There is disclosed a system for minimizing a power consumption level of a memory data storage device that operates in a high power mode when data is being written therein and operates in a low power mode when inactive. The system comprises: 1) a controller for receiving incoming data to be written to the memory data storage device; and 2) a first low power buffer coupled to the controller. The controller stores the incoming data in the first low power buffer until a predetermined amount of incoming data has been accumulated in the first low power buffer and transfers the accumulated predetermined amount of incoming data to the memory data storage device in a single data transfer.

The present invention is directed, in general, to electronic data storage technology and, more specifically, to an apparatus and method for providing a significant reduction in the power consumption of an electronic data storage system. The present invention is especially useful in providing a significant reduction in the power consumption of battery operated flash memory data storage systems.
A non-volatile data storage device is one that retains the data stored in it when external power to the device is shut off. One of the earliest non-volatile storage devices was punched paper tape. One of the most recent technologies for storing data in a non-volatile electronic data storage device is called xe2x80x9cflash memory.xe2x80x9d Flash memory is a programable semiconductor memory of a type called xe2x80x9cread-mostlyxe2x80x9d memory. Flash memory is so named because of the speed with which it can be reprogrammed. Flash memory uses an electrical erasing technology that can erase an entire flash memory array in a few seconds at most. Data written to flash memory remains in a non-volatile storage mode until the flash memory is deliberately erased. Flash memory requires a relatively high level of current (and a high level of electrical power to provide that current) when data is being written to the flash memory. A typical value of current required by flash memory when data is being written to the flash memory is sixty milliamps (60 mA).
CompactFlash(trademark) memory is a relatively new flash memory data storage system. CompactFlash(trademark) is a registered trademark of SanDisk Corporation. CompactFlash(trademark) memory is very useful in various types of technological applications and represents a significant advance over other flash memory data storage systems for a number of reasons. In comparison with other flash memory data storage systems, CompactFlash(trademark) memory has greater speed, greater durability, and smaller size. It is also packaged in a form that is very compatible with personal computers, especially laptop computers. CompactFlash(trademark) memory makes it possible to store several tens of Megabytes of data on a memory card that is no larger than an ordinary matchbook. CompactFlash(trademark) memory cards are now being used in digital cameras, in personal data assistants (PDAs), in MP3 audio players, and in other similar electronic data storage devices.
One of the drawbacks of CompactFlash(trademark) memory (and of flash memory data storage systems in general) is that its operation requires a relatively high level of current. The greater the speed with which a flash memory data storage system is accessed, the more current it requires for operation. Even at the slowest access speeds, flash memory data storage systems generally require a comparatively large amount of current for operation.
For this reason flash memory data storage systems have not been widely used in battery powered devices for gathering electronic data. This is especially true for battery powered devices that acquire data slowly over a relatively long period of time. The power requirements of a flash memory data storage system in such a device would require continual and frequent replacement of the batteries. In many applications this requirement would make the use of a flash memory data storage system impractical.
It would be advantageous to have a flash memory data storage system in which the power consumption is reduced compared to the power consumption in prior art flash memory data storage systems. It would also be advantageous that any reduction of the power consumption in such a flash memory data storage system be achieved without a corresponding reduction in the performance level of the flash memory data storage system.
To address the deficiencies of prior art electronic data storage systems, and especially those that require a relatively high level of current (and power) when data is being written to them, it is a primary object of the present invention to provide an improved electronic data storage system in which the power consumption of the electronic data storage system is reduced compared to the power consumption of prior art electronic data storage systems.
It is also an object of the present invention to provide an improved flash memory data storage system in which the power consumption of the flash memory data storage system is reduced compared to the power consumption in prior art flash memory data storage systems.
It is a further object of the present invention to provide an improved flash memory data storage system in which the reduction of the power consumption in the flash memory data storage system is achieved without a corresponding reduction in the performance level of the flash memory data storage system.
It is an additional object of the present invention to provide an improved flash memory data storage system for use in battery powered devices for gathering electronic data.
It is yet another object of the present invention to provide an improved flash memory data storage system for use in battery powered devices that acquire data slowly over a relatively long period of time.
Accordingly, in an advantageous embodiment of the present invention, there is provided, for use with a memory data storage device that operates in a high power mode when data is being written therein and operates in a low power mode when inactive, a system for minimizing a power consumption level of the memory data storage device comprising: 1) a controller capable of receiving incoming data to be written to the memory data storage device; and 2) a first low power buffer coupled to the controller, wherein the controller stores the incoming data in the first low power buffer until a predetermined amount of incoming data has been accumulated in the first low power buffer and wherein the controller transfers the accumulated predetermined amount of incoming data to the memory data storage device in a single data transfer.
In one embodiment of the present invention, the predetermined amount of incoming data is determined by a size of the predetermined amount of incoming data.
In another embodiment of the present invention, the size of the predetermined amount of incoming data is five hundred twelve bytes of data.
In still another embodiment of the present invention, the predetermined amount of incoming data is determined by a selected time duration during which the predetermined amount of incoming data has been accumulated.
In yet another embodiment of the present invention, the controller transfers the accumulated predetermined amount of incoming data to the memory data storage device when the memory data storage device is in the high power mode.
In a further embodiment of the present invention, the system further comprises a second low power buffer coupled to the controller capable of storing the incoming data when the accumulated predetermined amount of incoming data is being transferred from the first low power buffer to the memory data storage device.
In a still further embodiment of the present invention, the memory data storage device is of a battery powered type having a relatively high power consumption when data is written to the memory data storage device.
In a yet further embodiment of the present invention, the memory data storage device is a flash memory card.
The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.
Before undertaking the DETAILED DESCRIPTION OF THE INVENTION, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms xe2x80x9cincludexe2x80x9d and xe2x80x9ccomprise,xe2x80x9d as well as derivatives thereof, mean inclusion without limitation; the term xe2x80x9cor,xe2x80x9d is inclusive, meaning and/or; the phrases xe2x80x9cassociated withxe2x80x9d and xe2x80x9cassociated therewith,xe2x80x9d as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term xe2x80x9ccontrollerxe2x80x9d means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

Apparatus and method for reducing power consumption in an electronic data storage system


The present invention relates to steerable access sheath assembly including at least one electrode. Moreover, the present invention relates to a steerable sheath access device for use in cardiovascular procedures. Embodiments of the present invention including steerable access sheaths or introducers may provide cardiovascular access for various ablation tools and devices for the performance of various ablation procedures or procedures involving alternate energy sources.

a. Field of the Invention
The present invention relates to sheaths or introducers. More particularly, the present invention relates to a steerable short sheath access device or introducer for use in epicardial procedures, such as those used for the treatment of atrial fibrillation and ventricular tachycardias.
b. Background Art
Many medical procedures require the introduction of specialized medical devices into and/or around the human heart. In particular, there are a number of medical procedures that requires the introduction of specialized devices, including but not limited to catheters, dilators, and needles, to areas such as into the pericardial sac surrounding the heart in order to access the epicardial or outer surface of the heart. Catheters and access sheaths or introducers have been used for medical procedures for a number of years. It is necessary for introducers and catheters to exhibit a degree of flexibility to be able to maneuver through the vasculature of a patient during the performance of cardiac procedures. In addition, various configurations of introducers are necessary for the treatment of different cardiac conditions.
Atrial fibrillation and ventricular tachycardias are cardiac arrhythmias that result in an irregular heartbeat due to the irregular conduction of electrical impulses to the ventricles of the heart. It is believed that one method of treating atrial fibrillation is through the locating, accessing, stimulating, and ablation of epicardial neuroganglia. It is believed that atrial fibrillation can be controlled more completely by ablating neuroganglia heads located under (or inside) fat pads located on the epicardial surface of the heart. The fat pads are located at the junctions of the pulmonary veins, the inferior vena cava, and in the margin between the aorta and the superior vena cava, all of which may in fact be a major source of fibrillation. Current treatments that involve ablating alternate pathways internal to the heart may be ineffective in truly reaching neuroganlia and instead targets the legs of the neuroganglia, which can necessitate multiple ablations. As a result it is desirable to develop a method of targeting the neuroganlia heads so that the entire circuit can be resolved by ablating the head embedded in or below the fat pad.
In order to ablate the head of the fat pad located on the epicardial surface, it is necessary to use an ablation catheter that is able to access the epicardial surface of the heart. Traditional approaches to treating atrial fibrillation include the use of introducers or catheter systems that are inserted within the internal chambers of the heart to target areas for ablation. Traditional catheters and access devices, such as introducers, access these endocardial areas through a rigid elongated body that includes a curved portion for accessing areas of the heart and related vasculature for ablation. These traditional catheters and access devices can be too long in length to be used in certain pericardial procedures such as that for potential treatment of atrial fibrillation. Moreover, these traditional devices are not able to be maneuvered or steered to reach the epicardial surfaces for treatment or they may have to be curved throughout the pericardial sac and around the heart to reach the tissue areas of interest.

