original haematoma or through a complex process of rebleeds.
Days after the initial insult a zone of oedema can be identified on CT scans—surrounding the blood in the haematoma. The mechanism for oedema generation is also poorly understood but may be due to a combination of an inflammatory reaction in the tissue surrounding the clot as well as a direct mass effect of the clot exerting pressure on surrounding brain tissue. The impact of the isolated oedema can be significant; the effects of oedema on the volume of compromised brain tissue following ICH has been estimated to be up to 3 times the actual volume of the haematoma. The importance of overall effected tissue volume would appear to be one of the strongest predictors of outcome after ICH. Thus there is clinical interest in reducing any haemorrhage expansion and in reducing and/or minimizing the total lesion volume (blood and resulting oedema).
International Publications WO 2005/123118 and WO 2007/009895 relate to the use of Factor VIIa or Factor VIIa equivalents for preventing or attenuating haemorrhage growth, and/or oedema generation following intracerebral haemorrhage (ICH) in patients, including patients having received anticoagulant treatment.
Further trials and analysis have now revealed that a specifically defined subpopulation of patents may benefit in particular from treatment with Factor VIIa or a Factor VIIa equivalent. Thus, there is a further need in the art for improved methods and compositions for acute treatment of ICH, as well as for prevention and attenuation of later complications that result from ICH and from conventional modalities that are used to treat a herein defined subpopulation of patients with ICH.

Use of factor VIIa or factor VIIa equivalents for preventing or attenuating haemorrhage growth, and/or oedema generation following intracerebral haemorrhage (ICH) in a selected subpopulation of ICH patients


A storage medium, an apparatus, a system and a method for writing data to and reproducing data from storage medium is provided. The storage medium comprises a data area for storing data and a management area for storing management data corresponding to data stored in the data area. The management data stored in the management area comprises identification information identifying a route followed by the data stored in the data area in arriving in the data area. The apparatus comprises a data recorder for writing a received data into a data area and an identification information recorder for recording identification information into a management area. The identification information identifies a route followed by the data written to the data area in arriving in the data area.

The present invention relates generally to a recording medium for recording content such as audio data and video data for example, a recording apparatus compliant with such a recording medium, and a recording/reproducing system compliant with such a recording medium, and also including a mass storage medium.
In an electrically erasable non-volatile memory called an EEPROM (Electrically Erasable Programmable ROM), one bit is configured by two transistors. This configuration requires a large occupancy area, thereby restricting the growth in integration density. To solve this problem, a flash memory has been developed in which one bit is realized by one transistor by erasing all bits at once. The flash memory is expected to replace such recording media as magnetic disc and optical disc.
A so-called memory card is known in which the flash memory is used and which is constructed to be detachably mounted on various electronic devices. Use of this memory card can realize digital audio data recording/reproducing apparatuses that use the memory card instead of conventional disc media such as CD (Compact Disc) and MD (Mini Disc).
With systems for recording/reproducing audio data and video data to and from a flash memory based memory card, content such as music may be copied from a recording medium such as a CD to such a memory card. The copied music may then be reproduced from the memory card in a memory-card based reproducing apparatus.
It is also possible to use a mass storage recording medium, such as a hard disc drive (HDD) incorporated in a personal computer for example, as a personal server for storing the music, and for transferring the music the a memory card when desired.
For example, content data stored in a CD or downloaded through the Internet may first be stored on the HDD of a personal computer. The stored content data may then be copied or moved into a memory card. A reproducing apparatus to which the memory card is coupled may then reproduce the content data stored in the memory card. When content data is copied from the HDD to the memory card a copy of the content data remains on the HDD. When content data is moved, the content data is copied from the HDD to a memory card, and then the content data is erased from the HDD (the source of the copy).
In order to protect and enforce copyright protection of the content data, it is desirable to restrict the copying and movement of content data to a certain degree. If free copying and movement of content data are permitted, extensive copyright infringement is likely. On the other hand, from the viewpoint of content users, complete prohibition on procedures for copying or moving content data impairs many of the benefits of being able to transfer and use content data on a number of devices.
Therefore, it is desirable to provide a system including an appropriate management of content data copying and movement operations to ensure the ability to make personal copies of content data by a legitimate user, while protecting the copyrights of the content data.
It is therefore an object of the present invention to provide a method an apparatus that insures a proper management of copy and move operations of content data between recording media.
Another object of the invention is to provide a method and apparatus for ensuring the ability to make personal copies of content data by a legitimate user, while protecting the copyrights of the content data.
A further object of the invention is to provide a method and apparatus for controlling the number of copies of a particular content data are permitted to be made.
Still another object of the invention is to provide a method and apparatus for monitoring copy and move operations performed from a single content data source.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification and the drawings.
In accordance with the invention there is provided a recording medium having a data area for storing content data and a management area for storing management data. The management data is used to manage the data stored in the data area. The management data identifies the path through which the content data has traveled before being stored in the data area. This recording medium may comprise a non-volatile memory or a mass storage medium such as a hard disc drive, for example. The management data further identifies whether the content data stored in the recording medium has been copied or moved to or from another mass storage medium or non-volatile memory.
A recording apparatus compatible with the recording medium is also provided. The recording apparatus comprises a content data recorder for recording transferred content into the content data recording area and a management information recorder for recording management information into the management area. The management information is indicative a source of the content data. The management information identifies a distinction between a first case in which the stored content data is directly transferred from the original source, and a second case in which the stored content data is recorded in an intermediate storage device, such as a mass storage medium, before being stored in the content data recording area. The recording apparatus further comprises a controller for controlling any further copying or moving of the recorded content data based upon the management information. The recording apparatus still further comprises a management information updating apparatus for updating a value of the management data if the content data is copied to or from another storage medium, such as a mass storage medium.
According to the invention, copy and move operations for moving data to and from a recording medium can be enabled or disabled based upon the source of the data, and the type of recording medium.
More specifically, in accordance with the invention, if content recorded in the content data recording area of a recording medium is to have been copied from a mass storage recording medium, this content may be moved only to the mass storage recording medium from which it has been copied, thereby disabling any other copy and move operations. Further, if the content data has been directly transferred from a recording medium of a predetermined type onto a mass storage recording medium (i.e. the content exists on both the recording medium of the predetermined type and the mass storage recording medium at the same time), the management information is updated to be equivalent to management data in the case that the content data has been transferred from the mass storage recording medium to the recording medium of the predetermined type, thereby disabling any further copy and move operations. Still further, as for the content data recorded in the mass storage recording medium, a copy permission count controller can properly disable the copying of the content data from the mass storage recording medium to the recording medium of the predetermined type if a predetermined number of copies have already been made.
The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the apparatus embodying features of construction, combination(s) of elements and arrangement of parts that are adapted to effect such steps, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.

Recording medium, recording apparatus and recording/reproducing system for tracking use and transfer of data


The present invention provides a silver paste containing at least a silver powder, a binder resin, and an organic solvent, wherein the silver powder contains a first silver powder having a D50 of 3.50 to 7.50 μm and a second silver powder having a D50 of 0.80 to 2.00 μm, where D50 represents a 50% value of a volume-based cumulative fraction obtained by laser diffraction particle size distribution measurement; a copper content of the whole silver powder is 10 to 5000 ppm by mass; a copper content of the second silver powder is 80 ppm by mass or more; and the first silver powder contains substantially no copper. The present invention provides a silver paste containing a powder in a high concentration and excellent in printability, and provides a silver conductor film that has a high filling factor, a high film density, high electrical conductivity, and excellent migration resistance.

An electrically conductive paste containing a metal powder to be used for forming an internal electrode or an external electrode of an electronic component has been conventionally widely used. One of the reasons is that an electronically conductive paste containing a metal powder is applicable to various printing methods such as a screen printing method, an offset printing method, a gravure printing method, an inkjet method, a dipping method, a dispensing method, a brush coating method, and a spin coating method, and can form a thick film by performing coating printing once, and hence is advantageous for obtaining a high electrical conductivity as compared with, for example, an electrically conductive ink using an organic metal compound, or the like.
Besides, in order to obtain a high electrical conductivity, a content of the metal powder contained in the electrically conductive paste is preferably higher, and a coating film obtained by printing the paste is required to be dense and have a high density. When the content of the metal powder is high, definite conductivity can be obtained even in pattern formation further refined in the future.
For example, Patent Literature 1 (Japanese Patent Laid-Open No. 2005-174824) discloses the following invention: A metal colloidal particle is used instead of a metal powder for obtaining a highly dense and a highly conductive film, and an organic metal compound is used together to fill a gap between the metal colloidal particles with the organic metal compound, and thus, denseness is increased.
The metal colloidal particle and the organic metal compound contain a large amount of organic components, however, and therefore, if these are used as principal conductive components, a content of a metal component is lower than in a paste using a metal powder, and hence a conductor film with a low specific resistance cannot be obtained. In addition, it is difficult to apply to the above-described various printing methods, and if a large amount of a binder resin, such as a viscosity modifier or the like, is added to the paste for solving this problem, a metal ratio in a resultant coating film is further reduced.
Meanwhile, when a metal powder is used as an electrically conductive component of a paste, a conductor film having a low specific resistance can be obtained if the content of the metal powder is high, but printability is deteriorated as the content of the metal powder is higher. Therefore, in a silver paste, for example, a coating film density described in Patent Literature 2 is 5.4 g/cm3 at the most, and a coating film density described in Patent Literature 3 is about 5.70 g/cm3 at the most. Besides, Patent Literature 4 discloses an example of a nickel paste having a dry film density of 6.2 g/cm3.
In an electrically conductive paste, when a dense coating film is obtained for attaining a high electrical conductivity, printability is sacrificed as in these techniques, and thus, there is a trade-off (antinomic) relationship therebetween. Therefore, there is a demand for an electrically conductive paste capable of simultaneously attaining dense coating film formation and good printability.
There are known cases where two types of silver powders having different particle sizes, that is large and small sizes, are used for obtaining a dense coating film (Patent Literature 5 and Patent Literature 6). However, in particular, in a silver paste using a silver powder, a phenomenon designated as migration is known, and as the amount of the silver powder having a small size (of, for example, less than 0.5 μm) contained in the silver paste is larger, migration more easily occurs.
In order to inhibit the migration, various attempts have been conventionally made by addition of a migration inhibitor containing fluorine to a silver paste (Patent Literature 7), and addition of a mixed powder, an alloy powder, a compound powder or the like containing three elements of copper, tin and manganese to a silver powder (Patent Literature 8).


