gebhart/patrepeval huggingface dataset:
Gold-Coated Microelectrode Array With Thiol Linked Self-Assembled Monolayers for Engineering Neuronal Cultures (2004)

We report the use of a gold coating on microelectrode arrays (MEAs) to enable the use of the relatively reliable surface modification chemistry afforded by alkanethiol self-assembled monolayers (SAMs). The concept is simple and begins with planar MEAs, which are commercially available for neuronal cell culture and for brain slice studies. A gold film, with an intermediate adhesive layer of titanium, is deposited over the insulation of an existing MEA in a manner so as to be thin enough for transmission light microscopy as well as to avoid electrical contact to the electrodes. The alkanethiol-based linking chemistry is then applied for the desired experimental purpose. Here we show that polylysine linked to alkanethiol SAM can control the geometry of an in vitro hippocampal neuronal network grown on the MEA. Furthermore, recordings of neuronal action potentials from random and patterned networks suggest that the gold coating does not significantly alter the electrode properties. This design scheme may be useful for increasing the number of neurons located in close proximity to the electrodes. Realization of in vitro neuronal circuits on MEAs may significantly benefit basic neuroscience studies, as well as provide the insight relevant to applications such as neural prostheses or cell-based biosensors. The gold coating technique makes it possible to use the rich set of thiol-based surface modification techniques in combination with MEA recording.
Chiral Synthons by Ester Hydrolysis Catalyzed by Pig Liver Esterase (1989)

Abstract Development of efficient methodology to produce an optically pure enantiomer is of fundamental importance, particularly for the synthesis of biologically active natural products. Optically active compounds can be obtained by three different approaches, that is, resolution of racemates, use of a chiral pool or “chiron” (which are enantiomerically pure synthons), or asymmetric synthesis. Of these, one of the more challenging tasks involves asymmetric synthesis, which may be carried out either enzymatically or nonenzymatically. Whereas the nonenzymatic method enables us to introduce a chiral center with either a stoichiometric or catalytic amount of a chiral compound, the enzymatic method uses biological systems, such as microorganisms or isolated enzymes, to create the center of asymmetry. The purpose of this chapter is to survey asymmetric synthesis via the production of enantiomerically pure or enriched organic molecules by the enzymatic method focusing on the use of a hydrolytic enzyme, pig liver esterase (PLE; Enzyme Commission classification number, E.C. 3.1.1.1). Enzymes are classified into the following six groups based on the reactions they catalyze: Oxidoreductase (oxidation–reduction reactions); Transferase (transfer of functional groups); Hydrolase (hydrolysis reactions); Lyase (addition to double bonds or the reverse); Isomerase (isomerization reaction); and Ligase (formation of bonds coupled with pyrophosphate bond cleavage of ATP). Virtually all biochemical transformations are catalyzed in vivo by these six groups, and the biochemical aspects of these enzymes have been studied in detail. However, the practical utility of these enzymes in organic synthesis remains to be further exploited and refined. The ability of a substrate to associate with an enzyme is also one of the most significant problems. In some cases, these problems have been overcome and several enzyme reactions have been successfully used on a large scale. An enzyme reaction generally takes place when an intimate interaction between the reactant and the chiral catalyst (enzyme protein) is realized. This enzyme–substrate complex is designated as the Michaelis complex. Certain amino acid residues of the enzyme form a three‐dimensional structure as the active site. This site often contains reactive groups of the amino acids such as amino, mercapto, hydroxyl, carbonyl, carboxyl, guanidino, or imidazolyl. When the substrate is bound to the active site in a specific orientation, enantiotopic groups or faces of the substrate molecule are discriminated by the chiral enzyme. This discrimination is sufficiently sensitive to differentiate between the two hydrogen atoms in a methylene group. Thus the reaction proceeds stereospecifically. The enzyme can also distinguish among several substrates competing for an active site. Such substrate specificity is sometimes strict and sometimes broad. Synthetically useful enzymes should accept a wide range of substrates and exhibit high stereospecificity. Many enzymes meet these criteria, and PLE is one of them.
Insulin controls food intake and energy balance via NPY neurons (2017)