St. Jude Medical, Atrial Fibrillation Division, Inc.


An oil-in-water composition is provided. The composition includes an oil-in-water wherein the emulsion includes a) one or more antioxidants, b) one or more SPF boosters, c) one or more acrylate-based polymer capable of stabilizing the composition, d) one or more organic UV filters, e) one or more thickeners, f) one or more film formers; and g) one or more emulsifiers. The oil-in-water composition is provided in which the composition is essentially free of oxybenzone.

Skin acts as a natural barrier between the internal and the external environment and therefore plays an important role in vital biological functions such as protection against ultraviolet damage. Skin, however, is delicate and is easily damaged. For example, the negative effects of extended exposure to sunlight are well-known; for example, prolonged exposure causes sunburns. When skin is exposed to UV light having a wavelength of from about 290 nm to about 400 nm, long term damage can lead to serious conditions such as skin-aging.
As described in more detail below, the inventors of the instant disclosure discovered compositions and methods that protect the skin from UV damages. The components of the compositions interact to improve the SPF of the UV filters and provide water resistance. Thus, the compositions are useful for a variety of cosmetic compositions.
Accordingly, it is desirable to produce a stable formulation comprising an oil-in-water dispersion which is highly water resistant, maintains high levels of sunscreen protection, provides provide uniform skin coverage and is aesthetically pleasing, i.e., does not feel oily or 50 greasy.

Sunscreen composition with a high UV filter load


The invention concerns an internal-combustion engine, the engine comprising a first combustion chamber, a first piston displaceably guided in the first combustion chamber, the first piston facing the first combustion chamber with a first piston surface in a first direction, a second combustion chamber, a second piston displaceably guided in the second combustion chamber, the second piston facing the second combustion chamber with a second piston surface in a second direction, the first direction and the second direction being opposed to each other, the first piston and the second piston being coupled to each other so that they move simultaneously.

The invention concerns an internal-combustion engine with a first combustion chamber, a first piston displaceably guided in said first combustion chamber, this first piston facing said first combustion chamber with a first piston surface in a first direction, a second combustion chamber, a second piston displaceably guided in said combustion chamber, this second piston facing said second combustion chamber with a second piston surface in a second direction, said first direction and said second direction being opposed to each other.
Engines of this type are known as engines of the "boxer type". They can be used as stationary drives as well as for vehicles.
Despite substantial progress having been achieved in making internal-combustion engines more efficient, there is still a great need for further improvement of the efficiency of such engines, may it be two-cycle or four-cycle, otto- or diesel-engines.
It is the underlying purpose of the invention to provide a combustion engine having higher efficiency.


An embodiment of the invention may include a method, computer program product and computer system for image identification and classification. The method, computer program product and computer system may include a computing device which may receive one or more images of a first object from at least two angles linguistic data associated with the first object. The computing device may input the one or more images of the first object into one or more first neural networks and the linguistic data of the first object into one or more second neural networks. The computing device may combine the output of the one or more first neural networks and the one or more second neural networks and generate an identification model based on the combined output of the one or more first neural networks and the one or more second neural networks.

The present invention relates generally to a method, system, and computer program for image identification and classification. More particularly, the present invention relates to a method, system, and computer program for utilizing neural networks to identify an unknown piece of art.
Artistic expression and innovation has been a driving force in the human existence for millennia resulting in a vast corpus of work spanning every civilization from cavemen and the ancient Egyptians to today. The study of this vast corpus of artistic work has led to the understanding of the human existence and how we have come to live today. New artistic objects from the past are still being discovered today and the process of identifying those objects is a vitally complex and important field. Today, art identification relies mostly on human inspection, especially when it comes to newly discovered and unknown objects. When it comes to current technology, systems exist for comparing photographs of an object to a database of known objects of art. For example, a user can take a photo of a painting and input that photo into a program or application and the application can identify that painting if it is one that exists in the database of that program or application.

Object recognition and description using multimodal recurrent neural network

International Business Machines Corporation


A resist develop process involves the steps of dispensing a developer on a resist on a semiconductor wafer, forming the developer into a puddle where a portion of the resist dissolves into the developer, dispensing additional developer following development, rinsing the wafer with a rinsing agent, and drying the wafer surface. The additional developer dispense step replaces developer with resist dissolved therein with new developer prior to the rinsing step to prevent potential resist precipitation during the rinsing step which can lead to bridging.

Photolithography employing a resist film is applied to fabricating electronic devices, such as semiconductor devices. A substrate is coated with a layer of resist material to form a photoresist thereon. The layer of resist material typically comprises a polymer with additives, such as radiation sensitizers, plasticizers, and adhesion promoters. The substrate can be a semiconductor wafer from which integrated circuit chips are formed or a module used to support and interconnect semiconductor integrated circuit chips.
The resist layer is exposed patternwise to electromagnetic radiation to change the solubility of portions of the resist layer. The resist layer is developed with solvents which remove the soluble portions of the resist layer leaving the substantially insoluble portions and uncovering parts of the substrate for further processing. The substrate is then typically subjected to etching or deposition processes.
There are two general types of resists, positive and negative. During the exposure step, the areas on a negative resist exposed to light undergo polymerization and change from being soluble to being substantially insoluble. In contrast, areas on a positive resist exposed to light undergo photosolubilization and change from being substantially insoluble to soluble. Positive resists are the resists of choice for fabrication area processing of state-of-theart circuits because they have a better resolution capability than negative resists. Accordingly, positive resists can resolve smaller openings due to the smaller size of the polymers therein. However, there are many devices with image sizes greater than 5 .mu.m for which negative resists can be used.
After a wafer has been aligned and exposed, it is subject to a development process. During the development process, an exposed photoresist film having the predetermined pattern is developed with a developer to remove resist film to form a predetermined pattern of photoresist film on the wafer. Referring to FIGS. 1a-1d. a conventional resist develop process consists of a developer dispense step (puddle forming step) as shown in FIG. 1a, a puddle develop step as shown in FIG. 1b, a water rinse step as shown in FIG. 1c, and a spin dry step as shown in FIG. 1d. As used herein, "puddling" refers to retaining a developer in a puddle by surface tension over the surface of a workpiece and "puddle develop" refers to a developing process using a developer puddle formed by puddling.
In developing an exposed resist film la formed on a semiconductor wafer 1, the wafer 1 is mounted on a vacuum wafer chuck 2 as shown in FIG. 1a. A developer 3 is spread in the developer dispense step by a nozzle 30 or the like over the surface of the resist film 1a to cover the surface of the wafer 1. The developer 3 is retained in a puddle by surface tension over the surface of the resist film 1a and the wafer 1 as shown in FIG. 1b.
After the puddle develop step, the wafer surface is rinsed with water as shown in FIG. 1c. In particular, the wafer chuck 2 holding the wafer 1 rotates while water 5 is dispensed from the nozzle 40. Immediately following the rinse step, the rotational speed of the wafer chuck 2 increases to a higher speed to dry the wafer 1 as shown in FIG. 1d. However, some of the resist which dissolves in the developer may precipitate during the water rinse step in water and harden and dry on the wafer surface because the resist is insoluble.
Consequently, a bridging problem often results since precipitant can stick to the wafer. Bridging is a condition where two patterns are connected by a thin layer of photoresist. Bridging can result from overexposure, a poor mask definition, or a resist film that is too thick. This type of defect has a substantial negative impact on the open/short yields for L/S (line/space) structures.
FIG. 2a shows an example of bridging which occurs when a positive resist and a clear (or light) field mask are used or when a negative resist and a dark field mask are used. The hatched regions in FIG. 2a represent a so-called "island", which are not removed during the develop process. The shaded regions represent precipitant which has bridged adjacent islands which causes short circuiting.
FIG. 2b shows an example of bridging which occurs when a positive resist and a dark field mask are used or when a negative resist and a clear field mask are used. The hatched regions in FIG. 2b represent a photomasking "hole" on the surface of the substrate. The shaded regions represent precipitant which has filled an area of a hole which can cause open circuits to form.
Resist bridging has generally taken place during prior art fabrication processes. However, other factors in the fabrication processes have tended to have a greater impact on product yield. As processing methods have improved and devices have become smaller and smaller, resist bridging has become an increasingly larger problem and an important consideration in determining how to increase yields. More particularly, with smaller devices resist bridging becomes a substantial contributor to reducing yield. Accordingly, there is a need in the art to substantially eliminate bridging which occurs in the resist develop process.

