gebhart/patrepeval huggingface dataset:
Morphology of integral‐skin layers in hollow‐fiber gas‐separation membranes (2003)

Abstract The morphologies of polymeric integrally skinned asymmetric gas‐separation membranes are typically visualized as a thin gas‐selective skin region supported by a nonselective, low‐resistance porous structure. The validity of this visualization for defect‐free and defective membranes was investigated via scanning electron microscopy (SEM) in combination with traditional gas‐permeation measurements for previously reported ultrathin defect‐free hollow‐fiber membranes. Hollow‐fiber membranes were formed via a dry‐jet, wet‐quench process with a spinning solution composed of Matrimid® polyimide and components of varying volatility. For all the defect‐free membranes formed, SEM images revealed a prominent dense skin layer across the fibers' entire outer circumference. Skin‐thickness estimates from 36 SEM images and N 2 , O 2 , and He pure gas‐permeation measurements agreed to within 9, 7, and 24% for defect‐free membranes with 150‐, 300‐, and 600‐nm skin thicknesses, respectively. Defective membranes with O 2 /N 2 gas selectivities of Knudsen values, nominally 50 and 80% of dense film values, exhibited a well‐developed nodular, partially developed nodular, and uniform dense layer (no nodules) skin morphologies, respectively. These results provide in‐depth experimental evidence for the existence of a distinct dense integral‐skin layer and suggest that the presence of nodules in the membrane's final skin morphology correlate to gas‐permeation defects. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 399–411, 2003
Generalized MRI reconstruction including elastic physiological motion and coil sensitivity encoding (2008)

This article describes a general framework for multiple coil MRI reconstruction in the presence of elastic physiological motion. On the assumption that motion is known or can be predicted, it is shown that the reconstruction problem is equivalent to solving an integral equation--known in the literature as a Fredholm equation of the first kind--with a generalized kernel comprising Fourier and coil sensitivity encoding, modified by physiological motion information. Numerical solutions are found using an iterative linear system solver. The different steps in the numerical resolution are discussed, in particular it is shown how over-determination can be used to improve the conditioning of the generalized encoding operator. Practical implementation requires prior knowledge of displacement fields, so a model of patient motion is described which allows elastic displacements to be predicted from various input signals (e.g., respiratory belts, ECG, navigator echoes), after a free-breathing calibration scan. Practical implementation was demonstrated with a moving phantom setup and in two free-breathing healthy subjects, with images from the thoracic-abdominal region. Results show that the method effectively suppresses the motion blurring/ghosting artifacts, and that scan repetitions can be used as a source of over-determination to improve the reconstruction.
Structure Preserving Aggregation Method for Doubly-Fed Induction Generators in Wind Power Conversion (2021)

An aggregation method is proposed that transforms the multiple DFIGs into an equivalent DFIG model that retains the major collective dynamic characteristics of a group of DFIGs. It is intended for Electromagnetic Transients Simulation (EMT). The aggregated machine can take into account different speeds and parameters of each of the individual DFIGs and the connecting impedance of individual DFIGs. Starting with a State Variable (SV) model of an individual DFIG, aggregation is carried out recursively, by combining two DFIGs at a time and then reducing the order of the aggregate to match the state variable equations of a single DFIG so that the steady state performances are identical. Validation is carried out by comparing the detailed electromagnetic transient (EMT) simulation of the unreduced system with the reduced aggregate system. It is shown that the proposed aggregation method accurately matches the steady state response and also accurately reproduces the dominant transient response of the unreduced system. As the aggregate DFIG has the same number of state variables as a single DFIG, the overall wind farm's order is reduced significantly to increase the modelling and simulation efficiency.
The effect of propranolol on protein synthesis and phagocytosis by polymorphonuclear leukocytes from newborn, children and elderly individuals. (1986)

