A bicycle sprocket assembly having at least one subassembly including a sprocket support member and two sprockets. The support member has at least one engagement portion for coupling it to a bicycle freewheel and at least one fastening portion arranged in a radially external position with respect to the engagement portion. Both sprockets are fixed on the sprocket support member on the same side of the fastening portion.

Over recent years, the number of transmission ratios available on bicycle gear change devices has progressively increased and sprocket assemblies for the rear wheel of a bicycle having nine or ten sprockets are increasingly common on the market. The progressive increase in the number of sprockets requires ever increasing research for reducing the weight of the sprocket assembly. In U.S. Pat. No. 5,935,034, assigned to the same assignee as the present invention, a sprocket assembly is described that includes a support member having a radially internal portion shaped such that it couples with a freewheel device and a radially external fastener portion. Two sprockets are mounted on the opposite surfaces of the fastener portion. A third sprocket can be mounted on the support member in addition to the first two sprockets through a plurality of spacer bushings. U.S. Pat. No. 6,102,821 describes a sprocket assembly in which two sprockets are fixed on opposite sides of a sprocket support member by pins that engage with aligned holes of the sprockets and of the support member.
With the progressive increase in the number of sprockets, in addition to the need for reducing the weight of the assembly, there is also the need for arranging the sprockets in positions that are closer one to the other. As a consequence, the space available for the sprocket support member becomes more limited. On the other hand, this support member performs an important structural function and it is necessary to ensure that it has high rigidity and resistance characteristics.

Sprocket support member for a bicycle sprocket assembly


The liquid crystal display device includes a first substrate, a second substrate opposed to the first substrate, and a vertically aligned liquid crystal layer interposed between the first and second substrates, and has a plurality of pixels arranged in a matrix having rows and columns. Each pixel includes a first electrode formed on the first substrate, a second electrode formed on the second substrate, and the liquid crystal layer interposed between the first and second electrodes. The first substrate has a shading region in gaps between the plurality of pixels, and a wall structure is placed regularly on the surface of the first substrate facing the liquid crystal layer in the shading region. The first and second electrodes have at least one opening formed at a predetermined position in the pixel. At least an arbitrary row or column of pixels is composed of first pixels each having the first electrode to which a voltage of positive polarity with respect to the potential at the second electrode as the reference potential is supplied and second pixels each having the first electrode to which a voltage of negative polarity is supplied, arranged alternately, in a given vertical scanning period. At least one liquid crystal domain having axisymmetric alignment is formed when at least a predetermined voltage is applied across the liquid crystal layer, and the center axis of the axisymmetric alingment of the at least one liquid crystal domain is formed in or near the at least one opening.

The present invention relates to a liquid crystal display device and a fabrication method for the same, and more particularly, to a liquid crystal display device suitably used for portable information terminals (for example, PDAs), mobile phones, car-mounted liquid crystal displays, digital cameras, PCs, amusement equipment, TVs and the like.
The information infrastructure is advancing day to day, and equipment such as mobile phones, PDAs, digital cameras, video cameras and car navigators has penetrated deeply into people's lives. Liquid crystal display (LCD) devices have been adopted in most of such equipment. With increase of the information amount handled with the main bodies of the equipment, LCD devices are requested to display a larger amount of information, and are demanded by the market for higher contrast, a wider viewing angle, higher brightness, multiple colors and higher definition.
A vertical alignment mode using a vertically aligned liquid crystal layer has increasingly received attention as a display mode enabling high contrast and a wide viewing angle. The vertically aligned liquid crystal layer is generally obtained using a vertical alignment film and a liquid crystal material having negative dielectric anisotropy.
For example, Japanese Laid-Open Patent Publication No. 6-301036 (Literature 1) discloses an LCD device in which an inclined electric field is generated around an opening formed in a counter electrode that faces a pixel electrode via a liquid crystal layer, so that liquid crystal molecules surrounding liquid crystal molecules existing in the opening, which are in the vertically aligned state, are aligned in inclined directions around the opening as the center, to thereby improve the visual angle characteristics.
However, in the device described in Literature 1, it is difficult to generate an inclined electric field over the entire region of each pixel. Therefore, each pixel has a region in which liquid crystal molecules delay in response to a voltage, and this causes a problem of occurrence of an afterimage phenomenon.
Japanese Laid-Open Patent Publication No. 2002-55347 (Literature 2) discloses a technology in which slit electrodes (an opening pattern) are provided in both pixel electrodes and a counter common electrode and, in at least either the pixel electrodes or the common electrode, steps are provided in regions having the slit electrodes to distribute an inclined electric field in four directions uniformly using the opening pattern, to thereby achieve a wide viewing angle.
Japanese Laid-Open Patent Publication No. 2003-167253 (Literature 3) discloses a technology in which a plurality of projections are provided regularly in each pixel to stabilize the aligned state of liquid crystal domains having radially inclined alignment formed around the projections. This literature also discloses using an inclined electric field generated at openings formed in an electrode, together with the alignment regulating force of the projections, to regulate the alignment of liquid crystal molecules, and thus improve the display characteristics.
In recent years, a type of LCD device providing high-quality display both outdoors and indoors has been proposed (see Japanese Patent Gazette No. 2955277 (Literature 4) and U.S. Pat. No. 6,195,140 (Literature 5), for example). In this type of LCD device, called a transflective LCD device, each pixel has a reflection region in which display is done in the reflection mode and a transmission region in which display is done in the transmission mode.
The currently available transflective LCD devices adopt an ECB mode, a TN mode and the like. Literature 3 described above discloses adoption of the vertical alignment mode for, not only a transmissive LCD device, but also a transflective LCD device. Japanese Laid-Open Patent Publication No. 2002-350853 (Literature 6) discloses a technology in which in a transflective LCD device having a vertically aligned liquid crystal layer, the alignment (multi-axis alignment) of liquid crystal molecules is controlled with depressions formed on an insulating layer. The insulating layer is provided to make the thickness of the liquid crystal layer in a transmission region twice as large as that in a reflection region. According to this literature, the depressions are in the shape of a regular octagon, for example, and projections or slits (electrode openings) are formed at positions opposed to the depressions via the liquid crystal layer (see FIGS. 3 and 16 of Literature 6, for example).
Japanese Laid-Open Patent Publication No. 2001-125144 (Literature 7) discloses a technology of adopting dot inversion drive for a vertically aligned liquid crystal display device to thereby minimize roughness of display and achieve a high contrast ratio and wide viewing angle characteristics. In Literature 7, the dot inversion drive is executed at a predetermined pixel pitch, and distortion in an electric field generated in the boundary portions of adjacent pixel electrodes is used to define the aligned directions of liquid crystal molecules. This literature describes that the pixel electrode pitch is preferably not smaller than the thickness of the liquid crystal layer and also not larger than 20 μm, to make full use of the action of the electric field. The literature also describes that an opening is provided in the center of each pixel electrode to ensure fixation of the center of the radial alignment of liquid crystal molecules to the opening to thereby further stabilize the alignment.
The technology disclosed in Literature 3 has the following problems. Projections are provided in each pixel to form a plurality of liquid crystal domains in the pixel (that is, divide the pixel into domains), to thereby strengthen the alignment regulating force on liquid crystal molecules. According to examinations conducted by the inventors of the present invention, however, to obtain sufficient alignment regulating force, it is necessary to form an alignment control structure made of projections regularly placed inside each pixel, and this complicates the fabrication process. The contrast ratio may decrease due to light leakage occurring in the peripheries of the projections in the pixel. If a light-shading portion is provided to prevent decrease in contrast ratio, the effective aperture ratio may possibly decrease. Moreover, if the alignment regulating structure is provided on the counter substrate, the substrate alignment margin must be taken into consideration. Therefore, roughness of display due to deviation of the center axes of axisymmetrically aligned domains, and the decrease of the effective aperture ratio and/or the decrease of the contrast ratio will become further conspicuous.
In the technology disclosed in Literature 6, it is necessary to provide projections or electrode openings at positions opposed to the depressions formed for control of the multi-axis alignment. This technology therefore has the same problems as those described above.
In Literature 7, in which the directions in which liquid crystal molecules tilt are defined by use of a lateral electric field (an inclined electric field component in the substrate plane) generated between adjacent pixel electrodes by adopting the dot inversion drive, the stability of the aligned state is dependent on the shape of the electrodes. Also, sufficient alignment regulating force will not be exerted in a grayscale display state having a low electric field. Moreover, as is self-explanatory from the aligned directions of liquid crystal molecules existing in the four corners of each pixel electrode shown in FIG. 9 of Literature 7, the lateral electric field has directions different from each other (roughly orthogonal to each other) in each corner portion of the pixel electrode. This causes a problem of easily generating disclination (alignment defect) in the corner portions of each pixel.
In view of the above, an object of the present invention is providing a liquid crystal display device having at least one axisymmetrically aligned domain in each pixel, which can provide good axisymmetrically aligned domains even in a grayscale display state, is excellent in display quality and has wide viewing angle characteristics.


In a semiconductor single crystalline substrate provided with a protecting film to prevent autodoping on the reverse surface thereof, for growing a vapor-phase epitaxial layer on the main obverse surface thereof, a width of a chamfer is set for locating an edge-crown occurred in consequence of a vapor-phase epitaxial growth on the chamfer, and a gap of a distance is formed between a periphery of the protecting film and an innermost part of the chamfer on the reverse surface.

