gebhart/patrepeval huggingface dataset:
THE ENZYMATIC FORMATION OF HYDROXAMIC ACIDS FROM GLUTAMINE AND ASPARAGINE (1950)

Although glutamine and asparagine have a wide distribution in nature, heretofore the only metabolic function ascribable to them on the basis of known enzymatic processes has been their participation in the metabolism of ammonia (1, 2).We have recently reported the formation of hydroxamic acids by the enzyme-catalyzed replacement of the amide groups of glutamine and asparagine with hydroxylamine (3-5).The same enzyme extract also catalyzes the exchange of the amide group of glutamine and asparagine with (isotopic) ammonia ( 6).The process would have considerable biological significance if it could be shown that amino acids can participate in an analogous reaction to form peptide bonds.The enzymatic formation of hydroxamic acids from glutamine and asparagine described here is different from the enzymatic synthesis of y-glutamohydroxamic acid from glutamic acid (7, 8).The latter reaction, which has been used as a model for glutamine synthesis, requires the utilization of adenosinetriphosphate as an external source of energy, whereas the formation of y-glutamo-and /3-aspartohydroxamic acids from the corresponding amides proceeds without the utilization of energy-rich phosphate bonds.The enzyme preparations which synthesize the hydroxamic acids from the amides and hydroxylamine can also split hydroxamic acids.The enzyme systems are widely distributed in microorganisms.In the present report the enzymatic synthesis of glutamo-and aspartohydroxamic acids from the two natural amides by enzymes occurring in cell-free extracts of Proteus vulgaris X-19 is described in detail.Some observations on the synthesis of glutamine from glutamic acid are also included. EXPERIMENTALFor the estimation of the hydroxamic acids, the color reaction with ferric chloride as used by Lipmann and Tuttle (9) was employed.The synthetic hydroxamic acids were prepared to serve as standards.
Scheduling multiclass queueing networks and job shops using fluid and semidefinite relaxations (1999)

Thesis (Ph.D.)--Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 1999.
P‐glycoproteins encoded by <i>mdr 1b</i> in murine gravid uterus and multidrug resistant tumor cell lines are differentially glycosylated (1989)

There are 3 members of the multidrug-resistance gene family expressed in mouse. Only one of these, mdr 1b, and its gene product P-glycoprotein are induced to high levels in the mouse endometrium during pregnancy. It is shown here that P-glycoprotein in the gravid uterus is significantly larger (Mr 155,000) compared to P-glycoprotein encoded by mdr 1b in a murine multidrug-resistant cell line (Mr 140,000). However, both species co-migrate after enzymatic removal of N-linked sugars (Mr 125,000). These results demonstrate that differential glycosylation of the mdr 1b gene product contributes to molecular heterogeneity found in P-glycoprotein from normal and multidrug-resistant cells.
The Use of A-C Field Measurements to Determine the Shape and Size of a Crack in a Metal (1981)

An instrument designed to measure the a-c field accurately has been built and fully tested on steel, aluminium, and titanium. These field measurements can be interpreted in terms of crack size, which provides a new technique for nondestructive testing (NDT) that requires no prior calibration. This paper describes the basic electronic measuring system, theoretical derivations of the electrical-field distribution, and application to industrial problems such as crack measurement in threads, shafting, welded connections, etc.
Expression of<i>Toxoplasma gondii</i>-Specific Heat Shock Protein 70 during In Vivo Conversion of Bradyzoites to Tachyzoites (1998)

Stage conversion between bradyzoites and tachyzoites was investigated in C57BL/6 mice chronically infected with the ME-49 strain of Toxoplasma gondii. In order to promote bradyzoite-tachyzoite conversion, mice were treated in vivo with neutralizing doses of anti-gamma interferon (IFN-gamma) or anti-tumor necrosis factor alpha (TNF-alpha) antibodies. Expression of parasite-specific antigens SAG-1, SAG-2, and heat shock protein 70 (Hsp-70) was visualized in the central nervous system by immunocytochemistry and measured by photometric assay. The immunosuppressive effect of anti-IFN-gamma or anti-TNF-alpha treatment was immediate, leading to parasite stage conversion as indicated by the increased expression of tachyzoite-specific antigens (SAG-1 and SAG-2) and by rapid parasite replication. We also observed expression of high levels of Hsp-70 during a short period of conversion of bradyzoites to tachyzoites. Our data suggest that Hsp-70 may have an important role in the process of bradyzoite-tachyzoite conversion during the reactivation of chronic toxoplasmosis.
Early Results after Staged Hybrid Repair of Thoracoabdominal Aortic Aneurysms (2007)

