gebhart/patrepeval huggingface dataset:
Expanding metabolism for biosynthesis of nonnatural alcohols (2008)

Nature uses a limited set of metabolites to perform all of the biochemical reactions. To increase the metabolic capabilities of biological systems, we have expanded the natural metabolic network, using a nonnatural metabolic engineering approach. The branched-chain amino acid pathways are extended to produce abiotic longer chain keto acids and alcohols by engineering the chain elongation activity of 2-isopropylmalate synthase and altering the substrate specificity of downstream enzymes through rational protein design. When introduced into Escherichia coli, this nonnatural biosynthetic pathway produces various long-chain alcohols with carbon number ranging from 5 to 8. In particular, we demonstrate the feasibility of this approach by optimizing the biosynthesis of the 6-carbon alcohol, (S)-3-methyl-1-pentanol. This work demonstrates an approach to build artificial metabolism beyond the natural metabolic network. Nonnatural metabolites such as long chain alcohols are now included in the metabolite family of living systems.
Release of a Dye from Hydrogen-Bonded and Electrostatically Assembled Polymer Films Triggered by Adsorption of a Polyelectrolyte (2004)

The absorption of dyes within hydrogen-bonded and electrostatically assembled multilayers and subsequent release of the dyes from the films were studied in situ using FTIR-ATR. Multilayers were composed of poly(methacrylic acid), PMAA, and poly(ethylene oxide), PEO (hydrogen-bonded multilayers), or of PMAA and 22% quarternized copolymer of N-ethyl-4-vinylpyridium bromide and 4-vinylpyridine, Q22 (electrostatically stabilized multilayers). After multilayer deposition, the solution pH was changed to produce excess charge within the films. Dyes with charge opposite to the excess charge of the film (Rhodamine 6G for hydrogen-bonded films or Bromophenol Blue for electrostatically assembled multilayers) were then allowed to absorb within multilayers. In both systems, the dyes were uniformly included within the films. The top layers largely affected the loading capacity of the multilayers, suggesting weaker binding of the dyes with the top layers. Dye release into a 0.01 M phosphate buffer was significantly smaller as compared to release in the presence of 0.05-0.5 mg/mL solutions of adsorbing polymers whose charge was the same as the excess charge within the films. We found that with the PMAA/PEO films, dye release did not depend on the concentration of polymer in solution, but was largely controlled by the amount of charge accumulated within the adsorbing polymer layer on the top of the film. For electrostatically stabilized PMAA/Q22 systems, dye release increased with increasing concentration of Q22 in solution, suggesting a significant contribution of the competition of solution species in the release mechanism. Our findings contribute to the understanding of interactions of small molecules with polymer multilayers and might have ramifications for novel applications of multilayer films as new materials for the controlled delivery of chemicals.
Experimental schistosomiasis mansoni: modulation of granulomas by inhibition of collagen cross-link formation. Preliminary report (1992)

beta-Aminopropionitrile (BAPN) is an inhibitor of the lysyl oxidase required for cross-link formation in collagen maturation. The efficacy of BAPN, alone or in association with the anti-schistosomal drug, praziquantel (PZQ), was primarily assessed by measuring the reduction in liver and intestinal egg loads in murine schistosomiasis mansoni. Depending on the treatment group (PZQ, BAPN, BAPN + PZQ), organ-specific effects were observed using microscope image analysis. Most notable was the relatively small size of granulomas in the livers of BAPN-treated mice, which contrasted with the relatively large size and irregular shape of the granulomas in the intestinal tissues of these mice. Mice treated with the combination of BAPN and PZQ had decreased liver and spleen weights, and a significant reduction in the number of eggs trapped in both the liver (86%) and the intestine (99.1%), compared with untreated mice and those given PZQ alone. The lowest number of living eggs/g of tissue in both the liver and intestine was recorded in the combined BAPN + PZQ-treated group. These results suggest that the concurren treatment of infected mice with PZQ and BAPN enhances the release of eggs trapped in the intestine and also results in a significant reduction of liver egg load. The mechanism by which BAPN reduces the number of liver granulomas in PZQ-treated mice is currently being investigated.
Involvement of Ras-related Rho proteins in the mechanisms of action of Clostridium difficile toxin A and toxin B (1995)

