Methods for the identification of compounds which modulate, either inhibit or stimulate, biomolecules are provided. Nucleic acids, especially RNAs are preferred substrates for such modulation. The present methods are particularly powerful in that they provide novel combinations of techniques which give rise to compounds, usually “small” organic compounds, which are highly potent modulators of RNA and other biomolecular activity. In accordance with preferred aspects of the invention, very large numbers of compounds may be tested essentially simultaneously to determine whether they are likely to interact with a molecular interaction site and modulate the activity of the biomolecule. Pharmaceuticals, veterinary drugs, agricultural chemicals, industrial chemicals, research chemicals and many other beneficial compounds may be identified in accordance with embodiments of this invention.

Recent advances in genomics, molecular biology, and structural biology have highlighted how RNA molecules participate in or control many of the events required to express proteins in cells. Rather than function as simple intermediaries, RNA molecules actively regulate their own transcription from DNA, splice and edit mRNA molecules and tRNA molecules, synthesize peptide bonds in the ribosome, catalyze the migration of nascent proteins to the cell membrane, and provide fine control over the rate of translation of messages. RNA molecules can adopt a variety of unique structural motifs, which provide the framework required to perform these functions.
"Small" molecule therapeutics, which bind specifically to structured RNA molecules, are organic chemical molecules which are not polymers. "Small" molecule therapeutics include the most powerful naturally-occurring antibiotics. For example, the aminoglycoside and macrolide antibiotics are "small" molecules that bind to defined regions in ribosomal RNA (rRNA) structures and work, it is believed, by blocking conformational changes in the RNA required for protein synthesis. Changes in the conformation of RNA molecules have been shown to regulate rates of transcription and translation of mRNA molecules.
An additional opportunity in targeting RNA for drug discovery is that cells frequently create different mRNA molecules in different tissues that can be translated into identical proteins. Processes such as alternative splicing and alternative polyadenylation can create transcripts that are unique or enriched in particular tissues. This provides the opportunity to design drugs that bind to the region of RNA unique in a desired tissue, including tumors, and not affect protein expression in other tissues, or affect protein expression to a lesser extent, providing an additional level of drug specificity generally not achieved by therapeutic targeting of proteins.
RNA molecules or groups of related RNA molecules are believed by Applicants to have regulatory regions that are used by the cell to control synthesis of proteins. The cell is believed to exercise control over both the timing and the amount of protein that is synthesized by direct, specific interactions with mRNA. This notion is inconsistent with the impression obtained by reading the scientific literature on gene regulation, which is highly focused on transcription. The process of RNA maturation, transport, intracellular localization and translation are rich in RNA recognition sites that provide good opportunities for drug binding. Applicants' invention is directed to finding these regions for RNA molecules in the human genome as well as in other animal genomes and prokaryotic genomes.
Combinatorial chemistry is a recent addition to the toolbox of chemists and represents a field of chemistry dealing with the synthesis of a large number of chemical entities. This is generally achieved by condensing a small number of reagents together in all combinations defined by a given reaction sequence. Advances in this area of chemistry include the use of chemical software tools and advanced computer hardware which has made it possible to consider possibilities for synthesis in orders of magnitude greater than the actual synthesis of the library compounds. The concept of "virtual library" is used to indicate a collection of candidate structures that would theoretically result from a combinatorial synthesis involving reactions of interest and reagents to effect those reactions. It is from this virtual library that compounds are selected to be actually synthesized.
Project Library (MDL Information Systems, Inc., San Leandro, Calif.) is said to be a desktop software system which supports combinatorial research efforts. (Practical Guide to Combinatorial Chemistry, A. W. Czarnik and S. H. DeWitt, eds., 1997, ACS, Washington, D.C.) The software is said to include an information-management module for the representation and search of building blocks, individual molecules, complete combinatorial libraries, and mixtures of molecules, and other modules for computational support for tracking mixture and discrete-compound libraries.
Molecular Diversity Manager (Tripos, Inc., St. Louis, Mo.) is said to be a suite of software modules for the creation, selection, and management of compound libraries. (Practical Guide to Combinatorial Chemistry, A. W. Czarnik and S. H. DeWitt, eds., 1997, ACS, Washington, D.C.) The LEGION and SELECTOR modules are said to be useful in creating libraries and characterizing molecules in terms of both 2-dimensional and 3-dimensional structural fingerprints, substituent parameters, topological indices, and physicochemical parameters.
Afferent Systems (San Francisco, Calif.) is said to offer combinatorial library software that creates virtual molecules for a database. It is said to do this by virtually reacting precursor molecules and selecting those that could be actually synthesized (Wilson, C&EN, Apr. 27, 1998, p.32).
While only Project Library and Molecular Diversity Manager are available commercially, these products do not provide facilities to efficiently track reagents and synthesis conditions employed for the introduction of fragments into the desired compounds being generated. Further, these products are unable to track mixtures of compounds that are generated by the introduction of multiple fragments by the use of multiple reagents. Therefore, it is desirable to have available methods for handling mixtures of compounds, as well as methods for the tracking of chemical reactions or transformations utilized in the synthesis of individual compounds and mixtures thereof.
Combinatorial chemistry is a recent addition to the toolbox of chemists and represents a field of chemistry dealing with the synthesis of a large number of chemical entities. This is generally achieved by condensing a small number of reagents together in all combinations defined by a given reaction sequence. Advances in this area of chemistry include the use of chemical software tools and advanced computer hardware which has made it possible to consider possibilities for synthesis in orders of magnitude greater than the actual synthesis of the library compounds. The concept of "virtual library" is used to indicate a collection of candidate structures that would theoretically result from a combinatorial synthesis involving reactions of interest and reagents to effect those reactions. It is from this virtual library that compounds are selected to be actually synthesized.
Project Library (MDL Information Systems, Inc., San Leandro, Calif.) is said to be a desktop software system which supports combinatorial research efforts. (Practical Guide to Combinatorial Chemistry, A. W. Czarnik and S. H. DeWitt, eds., 1997, ACS, Washington, D.C.) The software is said to include an information-management module for the representation and search of building blocks, individual molecules, complete combinatorial libraries, and mixtures of molecules, and other modules for computational support for tracking mixture and discrete-compound libraries.
Molecular Diversity Manager (Tripos, Inc., St. Louis, Mo.) is said to be a suite of software modules for the creation, selection, and management of compound libraries. (Practical Guide to Combinatorial Chemistry, A. W. Czarnik and S. H. DeWitt, eds., 1997, ACS, Washington, D.C.) The LEGION and SELECTOR modules are said to be useful in creating libraries and characterizing molecules in terms of both 2-dimensional and 3-dimensional structural fingerprints, substituent parameters, topological indices, and physicochemical parameters.
Afferent Systems (San Francisco, Calif.) is said to offer combinatorial library software that creates virtual molecules for a database. It is said to do this by virtually reacting precursor molecules and selecting those that could be actually synthesized (Wilson, C&EN, Apr. 27, 1998, p.32).
While only Project Library and Molecular Diversity Manager are available commercially, these products do not provide facilities to efficiently track the reagents employed for the introduction of fragments into the desired compounds being generated. Further, these products are unable to track mixtures of compounds that are generated by the introduction of multiple fragments by the use of multiple reagents. Therefore, it is desirable to have available methods for handling mixtures of compounds, as well as methods for the tracking of chemical reactions or transformations utilized in the synthesis of individual compounds and mixtures thereof.
The selection of compounds for synthesis and screening is a critical step in any drug discovery process. This is particularly true for combinatorial chemistry-based discovery strategies, where a very much larger number of compounds can be conceived than can be prepared in a reasonable time frame. Computational chemistry methods have been applied to find the "best" sets of compounds for screening. One strategy optimizes the chemical "diversity" in a library in order to increase the likelihood of finding a hit with biological activity in a screen against a macromolecular target of unknown structure.
Targeting nucleic acids has been recognized as a valid strategy for interference with biological pathways and the treatment of disease. In this regard, both deoxyribonucleic acids (DNA) and ribonucleic acids (RNA) have been the target of numerous therapeutic strategies. A wide variety of "small" molecules, oligomers and oligonucleotides have been shown to possess binding affinity for nucleic acids. The vast majority of experience in interfering with nucleic acid function has been via the specific binding of ligands to a particular base, base pair, and/or primary sequence of bases in the nucleic acid target. Some compounds have also demonstrated a composite specificity that arises from recognition and interactions with both the primary and secondary structural features of the nucleic acid, such as preferential binding to A-T base pairs in the DNA minor groove, with little or no binding to corresponding RNA sequences.
Exploiting the knowledge of the three-dimensional structure of biological targets is a promising strategy from a drug design and discovery standpoint. This has been demonstrated by the design and development of numerous drugs and drug candidates targeted to proteins involved in various pathophysiological pathways. While three dimensional structures of proteins have been widely determined by techniques such as X-ray crystallography, molecular modeling and NMR, nucleic acid targets have been difficult to study. The literature reveals few three dimensional structures of biologically active RNA, including a tRNA, said to have been determined via X-ray crystallography. Quigley, et al., Nucleic Acids Res., 1975, 2, 2329; and Moras, et al., Nature (London), 1980, 288, 669. The difficulties associated with proper crystallization and study of nucleic acids by X-ray methods along with the increasing number of biologically important small RNAs have increased the need for new structure determination and drug discovery strategies for such targets.
Many approaches to predicting RNA structure have been discussed in the scientific literature. Essentially, these involve sequencing and genomic analysis of nucleic acids, such as RNA, as a first step to establish the primary sequence structure and potential folded structures of the target. A second step entails definition of structural constraints such as base pairing and long range interactions among bases based on information derived from cross-linking, biochemical and genetic structure-function studies. This information, together with modeling and simulation software, has allowed scientists to predict three dimensional models of RNA and DNA. While such models may not be as powerful as X-ray crystal structures, they have been useful in ascertaining some structural features and structure-function relationships.
