gebhart/patrepeval huggingface dataset:
Preassociating .alpha.-nucleophiles (1992)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreassociating .alpha.-nucleophilesLewis E. Fikes, David T. Winn, Robert W. Sweger, Morgan P. Johnson, and Anthony W. CzarnikCite this: J. Am. Chem. Soc. 1992, 114, 4, 1493–1495Publication Date (Print):February 1, 1992Publication History Published online1 May 2002Published inissue 1 February 1992https://pubs.acs.org/doi/10.1021/ja00030a062https://doi.org/10.1021/ja00030a062research-articleACS PublicationsRequest reuse permissionsArticle Views273Altmetric-Citations13LEARN 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-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
Reliability issues for silicon-on-insulator (2002)

Understanding the reliability implications for silicon-on-insulator (SOI) is crucial for its use in ULSI technology. The fabrication process of SOI material and the device operation, due to the buried oxide (BOX) layer, could present additional concerns for meeting reliability requirements. In this paper, we discuss the reliability issues with silicon-on-insulator (SOI) technology. We focus on partially depleted (PD) SOI CMOS technology using SIMOX and bonded substrate material. We compare the reliability mechanisms, namely channel hot electron (CHE), gate oxide time dependent dielectric breakdown (TDDB), bias temperature stress (BTS) and plasma-induced charging damage, to bulk CMOS. In addition, results from high performance microprocessors subjected to burn-in stress are presented. Finally, we discuss the circuitry implications for electrostatic discharge (ESD).
Protection against rotavirus-induced gastroenteritis in a murine model by passively acquired gastrointestinal but not circulating antibodies (1985)

Newborn mice suckled on dams immunized either orally or parenterally with primate rotavirus SA-11 were protected against diarrhea induced by SA-11 virus challenge. Experimental oral administration of milk from orally immunized dams protected suckling mice against challenge; protective activity was detected both in the anti-rotavirus immunoglobulin A (IgA) and IgG fractions, but IgA was more potent in vivo than IgG. Oral administration of milk from parentally immunized dams also protected suckling mice against challenge; in this case, protective activity was detected in the anti-rotavirus IgG fraction. In newborn mice foster-nursed by seronegative dams, circulating rotavirus-specific antibodies in high titer did not protect mice against oral SA-11 virus challenge. It appears that the most effective rotavirus vaccine will be that which induces an efficient production of antibodies active at the intestinal cell surface.
Protein Kinase C and Calcium Regulation of Adenylyl Cyclase in Isolated Rat Pancreatic Islets (2001)

Rat islets express several isoforms of adenylyl cyclase (AC), and the regulation of AC activity in isolated islets by Ca(2+) and protein kinase C (PKC) was investigated. At basal 2.8 mmol/l glucose, the muscarinic receptor agonist carbamylcholine chloride (CCh) evoked a concentration-dependent increase in cAMP generation with a maximum increase at least 4.5-fold above control. In contrast, forskolin and glucagon-like peptide 1 fragment 7-36 amide increased cAMP accumulation 23-fold and almost 10-fold, respectively. Cholecystokinin 26-33 sulfated amide (CCK) also stimulated cAMP production by up to eightfold, as did the phorbol ester, phorbol 12,13-dibutyrate (PDBu). PDBu and CCh or CCK responses were not additive. The effects of phorbol ester, CCh, and CCK were inhibited by as much as 75% by the PKC inhibitors GF 109203X and Ro-32-0432 and after PKC downregulation. In the absence of extracellular Ca(2+), PDBu-, CCh-, and CCK-induced cAMP production was inhibited by approximately 50% in each case. Chelation of intracellular Ca(2+) with 1,2-bis(o-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid tetraacetoxymethyl ester (BAPTA/AM) inhibited CCh- and CCK-stimulated cAMP generation by approximately 50% but did not inhibit the stimulatory effect of PDBu. Stringent Ca(2+) depletion by removal of extracellular Ca(2+) and inclusion of BAPTA/AM allowed for increased cAMP production in response to CCh and CCK; PKC inhibitors and PKC downregulation prevented this stimulation. Glucose stimulation also increased islet cAMP production, but PDBu did not potentiate the glucose response. The results suggest that Ca(2+) influx, Ca(2+) mobilization, and PKC activation play important roles in the modulation of AC activity in pancreatic islets.
Xanthohumol Isolated from Humulus lupulus Inhibits Menadione-Induced DNA Damage through Induction of Quinone Reductase (2005)

