New device and method are described for accurate etching and removal of thin layer by controlling the surface residence time, thickness and composition of reactant containing film. Etching of silicon dioxide at low pressure using a quartz crystal microbalance is illustrated. Usefulness of the invention in the manufacture of microelectronic devices is shown.

Aqueous solutions of etchants have long been used to remove thin films from substrates. However, there are a number of disadvantages of wet etching techniques. These disadvantages are especially apparent in the semiconductor industry where wet cleans and etches contribute to particulate and other contamination. Therefore, processes that use gaseous etchants are preferred.
Another undesirable feature of both wet and gaseous etches is that generally the etching is isotropic, and a controlled source of etchant designed for removal of thin layers is not used. Often, only a precise amount of the layer should be etched because there are features that need to be retained without damage. For instance, uncontrolled isotropic etching contributes to the formation of undesirable gaps when the material to be etched is sandwiched between two layers which are resistant to etching. For instance, as shown in FIG. 1, layer 1 and substrate 3 are resistant to etching and layer 2 is readily etched by the isotropic etching process. If an opening is created in layer 1, then isotropic etching of layer 2 produces a gap 4 in layer 2 underneath the opening in layer 1. It is clear, therefore, that what is needed is a controlled etching system which is able to etch the precise thickness of the layer of interest without overetching and accentuating the gap between unetched layers.
One of the most important cleaning and etching steps in the semiconductor industry is to remove native oxide from the surface of silicon. Oxide etching by immersion in aqueous solutions containing HF can yield pristine Si surfaces chemically passivated by hydrogen atom termination of silicon dangling bonds. Chemical passivation reduces reoxidation of silicon upon exposure to air, but it does not reduce contamination by particulates or large organic molecules. Integration of an aqueous silicon dioxide removal process with an evacuated, multichamber wafer processing tool designed to minimize particulate contamination is difficult. Hence, a process that takes place in the gas phase at low pressure, instead of in a liquid, is needed.
Silicon dioxide has been successfully etched or removed from the surface of a silicon wafer by a number of methods that do not use aqueous solutions and which take place with medium or low pressures of reactive molecules or ions. Examples include reactive ion etching (RIE), and heating the wafer to 900.degree. C. temperature for the reaction Si(s)+SiO.sub.2 (s)=SiO(g).sub.4. However, these techniques do not etch by reacting with the layer of material to be etched and a condensed film containing the reactant molecules. Therefore, they are not considered prior art and will not be discussed.
Prior art generally concerns reactions where films are present on a surface during reaction. Some art does not recognize the existence of films on the surface. Other art recognizes the existence of films and the role they play in etching, but does not recognize the importance of the films, nor how to properly control them. Inaccuracy and lack of control in the prior art often arise when there is inadvertent transition between regimes, as described herein infra.
In etching of silicon dioxide, prior art has reported different etch rates for TEOS, thermal silicon dioxide, and other types of silicon dioxide. The rate is limited by the reactivity of the reactant toward silicon dioxide. The reactivity varies according to structural and compositional differences in the silicon dioxide. The rate of passage of reactant through a film did not limit the rate of reaction with these oxides.
U.S. Pat. No. 4,264,374 to Beyer and Kastl discloses a way to use gaseous vapor to remove native oxide from silicon. Oxide etching by exposure to gaseous mixtures of HF, H.sub.2 O, and N.sub.2 near atmospheric pressure has very high selectivity for removal of silicon dioxide without removing silicon. As the pressure of a process increases, problems from contamination by particulates and gaseous impurities increase. Hence, a lower pressure process is needed.
The equipment described by Deal et. al (J. Appl. Phys. 36:3370, 1965) and Novak (Solid State Technology, 31:39, 1988) is currently available and is designed to etch oxide layers using gaseous mixtures containing HF and H.sub.2 O. However, the equipment is not designed to control the surface residence time, the thickness or composition of condensed films in the etching system. An inert gas is bubbled through water or through a solution of HF in water in a container called a bubbler. The pressure of water vapor or HF and water vapor entrained in the inert gas is equal to the vapor pressure at the temperature of the bubbler. Flow controllers regulate admission of the gases into an unheated chamber holding the substrate. The bubblers and gas lines are heated. In equipment described by Deal et al supra, the substrate can be heated, and the total pressure can be regulated by altering the pumping speed of the system. There is no quartz crystal microbalance in the system, and the substrate cannot be cooled. Etching is restricted to high chamber pressures. It is a flow system with no capability to isolate the reaction chamber from the vacuum pump.
Another method for removing oxide is mentioned by Nishino et al (Proceedings of the Symposium on Dry Process, Inst. of Elec. Eng. of Japan, Tokyo, Oct. 30, 1989, p. 90) in a report on microwave discharge cleaning of silicon. Exposure of silicon covered with a native oxide to gases from a heated container filled with ammonium fluoride or to a microwave discharge in NH.sub.3 and NF.sub.3 gas followed by raising the temperature of the silicon can remove the oxide. In a separate experiment, HF and sulfuric acid were formed following activation of precursor molecules in a discharge. Nishino et al does not deal with the type of gap illustrated in FIG. 1, nor with any other undesired effect induced by overetching, etc.
In summary, prior art apparatus for etching with condensed films containing reactant is not designed to control the composition and residence time of the film. The following items are missing in prior art equipments: a monitor of thin films such as a microbalance, a means to maintain the wafer as the coldest point in the chamber, separate gaseous sources of NH.sub.3 and HF, sources of NH.sub.3, H.sub.2 O, and HF, an ammonium bifluoride source, and low pressure sources such as effusion cells, or sources with a differentially pumped region, there is no ability to maintain the chamber wall temperature above the temperature of any reactant source which is a condensed liquid or solid, the vacuum pump cannot be isolated from the chamber, and there is no ability to simultaneously open/shutoff valves between gas sources and chambers.
The design of the prior art etching systems is necessarily dependent on the devices and methodologies known at the time and can be understood by considering the design of available systems, such as reactive ion etching systems, used for etching a surface when the reactant does not condense on the surface. The rate at which reactant strikes the surface to be etched is proportional to the pressure of the reactant in the chamber. As long as the reactant pressure is below its vapor pressure at the temperature of the substrate, reactant may adsorb on the surface for a short period of time, but is does not condense to form a multilayer. The pressure of reactant, and therefore the reaction rate, is controlled by varying the rate at which the reactant is admitted to the chamber and the rate at which the reactant is removed from the chamber, e.g., by the pump attached to the chamber. The admission rate of reactant to the chamber can be regulated with a flow meter. This type of equipment is also used in the prior art to carry out reactions when the reactant condenses on the surface of the substrate to be etched even though initiation and control of the reaction is very different when a condensed reactant film forms on the surface to be etched. The differences are more fully set forth below.
When a condensed reactant film forms on the surface, the composition of the condensed film is more important than the composition of the gas phase. The partial pressure of reactant in the gas phase is not as important because the gaseous reactant is not in direct contact with the surface to be etched. Instead, the condensed reactant film is in contact with the surface, and therefore the composition of the condensed reactant film is more important than the composition of the gaseous ambient in determining how fast the surface will be etched, and how much of the surface will be etched. The composition of the gas affects the reaction only indirectly as gaseous reactants are transported through the condensed film to the surface. A central problem is that condensed multilayer films can form on surfaces other than the layer to be etched, such as chamber walls or areas of the wafer-mount which may be colder than the surface of the wafer. The layers that form on these extraneous surfaces can serve as a source or sink for reactant so that there is no longer a definable relationship between the composition and timing of gases admitted to the chamber and the composition and residence time of reactant layers on the surface of the wafer to be etched.
Deal et al, supra, mention the presence of an aqueous film on the surface of the oxide during vapor phase etching, but do not recognize the importance of controlling the film. Instead, the systems described by Deal and Novak use flowmeters to admit reactant to the chamber. Referring to FIG. 2a, the operation of the prior art equipment may be described as follows: nitrogen from reservoir A passes through mass flow controllers B and into a bubbler C containing water or bubbler D containing a mixture of HF and water. After passing through the bubbler, the gas enters chamber E where a wafer F is mounted on a room temperature holder G. In some equipment, the gas and reaction products pass from chamber E through a regulating valve H before being pumped away.
Although suitable for etching reactions not involving a layer of condensed reactant, this system can cause difficulty in any reaction which occurs when condensed reactant forms on the surface of the layer to be etched. When a flowmeter admits gas to a chamber at a constant rate, the pressure rises slowly until the pressure is high enough for the chamber vacuum pump to remove the gas at the same rate at which it is admitted to the chamber. This slow pressure rise contributes to an ambiguous onset time for condensation, an indefinite film thickness and an ambiguous composition.
The formation of a film on a surface from constituents in the gas phase is known to be regulated by the temperature of the surface and the partial pressures of the gaseous constituents. Once the partial pressure of the gaseous constituents rises to a value equal to or greater than the vapor pressure, a condensed film will form. If the pressure rise is slow, the onset time for condensation is ambiguous. Once condensation begins, the partial pressure of the gaseous constituents of the film will remain equal to the vapor pressure of the constituents. Condensation continues, and the thickness of the condensed film increases because the system pump is unable to remove the constituents of the film at the same rate at which they are admitted.
Control of the extent of film removal by the apparatus described by Deal et. al. and by Novak, supra, is therefore difficult. Since a flow controller is used, the partial pressures of water and HF in the chamber rise slowly after initiation of flow. Thus, the time at which the condensation occurs and the reaction is initiated is not well defined. The thickness of the film increases with time. The composition of the gas above the film will change with time in a complex fashion because as the reaction proceeds (SiO.sub.2 +4HF=SiF.sub.4 +2H.sub.2 O), HF is consumed and H.sub.2 O is produced as a byproduct. Thus, the surface area of oxide being etched can affect the gaseous composition. Finally, condensation on the walls of the chamber serves as an additional unpredictable source or sink for HF because the gaseous HF will exchange with HF in the condensed film on the walls of the chamber.
Exchange of constituents in the gas with constituents in the condensed film can be understood by referring to FIG. 2b from p. 148 of Physical Chemistry by Farrington Daniels and Robert Alberty, 3rd ed. 1966, Wiley, N.Y. It shows how the equilibrium composition of the vapor of a two component mixture of benzene and toluene varies from the composition of the liquid as a function of temperature. Similar curves hold for all binary mixtures including HF/H.sub.2 O. The x axis shows the fractional composition of the mixture and the y axis shows the temperature. If vapor is admitted to a chamber with the composition of point b, it will condense on an object whose temperature is below about 94.degree. C. The composition of the vapor, represented by point d, is very different than the composition of the liquid represented by point c. In other words, as soon as condensation occurs, re-evaporation will alter the composition of both the condensed film and the gas phase.
The exact details of how these compositions change with time will have a complex dependence on the absolute and relative amount of condensed film on the walls and on the substrate, flow rates, absolute pressures etc. The absolute amount and relative amount of condensed film on the walls of the chamber and on the substrate will also depend on the ambient temperature and on the temperature difference between the substrate and the chamber. The actual curve for HF/H.sub.2 O binary mixtures shows the existence of an azeotrope. Azeotropes are certain fractional compositions of a binary mixture where the vapor, and liquid in equilibrium with the vapor, have the same composition. Although Deal et. al. mention use of the azeotrope in a bubbler as a supply of HF and water, they combine this with a bubbler containing water so that the gaseous composition inside the chamber is not the composition of the azeotrope.
U.S. Pat. No. 5,030,319 to Nishino et. al. provides an understanding of etching mechanisms where films that contain reactant are used for etching. However, the etching apparatus and method are in some ways more difficult to use despite an improved understanding of the films. For instance, a flow system is used to admit gases with all the potential problems mentioned above. In addition, reactant is created through reaction of precursor molecules activated by a plasma discharge instead of direct admission of the reactant. The formation of condensed multilayer reactant films, therefore, depends not only on temperatures, flow rates, pumping speeds, etc.; but also on the characteristics of the discharge and the reaction of activated precursor molecules. Furthermore, reactive radicals or molecules in the gas phase can consume, react with, or chemically transform films on the wafer or walls.
The Nishino patent teaches that a discharge in NH3 and NF3 forms HF which can combine with ammonia to form ammonium fluoride layers that react with SiO.sub.2 to form an ammonium hexafluorosilicate product. Reaction can also occur by dissolution of reactant within the product layer. The results indicate that not all the silicon dioxide which reacts is left behind as a film on the surface of the oxide. FIG. 2 of the Nishino patent shows the etching rate and film thickness for a 10 minute etching time as a function of the NH3 to NF3 ratio. The etching rate of around 10-40 Angstroms/min corresponds to removal of 100 to 400 Angstroms of silicon dioxide. If all the reacted silicon dioxide were converted to ammonium hexafluorosilicate product resident on the surface, the thickness would be approximately 300 to 1200 Angstroms, far thicker than the film thicknesses shown in Nishino's FIG. 2. Some of the silicon from the reacted silicon dioxide does not remain resident on the surface in the form of ammonium hexafluorosilicate. When the product film is thin, it can be "broken away", but after continued etching it can no longer be "broken away" and etching is terminated. The termination thickness of etched oxide in FIG. 15 of Nishino patent is about 1000 Angstroms, a thickness far larger than needed to prevent undercut shown in FIG. 1 of this application. The decrease in etching efficiency is presented as a problem which can be remedied by alternating several short reaction and product desorption cycles instead of etching for one long period of time.
If a thin film is formed with a short 10 minute discharge, the film remains permeable to reactant, if hydrogen is substituted for ammonia in the discharge HF is formed and in fact the presence of the film increases the reaction rate. The film does not inhibit the reaction.
Nishino further teaches that radicals such as O.sub.2 and fluorine atoms in the discharge influence the reactions in several ways. They can affect the selectivity of etching silicon vs. silicon dioxide. When H.sub.2 SiO.sub.4 and HF are formed in the discharge, fluorine atoms are consumed within the condensed film when it is thick, but fluorine atoms are not consumed when the condensed film is thin. When the film is thin, silicon is etched; when the film is thick, silicon is not etched. These reactions can complicate controlled etching.
It may be further noted that any apparatus using a condensed source of reactant at a temperature hotter than the wafer surface is able to make a transformation between regimes. If reactant is admitted slowly, there is no reaction initially, because an adsorbed film does not form. As the pressure of reactant slowly increases to near the vapor pressure at the temperature of the wafer, then an adsorbed film can form which etches the surface. The adsorbed film composition is closely related to the composition of the gases in the chamber. When the pressure exceeds the vapor pressure of the material in the chamber, there is condensation of a multilayer. The multilayer forms a reservoir, especially if it is a liquid multilayer, the composition of which is no longer directly connected to the composition of the gases in the chamber. No prior art system is designed and operated to stay in the regime where an adsorbed film of a layer or less is responsible for etching.
Furthermore, constant slow rate admission of reactant with flow controllers to a chamber using apparatus mentioned in the prior art does not lead to accurate etching or removal of thin layers, because the composition and residence time of the reactant film is not controlled: e.g., the time at which a condensed film of reactant is formed on the surface is uncertain, the length of time condensed film remains on the surface is unknown, condensed film can form on the walls of the chamber or portions of the wafer mount which are colder than the wafer, the fraction of the reactant which is admitted to the chamber and eventually condenses and reacts is unknown, the substrate is not cooled sufficiently to facilitate use of a low pressure source, the self limiting reaction thickness of solid products is uncertain, a wafer is not held at or slightly above the temperature of a source of condensed reactant so that reaction can occur within the adsorbed film regime, and the presence of activated radicals or molecules can complicate the composition of films.
It is clear from the above that improvements in the prior art apparatus and method are needed.

