gebhart/patrepeval huggingface dataset:
One-electron chemical reductions of phenylalkylsulfonium salts (1982)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOne-electron chemical reductions of phenylalkylsulfonium saltsPeter Beak and Thomas A. SullivanCite this: J. Am. Chem. Soc. 1982, 104, 16, 4450–4457Publication Date (Print):August 1, 1982Publication History Published online1 May 2002Published inissue 1 August 1982https://pubs.acs.org/doi/10.1021/ja00380a020https://doi.org/10.1021/ja00380a020research-articleACS PublicationsRequest reuse permissionsArticle Views850Altmetric-Citations59LEARN 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
Identification of Species with DNA-Based Technology: Current Progress and Challenges (2008)

One of the grand challenges of modern biology is to develop accurate and reliable technologies for a rapid screening of DNA sequence variation. This topic of research is of prime importance for the detection and identification of species in numerous fields of investigation, such as taxonomy, epidemiology, forensics, archaeology or ecology. Molecular identification is also central for the diagnosis, treatment and control of infections caused by different pathogens. In recent years, a variety of DNA-based approaches have been developed for the identification of individuals in a myriad of taxonomic groups. Here, we provide an overview of most commonly used assays, with emphasis on those based on DNA hybridizations, restriction enzymes, random PCR amplifications, species-specific PCR primers and DNA sequencing. A critical evaluation of all methods is presented focusing on their discriminatory power, reproducibility and user-friendliness. Having in mind that the current trend is to develop small-scale devices with a high-throughput capacity, we briefly review recent technological achievements for DNA analysis that offer great potentials for the identification of species.
Effects of Bradykinin on Pial Arteries and Arterioles<i>in vitro</i>and<i>in situ</i> (1983)

The effect of bradykinin on cerebrovascular resistance vessels was investigated by the use of in vitro and in situ preparations. Bradykinin, in the range of 10(-10) to 10(-5) M, elicited a concentration-dependent vasodilatation on both feline and human pial arteries in vitro; the half-maximal response was found to be approximately at 2.8 X 10(-7) M and 1.3 X 10(-8) M (EC50), respectively. This dilatatory effect of bradykinin in vitro was found only in arteries preconstricted with prostaglandin F2 alpha or 5-hydroxytryptamine. In order to determine the effects of bradykinin on the diameter of cat pial arteries in situ, perivascular microapplication was employed. The dose-response curves obtained showed vasodilatation; the EC50 and the maximal response (EAm) were 4.4 X 10(-7) M and 45.5% at 10(-5) M, respectively. Statistically significant (p less than 0.01) reactions were observed at 10(-7) M and higher concentrations of bradykinin. The observed effects were independent of initial vessel size (80-260 microns). These in situ findings are very similar to those found in vitro. The isolated guinea pig ileum was used to check the stability of the bradykinin solutions. In this instance, a concentration-dependent contraction was found when "freshly prepared" or "5 hours stored" bradykinin was applied, indicating no measureable degradation of bradykinin. We conclude that bradykinin is a powerful vasodilator of both human and feline pial arteries.
Stepped-Reflector Antenna for Dual-Band Multiple Beam Satellite Communications Payloads (2006)

A novel stepped-reflector antenna (SRA) suitable for dual-band multiple beam satellite payloads is introduced in this paper. The SRA system produces "flat-top" radiation patterns for receive beams and highly efficient Gaussian patterns for transmit beams over a geographic coverage region as seen by the geo-synchronous satellite. It combines the reflector improvements through the use of SRA with the feed horn advancements through the use of dual-band "high-efficiency horns" in order to realize an efficient multiple beam antenna (MBA) system supporting both downlink transmit and uplink receive signals of communication satellites. It is shown that the SRA provides a congruent set of spot beams on ground for both transmit and receive frequencies with the benefits of significantly improved edge-of-coverage gain, improved co-polar isolation among beams that re-use the same frequency channels, receive beam patterns that are less sensitive to satellite pointing error, and reduced number of reflector antennas when compared to conventional MBAs
Lower tocopherol serum levels in subjects with abdominal adiposity (1993)

The average tocopherol concentrations in this Swedish population were higher than in countries with a high incidence of coronary heart disease but similar to those in countries with a similar, intermediate incidence. The inverse correlation to abdominal adiposity may partly explain why this adiposity is a risk factor for coronary heart disease.
Emerging Uses for Genomic Information in Drug Discovery (1998)

