gebhart/patrepeval huggingface dataset:
Effects of β‐Adrenergic Receptor Activation on Intracellular Calcium and Membrane Potential in Adult Cardiac Myocytes (1992)

β‐Adrenergic Receptor Activation and Intracellular Ca 2+ . Introduction: β‐Adrenergic receptor agonists have been shown to increase the voltage‐dependent Ca 2+ current in cardiac myocytes. Additionally, adrenergic receptor activation has been shown to increase intracellular Ca 2+ , to increase systolic Ca 2+ transients and to enhance Ca 2+ uptake into the sarcoplasmic reticulum, thereby accelerating relaxation. The present study was designed first to characterize the influences of β‐adrenergic receptor activation on intracellular Ca 2+ activity as well as membrane potential in ventricular myocytes characterized as normal based on rigorous morphologic and electrophysiologic criteria. The second objective was to assess whether the increase in intracellular Ca 2+ activity elicited by β‐adrenergic receptor activation could elicit afterdepolarizations and triggered activity. Methods and Results: Intracellular Ca 2+ and whole‐cell voltage recordings were measured in cells in which indo‐1 free acid was delivered intracellularly through the recording pipette. Isoproterenol produced complex Ca 2+ transients underlying both early and delayed afterdepolarizations during pacing as well as aftertransients underlying triggered action potentials and delayed afterdepolarizations in the absence of pacing. The coupling interval of Ca 2+ i aftertransients was frequency dependent and followed that of the delayed afterdepolarizations. Ca 2+ i after transient amplitudes, however, exhibited a biphasic response with frequency revealing that factors other than pacing frequency alone contribute to control of the amplitude of the aftertransients. Inhibition of sarcoplasmic reticular release of Ca 2+ by ryanodine abolished Ca 2+ i aftertransients and afterdepolarizations otherwise elicited by isoproterenol. Conclusion: These data demonstrate that normal cells stimulated by β‐adrenergic agonists exhibit marked changes in intracellular Ca 2+ homeostasis that may serve as the substrate for abnormal ion fluxes that ultimately contribute to electrophysiologic derangements underlying arrhythmogenesis in the intact heart. ( J Cardiovasc Electrophysiol, Vol. 3, pp. 209–224, June 1992 )
Effect of Nitrogen on Microstructure and Properties of a Cast Cobalt-Base Superalloy (2011)

The effect of the nitrogen on the microstructure and properties of a cast Co-based superalloy K640S was investigated with the different level ranged from 24 ppm to 85 ppm. The results indicate that almost all nitrogen exist in the form of nitride precipitation in the vacuum induction melting. It is found that high N level would extend the solidification window during the solidification process, and then increase the quantity of the carbide eutectic phases and led to the distribution in the network form of the eutectics in the interdendritic regions. High nitrogen content (more than 40 ppm) can reduced the mechanical properties of the testing alloy. So, it is suggested that the nitrogen in the recycled Co-based superalloys should be controlled at a suitable level in order to avoid the degradation of their properties.
Shaping Gold Nanostar Electric Fields for Surface-Enhanced Raman Spectroscopy Enhancement via Silica Coating and Selective Etching (2016)

The application of gold nanostars in direct and indirect surface-enhanced raman spectroscopy (SERS) sensing has significantly grown in the past few years, mainly because of the particles’ excellent field enhancement properties. However, experimental demonstrations correlating SERS signal enhancements to specific morphology features of the nanostars are still scarce, primarily because of the complexity of the nanostar morphology itself. Herein, we have addressed this fundamental issue by synthesizing surfactant-free gold nanostars, coating them with a uniform silica layer, and then etching the silica away selectively with NaBH4 to expose increasing amounts of the metallic surface. We have then functionalized the nanoparticles with a Raman active molecule, aminothiophenol (ATP), and compared the resulting SERS spectra with those obtained on surfactant-free stars functionalized with ATP. Through comparison of the experimental results with the electric field intensities and distributions calculated via finite element simulations, we have observed a strong correlation between the Raman signal enhancements obtained experimentally and the heat losses calculated on three-dimensional representations of the same nanostructures. We believe that our model could be used to predict the effectiveness of nanostars at enhancing SERS signals based on their overall morphology, even when thorough experimental characterization is lacking.
Insights into polymer versus oligosaccharide synthesis: mutagenesis and mechanistic studies of a novel levansucrase from <i>Bacillus megaterium</i> (2007)