Taken together, these results suggest that insulin actions in NPY neurons is critical for maintaining energy balance and an impairment of this pathway may be causally linked to the development of metabolic diseases.
CONSIDERATION OF WORK EFFICIENCY AND MECHANICAL EFFICIENCY OF CONCRETE FORCE FEED WORK INTENDED FOR FOOTING BEAM AND SLAB (2010)

It is important to understand the content of the concrete force feed work and the pumpability beforehand to advance a concrete practice smoothly and safely when the concrete pumping method was adopted. A lot of researches on the concrete pumping method have been reported so far. However, the research that evaluates the working efficiency is extremely little. Moreover, the influence on the pumpability is not understood.In the present study, I conduct surveys of the force feed work and the mechanical efficiency of a concrete pump on actual construction fields. And, the numerical value that suits a present concrete pump industrial method is analyzed.
Modulation of Pancreatic Cancer Chemoresistance by Inhibition of TAK1 (2011)

The results of this study suggest that genetic silencing or inhibition of TAK1 kinase activity in vivo is a potential therapeutic approach to reversal of the intrinsic chemoresistance of pancreatic cancer.
Antithrombotic stent coatings: hirudin/iloprost combination. (1999)

Neointimal formation after stent implantation can cause luminal narrowing, called restenosis. Restenosis is induced by initial platelet adhesion and thrombus formation followed by immunocyte adhesion on the stent surface and on the injured vessel wall. The thrombus releases factors, which activates the proliferation of smooth muscle cells. Stents, coated with an antithrombotic surface, may prevent platelet adhesion and subsequent smooth muscle cell proliferation. This paper will review stent coating with poly-LD-lactic acid, a biodegradable polymer containing Iloprost, a synthetic prostacycline, and PEG-Hirudin as a method for reducing of restenosis.
MINMAX frame rate control using a rate-distortion optimized wavelet coder (2003)

This paper proposes a frame rate-control scheme with a MINMAX distortion criterion in the framework of a rate-distortion optimized motion compensated embedded wavelet coder. The MINMAX criterion aims to minimize the maximum distortion in a group of pictures (GOP) for a given bit rate. The proposed frame level bit allocation scheme combined with R-D optimized within frame allocation allows precise rate control up to the exact bit. A simplifying fast algorithm is developed using an initial prediction of the operating distortion and adaptive adjustment during GOP coding. Experiments demonstrate that as much as 1.1 dB gain over MPEG-2 TM5 and 0.9 dB over H263 TMN5 can be achieved as well as more consistent visual quality.
Sub-picowatt resolution calorimetry with a bi-material microcantilever sensor (2013)

We have designed and fabricated bi-material microcantilevers with low conductance by minimizing the width and thickness of the cantilevers while keeping them suitable for detection with an optical deflection technique. The conductance of a cantilever is determined experimentally to be 330 ± 20 nWK−1. Using this cantilever, we have measured less than 1 pW of heat flow through the cantilever. The thermal noise-limited resolution of the cantilever is expected to be ≈50 fW. Such cantilevers give us additional tools to probe thermal transport through nanostructures, especially through single molecules where picowatt-level sensitivity is necessary.
Shorted monopole antenna for curved shape phone housing in clamshell phone (2007)

A novel internal shorted monopole antenna suitable for applications of GSM /DCS/PCS tri-band antenna in clamshell phone is presented. The proposed antenna can be embedded into curved shape phone housing as an internal antenna and it occupies a very small volume 4times11times38 mmJ. The antenna is located at the bottom of the edge of the ground plane in main-board and its curved shape radiator can be designed into some special phone housings for clamshell phone. The obtained impedance bandwidth also covers the required bandwidth of the GSM (880-960 MHz), DCS (1710-1880 MHz) and PCS (1850-1990 MHz) bands.
A Hierarchy of Associations in Hippocampo-Cortical Systems: Cognitive Maps and Navigation Strategies (2005)