The female parts of hops (Humulus lupulus L.) show estrogenic effects as well as cancer chemopreventive potential. We analyzed the chemopreventive mechanism of hops by studying its antioxidative activities and its effect on the detoxification of a potentially toxic quinone (menadione). The detoxification enzyme quinone reductase [(NAD(P)H:quinone oxidoreductase, QR] protects against quinone-induced toxicity and has been used as a marker in cancer chemoprevention studies. Although the hop extract was only a weak quencher of free radicals formed from 1,1-diphenyl-2-picrylhydrazyl, it demonstrated strong QR induction in Hepa 1c1c7 cells. In addition, compounds isolated from hops including xanthohumol (XH) and 8-prenylnaringenin were tested for QR induction. Among these, XH was the most effective at inducing QR with a concentration required to double the specific activity of QR (CD value) of 1.7 +/- 0.7 microM. In addition, pretreatment of Hepa1c1c7 cells with XH significantly inhibited menadione-induced DNA single-strand breaks. The QR inhibitor dicumarol reversed the protective effect of XH against menadione-induced DNA damage. Because the expression of QR and other detoxifying enzymes is known to be upregulated by binding of the transcription factor Nrf2 to the antioxidant response element (ARE), the reporter activity mediated by ARE in HepG2-ARE-C8 cells was investigated after incubation with XH for 24 h. Under these conditions, XH increased ARE reporter activity in a dose-dependent manner. One mechanism by which XH might induce QR could be through interaction with Keap1, which sequesters Nrf2 in the cytoplasm, so that it cannot activate the ARE. Using LC-MS-MS, we demonstrated that XH alkylates human Keap1 protein, most likely on a subset of the 27 cysteines of Keap1. This suggests that XH induces QR by covalently modifying the Keap1 protein. Therefore, XH and hops dietary supplements might function as chemopreventive agents, through induction of detoxification enzymes such as QR.
Exploring Biomolecular Recognition Using Optical Biosensors (1999)

Understanding the basic forces that determine molecular recognition helps to elucidate mechanisms of biological processes and facilitates discovery of innovative biotechnological methods and materials for therapeutics, diagnostics, and separation science. The ability to measure interaction properties of biological macromolecules quantitatively across a wide range of affinity, size, and purity is a growing need of studies aimed at characterizing biomolecular interactions and the structural elements that drive them. Optical biosensors have provided an increasingly impactful technology for such biomolecular interaction analyses. These biosensors record the binding and dissociation of macromolecules in real time by transducing the accumulation of mass of an analyte molecule at the sensor surface coated with ligand molecule into an optical signal. Interactions of analytes and ligands can be analyzed at a microscale and without the need to label either interactant. Sensors enable the detection of bimolecular interaction as well as multimolecular assembly. Most notably, the method is quantitative and kinetic, enabling determination of both steady-state and dynamic parameters of interaction. This article describes the basic methodology of optical biosensors and presents several examples of its use to investigate such biomolecular systems as cytokine growth factor-receptor recognition, coagulation factor assembly, and virus-cell docking.
Transplantation tolerance: The concept and its applicability (1999)

Recent advances have enabled researchers to induce tolerance in animal transplant models. Although it has been relatively easy to do so in rodents, it has been much more difficult to translate such strategies into primates. Understanding the cellular and molecular mechanisms of the alloimmune response has prompted the development of novel strategies that may obviate the need for immunosuppression in humans. Mechanisms of tolerance and promising new therapies, as well as the inherent difficulties in bringing them into clinical practice, are reviewed.
Fabrication of 15 nm wide trenches in Si by vacuum scanning tunneling microscope lithography of an organosilane self-assembled film and reactive ion etching (1996)