An understanding of the structural features of specific motifs in nucleic acids, especially hairpins, loops, helices and double helices, has been found to be useful in gaining molecular insights. For example, a hairpin motif comprising a double helical stem and a single-stranded loop is believed to be one of the simplest yet most important structural element in nucleic acids. Such hairpin structures are proposed to be nucleation sites and serve as major building blocks for the folded three dimensional structure of RNAs. Shen, et al., FASEB J., 1995, 9, 1023. Hairpins are also involved in specific interactions with a variety of proteins to regulate gene expression. Feng, et al., Nature, 1988, 334, 165, Witherell, et al., Prog. Nucleic Acid Res. Mol Biol., 1991, 40, 185, and Phillipe, et al., J. Mol. Biol., 1990, 211, 415. Nucleic acid hairpin structures have therefore been widely studied by NMR, molecular modeling techniques such as constrained molecular dynamics and distance geometry (Cheong, et al., Nature, 1990, 346, 680 and Cain, et al., Nuc. Acids Res., 1995, 23, 2153), X-ray crystallography (Valegard, et al., Nature, 1994, 371, 623 and Chattopadhyaya, et al., Nature, 1988, 334, 175), and theoretical methods (Tung, Biophysical J., 1997, 72, 876, Erie, et al., Biopolymers, 1993, 33, 75, and Raghunathan, et al., Biochemistry, 1991, 30, 782.
The determination of potential three dimensional structures of nucleic acids and their attendant structural motifs affords insights into areas such as the study of catalysis by RNA, RNA-RNA interactions, RNA-nucleic acid interactions, RNA-protein interactions, and the recognition of small molecules by nucleic acids. Four general approaches to the generation of model three dimensional structures of RNA have been demonstrated in the literature. All of these employ sophisticated molecular modeling and computational algorithms for the simulation of folding and tertiary interactions within target nucleic acids, such as RNA. Westhof and Altman (Proc. Natl. Acad. Sci., 1994, 91, 5133) have described the generation of a three-dimensional working model of M1 RNA, the catalytic RNA subunit of RNase P from E. coli via an interactive computer modeling protocol. Leveraging the significant body of work in the area of cryo-electron microscopy (cryo-EM) and biochemical studies on ribosomal RNAs, Mueller and Brimacombe (J. Mol. Biol., 1997, 271, 524) have constructed a three dimensional model of E. coli 16S Ribosomal RNA. A method to model nucleic acid hairpin motifs has been developed based on a set of reduced coordinates for describing nucleic acid structures and a sampling algorithm that equilibriates structures using Monte Carlo (MC) simulations (Tung, Biophysical J, 1997, 72, 876, incorporated herein by reference in its entirety). MC-SYM is yet another approach to predicting the three dimensional structure of RNAs using a constraint-satisfaction method. Major, et al., Proc. Natl. Acad. Sci., 1993, 90, 9408. The MC-SYM program is an algorithm based on constraint satisfaction that searches conformational space for all models that satisfy query input constraints, and is described in, for example, Cedergren, et al., RNA Structure And Function, 1998, Cold Spring Harbor Lab. Press, p.37-75. Three dimensional structures of RNA are produced by that method by the stepwise addition of nucleotide having one or several different conformations to a growing oligonucleotide model.
Westhof and Altman (Proc. Natl. Acad. Sci., 1994, 91, 5133) have described the generation of a three-dimensional working model of M1 RNA, the catalytic RNA subunit of RNase P from E. coli via an interactive computer modeling protocol. This modeling protocol incorporated data from chemical and enzymatic protection experiments, phylogenetic analysis, studies of the activities of mutants and the kinetics of reactions catalyzed by the binding of substrate to M1 RNA. Modeling was performed for the most part as described in the literature. Westhof, et al., in "Theoretical Biochemistry and Molecular Biophysics," Beveridge and Lavery (eds.), Adenine, N.Y., 1990, 399. In general, starting with the primary sequence of M1 RNA, the stem-loop structures and other elements of secondary structure were created. Subsequent assembly of these elements into a three dimensional structure using a computer graphics station and FRODO (Jones, J. Appl. Crystallogr., 1978, 11, 268) followed by refinement using NUCLIN-NUCLSQ afforded a RNA model that had correct geometries, the absence of bad contacts, and appropriate stereochemistry. The model so generated was found to be consistent with a large body of empirical data on M1 RNA and opens the door for hypotheses about the mechanism of action of RNase P. However, the models generated by this method are less well resolved that the structures determined via X-ray crystallography.
Mueller and Brimacombe (J. Mol. Biol., 1997, 271, 524) have constructed a three dimensional model of E. coli 16S ribosomal RNA using a modeling program called ERNA-3D. This program generates three dimensional structures such as A-form RNA helices and single-strand regions via the dynamic docking of single strands to fit electron density obtained from low resolution diffraction data. After helical elements have been defined and positioned in the model, the configurations of the single strand regions is adjusted, so as to satisfy any known biochemical constraints such as RNA-protein cross-linking and foot-printing data.
A method to model nucleic acid hairpin motifs has been developed based on a set of reduced coordinates for describing nucleic acid structures and a sampling algorithm that equilibriates structures using Monte Carlo (MC) simulations. Tung, Biophysical J., 1997, 72, 876, incorporated herein by reference. The stem region of a nucleic acid can be adequately modeled by using a canonical duplex formation. Using a set of reduced coordinates, an algorithm that is capable of generating structures of single stranded loops with a pair of fixed ends was created. This allows efficient structural sampling of the loop in conformational space. Combining this algorithm with a modified Metropolis Monte Carlo algorithm afforded a structure simulation package that simplifies the study of nucleic acid hairpin structures by computational means.
Knowledge and mastery of the foregoing techniques is assumed to be part of the ordinary skill in the art. There has been a long-felt need in the art to provide methods for improved determination of the three-dimensional structure of important regulatory and other elements in nucleic acids, especially RNA. It is also been greatly desired to achieve improved knowledge about the nature of interactions between ligands and potential ligands or nucleic acids, especially RNA. The present invention is directed towards satisfaction of these objectives.
The process of drug discovery is changing at a fast pace because of the rapid progress and evolution of a number of technologies that impact this process. Drug discovery has evolved from what was, several decades ago, essentially random screening of natural products, into a scientific process that not only includes the rational and combinatorial design of large numbers of synthetic molecules as potential bioactive agents, such as ligands, agonists, antagonists, and inhibitors, but also the identification, and mechanistic and structural characterization of their biological targets, which may be polypeptides, proteins, or nucleic acids. These key areas of drug design and structural biology are of tremendous importance to the understanding and treatment of disease. However, significant hurdles need to be overcome when trying to identify or develop high affinity ligands for a particular biological target. These include the difficulty surrounding the task of elucidating the structure of targets and targets to which other molecules may be bound or associated, the large numbers of compounds that need to be screened in order to generate new leads or to optimize existing leads, the need to dissect structural similarities and dissimilarities between these large numbers of compounds, correlating structural features to activity and binding affinity, and the fact that small structural changes can lead to large effects on biological activities of compounds.
Traditionally, drug discovery and optimization have involved the expensive and time-consuming, and therefore slow, process of synthesis and evaluation of single compounds bearing incremental structural changes. When using natural products, the individual components of extracts had to be painstakingly separated into pure constituent compounds prior to biological evaluation. Further, all compounds had to he carefully analyzed and characterized prior to in vitro screening. These screens typically included evaluation of candidate compounds for binding affinity to their target, competition for the ligand binding site, or efficacy at the target as determined via inhibition, cell proliferation, activation or antagonism end points. Considering all these facets of drug design and screening that slow the process of drug discovery, a number of approaches to alleviate or remedy these matters, have been implemented by those involved in discovery efforts.
One way in which the drug discovery process is being accelerated is by the generation of large collections, libraries, or arrays of compounds. The strategy of discovery has moved from selection of drug leads from among compounds that are individually synthesized and tested to the screening of large collections of compounds. These collections may be from natural sources (Sternberg et al., Proc. Natl. Acad. Sci. USA, 1995, 92, 1609-1613) or generated by synthetic methods such as combinatorial chemistry (Ecker and Crooke, Bio/Technology, 1995, 13, 351-360 and U.S. Pat. No. 5,571,902, incorporated herein by reference). These collections of compounds may be generated as libraries of individual, well-characterized compounds synthesized, e.g. via high throughput, parallel synthesis or as a mixture or a pool of up to several hundred or even several thousand molecules synthesized by split-mix or other combinatorial methods. Screening of such combinatorial libraries has usually involved a binding assay to determine the extent of ligand-receptor interaction (Chu et al., J. Am. Chem. Soc., 1996, 118, 7827-35). Often the ligand or the target receptor is immobilized onto a surface such as a polymer bead or plate. Following detection of a binding event, the ligand is released and identified. However, solid phase screening assays can be rendered difficult by non-specific interactions.
Whether screening of combinatorial libraries is performed via solid-phase, solution methods or otherwise, it can be a challenge to identify those components of the library that bind to the target in a rapid and effective manner and which, hence, are of greatest interest. This is a process that needs to be improved to achieve ease and effectiveness in combinatorial and other drug discovery processes. Several approaches to facilitating the understanding of the structure of biopolymeric and other therapeutic targets have also been developed so as to accelerate the process of drug discovery and development. These include the sequencing of proteins and nucleic acids (Smith, in Protein Sequencing Protocols, Humana Press, Totowa, N.J., 1997; Findlay and Geisow, in Protein Sequencing: A Practical Approach, IRL Press, Oxford, 1989; Brown, in DNA Sequencing, IRL Oxford University Press, Oxford, 1994; Adams, Fields and Venter, in Automated DNA Sequencing and Analysis, Academic Press, San Diego, 1994). These also include elucidating the secondary and tertiary structures of such biopolymers via NMR (Jefson, Ann. Rep. in Med. Chem., 1988, 23, 275; Erikson et al., Ann. Rep. in Med. Chem., 1992, 27, 271-289), X-ray crystallography (Erikson et al., Ann. Rep. in Med. Chem., 1992, 27, 271-289) and the use of Computer algorithms to attempt the prediction of protein folding (Copeland, in Methods of Protein Analysis: A Practical Guide to Laboratory Protocols, Chapman and Hall, New York, 1994; Creighton, in Protein Folding, W. H. Freeman and Co., 1992). Experiments such as ELISA (Kemeny and Challacombe, in ELISA and other Solid Phase Immunoassays: Theoretical and Practical Aspects; Wiley, N.Y., 1988) and radioligand binding assays (Berson et al., Clin. Chim. Acta, 1968, 22, 51-60; Chard, in "An Introduction to Radioimmunoassay and Related Techniques," Elsevier press, Amsterdam/N.Y., 1982), the use of surface-plasmon resonance (Karlsson, Michaelsson and Mattson, J. Immunol. Methods, 1991, 145, 229; Jonsson et al., Biotechniques, 1991, 11, 620), and scintillation proximity assays (Udenfriend et al., Anal. Biochem., 1987, 161, 494-500) are being used to understand the nature of the receptor-ligand interaction.
