gebhart/patrepeval huggingface dataset:
Pentavalent organobismuth reagents. Part 3. Phenylation of enols and of enolate and other anions (1985)

The phenylation of enols and of enolate anions of ketones, β-diketones and keto esters has been studied using a range of Bi reagents. Under basic conditions C-phenylation is observed and, even hindered, perphenylated compounds are easily synthesized. Under neutral and acidic conditions ordinary ketones do not react and enolic systems give O-phenylation. A number of other anions have been phenylated under basic conditions, including the key compound indole which mainly gave 3-C-phenylation. All these reactions can be supposed to have one of two alternative mechanisms, which parallel the two mechanisms proposed for the phenylation of phenols.
Selectivity over unifunctional multicomponent catalysts with non-uniform distribution of components (1985)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelectivity over unifunctional multicomponent catalysts with non-uniform distribution of componentsDady B. DadyburjorCite this: Ind. Eng. Chem. Fundamen. 1985, 24, 1, 16–27Publication Date (Print):February 1, 1985Publication History Published online1 May 2002Published inissue 1 February 1985https://doi.org/10.1021/i100017a004Request reuse permissionsArticle Views72Altmetric-Citations15LEARN 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 InReddit PDF (1 MB) Get e-Alerts
Small is different: energetic, structural, thermal, and mechanical properties of passivated nanocluster assemblies (2003)

We explore, with the use of extensive molecular dynamics simulations, several principal issues pertaining to the energetics of formation of superlattices made through the assembly of passivated nanoclusters, the interactions that underlie the cohesion of such superlattices, and the unique mechanical, thermal and structural properties that they exhibit. Our investigations focus on assemblies made of crystalline gold nanoclusters of variable sizes, passivated by monolayers of alkylthiol molecules. An analytic optimal packing model that correlates in a unified manner several structural characteristics of three-dimensional superlattice assemblies is developed. The model successfully organizes and systematizes a large amount of experimental and simulation data, and it predicts the phase-boundary between different superlattice structural motifs that evolve as a function of the ratio between the chain-length of the extended passivating molecules and the radius of the underlying gold nanocluster. The entropic contribution to the formation free energy of the superlattice assembly is found to be large and of similar magnitude as the potential energy component of the free energy. The major contribution to the cohesive potential energy of the superlattice is shown to originate from van der Waals interactions between molecules that passivate neighboring nanoclusters. The unique mechanical, thermal, thermomechanical, and thermostructural properties of passivated nanocluster assemblies, are discussed.
Animal models of immobilization osteopenia. (1999)

There are numerous animal and human models to study the effects upon the skeleton of eliminating mechanical usage by immobilization (IM). Care must be taken in employing the various models. They all have the same pattern of bone loss, but they respond slightly differently in the location and the amount of bone loss, depending upon the degree of unloading. Experimental immobilization studies involving local disuse-induced bone loss models can lose up a baseline level of 60% of their trabecular bone mass. This baseline level suggests a physiological threshold where basal hormonal and cellular activity determined by genetics is reached in the absence of mechanical stimuli. During the transient, immediate, or acute phase of immobilization, remodeling-dependent bone loss occurs in bone adjacent to marrow and from an increase in bone resorption and a decrease in formation. At steady state, or chronic phase, bone mass has plateaued at baseline with cellular activities back to normal levels. Further lowering of immobilization-induced bone loss from immobilization baseline levels can occur with nonmechanical factors like estrogen deficiency. A reasonable working model of immobilization-induced bone loss uses Frost's mechanostat theory and skeletal adaptation to mechanical usage highway to show the IM-induced bone loss, the mechanical usage feedback from the overloaded osteopenic bone and the modification of the IM-induced baseline response with non-mechanical agents. Lastly, an investigator should employ the combination of IM plus OVX model for evaluating agents in the prevention and healing of osteoporosis because it combines the skeletal response of estrogen deficiency in postmenopausal osteoporosis and age-related bone loss due to decreased physical activity.
Characterization of the New World Monkey Homologues of Human Poliovirus Receptor CD155 (2008)

