gebhart/patrepeval huggingface dataset:
Nitrogen fixation via photoenhanced reduction on p-gallium phosphide electrodes (1978)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNitrogen fixation via photoenhanced reduction on p-gallium phosphide electrodesC. R. Dickson and A. J. NozikCite this: J. Am. Chem. Soc. 1978, 100, 25, 8007–8009Publication Date (Print):December 1, 1978Publication History Published online1 May 2002Published inissue 1 December 1978https://doi.org/10.1021/ja00493a039Request reuse permissionsArticle Views639Altmetric-Citations69LEARN 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 (428 KB) Get e-Alertsclose Get e-Alerts
Three-dimensional parallelization of microfluidic droplet generators for a litre per hour volume production of single emulsions (2014)

This paper looks at the design, fabrication and characterization of stackable microfluidic emulsion generators, with coefficients of variation as low as ~6% and with production rates as high as ~1 L h(-1). This work reports the highest throughput reported in the literature for a microfluidic device with simultaneous operation of liquid-liquid droplet generators. The device was achieved by stacking several layers of 128 flow-focusing droplet generators, organized in a circular array. These layers are interconnected via through-holes and fed with designated fractal distribution networks. The proposed layers were milled on poly(methylmethacrylate) (PMMA) sheets and the stack was thermo-compression bonded to create a three-dimensional device with a high density of generators and an integrated hydraulic manifold. The effect of stacking multiple layers was studied and the results show that fabrication accuracy has a greater impact on the dispersity of the emulsion than the addition of more layers to the stack. Particle crystallization of drugs was also demonstrated as a possible application of this technology in industry.
Basal Plane Dislocation Mitigation in 8º Off-Cut 4H-SiC through <i>In Situ</i> Growth Interrupts during Chemical Vapor Deposition (2009)

Conversion of basal plane dislocations (BPD) to threading edge dislocations (TED) in 8° off-cut 4H-SiC within an n+ buffer layer would eliminate the nucleation site for Shockley-type stacking faults in active device regions grown on such buffer layers. To that end, the propagation and conversion of BPDs through in situ growth interrupts is monitored using ultraviolet photoluminescence (UVPL) wafer mapping. The optimized growth interrupt scheme lasts for 45 minutes with a propane mass flow of 10 sccm at growth temperature. This scheme has shown a conversion efficiency of up to 99% for samples with electron (hole) concentrations < 5x1014 cm-3 (8x1015 cm-3). Samples subjected to a 45 or 90 minute interrupt under 10 sccm of propane, regardless of conversion efficiency, exhibit a “slit” in the surface morphology associated with each BPD and oriented perpendicular to the off-cut and BPD propagation direction. Repetition of the optimal interrupt sequence with a 5 μm epilayer spacer grown between the two interrupts resulted in the same conversion efficiency as a single optimal growth interrupt. Incorporation of the optimal interrupt into an n+ layer is more complicated as attempts to do so in layers doped with nitrogen to 2x1018, 2x1017 and 2x1016 cm-3 resulted in conversion efficiencies of ~6%.
Ultrafast switching in magnetic tunnel junction based orthogonal spin transfer devices (2010)

Orthogonal spin-transfer magnetic random access memory (OST-MRAM) uses a spin-polarizing layer magnetized perpendicularly to a free layer to achieve large spin-transfer torques and ultrafast energy efficient switching. We have fabricated and studied OST-MRAM devices that incorporate a perpendicularly magnetized spin-polarizing layer and a magnetic tunnel junction, which consists of an in-plane magnetized free layer and synthetic antiferromagnetic reference layer. Reliable switching is observed at room temperature with 0.7 V amplitude pulses of 500 ps duration. The switching is bipolar, occurring for positive and negative polarity pulses, consistent with a precessional reversal mechanism, and requires an energy of less than 450 fJ.
Aerodynamically Interacting Vertical-Axis Wind Turbines: Performance Enhancement and Three-Dimensional Flow (2019)