All of the foregoing paradigms and techniques are now available to persons of ordinary skill in the art and their understanding and mastery is assumed herein.
Likewise, advances have occurred in the chemical synthesis of compounds for high-throughput biological screening. Combinatorial chemistry, computational chemistry, and the synthesis of large collections of mixtures of compounds or of individual compounds have all facilitated the rapid synthesis of large numbers of compounds for ill vitro screening. Despite these advances, the process of drug discovery and optimization entails a sequence of difficult steps. This process can also be an expensive one because of the costs involved at each stage and the need to screen large numbers of individual compounds. Moreover, the structural features of target receptors can be elusive.
One step in the identification of bioactive compounds involves the determination of binding affinity of test compounds for a desired biopolymeric or other receptor, such as a specific protein or nucleic acid combination thereof. For combinatorial chemistry, with its ability to synthesize, or isolate from natural sources, large numbers of compounds for ill vitro biological screening, this challenge is magnified. Since combinatorial chemistry generates large numbers of compounds or natural products, often isolated as mixtures, there is a need for methods which allow rapid determination of those members of the library or mixture that are most active or which bind with the highest affinity to a receptor target.
From a related perspective, there are available to the drug discovery scientist a number of tools and techniques for the structural elucidation of biologically interesting targets, for the determination of the strength and stoichiometry of target-ligand interactions, and for the determination of active components of combinatorial mixtures.
Techniques and instrumentation are available for the sequencing of biological targets such as proteins and nucleic acids (e.g. Smith, in Protein Sequencing Protocols, 1997 and Findlay and Geisow, in Protein Sequencing: A Practical Approach, 1989) cited previously. While these techniques are useful, there are some classes and structures of biopolymeric target that are not susceptible to such sequencing efforts, and, in any event, greater convenience and economy have been sought. Another drawback of present sequencing techniques is their inability to reveal anything more than the primary structure, or sequence, of the target.
While X-ray crystallography is a very powerful technique that can allow for the determination of some secondary and tertiary structure of biopolymeric targets (Erikson et al., Ann. Rep. in Med. Chem., 1992, 27, 271-289), this technique can be an expensive procedure and very difficult to accomplish. Crystallization of biopolymers is extremely challenging, difficult to perform at adequate resolution, and is often considered to be as much an art as a science. Further confounding the utility of X-ray crystal structures in the drug discovery process is the inability of crystallography to reveal insights into the solution-phase, and therefore the biologically relevant, structures of the targets of interest.
Some analysis of the nature and strength of interaction between a ligand (agonist, antagonist, or inhibitor) and its target can be performed by ELISA (Kemeny and Challacombe, in ELISA and other Solid Phase Immunoassays: 1988), radioligand binding assays (Berson et al., Clin. 1968, Chard, in "An Introduction to Radioimmunoassay and Related Techniques," 1982), surface-plasmon resonance (Karlsson et al., 1991, Jonsson et al., Biotechniques, 1991), or scintillation proximity assays (Udenfriend et al., Anal. Biochem., 1987), all cited previously. Thc radioligand binding assays are typically useful only when assessing the competitive binding of the unknown at the biding site for that of the radioligand and also require the use of radioactivity. The surface-plasmon resonance technique is more straight forward to use, but is also quite costly. Conventional biochemical assays of binding kinetics, and dissociation and association constants are also helpful in elucidating the nature of the target-ligand interactions.
When screening combinatorial mixtures of compounds, the drug discovery scientist will conventionally identify an active pool, deconvolute it into its individual members via resynthesis, and identify the active members via analysis of the discrete compounds. Current techniques and protocols for the study of combinatorial libraries against a variety of biologically relevant targets have many shortcomings. The tedious nature, high cost, multi-step character, and low sensitivity of many of the above-mentioned screening technologies are shortcomings of the currently available tools. Further, available techniques do not always afford the most relevant structural information —the structure of a target in solution, for example. Instead they provide insights into target structures that may only exist in the solid phase. Also, the need for customized reagents and experiments for specific tasks is a challenge for the practice of current drug discovery and screening technologies. Current methods also fail to provide a convenient solution to the need for deconvolution and identification of active members of libraries without having to perform tedious re-syntheses and re-analyses of discrete members of pools or mixtures.
Therefore, methods for the screening and identification of complex chemical libraries especially combinatorial libraries are greatly needed such that one or more of the structures of both the target and ligand, the site of interaction between the target and ligand, and the strength of the target-ligand interaction can be determined. Further, in order to accelerate drug discovery, new methods of screening combinatorial libraries are needed to provide ways for the direct identification of the bioactive members from a mixture and to allow for the screening of multiple biomolecular targets in a single procedure. Straightforward methods that allow selective and controlled cleavage of biopolymers, while also analyzing the various fragments to provide structural information, would be of significant value to those involved in biochemistry and drug discovery and have long been desired. Also, it is preferred that the methods not be restricted to one type of biomolecular target, but instead be applicable to a variety of targets such as nucleic acids, peptides, proteins and oligosaccharides.
Accordingly, it is a principal object of the invention to identify molecular interaction sites in nucleic acids, especially RNA. A further object of the invention is to identify secondary structural elements in RNA which are highly likely to give rise to significant therapeutic, regulatory, or other interactions with "small" molecules and the like. Identification of tissue-enriched unique structures in RNA is another objective of the present invention.
It is another objective of the present invention to provide improved characterization of interactions between RNA and other nucleic acids and ligands or potential ligands therefor.
A further object of the invention is to compare molecular interaction sites of RNA with compounds proposed for interaction therewith.
In accordance with preferred embodiments of the present invention, the comparison of molecular interaction sites of RNA with compounds is achieved through comparison of numerical representations of the three-dimensional structure of the molecular interaction site with the three dimensional structure of the ligands in a fashion such that such interactions can be compared as to quality.
Another object of the present invention is the preparation of hierarchies of ligands ranked or ordered in accordance with in accordance with their ability to interact with molecular interaction sites of RNA and other nucleic acid targets.
Yet another object of the present invention is the establishment of databases of the numerical representations of three-dimensional structures of molecular interaction sites of nucleic acids and three-dimensional structures of libraries of ligands. Such databases libraries provide powerful tools for the elucidation of structure and interactions of molecular interaction sites with potential ligands and predictions thereof.
A principal object of the present invention is to provide novel methods for the determination of the structure of biomolecular targets and ligands that interact with them and to ascertain the nature and sites of such interactions.
A further object of the invention is to determine the structural features of biomolecular targets such as peptides, proteins, oligonucleotides, and nucleic acids such as the primary sequence, the secondary and folded structures of biopolymers, and higher order tertiary and quaternary structures of biomolecules that result from intramolecular and intermolecular interactions.
Yet another object of the invention is to determine the site(s) and nature of interaction between a biomolecular target aid a binding ligand or ligands. The binding ligand may be a "small" molecule, a biomolecule such as a peptide, oligonucleotide or oligosaccharide, a natural product, or a member of a combinatorial library.
A further object of the invention is to determine the relative binding affinity or dissociation constant of ligands that bind to biopolymer targets. Preferably, this gives rise to a determination of relative binding affinities between a biopolymer such as an RNA/DNA target and ligands e.g. members of combinatorially synthesized libraries.
A further object of the invention is to determine the absolute binding affinity or dissociation constant of ligands that bind to biopolymer targets.
A still further object of the present invention is to provide a general method for the screening of combinatorial libraries comprising individual compounds or mixtures of compounds against a biomolecular target such as a nucleic acid, so as to determine which components of the library bind to the target.
An additional object of the present invention is to provide methods for the determination of the molecular weight and structure of those members of a combinatorial library that bind to a biomolecular target.
Yet another object of the invention is to provide methods for screening multiple targets such as nucleic acids, proteins, and other biomolecules and oligomers simultaneously against a combinatorial library of compounds.
A still further object of the invention is to ascertain the specificity and affinity of compounds, especially "small" organic molecules to bind to or interact with molecular interaction sites of biological molecules, especially nucleic acids such as RNA. Such molecules may be and preferably do form ranked hierarchies of ligands and potential ligands for the molecular interaction sites, ranked in accordance with predicted or calculated likelihood of interaction with such sites.
Another object of the present invention is to alleviate the problem of peak overlap in mass spectra generated from the analysis of mixtures of screening targets and combinatorial or other mixtures of compounds. In a preferred embodiment, the invention provides methods to solve the problems of mass redundancy in combinatorial or other mixtures of compounds, and also provides methods to solve the problem of mass redundancy in the mixture of targets being screened.
A further object of the invention is to provide methods for determining the binding specificity of a ligand for a target in comparison to a control. The present invention facilitates the determination of selectivity, the identification of non-specific effects and the elimination of non-specific ligands from further consideration for drug discovery efforts.