In this letter we describe a hippocampo-cortical model of spatial processing and navigation based on a cascade of increasingly complex associative processes that are also relevant for other hippocampal functions such as episodic memory. Associative learning of different types and the related pattern encoding-recognition take place at three successive levels: (1) an object location level, which computes the landmarks from merged multimodal sensory inputs in the parahippocampal cortices; (2) a subject location level, which computes place fields by combination of local views and movement-related information in the entorhinal cortex; and (3) a spatiotemporal level, which computes place transitions from contiguous place fields in the CA3-CA1 region, which form building blocks for learning temporospatial sequences. At the cell population level, superficial entorhinal place cells encode spatial, context-independent maps as landscapes of activity; populations of transition cells in the CA3-CA1 region encode context-dependent maps as sequences of transitions, which form graphs in prefrontal-parietal cortices. The model was tested on a robot moving in a real environment; these tests produced results that could help to interpret biological data. Two different goal-oriented navigation strategies were displayed depending on the type of map used by the system. Thanks to its multilevel, multimodal integration and behavioral implementation, the model suggests functional interpretations for largely unaccounted structural differences between hippocampo-cortical systems. Further, spatiotemporal information, a common denominator shared by several brain structures, could serve as a cognitive processing frame and a functional link, for example, during spatial navigation and episodic memory, as suggested by the applications of the model to other domains, temporal sequence learning and imitation in particular.
Precursor and Cofactor as a Check Valve for Cephamycin Biosynthesis in Streptomyces clavuligerus (1999)

The biosynthesis of secondary metabolites is closely linked to primary metabolism via the supply of precursors, cofactors, and cellular energy. The availability of these precursors and cofactors can potentially be rate-limiting for secondary metabolism. A combined experimental and kinetic modeling approach was used to examine the regulation of flux in the cephamycin biosynthetic pathway in Streptomyces clavuligerus. The kinetic parameters of lysine 6-aminotransferase (LAT), the first enzyme leading to cephamycin biosynthesis and one which was previously identified as being a rate-limiting enzyme, were characterized. LAT converts lysine to alpha-aminoadipic acid using alpha-ketoglutarate as a cosubstrate. The K(m) values for lysine and alpha-ketoglutarate were substantially higher than those for their intracellular concentrations, suggesting that lysine and alpha-ketoglutarate may play a key role in regulating the flux of cephamycin biosynthesis. The important role of this precursor/cosubstrate was supported by simulated results using a kinetic model. When the intracellular concentrations and high K(m) values were taken into account, the predicted intermediate concentration was similar to the experimental measurements. The results demonstrate the controlling roles that precursors and cofactors may play in the biosynthesis of secondary metabolites.
Clinical evaluation of single-photon attenuation correction for 3D whole-body PET (1999)

The authors report on the first clinical evaluation of the /sup 137/Cs single photon transmission measurement that has been implemented on the Siemens/CTI ECAT ART. Thorax phantom studies are performed to verify the accuracy of the transmission measurement. Pre-injection (with patient repositioning) and post-injection transmission scans and attenuation corrected emission images of 25 patients are compared with respect to estimated linear attenuation coefficients and specific activities in organs, and standardized uptake values in lesions. The authors find that both pre- and post-injection transmission provide accurate estimates of attenuation correction factors. Post-injection estimates for mean attenuation coefficients and specific activities in larger regions of interest (ROIs) are nearly the same as pre-injection values, but exhibit 17-18% greater pixel standard deviation. Estimates of standardized uptake in smaller lesion ROIs are 13% higher with post-injection correction, but there is little difference in the ROI pixel variances.
Energy Band/Lattice Mismatch Engineering in Quaternary AlInGaN/GaN Heterostructure (1999)