A novel levansucrase was identified in the supernatant of a cell culture of Bacillus megaterium DSM319. In order to test for the contribution of specific amino acid residues to levansucrase catalysis, the wild-type enzyme along with 16 variants based on sequence alignments and structural information were heterologously produced in Escherichia coli. The purified enzymes were characterized kinetically and the product spectrum of each variant was determined. Comparison of the X-ray structures of the levansucrases from Gram-positive Bacillus subtilis and Gram-negative Gluconacetobacter diazotrophicus in conjunction with the corresponding product spectra identified crucial amino acid residues responsible for product specificity and catalysis. Highly conserved regions such as the previously described RDP and DXXER motifs were identified as being important. Two crucial structural differences localized at amino acid residues Arg370 and Asn252 were of high relevance in polymer compared with oligosaccharide synthesis.
Molecular characterization of a neuropathogenic and nonerythroleukemogenic variant of Friend murine leukemia virus PVC-211 (1992)

PVC-211 murine leukemia virus (MuLV) is a replication-competent, ecotropic type C retrovirus that was isolated after passage of the Friend virus complex through F344 rats. Unlike viruses in the Friend virus complex, it does not cause erythroleukemia but causes a rapidly progressive hind limb paralysis when injected into newborn rats and mice. We have isolated an infectious DNA clone (clone 3d) of this virus which causes neurological disease in animals as efficiently as parental PVC-211 MuLV. The restriction map of clone 3d is very similar to that of the nonneuropathogenic, erythroleukemogenic Friend murine leukemia virus (F-MuLV), suggesting that PVC-211 MuLV is a variant of F-MuLV and that no major structural alteration was involved in its derivation. Studies with chimeric viruses between PVC-211 MuLV clone 3d and wild-type F-MuLV clone 57 indicate that at least one determinant for neuropathogenicity resides in the 2.1-kb XbaI-ClaI fragment containing the gp70 coding region of PVC-211 MuLV. Compared with nonneuropathogenic ecotropic MuLVs, the env gene of PVC-211 MuLV encodes four unique amino acids in the gp70 protein. Nucleotide sequence analysis also revealed a deletion in the U3 region of the long terminal repeat (LTR) of PVC-211 MuLV clone 3d compared with F-MuLV clone 57. In contrast to the env gene of PVC-211 MuLV, particular sequences within the U3 region of the viral LTR do not appear to be required for neuropathogenicity. However, the changes in the LTR of PVC-211 MuLV may be responsible for the failure of this virus to cause erythroleukemia, because chimeric viruses containing the U3 region of F-MuLV clone 57 were erythroleukemogenic whereas those with the U3 of PVC-211 MuLV clone 3d were not.
New principle for measuring arterial blood oxygenation, enabling motion-robust remote monitoring (2016)

Finger-oximeters are ubiquitously used for patient monitoring in hospitals worldwide. Recently, remote measurement of arterial blood oxygenation (SpO<sub>2</sub>) with a camera has been demonstrated. Both contact and remote measurements, however, require the subject to remain static for accurate SpO<sub>2</sub> values. This is due to the use of the common ratio-of-ratios measurement principle that measures the relative pulsatility at different wavelengths. Since the amplitudes are small, they are easily corrupted by motion-induced variations. We introduce a new principle that allows accurate remote measurements even during significant subject motion. We demonstrate the main advantage of the principle, i.e. that the optimal signature remains the same even when the SNR of the PPG signal drops significantly due to motion or limited measurement area. The evaluation uses recordings with breath-holding events, which induce hypoxemia in healthy moving subjects. The events lead to clinically relevant SpO<sub>2</sub> levels in the range 80-100%. The new principle is shown to greatly outperform current remote ratio-of-ratios based methods. The mean-absolute SpO<sub>2</sub>-error (MAE) is about 2 percentage-points during head movements, where the benchmark method shows a MAE of 24 percentage-points. Consequently, we claim ours to be the first method to reliably measure SpO<sub>2</sub> remotely during significant subject motion.
An Efficient Approach for Sentence-based Opinion Retrieval (2011)

