gebhart/patrepeval huggingface dataset:
A QUANTITATIVE STUDY OF SEMICARBAZONE FORMATION (1932)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA QUANTITATIVE STUDY OF SEMICARBAZONE FORMATIONJames B. Conant and Paul D. BartlettCite this: J. Am. Chem. Soc. 1932, 54, 7, 2881–2899Publication Date (Print):July 1, 1932Publication History Published online1 May 2002Published inissue 1 July 1932https://doi.org/10.1021/ja01346a030RIGHTS & PERMISSIONSArticle Views1761Altmetric-Citations105LEARN 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 InReddit PDF (1 MB) Get e-Alerts Get e-Alerts
Addition of Chiral Glycine, Methionine, and Vinylglycine Enolate Derivatives to Aldehydes and Ketones in the Preparation of Enantiomerically Pure α‐Amino‐β‐Hydroxy Acids (1987)

Abstract Chiral enolates of imidazolidinones and oxazolidinones from the title amino acids react with carbonyl compounds to afford the corresponding alcohols in excellent yields (see Scheme 5 ). Furthermore, the addition to aldehydes proceeds with high diastereoselectivity to give, after acid hydrolysis, threo ‐α‐amino‐β‐hydroxy acids of high enantiomeric purity. Some of the threo ‐α‐amino‐β‐hydroxy acids prepared in this work are the proteinogenic ( S )‐threonine ( 26 ), the naturally occurring ( S )‐3‐phenylserine ( 28 ), and ( S )‐3‐hydroxyleucine ( 27 ) as well as the unnatural ( S )‐4,4,4‐trifluorothreonine ( 30 ) and ( S )‐3‐(4‐pyridyl)serine ( 31 ). The N ‐methylamide of (2 S ,3 R ,4 R ,6 E )‐3‐hydroxy‐4‐methyl‐2‐(methylamino)‐6‐octenoic acid ( 32 ), the unique amino acid in the immunosuppressive cyclosporine, was prepared by the new method. This report presents also information suggesting that both steric and stereoelectronic effects are responsible for the good stereoselectivities observed.
Unsupervised Learning of Word-Sequence Representations from Scratch via Convolutional Tensor Decomposition (2016)

Unsupervised text embeddings extraction is crucial for text understanding in machine learning. Word2Vec and its variants have received substantial success in mapping words with similar syntactic or semantic meaning to vectors close to each other. However, extracting context-aware word-sequence embedding remains a challenging task. Training over large corpus is difficult as labels are difficult to get. More importantly, it is challenging for pre-trained models to obtain word-sequence embeddings that are universally good for all downstream tasks or for any new datasets. We propose a two-phased ConvDic+DeconvDec framework to solve the problem by combining a word-sequence dictionary learning model with a word-sequence embedding decode model. We propose a convolutional tensor decomposition mechanism to learn good word-sequence phrase dictionary in the learning phase. It is proved to be more accurate and much more efficient than the popular alternating minimization method. In the decode phase, we introduce a deconvolution framework that is immune to the problem of varying sentence lengths. The word-sequence embeddings we extracted using ConvDic+DeconvDec are universally good for a few downstream tasks we test on. The framework requires neither pre-training nor prior/outside information.
Cloning and Functional Expression of an Inwardly Rectifying K <sup>+</sup> Channel From Human Atrium (1995)

