gebhart/patrepeval huggingface dataset:
The “weak base route” leading to transition metal–N-heterocyclic carbene complexes (2021)

N-Heterocyclic carbenes (NHCs) are nowadays ubiquitous in organometallic chemistry and catalysis. Recently, a synthetic method which makes use of weak bases and desirable solvents has emerged as a simple, widely applicable and cost-effective pathway to well defined M-NHC complexes. Herein, recent studies devoted to the weak base approach are examined in detail, in order to showcase the simplicity, scope and variations of the method with regards to the azolium salts, bases and the metal sources, as well as the reaction conditions used. Mechanistic investigations are presented, illustrating the formation of intermediates which are air and moisture stable, prior to the metallation step. Finally, the importance, limitations and future prospects of the weak base route are discussed.
Cloning and Characterization of a Gene Involved in Regulation of Sporulation and Cell Division of Streptomyces griseus. (1995)

A mutant of Streptomyces griseus, NY5, differs from the parent in sporulating when grown in a nutrient rich growth medium. Cloned genes of the wildtype organism in the multicopy plasmid pIJ702 transformed into the NY5 mutant cells resulted in converting the mutant phenotype of sporulating in rich medium to the parental genotype of not sporulating in rich medium. A 1.5 kb DNA fragment was sequenced and found to contain two open reading frame gene regions. Restriction deletion mapping and subcloning revealed a gene which when transformed in high copy number into S. griseus wildtype, mutant NY5 and S. lividans resulted in suppression of sporulation and fragmented cell growth. The gene, named ssgA (DDJB/EMBL/GenBank accession no. is D50051), encodes a 145 amino acid protein with a calculated size of 15.8 kDa. The predicted protein has a strong negative charge and shows no significant sequence homology to known proteins. Southern analysis detected regions in S. coelicolor and S. lividans DNA homologous to ssgA.
Simple, Chemoselective, Catalytic Olefin Isomerization (2014)

Catalytic amounts of Co(Sal(tBu,tBu))Cl and organosilane irreversibly isomerize terminal alkenes by one position. The same catalysts effect cycloisomerization of dienes and retrocycloisomerization of strained rings. Strong Lewis bases like amines and imidazoles, and labile functionalities like epoxides, are tolerated.
Electrochemically-reversible, single-electron oxidation of C60 and C70 (1993)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrochemically-reversible, single-electron oxidation of C60 and C70Qingshan Xie, Francisco Arias, and Luis EchegoyenCite this: J. Am. Chem. Soc. 1993, 115, 21, 9818–9819Publication Date (Print):October 1, 1993Publication History Published online1 May 2002Published inissue 1 October 1993https://pubs.acs.org/doi/10.1021/ja00074a066https://doi.org/10.1021/ja00074a066research-articleACS PublicationsRequest reuse permissionsArticle Views1073Altmetric-Citations143LEARN 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
Text Segmentation in Unconstrained Hand-Drawings in Whiteboard Photos (2012)

In this paper we present a robust method to detect handwritten text from unconstrained drawings on normal whiteboards. Unlike printed text on documents, free form handwritten text has no pattern in terms of size, orientation and font and it is often mixed with other drawings such as lines and shapes. Unlike handwritings on paper, handwritings on a normal whiteboard cannot be scanned so the detection has to be based on photos. Our work traces straight edges on photos of the whiteboard and builds graph representation of connected components. We use geometric properties such as edge density, graph density, aspect ratio and neighborhood similarity to differentiate handwritten text from other drawings. The experiment results show that our method achieves satisfactory precision and recall. Furthermore, the method is robust and efficient enough to be deployed in a mobile device. This is an important enabler of business applications that support whiteboard-centric visual meetings in enterprise scenarios.
Reactive power and voltage control in distribution systems with photovoltaic generation (2012)

This paper presents the interaction of traditional centralized voltage regulators such as load-tap-changing (LTC) transformers with the new emerging inverter-based distributed photovoltaic (PV) generators in reactive power and voltage control of distribution systems. Different reactive power control strategies for inverter-based PVs are considered and their interaction with LTC transformers is analyzed. The investigated objective function is the total electric losses for the 24 hours while satisfying the system operational constraints. Discrete Particle swarm optimization (DPSO) is used to determine the LTC operation scheme as an integer nonlinear optimization problem. The performance is validated by applying the proposed method to the standard IEEE 33 bus test system.
Metagenomic analysis and functional characterization of the biogas microbiome using high throughput shotgun sequencing and a novel binning strategy (2016)

