gebhart/patrepeval huggingface dataset:
The Chemistry of 2-Aminocycloalkanecarboxylic Acids (2001)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Chemistry of 2-Aminocycloalkanecarboxylic AcidsFerenc FülöpView Author Information Institute of Pharmaceutical Chemistry, University of Szeged, H-6701 Szeged, POB 121, Hungary Cite this: Chem. Rev. 2001, 101, 7, 2181–2204Publication Date (Web):June 27, 2001Publication History Received5 February 2001Published online27 June 2001Published inissue 1 July 2001https://pubs.acs.org/doi/10.1021/cr000456zhttps://doi.org/10.1021/cr000456zresearch-articleACS PublicationsCopyright © 2001 American Chemical SocietyRequest reuse permissionsArticle Views2270Altmetric-Citations317LEARN 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 SUBJECTS:Molecular structure,Monomers,Organic compounds,Peptides and proteins,Reaction products Get e-Alerts
Novel Regulation of Keratin Gene Expression by Thyroid Hormone and Retinoid Receptors (1996)

Expression of keratin proteins, markers of epidermal differentiation and pathology, is uniquely regulated by the nuclear receptors for retinoic acid (RAR) and thyroid hormone (T3R) and their ligands: it is constitutively activated by unliganded T3R, but it is suppressed by ligand-occupied T3R or RAR. This regulation was studied using gel mobility shift assays with purified receptors and transient transfection assays with vectors expressing various receptor mutants. Regulation of keratin gene expression by RAR and T3R occurs through direct binding of these receptors to receptor response elements of the keratin gene promoters. The DNA binding "C" domain of these receptors is essential for both ligand-dependent and -independent regulation. However, the NH2-terminal "A/B" domain of T3R is not required for either mode of regulation of keratin gene expression. Furthermore, v-ErbA, an oncogenic derivative of cT3R, also activates keratin gene expression. In contrast to the previously described mechanism of gene regulation by T3R, heterodimerization with the retinoid X receptor is not essential for activation of keratin gene expression by unliganded T3R. These findings indicate that the mechanism of regulation of keratin genes by RAR and T3R differs significantly from the mechanisms described for other genes modulated by these receptors.
Effects of L-Baclofen and D-Baclofen on the Auditory System: A Study of Click-Evoked Potentials from the Inferior Colliculus in the Rat (1995)

The drug baclofen is a potential treatment for severe tinnitus, but its action in relieving tinnitus is not known. Baclofen is available as an approved drug only in racemic form with about equal content of the two enantiomers. In the present paper we show that L-baclofen causes a considerable (40.7%) suppression of the amplitude of the second peak in the click-evoked response from the cochlear nucleus. Bipolar recordings from the external nucleus of the inferior colliculus showed that L-baclofen caused a reduction in the amplitude of three or four distinct peaks in this response. D-Baclofen had no detectable effect on the response from the cochlear nucleus, and had only a slight effect on one component of the response from the external nucleus of the inferior colliculus. The demonstrated effect of L-baclofen on excitation in the ascending auditory pathway indicates that this drug may be a potential treatment for hyperactive auditory disorders such as tinnitus and hyperacusis.
Synthesis and Photophysical Properties of Light-Harvesting Arrays Comprised of a Porphyrin Bearing Multiple Perylene-Monoimide Accessory Pigments (2002)