Resist develop process having a post develop dispense step


A method for making an IC package with transparent encapsulant includes providing a leadframe, where the leadframe includes a first die pad and a second die pad, disposing a first die on the first die pad and a second die on the second die pad, forming a cavity on the leadframe, where the cavity includes the first die pad and the second die pad, injecting an encapsulant material into the cavity and cutting the injected encapsulant material and the leadframe to form a first IC package and a second IC package. The encapsulant material is transparent for visible wavelengths. The injection of the encapsulant material is performed at an encapsulant temperature ranging from 140° C. to 160° C.

The present invention relates in general to integrated circuit (IC) packaging. More particularly, the invention provides an IC package with transparent encapsulant and a method for making thereof. Merely by way of example, the invention is described as it applies to a package in compliance with certain JEDEC standard, but it should be recognized that the invention has a broader range of applicability.
Integrated circuits are usually packaged before being used in electronic systems. Integrated circuit (IC) packages often protect the integrated circuits from the surrounding environment but also provide electrical connections to other components of the electronic systems. For example, the IC packages include a plurality of leads that are connected to the integrated circuits, and such leads can transmit or receive electrical signals from other components of the electronic systems. In another example, the IC packages also include encapsulant materials that cover and protect at least parts of the integrated circuits and/or the electrical connections between the integrated circuits and the leads.
For certain applications, the integrated circuits include optical sensors, which are used in light sensitive or light activated devices such as laser diodes. To meet this demand, IC packages with transparent windows have been developed. FIG. 1 is a conventional IC package with a transparent window. The IC package 1 can be used as a ceramic dual-in-line package (CERDIP) of a charge-coupled device (CCD). As shown in FIG. 1, the package 1 includes a die 11, a ceramic lower plate 12, a leadframe 14, a ceramic upper plate 15 and a window 10. The lower plate 12 serves as a die pad. The die 11 includes an integrated circuit coupled to a light sensor 19.
Additionally, a die sealant 13 is applied to one side of a central portion of the die pad 12, and the die 11 is attached to the die pad 12 through the die sealant 13 by a heat treatment. Moreover, a ceramic sealant 16 is applied to top fringes of the die pad 12, and the lead frame 14 is mounted on the die pad 12 through the sealant 16. Also, the ceramic sealant 16 is applied to the lead frame 14, and the upper ceramic plate 15 is fixed onto the leadframe 14 through the sealant 16. Alternatively, the ceramic plate sealant 16 is provided to the lower side of the ceramic upper plate 15, and the ceramic upper plate 15 is mounted onto the lead frame 14. Through a heat treatment, the ceramic plate sealant 16 is molten to seal the lead framed 14 to the ceramic upper plate 15. Additionally, the die 11 and the inner leads of the lead frame 14 are electrically connected by conductive wires 18. The transparent window 10 is sealed by a transparent window sealant 17. For example, the sealant 17 is melted to seal the transparent window 10 to the upper portion of the ceramic upper plate 15 through a heat treatment. Moreover, the lead frame 14 is trimmed, and the fabrication of the package 1 is completed.
The IC package 1 has various weaknesses. For example, the fabrication process for coating the ceramic sealant 16 on the lower side of the ceramic upper plate 15 is complex and costly. Additionally, the desired sealant effect is difficult to achieve between the ceramic upper plate 15 and the window sealant 17. If the window 10 is peeled off from the ceramic upper plate 15, the IC package 1 can be significantly damaged.
FIG. 2 is another conventional IC package with a transparent window. A die 21 is placed on a die pad 22 of a lead frame 23. Lead fingers of the lead frame 23 have electrical connections 25 with the die 21. The die 21 includes an integrated circuit coupled to a light sensor 26. The die 21 and the die pad 22 are covered by a predetermined volume of transparent plastic 24. Thereafter the transparent plastic 24 is molded to form an IC package 2 with a transparent window. The transparent plastic 24 often has an expansion coefficient larger than those of other types of molding compounds. This large expansion coefficient can result in disassociation of the transparent plastic 24 from other components of the IC package 2 after some time of use. For example, the IC package 2 includes a copper die pad, copper leads, and a die surface. The die surface is made of silicon-based material. Such disassociation often leads to cracks and thereby damages the IC package.
Hence it is highly desirable to improve techniques for integrated circuit packaging.

Method of making integrated circuit package with transparent encapsulant


An LCD driving inverter to drive a plurality of lamps mounted in an LCD module, includes: a main substrate having an input part connected to an external power source, a conversion circuit converting a direct current provided from the input part into an alternating current, a first transformer connected to the conversion circuit to convert voltage from the conversion circuit and a first output part providing the voltage from the first transformer to at least one of a plurality of lamps; a subsidiary substrate including a second transformer connected to the conversion circuit to convert the voltage from the conversion circuit and a second output part providing the voltage from the second transformer to at least another one of the plurality of lamps; and at least one spacing member disposed between the main substrate and the subsidiary substrate so that the subsidiary substrate is mounted to be spaced from a surface of the main substrate. Thus, the LCD driving inverter and a portable computer including the inverter having a plurality of output parts is minimized in the width dimension.

1. Field of the Invention
An aspect of the present invention relates to a liquid crystal display (LCD) driving inverter and a portable computer with the same, and more particularly, to an LCD driving inverter and a portable computer with the same including an improved configuration having a plurality of output units.
2. Description of the Related Art
Generally, an LCD driving inverter is connected to a lamp mounted in an LCD module to drive the lamp. The LCD module includes an LCD panel forming an image and a backlight unit disposed in back of the LCD panel and including a lamp to provide light to the LCD panel. If the LCD module employs a large-sized LCD panel, a plurality of lamps is needed to provide sufficient light to the large-sized LCD panel.
An LCD module comprising a plurality of lamps is disclosed in Korea Patent Application No. 10-2002-0053540. This conventional LCD module includes a plurality of lamps to provide light to an LCD panel and a plurality of inverters connected to each of the lamps in series so as to drive the lamps.
However, since the conventional LCD module includes the plurality of inverters, it may be difficult to assemble the LCD module and may increase in volume.
Specifically, in the case that the LCD module is mounted in a portable computer, it may be difficult to decrease the thickness of the portable computer.

LCD driving inverter and portable computer with the same


A magnetic recording medium comprises, on a substrate, a recording auxiliary layer, a recording holding layer, recording control layer, and a recording layer. The recording layer is constructed by using a ferri-magnetic material having perpendicular magnetization. The data can be recorded at a super high density by using the recording and reproducing head of the present invention, because the recording layer has the perpendicular magnetization. The disappearance of data, which would be otherwise caused by the thermomagnetic relaxation phenomenon, is suppressed after recording the data, because the recording layer has large coercive force at the room temperature. The data, which is recorded at the super high density on the magnetic recording medium, can be reproduced by using a magnetic resistance element carried on the recording and reproducing head.

1. Field of the Invention
The present invention relates to a magnetic recording medium comprising a magnetic film having perpendicular magnetization, the magnetic film being used for a recording layer. The present invention also relates to a recording and reproducing head and a magnetic recording and reproducing method for such a magnetic recording medium. In particular, the present invention relates to a magnetic recording medium on which any disappearance of data, which would be otherwise caused by the thermomagnetic relaxation phenomenon, is prevented or suppressed, and recording and reproduction can be performed at a surface recording density of not less than 20 Gbits/in2. The present invention also relates to a recording and reproducing head and a novel magnetic recording and reproducing method which are preferably used to perform recording and reproduction on such a magnetic recording medium.
2. Description of the Related Art
The hard disk (magnetic recording medium) is widely used as an external storage medium for computers and the like. Usually, the longitudinal magnetic recording is adopted for the hard disk, in which information is recorded in parallel to a recording film surface by using, for example, a ring-shaped magnetic head (hereinafter referred to as "ring head") carried on a floating type slider.
In recent years, a variety of data including, for example, graphic data, animation data, and document data are processed in various ways in advanced manners, in which a huge amount of information is dealt with. In order to successfully deal with such a huge amount of data, one of the most important technical tasks in the field of hard disk is to increase the surface recording density. At present, the hard disk has achieved a surface recording density of 4 Gbits/in2.
A means for achieving the high density process has been suggested, for example, in IEEE Transactions on Magnetics, Vol. MAG-15, No. 6, pp. 1456–1458 (1979). This document describes a perpendicular magnetic recording system and a perpendicular magnetic recording medium which are based on the use of a recording film of a Co—Cr film having perpendicular magnetization so that information is recorded in the perpendicular direction with respect to a recording film surface.
In order to further increase the surface recording density of the hard disk, it is known that the magnet (magnetic particle), which is a recording unit for constructing the recording layer, is allowed to have a small size. However, if the magnetic particles are allowed to have a minute size so that the surface recording density is increased to be not less than 10 to 20 Gbits/in2, the following problem arises. That is, the magnetic particles become unstable due to the thermomagnetic relaxation phenomenon, and the recorded data disappears.