The cardiac inward rectifier current (IK1) contributes to the shape and duration of the cardiac action potential and helps to set the resting membrane potential. Although several inwardly rectifying K+ channels (IRKs) from different tissues have been cloned recently, the nature and number of K+ channels contributing to the cardiac IK1 are presently unknown. To address this issue in human heart, we have used the reverse-transcriptase-polymerase chain reaction (PCR) technique with human atrial total RNA as a template to identify two sequences expressed in heart that are homologous to previously cloned IRKs. One of the PCR products we obtained was virtually identical to IRK1 (cloned from a mouse macrophage cell line); the other, which we named hIRK, exhibited < 70% identity to IRK1. A full-length clone encoding hIRK was isolated from a human atrial cDNA library and functionally expressed in Xenopus oocytes. This channel, like IRK1, exhibited strong inward rectification and was blocked by divalent cations. However, hIRK differed from IRK1 at the single-channel level: hIRK had a single-channel conductance of 36 pS compared with 21 pS for IRK1. We have identified single channels of 41, 35, 21, and 9 pS in recordings from dispersed human atrial myocytes. However, none of these atrial inward rectifiers exhibited single-channel properties exactly like those of cloned hIRK expressed in oocytes. Our findings suggest that the cardiac IK1 in human atrial myocytes is composed of multiple inwardly rectifying channels distinguishable on the basis of single-channel conductance, each of which may be the product of a different gene.
Backward-Wave Tubes (1953)

It has been surmised for some time that a travelingwave tube in which backward-traveling field components can be excited-such as for instance the "Millman" tube-may oscillate in a backward mode, the RF power emerging at the gun-end of the tube and its frequency depending only on the beam voltage. Experiments with the "Millman" tube show this to be so and oscillations have been observed in the first and second backward spatial-harmonic modes. The latter is excited between 600 and 900 volts, the tube oscillating between 5.9 and 6.4 mm. The former more powerful mode is excited between 1600 and 4000 volts, the tube tuning continuously between 6.0 and 7.5 mm, thus covering a frequency band of 10,000 mc. Power output of about 10 mw has been measured at 6.4 mm. The tube has also been studied as an amplifier and more than 20 db stable backward gain has been obtained. A simple theory of backward gain and of oscillation starting conditions is given.
Microgravity Manufacturing Via Fused Deposition (2003)

Manufacturing polymer hardware during space flight is currently outside the state of the art. A process called fused deposition modeling (FDM) can make this approach a reality by producing net-shaped components of polymer materials directly from a CAE model. FDM is a rapid prototyping process developed by Stratasys, Inc.. which deposits a fine line of semi-molten polymer onto a substrate while moving via computer control to form the cross-sectional shape of the part it is building. The build platen is then lowered and the process is repeated, building a component directly layer by layer. This method enables direct net-shaped production of polymer components directly from a computer file. The layered manufacturing process allows for the manufacture of complex shapes and internal cavities otherwise impossible to machine. This task demonstrated the benefits of the FDM technique to quickly and inexpensively produce replacement components or repair broken hardware in a Space Shuttle or Space Station environment. The intent of the task was to develop and fabricate an FDM system that was lightweight, compact, and required minimum power consumption to fabricate ABS plastic hardware in microgravity. The final product of the shortened task turned out to be a ground-based breadboard device, demonstrating miniaturization capability of the system.
MEMS devices and sensors in standard CMOS processing (2013)

Despite the usual approach of requiring a specific process and package for each MEMS device, it is possible to use standard CMOS plus a minimal post-processing, doable in any mainstream CMOS fab, to build many different types of MEMS devices and sensors. In addition to the ultra-low cost, high volume manufacturing capability, multiple sourcing and integration with other functions, this approach has the added benefits of smaller size and profile, improved performance and reduced time to market. These advantages come from the availability of many structural layers and several different materials in the process, which gives many additional degrees of freedom to the designer, enabling novel design concepts and new devices.
Electron transport and charge induction in cadmium zinc telluride detectors with space charge build up under intense x-ray irradiation (2010)

