gebhart/patrepeval huggingface dataset:
Improved measurement of stable isotope ratios in gas chromatography/mass spectrometry using the microwave-powered chemical reaction interface for mass spectrometry (1993)

The microwave-powered chemical reaction interface for mass spectrometry (CRIMS) has been successfully used for selective detection of analytes labeled with 13C, 15N and D following capillary gas chromatography separation with good analytical characteristics in biological applications. In this study we evaluated how an advanced data system coupled to a quadrupole mass analyzer could improve precision and sensitivity of stable isotope ratio measurements for 13C and 15N. The enrichments of 13C and 15N are determined by monitoring CO2 (m/z 44 and 45) and NO (m/z 30 and 31). These small molecules are produced from the analyte in the chemical reaction interface in the presence of SO2 as a reactant gas. Using caffeine and its 13C1, 15N2-labeled analog for these quantitative studies, we have found that the Vector 2 system improves overall precision (RSD = 0.6% for both carbon and nitrogen) and sensitivity of stable isotope measurements by at least a factor of two compared to the Vector 1 system, and by more than an order of magnitude compared to our older results. With the optimum system we are now able to measure an atom% enrichment of 0.0044 for 15N and 0.015 for 13C in caffeine in the presence of 300 ng of unlabeled material. This is more than half way between isotopic detection limits of conventional gas chromatography/mass spectrometry and the state-of-the-art, which is a gas chromatograph coupled to a chemical combustor and a dual-collector isotope ratio mass spectrometer.
What can we see with IVIM MRI? (2017)

Intravoxel Incoherent Motion (IVIM) refers to translational movements which within a given voxel and during the measurement time present a distribution of speeds in orientation and/or amplitude. The IVIM concept has been used to estimate perfusion in tissues as blood flow in randomly oriented capillaries mimics a pseudo-diffusion process. IVIM-based perfusion MRI, which does not require contrast agents, has gained momentum recently, especially in the field oncology. In this introductory review the basic concepts, models, technical requirements and limitations inherent to IVIM-based perfusion MRI are outlined, as well as new, non-perfusion applications of IVIM MRI, such as virtual MR Elastography.
A Novel Electricity Transaction Mode of Microgrids Based on Blockchain and Continuous Double Auction (2017)

The installed capacity of distributed generation (DG) based on renewable energy sources has increased continuously in power systems, and its market-oriented transaction is imperative. However, traditional transaction management based on centralized organizations has many disadvantages, such as high operation cost, low transparency, and potential risk of transaction data modification. Therefore, a decentralized electricity transaction mode for microgrids is proposed in this study based on blockchain and continuous double auction (CDA) mechanism. A buyer and seller initially complete the transaction matching in the CDA market. In view of the frequent price fluctuation in the CDA market, an adaptive aggressiveness strategy is used to adjust the quotation timely according to market changes. DG and consumer exchange digital certificate of power and expenditure on the blockchain system and the interests of consumers are then guaranteed by multi-signature when DG cannot generate power due to failure or other reasons. The digital certification of electricity assets is replaced by the sequence number with specific tags in the transaction script, and the size of digital certification can be adjusted according to transaction energy quantity. Finally, the feasibility of market mechanism through specific microgrid case and settlement process is also provided.
Accurate and Fast Harmonic Detection Based on the Generalized Trigonometric Function Delayed Signal Cancellation (2019)