An electronic endoscope system includes a light source apparatus, a CCD, and a processor apparatus. The light source apparatus applies illumination light to a target portion. The target portion includes a surface blood vessel and a subsurface blood vessel. The CCD captures light reflected from the target portion. The processor apparatus generates an image based on an imaging signal from the CCD. The processor apparatus has a suppression processor. Out of the surface blood vessel and the subsurface blood vessel in an image, the suppression processor reduces contrast of a non-target blood vessel relative to that of a target blood vessel to suppress or reduce display of the non-target blood vessel relative to that of the target blood vessel.

1. Field of the Invention
The present invention relates to an electronic endoscope system for capturing an image of a portion to be observed in a subject using an electronic endoscope.
2. Description Related to the Prior Art
Diagnoses and treatments using an electronic endoscope are common in the medical field. In an electronic endoscope system for capturing an image of a portion to be observed in a subject using an electronic endoscope, normal light observation using white light (hereinafter referred to as the normal light) as illumination light is performed. However, it is often difficult to observe details of tissue under the normal light observation. To observe the details, special light observation has been performed recently. Under the special light observation, an image is captured while narrowband light (hereinafter referred to as the special light) in a specific wavelength range is applied to the portion to be observed. Thereby, it becomes easy to observe details of specific tissue in the image captured. Under the specific light observation, an image shows clear contrast between tissue which absorbs the special light and remaining tissue. Thus, the tissue which absorbs the special light is enhanced in the image.
On the other hand, a technique to improve contrast of specific tissue by applying image processing to an image has been known. Thereby, the specific tissue is enhanced in the image. For example, by applying frequency enhancement processing for enhancing an image of a predetermined frequency, contrast of a blood vessel (hereinafter referred to as the surface blood vessel) located in a mucosal surface or a blood vessel (hereinafter referred to as the subsurface blood vessel) located below the surface blood vessel improves (see Japanese Patent Laid-Open Publication No. 2000-148987).
Under the special light observation, the tissue which absorbs the special light is enhanced. However, remaining tissue observable under the normal light observation is also shown in the image in the same manner as the normal light observation. Accordingly, the tissue which absorbs the special light is superposed on the remaining tissue observable under the normal light observation in the image displayed.
For example, under the normal light observation, a surface blood vessel is superposed on a subsurface blood vessel in an image. When the special light observation is performed, the image of the surface blood vessel, which absorbs the special light, is enhanced in a state that the surface blood vessel is superposed on the subsurface blood vessel. The subsurface blood vessel often hinders the close observation of the surface blood vessel.
Conversely, when the special light observation is performed using special light absorbed by the subsurface blood vessel to enhance the subsurface blood vessel, the subsurface blood vessel is enhanced while being superposed by the surface blood vessel. The surface blood vessel often hinders the close observation of the subsurface blood vessel.
On the other hand, frequency enhancement processing improves contrast of an image of a predetermined frequency. The frequency enhancement processing is applied to an image captured under the special light observation. However, tissue under observation may be enhanced incorrectly depending on a subject distance.
More specifically, when the subject distance is long, a subsurface blood vessel is narrow in an image captured. Accordingly, the frequency enhancement processing, aiming at the surface blood vessel, enhances the subsurface blood vessel instead. Conversely, when the subject distance is short, the surface blood vessel is wide in the image. Accordingly, frequency enhancement processing, aiming at the subsurface blood vessel, enhances the surface blood vessel instead.
Under the special light observation, the surface blood vessel is superposed on the subsurface blood vessel in an image. It is difficult to observe a target blood vessel when a non-target blood vessel is enhanced with the frequency enhancement processing.
To solve the problem, it is desired to improve visibility of the target blood vessel without being hindered by non-target blood vessel(s).

Electronic endoscope system including a suppression section


A method to alter the phenotype of animals, e.g., the progeny of egg laying vertebrates, which employs passive immunization, is provided.

The transforming growth factor β (TGF-β) superfamily encompasses a group of structurally related proteins. The proteins of the TGF-β family are initially synthesized as a large precursor protein which subsequently undergoes proteolytic cleavage at a cluster of basic residues approximately 110-140 amino acids from the C-terminus. The C-terminal regions, or mature regions, of the proteins are all structurally related and the different family members can be classified into distinct subgroups based on the extent of their homology. Although the homologies within particular subgroups range from 70% to 90% amino acid sequence identity, the homologies between subgroups are significantly lower, generally ranging from only 20% to 50%. The active species appears to be a disulfide-linked dimer of C-terminal fragments (Hammonds et al., 1991), although for some family members (Ling et al., 1986; Cheifetz et al., 1987), heterodimers have also been detected and appear to have different biological properties than the respective homodimers.
The TGF-β family includes Mullerian inhibiting substance (MIS) (Behringer et al., 1990), which is required for normal male sex development, Drosophila decapentaplegic (DPP) gene product, which is required for dorsal-ventral axis formation and morphogenesis of the imaginal disks (Padgett et al., 1987), the Xenopus Vg-l gene product, which localizes to the vegetal pole of eggs (Weeks et al., 1987), the activins, which can induce the formation of mesoderm and anterior structures in Xenopus embryos (Thomsen et al., 1991), and the bone morphogenetic proteins (BMPs, osteogenin, OP-1) which can induce de novo cartilage and bone formation (Sampath et al., 1990). Another member of the TGF-β superfamily, myostatin (also known as growth/differentiation factor-8 or GDF-8), is synthesized by skeletal muscle, and regulates the proliferation and differentiation of myoblasts. The members of the TGF-β family can thus influence a variety of differentiation processes, including adipogenesis, myogenesis, chondrogenesis, hematopoesis, and epithelial cell differentiation (Massague, 1987).
Because the members of the TGF-β family are involved in differentiation, the association of a particular TGF-β member with a certain characteristic in an animal and the manipulation of the expression of the gene(s) associated with that characteristic is of interest. For example, muscle mass in Belgian Blue cattle, due primarily to hyperplasia of muscle cells, is increased by approximately 20% (referred to as double-muscling) with a corresponding decrease in bone and fat mass (Shahin and Berg, 1985). Belgian Blue cattle are particularly valuable livestock as they utilize feed efficiently and give rise to a higher percentage of desirable cuts of meat (Casas et al., 1997). Double-muscling in Belgian Blue cattle was observed to be an inherited trait that was recessive because heterozygotes were normal or had only a modest increase in muscle mass. Molecular analyses found that these cattle expressed a non-functional myostatin protein (see, e.g., WO 99/02667). Another breed of cattle, the Piedmontese, and myostatin gene knock-out mice, also exhibit double-muscling (McPherron and Lee, 1997; Grobet et al., 1997; McPherron et al., 1997; Kambadur et al., 1997). Thus, myostatin has been hypothesized to regulate the amount of skeletal muscle mass in a negative manner.
To prepare transgenic species having increased muscle tissue, e.g., for livestock with high muscle and protein content, the delivery of mutated myostatin genes to animals has been proposed. See, e.g., WO 98/33887. Despite the advantages of double-muscling, double-muscled cattle often have undesirable traits. The myostatin gene becomes active during the embryonic stage, and any reduction in myostatin production causes excessive muscle development in utero, leading to larger offspring. Belgian Blue calves are generally 10-38% heavier than normal, dystocias are prevalent, requiring cesarean deliveries. These animals also exhibit abnormal reproduction due to poorly developed reproductive tracts and have other anatomical abnormalities such as macroglossia. Thus, transgenic animals having mutated myostatin genes, like Belgian Blue cattle, would likely require cesarean delivery and exhibit anatomical abnormalities, a serious burden to large animal producers. Additionally, there is public opposition to genetically engineered animals for human consumption.
Thus, what is needed is a method to prepare non-transgenic animals having increased muscle mass, preferably without an increase in fat content, as well as having acceptable performance, e.g., the animals utilize feed efficiency, and retain reproductive function and general health.