Recently, online opinions have received much attention, such as product reviews, economic analysis, political polls, etc. These opinions can provide people with valuable information and help them to make decisions. Therefore, how to effectively retrieve documents including opinions or comments specified by a target is becoming a popular research issue. A typical method for opinion retrieval is document-based method that splits each document into bag-of-word, and computes documental relevance and opinion separately. However, document-based methods neglect the contextual information and lead to the loss of the association between the opinion and its corresponding target which in turn affects the performance. In an extreme case, a relevant document full of irrelevant opinions will also be assigned a high ranking. In this paper, we will present a unified approach for opinion retrieval in the granularity of sentence because opinions would likely be expressed within one sentence. Thus, the association between an opinion and its corresponding target can be maintained and an overall score can be computed for each sentence. Moreover, we also tried to capture the contextual information of a sentence by its position. Compared with document-based approaches, experimental results on COSIB and COAE datasets showed that our approach achieved significant improvement.
Effects of dietary supplementation of multi-enzyme on growth performance, nutrient digestibility, small intestinal digestive enzyme activities, and large intestinal selected microbiota in weanling pigs1 (2014)

Two experiments were conducted to assess the effects of dietary supplementation of an exogenous multi-enzyme (EME) preparation to 35- to 65-d-old piglets on apparent total tract digestibility (ATTD), growth performance, digestive enzyme activities, and selected microbial populations in feces. In Exp.1, twenty eight 35-d-old piglets were randomly assigned to 7 dietary treatments (corn-soybean based diet supplemented with 0, 100, 150, 200, 250, 300, or 350 mg EME/kg) in a 14-d digestibility study. Piglets fed the diets supplemented with EME had greater ATTD of DM, CP, and GE (P = 0.001, 0.005, and 0.009, respectively) than those fed the diet without EME supplementation, and those ATTD values increased linearly and quadratically (P < 0.001) as the levels of supplemented EME increased. In Exp. 2, two hundred 35-d-old weanling piglets were randomly allocated to 20 pens. The pens were then randomly assigned to 5 dietary treatments (corn-soybean based diet supplemented with 0, 100, 150, 250, or 350 mg EME/kg) with 4 pens per treatment in a 30-d feeding experiment. Piglets has ad libitum access to diets and water, and they were weighed at the beginning (35-d-old), middle (50-d-old), and end (65-d-old) of the experiment. Fecal samples were grabbed directly from the rectum and digesta samples from duodenum, jejunum, and ileum were taken at the end of the experiment for the analysis of selected bacteria populations and digestive-enzyme activities. The ADG and ADFI tended to be greater with the increasing levels of supplemented EME in both periods, whereas G:F was improved (P = 0.012 and 0.017) by EME in the period of 35 to 50 d of age and during the overall experimental period. Furthermore, inclusion of EME in diet increased the counts of Lactobacilli spp. and Bacillus subtilis spp., but reduced the populations of Salmonella spp. and Escherichia coli spp. in the feces. The EME supplementation also enhanced (P < 0.05) the activities of amylase, lipase, and protease in the small intestine. The growth performance-enhancing effects of EME appeared to be mediated by the age of the piglet and the dose of EME used. Supplementation of corn-soybean meal diets for 35- to 65-d-old piglets with EME has a potential to enhance gut health condition, increase nutrient digestion, and increase growth performance.
Thermoresponsive Nanoparticles of Self-Assembled Block Copolymers as Potential Carriers for Drug Delivery and Diagnostics (2015)