Under intense x-ray irradiation, wide band gap semiconductor radiation detectors fabricated from crystals with low hole transport properties develop a steady-state space charge distribution that results from a dynamic equilibrium between charge carrier dynamics and the incident photon field. At a high enough x-ray flux, this space charge can collapse the electric field within the detector, resulting in the paralyzation of photon counting (i.e., high-flux polarization). However, well before polarization causes a catastrophic device failure, there can be enough space charge present to significantly modify the electric field. A modified field affects the electron transport and, therefore, signal generation within the sensor, which can ultimately degrade the performance of high-rate photon counting electronics. In this study, we analytically solve the fundamental equation of charge conservation to derive the modified electron transport in the presence of an exponential space charge distribution that results from the incident x-rays. We use these space-time solutions to calculate and study the time dependence of the resulting charge-induced signals. The predicted induced signals are compared throughout with numerical solutions of the full charge transport equation. In addition, we present analogous closed-form signals for a uniform distribution relevant to a broader class of γ-ray applications. Finally, we use these solutions to derive a two-parameter family of modified Hecht curves that naturally predict a voltage offset that appears due to the space charge.
Preserved Bone Health in Adolescent Elite Rhythmic Gymnasts despite Hypoleptinemia (2007)

High impact training is able to counterbalance bone effects usually encountered in hormonally disturbed subjects. Our results suggest that hypoleptinaemia might be related to direct osteogenic effects and indirect hormonal mechanisms including preservation of IGF and cortisol levels.
Improvement in Jitter Characteristics in Mark Edge Recording for Phase Change Media (1993)

This paper describes improvement in jitter characteristics in mark edge recording (MER) for phase change media at a high linear velocity. Jitter of the mark edge position, usually caused by thermal and/or intersymbol interference, can also increase due to overwrite when MER is used with phase change media. We have found that the main cause of jitter increase due to overwrite is the difference in absorptivity between the amorphous and the crystalline states. We were able to reduce jitter significantly by controlling absorptivity through the use of a Si reflective layer. It was also confirmed that this improvement in jitter characteristics can achieve high recording density of 0.59 µm/bit.
Individually optimized uniform contrast enhancement in CT angiography for the diagnosis of pulmonary thromboembolic disease—A simulation study (2013)

The optimization approach generated individually optimized biphasic injection functions yielding significantly better contrast enhancement compared to the DFT approach. This new approach has the potential to improve the diagnostic quality of CTPA for PE.
The effects of ovariectomy and estrogen replacement on trkA and choline acetyltransferase mRNA expression in the basal forebrain of the adult female Sprague-Dawley rat (1996)

Cognitive deficits associated with aging and with neurodegenerative diseases such as Alzheimer's disease have been attributed to degeneration of cholinergic neurons in the basal forebrain. Estrogen is known to provide trophic support to cholinergic neurons, although the mechanisms underlying the actions of estrogen have yet to be determined. Because cholinergic neurons require neurotrophic growth factors for their survival, it is possible that the trophic effects of estrogen on basal forebrain systems are caused by enhanced expression of neurotrophins or their receptors. To begin to examine this hypothesis, we used in situ hybridization analysis to determine the effects of ovariectomy (ovx) and estrogen replacement on trkA mRNA levels in the rat basal forebrain. Ten days of estrogen deprivation after ovx resulted in significant decreases in trkA mRNA levels in the horizontal limb of the diagonal band of Broca and the nucleus basalis of Meynert. Short-term estrogen replacement therapy restored trkA mRNA expression to a level comparable with ovary-intact animals. No changes in trkA mRNA levels were observed in the vertical limb of the diagonal band of Broca after ovx or estrogen replacement. To assess the functional status of cholinergic neurons in the absence and presence of estrogen, the effects of ovx and estrogen replacement on ChAT mRNA levels were also examined and found to reflect the changes observed in trkA mRNA expression. These studies suggest that the trophic effects of estrogen on basal forebrain cholinergic systems may be mediated, in part, through the signaling of neurotrophic growth factors through their receptors.
Low Energy X-Ray and $\gamma$-Ray Detectors Fabricated on n-Type 4H-SiC Epitaxial Layer (2013)

