gebhart/patrepeval huggingface dataset:
Photoreflectance Line Shape at the Fundamental Edge in Ultrapure GaAs (1970)

Reflectance modulation produced by an intense secondary light beam (photoreflectance) has been studied for wavelengths near the fundamental edge in ultrapure epitaxial layers of GaAs as a function of doping, temperature, and intensity of the modulating light beam. As the doping increases, the built-in electric field at the surface increases and the photoreflectance line shape stretches, in qualitative agreement with the predictions of the Franz-Keldysh theory. These results show directly that the photoreflectance is due to the modulation of the electric field in the Schottky surface barrier by photoexcited carriers. Since the line shape is much narrower than earlier electroreflectance measurements, we arrive at a more accurate value for the band gap of 1.420 eV at 300 \ifmmode^\circ\else\textdegree\fi{}K. As the temperature is lowered, the spacing in energy between adjacent peaks in the photoreflectance spectrum decreases, indicating that the electric field at the surface is decreasing. This temperature dependence is explained by a simple model for the surface consisting of a large density of electron traps located a fixed energy below the conduction-band edge. For all but the purest sample, the line shape is independent of the intensity of the modulating beam, consistent with the model that the secondary light beam is only slightly modifying the surface electric field. However, in the purest sample available (${n}_{e}=1.65\ifmmode\times\else\texttimes\fi{}{10}^{13}$ ${\mathrm{cm}}^{\ensuremath{-}3}$), a new effect is observed at the highest intensities of the modulating beam (\ensuremath{\sim} 0.1 ${\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}$). The qualitative features of the new line shape agree with the predictions for both the Burstein effect and exciton screening by free carriers. Since the discrete exciton is thermally quenched at 300 \ifmmode^\circ\else\textdegree\fi{}K, the new line shape may result from the Burstein effect.
Measles Encephalomyelitis — Clinical and Immunologic Studies (1984)

We studied 19 patients with postinfectious encephalomyelitis complicating natural measles-virus infections, and our results support the hypothesis that this demyelinating disease has a pathogenesis similar to that of experimental allergic encephalomyelitis. Early myelin destruction was demonstrated by the presence of myelin basic protein in cerebrospinal fluid, and lymphocyte proliferative responses to myelin basic protein were found in 8 of 17 patients tested. A lack of intrathecal synthesis of antibody against measles virus suggests that measles encephalomyelitis may not be dependent on virus replication within the central nervous system. Similar lymphoproliferative responses to myelin basic protein of lymphocytes from single patients with encephalomyelitis after rabies vaccine or after varicella or rubella virus infections suggest a common immune-mediated pathogenesis for the perivenular demyelinating disease that can follow the injection of neural tissues or infection by a variety of viruses.
Interferon-Induced Protein 10 and Interleukin 8 (1998)

Both IL-8 and IP-10 participate in the pathogenesis of PDR.
Furnace and Rapid Thermal Annealing of P+/n Junctions in  BF 2  +  ‐ Implanted Silicon (1985)

Shallow p‐n diodes with junction depths between 0.15 and 0.3 μm have been fabricated by rapid thermal and furnace annealing of boron fluoride implants made into single‐crystal wafers. The implants were performed at 30 keV with a dose of or . For very shallow junctions, the residual implant damage is found to degrade the reverse bias diode leakage characteristics. The residual damage can be nearly eliminated and shallow junction characteristics can be improved by preamorphizing the wafers with a single 50 keV silicon implant at a dose of .
Plasma fibrinogen is associated with cognitive decline and risk for dementia in patients with mild cognitive impairment (2007)