We discuss structural, optical and electrical properties of AlxInyGa1—x—yN/GaN heterostructures grown on sapphire and 6H-SiC substrates. The incorporation of In reduces the lattice mismatch in a much stronger way than the energy gap discontinuity. An In to Al ratio close to 1:5 should result in nearly strain-free heterostructures. The incorporation of In and resulting changes in the built-in strain in AlInGaN/GaN heterostructures strongly affect the transport properties of the two-dimensional (2D) electron gas at the heterointerface. Using the incorporation of In in order to increase the Al molar fraction preserving the same value of strain should allow us to greatly enhance the sheet carrier density at the AlGaInN/GaN heterointerface. Further work on improving In incorporation techniques is needed in order to meet these expectations.
Differential Effects of Abscisic Acid and Glycine Betaine on Physiological Responses to Drought and Salinity Stress for Two Perennial Grass Species (2012)

Abscisic acid (ABA) and glycine betaine (GB) may regulate plant responses to drought or salinity stress. The objectives of this controlled-environment study were to determine whether foliar application of ABA or GB improves turf quality under drought or salinity and whether improved stress responses were associated changes in antioxidant metabolism in two C3 turfgrass species, creeping bentgrass ( Agrostis stolonifera ) and kentucky bluegrass ( Poa pratensis ). Physiological parameters evaluated included turf quality, leaf relative water content, membrane electrolyte leakage (EL), membrane lipid peroxidation [expressed as malondialdehyde (MDA) content], and activity of superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX). Abscisic acid and GB were both effective in mitigating physiological damage resulting from drought or salinity for both grass species, but effects were more pronounced on kentucky bluegrass. The most notable effects of ABA or GB application were the suppression of EL and MDA accumulation and an increase in APX, POD, and SOD activities after prolonged periods of drought (21 days) or salinity stress (35 days). These results suggest foliar application of ABA or GB may alleviate physiological damage by drought or salinity stress in turfgrass and the maintenance of membrane stability and active antioxidant metabolism could contribute to the positive effects in the stress mitigation effects.
[Mechanism of azelaic acid action in acne]. (1989)

The physiopathologic mechanism of acne seems to be dependent on four main factors: a) sebum production and excretion; b) type of keratinization of the follicular channel; c) microbial colonization of the pilosebaceous unit and d) inflammatory reaction of the perifollicular area. Azelaic acid is effective in the treatment of acne because it possesses an activity against all of these factors. Azelaic acid is a competitive inhibitor of mitochondrial oxidoreductases and of 5 alpha-reductase, inhibiting the conversion of testosterone to 5-dehydrotestosterone. It also possesses bacteriostatic activity to both aerobic and anaerobic bacteria including Propionibacterium acnes. Azelaic acid is an anti-keratinizing agent, displaying antiproliferative cytostatic effects on keratinocytes and modulating the early and terminal phases of epidermal differentiation.
Nicotine receptor partial agonists for smoking cessation (2011)

Varenicline at standard dose increased the chances of successful long-term smoking cessation between two- and threefold compared with pharmacologically unassisted quit attempts. Lower dose regimens also conferred benefits for cessation, while reducing the incidence of adverse events. More participants quit successfully with varenicline than with bupropion. Two open-label trials of varenicline versus NRT suggested a modest benefit of varenicline but confidence intervals did not rule out equivalence. Limited evidence suggests that varenicline may have a role to play in relapse prevention. The main adverse effect of varenicline is nausea, but mostly at mild to moderate levels and tending to subside over time. Possible links with serious adverse events, including depressed mood, agitation and suicidal thoughts, have been reported but are so far not substantiated.There is a need for further independent community-based trials of varenicline, to test its efficacy and safety in smokers with varying co-morbidities and risk patterns. There is a need for further trials of the efficacy of treatment extended beyond 12 weeks. Cytisine may also increase the chances of quitting, but the evidence at present is inconclusive.
Source of heavy molecular ions based on Taylor cones of ionic liquids operating in the pure ion evaporation regime (2003)