1. Field of the Invention
This invention relates to a semiconductor single crystalline substrate for vapor-phase growth of an epitaxial layer on the main surface thereof and a method for the production thereof. More particularly, this invention relates to a semiconductor single crystalline substrate such that, when the vapor-phase growth of a very thick epitaxial layer is in process thereon, the otherwise possible occurrence of edge-crowns is precluded by the usage of the substrate and a method for the production of the semiconductor single crystalline substrate.
2. Description of the Prior Art
The technique of vapor-phase epitaxial growth resides in attaining vapor-phase growth of a single crystalline thin-film layer for use in the production of such integrated circuits as bipolar transistors and MOSLSI's. This technique constitutes a very important method because it allows epitaxial growth on a clean semiconductor single crystalline substrate with a uniform single crystalline thin film of which crystal orientation is identical with it of the semiconductor single crystalline substrate and permits formation of a steep impurity concentration gradient having a junction with a large difference of dopant concentration.
The reactors for vapor-phase epitaxial growth are known in three types, i.e., the vertical type (pancake type), the barrel type (cylindrical type), and the horizontal type. These reactors share a common operating principle of accomplishing the growth of an epitaxial layer, by first, mounting a given semiconductor single crystalline substrate on a susceptor which is a heating plate made of a graphite having a dense SiC coating provided on the surface of the plate, heating the substrate to a predetermined reaction temperature, and introducing a raw material gas into the reaction site for growing an epitaxial layer by thermal decomposition or reduction with hydrogen.
The semiconductor single crystalline substrate, for the sake of allowing an epitaxial layer of high quality to be grown thereon, is furnished with various devices.
The periphery of the semiconductor single crystalline substrate is given a beveled edge by a work called a chamfering. The substrate, while being handled or conveyed, tends to sustain cracks or chippings on the periphery thereof by collision against a hard object. The semiconductor single crystalline substrate, while the vapor-phase epitaxial growth is in process, induces abnormal growth called an edge-crown on the periphery thereof. The chamfering, therefore, is required to diminish these detrimental phenomena. Numerous inventions covering this technique of chamfering have been applied for patent. JP-A-49-43,881 as issued from one such patent application.
When a silicon epitaxial wafer with a very thick epitaxial layer is to be prepared for use such as, for example, in the production of such high breakdown voltage large-current elements as IGBT (insulated gate bipolar transistor) which are creating growing demands in recent years, the silicon epitaxial wafer to be used therein forms edge-crowns (62a, 62b, and 62c) of a hardly ignorable height in the peripheral part thereof on the obverse and on the reverse side as illustrated in FIG. 8, though this silicon epitaxial wafer has undergone the chamfering work. The dimensional tolerance heretofore observed in the chamfering work performed on the peripheral part of a substrate has been specified on the assumption that an epitaxial layer is to be grown to a thickness of some tens of micrometers at most. It is not necessarily proper for application to the growth of an epitaxial layer having a thickness exceeding 100 .mu.m.
When a very thick epitaxial layer is grown by the use of a vertical type reactor for vapor-phase epitaxial growth, the edge-crowns mentioned above occur in the peripheral part of an epitaxial wafer on the main obverse side and on the reverse side. The positions where the edge-crowns occur in the peripheral part of the substrate are fixed by the plane orientation of the substrate. When the plane orientation of the main obverse surface is {100}, for example, the edge-crowns occur each at four positions near the peripheral part of the main obverse surface in the direction of <011>.
As illustrated in FIG. 8, the edge crown 62a which occurs on the main obverse surface side (hereinafter referred to as "front crown") is formed on the interface between an epitaxial layer 63 grown on the main obverse surface side of a single crystalline substrate 51 and a facet appeared on a chamfered part 52. The edge crowns 62b and 62c which occur on the reverse surface side of the single crystalline substrate 51 (hereinafter referred to as "rear crowns") is formed on the interface between an epitaxial layer grown around the chamfered part on the reverse surface side of the substrate 51 and the facet appeared on the chamfered part 52 (62b), and on a plane in such a manner as to cover the edge of the peripheral part of a protecting film 53 for preventing the phenomenon of autodoping (62c).
The height of the edge-crowns are measured by referring the main obverse surface and the reverse surface of the single crystalline substrate 51 as the standard planes. The height Hi of the front crown 62a is measured by referring the surface of the epitaxial layer grown on the main obverse surface of the substrate 51 as the standard plane, and the height H2 of the rear crowns 62b and 62c is measured by referring the reverse surface of the substrate after the removal of the protecting film 53 as the standard plane.
When a conventional semiconductor single crystalline substrate is used, the height H1 of the front crown 62a, can be reached to 30 .mu.m in an epitaxial layer grown to about 100 .mu.m, depending on the growth conditions. If the height H1 of the front crown 62a exceeds 10 .mu.m, the subsequent process of a device fabrication will be at a disadvantage by causing the front crown 62a to contact with a mask for the formation of a photolithographic pattern at the peripheral part and consequently impairing the contact tightness between the mask and the epitaxial layer 63 and degrading the sharpness of the pattern.
If the height H2 of the rear crowns 62b and 62c exceeds 10 .mu.m, since the single crystalline substrate 51, while being vacuum chucked on the reverse surface side thereof, is bent concavely with the peripheral part thereof pushed up by the rear crown 62b, the subsequent process of a device fabrication will be at a disadvantage in impairing the contact tightness between the mask for the formation of a photolithographic pattern and the epitaxial layer 63 and consequently degrading the sharpness of pattern in the same manner as the front crown 62a occured on the main obverse surface side. Also, if the height H2 of the rear crown 62b exceeds 10 .mu.m, the single crystalline substrate 51 tends to be coupled with the susceptor during the growth of the epitaxial layer 63 and, deformation due to the thermal stress generated between the coupled spots of the substrate and the susceptor during cool down will eventually cause cracks and slips.
Heretofore, in the growth of a very thick epitaxial layer, efforts have been made to confine the heights of edge-crowns within 10 .mu.m by suitably selecting the type of a vapor-phase growth reactor, the shape of a pocket of the susceptor for retaining the substrate, and the growth conditions such as reaction temperature and growth rate.
When a barrel type vapor-phase growth reactor is used for growing an epitaxial layer in the place of the vertical type vapor-phase growth reactor, edge-crowns occur exclusively on the main obverse surface side. Since this type of reactor retains a single crystalline substrate by tilting against a substantially upright susceptor, and consequently an area of the chamfered part of the single crystalline substrate contacts with the lower lateral wall of the pocket of the susceptor inevitably, the contact area of the chamfered part of the single crystalline substrate tends to be coupled with the lower lateral wall of the pocket via the epitaxial deposition and inflicts cracks and slips thereon when the epitaxial layer is grown very thick.
When the depth of the pocket of the susceptor for retaining the substrate is made deeper, the reaction gas supply to the periphery of the poket becomes less. Thus, the height of edge-crowns decreases as the depth of the pocket is deeper. On the other hands, the epitaxial layer thickness becomes thinner by a low growth rate at the periphery of the layer, resulting the thickness distribution becomes worth.
The height of the front crown becomes lower and that of the rear crowns becomes higher when the growth rate is increased. Conversely, the height of the front crown becomes higher and that of the rear crowns becomes lower in proportion as the growth rate is decreased. In short, the edge-crowns on the obverse and the reverse surface side cannot be lower simultaneously by varying the growth rate.
The height of the rear crowns will be lower if the protecting film for preventing autodoping is not provided on the reverse surface side. However, when an epitaxial layer is grown by vapor-phase reaction on a heavily doped substrate without the protecting film, it entails autodoping which has an adverse effect on an impurity concentration profile in the transition zone of the substrate and on the impurity concentration distribution in the peripheral part of the epitaxial layer.

Semiconductor single crystalline substrate and method for production thereof


Prior to machining a workpiece, a warm-up control device for a machine tool is activated to perform a warm-up in which a main shaft rotary drive part and axes drive parts are driven. The amount of displacement of heat that is generated upon starting of the warm-up and changes with time is calculated every predetermined time period. Whether to end the warm-up is determined based on the thermal displacement amount. Whether to restart the warm-up after the end of the warm-up is determined based on the thermal displacement amount. When it is determined to restart the warm-up, the warm-up is restarted.

1. Field of the Invention
The present invention relates to a warm-up control device for a machine tool.
2. Description of the Related Art
The main shaft attached to a machine tool is rotated by a rotary drive means such as a motor. Therefore, it is known that a machining tool attached to a tip of the main shaft is displaced by the heat generated from the rotary drive means itself or heat generated from a main shaft bearing, causing errors. Moreover, when thermal displacement occurs in a base of the machine tool due to the heat generated by drive means such as a motor used for axis feeding for relatively displacing the positions of a workpiece and the tool, changes in temperature in the environment where the machine tool is installed, and the heat generated in driving of the abovementioned main shaft, the relative position between the workpiece and the tool becomes shifted, causing machining errors.
A method called "warm-up" has been known as a way to solve these problems. A warm-up is an operating method in which, especially due to the impact of thermal displacement of the main shaft caused by its rotation, the main shaft is idled in order to maintain machining accuracy, and then a workpiece is machined after thermal displacement of the main shaft becomes stable. Although the idling for achieving stable machining accuracy is performed until the thermal displacement in the machine tool is stabilized, how long the idling needs to be performed is determined based on the experiences or intuition of a skilled operator. Thus, whether the thermal displacement is definitely stabilized or not is uncertain. Moreover, it might take an unnecessarily long time for such warm-up.
Japanese Patent Application Laid-Open No. 2009-113138, for example, discloses a method that continuously measures the position of the tip of a tool by using a measuring device such as a laser interferometer, calculates the thermal displacement amount of the position of the tip of the tool from a result of the measurement, and ends the warm-up based on the calculated thermal displacement amount.
However, Japanese Patent Application Laid-Open No. 2009-113138 only describes that the way of ending the warm-up is to simply end the warm-up or to automatically start machining. When the warm-up is simply ended, the machining starting point on the tool at which the machining is started needs to be reset manually. In a case where an operator gets caught up in another work and leaves the machine tool after the end of the warm-up, the warm-up needs to be carried out again, which is not necessarily efficient. It is not particularly problematic to start machining automatically, but automatically resetting the machining starting point requires a measuring device that is capable of controlling the tool by using a numerical controller. However, not all machine tools are equipped with such measuring devices.


A method of manufacturing a reverse osmosis composite membrane, including: (i) bringing a mixed liquid containing carbon nanotubes, water, and an amine component into contact with a porous support, the mixed liquid being produced through a step of pressurizing and compressing an aqueous solution containing the carbon nanotubes while flowing the aqueous solution, followed by releasing or reducing a pressure to return a volume of the aqueous solution to an original volume to mix the carbon nanotubes; and then (ii) subjecting the amine component in the mixed liquid adhering to the porous support to a crosslinking reaction.

