gebhart/patrepeval huggingface dataset:
Antifouling Poly(β-peptoid)s (2011)

A new type of polymer highly resistant to nonspecific protein adsorption is reported. Poly(N-methyl-β-alanine) (PMeA) and poly(N-ethyl-β-alanine) (PEtA) synthesized via cobalt-catalyzed carbonylative polymerization of N-methylaziridine and N-ethylaziridine were end-functionalized with thiol groups and grafted onto Au surfaces. Protein adsorption was studied by the surface plasmon resonance (SPR) method. The amounts of representative single proteins adsorbed onto the PMeA- and PEtA-grafted surfaces were below the detection limit of SPR at the pg/mm(2) level. After exposure to full blood plasma and serum for 10 min, protein adsorption was at the level of ∼ 100 pg/mm(2), similar to the level of protein adsorption on poly(ethylene glycol) surfaces subjected to identical conditions. These poly(β-peptoid)s therefore provide excellent protein resistance comparable to the best antifouling materials known to date. The strong proton-accepting ability when forming hydrogen bonds is suggested to be an important attribute for these poly(β-peptoid)s as well as other poly(tertiary amide)s as antifouling materials.
Quadtree interconnection network layout (2003)

Quadtree data structure has been used in a number of applications. However, VLSI embedding of quadtree based parallel architecture using grid model has not been studied. This paper studies VLSI embedding of quadtree using grid model. H-tree layout for binary tree is extended for trivial quadtree layout, followed by two layout strategies for rectangular grids. Two generic layout styles (standard layout and X-layout) are proposed for higher order grids (e.g., hexagonal and octagonal grids). Base tile layout patterns are proposed for area compaction with recursive X-layout. In each case, layout dimensions and I/O bandwidth are computed. The authors demonstrate how the two generic layouts can be mixed to obtain higher I/O bandwidth and estimate the area sacrifice. An improved recursive layout mixing strategy is proposed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Assessment of carcinogenic volatile N-nitrosamines in tobacco and in mainstream and sidestream smoke from cigarettes. (1977)

&lt;p&gt;There is much focus on timing error resilience for the speed critical paths of processors. In the context of growing parameter variations with technology scaling and voltage scaling, resilience helps to ensure functional correctness. Moreover it allows the chip to stretch its operating voltage and frequency beyond the conventional limits to meet the demand for high performance and low power. Conventionally, timing error resilience is achieved through variation tolerant circuitry at the cost of undesirable power, area and throughput overheads. Such overheads are aggravated by the presence of large number of critical timing paths in the design. In this paper, we propose a slack-aware timing margin redistribution technique for error resilience using time borrowing error avoidance flip-flops (EAFFs) while minimizing overheads. The proposed algorithm designs the processor critical paths ground up by inserting EAFFs at places where positive slack is available in the subsequent fan-out stage. Experiment results on an industrial processor design show that a timing margin improvement of 11% of the clock period can be achieved on 64% of the critical paths and a 55% timing margin on 45% of the critical paths without any throughput degradation. The area and power overheads of the additional flip-flops are 0.2% and 5.4%, respectively.&lt;/p&gt;
New Perspectives on the Structure of Graphitic Carbons (2005)

Graphitic forms of carbon are important in a wide variety of applications, ranging from pollution control to composite materials, yet the structure of these carbons at the molecular level is poorly understood. The discovery of fullerenes and fullerene-related structures such as carbon nanotubes has given a new perspective on the structure of solid carbon. This review aims to show how the new knowledge gained as a result of research on fullerene-related carbons can be applied to well-known forms of carbon such as microporous carbon, glassy carbon, carbon fibers, and carbon black.
Mitochondria and Apoptosis (1998)

A variety of key events in apoptosis focus on mitochondria, including the release of caspase activators (such as cytochrome c), changes in electron transport, loss of mitochondrial transmembrane potential, altered cellular oxidation-reduction, and participation of pro- and antiapoptotic Bcl-2 family proteins. The different signals that converge on mitochondria to trigger or inhibit these events and their downstream effects delineate several major pathways in physiological cell death.
The Cluster 1 Type VI Secretion System Is a Major Virulence Determinant in Burkholderia pseudomallei (2011)