Toxins A and B of Clostridium difficile are responsible for pseudomembranous colitis, a disease that afflicts a substantial number of hospitalized patients treated with antibiotics. A major effect of these proteins is the disruption of the actin cytoskeleton. Recently, I. Just, G. Fritz, K. Aktories, M. Giry, M. R. Popoff, P. Boquet, S. Hegenbarth, and C. von Eichel-Streiber (J. Biol. Chem. 269:10706-10712, 1994) implicated Rho proteins as cellular targets of C. difficile toxin B, since pretreatment of cells or purified Rho with toxin prevented subsequent ADP-ribosylation of Rho by exoenzyme C3. Moreover, they showed that overexpression of Rho proteins in cells suppressed cell rounding normally associated with exposure of cells to C. difficile toxin B. Here we expand these findings by showing directly that Rho proteins are covalently modified by both C. difficile toxins A and B. In addition, we demonstrate that the stability of toxin-modified Rho in NIH 3T3 cells is dramatically reduced. Finally, we show that C. difficile toxins A and B do not have similar effects on the closely related Rac and CDC42 GTP-binding proteins.
Implementation of L2TP Compulsory Tunneling via RADIUS (2000)

This document discusses implementation issues arising in the provisioning of compulsory tunneling in dial-up networks using the L2TP protocol. This provisioning can be accomplished via the integration of RADIUS and tunneling protocols. Implementation issues encountered with other tunneling protocols are left to separate documents.
Human Papillomavirus Type 16 E6 Induces Self-Ubiquitination of the E6AP Ubiquitin-Protein Ligase (2000)

The E6 protein of the high-risk human papillomaviruses (HPVs) and the cellular ubiquitin-protein ligase E6AP form a complex which causes the ubiquitination and degradation of p53. We show here that HPV16 E6 promotes the ubiquitination and degradation of E6AP itself. The half-life of E6AP is shorter in HPV-positive cervical cancer cells than in HPV-negative cervical cancer cells, and E6AP is stabilized in HPV-positive cancer cells when expression of the viral oncoproteins is repressed. Expression of HPV16 E6 in cells results in a threefold decrease in the half-life of transfected E6AP. E6-mediated degradation of E6AP requires (i) the binding of E6 to E6AP, (ii) the catalytic activity of E6AP, and (iii) activity of the 26S proteasome, suggesting that E6-E6AP interaction results in E6AP self-ubiquitination and degradation. In addition, both in vitro and in vivo experiments indicate that E6AP self-ubiquitination results primarily from an intramolecular transfer of ubiquitin from the active-site cysteine to one or more lysine residues; however, intermolecular transfer can also occur in the context of an E6-mediated E6AP multimer. Finally, we demonstrate that an E6 mutant that is able to immortalize human mammary epithelial cells but is unable to degrade p53 retains its ability to bind and degrade E6AP, raising the possibility that E6-mediated degradation of E6AP contributes to its ability to transform mammalian cells.
GaAs bipolar transistors grown on (100) Si substrates by molecular beam epitaxy (1985)

We have investigated the properties of GaAs homojunction bipolar transistors grown on (100) oriented Si substrates by molecular beam epitaxy. In a structure with a base thickness of 0.2 μm, a small-signal common emitter current gain β of about 10 at a current density of 10 kA/cm2 has been obtained. Current densities as high as 105 000 A/cm2 were obtained in these devices without degradation demonstrating the excellent stability of this material. Since the minority-carrier lifetime is quite sensitive to defects in the base region, these measurements demonstrate the high quality of GaAs on Si substrates. From the collector current dependence of current gain, an ideality factor n=1.5 for the emitter junction was obtained, indicating that space-charge recombination is an important mechanism in these devices. We also demonstrate that the entire GaAs on Si wafer is phase ordered by observing the orientation effect in the mesa etching. These results show that excellent minority-carrier properties can be obtained in GaAs on Si epitaxial layers despite the somewhat large dislocation density due to lattice mismatch.
Solution polymerization of acrylamide to high conversion (1973)

