gebhart/patrepeval huggingface dataset:
Intracellular Survival of <i>Neisseria gonorrhoeae</i> in Male Urethral Epithelial Cells: Importance of a Hexaacyl Lipid A (2002)

Neisseria gonorrhoeae is a strict human pathogen that invades and colonizes the urogenital tracts of males and females. Lipooligosaccharide (LOS) has been shown to play a role in gonococcal pathogenesis. The acyl transferase MsbB is involved in the biosynthesis of the lipid A portion of the LOS. In order to determine the role of an intact lipid A structure on the pathogenesis of N. gonorrhoeae, the msbB gene was cloned and sequenced, a deletion and insertion mutation was introduced into N. gonorrhoeae, and the mutant strain was designated 1291A11K3. Mass spectrometric analyses of 1291A11K3 LOS determined that this mutation resulted in a pentaacyl rather than a hexaacyl lipid A structure. These analyses also demonstrated an increase in the phosphorylation of lipid A and an increase in length of the oligosaccharide of a minor species of the msbB LOS. The interactions of this mutant with male urethral epithelial cells (uec) were examined. Transmission and scanning electron microscopy studies indicated that the msbB mutants formed close associations with and were internalized by the uec at levels similar to those of the parent strain. Gentamicin survival assays performed with 1291A11K3 and 1291 bacteria demonstrated that there was no difference in the abilities of the two strains to adhere to uec; however, significantly fewer 1291A11K3 bacteria than parent strain bacteria were recovered from gentamicin-treated uec. These studies suggest that the lipid A modification in the N. gonorrhoeae msbB mutant may render it more susceptible to innate intracellular killing mechanisms when internalized by uec.
Codon Pair Bias Is a Direct Consequence of Dinucleotide Bias (2015)

Codon pair bias is a remarkably stable characteristic of a species. Although functionally uncharacterized, robust virus attenuation was achieved by recoding of viral proteins using underrepresented codon pairs. Because viruses replicate exclusively inside living cells, we posited that their codon pair preferences reflect those of their host(s). Analysis of many human viruses showed, however, that the encoding of viruses is influenced only marginally by host codon pair preferences. Furthermore, examination of codon pair preferences of vertebrate, insect, and arthropod-borne viruses revealed that the latter do not utilize codon pairs overrepresented in arthropods more frequently than other viruses. We found, however, that codon pair bias is a direct consequence of dinucleotide bias. We conclude that codon pair bias does not play a major role in the encoding of viral proteins and that virus attenuation by codon pair deoptimization has the same molecular underpinnings as attenuation based on an increase in CpG/TpA dinucleotides.
RÉSECTION INTESTINALE CHEZ LE PORC. I. — OBSERVATIONS PRÉLIMINAIRES (1970)

Les effets d'une rsection partielle ( 4 m) d'intestin grle, en rgion proximale ou distale, par rapport ceux de l'opration fictive (double transsection), ont t tudis chez qo porcs Large White mles castrs.
Synthesis of chiral nonionic superbases based on iminophosphoranes (2000)

Optically active azides derived from penta‐O‐acetylglycose tartaric acid and quinine when reacted with the proazaphosphatrane P(MeNCH2‐CH2)3N gave highly basic iminophosphoranes that are potential asymmetric catalysts and ligands for a variety of reactions. Preliminary results show that the enantiomers are formed in unequal proportions. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:251-253, 2000
A versatile organocatalyst for the asymmetric conjugate addition of nitroalkanes to enones (2005)

5-Pyrrolidin-2-yltetrazole performs as an improved catalyst for the asymmetric addition of a range of nitroalkanes to cyclic and acyclic enones, with good to excellent enantioselectivity.
[Hormonal control of the metabolism of collagen]. (1984)

