A hard bias structure for biasing a free layer in a MR element within a read head is comprised of a composite hard bias layer having a Co78.6Cr5.2Pt16.2/Co65Cr15Pt20 configuration. The upper Co65Cr15Pt20 layer has a larger Hc value and a thickness about 2 to 10 times greater than that of the Co78.6Cr5.2Pt16.2 layer. The hard bias structure may also include a BCC underlayer such as FeCoMo which enhances the magnetic moment of the hard bias structure. Optionally, the thickness of the Co78.6Cr5.2Pt16.2 layer is zero and the Co65Cr15Pt20 layer is formed on the BCC underlayer. The present invention also encompasses a laminated hard bias structure. The Mrt value for the hard bias structure may be optimized by adjusting the thicknesses of the BCC underlayer and CoCrPt layers. As a result, a larger process window is realized and lower asymmetry output during a read operation is achieved.

A magnetic disk drive includes circular data tracks on a rotating magnetic disk and read and write heads that may form a merged head on a slider that is attached to a positioning arm. During a read or write operation, the merged head is suspended over the magnetic disk on an air bearing surface (ABS). The sensor in a read head is a critical component in which different magnetic states are detected by passing a sense current there through and monitoring a resistance change. One form of magneto-resistance is a spin valve magnetoresistance (SVMR) or giant magnetoresistance (GMR) which is based on a configuration in which two ferromagnetic layers are separated by a non-magnetic conductive layer in the sensor stack. One of the ferromagnetic layers is a pinned layer in which the magnetization direction is fixed by exchange coupling with an adjacent anti-ferromagnetic (AFM) pinning layer. The second ferromagnetic layer is a free layer in which the magnetization vector can rotate in response to external magnetic fields. In the absence of an external magnetic field, the magnetization direction of the free layer is aligned perpendicular to that of the pinned layer by the influence of abutting hard bias layers. When an external magnetic field is applied by passing the sensor over a recording medium on the ABS plane, the magnetic moment of the free layer may rotate to a direction which is parallel to that of the pinned layer. A sense current is used to detect a resistance value which is lower when the magnetic moments of the free layer and pinned layer are parallel.
In a CPP configuration, a sense current is passed through the sensor in a direction perpendicular to the layers in the sensor stack. Alternatively, there is a current-in-plane (CIP) configuration where the sense current passes through the sensor in a direction parallel to the planes of the layers in the sensor stack.
Ultra-high density (over 100 Gb/in2) recording requires a highly sensitive read head in which the cross-sectional area of the sensor is typically smaller than 0.1×0.1 microns at the ABS plane. Current recording head applications are typically based on an abutting junction configuration in which a hard bias layer is formed adjacent to each side of a free layer in a GMR spin valve structure. As the recording density further increases and track width decreases, the junction edge stability becomes more important so that edge demagnification in the free layer is prevented. In other words, horizontal (longitudinal) biasing is necessary so that a single domain magnetization state in the free layer will be stable against all reasonable perturbations. The critical dimensions for sensor elements become smaller with higher recording density requirements and therefore the minimum longitudinal bias field necessary for free layer domain stabilization increases.
A high coercivity in the in-plane direction is needed in the hard bias layer to provide a stable longitudinal bias that maintains a single domain state in the free layer and thereby avoids undesirable Barkhausen noise. By arranging the flux flow of the free layer to be equal to the flux flow of the hard bias film, there are no magnetic poles at the abutting junction edges and the demagnetizing field in that vicinity becomes zero. This condition is realized when there is a sufficient in-plane remnant magnetization (Mr) which may also be expressed as Mrt since Mr is dependent on the thickness of the hard bias layer. Mrt is the component that provides the longitudinal bias flux to the free layer and must be high enough to assure a single magnetic domain in the free layer but not so high as to prevent the magnetic field in the free layer from rotating under the influence of a reasonably sized external magnetic field. Moreover, a high saturation magnetization (Ms) and a high squareness (S) value for Mr/Ms that approaches 1 in the hard bias layer is desired.
Referring to FIG. 1, a conventional read head 1 based on a GMR configuration is shown and is comprised of a substrate 2 upon which a first shield layer 3 and a first gap layer 4 are formed. There is a GMR element comprised of a bottom portion 5a, a free layer 6, and a top portion 5b formed on the first gap layer 4. Note that the GMR element generally has sloped sidewalls wherein the top portion 5b is not as wide as the bottom portion 5a. The GMR element may be a bottom spin valve in which an AFM pinning layer and pinned layer (not shown) are in the bottom portion 5a or the GMR element may be a top spin valve where the AFM and pinned layers are in the top portion 5b. There is a seed layer 7 formed on the first gap layer 4 and along the GMR element which ensures that the subsequently deposited hard bias layers 8 have a proper microstructure. Hard bias layers 8 form an abutting junction 12 on either side of the free layer 6. Leads 9 are provided on the hard bias layers 8 to carry current to and from the GMR element. The distance between the leads 9 defines the track width TW of the read head 1. Above the leads 9 and GMR element are successively formed a second gap layer 10 and a second shield layer 11.
The pinned layer in the GMR element is pinned in the Y direction by exchange coupling with an adjacent AFM layer that is magnetized in the Y direction by an annealing process. The hard bias layers 8 which are made of a material such as CoCrPt are magnetized in the X direction as depicted by vectors 13 and influence an X directional alignment of the magnetic vector 14 in the free layer 6. When a magnetic field of sufficient strength is applied in the Y direction from a recording medium by moving the read head 1 over a hard disk (not shown) in the Z direction, then the magnetization in the free layer switches to the Y direction. This change in magnetic state is sensed by a voltage change due to a drop in the electrical resistance for an electrical current that is passed through the MR element. In a CIP spin valve, this sense current Is is in a direction parallel to the planes of the sensor stack.
One concern about the output from a spin valve element during a feed back (read) operation is that the asymmetry sigma should be as small as possible in order to accurately reproduce the waveform from the recording medium. Asymmetry is determined by the variable magnetization direction of the free layer. Ideally, the magnetic moment 14 of the free layer 6 is orthogonal to the magnetic moment of the pinned layer when no external magnetic field is present. However, the actual angle between the aforementioned magnetic moments usually deviates somewhat from 90° because of other magnetic forces in the GMR element and thereby produces an asymmetric waveform in the output.
A soft magnetic film with a high saturation flux density and comprised of FeCoMo is employed as a magnetic pole layer in U.S. Patent Publication 2002/0150790. Referring to FIG. 2, those skilled in the art would recognize that a FeCoMo layer can be used to modify the read head in FIG. 1 by inserting a FeCoMo underlayer 15 with a high magnetic moment between the seed layer 7 and the hard bias layer 8 (FIG. 2). The underlayer 15 improves the biasing efficiency and serves to reduce output asymmetry. A further improvement in signal amplitude and asymmetry is expected if the FeCoMo layer (or moment) can be increased while the total Mrt is maintained or further reduced and the coercivity is maintained. Unfortunately, the thickness of a FeCoMo underlayer and the associated magnetic moment contribution is limited because a thicker FeCoMo film leads to a loss of coercivity (Hc) in the hard bias layer 8. Thus, a new hard bias structure is needed which allows the thickness of a body centered cubic (BCC) underlayer such as FeCoMo to be increased without lowering Hc in the adjacent hard bias layer. A combination of high coercivity to enhance edge junction pinning efficiency and a higher moment contribution from a BCC underlayer to further reduce asymmetry sigma has not been achieved in prior art hard bias structures to our knowledge.
In U.S. Pat. No. 6,643,107, the electrode layers on both sides of a GMR element are extended toward the center of a bottom spin valve and are located above a backed (conductive) layer on a free layer. This structure prevents dead zones at the edges of the free layer and improves output characteristics including asymmetry.
An MR sensor is described in U.S. Pat. No. 6,270,588 in which the Hex angle that is the angle between the direction of the exchange coupling magnetic bias applied to the pinned layer and the longitudinal bias direction is more than 90° in at least a portion of the pinned layer. As a result, improved wave shape and better wave symmetry is achieved.
An insulating hard bias layer made of cobalt ferrite or the like is used in U.S. Pat. No. 6,512,661 to avoid shunting of current away from a MR sensor which occurs with a conductive hard bias layer. A larger flux decay length is also provided which leads to a higher density recording capability.
In U.S. Pat. No. 6,519,121, a spin valve sensor with a composite pinned layer to improve biasing of the free layer is described. A CoFeHfO layer is formed on an AFM layer and a CoFe layer is formed on the CoFeHfO layer and adjacent to a spacer layer in a MR element. This configuration minimizes sense current shunting and improves the magnetoresistive effect.

Hard bias design for extra high density recording


Methods and pharmaceutical compositions for treating, and delaying the onset of, viral infection, are provided.

Viral infection of humans is a major health problem, and viral infection of domesticated animals is a major economic concern. Combating viral infection has proven to be highly effective in some cases like smallpox where the disease was essentially eradicated with the advent of smallpox vaccination. Although smallpox was essentially eradicated by about 1980, there is considerable justified fear of the emergence of a new epidemic of smallpox since there are existing stockpiles of the virus and bioterrorism has moved beyond the realm of possibility to reality. Other viral infections have been much more difficult to fight. Human immunodeficiency virus (HIV), hepatitis B and C, herpes simplex viruses (HSVs) and influenza are just a few prominent members of a list of viruses that pose significant health threats worldwide. Additionally, emerging viral infections continue to threaten the world with human epidemics, as is illustrated by the recent outbreak of severe acute respiratory syndrome (SARS), which has now been associated with coronavirus infection. Treatments currently available for many viral infections are often associated with adverse side effects. In addition, antiviral therapeutics directed towards specific viral gene products frequently have the effect of driving the selection of viruses to become resistant to such therapeutics, and viral strains resistant to current methods of treatment are an increasing problem. Accordingly, there is a clear and ever-present need for new antiviral treatments.