Use of passive myostatin immunization in egg laying vertebrates


A three step process for regenerating spent bleaching clays and acid-activated smectite catalyst granules includes: (1) an extraction step to remove a majority of entrained oil, preferably about 75% to about 95% by weight of the entrained oil, when regenerating bleaching clays; (2) an oxidation step to remove the majority of remaining carbonaceous adsorbates which are not removed by the preceding extraction step, and (3) an acid wash step to restore the acidity normally associated with fresh acid-activated bleaching clays. The features of steps 2 and 3 may be combined into a single step by using an appropriate oxidant, for example, a source of acidic protons, such as peracetic acid.

Acid-activated bentonite clays in the form of finely ground powders, commonly called bleaching clays or bleaching earths, are used to adsorb colored pigments, such as carotenoids and chlorophyll, as well as colorless contaminants, such as phospholipids, and hydroperoxides from edible and inedible oils. This process is called "bleaching" and serves both cosmetic and chemical purposes: (i) it reduces color--very clear, almost water white oils are produced that meet with U.S. consumer expectations, and (ii) it stabilizes the oil--both the colored pigments and colorless contaminants tend to destabilize the oil (i.e., cause the oil to become rancid more easily) if they are not removed.
Usually, the bleaching process includes adding a bleaching clay powder to a contaminated oil at levels in the range of about 0.35 to about 3.0 wt %, depending on the type and quality of oil being processed. The clay/oil mixture then is heated to a temperature in the range of about 90.degree. C. to about 120.degree. C. for about 20 to 30 minutes, after which time the now "spent" clay is separated from the bleached oil by filtration, using filter presses or pressure leaf filters. Typically, the filter cake resulting from the filtration operation contains the pigments and other contaminants removed from the oil, as well as considerable quantities, for example, about 25 to about 40 wt %, of entrained oil that is difficult to remove from the spent clay.
It is known that when extra processing, such as solvent or lye-extraction, is employed to remove the entrained oil from the spent clay, the extracted oil is of poor quality. In addition, the extra processing involved is both difficult and expensive. Accordingly, most oil refiners choose to dispose of spent bleaching clay from their operations by having it hauled away to landfill sites.
Unfortunately, spent bleaching clays also possess rather high surface areas, for example, about 250 to about 350 m.sup.2 /gm, and when the spent clays are saturated with entrained oils, they can spontaneously ignite. Because of this pyrophoric tendency, oil-laden spent bleaching clays are classified as hazardous landfill materials and premium rates are levied to dispose of them in landfill sites. From the standpoint of the individual refiner whose margins in this highly competitive industry are tight, these extra expenses are an additional and unwanted burden. From the standpoint of municipalities faced with the problems of acquiring and managing landfill sites, they are becoming increasingly stringent regarding the types of materials they will accept for these sites and striving to encourage recycling as a way of reducing demand. However, even though there has been a long felt need in the industry to recycle the oils and the bleaching clays, until the present invention, there has been no solution to this costly problem.
Although the dosage levels of bleaching clays used to process edible and inedible oils are actually quite low, the magnitude of this problem can be appreciated by considering the fact that about 10 million metric tons of edible and inedible oils were processed in the United States in 1990. At an average dosage level of about 0.75 percent by weight bleaching clay, processing would yield about 75,000 metric tons per year of spent clay plus an additional 30,000 metric tons per year of entrained oils that must be disposed of.
One approach to solving the disposal problems associated with the creation of spent bleaching clays from edible and inedible oil refining processes is to regenerate and recycle the spent clay. Although a number of processes have been described for the purpose of accomplishing this objective, all previous processes suffer from the inability to completely regenerate the spent clay. It is important to appreciate that since bleaching clays are used only once in a batch-type operation, if anything less than complete regeneration is accomplished, the economics of performing the regeneration, coupled with the cumulative loss in bleaching activity, would combine, after only a few cycles, to produce a regenerated clay that would be an unattractive alternative to the use of fresh bleaching clay. Table I shown below can be used to illustrate the loss in cumulative regenerated activity at different (constant) regeneration levels.
TABLE I ______________________________________ % % Regenerated activity remaining Regeneration after cycle per cycle 1 2 3 4 5 6 ______________________________________ 97.5 97.5 95.1 92.7 90.4 88.1 85.9 95 95 90.3 85.7 81.5 77.4 63.5 92.5 92.5 85.6 79.1 73.2 67.7 62.6 90 90 81.0 72.9 65.6 59.0 53.1 ______________________________________
The use of organic solvents presents a number of environmental and safety problems associated with their use. Included among them are the necessity for having: (1) processing systems which have fire and explosion safeguards; (2) equipment for capturing any vapors that might otherwise escape to the atmosphere; and (3) equipment for separating, purifying and recycling the organic solvents. These requirements all add considerably to the expense of utilizing any regeneration process which might require the use of organic solvents.
The possibility for regenerating spent bleaching earths has been studied by other workers. Bahl and Dayal, Research and Industry, 22, 145 (1977), pointed out that the simplest possible method of regenerating bleaching clays after their use in oil refining operations was to subject the oil-soaked clays to a controlled burning operation. They noted, however, that localized overheating of such oil-soaked clays during the burning operation was difficult to control, and further, that no value was derived from the entrained oil. Further, it was reported that with each burning cycle, the activity of the clay declines, and that a portion is lost as fines. Also it was noted that regeneration of finely powdered clays, such as the bleaching powders processed in accordance with the present invention, is rarely economical since the fine powdered clay escapes with the combustion gases during burning.
Simpson, et al. U.S. Pat. Nos. 2,246,127 and 2,449,016 disclose a regeneration procedure for granulated bleaching clays, used to treat petroleum oils, in which at least some residual matter is carbonized and the clay, together with a coating of activated carbon, is a more active adsorbent than the original clay. The Simpson, et al. U.S. Pat. Nos. '127 and '016 patents teach that solvents, used to extract oil from a bleaching clay, are generally not favored commercially because they are too expensive. A number of patents have issued based on organic solvent regeneration, such as disclosed in U.S. Pat. Nos. 2,286,815; 2,370,713; and 3,472,786. Fuege and Janssen, J. Amer. Oil Chemists' Soc., 28, 429 (1951), claim 96-97% regeneration of spent bleaching clays when using polar organic solvents, such as alcohols, ethers, and ketones. However, the degree of regeneration drops to the 79-80% range after about 20 cycles.
Some attempts to regenerate spent bleaching clays use both water and organic solvents during the regeneration process. Zerbe U.S. Pat. No. 2,352,064 discloses treating the clay with benzene and a benzene-alcohol mixture for regenerating spent clay; and then a water treatment. Likewise, Rhenania French Patent No. 869,534 discloses the use of water at the end of the regeneration procedure, after first washing the clay with an organic solvent, such as benzene or toluene, to remove oil and then using a mixed solvent such as benzene and 10% ethanol for extraction of resinous products. Martin U.S. Pat. No. 2,328,158 discloses the use of a blend of about 3 parts naphtha and 1 part of a ketone, and water maintained in a proportion of at least 5% to regenerate spent bleaching clays. Other processes disclose the use of organic solvent extractions in conjunction with high temperature heat treatments for spent clay regeneration, as disclosed in British Patent No. 491,338; Swiss Patent No. 237,380; Indian Patent No. 61,157; and German Patent No. 1,941,758.
More recently, Kalam and Joshi J. Amer. Oil Chemists' Soc., 65, 1917 (1988), report utilizing a hexane extraction step followed by high temperature aqueous regeneration, and point out that although numerous processes for regenerating spent bleaching earths already exist, they are either too complicated or too costly. Because of this, the general practice is still to simply discard the spent, oil-saturated material in landfill sites. In the Kalam and Joshi process, the spent, oil-saturated clay is first extracted with hexane and then dried at 110.degree. C. for six hours to remove all traces of solvent. Afterwards, the clay is autoclaved at temperatures in excess of 235.degree. C. for six hours. Regenerated clay from this process was found to possess about 80% as much bleaching activity as fresh bleaching clay. In a more successful variation of this process Ibid., 65, 1537 (1988), the clay is first extracted with hexane, as before, but then a small partial pressure of oxygen is maintained in the autoclave during the aqueous thermal regeneration. Best results were obtained at low slurry concentrations, e.g., 5 wt % spent clay, when temperatures were in excess of 200.degree. C., with 0.5 MPa of oxygen partial pressure, and conditions maintained for six hours. 100% regenerations were obtained, and could be maintained at that level through at least four cycles.
Waldmann and Eggers, Ibid., 68, 922 (1991), disclose the use of CO.sub.2 under supercritical conditions to extract and regenerate spent bleaching clay. Although good removal of oil was achieved (up to 97% in the case of palm oil), carotenoids present in vegetable oils appear not to be removed by this extraction process. The regenerated clay exhibited excellent (100%) efficiency for removing chlorophyll, but only about 50% as much activity as fresh bleaching clay for removing carotenoids, presumably because carotenoids already present were blocking adsorption sites normally used in the removal of the carotenoids. Model U.S. Pat. No. 4,124,528 discloses a similar process to regenerate spent activated carbon which had been used to treat waste water.
Surprisingly, the process of the present invention for regeneration of bleaching clays eliminates the disadvantages of prior art recycling processes and provides essentially complete regeneration of spent bleaching clays, and acid-activated clay catalysts. The process of the present invention yields a low grade oil from the bleaching clay regeneration process that is suitable for use as a fuel oil, for blending in animal feed, or as a source oil for the production of fatty acids, among other uses.
In accordance with another important aspect of the process of the present invention, granulated acid-activated smectite clay catalysts, e.g., olefin polymerization catalysts and other catalysts, e.g., for alkylation of olefins, in the form of acid-activated smectite clay granules, can be regenerated using the process of the present invention. As disclosed in this Assignee's copending application entitled "PROCESS OF ACID BINDING FINE SMECTITE CLAY PARTICLES INTO GRANULES", Ser. No. 08/011,273, filed Jan. 29, 1993 acid-activated smectite clay-based catalyst, in granule form, is manufactured by acid binding smaller (fine) smectite particles such that the bound clay particles, in the form of acid-bound granules, have sufficient breaking strength and structural integrity to perform as a olefin polymerization catalyst, with substantially increased yield (.apprxeq.100%) due to the capability of recycling all fine clay particles produced in grinding. The bentonite clay-based polymerization catalyst is manufactured by adhering together a plurality of smaller acid-activated bentonite clay particles, using a strong mineral acid, such as H.sub.2 SO.sub.4, as a binder. An acid-activated bentonite clay having a particle size distribution in the range of about 2 microns to about 200 microns, predominantly (>50%) in the range of about 45 microns to about 130 microns, preferably calcium bentonite, having calcium as a predominant exchangeable action, is mixed with a strong mineral acid, preferably H.sub.2 SO.sub.4, in an amount of about 1% to about 5% by weight, and water, preferably in an amount of about 50% to about 65% by weight to form the catalyst. The mixture is subjected to intensive mixing, curing and drying to form strong particles capable of grinding to a desired particle size distribution, e.g., -6 mesh to +60 mesh, U.S. Sieve Series, to form the catalyst. Fines resulting from the grinding step are completely recycled to the intensive mixing stage of the process to achieve 100% yield. Some adjustment of acid content of the mix may be needed to take into account the acid carried into the mix by recycled fines.
The acid-activated smectite clay-based catalyst granules (e.g., formed from acid-activated calcium bentonite), are primarily useful for treating extraction unit extract streams for recovery of aromatic hydrocarbons free from reactive olefins. The clay-based catalyst is characterized by its mildly acidic catalytic activity and at temperatures of between about 150.degree. C. and about 200.degree. C. (about 300.degree. F. to about 400.degree. F.), the acid sites on the clay promote polymerization and alkylation of olefins. Such acid-activated smectite clay-based granules also can be regenerated in accordance with the process of the present invention.