In contrast to Old World monkeys, most New World monkeys (NWMs) are not susceptible to poliovirus (PV), regardless of the route of infection. We have investigated the molecular basis of restricted PV pathogenesis of NWMs with two kidney cell lines of NWMs, TMX (tamarin) and NZP-60 (marmoset), and characterized their PV receptor homologues. TMX cells were susceptible to infection by PV1 (Mahoney) and PV3 (Leon) but not by PV2 (Lansing). Binding studies to TMX cells indicated that the formation of PV/receptor complexes increased when measured first at 4 degrees C and then at 25 degrees C, whereas PV2 did not significantly bind to TMX cells at either temperature. On the other hand, NZP-60 cells were not susceptible to infection by any of the PV serotypes. However, a low amount of PV1 bound to NZP-60 cells at 4 degrees C, but there was no increase of binding at 25 degrees C. In contrast, both NWM cell lines supported genome replication and virion formation when transfected with viral RNAs of either serotype, an observation indicating that infection was blocked in receptor-virus interaction. To overcome the receptor block, we substituted 3 amino acids in the marmoset receptor (nCD155), H80Q, N85S, and P87S, found in the human PV receptor, hCD155. Cells expressing the mutant receptor (L-nCD155mt) were now susceptible to infection with PV1, which correlated with an increase in PV1-bound receptor complexes from 4 degrees C to 25 degrees C. L-nCD155mt cells were, however, still resistant to PV2 and PV3. These data show that an increase in the formation of PV/receptor complexes, when measured at 4 degrees C and at 25 degrees C, correlates with and is an indicator of successful infection at 37 degrees C, suggesting that the complex formed at 25 degrees C may be an intermediate in PV uptake.
ICOS maintains the T follicular helper cell phenotype by down-regulating Krüppel-like factor 2 (2015)

The co-stimulators ICOS (inducible T cell co-stimulator) and CD28 are both important for T follicular helper (TFH) cells, yet their individual contributions are unclear. Here, we show that each molecule plays an exclusive role at different stages of TFH cell development. While CD28 regulated early expression of the master transcription factor Bcl-6, ICOS co-stimulation was essential to maintain the phenotype by regulating the novel TFH transcription factor Klf2 via Foxo1. Klf2 directly binds to Cxcr5, Ccr7, Psgl-1, and S1pr1, and low levels of Klf2 were essential to maintain this typical TFH homing receptor pattern. Blocking ICOS resulted in relocation of fully developed TFH cells back to the T cell zone and reversion of their phenotype to non-TFH effector cells, which ultimately resulted in breakdown of the germinal center response. Our study describes for the first time the exclusive role of ICOS and its downstream signaling in the maintenance of TFH cells by controlling their anatomical localization in the B cell follicle.
Investigation of the Applicability of the Free-wing Principle to Light, General Aviation Aircraft (1972)

Gust-alleviation benefits for aircraft employing an unconventional wing, free to pivot about a spanwise axis forward of its aerodynamic center and subject only to aerodynamic pitching moments imposed by lift and drag forces and a trailing-edge control surface are reviewed.
Insulin Receptor Isoforms A and B as well as Insulin Receptor Substrates-1 and -2 Are Differentially Expressed in Prostate Cancer (2012)

We found significant differences in the insulin signaling cascade between benign prostate tissue and prostate cancer. Histological benign tissue adjacent to cancer showed expression patterns similar to the malignancies. Our findings suggest a role of the insulin signaling pathway in prostate cancer and surrounding tissue and can hence be relevant for both novel diagnostic and therapeutic approaches in this malignancy.
Efficient correction of a mutation by use of chemically synthesized DNA. (1978)

The mutated base in the am3 lysis-defective mutant of the bacteriophage phiX174 has been corrected by a combined in vitro enzymatic DNA synthesis and in vivo replication of the heteroduplex product. Chemically synthesized oligodeoxyribonucleotides carrying the wild-type sequence have been used to prime DNA synthesis with am3 phiX174 DNA serving as a template. The resultant semisynthetic heteroduplex composed of an am3(+) strand and a wild-type (-) strand, with one mismatched base pair at position 587 on the phiX174 DNA sequence, was used to infect spheroplasts. The progeny phage were analyzed by a parallel plaque assay on wild-type host, Escherichia coli C, to screen for wild-type phenotype, and on E. coli HF4714, an amber suppressor strain, to determine the total progeny phage. When a 23-base-long synthetic primer was used, about one-third of total progeny were found to be wild type. Shorter primers yielded lower percentages of wild type; they also had poorer priming activity.
Die Totalsynthese des (+)‐Yohimbins und (−)‐β‐Yohimbins (1969)