In order to cope with global water shortage and water contamination, a water treatment technology involving using a reverse osmosis membrane (RO membrane) has been attracting attention. Of such membranes, a reverse osmosis membrane using an aromatic polyamide that can remove even an ion component, such as salt, with a pore diameter of 1 nm or less has been most widely spread in seawater desalination plants.
In a water treatment involving utilizing a reverse osmosis membrane, a permeate flux and desalination performance (NaCl rejection rate) reduce with time owing to the adhesion of dirt to the reverse osmosis membrane. Accordingly, the permeate flux and the desalination performance needs to be restored by periodically washing the reverse osmosis membrane. A washing method desired for the washing of the reverse osmosis membrane is washing with an aqueous solution containing a hypochlorite or active chlorine having an oxidizing power because the washing is excellent in decomposing and removing properties for a protein component and the like, microbicidal property, and sterilizing property.
However, the reverse osmosis membrane using the aromatic polyamide has low resistance to chlorine having an oxidizing power, and hence a portion in contact with chlorine deteriorates. Accordingly, the membrane involves a problem in that its desalination performance extremely reduces after washing with oxidizing chlorine relative to that before the washing.
Reverse osmosis membranes using carbon nanotubes have also been proposed (Non Patent Literatures 1 to 3). However, each of the proposals is inferior in performance to a reverse osmosis membrane currently available on the market, and shows no dramatic improvement in chlorine resistance.

Reverse osmosis composite membrane and method for manufacturing reverse osmosis composite membrane


A tire carrier assembly includes a rotation shaft and a housing have a bottom wall including a first aperture for receiving the rotation shaft. The housing also includes a sidewall extending upward from the bottom wall defining an interior space. The sidewall includes inner and outer surfaces. A sheave is disposed within the interior space of the housing and has a second aperture that receives the rotation shaft. The sheave also includes a gear member associated with it. Also included is a torque plate having a base, the base having opposing first and second surfaces and a third aperture formed therein. The third aperture has a gear portion formed around a periphery of the aperture. The torque plate also includes an arm portion projecting radially from the base. The gear portion of the torque plate is in operable engagement with the gear member of the sheave. An eccentric bushing having first and second opposing surfaces and an integrally formed bounding wall includes a fourth aperture receiving the rotation shaft. The first surface includes a cam formed thereon. The cam is positioned within the third aperture of the torque arm. A cable guide is positioned within the internal space of the housing and is located radially outboard relative to the sheave for positioning a cable about the sheave. The cable guide includes a lobe formed thereon for contacting a cable. A cover plate having a fifth aperture formed therein receives the rotation shaft. The cover plate is attached to the housing. The tire carrier assembly includes a frangible component that breaks upon the application of a predetermined force allowing the torque plate to freely rotate about the rotation shaft wherein the arm portion of the torque plate engages the inner surface of the sidewall of the housing allowing a controlled payout of cable wound about the sheave.

Various spare tire carriers have been utilized in the past and are well known in the art. Typically, spare tire carriers are designed to hold a spare wheel below the body frame of a vehicle. Generally, the spare tire carrier includes a cable associated with a winch or drive mechanism to raise and lower the tire when needed. Various U.S. patents including U.S. Pat. Nos. 4,059,197; 4,535,973; 4,600,352; 4,625,947; 5,251,877; 5,265,708 and 5,415,377 are related to spare tire carrier designs.
However, none of these prior art designs teach or suggest a spare tire carrier having overload protection with a controlled cable payout. Specifically, there is a need in the art for a spare tire carrier wherein a cable is released allowing the tire to separate from the tire carrier mechanism at a predetermined load; thereby allowing the cable to unwind from a spool such that the cable is prevented from being exposed to high loading forces. Additionally, there is a need in the art for a controlled cable payout in which the rate of the release of the cable can be controlled to avoid a rapid uncontrolled movement of a spare tire.

Spare tire carrier having overload protection with controlled cable payout


An object of the present invention is to provide a transgenic plant on which a useful phenotype is conferred by regulating expression of pseudo-response regulator (PRR) genes with an approach that is different from deletion of PRR genes. According to the present invention, there is provided a transgenic plant into which a polynucleotide encoding a protein comprising a CCT motif and a pseudo-receiver domain which is a common motif of plant pseudo-response regulator genes, a fusion polynucleotide of said polynucleotide and a polynucleotide encoding at least one transcription activation domain of a transcription factor, or a recombinant vector comprising said polynucleotide or fusion polynucleotide has been introduced.

It has been suggested that the circadian clock system in Arabidopsis thaliana is associated with increased biomass, determination of the time of flowering, and environmental stress responses (Non-Patent Document 1). As a result of research conducted using Arabidopsis thaliana, three plant clock-associated genes (i.e., the circadian clock-associated 1 (CCA1) gene, the late elongated hypocotyl (LHY) gene, and the timing of cab expression 1 (TOC1) gene) have been discovered, and the mechanisms of plant circadian rhythm have been proved to be based on the transcriptional feedback loop of such a plurality of genes. Among these, the TOC1 gene is one of pseudo-response regulator genes. At present, a total of 5 genes (i.e., PRR3, PRR5, PRR7, and PRR9, in addition to TOC1 (PRR1)) have been identified as pseudo-response regulator genes in Arabidopsis thaliana, and the expression levels thereof increase and decrease in the order of PRR9, PRR7, PRR5, PRR3, and PRR1 (TOC1) from dawn toward evening in a phase-graded manner.
The present inventors had focused on and studied the prr9 prr7 prr5 triple mutant of Arabidopsis thaliana (i.e., the d975 mutant). As a result of previous studies, the d975 mutant was found to exhibit industrially useful phenotypes such as flowering stem elongation (Non-Patent Document 3), delayed flowering (Non-Patent Document 2), and higher resistance against low temperature or dehydration (Non-Patent Document 4), in addition to a breakdown of the circadian clock system (Non-Patent Document 2). However, since the three PRR genes complement their functions each other, a single mutant would not exhibit a remarkable phenotype (Non-Patent Document 2). In addition, conferring of a useful phenotype by deletion of the three PRR genes as targets would be attended with the difficulty in preparation of a multiple mutant. Further, since the biochemical functions of PRR9, PRR7, and PRR5 proteins are unknown, suppression of the functions of the PRR proteins with the use of a low-molecular-weight compound or the like is not practical technically.
An example of a technique for conferring low temperature resistance or dehydration resistance is a method in which expression of the DREB1A gene or similar genes is induced under the control of a dehydration stress responsive promoter of Arabidopsis thaliana (Patent Document 1 and Non-Patent Document 5). While this method may be sufficient to confer stress resistance, increased biomass is not mentioned.
Increased biomass is observed for a mutant of the clock-associated gene, GIGANTEA (gi) (Non-Patent Document 6); however, this mutant is more susceptible to low temperature stress (Non-Patent Document 7). Thus, a plant exhibiting increased biomass and environmental stress resistance cannot be prepared by a method of deleting the function of this gene as a target.
Slightly decreased expression levels of the clock-associated genes (i.e., the circadian clock associated 1 (CCA1) gene and the late elongated hypocotyl (LHY)) are said to be correlated with the increased biomass (Non-Patent Document 8); however, a line in which expression of the CCA1 gene and the LHY gene was completely suppressed (i.e., the ccal lhy double mutant) rather exhibits a decreased biomass (Non-Patent Document 9). Thus, it is considered difficult to increase the biomass by targeting these genes.
While the biological clocks of long-day plants are almost the same as those of short-day plants (Non-Patent Document 10), seasonal responses utilizing such biological clocks are known to differ from each other (Non-Patent Document 11). Accordingly, the degree of effectiveness of conferring a useful phenotype on a short-day plant by modifying a clock gene of a long-day plant (i.e., Arabidopsis thaliana) is unknown.    (Patent Document 1) JP Patent Publication (Kokai) No. 2000-116260 A    (Non-Patent Document 1) Harmer, S. L., Hogenesch, J. B., Straume, M., Chang, H. S., Han, B., Zhu, T., Wang, X., Kreps, J. A., and Kay, S. A., 2000, Orchestrated transcription of key pathways in Arabidopsis by the circadian clock, Science 290 (5499): 2110-2113    (Non-Patent Document 2) Nakamichi, N., Kita, M., Ito, S., Yamashino, T., and Mizuno, T., 2005, Pseudo-response regulators, PRR9, PRR7 and PRR5, together play essential roles similar to the circadian clock of Arabidopsis thaliana, Plant Cell Physiol., 46 (5): 686-698    (Non-Patent Document 3) Yamashino, T., Ito, S., Niwa, Y., Kunihiro, A., Nakamichi, N., and Mizuno, T., 2008, Involvement of Arabidopsis clock-associated pseudo-response regulators in diurnal oscillations of gene expression in the presence of environmental time cues, Plant Cell Physiol., 49 (12): 1839-1850    (Non-Patent Document 4) Nakamichi, N., Kusano, M., Fukushima, A., Kita, M., Ito, S., Yamashino, T., Saito, K., Sakakibara, H., and Mizuno, T., 2009, Transcript profiling of an Arabidopsis pseudo-response regulator arrhythmic triple mutant reveals a role for the circadian clock in cold stress response, Plant Cell Physiol., 50 (3): 447-462    (Non-Patent Document 5) Kasuga, M., Liu, Q., Miura, S., Yamaguchi-Shinozaki, K., and Shinozaki, K., 1999, Improving plant drought, salt, and freezing resistance by gene transfer of a single stress-inducible transcription factor, Nat. Biotechnol., 17 (3): 287-291    (Non-Patent Document 6) Redei, G., 1960, Supervital mutants of Arabidopsis, Genetics 47: 443-460    (Non-Patent Document 7) Cao, S., Ye, M., and Jiang, S., 2005, Involvement of GIGANTEA gene in the regulation of cold stress response in Arabidopsis, Plant Cell Rep., 24 (11): 683-690    (Non-Patent Document 8) Ni, Z., Kim, E. D., Ha, M., Lackey, E., Liu, J., Zhang, Y., Sun, Q., and Chen, Z. J., 2009, Altered circadian rhythms regulate growth vigour in hybrids and allopolyploids, Nature 457 (7227): 327-331    (Non-Patent Document 9) Mizoguchi, T., Wheatley, K., Hanzawa, Y., Wright, L., Mizoguchi, M., Song, H. R., Carre, I. A., and Coupland, G., 2002, LHY and CCA1 are partially redundant genes required to maintain circadian rhythms in Arabidopsis, Dev Cell 2 (5): 629-641    (Non-Patent Document 10) Murakami, M., Tago, Y., Yamashino, T., and Mizuno, T., 2007, Comparative overviews of clock-associated genes of Arabidopsis thaliana and Oryza sativa, Plant Cell Physiol., 48 (1): 110-121 (Non-Patent Document 11) Hayama, R., Yokoi, S., Tamaki, S., Yano, M., and Shimamoto, K., 2003, Adaptation of photoperiodic control pathways produces short-day flowering in rice, Nature, 422 (6933): 719-722

Transgenic plant having increased biomass and improved environmental stress resistance, and process for production thereof


This invention relates to lens type functional retroreflective sheeting having retroreflective regions and visual functionality presenting regions, the retroreflective sheeting comprising:. a base sheet consisting of a support comprising a functional resin layer containing a functional pigment having light-storing or fluorescent properties, microspherical lens-embedding regions in which microspherical lenses are densely distributed on the surface of the functional resin layer of the support so as to form a mono-layer, and microspherical lens-free regions in which substantially no microspherical lens is embedded and the functional resin layer is exposed; PA1 a transparent protective film disposed above the microspherical lens-bearing surface of the base sheet; and PA1 bonds at which said base sheet and said transparent protective film are partly bonded together. This lens type functional retroreflective sheeting not only afford good visibility to viewers positioned in the direction of the light source (e.g., automobile drivers), but also afford good visibility at night to drivers and pedestrians positioned in directions different from the that of the light source.

