gebhart/patrepeval huggingface dataset:
Pyridine Syntheses. III. Preparation and Reactions of Some Penta-substituted Pyridines (1951)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPyridine Syntheses. III. Preparation and Reactions of Some Penta-substituted PyridinesReuben G. JonesCite this: J. Am. Chem. Soc. 1951, 73, 12, 5610–5614Publication Date (Print):December 1, 1951Publication History Published online1 May 2002Published inissue 1 December 1951https://pubs.acs.org/doi/10.1021/ja01156a034https://doi.org/10.1021/ja01156a034research-articleACS PublicationsRequest reuse permissionsArticle Views234Altmetric-Citations15LEARN 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
Characteristics of porous nickel-titanium alloys for medical applications. (2002)

We investigate the behavior of NiTi porous alloys, possessing the property of shape memory, by using different characterization methods XPS, Auger, DSC and SEM. The study mainly focuses on the determination of porosity, surface characteristics and the phase transformation. In the case of porous material the biomechanical compatibility is closely related to the internal structure and porosity distribution. To describe appropriately the influence of the properties of NiTi on the memory shape, two types of materials provided by different sources has been analyzed. Despite the fact that both materials present different pores size, they exhibit an open and interconnected porosity. Our measurements show that the temperature of the inception of the martensite-austenite phase transition occurs at 60 degrees C, which is by 20 degrees C greater than the body temperature. Moreover, we show that the surface characteristics can be greatly influenced by heat treatment. Furthermore, we observe that the R-phase occurs only for one of the used materials after its heat treatment. The correlation between the composition and the other characteristics measured has been found.
A cross-sectional study of the Birmingham Vasculitis Activity Score version 3 in systemic vasculitis (2010)

The BVAS v. 3 has been evaluated in a large cohort of patients with vasculitis and the important properties of the tool revalidated. This study increases the utility of the BVAS v. 3 in different populations of patients with systemic vasculitis.
Laser ablation of solids for elemental analysis by inductively coupled plasma mass spectrometry (1987)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLaser ablation of solids for elemental analysis by inductively coupled plasma mass spectrometryPeter. ArrowsmithCite this: Anal. Chem. 1987, 59, 10, 1437–1444Publication Date (Print):May 15, 1987Publication History Published online1 May 2002Published inissue 15 May 1987https://pubs.acs.org/doi/10.1021/ac00137a014https://doi.org/10.1021/ac00137a014research-articleACS PublicationsRequest reuse permissionsArticle Views1070Altmetric-Citations218LEARN 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
Intrinsic signal amplification by type III CRISPR-Cas systems provides a sequence-specific SARS-CoV-2 diagnostic (2021)

There is an urgent need for inexpensive new technologies that enable fast, reliable, and scalable detection of viruses. Here, we repurpose the type III CRISPR-Cas system for sensitive and sequence-specific detection of SARS-CoV-2. RNA recognition by the type III CRISPR complex triggers Cas10-mediated polymerase activity, which simultaneously generates pyrophosphates, protons, and cyclic oligonucleotides. We show that all three Cas10-polymerase products are detectable using colorimetric or fluorometric readouts. We design ten guide RNAs that target conserved regions of SARS-CoV-2 genomes. Multiplexing improves the sensitivity of amplification-free RNA detection from 10<sup>7</sup> copies/μL for a single guide RNA to 10<sup>6</sup> copies/μL for ten guides. To decrease the limit of detection to levels that are clinically relevant, we developed a two-pot reaction consisting of RT-LAMP followed by T7-transcription and type III CRISPR-based detection. The two-pot reaction has a sensitivity of 200 copies/μL and is completed using patient samples in less than 30 min.
17‐Pivalate in der Pregnanreihe (1983)

Abstract Die sterisch gehinderte 17‐Hydroxygruppe in Pregnanen läßt sich nur in Gegenwart einer 21‐Acetoxygruppe mit Pivalinsäureanhydrid/4‐(Dimethylamino)pyridin verestern. Nach dieser Methode wird aus 4c über 5c das Corticosteroid 6 synthetisiert. Dagegen kann das 21‐Desoxy‐17‐pivalat 2e nur auf Umwegen aus dem 21‐Pivalat 1d über das Umlagerungsprodukt 2b , das Mesylat 2c und das 21‐Bromid 2d hergestellt werden. Die weitere Überführung in das 6α‐Methylderivat 8 erfolgt über das 6‐Methylensteroid 7 .
Fishing Down Marine Food Webs (1998)