The abundant grid-connected power electronic devices and non-linear loads used widely have caused power system harmonic pollution. Harmonic detection is very important for selective harmonic compensation used to improve the power quality. To detect the individual harmonic component accurately and fast, a harmonic extraction based on generalized trigonometric function delayed signal cancellation (GTFDSC) is proposed to extract the fundamental component or the desired harmonic component. The proposed GTFDSC can be used to accurately extract the desired harmonic component under various harmonic scenarios because of its excellent filtering capability. What’s more, the parameters of the GTFDSC can be flexibly designed according to the distribution of the harmonic series of the input signal, thereby reducing the delay time and the number of operators. Furthermore, the GTFDSC is self-adjustable to fundamental frequency deviations by introducing the frequency feedback loop, and it is able to achieve excellent filtering capability and fast dynamic performances. Lastly, the experimental results are provided to verify the effectiveness of the proposed method.
Triphase catalysis. Kinetics of cyanide displacement on 1-bromooctane (1976)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTriphase catalysis. Kinetics of cyanide displacement on 1-bromooctaneSteven L. RegenCite this: J. Am. Chem. Soc. 1976, 98, 20, 6270–6274Publication Date (Print):September 1, 1976Publication History Published online1 May 2002Published inissue 1 September 1976https://pubs.acs.org/doi/10.1021/ja00436a034https://doi.org/10.1021/ja00436a034research-articleACS PublicationsRequest reuse permissionsArticle Views131Altmetric-Citations82LEARN 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
Nitroethylene: a stable, clean, and reactive agent for organic synthesis (1980)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNitroethylene: a stable, clean, and reactive agent for organic synthesisDarshan Ranganathan, C. Bhushan Rao, Subramania Ranganathan, Ashok K. Mehrotra, and Radha IyengarCite this: J. Org. Chem. 1980, 45, 7, 1185–1189Publication Date (Print):March 1, 1980Publication History Published online1 May 2002Published inissue 1 March 1980https://pubs.acs.org/doi/10.1021/jo01295a003https://doi.org/10.1021/jo01295a003research-articleACS PublicationsRequest reuse permissionsArticle Views4243Altmetric-Citations128LEARN 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
Temperature-jump investigation of the kinetics of imidazole substitution of an iron(III) porphyrin in aqueous solution (1972)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTemperature-jump investigation of the kinetics of imidazole substitution of an iron(III) porphyrin in aqueous solutionGerald B. Kolski and Robert A. PlaneCite this: J. Am. Chem. Soc. 1972, 94, 11, 3740–3744Publication Date (Print):May 1, 1972Publication History Published online1 May 2002Published inissue 1 May 1972https://pubs.acs.org/doi/10.1021/ja00766a012https://doi.org/10.1021/ja00766a012research-articleACS PublicationsRequest reuse permissionsArticle Views89Altmetric-Citations22LEARN 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
Spotting method of phage typing mycobacteria. Typing mycobacteria with routine test dilutions. (1963)

In recent years it has become increasingly apparent that the methods formerly used for identification and differentiation of tubercle bacilli implicated in human disease are no longer adequate. The acceptance, in varying degrees, into this group of the strains presently known as the unclassified mycobacteria has largely been responsible for this inadequacy. At the present time it is recognized that much-needed clinical studies of disease associated with some of the unclassified mycobacteria are hampered by the lack of adequate means of identifying strains. Until methods of identification of these strains are worked out, making it possible for investigators in widely separated areas to compare results, very little progress along this line is likely to be made. The chemical methods that have been developed by Konno (1) and the color characteristics found by Runyon (2), although among the best methods thus far used, are not sufficiently specific to indicate slight degrees of differences or closeness of relationships in strains under study in two laboratories where slight variations in cultural conditions may alter the appearances of strains having the same origin. Among pathogenic bacteria, only two methods have been found to provide really specific identification of strains of microorganisms, namely, the serologic method and the typing method. In the case of mycobacteria, serology has not thus far produced very practical means of differentiating between closely related strains. Attempts to phage type mycobacteria have been carried out by Froman (3), Hnatko (4), Takeya (5), Penso (6), Tokunaga (7), and others, and have resulted in the bacterial strains being assembled into groups that were susceptible, or resistant, to a certain number of strains of bacteriophage. With the exception of Tokunaga's work, the typing tests were made by spotting heavy concentrations of on bac-
Stability Order in Metal Chelate Compounds. II. 5-(<i>p</i>-Sulfophenylazo)-salicylate Complexes (1964)

Abstract The interaction of 5-(p-sulfophenylazo)-salicylic acid with zinc(II), copper(II), nickel-(II), cobalt(II), manganese(II), magnesium(II), calcium(II) and iron(III) has been investigated in aqueous media at 25.0±0.1°C and the ionic strength of 0.10 m. The stability constants for the 1 : 1 and 2 : 1 (ligand to metal) chelates of nickel, cobalt, manganese and magnesium, and for the 1 : 1 calcium chelate, as well as for the 2 : 1 ferric chelate, have been evaluated, and the resulting stability order with respect to the bivalent metals has been found to follow the sequence: calcium(II)&lt;magnesium(II)&lt;manganese(II)&lt;(zinc(II))&lt;copper(II)&lt;nickel(II)&lt;copper(II). The stability sequence, zinc(II)&lt;nickel (II), is contrary to that observed for the catechol chelates. A p-sulfophenylazo group demonstrated an electron-withdrawing effect, the magnitude of which was slightly greater than that of a sulfonate group. However, the effect of the former group on the chelate-stability has been found to be comparable with that of the latter. The present salicylate derivative is also a good chelating agent for iron (III) ion, even though the chelate system somehow becomes involved in a higher pH range.
Fluidity: A General Theory (1972)