Geneticists who study yeast, worms, and fruit flies have long recognized that an effective way to identify genes with functional relevance to a particular biologic process is to screen large numbers of mutagenized organisms. Researchers have recently used these primitive organisms to pinpoint genetic mechanisms in human diseases. This approach has succeeded mainly because genome-sequencing projects have discovered numerous invertebrate homologues of human genes. The gene involved in basal-cell carcinoma, for example, was cloned in part through its similarity to the patched gene of the fruit fly Drosophila melanogaster. 1,2 New work on two breast-cancer–susceptibility genes, BRCA1 and BRCA2, is . . .
The novel flightless-I gene brings together two gene families, actin-binding proteins related to gelsolin and leucine-rich-repeat proteins involved in Ras signal transduction. (1995)

The Drosophila melanogaster gene flightless-I, involved in gastrulation and muscle degeneration, has Caenorhabditis elegans and human homologues. In these highly conserved genes, two previously known gene families have been brought together, families encoding the actin-binding proteins related to gelsolin and the leucine-rich-repeat (LRR) group of proteins involved in protein-protein interactions. Both these gene families exhibit characteristics of molecular changes involving replication slippage and exon shuffling. Phylogenetic analyses of 19 amino acid sequences of 6 related protein types indicate that actin-associated proteins related to gelsolin are monophyletic to a common ancestor and include flightless proteins. Conversely, comparison of 24 amino acid sequences of LRR proteins including the flightless proteins indicates that flightless proteins are members of a structurally related subgroup. Included in the flightless cluster are human and mouse rsp-1 proteins involved in suppressing v-Ras transformation of cells and the membrane-associated yeast (Saccharomyces cerevisae) adenylate cyclase whose analogous LRRs are required for interaction with Ras proteins. There is a strong possibility that ligands for this group could be related and that flightless may have a similar role in Ras signal transduction. It is hypothesized that an ancestral monomeric gelsolin precursor protein has undergone at least four independent gene reorganization events to account for the structural diversity of the extant family of gelsolin-related proteins and that gene duplication and exon shuffling events occurred prior to or at the beginning of multicellular life, resulting in the evolution of some members of the family soon after the appearance of actin-type proteins.
Midkine Counteracts the Activin Signal in Mesoderm Induction and Promotes Neural Formation (1998)

Midkine (MK) is a heparin-binding growth factor that has been implicated in neural survival and differentiation, fibrinolysis, and carcinogenesis. It is expressed in the nervous system during early Xenopus development. In the present study, we demonstrated that injection of vegetal blastomeres with Xenopus MK at the 8-cell stage results in incomplete invagination. In the case of dorsal vegetal injection, hypertrophic neural tissue is produced. Animal caps isolated from embryos that have been injected with Xenopus MK and cultured with activin do not elongate, and all mesoderm markers examined, including both head and trunk/tail ones, are greatly diminished. In contrast, head-specific neural markers, XANF-1 and Xotx2, are induced, while trunk/tail neural markers, XlHbox6 and F-spondin, are decreased. Moreover, MK showes the same effects in animal caps injected with Xenopus Smad2 mRNA.
Managing secure and confidential video distribution (1991)

The author examines means to utilize video tapes for secure communication of confidential information within companies or related business sectors. A scrambling method is proposed which provides security both during transportation and on the shelf. The originator has control over the release and the end date, and can address the decoder site.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Electrochemical Li-Insertion Processes into Carbons Produced by Milling Graphitic Powders: The Impact of the Carbons’ Surface Chemistry (2002)

Carbon powders were prepared by milling graphite particles in different atmospheres including air, highly pure argon, nitrogen, and Part of the samples was further exposed to air after milling. The carbonaceous materials thus obtained were tested as Li-insertion anodes in nonaqueous Li salt solutions. It was found that the atmosphere in which the active mass was prepared had a pronounced impact on the specific surface area of the particles obtained, probably due to the effect of surface groups on the carbons developed in the milling process. It was also found that the atmosphere to which the powders were exposed had a remarkable impact on the electrochemical behavior of the carbon electrodes in Li-insertion processes. The milling of the graphite produces highly reactive carbon surface sites, which react readily with active gases such as oxygen and The surface groups thus formed influence the surface chemistry developed on these electrodes in solutions. Since the electrochemical behavior of Li-C insertion electrodes depends strongly on the nature of the passivation films developed on these electrodes at low potentials, the milling atmosphere strongly influences their electrochemical behavior. The electrochemical processes were studied by chronopotentiometry, cyclic voltammetry, and impedance spectroscopy, the electrodes' structure and morphology were explored by X-ray diffraction and scanning electron microscopy, and the carbons' surface chemistry was studied by Fourier transform infrared and X-ray photoelectron spectroscopy. © 2001 The Electrochemical Society. All rights reserved.
An Interactive 3D Fracture Modelling Environment (1996)