Molecular interaction sites of interleukin-2 RNA and methods of modulating the same


A method for the controlled introduction of a reducing agent into a nitrogen oxide-containing exhaust gas leaving an internal combustion engine through an exhaust line having a catalytic converter built in for reducing nitrogen oxide, includes detecting at least one operation-relevant parameter of the exhaust gas, of the catalytic converter and optionally of the engine to determine the nitrogen oxide rate. An intermediate value is determined for the reducing agent rate as a function of the nitrogen oxide rate. The intermediate value is reduced by a rate of the reducing agent desorbed by the catalytic converter or raised by a rate of the reducing agent adsorbed by the catalytic converter. An apparatus for performing the method includes a control unit. A device detects at least one operation-relevant parameter of the exhaust gas, of the catalytic converter and optionally of the engine. A reducing agent supply unit introduces the reducing agent into the exhaust line upstream of the catalytic converter. The control unit is intended to adjust a rate of the reducing agent introduced into the exhaust gas as a function of the parameters, while taking into account a rate of the reducing agent adsorbed by the catalytic converter or desorbed by the catalytic converter.

1. Field of the Invention
The invention relates to a method and an apparatus for the controlled introduction of a reducing agent into a nitrogen oxide-containing exhaust gas from an internal combustion engine, having a catalytic converter built into the exhaust line for reducing nitrogen oxide.
Due to the pollutant content in the exhaust gas, the use of fossil energy-carriers in internal combustion engines in the traction mode presents major problems in areas with high motor vehicle densities, above all in industrial countries. Pollutants that can be mentioned include, among others, nitrogen oxides, hydrocarbons, carbon monoxide, oxides of sulfur, and soot, which contribute to well-known environmental problems, such as acid rain and smog.
As environmental consciousness increases and as legal requirements in terms of pollutant emissions becomes stricter, a number of catalysts and soot filters have been developed that contribute to reducing the emission of the aforementioned pollutants. In order to reduce pollutants in the exhaust gas of Otto engines, catalysts containing noble metal, for instance, are known in which hydrocarbons and carbon monoxide are converted along with nitrogen oxides and residual oxygen to form carbon dioxide, nitrogen and/or water. In order to reduce pollutant emissions from Diesel engines, so-called particle filters are known which trap the soot particles contained in the exhaust gas. The elimination of the soot particles is carried out by burnoff in the particle filter. Work is also being done in many places to develop a regulated Diesel catalyst, with which the intent is for it to be possible to lower the nitrogen oxide content in the exhaust gas of a Diesel engine considerably. Due to the high residual content of oxygen from the air in the exhaust gas, this cannot be done with the known noble-metal-containing catalysts, of the kind used in vehicles with Otto engines and stoichiometric combustion.
Instead, in vehicles with Diesel and lean-mix engines, that is engines with superstoichiometric combustion, so-called deNOx catalysts are used, with which the nitrogen oxides contained in the exhaust gas are converted with a suitable reducing agent, usually ammonia, into environmentally friendly nitrogen and water by the selective catalytic reduction (SCR) process. The reducing agent or a precursor of the reducing agent is introduced into the exhaust gas upstream of the catalyst in terms of the exhaust gas flow direction and then enters the catalyst in a preferably homogeneous mixture with the nitrogen oxides contained in the exhaust gas.
Internal combustion engines are operated in the traction mode with variable load and rpm. Accordingly, the quantities of nitrogen oxide generated by per unit of time and the flow rates and temperatures of the exhaust gas are subject to major fluctuations. There is currently no known solution for adjusting the quantity of reducing agent introduced into the exhaust gas per unit of time in such a way that high precipitation rates for the nitrogen oxides and simultaneously a vanishingly slight escape of reducing agent are attained regardless of the operating state of the engine. A further difficulty is that ammonia is poisonous, and even at a concentration of only about 5 ppm it represents a considerable odor burden to the human being. For that reason, an escape of ammonia must unconditionally be avoided.
Patent Abstracts of Japan Publication No. JP-A 55093917 teaches the detection of the exhaust gas flow rate, the nitrogen oxide concentration in the exhaust gas, and the exhaust gas temperature, along with the temperature of the denitration catalyst. Through the use of those data and in accordance with the nitrogen oxide rate, a rate of introduction into the exhaust gas is performed that takes into account the catalytic activity of the catalyst, which is dependent on the catalyst temperature. It has been found that such a method, especially at positive and negative sudden load changes, does not prevent an escape of reducing agent or nitrogen oxide.

Method and apparatus for controlled introduction of a reducing agent into a nitrogen oxide-containing exhaust gas


A method and a system for determining an energy expenditure of a user by detecting unmeasurable loads using heart rate and work rate are described. Time-stamped heart rate data and work rate data can be collected by one or more sensing modules. A processor circuit can calculate a heart rate-based energy expenditure and a work rate-based energy expenditure. The processor circuit can output a hybrid energy expenditure based on a heart rate confidence parameter, an exercise type, a fraction of heart rate reserve, and a hear rate-based metabolic equivalents of task.

When walking or running without any additional loads, calorie burn can be accurately and robustly predicted from mechanics (e.g., gait speed and terrain incline). Speed and incline can be sensed using accelerometer, barometer, and GPS signals. However, if there are any additional loads that cannot be observed with these sensors (such as treadmill incline, a backpack, a heavy stroller, or inefficient movement patterns due to pathology) or if one of these sensors is not available (e.g., a user does not have a barometric sensor or is on an inclined treadmill where elevation is not actually changing with incline) then estimation of calories burn will be inaccurate.

Detecting unmeasurable loads using heart rate and work rate


When an optical disc apparatus reproduces information from an optical disc, it converges a reading light beam emitted from an LED to substantially collimated light and projects it to the optical disc to cause it to be reflected by reflection surface thereof so as to make it become a reading reflected light beam. Then, the apparatus converges the reading reflected light beam by a mark layer selection lens, detects the reading reflected light beam passing through the target position by a detection region located at the confocal point of the target position and generates a detection signal. Subsequently, the apparatus recognizes the presence or absence of a recording mark based on the detection signal to reproduce the information. Thus, the apparatus can detect the state of the reading reflected light beam observed when it passes the target position and can recognize the presence or absence of a recording mark.

1. Field of the Invention
The present invention relates to an optical disc apparatus and an optical disc replay method that can suitably be used, for instance, for an optical disc apparatus for reproducing information from an optical disc where information is recorded.
2. Description of the Related Art
Optical disc apparatus for emitting a light beam onto an optical disc such as a compact disc (CD), a digital versatile disc (DVD) or a Blu-ray disc (registered trademark: to be referred to as BD hereinafter) and reproducing information from the disc by reading reflected light have become very popular.
With regard to optical discs, it is known that the size of the light spot formed on the optical disc is defined to be about λ/NA (λ: light beam wavelength, NA: numerical aperture) and the resolution is proportional to this value. With the BD system, for example, about 25 GB of data can be recorded on an optical disc with a diameter of 120 mm.
Optical discs are being used to record various pieces of information such as audio contents, video contents and a variety of computer data. The quantity of information to be recorded on an optical disc has increased because of the availability of high definition images and high quality sounds, so that there is a demand for large capacity optical discs that can record a large number of contents.
Optical disc apparatus designed to form a plurality of layers of recording marks in the uniform recording layer of an optical disc in a recording operation have been proposed in order to realize large capacity optical discs (refer to, e.g., Jpn. Pat. Appln. Laid-Open Publication No. 2007-220206 [FIGS. 1, 4 and 5]).
Such an optical disc apparatus converges a light beam so as to focus the light beam onto a recording mark that may be formed on an optical disc and receives reflected light that is produced as the light beam is reflected by the recording mark that may be there. Then, the optical disc apparatus recognizes the presence or absence of a recording mark there from received light and executes a predetermined demodulation process and a predetermined decoding process in order to ultimately reproduce information.

