gebhart/patrepeval huggingface dataset:
Nitrogen-15 nuclear magnetic resonance spectroscopy of neomycin B and related aminoglycosides (1983)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNitrogen-15 nuclear magnetic resonance spectroscopy of neomycin B and related aminoglycosidesRobert E. Botto and Bruce CoxonCite this: J. Am. Chem. Soc. 1983, 105, 4, 1021–1028Publication Date (Print):February 1, 1983Publication History Published online1 May 2002Published inissue 1 February 1983https://pubs.acs.org/doi/10.1021/ja00342a062https://doi.org/10.1021/ja00342a062research-articleACS PublicationsRequest reuse permissionsArticle Views434Altmetric-Citations101LEARN 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-Alertsclose Get e-Alerts
One-step solution for the multistep out-of-sequence-measurement problem in tracking (2004)

In multisensor target tracking systems measurements from the same target can arrive out of sequence. Such "out-of-sequence" measurement (OOSM) arrivals can occur even in the absence of scan/frame communication time delays. The resulting problem - how to update the current state estimate with an "older" measurement - is a nonstandard estimation problem. It was solved first (suboptimally, then optimally) for the case where the OOSM lies between the two last measurements, i.e, its lag is less than a sampling interval - the 1-step-lag case. The real world has, however, OOSMs with arbitrary lag. Subsequently, the suboptimal algorithm was extended to the case of an arbitrary (multistep) lag, but the resulting algorithm required a significant amount of storage. The present work shows how the 1-step-lag algorithms can be generalized to handle an arbitrary (multistep) lag while preserving their main feature of solving the update problem without iterating. This leads only to a very small (a few percent) degradation of MSE performance. The incorporation of an OOSM into the data association process is also discussed. A realistic example with two GMTI radars is presented. The consistency of the proposed algorithm is also evaluated and it is found that its calculated covariances are reliable.
Mutagenesis identifies the critical amino acid residues of human endonuclease G involved in catalysis, magnesium coordination, and substrate specificity (2009)

Based on the mutational analysis and homology modeling, we proposed that human EndoG shared a similar catalytic mechanism with nuclease A from Anabaena.
Selective hydrolysis by exo- and endonucleases of phosphodiester bonds adjacent to an apurinic site (1989)

Partial depurination of d-ApA produced two UV260nm-absorbing isomers, d-SpA and d-ApS (where S represents the depurinated deoxyribose sugar), that provided simple model compounds with which to examine, by HPLC, the response of nucleases to phosphodiester bonds flanked 3' or 5' by an apurinic site. The structural identity of each compound was established by (i) reaction with methoxyamine to confirm the presence of an abasic deoxyribose group, and (ii) degradation of d-SpA under mild alkaline conditions to distinguish it from d-ApS. At an enzyme concentration which led to complete hydrolysis of d-ApA, snake venom phosphodiesterase readily cleaved d-SpA to 5'-dAMP but had no discernible effect on d-ApS. Calf spleen phosphodiesterase also failed to act on one isomer, in this instance d-SpA, but additionally reacted at a much slower rate (approximately 100 fold) with d-ApS than with d-ApA. Three single-strand specific endonucleases, nuclease P1, nuclease S1 and mung bean nuclease, all responded in an identical manner, hydrolysing d-ApS but not d-SpA. The possibility that the aldehyde group at the AP sites might be responsible for some of these observations was rejected after repeating the enzyme digestions with the methoxyamine-capped molecules and observing no differences from the reactions with d-SpA and d-ApS.
High-Aperture, Medium-Loss Alkali-Leadsilicate Fibers Prepared by the Double Crucible Technique (1977)

Alkali-leadsilicate optical fibers with a numerical aperture of 0,47 and optical losses of 50 dB/km – 60 dB/km between 800 nm and 1100 nm were fabricated by employing the double crucible technique.
A highly digestible sorghum mutant cultivar exhibits a unique folded structure of endosperm protein bodies (2000)

The endosperm of a sorghum mutant cultivar, with high in vitro uncooked and cooked protein digestibilities, was examined by transmission electron microscopy and alpha-, beta-, and gamma-kafirins (storage proteins) were localized within its protein bodies. Transmission electron microscopy micrographs revealed that these protein bodies had a unique microstructure related to high protein digestibility. They were irregular in shape and had numerous invaginations, often reaching to the central area of the protein body. Protein bodies from normal cultivars, such as P721N studied here, with much lower uncooked and cooked digestibilities are spherical and contain no invaginations. Immunocytochemistry results showed that the relative location of alpha- and beta-kafirins within the protein bodies of the highly digestible genotype were similar to the normal cultivar, P721N. Gamma-kafirin, however, was concentrated in dark-staining regions at the base of the folds instead of at the protein body periphery, as is typical of normal cultivars. The resulting easy accessibility of digestive enzymes to alpha-kafirin, the major storage protein, in addition to the increased surface area of the protein bodies of the highly digestible cultivar appear to account for its high in vitro protein digestibility.
Phosphorylation of microtubule‐associated protein tau by isoforms of c‐Jun N‐terminal kinase (JNK) (2004)