This study examined three-dimensional, volumetric mean velocity fields and corresponding performance measurements for an isolated vertical-axis wind turbine (VAWT) and for co- and counter-rotating pairs of VAWTs with varying incident wind direction and turbine spacings. The purpose was to identify turbine configurations and flow mechanisms that can improve the power densities of VAWT arrays in wind farms. All experiments were conducted at a Reynolds number of R e D = 7.3 × 10 4 . In the paired arrays, performance enhancement was observed for both the upstream and downstream turbines. Increases in downstream turbine performance correlate with bluff–body accelerations around the upstream turbine, which increase the incident freestream velocity on the downstream turbine in certain positions. Decreases in downstream turbine performance are determined by its position in the upstream turbine’s wake. Changes in upstream turbine performance are related to variations in the surrounding flow field due to the presence of the downstream rotor. For the most robust array configuration studied, an average 14% increase in array performance over approximately a 50° range of wind direction was observed. Additionally, three-dimensional vortex interactions behind pairs of VAWT were observed that can replenish momentum in the wake by advection rather than turbulent diffusion. These effects and their implications for wind-farm design are discussed.
Fast computation of low rank matrix approximations (2001)

Given a matrix A it is often desirable to find an approximation to A that has low rank. We introduce a simple technique for accelerating the computation of such approximations when A has strong spectral structure, i.e., when the singular values of interest are significantly greater than those of a random matrix with size and entries similar to A. Our technique amounts to independently sampling and/or quantizing the entries of A, thus speeding up computation by reducing the number of non-zero entries and/or the length of their representation. Our analysis is based on observing that the acts of sampling and quantization can be viewed as adding a random matrix E to A, whose entries are independent random variables with zero-mean and bounded variance. Since, with high probability, E has very weak spectral structure, we can prove that the effect of sampling and quantization nearly vanishes when a low rank approximation to A+E is computed. In fact, the stronger the spectral structure of A, the more of its entries we can afford to discard and, ultimately, the faster we can discover that structure. We give bounds on the quality of our approximation both in the L2 and in the Frobenius norm.
Spin warp NMR imaging and applications to human whole-body imaging (1980)

Describes a new nuclear magnetic resonance (NMR) imaging technique which the authors call 'spin warp imaging' and gives examples of its application to human whole-body imaging. The apparatus is based on a four-coil, air cored magnet (made by the Oxford Instrument Company) capable of accepting the whole human body. The magnet produces a static field of 0.04 T giving a proton NMR frequency of 1.7 MHz. The maximum field inhomogeneity is about 6*10-4 at a radius of 0.23 m, approximately twice the amount theoretically attainable with this configuration. The pulse sequence used is shown.
Cathodoluminescence of cubic boron nitride films deposited by chemical vapor deposition (2002)

Cathodoluminescence (CL) characteristics of cubic boron nitride (cBN) films deposited by chemical vapor deposition were investigated. Combined with the results from Fourier-transformed infrared spectroscopy and Raman spectroscopy, the dependence of the emission energy and intensity on the phase composition and crystallinity of the films was revealed. A broad emission band centered at about 3.12 eV for UCL (or US-1) as observed previously in undoped cBN single crystals synthesized by high-temperature, high-pressure method, and an emission band at about 2.48 eV for the A and B bands, due to multivacancy complexes of boron and nitrogen vacancies, were observed in the cBN films with high phase purity and high crystallinity. For the hexagonal boron nitride (hBN) phase, the main emission band up-shifted to high energy of 3.48–3.68 eV. A peak centered at 5.28 eV was observed in the spectra, which is believed the near-band-gap UV emission of hBN.
Large-Scale Roll-to-Roll Fabrication of Vertically Oriented Block Copolymer Thin Films (2013)

Large-scale roll-to-roll (R2R) fabrication of vertically oriented nanostructures via directed self-assembly of cylindrical block copolymer (c-BCP) thin films is reported. Nearly 100% vertical orientation of cylinders in sub-100 nm c-BCP films under optimized processing via a dynamic sharp temperature gradient field termed Cold Zone Annealing-Sharp or 'CZA-S' is achieved, with successful scale-up on a prototype custom-built 70 ft × 1 ft R2R platform moving at 25 μm/s, with 9 consecutive CZA units. Static thermal annealing of identical films in a conventional vacuum oven fails to produce comparable results. As a potential for applications, we fabricate high-density silicon oxide nanodot arrays from the CZA-S annealed BCP thin film template.
5,6-Dihydropyran-2-ones Possessing Various Sulfonyl Functionalities:  Potent Nonpeptidic Inhibitors of HIV Protease (2000)