Magneto-optical recording and reproducing method, using reproducing layer with high saturation magnetization


An operational amplifier includes differential amplification circuitry and current mirror circuitry. The differential amplification circuitry includes first and second differential amplification circuits disposed symmetrically in the upper and lower parts of a circuit diagram, and the current mirror circuitry includes first and second current mirror circuits disposed symmetrically in the upper and lower parts of the circuit diagram. The input ends of the first and second differential amplification circuits are connected to a non-inverting input terminal and a inverting input terminal, respectively. Output ends of the first and second differential amplification circuits on the sides of the respective non-inverting inputs are independently connected to the input ends of the first and second current mirror circuits Output ends of the first and second differential amplification circuits on the sides of the respective inverting inputs are independently connected to a positive power supply and a negative power supply, respectively. Output ends of the first and second current mirror circuits are connected together to a load impedance.

1. Field of the Invention
The present invention relates to operational amplifiers. More specifically, the invention relates to an operational amplifier in which one stage of voltage amplification circuitry is provided.
2. Description of the Related Art
An operational amplifier formed of a connection of a plurality of stages (for example, two stages) of phase inversion type voltage amplification circuits is conventionally known. The operational amplifier formed of such a connected plurality of stages of voltage amplification circuits however suffers from turning points (poles) in the frequency characteristic corresponding to the number of the stages, and a large phase delay as a whole results due to a phase delay in each stage, thereby deteriorating the frequency characteristic. In order to avoid such disadvantages, devices having one stage of voltage amplification circuits and allowing voltage amplification without phase inversion have been proposed.
FIG. 1 is an electric circuit diagram showing such an operational amplifier having one stage of voltage amplification circuits. Referring to FIG. 1, the operational amplifier includes in the upper and lower parts of the circuit diagram, a differential amplification circuit 1a formed of a differential connection of NPN transistors Q.sub.1 and Q.sub.2, and a differential amplification circuit lb formed of a differential connection of PNP transistors Q.sub.4 and Q.sub.5, respectively. A power supply voltage Vcc is supplied to the collector of transistor Q.sub.1, the collector of transistor Q.sub.2 is connected to a constant current circuit 5a, and the power supply voltage Vcc is supplied to constant current circuit 5a. The emitters of transistors Q.sub.1 and Q.sub.2 are both connected to constant current circuit 4b, and constant current circuit 4b is supplied with a power supply voltage -Vcc. The power supply voltage -Vcc is supplied to the collector of PNP transistor Q.sub.4, the collector of PNP transistor Q.sub.5 is connected to constant current circuit 5b, and constant current circuit 5b is supplied with the power supply voltage -Vcc. The emitters of transistors Q.sub.4 and Q.sub.5 are both connected to a constant current circuit 4a, and constant current circuit 4a is supplied with the power supply voltage Vcc. The bases of transistors Q.sub.1 and Q.sub.4 are connected to an input terminal IN.sub.1, and the bases of transistors Q.sub.2 and Q.sub.5 are connected to an input terminal IN.sub.2.
The collector of transistor Q.sub.2 is connected to the emitter of transistor Q.sub.21 with its base grounded, and the collector of transistor Q.sub.5 is connected to the emitter of a transistor Q.sub.22 which has also its base grounded. A power supply 6a is connected to the base of transistor Q.sub.21, and a power supply 6b is connected to the base of transistor Q.sub.22. A buffer circuit 3 for current amplification is connected to the connection point of the collectors of transistors Q.sub.21 and Q.sub.22. Z.sub.L is a load impedance for transistors Q.sub.21 and Q.sub.22 having their bases grounded and is actually an impedance inside the buffer circuit 3 in an actual circuit.
In the operational amplifier shown in FIG. 1, the current changes of differential amplification circuits 1a and 1b due to signals applied to input terminals IN.sub.1 and IN.sub.2 are extracted from the collectors of base-grounded transistors Q.sub.21 and Q.sub.22, the difference between the currents flowing through these transistors Q.sub.21 and Q.sub.22 is converted into a voltage value by the load impedance Z.sub.L, and the voltage value is output from an output terminal OUT.
The operational amplifier shown in FIG. 1 has advantages over the one formed of a plurality of stages of voltage amplification circuits in that it has a relatively simple circuit configuration, a higher gain band width product ft, and an excellent high frequency characteristic due to its reduced phase delay.
However, in the conventional operational amplifier shown in FIG. 1, the transistor Q.sub.2 of differential amplification circuit 1a and transistor Q.sub.5 of differential amplification circuit 1b, and base-grounded transistors Q.sub.21 and Q.sub.22 are connected together as loads to constant current circuits 5a and 5b in the upper and lower parts, respectively. The current of constant current circuit 5a flow through transistors Q.sub.2 and Q.sub.21. The current of constant current circuit 5b flow through transistors Q.sub.5 and Q.sub.22. The characteristic changes of constant current circuits 5a and 5b adversely affect the operations of transistors Q.sub.21 and Q.sub.22 having their bases grounded. More specifically, if the characteristics of the constant current circuits 5a and 5b in the upper and lower parts are not uniform at the time of manufacture, the balance of the current to be shunted, and thereby to flow through transistors Q.sub.21 and Q.sub.22, changes between the upper and lower parts, thus producing a difference between the operation currents of transistors Q.sub.21 and Q.sub.22. As a result, an unnecessary D.C. component is output as an offset voltage to output terminal OUT at the final stage.
Furthermore, if the power supply voltage Vcc changes, or the temperature changes, the currents of constant current circuits 5a and 5b change, thus changing the operation currents of base-grounded transistors Q.sub.21 and Q.sub.22, and, therefore, the frequency characteristics of transistors Q.sub.21 and Q.sub.22 also change.


In order to improve a multiple-spindle turning machine, comprising a machine frame, a cylinder rotatable around an essentially horizontal rotational axis relative to the machine frame, work piece spindles arranged on the cylinder in respective individual positions with spindle axes, which are aligned essentially parallel to the rotational axis and which during the machining of a work piece are movable relative to the cylinder by means of linear drives in the direction of their spindle axis and independently of one another, and tools arranged on tool supports for machining the work pieces held in the work piece spindles, in such a way as to allow the respective work piece spindle to be positioned as precisely as possible in the direction of its spindle axis, it is proposed that each of the work piece spindles is allocated its own linear drive disposed on the cylinder to move it in the direction of the spindle axis, and that the work piece spindle is constantly coupled to the linear drive.

The invention relates to a multiple-spindle turning machine, comprising a machine frame, a cylinder rotatable around an essentially horizontal rotational axis relative to the machine frame, work piece spindles arranged on the cylinder in respective individual positions with spindle axes, which are aligned essentially parallel to the rotational axis and which during the machining of a work piece are movable in the direction of their spindle axis and independently of one another relative to the cylinder by means of linear drives, and tools arranged on tool supports for machining the work pieces held in the work piece spindles.
Such a multiple-spindle turning machine is known from the patent publication DE-OS 25 28 001, this publication disclosing work piece spindles, which are arranged on a cylinder and have disc cams as linear drives, said linear drives being firmly disposed in the machine frame and only acting on the work piece spindles to displace these in the direction of their spindle axes when these stand in the respectively provided spindle stations. Each spindle station has a linear drive allocated to it which acts on the work piece spindle standing in this station for displacement thereof in the direction of its spindle axis.
The disadvantage of such a solution is that exact position of the individual work piece spindles in the direction of their spindle axis is not possible.
Therefore, the object of the invention is to improve a multiple-spindle turning machine of the specified type so that it enables the respective work piece spindle to be positioned as precisely as possible in the direction of its spindle axis.


The present invention relates to a method of separating antibodies from other compound(s) in a liquid sample, wherein a mobile phase comprising said sample is contacted with a multi-modal separation matrix to adsorb undesired compounds while the antibodies remain free in the liquid, wherein the multi-modal separation matrix comprises first groups, which are capable of interacting with negatively charged sites of the target compounds, and second groups, which are capable of at least one interaction other than charge-charge interaction with said target compounds. The invention also relates to a chromatography column packed with the above-described multi-modal separation matrix and a filter having such multi-modal groups adsorbed to its surface.