Method and composition for reducing expression of ROCK-II


A method of diminishing a step difference 41 in a multi-layered semiconductor device which comprises determining a location 40 of a step difference 41 on a multi-layered semiconductor device 50 to be formed by utilizing a plurality of conducting layers 35 and a plurality of insulating layers 36 sequentially formed such that the layers are sequentially stacked on a surface of a substrate to form a step difference 41 location 40 on the substrate is disclosed. A conducting layer 3 is deposited on the substrate. A first dummy layer 3C is formed at the step difference location while simultaneously forming a gate electrode 3A and a gate electrode line 3B by performing a mask patterning process. A first insulating layer 5 is deposited on the gate electrode 3A, gate electrode line 3 and the first dummy insulating layer 5A. A second conducting layer 6 is deposited on the first insulating layer 5. A second dummy layer 6B, having a predetermined size to diminish the step difference at the step difference location is formed while simultaneously forming a charge storage electrode 6A by performing a mask patterning process. A second insulating layer 9 is deposited on the resulting structure such that the step difference is diminished to permit overlying layers deposited at the location of the now diminished step difference to be removed without forming a stringer. A semiconductor device which includes the dummy layers is also disclosed.

1. Field of the Invention
The invention relates to a method for manufacturing a plurality of dummy and insulating layers to control the coverage of a step difference in a multi-layered semiconductor device, and more particularly to a method for providing stacked dummy and insulating layers at a region proximate a structure in the semiconductor device having a step difference in order to diminish the step difference and to a semiconductor device which includes the dummy and insulating layers.
2. Information Disclosure Statement
Generally, as the semiconductor device becomes more highly integrated it becomes a multi-layered structure which includes a plurality of conducting layers, insulating layers, metal layers, or the like, as necessary for its operation. As a result, the structure includes a step difference in its structure. For example, it is assumed that when manufacturing a DRAM 16 semiconductor device, four polysilicon layers and two metal layers are used, as shown in FIG. 1. When an insulating layer 9 is deposited on the resulting structure of a stacked capacitor 15, the step difference 41 occurs at the side of the resulting structure of the stacked capacitor 15. In order to form a bit line electrode 10B, if a portion of the conducting layer 10 for bit line deposited on the resulting insulating layer 9 is etched, as shown in FIG. 2, a stringer 10A, which is a remaining portion of the conducting layer 10, remains on the slope of the resulting insulating layer 9, (T at FIG. 2) which results in a bridge phenomenon in which the stringer 1OA is undesirably connected to an adjacent conducting layer (not shown) which is to be deposited thereover. Also, because of the uneven thickness of the deposited conducting layer at the locations of the step differences, a break may occur in the conducting layer which interferes with the operation of the resulting device.
Therefore, it is an object of the invention to solve the problems set forth above and to provide a method for forming a sloped layer comprising a plurality of dummy layers and insulating layers at a location on the semiconductor device having a structure defining a step difference to contour the coverage of the step difference in semiconductor device.
It is a further object of the present invention to provide a semiconductor device which includes dummy layers and insulating layers to contour a step difference therein.
The preceding objects should be construed as merely presenting a few of the more pertinent features and applications of the invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to both the summary of the invention and the detailed description, below, which describe the preferred embodiment in addition to the scope of the invention defined by the claims considered in conjunction with the accompanying drawings.

Method for alleviating the step difference in a semiconductor and a semiconductor device

Hyundai Electronics Industries Co., Ltd.


Provided is a paper shredder comprising a housing (6) and a paper shredder head (4), wherein a transmission mechanism (5) and a motor are provided in the paper shredder head (4); the motor comprises a motor body (1), the motor body (1) having an output shaft (12) and a motor housing (11) sleeve connected on the output shaft (12); the motor housing (11) is provided with a heat dissipation device, the heat dissipation device comprising an air intake device (2) and an air output device (3); the air intake device (2) has a cold air inlet and the air output device (3) has a hot air outlet; the air intake device (2) is provided on one side of the output shaft (12) and the air output device (3) is provided on the other side of the output shaft (12); at the position where the air intake device (2) is provided on the motor housing (11) there is an air intake hole (13) opened correspondingly to communicate with an inner chamber of the motor housing (11), and at the position where the air output device (3) is provided on the motor housing (11) there is an air output hole (14) opened correspondingly to communicate with the inner chamber of the motor housing (11), such that a relatively isolated and independent heat dissipating air channel is formed internally from the cold air inlet, via the inner chamber of the motor housing (11), to the hot air outlet.

1. Field of the Invention
The present invention relates to a motorized paper shredder. The present invention is based on Chinese Utility Model Application No. 201020543836.3, filed on Sep. 27, 2010, and Chinese Utility Model Application No. 201120246575.3, filed on Jul. 13, 2011. The contents of the above-mentioned applications are incorporated herein by reference.
2. Description of Related Art
A motor, also called electric motor, is an energy conversion or transfer electromagnetic apparatus that functions according to the law of electromagnetic. It's main use to generate drive torque, thereby becoming the appliance or a power source of the various mechanical. Because motor operation is developed by solenoid cutting action, and the current resistance of the effect must produce heat, the greater the current, the more heat it generates. In continuous operation, the motor will accumulate a large amount of heat affecting the overall performance of the motor, thereby reducing the efficiency of the motor operation, thereby increasing the running cost of the motor.
To solve the above problem, Chinese Utility Model No. 201290050, discloses a "motor heat dissipating device" on Aug. 12, 2009, it's technical features comprises a motor body, a housing for covering the motor body, a cooling water tank and a pump, said housing is equipped with a water outlet hole and a water inlet hole and with external piping, connects with the cooling water tank to form a circulating loop; the pump is installed in between the cooling water tank and the water inlet hole; the housing seals the motor body, and there is a water holding space in between the housing and the motor body; when the motor is in operation, the pump pumps water from the cooling water tank, and through the water inlet hole, pumps the water into the water holding space and by using the hydro-cooling method, cools the motor body; the water then flows, through the water outlet hole, back the cooling water tank to allow repeated use. The motor heat dissipating device of this invention adapts the hydro-cooling method, pumping cooling water from the cooling water tank to cool off the heat giving off from the motor, and via the cooling water tank to loop cooling water and heat exchange. This method can increase heat dissipation, enhance motor operation efficiency, and thereby reducing the running cost of the motor. However, the structure of this type of water-cooling heat dissipating device is more complicated and subject to set up additional external cooling water loop pipe, when used in combination with other mechanical components is not easy.
In addition, the rotor of the motor is provided with a number of coils, when the motor is operating, the coils give off the most heat, and then the coil of the stator of the motor give off the second most heat. The heat from the rotor may be conducted through air to the motor housing; there is a low thermal conductivity between the rotor and the motor housing, hence, thermal conduction is slow. Whereas, CN201290050 technical solution focuses on heat dissipation on the motor housing, the heat dissipation effect is limited
Chinese Patent Publication No. CN2751887Y discloses a heat dissipating device for paper shredder wherein, on one side of the motor a heat dissipating fan is installed and on the other side of the motor several heat dissipating holes are provided. The shortcoming of this invention is that the heat dissipating from the heat dissipating holes still remain in the paper shredder housing, and mixed with the heat dissipating from other components, affecting the cooling efficiency of the motor. Because heat dissipating fan is mounted on one side of the motor while the other side of the motor is mounted with an output shaft, no further fan can be mounted, because the high speed rotation of the output shaft can shake off a fan mounted on it, and to cause mechanical failure. This also constitute a constraint to designers on further increasing the cooling efficiency.
In another prior art, it provides a motor heat dissipating device having the structure: having heat dissipating holes directly on motor housing body. The motor heat dissipating device with this structure although may allow the heat from inside of the motor to dissipate from the dissipating holes, however, this type of heat dissipation is conducted by natural flow of air, hence heat dissipating efficiency is low, and heat is easily accumulated inside the motor. In another type of motor heat dissipating device, the heat dissipating device is arranged around the motor housing body, and allows close fit of the heat dissipating device and the motor housing body, with this structural characteristics, the heat dissipating area and efficiency are increased for the motor heat dissipating device, however, the device may be bulky, requires the motor to occupy more space.
There are other prior arts also provide a number of motor's cooling structures, but their structures are complex and assembly are not easy, and required higher manufacturing costs.
Therefore, with these deficiencies in the prior arts, there is a need to provide a paper shredder, where this paper shredder would have a heat dissipating device for the motor, with great cooling effect, can achieve rapid cooling of the motor, have a long continuous shredding time short motor recovering time long operating life simple structure easy assembly, and with characteristics to facilitate market-oriented promotion and application.


A first future time occurs sooner than a second future time. The first future time indicates when the first and second future times are to be evaluated. The second future time provides a boundary between schedules occurring sooner and schedules occurring later. A schedule is generated and added to a database stored in a non-volatile storage. The schedule is for executing, in relation to an incident, an incident-handling action corresponding to a condition matching the incident. The schedule has an execution time at which to execute the incident-handling action in relation to the incident. Where the execution time is sooner than the second future time, the schedule is added to a queue stored in a volatile memory. Upon a current time equaling the execution time, the schedule is removed from the queue and correspondingly executing the incident-handling action in relation to the incident.