Schottky barrier diode (SBD) radiation detectors have been fabricated on n-type 4H-SiC epitaxial layers and evaluated for low energy x- and γ-rays detection. The detectors were found to be highly sensitive to soft x-rays in the 50 eV to few keV range and showed 2.1 % energy resolution for 59.6 keV gamma rays. The response to soft x-rays for these detectors was significantly higher than that of commercial off-the-shelf (COTS) SiC UV photodiodes. The devices have been characterized by current-voltage (I-V) measurements in the 94-700 K range, thermally stimulated current (TSC) spectroscopy, x-ray diffraction (XRD) rocking curve measurements, and defect delineating chemical etching. I-V characteristics of the detectors at 500 K showed low leakage current ( nA at 200 V) revealing a possibility of high temperature operation. The XRD rocking curve measurements revealed high quality of the epitaxial layer exhibiting a full width at half maximum (FWHM) of the rocking curve ~3.6 arc sec. TSC studies in a wide range of temperature (94-550 K) revealed presence of relatively shallow levels ( ~0.25 eV) in the epi bulk with a density ~7×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> related to Al and B impurities and deeper levels located near the metal-semiconductor interface.
Communications realism for network simulations (2002)

The digital battlefield will present unprecedented requirements for the transfer of digital information (voice, data, and imagery). Realizing the vision of the Army's 21st century information transport architecture will require application of advanced modeling and simulation technology for performing architecture analysis, "what-if" drills, systems design, testing, and user training. The models and simulations must include communications realism, which is a simulation feature through which a synthetic environment reflects the same communications problems that exist in a real environment. Communications realism for link-level simulations has been achieved in the Integrated Terrain-Environment-Multipath Model (ITEMM). The paper describes the ITEMM, its real-time simulation algorithms, and work in progress to evolve these into a Real-Time Communications network Simulator (RTCNS) for use in a distributed interactive simulation (DIS) environment. It also describes how communication realism has been modeled for stationary and moving platforms and provides a detailed technical description of real-time simulation algorithms developed for modeling mobile radio links.
Synthesis of 5,5′′-<i>Bis</i>functionalized 2,2′ : 6′,2′′-Terpyridines using Functionalized Pyridine Building Blocks (1999)

5,5′′-Bis(hydroxytetramethylenoxymethyl)-2,2′ : 6′,2′′-terpyridine was synthesized in high yields utilizing organotin intermediates and Stille coupling procedures. Different functionalized pyridine precursors were prepared.
Phylogeny of the Stapes Prosthesis (2008)

An overview of the complicated phylogenetic tree for stapes prostheses gives great perspective to the history of stapedectomy and insights into many characteristics that are useful for designing new stapes prostheses.
Mesonephric contribution to testis differentiation in the fetal mouse (1993)

Testes from 11.5-day-old mouse embryos, with and without attached mesonephroi, were cultured for 7 days. Isolated testes failed to develop well-differentiated testis cords: however, when cultured attached to a mesonephros from either a male or a female donor embryo, testes developed cords that were normal in appearance. Testes cultured next to a mesonephric region but separated from it by a permeable filter, did not develop normal cords, nor did testes grafted to fragments of embryonic limb or heart. When testes were grafted to mesonephric regions from mice carrying a transgenic marker, the marker was found in some of the peritubular myoid cells and other interstitial cells of the testis, but not in the Sertoli cells or the germ cells. We conclude that after 11.5 days post coitum, cells can migrate from the mesonephric region into the differentiating testis and can contribute to the interstitial cell population, and that this contribution is necessary for the establishment of normal cord structure. The germ cells in all cultured testes, whether or not differentiated cords were present, were T1 prospermatogonia: no meiotic germ cells were seen.
A fuzzy logic based criterion for selecting relevant process parameters for design of nonwoven products (2006)

In this paper, we present a new fuzzy logic based selection criterion which takes into account both the conformity of human knowledge on nonwoven process technology and the sensitivity of measured data to the functional properties. This selection criterion permits to rank all process parameters (input variables) and select the most relevant parameters as input variables of the model for designing nonwovens products. Compared with the other relevant parameter selection criteria, the proposed method is more robust and less sensitive to measuring noises. This method has been validated using mathematical simulation and real data of a textile nonwoven process
Analysis of the NRT2 Nitrate Transporter Family in Arabidopsis. Structure and Gene Expression (2002)