The immune system is composed of many interdependent cell types that collectively protect the body from bacterial, parasitic, fungal, viral infections and from the growth of tumour cells. The guards of the immune system are macrophages that continually roam the bloodstream of their host. When challenged by infection or immunisation, macrophages respond by engulfing invaders marked with foreign molecules known as antigens. This event, mediated by helper T cells, sets forth a complicated chain of responses that result in the stimulation of B-cells. These B-cells, in turn, produce proteins called antibodies, which bind to the foreign invader. The binding event between antibody and antigen marks the foreign invader for destruction via phagocytosis or activation of the complement system. A number of different classes of antibodies, also known as immunoglobulins, exist, such as IgA, IgD, IgE, IgG, and IgM. They differ not only in their physiological roles but also in their structures. From a structural point of view, IgG antibodies have been extensively studied, perhaps because of the dominant role they play in a mature immune response. Polyclonal antibodies are produced according to standard methods by immunisation of an animal with the appropriate antigen. In response, the animal will produce antibodies which are polyclonal. However, for many purposes, it is desired to have a single clone of a certain antibody, known as monoclonal antibodies. Monoclonal antibodies (MAbs) are produced by hybrid or fused cells comprised of a fusion between a normal B-cell, which produces only a single antibody, to an abnormal myeloma tumour cell. The resulting hybrid, known as a hybridoma, is these days used in standard methods for the production of antibodies.
The biological activity that the immunoglobulins possess is today exploited in a range of different applications in the human and veterinary diagnostic, health care and therapeutic sector. In fact, in the last few years, monoclonal antibodies and recombinant antibody constructs have become the largest class of proteins currently investigated in clinical trials and receiving FDA approval as therapeutics and diagnostics. Complementary to expression systems and production strategies, efficient purification protocols are required to obtain highly pure antibodies in a simple and cost-efficient manner.
Traditional methods for isolation of immunoglobulins are based on selective reversible precipitation of the protein fraction comprising the immunoglobulins while leaving other groups of proteins in solution. Typical precipitation agents are ethanol, polyethylene glycol, lyotropic salts such as ammonium sulphate and potassium phosphate, and caprylic acid. Typically, these precipitation methods are giving very impure products while at the same time being time consuming and laborious. Furthermore, the addition of the precipitating agent to the raw material makes it difficult to use the supernatant for other purposes and creates a disposal problem, which is particularly relevant when speaking of large-scale purification of immunoglobulins.
An alternative method for isolation of immunoglobulins is chromatography, which embraces a family of closely related separation methods. The feature distinguishing chromatography from most other physical and chemical methods of separation is that two mutually immiscible phases are brought into contact wherein one phase is stationary and the other mobile. The sample mixture, introduced into the mobile phase, undergoes a series of interactions with the stationary and mobile phases as it is being carried through the system by the mobile phase. Interactions exploit differences in the physical or chemical properties of the components in the sample. These differences govern the rate of migration of the individual components under the influence of a mobile phase moving through a column containing the stationary phase. Separated components emerge in the order of increasing interaction with the stationary phase. The least retarded component elutes first, the most strongly retained material elutes last. Separation is obtained when one component is retarded sufficiently to prevent overlap with the zone of an adjacent solute as sample components elute from the column. Efforts are continuously being made to design the optimal stationary phase for each specific separation purpose. Such a stationary phase is commonly comprised of a support or base matrix to which a ligand comprising functional i.e. binding groups has been attached. Reference is commonly made to each kind of chromatography based on the principle of interaction it utilises, such as ion-exchange chromatography, hydrophobic interaction chromatography and affinity chromatography.
Ion exchange chromatography is frequently used in protocols for the isolation of immunoglobulins. In anion exchange chromatography, negatively charged amino acid side chains of the immunoglobulin will interact with positively charged ligands of a chromatography matrix. In cation exchange chromatography on the other hand, positively charged amino acid side chains of the immunoglobulin will interact with negatively charged ligands of a chromatography matrix.
Hydrophobic interaction chromatography (HIC) is another method described and used in protocols for the isolation of immunoglobulins. If a highly pure immunoglobulin product is the object, it is commonly recommended to combine HIC with one or more further steps. In HIC, in order to make the immunoglobulin bind efficiently to the HIC matrix, addition of lyotropic salts to the mobile phase is required. The bound immunoglobulin is subsequently released from the matrix by lowering the concentration of lyotropic salt. Thus, a disadvantage of this procedure is the necessity to add lyotropic salt to the raw material, as this may cause problems and a consequently increased cost to the large-scale user. For example, for raw materials such as whey, plasma, and egg yolk, the addition of lyotropic salts to the raw materials would in many instances be prohibitive in large-scale applications, as the salt could prevent any economically feasible use of the immunoglobulin depleted raw material. An additional problem in large-scale applications would be the disposal of several thousand litres of waste.
Affinity chromatography is based on specific interactions between a target biomolecule and a biospecific ligand in a principle of lock-key recognition. Thus, the target and ligand will constitute an affinity pair, such as antigen/antibody, enzyme/receptor etc. Protein-based affinity ligands are well known, such as Protein A and Protein G affinity chromatography which are both widespread methods for isolation and purification of antibodies. It is well known that Protein A chromatography provides an outstanding specificity, particularly towards monoclonal antibodies, and consequently high purities are obtainable. Used in combination with ion exchange, hydrophobic interaction, hydroxyapatite and/or gel filtration steps, Protein A-based methods have become the antibody purification method of choice for many biopharmaceutical companies, see e.g. WO 8400773 and U.S. Pat. No. 5,151,350. However, due to the peptide bonds of the proteins, protein A matrices present a certain degree of alkaline sensitivity. In addition, when Protein A matrices are used to purify antibodies from cell culture media, proteases originating from the cells may cause leakage of Protein A, or peptide fragments thereof.
An attempt to reduce ligand leakage from affinity chromatography matrices has been is presented in WO 03/041859 (Boehlinger Ingelheim Pharma KG), wherein it is suggested to pretreat e.g. Protein A matrices with at least one surfactant to reduce ligand leakage. The affinity matrix may be treated e.g. with 5-15 bed volumes of surfactant. The contact time is crucial for the effectiveness of the process. For example, at room temperature, a contact time of at least 16 h is required for a reduction in leakage.
An alternative approach to the problem of ligand leakage from affinity chromatography matrices is provided in U.S. Pat. No. 4,983,722 (Miles Inc.), wherein Protein A is selectively isolated from a liquid containing antibody and Protein A by exposure thereof to an anion exchange material. Both components are adsorbed to the anion-exchange material, and the antibodies and Protein A are then sequentially eluted under conditions of increasing ionic strength. An illustrative anion exchanger is diethylaminoethyl (DEAE) Trisacryl M or DEAE Sepharose™.
WO 2004/076485 (Lonza Biologics Plc.) relates to antibody purification by Protein A and ion exchange chromatography. The ion exchange step comprises loading the antibody purified on Protein A on an ion exchange material under conditions which allow for the binding of Protein A and collecting the antibody in the flow-through. The anion exchanger is a quaternary amine-based anion exchanger, most preferably Sepharose™ Q (Amersham Biosciences, now GE Healthcare).
U.S. Pat. No. 5,429,746 (SmithKline Beecham Corp.) relates to a process wherein the antibody is first adsorbed to a Protein A chromatographic support and eluted; then adsorbed to a cation exchange chromatographic support and selectively eluted there from; and finally adsorbed to a HIC support and eluted. The mixture applied to the HIC column, following affinity and/or cation exchange chromatography, may contain immunoglobulin aggregates, misfolded species, host cell proteins and residue material from the affinity chromatography step.
U.S. Pat. No. 6,498,236 (Upfront Chromatography) is directed to specific problems caused by small differences in molecular weight between protein-based affinity ligands and target immunoglobulins. Thus, a method is disclosed for the isolation or purification of immunoglobulins from a solution, such as a hybridoma cell culture supernatant, animal plasma or ser, which method is suggested as an alternative to the use of Protein A, Protein G, synthetic peptides and other relatively high molecular weight ligands. The solid phase matrices used in the disclosed method are defined by the formula M-SP1-X-A-SP2-ACID, wherein M designates the matrix backbone, SP1 designates a spacer, X designates O, S or NH, A designates a mono- or bicyclic optionally substituted aromatic or heteroaromatic moiety, SP2 designates an optional spacer and ACID designates an acidic group. The specific substituents are stated to be decisive as to whether the matrix will be binding immunoglobulins efficiently.
U.S. Pat. No. 5,945,520 (Burton et al) discloses mixed mode chromatographic resins which exhibit a hydrophobic character at the pH of binding and a hydrophilic and/or electrostatic character at the pH of desorption. The resin is specifically designed to bind the target compound from an aqueous solution at both a low and high ionic strength. Thus, the adsorption step utilises HIC, while desorption is based on charge repulsion.
U.S. Pat. No. 6,702,943 (Johansson et al) discloses a method for removal of a target substance from a liquid by adsorption thereof to a matrix carrying a plurality of ligands comprising anion-exchanging groups and a hydrophobic structure. More specifically, the ligands contain an aromatic ring in the proximity of the positively charged anion-exchanging groups. It is stated that inclusion of other groups capable of electron donor-electron acceptor interactions may enhance the strength of the interaction between the substance and the adsorbent. The desired substances are stated to be cells, parts of cells and substances comprising peptide structures. The break-through capacity of the matrix is defined for reference proteins such as bovine serum albumin and IgG. The ligands disclosed are denoted "high salt ligands" due to their capability of adsorbing target substances at high concentrations of salt such as 0.25M NaCl.
Further, WO 01/38228 (Belew et al.) discloses another method for removal of a negatively charged substance from a liquid by binding thereof to a matrix that comprises mixed mode anion-exchanging ligands. Each ligand comprises a positively charged nitrogen and a thioether linkage at a distance of 1-7 atoms from said charged nitrogen. Similar to the above, the desired substances, such as cells, parts of cells and substances comprising peptide structures are adsorbed at salt concentrations in the region of 0.25M NaCl.
Ceramic hydroxyapatite has been suggested as useful for immunoglobulin polishing. More specifically, it has been reported (Chromatography, tech note 2849; S. G. Franklin, Bio-Rad Laboratories, Inc., 2000 Alfred Nobel Drive, Hercules, Calif. 94547 USA) that IgG1 can be resolved from an IgG1-Protein A complex in unfractionated media on CHT ceramic hydroxyapatite (Bio-Rad). More specifically, hydroxyapatite (Ca10(PO4)6(OH)2) is a form of calcium phosphate, which has been shown to possess unique separation properties. However, hydroxyapatite-based matrices are also known to involve certain disadvantages. For example, due to Ca-leakage, they are unstable at acidic pH values, and they are sensitive to chelating agents such as EDTA. In addition, it has been shown that it is difficult to develop, and to scale up, a robust and reproducible purification method using hydroxyapatite-based matrices, e.g. because it has been difficult to pack hydroxyapatite, and to maintain the performance in large columns. Finally, there is a risk of alterations of the resin properties caused by metal ion contamination and exchange of calcium ions, which alteration is a serious concern for regulatory authorities.
Johansson et al (Journal of Chromatography A, 1016 (2003) 21-33: "Preparation and characterization of prototypes for multi-modal separation media aimed for capture of negatively charged biomolecules at high salt conditions") describes screening of prototypes of multi-modal ligands for the capture of negatively charged proteins from high conductivity mobile phases. It was found that non-aromatic multi-modal anion-exchange ligands based on weak ion-exchange ligands (primary and secondary amines) were optimal for the capture of proteins by adsorption at high salt conditions.