On the basis of previous SAR findings and molecular modeling studies, a series of compounds were synthesized which possessed various sulfonyl moieties substituted at the 4-position of the C-3 phenyl ring substituent of the dihydropyran-2-one ring system. The sulfonyl substituents were added in an attempt to fill the additional S(3)' pocket and thereby produce increasingly potent inhibitors of the target enzyme. Racemic and enantiomerically resolved varieties of selected compounds were synthesized. All analogues in the study displayed decent binding affinity to HIV protease, and several compounds were shown to possess very good antiviral efficacy and safety margins. X-ray crystallographic structures confirmed that the sulfonamide and sulfonate moieties were filling the S(3)' pocket of the enzyme. However, the additional substituent did not provide improved enzymatic inhibitory or antiviral activity as compared to the resolved unsubstituted aniline. The addition of the sulfonyl moiety substitution does not appear to provide favorable pharamacokinectic parameters. Selected inhibitors were tested for antiviral activity in clinical isolates and exhibited similar antiviral activity against all of the HIV-1 strains tested as they did against the wild-type HIV-1. In addition, the inhibitors exhibited good antiviral efficacies against HIV-1 strains that displayed resistance to the currently marketed protease inhibitors.
Genomic organization of the human homologue of the rat pancreatic elastase I gene (1992)

The homologue of the rat pancreatic elastase I gene was found in the human genome, but its transcription was completely suppressed in the adult human pancreas as we reported previously. In this study, we characterized the complete structure of the eight putative exons of the silent gene for human elastase I. A genotype analysis of the exon 1 DNA sequence revealed that at least two allelic elastase I genes are present in human genomes. A primate-specific repetitive DNA element (MER1) was identified in the 3'-flanking region of the human elastase I gene. The primary structure of human preproelastase I, deduced from the sequences of the eight exons, showed an 89% identity with that of porcine or rat pancreatic preproelastase I. The amino acid residues of the serine protease catalytic triad and the eight cysteine residues conserved in the elastase family were present at positions equivalent to those observed in porcine and rat elastase I, suggesting that the gene product may function as an elastolytic enzyme if this gene is expressed in any tissue.
Low complexity optimal algebraic multicast codes (2003)

We present a low complexity algorithm for designing algebraic codes that achieve the information theoretic capacity for the multicast problem on directed acyclic networks. These codes operate over field sizes which are significantly smaller than those previously known, leading to significantly lower design and implementation complexity, and network link usage. These codes can be extended for networks with cycles and delays, and for robustness properties. A network is represented by a directed graph g = (V, E) with a vertex set V and edge set E. Multiple edges are allowed between vertices, and g is acyclic. A source node 8 €- V generating information at rate R, and a set of N receiver nodes R = {Tl,r2, . , rN} C V, are specified. Nodes are allowed to transmit on outgoing edges any causal function of information on incoming edges. The multicast capacity is defined as the maximum rate at which identical information can be decoded by each node in R. The multicast network coding problem is the 4-tuple (g, s, R, R), and it is said to have a solution if there exist causal functions for each node in V such that the multicast capacity equals R. The solution comprises these functions at each node in V and the decoders at nodes in ‘R. Let C S mini {Ci}, where Ci is the min-cut max-flow capacity of the network between s and ‘ft. For any e > O, the multicast network coding problem (G, s, R, C — e) was shown by a random coding argument in [1] to have a solution. Further, [2] defined an IF2tn -linear network as follows. Source bits are concatenated in blocks of length m to form symbols in the finite field . Nodes in V perform linear combinations (over IF2m) of the symbols on incoming edges to obtain symbols on outgoing edges. They show that for 2m > NC there exist IF2tn -linear networks which solve the network coding problem.
Studies on Disease-Modifying Antirheumatic Drugs. II. Synthesis and Activity of the Metabolites of Ethyl 4-(3,4-Dimethoxyphenyl)-6,7-dimethoxy-2-(1,2,4-triazol-1-ylmethyl)quinoline-3-carboxylate (TAK-603). (1998)