The full spray emitted by Taylor cones of the ionic liquid 1-ethyl-3-methyl imidazolium tetrafluoroborate (EMI+BF4−) held in a vacuum is investigated at room temperature by time of flight mass spectrometry. The current is composed mainly of ions under most conditions studied, but contains a small component of nanometer drops that tends to dominate the emitted mass flow. Exceptionally, drop ejection vanishes close to the smallest flow rate at which the Taylor cone is steady. The present discovery of a stable strictly ionic regime in Taylor cones of substances other than liquid metals owes much to earlier observations with sulfuric acid, where most but not all the current was ionic. Most striking is the fact that this purely ionic regime is obtained at an electrical conductivity K of only 1.3 S/m, much smaller than that of sulfuric acid, and smaller than that at which formamide electrolytes with K&gt;2 S/m do still emit substantial drop currents. The ion emission includes primarily the dimer (EMI–BF4)EMI+, accompanied by fair currents of the monomer EMI+ and the trimer ions. The modest spread of ion energies observed and considerable currents attained (0.6 μA) suggests the use of this and other ionic liquids as ion beam sources with a much wider range of mass/charge and chemical compositions than previously available. The present data provide a direct proof of the reality of the often doubted mechanism of ion evaporation from liquid surfaces.
Studies in Selective Toxicity. I. Syntheses of N-Alkylbenzenesulfonanilides (1956)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudies in Selective Toxicity. I. Syntheses of N-AlkylbenzenesulfonanilidesM. NEEMAN and A. MODIANOCite this: J. Org. Chem. 1956, 21, 6, 667–670Publication Date (Print):June 1, 1956Publication History Published online1 May 2002Published inissue 1 June 1956https://pubs.acs.org/doi/10.1021/jo01112a021https://doi.org/10.1021/jo01112a021research-articleACS PublicationsRequest reuse permissionsArticle Views55Altmetric-Citations2LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Examination of Polysulfide Sealants by Scanning Electron Microscopy (1987)

A procedure was developed for the examination of polysulfide sealants by scanning electron microscopy. This procedure was applied to manganese dioxide and dichromate-cured elastomers. Calcium carbonate filler was identified in both types of sealants and the particle size was found to be < 4 um. A technique was developed for the removal of the surface calcium carbonate exposing other solid additives. Amongst these, manganese dioxide was most obvious due to the large particle size and abundance. The presence of chromium containing particles could not be established and in practical terms it can be considered as a solution in the polysulfide. This implies a homogeneous phase reaction between the dichromate curing agent and the prepolymer and consequently a greater likelihood of a more complete curing of the polymer than that effected by manganese dioxide. Polysulfide sealants are used extensively in aircraft where there is a requirement for sealing metal joints and fasteners in integral fuel tanks, water tanks and canopies. The sealants are based on polysulfide polymers cured by the addition of a strong oxidizing agent. Australia
Preparation and Properties of Aluminum Oxide Films Obtained by Glow Discharge Technique (1971)

Amorphous aluminum oxide films have been deposited on silicon substrates by decomposing aluminum trichloride in an rf induced glow discharge of oxygen. Among various deposition parameters, it is shown that the reactant gas pressures affect greatly the deposition rate and the resultant film quality. The properties of these films such as infrared transmission, etch rate, film structure, resistivity, dielectric constant, and dielectric strength are described. Aluminum‐aluminum oxide‐silicon (MAS) structures were prepared and characterized by the positive values of flat band voltage, distortion of C‐V curves, and a large, positive shift in flat band voltage under negative bias at an elevated temperature. The field effect electron mobility was as low as 70 cm2/V · sec, while it could be improved by the annealing at around 700°C, or by putting a thin layer of thermally oxidized silicon dioxide between the aluminum oxide and the silicon.