gebhart/patrepeval huggingface dataset:
Amino Acid Intermediates: α-Amino-γ-lactones (1948)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAmino Acid Intermediates: α-Amino-γ-lactonesJeanne Fillman and Noel AlbertsonCite this: J. Am. Chem. Soc. 1948, 70, 1, 171–174Publication Date (Print):January 1, 1948Publication History Published online1 May 2002Published inissue 1 January 1948https://pubs.acs.org/doi/10.1021/ja01181a050https://doi.org/10.1021/ja01181a050research-articleACS PublicationsRequest reuse permissionsArticle Views232Altmetric-Citations25LEARN 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
Computational Mechanistic Study of the Hydrogenation of Carbonate to Methanol Catalyzed by the Ru<sup>II</sup>PNN Complex (2012)

Density functional theory computations have been carried out to study the mechanism of hydrogenation-based transformation of dimethyl carbonate to methanol, catalyzed by Ru(II)PNN catalyst. The energetic results show that the catalytic transformation includes three sequential stages consistently involving the catalyst: (stage I) transformation of dimethyl carbonate (3) to methyl formate (5) and methanol; (stage II) transformation of methyl formate 5 to formaldehyde and methanol; (stage III) hydrogenation of formaldehyde to methanol. Stages I and II proceed similarly and follow three steps: hydrogen activation, formation of a hemiacetal intermediate via stepwise hydrogen transfer to dimethyl carbonate in stage I or methyl fomate in stage II, and subsequent decomposition of the hemiacetal intermediate to afford methanol. Hydrogenation via carbonyl insertion into the Ru-H bond is less favorable than the stepwise hydrogen-transfer mechanism. Decomposition of hemiacetal takes places by first breaking the hemiacetal O-H bond to give an alkoxide complex, followed by deprotonation of the benzylic arm ligand to the adjacent methoxy group. Comparing the hydrogenation steps in the three stages, hydrogenation in stage I is most difficult, that in stage II is less difficult, and that in stage III is easiest in terms of both kinetics and thermodynamics. This can be ascribed to the stronger electrophilicity of the carbonyl group in methyl formate or formaldehyde than that in dimethyl carbonate and fewer steric effects between the catalyst and methyl formate or formaldehyde than that between the catalyst and dimethyl carbonate. Thermodynamically, both stages I and II are uphill, but stage III is downhill significantly, which is the driving force for the catalytic transformation. The study indicates that the methanol product could facilitate the hydrogen activation involved in the transformation, implying that transformation could be accelerated by initially adding methanol.
Ambipolar light-emitting organic field-effect transistors using a wide-band-gap blue-emitting small molecule (2007)

The authors applied a wide-band-gap (2.9eV) molecule of 4,-4′-bis(styryl)biphenyl (BSBP) as an active layer in light-emitting organic field-effect transistors. They found that BSBP provided both relatively high field-effect hole mobility of 0.01cm2∕Vs and photoluminescence efficiency of 20% in thin film. They achieved ambipolar operation by without breaking vacuum through devices’ preparation and measurements, applying aluminum contacts, and inserting a hydroxyl-free poly(methylmethacrylate) layer, and light emission was observed when the device was operated in the ambipolar mode. The results presented here will open the way to fabricating efficient light-emitting transistors with high mobility.
Lack of clonal BCRA2 gene deletion on chromosome 13in chronic lymphocytic leukaemia (1997)

Chromosome 13q deletion is among the most common cytogenetic abnormalities in chronic lymphocytic leukaemia (CLL). We investigated the 13q14.3 deletion in 44 CLL patients by Southern blotting following purification of clonal B CLL cells to >90%. Two sets of probes were used to investigate the site of clonal deletion, the D13S25 and D13S319 markers (at 13q14.3) and probes for exons 11 and 26-27 of the BRCA2 gene (at 13q12). Homozygous and heterozygous deletion at the 13q14.3 region was found in five and 17 patients, respectively. Despite the recent report of the BRCA2 gene involvement in >80% of CLL patients, we failed to detect a single case of homozygous or heterozygous deletion involving the 13q12 region. Our data support previous findings that the 13q14.3, and not the 13q12 region, is the major site of candidate tumour suppressor gene(s) in CLL.
Diagnosis of single photon emission tomography images using artificial neural networks (1992)

The authors discuss work being performed to apply artificial neural networks (ANNs) to the diagnosis of single photon emission computerized tomography images of the human brain. At this early stage work is concentrating on using ANNs to recognise the presence of regions of abnormal blood perfusion due to Baso-spasm. >
OleDetection Forensics and Anti-forensics of Steganography in OLE2-Formatted Documents (2009)