Large-scale and complex systems can routinely generate incidents that have to be addressed in order to ensure the smooth running of such systems. For instance, in large-scale and complex computing systems in particular, both hardware and software can generate faults or even fail, among other types of incidents. To ensure that these systems continue running properly, such incidents have to be handled promptly.

Hewlett Packard Enterprise Development LP


A dual derailleur bicycle gearshift comprises a first cable pull member pivotally secured to a support for rotation about a first axis and a second cable pull member pivotally secured to the first cable pull member for rotation about a second axis perpendicular to the first axis, wherein the second cable pull member defines a single actuator that is centered on both axes for pivotal movability within a first arc located within a first plane that extends axially of and contains the first axis to rotate the second cable pull member about the second axis and pivotal movability within a second arc located within a second plane that extends axially of and contains the second axis to rotate the first cable pull member about the first axis. In a handlebar mounted embodiment the first cable pull member rotates about a longitudinal axis of the bicycle's handlebar and the actuator is a yoke centered on both axes and having one end defining the second cable pull member. In a handlebar stem mounted embodiment the actuator is a lever and the first cable pull member is notched for centering the lever on both axes. In each embodiment a first bracket member stationary with the support provides anchorage for a casing associated with a cable pulled by the first cable pull member, and a second bracket member rotatable with the first cable pull member provides anchorage for a casing associated with a cable pulled by the second cable pull member.

This invention pertains generally to a gearshift for use on a dual derailleur type of multi-speed bicycle, more particularly to a gearshift of such type wherein a unitary structure provides manually operable actuator means accessible for controlling the bicycle's front and rear derailleurs, still more particularly to such a gearshift having a single actuator for either independently or simultaneously controlling both the front and rear derailleurs, specifically to the provision of such a gearshift having said single actuator pivotally centered on perpendicular first and second axes for a uniform mode of manipulation about both axes, to the provision of embodiments of such gearshift which may be applied to or retrofitted on any configuration of dual derailleur bicycle, and to the provision of at least one embodiment of such gearshift wherein said single actuator is manipulable while maintaining a hold on both ends of the bicycle's handlebar.
A dual derailleur bicycle is one having multiple front sprockets (typically two or three) of different pitch diameter mounted on the bicycle's pedal crank axis, multiple rear sprockets (typically five, six or seven) of different pitch diameter mounted on the bicycle's rear wheel axis and a roller chain forming a closed loop about one each of said front and rear sprockets. Different gear ratios are effected between the pedal crank and rear wheel axes for greater speed or easier pedaling depending upon which one of the front and rear sprockets are connected together by the roller chain. The roller chain is transferred from one to another of the front and rear sprockets by front and rear derailleur devices which are mounted on the bicycle adjacent the front and rear sprockets, respectively. The front derailleur, when moved alternately in opposite directions axially of the pedal crank axis, derails the roller chain from one front sprocket and positions it upon another, and the rear derailleur, when moved alternately in opposite directions axially of the rear wheel axis, derails the roller chain from one rear sprocket and positions it upon another. The. derailleurs are caused to move from one sprocket alignment position to another by linear movement of a pair of cables which are connected at one end to the derailleurs and which extend from same to a gearshift device which the rider operates to effect said linear movement of the cables.
A conventional gearshift provides two actuators, originally levers, more recently twistgrips, one for linearly positioning the cable leading to the front derailleur and the other for linearly positioning the cable leading to the rear derailleur. Depending upon the direction of movement of the two actuators the cables are caused to either pull the derailleurs from one sprocket alignment position to another or allow spring biases incorporated in the derailleurs to return the derailleurs to a previous sprocket alignment position.
The prior art provides such gearshift means in several configurations. In earliest configuration the gearshift is a unitary structure having two levers pivotally secured to and positioned upright on a common support bracket that is attached to the bicycle's frame or on the stem that supports the bicycle's handlebar. If mounted on the frame, the frame is equipped with pulley wheels or fixed guides which route the cables from the gearshift to the derailleurs. If mounted on the handlebar stem at least a portion of each cable extending from the gearshift to the bicycle's frame is enclosed in a flexible tubular casing which enables linear movement of the cables in an arcuate path in order that the bicycle can be steered; the casings having their ends stopped to prevent linear movement of the casings while permitting linear movement of the contained cables.
All such frame or stem mounted gearshifts have required the rider to release his grasp of one handgrip or the other in order to manipulate the lever which is positioned on one side or the other of the bicycle's frame or handlebar stem, as the case may be.
In order to improve safety and increase convenience in a later configuration the gearshift has comprised two distinct structures each carrying one lever; i.e., the system comprises two single-lever gearshift devices, one for controlling the front derailleur and the other for controlling the rear derailleur, which are mounted as close as possible to the handgrips for operation using the hand nearest each gearshift device while maintaining a grasp of both handgrips.
In one arrangement the support brackets of the two gearshifts are inserted into the ends of the tubular handlebar with the levers projecting outboard of the handgrips and the rider lifts or lowers the levers using his fingers or palms while a portion of his palms remains on the handgrips.
In another arrangement the support brackets of the two gearshifts are clamped on top of the handlebar inboard of and as close as possible to the handgrips. In this configuration the levers have been positioned on their sides for pivoting about vertical axes and the rider manipulates them with his thumbs while substantially maintaining his grasp of both handgrips. This arrangement has proven to be less than wholly satisfactory because it strains the hands to operate the levers while still holding onto the handgrips and the rider finds himself releasing a handgrip to operate an adjacent lever.
A recent improvement in such "two gearshift" configurations substitutes twistgrips for the levers. The twistgrips are cylindrical members concentrically rotatable about the longitudinal axis of straight end portions of a bicycle handlebar and are axially positioned on same inboard of and as close as possible to the handgrips conventionally provided on the handlebar and which remain stationary on the ends of the handlebar. The derailleur cables are connected to the twistgrips such that rotation of the twistgrips about the handlebar effects linear movement of the derailleur cables. To operate either twistgrip the rider wraps his hand around the twistgrip and rotates it one way or the other about the longitudinal axis of the handlebar while a portion of his palm overlies and rotates about the handgrip, ready to grasp it tightly should the need arise. The clamp fastening standard brake levers tends to interfere with such mode of operation because the relatively short levers require securing the clamps immediately adjacent the handgrips. More comfortable operation of such twistgrip gearshifts requires a specially designed brake lever that permits its clamp to be located further inboard from the handgrip so that a space is provided between such clamp and the handgrip for mounting a twistgrip gearshift immediately adjacent to the handgrip.
Although favored over prior concepts it is clear that the twistgrip gearshift has its limitations, including a diminished grasp of the handgrip during rotation of the twistgrip.
Of course a continuing limitation of all the above described configurations is that the rider must still operate two actuators to obtain a single result where simultaneous operation of both derailleurs is required.
It is not always obvious which actuator is to be repositioned or whether both actuators are to be repositioned simultaneously in order to effect a given desired gear ratio. Many riders find it inconvenient and awkward having to manipulate two actuators in order to obtain a single result and experience difficulty in quickly obtaining the required combination of front and rear sprockets; e.g., for instantly shifting from highest to lower gear when stopping for easy startup and when suddenly confronted by a hill. Accordingly, a more convenient means has long been desired.
U.S. Pat. No. 3,808,907 to Yamaguchi discloses a gearshift for a dual derailleur bicycle wherein the gearshift has a single lever that is pivotable about a first axis for controlling one derailleur and is also pivotable about a second axis perpendicular to the first axis for controlling the other derailleur, but does not provide such lever centered on both axes of its pivotal movement. Instead, in each of five embodiments, although the lower end portion of Yamaguchi's lever is pivotally secured for rotation about a first axis so that only the upper end of the lever pivots uniformly about the first axis as shown in Yamaguchi's FIG. 3 for control of one derailleur cable, as recited in each of four claims, for control of the other derailleur cable the lever is "oscillatable on a pivot extending radially from" either a drum or a bevel gear that defines the second axis of the lever's pivotal movability, such drum or bevel gear holding the lever as a whole including its lower end portion positioned a substantial distance away from the second axis, with the undesirable result that the whole body of the lever must be moved arcuately about the second axis, whereby, instead of only the upper end of the lever comfortably pivoting from a centered position on the second axis, the operator experiences an awkward up and down movement of the lever as shown in Yamaguchi's FIG. 4.
Yamaguchi's gearshift is further limited by unnecessary complexity and therefore added cost and excessive weight as well as bulkiness requiring more space on a bicycle, all of which critically limit the practical usefulness of Yamaguchi's gearshift.
The present improvement provides a single actuator gearshift having its actuator centered on both the first and second axes of its pivotal movability so that the actuator pivots in a comfortable and uniform manner for control of either derailleur, and which is characterized by fewness of parts, lowest cost, compactness, light weight, and also, compatibility with any configuration of dual derailleur bicycle. A handlebar mounted embodiment adds the safety and convenience afforded by the twistgrip type of gearshift with the added advantage of a single actuator mode of operation for instant and easily learned shifting through all the gears.


