gebhart/patrepeval huggingface dataset:
Low‐power adiabatic sequences for in vivo localized two‐dimensional chemical shift correlated MR spectroscopy (2010)

Novel low-power adiabatic sequences are demonstrated for in vivo localized two-dimensional correlated MR spectroscopy, such as correlated spectroscopy and total correlated spectroscopy. The design is based on three new elements for in vivo two-dimensional MRS: the use of gradient modulated constant adiabaticity GOIA-W(16,4) pulses for (i) localization (correlated spectroscopy and total correlated spectroscopy) and (ii) mixing (total correlated spectroscopy), and (iii) the use of longitudinal mixing (z-filter) for magnetization transfer during total correlated spectroscopy. GOIA-W(16,4) provides accurate signal localization, and more importantly, lowers the SAR for both total correlated spectroscopy mixing and localization. Longitudinal mixing improves considerably (fivefolds) the efficiency of total correlated spectroscopy transfer. These are markedly different from previous 1D editing total correlated spectroscopy sequences using spatially nonselective pulses and transverse mixing. Fully adiabatic (adiabatic mixing with adiabatic localization) and semiadiabatic (adiabatic mixing with nonadiabatic localization) methods for two-dimensional total correlated spectroscopy are compared. Results are presented for simulations, phantoms, and in vivo two-dimensional spectra from healthy volunteers and patients with brain tumors obtained on 3T clinical platforms equipped with standard hardware. To the best of our knowledge, this is the first demonstration of in vivo adiabatic two-dimensional total correlated spectroscopy and fully adiabatic two-dimensional correlated spectroscopy. It is expected that these methodological developments will advance the in vivo applicability of multi(spectrally)dimensional MRS to reliably identify metabolic biomarkers.
Exploiting manifold geometry in hyperspectral imagery (2005)

A new algorithm for exploiting the nonlinear structure of hyperspectral imagery is developed and compared against the de facto standard of linear mixing. This new approach seeks a manifold coordinate system that preserves geodesic distances in the high-dimensional hyperspectral data space. Algorithms for deriving manifold coordinates, such as isometric mapping (ISOMAP), have been developed for other applications. ISOMAP guarantees a globally optimal solution, but is computationally practical only for small datasets because of computational and memory requirements. Here, we develop a hybrid technique to circumvent ISOMAP's computational cost. We divide the scene into a set of smaller tiles. The manifolds derived from the individual tiles are then aligned and stitched together to recomplete the scene. Several alignment methods are discussed. This hybrid approach exploits the fact that ISOMAP guarantees a globally optimal solution for each tile and the presumed similarity of the manifold structures derived from different tiles. Using land-cover classification of hyperspectral imagery in the Virginia Coast Reserve as a test case, we show that the new manifold representation provides better separation of spectrally similar classes than one of the standard linear mixing models. Additionally, we demonstrate that this technique provides a natural data compression scheme, which dramatically reduces the number of components needed to model hyperspectral data when compared with traditional methods such as the minimum noise fraction transform.
Noise performance of erbium-doped fiber amplifier pumped at 1.49 mu m, and application to signal preamplification at 1.8 Gbit/s (1989)

Direct measurements of the noise figure of an erbium-doped fiber amplifier are described. With an amplifier gain as high as 36 dB, a noise figure as low as 4.1 dB was measured. Noise figures remained below 6 dB for signal wavelengths within the high gain (G>20 dB) region of the amplifier. An optical receiver sensitivity of -43 dBm at 1.8 Gb/s, corresponding to 215 photons/b, was achieved using the fiber amplifier as an optical preamplifier for a direct detection receiver.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Nanomolar Inhibitors of AmpC β-Lactamase (2002)