Abstract An original three dimensional (3D) fracture modelling environment which is designed to allow users to interactively construct near well fracture models suitable for use as input to fluid flow simulators is described. Data input consists of a surface model of the seismic scale structure, well fracture data, and user defined parameters. Sedimentary discontinuities and faults can be extrapolated from the wells in 3D. Within this near well model tension fractures can be generated using a genetic process which aims to reproduce the initiation, growth and interaction of fractures in order to create realistic fracture systems. Graphs are available for calibrating the fractures to assumed statistical distributions.
AMD3100 Mobilizes Endothelial Progenitor Cells in Mice, But Inhibits Its Biological Functions by Blocking an Autocrine/Paracrine Regulatory Loop of Stromal Cell Derived Factor-1 In Vitro (2007)

Endothelial progenitor cells (EPCs), a CXCR4-bearing cell line, are thought to positively influence reendothelialization, vascular repair, and angiogenesis. AMD3100, a highly selective antagonist of stromal cell derived factor (SDF)-1 that binds to its receptor, CXCR4, has been shown to induce rapid mobilization of hematopoietic stem cells in mice, dogs, and humans. Results of this study indicate that AMD3100 injection can induce a rapid and potent mobilization of EPCs in mice compared with saline injection. The study demonstrates that murine spleen-derived EPCs can produce high levels of SDF-1 in vitro. Blocking this endogenous SDF-1 with AMD3100 decreases the number of EPCs; inhibits the proliferation, migration, and adhesion of EPCs; and induces EPC apoptosis. In addition, AMD3100 inhibits ectogenous SDF-1alpha induced improvement of EPC functions. However, AMD3100 incubation does not change the functions of CXCR4-negative cell line HPDE6. In conclusion, AMD3100 can be regarded as a potent mobilizer of EPCs in mice. EPCs have an autocrine/paracrine SDF-1 loop, and breaking this loop with AMD3100 can inhibit the EPC functions in vitro.
A packaged optical slot-waveguide ring resonator sensor array for multiplex label-free assays in labs-on-chips (2009)

We present the design, fabrication, and characterisation of an array of optical slot-waveguide ring resonator sensors, integrated with microfluidic sample handling in a compact cartridge, for multiplexed real-time label-free biosensing. Multiplexing not only enables high throughput, but also provides reference channels for drift compensation and control experiments. Our use of alignment tolerant surface gratings to couple light into the optical chip enables quick replacement of cartridges in the read-out instrument. Furthermore, our novel use of a dual surface-energy adhesive film to bond a hard plastic shell directly to the PDMS microfluidic network allows for fast and leak-tight assembly of compact cartridges with tightly spaced fluidic interconnects. The high sensitivity of the slot-waveguide resonators, combined with on-chip referencing and physical modelling, yields a volume refractive index detection limit of 5 x 10(-6) refractive index units (RIUs) and a surface mass density detection limit of 0.9 pg mm(-2), to our knowledge the best reported values for integrated planar ring resonators.
Effects of 1α,25‐Dihydroxyvitamin D<sub>3</sub> on the Transglutaminase Activity of Transformed Mouse Epidermal Cells in Culture (1989)

Induction of the transglutaminase activity of a transformed mouse epidermal cell line (PAM 212 cells) by 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25-(OH)2-D3), the active form of vitamin D3, was investigated. Addition of 1 alpha,25-(OH)2-D3 to a culture medium stimulated twice the transglutaminase activity at a concentration of 10(-7) M, but vitamin D3, prostaglandin E1, E2, and F2 alpha failed to show this induction. Phorbol 12-o-tetradecanoylphorbol-13-acetate (TPA) and dexamethasone also induced an increase in transglutaminase activity. Exposure to both 1 alpha,25-(OH)2-D3 and retinoic acid caused remarkably synergistic effects on the induction of transglutaminase in the PAM 212 cells. In contrast, simultaneous addition of 1 alpha,25-(OH)2-D3 and TPA was antagonistic and resulted in less than additive induction. Vitamin D3 also showed a similar but lesser effect. These results suggest that 1 alpha,25-(OH)2-D3 induces the transglutaminase activity via mechanisms disparate from those of retinoic acid and modifies epidermal differentiation.
Gender differences in drug metabolism regulated by growth hormone (1995)

