gebhart/patrepeval huggingface dataset:
Synthetic and structural studies of sapphyrin, a 22-.pi.-electron pentapyrrolic "expanded porphyrin" (1990)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthetic and structural studies of sapphyrin, a 22-.pi.-electron pentapyrrolic "expanded porphyrin"Jonathan L. Sessler, Michael J. Cyr, Vincent Lynch, Ellen McGhee, and James A. IbersCite this: J. Am. Chem. Soc. 1990, 112, 7, 2810–2813Publication Date (Print):March 1, 1990Publication History Published online1 May 2002Published inissue 1 March 1990https://pubs.acs.org/doi/10.1021/ja00163a059https://doi.org/10.1021/ja00163a059research-articleACS PublicationsRequest reuse permissionsArticle Views1634Altmetric-Citations247LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
Performance evaluation of a high-speed high-power switched reluctance motor drive (2015)

Due to its simple construction, robust structure, and lack of magnetic source on the rotor, switched reluctance machine (SRM) is a good candidate for high speed operation. In this paper, the drive and performance parameters of a high speed high power SRM designed for traction applications are investigated, both in single pulse and current control modes within its entire speed range. Torque-speed characteristics, efficiency map, and torque ripple maps have also been developed. The limitations posed by the design of the motor, the drive system, and the power electronics are described.
A high-performance interpretive approach to schema-directed parsing (2007)

XML delivers key advantages in interoperability due to its flexibility, expressiveness, and platform-neutrality. As XML has become a performance-critical aspect of the next generation of business computing infrastructure, however, it has become increasingly clear that XML parsing often carries a heavy performance penalty, and that current, widely-used parsing technologies are unable to meet the performance demands of an XML-based computing infrastructure. Several efforts have been made to address this performance gap through the use of grammar-based parser generation. While the performance of generated parsers has been significantly improved, adoption of the technology has been hindered by the complexity of compiling and deploying the generated parsers. Through careful analysis of the operations required for parsing and validation, we have devised a set of specialized byte codes, designed for the task of XML parsing and validation. These byte codes are designed to engender the benefits of fine-grained composition of parsing and validation that make existing compiled parsers fast, while being coarse-grained enough to minimize interpreter overhead. This technique of using an interpretive,validating parser balances the need for performance against the requirements of simple tooling and robust scalable infrastructure. Our approach is demonstrated with a specialized schema compiler, used to generate byte codes which in turn drive an interpretive parser. With almost as little tooling and deployment complexity as a traditional interpretive parser, the byte code-driven parser usually demonstrates performance within 20% of the fastest fully compiled solutions.
Orally active aldose reductase inhibitors: indazoleacetic, oxopyridazineacetic, and oxopyridopyridazineacetic acid derivatives (1992)

Benzothiazole side chains featured in zopolrestat (1a) and its congeners were incorporated into oxophthalazineacetic acid replacements, including indazole, pyridazinone, and pyridopyridazinone with a pendant acetic acid moiety. Potent aldose reductase inhibition activity among resulting compounds is as widespread as it is in the earlier zopolrestat series, thus lending further support to our hypothesis that there is a binding site on the aldose reductase enzyme with strong affinity for benzothiazoles. Representative new compounds 1-[(5,7-difluoro-2-benzothiazolyl)-methyl]-1H-indazoleacetic acid (62), [6-[[5-(trifluoromethyl)benzothiazol-2-yl]methyl]-8-oxo- 6H-pyrido[2,3-d]-pyridazin-5-yl]acetic acid (70), 3,4-dihydro-4-oxo-5,6-dimethyl-3-[(5,7-difluorobenzothiazol-2-yl) methyl]-1-pyridazineacetic acid (79), and 3,4-dihydro-4-oxo-5,6-cyclohexano-3-[[5-(trifluoromethyl) benzothiazol-2-yl]-methyl]-1-pyridazineacetic acid (82) are potent aldose reductase inhibitors with IC50s of 30, 2.1, 5, and 52.2 nM, respectively. The best of these compounds, 79 and 82, also inhibit accumulation of sorbitol in rat sciatic nerve in a model of diabetic complications, when administered orally at 10 mg/kg. The inhibition values are 76 and 61%, respectively. In addition to benzothiazole, we have examined its surrogates effective in potentiating aldose reductase inhibition activity, including benzoxazole and aryl[1,2,4]oxadiazole. Structure-activity relationships emerging from this program are also discussed.
A novel process for methanol synthesis. Progress report, June 1, 1993--September 30, 1993 (1993)