Abstract The solution polymerization of acrylamide initiated by 4,4′‐azobis‐4‐cyanovaleric acid (ACV) at high monomer concentrations in the temperature range 25–50°C has been studied. Molecular weight distributions were measured by gel permeation chromatography and by electron microscopy. Molecular weight measurements show that transfer to monomer plays a dominant role in controlling the molecular weight averages.
Parathyroid Hormone Secretion and Action: Evidence for Discrete Receptors for the Carboxyl-Terminal Region and Related Biological Actions of Carboxyl-Terminal Ligands (2004)

PTH is a major systemic regulator of the concentrations of calcium, phosphate, and active vitamin D metabolites in blood and of cellular activity in bone. Intermittently administered PTH and amino-terminal PTH peptide fragments or analogs also augment bone mass and currently are being introduced into clinical practice as therapies for osteoporosis. The amino-terminal region of PTH is known to be both necessary and sufficient for full activity at PTH/PTHrP receptors (PTH1Rs), which mediate the classical biological actions of the hormone. It is well known that multiple carboxyl-terminal fragments of PTH are present in blood, where they comprise the major form(s) of circulating hormone, but these fragments have long been regarded as inert by-products of PTH metabolism because they neither bind to nor activate PTH1Rs. New in vitro and in vivo evidence, together with older observations extending over the past 20 yr, now points strongly to the existence of novel large carboxyl-terminal PTH fragments in blood and to receptors for these fragments that appear to mediate unique biological actions in bone. This review traces the development of this field in the context of the evolution of our understanding of the "classical" receptor for amino-terminal PTH and the now convincing evidence for these receptors for carboxyl-terminal PTH. The review summarizes current knowledge of the structure, secretion, and metabolism of PTH and its circulating fragments, details available information concerning the pharmacology and actions of carboxyl-terminal PTH receptors, and frames their likely biological and clinical significance. It seems likely that physiological parathyroid regulation of calcium and bone metabolism may involve receptors for circulating carboxy-terminal PTH ligands as well as the action of amino-terminal determinants within the PTH molecule on the classical PTH1R.
Matrix‐assisted laser desorption/ionization mass sectrometry of restriction enzyme‐digested plasmid DNA using an active nafion substrate (1994)

Matrix-assisted laser desorption/ionization using a 3-hydroxypicolinic acid matrix from an active Nafion substrate has been used for detection of restriction enzyme-digested double-stranded plasmid DNA using time-of-flight mass spectrometry. DNA strands of up to 267 base pairs were detected with minimal sample purification, although only as species corresponding to single-stranded DNA.
Cross-coupling of benzylic acetates with arylboronic acids: one-pot transformation of benzylic alcohols to diarylmethanes (2005)

Benzylic acetates reacted with arylboronic acids in the presence of a DPEphos-[Pd(eta3-C3H5)Cl]2 catalyst when tert-amyl alcohol was used as a solvent, and the catalytic cross-couplings produced diarylmethanes in high yields (up to 94% isolated yield).
Inhibition of fibronectin binding to platelets by proteolytic fragments and synthetic peptides which support fibroblast adhesion. (1985)

To define regions within fibronectin (Fn) recognized by platelet binding sites, inhibition of Fn binding by an Fn fragment and synthetic peptides has been analyzed. A highly purified 120-kDa chymotryptic fragment, which has cell attachment activity but did not bind to insolubilized heparin or gelatin, inhibited Fn binding to platelets with an ID50 approximately 3 microM. Previous work indicates that fibroblasts attach to an 11.5-kDa subfragment of this 120-kDa fragment, and that one of four 30-residue synthetic peptides containing sequences from this region supports cell attachment. Only the peptide containing the COOH terminus of the 11.5-kDa fragment inhibited Fn binding to platelets, with an ID50 approximately 10 microM and is the peptide which supports fibroblast attachment. Of the smaller peptides studied from this sequence, all peptides containing the Arg-Gly-Asp-Ser sequence, including the tetrapeptide itself, were active in inhibiting Fn binding to platelets (ID50 values approximately 10-20 microM). The same peptides support fibroblast attachment. Those which lacked this sequence including Gly-Asp-Ser-Pro and Thr-Gly-Arg-Gly (immediately adjacent tetrapeptides) lacked both activities. Further evidence for specificity of inhibition was provided by structurally modified peptides in which substitution of a Glu for Asp abolished inhibitory activity and substitution of Lys for Arg or Ala for Gly reduced activity 6- and 8-fold, respectively. In addition, Arg-Gly-Asp-Ser-containing peptides inhibited the rate and extent of thrombin-induced platelet aggregation. These data suggest that the Arg-Gly-Asp-Ser tetrapeptide contains a recognition specificity involved in the binding of Fn to platelets and that platelets share features of this recognition specificity with fibroblasts.
Developments in broadband antennas (1964)