Process for regenerating spent acid-activated bentonite clays and smectite catalysts


Disclosed are organosilicon crosslinked polymers and crosslinkable prepolymers that are the reaction product of (a) a cyclic polysiloxane in which each silicon atom is substituted with (i) a saturated, substituted or unsubstituted alkyl or alkoxy group or a substituted or unsubstituted aryl or aryloxy group, and (ii) a substituted or unsubstituted hydrocarbon group having at least one carbon-carbon double bond that is reactive in hydrosilation, (b) at least one organosilicon compound having at least two .tbd.SiH groups, and optionally (c) a hydrocarbon polyene having at least two nonaromatic carbon-carbon double bonds that are reactive in hydrosilation. A process for preparing the polymers and prepolymers and for preparing the cyclic polysiloxanes is also disclosed.

Leibfried, in U.S. Pat. Nos. 4,900,779, 4,902,731 and 5,013,809, and Bard and Burnier in U.S. Pat. Nos. 5,008,360 and 5,068,303, describe crosslinked organosilicon polymers and crosslinkable organosilicon prepolymers comprising alternating polycyclic hydrocarbon residues and cyclic polysiloxane or siloxysilane residues linked through carbon-to-silicon bonds. These polymers are useful, for example, in structural and electronic applications.
Although cyclic trisiloxanes were disclosed for use in the preparation of organosilicon polymers and prepolymers in U.S. Pat. 5,013,809 (Leibfried) and in Research Disclosure 326103 (June, 1991), these cyclic trisiloxanes were required to have two or more hydrogen atoms bound to silicon. Only cyclosiloxanes containing four or more silicon atoms were used in the preparation of these polymers and prepolymers, because cyclotrisiloxanes are not readily available and are unstable. It is also known that cyclotrisiloxanes with hydrogen atoms and methyl groups bonded to every silicon atom are not storage-stable.
Cyclopolysiloxanes in which some of the Si atoms are substituted with unsaturated polycyclic groups have been disclosed in U.S. Pat. No. 4,599,440, e.g., the reaction product of pentamethylcyclotrisiloxane and 5-ethylidenebicyclo(2,2,1)hept-2-ene. None of these compounds have unsaturated hydrocarbon groups on every silicon atom.

Fully substituted cyclopolysiloxanes and their use for making organosilicon polymers


Photographic film is dried in a film dryer having a pattern of film guide rollers inside a hollow drying chamber contained in an outer drying housing. A continuous film strip is passed through the chamber and around the rollers so that long lengths of the film between adjacent sets of guide rollers pass through the chamber in substantially parallel directions for exposure to warm drying air passing through the chamber. A supply of warm air is introduced into a supply plenum contained in the housing on one side of the guide rollers and a similar exhaust plenum is contained in the housing on the opposite side of the rollers. The supply plenum has a pattern of inlet openings arranged so that supply of warm air in the plenum is directed into the chamber to flow adjacent to and substantially parallel to the lengths of film supported on the rollers sufficiently to dry the film before it exits the housing. Air is withdrawn from the exhaust plenum after the air has flowed past the lengths of film. The parallel pattern of airflow through the chamber is controlled so that airflow is smooth past the lengths of film. The parallel direction of airflow through the chamber inhibits dirt particles contained within the chamber from impinging upon the emulsion surface of the film as the film dries in the chamber.

In processing photographic films, the film passes through water-based chemical solutions and is then dried. The drying process involves running the film over multiple rollers inside a cabinet and blowing heated air across the film. A problem which exists with most film dryers on the market today is that the film itself generates a small amount of dirt as it runs over the film rollers. All existing film dryers circulate the heated air through large portions of a cabinet known as a "drybox." In circulating the air through the drybox, some of these dirt particles become embedded in the emulsion of the film. The emulsion is a coating applied to the surface of the film for protection and is very sticky when wet. In the existing film dryers, as the warm air used to dry the film is moved throughout the drybox, it is moved in a perpendicular or circular direction with respect to the film and deposits dirt on the emulsion surface of the film.


A device for reversing chiller airflow in an aircraft galley includes an air bypass port connected between a supply airflow duct and a return airflow duct, and an air recirculation bypass flap is movable between a closed position allowing normal airflow circulation through the supply airflow duct and an open position blocking the supply airflow duct and diverting chilled supply airflow to the return airflow duct for recirculation. The air recirculation bypass flap is electrically actuated by a solenoid responsive to a bay door position detector.

This invention relates generally to transport aircraft galley systems, and more particularly relates to systems to air chiller supply air recirculation systems used to cool aircraft galley food carts.
Aircraft galley systems for modern transport aircraft incorporate food carts which are cooled to prevent food spoilage prior to use by the cabin attendants for distribution of food to passengers. These food carts are typically interfaced with cold air supply systems in the galley designed deliver cooled air via air ducts to cool the interiors of the food carts. Galley cooling systems are typically mounted in a galley cabinet, so that cool air is discharged from the galley cooling system and circulates over or through galley food carts in a galley cabinet to return to the galley cooling system to again be cooled and discharged. However, such galley chilling systems can be misused for cooling an indoor space of a galley area in hot, humid climates during in-flight operation by opening bay doors of galley chilled compartments, which makes it difficult to maintain chilled food in galley food carts at or below a required set temperature, and typically results in the ingestion of a large volume of warm, moist air in the galley cooling systems, which in turn can cause freezing of an evaporator of a galley air chiller unit, requiring premature and/or unscheduled defrost cycles in such galley air chillers.
An air conditioning dehumidification system is known that is provided with indoor and outdoor air, in which indoor air not cooled by passing through a heat exchanger but is directed by a face and bypass damper through a bypass duct extending around the heat exchanger from an input mixing plenum to an output mixing plenum at the output of the heat exchanger, to control cooling of air flowing through the input mixing plenum. Another air conditioning system is known in which a rate of cooling is controlled by varying the operation of refrigerant compressors and by varying flow of recirculating air between a path through an expansion unit where air is cooled and a path bypassing the expansion unit. First and second dampers are controlled by a thermostat, so that the first damper is closed as the second damper is opened.
It would be desirable to provide an apparatus that can reverse chiller airflow in an aircraft galley chilling system to avoid premature and/or unscheduled defrost cycles in galley air chillers from the unnecessary ingestion of moist air when aircraft galley food cart bay doors are opened, and that helps maintain chilled food in aircraft galley food carts at or below a set temperature to limit food poisoning risks. The present invention meets these and other needs.

Device for reversing chiller airflow in an aircraft galley


A fluid pressure circuit includes an HST circuit having a variable capacity fluid pressure pump configured to be driven by a mechanism to perform forward-reverse rotation, a fluid pressure motor configured to be driven by fluid discharged from the fluid pressure pump to perform forward-reverse rotation, a first line configured to connect a first port of the fluid pressure pump and a first port of the fluid pressure motor, and a second line configured to connect a second port of the fluid pressure pump and a second port of the fluid pressure motor; an accumulator connected in parallel with the fluid pressure pump; an accumulator pump configured to accumulate pressure fluid in the accumulator; and an accumulator switching valve configured to switch connection between the fluid pressure motor and the accumulator.