A bench-scale reactor is being used to conduct studies of the conversion of synthesis gas to methanol (MeOH) in the liquid phase by a novel process. In previous report, we provided evidence for a two step reaction in series, the carbonylation reaction mainly taking place close to the copper chromite surface, and the hydrogenolysis reaction taking place on the surface of the copper chromite. The interaction between the two catalysts enhanced the rate of MeOH formation. We have previously shown that, under present operating conditions, the methyl formate (MeF) concentration is not in equilibrium. The presence of H{sub 2}O results in a drop in the rate of MeF generation by the carbonylation reaction. In this quarter, preparation of the final report was continued.
An Imaging Model Incorporating Ultrasonic Transducer Properties for Three-Dimensional Optoacoustic Tomography (2010)

Optoacoustic tomography (OAT) is a hybrid imaging modality that combines the advantages of optical and ultrasound imaging. Most existing reconstruction algorithms for OAT assume that the ultrasound transducers employed to record the measurement data are point-like. When transducers with large detecting areas and/or compact measurement geometries are utilized, this assumption can result in conspicuous image blurring and distortions in the reconstructed images. In this work, a new OAT imaging model that incorporates the spatial and temporal responses of an ultrasound transducer is introduced. A discrete form of the imaging model is implemented and its numerical properties are investigated. We demonstrate that use of the imaging model in an iterative reconstruction method can improve the spatial resolution of the optoacoustic images as compared to those reconstructed assuming point-like ultrasound transducers.
Soil Permittivity Response to Bulk Electrical Conductivity for Selected Soil Water Sensors (2013)

Bulk electrical conductivity (σ a ) can dominate the low frequency dielectric loss spectrum in soils, causing changes in the permittivity and errors in estimated water content. We examined the dependence of measured apparent permittivity ( K a ) on σ a in contrasting soils using time‐domain reflectometry (TDR), a digital time‐domain transmission (TDT) sensor, and a capacitance sensor (5TE) during near saturated solute displacement experiments. Sensors were installed in columns packed with fine sand or a clay loam soil. Displacement experiments were completed by first equilibrating columns with 0.25 dS m −1 CaCl 2 , introducing a step pulse of ∼4.7 dS m −1 CaCl 2 and, after equilibration, displacing the resident solution with 0.25 dS m −1 CaCl 2 . Using TDR, measured K a increased with increasing σ a ; however, the slope of this response averaged 3.47 m dS −1 for clay loam compared with 0.19 m dS −1 for sand. The large response in the clay loam was attributed to relaxation losses that narrowed the effective bandwidth from 821 to an estimated 164 MHz. In contrast, the effective frequency in sand averaged 515 MHz. Permittivity measured using the TDT probe exhibited little or no sensitivity to σ a (<0.32 m dS −1 ) in both media. Measured K a using the 5TE probe declined with increasing σ a up to 1 to 1.8 dS m −1 and then increased thereafter with net negative responses for sand (Δ K a /Δσ a = −3.1 m dS −1 ) and net positive responses for the clay loam (Δ K a /Δσ a = 2.9 m dS −1 ). Consideration of the K a –σ a response is required for accurate soil water content estimation (±0.03 m 3 m −3 ) in the presence of solution EC variations using TDR in fine‐textured soils or the 5TE sensor in all media. Large differences in the sampling volumes between 5TE‐measured bulk EC and permittivity confounded the K a –σ a response in the presence of a concentration gradient.
Isoform specific anti-TGFβ therapy enhances antitumor efficacy in mouse models of cancer (2019)