The metabolites of ethyl 4-(3,4-dimethoxyphenyl)-6,7-dimethoxy-2-(1,2,4-triazol-1-ylmeth yl)quinoline -3-carboxylate (1, TAK-603), which is under clinical evaluation as a new type of disease-modifying antirheumatic drug (DMARD), were prepared to confirm their structures and to study their pharmacological properties. Of the metabolites identified, the 4-(4-hydroxy-3-methoxyphenyl) derivative (2c, M-I) was found to have an anti-inflammatory effect in an adjuvant arthritic rat model, although its potency in this model was slightly lower than that of the parent compound.
Estimating Local Compliance in a Beam From Bending Measurements Part II. Optimal Estimation of Local Compliance (2007)

We present a method for optimally estimating local elasticity properties along a beam where each estimate is specific to an increment in a subdivision of the beam's length.Previous research indicates that knowledge of localized elasticity values can improve the estimation of strength.Immediate application is expected in the machine stress-rated (MSR) lumber production process.A sequence of bending measurements on overlapping bending spans, as commonly obtained in the MSR process, serves as input to the estimation method.The sequence of bending measurements is modeled as an autoregressive moving average (ARMA) random process.Autoregression coefficients are estimated from a priori information and refined as additional data are obtained.Moving average weight coefficients come from span functions computed by methods in Part I.A Kalman filter, defined from coefficients of the ARMA process, is applied to the measurements, and local estimates are obtained.Estimated local elasticity results are presented for both a simulated and a real wood beam.One set of experiments shows that as a modeled correlation coefficient is decreased from an artificially high value, the result evolves from local elasticity estimates that appear much the same as measured elasticity, but without an obvious noise component, to local estimates having more detail.This leads naturally to a suggestion for a practical, non-disruptive introduction of the estimation method to a MSR production line.Grade yield improvement is likely an immediate benefit along with a capability for further research into the estimation method and grading algorithms.
A novel zinc-chelating small molecule exhibits cancer cell growth inhibition <i>in vitro</i> and <i>in vivo</i> by induction of tumor suppressors early growth response 1 (Egr-1) and Krüppel-Like Factor 4 (KLF4) (2007)

14084 Background: Lead compound LT-253 was selected from a group of 2-indolyl imidazol [4,5-d] phenanthroline derivatives with anticancer activity. It shows potent and selective anti-proliferative activity against several human cancer types in vitro, and in vivo in xenograft mouse models of human colon carcinoma (HT-29) and non-small cell lung carcinoma (H460). Methods: The mechanism of cell growth inhibition of LT-253 was investigated in HT-29 colon cancer cells using the XTT cell proliferation assay, flow cytometry and apoptosis assays. In vitro and in vivo zinc chelation was determined by competition assays using fluorescent and chromophoric chelators. Gene expression studies were performed by human genome microarray analysis and confirmed by quantitative real- time PCR. The transcription factor activity profile of LT-253-treated cells was determined by a multiplex transcription factor array and electrophoretic mobility shift assays. The functional role of specific genes was evaluated by siRNA gene knock-down. Results: LT-253 functions as chelator of zinc in vitro, and of intracellular labile zinc in HT-29 cells. Moreover, LT-253-mediated HT-29 cell growth inhibition was reversed by zinc supplementation. Gene expression profiling confirmed sustained changes in zinc-sensitive genes such as metallothionine and several zinc transporters, but not copper-sensitive or iron-sensitive genes. LT-253 induces cancer cell growth inhibition primarily through G1/S phase cell cycle arrest. Gene expression and transcription factor activities of both Egr-1 and KLF4 are induced within 4 hr post LT-253 treatment. Moreover, increased expression of both Egr-1 and KLF4 is observed in LT-253-sensitive cancer cell lines of various origins. Importantly, Egr-1 and KLF4 gene knock-down by siRNA reversed the LT-253-mediated cell growth inhibition of HT-29 cells. Conclusion: Selective chelation of intracellular labile zinc pool by LT-253 triggers immediate induction of stress-responsive tumor suppressor Egr-1 and sustained induction of zinc-responsive tumor suppressor KLF4, leading to G1/S phase cell cycle arrest and inhibition of tumor growth. No significant financial relationships to disclose.
Energy reflectance in the ear canal can exceed unity near spontaneous otoacoustic emission frequencies (1998)