Nitrate is an essential element for plant growth, both as a primary nutrient in the nitrogen assimilation pathway and as an important signal for plant development. The uptake of nitrate from the soil and its translocation throughout the plant has been the subject of intensive physiological and molecular studies. Using a reverse genetic approach, the AtNRT2.1 gene has been shown to be involved in the inducible component of the high-affinity nitrate transport system in Arabidopsis. The Arabidopsis Genome Initiative has released nearly the whole genome sequence of Arabidopsis, allowing the identification of a small NRT2 multigene family in this species. Thus, we investigated the phylogenetic relationship between NRT2 proteins belonging to several kingdoms and compared the structure of the different members of the Arabidopsis family. We analyzed, by semiquantitative reverse transcriptase-polymerase chain reaction, the expression pattern of each gene depending on plant organ and development or nutritional status, and compared the relative level of each gene by real-time polymerase chain reaction. We also evaluated the significance of each paralog on the basis of the relative levels of gene expression. The results are discussed in relation with distinct roles for the individual members of the AtNRT2 family.
The truth about metagenomics: quantifying and counteracting bias in 16S rRNA studies (2015)

Bias in 16S studies due to DNA extraction and PCR amplification will continue to require attention despite further advances in sequencing technology. Analysis of mock communities can help assess bias and facilitate the interpretation of results from environmental samples.
Rapid Hippurate Hydrolysis Method for Presumptive Identification of Group B Streptococci (1975)

A rapid test to detect the hydrolysis of sodium hippurate by beta-hemolytic streptococci within 2 h was developed. All group B streptococci tested were positive using this method and all other groups were negative.
Structure of the inclusion complex of β-cyclodextrin with 1,12-dodecanedioic acid using synchrotron radiation data; a detailed dimeric β-cyclodextrin structure (2000)

A detailed crystal structure study of the dimeric inclusion complex of beta-cyclodextrin (betaCD) with 1,12-dodecanedioic acid is presented [IUPAC name: beta-cyclodextrin-1,12-dodecanedioic acid (2/1)]. The structure was solved with synchrotron high-resolution data (0.65 A) at 100 K [crystal data: P1, Z= 1, a = 18.153 (7), b = 15.456 (8), c = 15.251 (4) A, alpha = 102.81 (2), beta = 113.13 (2), gamma = 99.90 (3)degrees, V = 3,673 (3) A3, R = 0.0474 for 25,134 unique reflections with I > 2sigma(I)]. Moreover, the room-temperature structure is used for comparison [crystal data: P1, Z = 1, a = 18.220 (3), b = 15.488 (3), c = 15.409 (3) A, alpha = 102.903 (6), beta = 113.122 (5), gamma = 99.708 (5)degrees, V = 3735.2 (12) A3, R = 0.0828 for 8,235 unique reflections with I > 2sigma(I)]. Combining the high-resolution data and the low-temperature made possible the location of the disordered guest molecule, 1,12-dodecanedioic acid, inside the wide cavity of the macrocycle formed by two betaCD monomers. Moreover, almost all the H atoms of the betaCD macrocycle and many of the water molecules have been located in the low-temperature structure. Thus, for the first time, it has been possible to show in detail, up to now only given by neutron diffraction data, that two betaCD monomers self-assemble through O3...O3 intermolecular hydrogen bonds to form the betaCD dimer, as well as describe the hydrogen-bonding scheme between the dimer's hydroxyl groups among themselves and with water molecules in the lattice. The long guest threads through two host molecules forming a [3]pseudorotaxane. Its polar carboxyl groups, fully hydrated at the primary faces of the betaCD dimers, influence their packing so that those faces are exposed to the solvent. This is in contrast to the packing of the beta-cyclodextrin complexes of the corresponding aliphatic monoacids, where the dimeric complexes form channels in order to isolate the terminal methyl group from the water environment of the lattice.