This study was aimed to investigate the relationship between plasma fibrinogen level and risk for cognitive decline and dementia in patients with mild cognitive impairment (MCI). Elderly patients with suspected cognitive impairment were screened and evaluated periodically. One hundred and eighty-five patients who met the criteria for MCI were enrolled. Blood coagulation functions and plasma fibrinogen levels were measured at baseline. Hyperfibrinogenaemia was defined as plasma fibrinogen > or =3.0 g/l. Global cognitive function was assessed serially with Mini-Mental State Examination (MMSE). The enrolled patients were followed for 2 years to observe if dementia was developed. There were 185 patients diagnosed as MCI, of which 17 (9.2%) deceased, 15 (8.1%) lost to follow-up, and 68 (36.8%) developed dementia during follow-up. Mean of MMSE score of the enrolled patients declined significantly during follow-up (22.0 +/- 3.0 vs. 18.1 +/- 5.8, p < 0.001). Patients with hyperfibrinogenaemia at baseline had greater MMSE decrement during follow-up than patients with normal fibrinogen level (-5.4 +/- 5.4 vs. -3.5 +/- 4.5, p < 0.05). Linear regression indicated that plasma fibrinogen level was associated with cognitive decline (R = 0.17, p < 0.05). Patients with hyperfibrinogenaemia had an increased risk for dementia and vascular dementia compared with patients with normal level of plasma fibrinogen (log rank test, p < 0.05). There was a trend that hyperfibrinogenaemia also increased risk for dementia of Alzheimer's type (p = 0.061). It can be concluded that plasma fibrinogen level may be associated with cognitive decline, and hyperfibrinogenaemia may increase risk for dementia in patients with MCI.
Intramolecular Hydrogen Bonding in Derivatives of .beta.-Alanine and .gamma.-Amino Butyric Acid; Model Studies for the Folding of Unnatural Polypeptide Backbones (1994)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntramolecular Hydrogen Bonding in Derivatives of .beta.-Alanine and .gamma.-Amino Butyric Acid; Model Studies for the Folding of Unnatural Polypeptide BackbonesGregory P. Dado and Samuel H. GellmanCite this: J. Am. Chem. Soc. 1994, 116, 3, 1054–1062Publication Date (Print):February 1, 1994Publication History Published online1 May 2002Published inissue 1 February 1994https://pubs.acs.org/doi/10.1021/ja00082a029https://doi.org/10.1021/ja00082a029research-articleACS PublicationsRequest reuse permissionsArticle Views1869Altmetric-Citations238LEARN 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
Cyclic Carbonate Synthesis Catalysed by Bimetallic Aluminium–Salen Complexes (2010)

The development of bimetallic aluminium-salen complexes [{Al(salen)}(2)O] as catalysts for the synthesis of cyclic carbonates (including the commercially important ethylene and propylene carbonates) from a wide range of terminal epoxides in the presence of tetrabutylammonium bromide as a cocatalyst is reported. The bimetallic structure of one complex was confirmed by X-ray crystallography. The bimetallic complexes displayed exceptionally high catalytic activity and in the presence of tetrabutylammonium bromide could catalyse cyclic carbonate synthesis at atmospheric pressure and room temperature. Catalyst-reuse experiments demonstrated that one bimetallic complex was stable for over 60 reactions, though the tetrabutylammonium bromide decomposed in situ by a retro-Menschutkin reaction to form tributylamine and had to be regularly replaced. The mild reaction conditions allowed a full analysis of the reaction kinetics to be carried out and this showed that the reaction was first order in aluminium complex concentration, first order in epoxide concentration, first order in carbon dioxide concentration (except when used in excess) and unexpectedly second order in tetrabutylammonium bromide concentration. Further kinetic experiments demonstrated that the tributylamine formed in situ was involved in the catalysis and that addition of butyl bromide to reconvert the tributylamine into tetrabutylammonium bromide resulted in inhibition of the reaction. The reaction kinetics also indicated that no kinetic resolution of racemic epoxides was possible with this class of catalysts, even when the catalyst was derived from a chiral salen ligand. However, it was shown that if enantiomerically pure styrene oxide was used as substrate, then enantiomerically pure styrene carbonate was formed. On the basis of the kinetic and other experimental data, a catalytic cycle that explains why the bimetallic complexes display such high catalytic activity has been developed.
Mycobacterium tuberculosis Exploits Asparagine to Assimilate Nitrogen and Resist Acid Stress during Infection (2014)