A computing platform configured to (i) cause a client station to display, via a graphic user interface (“GUI”), a set of line items and a set of given attribute values that may be bulk associated with the line items, (ii) receive, from the client station, a request to activate a bulk association mode for bulk associating the line items with a given attribute value, (iii) cause the client station to display, via the GUI, a bulk association view indicating that the bulk association mode has been activated, the bulk association view comprising a target region for receiving user input comprising a selection of the line items to be bulk associated with the given attribute value, (iv) receive, from the client station, an indication that the user input has been received, and (v) based on the user input, update each respective line item with the given attribute value.

Software applications are used on a regular basis to perform and manage tasks in users' personal and professional capacities. As some examples, software applications may assist users with managing tasks related to email communications, customer relationship management, billing and payroll processing, human resources management, and construction management. Many other types of software applications exist.
Software applications handle a large volume of data and can be complex. It is therefore desirable for software applications to provide sophisticated features and tools which can enhance a user's ability to interact with the software application and the overall user experience. Thus, any tool that can improve a user's interaction with a software application is desired.

Computer system and method for bulk associating attribute values with data records


A double crystal monochromator including two identical, parallel crystals, each of which is cut such that the normal to the diffraction planes of interest makes an angle less than 90 degrees with the surface normal. Diffraction is symmetric, regardless of whether the crystals are symmetrically or asymmetrically cut, enabling operation of the monochromator with a fixed plane of diffraction. As a result of the inclination of the crystal surface, an incident beam has a footprint area which is elongated both vertically and horizontally when compared to that of the conventional monochromator, reducing the heat flux of the incident beam and enabling more efficient surface cooling. Because after inclination of the crystal only a fraction of thermal distortion lies in the diffraction plane, slope errors and the resultant misorientation of the diffracted beam are reduced.

This invention relates to an improved monochromator, and in particular, to a double crystal monochromator in which the surface plane of each of two crystal blocks is inclined with respect to diffraction planes of interest, and more particularly, in which each of two single crystals is cut such that the normal to the diffraction planes of interest makes an angle close to but less than 90 degrees with the crystal surface normal.
The high heat load associated with the powerful and concentrated x-ray beams generated by insertion devices in synchrotron radiation facilities is a very significant factor in the design of monochromators and other optical devices. For example, the undulator source on the Advanced Photon Source ring under construction at Argonne National Laboratory will generate up to 10,000 W of heat on an approximately 1 cm.sup.2 area of the first optics located approximately 24 m from the source. Peak normal flux will be as high as 500 W/mm.sup.2.
For x-ray beams with low to moderate total power and power density, the first of double crystal monochromators may be cooled to reduce the thermal distortions, for example, by pumping a coolant (e.g., water) through appropriately configured cooling channels in the crystal.
The combination of high total power and very high power density found in high power undulator beams is such that conventional cooling of the first crystal as described above is not sufficient to reduce to acceptable levels the high temperatures and resulting thermal strain and stress.
A number of monochromator system designs have been suggested. Broadly categorized, the purposes of these designs are: (a) to reduce the incident power on the first crystal, (b) to reduce the heat flux on the crystal, and (c) to reduce the undesirable misorientation of the diffracted beam due to thermal distortion in the diffraction planes.
Monochromators of type (a) above which are designed to reduce the power of the incident beam may, for example, use filters of the absorbing type (e.g., carbon filters) or use the reflecting properties of a mirror and/or the diffracting properties of a crystal. A transmission x-ray mirror will reflect unwanted low-energy photons while transmitting the desired x-ray pass energy along with all other x rays above the mirror's cutoff energy. (See further, Cowan et al., "Self-Filtering Crystal Monochromators for Synchrotron X Radiation", Rev.Sci.Instrum. (1989) 60(7), 1987).
One way to accomplish purpose (b) above, reducing the heat flux on the crystal, is to increase the area of the beam footprint on the crystal surface by using an asymmetrically cut crystal in which the Bragg diffracting crystal planes are no longer parallel to the surface of the crystal, but make an angle ("cut angle") with the surface. Because the angle of incidence and the angle of exit relative to the surface are unequal, diffraction is also said to be asymmetric. Cutting an asymmetric crystal such that the angle of the diffracting planes relative to the surface is slightly less than the Bragg angle will make the angle of incidence small and the resultant footprint area of the beam on the surface relatively large. (See further, Evans et al., "A `Parallel-Beam` Concentrating Monochromator for X-Rays," Acta Cryst., 1,124, 1948). However, the range in which the monochromator may be tuned is then restricted because the beam must impinge at angles larger than the critical angle for total reflection, where a crystal acts more or less as a mirror. It is possible to tune such a monochromator, however, by rotating the crystal around the surface normal. One disadvantage here is that the position of the footprint on the crystal changes, which, for example, complicates the task of cooling the crystal.
The inclined monochromator of the present invention avoids the problems of asymmetric diffraction while successfully achieving both purposes (b) and (c) above. In addition, it can utilize thermal filters referred to above in (a).
In the inclined monochromator, crystal blocks are cut such that the normal to the diffraction planes of interest makes a prescribed "inclination" angle with the crystal surface normal. For the inclined crystal, both the incident and diffracted beams make the same angle with respect to the surface normal, and, therefore, diffraction is symmetric. Because of the multiplicity of diffraction planes in a crystal, a conventional (symmetrically cut) crystal may be inclined from its conventional setup for the same effect although one is restricted to only a few preset inclination angles. In such cases, diffraction is symmetric regardless of whether the crystal is symmetrically or asymmetrically cut. For example, in a symmetrically cut (111) silcon crystal, there are other (111) planes that are at 70.5 inclination angle with respect to the surface.
The advantages of the inclined monochromator are significant. Using the inclined monochromator the incident beam is spread both vertically and horizontally on the first crystal, providing a larger footprint area and thus reduced heat flux when compared to the conventional monochromator. Because the planes of diffraction are chosen apriori, the monochromator can be operated in a manner identical to that for the conventional monochromator, and the tuning range is practically similar to that of a conventional crystal; Bragg angles at high energies become quite small in both cases, but the critical angle for total external reflection is not reached. An additional, overriding advantage of the inclined monochromator for high heat load applications is that because there is an angle between the surface normal and the diffraction planes only a fraction of the thermal distortion will lie in the diffraction planes, significantly reducing undesirable misorientation of the diffracting planes and thus the diffracting rays from the first crystal of the double-crystal monochromator system.
It is therefore a primary object of this invention to provide a crystal monochromator which under the high heat load associated with recently developed and developing x-ray beams has an acceptable and optimal performance, as measured by the fraction of photons in the desired energy bandwidth that is diffracted from the double-crystal monochromator system and reaches the users' sample.
In the accomplishment of the foregoing object, it is another important object of this invention to provide a monochromator which may be operated with a fixed plane of symmetric diffraction, without sacrificing tunability.
It is another important object of this invention to provide a monochromator which when compared to the conventional monochromator decreases the incident heat flux of the beam by spreading it over a greater area of the crystal surface.
It is a further object of this invention to present a crystal monochromator in which undesirable misorientation of the diffracted rays from the first crystal is reduced by reducing thermal distortion in the diffraction planes.
A yet further object of the present invention is to present an inclined diffraction crystal which provides for a more efficient cooling by spreading the footprint of the incident beam horizontally, so that the footprint becomes very elongated and narrow, and easily cooled, a significant advantage particularly for cryogenic cooling.
Additional objects, advantages and novel features of the invention will become apparent to those skilled in the art upon examination of the following and by practice of the invention.