Device and method for accurate etching and removal of thin film

International Business Machines Corporation


We have cloned and sequenced the cDNA encoding the 61 kD active fragment of a unique porcine chondrocyte nucleotide pyrophosphohydrolase (NTPPHase) from a porcine chondrocyte library. Degenerate oligonucleotides, corresponding to the N-terminal amino acid sequence of this peptide were hybridized to porcine chondrocyte cDNA and used to amplify DNA encoding the N-terminal sequence of 61 kD with the polymerase chain reaction (PCR). The PCR products were then used as probes to clone the entire open reading-frame for the 61 kD fragment from a porcine chondrocyte cDNA library. The length of the cloned cDNA was 2509 bp. Translation of the open-reading-frame predicts the 61 kD fragment to be a 459 amino acid protein. BLAST and FASTA analysis confirmed that this amino acid sequence was unique and did not possess high homology to any known proteins in the non-redundant protein data base. Limited homology (17%) between the 61 kD fragment and several prokaryotic and eukaryotic ATP pyrophosphate-lyase (adenylate cyclase) was detected. Northern blot analysis of porcine chondrocyte RNA showed that the DNA encoding the 61 kD fragment hybridized to a 4.3 kbp RNA transcript. Human chondrocyte RNA also hybridized to this porcine DNA probe. Coupled in vitro transcription translation of an expression vector containing the DNA insert in frame showed the expression of a 61 kD protein.