We present the synthesis and characterization of new light-harvesting arrays containing two, four, or eight perylene-monoimide accessory pigments attached to a zinc porphyrin. Each perylene is substituted with one or three 4-tert-butylphenoxy substituents. A 4,3'- or 4,2'-diarylethyne linker joins the perylene N-imide position and the porphyrin meso-position, affording divergent or convergent architectures, respectively. The architectures are designed to provide high solubility in organic media and facile perylene-to-porphyrin energy transfer, while avoiding charge-transfer quenching of the excited porphyrin product. For the array containing four perylenes per porphyrin in both nonpolar (toluene) and polar (benzonitrile) media and for the array containing eight perylenes per porphyrin in toluene, the photoexcited perylene-monoimide dye (PMI) decays rapidly ( approximately 3.5 ps) and predominantly (>or=90%) by energy transfer to the zinc porphyrin to form the excited zinc porphyrin (Zn), which has excited-state characteristics (lifetime, fluorescence yield) comparable (within approximately 10%) to those of the isolated chromophore. For the array containing eight perylenes in benzonitrile, PMI decays approximately 80% by energy transfer (forming Zn) and approximately 20% by hole transfer (forming PMI- Zn+); Zn subsequently decays approximately 20% by electron transfer (also forming PMI- Zn+) and approximately 80% by the normal routes open to the porphyrin monomer (intersystem crossing, internal conversion, fluorescence). In addition to rapid and efficient perylene-to-porphyrin energy transfer, the broad blue-green to yellow absorption of the perylene dyes complements the blue absorption of the porphyrin, resulting in excellent light harvesting across a significant spectral region. Collectively, the work described herein identifies multiperylene-porphyrin arrays that exhibit suitable photochemical properties for use as motifs in larger light-harvesting systems.
Learning question classifiers (2002)

In order to respond correctly to a free form factual question given a large collection of texts, one needs to understand the question to a level that allows determining some of the constraints the question imposes on a possible answer. These constraints may include a semantic classification of the sought after answer and may even suggest using different strategies when looking for and verifying a candidate answer.This paper presents a machine learning approach to question classification. We learn a hierarchical classifier that is guided by a layered semantic hierarchy of answer types, and eventually classifies questions into fine-grained classes. We show accurate results on a large collection of free-form questions used in TREC 10.
Elicitation of Resveratrol in Peanut Kernels by Application of Abiotic Stresses (2005)

Application of no postharvest stress or by size reduction, grinding, chopping, or slicing and exposure to UV light or ultrasound were investigated for the elicitation of trans-resveratrol, total phenolic compounds, and antioxidant activity (AOA) in peanut kernels. AOA and total phenolic compounds did not increase in stressed peanuts over incubation times 0-48 h at 25 degrees C; however, an increase in trans-resveratrol concentration over time occurred. Slicing (2 mm), ultrasound exposure for 4 min at 25 degrees C, and incubation for 36 h produced the highest level of trans-resveratrol synthesis in peanuts, increasing concentrations from 0.48 +/- 0.08 microg/g in untreated peanuts to 3.96 +/- 0.96 microg/g. AOA in stressed peanuts was negatively correlated with trans-resveratrol concentration, indicating that as AOA decreased trans-resveratrol concentration increased.
Molecular analysis of the psa permease complex of Streptococcus pneumoniae (2004)

The psaBCA locus of Streptococcus pneumoniae encodes a putative ABC Mn2+-permease complex. Downstream of the operon is psaD, which may be co-transcribed and encodes a thiol peroxidase. Previously, there has been discordance concerning the phenotypic impact of mutations in the psa locus, resolution of which has been complicated by differences in mutant construction and the possibility of polar effects. Here, we constructed unmarked, in frame deletion mutants DeltapsaB, DeltapsaC, DeltapsaA, DeltapsaD, DeltapsaBC, DeltapsaBCA and DeltapsaBCAD in S. pneumoniae D39 to examine the role of each gene within the locus in Mn2+ uptake, susceptibility to oxidative stress, virulence, nasopharyngeal colonization and chain morphology. The requirement for Mn2+ for growth and transformation was also investigated for all mutants. Inductively coupled plasma mass spectrometry (ICP-MS) analysis provided the first direct evidence that PsaBCA is indeed a Mn2+ transporter. However, this study did not substantiate previous reports that the locus plays a role in choline-binding protein pro-duction or chain morphology. We also confirmed the importance of the Psa permease in systemic virulence and resistance to superoxide and hydrogen peroxide, as well as demonstrating a role in nasopharyngeal colonization for the first time. Further evi-dence is provided to support the requirement for Mn2+ supplementation for growth and transformation of DeltapsaB, DeltapsaC, DeltapsaA, DeltapsaBC, DeltapsaBCA and DeltapsaBCAD mutants. However, transformation, as well as growth, of the DeltapsaD mutant was not dependent upon Mn2+ supplementation. We also show that, apart from sensitivity to hydrogen peroxide, the DeltapsaD mutant exhibited essentially similar phenotypes to those of the wild type. Western blot analysis with a PsaD antiserum showed that deleting any of the genes upstream of psaD did not affect its expression. However, we found that deleting psaB resulted in decreased expression of PsaA relative to that in D39, whereas deleting both psaB and psaC resulted in at least wild-type levels of PsaA.
The ILT2(LIR1) and CD94/NKG2A NK cell receptors respectively recognize HLA-G1 and HLA-E molecules co-expressed on target cells (1999)