Conventionally, retroreflective sheeting capable of reflecting incident light back toward the light source has been well known, and such sheeting is widely used in the above-described fields of application owing to good visibility at night on the basis of its retroreflectivity. For example, road signs, construction signs and other signs using retroreflective sheeting have excellent characteristics in that, at night or the like, they reflect light from a light source (e.g., the headlamps of a moving vehicle such as automobile) back toward the light source (i.e., the moving vehicle) and afford good visibility to the viewer of the signs (i.e., the driver of the vehicle), thus permitting the transmission of correct information.
Thus, retroreflective sheeting generally reflects light from a light source back toward the light source and hence affords good visibility in the direction of the light source. However, when the viewer is positioned in a direction different from that of the light source, its visibility is markedly reduced. Moreover, owing to the nature of retroreflective sheeting, the difference between the angle of incidence of light from the light source of a vehicle such as an automobile and the angle of observation of the driver of the vehicle increases as the light source comes nearer, resulting in a marked reduction in visibility. Recently, with the development of road systems and the diversification of provided information, the amount of information displayed on each sign is increasing. With consideration for the speed of vehicles, it may be very difficult for the drivers to read necessary information in a very short period of time when they are within the visible range of retroreflected light.
Accordingly; in the case of applications requiring the provision of more correct information, pronounced propaganda effects and the like, conventional retroreflective sheeting having retroreflectivity alone is limited in visibility. In particular, there is a strong demand for excellent retroreflective sheeting which can always afford good visibility to viewers at night even when the viewers are positioned in directions different from that of the light source.
In order to meet this demand, various attempts have been made to improve the visibility of retroreflective sheeting. For example, Japanese Patent Laid-Open No. 173008/'93 discloses encapsulated lens retroreflective sheeting having both retroreflectivity and light-storing luminosity wherein a transparent resin layer is used as a support for partially embedding retroreflective microspherical lenses (i.e., microspherical lenses having a deposited metal film coating the approximately hemispherical surfaces thereof and hence exhibiting retroreflectivity) and a layer of a light-storing luminescent substance is disposed on the back surface (i.e., the surface opposite to the light incidence side) of the support. However, owing to the structure of this retroreflective sheeting, the light radiating from the luminescent substance is intercepted by the embedded retroreflective microspherical lenses, so that the amount of light emitted thereby is very small. Consequently, this retroreflective sheeting is totally unsatisfactory for the purpose of improving visibility.
Moreover, the specification of PCT International Application Publication No. WO93/14422 discloses photoluminescent encapsulated cube-corner retroreflective sheeting which contains a phosphorescent pigment in the bonds for bonding the cube corner-forming surface to the support, and also suggests a method for imparting fluorescent properties to encapsulated lens retroreflective sheeting. However, even in the retroreflective sheeting described in the specification of this international application, the phosphorescent pigment fails to emit a sufficient amount of light. Consequently, signs made of this retroreflective sheeting will not have such a high degree of visibility that the information displayed thereby can be recognized from some distance.
Furthermore, the specification of PCT International Application Publication No. WO96/18920 discloses ultraviolet-excited luminous retroreflective sheeting of the encapsulated lens structure wherein the bonds at which a base sheet having retroreflective microspherical lenses partially embedded in a support is partly bonded to a protective film are formed on the protective film or base sheet as an ultraviolet-excited luminous layer by printing an ultraviolet-excited luminous resin composition, and these bonds are then fused to the base sheet or protective film by the application of heat or bonded thereto with the aid of a suitable adhesive. Moreover, this specification also suggests ultraviolet-excited luminous retroreflective sheeting wherein an ultraviolet-excited luminous support is prepared by forming the support of an ultraviolet-excited luminous resin composition or providing at least on the microspherical lens-embedding side of the support with an ultraviolet-excited luminous layer formed of an ultraviolet-excited luminous resin composition, and this support is partly heated and melt-formed by means of an embossing roll or the like to form bonds for bonding the protective film partly to the base sheet.
However, the retroreflective sheeting described in the specification of the aforementioned WO96/18920 involves problems in that the ultraviolet-excited luminous layer consists essentially of only the bonds for bonding the protective film to the base sheet and the proportion thereof to the total surface area of the retroreflective sheeting is very small and in that the amount of luminescent substance incorporated in the bonds cannot be increased so much. Consequently, it has been found that the amount of light emitted by the luminescent substance tends to be insufficient and, moreover, the retroreflective sheeting also has disadvantages such as poor adhesion of the ultraviolet-excited luminous layer to the protective film and difficulty in forming an adhesive layer on the formed ultraviolet-excited luminous layer.
On the other hand, several methods for embedding retroreflective microspherical lenses in some part of a support are also known. For example, U.S. Pat. No. 4,075,049 discloses a method for the preparation of a base sheet which comprises the steps of embedding the approximately hemispherical parts of glass beads in a temporary support (e.g., polyethylene-laminated paper) so as to form a mono-layer, depositing a lightreflecting material on the glass bead-bearing surface thereof, forcing part of the glass bead layer into the polyethylene layer of the temporary support by heating and pressing the glass bead-bearing side of the temporary support by means of a mold having a raised pattern, and pressing a support having an adhesive layer against the glass bead-bearing side of the temporary support to transfer the glass beads not buried in the polyethylene layer to the support.
However, the purpose of the method described in this U.S. patent lies in the fact that, in the fabrication of encapsulated lens retroreflective sheeting, the support of the base sheet is thermoformed by means of a mold having the same raised pattern as the raised pattern of the aforesaid mold so as not to incorporate glass beads in the bonds for bonding a protective film to the base sheet. Although this method may be employed in cases where it is desired to prevent a very small part of the glass bead layer from being transferred to the support, it is not easy to prevent a large part (e.g., more than half) of the glass bead layer from being transferred to the support and, therefore, this proposed method is not considered to be suitable in such cases.
It is an object of the present invention to provide lens type functional retroreflective sheeting which have both retroreflective regions and visual functionality presenting regions and hence exhibit good visibility even at night or the like, as well as methods of producing the same.

Lens type functional retroreflective sheeting and method of producing same


A method and apparatus for manufacturing a cushioning package containing an article to be packaged. The apparatus includes a cushioning sheet forming unit to form a cushioning sheet by heat-sealing flexible elongated resin sheets which are continuously fed in a longitudinal direction and placed one on another in advance in a width direction of the sheet, the cushioning sheet including small sacs. Downstream from the cushioning sheet forming unit, an article storage space forming unit is provided for forming an article storage space by folding the cushioning sheet along a longitudinal centerline. A sheet adhering unit adheres the overlapped cushioning sheets. An article disposing unit inserts the article to be packaged into the article storage space, and an air filling unit fills the small sacs with air. Sequential performance of the above steps achieves efficient manufacturing of cushioning package.

Conventionally, cushioning packages with a cushioning sheet being able to be filled with air have often been used in order to package an article, such as electrical appliances and parts for machines, which needs to be protected.
For example, FIG. 12 shows a cushioning package 101 that is described by the Official Gazette of Japanese Utility Model Registration No. 3009233. This is a cushioning package having an article storage space 103 sandwiched by a cushioning sheet that is composed of a plurality of small sacs 102, and the packaged article 104 disposed in the article storage space 103 is protected by the small sacs 102 filled with air.
The above-mentioned cushioning package 101 is, however, one wherein the small sacs 102 are filled with air after the article 104 to be packaged has been contained, and because manufacturing of the cushioning package 101 itself, containing of the article 104 and filling the small sacs 102 with air cannot be performed at the same time, a complicated process has been required in order to manufacture a cushioning package containing an article to be packaged therein.
Thus, the present invention aims to provide a method of manufacturing a cushioning package containing an article to be packaged and a manufacturing apparatus thereof, which can achieve simultaneous manufacturing of the cushioning package, containing of an article to be packaged and filling the package with air.

Method and system for producing shock absorbing package containing packaged article


Disclosed is a molten carbonate fuel cell capable of preventing the leakage of a fuel gas due to deterioration of material by suppressing a high temperature generated at a hot section within a unit cell, thereby improving the reliability thereof. The present invention provides a molten carbonate fuel cell including a plurality of stacked unit cells 8, and separator plates 3 interposed between the adjacent unit cells, the respective unit cells having porous fuel electrode plates 9a and 9b, air electrode plates 11a and 11b, and electrolyte plates 10 interposed between these electrode plates; wherein the separator plate 3 forming a body 1 of the unit cell 8 is provided with at a center thereof intake internal manifolds 12a and 13a arranged at regular intervals for taking in fuel gas R and oxidant gas O towards a center of the body, and at both sides thereof exhaust internal manifolds 12b, 12c, 13b and 13c for exhausting the reacted fuel gas R and the reacted oxidant gas O, as well as forming passages for the fuel gas R ad the oxidant gas O at both sides thereof.