Abstract TGFβ is a pleotropic cytokine, which has emerged as a potential target in cancer treatment due to its dual role in tumorigenesis and homeostasis. There are three isoforms of TGFβ (TGFβ1, TGFβ2 and TGFβ3), which are secreted by immune and nonimmune cells as an inactive latent complex. Depending on the local context and players, TGFβ can adopt opposing roles in carcinogensis and in modulating the immune system. However, the expression of TGFβ isoforms within the tumor microenvironment and isoform specific inhibition remains to be investigated. The main source of TGFβ isoforms in the tumor microenvironment of B16 melanoma are infiltrating immune cells, with TGFβ1 and TGFβ3 being highly expressed on myeloid and dendritic cells. The CD45− population from B16 tumors demonstrated a lower expression of both TGFβ isoforms. Compared to untreated control animals, anti-TGFβ3 therapy resulted in the greatest delay in B16 tumor growth, followed by anti-TGFβ1 therapy and pan-TGFβ blockade. However, none of the therapies resulted in improved overall survival. Similar results were achieved in a 4T1 breast model. T cell functional assays demonstrated that anti-TGFβ3 resulted in CD8+ T cells with greater cytolytic ability as they showed higher granzyme B expression and killing against B16 cells when plated ex-vivo. Anti-TGFβ1 treatment resulted in greater interferon-γ production by CD8+ T cells, suggesting an increase in antigen-specificity. Isoform specific TGFβ inhibition in combination with immune checkpoint blockade demonstrated improved tumor control and survival. This provides rationale for the use of anti-TGFβ therapy in stroma poor tumors, such as melanoma, and for its potential to enhance the effectiveness of existing therapies.
Synthesis and biological assays of a peptide from a tuberculin-active protein (1980)

The octapeptide Asp-Gly-Gly-Ser-Glu-Ser-Glu-Gly and the hexadecapeptide Asp-Gly-Gly-Ser-Glu-Ser-Glu-Gly-Lys-Asn-Gly-Ser-Gln-Met-Arg-Leu, part of a tuberculin-active intracellular mycobacterial protein, were synthesized. The synthetic peptides were shown to possess tuberculin activity by their ability to elicit a delayed-type allergic reaction in skin tests on Mycobacterium tuberculosis-sensitized guinea pigs. Purified protein derivative, the complex mixture of proteins of unknown composition which are excreted into the culture medium by M. tuberculosis and which is in wide use as a tuberculin-active preparation, was shown to cross-react weakly in the radioimmunoassays with the synthetic octapeptide when the 125I-labeled octapeptide and an anti-octapeptide antiserum were used.
Silicon carbide junction field effect transistors applied to solid-state power modulators (2004)

A new generation of power semiconductor devices is emerging based on the maturation of semiconducting silicon carbide. In this paper, alternatives to the divider resistors are presented using newly available 600-V, 2-A SiC JFETs. Two configurations are possible. The first employs a series combination of JFETs with shorted gate-source terminals operating as current limiting diodes. This allows a greater voltage to be blocked by the IGBT than can be blocked by currently available SiC JFETs. The superior thermal properties of SiC JFETs permit the larger bias currents required to drive the large IGBT gate capacitance at high repetition rates to be sourced. The second configuration is highly efficient and avoids thermal loading of the SiC JFET. The SiC current limiting diodes are replaced by a single SiC JFET switched concurrently with the IGBT. This configuration requires the SiC JFET to block the full voltage blocked by the IGBT, a capability expected in later generations of SiC JFETs. The gate drivers demonstrated in this paper are also applicable to power modulators using large arrays of silicon power MOSFETs. The near-term prospect for very fast SiC JFETs as replacements for silicon MOSFETs in power modulators is also discussed
Exosomes: New Tuberculosis Biomarkers – Prospects From the Bench to the Clinic (2012)