Inclined monochromator for high heat-load synchrotron x-ray radiation

The United States of America as represented by the United States Department of Energy


An embodiment of a geiger-mode avalanche photodiode includes: a body of semiconductor material, having a first surface and a second surface; a cathode region of a first type of conductivity, which extends within the body; and an anode region of a second type of conductivity, which extends within the cathode region and faces the first surface, the anode and cathode regions defining a junction. The anode region includes at least two subregions, which extend at a distance apart within the cathode region starting from the first surface, and delimit at least one gap housing a portion of the cathode region, the maximum width of the gap and the levels of doping of the two subregions and of the cathode region being such that, by biasing the junction at a breakdown voltage, a first depleted region occupies completely the portion of the cathode region within the gap.

As is known, in the technical field of photon detection, the need is felt to have devices that enable detection of electromagnetic radiation with a high sensitivity, and hence that enable detection of even a limited number, of photons associated with the electromagnetic radiation itself.
For this purpose, the so-called "geiger-mode avalanche photodiodes" (GM-APDs) are known, which theoretically enable detection of individual photons.
A geiger-mode avalanche photodiode, also known as single-photon avalanche diode (SPAD), is formed by an avalanche photodiode (APD), and hence comprises a junction made of semiconductor material, which has a breakdown voltage VB and is biased, in use, with a reverse-biasing voltage VA higher in absolute value than the breakdown voltage VB of the junction (which, as is known, depends upon the semiconductor material and upon the level of doping of the least doped region of the junction itself), typically higher than 10-20%. In this way, the junction has a particularly extensive depleted region, present in which is a non-negligible electrical field. Hence, the generation of a single electron-hole pair, caused by absorption within the depleted region of a photon incident on the SPAD within the depleted region, may be sufficient to trigger an ionization process. The ionization process in turn causes an avalanche multiplication of the carriers, with gains in the region of 106, and consequent generation in short times (hundreds of picoseconds) of the so-called avalanche current, or more precisely of a pulse of the avalanche current.
The avalanche current may be appropriately collected, typically by means of external circuitry coupled to the junction, for example by appropriate anode and cathode contacts, and represents an output signal of the SPAD, also referred to as "output current". In practice, in principle, for each photon absorbed, a pulse of the output current of the SPAD is generated.
It is noted that, strictly speaking, present across the junction is an effective voltage Ve, which coincides with the reverse-biasing voltage VA only in the absence of photons. In fact, in the presence of photons, and hence of current generated within the SPAD, the effective voltage Ve across the junction is less, in absolute value, than the reverse-biasing voltage VA. However, in the present document it is assumed, except where otherwise explicitly stated, that the effective voltage Ve across the junction coincides with the reverse-biasing voltage VA.
It is likewise noted that, upon generation of the output current, or rather of corresponding pulses of the output current, there may concur not only both of the carriers of each electron-hole pair that has been generated following absorption of a photon within the depleted region, but also, given the reverse biasing of the junction, the minority carriers of the electron-hole pairs that have been generated following absorption of a photon outside the depleted region, hence in a quasi-neutral region, i.e., with a substantially zero electrical field. For example, assuming a junction of a PN type with the P region set, with respect to the direction of propagation of the photons, upstream of the N region, both the electrons of the electron-hole pairs generated in the non-depleted portion of the P region of the junction (also known as "dead layer") and the holes of the electron-hole pairs generated in the non-depleted portion of the N region of the junction (generally known as "epilayer") may contribute to the output current.
In particular, the aforementioned minority carriers may cause generation of corresponding output current pulses in the case where they manage to diffuse as far as the depleted region before recombining.
However, even though they may also contribute to photon detection, the minority carriers of the electron-hole pairs that have been generated outside the depleted region typically require, in order to be able to reach the depleted region, diffusion times ranging (according to the generation point and the level of doping) between hundreds of picoseconds and tens of nanoseconds; therefore, they may hence be collected at the anode and cathode terminals with considerable delays. In this way, a deterioration of the performance of the SPADs may occur, in terms of rapidity in generation of an output current pulse following absorption of a photon, i.e., in terms of the so-called response time (timing) of the SPAD. In particular, the generation, in the output current, of so-called "diffusion tails" may occur.
That the reverse-biasing voltage VA is appreciably higher than the breakdown voltage VB causes the avalanche-ionization process, once triggered, to be self-sustaining. Consequently, once triggered, the SPAD is no longer able to detect photons, with the result that, in the absence of appropriate remedies, the SPADs described manage to detect arrival of a first photon, but not arrival of subsequent photons.
In order to be able also to detect these subsequent photons, it is necessary to quench the avalanche current generated within the SPAD, stopping the avalanche-ionization process, and in particular lowering, for a period of time known as "hold-off time", the effective voltage Ve across the junction, so as to inhibit the ionization process and quench the avalanche current, as described hereinafter. Next, the initial conditions of biasing of the junction are restored, in such a way that the SPAD is again able to detect photons. In order to reduce the effective voltage Ve across the junction after absorption of a photon, SPADs may adopt so-called "quenching circuits", either of an active or passive type. In particular, in the case of quenching circuits of a passive type, it is common to use quenching resistors, as described for example in United States Patent Applications Publication Nos.: US2010/0271108 and US2010/0148040, which are incorporated by reference.
As is known, the gain and probability of detecting a photon, i.e., the sensitivity of the SPAD, are directly proportional to the value of the reverse-biasing voltage VA applied to the SPAD. In fact, the more the reverse-biasing voltage VA exceeds, in absolute value, the breakdown voltage VB, the higher the probability of occurrence of an avalanche generation of charge carriers, given that it entails a widening of the depleted region and of the electrical field present therein.
However, high reverse biasing voltages VA are such that, even in the absence of incident photons (a dark condition), a single charge carrier, generated, for example, by transfer of thermal energy, may be sufficient to trigger the avalanche-ionization process, generating a so-called "dark current", which may adversely interfere with normal use of the SPAD.
In particular, the generation of dark current may occur not only in the case where the aforementioned thermally generated carrier is generated within the depleted region, but also in the case where this thermally generated carrier is generated outside the depleted region and manages in any case to diffuse until it reaches the depleted region before recombining. In particular, given the reverse biasing of the junction of the SPAD, in addition to all the carriers generated thermally in the depleted region of the junction, also the minority carriers generated thermally outside the depleted region may contribute to the dark current, these latter minority carriers only in the aforesaid case where they manage to diffuse as far as the depleted region.
In practice, each of the aforementioned thermally generated minority carriers may generate a corresponding output current pulse, to which there does not correspond an effective detection of a photon. Under dark conditions, these output current pulses have a Poisson statistic, and the corresponding statistical mean value is known as "dark count rate" or "dark-noise rate".
From a quantitative standpoint, the performance of a generic SPAD is quantified through the so-called quantum-detection efficiency (QDE), which is defined as the ratio between a first number of photons detected equal to the difference between the mean number of photons detected per unit time and the mean dark noise rate in said unit time, and a second number equal to the mean number of photons that effectively impinge on the SPAD in said unit time.
In greater detail, the quantum-detection efficiency QDE is equal to the product of a photon-absorption efficiency n and of an avalanche-triggering probability, the latter being defined as the probability of an electron-hole pair generated in the depletion region effectively triggering a self-sustaining avalanche-ionization process; in particular, this probability is not equal to unity, because there is a non-negligible probability of the carriers of the pair losing energy on account of lattice scattering, thus recombining in such a way that the avalanche-ionization process aborts.
As regards the photon-absorption efficiency η, to a first approximation (neglecting the contributions of the aforementioned minority carriers) it is given byη=(1−R)·e−αD·(1−e−αW)  (1)where: α is a coefficient of absorption of the photons by the semiconductor that forms the generic SPAD, and is inversely proportional to the wavelength of the photons; R is a power-reflection coefficient of an air-semiconductor interface or else an air-dielectric interface in the case where the photons, before impinging on the junction, impinge on one or more anti-reflection dielectric layers; W is the thickness of the depleted region; and D is the thickness of the non-depleted portion of the region of the junction that is located upstream with respect to the direction of propagation of the photons (in practice, the dead layer, i.e., the portion of semiconductor that the photons traverse before reaching the depleted region).
In order to improve the performance of SPADs, and in particular in order to optimize the signal-to-noise ratio, i.e., the ratio between an effective output current, which derives just from the absorption of photons, and the dark current, it is hence expedient to limit as much as possible the lattice defectiveness of the SPADs themselves. In fact, the main contribution to the dark count rate is given by the so-called phenomenon of Shockley-Read-Hall (SRH) generation through the so-called generation-recombination (G-R) centers, which are located within the forbidden band of the semiconductor material that forms the junction of the SPAD and are caused by lattice imperfections. By reducing the dark count rate, the duration of the so-called quiescence interval, i.e., the mean time interval that elapses between two successive output current pulses (in conditions of dark), increases. Given that, during the quiescence interval, it is possible to detect correctly arrival of the photons, the lower the dark count rate, the higher the probability of absorbing photons and of triggering the avalanche-ionization process, thus improving the overall performance of the SPADs in terms of signal-to-noise ratio. In this connection, given the same dark count rate, the signal-to-noise ratio may, be improved by increasing the quantum-detection efficiency QDE.
Traditionally, the junctions of SPADs of a known type are formed by means of direct ion-implantation processes, which entail the inevitable introduction of lattice imperfections, notwithstanding the execution of subsequent thermal treatments for the annealing of the defects and deactivation of the impurities.
In addition, principally on account of the aforementioned thermal treatments, the SPADs have respective junctions such that the corresponding dead layers have non-negligible thicknesses (up to a few hundreds of nanometers), with consequent decrease in the quantum-detection efficiency QDE, and hence decrease in the signal-to-noise ratio, in particular as regards highly energetic photons (for example, photons in the so-called "blue-near ultraviolet"). Again, the presence of dead layers with non-negligible thicknesses entails non-negligible dark currents, as well as possible deterioration in the performance in terms of response times, on account of the generation of diffusion tails.
Similar considerations may be made for the so-called SPAD arrays, and in particular for the so-called "silicon photomultipliers" (SiPMs), used to improve the performance that may be obtained with individual SPADs.
In detail, an SiPM is a particular SPAD array, formed by an array of SPADs grown on one and the same substrate and provided with respective quenching resistors (for example, of a vertical type) integrated in the SPADs, these quenching resistors being uncoupled and independent of one another. In addition, the anode and cathode contacts of each SPAD are configured so that they may be coupled to a single voltage generator. Consequently, the SPADs of the SiPM may be biased at one and the same reverse-biasing′ voltage VA; in addition, the avalanche currents generated inside them are multiplexed together so as to generate an output signal of the SiPM equal to the summation of the output signals of the SPADs.
In practice, the SiPM is a device with a wide area and high gain, capable of supplying, on average, an electrical output signal (current) proportional to the number of photons that impinge on the SiPM; however, SiPMs may present the same drawbacks as do the SPADs that compose them.