A conventional HST circuit for traveling a wheel loader will be described, the HST circuit being configured as a closed circuit having a hydraulic pump and a hydraulic motor (see, e.g., Patent Citation 1). Referring to FIG. 8, a hydraulic pump 1 is a variable capacity bidirectionally-rotatable pump to be driven by a drive mechanism 2 such as an engine. In the case of performing forward rotation F of the hydraulic pump 1, oil discharged from the hydraulic pump 1 flows into a bidirectionally-rotatable hydraulic motor 4 through a line 3, and then, flows out to a line 5. The oil having passed through the line 5 flows into the hydraulic pump 1. Forward rotation F of the hydraulic motor 4 occurs due to a pressure difference between before and after the hydraulic motor 4.
In the case of performing reverse rotation R of the hydraulic pump 1, the oil discharged from the hydraulic pump 1 flows into the hydraulic motor 4 through the line 5, and then, flows out to the line 3. The oil having passed through the line 3 flows into the hydraulic pump 1. Reverse rotation R of the hydraulic motor 4 occurs due to the pressure difference between before and after the hydraulic motor 4.
Relief valves 6, 7 are further installed in the circuit. These relief valves 6, 7 are set to a predetermined relief pressure. When a high pressure generated at the line 3 reaches the relief pressure, the relief valve 6 is operated such that the oil flows out to a low-pressure line 8, thereby preventing overload of the line 3. Similarly, a high pressure generated at the line 5 reaches the relief pressure, the relief valve 7 is operated such that the oil flows out to a low-pressure line 9, and in this manner, overload of the line 5 is prevented.
The hydraulic pump 1 is configured so that the amount of oil discharged from the hydraulic pump 1 can be controlled from 0 (zero) to the maximum value by changing the tilting amount of a swash plate 1a from 0 (zero) to the maximum value in accordance with an external signal (not shown).
Referring to FIG. 9, there has been proposed another HST circuit used for travelling a vehicle (also referred to as a travelling HST circuit), which is configured for effectively utilizing high-pressure oil such that an accumulator 10A is connected to a hydraulic motor, that high-pressure oil generated from the hydraulic motor upon deceleration of a vehicle is accumulated in the accumulator 10A, and that the high-pressure oil accumulated in the accumulator 10A is used upon start of the vehicle (see Patent Citation 2).


For increasing a dynamic range, and for signal processing according the gain of an amplifying unit, an imaging apparatus comprises a pixel configured to generate a pixel signal by photoelectric conversion, an amplifying unit amplifying the pixel signal generated by the pixel using a plurality of gains and outputting a plurality of pixel signals corresponding to the plurality of gains, a synthesizing unit selecting one of the plurality of pixel signals output by the amplifying unit in accordance with the size of the pixel signal output by the amplifying unit and outputting a signal based on the selected pixel signal, and a signal processing unit processing the signal output by the synthesizing unit in accordance with the gain of the amplifying unit corresponding to the pixel signal selected by the synthesizing unit.

1. Field of the Invention
The present invention relates to an imaging apparatus.
2. Description of the Related Art
For imaging apparatuses, there has been a demand for an increase in S/N and in dynamic range. A method for meeting the demand is disclosed in Japanese Patent Application Laid-Open No. 2004-15701. In this method, a gain applied before AD conversion is switched depending on the size of an analog signal. A higher gain is applied to a smaller analog signal to relatively reduce the adverse effect of possible subsequent noise. This allows the S/N to be improved. An imaging apparatus includes an image processing unit configured to carry out various types of image processing after reading images. For example, in the imaging apparatus in Japanese Patent Application Laid-Open No. 2004-15701, the image processing unit is connected to the latter stage of a noise canceller and a gain mismatch circuit. To carry out processing such as gain correction and shading correction, the image processing unit may require information on at what gain each pixel data has been read. As illustrated in FIG. 1 and FIG. 10 of Japanese Patent Application Laid-Open No. 2004-15701, gain information applied before AD conversion is output to the latter stage as an M-bit signal, separately from output N-bit data.
However, when the image data and the gain information are separately output to the latter stage as in the case of Japanese Patent Application Laid-Open No. 2004-15701, the number of required output lines is increased, and the system becomes complicated.


A voltage regulator for a static random access memory operating either in a standby mode or a operation mode is provided. The voltage regulator includes a reference voltage generating circuit for generating a reference voltage, a first control circuit connected to the reference voltage generating circuit for providing power supply during the standby mode of the SRAM, and a second control circuit connected to the reference voltage generating circuit for providing power in response to an enabling signal during the operation mode of the SRAM.

1. Field of the Invention
The invention relates to a voltage regulator and in particular to a voltage regulator used to support an internal power supply for SRAM core power consumption.
2. Related Art
A digital system usually needs to constantly read and store digital data during operations. Therefore, memory units with the function of keeping data are important elements in a digital system. They can be categorized into the following types: the random access memory (RAM), the serial access memory (SAM), and the content access memory (CAM).
Memories are a main concern in low-power and high-speed designs. In a processor based SoC (System on Chip), they limit most of the time the speed and are the main part of the power consumption. No memory technology can simultaneously maximize speed and capacity at lowest cost and power.
For innovative portable and wireless devices, Systems on Chip (SoCs) containing several processors, memories and specialized modules are obviously required. Performances but also low-power are main issues in the design of such SoCs. SoCs contain millions of transistors and have to work at lower and lower supply voltages to avoid too  high power consumption. Consequently, ROM and SRAM memories have to be designed to work at very low supply voltages and to be very robust while considering wire delays, signal input slopes, noise and crosstalk effects.
Low Power SRAM features low power consumption, making it the ideal memory for mobile devices such as cellular phones and PDAs. Most of these electrical devices have to operate either in standby mode or in operation mode. Since power consumption of memories are the main consumers, circuits may reduce their power consumption are very important.


A lightweight visor of semi-rigid plastic mesh material is sized to provide filtered sun ray incidence with minimum wind resistance to and through to the head of the wearer. The visor is crescent-shaped with the outer and larger curvature of the crescent forming the visor brim and the inner and smaller curvature of the crescent forming the head-contacting surface of the visor. The smaller curvature of the crescent is always maintained with a curvature that is greater than the head of the wearer and is provided with a soft liner disposed in the plane of the visor for contact to the head of the wearer. Provision is made for the removably detachable mounting of light-obstructing shades, each shade occupying less than one-third of the total area of the visor.

NOT APPLICABLE
NOT APPLICABLE
NOT APPLICABLE
This invention relates to visors. More particularly, a sun visor is disclosed which is particularly useful for actively played games, such as tennis. The visor stores in a flat disposition, fits to the head in a shaped arcuate disposition, and supports detachably removable shading.
Visors are well known. The following are exemplary of such constructions:
Krasno, U.S. Pat. No. 2,769,308 entitled Thermal Applicator for Head illustrates a headband-type visor having an integral bill that can be saturated with water for desired cooling.
Ryan, U.S. Pat. No. 3,585,643 entitled Sun Hat illustrates in a visor the combination of a headband and flat sunshade surface, which is capable of being disposed, at various angles with respect to the sun.
Goldstein, U.S. Pat. No. 4,096,589 entitled Adjustable Eye Shade sets forth a headband with a detachable visor element.
Townsend Jr., U.S. Pat. No. 4,292,689 entitled Visored Hat Construction sets forth a visor and integral headband. The visor surface is disposed in a flat or planar disposition with respect to the head of the wearer. This reference establishes criteria for such visors. Such visors should have:
a) Extraordinary light weight;
b) Unobstructed lateral vision;
c) Low wind resistance;
d) Perspiration and stain resistance;
e) Filtered sun rays incidence to the head of the wearer;
f) Hat size adjustability; and,
g) Structural integrity and durability.
Townsend Jr., U.S. Pat. No. 4,945,575 entitled Sun Visor sets forth a visor and integral headband which is maintained in a planar disposition. Unlike Townsend Jr. ""689, the planar visor contains an open cell structure, which tapers in thickness to provide varying overhead light cut-off angles that shield the wearer""s eyes from the direct rays of the sun. This provides a headband of increased thickness immediate to the head of the wearer.
A lightweight visor of semi-rigid plastic mesh material is sized to provide filtered sun ray incidence with minimum wind resistance to and through to the head of the wearer. The visor is crescent-shaped with the outer and larger curvature of the crescent forming the visor brim and the inner and smaller curvature of the crescent forming the head-contacting surface of the visor. The smaller curvature of the crescent is always maintained with a curvature that is greater than the head of the wearer and is provided with a soft liner disposed in the plane of the visor for contact with the head of the wearer. Provision is made for the removably detachable mounting of light obstructing shades, each shade occupying less than one-third of the total area of the visor. Banding of the visor at the smaller curvature of the crescent to the head occurs with a soft elastic cord, which is preferably of elastic, spiraled construction. The hat construction has high structural integrity and durability. The visor is mounted to the head by drawing the respective ends of the crescent across the back of the head with a soft elastic cord, enabling a single-size visor to accommodate a wide range of head sizes and shapes. The smaller curvature of the crescent is drawn across the forehead and sides of the head into firm retaining contact at the soft liner imparting maximum perspiration and stain resistance to the visor. When the visor is drawn to the head it forms the crescent-shaped semi-rigid plastic mesh material into an arcuate disposition with the concave side shading the eyes of the wearer. The arcuate configuration of the semi-rigid plastic mesh imparts rigidity, gathers the visor to the head of the wearer with its residual wind resistance, and allows substantially unobstructed lateral vision. The detachably removable light-obstructing shades can be used alone or in combination to prevent sun glare or attenuate brightness.