1. Field of the Invention
The present invention relates generally to the manipulation of genetic materials and particularly to the manufacture and use of specific DNA sequences useful in recombinant procedures to secure the production of peptides having one or more properties of nucleotide pyrophosphohydrolase.
2. Background of the Art
Calcium pyrophosphate dihydrate (CPPD) crystal deposition in human articular cartilage is a common age-dependent event often associated with degeneration of articular tissues and/or with acute attacks of arthritis (D. McCarty, et al., 56 Ann. Intern. Med. 711-737 (1962)). Prospects for preventing or reversing CPPD crystal deposition depends on a better understanding of inorganic pyrophosphate (PP.sub.i) metabolism in joint tissues. Synovial fluid PP.sub.i levels are nearly always greater than those of plasma and correlate directly with the degree of radiographically evident joint degeneration (L. Ryan, et al., In Arthritis and Allied Conditions, 12th ed., D. McCarty, et al., editors, pp. 1835-1855 (1993)). PP.sub.i is released into the ambient medium when cartilage slices or isolated chondrocytes but not other joint tissues are cultured in vitro, suggesting that this tissue is the source of synovial fluid PP.sub.i. Detergent extracts of CPPD crystal-encrusted degenerated cartilage contained increased nucleotide pyrophosphohydrolase (NTPPHase) activity relative to normal or degenerated cartilage without crystals (J. Tenenbaum, et al., 24 Arthritis Rheum. 294-300 (1981)). This enzyme generates PP.sub.i from ATP and other nucleotides. NTPPHase is an ectoenzyme in canine (L. Ryan, et al., 27 Arthritis Rheum. 404-409 (1984)) and in human (A. Caswell, et al., 847 Biochem. Biophys. Acta. 40-47 (1985)) chondrocytes. ATP levels were significantly higher in knee joint fluids containing CPPD crystals compared with fluids from osteoarthritis (217 vs. 98 nM) (L. Ryan, et al., 18 J. Rheumatol. 716-720 (1991)) despite higher activity of NTPPHase in the former (J. Rachow, et al., 28 Arthritis Rheum. 1283-1288 (1985)).
EctoNTPPHase activity is also associated with vesicles derived from chondrocytes in epiphyseal cartilage, termed matrix vesicles, and is thought by some investigators important for in vitro calcification (S. Siegal, et al., 258 J. Biol. Chem. 8601-8607 (1983); A. Caswell, et al., 924 Biochem. Biophys. Acta. 276-283 (1987)). Addition of ATP to vesicles isolated from adult porcine (B. Derfus, et al., 35 Arthritis Rheum. 231-240 (1992)) or human (L. Ryan, et al., 35 Arthritis Rheum. 1520-1525 (1992)) hyaline articular cartilage, termed articular cartilage vesicles (ACV), formed a mineral phase tentatively identified as monoclinic CPPD.
The inventors have noted an enzyme activity on the exterior of many cells which generates inorganic pyrophosphate (PP.sub.i), a necessary constituent of pathologic crystals which form in cartilages of patients with a specific form of arthritis termed calcium pyrophosphate dihydrate (CPPD) crystal deposition disease. The enzyme is called nucleotide pyrophosphohydrolase (NTPPH) because of one reaction which it catalyzes, the hydrolysis of nucleoside triphosphates such as ATP to a nucleoside monophosphate and PP.sub.i. This enzyme activity is very likely an important if not essential factor in the generation of PP.sub.i which then forms CPPD crystals.
There are many forms of NTPPH. One specific form has been characterized in our laboratory and is termed 127 kD NTPPH, based upon its molecular weight. Antibodies raised against porcine (pig) 127 kD NTPPH have been used to determine the tissue distribution, and 127 kD NTPPH was found only in tissues in or around joints. Within these articular tissues, 127 kD is most concentrated in cartilage. In chondrocytes, the cells of cartilage, 127 kD NTPPH is restricted to vesicles termed articular cartilage vesicles (ACV). These are important structures which can mineralize to form CPPD crystals when a substrate such as ATP is added. These are the only structures that have ever been found to serve as a nidus for CPPD formation and they are very enriched in the 127 kD enzyme.
The native 127 kD enzyme is attached to the membranes of these vesicles. However, antibody to 127 kD NTPPH also identifies putative breakdown fragments that are of lower molecular weight, that are soluble, and that still possess enzyme activity. These have been identified in the joint fluid surrounding cartilage and in the serum of humans, but not in tissues. In joint fluid and serum the activity of this enzyme has been found to be elevated in patients who have CPPD crystals in their cartilage and to a lesser degree in patients who have osteoarthritis.
It would be advantageous to clone cDNA encoding nucleotide pyrophosphohydrolase so that sufficient quantities of NTPPH can be generated for use in further studies and diagnostic testing.

Cloned nucleotide pyrophosphohydrolase and uses thereof


Provided is a substrate for forming a pattern comprising an inorganic layer having a modified surface, wherein the modified surface is formed by coating a surface of the inorganic layer with a bifunctional molecule comprising a functional group having an affinity for a nanocrystal at one end of the molecule and a functional group having an affinity for the inorganic layer at the other end of the molecule. A method for forming a pattern of nanocrystals is also provided.

1. Field of the Invention
The present invention relates to a substrate that can be used for the patterning of nanocrystals, and to a method for forming a pattern of nanocrystals using the substrate. More specifically, the substrate comprises an inorganic layer having a modified surface, wherein the modified surface is formed by coating a surface of the inorganic layer with a bifunctional molecule comprising a functional group having an affinity for a nanocrystal at one end of the molecule, and a functional group having an affinity for the inorganic layer at the other end of the molecule. A method for forming a pattern of nanocrystals using the substrate is also provided.
2. Description of the Related Art
A nanocrystal is a single crystal particle having a cross-section of only a few nanometers. Since a nanocrystal has a large surface area per unit volume, most of the constituent atoms of the nanocrystal are present on the surface of the nanocrystal. As a consequence of this characteristic structure, a nanocrystal exhibits quantum confinement effects and demonstrates electrical, magnetic, optical, chemical and mechanical properties that are substantially different from those inherent to the constituent atoms of the nanocrystal. In particular, semiconductor nanocrystals have high luminescence efficiency and a small half bandwidth within the photoluminescence ("PL") spectrum, making their use advantageous for application to light-emitting materials. As a result, semiconductor nanocrystals have received a great deal of attention for their potential use as materials for light-emitting layers of various electroluminescent ("EL") devices and display devices.
For example, a prior art electroluminescent device, as shown in FIG. 1A, may have a structure including a cathode 10, an electron transport layer 20, a nanocrystal light-emitting layer 30, a hole transport layer 40, and an anode 50, that are sequentially stacked on a substrate. Application of the nanocrystals as light-emitting layer materials for various display devices, as shown in FIG. 1B, shows that the nanocrystal light-emitting layer 30 be patterned into nanocrystal patterns that correspond to each red, green and blue ("RGB") wavelength. Furthermore, with the recent trend toward display devices of reduced size and weight, there is an increased demand for pattern miniaturization.
In an attempt to find techniques for forming a pattern of nanocrystals, studies have been conducted utilizing various methods that include ink-jet printing, a self-assembly method, and the like. However, recently a nanoimprinting lithography ("NIL") technique has attracted a great deal of interest across a variety of fields, including the semiconductor industry, as a promising ultra-fine patterning technique for use in nano-devices. Nanoimprinting lithography can transfer high-resolution fine patterns on a substrate through a low-cost and simple process, and therefore nanocrystal patterns can be formed in an inexpensive and effective manner.
Nanoimprinting lithography is a convenient method for forming patterns of nanocrystals by preparing a nanocrystal thin film on a patterned stamp and then repeatedly stamping the thus-formed thin film on the desired substrate. For example, according to the nanoimprinting method, patterned nanocrystal thin films can be formed on inorganic layers of inorganic electroluminescent (EL) devices. The nanocrystal thin films patterned according to the nanoimprinting lithography methods can be used for a wide variety of applications including inorganic EL devices, backlight units (BLU), nano-bio devices, and the like.
Research is currently ongoing to develop a method capable of more stably forming a desired pattern for use in nanoimprinting lithography. In this regard, the most important thing is to ensure the efficient transfer of nanocrystals, in a desired pattern, to the substrate. That is, if there is no strong attractive force between the nanocrystal thin film formed on a stamp, and the inorganic layer formed on the substrate, to which the nanocrystal thin film will be applied, the thin film is poorly transferred and remains on the stamp. Consequently, it is impossible to achieve transfer of a uniform nanocrystal pattern onto the substrate. Further, even when the nanocrystal thin film transfers sufficiently onto the substrate, it may be impossible to maintain the original uniform state of the thin film due to the separation of nanocrystals in subsequent post-treatment processes.
In an attempt to solve these problems, a method for modifying the surface of the stamp has been proposed. However, such a surface modification technique is problematic due to the high level of complexity involved.

Substrate for patterning and method for forming a pattern of nanocrystals using the same


A multifunctional telescopic monopolar/bipolar electrosurgery pencil is disclosed for use with an electrosurgery unit (ESU). The monopolar/bipolar electrosurgery pencil includes a bipolar electrode having an insulator sandwiched between an active electrode and a return electrode wherein the bipolar electrode is connected to a handpiece capable of alternately effectuating cutting and coagulation with the bipolar electrode. The monopolar/bipolar electrosurgery pencil is capable of functioning as both a monopolar and bipolar device and can be used for open and closed laparoscopic and endoscopic procedures. Telescopic means for adjusting the length of the bipolar electrode is also provided as are means for smoke evacuation and suction/irrigation. The multifunctional telescopic monopolar/bipolar device can also be adapted for use with an ESU argon beam coagulator.