Optical disc apparatus and optical disc replay method


One embodiment provides a method, including: utilizing at least one processor to execute computer code that performs the steps of: using an electronic device to engage in an interactive session between a user and a virtual assistant; receiving, at the electronic device, audio input from the user, wherein the audio input comprises a problem-solving query corresponding to a request by the user for assistance in solving a problem related to at least one object; parsing the audio input to identify at least one annotated video file corresponding to the at least one object and the problem-solving query; determining a state of the object and a location in the at least one annotated video file corresponding to the state of the object; and providing, to the user and based on the location in the at least one annotated video file, instructional output related to the problem-solving query.

On a daily basis users frequently encounter and interact with a variety of mechanical and/or electronic devices ("devices"), for example, laptop and personal computers, tablet devices, smart phones, televisions, household appliances (e.g., washing machines, drying machines, etc.), and the like. Users often require help installing, operating, or troubleshooting these devices. A user may seek out the information they need to address their device-related query from a variety of different sources. For example, a user may read an instructional manual associated with the relevant device, a user may watch an instructional video associated with the relevant device and/or the relevant issue, a user may call into a call-center to obtain assistance from another individual, and the like.

Interactive voice based assistant for object assistance

INTERNATIONAL BUSINESS MACHINES CORPORATION


The invention relates to a security box, preferably for installation in a safe or the like, of the type comprising a six-sided box (1) of metal, for example. According to the invention, a detector is disposed to detect improper opening of the box, a protective shell (9) is disposed to detect damage to the box, an electronics unit (11) is disposed to trigger a dye system if improper opening or damage is detected, and the dye system is disposed, upon triggering, to discolor the contents of the box.

It is a well known problem that safes are sometimes subjected to mechanical damage in connection with burglaries. If the burglary is successful, currency and other negotiable documents stored in the safe can be used by the burglars despite substantial damage to the safe.
Insurance companies normally assign each type of safe a highest value of the content stored therein, for which compensation can be given by the insurance company in the event of a burglary. Amounts in excess thereof stolen from such a safe are not reimbursed by the insurance company. Due to, among other things, inflation, older safes thus have a lower and lower "utility value" for the user and it would be desirable to be able to increase the amount which can be stored in the safe.
In order to discourage burglars from breaking into safes and at the same increase the monetary value which can be stored in old or new safes, the present invention is suggested.
It is of course previously known to place special boxes or cassettes in large safes or strong-boxes. These boxes are normally only provided with ordinary locks, but they can also be provided with combination locks. The boxes are often pre-mounted at the factory and are often provided with some sort of alarm device.
One example of the latter is described in Austrian patent specification No. 381976, where a safe with an inner module is provided with an electronic monitoring unit.
U.S. patent specification No. 952,761 describes providing a safe with an inner box, the door of which is mechanically coupled to a tube element containing chemicals designed to discolor currency and negotiable documents stored in a compartment in the box. The tube element is broken mechanically if the door to the box is opened in an improper manner.


A brazing sheet includes a core material containing an aluminum alloy including magnesium, a bonding material laminated on at least one side of the core material, and a flux layer. The flux layer is laminated on one side of the bonding material and includes a flux composition. The flux composition includes [A] a flux component containing KAlF4, and [B] AlF3. A substance mass S1 (mol) of magnesium in the bonding material when heated at 585° C., a substance mass S2 (mol) of [A] the flux component containing KAlF4 in the flux layer and a substance mass S3 (mol) of [B] AlF3 satisfy the specific expression.

With recently increasing concerns about environmental issues, weight reduction has been performed more and more for better fuel efficiency typically in the automobile industry. To meet the requirement in weight reduction, investigations have been made actively so as to allow aluminum clad materials (brazing sheets) for automobile heat exchangers to have a lesser wall thickness and a higher strength. The brazing sheets generally have a three-layer structure including layers of a sacrificial material (e.g., Al—Zn material), a core material (e.g., Al—Si—Mn—Cu material), and a brazing material (e.g., Al—Si material) laminated in this order. For higher strength, investigations have been made to add magnesium (Mg) to the core material, namely to strengthen the core material by Mg2Si precipitation.
In addition, flux brazing is widely employed for the bonding of a brazing sheet to assembly a heat exchanger. The flux contributes to better brazeability, and one containing KAlF4 as a principal component is generally employed.
However, the customary flux, when used in a brazing sheet having a core material including an aluminum alloy containing magnesium disadvantageously adversely affects the brazeability. Upon heating for brazing, magnesium in the core material migrates into the flux in the brazing material surface and reacts with the flux component to form high-melting-point compounds such as KMgF3 and MgF2. This consumes the flux component and probably causes the disadvantage. To prevent this, a flux composition for a magnesium-containing aluminum alloy should be developed so as to advance the weight reduction typically of automobile heat exchangers.
Under these circumstances, to help a brazing sheet including a magnesium-containing aluminum alloy as a core material, there have been made investigations on (1) a flux composition further containing CsF in addition to the customary flux component (see JP-A-S61-162295); and (2) a flux composition further containing CaF2, NaF, or LiF in addition to the customary flux component (see JP-A-S61-99569).
However, the flux composition (1) further containing CsF is not suitable for mass production and is poorly practical, because Cs is very expensive. In turn, the flux composition (2) further containing CaF2 or another specific compound exhibits better fluidity as the flux, because the added compound helps the flux to have a lower melting point. Even this flux composition, however, fails to provide sufficiently better brazeability, because even this flux reacts with magnesium as in the customary technique. Independently, a brazing sheet exhibits better brazeability by increasing the applied amount of a flux. However, such increased applied amount causes higher cost. To prevent this, demands have been made to develop a flux that enables satisfactory brazing with low cost.


An object is to smoothly convey toner from a developer containing chamber to a developing chamber even when an opening that provides communication between the developer containing chamber and the developing chamber has a connecting part for adding strength to the apparatus. A sheet member that conveys a developer from an opening to the outside of a developer containing chamber has an entering portion that is formed by a first slit extending from a free end of the sheet member and positioned to cross a connecting part as viewed in a direction orthogonal to a longitudinal direction of a shaft member. The entering portion is configured to enter the outside of the developer containing chamber from the inside of the developer containing chamber. The entering portion overlaps in position with the connecting part as viewed in the direction orthogonal to the longitudinal direction of the shaft member.

Conventionally, a cartridge method has been used in an image forming apparatus that performs an electrophotographic image forming process. In the cartridge method, an image bearing member and a process means that acts on the image bearing member are integrated into a cartridge, which can be attached to and removed from the image forming apparatus. The cartridge method is very user friendly in that users can perform maintenance on the apparatus without relying on service persons. The cartridge method has been widely used in image forming apparatuses.
Conventionally, a process cartridge has included a developing device that develops an electrostatic latent image on an image bearing member with developer. The developing device includes a developing chamber internally provided with a developer bearing member, and a developer containing chamber configured to contain developer. The developing chamber and the developer containing chamber have an opening (developing opening) therebetween, which allows developer to pass therethrough. An agitating means supplies developer from the developer containing chamber to the developing chamber.
The agitating means includes a shaft member rotatably provided in the developer containing chamber, and an elastic sheet secured to the shaft member. A configuration is known in which, in order for the agitating means to smoothly supply developer to the developing chamber and loosen dense developer in the developing chamber, a leading edge of the elastic sheet enters the developing chamber from the developer containing chamber (see Patent Literature (PTL) 1).
Since the developing device has the developing opening which serves as a path of the developer, the strength of the developing device may be degraded. For adding strength to the developing device, two opposite sides of the developing opening extending in the axial direction of the developer bearing member may be partially connected to each other by a connecting part, such as a rib.
However, the connecting part hinders the leading edge of the elastic sheet from entering the developing chamber. To solve this problem, the elastic sheet may have a notched portion at a position facing the connecting part so as to avoid contact with the connecting part (see PTL 2). With this configuration, however, the developer around the connecting part may not be able to be conveyed to the developing chamber, or the developer on the back side of the connecting part may not be able to be loosened.
There is a configuration in which the developing chamber also includes an agitating means. This configuration, which requires a total of two agitating means, may cause an increase in cost and size of the apparatus (see PTL 3).