The Burkholderia pseudomallei K96243 genome encodes six type VI secretion systems (T6SSs), but little is known about the role of these systems in the biology of B. pseudomallei. In this study, we purified recombinant Hcp proteins from each T6SS and tested them as vaccine candidates in the BALB/c mouse model of melioidosis. Recombinant Hcp2 protected 80% of mice against a lethal challenge with K96243, while recombinant Hcp1, Hcp3, and Hcp6 protected 50% of mice against challenge. Hcp6 was the only Hcp constitutively produced by B. pseudomallei in vitro; however, it was not exported to the extracellular milieu. Hcp1, on the other hand, was produced and exported in vitro when the VirAG two-component regulatory system was overexpressed in trans. We also constructed six hcp deletion mutants (Δhcp1 through Δhcp6) and tested them for virulence in the Syrian hamster model of infection. The 50% lethal doses (LD(50)s) for the Δhcp2 through Δhcp6 mutants were indistinguishable from K96243 (<10 bacteria), but the LD(50) for the Δhcp1 mutant was >10(3) bacteria. The hcp1 deletion mutant also exhibited a growth defect in RAW 264.7 macrophages and was unable to form multinucleated giant cells in this cell line. Unlike K96243, the Δhcp1 mutant was only weakly cytotoxic to RAW 264.7 macrophages 18 h after infection. The results suggest that the cluster 1 T6SS is essential for virulence and plays an important role in the intracellular lifestyle of B. pseudomallei.
Drosophila spectrin. II. Conserved features of the alpha-subunit are revealed by analysis of cDNA clones and fusion proteins. (1987)

Drosophila alpha-spectrin cDNA sequences were isolated from a lambda gt11 expression library. These cDNA clones encode fusion proteins that include portions of the Drosophila alpha-spectrin polypeptide as shown by a number of structural and functional criteria. The fusion proteins elicited antibodies that reacted strongly with Drosophila and vertebrate alpha-spectrins and a comparison of cyanogen bromide peptide maps demonstrated a clear structural correspondence between one fusion protein and purified Drosophila alpha-spectrin. Alpha-spectrin fusion protein also displayed calcium-dependent calmodulin-binding activity in blot overlay experiments and one fusion protein bound specifically to both Drosophila and bovine brain beta-spectrin subunits on protein blots. A region of the Drosophila cDNA cross-hybridized at lowered stringency with an avian alpha-spectrin cDNA. Together these data show that the composition, structure, and binding properties of the spectrin family of proteins have been remarkably well conserved between arthropods and vertebrates. Drosophila cDNA hybridized to an mRNA of greater than or equal to 9 kb on blots of total Drosophila poly A+ RNA; and hybridized in situ to a single site in polytene region 62B, 1-7. This result and Southern blot analysis of genomic DNA indicate that the sequences are likely to be single copy in the Drosophila genome.
NCAM is ubiquitylated, endocytosed and recycled in neurons (2007)

The neural cell adhesion molecule NCAM plays an important role during neural development and in the adult brain. To study the intracellular trafficking of NCAM in neurons, two major isoforms, NCAM140 or NCAM180, were expressed in primary cortical neurons and in the rat B35 neuroblastoma cell line. NCAM was endocytosed and subsequently recycled to the plasma membrane, whereas only a minor fraction was degraded in lysosomes. In cortical neurons, endocytosis of NCAM was detected in the soma, neurites and growth cones in a developmentally regulated fashion. Furthermore, we found that NCAM is mono-ubiquitylated at the plasma membrane and endocytosis was significantly increased in cells overexpressing ubiquitin. Therefore, we propose that ubiquitylation represents an endocytosis signal for NCAM.
Production of lymphokines by circulating human T lymphocytes that express or lack receptors for interleukin 2. (1984)