Microtubule-associated protein tau in a hyperphosphorylated state is the major component of the filamentous lesions that define a number of neurodegenerative diseases commonly referred to as tauopathies. Hyperphosphorylation of tau at most sites appears to precede filament assembly. Many of the hyperphosphorylated sites are serine/threonine-proline sequences. Here we show that c-Jun N-terminal kinases JNK1, JNK2 and JNK3 phosphorylate tau at many serine/threonine-prolines, as assessed by the generation of the epitopes of phosphorylation-dependent anti-tau antibodies. Of the three protein kinases, JNK2 phosphorylated the most sites in tau, followed by JNK3 and JNK1. Phosphorylation by JNK isoforms resulted in a greatly reduced ability of tau to promote microtubule assembly. These findings extend the number of candidate protein kinases for the hyperphosphorylation of tau in Alzheimer's disease and other neurodegenerative disorders.
Nanostructuring Titania: Control over Nanocrystal Structure, Size, Shape, and Organization (1999)

Control over crystal structure, size, shape, and organization of TiO2 nanocrystals has been achieved by means of wet chemistry. Hydrolysis and polycondensation of titanium alkoxide [Ti(OR)4] has been performed in the presence of tetramethylammonium hydroxide (Me4NOH). This base both catalyzes the reaction and provides an organic cation that stabilizes the anatase polyanionic cores formed in this medium. These anatase clusters are organized so as to favour self-assembly into intermediate nanocrystals, which, in turn, self-assemble into superlattices. This self-assembling process has been exploited for the processing of highly structured titania films. Furthermore, larger anatase TiO2 nanocrystals of different sizes and shapes have been obtained by adjusting the relative concentrations of titanium alkoxide and Me4NOH, the reaction temperature, and the pressure. HRTEM, XRD, and EXAFS have been used to characterize the various samples and to elucidate the growth of titania anatase. Our observations are in accordance with theoretically predicted condensation and growth pathways. The formation of mesoscopic structures through a self-assembling process of the multiply charged polytitanate anions in the presence of Me4N+ is also discussed.
Condensation on Superhydrophobic Surfaces: The Role of Local Energy Barriers and Structure Length Scale (2012)

Water condensation on surfaces is a ubiquitous phase-change process that plays a crucial role in nature and across a range of industrial applications, including energy production, desalination, and environmental control. Nanotechnology has created opportunities to manipulate this process through the precise control of surface structure and chemistry, thus enabling the biomimicry of natural surfaces, such as the leaves of certain plant species, to realize superhydrophobic condensation. However, this “bottom-up” wetting process is inadequately described using typical global thermodynamic analyses and remains poorly understood. In this work, we elucidate, through imaging experiments on surfaces with structure length scales ranging from 100 nm to 10 μm and wetting physics, how local energy barriers are essential to understand non-equilibrium condensed droplet morphologies and demonstrate that overcoming these barriers via nucleation-mediated droplet–droplet interactions leads to the emergence of wetting states not predicted by scale-invariant global thermodynamic analysis. This mechanistic understanding offers insight into the role of surface-structure length scale, provides a quantitative basis for designing surfaces optimized for condensation in engineered systems, and promises insight into ice formation on surfaces that initiates with the condensation of subcooled water.
Delayed erythropoietin therapy reduces post-MI cardiac remodeling only at a dose that mobilizes endothelial progenitor cells (2006)