The hybrid approach for patients with TAAAs may reduce complications in the average, low-risk patient and may extend the indications for repair to patients considered higher risk based on age, comorbidities, or anatomic considerations.
Rearrangement approaches to cyclic skeletons. 6. Total synthesis of (.+-.)-ptilocaulin on the basis of formal bridgehead substitution and photochemical [1,3] acyl migration of a bicyclo[3.2.2]non-6-en-2-one system (1988)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRearrangement approaches to cyclic skeletons. 6. Total synthesis of (.+-.)-ptilocaulin on the basis of formal bridgehead substitution and photochemical [1,3] acyl migration of a bicyclo[3.2.2]non-6-en-2-one systemTadao Uyehara, Toshiaki Furuta, Yasuhiro Kabawawa, Junichi Yamada, Tadahiro Kato, and Yoshinori YamamotoCite this: J. Org. Chem. 1988, 53, 16, 3669–3673Publication Date (Print):August 1, 1988Publication History Published online1 May 2002Published inissue 1 August 1988https://pubs.acs.org/doi/10.1021/jo00251a004https://doi.org/10.1021/jo00251a004research-articleACS PublicationsRequest reuse permissionsArticle Views263Altmetric-Citations24LEARN 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
ChemInform Abstract: Effects of Ultrasound and Microwaves on Selective Reduction: Catalyst Preparation and Reactions (2014)

Abstract Review: 145 refs.
Kinetic and Spectroscopic Studies of N694C Lipoxygenase:  A Probe of the Substrate Activation Mechanism of a Nonheme Ferric Enzyme (2007)

Lipoxygenases (LOs) comprise a class of substrate activating mononuclear nonheme iron enzymes which catalyze the hydroperoxidation of unsaturated fatty acids. A commonly proposed mechanism for LO catalysis involves H-atom abstraction by an FeIII-OH- site, best described as a proton coupled electron transfer (PCET) process, followed by direct reaction of O2 with the resulting substrate radical to yield product. An alternative mechanism that has also been discussed involves the abstraction of a proton from the substrate by the FeIII-OH leading to a sigma-organoiron intermediate, where the subsequent sigma bond insertion of dioxygen into the C-Fe bond completes the reaction. H-atom abstraction is favored by a high E(o) of the FeII/FeIII couple and high pK(a) of water bound to the ferrous state, while an organoiron mechanism would be favored by a low E(o) (to keep the site oxidized) and a high pK(a) of water bound to the ferric state (to deprotonate the substrate). A first coordination sphere mutant of soybean LO (N694C) has been prepared and characterized by near-infrared circular dichroism (CD) and variable-temperature, variable-field (VTVH) magnetic circular dichroism (MCD) spectroscopies (FeII site), as well as UV/vis absorption, UV/vis CD, and electron paramagnetic resonance (EPR) spectroscopies (FeIII site). These studies suggest that N694C has a lowered E degrees of the FeII/FeIII couple and a raised pKa of water bound to the ferric site relative to wild type soybean lipoxygenase-1 (WT sLO-1) which would favor the organoiron mechanism. However, the observation in N694C of a significant deuterium isotope effect, anaerobic reduction of iron by substrate, and a substantial decrease in k(cat) (approximately 3000-fold) support H-atom abstraction as the relevant substrate-activation mechanism in sLO-1.
Reconstruction of frozen-core all-electron orbitals from pseudo-orbitals (2001)