New and improved data hiding techniques pose a problem for forensic analysts investigating computer crime. Computer criminals are able to hide information using stego-channels available in commonly used document formats, thereby hindering an investigator from acquiring possibly important evidence. In this paper, we focus on detecting the use of stego-channels in the unused or dead space regions in the Object Linking and Embedding 2 (OLE2) specification used primarily by Microsoft's Office. The OleDetection algorithm presented in this paper is focused on detecting the use of these stego-channels using a three-step process comprising the detection of dead regions in a document, the extraction of binary data and the generation of appropriate statistics using kurtosis and byte-frequency distribution, and the comparison of the calculated statistics with threshold values, which determines whether or not the document contains hidden data. This algorithm extends the work done by the StegOle algorithm. Our experimental results show that the OleDetection algorithm can correctly identify 99.97 percent of documents with previous stego-channel techniques with a false positive rate of only 0.65 percent. In addition, we present an anti-forensic technique wherein OLE2 documents can be modified to hide data with greater detection avoidance characteristics; thus reducing the accuracy of the current OleDetection implementation.
Long-term impaired neutrophil migration in mice overexpressing human interleukin-8. (1994)

The proinflammatory chemokine interleukin-8 (IL-8/NAP-1) has been implicated in recruiting neutrophils to sites of acute and chronic tissue inflammation. In transgenic mice, elevated serum IL-8 levels ranging from 1 to 118 ng/ml were correlated with proportional increases in circulating neutrophils and proportional decreases in L-selectin expression on the surface of blood neutrophils. No change in the expression of the beta 2-integrins Mac-1 and LFA-1 was apparent on peripheral blood neutrophils of the IL-8 transgenic mice. Additionally, L-selectin expression on bone marrow neutrophils and neutrophil precursors was normal in all transgenic lines. IL-8 transgenic mice demonstrated an accumulation of neutrophils in the microcirculation of the lung, liver and spleen. Moreover, there was no evidence of neutrophil extravasation, plasma exudation or tissue damage in any IL-8 transgenic mice. Neutrophil migration into the inflamed peritoneal cavity was severely inhibited in IL-8 transgenic mice, but not in nontransgenic littermates. The IL-8 transgenic mice should serve as useful models for studying the putative role of neutrophils in mediating tissue damage in models of inflammation, such as hepatic ischemia and reperfusion injury, cecal puncture and ligation, and glomerulonephritis.
Electrochemical functionalization of SWNT bundles in acid and salt media as observed by Raman and X‐ray photoelectron spectroscopy (2008)

Abstract We carried out electrochemical functionalization of single‐walled carbon nanotube mats (buckypaper) in HCl and KCl aqueous solutions by exposing them to electrochemical potentials above the Cl – oxidation potential and high Faradaic currents. Formation of C‐Cl covalent bonds was established by X‐ray Photoelectron Spectroscopy (XPS). Combining results from Raman, XPS and conductivity measurements, we find a significantly higher degree of covalent functionalization in the HCl solution as compared to the KCl one. We also discuss the impact of electrochemical doping and functionalization on the morphology and the conductivity of the SWNT sample. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation between Bone Mineral Density Measured by Dual-Energy X-Ray Absorptiometry and Hounsfield Units Measured by Diagnostic CT in Lumbar Spine (2013)

The trabecular area HU value consistently decreases with age. Based on the strong positive correlation between HU value and bone mineral density, CT-based HU values might be useful in detecting bone mineral diseases, such as osteoporosis.
Identification of a Soluble, High-Affinity Salicylic Acid-Binding Protein in Tobacco (1997)

Salicylic acid (SA) is a key component in the signal transduction pathway(s), leading to the activation of certain defense responses in plants after pathogen attack. Previous studies have identified several proteins, including catalase and ascorbate peroxidase, through which the SA signal might act. Here we describe a new SA-binding protein. This soluble protein is present in low abundance in tobacco (Nicotiana tabacum) leaves and has an apparent molecular weight of approximately 25,000. It reversibly binds SA with an apparent dissociation constant of 90 nM, an affinity that is 150-fold higher than that between SA and catalase. The ability of most analogs of SA to compete with labeled SA for binding to this protein correlated with their ability to induce defense gene expression and enhanced resistance. Strikingly, benzothiadiazole, a recently described chemical activator that induces plant defenses and disease resistance at very low rates of application, was the strongest competitor, being much more effective than unlabeled SA. The possible role of this SA-binding protein in defense signal transduction is discussed.
Operation of a Caterpillar 3516 Spark-Ignited Engine on Low-Btu Fuel (1987)