The effect of propranolol on protein synthesis by polymorphonuclear (PMN) leukocytes was assessed in subjects from four age categories: elderly individuals, grown-up children, small children and newborn babies. This function was inhibited in PMN cells from individuals of all age groups, but inversely proportional to the age of the individual, i.e. the younger the subject, the more inhibited was the protein synthesis by his PMN leukocytes. The phagocytic capacity of the PMN cells of elderly subjects was decreased in comparison with that of individuals from the younger age groups. Propranolol inhibited this cell function in cells from subjects of all categories, although the inhibition was more pronounced in the cells of the younger groups. The difference in the degree of inhibition of the cell function observed in the various age groups may indicate different functional properties of the cell membrane.
Incorporation of Fluorotyrosines into Ribonucleotide Reductase Using an Evolved, Polyspecific Aminoacyl-tRNA Synthetase (2011)

Tyrosyl radicals (Y·s) are prevalent in biological catalysis and are formed under physiological conditions by the coupled loss of both a proton and an electron. Fluorotyrosines (F&lt;sub&gt;&lt;i&gt;n&lt;/i&gt;&lt;/sub&gt;Ys, &lt;i&gt;n&lt;/i&gt; = 1–4) are promising tools for studying the mechanism of Y· formation and reactivity, as their p&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;a&lt;/sub&gt; values and peak potentials span four units and 300 mV, respectively, between pH 6 and 10. In this manuscript, we present the directed evolution of aminoacyl-tRNA synthetases (aaRSs) for 2,3,5-trifluorotyrosine (2,3,5-F&lt;sub&gt;3&lt;/sub&gt;Y) and demonstrate their ability to charge an orthogonal tRNA with a series of F&lt;sub&gt;&lt;i&gt;n&lt;/i&gt;&lt;/sub&gt;Ys while maintaining high specificity over Y. An evolved aaRS is then used to incorporate F&lt;sub&gt;&lt;i&gt;n&lt;/i&gt;&lt;/sub&gt;Ys site-specifically into the two subunits (α2 and β2) of Escherichia coli class Ia ribonucleotide reductase (RNR), an enzyme that employs stable and transient Y·s to mediate long-range, reversible radical hopping during catalysis. Each of four conserved Ys in RNR is replaced with F&lt;sub&gt;&lt;i&gt;n&lt;/i&gt;&lt;/sub&gt;Y(s), and the resulting proteins are isolated in good yields. F&lt;sub&gt;&lt;i&gt;n&lt;/i&gt;&lt;/sub&gt;Ys incorporated at position 122 of β2, the site of a stable Y· in wild-type RNR, generate long-lived F&lt;sub&gt;&lt;i&gt;n&lt;/i&gt;&lt;/sub&gt;Y·s that are characterized by electron paramagnetic resonance (EPR) spectroscopy. Furthermore, we demonstrate that the radical pathway in the mutant Y&lt;sub&gt;122&lt;/sub&gt;(2,3,5)F&lt;sub&gt;3&lt;/sub&gt;Y-β2 is energetically and/or conformationally modulated in such a way that the enzyme retains its activity but a new on-pathway Y· can accumulate. The distinct EPR properties of the 2,3,5-F&lt;sub&gt;3&lt;/sub&gt;Y· facilitate spectral subtractions that make detection and identification of new Y·s straightforward.
Seedless, copper-induced synthesis of stable Ag/Cu bimetallic nanoparticles and their optical properties (2016)

In this study, we demonstrate a sensitive and selective method for the seedless synthesis of Ag@Cu bimetallic nano-structured material based on the competitive coordination chemistry of cysteine with Cu<sup>2+</sup> and Ag<sup>+</sup>.
Numerical prediction of coherent integration time at 75 Hz, 0.03 temporal resolution at 3250 km (2006)