We investigate the numerical feasibility of reconstructing frozen-core all-electron molecular orbitals from corresponding pseudo-orbitals. We perform density-functional calculations on simple atomic and molecular model systems using ultrasoft pseudopotentials to represent the atomic cores. We apply a transformation due to Blöchl [Phys. Rev. B 50, 17953 (1994)] to each calculated pseudo-orbital to obtain a corresponding frozen-core all-electron molecular orbital. Our model systems include the reconstruction of the 5d orbital of a gold atom, and the occupied valence states of the TiO2 molecule. Comparison of the resulting all-electron orbitals to corresponding ones that were obtained from calculations in which the core electrons were explicitly included indicates that all-electron molecular orbital reconstruction is a feasible and useful operation in reproducing the correct behavior of molecular orbitals in the nuclear core regions.
Electronic spectra of polyatomic molecules with resolved individual rotational transitions: Benzene (1981)

The density of rotational transitions for a polyatomic molecule is so large that in general many such transitions are hidden under the Doppler profile, this being a fundamental limit of conventional high resolution electronic spectroscopy. We present here the first Doppler-free cw two-photon spectrum of a polyatomic molecule. In the case of benzene, 400 lines are observed of which 300 are due to single rotational transitions, their spacing being well below the Doppler profile. The resolution so achieved is 1.5×107. Benzene is a prototype planar molecule taken to have D6h symmetry in the ground as well as in the first excited state. From our ultra-high resolution results it is found that benzene in the excited S1 state is a symmetric rotor to a high degree. A negative inertial defect is found for the excited state. The origin of this inertial defect is discussed.
Scattering of a sound wave from a grating of hollow elastic bars in a viscoelastic layer (1977)

The problem of the scattering of a normally incident plane sound wave by an infinite grating of hollow elastic bars in a viscoelastic layer between two fluid haft spaces is solved by the method of partial domains. The solution in the layer is formulated in terms of inhomogeneous plane dilatational and shear waves. The attenuation is found to be always normal to the plane of the grating. The evanescent waves in the viscoelastic medium necessarily cannot propagate parallel to the grating as is the case for an elasticlike or fluid medium. The dependence of the grating transmissivity on parameters of the individual bars and the complex-valued, frequency dependent, material properties of the layer is analyzed quantitatively. By using measured viscoelastic material properties as input to the model, comparisons of predictions of transmissivity are made with experimental data. [Work supported by NAVSEA.]
Diffusion of Methylaluminoxane (MAO) in Toluene Probed by 1H NMR Spin-Lattice Relaxation Time (2001)

A critical evaluation of model-fitted and observed 1H NMR spin-lattice relaxation time data (T1) of methylaluminoxane (MAO) dissolved in toluene suggests that the relaxation time of MAO is predominantly controlled by rotational motions. Within the Al concentration (CAl) range (10–3 M < CAl < 1 M) and the temperature range (90°C > T > 20°C) studied, the diffusion of MAO contributes with less than 20% (at the maximum concentration investigated) to the overall relaxation rate. For concentrations smaller than 0.5 M, the diffusion has no significant impact on the spin-lattice relaxation time (< 5%). Nevertheless, the diffusion coefficient of MAO can be estimated from the rotational correlation time, as derived from a spin-lattice relaxation time model discussed thoroughly in this work. This model gives information on the molecular dimension of MAO ((19.4 ± 0.4) Å), the activation energy of the diffusion process ((11.2 ± 0.7) kJ/mol), and the temperature/concentration dependence of the viscosity of the MAO solution.
Application of Trabecular Surface Remodeling Simulation to Design of Implant (2000)

mm
Segregation analysis of 159 soft tissue sarcoma kindreds: Comparison of fixed and sequential sampling schemes (1992)

In this study we compared parameter estimates and model hypotheses in pedigree data collected by fixed sampling with estimates and hypotheses derived by sequential sampling. Employing a fixed sampling scheme, we previously analyzed data on relatives of 159 childhood sarcoma patients. We have now extracted from that data set individuals who would have been included in a sequentially sampled study. We applied segregation analysis to the truncated data, to determine the mode of inheritance and major locus parameter estimates. With data from both sampling schemes we made a family-by-family comparison to determine each family's contribution to a major gene model. The two sampling schemes yielded similar results: we detected segregation of a dominant major gene and obtained similar major locus parameter estimates. However, the sequential sampling scheme derived these conclusions from data on 982 relatives rather than the 2,451 ascertained in the fixed sampling scheme. The sequential sampling scheme failed to identify only one of the kindreds likely to be segregating the gene. For this data set, the sequential sampling scheme would have provided an efficient mechanism to discriminate genetic hypotheses and would have permitted focus of resources on the specific kindreds likely to segregate a major gene.
Direct measurement of the energy spectrum of an intense proton beam (1983)