In the past, electrosurgical devices had an active electrode that was used for performing cutting and coagulation, and a return electrode which usually comprised an adhesive for attachment to a patient's skin. When the electrosurgery unit surgery pencil was activated, the RF energy circulated from the active electrode to the return electrode through the patient's body with the distances between the active and return electrodes being fairly significant.
This prior art system presents several deficiencies and creates, a number of problems that can be dangerous for the patient. First, because of the significant distance between the active and return electrodes, high voltages at high frequencies are transversed through the body in order to close the circuit between the active and return electrodes. These high voltages and frequencies can be very dangerous to the patient. Second, due to the fact that the body has an electrical resistance, the cutting and coagulation affects are significantly diminished as the distance between the active and return electrodes is increased. Accordingly, high power from the ESU is needed in order to obtain effective cutting and coagulation performance. Again, the high power required from the ESU can be dangerous to the patient.
Third, in many cases, patients have incurred significant burns because of poor contact between the return electrode and the patient's skin. Finally, dangerous capacitive coupling has occurred in laparoscopic surgery which has resulted in dangerous burns to the patient. These burns could not be detected because they are out of the field of view of the laparoscope thereby putting the patient's life in danger.
A bipolar function for open and laparoscopic procedures is presently being used with the bipolar suction of the ESU. However, this system and the related instruments are used only to stop bleeding within a patient and is not capable of performing a cutting operation.
As previously stated in the section referred to as "related application", the present invention is related to the same inventor's pending patent application entitled "Telescopic Surgical Device and Method Therefor". The similarities between the telescopic pencil described in the pending application and the present invention described in this application is that both inventions refer to a telescopic pencil which can have multifunctional applications. The main difference between the inventions is that the pending telescopic pencil patent application refers to a monopolar pencil only which has only one contact for the electrode while the ESU pencil of the present invention described in this application can be used as a monopolar instrument, a monopolar/bipolar instrument or a bipolar instrument. The ESU pencil of the present invention has an electrode which comprises two contacts, one which is used as an active electrode and another which is used as a return electrode when the instrument is used as a bipolar functioning instrument for a monopolar/bipolar functioning instrument. Alternatively, when the instrument is only used as a monopolar functioning instruments a separate electrode is applied to a different part of the patient's body, usually on the patient's leg. This separate electrode functions as the return electrode.

Multifunctional telescopic monopolar/bipolar surgical device and method therefore


The present invention provides an artificial microstructure including a first metal wire, a second metal wire parallel to the first metal wire, at least one first metal wire branch and at least one second metal wire branch. The at least one first metal wire branch and the at least one second metal wire branch are distributed in an interlacement arrangement. One end of the at least one first metal wire branch is connected to the first metal wire; the other end is a free end facing towards the second metal wire. One end of the at least one second metal wire branch is connected to the second metal wire, and the other end of the at least one second metal wire is a free end facing towards the first metal wire. The present invention also discloses a metamaterial with the artificial microstructures.

Permittivity is a parameter of a material responding to the electric field. The material can generate induced charges under the action of external electric field, but resulting in weakening the electric field. The ratio of the external electric field of original vacuum to the electric field of the final material is called permittivity. Any kind of material has its specific permittivity value or permittivity curve in the natural world. When the material with high permittivity is placed in the electric field, the strength of the electric field will produce a considerable decrease in dielectric material. The material with high permittivity, such as dielectric insulator, is often used to produce capacitors. The electromagnetic wave has a very short wavelength in dielectric material with high permittivity, which can greatly reduce the size of the radio frequency and microwave devices.
With the rapid development of science and technology, people constantly set higher and higher standards for material application. In some cases, the needed permittivity value of the material is much greater than that of the existing material in the nature world. The existing dielectric with high permittivity can not meet the standards, which will become the bottleneck in the development of technology and related product research. Thus, artificial metamaterials are applied to achieve these purposes and solve these problems.
Metamaterial is new artificial composite structure material with extraordinary physical characteristic which does not exist in the natural materials. By placing the microstructures in ordered arrangement, the relative permittivity and the permeability of each point are changed in space. The metamaterial has the permittivity and the permeability that the common materials do not exist within a certain range to effectively control the propagation characteristics of electromagnetic waves.
The metamaterial includes a substrate and a plurality of artificial microstructures attached to the substrate. The artificial microstructures are composed of metal wires and have a certain geometrical shape formed by the metal wires. The artificial microstructures are placed on the substrate in an array arrangement. The substrate is a structure that serves to support the arranged artificial microstructures. The substrate can be made of any materials different from that of the artificial microstructures. The two different types of materials of the substrate and the artificial microstructures are overlapped together to produce an equivalent permittivity and permeability in space, and the two physical parameters respectively correspond to the electric field response and magnetic field response of the entire material. The electromagnetic response of the metamaterial is dependent on the characteristics of the artificial microstructures, and the electromagnetic responses of the artificial microstructures are mostly dependent on the topological characteristics of the metal wires and the size of metamaterial units. The size of each metamaterial unit is depended on the needed electromagnetic waves responded by the artificial microstructures. The size of each artificial microstructure is usually about one tenth of the wavelength of the electromagnetic waves that need to respond, otherwise the arrangement formed by the artificial microstructures cannot be considered to be continuous.
Referring to FIG. 1, in the typical production process of metamaterial, "I" shaped artificial microstructures are usually applied to change the distribution of the permittivity in space. The metamaterial can be formed by the array arrangement of substrate units attached by artificial microstructures. The size range of each substrate unit is from one tenth to one fifth of the wavelength of the electromagnetic waves. In a limited space, the change range of the size of the "I" shaped artificial microstructure is limited, and accordingly the changeable range of the permittivity of the metamaterial unit is limited too.

Artificial microstructure and metamaterial using the same

KUANG-CHI INSTITUTE OF ADVANCED TECHNOLOGY


The present invention concerns a method for transcoding a N bits word into a M bits word with M<N. The invention is applicable in various fields and more particularly in the display field. The method comprises the following steps:-breaking down the N bits word into an exponent part and a mantissa part having each a size which varies according to the value of said N bits word, the size of the mantissa part increasing with the value of said N bits word, and -encoding the exponent part of the N bits word into a variable number of bits A and removing, if need be, least significant bits of the mantissa part in order to obtain a mantissa with a variable number of bits B, with A+B=M.

The invention will be described in the field of the plasma display device. The transcoding method is used after a degamma function in a display receiver. FIG. 1 is a standard implementation circuit for encoding video data into subfield data. This circuit comprises a first memory 100 comprising 1024×12 bits for handling 10 bits video data YI[9:0]. A first look up table is stored in the memory 100 and used for remapping these data as described in EP patent application No. 1 353 314 for implementing the metacode concept or in EP patent application No 1 256 954 for implementing a Gravity Center Coding. At the output of the memory 100, 12 bits video signal YA[11:0] is obtained. The available 12-bits correspond to 8-bits integer resolution and 4-bits fractional resolution. Then, the 12-bits of video signal YA [11-0] are forwarded to a dithering circuit 110. In this circuit 110, the 4-bits of fractional resolution are added with the 4-bits of dithering and then truncated.
The video signal YB[7,0] from the circuit 110 is then forwarded to a second memory 120 comprising 256×16 bits. A second look-up table is stored in the memory 120 and is used for transforming the data YB[7:0] into subfield data SF[15:0].
Until now, a degamma function is implemented in the look-up table of the memory 100. Otherwise, in order not to lose significant bits, much more bits (typically 16 bits) would be required after the degamma function than the video input has. So, if the degamma function is made before the memory 100, this memory must have more inputs (16 bits), which will drastically increase the size of this memory. To go from 10 to 16 bits, the size of the memory is multiplied by 64.
And, on another hand, if a user wants to change the value of the degamma, to use a different degamma for each color or to use a specific degamma function, a specific look-up table should be generated for each case (if the degamma function can be known) and all of them should be stored.
For these reasons, it is necessary to separate the degamma function from the look-up table of the memory 100 and to create a transcoding circuit for transcoding 16 bits data (coming for example from a degamma block) into 10 bits data.
An object of the invention is to propose a method for transcoding a 16 bits word into a 10 bits word and, more generally, a method for transcoding a N bits word into a M bits word, N>M.

Method and device for transcoding N-bit words into M-bit words with M smaller N


In certain aspects, provided herein are methods and kits for detecting the presence of C. difficile in a biological sample. Also provided herein are methods of selecting of identifying a subject that would benefit from C. difficile treatment.

C. difficile infection (CDI) is an antibiotic-resistant, intestinal bacterial infection that causes mild to life-threatening diarrhea. In the field of fecal-based diagnostics, researchers have determined a variety of bacterial detection methods, including methods related to gene-amplification, enzyme-linked immunosorbent assay (ELISA), and bacterial culture. In a clinical setting, these techniques have varying levels of applicability, with the main limitation being that they must be performed in a controlled laboratory setting and typically require the patient to provide a stool sample. In addition, bacterial culture and gene amplification techniques such as polymerase chain reaction (PCR) also take hours to produce results and require complex laboratory equipment, and ELISA requires technicians to add multiple reagents to produce results. Thus, there is a need for advancements in fecal diagnostics for improving time to yield results, lowering technical complexity, and making diagnostic testing more accessible at point-of-care.


A method enables users to make corrections to printed forms using a computer arrangement. The printed form is scanned and displayed to the user on a display of the computer arrangement. The user selects one or more regions of the printed form to be corrected. The selected regions are digitally whited out to create a corrected image that can be output.

1. Field of the Invention
The present invention relates generally to pre-printed forms and, more particularly, to computer software for correcting errors made while filling out pre-printed forms.
2. Description of the Related Art
Despite the widespread use of computers in modern society, pre-printed forms are still commonly used to collect and process information. On a weekly basis, people are asked to fill out completed forms to apply for jobs, enroll children in schools, register children for recreational activities, order goods by mail, subscribe to magazines, register to vote, and apply for a driver's license. People frequently make mistakes when completing forms, for example, by entering information in the wrong place on the form. Means available to most people to correct errors when another form is not available are somewhat limited. People can strike out the incorrect information or otherwise annotate the document to indicate the error. In some cases, correction tape or white-out can be used to mask the incorrect information. However, these common solutions are not entirely satisfactory in that the result may reflect lack of care on the part of the person completing the form.