1. Field of the Invention
The present invention relates to a fuel cell using molten carbonate as an electrolyte, and more particularly, to a molten carbonate fuel cell capable of preventing the leakage of a fuel gas due to deterioration of material by suppressing a high temperature generated at a hot section within a unit cell, thereby improving the reliability thereof.
2. Background of the Prior Art
A fuel cell is a power generating apparatus for converting chemical energy into electrical energy using an electrochemical reaction, and is highlighted as a new electrical energy source, because of being an environmental friendly apparatus and having a high power-generating efficiency. Such a fuel cell has a characteristic of continuously generating the power by supplying a fuel through an oxidation reaction of hydrogen and a reduction reaction of oxygen in the air.
In particular, a molten carbonate fuel cell among fuel cells utilizes molten carbonate as an electrolyte, so that the operation is carried out at a high temperature of 650° C. and the speed of the electrochemical reaction is quick. Contrary to a low-temperature fuel cell, electrode reactions occur when the carbonate electrolyte is molten at a high temperature, thereby generating the power at a relatively high temperature. Since the oxidation-reduction reactions of hydrogen and oxygen do not require a catalyst made of noble metal such as expensive platinum, there are features of facilitating the utilization of a nontoxic gas, such as carbon monoxide, and a coal gas. Another feature is to anticipate a high thermal efficiency above about 80% due to the utilization of electricity and waste heat.
The molten carbonate fuel cell has porous anode/cathode electrodes having a wide surface area for facilitating the smooth procedure of the oxidation-reduction reactions of hydrogen and oxygen. The molten carbonate impregnated in a porous ceramic interposed between the porous anode/cathode electrodes functions as a shield of preventing direct contact between the fuel mainly made of hydrogen and the oxidant made of oxygen, and a passage for guiding carbonate ions (CO32−) produced from an air electrode to a fuel electrode.H2+CO32−→H2O+CO2+2e− (fuel electrode)1/20O2+CO2+2e−→CO32− (air electrode)
However, since a unit cell forming one cell generates a low electromotive force of 1 V, it is no properly to be practically used. Such unit cells are stacked, with conductive separator plates interposed between two adjacent unit cells, to constitute the power generating system.
Specifically, the unit cell includes a pair of porous electrode plates (fuel electrode and air electrode), and an electrolyte plate consisting of alkali carbonate interposed between these electrode plates. These fuel cells are stacked one above another, and a conductive separator plate is interposed between two adjacent unit cells. The separator plate electrically connects these unit cells, and provides the fuel electrode with a passage of a fuel gas and the air electrode with a passage of an oxidant gas.
Such the fuel cell of stacked structure requires a manifold for distributing and collecting the reaction gas. The gas to be required for the reaction is supplied via an inlet manifold, and after passing through the air electrode and the fuel electrode, is outwardly discharged via a manifold opposed to the inlet manifold. Each unit cell is provided with a wet seal formed by molten carbonate, in order to prevent the fuel and the oxidant from being mixed within the fuel cell. The body of the fuel cell and the manifold are also wet-sealed together in order to prevent the reaction gases from leaking out.
In case of the fuel cell, however, a part of energy contained in the fuel is converted into the electrical energy, and the remainder is converted into the atmospheric heat. Accordingly, in case of the stacked fuel cell, the heating value is varied depending upon a degree of the stack. The more the fuel cells are stacked, the more the heating value is generated. Therefore, the hot section is produced at the outlet of the gas.
This high temperature has an influence on the components of the fuel cell, i.e., the electrodes, the electrolyte and the separator plates. Specifically, there are some situations: change of the porous structure, and evaporation of the liquid electrolyte, which are due to the high temperature; consumption of the electrolyte and deformation of the separator plates, which are due to the increased corrosion of the metal separator plate; and leakage of the fuel gas, due to these causes. Therefore, the lifetime of the fuel cell is significantly reduced.
In order to suppress the production of the hot section, a method is widely used to cool it by overly supplying the oxidant gas mainly comprising air. The oversupply of air at the defined passage provides the gas flow with a resistance, thereby causing the pressure to be increased.
The conventional molten carbonate fuel cell isolates the fuel from the oxidant gas by use of the electrolyte impregnated in the porous ceramic in a type of wet seal. However, since the oversupply of the oxidant for suppressing the production of the hot section causes the high pressure to be produced within the passage, the fuel gas is leaked out due to the rupture of the wet seal, thereby significantly shortening the life of the fuel cell body.
Another method is used to reduce the degree of the electrode reactions, i.e., lower the current density, so that the production of the hot section may be suppressed by use of the small heating value. However, the utilization of the lower current density causes the usage of the molten carbonate fuel cell to be highly limited as a power-generating plant having a high output.
One method employing internal and external manifolds in the fuel cell body is disclosed in Japanese Laid-Open Patent Publication No. 62-202465. Intake and exhaust of the fuel gas are distributed at its center by use of the internal manifold, and the fuel gas is exhausted by use of internal manifolds at both sides. The oxidant gas mainly used for cooling due to a lot amount of gases flows from one surface of the stacked fuel cell to the other opposed surface by use of the external manifold. When using a lot amount of oxidant gases in a long passage of oxidant gas, the leakage of the fuel gas due to the pressure generation is not evitable.
Another method, similar to the above-mentioned method, is disclosed in Japanese Laid-Open Patent Publication No. 61-248364. The fuel gas is supplied from internal manifolds provided at both sides of a separator plate, and is collected and exhausted to a center internal manifold, so that the fuel gas and the oxidant gas are perpendicularly crossed. Since the oxidant gas in charge of cooling the fuel cell body flows from one surface of the stacked fuel cell to the other opposed surface, it is difficult to supply a lot amount of oxidant gases using the pressure generated by means of the long passage.


A safety device made of soft conformable cushioning material to be formed about the handle of manual work implements or tools to protect the hands of the user. The material is brightly colored to attract the eye and prevent the loss or misplacement of the tools. The material may be a polymer or rubber foam with or without a smooth outer surface. The user of any hand tool can modify the tool with the safety material by measuring, cutting and trimming to fit, then attaching the material to the handle of the tool by an adhesive.

The present invention relates to manual tools and will particularly pertain to the new and improved safety attachment to the portions of the tool, usually referred to as the handle, contacted by the hands of the user during the use of the tool.
The frequency and the dangers of misplaced tools is so prevalent that comic relief is given to the situation. How many cartoon and real life characters have stepped on the upturned rake or hoe to their mortification| While this is funny when there is no permanent damage, it only happens in the movies. Serious injury about the home and work site is a major problem and usually includes the use of tools. One major concern addressed by this invention is safety.
For example, a hammer or rake or shovel or hoe or pick or hedge clippers laying in the yard or about any work place pose real dangers because the normal coloration of the tool blends into the background. The wooden handles of these tools takes on a brown or tan color and the blades or tines are most always rust colored. These things become unguided missiles when run over by other machinery, such as rotary mowers. The possibility of accidently stepping on these tools is also increased by their camouflage.
Further, it is not necessarily forgetfulness that the tools are left in the work place. The blending of the tool into its background leads to loss through a lack of visibility. In a construction environment, where there are many workers handling several different manual tools, the loss of the tools through misplacement is a significant cost.
The use of hand tools produces significant friction between the user's hands and the handle of the implement. The wooden or metal handles of hand tools become difficult to control when they become wet during use sometimes creating accidents and injury through misdirection of the tool. The occasional users of such equipment may incur injuries to the hands, if not sufficiently protected. Conventional protection includes work gloves which, in themselves, are a source of irritation whether it is forgetting to carry them or the heat or perspiration resulting from their use. The hand injuries resulting from the use of hand tools include blisters, sprains, strains, and general soreness produced by the shock transmitted by the tools to the hands. Several patents show hand tools with various protective devices attached to the handles, e.g. U.S. Pat. Nos. 4,832,132; 4,089,379; 4,054,313; 3,981,043; 3,874,686; 3,237,950; 1,976,411; 1,942,493; 1,752,064; 1,632,227; and 1,248,445.


A semiconductor memory device that includes a memory cell array having a plurality of memory cells that are connected between a bit line pair, which transfers data to the bit line pair, a precharge circuit for precharging the bit line pair to a precharge voltage level during a precharge period, and one or more bit line sense amplifiers which are connected between the bit line pair and detect a voltage difference of the bit line pair to amplify a level of the bit line pair. The semiconductor memory device includes one or more FINFETs.