Organosilane precursor molecules, here (aminoethylaminomethyl)phenethyltrimethoxysilane, or PEDA, are chemisorbed onto a Si surface forming a monolayer thick film. These films are patterned using the scanning tunneling microscope to locally modify the chemical reactivity and are then used as a template for selective electroless plating of a thin Ni film. Reactive ion etching in a C2F6/O2 mixture transfers this pattern into the substrate. Improvement over previous lithographic performance is achieved by growing the films on a passivated and lightly oxidized Si surface, optimizing the patterning conditions, and improving the metallization and etch chemistry. In this way, we have generated deep trenches on the order of 15±4 nm width, with edge roughness of 3 nm. We believe this demonstrates the resolution limiting factors of this lithographic process.
Communication overhead on the Intel iPSC-860 hypercube (1990)

Experiments were conducted on the Intel iPSC-860 hypercube in order to evaluate the overhead of interprocessor communication. It is demonstrated that: (1) contrary to popular belief, the distance between two communicating processors has a significant impact on communication time, (2) edge contention can increase communication time by a factor of more than 7, and (3) node contention has no measurable impact.
Comparative transfection of DNA into primary and transformed mammalian cells from different lineages (2010)

In general, the Amaxa electroporation/nucleofection system appears superior to other chemical systems. However, there are cell-type and species specific differences that need to be evaluated empirically to optimize the conditions for transfection efficiency and cell survival.
Image analysis of androgen receptor immunostaining in metastatic prostate cancer heterogeneity as a predictor of response to hormonal therapy (1993)

The greater AR heterogeneity in poor responders may reflect a greater genetic instability in tumors that have progressed further toward androgen independence and may be a valuable predictor of progression.
Observing the Biofilm Matrix ofStaphylococcus epidermidisATCC 35984 Grown Using the CDC Biofilm Reactor (2010)

Bacteria flourish in nearly every environment on earth. Contributing to their ability to grow in many esoteric locations is their development into a biofilm structure. In an effort to more accurately model the growth environment of biofilms in nature, a Center for Disease Control and Prevention (CDC) biofilm reactor has been developed that mimics nature-like shear forces and renewable nutrient sources. To date, there has been no confirmation by scanning electron microscopy (SEM) that mature biofilms develop on a surface when grown using the CDC biofilm reactor. Three different SEM methods were used to collect images of Staphylococcus epidermidis ATCC 35984 that was to be grown using the CDC biofilm reactor. In addition, two different fixative techniques were used in each of the imaging methods. Results indicated that after 48 hours of growth in the reactor, S. epidermidis ATCC 35984 does produce a significant network of matrix components and 3D mushroom- or pillar-like structures with signs of water channel development. In conclusion, S. epidermidis ATCC 35984 grown using the CDC biofilm reactor does appear to display signs of mature biofilm development. These results could be important for studies wherein mature biofilms are needed for in vitro and/or in vivo applications.
The internal ribosome entry site (IRES) of hepatitis C virus visualized by electron microscopy (2001)

Translation of hepatitis C virus (HCV) RNA is initiated via the internal ribosome entry site (IRES), located within the 5' untranslated region. Although the secondary structure of this element has been predicted, little information on the tertiary structure is available. Here we report the first structural characterization of the HCV IRES using electron microscopy. In vitro transcribed RNA appeared as particles with characteristic morphology and gold labeling using a specific oligonucleotide confirmed them to be HCV IRES. Dimerization of the IRES by hybridization with tandem repeat oligonucleotides allowed the identification of domain III and an assignment of domains II and IV to distinct regions within the molecule. Using immunogold labeling, the pyrimidine tract binding protein (PTB) was shown to bind to domain III. Structure-function relationships based on the flexible hinge between domains II and III are suggested. Finally, the architecture of the HCV IRES was seen to be markedly different from that of a picornavirus, foot-and-mouth disease virus (FMDV).
Flecainide (1994)