The present disclosure relates to a system and a method for combustion of solid fuels. The combustion system includes burners which supply a mixed flow of fuel and air through a fuel nozzle to the combustion chamber for example of a boiler. The mixed flow of fuel and primary air is supplied to the burner through a duct from a pulverizer where the fuel is grinded to the required finesse. The duct further bends in such a way that one portion is vertical with respect parallel to axis of the boiler 1 A-A is vertical duct and other portion is horizontal duct which is parallel to axis B-B of the fuel nozzle.

Boilers for electric power generation often have combustion systems with furnaces that are fired with solid fuel, such as bituminous coal, lignite, biomass, etc.; these combustion systems are usually provided with mills and ducting for supplying the pulverized fuel to one or more burners. Combustion system for lignite coals commonly operate in such way that the nitrogen oxide emissions (NOx) are achieved without application of secondary measures such as selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR) technology. The current limits in Europe referred to NOx emission are less than 200 mg/m3 (dry flue gas, reference 6% Oxygen (O2), measured as Nitrogen dioxide (NO2)).
Generally, during the combustion process of fossil fuels pollutants such as Nitrogen oxides (NOx) are generated. If allowed to enter the atmosphere, these pollutants can detrimentally impact the environment and pose health hazards to humans and animals. U.S. Pat. No. 4,669,398 discloses a pulverized a fuel firing apparatus comprising a pulverized fuel injection compartment so constructed that the combined amount of primary air and secondary air to be consumed is less than the theoretical amount of air required for the combustion of the pulverized fuel, a second pulverized fuel injection compartment so constructed that the combined primary and secondary air amount is substantially equal to the theoretical air for the pulverized fuel, and a supplementary air compartment for injecting supplementary air into the furnace. The three compartments are arranged close to one another and control the NOx production upon combustion of the pulverized fuel.
State-of-the-art combustion systems for lignite are designed to achieve the actual NOx emission limits of less than 200 mg/m3. It is likely that soon more stringent norms will be applicable. Consequently there is need to provide combustion systems which achieve actual emissions level much less than 200 mg/m3.


A method and system are disclosed for a transmitter to maintain priority on a communication channel in a multiple wireless communication system environment. An exemplary method for maintaining priority includes transmitting a priority signal to maintain priority for the transmitter on the communication channel. The priority signal may be pseudo-random noise (PRN) signals. In one embodiment, the PRN signals are transmitted in response to activity sensed on the communication channel, one cause of which may be a contending transmitter transmitting on the communication channel. In this embodiment the step of transmitting is for a predetermined duration and causes the contending transmitter to stop transmitting on the communication channel. In an alternate embodiment, the transmission of the PRN signals is periodic and occurs sufficiently often to cause the contending transmitter to abstain from ever transmitting on the communication channel.

Wireless communications in general and, wireless cellular communications systems in particular, are becoming increasingly popular. Cellular communication systems are well known, and generally include cell sites, each of which serves a coverage area or cell. The cell site is the location within a cell that contains the hardware (e.g. an antenna, a radio base station, etc) required to communicate with a mobile end unit (e.g. a wireless mobile phone). The entire area over which service is provided is generally subdivided into a plurality of such cell sites, and channels are allocated to each cell site in accordance with a frequency reuse plan. A mobile end unit operating within a particular cell communicates with the cellular system through the cell site covering that cell. The various cell sites are typically connected either directly or, indirectly, to a land-line network, such as the public switched telephone network (PSTN).
Cellular communications systems originally were used to provide analog mobile telephone services. Today, cellular communications systems are used to provide a wide variety of wireless communication services. As used herein, the term wireless communication service is used to identify any logically discreet use of the wireless spectrum. Examples of such wireless services include analog mobile telephone service, digital mobile telephone service, personal base station (PBS) service, cellular office service (COS), and cellular digital packet data (CDPD) service. Personal base station service is provided using a PBS, which is a device that allows a cellular telephone to function as a cordless land-line telephone when used in the vicinity of the PBS. A PBS is usually located in the home and serves the cellular telephones within that home. COS is similar to PBS service, however COS is intended for use in an office environment as a wireless PBX. Accordingly, COS systems typically serve many more cellular telephones than does a PBS. A CDPD network is comparable to the cellular telephone network, except that data, rather than voice, is communicated between a mobile end unit and the PSTN or some other type of data network such as the Internet.
Wireless communication service providers are generally licensed to operate a wireless system in a particular geographic area using a specified frequency spectrum for radio communication between mobile end units and base stations. For example, a typical wireless service provider may have a license to operate in a 25 MHz spectrum. One-half of the spectrum (12.5 MHz) would be used for transmission by the base stations and the other half would be used for reception by the mobile end units. The 25 MHz spectrum may be divided into 416 channel pairs, each channel being 30 kHz wide. Each of the 416 channel pairs is capable of handling the communication between one mobile end unit and a base station. As indicated above, the wireless service providers are increasing the types of wireless services they provide and, the radio spectrum they license (e.g. 25 MHz, as in the instant example) must be shared among those different services.
For example, the wireless service provider, in addition to offering analog or digital cellular telephone service, may also provide PBS, COS and/or CDPD service. Analog or digital cellular telephone service is provided through the use of public cell sites. As discussed above, the entire area over which service is provided is subdivided into a plurality of such cell sites, and channels are allocated to each cell site in accordance with a frequency reuse plan, whereby customers in sufficiently separated cell sites use identical channels of communication without suffering any interference with each other. Because radio spectrum is a scarce resource, typically only 3 or 4 channels can be allocated to each cell site in such a system. The term "macrocellular system" is used hereinafter to refer to cellular systems with relatively large cell sites, such as an analog or digital cellular telephone system. The term "microcellular system" is used to refer to cellular systems with relatively small cell sites, such as PBS, COS, and sometimes CDPD systems, within the coverage area of the macrocellular system. The channels available to a microcellular system encompass a subset of the entire spectrum (i.e. not including, for example, testing channels, analog control channels, etc.) that the wireless service provider is licensed to use. A problem can arise when a system, which is not explicitly frequency planned, "pops-up" within the area serviced by a macrocellular system and begins using spectrum already allocated to the macrocellular system.
Consider a conventional radio base station of a macrocellular system that transmits and receives on its assigned forward and reverse channel pairs. In addition to monitoring the received signal strength (RSS) for information and/or interference on the reverse channel while transmitting on the forward channel, the base station also monitors the reverse channel (and/or the forward channel) at times when it is not transmitting on the forward channel and, accordingly, is not expecting to receive information on the reverse channel (and/or the forward channel). If the RSS on any one of its assigned channels not currently in use is above a predetermined threshold, indicating conflicting activity on the channel (one cause of which may be a cellular phone in a microcellular system establishing communication on the channel), the base station may react in a manner that negatively impacts its overall performance. For example, the base station may stop using the channel entirely, in which case, the base station may be left with an insufficient number of channels to handle call traffic during peak calling hours. The base station may alternatively ignore the disruptive use by the microceflular system and, may eventually assign one of its own calls to the channel. The microcellular system, like the radio base station of the macrocellular system, typically monitors the channel it is currently using for potential conflicting use and, will stop using the channel if conflicting use is detected thereon. Thus, although the base station's assignment of a call to the channel ideally will "scare away" the microcellular system, the microcellular system's delay in surrendering the channel will noticeably degrade the sound quality of the macrocellular system's call and vice versa.

Method and apparatus for maintaining channel priority in a multiple wireless communication system environment


Polymers derived from polymers represented by Formula (A) (d is 20xcx9c500; and Rs, which may be the same or different, represent each H, alkyl or benzyl) by substituting a part or all of the consisting peptide bonds by (1) hydrazino-Glu (Formula B), and saccharide-modified Glu (Formula C) or by (2) hydorazino-Glu (Formula B), and saccharide-modified Glu (Formula C), and drug bonded Glu (Formula D). These polymers, which are carriers optionally bonded to drugs capable of migrating into target organs (cells), are useful as medicines