The mean trophic level of the species groups reported in Food and Agricultural Organization global fisheries statistics declined from 1950 to 1994. This reflects a gradual transition in landings from long-lived, high trophic level, piscivorous bottom fish toward short-lived, low trophic level invertebrates and planktivorous pelagic fish. This effect, also found to be occurring in inland fisheries, is most pronounced in the Northern Hemisphere. Fishing down food webs (that is, at lower trophic levels) leads at first to increasing catches, then to a phase transition associated with stagnating or declining catches. These results indicate that present exploitation patterns are unsustainable.
Perylenetetracarboxylic Diimide Derivatives Linked with Spirobifluorene (2012)

A series of perylenetetracarboxylic diimide (PDI) compounds linked with spirobifluorene have been prepared. The orthogonal configuration of the PDI subunits efficiently hindered their molecular aggregation in solution. Energy transfer from a 1,7-diphenoxyl group substituted PDI (PO-PDI) to a 1,7-dipyrrolidinyl group substituted PDI (PY-PDI) occurred with a large efficiency when PO-PDI was selectively excited, despite the orthogonal orientation of the two units. This observation was in direct conflict with predictions derived from the Förster theory. More interestingly, this efficient energy transfer also occurred in the solid state.
Incidence and clinical symptoms of <i>Aeromonas</i>-associated travellers' diarrhoea in Tokyo (1997)

In a survey examining the causes of travellers' diarrhoea treated in Tokyo between July 1986 and December 1995, Aeromonas species were isolated from 1265 (5.5%) of 23,215 travellers returning from developing countries. Aeromonas species were the fourth most frequent enteropathogen isolated, following enterotoxigenic E. coli (8.5%), Salmonella spp. (7.6%) and Plesiomonas shigelloides (5.6%). Aeromonas species were found in 1191 (5.6%) of 21,257 patients with diarrhoea and in 74 (3.8%) of 1958 healthy individuals without diarrhoea. Mixed infection was observed in 512 (40.5%) cases. No significant difference in the prevalence of Aeromonas by year, season, age distributions, or sex was observed, but a slight difference was noted depending on the country where the travellers visited. Of the 1265 Aeromonas isolates, 893 strains (70.6%) were A. veronii biovar sobria, 330 (26.1%) were A. hydrophila, and 42 (3.3%) were A. caviae. The clinical symptoms of patients from whom Aeromonas species was isolated as the only potential enteric pathogen were almost similar, which were watery diarrhoea (about 60%), abdominal cramps (43%), fever (around 15%), and nausea or vomiting (13%). Although the severity of illness was milder than that of enterotoxigenic E. coli alone, these data suggest that Aeromonas species are important enteric pathogens in travellers' diarrhoea.
Chemical synthesis of proteins using hydrazide intermediates (2015)

Abstract Protein chemical synthesis offers useful and otherwise-difficulty-to-obtain biomacromolecules for biological and pharmaceutical studies. Recently, the hydrazide chemistry has drawn attentions in this field as peptide or protein hydrazides can be used as key intermediates for different synthesis and modification purposes. Besides being a traditional bioorthogonal chemical handle, a hydrazide group can serve as a readily accessible precursor of a thioester. This strategy significantly improves the efficiency and scope of native chemical ligation for protein chemical synthesis. Here we review the chemical transformations of peptide or protein hydrazides and total/semi/enzymatic protein synthesis methods involving peptide or protein hydrazides. Several examples of protein chemical synthesis using peptide hydrazides as key intermediates are described.
V-BLAST detection ordering method with H-ARQ (2008)

This paper proposes a detection ordering method for vertical Bell Labs layered space-time (V-BLAST) systems with multiple hybrid automatic repeat request (H-ARQ) processes. The proposed method uses the H-ARQ combining gain at each recursion stage of V-BLAST for deciding V-BLAST detection ordering. Using the proposed method, we can fully exploit the H-ARQ combining gain. Simulation results show that the proposed method improves bit error rate (BER) and throughput performance.
Advanced Semiconductor Lasers and Their Applications. Volume XXXI (1999)

Abstract : This volume of Trends in Optics and Photonics (TOPS) collects the papers from the 3rd ASLA conference, held July 21-23, 1999, in Santa Barbara, California. Continuing the tradition of diversity of this conference, the papers presented covered wavelengths from the visible to sub-millimeter, with spectral properties ranging from oscillations and chaos to high-purity single-mode operation. A particularly strong application area as always was sensing and spectroscopy; here, new sensor configurations were demonstrated in parallel with, or making use of, new diode laser characteristics. We hope you find these papers interesting and useful in your own work, and look forward to seeing you at the next ASLA meeting in 2001.
Update on the Cytogenetics and Molecular Genetics of Chordoma (2005)