This study is a pioneer research on the phylogenetic and functional characterization of the microbial community populating biogas reactors. By applying for the first time high-throughput sequencing and a novel binning strategy, the identified genes were anchored to single genomes providing a clear understanding of their metabolic pathways and highlighting their involvement in anaerobic digestion. The overall research established a reference catalog of biogas microbial genomes that will greatly simplify future genomic studies.
New Point-Focusing Monochromator (1954)

A method is described here for cutting and bending a single\ncrystal for a point-focusing monochromator which does not\nproduce a nondevelopable surface.
A position sensitive proportional counter with high spatial resolution (1973)

A parallel plate X-ray proportional counter with position sensitive anode is described. It is capable of resolving 0.2 mm in the soft X-ray region over a circular area a few centimetres across, while retaining good energy resolution.
Analysis of Ground-Based Radar for Space Surveillance in China (2008)

The increasing space debris threaten seriously the safety of spacecraft in low earth orbit(LEO),especially the manned spacecraft.Spatial debris disseminate mostly in LEO,within the detection range of ground radar capable of working at any time under any weather condition,so that developing ground-based surveillance radar is much more realistic in our country.On the demand of space debris exploration,this paper analyses the basic performance of the ground-based surveillance radar,gives out some simulation results of the radar detection capability.In the end,the chief technology analysis of the radar system is presented.
Kinetics of silane grafting and moisture crosslinking of polyethylene and ethylene propylene rubber (1992)

Abstract Peroxide initiated graft copolymerization of vinyl trimethoxy silane (VTMO) and vinyl triethoxy silane (VTEO) onto polyethylene (PE) and ethylene propylene copolymer (EPR) was studied. The kinetics of grafting, studied by differential scanning calorimetry, are the same for all the systems and the activation energy for VTMO is 170 ± 4 KJ/mol. Activation energy for VTEO is 185 ± 5 KJ/mol. The VTMO and VTEO graft copolymers of PE and EPR were prepared by reactive processing in a Brabender extruder in the temperature range of 150–200°C. Moisture catalyzed crosslinking of the silane grafted copolymer was also studied. The influence of the structure of the catalyst, its concentration, moisture concentration, temperature, and time on degree and rate of crosslinking has been evaluated. Crosslinking reactions follow first order kinetics with respect to both catalyst and moisture concentration. Activation energy ( E a ) of the crosslinking reaction has been determined as 65 KJ mol −1 . The mechanism of grafting and crosslinking is discussed.
FUNCTIONS AND MECHANISMS OF RNA EDITING (2000)

RNA editing can be broadly defined as any site-specific alteration in an RNA sequence that could have been copied from the template, excluding changes due to processes such as RNA splicing and polyadenylation. Changes in gene expression attributed to editing have been described in organisms from unicellular protozoa to man, and can affect the mRNAs, tRNAs, and rRNAs present in all cellular compartments. These sequence revisions, which include both the insertion and deletion of nucleotides, and the conversion of one base to another, involve a wide range of largely unrelated mechanisms. Recent advances in the development of in vitro editing and transgenic systems for these varied modifications have provided a better understanding of similarities and differences between the biochemical strategies, regulatory sequences, and cellular factors responsible for such RNA processing events.
Influence of polyethylene glycol on lactate dehydrogenase (1998)

It is well established that polyethylene glycol (PEG) shifts the equilibrium in oligomeric protein systems to form higher molecular weight associates. We used this effect of PEG to evaluate a modification of functional properties of LDH from pig skeletal muscles. PEG decreases the rate of heating-induced LDH inactivation in the concentration dependent manner. Michaelis constant and maximal velocity of the enzyme as well as inhibition of LDH by high pyruvate concentrations were affected by PEG. Enzyme preincubation with PEG suppresses also the formation of ternary inactive complex NAD-pyruvate-LDH.
A strategy for sampling on a sphere applied to 3D selective RF pulse design (1994)

Conventional constant angular velocity sampling of the surface of a sphere results in a higher sampling density near the two poles relative to the equatorial region. More samples, and hence longer sampling time, are required to achieve a given sampling density in the equatorial region when compared with uniform sampling. This paper presents a simple expression for a continuous sample path through a nearly uniform distribution of points on the surface of a sphere. Sampling of concentric spherical shells in k-space with the new strategy is used to design 3D selective inversion and spin-echo pulses. These new 3D selective pulses have been implemented and verified experimentally.
Synthesis of polysaccharide-b-PEG block copolymers by oxime click (2012)