The present invention relates to saccharide-modified polymers which are useful as carriers capable of migrating into target organs (cells), drug-containing polymers using them and the process for the preparation thereof.
The drug delivery systems into the target organs comprising low-molecular drugs bonded to high-molecular compounds as carriers capable of migrating into target organs have been studied in order to obtain the aimed pharmaceutical effect of the drugs on the target organs and to reduce the side effects of the drugs on the other organs.
For example, it is disclosed that drug delivery systems into liver comprising of drugs modified with the compounds obtained by combination of galactose and proteins or high-molecule compounds based on the fact that the receptors specific for galactose exist in liver parenchymal cell in High-Molecule Vol. 46, No. 11, 843-848 (1997).
In addition, it is disclosed that poly-L-glutamic acid derivatives wherein a part of or all of the consisting peptide bonds in the poly-L-glutamic acid of the formula
(wherein, Xa is degree of polymerization of 20xcx9c540, Ra is hydrogen, lower alkyl or benzyl.) are replaced with a group of the formula
is useful as a carrier of drugs capable of migrating into liver in the Japanese Patent Application Kokai Hei 7-228688. The drugs have been conjugated to carboxyl group in the said glutamic acid via amide bond, ester bond or ion bond etc. directly. Vitamin K5 is described as an example of drugs in this publication.
Further, it is disclosed that polymers of PGE1-containing L-glutamic acid derivative (abbreviated as polymer PA) of the formula
is as high-molecule prodrug of PGE1 capable of migrating into liver in International. J. Pharmaceutics, 155, 65-74 (1997). The drug (PGE1) is conjugated to L-glutamic acid via amide bond through ethylenediamine (xe2x80x94NHxe2x80x94CH2CH2xe2x80x94NHxe2x80x94) as a spacer.
In the process for the preparation of the said polymer PA, which comprises amidation by condensation between PGE1 and ethylenediamine as a spacer (reacting the activated ester of PGE1 with ethylenediamine using carbodiimide (CDI) etc.), the reaction was carried out in an alkaline condition. Therefore, there is a problem that the drug which is unstable in an alkaline condition (e.g. PGE1) would be decomposed and that the introducing rate of drugs into poly-L-glutamic acid does not increase. In this publication, quantity of drugs (PGE1) introduced into one molecule of polymer (degree of polymerization of L-glutamic acid=101) is 1.6 molecule.
The present inventors have dissolved such a problem by using hydrazine (xe2x80x94NHxe2x80x94NHxe2x80x94) instead of ethylenediamine (xe2x80x94NHxe2x80x94CH2CH2xe2x80x94NHxe2x80x94) as a spacer in the reaction of drugs (e.g. PGE1) and L-glutamic acid. That is to say, the reaction to introduce the drugs (PGE1) is carried out in a weak acidic condition, so it is possible to introduce the drugs constantly, even if it is unstable in an alkaline condition. Based on this reaction, they have improved the introducing rate of drugs (e.g. PGE1) into poly-L-glutamic acid, and then succeeded in synthesis of drugs-containing polymers showing the superior effect. In addition, it has proved that any compounds can be introduced into the polymer constantly by using this reaction. For example, quantity of drugs (PGE1) introduced into one molecule polymer of the present invention (degree of polymerization of L-glutamic acid=97) is 5 molecule, which means the polymer of the present invention has 3-folds superiority in introducing rate of drug to compare with the polymer of the said publication.
In addition, the polymer using hydrazine of the present invention shows superiority in both accumulation of drugs into liver after administration and effects of drugs (cytoprotective activity of PGE1) to the polymers using ethylelendiamine.
Further, there is a merit that such a reaction between hydrazine and the drug (PGE1) has been carried out by a simple procedure comprising of only stirring them at room temperature.
The present invention relates to
(1) the polymer (abbreviated as Polymer P1.) wherein a part of or all of the consisting peptide bonds in the poly-L-glutamic acid of the formula (A)
(wherein, degree of polymerization d is 20xcx9c500, R is hydrogen, C1xcx9c6 alkyl or benzyl, with the proviso that each multiple R may be same or different.)
xe2x80x83are replaced with a group of the formula
xe2x80x83wherein
(wherein, G is a modified saccharide capable of conjugating to hydrazine))
as essential substituents with the proviso that when the number of replacement groups of the formula (C) is 2 or more, all of said groups are the same,
(2) the polymer (abbreviated as Polymer P2) wherein a part of or all of the peptide bonds in the poly-L-glutamic acid of the formula (A)
xe2x80x83(wherein, all the symbols are defined as hereinbefore)
xe2x80x83(wherein,
xe2x80x83is defined as hereinbefore,
(wherein, D is a drug))
with the proviso that (1) groups of both the formula (C) and (D) are essential substituents, (2) when the number of replacement groups of the formula (C) or (D) is 2 or more, all of said groups of the formula (C) or (D) are the same and (3) the number of replacement groups of the formula (B) may be 0), and (3) the process for the preparation thereof.
Polymer P1 is a carrier polymer capable of migrating into target organs (cells) and Polymer P2 is a drug-containing polymer, which is obtained by utilizing the said carrier polymer, capable of migrating into target organs (cells).
The delivery of the polymer of the present invention into target organs (cells) depends upon the saccharide (represented by G) conjugated to glutamic acid. It is known that various kinds of receptors for saccharides exist in organs (cells) and, new receptors may be found in the future study. It is possible to obtain the drug delivery system into target organs (cells) by choice of saccharide (G) capable of conjugating to the aimed organs (cells) including such known or new receptors.
For example, in case of monosaccharide, galactose receptor, mannose receptor and fucose receptor exist in liver parenchymal cells, liver nonparenchymal cells (endotherial cells and Kupffer cells) and Kupffer cells, respectively, so it is possible to obtain drug delivery system into liver (the said liver cells) by conjugate of galactose, mannose or fucose derivative (corresponds to Polymer P1 and P2 of the present invention in which
is a group of the formula of (G1), (G2) and (G3) described hereinafter.). For example, in case of oligosacchardies such as di, tri or tetrasaccharides etc. or multi-saccharides, the delivery of the polymer of the present invention into target organs (cells) depends upon the terminal saccharide. For example, the terminal saccharide of lactose which is one of disaccharide (corresponds to Polymer P1 and P2 of the present invention in which
is a group of the formula (G4a) and (G5a).) is galactose, so such a polymer migrates into liver parenchymal cell mainly. As for the aimed saccharide, natural ones or artificial ones which are synthesized may be used.
The symbols and degree of polymerization etc. of Polymer P1 and P2 of the present invention are explained in detail as follows:
The symbol d in the formula (A) in Polymer P1 and P2 of the present invention means the degree of polymerization of L-glutamic acid which is a unit of the polymer of the present invention and it is an integer of 20xcx9c500, preferably 40xcx9c300 and more preferably 50xcx9c150.
The number of replacement of group of the formula (B) in Polymer P1 (corresponds to y2 described hereinafter.) is 5xcx9c250 and preferably 5xcx9c50.
The number of replacement of group of the formula (C) (corresponds to z2 described hereinafter.) is 10xcx9c100, and preferably 20xcx9c60.
The number of replacement of group of the formula (B) in Polymer P2 (corresponds to y3 described hereinafter.) is 0xcx9c250, and preferably 0xcx9c50.
The number of replacement of group of the formula (C) (corresponds to Z3 described hereinafter.) is 10xcx9c100, and preferably 20xcx9c60. The number of replacement of group of the formula (D) (corresponds to W3 described hereinafter.) is 1xcx9c20, and preferably 1xcx9c10.
The average of molecule weight of Polymer P1 is 5,000xcx9c150,000. For example, the average of molecule weight of Polymer P1 using monosaccharide
is a group of the formula (G1), (G2) and (G3) described hereinafter.) or disaccharide such as lactose derivative
is a group of the formula (G4a) and (G5a) described hereinafter.) is 5,000xcx9c100,000 and preferably 10,000xcx9c30,000.
C1-6 alkyl in the formula (A) in Polymer P1 and P2 means methyl, ethyl, propyl, butyl, pentyl or hexyl or its isomer.
Each R is preferably, i) hydrogen or the said C1xcx9c6 alkyl (when multiple R are alkyl, they are the same.), ii) hydrogen or benzyl, or iii) hydrogen only, and more preferably, iii) hydrogen only.
The sacchardie represented by G in the formula (C) in Polymer P1 and P2 may be selected in accordance with the receptors which are know or may be found in the future study exist in the organs (cells), as mentioned before. The modified saccharides represented by G capable of conjugating to hydrazine include, for example, 2-iminoethyl-1-thiosaccharide derivatives and saccharides comprising a group wherein the linkage is cleaved etc.
The said 2-iminoethyl-1-thiosaccharide derivative represented by G include, for example, a group of the formula (if it is represented by
In addition, the said saccharide containing a group, wherein the linkage is cleaved, represented by G include, for example, group of the formula (if it is represented by
(wherein, Q is a saccharide chain containing 1xcx9c10 of saccharide.).
Further, 1xcx9c10 of saccharide represented by Q in the above formula include, for example, the saccharide of the formula
(wherein, each p, q and r is 0 or an integer of 1xcx9c9.), preferably galactose, mannose and fucose (corresponds to a group in which each p, q, r is 0 in the above formula) and more preferably galactose.
is preferably a group of the formula
and more preferably group of the formula (G1), (G4a) and (G5a).
In Polymer P2, glutamic acid and drugs represented by D is conjugated via various kinds of bonds such as hydorazon bond or amide bond etc. through hydrazino (xe2x80x94NHxe2x80x94NH2) which is introduced to L-glutamic acid in accordance with the structure of drugs.
The drugs represented by D included any drugs, and preferably, the drug which is unstable in an alkaline condition. Such an alkaline condition means pH8xcx9c11 preferably. Of course, it is possible to apply the drugs other than ones which are unstable in an alkaline condition.
Concrete drugs include PGs (e.g. PGEs, PGFs, PGDs), PGIs, naphthyloxyacetic acid derivatives, bicycloalkanoic acid derivatives, guanidinobenzoic acid derivatives, rhodanine acetic acid derivatives, cinnamoic acid derivatives, valproic acid derivatives, Vitamins, anti-allergic agents, anti-vital, anti-cancer agents etc.
PGs include natural PG such as PGE1, PGE2, PGF1xcex1, PGF2xcex1, PGD1, PGD2 etc. and its derivatives.
For example, natural PGE1 and PGE2 are the compounds shown by the following structures, respectively:
and PGD1 and PGD2 are the compounds shown by the following structures, respectively:
The concrete PGs include the compounds of the following formula
(wherein,
is
Rc is hydrogen or various kinds of substituents of carboxyl group such as C1xcx9c12 alkyl, benzyl etc.,
A is C2xcx9c10 alkylene (1) in which optional carbon atom may be replaced with CO and/or (2) may have one or more double bond(s),
B is C1xcx9c10 alkyl, C2xcx9c10 alkenyl or C2xcx9c10 alkynyl may be substituted with phenyl, phenoxy or cycloalkyl (wherein each ring may be substituted with C1xcx9c6 alkyl, C2xcx9c6 alkenyl, C2xcx9c6 alkynyl, C1xcx9c6 alkoxy or halogen etc.),
xe2x80x83is ethylene, trans-vinylene or ethynylene.).
PGs include preferably PGEs or PGDs (the compounds of the formula
in the above formula), more preferably PGEs (the compounds of the formula
in the above formula).
Such compounds include
PGE1, PGE2, 17,20-dimethyl-trans-xcex942-PGE1, 6-keto-17,20-dimethyl-trans-xcex942-PGE1 methyl ester, 16,16-dimethyl-trans-xcex942-PGE1 methyl ester etc.
PGEs and PGDs may be conjugated to L-glutamic acid via hydorazon bond at the 9th and 11th position carbon, respectively. For example, PGE1 may be conjugated to L-glutamic acid as shown as following structure:
In addition, PGFs may be conjugated to L-glutamic acid via amide bond between the carboxyl group and amine group of hydrazine which is introduced.
PGIs include natural PGI2 and its derivatives, for example, the compounds disclosed in Japanese Patent Application Kokai Sho 54-130543 and Sho 55-64541 (corresponding to GBP-2017699). PGls may be conjugated to L-glutamic acid via amide bond.