Coherence time of sound is modeled for a 3250 km section in the Pacific at 75 Hz, 0.03 s resolution between a source and receiver both moored high above the ocean floor. The model is based on the temporal evolution of a standard spectrum of internal gravity waves and an accurate approximation for the acoustic wave equation. The probability is 0.6 that the signal-to-noise (s/n) ratio first decreases at times of 13 min or less. Afterward, the s/n usually increases, reaching a peak near 40 min. This is longer than the experimentally reported coherence time of 12.7 min. The discrepancy could be due to the fact that the experimental value was obtained assuming that movement between the source and receiver could be accounted for using a single Doppler speed correction for each transmission lasting between 10 and 40 min. However, accelerations of the source and receiver appear to be too large to use the single Doppler speed correction. Coherence times from the data should be re-analyzed with a variable Doppler scheme to see if they are consistent with the 40 min coherence time predicted from the model
Electro-Optical Characteristics and Analysis of 1×1 mm2Large-Area InGaN/GaN Green LED (2011)

본 논문은 InGaN/GaN 다중양자우물 구조를 가지는 녹색 발광다이오드의 활성층 내 인듐(In) 조성비와 piezoelectric field에 대한 전계 흡수 현상을 연구하였다. 활성층 내 결정학적 성질과 In 조성비는 double crystal X-ray diffraction 측정으로 분석하였으며, <TEX>$1{\times}1\;mm^2$</TEX> 대면적 칩을 제작하여 발광특성을 조사하였다. 또한, 활성층 내 piezoelectric field는 electro-reflectance spectroscopy로부터 측정한 compensation voltage를 이용해 계산하였고, 인가전압에 따른 photocurrent의 변화를 측정함으로써 녹색 발광 소자의 전기 광학적 특성을 분석하였다. We investigated the effects of piezoelectric field on the electro-absorption characteristics in InGaN/GaN multiple-quantum well (MQW) green light emitting diodes (LED). Double crystal X-ray diffraction measurement was performed to study the crystalline property and indium (In) composition in the MQW active layer. To measure the electro-luminescence and electro-reflectance (ER) spectroscopy, we fabricated the <TEX>$1{\times}1\;mm^2$</TEX> large-area green LED chip. The piezoelectric field inside the LED structure was evaluated from the Vcomp in active layer by the ER spectra. Finally, we analyzed the electro-absorption characteristics of the green LED by using the photo-current spectroscopy.
Denaturation and Renaturation of Self-Assembled Yeast Iso-1-cytochrome c on Au (2004)

We have made surface plasmon resonance (SPR) measurements of yeast iso-1-cytochrome c (Cyt c) on a gold surface. Angle-resolved SPR curves are recorded as a function of urea concentration before and after self-assembly of the Cyt c. Exposure to a urea solution causes denaturation of Cyt c, which shifts the minimum in the SPR curve to a larger angle and decreases the signal amplitude. The Gibbs free energy change for denaturation of the protein on Au is calculated from the change of the SPR signal amplitude with urea concentration. We find that (1) Cyt c can be reversibly denatured and renatured, depending on the urea concentration, and (2) the Gibbs free energy change for denaturation of Cyt c on Au surface in water, DeltaG degrees (water), is 1.5 kcal/mol, which is approximately 4 times less than that in bulk solution.
Some issues on self-calibration and critical motion sequences (2000)

This paper is concerned with the problem of selfcalibration. First some general concepts are discussed, then several methods are briefly discussed. In the second part of the paper the problem of critical motion sequences is treated. This problem could cause an important limitation to the practical use of self-calibration. In this context several interesting results are presented. \t 18486 self-calibration, critical motion sequences, absolute conic, ambiguous reconstruction. 1. INTRODUCTION Since it became clear that it was possible to obtain a projective reconstruction (i.e. a reconstruction determined up to an arbitrary projective transformation) from a set of uncalibrated images of a scene [4, 7], researchers have tried to obtain ways to upgrade this reconstruction to a metric one (i.e. determined up to an arbitrary euclidean transformation and a scalefactor). In general three types of constraints could be applied to achieve this: scene constraints, camera motion constrai...
Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis (2011)

Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability(1). Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals(2,3), and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk(4). Modestly powered genome-wide association studies (GWAS)(5-10) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility(11). Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis.
Surface chemistry controlled diameter-modulated semiconductor nanowire superstructures (2013)