Mycobacterium tuberculosis is an intracellular pathogen. Within macrophages, M. tuberculosis thrives in a specialized membrane-bound vacuole, the phagosome, whose pH is slightly acidic, and where access to nutrients is limited. Understanding how the bacillus extracts and incorporates nutrients from its host may help develop novel strategies to combat tuberculosis. Here we show that M. tuberculosis employs the asparagine transporter AnsP2 and the secreted asparaginase AnsA to assimilate nitrogen and resist acid stress through asparagine hydrolysis and ammonia release. While the role of AnsP2 is partially spared by yet to be identified transporter(s), that of AnsA is crucial in both phagosome acidification arrest and intracellular replication, as an M. tuberculosis mutant lacking this asparaginase is ultimately attenuated in macrophages and in mice. Our study provides yet another example of the intimate link between physiology and virulence in the tubercle bacillus, and identifies a novel pathway to be targeted for therapeutic purposes.
A 128×4 channels 1.5D curved linear array for medical imaging (2002)

1.5D transducer arrays represent a promising improvement in ultrasonic B-mode imaging. The reduction of the slice thickness and the correction of phase aberration are potential applications of 1.5D arrays, while keeping the number of electronic channels on ultrasound beamformers between 64 and 256. The authors present the design and manufacturing, using a high density interconnection process, of a 1.5D curved linear array with 128/spl times/4 independent elements, allowing dynamic focusing in the elevation plane.
Pharmacokinetics of Ertapenem following Intravenous and Subcutaneous Infusions in Patients (2009)

Steady-state pharmacokinetics of ertapenem were compared in patients after 1-g intravenous and subcutaneous (s.c.) infusions. Bioavailability was 99%+/-18% after s.c. administration, but peaks were reduced by about (43+/-29 versus 115+/-28 microg/ml) and times to peak were delayed. Simulations based on unbound concentrations show that time over the MIC should always be longer than 30% to 40% of the dosing interval, suggesting that s.c. infusion could be an alternative in patients with reduced vascular access.
Molecular cloning of gp49, a cell-surface antigen that is preferentially expressed by mouse mast cell progenitors and is a new member of the immunoglobulin superfamily (1991)

gp49 is a Mr 49,000 glycoprotein expressed on the surface of mouse bone marrow-derived mast cells, which are progenitors for the major in vivo mast cell subclasses, typified by intestinal mucosal mast cells and serosal mast cells. The amino-terminal amino acid sequence of gp49 was determined after isolation of the solubilized membrane protein by affinity chromatography with the B23.1 anti-gp49 monoclonal antibody. Redundant oligonucleotides were used to isolate a full-length 1.3-kilobase cDNA from a mouse mast cell library. The predicted amino acid sequence contains a signal peptide of 23 residues, an extracellular domain of 215 residues with three potential sites of N-linked glycosylation, a transmembrane domain of 23 residues, and a cytoplasmic tail of 42 residues. Hybridization of the gp49 cDNA was limited to mRNA extracted from those cell types that also bound the B23.1 monoclonal antibody as assessed by cytofluorographic analyses. The predicted extracellular domain of gp49 contains two regions of 48 and 51 amino acids, each flanked by cysteine residues. Both regions meet criteria for being C2-type domains of the immunoglobulin superfamily based upon the alignment of consensus amino acids and their predicted secondary structure organization. Thus, gp49, a membrane glycoprotein preferentially expressed by the progenitor mast cell population, is a new member of the immunoglobulin superfamily.
Comparative Kinetics of Bacterial Reduction of Chromium (1998)

Most previous studies of bacterial reduction of chromium have been done with pure cultures that are not likely to be found in ground water, and at hexavalent chromium concentrations much greater than typically present in contaminated ground water. Further, most previous work has been performed with complex laboratory substrates that would not be suitable for in situ application. In this study, mixed cultures were enriched from three diverse soil sources: surface soil, subsurface soil, and river sediment. The enrichment medium contained 10 mg Cr6+/L and sucrose as the carbon source. The three mixed cultures obtained from the diverse soil samples were transferred to batch reactors and exhibited similar chromium reduction enzyme kinetics at stationary phase. The maximum specific reduction rates were between 0.98 and 3.3 mg Cr6+/(g dry cellss˙h) and the half velocity constants were between 0.39 and 1.48 mg Cr6+/L. The relatively narrow range of values for kinetic parameters suggests that a conservative engineering design for in situ remediation could be applied over a wide range of contaminated sites at the Cr(VI) concentrations examined.
Pretreatment with inducers of ER molecular chaperones protects epithelial cells subjected to ATP depletion (1999)