The use of an engine-generator package, fueled by landfill gas, to produce usable electrical power has generated considerable interest among both landfill operators and engine manufacturers. Landfill gas operation presents some unusual technical challenges that require preparation of the gas prior to engine consumption as well as modifications to the spark-ignited engine. The primary obstacles to landfill gas operation are the low-Btu content of the gas, its poor combustion characteristics, and fluctuations in the heating value of the gas. Even so, the engine was not derated from the standard natural gas generator set rating of 762 kW net electrical output. In addition, the engine performance was optimized to meet the EPA site laws for stationary gas engines while still maintaining very low brake specific fuel consumption (BSFC). Finally, 90 days of continuous operation demonstrated engine durability.
Self-organized ordered silver nanoparticle arrays obtained by solid state dewetting (2014)

Spontaneous dewetting of a silver layer on a templated silica substrate is proposed as a promising low-cost process to produce self-organized metallic nanostructures. Periodic gratings with inverted pyramid pattern and periods ranging from 200 to 1000 nm are fabricated by nanoimprint on a sol-gel silica layer. A silver layer is then deposited on the templated substrate by magnetron sputtering and annealed to form an array of well-organized islands by solid-state dewetting. The resulting islands are shown to have reduced diameter and size dispersion compared to arrays obtained in the same conditions on flat substrates. The density of defects in the periodic array is determined as a function of silver layer thickness and is lower than 10% in optimal conditions. Optical transmission spectra of periodic arrays are measured, showing extinction peaks that can be related to plasmon resonance. This resonance can be tuned by adjusting the period and particle diameter.
Dynamic State-Space Partitioning in External-Memory Graph Search (2011)

The scalability of optimal sequential planning can be improved by using external-memory graph search. State-of-the-art external-memory graph search algorithms rely on a state-space projection function, or hash function, that partitions the stored nodes of the state-space search graph into groups of nodes that are stored as separate files on disk. Search performance depends on properties of the partition; whether the number of unique nodes in a file always fits in RAM, the number of files into which the nodes of the state-space graph are partitioned, and how well the partition captures local structure in the graph. Previous work relies on a static partition of the state space, but it can be difficult for a static partition to simultaneously satisfy all of these criteria. We introduce a method for dynamic partitioning and show that it leads to improved search performance in solving STRIPS planning problems.
Identity harmonization for federated HPC, grid and cloud services (2016)

With the increasing acceptance of multiple authentication mechanisms, federated infrastructures need to provide means of keeping consistency between multiple user identities. Although the current authentication and authorization infrastructures are designed to support multiple ways of authentication (SAML, OpenID Connect, X.509), they are missing unified protocols and interfaces to harmonize multiple user identities. This article introduces the concept of identity harmonization for federated cloud services. Our approach is based on the standardized System for Cross-domain Identity Management (SCIM) protocol. We add the support for account linking and per-service verification. Furthermore, the concept is put into context of currently existing federated infrastructures and is exemplified within a federated e-infrastructure currently developed in the course of the INDIGO-Datacloud project. The concept is evaluated in the INDIGO testbed in terms of deployability, scalability, provisioning and deprovisioning of user accounts, as well as maintenance and integration effort.
Persistent diplopia after retrobulbar anesthesia (2004)

Fifty percent of the cases of diplopia were associated with either direct trauma or anesthetic myotoxicity to the extraocular muscles, in which overactions were more common than underactions. Thirty-two percent of the patients were presumed to have sensory strabismus, which suggested the importance of preoperative examination for strabismus as well as providing an explanation about the risk of postoperative diplopia before surgery.
Method to model actions for discrete-event simulations of logistics networks (2017)

Managers of logistics networks have the complex task of continuously maintaining their network in good operating conditions under a changing environment. Thus, they need to identify promising actions to adapt and improve the logistics network. Such actions could be the relocation of stock or the adjustment of transport relations. In order to support the managers, the authors have previously proposed a decision support system (DSS) based on discrete-event simulation (DES). The DSS automatically examines possible actions and suggests the best actions found to the managers. Since a data-driven DES approach is used for this DSS, all actions can be described as changes to a database. In this paper, an approach for modeling, integrating and executing user-generated actions into the DSS is described, in order to increase its flexibility and usability. In conclusion, the authors propose to develop a domain-specific modeling language for modeling actions for DES models.
Electrical Resistivity of Undoped GaAs Single Crystals Grown by Magnetic Field Applied LEC Technique (1983)

We have grown undoped GaAs single crystals by magnetic field applied LEC (MLEC) technique and measured their electrical and optical properties. The most striking result was that the electrical resistivity of undoped GaAs changed from being semi-insulating (10 8 ohm-cm) to semi-conducting (10 ohm-cm) by increasing the magnetic field (0 to 1300 Oe). PL, DLTS and SIMS measurements suggest that the decrease of resistivity is mainly due to the decrease in concentration of the deep level defects.
Matrix effects on proficiency testing materials. Impact on accuracy of cholesterol measurement in laboratories in the nation's largest hospital system. (1993)