This paper summarizes the results of hormonal studies applying to collagen metabolism that were published during the last 10 years. This general review demonstrates that most of the hormones, when they act on this metabolism, either decrease the amount of synthesized collagen or increase its catabolism. This effect is demonstrated on whole living animals, in isolated organs, in pathological cases such as corticosteroid induced osteoporosis, and more directly in cell cultures. At physiological levels, some of the effects may be slight or biphasic but at pharmacological levels glucocorticoids and estrogens are strongly inhibiting. These inhibiting effects may be ascribed to various stages of collagen biosynthesis: transcription of the genes, translation of mRNA, post-translational reactions, that are particularly developed in the case of collagen and particularly sensitive to the hormone action. Intracellular degradation of collagen represents an important way of control for this biosynthesis and is noticeably activated by the system of cAMP and some prostaglandins. Finally, collagenases acting on the extracellular fibrils are stimulated by several groups of hormones such as thyroid hormone, testosterone, parathyroid hormone. This increase in catabolism acts in the sense of a fast decrease in the amount of collagen, confirming that most of the hormonal systems are aimed at decreasing both the synthesis of new collagen and the number of mature fibers existing in a given connective tissue. On the other hand, many growth factors and several hormones such as insulin and somatomedins are able to activate the mitoses in the cells that are know to produce collagen, and for this reason, indirectly stimulate the synthesis of this fibrous protein. It is of interest to point out that every time the organism needs depositing more collagen in any zone of the extracellular matrix, it has to send mobile cells from other tissues or to activate the divisions of the cells already present in the concerned tissue. This process is particularly conspicuous in the case of inflamed tissues. It is proposed as a general rule that decreases in the collagen amounts may be triggered by very fast hormonal mechanisms acting both to stop biosynthesis and to activate degradation, whereas the increase in collagen layering depends on indirect and slow mechanisms in which cell divisions represent the first event.
Kinetics and mechanism of the alkali catalysed condensation of <i>o</i>‐ and <i>p</i>‐methylol phenols by themselves and with phenol (1962)

Abstract The kinetics of the alkali‐catalysed condensation of ortho and para methylol phenols, each by itself and with phenol has been studied under various experimental conditions with the help of quantitative paper chromatography. At low concentrations of the reactants and catalyst, the self‐condensation of saligenin gives mainly 3‐methylol 2′,4‐dihydroxy diphenyl methane (DPM) and that of p ‐methylol phenol 5‐methylol 2,4′‐DPM, the apparent first‐order rate constant at 80°C. and activation energy being 1.60ċ10 −5 sec −1 and 16.0 kcal./mole for the former and for the latter 1.67ċ10 −5 sec −1 and 17.3 kcal./mole However at higher concentrations, p ‐methylol phenol gives also p,p ′‐DPM, 2,4‐dimethylol phenol, and small amounts of 3‐methylol 4,4′‐DPM. When phenol and one of the methylol phenols are made to react, both the self‐condensation and the inter‐condensation take place, the former much more rapidly than the latter. A large excess of phenol is needed to suppress the self‐condensation. The apparent energies of activation for the formation of o,o ′‐, o,p ′‐ and p,p ′‐DPMs are 21.4, 18.7, and 17.0 kcal./mole respectively. Evidence is presented for the probable mode of formation of monomethylol dinuclear compounds in the alkali‐catalysed phenol‐formaldehyde reaction.
Ultraviolet-Enhanced Ozonation of Organic Compounds: 1,2-Dichloroethane and Trichloroethylene as Model Substrates (1986)

Abstract 1,2–Dichloroethane (DCE) and trichloroethylene (TCE) were used as model compounds to study the oxidation of organic chemicals by ozone/ultraviolet radiation, ozone, and hydrogen peroxide/ultraviolet radiation. It was found that ozone/ultraviolet radiation oxidized both 1,2–dichloroethane and trichloroethylene in batch systems, at pH = 2 (phosphate buffer). At ozone concentrations in the 1 to 5 mg/L range, the reaction was first order in both ozone and substrate. At pH = 2 and initial ozone concentration 2.2–2.6 mg/L, rate constants (k)Q = 25 and 130 M-1sec-1 were observed for the ozone/ultraviolet radiation oxidation of DCE and TCE, respectively. The rat e constants for ozone oxidation of DCE and TCE without ultraviolet radiation were 4.3 and 47 M-1sec-1, respectively. The higher rate of TCE oxidation implies that direct reaction occurs with the double bond. Finite reaction rate of DCE with ozone, and substantial increases in rate at higher pH imply the participatation of hydroxyl radicals in the oxidation of both compounds. For example, at pH = 7, initial ozone concentration of 2.3 mg/L, the ko for TCE oxidation by ozone/ultraviolet radiation is approximately 500 M−1 sec−1 almost too fast to measure in a batch system.The rate also is increased by increased ultraviolet radiation intensity, and by the presence of hydrogen peroxide, which acts as a catalyst.
Large-scale supercoiled plasmid preparation by acidic phenol extraction. (1994)