We examined the cardiac effects of chronic erythropoietin (EPO) therapy initiated 7 days after myocardial infarction (MI) in rats. A single high dose of EPO has been shown to reduce infarct size by preventing apoptosis when injected immediately after myocardial ischemia. The proangiogenic potential of EPO has also been reported, but the effects of chronic treatment with standard doses after MI are unknown. In this study, rats underwent coronary occlusion followed by reperfusion or a sham procedure. Infarcted rats were assigned to one of three treatment groups: 1) 0.75 microg/kg darbepoetin (MI+darb 0.75, n = 12); 2) 1.5 microg/kg darbepoetin (MI+darb 1.5, n = 12); 3) vehicle (MI+PBS, n = 16), once a week from day 7 postsurgery. Sham rats received the vehicle alone (n = 10). After 8 wk of treatment, the animals underwent echocardiography, left ventricular pressure-volume measurements, and peripheral blood endothelial progenitor cell (EPC) counting. MI size and capillary density in the border zone and the area at risk (AAR) were measured postmortem. The AAR was similar in the three MI groups. Compared with MI+PBS, the MI+darb 1.5 group showed a reduction in the MI-to-AAR ratio (20.8% vs. 38.7%; P < 0.05), as well as significantly reduced left ventricle dilatation and improved cardiac function. This reduction in post-MI remodeling was accompanied by increased capillary density (P < 0.05) and by a higher number of EPC (P < 0.05). Both darbepoetin doses increased the hematocrit, whereas MI+darb 0.75 did not increase EPC numbers or capillary density and had no functional effect. We found that chronic EPO treatment reduces MI size and improves cardiac function only at a dose that induces EPC mobilization in blood and that increases capillary density in the infarct border zone.
Inhibition of brain glutamine accumulation prevents cerebral edema in hyperammonemic rats (1991)

The mechanism of brain swelling during hyperammonemia is not understood, but glutamine accumulation is consistently observed. We tested the hypothesis that brain swelling associated with hyperammonemia is a consequence of the osmotic effect of intracellular glutamine accumulation in brain. Increases in plasma ammonium levels from 31 +/- 3 to 601 +/- 38 mumol/l (+/- SE) were produced by 6 h of infusion of ammonium acetate in anesthetized rats. Hyperammonemia resulted in increased brain water content accompanied by more than a tripling of brain glutamine concentration compared with control rats receiving sodium acetate (5.6 +/- 0.4 vs. 18.8 +/- 0.4 mmol/kg). Inhibition of glutamine synthetase activity by pretreatment with L-methionine sulfoximine prevented both the increase in brain glutamine levels and the increase in brain water content despite elevated plasma ammonium levels (908 +/- 196 mumol/l). Thus cerebral edema during hyperammonemia is associated with glutamine accumulation. We suggest that accumulated glutamine may serve as an idiogenic osmole causing swelling. Because brain swelling eventually leads to increased intracranial pressure and tissue hypoxia, these data suggest a unifying mechanism to account for the many pathophysiological abnormalities found during coma associated with various forms of liver disease, inborn errors of metabolism, and Reye's syndrome.
Stem cells: the intestinal stem cell as a paradigm (2000)

Stem cell research provides a foundation for therapeutic advancement in oncology, clinical genetics and a diverse array of degenerative disorders. For example, the elucidation of pathways governing proliferative regulation and differentiation within cellular systems will result in medical strategies aimed at the root cause of cancer. At present the characterization of reliable stem cell markers is the immediate aim in this particular field. Over the past 30 years investigators have determined many of the physical and functional properties of stem cells through careful and imaginative experimentation. Intestinal stem cells reside at the crypt base and give rise to all cell types found within the crypt. They readily undergo altruistic apoptosis in response to toxic stimuli although their progeny are hardier and will regain stem cell function to repopulate the tissue compartment, giving rise to the concept of a proliferative hierarchy. Contention exists when deciding whether the full complement of cells within a crypt is derived from either a single or multiple stems. Evidence has also arisen to challenge the long held view that colorectal tumours arise from a single mutated stem cell, as early adenomas from a human XO/XY mosaic contained distinct clones. Mechanisms governing the stem cell cycle and subsequent proliferative activity largely remain obscure. The adenomatous polyposis coli gene product has, however, been shown to promote the degradation of beta-catenin, an enhancer of cell proliferation, thereby downregulating this activity in healthy individuals.
Verifiable secret redistribution for archive systems (2003)

We present a new verifiable secret redistribution protocol for threshold sharing schemes that forms a key component of a proposed archival storage system. Our protocol supports redistribution from (m,n) to (m',n') threshold sharing schemes without requiring reconstruction of the original data. The design is motivated by archive systems for which the added security of threshold sharing of data must be accompanied by the flexibility of dynamic shareholder changes. Our protocol enables the dynamic addition or removal of shareholders, and also guards against mobile adversaries. We observe that existing protocols either cannot be extended readily to allow redistribution between different access structures, or have vulnerabilities that allow faulty old shareholders to distribute invalid shares to new shareholders. Our primary contribution is that in our protocol, new shareholders can verify the validity of their shares after redistribution between different access structures.
Analysis of droop control methods in DC microgrid (2014)

This paper deals with the droop control of load sharing among multiple sources in DC microgrid. The DC Electrical Power Distribution System (EPDS) with parallel sources are under study in this paper. The voltage-fed and the current-fed paradigms are investigated including the cases when the cable impedances cannot be neglected. Global voltage feedback and local voltage feedback are discussed in terms of current-fed approach. The effect of different methods on the power sharing accuracy is presented. In addition, an enhanced voltage compensation method is proposed for both approaches. The analysis is validated by simulation studies.
Glass waveguides on silicon for hybrid optical packaging (1989)