1. Field of the Invention
The present invention relates to a semiconductor memory device and, more particularly, to a semiconductor memory device including FINFETs.
2. Description of the Related Art
Because a semiconductor memory device is becoming widely used as a memory device for a portable terminal device, for example, a cellular phone, a PDA, a digital camera, etc., the demand for miniaturization of the semiconductor memory device is increased. To this end, a semiconductor memory device should be designed to reduce a layout area size of a core region of the semiconductor device so more circuit elements can be arranged on the semiconductor device and/or the overall size of the semiconductor device may be reduced.
FIG. 1 is a circuit diagram illustrating a core region of a conventional semiconductor memory device.
Referring to FIG. 1, a core region of a conventional semiconductor device may include a memory cell array 1, a precharge circuit 21, a bit line sense amplifier 22 and a data I/O circuit 23. The memory cell array 1 may read and/or write data in response to a signal transmitted via a word line WL and a bit line pair BL and /BL. The precharge circuit 21 may precharge the bit line pair BL and /BL to a precharge voltage level in response to a precharge control signal PEQ. The bit line sense amplifier 22 may detect and/or amplify a voltage difference of the bit line pair BL and /BL in response to a sensing control signal pair LA and /LA, and the data I/O circuit 23 may transmit data of the bit line pair BL and /BL to a local data I/O line pair LIO and /LIO or may transmit data of the local data I/O line pair LIO and /LIO to the bit line pair BL and /BL in response to a column selecting signal CSL.
The components of FIG. 1 are explained below.
The memory cell array 1 may include a plurality of memory cells MC, each of which includes at least one n-type Metal Oxide Semiconductor Field Effect Transistor (n-MOSFET) (not shown) or p-type Metal Oxide Semiconductor Field Effect Transistor (p-MOSFET) (not shown) and a capacitor (not shown) which may be connected between the word line WL and the bit line pair BL and /BL.
The precharge circuit 21 may include first and second n-MOSFETs NM1 and NM2, which may be connected directly between the bit line pair BL and /BL, may have a gate to which a precharge control signal PEQ may be applied, and may precharge the bit line pair BL and /BL to a precharge voltage VCC/2 level in response to the precharge control signal PEQ. The precharge circuit 21 may also include a third n-MOSFET NM3, which may be connected between the bit line pair BL and /BL, may have a gate to which the precharge control signal PEQ may be applied, and may precharge the bit line pair BL and /BL to the precharge voltage VCC/2 level in response to the precharge control signal PEQ.
The bit line sense amplifier 22 may include a p-type sense amplifier and an n-type sense amplifier that may be connected to the bit line pair BL and /BL, respectively. The p-type sense amplifier may be serially connected between the bit line pair BL and /BL; may include first and second p-MOSFETs PM1 and PM2, which may have a gate connected to the bit line pair BL and /BL and a common source to which a sensing control signal LA may be applied; and may detect data of a low level of one of the bit line pair BL and /BL to amplify the other line of the bit line pair BL and /BL to a power voltage VCC level. The n-type sense amplifier may be serially connected between the bit line pair BL and /BL; may include fourth and fifth n-MOSFETs NM4 and NM5, which may have a gate connected to the bit line pair BL and/or /BL and a common source to which an inverted sensing control signal /LA may be applied; and may detect data of a high level of one of the bit line pair BL and /BL to amplify the other line of the bit line pair BL and /BL to a ground voltage level, for example, 0 Volts.
The data I/O circuit 23 may include a sixth n-MOSFET NM6, which may be connected between the bit line BL and the local data I/O line LIO and may have a gate to which the column selecting signal CSL may be applied, and a seventh n-MOSFET NM7, which may be connected between an inverted bit line /BL and an inverted local data I/O line /LIO and may have a gate to which the column selecting signal may be applied; and may electrically connect the bit line pair BL and /BL and the local data I/O line pair LIO in response to the column selecting signal CSL.
An operation of the conventional semiconductor memory device of FIG. 1 is explained below with reference to FIG. 2.
For illustrative purposes, assume that data having a value of "0" is stored in a 0-th memory cell MC0 of the memory cell array 1 and the conventional semiconductor memory device in FIG. 1 reads data in the 0-th memory cell MC0 by a reading operation.
At a time T0 in FIG. 2, the conventional semiconductor memory device may be in a precharge state, word lines WL0 to WLN may have a low level, and a bit line precharge control signal PEQ may have a high level. The n-MOSFETs NM1 to NM3 of the precharge circuit 21 may be activated to precharge the bit line pair BL and /BL to a precharge voltage VCC/2.
At a time T1, the bit line precharge control signal PEQ may transition from a high level to a low level and the 0-th word line WL0 may transition from a low level to a high level so that the 0-th memory cell MC0 may be selected and data of the 0-th memory cell MC0 may be outputted to the bit line pair BL and /BL. As a result, a voltage of the bit line BL may gradually drop and the inverted bit line /BL may maintain the precharge voltage VCC/2 level.
At a time T2, a voltage of a sensing control signal LA may change from the precharge voltage VCC/2 to a power voltage VCC and a voltage of an inverted sensing control signal /LA may change from the precharge voltage VCC/2 to a ground voltage, for example, 0 Volts so that the power voltage VCC may be applied to the sources of the first and second p-MOSFETs PM1 and PM2 of the bit line sense amplifier 22, and the ground voltage, for example, 0 Volts may be applied to drains of the fourth and fifth n-MOSFETs NM4 and NM5.
At a time T3, if a voltage difference between the sensing control signal LA and the bit line BL is greater than a threshold voltage VTm of the MOSFET, the second p-MOSFET PM2 of the bit line sense amplifier 22 may be activated to apply the power voltage VCC to the inverted bit line /BL so that a voltage of the inverted bit line /BL may be increased. If a voltage difference between the inverted sensing control signal /LA and the inverted bit line /BL is greater than the threshold voltage VTm of the MOSFET, the fourth n-MOSFET NM4 may be activated to drop a voltage of the bit line to the ground voltage, for example, 0 Volts.
Accordingly, if the voltage difference between the sensing control signal LA and the bit line BL or the voltage difference between the inverted sensing control signal /LA and the inverted bit line /BL is greater than the threshold voltage VTm of the MOSFET, the bit line sense amplifier 22 may be activated and start an operation for amplifying the bit line pair BL and /BL.
At a time T4, if an amplification operation of the bit line pair BL is stabilized, the column selecting signal CSL may transition from a low level to a high level and data of the bit line pair BL may be transmitted to the local data I/O line pair LIO and /LIO so that data of the memory cell MC0 may be read.
At a time T5, if the read operation is completed, the 0-th word line WL0 may transition from a high level to a low level again to keep data of the 0-th memory cell MC0 in a storing state.
At a time T6, for the next read or write operation, the bit line precharge control signal PEQ may transition from a low level to a high level again to precharge the bit line pair BL and /BL to the precharge voltage VCC/2, whereby the semiconductor memory device becomes the precharge state again.
A write operation of the semiconductor memory device is performed based on the same principles as described with respect to the read operation described in FIG. 2, and thus, a description of the write operation will be omitted for the sake of brevity.
As described above, in a conventional semiconductor memory device, a MOSFET is used to form the memory cell MC, the precharge circuit 21, the bit line sense amplifier 22, and/or the data I/O circuit 23 and may be activated or deactivated to read or write data of the memory cell in response to a plurality of control signals PEQ, LA, /LA, and CSL and a voltage level of the bit line pair BL and /BL.
The MOSFET of FIG. 1 is a planar type transistor, and when the MOSFET is an n-MOSFET, as shown in FIG. 3, the MOSFET includes an n-type drain and an n-type source formed to be separated from each other and a gate electrode formed on a p-type substrate between the n-type drain and the n-type source.
The n-MOSFET may apply a voltage of more than the threshold voltage VTm to a gate to sufficiently induce electrons on a surface of the gate to form a channel so that an electric current may flow between the source and the drain through a channel. The conventional n-MOSFET has the threshold voltage VTm of about 0.7 Volts.
Even though not shown, similar to the n-MOSFET of FIG. 3, the p-MOSFET includes a p-type drain and a p-type source formed to be separated from each other and a gate electrode formed on an n-type substrate between the p-type drain and the p-type source and has the threshold voltage VTm of about 0.7 Volts.
Moreover, the second p-MOSFET PM2 of the bit line sense amplifier 22 may be activated to start the sensing operation if a voltage difference between the sensing control signal LA and the bit line BL is greater than about 0.7 Volts and the voltage difference VGS between the gate and the source of the second p-MOSFET PM2 is greater than about 0.7 Volts as shown at the time T3 of FIG. 2.
As described above, in a conventional semiconductor memory device the transistors are horizontally formed on the substrate as shown in FIG. 3 and occupy a relatively wide area and thus, the transistors cannot be formed in a smaller area without detrimental affects.
For example, conventionally, if an area on which the transistor is formed is reduced to reduce the size of the semiconductor memory device; the length of the gate of the MOSFET is reduced, which may cause several problems. For example, the source and the drain of the MOSFET may be too closed to each other. In this case, the impurity doping density should be increased, and the channel area is affected by interaction between the source and the drain. As a result, a characteristic of the transistor as an active switching element, which controls an operation of the transistor by adjusting a gate voltage of the MOSFET, may be degraded so that electrical characteristics of the MOSFET, for example, a stable threshold voltage, may be degraded.
As described above, there are limitations to reducing the layout area size of a core region of the conventional semiconductor memory device, and even though the layout area size of the core region may be reduced by reducing the gate length, e.g., the channel area between the source and the drain of a plurality of transistors, operation characteristics of the semiconductor memory device may be degraded.


The subject invention provides for novel synergistic compositions useful for inactivating viruses or inducing apoptosis in tumor cells and for treating cancer or retroviral infections. Generally, the compositions comprise one or a plurality of ligands that oxidatively attack a zinc finger of pADPRT in combination with one or a plurality of agents selected from the group consisting of: agents that decrease cellular levels of glutathione and ligands that non-covalently bind to the nicotinamide site of pADPRT but do not effect zinc ejection from a zinc finger of pADPRT.