Developer containing chamber, developing device, process cartridge, and image forming apparatus


A process of producing a nonaqueous resin dispersion, particularly useful for a liquid developer in electrostatic photographic, which comprises subjecting to photopolymerization a system containing at least a monomer (A) having one polymerizable double bond, which is soluble in a nonaqueous solvent but becomes insoluble upon polymerization thereof, and at least a dispersion stabilizing resin (P) which is a polymer having a weight average molecular weight of from 1.times.10.sup.4 to 1.times.10.sup.6 and containing a specific repeating unit represented by formula (I) in an amount of at least 50% by weight based on the weight of the polymer and has a specific functional group represented by formula (II) bonded to the side chain of the polymer and/or only one terminal of the main chain of the polymer, the photopolymerization reaction being carried out in the nonaqueous solvent by irradiating the system with ultraviolet rays having a wavelength of not longer than 400 n.m.: ##STR1##

Nonaqueous dispersed resin particles being used as a liquid developer for electrostatic photography, a printing ink, a coating material, etc., are the particles of a resin capable of fixing the coexisting pigment or dye as a film thereof and are required to be fine particles and stably dispersed. In particular, since the resin particles dispersed in a nonaqueous solvent having a high electric resistant give influences on image qualities of the developed images, the dispersed resin particles are required to have a good dispersibility.
As a process of producing the nonaqueous dispersed resin particles, a so-called nonaqueous dispersion polymerization reaction wherein a monomer which is soluble in a nonaqueous dispersing solvent and becomes insoluble upon polymerization is granulated by a polymerization reaction in the nonaqueous dispersing solvent and in the presence of a dispersion stabilizing resin soluble in the solvent to provide a nonaqueous resin dispersion containing the particles, is known and various processes are proposed, for example, in K. E. J. Barrett, Dispersion Polymerization in Organic Dedia, published by John Wiley & Sons, 1975; Sooichi Muroi, Cho Biryushi Polymer no Saisentan Gijutu (Highest Technology of Super Fine Particle Polymer), Chapter 2, published by C M C K.K., 1991; etc.
According to the nonaqueous dispersion polymerization reaction, the improvement of productivity such as saving of energy consumption, simplification of steps involved, etc., is attained and a particle dispersion having preferred characteristics such as fine particle sizes and a narrow particle distribution can be obtained as compared to a so-called mechanical process through kneading, grinding, and wet dispersion steps.
However, when bonding of the soluble dispersion stabilizing resin and the insoluble dispersed resin particles is insufficient, the dispersion stabilizing resin tends to diffuse in the solution, whereby the dispersion stabilizing resin is released from the resin particles after storage or repeated use of the resin particle dispersion for a long period of time, causing precipitation, aggregation, and using such dispersed resin particles for a liquid developer, since the resin particles once aggregated and accumulated are reluctant to redisperse, the particles attach to everywhere of a developing machine, which results in staining of images and machine troubles of the developing machine such as clogging of a liquid-sending pump, etc.
For overcoming these defects, a means of chemically bonding the soluble dispersion stabilizing resin and insoluble latex particles is proposed as disclosed in U.S. Pat. No. 3,990,980.
That is, according to the disclosed process, dodecyl methacrylate is copolymerized with glycidyl methacrylate having a polymerizable double bond group to synthesize a random copolymer soluble in a nonaqueous solvent, esterifying the random copolymer by a high-molecular reaction with methacrylic acid to provide a dispersion stabilizing resin having introduced therein a methacryloyloxy group, and subjecting the dispersion stabilizing resin to a polymerizing gradulation reaction.
However, in a liquid developer using the dispersed resin particles thus obtained by the foregoing process, the dispersion stability to the spontaneous precipitation of the dispersed resin particles is improved to some extent but the improvement is yet insufficient. When the liquid developer containing the dispersed resin particles is used for a developing apparatus, there is a problem that the liquid developer is insufficient in redispersion stability to put in practical use, such that the toners (dispersed resin particles) attached to each part of the developing apparatus are solidified in the form of film, which is not liable to redisperse and further causes machine troubles, staining of copy images, etc.
Also, in the production process of resin particles described in the foregoing U.S. patent, for producing monodisperse particles having a narrow particle distribution, there is a great restriction on the combination of a dispersion stabilizing resin being used and a monomer being insolubilized, and in general, resin particles having a wide particle distribution containing a large amount of coarse particles or polydisperse resin particles having at least 2 mean particle sizes are formed. Also, in the production process, it is difficult to obtain monodisperse resin particles having a narrow particle distribution and a desired mean particle size, and large resin particles having particle sizes of at least 1 .mu.m and very fine resin particles having particle sizes of smaller than 0.1 .mu.m are formed. Furthermore, in the foregoing production process, there is a problem that the dispersion stabilizing resin being used must be produced by a complicated production process requiring a long period of time.
For solving these problems, a process of using the dispersion stabilizing resin obtained by a process wherein in the polymer as described above, the polymerizable double bond group being bonded to the polymer of the dispersion stabilizing resin is bonded parting from the polymer main chain with at least 10 total atoms such that the copolymerization reactivity with the monomer which becomes the dispersed resin particles by being solubilized is not sterically hindered (e.g., U.S. Pat. No. 4,618,557 and JP-A-60-185962 ("JP-A" as used herein means an "unexamined published Japanese patent application")), a process of introducing the polymerizable double bond group to one end only of the polymer main chain of the soluble polymer (e.g., JP-A-1-282566), etc., is disclosed.
As described above, it is important that in the nonaqueous dispersed resin particles having a good dispersion stability, the dispersion stabilizing resin is efficiently bonded to the component becoming an insoluble resin by causing a reaction in the polymerizing granulation reaction such that they are not separated even in a severe using condition.
In the conventional known process as described above, the polymerizing granulation of a dispersion stabilizing resin and a monomer is carried out by adding thereto a polymerization initiator in a nonaqueous solvent.
For example, in the case of a radical polymerization reaction using an azobis compound, a peroxide compound, etc., as is known, since the stability of the initiation radical and the growth radical is low, the elemental reactions (e.g., recombination, chain transfer, stop, hydrogen abstraction, etc.) of a polymer proceed complicatedly, which results in making it difficult to attain efficient bonding of a resin component for a dispersion stability and an insolubilized resin component or forming gelled materials by the progress of a polymerization reaction.
Also, in an ionic polymerization reaction using a ionic polymerization initiator such as an alkyl metal compound, a Lewis acid, a Grignard reagent, etc., since the initiator and a growth living polymer react with an active hydrogen compound such as water, etc., to lose the initiating faculty, there is a problem that a severe purification of a solvent, monomers, etc., is required or the kind of the monomer forming resin particles is restricted.

Process of producing nonaqueous resin dispersion and liquid developer for electrostatic photography


A resource authorization system includes an authorization routing service that is executed on a computing device to authenticate a client to form a client login session, and to receive, from the client, a request to establish a connection to one or more of the resources of a distributed computing system. The authorization routing service then obtains a list of the resources associated with the client login session in which the list of resources includes those that the client is authorized to communicate with. When the requested resource is included in the list of resources, the authorization routing service authenticates the requested resources to form a resource login session, and establish the connection by communicatively coupling the client login session and the resource login session. The resource login session is established independently of the client login session.

Computing environments used by enterprises often include numerous computing devices operated by multiple personnel. In many cases, certain computing devices may include sensitive data or may be used to provide some form of control over how a computing environment and/or other system in the enterprise operates. In such cases, an authentication mechanism may be implemented on these sensitive computing devices to ensure that only certain personnel are able to view and/or manipulate their operation.

Resource authorization system and method


A fluid-cooled stator assembly for electrical machines. The stator assembly may include a stator core having a back iron portion and a plurality of stator teeth. Each of the plurality of stator teeth may be separated from each other by at least one of plurality of slots, the slots being structured to receive placement of stator windings. The apparatus also includes a thermal management conduit that is positioned at various locations about the stator assembly, including within or along the back iron portion, stator teeth, slots, and/or among the stator windings. Further, the thermal management conduit may provide insulation for one or more coils of the stator windings. Additionally, at least a portion of the thermal management conduit may be formed from a thermally conductive polymer. The thermal management conduit is configured to convey a thermal management fluid in a heat exchange relationship with the stator assembly.

Embodiments of the present disclosure generally relate to thermal management for electromagnetic systems. More particularly, but not exclusively, embodiments of the present disclosure relate to fluid-cooled stator assemblies that include thermally conductive polymer conduits.
During operation, electromagnetic systems, such as, for example, the electromagnetic systems of electric motors, generators, and alternators, among other electrical machines, typically experience electrical and/or mechanical losses. Such losses often contribute to the generation of thermal energy that, if not at least partially dissipated, may adversely impact the efficiency and/or life span of the associated electrical machine. Moreover, such dissipation of generated thermal energy may at least assist in the ability of an electrical machine to reliably operate over a range of loads and/or operating conditions.
Historically, electrical machines having electromagnetic systems have been air cooled. While air cooling may generally be convenient, when compared to liquid cooling, the heat transfer coefficients achieved using air cooling are typically relatively low. Thus, to compensate for generally low cooling efficiency, the air cooling systems of electrical machines are often equipped to attain a relatively high air flow rate across at least the electromagnetic system. Yet, such relatively high air flow rates are typically achieved, as well as the associated relatively large pressure differentials, via use of relatively large, loud, and/or costly air handling equipment.
In contrast, liquid cooling may provide heat transfer coefficients that are significantly higher than the heat transfer coefficients that are attained using air cooling. However, traditionally, liquid cooling systems have relied on direct contact between a liquid coolant and a heat-generating portion of the electromagnetic system. As a result, liquid cooling systems typically utilized a complicated system to contain, recycle, and/or replenish the liquid coolant. Further, such direct contact may limit the types of liquid coolants available for cooling to those that will not short, corrode, and/or otherwise degrade the performance of the electromagnetic system and/or of the associated electrical machine.