Thermally responsive hydrogel nanoparticles composed of self-assembled polystyrene-b-poly(N-isopropylacrylamide)-b-polystyrene block copolymers and fluorescent probe 1-anilinonaphthalene-8-sulfonic acid have been prepared by aerosol flow reactor method. We aimed exploring the relationship of intraparticle morphologies, that were, PS spheres and gyroids embedded in PNIPAm matrix, as well PS-PNIPAm lamellar structure, to probe release in aqueous solution below and above the cloud point temperature (CPT) of PNIPAm. The release was detected by fluorescence emission given by the probe binding to bovine serum albumin. Also, the colloidal behavior of hydrogel nanoparticles at varying temperatures were examined by scattering method. The probe release was faster below than above the CPT from all the morphologies of which gyroidal morphology showed the highest release. Colloidal behavior varied from single to moderately aggregated particles in order spheres-gyroids-lamellar. Hydrogel nanoparticles with tunable intra particle self-assembled morphologies can be utilized designing carrier systems for drug delivery and diagnostics.
A Low‐Temperature‐Grown Oxide Diode as a New Switch Element for High‐Density, Nonvolatile Memories (2006)

A one-diode/one-resistor structure, Pt/NiO/Pt/p-NiOx/n-TiOx/Pt, has been fabricated. This novel structure exhibits bistable resistance switching under forward bias, while the diode suppresses resistance switching in the Pt/NiO/Pt memory cell under reverse bias (see figure). Its low processing temperature and small cell size, as well as excellent rectifying characteristics, make this Pt/p-NiOx/n-TiOx/Pt diode structure a promising switch element for high- density, nonvolatile memory devices with 3D stack and cross-point structures.
Electron-metal-surface interaction potential with vacuum tunneling: Observation of the image force (1984)

It is shown that the classical image potential plays an important role in the correct interpretation of vacuum-tunneling experiments. The logarithmic derivative of the tunnel current with respect to the electrode separation is nearly constant and approximately equal to the square root of the average work function. From the experimental tunnel-voltage dependence with the electrode separation we obtain the barrier height as a function of distance.
Heparin-binding lectin from human placenta: further characterization of ligand binding and structural properties and its relationship to histones and heparin-binding growth factors (1991)

We have previously demonstrated that the heparin-binding lectin of human placenta dissociates into up to four distinct polypeptides with molecular weights of 14,400, 15,000, 16,200, and 16,700 (Kohnke-Godt, B., & Gabius, H.-J. (1989) Biochemistry 28, 6531-6538). Stable complexes to ligands can shift the molecular weight appearance of the lectin to higher values. They can be dissociated in the additional presence of 9 M urea or by enzymatic degradation of heparin in model studies. The binding of heparin is rather stable over a range of salt concentrations from 1 to 3 M NaCl. Chemical modification with group-specific reagents to arginine, lysine, histidine, tyrosine, and tryptophan results in substantial inactivation of binding activity. Further amino-terminal sequence analyses point to a high-scoring relationship in this region to histone sequences, namely, histone H2B, but to no published sequences for any heparin-binding growth factor. Calculation of relatedness on the basis of differences in amino acid composition corroborates the conclusion of molecular distinction between the lectin, histones H2A and H2B, and the fibroblast growth factor as well as angiogenin. Histones only weakly agglutinate type II erythrocytes in contrast to the lectin. The immobilized lectin exhibits two classes of binding sites with KD values of 3 and 110 nM in contrast to one estimated KD value of 250 nM with a commercially available histone fraction. Both fractions retain binding activity to biotinylated heparin in transblots and are immunologically cross-reactive to antibodies, raised against the lectin as antigen. Subcellular fractionation clearly demonstrates that heparin-inhibitable hemagglutination activity and immunologically cross-reactive protein bands, characteristic for the lectin, but not unequivocally distinguishable from certain histone fractions in blots, are not confined to the nuclear fraction in the human placenta.
<title>New nonlinear speckle and noise-reduction algorithm</title> (1997)