Method and apparatus to digitally whiteout mistakes on a printed form


Methods, systems, and devices for memory device operation are described. A memory device may operate in different modes in response to various conditions and user constraints. Such modes may include a power-saving or low power mode. While in the low power mode, the memory device may refrain from operations, such as self-refresh operations, on one or more of the memory array(s) included in the memory device. The memory device may deactivate external interface components and components that may generate operating voltages for the memory array(s), while the memory device may continue to power circuits that store operating information for the memory device. The memory device may employ similar techniques in other operating modes to accommodate or react to different conditions or user constraints.

The following relates generally to operating a memory system and more specifically to a memory device low power mode.
Memory devices are widely used to store information in various electronic devices such as computers, wireless communication devices, cameras, digital displays, and the like. Information is stored by programing different states of a memory device. For example, binary devices most often store two states, often denoted by a logic "1" or a logic "0." In other systems, more than two states may be stored. To access the stored information, a component of the electronic device may read, or sense, the stored state in the memory device. To store information, a component of the electronic device may write, or program, the state in the memory device.
Various types of memory devices exist, including magnetic hard disks, random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase change memory (PCM), and others. Memory devices may be volatile or non-volatile. Non-volatile memory (e.g., FeRAM, PCM, RRAM) may maintain their stored logic state for extended periods of time even in the absence of an external power source. Volatile memory devices (e.g., DRAM) may lose their stored state over time unless they are periodically refreshed by an external power source.
In some cases, a memory device may have limited power resources. Solutions for decreasing the amount of power consumed by a memory device may be desired.


Signaling paths and communication sessions, such as voice-over-IP sessions, can be established in substantially shorter and predictable time periods than previously thought possible over carrier-based, peer-to-peer networks (P2P). Instead of requiring a signaling pathway to traverse a large number of hops/nodes, novel architectures permit a signaling pathway to traverse a few designated host and anchor nodes that are part of a core of a P2P network. The novel architectures and related methods also make it possible to easily manage and maintain P2P networks.

Peer-to-peer networks are completely decentralized networks consisting of identical nodes, each of which can act as a "client" (in the sense of a traditional client-server network) and assume the responsibilities of a server at the same time. Because each element of a peer-to-peer (sometimes referred to as "P2P") network is the same, they are easily scalable. For example, a peer-to-peer network may grow by simply adding more nodes (e.g., telephones, computers, personal digital assistants ("PDAs")). In addition to being easily scalable it is fairly straightforward to maintain the reliability of peer-to-peer networks.
Typically, nodes or peers within a P2P network monitor each other. If a node or peer fails one or more of the remaining nodes takes over the responsibilities of the failed node. The architectural simplicity of peer-to-peer networks make them attractive for use with certain types of services, such as voice-over-Internet Protocol ("VoIP"). As issues involving the ease of configuring a network and the maintenance costs of a network grow peer-to-peer networks may provide advantages over existing carrier grid networks.
In a conventional peer-to-peer network each node or peer (the two words will be used interchangeably herein) stores attributes known as "key, value" pairs. For example, a key may indicate a user identification ("user ID") while a value may represent the address of a node. To establish a communication session between a source and destination node in a conventional peer-to-peer network the address of the destination node must be determined by locating a given key,value pair within a node that includes the value (i.e., address) of the destination node using only the key transmitted by the source node. More specifically, each node in the network that receives the transmitted key compares the key to key,value pairs stored in its look-up table or the like. Assuming at least one node contains the key,value pair associated with the destination node, the value (i.e., address) of the destination is returned to the source. Thereafter, the source sets up a signaling path with the destination node. Said another way, if one user wishes to make a VoIP telephone call to another, the caller transmits the intended recipient's user ID to other users (i.e., their devices) in the peer-to-peer network. Using lookup tables and search functions, the address of the recipient is found and returned to the caller to permit the establishment of a signaling path, and eventually a communication session, between the caller and the recipient.
Early peer-to-peer networks "flooded" requests to establish sessions into the entire network or parts of it until the desired key,value pair was identified (i.e., until the address of the recipient of a call was located). However, flooding does not work well in large peer-to-peer networks. To overcome the disadvantages of such a technique, many recent peer-to-peer networks have begun to use distributed hash tables ("DHT") to store and retrieve key, value pairs.
For example, using DHTs peer-to-peer networks assign a hashed key to each node in the network. By assigning hashed keys to nodes in the network, the time it takes to locate the address of an intended recipient of a call and the like is decreased.
In mathematical terms, it can be said that techniques which use DHTs guarantee an upper bound of O (log N) steps (which corresponds to a time period). In other words, the use of DHTs assures that the maximum number of steps it will take to identify a user (i.e., establish a session) within a peer-to-peer network is O(log N). This provides a way to estimate the time period it will take to locate a recipient's address; a distinct advantage over flooding techniques which, in some cases, would require an indeterminate number of steps or time period to locate a recipient.
Though the use of DHTs provides advantages over earlier techniques, the way they are presently used is still inadequate for use in voice applications/services. More particularly, while present techniques utilizing DHTs provide acceptable time periods to locate a recipient's address for file sharing and other data transfer applications/services, they provide unacceptable time periods when used in voice/video applications. Roughly speaking, using an existing DHT technique it takes an average of 10 steps to find a key, value pair in a network of 1 million nodes. However, in a worst case scenario it may take as many as 20 steps. Using 10 or 20 steps to locate the address of an intended recipient in voice or video applications is undesirable (i.e., it takes too long). Further, as a conventional P2P network gets larger, there also exists the possibility that the number of steps will increase as the number of nodes in the network increases. Thus, while it is still possible to determine the number of steps required to establish a session this number may be too high to provide an acceptable service/application.
Accordingly, it is desirable to provide methods, devices and architectures were DHTs can be used by nodes within a P2P network to establish signaling and communication sessions within an acceptable time period in voice, video and similar applications.

Methods, devices and architectures for establishing peer-to-peer sessions


A battery unit has a battery encapsulation formed by first and second encapsulation parts joined by a weld along a weld zone, with a battery contained in the battery encapsulation between the first and second encapsulation parts. Either the battery has a recess exstending along the weld zone, or overlaping edges of the first and second encapsulation parts are bent away from the battery to form a recess. The recess provides a heating insulating space that protects the battery from damage during welding along the weld zone.

1. Field of the Invention
The present invention relates to a battery adapted to be located in a battery encapsulation, of the type having first and second encapsulation parts joined by a weld along a weld zone.
The invention also relates to such a battery encapsulation, and a battery unit having such a battery and such a battery encapsulation, the battery being located in the encapsulation.
The invention also relates to an implantable medical device that has such a battery unit. Typically, the implantable medical device is a heart stimulating apparatus.
It should be noted that the invention particularly relates to a battery unit, a battery and a battery encapsulation wherein the first and second encapsulation parts are joined by welding with the battery being disposed in the encapsulation, generally in its operative position in the encapsulation.
2. Description of the Prior Art
Since the invention is particularly applicable to batteries and battery units of implantable medical devices such as heart stimulating apparatuses the background of the invention is described with reference to such an application.
Batteries for implantable medical apparatuses are encapsulated in encapsulations made of a material compatible with the human body. Such materials are metals such as stainless steel or titanium.
The encapsulation is constituted of two or more parts that have to be joined with the battery positioned inside the encapsulation. Preferably the encapsulation parts are joined by means of welding along overlapping edges thereof.
Welding will result in heat being generated in the very vicinity of the battery itself. Normally, the battery is covered with an electrically insulating material, for example a polymer. The heat might negatively affect the battery or the insulating material covering it since the battery is located close to the weld during the welding.
The conventional way to solve this problem is to use a support element, usually a polymer structure, which separates the battery from the encapsulation in the weld region. The support element may have a recess opposite the weld, thereby providing a clearance between itself and the weld zone or weld region. The support element thus prevents heat transfer through conduction directly to the support element, and the battery. However, some space that could otherwise have been used as battery space is lost in the encapsulation due to the presence of the support element. The support element also adds cost to the battery unit.


A new class of superconducting compositions, and methods for making and using them are described. These compositions exhibit superconductivity at temperatures in excess of 26° K. and are comprised of transition metal oxides having at least one additional element therein which may create a multi-valent state of the transition metal oxide. The composition can be a ceramic-like material having a layer-like crystalline structure, where the structure is distorted having either an oxygen excess or deficiency. An example is RE-AE-TM-O, where RE is a rare earth or rare earth-like element, AE is an alkaline earth element, TM is a transition metal element (such as Cu) and O is oxygen.