A novel method for large-scale plasmid preparation is described. Crude extracts are subjected to acidic phenol extraction to remove any contaminants present in the aqueous phase. The supercoiled plasmid DNA, which preferentially remains in the organic phase and inter-phase, is extracted back into the aqueous phase with 1.5 M TRIZMA base, from which it is precipitated. The resultant plasmid DNA is highly pure and satisfactory for any subsequent procedures. The method is extremely economical and takes only 3-4 h.
ATM Activation and Signaling under Hypoxic Conditions (2008)

The ATM kinase has previously been shown to respond to the DNA damage induced by reoxygenation following hypoxia by initiating a Chk 2-dependent cell cycle arrest in the G(2) phase. Here we show that ATM is both phosphorylated and active during exposure to hypoxia in the absence of DNA damage, detectable by either comet assay or 53BP1 focus formation. Hypoxia-induced activation of ATM correlates with oxygen concentrations low enough to cause a replication arrest and is entirely independent of hypoxia-inducible factor 1 status. In contrast to damage-activated ATM, hypoxia-activated ATM does not form nuclear foci but is instead diffuse throughout the nucleus. The hypoxia-induced activity of both ATM and the related kinase ATR is independent of NBS1 and MRE11, indicating that the MRN complex does not mediate the DNA damage response to hypoxia. However, the mediator MDC1 is required for efficient activation of Kap1 by hypoxia-induced ATM, indicating that similarly to the DNA damage response, there is a requirement for MDC1 to amplify the ATM response to hypoxia. However, under hypoxic conditions, MDC1 does not recruit BRCA1/53BP1 or RNF8 activity. Our findings clearly demonstrate that there are alternate mechanisms for activating ATM that are both stress-specific and independent of the presence of DNA breaks.
Spray Congealing of Pharmaceuticals: Study on Production of Solid Dispersions Using Box-Behnken Design (2012)

This work aimed at evaluating the spray congealing method for the production of microparticles of carbamazepine combined with a polyoxylglyceride carrier. In addition, the influence of the spray congealing conditions on the improvement of drug solubility was investigated using a three-factor, three-level Box-Behnken design. The factors studied were the cooling air flow rate, atomizing pressure, and molten dispersion feed rate. Dependent variables were the yield, solubility, encapsulation efficiency, particle size, water activity, and flow properties. Statistical analysis showed that only the yield was affected by the factors studied. The characteristics of the microparticles were evaluated using X-ray powder diffraction, scanning electron microscopy, differential scanning calorimetry, and hot-stage microscopy. The results showed a spherical morphology and changes in the crystalline state of the drug. The microparticles were obtained with good yields and encapsulation efficiencies, which ranged from 50 to 80% and 99.5 to 112%, respectively. The average size of the microparticles ranged from 17.7 to 39.4 µm, the water activities were always below 0.5, and flowability was good to moderate. Both the solubility and dissolution rate of carbamazepine from the spray congealed microparticles were remarkably improved. The carbamazepine solubility showed a threefold increase and dissolution profile showed a twofold increase after 60 min compared to the raw drug. The Box-Behnken fractional factorial design proved to be a powerful tool to identify the best conditions for the manufacture of solid dispersion microparticles by spray congealing.
A statistical model for domain-independent text segmentation (2001)

We propose a statistical method that finds the maximum-probability segmentation of a given text. This method does not require training data because it estimates probabilities from the given text. Therefore, it can be applied to any text in any domain. An experiment showed that the method is more accurate than or at least as accurate as a state-of-the-art text segmentation system.
Characterization of high density lipoprotein subspecies: structural studies by single vertical spin ultracentrifugation and immunoaffinity chromatography (1987)