Gender differences in drug metabolism in rats have been known for more than 60 years when it was first reported that the much shorter duration of drug action in the male was due to the effects of testicular androgens. More recent studies have demonstrated that this sexual dimorphism in rat drug metabolism results from the differential expression of a possible dozen, or so sex-dependent hepatic forms of cytochrome P450. Moreover, it is the sexually dimorphic plasma profiles of growth hormone, and not androgens, that directly regulate the expression of these individual forms of hepatic cytochrome P450. Male rats secrete growth hormone in an "on-off" episodic rhythm in which interpulse periods contain no detectable levels of the hormone. Growth hormone secretion in the female rat is also pulsatile, but can be characterized as "continuous" since hormone levels are always present in the circulation. It would appear that the duration of the interpulse period is at least one "signal" in the growth hormone profile regulating hepatic expression of the sex-dependent forms of cytochrome P450, and thus establishing the gender differences in drug metabolism. The exaggerated gender differences in rat drug metabolism (i.e. 300-500%) have made it the standard, and understandably an ideal model in which to investigate the mechanisms regulating these dimorphisms. However, it is also possible that these studies have limited value when extrapolated to other species, such as humans, in which the magnitude of the sexual differences are much smaller, and the dimorphism may be reversed (F > M). In this regard, the mouse model, in which the sexual differences (F > M) in drug metabolizing enzyme activities vary by only 40-100%, are also regulated by sex-dependent plasma growth hormone profiles, and may be more representative of the vast majority of outbred species in which only subtle gender differences occur in drug metabolism.
Glycosylation Affects both the Three-Dimensional Structure and Antibody Binding Properties of the HIV-1<sub>IIIB</sub>GP120 Peptide RP135 (1997)

We have prepared glycosylated analogues of the principal neutralizing determinant of gp120 and studied their conformations by NMR and circular dichroism spectroscopies. The 24-residue peptide from the HIV-1IIIB isolate (residues 308-331) designated RP135, which contains the immunodominant tip of the V3 loop, was glycosylated with both N- and O-linked sugars. The structures of two glycopeptides, one with an N-linked beta-glucosamine (RP135NG) and the other with two O-linked alpha-galactosamine units (RP135digal), were studied by NMR and circular dichroism spectroscopies. Molecular dynamics calculations based on the NMR data obtained in water solutions were performed to explore the conformational substates sampled by the glycopeptides. The data showed that covalently linking a carbohydrate to the peptide has a major effect on the local conformation and imparts additional minor changes at more distant sites of partially defined secondary structure. In particular, the transient beta-type turn comprised of the -Gly-Pro-Gly-Arg- segment at the "tip" of the V3 loop is more highly populated in RP135digal that in the native peptide and N-linked analogue. Binding data for the glycopeptides with 0.5beta, a monoclonal antibody mapped to the RP135 sequence, revealed a significant enhancement in binding for RP135digal as compared with the native peptide, whereas binding was reduced for the N-linked glycopeptide. These data show that glycosylation of V3 loop peptides can affect their conformations as well as their interactions with antibodies. The design of more ordered and biologically relevant conformations of immunogenic regions from gp120 may aid in the design of more effective immunogens for HIV-1 vaccine development.
Rayleigh anomaly-surface plasmon polariton resonances in palladium and gold subwavelength hole arrays (2009)

Surface plasmon polaritons (SPPs) and Rayleigh anomalies (RAs) are two characteristic phenomena exhibited by periodic grating structures made of plasmonic materials. For Au subwavelength hole arrays, SPPs and RAs from opposite sides of the film can interact under certain conditions to produce highly intense, narrow spectral features called RA-SPP resonances. This paper reports how RA-SPP effects can be achieved in subwavelength hole arrays of Pd, a weak plasmonic material. Well-defined resonances are observed in measured and simulated optical transmission spectra with RASPP peaks as narrow as 45 nm (FWHM). Dispersion diagrams compiled from angle-resolved spectra show that RA-SPP resonances in Pd hole arrays shift in wavelength but do not decrease significantly in amplitude as the excitation angle is increased, in contrast with RA-SPP peaks in Au hole arrays. The apparent generality of the RA-SPP effect enables a novel route to optimize resonances in non-traditional plasmonic media.
Modeling of Photovoltage and Photocurrent in Dye-Sensitized Titanium Dioxide Solar Cells (2001)

By means of two-dimensional simulation calculations, a detailed analysis of the nanocrystalline TiO2 dye-sensitized solar cell (DSC) has been performed. A simplified scheme of the nanoporous structure, which is treated as if the TiO2 film is a continuous medium, is used for modeling. On the basis of material parameters, the model permits the determination of steady-state charge-carrier distributions, the calculation of I−V curves under illumination, dark characteristics, and the spectral response of a DSC. The spatial resolution of the model allows for the answer to the question of the spatial distribution of both the electric and the electrochemical potential in the cell. Thus, a deeper insight into the operation mechanism of a DSC is obtained. Nonnegligible drift currents are found. It is shown quantitatively that the electric potential drops mainly at the TCO/TiO2 interface and not at a Helmholtz layer. The role of the dark interfacial electrical potential difference (built-in potential) for the function of a DSC is discussed. It is shown that, contrary to a conventional p−n junction solar cell, higher photovoltages than those of the dark interfacial electrical potential difference can be obtained.