A time-resolved magnetic spectrometer has been used to measure the energy spectrum of an intense (0.5 TW/cm/sup 2/) proton beam. A thin (2400 A) gold foil placed at the focus of an ion diode Rutherford scattered protons by 90/sup 0/ into the spectrometer, reducing the beam intensity to a level suitable for magnetic analysis. The scattered beam was collimated by two 1 mm diameter apertures separated by 12.3 cm. The collimated protons were deflected in a 12.7 cm diameter, 6.65 Kg samarium-cobalt permanent magnet. The deflected protons were recorded simultaneously on CR-39 and eight 1 mm/sup 2/ by 35 ..mu..m thick PIN diodes. A Monte Carlo computer code was used to calculate the sensitivity and resolution of the spectrometer. Data taken on Proto-I show a 150 keV to 250 keV wide proton energy spectrum at each instant in time.
Protocol Independent Use Cases for an Interface to the Routing System (2014)

Programmatic interfaces to provide control over individual forwarding
devices in a network promise to reduce operational costs while
improving scaling, control, and visibility into the operation of large
scale networks. To this end, several programmatic interfaces have been
proposed. OpenFlow, for instance, provides a mechanism to replace the
dynamic control plane processes on individual forwarding devices
throughout a network with off box processes that interact with the
forwarding tables on each device. Another example is NETCONF, which
provides a fast and flexible mechanism to interact with device
configuration and policy. There is, however, no proposal which
provides an interface to all aspects of the routing system as a
system. Such a system would not interact with the forwarding system on
individual devices, but rather with the control plane processes
already used to discover the best path to any given destination
through the network, as well as interact with the routing information
base (RIB), which feeds the forwarding table the information needed to
actually switch traffic at a local level. This document describes a
set of use cases such a system could fulfill. It is designed to
provide underlying support for the framework, policy, and other drafts
describing the Interface to the Routing System (I2RS).
Fluorous Extraction (2017)

Approaches for analytical-scale extraction are developing rapidly as new strategies are implemented to improve sample throughput, to minimize material use in laboratory methods, and to develop on-site capabilities. In this contribution, definitions and recommendations for symbols for the terms used in analytical extraction are presented. Exhaustive, microextraction, elevated temperature, microwave- and ultrasound-assisted, parallel batch, flow through systems, and membrane extraction approaches are discussed. An associated tutorial titled “Extraction” provides a detailed introduction to the topic.
Role of S‐nitrosoglutathione reductase (GSNOR) Dysregulation and Nitrosative Stress in Heart Failure With Preserved Ejection Fraction (2022)

Background Heart failure with preserved ejection fraction (HFpEF) is the most predominant form of heart failure in the United States. This multi‐system pathology results in a 5‐year mortality rate for which there are very few treatment options. The obese ZSF1 rat model has previously been shown to recapitulate much of the human phenotype including obesity, metabolic syndrome, diabetes, and hypertension. In this study, we investigated the complex and largely unknown role of abnormal nitric oxide signaling and nitrosative stress in the pathobiology of HFpEF. Materials and Methods Male ZSF1 rats and normotensive controls of Wistar Kyoto (WKY) background strain (n=7 each group) were studied at 10, 14 and 18 weeks of age to monitor disease progression and alterations in nitric oxide signaling. Cardiac protein nitrosylation (RxNO) was measured by chemiluminescence. Analysis of circulating plasma nitrite bioavailability was performed using high performance liquid chromatography. GSNOR, one of the enzymes that degrade nitrosothiols, mRNA expression was measured and plotted as relative fold difference to WKY expression in this model of cardiometabolic HFpEF. Results ZSF1 rats exhibited significantly increased cardiac protein nitrosylation as the HFpEF phenotype progressed from 10 to 18 weeks of age as compared to the WKY rat group. GSNOR mRNA expression was significantly decreased in the ZSF1 rat relative to the WKY at all time points. During the later 18‐week timepont, cardiac GSNOR activity was found to be decreased compared to that of the WKY. Circulating plasma nitrite, a measure of eNOS function, was decreased in the ZSF1 rat at 14 and 18 weeks compared to the WKY at subsequent aging timepoints. These data correlate to an increasing left ventricular end diastolic pressure (LVEDP) and decreased vascular relaxation as the ZSF1 animals age and develop more severe HFpEF disease pathology. Conclusion Our data suggests that nitric oxide signaling is dysregulated in the setting of HFpEF resulting in a significant increase in cardiac protein nitrosylation coupled with a reduction in circulating nitrite and NO signaling in the vasculature. Excessive cardiac nitrosative stress resulting in pathological myocardial signaling has been previously implicated as a driver of HFpEF. Reduced vascular nitrite bioavailability resulting in attenuated physiological NO signaling could account for the profound vascular dysfunction observed in HFpEF patients. Future studies are aimed at the further elucidation of the role of various NO storage pools in HFpEF.
Dual-polarization microchip lasers at 1.53 &#x03BC;m (2006)