Cancer and viral infections are a serious threat to modern society. Malignant cancerous growths, due to their unique characteristics, pose serious challenges for modern medicine. These characteristics include: uncontrollable cell proliferation resulting in unregulated growth of malignant tissue, an ability to invade local and even remote tissues, lack of differentiation, lack of detectable symptoms and most significantly, the lack of effective therapy and prevention.
Cancer can develop in any tissue of any organ at any age. The etiology of cancer is not clearly defined but mechanisms such as genetic susceptibility, chromosome breakage disorders, viruses, environmental factors and immunologic disorders have all been linked to a malignant cell growth and transformation.
Antineoplastic chemotherapy currently encompasses several groups of drugs including alkylating agents, purine antagonists and antitumor antibiotics. Alkylating agents alkylate cell proteins and nucleic acids preventing cell replication, disrupting cellular metabolism and eventually leading to cell death. Typical alkylating agents are nitrogen mustard, cyclophosphamide and chlorambucil. Toxicities associated with alkylating agents treatment include nausea, vomiting, alopecia, hemorrhagic cystitis, pulmonary fibrosis and an increased risk of development of acute leukemia.
Purine, pyrimidine and folate antagonists are cell cycle and phase specific and, in order to promote an anti-tumor effect, they require cells to be in the cell replication cycle and in the DNA synthesis phase of replication. The purine antagonists such as 6-mercaptopurine or 6-thioguanidine inhibit de novo purine synthesis and interconversion of purines. The pyrimidine antagonists, such as cytarabine, 5-fluorouracil or floxuridine inhibit DNA synthesis by inhibiting deoxycytidylate kinase and DNA polymerase.
Folate antagonists, e.g., methotrexates, bind tightly with the intracellular enzyme dihydrofolate reductase ultimately leading to cell death resulting from an inability to synthesize pyrimidines. Toxicities associated with the use of these compounds include alopecia, myelosuppression, vomiting, nausea, and cerebellar ataxia, among others.
Plant alkaloids such as vincristine, vinblastine or podophyllotoxins etoposide and teniposide generally inhibit mitosis and DNA synthesis and RNA dependent protein synthesis. Toxicities of these drugs are similar to those described above and include myopathy, myelosuppression, peripheral neuropathy, vomiting, nausea and alopecia.
Antitumor antibiotics such as doxorubicin, daunorubicin and actinomycin act as intercalators of DNA, preventing cell replication, inhibiting synthesis of DNA-dependent RNA and inhibiting DNA polymerase. Bleomycin causes scission of DNA and mitomycin acts as inhibitor of DNA synthesis by bifunctional alkylation. Toxicities of these antibiotics are numerous and severe and include necrosis, myelosuppression, anaphylactic reactions, anorexia, dose-dependent cardiotoxicity and pulmonary fibrosis.
Other compounds used for chemotherapeutical treatment of cancer are inorganic ions such as cisplatin, biologic response modifiers such as interferon, enzymes and hormones. All these compounds, similarly to those mentioned above, are accompanied by toxic adverse reactions.
Thus, it would be extremely advantageous to provide safe and non-toxic chemotherapeutic compositions which would effectively inhibit cancer cell proliferation and suppress neoplastic growth. The Merck Manual, 1218-1225 (1987), 15th Ed. Novel synergistic compositions of this invention provide such treatment.
Similar to cancer, the high degree of infectiousness and fast reproduction cycle of viruses within host organisms make viruses a nuisance and a health hazard.
There is no simple treatment of viral diseases. Viruses are not susceptible to antibiotics. The only available treatment of viral diseases is chemotherapy utilizing viral replication inhibitors in host cells. The Merck Manual, 170, 14th Ed. (1982). Examples of these chemical agents are idoxuridine, acyclovir, ribavirin, vidarabine, gancyclovir, adenine arabinoside (ABA-A) and AZT. These, and other viral replication inhibitors, however, are cytotoxic, hepatotoxic, neurotoxic, nephrotoxic and teratogenic. Virus Diseases, 1-6, Crown Publishers, N.Y. (1978).
Human immunodeficiency virus (HIV) infections known as acquired immunodeficiency syndrome (AIDS), presently constitute a worldwide health hazard. HIV infections are almost always fatal due to a weakened immunoresistance, leading to opportunistic infections, malignancies and neurologic lesions.
There is no effective treatment for AIDS other than the treatment of the opportunistic infections, neoplasms and other complications. Available cytostatic (AZT) and antiviral (acyclovir) drugs are extremely toxic and cause severe adverse reactions. In addition, opioid drug addiction coincides with the emergence of AZT resistance, Chuang et al., NIDA Res. Monograph: Problems of Drug Dependence 14:419 (1993), thereby reducing the efficacy of AZT treatment for opioid-addicted AIDS patients.
Thus it would be highly desirable to have available an effective and yet nontoxic treatment of viral diseases, in particular, AIDS, and further for AZT-resistant patients or viral strains.
Cytomegalovirus (CMV), a dangerous co-infection of HIV, is a subgroup of highly infectious viruses having the propensity for remaining latent in man. CMVs are very common among the adult population and as many as 90% of adults have been exposed to and experienced CMV infections. CMVs are normally present in body liquids such as blood, lymph, saliva, urine, feces, milk, etc. CMV infections may cause abortion, stillbirth, postnatal death from hemorrhage, anemia, severe hepatic or CNS damage. Particularly dangerous are CMV infections afflicting AIDS patients, where CMV may cause pulmonary, gastrointestinal or renal complications. There is no specific therapy for CMVs. CMV is resistant to acyclovir, and to other known antiviral drugs.
Thus, it would be extremely advantageous to have available a drug which would effectively inhibit CMV infections.
Recently, a series of highly effective anti-tumor and anti-viral drugs were identified. These drugs include: substituted and unsubstituted 6-amino-1,2-benzopyrones which are the subject of copending U.S. patent application Ser. No. 08/237,969 filed on May 3, 1994, entitled "6-Amino-1,2-Benzopyrones Useful for Treatment of Viral Diseases;" 5-iodo-6-amino-1,2-benzopyrones and 5-iodo-6-nitroso-1,2-benzopyrones which are the subject of copending U.S. patent applications Ser. No. 07/600,593 filed on Oct. 19, 1990 entitled "Novel 5-Iodo-6-Amino-1,2-Benzopyrones and Their Metabolites Useful as Cytostatic and Antiviral Agents" and Ser. No. 08/021,989 filed on Feb. 24, 1993 entitled "Novel 5-Iodo-6-Amino-1,2-Benzopyrones and Their Metabolites Useful as Cytostatic Agents;" 3-nitrosobenzamides, 6-nitroso-1,2-benzopyrones and nitroso-1-(2H)-isoquinolinones which are the subject of copending U.S. patent applications Ser. Nos. 07/780,809, 07/893,429 and 07/965,541 filed Oct. 22, 1991, Jun. 4, 1992 and Nov. 2, 1992, respectively, and entitled "Adenosine Diphosphoribose Polymerase Binding Nitroso Aromatic Compounds Useful As Retroviral Inactivating Agents, Anti-retroviral Agents and Anti-tumor Agents;" various iodo-nitro compounds and iodo-nitroso compounds, which are the subject of copending U.S. patent application Ser. No. 08/060,409 filed on May 12, 1993, entitled "Novel Aromatic Nitro Compounds and Their Metabolites Useful as Anti-Viral and Anti-Tumor Agents," and U.S. patent application Ser. No. 08/076,313 filed Jun. 11, 1993, entitled "Novel Aromatic Nitro and Nitroso Compounds and Their Metabolites Useful as Anti-Viral and Anti-Tumor Agents," the disclosures of which are incorporated herein by reference.
These drugs are of remarkably low toxicity, yet highly effective inhibitors of tumors and viral replication in cell cultures. Their therapeutic spectrum appears to be particularly useful for suppression and inhibition of cancer growth and the treatment of viral infections.
The mechanisms of action of poly (ADP ribose) transferase polymerizing ("pADPRT") CCHC-oxidizing ligands such as aromatic C-nitroso compounds have been recently elucidated. C-nitroso ligands exert cellular action on two levels. Kun et al., Biochemie, in press (1994). One level comprises inactivation of pADPRT by zinc ejection. Recently published experiments have shown that aromatic C-nitroso ligands of pADPRT preferentially destabilize one of the two zinc fingers of the enzyme coincidentally with a loss of enzymatic activity but not DNA binding capacity of the protein. Buki et al., FEBS Lett. 290:181-185 (1991). Based on the similarity to results obtained by site-directed mutagenesis, Gradwohl et al., Proc. Natl. Sci. USA 87:2990-2992 (1990), it appears that the primary attack of C-nitroso ligands occurred at zinc finger F1, Buki et al., FEBS Lett. 290:181-185 (1991). 6-nitroso-1,2 benzopyrone ("NOBP") and 3-nitrosobenzamide ("NOBA"), two C-nitroso compounds that inactivate pADPRT at one zinc finger site completely suppressed the proliferation of leukemic and other malignant human cells and subsequently produced cell death. Tumoricidal concentrations of the drugs were relatively harmless to normal bone marrow progenitor cells and to superoxide formation by neutrophil granulocytes. The cellular mechanisms elicited by the C-nitroso compounds consists of apoptosis due to DNA degradation by the nuclear calcium/magnesium dependent endonuclease. Rice, et al. Proc. Natl. Sci. USA 89:7703-7707 (1992). This endonuclease is maintained in a latent form by poly(ADP-ribosyl)ation, but inactivation of pADPRT by C-nitroso drugs de-represses the DNA-degrading activity.
In contrast to the "classical" zinc finger structures identified in a large number of transcription factors where the zinc ligands are CCCC or CCHH, Klug and Rhodes, Trends in Biochem. Sci. 12:464-469 (1987), pADPRT contains two zinc chelates that are asymmetrical, i.e. the ligands are CCHC, Gradwohl et al., Proc. Natl. Acad. Sci. 87:2990-2994 (1990). This seemingly minor modification of the chelate has significant chemical consequence with respect to its stability as it exists in the zinc finger within the protein molecule. Buki et al., FEBS Lett. 290:181-185 (1991). Whereas CCCC or CCHH zinc fingers require basic pH and organomercurials to release zinc ion, Giedroc et al., J. Inorg. Biochem. 28:155-169 (1986), zinc ion exchange between the CCHC zinc fingers of pADPRT and external zinc under physiological circumstances, and oxidative destruction of the CCHC chelates by relatively mild oxidizing agents that are made selective by also being ligands of pADPRT has been demonstrated, Buki et al., FEBS Lett. 290:181-185 (1991). This represents a significant biochemical correlation. The F1 finger, Gradwohl et al., Proc. Natl. Acad. Sci. 87:2990-2994 (1990), of pADPRT is first inactivated by the oxidative ligands, resulting in a loss of DNA-stimulated pADPRT activity without major alterations of the DNA binding ability of pADPRT, but excess oxidant destroys both zinc fingers, Buki et al., FEBS Lett. 290:181-185 (1991).