A method of fabricating a gas turbine casing out of composite material of varying thickness, the method including making a strip-shaped fiber texture by three-dimensional weaving; winding the fiber texture as a plurality of superposed layers onto a mandrel of profile corresponding to the profile of the casing that is to be fabricated, so as to obtain a fiber preform of shape corresponding to the shape of the casing that is to be fabricated; and densifying the fiber preform with a matrix; wherein, before beginning to wind the fiber texture onto the mandrel, a reinforcing band of width smaller than the width of the fiber texture is placed on the mandrel in a zone that is to form a retention zone of the casing.

In a gas turbine aeroengine, the fan casing performs several functions. It defines the air inlet passage into the engine, it supports an abradable material facing the tips of the blades of the fan, it supports an optional soundwave absorber structure for acoustic treatment at the inlet of the engine, and it supports a retention shield or retention zone. The retention shield, or retention zone, constitutes a debris trap for retaining centrifugally-projected debris, such as objects that have been ingested or fragments of blades that have been damaged, so as to prevent them from passing through the casing and reaching other portions of the aircraft.
Casings, such as a fan casing, used to be made of metal material, but they are now made of composite material, i.e. from a fiber preform that is densified with an organic matrix, thereby enabling parts to be made that present smaller overall weight than the same parts would present when made out of metal material, while still presenting mechanical strength that is at least equivalent, if not greater.
A fan casing is made out of composite material with an organic matrix by winding a fiber texture onto a mandrel.
In order to form the retention zone, a thicker zone is formed in the casing, generally in the central portion of the casing. Such a thicker zone is generally made by increasing the size of the warp yarns used, or else by adding warp yarns.
Nevertheless, such a solution, in which the extra thickness forming the retention zone is obtained by adding warp yarns or by locally increasing their size, modifies the volume ratio between the warp yarns and the weft yarns in the thicker zone compared with the remainder of the casing. The volume ratio between the warp yarns and the weft yarns is determined so as to improve the ability of the casing to withstand cracking. The present solution thus tends to depart from the equilibrium ratio (50/50), and thus has the potential of reducing the ability of the casing to withstand cracking.
In order to limit modification to the volume ratio between the warp yarns and the weft yarns, it is known to increase the number of turns of fiber texture around the mandrel so as to obtain the desired thickness for the retention zone while limiting the increase in the size of the warp yarns or limiting any addition of warp yarns. Nevertheless, such a solution increases the thickness of the casing over its entire length, thereby increasing the weight of said casing.

Casing of reinforced composite material, and a method of fabricating it


The present invention relates to a therapeutic agent for neurodegenerative disorders, comprising a xanthine derivative represented by formula (I):