In this paper, we report on a microchip laser containing a birefringent element designed for emitting two orthogonal linear polarizations at 1.53 /spl mu/m. Then we investigate the polarization-resolved intensity noise and isolate the role of the nonlinear coupling on the relaxation oscillation frequencies.
Effects of a Synthetic Factor Xa Inhibitor (JTV-803) on Various Laboratory Tests (2002)

Synthetic direct inhibitors of factor Xa are capable of prolonging the global anticoagulant assay times in a concentration-dependent fashion. The relative degree of thrombin generation inhibition at an equivalent prolongation is not similar to the results observed with heparins and oral anticoagulant drugs. In addition, the direct factor Xa inhibitors prolong the Russell's viper venom test (RWT) and Heptest clotting times. Ecarin clotting time (ECT) and thrombin time (TT) remain unaffected. The kinetics of factor Xa inhibition are markedly different than those observed with pentasaccharide and heparins. Therefore, the methods developed for heparins and pentasaccharides may not be applicable for the monitoring of factor Xa inhibitors. To test the feasibility of using the prothrombin time (PT), International Normalized Ratio (INR), activated partial thromboplastin time (aPTT), Heptest, thrombin time, RVVT, ECT, and a modified anti-Xa amidolytic assay, to monitor a synthetic factor Xa inhibitor, normal human pool plasma samples were spiked with a synthetic factor Xa inhibitor in the concentration range of 0 to 1 microg/mL and 0 to 25 microg/mL. Different laboratory tests were performed and INR and other ratios were calculated. The anticoagulant effects on whole blood were measured using the activated clotting time (ACT). Further studies on the effect of factor Xa inhibitor on platelet aggregation; factor II, VII, and X functional levels; and fibrinopeptide A (FPA) generation were carried out at equivalent INR levels in comparison to oral anticoagulant and antithrombin agents. FPA generation at equivalent anticoagulant level in comparison to heparin (twice the baseline) was also carried out. Factor Xa inhibitor produced a concentration-dependent prolongation of the ACT. ACT was doubled at a concentration of 4 to 5 microg/mL. There was a marked difference in the prolongation of the PT by a synthetic factor Xa inhibitor dependent on the ISI of the PT reagent used. When the results were calculated to determine INR, marked variations were noted between the recombinant thromboplastin and rabbit brain thromboplastin. The rabbit brain thromboplastin reagent gave markedly high INR values. Similar results were observed when different aPTT reagents were studied. In the anti-Xa assay, modification of the incubation time was employed to extend the proper sensitivity range. These studies warrant further investigation to understand the mechanism of action of factor Xa inhibitors.
Double feature selection and cluster analyses in mining of microarray data from cotton (2008)

The novel application of double feature selection analysis led to the discovery of species- and stage-specific genetic expression patterns, which are biologically relevant to the genetic programs that underlie the differences in the fiber phenotypes in Pima and TM1. These results promise to have profound impacts on the ongoing efforts to improve cotton fiber traits.