beta-lactamases are the most widespread resistance mechanism to beta-lactam antibiotics, such as the penicillins and the cephalosporins. In an effort to combat these enzymes, a combination of stereoselective organic synthesis, enzymology, microbiology, and X-ray crystallography was used to design and evaluate new carboxyphenyl-glycylboronic acid transition-state analogue inhibitors of the class C beta-lactamase AmpC. The new compounds improve inhibition by over 2 orders of magnitude compared to analogous glycylboronic acids, with K(i) values as low as 1 nM. On the basis of the differential binding of different analogues, the introduced carboxylate alone contributes about 2.1 kcal/mol in affinity. This carboxylate corresponds to the ubiquitous C3(4)' carboxylate of beta-lactams, and this energy represents the first thermodynamic measurement of the importance of this group in molecular recognition by class C beta-lactamases. The structures of AmpC in complex with two of these inhibitors were determined by X-ray crystallography at 1.72 and 1.83 A resolution. These structures suggest a structural basis for the high affinity of the new compounds and provide templates for further design. The highest affinity inhibitor was 5 orders of magnitude more selective for AmpC than for characteristic serine proteases, such as chymotrypsin. This inhibitor reversed the resistance of clinical pathogens to the third generation cephalosporin ceftazidime; it may serve as a lead compound for drug discovery to combat bacterial resistance to beta-lactam antibiotics.
ChemInform Abstract: LOW‐THERMAL‐EXPANSION POLYCRYSTALLINE ZIRCONYL PHOSPHATE CERAMIC (1985)

Abstract Die Synthese von Wärmeschock‐beständigem Material aus 2 ZrO 2 ‐ P 2 O 5 wird untersucht.
Method for near-net forming of a sand mold with digital flexible extrusion technology (2017)

In order to further improve the precision forming efficiency of a sand mold digital patternless casting and reduce the amount of sand mold cutting, a method for near-net forming of the sand mold with digital flexible extrusion technology was put forward. The theory, optimization algorithm and technology for sand mold nearnet forming were studied. Experimental results show that the sand mold forming efficiency can be increased by 34%, and the molding sand can be reduced by 44%. The method for near-net forming of a sand mold with digital flexible extrusion technology can effectively promote the application of digital patternless casting technology in the mass production of castings and thus greatly improves the efficiency and automation of sand mold manufacturing.
Identification and Evaluation of High-Performance EOR Surfactants (2006)

Abstract We report results for a number of promising EOR surfactants based upon a fast, low-cost laboratory screening process that is highly effective in selecting the best surfactants to use with different crude oils. Initial selection of surfactants is based upon desirable surfactant structure. Phase behavior screening helps to quickly identify favorable surfactant formulations. Salinity scans are conducted to observe equilibration times, microemulsion viscosity, oil and water solubilization ratios and interfacial tension. Co-surfactants and co-solvents are included to minimize gels, liquid crystals and macroemulsions and to promote rapid equilibration to low-viscosity microemulsions. Branched alcohol propoxy sulfates, internal olefin sulfonates, and branched alpha olefin sulfonates have been identified as good EOR surfactants using this screening process. These surfactants are available at low cost and are compatible with both polymers and alkali such as sodium carbonate and thus are good candidates for both surfactant- polymer and alkali-surfactant-polymer EOR processes. One of the best formulations was tested in both sandstone and dolomite cores and found to give excellent oil recovery and low surfactant retention.
Development of a Digital Image Database for Chest Radiographs With and Without a Lung Nodule (2000)

This database can be useful for many purposes, including research, education, quality assurance, and other demonstrations.
Enhancing specific strength and stiffness of phenolic microsphere syntactic foams through carbon fiber reinforcement (2009)

Abstract Composite syntactic foams with different densities were fabricated with hollow phenolic microspheres, a phenolic resin binder, and a small addition of chopped carbon fibers. Compressive, shear, and tensile properties were studied for the syntactic foams with and without carbon fibers. Two fiber layer orientations, either parallel (P‐type) or perpendicular (N‐type) to the loading direction, were considered in the mechanical testing. For N‐type foams, mechanical properties were weakly dependent on foam density. For P‐type foams, the mechanical properties of the foams were strongly dependent on the strength of the supporting matrix. The specific strength and specific stiffness of the P‐type foams were significantly enhanced compared with the neat foams. These findings indicate that fiber reinforcement is an effective way to enhance the mechanical performance of syntactic foams, and the enhanced performance should lead to applications as a foam core material for sandwich structures. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Demonstration of Allelic Exchange in the Slow-Growing Bacterium <i>Mycobacterium avium</i> subsp. <i>paratuberculosis</i> , and Generation of Mutants with Deletions at the <i>pknG, relA</i> , and <i>lsr2</i> Loci (2008)