The capacity for circulating human T cells which have or lack receptors for interleukin 2 (IL 2) to produce IL 2, interleukin 3 (IL 3), and interferon-gamma (IFN-gamma) under the stimulus of phytohemagglutinin was studied. By using the monoclonal anti-Tac antibody which reacts against IL 2 receptors on human T cells, concanavalin A-treated T cells were separated into IL 2 receptor-positive (Tac+ T cells) and IL 2 receptor-negative (Tac- T cells) lymphocytes. The results show that Tac+ T cells secreted IL 2 and IFN-gamma but not IL 3. Tac- T cells produced IL 2 and IL 3 but not IFN-gamma. It is concluded that: 1) both T cells lacking and T cells having receptors for IL 2 produce IL 2, but only IL 2 receptor-negative T cells appear to secrete IL 3; and 2) virtually all of the T cells that produce IFN-gamma after PHA stimulation express receptors for IL 2.
DECOMPOSITION OF SODIUM HYPOCHLORITE: THE UNCATALYZED REACTION (1956)

The decomposition of sodium hypochlorite has been re-examined. The results show that Foerster and Dolch’s mechanism of the decomposition to chlorate and chloride is correct; they postulated a slow bimolecular reaction to chlorite and chloride, followed by a faster reaction of chlorite with more hypochlorite. Values of the rate constants of both steps are reported; they make the activation energies 24.8 kcal./gm-molecule for the first step and 20.8 kcal./gm-molecule for the second. The rates are such that at 40 °C. a solution of sodium hypochlorite will contain about 1% as much chlorite as hypochlorite. The rate is strongly affected by changing ionic strength; at low ionic strengths it is nearly constant or falls slightly; above about 0.8, the rate rises and at high ionic strengths the rise is quite rapid. No signs of specific catalytic effects of sodium chloride, hydroxide, or carbonate could be observed, and it seems probable that earlier reports of this were due to variations in ionic strength. The decomposition to chloride and oxygen has been measured and is a unimolecular reaction, which is possibly, but not certainly, uncatalyzed. Values of its rate constant are reported; they also are much altered by changing the ionic strength.
Is assigning community service beneficial (2008)

The term “mandatory” community service is contradictory. When community service is mandated, i.e. a program bestows a certain task to be completed, instead of allowing free choice, the service is more beneficial to those serving and those being served. If a person were to be allowed to choose the service he or she wishes to complete, that person is more likely going to choose the easiest form of service because the service is mandatory.
IL-10, T lymphocyte inhibitor of human blood cell production of IL-1 and tumor necrosis factor (1992)

Abstract We have identified and purified a factor that inhibits the production of IL-1 beta and TNF by stimulated human mononuclear cells. The activity is produced by the T cell lines Hut-78 and Mo constitutively under serum-free conditions. Crude conditioned media have titers of up to 100 U/ml (one unit defined as the reciprocal of the dilution producing 50% inhibition). The activity resides mainly in a single size peak of 30 to 35 kDa and an isoelectric point around 8. Other cytokines in this size range that have been reported to be inhibitory for IL-1 and TNF production include TGF-beta, IL-4, and IL-6; these factors were excluded by lack of detection, neutralizing antibody, and low activity compared with our factor. Another factor with these size and charge properties is IL-10, which inhibits T cell cytokine production. By polymerase chain reaction analysis, Mo and HuT-78 lines contain IL-10 transcripts whereas JURKAT is negative; this correlates with inhibitor bioactivity from the three lines. Use of mAb specifically showed the inhibitor to be IL-10.
Tissue-Engineered Skeletal Muscle Organoids for Reversible Gene Therapy (1996)

Genetically modified murine skeletal myoblasts were tissue engineered in vitro into organ-like structures (organoids) containing only postmitotic myofibers secreting pharmacological levels of recombinant human growth hormone (rhGH). Subcutaneous organoid implantation under tension led to the rapid and stable appearance of physiological sera levels of rhGH for up to 12 weeks, whereas surgical removal led to its rapid disappearance. Reversible delivery of bioactive compounds from postmitotic cells in tissue engineered organs has several advantages over other forms of muscle gene therapy.
Discovery of positive allosteric modulators and silent allosteric modulators of the μ-opioid receptor (2013)