We have investigated the potential cytoprotective role of endoplasmic reticulum (ER) molecular chaperones in a cultured cell model of renal ischemia. Madin-Darby canine kidney (MDCK) cells were pretreated with tunicamycin (an inducer of ER but not cytosolic molecular chaperones) for 12-16 h, followed by 6 h of ATP depletion. A rapid and severe depletion of cellular ATP was noted in both control and tunicamycin-treated cells. Trypan blue exclusion assays indicated that pretreatment of MDCK cells with tunicamycin reduced ATP depletion-induced cell damage by approximately 80% compared with nonpretreated controls. This apparent cytoprotective effect was also found following pretreatment with another inducer of ER molecular chaperones (i.e., A23187). For example, A23187 was found to reduce lactate dehydrogenase release by approximately 50% compared with untreated controls, whereas E-64, a cysteine protease inhibitor which may affect degradation of some proteins in the ER, had little or no effect on cell injury. Moreover, a fluorescent assay confirmed the marked reduction in cell damage following ATP depletion (up to 80% reduction in tunicamycin-pretreated cells). Together, these findings are consistent with the notion that induction of ER molecular chaperones leads to the acquisition of cytoprotection in the face of ATP depletion. However, inhibition of protein translation by cycloheximide was found to only partially attenuate the observed cytoprotective effect, raising the possibility that other, as yet to be identified, nonprotein synthesis-dependent mechanisms may also play a role in the observed cytoprotection.
Self-discharge losses in lithium-ion cells (2004)

The self-discharge losses in several lithium-ion cell designs have been measured by three different methods. The losses are separated into time-dependent and state-of-charge dependent contributions. For most cycling conditions, the time-dependent self-discharge losses are dominant; however, after several months of stand on open circuit or float charge, the state-of-charge dependent losses become significant. The self-discharge rate has been found to not increase monotonically with state-of-charge, but to drop somewhat at intermediate states of charge. The implications of these measurements for maintaining balanced cell capacities in batteries and establishing optimum storage voltage levels for batteries are discussed.
Escherichia coli thioesterase I, molecular cloning and sequencing of the structural gene and identification as a periplasmic enzyme (1993)

The structural gene for Escherichia coli thioesterase I (called tesA) has been cloned by use of sequence data obtained from the purified protein. The tesA gene was mapped at 530 kilobase pair of the E. coli physical map (minute 11.6 of E. coli genetic map). The DNA sequence of the tesA gene was obtained and the deduced protein sequence showed that thioesterase I consists of 182 amino acids and has a molecular mass of 20.5 kDa. Comparison of the DNA and protein sequence data suggested that a leader sequence of 26 amino acid residues is cleaved from the primary translation product, and this processing was confirmed by NH2-terminal sequencing of the primary translation product synthesized in vitro. These data predicted that thioesterase I (long believed to be a cytoplasmic protein) is exported to the cell periplasm, a prediction supported by release of the enzyme from cells upon osmotic shock. The TesA protein sequence does not exhibit any significant overall sequence similarity with other known proteins, although the sequence does contain two small sequence elements found in several other thioesterases. One of these elements is a sequence similar to the serine esterase active sites found in serine proteases and four other thioesterases. A serine residue within this TesA element was shown to be covalently labeled with [3H] diisopropyl fluorophosphate, a potent inhibitor of TesA activity. The second sequence element is a histidine-containing sequence found close to the carboxyl terminus that is also found in the carboxyl termini of the four known active serine thioesterases. The physiological role of thioesterase I is unclear. A strain carrying a null mutation of the tesA gene was constructed and found to have no growth phenotype. Moreover, a strain carrying a plasmid that gave massive overproduction of TesA (approximately 100-fold higher than that of the wild type) also grew normally. In addition a strain containing double null mutations in both tesA and tesB (the structural gene for E. coli thioesterase II) also failed to display any growth phenotype. Analysis of the fatty acid compositions of phospholipid, lipid A, and lipoprotein of the above strains showed no significant changes from a wild type strain.
A new and versatile reagent for incorporating multiple primary aliphatic amines into synthetic oligonucleotides (1989)