Mycobacterium avium subsp. paratuberculosis is the causative pathogen of Johne's disease, a chronic inflammatory wasting disease in ruminants. This disease has been difficult to control because of the lack of an effective vaccine. To address this need, we adapted a specialized transduction system originally developed for M. tuberculosis and modified it to improve the efficiency of allelic exchange in order to generate site-directed mutations in preselected M. avium subsp. paratuberculosis genes. With our novel optimized method, the allelic exchange frequency was 78 to 100% and the transduction frequency was 1.1 x 10(-7) to 2.9 x 10(-7). Three genes were selected for mutagenesis: pknG and relA, which are genes that are known to be important virulence factors in M. tuberculosis and M. bovis, and lsr2, a gene regulating lipid biosynthesis and antibiotic resistance. Mutants were successfully generated with a virulent strain of M. avium subsp. paratuberculosis (M. avium subsp. paratuberculosis K10) and with a recombinant K10 strain expressing the green fluorescent protein gene, gfp. The improved efficiency of disruption of selected genes in M. avium subsp. paratuberculosis should accelerate development of additional mutants for vaccine testing and functional studies.
Joint Source-Channel Optimization over Wireless Relay Networks (2011)

Cooperative communications have received considerable attention for wireless multimedia applications as a technique to improve reliability and service coverage. To apply such cooperation over slow fading channels, we consider exploiting the spatial diversity in multiple relay networks. In this paper, we focus on amplify-and-forward relaying schemes, namely, orthogonal amplify-and-forward, selective relaying, and distributed beamforming, for the cooperative wireless multimedia transmission. Furthermore, the successive refinement source coding is exploited such that the multimedia signal is encoded into multiple layers and the quality of its reconstruction at the receiver is improved when more layers are received correctly. We study two strategies for the layered source transmission, namely, progressive transmission and superposition coding. With our developed framework, we propose suboptimal resource allocation algorithms to efficiently assign rate, power, and channel uses to different layers so as to maximize the quality of the multimedia signal reconstructed at the receiver. The proposed optimization methodology is simple and only requires the knowledge of the channel statistics compared to the existing algorithms. As a result, the receiver only requires to feedback the determined rate, power, and channel uses to the transmitter whenever the channel statistics or the layered source transmission strategy changes.
Circulating microRNA-203 predicts prognosis and metastasis in human colorectal cancer (2015)

High levels of serum miR-203 associate with poor survival and metastasis, suggesting it to be a promising non-invasive prognostic and metastasis-predictive biomarker in patients with CRC.
A Practical Anisotropic Vector Hysteresis Model Based on Play Hysterons (2017)

An anisotropic vector hysteresis model based on the improved isotropic vector play operator has been presented to predict the magnetization behavior of anisotropic hysteresis materials. The required parameters can be identified from the major hysteresis loops in all principal axes, which can be easily measured, or are directly available from magnetic material manufacturers. The presented model, which has been successfully implemented in 2-D and 3-D transient finite-element analysis, is validated by numerical experiments and measured data cited from TEAM problem 32, and is applied to simulate a synchronous reluctance motor with an axially laminated anisotropic rotor.
Understanding the fundamentals of acid-induced ionic liquid-based aqueous biphasic system (2018)

Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have demonstrated exceptional performance in bioseparation processes. However, IL-based ABS are of limited interest for metal extraction as most metals are not stable in their neutral or alkaline pH conditions. In the quest for better extraction systems for metals, the development of IL-based ABS with highly acidic solutions (AcABS), induced by the mixture of a hydrophilic IL ([P44414]Cl), a mineral acid (HCl, HNO3 or H2SO4) and water, opens new possibilities. A comprehensive investigation of fundamental aspects of IL-based AcABS was performed, including the temperature dependence of the phase diagrams, tie-lines and ion exchange behavior, evidencing the unique characteristics of these new systems. In particular, the favorable biphasic formation with an increase in temperature showcases the lower critical solution temperature (LCST) behavior of the phosphonium-based IL and opens many possibilities for AcABS application by creating stimuli responsive systems. The anion exchange identified highlights the IL-based AcABS complexity that renders the analytical characterization of the phases mandatory, instead of the traditional method coupling an empirical fit of the binodal with the lever-arm rule. Through judicious selection of the inorganic acid, different extraction systems can be obtained by tuning the degree of anion-exchange, underlining the versatility of the proposed AcABS system.
Input selection for multivariable extremum seeking control with application to real-time optimization of a chilled-water plant (2017)

Extremum Seeking Control (ESC) has been recognized as a potential model-free control solution for applications where model acquisition is difficult and/or cost prohibitive, e.g. for building HVAC systems. Such systems have large numbers of candidate inputs that could be used for ESC, however, it is not economically necessary to include all of them as manipulated inputs. This study presents a Hessian estimation based automatic input selection strategy for multi-variable ESC. The Hessian estimation strategy in the Newton based ESC is applied, and the singular values of the estimated Hessian matrix are used to decide the subset of inputs for the underlying ESC. The finite impulse response (FIR) filter is used for isolating the Hessian elements with faster transient performance than the infinite impulse (IIR) filter. Also, an optimal dither frequency design is performed to avoid undesirably close spacing between the associated frequency components and the use of large roll-off filters. The proposed approach is illustrated with a three-input numerical example, and the simulation is under way for a Modelica model for a chilled-water plant.
Structural and electrical characterization of <i>a</i> ‐plane GaN grown on <i>a</i> ‐plane SiC (2003)

Planar nonpolar () a-plane GaN thin films were grown on () a-plane 6H-SiC substrates via metalorganic chemical vapor deposition by depositing a high temperature AlN buffer layer prior to the epitaxial GaN growth. The orientation of the GaN film and AlN buffer layer directly match that of the SiC substrate, as determined by on- and off-axis X-ray diffraction measurements. The morphological evolution of GaN grown on the AlN buffer layers was investigated using atomic force microscopy. Microstructural characterization of the coalesced a-plane GaN films provided by plan-view transmission electron microscopy revealed threading dislocation and stacking fault densities of ∼3 × 1010 cm−2 and ∼7 × 105 cm−1, respectively. Structural comparisons to a-plane GaN films grown on r-plane sapphire substrates are presented. Si-doped films were grown with a variety of Si/Ga ratios and electrically characterized using Hall effect measurements. A maximum Hall mobility of 109 cm2/Vs was attained at a carrier concentration of 1.8 × 1019 cm−3.
Trp64Arg Variant of theβ 3-Adrenoceptor and Insulin Resistance in Obese Postmenopausal Women1 (1998)

There is controversy regarding the role of the Trp64Arg variant of the beta3-adrenergic receptor (beta3AR) gene in the pathogenesis of insulin resistance. The modest effect of the variant as well as differences in study design, gender, age, and genetic background may contribute to divergent results among investigations. Insulin sensitivity (euglycemic clamp and tracers) was measured in 13 obese women (57 +/- 6 yr old) heterozygous for the beta3AR variant and in 14 women (57 +/- 4 yr old) homozygous for the normal gene. Groups were matched for age, body composition, intraabdominal fat, sc abdominal fat, physical activity level, and aerobic capacity. Exogenous glucose infusion during the clamp was significantly lower (P = 0.03) in beta3AR heterozygotes (241 +/- 135 mg/min) vs. normal homozygotes (379 +/- 172 mg/min). Basal endogenous glucose production was not different (P = 0.20) between heterozygotes (175 +/- 27 mg/min) and normal homozygotes (164 +/- 14 mg/min). Endogenous glucose production during hyperinsulinemia was also not different (P = 0.22) between heterozygotes (77 +/- 57 mg/min) and normal homozygotes (56 +/- 16 mg/min). Total glucose disposal adjusted for residual endogenous glucose production was lower (P = 0.049) for heterozygotes (320 +/- 111 mg/min) than for normal homozygotes (441 +/- 183 mg/min). Our results suggest that obese postmenopausal women who are heterozygous for the Trp64Arg variant in the beta3AR gene have greater insulin resistance than age-, body composition-, and physical activity-matched women homozygous for the normal gene.
System for testing adequacy of human hearing (1995)