Flecainide is a Class IC antiarrhythmic agent whose primary electrophysiologic effect is a slowing of conduction in a wide range of cardiac tissues. It is well absorbed and effective in suppressing isolated premature ventricular contractions (PVCs) or nonsustained ventricular arrhythmia but has only a modest efficacy when electrophysiologic testing is used as an endpoint. Its adverse effect on mortality in the CAST trial suggested a propensity to proarrhythmia--a phenomenon to which the Class IC agents appear particularly prone. Despite the applicability of the CAST study only to patients with a prior myocardial infarction, there has been a shift away from flecainide in ventricular arrhythmia, but the low noncardiac side effect profile of the agent allows for its continued use in a wide variety of supraventricular arrhythmias.
A Multilinear Constraint on Dichromatic Planes for Illumination Estimation (2006)

A new multilinear constraint on the color of the scene illuminant based on the dichromatic reflection model is proposed. The formulation avoids the problem, common to previous dichromatic methods, of having to first identify pixels corresponding to the same surface material. Once pixels from two or more materials have been identified, their corresponding dichromatic planes can be intersected to yield the illuminant color. However, it is not always easy to determine which pixels from an arbitrary region of an image belong to which dichromatic plane. The image region may cover an area of the scene encompassing several different materials and, hence, pixels from several different dichromatic planes. The new multilinear constraint accounts for this multiplicity of materials and provides a mechanism for choosing the most plausible illuminant from a finite set of candidate illuminants. The performance of this new method is tested on a database of real images.
Receptor‐Mediated Endocytosis and the Cellular Uptake of Low Density Lipoprotein (1982)

During receptor-mediated endocytosis various extracellular nutritional and regulatory molecules bind to plasma membrane receptors and rapidly enter target cells. In many systems (including those for certain plasma transport proteins, protein hormones, glycoproteins, toxins and viruses, and other plasma proteins) the receptors cluster in discrete regions of the surface membrane called coated pits, which invaginate into the cell to form endocytic vesicles. The extracellular ligand enclosed in the endocytic vesicle is delivered to intracellular sites, frequently to lysosomes, where it is degraded. In one system of receptor-mediated endocytosis, namely the one for plasma low density lipoprotein (LDL), the receptor functions to internalize LDL. The LDL is delivered to lysosomes where it is degraded and its cholesterol is released for use in the synthesis of membranes, steroid hormones and bile acids. Three recent advances in the LDL receptor system are reviewed: (1) the development of a method for purifying the receptor to apparent homogeneity and the demonstration that the LDL-binding site is contained within a glycoprotein of relative molecular mass 164000 and an acidic isoelectric point of 4.6; (2) the production of monoclonal antibodies directed against the receptor and the use of these antibodies as probes for receptor-mediated endocytosis; and (3) the use of monovalent carboxylic ionophores (such as monensin) to demonstrate by immunofluorescence that the LDL receptor enters the cell together with LDL, after which it recycles to the surface.
Bulge-Specific Cleavage in Transactivation Response Region RNA and Its DNA Analog by Neocarzinostatin Chromophore (1995)

On the basis of the finding that in the absence of thiol the nonprotein chromophore of the antitumor drug neocarzinostatin (NCS-chrom) induces highly efficient site-specific cleavage at a single site on the 3' side of a bulge in single-stranded DNA involving entirely 5' chemistry [Kappen, L. S., & Goldberg, I. H. (1993) Science, 261, 1319-1321], transactivation response region (TAR) RNA (29-mer) and its DNA analogue which presumably contain bulge structures were tested as potential substrates for NCS-chrom. In TAR RNA NCS-chrom generates a distinct but weak band due to cleavage at U24 in the bulge. Cleavage at U24 has a pH dependence and time course similar to those for previously studied DNA bulges. This band is not produced in drug reactions containing glutathione, by the protein component of native NCS, or by inactivated NCS-chrom. Cleavage at U24, albeit weak, occurs in an RNA substrate made up of two linear RNA oligomers which presumably can form a bulge akin to that in TAR RNA. In the DNA analogue of TAR RNA, as well as in a DNA duplex made of two linear oligomers that can form a similar bulge, NCS-chrom causes strand cleavage at the T residues in the bulge and at the bases flanking the bulge. Cleavage at T25 in the bulge involves, in addition to 5' chemistry, 4' attack which results in a fragment with mobility characteristic of 3'-phosphoglycolate-ended fragments. Experiments using DNA substrate having deuterium selectively at the 4' or 5' positions of T25 confirm 4' attack and show kinetic shuttling between the two positions.(ABSTRACT TRUNCATED AT 250 WORDS)
Pemphigus vulgaris autoantibodies induce apoptosis in HaCaT keratinocytes (2004)