Previous studies on NK recognition of HLA-G1 employed as targets 721.221 transfectants (.221-G1) that unknowingly co-expressed the HLA-E molecule, subsequently found to be a major ligand for the CD94/NKG2 receptors. In the present study we re-evaluated the relative role played by CD94/NKG2 and ILT2(LIR1) molecules in recognition of HLA-G1 by NK clones. We employed as targets .221-G1 cells and a surface HLA-E-negative transfectant, .221-G1(Eneg), generated by site-directed mutagenesis of the HLA-G1 leader sequence. The antagonistic effects of receptor- (ie. CD94/NKG2A, ILT2) and ligand-specific mAb (i.e. HLA-G, HLA-E) were assessed. In addition, binding of an ILT2-Ig fusion protein to the .221-AEH, expressing only HLA-E, and the .221-G1(Eneg) transfectants was analyzed. Our data demonstrate that NK recognition of cells expressing HLA-G1 involves at least two non-overlapping receptor-ligand systems: the CD94/NKG2 interaction with HLA-E, and the engagement of the ILT2(LIR1) receptor by HLA-G1 molecules.
A Cholera Toxin B-subunit Variant That Binds Ganglioside GM1 but Fails to Induce Toxicity (2001)

Entry of cholera toxin (CT) into target epithelial cells and the induction of toxicity depend on CT binding to the lipid-based receptor ganglioside G(M1) and association with detergent-insoluble membrane microdomains, a function of the toxin's B-subunit. The B-subunits of CT and related Escherichia coli toxins exhibit a highly conserved exposed peptide loop (Glu(51)-Ile(58)) that faces the cell membrane upon B-subunit binding to G(M1). Mutation of His(57) to Ala in this loop resulted in a toxin (CT-H57A) that bound G(M1) with high apparent affinity, but failed to induce toxicity. CT-H57A bound to only a fraction of the cell-surface receptors available to wild-type CT. The bulk of cell-surface receptors inaccessible to CT-H57A localized to detergent-insoluble apical membrane microdomains (lipid rafts). Compared with wild-type toxin, CT-H57A exhibited slightly lower apparent binding affinity for and less stable binding to G(M1) in vitro. Rather than being transported into the Golgi apparatus, a process required for toxicity, most of CT-H57A was rapidly released from intact cells at physiologic temperatures or degraded following its internalization. These data indicate that CT action depends on the stable formation of the CT B-subunit.G(M1) complex and provide evidence that G(M1) functions as a necessary sorting motif for the retrograde trafficking of toxin into the secretory pathway of target epithelial cells.
Regulation of melastatin, a TRP-related protein, through interaction with a cytoplasmic isoform (2001)

The TRP (transient receptor potential) superfamily includes a group of subfamilies of channel-like proteins mediating a multitude of physiological signaling processes. The TRP-melastatin (TRPM) subfamily includes the putative tumor suppressor melastatin (MLSN) and is a poorly characterized group of TRP-related proteins. Here, we describe the identification and characterization of an additional TRPM protein TRPM4. We reveal that TRPM4 and MLSN each mediate Ca(2+) entry when expressed in HEK293 cells. Furthermore, we demonstrate that a short form of MLSN (MLSN-S) interacts directly with and suppresses the activity of full-length MLSN (MLSN-L). This suppression seems to result from the inhibition of translocation of MLSN-L to the plasma membrane. We propose that control of translocation through interaction between MLSN-S and MLSN-L represents a mode for regulating ion channel activity.
Correction for scattered radiation and other background signals in dual‐energy computed tomography material thickness measurements (1988)