Naphthyloxyacetic acid derivatives include, for example, the compounds disclosed in Japanese Patent Application Kokai Hei 6-87811 (corresponding to U.S. Pat. No. 5,480,998), for example, [5-[2-[1-phenyl-(3-pyridyl)methylildenaminooxy]ethyl]-7,8-dihydronahthalene-1-yloxy]acetic acid shown by the formula
Such a naphthyloxyacetic acid compound may be conjugated to L-glutamic acid via amide bond at the terminal amino group of hydrazine as shown by the following structure:
Bicycloalkanoic acid derivatives include, for example, the compounds disclosed in Japanese Patent Application Hei 9-140959 (corresponding to Japanese Patent Application Kokai Hei 11-29548).
Guanidinobenzoic acid derivatives include, for example, the compounds disclosed in Japanese Patent Application Kokai Sho 51-138642 (corresponding to U.S. Pat. No. 4,021,472).
Rhodanine acetic acid derivatives include, for example, the compounds disclosed in Japanese Patent Application Kokai Sho 57-40478 (corresponding to U.S. Pat. No. 4,464,382).
Cinnamoic acid derivatives include, for example, the compounds disclosed in 1) Japanese Patent Application Kokai Sho 55-313 (corresponding to U.S. Pat. No. 4,226,878), 2) Japanese Patent Application Kokai Sho 57-131769 (corresponding to U.S. Pat. No. 4,607,046) and 3) WO 98/27053.
Valproic acid derivatives include, for example, the compounds disclosed in Japanese Patent Application Kokai Hei 7-316092 (corresponding to EP-0632008A1).
[The Process for the Preparation of the Polymer of the Present Invention]
The polymer of the present invention may be prepared by the method described hereinafter in Examples, known methods or the method of the following reactions (1)xcx9c(3).
(1) introducing of hydrazine to poly-L-glutamic acid,
(2) introducing of saccharide (corresponds to G),
(3) introducing of drugs (corresponds to D).
In the reaction (1), poly-L-glutamic acid of the formula (A)
(wherein, all the symbols are defined as hereinbefore.)
is reacted with hydrazine shown by the formula NH2xe2x80x94NH2 in an organic solvent such as dimethylformadmide (DMF) etc. or without solvent at room temperature (10xcx9c25xc2x0 C.) to prepare the polymer of the formula (II)
(wherein, d1, x1 and y1 are mol (degree of polymerization) of L-glutamic acid connecting COOR1 (wherein, R1 is C1xcx9c6 alkyl or benzyl), L-glutamic acid connecting COOH and L-glutamic acid connecting NH2, respectively. With the proviso that, (1) sum of d1, x1 and y1 equals to d, (2) d1 may be 0, (3) each L-glutamic acid connecting COOR1 (wherein, R1 is defined as hereinbefore.), COOH and NH2 may be bonded at random in order.) (see the method described in J. Appl. Biochem., 2: 25 (1980)).
In the reaction (2), for example, saccharide (G) may be conjugated to hydrazine in the polymer of the formula (II) described hereinafter
(a) by reacting the polymer of the formula (II)
(wherein, all the symbols are defined as hereinbefore.)
xe2x80x83and 2-imino-2-methoxyethyl-1-thiosaccharide in a weak alkaline condition (e.g. in borate buffer solution (pH9xcx9c10)) or
(b) by reacting the polymer of the formula (II) and various kinds of saccharides, and then followed by reduction, if optionally.
2-Imino-2-methoxyethyl-1-thiosaccharide which is the starting material in the reaction (a) include, for example, 2-imino-2-methoxyethyl-1-thiogalactoside, 2-imino-2-methoxyethyl-1-thiomanoside or 2-imino-2-methoxyethyl-1-thiofucoside of the formula
2-Imino-2-methoxyethyl-1-thiosaccharide is known compound or may be prepared by reacting cyanomethyl-1-thiosaccharide and sodium methoxide in methanol at room temperature (10xcx9c25xc2x0 C.). (see the method described in Biochemistry Vol.15, No.18, 3956-3962 (1976)).
The saccharide which is starting material in reaction (b) include, for example, the compound of the formula
(wherein, Q is defined as hereinbefore.).
The polymer of the present invention wherein the formula
(wherein, Q is defined as hereinbefore.)
may be prepared by reacting aldehyde at the reductive terminal group of glucose of the saccharide which is used in the reaction and hydrazine in the polymer of the formula (II). This reaction is carried out in a weak acidic condition (e.g. in citrate buffer solution (pH4xcx9c6)) at room temperature (10xcx9c25xc2x0 C.).
And then, the polymer of the present invention wherein the formula
(wherein, Q is defined as hereinbefore.)
may be prepared by reduction, if optionally.
This reduction is called as reductive amidation. It may be carried out using reductive agent such as sodium borohydride, sodium cyanoborohydride etc. in a weak alkaline condition (e.g. in borate buffer solution (pH8xcx9c9)), at 30xcx9c50xc2x0 C. By the same procedure, an ordinal saccharide may be conjugated to hydrazine.
By the known reaction other than the above (a) and (b), saccharide (G) may be conjugated to hydrazine in the polymer of the formula (II).
By the series of the above reactions, the polymer of the present invention (corresponds to the said polymer P1) of the formula (I-1)
(wherein, d2, x2, y2 and z2 are mol (degree of polymerization) of L-glutamic acid connecting COOR1 (wherein, R1 is defined as hereinbefore.), L-glutamic acid connecting COOH, L-glutamic acid connecting NH2 and L-glutamic acid connecting G (saccharide), respectively. With the proviso that (1) sum of d2, x2, y2 and z2 equals to d, (2) d2 may be 0, (3) each L-glutamic acid connecting COOR1 (wherein, R1 is defined as hereinbefore), L-glutamic acid COOH, L-glutamic acid NH2 and L-glutamic acid G (saccharide) may be connected at random in order.) may be prepared.
In reaction (3), various kinds of reactions will be carried out in accordance with the structure of drugs.
1) Drugs possessing keto group (xe2x80x94COxe2x80x94) may be conjugated via hydorazon bond which is formed by dehydro-condensation reaction with hydrazine in the polymer of the formula (I-1). This reaction is carried out in a weak acidic condition (e.g. in citrate buffer solution (pH4xcx9c6)), at room temperature (10xcx9c25xc2x0 C.).
2) Drugs possessing carboxyl group (xe2x80x94COOH) may be conjugated via amide bond which is formed by amidation with amino group at the terminal of hydrazine in the polymer of the formula (I-1). This reaction is well known, it may be carried out, for example,
(1) by the method with using acid halide,
(2) by the method with using mixed acid anhydride,
(3) by the method with using conducing agent (EDC and DCC etc.).
3) Besides the above, drugs may be introduced to poly-L-glutamic acid via various kinds of bonds by known method.
And then, NH2 in hydrazine in the group may be capped with saccharide by reacting the polymer prepared in reaction (3) and the same saccharide as introduced in the reaction (2) again, if optionally.
The drug-containing polymer of the present invention (corresponds to Polymer P2) of the formula (I-2)
(wherein, d3, x3, y3, z3 and w3 are mol (degree of polymerization) of L-glutamic acid connecting COOR1 (wherein, R1 is defined as hereinbefore.), L-glutamic acid connecting COOH, L-glutamic acid connecting NH2, L-glutamic acid connecting G (saccharide) and L-glutamic acid connecting D(drug). With the proviso that (1) the sum of d3, x3, y3, z3 and w3 equals to d, (2) d3 and y3, independently, may be 0, (3) L-glutamic acid connecting COOR1 (wherein, R1 is defined as hereinbefore.), COOH, NH2, G (saccharide) and D (drug) may be conjugated at random in order.) may be prepared by series of these reactions.
In each reaction in the present specification, obtained products may be purified by conventional techniques. For example, purification may be carried out by distillation at atmospheric or reduced pressure, by high performance liquid chromatography, by thin layer chromatography or by column chromatography using silica gel or magnesium silicate, by washing or by recrystallization. Purification may be carried out after each reaction, or after a series of reactions.
[Starting Materials and Reagents]
The starting materials and reagents in the present invention are known per se or may be prepared by known methods.
Industrial Applicability
It has been confirmed that the polymer of the present invention represented as Polymer P1 possesses capability of migrating into target organs as shown hereinafter in Experiment. It is expected that the said polymer is decomposable in natural condition and that it is safe one, because it is natural high molecule compound. Therefore, the said polymer is useful as a carrier.
In addition, it has been confirmed that the drug-containing polymer of the present invention represented as Polymer P2 also possesses capability of migrating into target organs and superior effect as shown hereinafter in Experiments.
The following abbreviations in Experiments and Examples mean as follows:
PLGA: poly-L-glutamic acid,
HZ: hydrazine,
ED: ethylenediamine,
[3H]PGE1-:
PGE1 bonded to hydrazine or ethylenediamine wherein the said
PGE1 is labeled with 3H partially,
Gal: 1-thiogalactpyranosyl-2-imino-ethyl,
-HZ-Lac (reductive): a group of the formula
DMF: dimethylformamide,
MeOH: methanol,
MeONa: sodium methoxide,
EtOH: ethanol.
Experiment 1: Biodistribution of the Carrier Polymer of the Present Invention (Polymer P1)
PLGA-HZ-Gal (prepared in Example 3) and PLGA-HZ-Lac (prepared in Example 5) were labeled with 111In and were injected into mouse through its tail vein at dose of 1 mg/kg to analyze biodistribution of them. The results are shown in Tables 1 and 2 (Each value in Tables means the percentage of concentration in 1 ml of plasma, the percentage of amount of accumulation in each organ and the percentage of urinary excretion of the said PLGA derivatives (meanxc2x1S.D.), respectively at various times after administration.).
About 60% of PLGA-HZ-Gal which was administered was accumulated into liver at 10 min. after administration. The same level of accumulation of it was observed in liver at 60 min.
About 60% of PLGA-HZ-Lac which was administered was accumulated into liver at 10 min. after administration. The same level of accumulation of it was observed in liver at 60 min.
From the mentioned, it has proved that the carrier polymer of the present invention showed high level of accumulation and long-term accumulation of it in liver.
Experiment 2: Biodistribution of the Drug-containing Polymer of the Present Invention (Polymer P2)
Biodistribution of [3H]PGE1-HZ-PLGA-HZ-Gal (prepared in Example 4, degree of polymerization=97) and [3H]PGE1-ED-PLGA-ED-Gal (Comparison: the polymer described in International J. Pharmaceutics, 155, 65-74 (1997), degree of polymerization=101) was analyzed by the same procedure as described in Experiment 1. The results are shown in Tables 3 (Invention) and 4 (Comparison) (Each value in Tables means the percentage of concentration in 1 ml of plasma, the percentage of amount of accumulation in each organ and the percentage of urinary excretion of the said [3H]PGE1 derivatives (meanxc2x1S.D.), respectively at various times after administration.).
As shown in Table 3, 70% of drug which was administered was accumulated into liver at 5 min. after administration. In addition, 85% and 70% of drug were observed to be accumulated to liver at 1 hour and 24 hours after administration, respectively.
On the other hand, in Comparison (Table 4) group, 40% and 45% of drug which was administered were accumulated to liver at 5 min. and 1 hour after administration, respectively.
Therefore, it has proved that it is possible to deliver the drug at the higher concentration continuously into liver using the drug-containing polymer of the present invention.
Experiment 3: Effect of the Drug (PGE1)-containing Polymer of the Present Invention (Polymer P2) on CCl4 Induced Liver Damage
A solution of 10% (v/v) of CCl4 in sesame oil at dose of 10 ml/kg was administered into mouse abdominal cavity, and then drug (saline solution (Control), Free-PGE1 (Comparison), drug (PGE1)-containing polymer of the present invention PGE1-HZ-PLGA-HZ-Lac (reductive) (prepared in Example 6)) were injected into mouse through its tail vein at the setting dose. After the mouse had been fasted for 18 hours (25xc2x0 C., water was freely given), blood was collected to assay GPT level (IU/L) in plasma. The results are shown in Table 5.
As shown in Table 5, the drug (PGE1)-containing polymer of the present invention showed inhibition effect on increasing GPT level in plasma of CCl4 induced liver damage significantly to compare with the group consisting of saline solution (Control group). In addition, the inhibition rate of increasing GPT level in the Invention group was three-time superior to that in the group consisting of free PGE1 at the corresponding dose.