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Patrick M. Zurek, William M. Rabinowitz; System for testing adequacy of human hearing. J. Acoust. Soc. Am. 1 October 1995; 98 (4): 1835–1836. https://doi.org/10.1121/1.413357 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAcoustical Society of AmericaThe Journal of the Acoustical Society of America Search Advanced Search |Citation Search
ASSEMBLY AND RF TUNING OF THE LINAC4 RFQ AT CERN (2012)

The fabrication of Linac4 is progressing at CERN with the goal of making a 160 MeV H- beam available to the LHC injection chain as from 2015. In the Linac4 the first stage of beam acceleration, after its extraction from the ion source, is provided by a Radiofrequency Quadrupole accelerator (RFQ), operating at the RF frequency of 352.2 MHz and which accelerates the ion beam to the energy of 3 MeV. The RFQ, made of three modules, one meter each, is of the four-vane kind, has been designed in the frame of a collaboration between CERN and CEA and has been completely machined and assembled at CERN. The paper describes the assembly of the RFQ structure and reports the results of RF low power measurements, in order to achieve the required accelerating field flatness within 1% of the nominal field profile.
Scanning frequency comb microscopy (SFCM) shows promise for sub-10 nm dopant profiling (2014)

When a mode-locked ultrafast laser is focused on the tunneling junction of a scanning tunneling microscope a microwave frequency comb, at harmonics of the pulse repetition frequency of the laser, is superimposed on the DC tunneling current. A clean semiconductor sample, biased to form a nanoscale depletion region at the base of the tunneling junction, attenuates these harmonics. Simulations suggest that the dependence of the measured attenuation on the applied DC bias may be used to determine the local concentration of dopant atoms with a resolution as fine as the radius of the tunneling junction - which is much smaller than radius of the tip electrode.
Model-based dynamic engineering of Escherichia coli for N-acetylglucosamine overproduction (2022)

N-acetylglucosamine (GlcNAc), a glucosamine derivative, has a wide range of applications in pharmaceutical fields, and there is an increasing interest in the efficient production of GlcNAc genetic engineered bacteria. In this work, <i>Escherichia coli</i> ATCC 25947 (DE3) strain was engineered by a model-based dynamic regulation strategy achieving GlcNAc overproduction. First, the GlcNAc synthetic pathway was introduced into <i>E. coli</i>, and through flux balance analysis of the genome-scale metabolic network model, metabolic engineering strategies were generated to further increase GlcNAc yield. Knock-out of genes <i>poxB</i> and <i>ldhA,</i> encoding pyruvate oxidase and lactate dehydrogenase, increased GlcNAc titer by 5.1%. Furthermore, knocking out N-acetylmuramic acid 6-phosphate etherase encoded by <i>murQ</i> and enhancing glutamine synthetase encoded by <i>glnA</i> gene further increased GlcNAc titer to 130.8 g/L. Analysis of metabolic flux balance showed that GlcNAc production maximization requires the strict dynamic restriction of the reactions catalyzed by <i>pfkA</i> and <i>zwf</i> to balance cell growth and product synthesis. Hence, a dynamic regulatory system was constructed by combining the CRISPRi (clustered regularly interspaced short palindromic repeats interference) system with the lactose operon <i>lacI</i> and the transcription factor pdhR, allowing the cell to respond to the concentration of pyruvate and IPTG to dynamically repress <i>pfkA</i> and <i>zwf</i> transcription. Finally, the engineered bacteria with the dynamic regulatory system produced 143.8 g/L GlcNAc in a 30-L bioreactor in 55 h with a yield reaching 0.539 g/g glucose. Taken together, this work significantly enhanced the GlcNAc production of <i>E. coli.</i> Moreover, it provides a systematic, effective, and universal way to improve the synthetic ability of other engineered strains.