Affinity columns containing anti-apolipoprotein A-I or A-II were used to fractionate plasma into subpopulations of lipoprotein particles containing: a) apoA-I [Lp(A-I)], b) apoA-I and A-II [Lp(A-I with A-II)], and c) apoA-I but no A-II [Lp(A-I without A-II)]. Single vertical spin and electron microscopy analyses of these HDL subpopulations demonstrated that acid elution from the affinity columns caused no detectable change in size and density of the three subpopulation particles. Analysis by nondenaturing gradient gel electrophoresis of the three subpopulations found in four normal subjects identified nine HDL subspecies, designated [1] through [9] in order of increasing size; [3-7] were the major subspecies. Lp(A-I with A-II) is composed primarily of subspecies [3],[5], and [6], and may contain some subspecies [2] and [7], while Lp(A-I without A-II) represents mainly [4] and [7] and the minor subspecies [1],[2],[8], and [9]. HDL subspecies [4],[5], and [6] are found in the standard sequential flotation density cuts for both HDL3 and HDL2, which illustrates the limitations of the latter terminology. Using single vertical spin ultracentrifugation, HDL fractions were located and isolated for physical and chemical analyses, including immunoassay for apoA-I, A-II, and C-II. The distribution of the Lp(A-I without A-II) particles corresponded closely to the apoC-II distribution. An apoA-I-rich, cholesteryl ester- and phospholipid-poor subspecies was identified in the dense HDL fractions. HDL subspecies [7] was found to contain at least three separate subspecies designated [7a], [7b], and [7c]. Based on these and previously published results (Brouillette, C. G., et al. 1984. Biochemistry. 23: 359-367), we propose that the HDL subspecies adjacent in size generally differ by the association/lack of association of a hinge-like domain of amphipathic helixes in a single molecule of apoA-I.
Additions and Corrections - A Total Synthesis of dl-Δ'-Tetrahydrocannabinol, the Active Constituent of Hashish. (1965)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAdditions and Corrections - A Total Synthesis of dl-Δ'-Tetrahydrocannabinol, the Active Constituent of Hashish.R. Mechoulam and Y. GaoniCite this: J. Am. Chem. Soc. 1965, 87, 24, 5811Publication Date (Print):December 1, 1965Publication History Published online7 May 2004Published inissue 1 December 1965https://pubs.acs.org/doi/10.1021/ja00952a620https://doi.org/10.1021/ja00952a620research-articleACS PublicationsRequest reuse permissionsArticle Views112Altmetric-Citations-LEARN 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
Deciphering Three Beneficial Effects of 2,2′-Bipyridine-<i>N</i>,<i>N</i>′-Dioxide on the Luminescence Sensitization of Lanthanide(III) Hexafluoroacetylacetonate Ternary Complexes (2011)

Lanthanide hexafluoroacetylacetonate ternary complexes with 2,2'-bipyridine-N,N'-dioxide, [Ln(hfa)(3)(bpyO2)], were synthesized for Ln = Eu, Gd, Tb, and Lu and fully characterized by elemental, thermal, and mass-spectrometric analyses. The X-ray crystal structure of [Eu(hfa)(3)(bpyO2)]·0.5C(6)H(6) reveals an octa-coordinate metal ion lying in a severely distorted trigonal dodecahedron geometry; the Eu-O distances lie in the range 2.36-2.44 Å with no significant difference between hfa(-) and bpyO2. A detailed comparative photophysical investigation has been carried out to determine the exact influence of the introduction of bpyO2 in the inner coordination sphere of the metal ion in replacement of the two water molecules in [Ln(hfa)(3)(H(2)O)(2)]. While this replacement is detrimental for Tb, it leads to a 15-fold increase in the overall quantum yield for Eu. This large improvement originates from (i) a better sensitization efficiency, the ancillary ligand being responsible for 3/4 of the energy transfer, (ii) elimination of nonradiative deactivation pathways through harmonics of O-H vibrations, and (iii) reduction in the radiative lifetime. The latter influence is rarely documented, but it accounts here for a ≈25% increase in the intrinsic quantum yield, so that more attention should be given to this parameter when designing highly luminescent lanthanide complexes.
Mouse model of G <sub>M2</sub> activator deficiency manifests cerebellar pathology and motor impairment (1997)