Chordoma is a rare mesenchymal tumour of complex biology for which only histologic and immunohistochemical criteria have been defined, but no biomarkers predicting the clinical outcome and response to treatment have yet been recognised. We herein review the interdisciplinary information achieved by epidemiologists, neurosurgeons and basic scientists on chordoma, usually a sporadic tumour, which also includes a small fraction of familial cases. Main focus is on the current knowledge of the genetic alterations which might pinpoint candidate genes and molecular mechanisms shared by sporadic and familiar chordomas. Due to the scarcity of the investigated tumour specimens and the multiple chromosome abnormalities found in tumours with aberrant karyotypes, conventional cytogenetics and Fluorescence In Situ Hybridization failed to detect recurrent chordoma-specific chromosomal rearrangements. Genome-wide approaches such as Comparative Genomic Hybridization (CGH) are yet at an initial stage of application and should be implemented using BAC arrays either genome-wide or targeting selected genomic regions, disclosed by Loss of Heterozygosity (LOH) studies. An LOH region was shown by a systematic study on a consistent number of chordomas to encompass 1p36, a genomic interval where a candidate gene was suggested to reside. Despite the rarity of multiplex families with chordoma impaired linkage studies, a chordoma locus could be mapped to chromosome 7q33 by positive lod score in three independent families. The role in chordomagenesis of the Tuberous Sclerosis Complex (TSC) genes has been proved, but the extent of involvement of TSC1 and TSC2 oncosuppressors in chordoma remains to be assessed. In spite of the scarce knowledge on the genetics and molecular biology of chordoma, recent initiation of clinical trials using molecular-targeted therapy, should validate new molecular targets and predict the efficacy of a given therapy. Comparative genetic and biomolecular studies should enhance the molecular taxonomy of chordoma which might have a prognostic significance and better orient the therapeutic options.
A Companding Technique for PAPR Reduction of OFDM Systems (2008)

A companding technique using the hyperbolic tangent transform is proposed for reducing the peak-to-average-power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals. This technique is practical and can be implemented easily in integrated circuit design. The PAPR value of an OFDM system and the optimal companding coefficient to attain the minimum quantization error are derived. Error probability performance of the system after the companding is evaluated. Our simulation results exhibits that the system with the suggested scheme has nearly the same performance as the systems with the μ-law or A-law companding techniques.
International Space Station Robotics: A Comparative Study of ERA, JEMRMS and MSS (2002)

Robotic manipulators are essential for the construction and maintenance of the International Space Station (ISS). Manipulators will also be used to support experiments, extra-vehicular activity (EVA) and scientific activities onboard the ISS. The Canadian, Japanese and European Space Agencies are developing and delivering ‘robotic arms’, each with a specific role to play over the lifetime of the ISS. Each robotic manipulator has a unique design and task specific characteristics.
Direct autoregulation and gene dosage compensation by POU-domain transcription factor Brn3a (2002)

Brn3a is a POU-domain transcription factor expressed in peripheral sensory neurons and in specific interneurons of the caudal CNS. Sensory expression of Brn3a is regulated by a specific upstream enhancer, the activity of which is greatly increased in Brn3a knockout mice, implying that Brn3a negatively regulates its own expression. Brn3a binds to highly conserved sites within this enhancer, and alteration of these sites abolishes Brn3a regulation of reporter transgenes. Furthermore, endogenous Brn3a expression levels in the sensory ganglia of Brn3a(+/+) and Brn3a(+/-) mice are similar, demonstrating that autoregulation can compensate for the loss of one allele by increasing transcription of the remaining gene copy. Conversely, transgenic overexpression of Brn3a in the trigeminal ganglion suppresses the expression of the endogenous gene. These findings demonstrate that the Brn3a locus functions as a self-regulating unit to maintain a constant expression level of this key regulator of neural development.
Advances in LED packaging and thermal management materials (2008)

Heat dissipation, thermal stresses and cost are key light-emitting diode (LED) packaging issues. Heat dissipation limits power levels. Thermal stresses affect performance and reliability. Copper, aluminum and conventional polymeric printed circuit boards (PCBs) have high coefficients of thermal expansion, which can cause high thermal stresses. Most traditional low-coefficient-of-thermal-expansion (CTE) materials like tungsten/copper, which date from the mid 20th century, have thermal conductivities that are no better than those of aluminum alloys, about 200 W/m-K. An OIDA LED workshop cited a need for better thermal materials. There are an increasing number of low-CTE materials with thermal conductivities ranging between that of copper (400 W/m-K) and 1700 W/m-K, and many other low-CTE materials with lower thermal conductivities. Some of these materials are low cost. Others have the potential to be low cost in high-volume production. High-thermal-conductivity materials enable higher power levels, potentially reducing the number of required LEDs. Advanced thermal materials can constrain PCB CTE and greatly increase thermal conductivity. This paper reviews traditional packaging materials and advanced thermal management materials. The latter provide the packaging engineer with a greater range of options than in the past. Topics include properties, status, applications, cost, using advanced materials to fix manufacturing problems, and future directions, including composites reinforced with carbon nanotubes and other thermally conductive materials.
Block-oriented compression techniques for large statistical databases (1997)