1 Provided that sputum can be obtained. 2 This method can discriminate between most NTM (exceptions are M. gordonae, M. kansasii, M. szulgai and M. marinum); but it cannot distinguish between other members of the Mtb complex (M
Ventral neural patterning by <i>Nkx</i> homeobox genes: <i>Nkx6.1</i> controls somatic motor neuron and ventral interneuron fates (2000)

There is growing evidence that sonic hedgehog (Shh) signaling regulates ventral neuronal fate in the vertebrate central nervous system through Nkx-class homeodomain proteins. We have examined the patterns of neurogenesis in mice carrying a targeted mutation in Nkx6.1. These mutants show a dorsal-to-ventral switch in the identity of progenitors and in the fate of postmitotic neurons. At many axial levels there is a complete block in the generation of V2 interneurons and motor neurons and a compensatory ventral expansion in the domain of generation of V1 neurons, demonstrating the essential functions of Nkx6.1 in regional patterning and neuronal fate determination.
Three-dimensional profiles for analysing protein sequence–structure relationships (1992)

In the method of 3D (three-dimensional) profiles, each residue position in a protein is characterized by its environment and is represented by a row of 20 numbers in a table, the profile. These numbers are the statistical preferences (called 3D-1D scores) of each of the 20 amino acids for this environment. A profile is computed from the coordinates of a protein model, and it gives a score S for any amino acid sequence folded as the model. To date 3D profiles have found three applications. The first is to identify other protein sequences which are folded in the same general pattern as the structure from which the profile was prepared. These are sequences which have high scores for the profile computed from the model. The second is to assess the validity of protein models, however determined. Correct models are found to give profiles that have high scores for their own amino acid sequences, and incorrect models are found to have lower scores. The example of the X-ray structure determination of diphtheria toxin is discussed. The third application is to assess which is the stable oligomeric state of a folded protein. Several examples suggest that the highest profile score for a sequence is achieved when the protein is aggregated into its most stable oligomeric state.
Application of two approaches to model chlorine residuals in Severn Trent Water Ltd (STW) distribution systems (1997)

Increasingly, those who work in the field of drinking water have demonstrated an interest in developing models for evolution of water quality from the treatment plant to the consumer's tap. To date, most of the modelling efforts have been focused on residual chlorine as a key parameter of quality within distribution systems. This paper presents the application of a conventional approach, the first order model, and the application of an emergent modelling approach, an artificial neural network (ANN) model, to simulate residual chlorine in a Severn Trent Water Ltd (U.K.) distribution system. The application of the first order model depends on the adequate estimation of the chlorine decay coefficient and the travel time within the system. The success of an ANN model depends on the use of representative data about factors which affect chlorine evolution in the system. Results demonstrate that ANN has a promising capacity for learning the dynamics of chlorine decay. The development of an ANN appears to be justifiable for disinfection control purposes, in cases when parameter estimation within the first order model is imprecise or difficult to obtain.
Nigexine, a Phospholipase A2 from Cobra Venom with Cytotoxic Properties Not Related to Esterase Activity (1989)