The authors demonstrate that semiconductor nanowire diameter can be rationally controlled as a function of axial position during vapor–liquid–solid synthesis. Such nanoscale structural tuning is achieved with a “molecular resist,” specifically tetramethyltin, that adsorbs on the nanowire sidewall and restricts radial deposition without destabilizing the growth front. The temporal modulation of tetramethyltin delivery during Ge nanowire growth yields user-programmable diameter-modulated superstructures with sub-100 nm periodicities. The authors also investigate the effect of Sn accumulation in the growth catalyst and propose a second-order kinetic rate law that accurately predicts changes to nanowire axial growth rate.
Gold Nanoparticle Superlattices: Novel Surface Enhanced Raman Scattering Active Substrates (2009)

We developed a cheap and rapid method for the fabrication of 3D nanoparticle superlattices (SLs) of Au@SGAN and Au@MSA (N-acetyl glutathione (SGAN) and mercaptosuccinic acid (MSA) protected gold nanoparticles, respectively) in gram scale, at a liquid−liquid interfaces under flowing nitrogen gas. While available methods take several weeks to make crystalline SLs, the present route makes them in a day. Morphology of these crystals was examined with scanning electron microscopy (SEM), and their structures were probed using transmission electron microscopy (TEM). The surface enhanced Raman scattering (SERS) studies of these crystals were done using crystal violet (CV) molecules as the analyte which exhibited a detection limit of 10−8 M. The SERS spectrum was used to map the Raman images of the superlattce crystals. SERS from the edges of the crystal showed more enhancement than from the flat surfaces, which is in good agreement with theoretical reports of such anisotropic structures. The sides of the crystals are not sharp, and they show corrugations at the nanometer scale. This helps to produce more “hot spots” at the edges, which result in larger electric field enhancement from these locations. The enhancement factors (EF) for Au@MSA and Au@SGAN SLs were calculated to be around 1.47 × 106 and 3.60 × 105, respectively. More enhancements from Au@MSA SL compared to that of Au@SGAN could be attributed to the smaller chain length of the MSA molecule, which allows closer analyte approach to the nanoparticle surface.
Coordination Complexes of Tin( IV ) Chloride with Unidentate Nitrogen Bases (2004)

A single crystal X-ray study shows the product of reaction between quinuclidine, ‘qn’, and tin( IV ) chloride in toluene solution to be, unusually, a five-coordinate neutral complex [qnSnCl4]. Sn—N is 2.282(5) Å in an axial site of a trigonal bipyramidal array, trans to an Sn—Cl bond 2.367(2) with Sn—Cl (equatorial) 2.323(2)–2.333(2) Å. With 1,4-pyrazine, ‘pz’, as adumbrated by earlier spectroscopic work, a 1 : 2 (centro-symmetric) adduct, trans -[pz2SnCl4] is obtained (rather than a pyrazine bridged polymer) [Sn—N 2.246(1), Sn—Cl 2.3883(4), 2.3980(4) Å].
Hybrid Nano-Structured Platinum-Based Catalyst/Enzyme Anode for Oxidation of Ethanol and Ethylene Glycol (2012)

A hybrid anode based on nano-structured PtRu and NAD+-dependant alcohol dehydrogenase was constructed to oxidize ethanol and ethylene glycol. The hybrid anode performs better than either the enzyme or catalyst alone. This work can potentially lead to hybrid catalysts that can be used to efficiently oxidize complex molecules such as sugars and other polyols.
Pulse shaping and compression using SHG with QPM gratings in the presence of the group velocity dispersion (2000)

We develop a theory which incorporates group velocity dispersion in the description of ultrafast SHG with QPM gratings and show how it can be accounted for in the design of the QPM grating shaper.
Effects of myocardial function and systemic circulation on regional coronary perfusion (2020)