Carrier polymers migrating into target organs and drug-containing polymers


Novel solid state gain mediums provide monolithic lasers with short cavity lengths and with the ability to efficiently lase in the lowest order TEM.sub.00 mode. Unoptimized optical power conversion efficiency of 35% has been achieved with the novel solid state gain mediums in monolithic lasers that have a cavity length as short as 0.5 mm. With proper values for the output mirror reflectivity and low loss host crystals, the optical power conversion efficiency is approximately 50%. Moreover, when in optical contact with a frequency doubling optically non linear crystal, the novel solid state gain mediums in the monolithic lasers can produce coherent visible light.

For the past twenty years, optically pumped solid state lasers have found widespread application as a source of coherent radiation. In applications that require lasers that have very short cavity lengths (hereafter referred to as "microlasers"), the preferred solid state gain medium has been neodymium doped yttrium aluminum garnet (Nd:Y.sub.3 Al.sub.5 O.sub.12) (hereafter referred to as "Nd:YAG") because of the composition's advantageous physical characteristics. 1% Nd:YAG has a maximum Nd-ion absorption coefficient at pump wavelengths between 0.8 to 0.82 micrometers of approximately 8 inverse centimeters. This allows a laser that employs Nd:YAG as the solid state gain medium to have short cavity lengths, as short as 2.5 millimeters, and yet still have 99% pump light absorption. Moreover, the stimulated emission cross section of Nd:YAG for the transition at 1.06 micrometers is relatively high, 4.6.times.10.sup.-19 centimeters.sup.2. This translates into low lasing thresholds and high gain which are both important considerations for microlasers which have a low gain length compared to conventional solid state lasers.
Nonetheless, despite Nd:YAG's advantageous physical characteristics, research into the physical characteristics of other complex host crystal-ion combinations for use as solid state gain mediums in lasers is continuing.

Solid state gain mediums for optically pumped monolithic laser


An ultrasound transducer comprising an array of individual piezoelectric transducer elements mounted upon an improved backing comprising rigid polymeric or polymer-coated particles fused into a macroscopically rigid structure having remnant tortuous permeability to provide high acoustic attenuation and to permit fluid passage into the backing structure during fabrication.

There is a substantial interest in miniaturizing medical imaging ultrasound transducers so that they can be inserted into various body openings to gain better access to body parts for ultrasound imaging purposes. An example is one or more transducer arrays mounted on a gastroscope for insertion down a patient's throat so that the heart can be imaged from the esophagus. Transesophageal probes having one 64-element transducer array as well as a pair of transducer arrays arranged orthogonally have been employed to obtain duplex orthogonal ultrasound images of the heart.

Ultrasound transducer with improved rigid backing


A water heating apparatus includes: a water container configured to heat water via a convection process by receiving the water through an inlet and passing water through an outlet; and one positive temperature coefficient (PTC) heating element or a plurality of PTC heating elements arranged within the water container and configured to be immersed during the convection process. The plurality of PTC heating elements have a gap between each PTC heating element. Further, the water heating apparatus includes at least one ultrasonic transducer attached to the water container and configured to project ultrasound onto and around the PTC heating element or the plurality PTC heating elements within the water container and to descale the PTC heating element or the plurality of PTC heating elements.

This disclosure relates generally to water heating systems, and more particularly, to electrical water heating systems that regulate temperature and reduce scale buildup on heating elements.
Typically, heat transfer from electrical heating elements to water is predominantly performed by convection, that is, warmer water moves into and mixes with colder water. This mixing can occur in the thermal boundary layer, which is an area of fluid close to a solid surface. Further, the rate of heat transfer is directly proportional to the temperature difference across the thermal boundary layer.
In electrical water heaters at steady-state, the heat transfer rate into the water balances the heat generated by the electricity. When a portion of a heating element becomes dry via a drop in water level or from an air bubble in the incoming water becoming trapped adjacent to the heat element, the heat transfer drops. This results in a localized temperature increase in the element. Steam may be generated where the water contacts the bubble. This too acts as an insulator and inhibits the transfer of heat from the heating element to the water. This causes the temperature of the steam trapped next to the heating element to continue rising. In turn, the increased temperature causes the steam to build pressure. For example, at a temperature of 150° C., steam has a vapor pressure of approximately 5 bar, which is five times that at a temperature of 100° C. As water is predominantly incompressible, every part of the water heating system that may become closed, sealed or blocked may be subject to the rising steam pressure, even if the temperature is much lower in the rest of the heating system.
A conventional water heating system typically utilizes electrical conductors such as nichrome as electrical heating elements. Under resistive heating, the temperature of nichrome can reach upwards of 2000° F. or 1000° C. without melting. However, this temperature is above the critical point of water, where the saturation pressure is 221 bar. It is impractical to build pressure vessels to withstand such extreme pressures. Normal practice is to fit pressure relief valves to limit the maximum pressure that a water heater can experience. These add to the complexity, weight and maintenance needs of the water heater.
Moreover, when scale is deposited onto the surface of heating elements, the scale surface temperature will change little, but the surface roughness, created by the deposited scale, will increase the deposition rate of scale in a vicious circle. As scale is built up, the resulting temperature differential across the scale leads to an increase in element temperature to maintain thermal equilibrium. As electrical resistance in metals tends to increase linearly with temperature, the increased temperature increases its electrical resistance. For example, a temperature increase of 250° C. from 20° C. in copper will double its resistance. The increased resistance will lead to a reduced power output, assuming constant voltage is applied. Thus the effect of scale is to reduce the heat output of the heater. With time, the scale buildup and consequent power reduction may make the heater inoperable. The increased element temperature may also lead to premature failure of the element.
Conventional means for descaling may include flushing a chemical descaler through the water heating system, or opening up the system and physically cleaning the elements, either by brushing or using ultrasound cleaning. Chemical descalers are normally acids that dissolve scale. These acids are corrosive and often toxic. As such, care needs to be taken to ensure that the acids are adequately flushed before returning the heating system to service. Brushing can be effective at removing large scale deposits, but may not remove deposits in inaccessible parts. Lastly, ultrasonic cleaning operates at slower process speeds. Additionally, all of the above mentioned processes require taking the heater off-line, which may incur significant disruption and cost.