The present invention relates to a therapeutic agent for neurodegenerative disorders.
Most of the compounds according to the present invention are known compounds, and their adenosine A2-receptor antagonism, anti-Parkinson""s disease action, anti-depressive action, anti-asthmatic action, inhibitory action on bone absorption and action on central excitation are known [Japanese Published Examined Patent Application No. 26516/72, J. Med. Chem., 34, 1431 (1991), J. Med. Chem., 36, 1333 (1993), WO 92/06976, Japanese Published Unexamined Patent Application No. 211856/94, Japanese Published Unexamined Patent Application No. 239862/94, WO 95/23165, Japanese Published Unexamined Patent Application No. 16559/94 and WO 94/01114).
However, it is not known that said compounds have an inhibitory action on neurodegeneration.
The present invention relates to a therapeutic agent for neurodegenerative disorders, comprising, as an active ingredient, xanthine derivatives represented by formula (I):
wherein R1, R2 and R3 independently represent hydrogen, lower alkyl, lower alkenyl or lower alkynyl; R4 represents cycloalkyl, xe2x80x94(CH2)nxe2x80x94R5 (wherein R5 represents substituted or unsubstituted aryl, or a substituted or unsubstituted heterocyclic group, and n is an integer of 0 to 4), or the following group:
wherein Y1 and Y2 independently represent hydrogen, halogen or lower alkyl, and Z represents substituted or unsubstituted aryl, the following group:
wherein R6 represents hydrogen, hydroxy, lower alkyl, lower alkoxy, halogen, nitro or amino, and m is an integer of 1 to 3, or a substituted or unsubstituted heterocyclic group; and X1 and X2 independently represent O or S, or pharmaceutically acceptable salts thereof.
As the active ingredient for the therapeutic agent for neurodegenerative disorders, preferred compounds are compounds of formula (I) wherein X1 and X2 are O, or pharmaceutically acceptable salts thereof; or compounds of formula (I) wherein R4 is the following-group:
wherein Z has the same meaning as defined above, or pharmaceutically acceptable salts thereof, and specifically preferred compounds are compounds of formula (I) wherein X1 and X2 are O and R4 is the group defined above, or pharmaceutically acceptable salts thereof.
Further, the present invention relates to a method of treating neurodegenerative disorders, which comprises administering an effective dose of a xanthine derivative represented by formula (I) or a pharmaceutically acceptable salt thereof.
Furthermore, the present invention relates to use of a xanthine derivative represented by formula (I) or a pharmaceutically acceptable salt thereof for manufacturing a pharmaceutical composition useful for treatment of neurodegenerative disorders.
Hereinafter, the compound represented by formula (I) is referred to as compound (I).
In the definition of compound (I), the lower alkyl and the lower alkyl moiety in the lower alkoxy mean a straight-chain or branched C1 to C6 alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl and hexyl; the lower alkenyl means a straight-chain or branched C2 to C6 alkenyl group such as vinyl, allyl, methacryl, crotyl, 3-butenyl, 2-pentenyl, 4-pentenyl, 2-hexenyl and 5-hexenyl; the lower alkynyl means a straight-chain or branched C2 to C6 alkynyl group such as ethynyl, propargyl, 2-butynyl, 3-butynyl, 2-pentynyl, 4-pentynyl, 2-hexynyl, 5-hexynyl and 4-methyl-2-pentynyl; the aryl means phenyl or naphthyl; the cycloalkyl means a C3 to C8 cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl; examples of the heterocyclic groups are furyl, thienyl, pyrrolyl, pyranyl, thiopyranyl, pyridyl, thiazolyl, imidazolyl, pyrimidyl, triazinyl, indolyl, quinolyl, purinyl and benzothiazolyl; and the halogen includes fluorine, chlorine, bromine and iodine. The substituted aryl and the substituted heterocyclic group have 1 to 3 independently-selected substituents such as lower alkyl, hydroxy, substituted or unsubstituted lower alkoxy, halogen, nitro, amino, lower alkylamino, di(lower alkyl)amino, trifluoromethyl, tri-fluoromethoxy, benzyloxy, phenyl, phenoxy, lower alkanoyl, lower alkanoyloxy, aroyloxy, aralkanoyloxy, carboxy, lower alkoxycarbonyl, lower alkylcarbamoyl, di(lower alkyl)-carbamoyl, sulfo, lower alkoxysulfonyl, lower alkylsulfamoyl and di(lower alkyl)sulfamoyl. The lower alkyl and the alkyl moiety of the lower alkoxy, lower alkylamino, di(lower alkyl)amino, lower alkanoyl, lower alkanoyloxy, lower alkoxycarbonyl, lower alkylcarbamoyl, di(lower alkyl)-carbamoyl, lower alkoxysulfonyl, lower alkylsulfamoyl and di(lower alkyl)sulfamoyl have the same meaning as the lower alkyl defined above. The halogen has the same meaning as the halogen defined above. Examples of the substituents for the substituted lower alkoxy are hydroxy, lower alkoxy, halogen, amino, azido, carboxy and lower alkoxycarbonyl. The alkyl moiety of the lower alkoxy and lower alkoxycarbonyl has the same meaning as the lower alkyl defined above, and the halogen has the same meaning as the halogen-defined above. The aroyl moiety of the aroyloxy includes benzoyl and naphthoyl. The aralkyl moiety of the aralkanoyloxy includes benzyl and phenethyl.
The pharmaceutically acceptable salts of compound (I) include pharmaceutically acceptable acid addition salts, metal salts, ammonium salts, organic amine addition salts and amino acid addition salts.
The pharmaceutically acceptable acid addition salts of compound (I) include inorganic acid addition salts such as hydrochloride, sulfate and phosphate, and organic acid addition salts such as acetate, maleate, fumarate, tartrate, citrate and methanesulfonate; the pharmaceutically acceptable metal salts include alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts such as magnesium salt and calcium salt, aluminum salt, and zinc salt; the pharmaceutically acceptable ammonium salts include ammonium and tetramethylammonium; the pharmaceutically acceptable organic amine addition salts include salts with morpholine and piperidine; and the pharmaceutically acceptable amino acid addition salts include salts with lysine, glycine and phenylalanine.
Compound (I) including a novel compound can be produced by the methods disclosed in the above-mentioned publications or according to the methods. The desired compound in the process can be isolated and purified by purification methods conventionally used in synthetic organic chemistry, such as filtration, extraction, washing, drying, concentration, recrystallization and various kinds of chromatography.
In the case where a salt of compound (I) is desired and it is produced in the form of a desired salt, it may be subjected to purification as such. In the case where compound (I) is produced in the free form and its salt is desired, it is dissolved or suspended in a suitable solvent, and then an acid or a base may be added thereto to form the salt.
Compound (I) and pharmaceutically acceptable salts thereof may be in the form of adducts with water or various solvents, which can satisfactorily be used as the therapeutic agent of the present invention.
Some of compounds (I) have optical isomers, and all potential stereoisomers and mixtures thereof can satisfactorily be used as the therapeutic agent of the present invention.
Examples of compound (I) are shown in Table 1.
Compound 1: (E)-1,3-diethyl-8-(3,4-dimethoxystyryl)-7-methylxanthine (Japanese Published Unexamined Patent Application No. 211856/94)
Melting point: 190.4-191.3xc2x0 C.
Elemental analysis: C20H24N4O4
Calcd. (%): C 62.48, H 6.29, N 14.57
Found (%): C 62.52, H 6.53, N 14.56
IR(KBr) xcexdmax(cmxe2x88x921): 1697, 1655, 1518
NMR(CDCl3, 270 MHz) xcex4(ppm): 7.74(1H, d, J=15.5 Hz), 7.18(1H, dd, J=8.3, 1.9 Hz), 7.08(1H, d, J=1.9 Hz), 6.89(1H, d, J=8.3 Hz), 6.77(1H, d, J=15.5 Hz), 4.21(2H, q, J=6.9 Hz), 4.09(2H, q, J=6.9 Hz), 4.06(3H, s), 3.96(3H, s), 3.93(3H, s), 1.39(3H, t, J=6.9 Hz), 1.27(3H, t, J=6.9 Hz)
Compound 2: (E)-8-(3,4-dimethoxystyryl)-1,3-dipropyl-7-methylxanthine (WO 92/06976)
Melting point: 164.8-166.2xc2x0 C. (Recrystallization from 2-propanol/water)
Elemental analysis: C22H28N4O4
Calcd. (%): C 64.06, H 6.84, N 13.58
Found (%): C 64.06, H 6.82, N 13.80
IR(KBr) xcexdmax(cmxe2x88x921): 1692, 1657
NMR(DMSO-d6, 270 MHz) xcex4(ppm): 7.60(1H, d, J=15.8 Hz), 7.04(1H, d, J=2.0 Hz), 7.28(1H, dd, J=2.0, 8.4 Hz), 7.18(1H, d, J=15.8 Hz), 6.99(1H, d, J=8.4 Hz), 4.02(3H, s), 3.99(2H, t), 3.90xe2x88x923.80(2H, m), 3.85(3H, s), 3.80(3H, s), 1.85xe2x88x921.50(4H, m), 1.00xe2x88x920.85(6H, m)
Compound 3: (E)-1,3-diethyl-8-(3-methoxy-4,5-methylenedioxy styryl)-7-methylxanthine (Japanese Published Unexamined Patent Application No. 211856/94)
Melting point: 201.5-202.3xc2x0 C.
Elemental analysis: C20H22N4O5
Calcd. (%): C 60.29, H 5.57, N 14.06
Found (%): C 60.18, H 5.72, N 13.98
IR(KBr) xcexdmax(cmxe2x88x921): 1694, 1650, 1543, 1512, 1433
NMR(DMSO-d6, 270 MHz) xcex4(ppm): 7.58(1H, d, J=15.8 Hz), 7.23(1H, d, J=15.8 Hz), 7.20(1H, d, J=1.0 Hz), 7.09(1H, d, J=1.0 Hz), 6.05(2H, s), 4.09xe2x88x924.02(2H, m), 4.02(3H, s), 3.94xe2x88x923.89(2H, m), 3.89(3H, s), 1.25(3H, t, J=7.2 Hz), 1.13(3H, t, J=6.9 Hz)
Compound 4: (E)-8-(3,4,5-trimethoxystyryl)caffeine (Japanese Published Examined Patent Application No. 26516/72)
IR(KBr) xcexdmax(cmxe2x88x921): 1702, 1667, 1508, 1432
NMR(DMSO-d6, 270 MHz) xcex4(ppm): 7.61(1H, d, J=16.0 Hz), 7.25(1H, d, J=16.0 Hz), 7.09(2H, s), 4.03(3H, s), 3.85(6H, s), 3.71(3H, s), 3.45(3H, s), 3.21(3H, s)
MS(EI) 386(M+)
Hereinafter, the pharmacological activity of compound (I) is shown by the following Test Examples.
Test Example 1: Inhibitory Action on Neurodegeneration
The experiment was conducted according to the method of Sundstrom et al. (Brain. Res. Bulletin, 21, 257-263 (1988)).
In the experiment, 9- to 10-week-old male C57BL/6NCrj mice (supplied by Nippon Charles River) were used. During the period of preliminary breeding, the animals were kept in a laboratory at room temperature (22 to 24xc2x0 C.) under 50 to 60% humidity and allowed food and water ad libitum.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (abbreviated hereinafter as MPTP HCl (RBI Co., Ltd.)) was dissolved at a concentration of 4 mg/ml in physiological saline. A test compound was suspended at a concentration of 1 mg/ml in 0.3% dimethyl sulfoxide (DMSO). Each test group consisted of 9 to 10 animals, and a control group was intraperitoneally given physiological saline, and an MPTP HCl administration group and an MPTP HCl+test compound administration group were intraperitoneally given MPTP HCl (40 mg/kg).
After 1 hour, the control group and the MPTP HCl administration group were orally given 0.3% Tween, and the MPTP HCl+test compound administration group was orally given the test compound (10 mg/kg). After 1 week, the animals were decapitated, and the striatum was removed therefrom under cooling on ice. The striatum was stored in a deep freezer ( less than xe2x88x9280xc2x0 C.) before a binding experiment.
A [3H]-mazindol binding test was conducted in the following method. A striatum and 300 xcexcl of buffer (120 mM NaCl, 5 mM KCl, 50 mM Tris, pH 7.9) were put into a micro-centrifuge tube and homogenized by portable homogenizer S-203 (manufactured by Iuchi) and centrifuged at 15,000 rpm, 4xc2x0 C. for 5 minutes (by KUBOTA 1710). The precipitates were suspended in 300 xcexcl of buffer and then centrifuged again at 15,000 rpm, 4xc2x0 C. for 5 minutes. The precipitates were suspended in 500 xcexcl of buffer and then distributed into four test tubes in 100 xcexcl portions. The remaining suspension (100 xcexcl) was used for protein quantification. To determine non-specific binding, nomifensine maleate (RBI Co., Ltd.) (final concentration: 10 xcexcM) as an inhibitor of dopamine uptake was added to two test tubes among the four test tubes. The binding reaction was initiated by adding 25 xcexcl of [3H]-mazindol (final concentration: 10 nM) (Spec. Act. 888 GBq/mmol, a product of NET). The mixture was incubated for 1 hour under cooling on ice, and the striatum homogenate was adsorbed onto a glass filter (Whatman, GF/B) in a cell harvester and washed three times with 5 ml of buffer. The radioactivity on the glass filter was measured with a liquid scintillation counter. For each striatum, specific [3H]-mazindol binding was determined by subtracting the average of non-specific [3H]-mazindol binding from the average of total [3H]-mazindol binding.
Protein quantification was conducted by use of a Bio-Rad DC protein assay kit (Bio-Rad Co., Ltd.) with bovine serum albumin (Sigma Co., Ltd.) as a standard. Specific [3H]-mazindol binding was expressed as the amount of bound [3H]-mazindol per unit weight of protein, and the meanxc2x1standard error was determined for each group (9-10 animals).
In Table 2, the results are expressed in terms of the amount of specifically bound [3H]-mazindol (fmol/mg protein) in the striatum.
According to the test results, the reduction of the amount of specifically bound [3H]-mazindol by administration of MPTP HCl was inhibited by compound 1. That is, it was revealed that compound 1 exhibits inhibitory action on degeneration of dopaminergic neurons.
Test Example 2: Acute Toxicity Test
Test compounds were orally or intraperitoneally administered to groups of dd+strain male mice weighing 20xc2x11 g, each group consisting of three mice. Seven days after the administration, the mortality was observed to determine a minimum lethal dose (MLD) of each compound.
The MLD value of Compound 1 was greater than 1000 mg/kg for oral administration.
Compound (I) or pharmaceutically acceptable salts thereof have inhibitory action on neurodegeneration and are useful as a therapeutic agent for neurodegenerative disorders such as Alzheimer""s disease, progressive supranuclear palsy, AIDS brain fever, propagating spongy brain fever, Huntington""s chorea, multiple sclerosis, amyotrophic lateral sclerosis (ALS), multi-system atrophy, brain ischemia, and attention deficit hyperactivity disorder.
Compound (I) or pharmaceutically acceptable salts thereof can be used as such or in the form of various pharmaceutical compositions. The pharmaceutical compositions of the present invention can be prepared by uniformly mixing an effective amount of compound (I) or a pharmaceutically acceptable salt thereof as an active ingredient with pharmaceutically acceptable carriers. The pharmaceutical compositions are preferably in a unit dosage form suitable for rectal administration, oral or parenteral including subcutaneous, intravenous and intramuscular administration administration, etc.
For preparing a pharmaceutical composition for oral administration, any useful pharmaceutically acceptable carriers can be used. For example, liquid preparations for oral administration such as suspension and syrup can be prepared using water; sugars such as sucrose, sorbitol and fructose; glycols such as polyethylene glycol and propylene glycol; oils such as sesame oil, olive oil and soybean oil; preservatives such as a p-hydroxybenzoate; flavors such as strawberry flavor and peppermint, etc. Powder, pills, capsules and tablets can be prepared using excipients such as lactose, glucose, sucrose and mannitol; disintegrating agents such as starch and sodium alginate; lubricants such as magnesium stearate and talc; binders such as polyvinyl alcohol, hydroxypropyl cellulose and gelatin; surfactants such as fatty acid esters; plasticizers such as glycerin, etc. Tablets and capsules are the most useful oral unit dosage because of the readiness of administration. For preparing tablets and capsules, solid pharmaceutical carriers are used.
Injectable preparations can be prepared using carriers such as distilled water, a salt solution, a glucose solution and a mixture of a salt solution and a glucose solution. The preparation can be prepared in the form of solution, suspension or dispersion according to a conventional method by using a suitable auxiliary.
Compound (I) or a pharmaceutically acceptable salt thereof can be administered orally in the pharmaceutical form described above or parenterally as the injection. The effective dose and administration schedule vary depending on the mode of administration, age, weight, and symptoms of a patient, etc. However, generally, compound (I) or a pharmaceutically acceptable salt thereof is administered in a dose of 1 to 900 mg/60 kg/day, preferably in a dose of 1 to 200 mg/60 kg/day.
Certain embodiments of the present invention are described in the following examples.