Superconductivity is usually defined as the complete loss of electrical resistance of a material at a well-defined temperature. It is known to occur in many materials, including about a quarter of the elements of the periodic table and over 1000 alloys and other multi-component systems. Generally, superconductivity is considered to be a property of the metallic state of a material since all known superconductors are metallic under the conditions that cause them to be superconducting. A few normally non-metallic materials, for example, become superconducting under very high pressure wherein the pressure converts them to metals before they exhibit superconducting behavior.
Superconductors are known to be very attractive for the generation and energy-saving transport of electrical power over long distances, and as materials used to form the coils of very strong magnets. These magnets are used in, for example, plasma and nuclear physics, nuclear magnetic resonance medical diagnosis systems, and in connection with the magnetic levitation of fast trains. Other potential uses of superconducting materials occur in power generation systems using thermonuclear fusion where very large magnetic fields must be provided, superconducting magnets being the only possible means for providing such high fields. In addition to these applications, superconductors are known in high speed switching devices, such as Josephson type switches, and in high density packaging and circuit layouts. Superconductors also are used in different types of electronic instrumentation, such as magnetic susceptometers and magnetometers.
While the advantages of superconductors are quite obvious to scientists and engineers, the common disadvantage of all presently known superconductive materials lies in their very low transition temperature. This temperature is often called the critical temperature Tc and is the temperature above which superconductivity will not exist. Usually Tc is on the order of a few degrees Kelvin. The element with the highest Tc is niobium whose Tc is 9.2° K. The composition having the highest previously known Tc is Nb3Ge which exhibits a Tc of about 23° K at ambient pressure. Transition metal alloy compounds of the A15(Nb3Sn) and B1(NbN) structure have been shown to have high superconducting transition temperatures. Among the A15 compounds is the aforementioned composition Nb3Ge. Some of these compositions are described in J. Muller, Rep. Prog. Phys. 43, 663 (1980), and M. R. Beasley et al, Phys. Today, 37 (10), 60 (1984).
It is known in the art that a small number of oxides will exhibit superconductivity. Reference is made to D. C. Johnston et al, Mat. Res. Bull. 8, 777 (1973), which describes high temperature superconductivity in the Li—Ti—O system with superconducting onsets as high as 13.7° K. These materials have multiple crystallographic phases including a spinel structure exhibiting the high Tc. Other metallic oxides, such as the perovskite Ba—Pb—Bi—O system can exhibit superconductivity due to high electron-phonon coupling in a mixed valent compound, as described by G. Binnig et al, Phys. Rev. Lett., 45, 1352 (1980), and A. W. Sleight et al, Solid State Communications, 17, 27 (1975).
As is evident from the foregoing, superconductors presently known require liquid helium for cooling and this, in turn, requires an elaborate technology and a considerable investment in cost and energy. Accordingly, it is a primary object of the present invention to provide new compositions which exhibit high Tc and methods for using and producing the same.
It is another object of the present invention to provide new superconducting compositions and methods for using and making them where cooling with liquid helium is not required in order to have superconductive properties in the compositions.
It is another object of the present invention to provide novel superconductive materials that are multi-valent oxides including transition metals, the compositions having a perovskite-like structure.
It is a further object of the present invention to provide novel superconductive compositions that are oxides including rare earth and/or rare earth-like atoms, together with copper or other transition metals that can exhibit mixed valent behavior.
It is a still further object of the present invention to provide novel superconductive compositions exhibiting high Tc, where the compositions are oxides including a phase having a layer-like structure and including copper.
It is a still further object of the present invention to provide new superconductive compositions exhibiting high Tc, where the superconductive compositions include layered structures including a rare earth and/or rare earth-like element and a transition metal.
It is another object of this invention to provide a new class of superconducting compositions characterized by a Tc greater than 26° K, and methods for making and using these compositions.
It is another object of this invention to provide new compositions and methods for using them, where the compositions include a multi-valent oxide of copper and exhibit a Tc greater than 26° K.
The basis for our invention has been described by us in the following previously published article: J. G. Bednorz and K. A. Muller, Zeitschrift fur Physik B—Condensed Matter, 64, pp. 189-193.
Another article of interest by us is J. G. Bednorz, K. A. Muller, M. Takashige, Europhysics Letters, 3(3), pp. 379-385 (1987).

Superconductive compounds having high transition temperature, and methods for their use and preparation

International Business Machines Corporation


An information recording medium including a substrate, an intermediate conductive layer, and a high molecular weight layer. When the high molecular weight layer is heated to close to its glass (transition) temperature by applying an AC field in order to induce thermal motion in molecular electric coupling poles present in the high molecular weight layer, the coupling poles are polarized by an external electric field applied between a microscopic probe tip and the intermediate conductive layer, the polarization becoming fixed when the temperature of the layer drops.

The present invention relates to information recording media, and more particularly to a high molecular weight information recording medium which permits data bits to be written when the medium is heated to its glass (transition) temperature and polarized. The invention relates also to the method of writing data bits in such a high molecular weight information recording medium.
As a result of recent developments in electronic and telecommunications technology, the demand for high density recording (information storage) media has greatly increased. Currently, magnetic disks, CD-ROMs, and DVD-ROMs are most commonly used for storing data bits. Writing and reading data bits in these recording media are commonly achieved by means of the application of an electric field or be varying the optical characteristics of the medium. However, because of the limitations of mechanical precision and wavelength, it is difficult to improve the recording density of such recording media. In order to meet the demand for high density recording media, most recording media designers and manufacturers have invested a lot of money in developing ultra high density recording media suitable for repeatedly writing and reading data bits. The result has been the development of microscope scanning probe type storage technology, which involves using a microscopic scanning probe as the center of the writing mechanism for processing the material surface directly, so as to write information data in the recording medium by changing the number of the molecules, atoms, or electric charges. By means of this general method, the storage density can be greatly improved, for example, to several hundred times that of conventional CD-ROMs (several G bits/in.sup.2 to thousands of G bits/in.sup.2), which greatly reduces the unit cost of the medium.
There are several known methods of using a microscope scanning probe to write data bits in a recording medium. These methods include the thermo-mechanical data storage method, the charge storage method, and the gold dot storage method, summaries of which follow:
1. The Thermo-mechanical Data Storage Method
According to this method, a microscope scanning probe is adhered to a piezoelectric driving device, and the recording medium, which is usually in the form of a disk, is put on a low-speed precision air bearing. The speed of the air bearing relative to the microscope scanning probe is about 10-100 mm/s. A laser diode of 30 mW is focused onto the atomic force microscope scanning probe to increase its temperature to a level sufficient for softening the disk, and then the probe is driven by a piezoelectric ceramic at the end thereof to press out a mark on the disk.
The size of the mark is less than approximately several hundred angstoms, and the mark is composed of a pit surrounded by a ridge which is formed from the material displaced by the tip of the probe. This pattern represents a density of about 25 G bits/in.sup.2, a more than 20 times increase in area density compared with conventional optical recording. However, this method can only write data bits in the same disk for one time, and does not allow the storage data bits to be modified. Another drawback of this method is that the coarseness tolerances for the disk surface are extremely low. Furthermore, this method is subject to dust protection and vibration problems.
2. The Charge Storage Method
This method involves making a mark on the recording medium by concentrating the electric charges of a particular material on a particular area by means of an electric field. When reading, a small voltage is applied to between the probe and the recording medium. Because of the effect of the static electricity of electric charges in the recording material, the previous record is read out when scanning. Because the tip of the probe is tiny (on the order of several angstroms or several tens of nanometers), the data density is high. An example of this method is found in U.S. Pat. No. 5,216,661, entitled "ELECTRON DENSITY STORAGE DEVICE USING A STM". This method can achieve ultrahigh density data writing and reading requirements. However, the recording medium is not stable and is vulnerable to temperature variations, background radiation, light rays and humidity. As a result, data stored on this type of medium cannot be kept for long (about several weeks only). Furthermore, because the organometallic material for the recording medium is obtained through a special extracting or synthesizing technique, manufacture of the recording medium is not easy.
3. The Gold Dot Storage Method
According to this method, the microscope scanning probe is coated with a layer of gold, and a negative voltage is applied to the disk, which is made from silicon, causing gold atoms at the tip of the probe to be evaporated and adhered to the disk. Because the tip of the microscope scanning probe is tiny, and the number of atoms evaporated is small, a large number of tiny gold dots can be formed on the surface of the disk. Through a proper selection of the probe size, and proper settings of the voltage value, the actuating time and the contact force, minimized gold dots can be achieved. The storage density of this method can reach 100 G bits/in* or even 1 T bits/in*. However, this method wastes a lot of gold atoms, and therefore the service life of the probe is short. Furthermore, this method will change the surface profile of the recording material, preventing repeated storage.

High molecular weight information recording medium and related data writing method

Industrial Technology Research Institute


A network-based verification of call connections is provided between a telecommunications subscriber terminal and a telecommunications service device selected by a service call number. This verification provides a way of enabling secure protection against an undesired selection of a service device and/or the selection of an undefined service device. A system and a method are provided in which during a call set-up, the selected call number is evaluated on the basis of at least one service call number stored in a communication network and/or at least one service call number area. In response to the identification of a service call number, the transmission of a defined confirmation information message from the telecommunication subscriber terminal is requested for the verification of the call connection, and in response to a mismatch between the requested confirmation information message and the confirmation information message transmitted, or not, by the telecommunication subscriber device, the call set-up is interrupted.