A survey is presented for the purpose of providing the nonspecialist with a basic understanding of the remarkable advances that have taken place over the past decade in the field of broadband antennas
Interactive risk factors for treatment adherence in a chronic psychotic disorders population (1999)

This study identified the unique and primary contributions of several concurrent risk factors for poor adherence to treatment recommendations in a clinic population of individuals with chronic psychotic disorders, i.e. 48% had DSM-IV diagnoses of schizoaffective disorder, 38% had schizophrenia, paranoid type, 12% had schizophrenia, undifferentiated type, and 2% had affective disorder with psychotic features. The target cohort consisted of 87 consecutive admissions to a continuing day treatment program. As part of a services-oriented quality assurance program, clinical staff completed rating scales for all patients. These included the BASIS-32 rating scale, which consisted of the following five subscales: psychosis; depression/anxiety; impulsive/addictive behavior; relation to self and others; and daily living and role functioning, and the Working Alliance Inventory-short form (therapist version), which consisted of the following three subscales: goal; task; and bond. These data were used to identify risk factors that weaken a patient's adherence to medication and non-medication treatment during the first 2 weeks of treatment in the clinic. Medication treatment consisted of both typical and atypical neuroleptic medications, with most patients being on multiple medications. Correlational analyses suggested that many of the risk factor variables were significantly associated with poor treatment adherence. Regression analyses suggested that the degree of psychoticism was most strongly associated with poor adherence to medication treatment and that difficulties relating to self and others were the strongest predictor of poor adherence to non-medication treatment. A large-sample services research design such as this can begin to determine patterns of associations between previous identified risk factors and poor treatment adherence in individuals with chronic psychotic disorders.
The COQ5 Gene Encodes a Yeast Mitochondrial Protein Necessary for Ubiquinone Biosynthesis and the Assembly of the Respiratory Chain (1997)

Saccharomyces cerevisiae is a facultative anaerobe capable of meeting its energy requirements by fermentation and is thus an ideal system for studying the biogenesis of respiring mitochondria. We have isolated a respiration-deficient mutant exhibiting a pleiotropic loss of the mitochondrial electron transport chain. The corresponding wild-type gene, COQ5, was cloned, sequenced, and able to restore respiratory growth. Deletion of the chromosomal COQ5 gene results in a respiration deficiency and reduced levels of respiratory protein components. Exogenously added decylubiquinone can partially restore electron transport chain function to mitochondrial membranes from the deletion mutant. The COQ5 nucleotide sequence predicts a polypeptide of 307 amino acids containing a mitochondrial targeting signal. COQ5p is 43% identical to the polypeptide predicted by the Escherichia coli open reading frame, o251 (1). The COQ5 gene, when introduced into E. coli, complements the respiratory deficiency of an ubiE mutant that maps near o251, suggesting that it is the yeast homolog of the ubiE gene product. We conclude that the COQ5 gene encodes the mitochondria-localized 2-hexaprenyl-6-methoxy-1,4-benzoquinone methyltransferase of the yeast ubiquinone biosynthetic pathway.
Plasma chromatography of isomeric halogenated nitrobenzenes (1974)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPlasma chromatography of isomeric halogenated nitrobenzenesFrancis W. Karasek and David M. KaneCite this: Anal. Chem. 1974, 46, 6, 780–782Publication Date (Print):May 1, 1974Publication History Published online1 May 2002Published inissue 1 May 1974https://pubs.acs.org/doi/10.1021/ac60342a039https://doi.org/10.1021/ac60342a039research-articleACS PublicationsRequest reuse permissionsArticle Views79Altmetric-Citations23LEARN 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
Regulation of megakaryocyte development by interleukin-6 (1989)