Both beam hardening and the detection of scattered radiation cause nonlinearity errors in x-ray computed tomography (CT), leading to artifacts and CT number inaccuracies. Dual-energy measurements can be used to correct beam hardening effects to a high degree of accuracy. However, in the imaging of thick body sections the transmitted intensity of the primary beam is low, making scatter the most significant cause of CT number inaccuracy. Furthermore, the scatter-to-primary ratio is energy dependent, causing a shift in the apparent effective atomic number of the absorbing material. We have measured scatter under a variety of conditions on a third generation CT scanner with dual-energy capability in order to determine its effect on the accuracy of quantitative measurements. The effects of off focus radiation, detector cross-talk, and detector dark current were also accounted for in the analysis of the measured scatter data. Our results indicate that on this well collimated system, an accurate correction for scatter can be made based on the detected intensity in projections.
Carnitine protects mitochondria and removes toxic acyls from xenobiotics. (2001)

The carnitine system is altered by several xenobiotics (drugs and chemicals). These alterations are responsible for most toxic effects, which can be reverted or minimized by L-carnitine administration. Formation of nonmetabolizable acyl coenzyme A (CoA) is a typical step in the biotransformation of pivaloyl antibiotics, valproate and ifosfamide. The elevated levels of acylcarnitine occurring in human urine due to impaired metabolism of specific acyl CoA support the role of L-carnitine as an acceptor of specific, nonmetabolizable acyl CoA. The consequence of this process is a secondary carnitine deficiency. The formation of stable complexes with an essential component of mitochondrial membrane, cardiolipin, and the inhibition of myocardial specific isoform of carnitine-palmitoyl transferase are presumably the basis of adriamycin cardiotoxicity. L-carnitine interacts with cardiolipin, modifying membrane permeability and protecting the functions of the mitochondria. This mechanism can be proposed to explain the protective effects of L-carnitine against adriamycin cardiotoxicity, ammonium acetate and zidovudine-induced mitochondrial ultrastructural and functional alterations. Cisplatin, cephalosporin and carbapenem antibiotics inhibit carnitine reabsorption in renal tubules and cause proximal tubular damage. The study of peroxisomal producing agents belonging to largely different chemical classes showed that these agents caused carnitine system perturbations which may have the potential to be highly relevant biomarkers of exposure to the nongenotoxic peroxisomal proliferating agent class of hepatic tumorigens.
Electrochemical Reactivity in Room-Temperature Ionic Liquids (2008)

International audience
Sequence of a cellulase gene of the thermophilic bacterium Clostridium thermocellum (1985)

The nucleotide sequence of the celA gene, encoding the extracellular endoglucanase A of Clostridium thermocellum, was determined and compared with the NH2-terminal amino acid sequence of the purified enzyme. The mature protein appeared to be extended by a signal sequence of 32 amino acids. A segment of 23 amino acids was duplicated at the COOH-terminal end of the protein. The putative GUG initiation codon was preceded by an AGGAGG sequence, typical of procaryotic ribosomal binding sites. The segment of DNA presumably specifying transcriptional initiation contained a high percentage of adenine and thymine residues, including an adenine-thymine tract extending over 54 base pairs.
Topoisomerase IV, not gyrase, decatenates products of site-specific recombination inEscherichia coli (1997)