Regulating temperature and reducing buildup in a water heating system


A controller controls a pressurizing actuator in such a manner that a pressure chamber changes from a first state where a volume of the pressure chamber is V1 to a second state where the volume is V2 larger than V1 and then returns from the second to the first state to cause ink to be ejected from an ejection opening, that a time length Tv1 from a time point at which the pressure chamber starts to change from the first to the second state to a time point at which the pressure chamber is in the second state becomes 33% or more of a characteristic vibration period Td of ink filled in a first ink passage extending from an outlet of the pressure chamber to the ejection opening, and that the time length Tv1 becomes 83% or less of the characteristic vibration period Td.

1. Field of the Invention
This invention relates to an inkjet recording apparatus and a method for controlling the inkjet recording apparatus.
2. Description of the Related Art
In some of inkjet recording apparatuses for performing printing by the inkjet method, ink is ejected from a nozzle when pressure is applied to ink contained in a pressure chamber. Among those apparatuses, an inkjet recording apparatus employing a so-called fill before fire method is disclosed in JP-A-2003-305852, which is capable of applying pressure to ink by temporarily increasing a volume of a pressure chamber and returning the volume of the pressure chamber to the original volume after an elapse of a predetermined time period.

Inkjet recording apparatus and control method for the same


A method for preserving interlevel dielectric in a gate cut region includes recessing a dielectric fill to expose cap layers of gate structures formed in a device region and in a cut region and forming a liner in the recess on top of the recessed dielectric fill. The liner includes a material to provide etch selectivity to protect the dielectric fill. The gate structures in the cut region are recessed to form a gate recess using the liner to protect the dielectric fill from etching. A gate material is removed from within the gate structure using the liner to protect the dielectric fill from etching. A dielectric gap fill is formed to replace the gate material and to fill the gate recess in the cut region.

Technical Field
The present invention relates to semiconductor processing, and more particularly to methods and devices having an improved gate line end that avoids shorts between epitaxy structures and between contacts/silicide regions.
Description of the Related Art
One commonly employed technique for forming gate structures involves forming a line-type gate electrode structure above a layer of insulating material that is formed above an active region defined in a semiconductor substrate. Typically, the line-type gate electrode structures are formed by defining long parallel line-type structures, i.e., gate electrode structures that extend across multiple spaced-apart active regions and the isolation regions formed in the substrate between such spaced-apart active regions. At some point later in the process flow, these long, line-type gate electrode structures are subsequently "cut" by performing an etching process to define the gate electrodes having the desired length in the "gate-width" direction of the transistor device. This results in substantially rectangular shaped gate structures (when viewed from above) having the desired dimensions in the gate-length and gate width directions.
After the gate electrodes are patterned, a sidewall spacer is typically formed around the perimeter of the substantially rectangular shaped gate structure, i.e., the spacer if formed adjacent on all four side sidewalls (two sidewalls and two end surfaces) of each of the patterned gate electrodes. In some cases, a thin liner layer may be formed on the gate structure prior to forming the sidewall spacer. The sidewall spacer, in combination with the gate cap layer, function to protect the gate electrode structure in subsequent processing operations.
In the case where transistor devices are manufactured using so-called gate-first processing techniques, the gate structures (gate electrode plus the gate insulation layer) formed as described above are final gate structures for the device. In the situation where transistor devices are manufactured using so-called gate-last processing techniques, the gate structures (gate electrode and gate insulation layer) formed as described above are sacrificial in nature and will be subsequently removed (after several process operations are performed) and replaced with a final gate structure for the device. In the gate-last processing technique, the final gate structure typically includes one or more layers of high-k insulating material and one or more layers of metal that constitute at least part of the conductive gate electrode of the final gate structure.
Unfortunately, as device dimensions have decreased and packing densities have increased, it is more likely that, when epi semiconductor material is formed in the source/drain regions, some of the epi material may undesirably form on the end surfaces of the polysilicon/amorphous silicon gate electrode. This may occur for several reasons. As noted above, after the gate structures are patterned, a sidewall spacer is formed around all four sides of the gate structure so as to, along with the gate cap layer, encapsulate and protect the gate electrode during subsequent processing operations. As packing densities have increased, the end-to-end spacing between two different gate electrode structures formed above two different active regions has decreased, thereby limiting the physical size, i.e., the width, of the protective sidewall spacers. Additionally, as the pitch between adjacent gate structures has decreased, the width of the protective sidewall spacers must also be decreased.
With respect to forming a sidewall spacer on a device, the duration of the etching process performed to form the spacer is typically increased to ensure that the layer of spacer material is completely cleared from the surfaces of the source/drain regions of the device. This over-etching also tends to reduce the width of the protective spacer. All of these factors and others tend to result in an undesirable thinning of the spacer, particularly at the corner of the gate electrode (the intersection between the side surfaces and the end surfaces of the gate electrode). It is not uncommon that, due to these factors and others, some portion of the polysilicon or amorphous silicon gate electrode material will be exposed at the time epi semiconductor material is formed in the source/drain regions of a planar or FinFET device. As a result, epi semiconductor material will undesirably form on the exposed portions of the gate electrode layer.
The extent and amount of undesirable epi semiconductor material formation will vary depending upon the particular application and the quality of the manufacturing processes used to manufacture the device. In a worst case scenario, this undesirable epi semiconductor material may form around the entire end surface of a particular gate electrode so as to effectively from a conductive "bridge" between one or both of the source/drain regions and the gate electrode. In another example, such undesirable epi semiconductor material may span the space between the opposing end surfaces of two spaced-apart gate electrode structures, wherein the epi material may form on one or both of the spaced-apart gate structures. As a result of such undesirable and unpredictable epi formation, the resulting semiconductor devices and the integrated circuits including such devices may completely fail or operate at less than acceptable performance levels.

This patent is subject to a terminal disclaimer.

Gate cut with high selectivity to preserve interlevel dielectric layer

INTERNATIONAL BUSINESS MACHINES CORPORATION


A method whereby the image of a bar code is located in a digitized image of an object traveling along a conveyor belt; the orientation of the longitudinal axis of the code with respect to a reference system of the image is determined, and the code is scanned along lines parallel to the longitudinal axis of the code to generate respective vectors describing the pattern of the code image brightness signal along the respective line; and the vectors are digitized and projected to generate a real-number vector containing the coordinates of the brightness signal transition points indicating the shape and location of the code elements.

The present invention relates to a method of reading an object-applied bar code.
As is known, reading a bar code from an image picked up by a CCD telecamera poses various problems involving several factors.
A first factor is the poor definition of the image. To obtain the largest possible scanning field using a low-cost processing system, the acquired images must comprise the smallest possible number of pixels. At present, normal data acquisition systems require that the sampling frequency be at least twice the maximum frequency of the sampled signal, so that, in the case of a bar code, if the module is defined as the nominal dimension of the smallest component element (bar or space), an exact reconstruction of the corresponding square wave would require an enormous number of pixels per module.
A second factor involves random code orientation and anisotropy of the telecamera. As the orientation of acquired codes is not normally fixed with respect to the axes of the telecamera, systems must be used which are capable of reading the code regardless of how it is oriented, or which are capable of rotating the image accordingly. Moreover, as the pixels of any telecamera are square, the code image varies according to orientation of the code. In short, the difficulties encountered in reading the code differ according to its orientation.
A third factor involves grey level quantization and acquisition noise. As is known, a pixel is always coded by a finite number of grey levels, whereas the high acquisition speed demanded by current scanning systems prevents, the use of analog-digital converters with a large number of significant bits. Moreover, the thermal noise of the telecamera and the analog part of the read system has a negative effect on the accuracy of the sampled signal.
A fourth factor is blooming of the image, due to the code image being acquired by a system of lenses inevitably involving a certain amount of aberration and lack of uniformity, and due to the distance of the code from the telecamera not always being accurately known.
A fifth factor involves illumination of the code. As is known, the code is illuminated by a lighting device set up in a fixed position, so that the distance between the lighting device and the code, and the distance between the code and the telecamera vary continually according to the location of the code within the scanning field, thus resulting at times in the acquisition of poorly illuminated codes and, hence, in acquisition accompanied by severe quantization noise. On the other hand, if the code is a reflecting type or covered with a film of plastic material, even the best illumination system may result in reflection capable of dazzling the telecamera.
Finally, a sixth factor involves flaws in the code itself (smudges, chafing, poor contrast, tears, incorrect relationship between the code elements, etc.) due to printing errors or deterioration of the print medium.

Method of reading an object-applied bar code