Abstract Mit dem Dieckmann ‐Ringschluß des leicht herstellbaren Diesters 4a gelingt ein einfacher Aufbau des Yohimban‐Gerüstes mit guter Ausbeute. Durch Reduktion des Yohimbinons ( 6b ) sowie durch Hydrolyse der Säureamide 7c und 8c wurden das (±)‐Yohimbin ( 7a ) und das (±)‐β‐Yohimbin ( 8a ) synthetisiert. Die racem . Produkte ließen sich mit N ‐Acetyl‐L‐leucin bzw. L ‐Camphersulfonsäure spalten.
Expression in yeast of a Plasmodium vivax antigen of potential use in a human malaria vaccine. (1987)

DNA coding for 234 amino acids of the circumsporozoite (CS) protein of Plasmodium vivax was incorporated into yeast expression vectors. The DNA encoded all the repeat domain and codons for a highly conserved sequence, KLKQP, found in CS proteins from all malaria parasites. Yeast cells transformed with these autonomously replicating plasmids expressed, upon induction, high levels of the CS polypeptide. The malaria antigen was purified in good yields from yeast extracts and was injected into mice using alum as adjuvant. The antibodies recognized the authentic CS protein, and at high dilutions, they inhibited the invasion of hepatocytes by sporozoites in vitro.
Construction and Immunological Evaluation of Multivalent Hepatitis B Virus (HBV) Core Virus-Like Particles Carrying HBV and HCV Epitopes (2010)

A multivalent vaccine candidate against hepatitis B virus (HBV) and hepatitis C virus (HCV) infections was constructed on the basis of HBV core (HBc) virus-like particles (VLPs) as carriers. Chimeric VLPs that carried a virus-neutralizing HBV pre-S1 epitope corresponding to amino acids (aa) 20 to 47 in the major immunodominant region (MIR) and a highly conserved N-terminal HCV core epitope corresponding to aa 1 to 60 at the C terminus of the truncated HBcDelta protein (N-terminal aa 1 to 144 of full-length HBc) were produced in Escherichia coli cells and examined for their antigenicity and immunogenicity. The presence of two different foreign epitopes within the HBc molecule did not interfere with its VLP-forming ability, with the HBV pre-S1 epitope exposed on the surface and the HCV core epitope buried within the VLPs. After immunization of BALB/c mice, specific T-cell activation by both foreign epitopes and a high-titer antibody response against the pre-S1 epitope were found, whereas an antibody response against the HBc carrier was notably suppressed. Both inserted epitopes also induced a specific cytotoxic-T-lymphocyte (CTL) response, as shown by the gamma interferon (IFN-gamma) production profile.
Nanostructured Materials for Electrochemical Energy Conversion and Storage Devices (2008)

Abstract One of the greatest challenges for our society is providing powerful electrochemical energy conversion and storage devices. Rechargeable lithium‐ion batteries and fuel cells are amongst the most promising candidates in terms of energy densities and power densities. Nanostructured materials are currently of interest for such devices because of their high surface area, novel size effects, significantly enhanced kinetics, and so on. This Progress Report describes some recent developments in nanostructured anode and cathode materials for lithium‐ion batteries, addressing the benefits of nanometer‐size effects, the disadvantages of ‘nano’, and strategies to solve these issues such as nano/micro hierarchical structures and surface coatings, as well as developments in the discovery of nanostructured Pt‐based electrocatalysts for direct methanol fuel cells (DMFCs). Approaches to lowering the cost of Pt catalysts include the use of i) novel nanostructures of Pt, ii)new cost‐effective synthesis routes, iii) binary or multiple catalysts, and iv) new catalyst supports. magnified image
Magnitude-dependent regulation of pulmonary endothelial cell barrier function by cyclic stretch (2003)