Fluid-cooled stator assemblies having multilayer and multifunctional tubing


This invention provides. (1) a method for producing a silicon network polymer which comprises subjecting a trihalosilane to the electrode reaction using a perchlorate as the electrolyte, an aprotic solvent as the reaction solvent, Mg, Cu or Al as one electrode material and an electronically conductive material which is the same as or different from said one electrode as a counter electrode material with the polarity of electrodes being switched from time to time, and PA1 (2) a method for producing a silicon network polymer which comprises subjecting a trihalosilane to concurrent sonication and electrode reaction using a perchlorate as the electrolyte, an aprotic solvent as the reaction solvent, Mg, Cu or Al as one electrode material and an electronically conductive material which is the same as or different from said one electrode as a counter electrode material with the polarity of electrodes being switched from time to time.

Silicone network polymers are attracting attention as optoelectronic materials, ceramic precursors and so on.
Heretofore, a linear polysilane containing Si--Si linkages in the backbone chain has been synthesized from a dichlorosilane as the starting compound by heating the starting compound together with sodium metal at a temperature not below 100.degree. C. A silicon network polymer, however, cannot be synthesized by subjecting a trichlorosilane as such to the same conditions as above. Thus, in order to synthesize a silicon network polymer, it is necessary to modify not only the starting compound but also the reaction conditions. Therefore, a synthetic method employing a sonication technique in combination with a very strong reducing system, e.g. a sodium metal-potassium alloy system (J. Am. Chem. Soc. 110 (1988) 234) and a method using an alkali metal, e.g. sodium metal, and an appropriate auxiliary agent such as 12-crown-4 (Macromolecules 1990, 23, 3423-3426) have been proposed. However, these methods are disadvantageous in that they do not provide for molecular weight control and that the use of alkali in a large amount presents a major safety problem in commercial production runs. Thus, neither of the methods can be utilized for production on a commercial scale.
As a technology for synthesizing linear polysilanes, several processes involving electrode reactions which permit molecular weight control and are safe have been reported (J. Chem. Soc. Chem. Commun., 1990, 1160, Electrochem. Acta, 35, 1867 (1990), Denki Kagaku Oyobi Kogyo Butsuri Kagaku 59, 5, 421 (1991), JP Kokai H-3-104893, etc.). However, none of the above-cited literature consider production of a silicon network polymer and, for that matter, none provide information on how such a silicon network polymer could ever be obtained.
Therefore, the development of an electrode reaction technology for producing silicone network polymers has been awaited.

Method for producing silicon network polymers


A catheter retainer is disclosed that includes an adhesive pad with projections. The catheter is secured to the pad by being tied to the projections.

This invention relates to a catheter retainer.
Catheter retainers are well known. For example, one form of catheter retainer is shown in European Patent No. 37918, and another example is shown in British Patent Application No. 2 199 499. Another method of retaining a catheter on the body of a patient is shown in British published patent application number 2 211 417. Many other designs are known. However, none of the catheter retainers presently commercially available are entirely satisfactory. Surgeons therefore still quite frequently stitch a catheter to the skin of the wearer. This is frequently done when it is desired to drain a wound and yet hold the wound largely closed. This procedure of course involves a risk of infection and may be painful for the patient.
Prior art catheter retainers are unsatisfactory for a number of reasons. Firstly the retainer may be size dependent. In other words, for catheters of different diameter, a different catheter retainer device may be required. Another disadvantage is that known catheter retainers are often hard and rigid, and therefore uncomfortable to wear. Wearing them may promote lesions or maceration of the skin and so give rise to problems other than that for which the patient is in hospital. Another disadvantage of known catheter retainers is that they are hard to clean. Also, when used with catheters which are of a silicone rubber, a material commonly used for catheters, the catheter tubes are hard to lock in position relative to the retainer because of the slipperiness of the tube. As a result, patients can inadvertently pull catheters out. Yet another disadvantage of known catheter retainers is that the clamping pressure which most of them need to apply tends to collapse the catheter or the drainage tube. In consequence, the efficiency of drainage is adversely affected.
It would be desirable if there existed a catheter retainer which overcomes or at least greatly mitigates these disadvantages.


A photomask manufacturing method includes a defect information storage step of storing defect information of a mask blank, provided with an identification marker on an end face thereof, into an information storage device in correspondence to the identification marker, a placing orientation determination step of determining a placing orientation of the mask blank with respect to an exposure/writing apparatus, and an orientation correction step of performing rotation control of a rotating apparatus so that an orientation of the mask blank coincides with the determined placing orientation.

In advanced manufacturing of masks, there has been employed a technique that feeds back the quality of mask blanks being a material of the masks. For example, a method is known that performs pattern formation while avoiding a defective portion of a mask blank (see, e.g. Japanese Unexamined Patent Application Publication (JP-A) No. 2001-33941 (Patent Document 1)).
In order to perform such feedback, it is necessary to identify individual mask blanks. For this purpose, there have been proposed, for example, a mask blank formed with an identification marker for identifying or managing a mask blank glass substrate and a mask blank provided with an optically readable area code on an end face or the like of a mask blank glass substrate (see, e.g. Japanese Unexamined Patent Application Publication (JP-A) No. 2006-309143 (Patent Document 2)).


The present application concerns automated optimization, customization or production methods for the design of a solar photovoltaic array, involving one or more or all components in a photovoltaic array, in which the products include system designs, production drawings, permitting and construction drawings, layouts for the mechanical and electrical systems, bill of materials and financial return analyses of such a photovoltaic array.