The oxime click reaction is shown to be a straightforward methodology for the synthesis of poly(ethylene glycol) (PEG)-polysaccharide diblock copolymers. The method is applicable to unmodified polysaccharides with a reductive end as demonstrated for dextran, hyaluronic acid and chitosan. Notably the oxime click reaction is applied for the first time to the end modification of polysaccharides.
Oxidation of Steroids. III. Selective Oxidations and Acylations in the Bile Acid Series<sup>1</sup> (1950)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxidation of Steroids. III. Selective Oxidations and Acylations in the Bile Acid Series1Louis F. Fieser and Srinivasa RajagopalanCite this: J. Am. Chem. Soc. 1950, 72, 12, 5530–5536Publication Date (Print):December 1, 1950Publication History Published online1 May 2002Published inissue 1 December 1950https://pubs.acs.org/doi/10.1021/ja01168a046https://doi.org/10.1021/ja01168a046research-articleACS PublicationsRequest reuse permissionsArticle Views1261Altmetric-Citations184LEARN 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
Facile Synthesis of Fluorine‐Substituted Benzothiadiazole‐Based Organic Semiconductors and Their Use in Solution‐Processed Small‐Molecule Organic Solar Cells (2012)

A facile new protocol for the synthesis of iodinated derivatives of fluorinated benzothiadiazoles is demonstrated for the production of p-type semiconducting materials. The newly synthesized small-molecule compounds bis[TPA-diTh]-MonoF-BT and bis[TPA-diTh]-DiF-BT exhibited a power conversion efficiency of 2.95% and a high open-circuit voltage of 0.85 V in solution-processed small-molecule organic solar cells.
Plasmid-determined alcohol dehydrogenase activity in alkane-utilizing strains of Pseudomonas putida (1976)

We have identified an alcohol dehydrogenase activity in Pseudomonas putida strains carrying the CAM-OCT degradative plasmid that were grown on octane. The activity is nicotinamide adenine dinucleotide independent, sediments at 48,000 x g, and shows 20-fold greater activity with octanol rather than butanol as substrate. The enzyme is inducible by unoxidized alkane and is present only in strains that have the OCT plasmid genes for alkane degradation with a wild-type alcO locus. No analogous chromosomal dehydrogenase could be detected. Wild-type and actanol-negative mutants (alcA-) without plasmids both contain a constitutive nicotinamide adenine dinucleotide-linked soluble alcohol dehydrogenase activity. This means that alcA- mutants are cryptic for octanol oxidation and suggests that the particulate plasmid-coded alcohol dehydrogenase activity is active on surface- or membrane-bound substrate.
Isotopic characterisation of 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethylamphetamine (ecstasy) (2002)

Combined delta2H, delta13C and delta15N isotopic analysis of MDA and MDMA extracted from seized "ecstasy" tablets provides an isotopic "fingerprint" of the active ingredient allowing individual tablets to be linked to a common batch. Correlating these data with 2H NMR analysis of the extracts has the potential to study both the natural precursor materials and synthetic pathways used in the preparation of MDA and N-substituted homologues.
Protein–Polymer Hybrid Amphiphiles (2008)

Abstract Biohybrid amphiphiles composed of a protein head group and a hydrophobic polymer tail self‐assemble in water in a similar way as low molecular weight surfactants. Owing to the presence of the protein, biohybrid amphiphiles, and their assemblies, however, hold the additional feature of a built‐in (bio)functionality. These compounds therefore are promising building blocks for the synthesis of functional nanometer‐sized materials. We discuss recent advances in the relatively young field of protein–polymer hybrid amphiphiles, which so far mainly involved exploratory and fundamental studies providing a conceptual basis for the development of more complex systems with interesting applications in the future. magnified image
A 15-ns CMOS 64K RAM (1986)

The RAM was built using a technology with self-aligned TiSi/SUB 2/, single-level metal, an average minimum feature size of 1.35 /spl mu/m, and a minimum effective channel length of 1.1 /spl mu/m. An access of 10 ns is possible with the word line stitched on a second level of metal and some minor redesign. High speed is achieved through innovative circuits and design concepts. Novel CMOS circuits include a sense-amp set signal generator, a row decoder, and an input circuit. A layout-rule-independent graphics tool, which was used for the artwork design, is discussed.
Negative Charge Carrier Transport in Poly(methylmethacrylate-co-9-anthracenyl-methylmethacrylate) Thin Films (2000)

We have investigated the current–voltage characteristics of devices made of poly(methylmethacrylate-co-9-anthracenyl-methylmethacrylate) (10 : 1) sandwiched between aluminium electrodes. We found that the negative charge carrier mobility in this copolymer is equal to 3 × 10—11 cm2/Vs and that the negative charge carrier traps are distributed following an exponential distribution with a characteristic energy of 77 meV.
Nitride RCLEDs Grown by MBE for POF Applications (2002)