Ventilator-induced lung injury syndromes are characterized by profound increases in vascular leakiness and activation of inflammatory processes. To explore whether excessive cyclic stretch (CS) directly causes vascular barrier disruption or enhances endothelial cell sensitivity to edemagenic agents, human pulmonary artery endothelial cells (HPAEC) were exposed to physiologically (5% elongation) or pathologically (18% elongation) relevant levels of strain. CS produced rapid (10 min) increases in myosin light chain (MLC) phosphorylation, activation of p38 and extracellular signal-related kinase 1/2 MAP kinases, and actomyosin remodeling. Acute (15 min) and chronic (48 h) CS markedly enhanced thrombin-induced MLC phosphorylation (2.1-fold and 3.2-fold for 15-min CS at 5 and 18% elongation and 2.1-fold and 3.1-fold for 48-h CS at 5 and 18% elongation, respectively). HPAEC preconditioned at 18% CS, but not at 5% CS, exhibited significantly enhanced thrombin-induced reduction in transendothelial electrical resistance but did not affect barrier protective effect of sphingosine-1-phosphate (0.5 microM). Finally, expression profiling analysis revealed a number of genes, including small GTPase rho, apoptosis mediator ZIP kinase, and proteinase activated receptor-2, to be regulated by CS in an amplitude-dependent manner. Thus our study demonstrates a critical role for the magnitude of CS in regulation of agonist-mediated pulmonary endothelial cell permeability and strongly suggests phenotypic regulation of HPAEC barrier properties by CS.
P2Y12 inhibitors: differences in properties and mechanisms of action and potential consequences for clinical use (2009)

Currently, clopidogrel is recommended for treatment of patients with acute coronary syndrome and/or percutaneous coronary intervention. However, the delayed onset of the effect and the occurrence of poor platelet inhibition responders with clopidogrel as well as non-compliance to dual antiplatelet treatment are associated with a raised risk of stent thrombosis. The molecular target of the active metabolite of clopidogrel and several emerging antiplatelet treatments is the P2Y(12) receptor, which is the main platelet receptor responsible for ADP-induced platelet aggregation. Active metabolites of the thienopyridine prodrugs (ticlopidine, clopidogrel, and prasugrel) covalently bind to the P2Y(12) receptor and are irreversible, indirect platelet inhibitors. The newer, direct-acting P2Y(12) inhibitors (cangrelor and ticagrelor) change the conformation of the P2Y(12) receptor, resulting in reversible, concentration dependent inhibition of the receptor. An understanding of the similarities and differences in the properties and mechanisms of action of these new inhibitors compared with clopidogrel is needed in order to optimize the development and use of these agents in clinical practice. The objectives of this systematic review are to summarize the pharmacokinetics, pharmacodynamics, and pharmacogenetics of the different P2Y(12) inhibitors and to discuss the clinical implications for treatment of patients.
Purification and biochemical characterization of human pluripotent hematopoietic colony-stimulating factor. (1985)

Pluripotent hematopoietic colony-stimulating factor (pluripotent CSF), a protein that is constitutively produced by the human bladder carcinoma cell line 5637, has been purified from low serum (0.2% fetal calf serum)-containing conditioned medium. The purification involved sequential ammonium sulfate precipitation, ion-exchange chromatography, gel filtration, and reversed-phase high-performance liquid chromatography. The purified protein has a molecular weight of 18,000 in NaDodSO4/polyacrylamide gel electrophoresis, both by the silver staining technique and by elution of biological activity from a corresponding gel slice, and has an isoelectric point of 5.5. Pluripotent CSF supports the growth of human mixed colonies, granulocyte-macrophage colonies, and early erythroid colonies and induces differentiation of the human promyelocytic leukemic cell line HL-60 and the murine myelomonocytic leukemic cell line WEHI-3B (D+). The specific activity of the purified pluripotent CSF in the granulocyte-macrophage colony assay is 1.5 X 10(8) units/mg of protein.
Bile Changes after Liver Surgery: Experimental and Clinical Lessons for Future Applications (2010)