The second level of activity comprises induction of an pADPRT-degrading aminopeptidase that completely digests pADPRT, whereby the pADPRT-binding sites on DNA become available to endonucleolytic degradation. Kun et al., Biochemie, in press (1994). Auto-poly-ADP-ribosylation protects pADPRT from digestion of aminopeptidase, hence inactivation of poly-ADP-ribosylation (as by aromatic C-nitroso ligands) is a prerequisite to proteolytic pADPRT degradation, leading to apoptosis. Therefore, pADPRT CCHC-oxidizing ligand, such as C-nitroso compounds, are effective anti-tumor compounds.
Retroviral nucleocapsid ("NC") proteins and their respective gag precursors from all strains of known retroviruses contain at least one copy of a zinc-binding polypeptide sequence of the type Cys-X.sub.2 -Cys-X.sub.4 -His-X.sub.4 -Cys ("CCHC"), i.e., a zinc finger domain. Henderson et al., Biol. Chem. 256:8400-8406 (1981). This CCHC sequence is essential for maintaining viral infectivity, Gorelick et al., Proc. Natl. Acad. Sci. USA 85:8420-8424 (1988) and Gorelick et al., J. Virol. 64:3207-3211 (1990), therefore, it represents an attractive target for viral chemotherapy. The HIV-1 gag proteins function by specifically binding to the HIV-1 RNA, anchoring it to the cell membrane for budding of viral particles. Meric et al., J. Virol. 63:1558-1658 (1989); Gorelick et al., Proc. Natl. Acad. Sci. USA 85:8420-8424 (1988); Aldovini et al., J. Virol. 64:1920-1926 (1990); and Lever et al., J. Virol. 63:4085-4087 (1989). Site-directed mutagenesis studies demonstrated that modification of Cys or His residues results in defective viral RNA packaging and noninfectious viral particles are formed. Aldovini et al., J. Virol. 64:1920-1926 (1990) and Lever et al., J. Virol. 63:4085-4087 (1989).
Based on the occurrence of CCHC zinc binding sites in both retroviral nucleocapsid and gag-precursor proteins and in poly(ADP-ribose) polymerase it was reasoned that pADPRT CCHC-oxidizing ligands may also have anti-retroviral effects. Recently it was demonstrated that NOBA and NOBP inhibit infection of human immunodeficiency virus HIV-1 in human lymphocytes and also eject zinc from isolated HIV-1 NC zinc fingers and from intact HIV-1 virions. U.S. Ser. No. 0/087,566 filed Jul. 2, 1993; U.S. Ser. No. 08/076,313 filed Jun. 11, 1993; Rice et al., Nature 361:473-475 (1993); Rice et al., Prac. Natl. Acad. Sci. 90:9721-9724 (1993); Chuang et al., FEBS Lett. 326:140-144 (1993); and Wondrak et al., J. Biol. Chem. in press (1994). The zinc-ejected HIV-1 virions exhibit complete loss of infectivity in human lymphocytes. U.S. Ser. No. 0/087,566 filed Jul. 2, 1993 and U.S. Ser. No. 08/076,313 filed Jun. 11, 1993. It was of special interest that the infectious cycle of AZT-resistant rhesus macaque (MMU-23740)-derived SIV was equally inhibited by NOBA, Chuang et al., FEBS Lett. 326:140-144 (1993), an observation that is particularly relevant to opioid drug abusers where addiction coincides with the emergence of AZT resistance, Chuang et al., NIDA Res. Monograph: Problems of Drug Dependence 14:419 (1993). Therefore, the pADPRT CCHC-oxidizing ligands are effective anti-viral compounds.
While these C-nitroso pADPRT CCHC-oxidizing ligands have been found to be quite effective in in vitro tests, they are relatively water insoluble at physiological pH, exhibit limited stability and limited predictability of delivery to the affected cells due to their solubility and stability characteristics. In addition, the relative chemical instability of aromatic C-nitroso pADPRT CCHC-oxidizing ligands towards glutathione ("GSH") is a distinct disadvantage for their direct application in vivo. Recently precursor molecules which generate active C-nitroso compounds in vivo have been prepared to overcome some of these difficulties.
One recently prepared precursor, a cysteine sulfinic adduct of 3-nitrosobenzamide, releases the C-nitroso molecule at weakly basic conditions. Kun et al., U.S. Pat. No. 5,262,564 issued on Nov. 16, 1993. This sulfinic adduct is an effective C-nitroso donor molecule in cell cultures. Id.
As an alternative method, stable precursor C-nitro molecules which serve as pro-drugs for the active C-nitroso pADPRT CCHC-oxidizing ligands were recently prepared. U.S. patent application Ser. No. 08/076,313 filed on Jun. 11, 1993, which is incorporated herein by reference. A prototype of these pro-drugs, 4-iodo-3-nitrobenzamide ("INO.sub.2 BA") has been shown to be stable, having a shelf life of at least one year. Mendeleyev et al., "Chemotherapeutic Activity of 4-Iodo-3-Nitrobenzamide I: Metabolic Reduction to the 3-Nitroso Derivative and Induction of Apoptosis in Tumor Cells in Culture," submitted (1994) (hereinafter "Mendeleyev et al. (1994).")
The aromatic iodo-nitro pro-drugs are slowly but steadily enzymatically reduced within cells to the active aromatic iodo-nitroso compounds such that tumor cell apoptosis or inactivation of viral replication is induced. Id. See also Chuang et al., Biochemical Pharmacology, submitted (1995). These aromatic iodo-nitro compounds thus provide a ready source of in vivo anti-tumor C-nitroso compounds.
On the benzene ring, ortho-iodo-substitution has been shown to facilitate the electrochemical reduction of the nitro group. Fry, The Chemistry of Amino, Nitroso and Nitro Compounds and Their Derivatives. Part I., S. Patai, ed., 319-335, John Wiley and Sons, N.Y. (1982). Recently the fluoro-, chloro- and bromo-analogues of INO.sub.2 BA were tested for anti-tumor activity. These analogues were less effective than INO.sub.2 BA. Mendeleyev et al. (1994). Unsubstituted nitrobenzamides are at least 10-15 times less effective than INO.sub.2 BA. Id. Thus, it is highly probable that the metabolic reduction of aromatic iodo-nitro compounds in cells is activated by the presence of the iodo group ortho to the nitro group. Id.
It is known that glutathione adds to aromatic nitroso compounds to form labile semimercaptal adducts. Eyer, Chem. Biol. Interactions 24:227-239 (1979); Umemoto et al., Chem. Biol. Interactions 68:57-69 (1988); Ellis et al., Chem. Biol. Interactions 82:151-163 (1992). The semimercaptals undergo oxygen atom migration to yield sulfinimides that hydrolyze to the corresponding aromatic amines plus glutathione sulfinic acid. In addition, it has recently been shown that both NOBA and 4-iodo-nitrosobenzamide ("INOBA") are rapidly reduced to the corresponding hydroxyl amines by GSH and ascorbate in in vitro chemical tests. Since many cell types produce GSH, these reduction pathways can quickly reduce the active C-nitroso compounds available in vivo, thereby diminishing the efficacy of the C-nitroso compounds in vivo.
It was thus reasoned that agents which decrease intracellular levels of GSH ("GSH decreasing agents") would decrease the rate at which the active C-nitroso ligands are reduced to the corresponding amines in the cell. Recently, it has been shown that DL-buthionine sulfoximine ("BSO"), an agent that inhibits GSH biosynthesis, Meister, Pharmacology and Therapeutics 51:155-194 (1991), exhibits synergistic apoptosis-inducing potency when administered in combination with pADPRT CCHC-oxidizing ligands in several types of cancer cells. Mendeleyev et al. (1994). BSO also exhibited synergistic anti-viral activity when administered in combination with pADPRT CCHC-oxidizing ligands in cells infected with SIV. Chuang et al., "Chemotherapeutic Activity of 4-Iodo-3-Nitrobenzamide and 5-Iodo-6-Amino-Benzopyrone on Simian Immunodeficiency Virus (SIV) in Cultures of CEM .times.174 Cells," submitted (1994) (hereinafter "Chuang et al. (1994)").
It is therefore a primary object of this invention to provide stable, soluble, non-toxic, highly effective antineoplastic and/or anti-viral synergistic compositions that inactivate pADPRT and NC p7 zinc fingers oxidatively.
pADPRT ligands that oxidize CCHC zinc fingers are not unique inhibitors of pADPRT. Inhibitory ligands of pADPRT that do not attack zinc have been identified. Such a prototype ligand, 6-amino-1,2-benzopyrone has been shown to have anti-tumor effects. Hakam et al., FEBS Lett. 193:1-4 (1991). These ligands bind non-covalently to the nicotinamide site and internal DNA-seeking domains of pADPRT. Bauer et al., manuscript in preparation (1994). In contrast, CCHC-oxidizing ligands also bind non-covalently to the nicotinamide site, but initially attack the F1 zinc finger oxidatively. Id. The respective molecular pharmacological action of both of these types of pADPRT-inhibitory ligands has been studied in a bovine endothelial cell line that has been transfected and transformed with E-ras and, by cellular cloning, the tumorigenic phenotype has been isolated. Id. Synergistic cytocidal effects of pADPRT CCHC-oxidizing ligands in combination with non-covalent pADPRT-inhibitory ligands has been demonstrated. U.S. Ser. No. 08/076,313 filed Jun. 11, 1993.
pADPRT ligands that oxidize CCHC zinc fingers are also not unique as potential anti-HIV drugs at the DNA level. Ligands of pADPRT that do not attack zinc fingers were also shown to be anti-retroviral, Cole et al., Biochem. Biophys. Res. Commun. 180:504-514 (1991), by mechanisms that relate to the drug-induced binding of pADPRT to either the reverse transcriptase template, Buki et al., Biochem. Biophys. Res. Commun. 180:496-503 (1991), or probably to transcription factors required for retroviral synthesis.
A prototypical molecule, 5-iodo-6-amino-1,2-benzopyrone ("IABP") blocked the infectious cycle of HIV as tested in various cell lines, Cole et al., Biochem Biophys. Res. Commun. 180:504-514 (1991), but had no influence on the CCHC zinc fingers of pADPRT or on the p7 NC protein of retroviruses. Thus, reversible inhibition of pADPRT as well as covalent inactivation of pADPRT by zinc ejection can abrogate HIV or SIV infection, in addition to a direct effect of the pADPRT CCHC-oxidizing ligands on the retroviral zinc fingers of the virion p7, Rice et al., Nature 361:473-475 (1993) and Wondrak et al., J. Biol. Chem. 269:21948-21950 (1994), pointing to a hitherto unrecognized role of pADPRT in the life cycle of retroviruses.
Based on this newly recognized role of pADPRT on the retroviral life cycle and the observance of synergy between pADPRT CCHC-oxidizing ligands in combination with non-covalent pADPRT-inhibitory ligands in cancer cells, it was reasoned that non-covalent ligands of pADPRT in combination with CCHC-oxidizing ligands would increase anti-retroviral activity as compared to such ligands acting independently.
It is therefore also a primary objective of this invention to provide non-toxic, highly effective anti-tumor and/or anti-viral synergistic compositions that inactivate pADPRT and NC p7 zinc fingers oxidatively, and that also inhibit pADPRT non-covalently.

Synergistic compositions useful as anti-tumor agents