Megakaryocytes develop in densely seeded normal mouse bone marrow (BM) cells cultured in agar or in liquid medium. This formation of megakaryocytes is enhanced by the myeloid differentiation-inducing protein MGI-2, which we have shown to be interleukin-6 (IL-6). Monoclonal antibody (MoAb) that specifically neutralizes mouse IL-6 but not human IL-6 inhibited megakaryocyte development in cells cultured either with or without the addition of mouse IL-6 but did not inhibit megakaryocyte development induced by human IL-6. This MoAb to mouse IL-6 that does not neutralize mouse IL-3 also inhibited mouse IL-3-induced megakaryocyte development. Antibody to mouse GM-CSF did not inhibit the formation of megakaryocytes. The results show that the induction of megakaryocyte development by IL-3 is due to the production of IL-6 in the BM cultures. The present experiments demonstrate a new property of IL-6 and indicate that IL-6 is a regulatory protein of normal megakaryocyte development.
<title>8 X 8 holographic single-mode fiber switch based on electrically addressed nematic liquid crystal deflectors</title> (2000)

We present the design and the system characterization of a 8 X 8 free-space optical switching matrix based on the cascade on two 1D deflectors. These devices are based on phase ramps generated into parallel aligned nematic liquid crystal cells. Each cell is divided into 8 arrays with 309 2.5 micrometers -wide electrodes. Each of these arrays is addressed by Tape Automatic Bounded circuits which are reported onto the transparent Indium Tin Oxide on glass substrate. A specific software allows to determine the supply voltages required to establish a given set of interconnections. The two liquid crystal cells, which have been optimized to operate in the 1.55 micrometers window, have an efficiency higher than 70% for deflection angles up to 2.5 degree(s). These cells have been associated with single mode fiber and diffractive lens arrays into a rack-mounted demonstrator, which include the required optics to achieve polarization diversity. The average insertion loss is 9.0 dB with a maximum of 12.5 dB; the polarization dependent loss is lower than 1 dB, and worst case isolation is about 30 dB.
Intracellular Aspects of the Process of Protein Synthesis (1975)

The title of the Nobel Lecture of George Palade (1 August, p. 347) should have been "Intracellular aspects of the process of protein secretion."
Polarized ethylenes. IV. Synthesis of polarized ethylenes using thioamides and methyl dithiocarboxylates and their application to syntheses of pyrazoles, pyrimidines, pyrazolo[3,4‐d]pyrimidines, and 5‐aza[2.2.3]cyclazines (1990)

Abstract Polarized ethylenes having both electron‐donating (an amino or a methylthio group) and electron‐accepting (cyano, carbamoyl, methyl ester) groups on the adjacent two olefinic carbon atoms were prepared by the condensation of S‐alkylthioamidinium salts or methyl dithiocarboxylates with the corresponding active methylene compounds in good yields. These polarized ethylenes were alternatively synthesized by the reaction of thioamides or methyl dithiocarboxylates with tetracyanoethylene oxide in good yields. Reactions of these polarized ethylenes with hydrazine or guanidine derivatives occurred smoothly to give the corresponding pyrazole and pyrimidine derivatives in good yields. The synthesis of 5‐aza[2.2.3]cyclazine derivatives using polarized ethylenes is also described.
Determination of Swell Potential of Al-Qatif Clay (1993)

Abstract Knowledge of the swell potential of expansive soil at the outset of an investigation can be helpful in avoiding possible damage to the structure. A review is presented of several methods that have been proposed to identify swell potential and test techniques, which are used to quantify the amount of swell. A site investigation was conducted to obtain hand-carved block specimens from a fresh excavation site near Al-Qatif, Eastern Province of Saudi Arabia. Laboratory tests were used to determine geotechnical and physicochemical properties and mineralogical composition. The results of a range of laboratory tests, including oedometer types, filter paper, triaxial, and new stainless steel tank apparatus, showed the problems associated with investigating swell behavior of soils. A field swelling test was conducted, and results are compared with laboratory tests to establish guidelines for estimation of swell potential.