Pemphigus vulgaris (PV) is an autoimmune disease characterized by binding of IgG autoantibodies to epidermal keratinocyte desmosomes. IgG autoantibodies obtained from a patient with mucocutaneous PV reacted with plakoglobin (Plkg) in addition to desmoglein-3 (Dsg3) and Dsg1. Immunofluorescence analysis confirmed that IgG autoantibodies, unlike antibodies from a healthy volunteer, caused disruption of cell-cell contacts in HaCaT keratinocytes. Moreover, apoptosis was enhanced in cells treated with autoantibodies compared to those treated with normal antibodies. The apoptotic process induced by IgG autoantibodies was characterized by caspase-3 activation, Bcl-2 depletion and Bax expression. The present report demonstrates that PV IgG autoantibodies promote apoptosis in HaCaT keratinocytes.
Chiral inversion of the second generation IMiD™ CC‐4047 (ACTIMID™) in human plasma and phosphate‐buffered saline (2003)

CC-4047 is a racemic second-generation immunomodulatory drug currently in clinical development for various oncologic indications. It has potent effects on key cytokines including tumor necrosis factor-alpha, interleukin (IL-10), and interferon (IFN-gamma). The S-isomer of CC-4047 has been reported to be the more potent enantiomer of the racemate. In this article we report on the rapid racemization of the S-isomer of CC-4047 in human plasma and phosphate-buffered saline. These results support the further development of the racemate instead of the S-isomer.
Intense second harmonic generation and long-range structural ordering in thin films of an organic salt grown by organic vapor phase deposition (1996)

We discuss the growth of thin films of the organic salt, 4′-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST) by the novel process of organic vapor phase deposition (OVPD). These films show long-range structural ordering and very intense second harmonic generation efficiencies (SHG) significantly greater (when normalized for thickness) than that of randomly oriented pure DAST powders. This is the first demonstration of such intense SHG radiation and long-range ordering for a thin film sample of a nonlinear organic salt. Furthermore, this work suggests that OVPD represents a general technique for growing thin films of highly polar, nonlinear optical materials such as DAST.
A transferrin receptor antibody represents one signal for the induction of IL 2 production by a human T cell line. (1986)

We previously demonstrated a two-signal requirement for the activation of the human T cell lines Jurkat and HUT 78. Interleukin 2 (IL 2) production by these lines can be induced by phytohemagglutinin (PHA), T3 antibodies, or calcium ionophores, but only in combination with phorbol myristate acetate (PMA). To obtain further information about surface structures involved in T cell activation, we produced a monoclonal antibody that could substitute for PMA in the activation of HUT 78. This antibody, designated J64, induced IL 2 secretion by HUT 78 in combination with PHA, T3 antibodies, or calcium ionophores, however not by itself. J64 also had other PMA-like effects on HUT 78, such as an increase in IL 2 receptor expression and an inhibition of cell growth. J64 was shown to immunoprecipitate the transferrin receptor (TfR). However, it bound to an epitope different from those recognized by other TfR antibodies and different from the transferrin-binding site. In addition, other previously described TfR antibodies did not, like J64, function as activating stimuli for HUT 78. Possible mechanisms for activation signaling in T cells involving the TfR are discussed.