μ-Opioid receptors are among the most studied G protein-coupled receptors because of the therapeutic value of agonists, such as morphine, that are used to treat chronic pain. However, these drugs have significant side effects, such as respiratory suppression, constipation, allodynia, tolerance, and dependence, as well as abuse potential. Efforts to fine tune pain control while alleviating the side effects of drugs, both physiological and psychological, have led to the development of a wide variety of structurally diverse agonist ligands for the μ-opioid receptor, as well as compounds that target κ- and δ-opioid receptors. In recent years, the identification of allosteric ligands for some G protein-coupled receptors has provided breakthroughs in obtaining receptor subtype-selectivity that can reduce the overall side effect profiles of a potential drug. However, positive allosteric modulators (PAMs) can also have the specific advantage of only modulating the activity of the receptor when the orthosteric agonist occupies the receptor, thus maintaining spatial and temporal control of receptor signaling in vivo. This second advantage of allosteric modulators may yield breakthroughs in opioid receptor research and could lead to drugs with improved side-effect profiles or fewer tolerance and dependence issues compared with orthosteric opioid receptor agonists. Here, we describe the discovery and characterization of μ-opioid receptor PAMs and silent allosteric modulators, identified from high-throughput screening using a β-arrestin-recruitment assay.
Rapid Desensitization and Uncoupling of Human β-Adrenergic Receptors in anin VitroModel of Lactic Acidosis* (1984)

Adrenergic responsiveness in many tissues may be impaired in the presence of lactic acidosis. The purpose of this study was to examine how human neutrophil beta 2-adrenergic receptors may be altered in an in vitro model of lactic acidosis. Receptor coupling was assessed by constructing curves for the competition of isoproterenol with [125I]iodocyanopindolol for beta-adrenergic receptors. Receptors were exposed to control (2 mM lactate, pH 7.4), lactic acidosis (16 mM lactate, pH 7.1), lactate excess (16 mM lactate, pH 7.4), and low pH (2 mM lactate, pH 7.1) conditions. Prior exposure of beta-adrenergic receptors on whole cells to lactic acidosis resulted in a 61% reduction in isoproterenol-stimulated cAMP accumulation (P less than 0.005). This desensitization was not accompanied by down-regulation. After exposure to lactic acidosis, beta-adrenergic receptors were uncoupled sufficiently that a high affinity state could not be detected. Both lactate excess and low pH were necessary to fully express the desensitization and uncoupling defects. The uncoupling was rapid (40 min) and occurred in cell-free membrane preparations. Thus, in an in vitro model of lactic acidosis, rapid desensitization and uncoupling occur which do not appear to require protein synthesis.
T Cell Receptors In Murine Autoimmune Diseases (1989)

Exhausted CD8 T (Tex) cells are a distinct cell lineage that arise during chronic infections and cancers in animal models and humans. Tex cells are characterized by progressive loss of effector functions, high and sustained inhibitory receptor expression, ...Read More
Intact function of Lgr5 receptor-expressing intestinal stem cells in the absence of Paneth cells (2012)

Lifelong self-renewal of the adult intestinal epithelium requires the activity of stem cells located in mucosal crypts. Lgr5 and Bmi1 are two molecular markers of crypt-cell populations that replenish all lineages over time and hence function as stem cells. Intestinal stem cells require Wnt signaling, but the understanding of their cellular niche is incomplete. Lgr5-expressing crypt base columnar cells (CBCs) reside deep in the crypt, mingled among mature Paneth cells that are well positioned for short-range signaling. Partial lineage ablation previously had implied that Paneth cells are nonessential constituents of the stem-cell niche, but recently their absence was reported to interfere with Lgr5(+) CBCs, resurrecting an appealing idea. However, previous mouse models failed to remove Paneth cells completely or permanently; defining the intestinal stem-cell niche requires clarity with respect to the Paneth cell role. We find that Lgr5(+) cells with stem-cell activity cluster in future crypts early in life, before Paneth cells develop. We also crossed conditional Atoh1(-/-) mice, which lack Paneth cells entirely, with Lgr5(GFP) mice to visualize Lgr5(+) CBCs and to track their stem-cell function. In the sustained absence of Paneth cells, Lgr5(+) CBCs occupied the full crypt base, proliferated briskly, and generated differentiated progeny over many months. Gene expression in fluorescence-sorted Lgr5(+) CBCs reflected intact Wnt signaling despite the loss of Paneth cells. Thus, Paneth cells are dispensable for survival, proliferation, and stem-cell activity of CBCs, and direct contact with Lgr5-nonexpressing cells is not essential for CBC function.
Objectively Assessed Physical Activity and Subsequent Health Service Use of UK Adults Aged 70 and Over: A Four to Five Year Follow Up Study (2014)