The GM2 activator deficiency (also known as the AB variant), Tay-Sachs disease, and Sandhoff disease are the major forms of the GM2 gangliosidoses, disorders caused by defective degradation of GM2 ganglioside. Tay-Sachs and Sandhoff diseases are caused by mutations in the genes (HEXA and HEXB) encoding the subunits of beta-hexosaminidase A. The GM2 activator deficiency is caused by mutations in the GM2A gene encoding the GM2 activator protein. For degradation of GM2 ganglioside by beta-hexosamindase A, the GM2 activator protein must participate by forming a soluble complex with the ganglioside. In each of the disorders, GM2 ganglioside and related lipids accumulate to pathologic levels in neuronal lysosomes, resulting in clinically similar disorders with an onset in the first year of life, progressive neurodegeneration, and death by early childhood. We previously have described mouse models of Tay-Sachs (Hexa -/-) and Sandhoff (Hexb -/-) diseases with vastly different clinical phenotypes. The Hexa -/- mice were asymptomatic whereas the Hexb -/- mice were severely affected. Through gene disruption in embryonic stem cells we now have established a mouse model of the GM2 activator deficiency that manifests an intermediate phenotype. The Gm2a -/- mice demonstrated neuronal storage but only in restricted regions of the brain (piriform, entorhinal cortex, amygdala, and hypothalamic nuclei) reminiscent of the asymptomatic Tay-Sachs model mice. However, unlike the Tay-Sachs mice, the Gm2a -/- mice displayed significant storage in the cerebellum and defects in balance and coordination. The abnormal ganglioside storage in the Gm2a -/- mice consisted of GM2 with a low amount of GA2. The results demonstrate that the activator protein is required for GM2 degradation and also may indicate a role for the GM2 activator in GA2 degradation.
Human Monoclonal Antibodies Reactive with Cell Surface Antigens on Human Leukemia Cell Lines: Many Antibodies Are (Auto)antibodies (1990)

Primary Epstein Barr Virus (EBV) transformants from peripheral blood mononuclear cells (PBM) established in macrocultures were screened for the secretion of antibodies reactive with cell surface antigens on one or another of two indicator human leukemic cell lines and fused with the HMMA2.11TG/0 human fusion partner. Human monoclonal antibodies (HuMAbs) were readily obtained. Relative oligoclonality of the primary EBV macrocultures was documented by the number of antibody secreting hybridomas (1-100%). The method permitted preselection for fusion of transformants producing antibodies of certain specificities and/or class. Fourteen HuMAbs, primarily of the IgM class, have been obtained. Those IgM HuMAbs obtained from patients with active diseases, e.g. Acute Lymphoblastic Leukemia (3 HuMAbs), and HIV infection (4 HuMAbs), were found to have a relatively broad spectrum of reactivity with cell lines of various hematopoietic lineages and normal cells, although several show selective reactivity with T cell lineage tumors or a selected population of cells. HuMAbs from normal donors of both the IgG and IgM class were obtained. The IgM HuMAbs from one volunteer reacted primarily with autologous and allogeneic macrophages (autologous PBM from the other patients were not available) as well as a diverse number of hematopoietic cell lines. From others, the IgG HuMAbs demonstrated a more restricted spectrum of reactivity, while the IgM HuMAbs reacted with both autologous and allogeneic normal cells. Thus, the B cell repertoire contains cells capable of secreting cell surface reactive antibodies and many of these antibodies express characteristics of autoantibodies. Those that did not react with autologous or allogeneic PBM may react with other autoantigens which have been expressed on the malignant cells used as screening targets or may represent true antitumor antibodies.
Global Warming: Economic Policy Responses (1991)

Global warming is debated largely in environmental terms. The contributions in this book focus instead on the economic effects of global warming, providing an excellent summary of current thinking on this important issue. They raise such crucial questions as: Which countries will suffer the most from climate change? What economic initiatives could be adopted to reduce carbon dioxide emissions and chlorofluorocarbons? How will different nations fare under various proposals? What are the prospects for international cooperation?