Data links by means of plastic optical fibres (POF) demand efficient light emitting diodes (LEDs) at 510 nm, the most promising candidate being nitride-based resonant-cavity LEDs (RCLEDs). These devices include InGaN/GaN multiple-quantum-well (MQW) structures, and GaN/AlGaN distributed Bragg reflectors. Molecular beam epitaxy (MBE) offers some advantages for the fabrication of nitride RCLEDs, like high In incorporation in the active region, and control of the interface quality in the mirror. The main steps in the development of nitride-based RCLEDs using radio-frequency plasma-assisted MBE are addressed, with emphasis in a) p-type doping of GaN by MBE; b) the optimisation of growth, the design and characterisation of AlGaN/GaN stacks for a reflector in the micro-cavity; and c) the growth of InGaN layers, InGaN/GaN MQWs, and conventional InGaN LEDs, which are studied by structural, electrical and optical techniques. The design and fabrication of nitride RCLEDs, which satisfy spectral and thermal specifications for POF applications, are finally described.
Phenylmaleic Anhydride as a Diene in the Diels-Alder Reaction (1951)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhenylmaleic Anhydride as a Diene in the Diels-Alder ReactionLeonard E. Miller and D. J. MannCite this: J. Am. Chem. Soc. 1951, 73, 1, 45–48Publication Date (Print):January 1, 1951Publication History Published online1 May 2002Published inissue 1 January 1951https://pubs.acs.org/doi/10.1021/ja01145a018https://doi.org/10.1021/ja01145a018research-articleACS PublicationsRequest reuse permissionsArticle Views107Altmetric-Citations9LEARN 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
Use of the DiversiLab System for Species and Strain Differentiation of <i>Fusarium</i> Species Isolates (2005)

Advances in molecular typing of fusariosis would facilitate the study of its epidemiology. We tested 26 such isolates by the commercially available Diversi Lab System. The system utilizes automated repetitive sequence-based PCR (rep-PCR) and web-based data analyses. rep-PCR dendrogram cluster analysis showed agreement with species sequence identification (elongation factor 1 alpha gene). Additionally, subtype differences within the same species were noted.
Smoothed Analysis: Analysis of Algorithms Beyond Worst Case (2011)

Abstract Many algorithms perform very well in practice, but have a poor worst-case performance. The reason for this discrepancy is that worst-case analysis is often a way too pessimistic measure for the performance of an algorithm. In order to provide a more realistic performance measure that can explain the practical performance of algorithms, smoothed analysis has been introduced. It is a hybrid of the classical worst-case analysis and average-case analysis, where the performance on inputs is measured that are subject to random noise. We give a gentle, not too formal introduction to smoothed analysis by means of two examples: the k -means method for clustering and the Nemhauser/Ullmann algorithm for the knapsack problem.
LuxR Homologue SmcR Is Essential for Vibrio vulnificus Pathogenesis and Biofilm Detachment, and Its Expression is Induced by Host Cells (2013)

Quorum sensing is a cell-to-cell communication system known to control many bacterial processes. In the present study, the functions of quorum sensing in the pathogenesis of Vibrio vulnificus, a food-borne pathogen, were assessed by evaluating the virulence of a mutant deficient in SmcR, a quorum-sensing regulator and homologue of LuxR. When biofilms were used as an inoculum, the smcR mutant was impaired in virulence and colonization capacity in the infection of mice. The lack of SmcR also resulted in decreased histopathological damage in mouse jejunum tissue. These results indicated that SmcR is essential for V. vulnificus pathogenesis. Moreover, the smcR mutant exhibited significantly reduced biofilm detachment. Upon exposure to INT-407 host cells, the wild type, but not the smcR mutant, revealed accelerated biofilm detachment. The INT-407 cells increased smcR expression by activating the expression of LuxS, an autoinducer-2 synthase, indicating that host cells manipulate the cellular level of SmcR through the quorum-sensing signaling of V. vulnificus. A whole-genome microarray analysis revealed that the genes primarily involved in biofilm detachment and formation are up- and downregulated by SmcR, respectively. Among the SmcR-regulated genes, vvpE encoding an elastolytic protease was the most upregulated, and the purified VvpE appeared to dissolve established biofilms directly in a concentration-dependent manner in vitro. These results suggest that the host cell-induced SmcR enhances the detachment of V. vulnificus biofilms entering the host intestine and thereby may promote the dispersal of the pathogen to new colonization loci, which is crucial for pathogenesis.
Battery Separators (2004)

Abstract For Abstract see ChemInform Abstract in Full Text.