Abstract: or a pharmaceutically acceptable salt thereof as an active ingredient wherein X1, X2, R1, R2, R3 and R4 are herein defined.


An integrated semiconductor memory includes programmable elements, which are arranged in a continuous region on a chip area of the integrated semiconductor memory. Operating parameters, for example, word line addresses of defective word lines are stored in the programmable elements in a compressed data format during the fabrication process of the integrated semiconductor memory. Upon activation of the integrated semiconductor memory, the compressed data are read out by a read-out circuit and fed to a decompression circuit. The decompression circuit generates, from a bit sequence of the compressed data with the aid of a decompression algorithm, a bit sequence of decompressed data which are evaluated by a control circuit. The storage of the operating parameters in the compressed data format and the arrangement of the programmable elements in a compact region significantly reduce the space requirement on the semiconductor chip.

In integrated semiconductor memories, for example, DRAM (dynamic random access memory) semiconductor memories, operating parameters that determine the operating behavior of the integrated semiconductor memory are partly programmed into the semiconductor memory as early as in the production process. Such operating parameters relate to the setting of voltage values of an internal voltage network, the setting of delay parameters, and principally, also the activation of redundant structures.
FIG. 3 shows an integrated semiconductor memory 100 having a memory cell array 10. Within the memory cell array, memory cells SZ are arranged along word lines WL and bit lines BL. FIG. 3 illustrates in an exemplary manner a DRAM memory cell SZ comprising a selection transistor AT and a storage capacitor SC. In order to write an item of information to the memory cell or in order to read an item of information from the memory cell, the selection transistor AT is turned on by a corresponding control signal on the word line WL so that the storage capacitor SC is conductively connected to the bit line BL.
In the case of reading out an item of memory information, on the bit line BL, there is a potential increase or potential decrease relative to a precharge potential of the bit line, which is detected by a sense amplifier 11 and fed to an output terminal DQ of the integrated semiconductor memory in amplified fashion. When an item of information is read in, the signal level applied to the data terminal DQ is amplified by the sense amplifier 11 and written to the storage capacitor SC of the memory cell SZ via the bit line BL.
For controlling read and write accesses, the integrated semiconductor memory has a control circuit 40 and an address register 50. For selecting one of the memory cells SZ, a word line address X and a bit line address Y are applied to an address terminal A50. A memory cell of the memory cell array 10 is unambiguously identified based on the word and bit line addresses. When a control terminal S40 is driven with a write command WR, the memory cell array 10 is driven by the control circuit 40 such that a datum present at the data terminal DQ is written to the memory cell selected by the word and bit line addresses. If a read command RD is applied to the control circuit 40, the memory cell array 10 is configured by the control circuit 40 such that a memory cell SZ selected by the word line and bit line addresses is read at the data terminal DQ.
In the context of the production process, the memory cells along a word line are subject to extensive functional tests. If it is ascertained that defective memory cells are connected to a word line, or the word line itself has a defect, then the affected word line is generally replaced by a redundant word line WLr. Accordingly, the memory cells SZ connected to the defective word line WL are replaced by redundant memory cells SZr connected along the redundant word line WLR.
If a memory cell arranged along the defective word line is accessed during a read and write access, the control circuit 40 activates the redundant word line WLr, instead of the defective word line. For this purpose, the control circuit 40 must know the word line address X of the defective word line. If, for example, the word line WL is detected as defective in the production process or during subsequent testing, then the word line address X of the defective word line is stored in fuse elements of a fuse bank.
FIG. 3 shows five different fuse banks 21, 22, 23, 24, 25 at the edge of the memory cell array 10. The fuse banks are assigned to redundancy bit or word line decoders. The fuse banks are connected to read-out circuits 31, 32, 33, 34, 35 for the read-out of the respective fuse bank. The word line addresses of defective word lines that are programmed in the fuse banks are converted into a data record comprising a bit sequence B by the read-out circuits and forwarded to the control circuit 40. From activation of the integrated semiconductor memory, the control circuit 40 evaluates the bit sequences from the read-out circuits, so that the control circuit 40 then knows the addresses of the defective word lines.
FIG. 4 shows an enlarged illustration of the fuse bank 21 connected to the read-out circuit 31. The fuse bank 21 includes a plurality of fuse units 210, 220, 230, 240, 250, 260. Each of the fuse units illustrated in FIG. 4 includes fuse elements 0, . . . 7. The fuse elements may be formed as fusible links, for example, which are destroyed during programming in the production process by irradiation with a laser pulse. The respective programming state of the fuse element is detected by the read-out circuit 31. If, for example, when reading the fuse element 0 of the fuse unit 210, the read-out circuit 31 ascertains that the associated fusible link has been destroyed, this corresponds to a programming state "1," for example. If, by contrast, the fusible link of the fuse element 0 has not been destroyed, this programming state corresponds to a logic "0." It is possible, for example, for an address bit of a word line address assigned to a defective word line to be stored in a respective fuse element of a fuse unit. When the fuse unit 210 is read, the read-out circuit thus generates a bit sequence including address bits 0, . . . , 7 of the stored word line address.
Each of the fuse units 210, . . . , 260 illustrated in FIG. 4 is assigned a redundant structure, for example, a redundant word line, by a redundancy bit or word line decoder. For deciding whether a fuse unit contains a valid address of a defective word line, the respective fuse element 0 of a fuse unit is used as a signaling bit. If the fuse element 0 of the fuse unit 210 has the programming state "1", for example, then the programming states of the fuse elements 1, . . . , 7 of the fuse unit 210 specify the address bits of the word line address X of the defective word line, which is replaced by the redundant word line assigned to the fuse unit 210.
The number of fuse elements of a fuse unit is dependent on the address range in which the redundant structure is intended to be used. However, each fuse element requires a considerable proportion of chip area CF. Reducing this proportion of the chip area becomes more desirable, the less the layout of the fuse elements can be reduced in size from memory generation to memory generation. The fuse elements are irradiated with high-energy radiation of a laser during programming. By virtue of the wavelength used, limits are imposed on arbitrarily reducing the size of the fuse elements in the context of scaling of the circuit layout. Relative to the rest of the circuit components, the fuse elements are thus occupying an ever larger space on the semiconductor chip.
The layout of the fuse elements with the associated read-out circuit has hitherto been positioned in proximity to the redundant structure. In order to configure the layout of a fuse bank in a manner as far as possible optimized with respect to area, fuse banks adjacent to one another are combined. The space taken up by necessary safety regions between a fuse bank and other circuit components of the integrated semiconductor memory can be reduced in this way. With dispersed redundant structures on the semiconductor chip, a further minimization of these safety zones is almost no longer possible at the present time.
In the unprogrammed state, the fuse elements of a fuse unit have the logic state "0." Since the word line address X=0000000 of a defective word line cannot be distinguished from this presetting, instead of seven fuse elements, a total of eight fuse elements are used in the exemplary embodiment of FIG. 4. In this case, the fuse element 0, i.e., the master fuse, is no longer part of the word line address, but rather determines whether the redundant structure assigned to the fuse unit 210 is activated. Therefore, it no longer represents an address bit. If the fuse element 0 is programmed with the logic state "1," for example, then the redundant word line assigned to the fuse unit 210, for example, is used instead of the regular word line, the word line address of which is determined by the programming state of the fuse elements 1, . . . , 7. This means that half of all programmable combinations of programming states of the fuse unit 210 are not utilized. Furthermore, at the present time, chip area is wasted, particularly, when the redundant structure is not used at all.
An integrated semiconductor memory in which the number of fuse elements required for programming operating settings of the integrated semiconductor memory is reduced, and a method for operating an integrated semiconductor memory in which the operating settings stored in a reduced number of fuse elements can be evaluated by a control circuit, are desirable.