The equation varphi = B(V - V(o))/V(o), which reproduces the fluidity of simple liquids accurately over ranges between freezing and boiling points, is here shown to hold to pressures of at least 500 atm, and nearly to critical volumes. Fluidity can vary continuously above the critical region into that of compressed gas, where the parameter B becomes a function of temperature.The parameter V(o) is a "corresponding states" fraction of the critical molal volume. It is identical with the molal volume of the solid only in cases where molecules are free to rotate as they do in the liquid.Parameter B is a measure of the extent to which the external momentum that produces viscous flow is absorbed by the molecules of the liquid. Such damping can result from molecular mass, e.g., Ne, Ar, Kr; flexibility, normal alkanes; or rotational inertia, SiBr(4) against SiCl(4).
ChemInform Abstract: A Compilation and Analysis of Structural Data of Distorted Bridgehead Olefins and Amides (1993)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Controlled Reduction of Tertiary Amides to the Corresponding Alcohols, Aldehydes, or Amines Using Dialkylboranes and Aminoborohydride Reagents (2016)

Dialkylboranes and aminoborohydrides are mild, selective reducing agents complementary to the commonly utilized amide reducing agents, such as lithium aluminum hydride (LiAlH4) and diisobutylaluminum hydride (DIBAL) reagents. Tertiary amides were reduced using 1 or 2 equiv of various dialkylboranes. The reduction of tertiary amides required 2 equiv of 9-borabicyclo[3.3.1]nonane (9-BBN) for complete reduction to give the corresponding tertiary amines. One equivalent of sterically hindered disiamylborane reacts with tertiary amides to afford the corresponding aldehydes. Aminoborohydrides are powerful and selective reducing agents for the reduction of tertiary amides. Lithium dimethylaminoborohydride and lithium diisopropylaminoborohydride are prepared from n-butyllithium and the corresponding amine-borane. Chloromagnesium dimethylaminoborohydride (ClMg(+)[H3B-NMe2](-), MgAB) is prepared by the reaction of dimethylamine-borane with methylmagnesium chloride. Solutions of aminoborohydride reduce aliphatic, aromatic, and heteroaromatic tertiary amides to give the corresponding alcohol, amine, or aldehyde depending on the steric requirement of the tertiary amide and the aminoborohydride used.
Inhibition of Amyloid Fibril Formation by Peptide Analogues Modified with α‐Aminoisobutyric Acid (2004)

Breaking up is not hard to do with an α-aminoisobutyric (Aib) acid β-breaker, which has a remarkably restricted conformation. A novel approach to the inhibition of amyloid formation was developed that uses peptides modified with Aib (see figure). The similarity of Aib to hydrophobic amino acids, often found in amyloidogenic sequences, allows its integration into recognition motifs.
Image Analogy with Gaussian Process (2018)

Image analogy is the process of creating an image filter that precisely reflects the characteristics contained in the training data. Recently, the image analogy problem was generally handled by deep neural network (DNN) with the development of a deep learning technology. Generally, DNN suffers from a fatal problem in that it requires large amounts of data for training. However, as pairs of images with the same relationship are needed for an image analogy, it is hard to collect sufficient data for image analogy using DNN. In order to solve this problem, we propose an image analogy method using a Gaussian process. In this method, a Gaussian process regression is used instead of DNN regression to adjust the feature vectors which will be used in creating filtered image. Additionally, in order to accelerate the training speed of Gaussian process, we also propose novel sampling methods that select salient instances from a given dataset. Our experiment result demonstrates that the proposed image analogy method using a Gaussian process with salient instance sampling performs significantly better than DNN in environments with small dataset size.
Individual cell voltage equalizers (ICE) for reliable battery performance (2002)

The individual cell voltage equalizer (ICE) is a two-terminal voltage-controlled current shunt. The ICE unit is connected to the positive and negative terminals of each cell in a battery string. ICE provides each cell with an alternate current path for string float current. Using ICE makes it possible to check battery cells by using a simple digital voltmeter, when cell voltages deviate by more than +or-0.05 V per cell and capacity testing or replacement is required. ICE was designed to monitor and control individual cells in stationary battery strings. ICE monitors cell voltages and acts as current shunt by allowing current to bypass cells with high voltages. Conversely, current will pass through low voltage cells to bring voltage back to the current level. ICE was designed with limited shunting ability. Thus, weak cells are identified before failure. The result is timely and orderly cell replacement.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Role of cAMP in interleukin-1-induced kappa light chain gene expression in murine B cell line. (1990)