The objective of this collaborative study with the Department of Veterans Affairs (VA), College of American Pathologists (CAP), and the Centers for Disease Control and Prevention (CDC) was to quantitate the matrix-induced biases of cholesterol measurements on the CAP Comprehensive Chemistry Surveys materials used in proficiency testing (PT). A total of 174 VA Medical Centers outpatient clinics and clinical laboratories participate in the VA-CDC National Cholesterol Standardization and Certification Program. This study was conducted in 112 VA laboratories that have been standardized for measuring cholesterol accurately (within +/- 3.0% of the CDC reference-method values) using fresh, unfrozen, unadulterated human serum samples. Fresh serum samples and 1990 CAP Surveys materials were sent by overnight mail, and the laboratories were asked to analyze them simultaneously in triplicate in a single analytic batch run. The results showed significant matrix-effect biases with the CAP Surveys materials with six of the eight major peer groups, despite the fact that accuracy of cholesterol measurements was maintained with fresh serum samples. The magnitude and direction (positive or negative) of the matrix-effect biases were instrument, reagent, and method specific using the following peer groups: du Pont Dimension (-8.9%); Beckman CX4, CX5, and CX7 (-5.5%); Kodak Ektachem 400, 500, and 700 (+4.4%); Instrumentation Laboratory Monarch (-3.1%); Baxter Paramax (-2.4%); Technicon SMAC and RA (+1.3%); Hitachi/BMD 704 through 747 (+0.4%); and Abbott Spectrum (-0.3%). The CAP PT materials used currently do not behave in a manner identical to fresh human serum when measuring cholesterol on many, but not all, analytic systems. The observed biases due to "matrix effects" with PT materials will cause incorrect conclusions about the accuracy of many laboratory procedures performed on fresh patient specimens. This matrix-effect phenomenon will severely hamper interlaboratory accuracy transfer, standardization efforts, and monitoring performance of a laboratory's testing accuracy with the use of the current survey materials used in PT programs. Collaborative efforts are needed to (1) improve PT fluids to analytically behave more like fresh, human serum; (2) improve instrument design and reagent formulation; and (3) select methods and methodologic parameters that are more "robust" and less sensitive to the exact character of processed calibrators, quality control, and PT materials.
Temperature Error of the Vaisala RS90 Radiosonde (1997)

The new F-Thermocap sensor used on the Vaisala RS90 radiosonde is a miniaturized capacitive sensor designed to decrease the solar radiation error and the time lag error that exists with the Thermocap sensor used on the RS80 radiosonde. The heating and response characteristics of the F-Thermocap sensor were evaluated by developing a heat balance model, RS90COR, that calculates the temperature of the sensor relative to the air temperature in various flight environments. The temperature of the F-Thermocap sensor was found to be essentially identical to that of the atmosphere in all nighttime environments. In daytime conditions solar heating of the sensor increases its temperature to slightly above that of the ambient air. The daytime error increases with altitude but remains less than 0.5°C to an altitude of 35 km. The time lag error of the miniaturized sensor is insignificant. The RS90COR modeling results were validated by using model-predicted errors to correct RS90 and RS80 temperature profiles from sondes flown on the same balloon. The corrected profiles agreed, except for a temperature bias of 0.1°–0.3°C that results from a calibration or electronics error in one or both of the sondes. A new source of temperature error in daytime flights of RS80, RS90, and VIZ radiosondes has been discovered that relates to the orientation of the sensor with respect to the impinging solar radiation. This orientation error is smallest in the RS90 sensor.
Measurement of Ultrafast Phenomena in the Femtosecond Time Domain (1983)

Considerable progress has taken place in the generation and application of ultrashort optical pulses. The methods and techniques for extending time-resolved measurements into the femtosecond (10(-15) second) time domain are described, and recent applications and fertile areas for investigation with femtosecond pulses are discussed.
Time-Domain System Identification Methods for Aeromechanical and Aircraft Structural Modeling (2004)

Time-domain model structures and algorithms are described that are suitable for the identification of aeromechanical and aircraft structural models from input-output data. An efficient batch subspace identification algorithm and its online version are presented. The batch algorithm was implemented and evaluated for structural mode identification of the V-22 tilt rotor and for the identification of models of aeromechanical instability. The online algorithm is demonstrated with a numerical example in which structural modes are identified and tracked as they appear. Our results and comparisons with current aircraft industry practice show several advantages of time-domain subspace methods over Prony and frequency-domain methods. Specific advantages include the ability to identify multiple structural modes simultaneously from a single experiment, the ability to use online system identification, and the ability to identify open-loop systems from closed-loop experimental data. These advantages have a significant effect on the number of ground and flight tests required and on how to perform testing in unstable flight regimes.