Technological developments designed to harvest solar energy have greatly accelerated in recent years. One particular aspect of this has been the use of photovoltaic (PV) modules consisting of a multitude of interconnected photovoltaic cells. Each solar cell produces about 0.6V when illuminated by sunlight, thus with a module of 72 such cells, can yield a total of about 40 volts or about 300 Watts. Arrays of modules form panels, mounted on a support system usually referred to as a rack. This includes not only roof-mounted systems but also commercial and large-scale ground-mounted utility plants designed to introduce the generated electrical power into the grid.
While this technology has become the world standard for solar energy harvesting, much of the technical aspects of PV implementations are still in rapid development. Solar cell technology is far from being settled, as efforts are being made to improve the amount of energy collected per unit dollar of investment. Thus every aspect of the PV design and its implementation in the field is under scrutiny in order to minimize the cost-to-benefit ratio. With rapid declines in the prices of solar modules in recent years, the cost of solar modules has become a significantly smaller fraction of the total cost of the photovoltaic power system. Besides the cost of modules, important factors can include: costs associated with the land procurement; labor for design, construction and management; materials for the electrical components of the solar plant itself and those components required to integrate the power into the local electrical grid, as well as the mechanical infrastructure; operations and maintenance (O&M) costs, cost of capital (e.g., loan repayments). These are all variables that can be potentially adjusted. More non-controllable factors, which can impact the productivity and profit of a PV solar plant, include the solar insolation at a given position on the Earth (latitude and longitude), geological conditions in soil or terrain, and the meteorological conditions, not only on a seasonal or annual basis, but perhaps on a diurnal basis as well.
To aid in understanding the overall problem, a few examples might help to clarify the situation and its inherent complexity. For instance, an obvious adjustable variable is the tilt (elevation of a PV module) towards the Sun. A lower tilt may produce less power but it results in such reduced wind loading that the structural costs are reduced. Moreover, a lower tilted panel also is subject to larger accumulation of dirt and debris. Additionally, a lower tilted panel could be subject to greater snow loading and thus greater structural costs. These are all considerations that impact the design of the PV panel structural support system.
Another variable that can be changed is the effectiveness of land utilization given how modules are organized at site. In other words, a variable that can change is the module packing density or ground coverage ratio (GCR: defined as panel dimension projected onto the ground divided by panel row spacing), as it can be optimized for maximum energy harvest or maximum return on investment. Another possibility is to align solar modules with different azimuths. This is particularly important as it can optimize the internal return of return (IRR) given a grid utility's Time of Day (TOD) payment factors. Since utilities pay more for electricity at peak times, they provide TOD tables that weight the value of the power produced to match their hourly demand. An internal-rate-of-return (IRR) maximized fixed structure will, when viewed as an entire array, be aimed at the most valuable azimuthal angle. For example, a utility in Arizona might want more of its production after 4 PM, while a utility a few hundred miles west in California could want more of its production between noon and 2 PM, and the optimal array for either of these scenarios would have a different azimuth.
One of the many technical factors that can impact a project financially is that of the electrical and mechanical module support system, impacted by local conditions such as wind, snow, soil conditions, and seismic conditions as well. There are three basic groups of support system designs that vary in their ability to adjust the position of the module towards the instantaneous position of the Sun. The first group involves a static rack that provides no instantaneous adjustment, and the position is permanently fixed. However, such racks can be seasonally adjusted but remain fixed in daily operation.
The second and third groups involve tracking the Sun to collect more solar light, accounting for the fact that the Sun does not move in a constant declination. Such a requirement has financial implications that are not readily obvious from a simplistic assessment of a PV power plant design, as its implementation and the form of this implementation yields opposing results.
The second possible module support system method is to move the module or panel along an axis (single-axis tracking), tracking the Sun as it moves across the sky in its diurnal arc. There are several implementations of this type of tracking: vertical single axis tracker; horizontal single-axis tracker; and equatorial or polar tracker. Each one of these variations of single-axis tracking possesses advantages and disadvantages and for particular needs and sites. An obvious advantage is that more solar power is collected. Disadvantages include either increased shading or decreased GCR, and greater costs in maintenance and/or replacement due to the larger number of mechanical and/or electrical parts. Even a specific type of single-axis tracker can have different tracking ranges, tilt angle, and tracking accuracies that depend on tracking methods.
The third method is dual-axis tracking, which provides movements that follow the diurnal and seasonal paths of the Sun. Each axis requires some sort of mechanism to provide the movement, normally by gearing and a motor. This type of tracking provides the most collected solar light, but because of the potential of shading of one panel to another at certain times of the day, there is a reduction in the attainable solar power collected. Thus a design with dual-axis tracking may require a greater separation between panels to reduce losses imposed by shading of one panel by another at extreme hour angles. Thus GCR is reduced.
Modules are usually warranted for several decades, but tracking systems that are robust enough to last a similar period of time, requiring no or little maintenance, are rare and expensive. Thus long-term maintenance of the mechanics of tracking along with availability risks have to be considered as part of the overall problem of designing a solar PV plant.
A static module support system eliminates the need for maintenance associated with a tracking system, and thus presents a viable option for optimal system designs, particularly in areas where O&M labor costs are high or areas that are closer to the equator where dual-axis tracking systems offer less of a performance advantage. Thus dual-axis tracking is more beneficial at more northerly locations. There are a great variety of static support systems, each of which possesses advantages and disadvantages.
A common approach for static, or fixed, racks is to cover an area with linear configurations of module arrays, with the long axis normally parallel to, or nearly so, a line of latitude. The modules are then oriented so that the normal to the PV module surface is oriented to maximize incident flux for a particular time of the year, at the declination when the sun crosses the local meridian. This is the tilt angle of a module. This traditional and commonplace approach makes the construction simple as a replication of a single design, such as the module support, is repeated as needed.
If a static support rack is chosen, then a decision is required to set the tilt and azimuth angles to particular values given a value of GCR. The tilt and azimuth angle would achieve a desired goal, such as maximizing energy that could be achieved over a certain period of time or during a certain part of the day. Importantly, other adjustable parameters include, height above the ground (or ground clearance), spacing between the rows of modules, and bank (permanent EW angle bias of a module, e.g., EW tilt). These all add complexity to designing a static support rack. For example, increasing ground clearance (height) increases structural and electrical costs but saves operational costs for the life of the project, and increasing row spacing decreases shading and increases system performance but also decreases GCR, while increasing electrical, module packing density, and operational costs.
In the case of bank, a geographic variation would be possible if the terrain of the site possesses irregularities. Moreover, it can be non-zero if there are other non-controllable aspects involved such as shading and persistent diurnal meteorological conditions.
Other local variations can also influence IRR or other figures-of-merit, such as soil conditions, site undulations, and local geographical features such as forests or buildings. Any and all of these can influence the energy collected. Grade or soil characteristics will also influence the selection of foundation or rack design. Costs that are affected by site-specific features are also important to take into consideration—for example, sites with sandy soil generate far less skin friction for ground penetrating piles than do sites with clay-like soil, and thus require far longer piles and higher costs.
Foundation type is one of many other variables that need to be considered as part of the design. These include above-ground concrete ballast, subterranean poured concrete foundation, post/pile driven, or ground screws. Bedrock that is just below the basal subsoil will require a different mounting approach.
Sites that have high load bearing characteristics and, for example, 5-12 feet of penetrable soil, are well suited for a pile driven module rack. On the other hand, if sites cannot endure surface penetration, landfills for example where landfill caps cannot be disturbed, then this will force the use of more costly above-ground footings, more costly above-ground electrical wiring conduits, and more costly inverter installations. All of these factors must be taken into account.
Other design variables are the costs and types of wirings for direct current (DC) and separately for alternating current (AC). Costs and warranties for inverter types, switchgear, power management systems, cooling equipment, combiner boxes, DC-DC optimizers, and energy storage facilities will also affect the optimum solution. A mechanical system design with higher energy production and lower cost than an alternative mechanical system design might require an electrical system with higher cost than the electrical system needed by that alternative mechanical design.
Modules are often clustered in strings in physical and electrical combinations that are sized according to GCR requirements, power requirements, and inverter input (as well as other variables, well-known to the person skilled in the art). For example, photovoltaic designers typically combine 18 to 21 modules into a string, and combine these strings to produce an array or panel. However, common practice is subject to change when other options, in concert with other parameters or variables, are taken into account.
Another example would be the design of a solar array with different rows of modules having different mechanical and electrical design parameters to optimize one user's needs. No current approach addresses this user or is able to find the optimum solution that could have, for example, the rows of panels on the peripheries of the array would require a different structural quality and wall thickness than the interior rows. This type of structurally optimum solution leverages the fact that interior rows see reduced wind loading due to the presence of the surrounding rows. Similarly no current approach is able to design different strings with different module and wiring configurations, or to design back rows that can have higher tilts due to lack of shading concerns.
Computer-aided performance optimizations are also in a rudimentary form. For instance, consider the literature available on "tilt" optimization. Some suggest tilt angles that are simple functions of latitude, but this fails to consider site specifics (such as typically cloudy winters or morning fog in summer). At best, some consultants offer to provide "tilt optimization" services as a detailed, hands-on process. No other tools allow one to run a "batch" of simulations at various tilt angles to determine the best angle from a performance perspective.
While all of these approaches work to a degree, they are either overly simplistic or laborious, and thus time consuming. Given the somewhat large number of variables and constraints involved, no design of a solar power plant or array can be accomplished in even a finite amount of time that is reliably accurate, detailed, and optimized (financially or otherwise).
There are several existing tools that will help facilitate the look of what a PV plant will look like when imposed upon, say, an image from Google Maps or other equivalent mapping service. Boundary points are interactively defined and with various parameters selected (row spacing, PV module type) the program will present a first-order look of a design. There is neither any optimization nor any automated design production in such approaches.
A few services (e.g., Helioscope from Folsom Labs; Helios3D from Schletter GmbH) exist to define a visual design automatically based on a user's input. However, these methods are suboptimal for the extensive task to be performed. A basic design is derived and the parts replicated ad nauseum; this is essentially multiplying a number of parts for a Bill-of-Materials (BOM) for a solar "kit" to fill the desired geographic area or capacity needs. There is no direct customization of the parts or configuration of the modules. These attempts at design culminate in a single fixed design.
In addition to these visual design programs, there are a variety of PV plant simulators that have been developed. The best and most useful is that of the System Advisor Model (SAM) developed by the US National Renewable Energy Laboratory. It provides a simulation based upon extensive input parameters.
In current practice, simulations are already used to determine the performance of a design. Unfortunately, the process of refining that design is not automated. For example, there is no optimization within current standard simulations; that is, current practice does not simulate multi-variable mechanical and electrical design parameters, multi-dimensional considerations including meteorological, environmental and cost factors, or a specific solar project's optimization goals.
At present the industry lacks sufficiently detailed tools to aid in the evaluation of the plurality of inputs and outputs of various system designs, given the large number of variables or parameters involved. The number of permutations of the design parameters rapidly becomes so large that it is infeasible to attempt to "brute force" an optimal solution by simply evaluating the system model for every possible permutation. For this reason, the solar industry typically uses excessive standardization in photovoltaic project design and ignores more effective solutions to handle large numbers of permutations. This is in stark contrast to the lack of granularity in sensitivity analysis that can be achieved with the standard few iterations of a human PV design engineer or team of engineers.

System and methods for solar photovoltaic array engineering


An image display apparatus includes a projection unit configured to project an image and a plurality of concave reflectors in which contact surfaces with optical axes of the concave reflectors with respect to the optical axis of the projection unit are disposed at different angles from one another. A first concave reflector of the plurality of concave reflectors reflects at least a portion of an image projected by the projection unit to form a first image based on the image. A second concave reflector of the plurality of concave reflectors transmits a portion of an image projected by the projection unit and reflects a portion of the image to form a second image based on the image.

Field of the Invention
The present invention relates to an image display apparatus.
Description of Related Art
A head-up display (HUD) for displaying driving information on a windshield of a vehicle by superimposing the driving information on a driver's field of view has been developed. The driving information is, for example, information on a speed and car navigation. In a conventional HUD, vehicle information is invisible to both a driver and a fellow passenger sitting in a passenger seat due to a narrow viewing angle.
Thus, a display apparatus that allows a driver and a fellow passenger to view driving information by placing a half-mirror between a display body and a display unit to change an angle of a display surface on which an image is displayed has been proposed (for example, refer to Japanese Utility Model No. 63-158428 (hereinafter, Patent Document 1)). In addition, the display body is a fluorescent display tube or a liquid crystal panel, and driving information is displayed thereon. Also, the display unit is a semi-transparent mirror provided at an inner surface of a windshield of a vehicle, and a display light projected from the display body is projected on the display unit. With the technology described in Patent Document 1, a driver may view driving information that is transmitted through the half-mirror and displayed on the display unit, and a fellow passenger may view the driving information reflected by the half-mirror.
In addition, a display apparatus that projects driving information from a projector to a holographic optical system by placing the holographic optical system on a windshield has been proposed (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2011-180177 (hereinafter, Patent Document 2)). With the display apparatus described in Patent Document 2, a driver and a fellow passenger may view driving information when a projected image of the driving information is diffracted at two angles by an interference pattern pre-recorded in two or more layers of the holographic optical system. With the technology described in Patent Document 2, a driver may view a first diffracted light due to a first layer of a holographic optical element, and a fellow passenger may view a second diffracted light due to a second layer of the holographic optical element.