Community-based programs are needed which are successful in engaging older adults in their late 70s and 80s in more walking, MVPA and activity that helps them avoid loss of physical function. There is a potential for cost savings to health services through reduced reliance on prescriptions and fewer unplanned hospital admissions.
New Natural Colchicinoids: Indications of Two Possible Catabolic Routes for the Colchicine Alkaloids (1990)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNew Natural Colchicinoids: Indications of Two Possible Catabolic Routes for the Colchicine AlkaloidsTaleb H. Al-Tel, Musa H. Abu Zarga, Salim S. Sabri, Alan J. Freyer, and Maurice ShammaCite this: J. Nat. Prod. 1990, 53, 3, 623–629Publication Date (Print):May 1, 1990Publication History Published online1 July 2004Published inissue 1 May 1990https://doi.org/10.1021/np50069a013RIGHTS & PERMISSIONSArticle Views190Altmetric-Citations21LEARN 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 (472 KB) Get e-Alerts Get e-Alerts
Green Chemical Approaches toward High-Quality Semiconductor Nanocrystals (2002)

Green chemistry principles have gradually been implemented into the development of the synthetic chemistry of high-quality semiconductor nanocrystals. In comparison with the original organometallic approach, the resulting alternative routes are safe, simple, inexpensive, reproducible, versatile, "user friendly", and yield nanocrystals with well-controlled size, shape, and size/shape distribution. Further developments in this direction will promote the understanding of crystallization in general.
THE PRODUCTION OF PARTHENOGENETIC MAMMALIAN EMBRYOS AND THEIR USE IN BIOLOGICAL RESEARCH (1974)

Summary and Conclusions 1. The eggs of many mammalian species show signs of early parthenogenetic development as they age after ovulation and oocytes may form transplantable terato‐carcinomas. These cases of apparently spontaneous parthenogenetic development suggest that the cells of the female germ line have an inherent tendency to divide and differentiate. 2. The ovulated eggs of virgin female mammals may be stimulated to start parthenogenetic development by a wide variety of treatments. Most of these damage the egg so that it does not develop beyond the 4 cell stage. However if the eggs are exposed to electrical activation, hyaluronidase treatment, or temperature shock then in many cases they will develop into blastocysts. 3. These blastocysts may be either haploid or diploid. Haploid blastocysts may be formed either by the egg extruding the nucleus of the second polar body or by the egg dividing in half, so that the female pronucleus is in one cell and the nucleus of the second polar body is in another cell. Diploid blastocysts are formed by the retention of the nucleus of the second polar body within the egg. The way in which the egg develops may be controlled by altering the osmolarity of the culture medium, the age of the egg at the time of activation, or the strain of animal used. 4. The action of the sperm on the egg can be defined by comparing the events of normal fertilization and parthenogenetic activation. Both these stimuli cause the egg to expose binding sites for Concanavalin A to synthesize DNA and to divide. However, the release of cortical granules, which occurs after fertilization, does not appear to be induced by parthenogenetic activation, and it is significant that parthenogenones lack the sperm nucleus and mitochondria. 5. The majority of parthenogenones die soon after implantation. Death at this time occurs with parthenogenones obtained from the activated eggs of both inbred and outbred stocks. Death might be caused by recessive lethal mutations or by extra‐genetic effects of the maternal chromosomes. 6. Parthenogenones contain endogenous A‐type particles which shows that these bodies are inherited through the female germ line. 7. Parthenogenones may in the future provide both a method for chromosome mapping and a source of haploid cells. At present the use of mammalian parthenogenones in biological research is restricted by the heavy embryonic losses which occur around the time of implantation. This means that the role of the sperm, gene activity and virus expression must be studied during a very limited period. Part of the mortality before implantation is the consequence of the damage which the egg suffers during activation and it should be possible to reduce this loss by improving the techniques for activation. It may also be possible to increase the quantity of cells derived from haploid and diploid mammalian embryos by deriving teratocarcinomas from them.