Disk I/O has long been a performance bottleneck for very large databases. Database compression can be used to reduce disk I/O bandwidth requirements for large data transfers. The authors explore the compression of large statistical databases and propose techniques for organizing the compressed data such that standard database operations such as retrievals, inserts, deletes and modifications are supported. They examine the applicability and performance of three methods. Two of these are adaptions of existing methods, but the third, called tuple differential coding (TDC), is a new method that allows conventional access mechanisms to be used with the compressed data to provide efficient access. They demonstrate how the performance of queries that involve large data transfers can be improved with these database compression techniques.
Polymer swelling 2: A restudy of poly(styrene‐co‐divinylbenzene) swelling in terms of the cross‐link density<sup>1</sup> (1986)

Abstract A very convenient and reliable gravimetric method was developed for measuring swelling of poly(styrene‐co‐divinylbenzene) in particulate form. The method is based on the gravimetric procedure reported earlier 2 for monitoring liquid uptake by thin (<0.3 mm) microporous composite films, consisting of swellable particulate (80% by weight) enmeshed in poly(tetrafluoroethylene) microfibers (20%). The swellability S (in milliliter of liquid absorbed per gram of polymer in equilibrium with excess liquid) for six sty‐co‐DVB polymers with crosslink densities ranging from 0.01 to 0.12 was measured in 19 organic liquids. In each study of S as a function of the relationship was given by where is the average number of carbon atoms in the “backbone” of the polystyrene segments between cross‐link junction, C is the relative swelling power of the liquid, and is the critical cross‐link density above which S is equal to zero.
(+)- and (−)-<i>s</i><i>yn</i>-2-Isobutyl-4-methylazetidine-2,4-dicarboxylic Acids from the Extract of<i>Monascus</i><i>p</i><i>ilosus</i>-Fermented Rice (Red-Mold Rice) (2004)

The structures of two enantiomeric azetidine-type amino acids isolated from the n-butanol-soluble fraction of the 70% ethanol extract of red-mold rice fermented with Monascus pilosus were established to be (+)- [1; (+)-monascumic acid] and (-)-syn-2-isobutyl-4-methylazetidine-2,4-dicarboxylic acids [2; (-)-monascumic acid] based on spectroscopic methods.
FM‐dyes as experimental probes for dissecting vesicle trafficking in living plant cells (2004)

FM-dyes are widely used to study endocytosis, vesicle trafficking and organelle organization in living eukaryotic cells. The increasing use of FM-dyes in plant cells has provoked much debate with regard to their suitability as endocytosis markers, which organelles they stain and the precise pathways they follow through the vesicle trafficking network. A primary aim of this article is to assess critically the current status of this debate in plant cells. For this purpose, background information on the important characteristics of the FM-dyes, and of optimal dye concentrations, conditions of dye storage, and staining and imaging protocols, are provided. Particular emphasis is placed on using the FM-dyes in double labelling experiments to identity specific organelles. In this way, staining of the Golgi with FM4-64 has been demonstrated for the first time.
On strip packing With rotations (2005)

We present an asymptotic fully polynomial time approximation scheme for two-dimensional strip packing with rotations. In this problem, a set of rectangles need to be packed into a rectangle (strip) of fixed width and minimum height, and these rectangles can be rotated by 90°. Additionally, we present a simple asymptotic polynomial time approximation scheme, and give an improved algorithm for two-dimensional bin packing with rotations.
Active-RC filters using two-stage OTAs with and without feed-forward compensation (2011)

In this study, the design of active-RC filters using opamps with and without feed-forward-compensation is considered. Accurate analysis of the passive compensation scheme suggested in literature for lossless and lossy integrators using feed-forward-compensated opamps is carried out. The compensation for the lossy and lossless integrators using negative impedance converter for active filters using two cascaded gms in place of opamps is explored. Novel building blocks for realising the negative capacitance needed for exact compensation are proposed. To study the efficacy of the proposed compensation technique, a two-integrator loop biquad is considered. The PSPICE simulation results of Tow-Thomas biquad are presented to highlight the performance improvement obtained using the proposed compensation techniques.
Modeling personalized email prioritization (2011)

Email overload, even after spam filtering, presents a serious productivity challenge for busy professionals and executives. One solution is automated prioritization of incoming emails to ensure the most important are read and processed quickly, while others are processed later as/if time permits in declining priority levels. This paper presents a study of machine learning approaches to email prioritization into discrete levels, comparing ordinal regression versus classifier cascades. Given the ordinal nature of discrete email priority levels, SVM ordinal regression would be expected to perform well, but surprisingly a cascade of SVM classifiers significantly outperforms ordinal regression for email prioritization. In contrast, SVM regression performs well -- better than classifiers -- on selected UCI data sets. This unexpected performance inversion is analyzed and results are presented, providing core functionality for email prioritization systems.