In the telephone number space of the public telephone network, essentially irrespective of whether the telephone network takes the form of a fixed network or a mobile network, the number of service facilities selectable by dialing a service telephone number appears to be rising steadily. Via such selectable service devices, for example, it may be possible to retrieve announcement and/or information services via the telecommunications network or also to enable audio and/or video conferences. Normally the service telephone numbers associated with the respective service devices for selecting particular services are subsumed in special telephone number ranges.
In this respect there are destination telephone numbers for which the connection charges are significantly higher than the normal rate. In Germany, for example, destination telephone numbers having higher connection charges may be found, for instance, in the telephone number ranges 00xx, 0137xx, 015xx, 016xx, 017xx etc. There also, for example, are destination telephone numbers having rates that can be freely determined by the respective provider. Such destination telephone numbers exist, for example, in the telephone number ranges 11xx, 012xx, 019xx, the service telephone numbers in the number range 0190x and the future number range 0900x being used in Germany, for example.
Telephone numbers having higher rates and/or for which the rates can be freely set may be used by companies for marketing the most varied contents and/or services that go beyond the basic use of the telecommunications network. Examples of services offered for a fee, that is, so-called added-value services, include, among others, information services, ordering hotlines, special consultations and/or weather information by telephone.
For example, in Germany, the telephone numbers from the 0190x range are currently allotted to the network operators of the respective telephone network in blocks of 1000, the telephone numbers 090-1 through 0190-9 being based on fixed rate structures in this case. For telephone numbers from the subrange 0190-0, no rate limits are currently prescribed, for example, in order to allow interested providers of fee-based services to set their own rates appropriate to the respective added-value service. This meets the market's requirements for flexible, performance-related rates, while providing users of such services with an anonymous, convenient method of payment by telephone bill without having to divulge bank data or a credit card number. Normally, the user of such a service pays by his call, that is, the collection occurs via the telephone bill, and the call for an added-value service use in this case would be charged at a higher fee than a regular telephone connection. In addition to legitimate providers making offers of value, however, dubious providers also use this form of marketing.
The telephone numbers of the dubious providers may be priced extremely high. Service offers from dubious providers often consciously exploit human weaknesses such as inattentiveness, credulity, and/or fear mongering. Further, the service users may be in part consciously or with fraudulent intent left in the dark regarding, for example, the amount of fees incurred with the use of the fee-based service. The number of subscribers who want to protect themselves against this growing threat is rising steadily. Frequently, however, the destinations or offers which are desirable or undesirable from the subscriber's perspective lie in close proximity in the telephone number space, are mixed and/or are subject to constant change such that the undesirable destinations are not known at all.
The current method of selecting providers, for example, of fee-based services, via specific telephone number ranges such as the (0)190 telephone number range, does not sufficiently ensure that service users are comprehensively informed about the type, content, and fees incurred following the selection of the respective service device and that the service users availing themselves of the service thus offered always do so in a conscious manner. Consequently, in principle, this affects, albeit in different ways, all service users who make use of a fee-based service, for example, those by telephone, fax, SMS, MMS or PC.
Furthermore, dubious providers seek to generate calls to their service telephone number by all means. One available example of this is the so-called dialer, i.e., software which is able to establish connections at times without the knowledge on the part of an owner of a PC/computer. This can affect, for example, those Internet users who have not implemented appropriate protective measures such as the use of hardware/software-based dialer blockers, virus scanners or firewalls. Thus, for such users, the dialers may initially install themselves unbeknownst to the user and subsequently, following the installation of the software, for example, after the immediate disconnection of the current connection, may establish a telephone connection to a fee-based service telephone number automatically via the standard connection function in the remote data transmission network when the user dials into the Internet and/or directly when the operating system is launched.
Some defense options are available against undesired service use.
For example, when using the Internet, a hardware-based dialer blocker may be interconnected between the telephone jack and the modem. For this purpose, the dialer blocker is configured in such a way that a predefined number of telephone numbers can be programmed into it. A connection can be established exclusively via these telephone numbers. Any attempt to establish a connection via a telephone number that deviates from them is prevented.
Furthermore, software-based dialer warning programs such as "190-Warner" or "YAW" may be installed on a PC in order to monitor the remote data transmission network and/or the TAPI (Telephone Application Programming Interface) and CAPI (Cryptography Application Program Interface) interfaces. In this case, the user may specify which programs or via which telephone numbers an online connection may be established in an outgoing direction. All connection attempts beyond these restrictions are blocked and are deblocked or cleared only following an express authorization by the user.
Moreover, modern private branch exchanges may normally be programmed using a so-called black list. Depending on the technical design of the equipment, such a black list holds a certain number of freely programmable telephone numbers. In the event of a dialing attempt to the outside, that is, an outgoing telephone connection via a telephone number contained in the black list, the equipment blocks or rejects the connection set-up.
Further, net-based approaches on the part of the respective network operator may be available for blocking telephone number ranges for a certain subscriber terminal device. The protective mechanism here lies in the fact that upon request from a subscriber, the network operator ensures in his technical facilities such as, for example, the switching exchanges that from the respective subscriber terminal device it is not possible to select, for example, the 0190 telephone number range in the outgoing direction, that is, that this range is blocked. This permanent barrier also prevents any use of desired services within this telephone number range.
Security packages also may be available which allow incoming and outgoing connections on the user side to be admitted based on a white list or to be blocked on the basis of a black list. In detail, a variable connection barrier allows the user himself to block outgoing dial-up connections on his telephone, for example connections to 0190 telephone numbers, it being possible in each case to block only one of several predefined telephone number ranges.
Variable telephone number blocking, which is controlled via a telephone number list, allows the user to generate either white lists or black lists. Consequently, it is possible on the basis of a black list to block outgoing dial-up connections to undesired telephone numbers or telephone number groups as non-admissible destinations, while all other telephone numbers remain accessible. Alternatively, it is possible on the basis of a black list to clear only the outgoing dial-up connections to desired telephone numbers or telephone number groups as admissible destinations, while blocking all other telephone numbers. In this manner, the user is able to define up to 10 telephone numbers or telephone number groups, each having a maximum of 20 digits, and to program them by numeric code via the subscriber terminal device itself.
These available list spaces or the available capacities, however, are often insufficient for a differentiated filtering of telephone connections required from the perspective of the subscriber. In order to obtain sufficient security, entire telephone number ranges must be blocked as a consequence of this limited capacity. This has the consequence that the legitimate offers contained in these ranges are likewise no longer available.
All of the above-mentioned defense measures thus have one common disadvantage in that free access to service offers via a telecommunications network is made difficult or even impossible. In addition there is the fact that in some cases the task of taking possible protective measures may be too demanding for a layperson even if the person is prepared to bear the additional financial cost.

Network-based securing of added-value services against automated connections


An embodiment of the technology described herein is an auxiliary power unit assembly. The auxiliary power unit assembly includes an auxiliary power unit being installable in an aircraft having a cabin, a duct connecting the cabin and the auxiliary power unit, and an airflow management feature in the duct.

The technology described herein relates generally to an auxiliary power unit installable (or installed) in an aircraft, and more particularly to the management of airflow from the cabin of an aircraft to such an auxiliary power unit.
Auxiliary power units, frequently comprising gas turbine engines, are installed in some aircraft to provide mechanical shaft power to electrical and hydraulic equipment such as electrical power generators and alternators and hydraulic pumps, as opposed to the main engines which provide propulsion for the aircraft. The inlet of the compressor of such auxiliary gas turbine engines receives air from the atmosphere. Because the density of air decreases with increasing altitude, such auxiliary gas turbine engines, at increased altitude, must either work harder to produce a desired shaft power resulting in an increased operating temperature or must reduce the output shaft power to stay within an operating temperature limit.
Auxiliary power units, much like other types of equipment, also produce a certain amount of noise during operation. Such noise is often transmitted to an aircraft cabin to varying degrees both by the gas turbine engine or engines which propel the aircraft in flight as well as by the auxiliary power unit. Such noise can reach unacceptable levels, and even at modest levels can become objectionable in such a confined space over prolonged periods of time.
Known noise reduction systems include baffle mufflers often used for automobiles, Herschel Quincke tubes, and active noise canceling headphones which detect noise frequencies and emit such noise frequencies with an opposite phase. Piezoelectric materials are known wherein electricity applied to the materials produces dimensional changes in the materials.
Still, scientists and engineers continue to seek improved auxiliary power units for aircraft.


Endodiagnostic methods utilize differential thermal relaxation and IR and visible imaging to differentiate between normal and abnormal interior body structures and tissue. With the use of a separate or integrated visible endoscope, an interior body site to be examined is visualized and then the area of interest is flooded with a cooling liquid. Upon contact with the area of interest, an immediate cooling of the flush site takes place, thus providing a temperature differential of approximately 25 degrees Fahrenheit of the cooled site compared to surrounding body-temperature tissue. As the area warms back to the surrounding tissue temperature, abnormal areas can be visualized because their temperature warms at a different rate compared to normal structure or tissue. As time progresses the contrast between normal and abnormal reaches a maximum and then declines as both relax back to body temperature. During the relaxation period infrared emissions within the range including 2 to 14 micrometers are visualized in the form of encoded images to permit differential analysis. This is done via endoscopic apparatus having separate or integrated IR and visible channels. The IR channel preferably comprises a refractive objective lens for forming a real image of interior structure of interest, a relay system consisting solely of refracting elements for transferring the real image to an intermediate image plane conjugate to the objective image plane, and a refracting coupling lens for forming a final image of the intermediate image in a detector plane for an IR detector sensitive in the range including 2 to 14 micrometers.