Analysis of the composition and quality of bile is probably underused as a tool for the pre-operative screening and early post-operative monitoring of patients at high risk of developing liver failure following major hepatobiliary procedures.
Vicarious Nucleophilic Substitution of Hydrogen in Nitrobenzoic Acids (1986)

The vicarious nucleophilic substitution of hydrogen in three isomeric nitrobenzoic acids 2-4 was studied. The negatively charged carboxylate anion substituent does not disturb the reaction course which proceeds with good to moderate yields to give products 6 and 7.
Supercontraction Stress in Spider Webs (2004)

Silk produced from the major ampullate (MA) gland supercontracts when wet, and in this paper, we investigate the consequences of high humidity and of the added load of water droplets condensing from saturated air on the mechanical integrity of the spiders' orb web. We measured the development of the supercontraction stress (sigma(sc)) with time when fixed lengths of MA silk from Nephila clavipes and Argiope aurantia were exposed to increasing humidity. Supercontraction generated stresses of about 50 MPa, and extension of these samples to stresses between 150 and 1100 MPa show a time dependent relaxation over 1000 s to approximately 75% of the initial tension but show no indication of failure. We conclude that supercontraction can maintain tension in webs and does not limit the ability of the web to support loads in excess of the supercontraction stress.
Role of the Rho-ROCK (Rho-Associated Kinase) Signaling Pathway in the Regulation of Pancreatic β-Cell Function (2008)

Extracellular matrix has a beneficial impact on beta-cell spreading and function, but the underlying signaling pathways have yet to be fully elucidated. In other cell types, Rho, a well-characterized member of the family of Rho GTPases, and its effector Rho-associated kinase (ROCK), play an important role as downstream mediators of outside in signaling from extracellular matrix. Therefore, a possible role of the Rho-ROCK pathway in beta-cell spreading, actin cytoskeleton dynamics, and function was investigated. Rho was inhibited using a new cell-permeable version of C3 transferase, whereas the activity of ROCK was repressed using the specific ROCK inhibitors H-1152 and Y-27632. Inhibition of Rho and of ROCK increased spreading and improved both short-term and prolonged glucose-stimulated insulin secretion but had no impact on basal secretion. Inhibition of this pathway led to a depolymerization of the actin cytoskeleton. Furthermore, the impact of the inhibition of ROCK on stimulated insulin secretion was acute and reversible, suggesting that rapid signaling such as phosphorylation is involved. Finally, quantification of the activity of RhoA indicated that the extracellular matrix represses RhoA activity. Overall these results show for the first time that the Rho-ROCK signaling pathway contributes to the stabilization of the actin cytoskeleton and inhibits glucose-stimulated insulin secretion in primary pancreatic beta-cells. Furthermore, they indicate that inhibition of this pathway might be one of the mechanisms by which the extracellular matrix exerts its beneficial effects on pancreatic beta-cell function.
Definition of the minimal viral components required for the initiation of unprimed RNA synthesis by influenza virus RNA polymerase (2002)

The first 11 nt at the 5' end of influenza virus genomic RNA were shown to be both necessary and sufficient for specific binding by the influenza virus polymerase. A novel in vitro transcription assay, in which the polymerase was bound to paramagnetic beads via a biotinylated 5'-vRNA oligonucleotide, was used to study the activities of different forms of the polymerase. Complexes composed of co-expressed PB1/PB2/PA proteins and a sub-complex composed of PB1/PA bound to the 5'-vRNA oligonucleotide, whereas PB1 expressed alone did not. The enriched 5'-vRNA/PB1/PB2/PA complex was highly active for ApG and globin mRNA primed transcription on a model 3'-vRNA template. RNA synthesis in the absence of added primers produced products with 5'-terminal tri- or diphosphate groups, indicating that genuine unprimed initiation of transcription also occurred. No transcriptase activity was detected for the PB1/PA complex. These results demonstrate a role for PA in the enhancement of 5' end binding activity of PB1, a role for PB2 in the assembly of a polymerase complex able to perform both cap-dependent and -independent synthesis and that NP is not required for the initiation of replicative transcription.