The murine lymphoid cell line 70Z/3 has been extensively used to study the intracellular mechanisms of interleukin-1 (IL-1) action. In these cells IL-1 is known to induce kappa gene expression but the signal transduction pathway has yet to be defined. IL-1-induced kappa expression is associated with stimulation of Na+/H+ exchange and activation of protein kinase C, but these events are not sufficient to trigger kappa expression. Thus, other signals must be present. Because cAMP is a well recognized second messenger, we sought to determine whether cAMP is the signal that triggers IL-1-induced kappa expression. To that end we first measured intracellular levels of cAMP following IL-1 treatment. The results showed that exposure of 70Z/3 cells to IL-1 alpha induced a rapid and a transient increase in cAMP, it peaked at 5 min and was back to base-line level at 20 min. Prostaglandin E2 (PGE2) also increased cAMP with similar kinetics to IL-1 alpha but the increased levels were far greater. IL-1 alpha-induced increase in cAMP proved not be a sufficient signal because an increase in intracellular cAMP by N6,O2'-dibutyryl cAMP (Bt2cAMP) or PGE2 failed to increase surface IgM or to increase kappa mRNA level. Although when used alone they had no effect, Bt2cAMP and PGE2 were found to amplify the IL-1 alpha-induced kappa expression. IL-1 alpha transiently activated NF-kappa B transcription factor. But this effect could not be simulated by Bt2cAMP or PGE2. This observation provides further evidence that cAMP is not a trigger of kappa expression. Although Bt2cAMP or PGE2 when used alone had no effect, they did consistently modify the level of NF-kappa B activity induced by IL-1 alpha. Results of this study show that cAMP is not sufficient to induce NF-kappa B or kappa expression. Therefore, the role of cAMP may not be trigger but rather to modulate the IL-1 alpha-induced kappa expression. Regulation of the response could occur at one or a number of points along the signal pathway. Such a regulatory role is supported by the observation that cAMP modulates the IL-1 alpha-induced NF-kappa B activity.
Stabilized HIV-1 Envelope Glycoprotein Trimers Lacking the V1V2 Domain, Obtained by Virus Evolution (2010)

The envelope glycoproteins (Env) are the focus of HIV-1 vaccine development strategies based on the induction of humoral immunity, but the mechanisms the virus has evolved to limit the induction and binding of neutralizing antibodies (NAbs) constitute substantial obstacles. Conserved neutralization epitopes are shielded by variable regions and carbohydrates, so one strategy to increase their exposure and, it is hoped, their immunogenicity is to delete the overlying variable loops. However, deleting the variable regions from Env trimers can be problematic, because hydrophobic patches that are normally solvent-inaccessible now become exposed, causing protein misfolding or aggregation, for example. Here, we describe the construction and characterization of recombinant gp140 trimers lacking variable domains 1 and 2 (ΔV1V2). The design of the trimers was guided by HIV-1 evolution studies that identified compensatory changes in V1V2-deleted but functional Env proteins (Bontjer, I., Land, A., Eggink, D., Verkade, E., Tuin, K., Baldwin, C., Pollakis, G., Paxton, W. A., Braakman, I., Berkhout, B., and Sanders, R. W. (2009) J. Virol. 83, 368-383). We now show that specific compensatory changes improved the function of ΔV1V2 Env proteins and hence HIV-1 replication. The changes acted by reducing the exposure of a hydrophobic surface either by replacing a hydrophobic residue with a hydrophilic one or by covering the surface with a glycan. The compensatory changes allowed the efficient expression of well folded, soluble gp140 trimers derived from various HIV-1 isolates. The evolved ΔV1V2 Env viruses were extremely sensitive to NAbs, indicating that neutralization epitopes are well exposed, which was confirmed by studies of NAb binding to the soluble ΔV1V2 gp140 trimers. These evolved ΔV1V2 trimers could be useful reagents for immunogenicity and structural studies.
Microbiologic Methods Utilized in the MAL-ED Cohort Study (2014)

A central hypothesis of The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) study is that enteropathogens contribute to growth faltering. To examine this question, the MAL-ED network of investigators set out to achieve 3 goals: (1) develop harmonized protocols to test for a diverse range of enteropathogens, (2) provide quality-assured and comparable results from 8 global sites, and (3) achieve maximum laboratory throughput and minimum cost. This paper describes the rationale for the microbiologic assays chosen and methodologies used to accomplish the 3 goals.