1. Field of the Invention
This invention relates generally to the field of endoscopic surgery and more particularly to diagnostic systems employing novel endoscopic apparatus and methods operating at and beyond the two (2) micron region of the spectrum.
2. Description of the Prior Art
Endoscopic surgery (ES) continues its rapid evolutionary progress as a minimal access surgical technique that reduces patient trauma while not compromising the operating field. Operations are performed in a closed physiological environment though the use of specialty designed, elongated instruments that are introduced into body cavities via relatively small cannulas (5 to 10 mm or so) and manipulated with visual guidance provided with either direct optical systems or, more recently, video systems. Compared with open surgical procedures, one major advantage of ES flows from the reduction in the severity of parietal wounds even though several cannula are usually used to gain access to the surgical sight. And, there are other advantages including a lessening of postoperative catabolic response, reduction in interior cooling and desiccation due to evaporation, fewer retraction related injuries, fewer adhesions and infections, and shorter hospital stays, along with associated costs.
ES approaches have commonly been used for laparoscopic surgery and are more frequently being adapted to other procedures such as endoluminal, perivisceral, intra-articular, thoracic, and combinations of these.
However, if the benefits of ES are to be more fully realized, diagnostic procedures are needed that will permit rapid in situ evaluation of pathology while the surgical procedures are in progress. Presently, this is not possible without significant time delays and the use of relatively complicated x-ray techniques requiring the injection of contrast dyes.
The negative impact caused by the lack of rapid least-invasive diagnostic procedures can be illustrated by considering one common ES procedure, the laparoscopic cholecystectomy for removal of the gall bladder. As is known, the cystic duct connects the gall bladder to the common bile duct which, in turn, leads to the duodenum. During a laparoscopic cholecystectomy, a diseased gall bladder is excised and removed from the body. In 3-5% of patients with diseased gall bladders, stones are not only present in the gall bladder but are also present in the cystic duct or in the vicinity of the sphincter connecting the cystic duct with the common bile duct. Retained stones present in the sphincter may cause post-operative discomfort to the patient and/or require further surgical intervention.
In the current art, this discomfort may be avoided by performing a cholangiogram during the cholecystectomy. To accomplish this, a fluoroscope is used to visualize any stones present. If a stone is observed from the cholangiogram, a secondary procedure is conducted in which a slit is made through the cystic duct. A flexible endoscope is then passed through this slit to observe the retained stones. A working channel within the flexible endoscope is equipped with a grasping forceps to remove any stones found. The flexible endoscope is of small enough diameter (.about.2 mm) to allow entrance into the 6 mm diameter cystic duct.
This secondary procedure has the disadvantage that it is very time-consuming and expensive because the cholecystectomy must be interrupted to bring in the fluoroscope and technician. Also, it is not preferred to expose the operating room personnel to the necessary radiation to conduct the fluoroscopy. In fact, in some 80% of the currently administered laparoscopic cholecystectomies, the cholangiogram is omitted, and the patient is at risk of having retained stones in the cystic duct.
Clearly, this and similar procedures require an alternate diagnostic tool for visualizing stones or other abnormalities while ES procedures are being conducted, and it is a primary object to this invention to provide endoscopic apparatus and methods by which such diagnoses may be conducted.
While infrared radiation has been used in the medical field for thermotreatment and other purposes, it appears to have never been used for purposes of diagnosis as advocated hereinafter. Examples of its use from the patent literature are the following:
U.S. Pat. No. 4,122,853 (Smith) discussed a means for treatment using an infrared laser beam. There is no discussion of means for viewing an IR-emitting object;
U.S. Pat. Nos. 4,945,409 (Nakamura) and 4,951,133 (Onoda) discuss miniature cameras which can be used as an endoscope in the UV, Visible, and IR. A filter from a light source rotates to choose the proper wavelength region. The IR region is confined to near IR less than one (1) micron, and there is no discussion regarding self-emission of the body in the mid-IR. Similarly, the Japanese patents are confined to near-IR wavelengths less than 1.2 microns and only to objects that are illuminated by an external source;
U.S. Pat. No. 4,418,689 (Kanazawa) describes an endoscope used with a laser. There is no discussion of an endoscope used in the infrared;
U.S. Pat. No. 4,786813 (Svanberg et.al.) describes a system for detecting fluorescence of an object. The device is limited to wavelengths less than 0.7 microns and only emissions stimulated by external excitation;
U.S. Pat. No. 4,872,458 (Kanehira et.al) describes a thermotherapy device inserted through a conventional visible light flexible or rigid endoscope. In this patent, a heat source generating far-infrared radiation is used for treatment. There is no attempt at visualizing the infrared energy through the endoscope; and
U.S. Pat. No. 5,147,354 (Boutacoff et.al.) describes a fiber optic Ho:Yag laser delivery system that can be inserted through an operating channel of a conventional endoscope. Again, there is no attempt to visualize infrared energy.
Consequently, in addition to the primary purpose of the invention, it is an important purpose to provide an endoscope for visualizing interior body structures by providing visible encoded images formed from their infrared emissions.
It is another object of the invention to provide endoscopic systems by which encoded images from infrared emissions from interior body structures can be observed along with images formed from visible light over the same region of interest so that diagnoses may be made via the infrared images and endosurgical procedures performed via the visible images.
It is yet another object of the present invention to provide endoscopic systems in which encoded infrared images and visible light images can be aligned in optical registration for endodiagnostic and endosurgical procedures.
It is still another object of the present invention to provide a means for the use of infrared endodiagnostic procedures for the study of the relationships among infrared images, tissue, and interior body structures to provide a basis for distinguishing normal form abnormal.
It is another object of the present invention to provide an endodiagnostic procedure for detecting the presence of residual stones during and endocholecystectomy.
Other objects of the invention will be apparent and will appear hereinafter in the following detailed description when read in connection with the drawings.

Endodiagnostic method using differential thermal relaxation and IR imaging


A window hatch is created in a displayed window. Once the hatch is created, a portion of the displayed window delimited by the hatch disappears, revealing the window underneath. Multiple invocations of the hatch operation bore through lower, underlying windows until the desired window is reached. Thus, portions of the desired underlying window show through the window hatch, while the top window remains in view. The window hatch can be adjusted in size and shape. The underlying window can be repositioned so that the desired information shows through the hatch. Various navigation and information cues are available to assist the user in understanding the relationship of the various windows and correctly positioning the window hatch.

This invention relates generally to graphical user interfaces for computer systems. More particularly, it relates to an improved user interface which allows user defined window hatches to reveal portions of underlying windows in an overlying window in a windowing user interface.
It is typical in many graphical user interfaces to use windows for displaying the interface of various applications and tasks which are running in a current computer system session. The window is generally a rectangular region in which text or graphical information is presented to the user regarding output from or input to the particular owning task or application. As the "real estate" on the computer display is limited, most modern graphical user interfaces also allow the windows to overlap each other so that most of the display space is devoted to the window owned by the application or task to which the user is currently devoting his attention. This in focus or primary window appears to be on top of the interface. An unfortunate side effect is that at least a portion of, if not all, an underlying window is obscured by the top window. Although obscured, the computer will continue to write to underlying windows with output from the respective owning application. At times, however, the degree to which information can be buried by the plethora of windows can be very frustrating to the user.
It is possible to close, reposition or minimize the overlying windows to reveal needed information which is obscured. However, if the user needs information in both windows, this involves a great deal of manipulation by the user of window controls, traversing between windows repetitively. In such a case, it is inconvenient to close or minimize the windows to repetitively change the focus of the interface bring one or the other window to the top of the user interface. Further, repositioning may be problematic where the needed information is present both in the top window and a lower window. Due to the way that the respective windows are formatted, it can be impossible for the needed information to coexist on the screen at the same time.
There are situations where it would be convenient to be able to observe parts of lower windows which are covered by the top window without rearranging the desktop by moving or minimizing windows or changing the user focus in the user interface. For example, the user may wish to periodically check the progress of a process running in the background without disturbing the window to which his primary attention is directed. There are numerous data entry operations where it would be convenient to refer to underlying windows.
The prior art has recognized the problem addressed by the present invention. One solution proposed by many has been to make the overlying window completely or partially transparent. In some solutions, the transparency is activated if a top window overlies an object which has been designated to be shown through an overlying window. Other solutions suggest blending all the windows in the interface so that all of the objects in the interface in any window may be perceived. However, in these interfaces, the display gets very confusing as to which objects belong to a particular window, particularly in overlapping regions. When very many windows are displayed in an interface, this approach is unworkable. Further, most of these solutions are "all or nothing", either all of the windows are made transparent or all of an underlying object is exposed. Many times these actions occur without user direction. In other words, the user is not allowed to tailor the interface to his current needs.
Another solution proposed has been to define a "port hole" window in a portion of a window which may be covered by subsequent actions in the interface. The designated portion is always presented on top of the interface. Thus, there seems to be a port hole in the overlying window.
The port hole solution allows the user to tailor his interface. However, there are several problems with this approach; some of these problems also occur in the transparent window approaches described above. First, it requires that the user anticipate what information will need to be kept on top of the interface. A user may not realize until later that the information is desired; the user would be required to backtrack to designate the information to be surfaced. Second, the prior art methods do not give the user a good idea of the window structure of the interface. Third, it does not allow the user to place where the underlying information comes through the top window so that it is in a convenient place in the top window, i.e. does not hide or confuse important information.
This invention represents an improved solution to this problem.

Window hatches in graphical user interface