Cardiac-coronary interaction and the effects of its pathophysiological variations on spatial heterogeneity of coronary perfusion and myocardial work are still poorly understood. This hypothesis-generating study predicts spatial heterogeneities in both regional cardiac work and perfusion that offer a new paradigm on the vulnerability of the subendocardium to ischemia, particularly at the apex. We propose a mathematical and computational modeling framework to simulate the interaction of left ventricular mechanics, systemic circulation, and coronary microcirculation. The computational simulations revealed that the relaxation rate of the myocardium has a significant effect whereas the contractility has a marginal effect on both the magnitude and transmural distribution of coronary perfusion. The ratio of subendocardial to subepicardial perfusion density (<i>Q</i><sub>endo</sub><i>/Q</i><sub>epi</sub>) changed by -12 to +6% from a baseline value of 1.16 when myocardial contractility was varied by +25 and -10%, respectively; <i>Q</i><sub>endo</sub><i>/Q</i><sub>epi</sub> changed by 37% when sarcomere relaxation rate, <i>b</i>, was faster and increased by 10% from the baseline value. The model predicts axial differences in regional myocardial work and perfusion density across the wall thickness. Regional myofiber work done at the apex is 30-50% lower than at the center region, whereas perfusion density in the apex is lower by only 18% compared with the center. There are large axial differences in coronary flow and myocardial work at the subendocardial locations, with the highest differences located at the apex region. A mismatch exists between perfusion density and regional work done at the subendocardium. This mismatch is speculated to be compensated by coronary autoregulation.<b>NEW & NOTEWORTHY</b> We present a model of left ventricle perfusion based on an anatomically realistic coronary tree structure that includes its interaction with the systemic circulation. Left ventricular relaxation rate has a significant effect on the regional distribution of coronary flow and myocardial work.
A self-consistent kinetic plasma model with rapid convergence (1991)

Algorithms for very efficient solution of kinetic equations have previously been developed and used to obtain a self-consistent kinetic description of electrons and ions in various plasmas, including RF glow discharges. Since RF discharge calculations may take many thousands of cycles to converge, a solution which follows the time evolution throughout this process is inevitably computationally costly. The authors have implemented a 'scaleup' procedure which obviates the need to follow the entire time evolution in this or other plasma models. When the applied RF frequency lies between the electron plasma frequency and the ion plasma frequency. By running the full calculation for a short-time, information which permits an extrapolation of the time evolution over a very long time, or a scaleup, is extracted. A detailed description of the basis for the scaleup is given, as well as an example of the use of a scaleup procedure, as applied to a moderately high-pressure RF discharge in helium.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
BioRID Dummy Responses in Matched ABTS and Conventional Seat Tests on the IIHS Rear Sled (2011)

The tests show that ABTS seats involved significantly higher neck tensions, rearward shear forces, and extension moments than matched conventional seats. Overall, ABTS seats applied more load on the head and spine, had less control of neck kinematics, and had higher risks for whiplash and more severe injury than conventional seats in the same vehicle model.
Lack of neprilysin suffices to generate murine amyloid‐like deposits in the brain and behavioral deficit in vivo (2006)

Accumulation of the beta-amyloid peptide (Abeta) in the brain is a major pathological hallmark of Alzheimer's disease (AD), leading to synaptic dysfunction, neuronal death, and memory impairment. The levels of neprilysin, a major Abeta-degrading enzyme, are decreased in AD brains and during aging. Because neprilysin cleaves Abeta in vivo, its down-regulation may contribute to the pathophysiology of AD. The aim of this study was to assess the consequences of neprilysin deficiency on accumulation of murine Abeta in brains and associated pathologies in vivo by investigating neprilysin-deficient mice on biochemical, morphological, and behavioral levels. Aged neprilysin-deficient mice expressed physiological amyloid precursor protein (APP) levels and exhibited elevated brain Abeta concentrations and amyloid-like deposits in addition to signs of neuronal degeneration in their brains. Behaviorally, neprilysin-deficient mice acquired a significantly weaker conditioned taste aversion that extinguished faster than the aversion of age-matched controls. Our data establish that, under physiological APP expression levels, neprilysin deficiency is associated with increased Abeta accumulation in the brain and leads to deposition of amyloid-like structures in vivo as well as with signs of AD-like pathology and with behavioral deficits.