There is some controversy in the literature over whether the so-called "active mechanism" or "cochlear amplifier" is actually a power amplifier that can produce an output signal with more power than its input, or whether it simply minimizes dissipative losses within the cochlea without providing an actual power gain greater than unity. A corollary of this controversy is whether spontaneous otoacoustic emissions (SOAEs) represent the output of a nonlinear oscillator mechanism, i.e., a power amplifier which can produce an oscillatory output signal in the absence of an input oscillatory signal, or whether they represent the output of a noise-driven, passive, nonlinear system. This paper describes measurements of energy reflectance, and acoustic impedance in the ear canals of human subjects with strong SOAEs. The reflectance, and the resistive and reactive parts of the acoustic impedance, all show a frequency fine structure which correlates with SOAE frequencies, and which becomes more pronounced at low stimulus levels. In some ears at some SOAE frequencies, energy reflectance exceeds unity, and correspondingly, acoustic resistance is negative. This result demonstrates that there is a power gain at these frequencies: The power reflected from the cochlea to the ear canal exceeds the power incident. It is also consistent with the theory that these SOAEs are produced by a nonlinear oscillator mechanism in the cochlea.
The PKD1 gene product, "polycystin-1," is a tyrosine-phosphorylated protein that colocalizes with alpha2beta1-integrin in focal clusters in adherent renal epithelia. (1999)

Mutations in the PKD1 gene are responsible for autosomal dominant polycystic kidney disease (ADPKD). Although PKD1 has been cloned and shown to be expressed at high levels in the fetal ureteric bud and ADPKD cystic epithelia in the human kidney, the function of its encoded protein, "polycystin-1" is unknown. In this study we used primary and immortalized human renal epithelial cell lines derived from normal fetal, adult, and ADPKD kidneys, that endogenously express PKD1, to study the biologic function of the polycystin-1 protein. ADPKD renal epithelial cells expressed high levels of polycystin-1 protein and showed increased adhesion to type I collagen by comparison with normal adult human renal epithelia that expressed little polycystin. Adherent ADPKD cells also expressed high levels of alpha2beta1-integrin and their attachment was inhibited by a functional monoclonal antibody to alpha2-integrin. Double labeling and confocal microscopy as well as coimmunoprecipitation analysis showed overlapping colocalization of polycystin-1 with alpha2beta1-integrin as well as with the focal adhesion proteins vinculin and paxillin in multiprotein clusters localized to focal areas of cell membrane contact with type I collagen matrix after short periods of attachment. Immunoprecipitation and Western immunoblot studies also showed that polycystin-1 was posttranslationally modified by tyrosine phosphorylation. These studies suggest that the PKD1-encoded protein is part of a large multiprotein complex in epithelial cells that functions in the regulation of extracellular matrix interactions with the plasma membrane and cell cytoskeleton.
Superconducting fault current limiters (1995)

Three different superconducting fault limiter designs are described in relation to low temperature (metallic) superconductors operating at 4.2 K and high temperature (ceramic) superconductor at 77 K. The three devices described are: a resistive superconducting fault current limiter (SCFCL); a saturated inductive SCFCL; and a shielded inductive SCFCL. Resistive type SCFCLs operating at 4.2 K are being considered for application by some utilities, despite being harnessed with the technology and operating costs associated with using liquid helium; the relatively low weight and volume makes it attractive in some applications. The shielded inductive type incorporating high T/sub c/ superconductor discs may be considered the most practical. Using near term state-of-the-art technology and operating at 77 K with bulk liquid nitrogen would make the device virtually maintenance free and life time expectancy should be in excess of 30-40 years.<
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