DNA replication and recombination generate intertwined DNA intermediates that must be decatenated for chromosome segregation to occur. We showed recently that topoisomerase IV (topo IV) is the only important decatenase of DNA replication intermediates in bacteria. Earlier results, however, indicated that DNA gyrase has the primary role in unlinking the catenated products of site-specific recombination. To address this discordance, we constructed a set of isogenic strains that enabled us to inhibit selectively with the quinolone norfloxacin topo IV, gyrase, both enzymes, or neither enzyme in vivo. We obtained identical results for the decatenation of the products of two different site-specific recombination enzymes, phage lambda integrase and transposon Tn3 resolvase. Norfloxacin blocked decatenation in wild-type strains, but had no effect in strains with drug-resistance mutations in both gyrase and topo IV. When topo IV alone was inhibited, decatenation was almost completely blocked. If gyrase alone were inhibited, most of the catenanes were unlinked. We showed that topo IV is the primary decatenase in vivo and that this function is dependent on the level of DNA supercoiling. We conclude that the role of gyrase in decatenation is to introduce negative supercoils into DNA, which makes better substrates for topo IV. We also discovered that topo IV has an unexpectedly strong DNA relaxation activity that, together with gyrase and topo I, is able to set the supercoiling levels in Escherichia coli.
Identification of the IgG binding site of the human low affinity receptor for IgG Fc gamma RII. Enhancement and ablation of binding by site-directed mutagenesis. (1994)

Fc receptor-antibody interactions are key mechanisms through which antibody effector functions are mediated. The low affinity receptor for IgG, Fc gamma RII, is expressed on most hematopoietic cells, and through the binding of immune complexes mediates a large spectrum of biological responses vital for resistance to infection and the regulation of immunity. In this study the key residues of human Fc gamma RII involved in the interaction with IgG1 have been identified. Chimeric receptors composed of extracellular regions of Fc gamma RII and the Fc epsilon RI alpha chain have been used to localize the IgG1 binding site of Fc gamma RII to an 8-residue stretch in the second extracellular domain, Asn154 to Ser161. Site-directed mutagenesis of this region revealed that substitution of Ile155 or Gly156 with alanine ablated the binding of human and mouse IgG1, whereas replacement of Leu159, Phe160, or Ser161 with alanine enhanced binding. Molecular modeling has been used to generate a putative 3-dimensional model structure of the second extracellular domain of Fc gamma RII, suggesting that the binding site lies in an exposed loop region at the interface of domains 1 and 2.
Colloidal CdTe/HgTe quantum dots with high photoluminescence quantum efficiency at room temperature (1999)

We have used an aqueous colloidal growth technique to form hybrid CdTe/HgTe quantum dots with a broad, strong fluorescence in the infrared (800–1200 nm). The quantum efficiency is high, around 44%, when pumped in the visible (488 nm), and the excited state lifetime is around 130 ns, making the material interesting as an optical amplifier medium. Using a pump-probe experiment, we have demonstrated weak optical amplification in a dilute aqueous suspension of CdTe/HgTe dots in the short wavelength wing of the emission spectrum at 808 nm.
Protective Immunity Using Recombinant Human IL-12 and Alum as Adjuvants in a Primate Model of Cutaneous Leishmaniasis (1999)

Protection from cutaneous leishmaniasis, a chronic ulcerating skin lesion affecting millions, has been achieved historically using live virulent preparations of the parasite. Killed or recombinant Ags that could be safer as vaccines generally require an adjuvant for induction of a strong Th1 response in murine models. Murine rIL-12 as an adjuvant with soluble Leishmania Ag has been shown to protect susceptible mice. We used 48 rhesus macaques to assess the safety, immunogenicity, and efficacy of a vaccine combining heat-killed Leishmania amazonensis with human rIL-12 (rhIL-12) and alum (aluminum hydroxide gel) as adjuvants. The single s.c. vaccination was found to be safe and immunogenic, although a small transient s.c. nodule developed at the site. Groups receiving rhIL-12 had an augmented in vitro Ag-specific IFN-gamma response after vaccination, as well as increased production of IgG. No increase in IL-4 or IL-10 was found in cell culture supernatants from either control or experimental groups. Delayed hypersensitivity reactions were not predictive of protection. Intradermal forehead challenge infection with 107 metacyclic L. amazonensis promastigotes at 4 wk demonstrated protective immunity in all 12 monkeys receiving 2 microgram rhIL-12 with alum and Ag. Partial efficacy was seen with lower doses of rhIL-12 and in groups lacking either adjuvant. Thus, a single dose vaccine with killed Ag using rhIL-12 and alum as adjuvants was safe and fully effective in this primate model of cutaneous leishmaniasis. This study extends the murine data to primates, and provides a basis for further human trials.