The venoms of the Naja species are known to be cytotoxic. This toxicity has been attributed to the presence of small nonenzymatic polypeptides of 60 amino acid residues, designated as cardiotoxins or cytotoxins. We investigated the cytotoxic potency of Naja nigricollis venom fractions and isolated another type of cytotoxic component which is even more potent than cardiotoxins. This cytotoxic compound, which was designated as nigexine, was purified to homogeneity and its amino acid sequence was determined. Nigexine is a basic phospholipase A2 consisting of a single chain of 118 amino acids. A detailed investigation of the cytotoxic effects on epithelial FL cells, C-13T neuroblastoma cells, and promyelocytic leukemia HL 60 cells revealed that nigexine not only altered cell viability but also prevented cell proliferation. This is a property that was specific to nigexine since other phospholipases A2 from various sources had no detectable cytotoxic activity. The cytotoxic activity of nigexine was not dependent on the presence of divalent cations, unlike its enzymatic activity. In particular, the cytotoxic activity of nigexine was identical in the presence or absence of either 2 mM Ca2+ or Sr2+, or 6 mM EDTA. We also present evidence based on chemical modifications that cytotoxic activity was not correlated with enzymatic activity. Thus, modification with parabromophenacyl bromide totally abolished the enzymatic activity of nigexine, which nevertheless retained 6-20% of the cytotoxicity of native nigexine. Conversely, treatment with cyanogen bromide gave a compound that retained 7% of the enzymatic activity of the parent molecule but was devoid of detectable cytotoxicity.
Amino acid 489 is encoded by a mutational "hot spot" on the beta 3 integrin chain: the CA/TU human platelet alloantigen system (1993)

A new platelet alloantigen, termed CA, has recently been implicated in a case of neonatal alloimmune thrombocytopenia (NATP) in a Filipino family in Canada. Maternal anti-CA serum reacted with glycoprotein (GP) IIIa and maintained its reactivity after removal of high mannose carbohydrate residues from GPIIIa. The monoclonal antibody (MoAb) AP3 partially blocked binding of anti-CA to GPIIIa, suggesting that the CA polymorphism is proximal to the AP3 epitope. Platelet RNA polymerase chain reaction (PCR) was used to amplify the region of GPIIIa cDNA that encodes this region of the protein. DNA sequence analysis showed a G<==>A nucleotide substitution at base 1564 that results in an arginine (Arg) (CGG)<==>glutamine (Gln) (CAG) polymorphism in amino acid (AA) 489. Further analysis of PCR-amplified genomic DNA from 27 normal individuals showed that AA 489 is encoded by a mutational "hot spot" of the GPIIIa gene, as three different codons for the wild-type Arg489 of GPIIIa were also found. The codon usage for Arg489 was found to be: CGG (63%), CGA (37%), and CGC (< 1%). These frequency data were valuable in determining the relationship of the CA alloantigen to the serologically defined TU GPIIIa polymorphism that is present in low frequency in the Finish population. Analyses of PCR-amplified genomic DNA showed the CA and TU alloantigens to be identical at the molecular level. Definition of these new molecular variants of the beta 3 integrin chain should prove valuable in the diagnosis of NATP in these two geographically disparate populations, and it may also provide useful genetic markers for examining other pathologic variations of the GPIIb-IIIa complex.
Comparative analysis of double-stranded RNA degradation and processing in insects (2017)

RNA interference (RNAi) based methods are being developed for pest management. A few products for control of coleopteran pests are expected to be commercialized soon. However, variability in RNAi efficiency among insects is preventing the widespread use of this technology. In this study, we conducted research to identify reasons for variability in RNAi efficiency among thirty-seven (37) insects belonging to five orders. Studies on double-stranded RNA (dsRNA) degradation by dsRNases and processing of labeled dsRNA to siRNA showed that both dsRNA degradation and processing are variable among insects belonging to different orders as well as among different insect species within the same order. We identified homologs of key RNAi genes in the genomes of some of these insects and studied their domain architecture. These data suggest that dsRNA digestion by dsRNases and its processing to siRNAs in the cells are among the major factors contributing to differential RNAi efficiency reported among insects.
Technical design issues for a field-portable supercritical fluid extractor (1995)

Supercritical fluid extraction is gaining acceptance as an alternative sample preparation method for trace organic analysis. The development of SFE instrumentation optimized for field use requires taking several technical design issues including size and weight requirements, user-friendly operation, and technical performance capabilities into consideration. Parameters associated with a prototype SFE instrument under development for potential use in conducting on-site inspections of the Chemical Weapons Convention and its preliminary technical and operational performance are described.