A novel and versatile phosphorarnidite, N-Fmoc-O 1 -DMT-O 2 -cyanoethoxydiiopropylamino-phosphinyl-3-amino-1,2-propanediol (1, Fig. 1), has been synthesized and used to incorporate primary aliphatic amines into synthetic oligonucleotides. Its convenient preparation and use in solid phase oligonucleotide synthesis is described. Using phosphoramidite 1, an amino-modified oligonucleotide probe complementary to M13mp18 DNA was constructed with five primary amines attached to the 5′-terminus. The amino-modified oligonucleotide was subsequently labeled with biotin and employed in a dot-blot hybridization assay. As little as 0.5 ng of M13mp18 target DNA was colorimetrically detected
Development of 1-((1,4-trans)-4-Aryloxycyclohexyl)-3-arylurea Activators of Heme-Regulated Inhibitor as Selective Activators of the Eukaryotic Initiation Factor 2 Alpha (eIF2α) Phosphorylation Arm of the Integrated Endoplasmic Reticulum Stress Response (2017)

Heme-regulated inhibitor (HRI), an eukaryotic translation initiation factor 2 alpha (eIF2α) kinase, plays critical roles in cell proliferation, differentiation, adaptation to stress, and hemoglobin disorders. HRI phosphorylates eIF2α, which couples cellular signals, including endoplasmic reticulum (ER) stress, to translation. We previously identified 1,3-diarylureas and 1-((1,4-trans)-4-aryloxycyclohexyl)-3-arylureas (cHAUs) as specific activators of HRI that trigger the eIF2α phosphorylation arm of ER stress response as molecular probes for studying HRI biology and its potential as a druggable target. To develop drug-like cHAUs needed for in vivo studies, we undertook bioassay-guided structure-activity relationship studies and tested them in the surrogate eIF2α phosphorylation and cell proliferation assays. We further evaluated some of these cHAUs in endogenous eIF2α phosphorylation and in the expression of the transcription factor C/EBP homologous protein (CHOP) and its mRNA, demonstrating significantly improved solubility and/or potencies. These cHAUs are excellent candidates for lead optimization for development of investigational new drugs that potently and specifically activate HRI.
Acid-Induced Denaturation of Myoglobin Studied by Time-Resolved Electrospray Ionization Mass Spectrometry (1997)

The acid-induced denaturation of holo-myoglobin (hMb) following a pH-jump from 6.5 to 3.2 has been studied by electrospray ionization (ESI) mass spectrometry in combination with a continuous flow mixing technique (time-resolved ESI MS). Different protein conformations are detected by the different charge state distributions that they generate during ESI. The changes in intensity of the peaks in the mass spectrum as a function of time can be described by two exponential lifetimes of 0.38 +/- 0.06 s and 6.1 +/- 0.5 s, respectively. The acid-induced denaturation of hMb was also studied in stopped-flow experiments by monitoring changes in the Soret absorption. The lifetimes measured by this method are in good agreement with those obtained by time-resolved ESI MS. The shorter lifetime is associated with the formation of a transient intermediate which shows the mass of the intact heme-protein complex but leads to the formation of much higher charge states during ESI than native hMb at pH 6.5. This form of hMb has an absorption spectrum similar to that of the native protein, indicating a relatively unperturbed chromophore environment inside the heme binding pocket. The intermediate can thus be characterized as an unfolded form of hMb with essentially intact heme-protein interactions. The longer of the two lifetimes is associated with the formation of a product which has a blue-shifted absorption spectrum with a much lower maximum absorption coefficient than observed for native hMb. In the ESI mass spectrum, this product appears as the apoprotein with high charge states which indicates the disruption of the native heme-protein interactions and a considerable degree of unfolding compared to native apo-myoglobin. The mechanism of acid-induced denaturation of hMb, therefore, appears to follow the sequence (heme-protein)native --> (heme-protein)unfolded --> heme + (protein)unfolded.