This patent is subject to a terminal disclaimer.

Geiger-mode avalanche photodiode with high signal-to-noise ratio, and corresponding manufacturing process


A method of fixedly supporting a biopsy specimen in an embedding cassette in a process for embedding a biopsy specimen sampled from the human body by a doctor for microscopic inspection, which method comprises putting the specimen in the cassette, pouring a fixedly supporting agent into the space surrounding the specimen to embed the specimen therein, and gelling the supporting agent in this state by immersing the same in a solution of a mannan gelating agent. The supporting agent to be used here is one obtained by dissolving purified mannan powder in a solvent prepared by adding an antiseptic to water. The embedding cassette to be used here comprises a lid and a container. The central portion of a flat frame is caused to protrude toward one side thereof to form a flat container. At least either the lid or the bottom of the container is formed of a transparent porous plate. A protruding edge is formed along the circumference of the opening of the container, the edge protruding toward the other side of the flat frame, and through holes communicating with both sides are formed in the flat frame in the periphery of the container.

Conventionally, when engaged in a work necessary to achieve the object as described above, the clinician places a biopsy specimen into a flat cassette with a lid made of an opaque porous plate, closes the lid, puts the cassette into a capsule where an antiseptic agent has been placed that prevents the specimen from degrading, and sends the capsule to a pathological laboratory for inspection.
In the pathological laboratory, the tester takes out the embedding cassette from the capsule, opens the lid of the cassette, and compares the biopsy specimen therein with the description on a bill attached to the specimen, to confirm that the specimen properly coincides with the description. Then, he places again the specimen into the cassette, puts it in a vessel containing alcohol or xylene, and submits it to processes comprising dehydration, removal of fat, removal of alcohol, and immersing it in an embedding agent consisting of paraffin or a resin in succession.
Then, the tester opens the lid of the embedding container, picks up the biopsy specimen directly with a pair of forceps, and transfers it to another embedding plate prepared in advance. He places the bottom of the embedding cassette which is made of a porous plate above the biopsy specimen placed on the embedding plate, with some spacing there between, and pours an embedding agent consisting of molten paraffin or resin over the bottom, to embed the biopsy specimen together with a part of the embedding cassette with the embedding agent. In this state, the embedding agent is allowed to cool so that the biopsy specimen embedded together with the part of the embedding cassette in the embedding agent is hardened to form an embedded block.
Then, the pathologist cuts the biopsy specimen kept in the embedded block with a microtome together with the embedding agent, into thin sections, and examines them with a microscope.
The above described processes employing the conventional embedding cassette have following problems which remain to be improved.
Firstly, during embedding operation, the biopsy specimen is picked up directly with forceps before it is transferred to the embedding plate. This operation may distort the specimen locally by pressure, and inflict damages thereupon, which may interfere with proper treatment of the specimen for laboratory inspection.
Secondarily, if a plurality of specimens are placed in the embedding cassette in the order of sampling or according to sampled sites, they may be placed in a different arrangement from the original one by accident when they are transferred to a separate embedding plate. Further, while they are transferred to a separate embedding plate, they may be wrongly intermingled with biopsy specimens from a different embedding cassette, or some of them may be exchanged for wrong specimens from a different cassette. If such wrong operations happen, they would bring a grave effect on the results of microscopic inspection which takes place following the transference.
Thirdly, after being embedded, a part of the biopsy specimen necessary for inspection is cut by the pathologist with a microtome into thin sections which are then observed by microscopy. However, as the technician who is responsible for embedding the biopsy specimen and the pathologist are generally different persons, the technician finds it difficult to locate the part of the specimen which the pathologist would desire to inspect, and thus finds it difficult to place the biopsy specimen on the embedding plate so as to allow the pathologist to cut the desired part thereof with a microtome. In short, with the conventional method it is very difficult for the pathologist to cut rightly the part of the specimen necessary for inspection into thin sections.
Fourthly, each time the tester compares the biopsy specimen with the description on a bill attached thereto in the embedding cassette, he must open the lid of the cassette. This confirmation work requires a considerable time. In addition, when the lid is opened, the biopsy specimen may fall by accident from the cassette.
Fifthly, as the embedding cassette is partly composed of a porous plate, the biopsy specimen may be lost by flowing through a pore, when it is sufficiently small to pass through the pore.
As the sixth problem, the embedded block requires a certain thickness because it must withstand the pressure from the cutting edge of a microtome, when cut into thin sections. In a big hospital or laboratory a vast number of waste blocks are produced, and to make the most of the space necessary for their storage, they are laid one over the other. For them to be laid one over the other neatly, they should be made as thin as possible.
The first object of this invention is to dispense with the use of forceps or other mechanical means which, in conventional methods, are used to transfer a biopsy specimen to an embedding plate, and thereby to protect the specimen from distortion by pressure which may lead to local damages.
The second object is to prevent a plurality of biopsy specimens which are placed properly in an embedding cassette from being placed in a different arrangement from the original one when they are transferred to a separate embedding plate, or from being confounded with other wrong biopsy specimens.
The third object is to permit the pathologist to cut properly a part of biopsy specimen necessary for inspection into thin sections, and thereby to make a proper inspection on them.
The fourth object is to facilitate the work involved in conforming that the biopsy specimen placed in an embedding cassette corresponds rightly with the description on a bill attached to the specimen, and further to prevent the specimen from being lost by accident during this confirmation work.
The fifth object is to prevent the biopsy specimen from flowing through a pore of the porous plate of an embedding cassette.
The sixth object is to reduce the thickness of an embedded block while maintaining its mechanical strength.

Method of fixedly supporting biopsy specimen and embedding cassette