Work on deposited glass waveguides on silicon to form waveguides and filters is reviewed. The choice of these particular waveguides makes sense only as part of a consistent approach to optoelectronic packaging. Hybrid optical packaging on silicon (HOPS) is described and briefly compared with other techniques. For these packages, two waveguides were developed: a tight mode waveguide with a silicon nitride rib core for matching a semiconductor laser and a loose mode waveguide with a phosphosilicate glass core for matching an optical fiber.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Thermodynamic Analysis of Various Types of Hydride Vapor Phase Epitaxy System for High-Speed Growth of InN (2006)

The hydride vapor phase epitaxy (HVPE) of InN with various configurations was studied by thermodynamic analysis. For the high-speed growth of InN, analyses of the source zone and InN growth zone were performed. It was shown that the use of Cl2 instead of HCl as a chlorine source is necessary for the HVPE of InN. An additional supply of Cl2 was found to be effective for the preferential generation of a reactive InCl3 precursor. A new system, the (In–Cl2)–Cl2–NH3 system, was proposed for the HVPE of InN with a high growth rate.
Irinotecan: a new treatment in metastatic colorectal cancer (2000)

Objective. Historically, outcomes of metastatic colorectal cancer therapy have been disappointing, with fluorouracil (5-FU) producing response rates of no more than 15%. The addition of leucovorin increases response rates; however, survival rates are largely unaffected. Recently, the topoisomerase I inhibitor, irinotecan, has proved active in metastatic colorectal cancer and is indicated as second-line therapy following disease recurrence or progression after 5-FU-based therapy. More recently, irinotecan plus 5-FU-LV was compared with 5-FU-LV as first line treatment of colorectal cancer, showing impressive results. This article discusses the role of irinotecan, as a single agent and in combination with 5-FU-LV, in the treatment of advanced colorectal cancer. Data sources. A MEDLINE search was conducted using 5-fluorouracil, irinotecan, leucovorin, and metastatic colorectal cancer as primary search terms. Reference lists, bibliographies of pertinent articles, and abstracts from the American Society of Clinical Oncology and the European Society for Medical Oncology annual meetings were also identified and reviewed. Clinical literature was reviewed and analyzed. Data synthesis. Results of studies comparing irinotecan with continuos infusion 5-FU or best supportive care suggest that irinotecan is superior to either treatment as second-line therapy of metastatic colorectal cancer. Based on these study results, along with irinotecan's lack of cross-resistance with other chemotherapy agents and mechanism of action that differs from 5-FU, phase III trials evaluating the use of irinotecan in combination with 5-FU-LV as first-line treatment for advanced colorectal cancer were conducted. The results of a pivotal trial evaluating irinotecan plus 5-FU-LV in this setting show superior response rates (RRs), time to tumor progression (TTP), and median survival times (MSTs) when compared with 5-FU-LV alone. This combination represents a major advance in the treatment of metastatic colorectal cancer and should be considered the first-line treatment standard.
Transferable Plasmid-Mediated Resistance to Streptomycin in Clinical Isolate of Yersinia pestis (2001)

Plasmid-mediated high-level resistance to multiple antibiotics was reported in a clinical isolate of Yersinia pestis in Madagascar in 1997. We describe a second Y. pestis strain with high-level resistance to streptomycin, isolated from a human case of bubonic plague in Madagascar. The resistance determinants were carried by a self-transferable plasmid that could conjugate at high frequencies to other Y. pestis isolates. The plasmid and the host bacterium were different from those previously associated with multiple-drug resistance, indicating that acquisition of resistance plasmids is occurring in this bacterial species. Emergence of resistance to streptomycin in Y. pestis represents a critical public health problem since this antibiotic is used as the first-line treatment against plague in many countries.
Digital image stabilization based on statistical selection of feasible regions (2009)

This paper presents a novel and robust approach for digital image stabilization system based on a statistical region analysis for dominant motion selection. The proposed stabilization system adaptively employs the feature-histogram for feasible region selection resulting in stabilization of undesired camera fluctuation regardless of object's movement. The main difference between the previous and proposed approaches is that existing state-of-the-art methods use points, edges, or bit-plane patterns to select the feasible regions, whereas the proposed algorithm employs a feature-histogram. Experimental results show that the proposed algorithm improves the stabilization performance by 7% on average with four times less computation than the existing methods by skipping motion estimation and feature detection in disqualified blocks. Therefore, the proposed algorithm is suitable for consumer applications such as video camcorders and digital cameras.