This new paper presents a nonlinear filtering technique for speckle noise reduction when the statistical clutter model is known. It is assumed that the noise or image statistical contributions are not known. The method has been successfully used for speckle noise reduction on electro-optical and SAR images for pre-filtering in multi-sensor image registration applications. A detailed software description of this speckle and noise reduction algorithm is also presented.
Novel substituted epoxide initiators for the carbocationic polymerization of isobutylene (2000)

This article presents the first detailed account of the discovery that substituted epoxides can initiate the carbocationic polymerization of isobutylene. α-Methylstyrene epoxide (MSE), 2,4,4-trimethyl-pentyl-epoxide-1,2 (TMPO-1), 2,4,4-trimethyl-pentyl-epoxide-2,3 (TMPO-2), and hexaepoxi squalene (HES) initiated isobutylene polymerization in conjunction with TiCl4. MSE, TMPO-2, and HES initiated living polymerizations. A competitive reaction mechanism is proposed for the initiation and propagation. According to the proposed mechanism, initiator efficiency is defined by the competition between the SN1 and SN2 reaction paths. A controlled initiation with external epoxides such as MSE should yield a primary hydroxyl head group and a tert-chloride end-group. The presence of tert-chloride end-groups was verified by NMR spectroscopy, whereas the presence of primary hydroxyl groups was implied by model experiments. Multiple initiation by HES was verified by diphenyl ethylene end-capping and NMR analysis; the resulting star polymer had an average of 5.2 arms per molecule. A detailed investigation of the reaction mechanism and the characterization of the polymers are in progress. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 444–452, 2000
On the Airline Schedule Perturbation Problem Caused by the Ground Delay Program (1997)

The ground delay program is one of several programs that the Federal Aviation Administration is currently administering for efficient and equitable use of scarce airspace and airport capacity. In this paper, we study airline schedule perturbation problem caused by the ground delay program with the goal of improving airline dependability statistics defined by Department of Transportation as percentage of flights delayed more than 15 minutes. The problem is modeled as an integer program. To solve the model, we have derived valid inequalities for the integer programming formulation for strengthening the LP relaxation bound. The number of integer variables was reduced dramatically based on analysis of the model and its impact on the problem solubility was shown to be of significant importance. A heuristic procedure based on solving a restricted version of the model has been designed for finding good feasible solutions. Computational results indicate the effectiveness of the model reduction and the valid inequalities. Realistic problems have been solved to optimality within seconds on microcomputers. Improvement on airline dependability statistics has been shown to be substantial.
Nonlinear PEH array for broadband energy harvesting (2015)

To better cater to the need on power resource of remote electronics and wireless sensors, harvesting energy from surrounding ambient environment is believed to be a promising solution and attracts lots of researching attention. Proposed harvester utilizes piezoelectric effect of material to convert vibration energy into electricity. To improve the efficiency of energy harvester, special effort is paid to broaden the bandwidth because the vibration source in ambient environment scattered over a wide frequency range. Many techniques such as multi-modal, oscillator arrays, active and passive tuning and nonlinear techniques have been used for broadband energy harvesting. Hence, this study proposed a nonlinear piezoelectric energy harvester (PEH) array which utilizes nonlinear oscillation technique. The proposed PEH consists of array of alumina cantilever beams which have a magnet embedded in the tip masses at their free end. Stationary magnets were carefully placed to interact with them. The specification of PEH was adjusted so that output from each beam could match up with another. The behavior of nonlinear PEH array was investigated through harmonic vibration test including both forward direction sweep and backward direction sweep. Later, optimum resistance is determined and power output from PEH was calculated. Furthermore, advantages of proposed PEH were obtained by comparing with linear PEH array. Based on the analysis of experiment data, it was concluded that proposed PEH was able to be functional over a much wider vibration frequency range compared with linear array.
Characterization of several amino acid transports and glutamine metabolism in MOLT4 human T4 leukemia cells (2006)

The transport system responsible for glutamine, alanine and glutamate in MOLT4 human T4 leukemia cell line were characterized. Kinetic studies of sodium-dependent glutamine and alanine transport exhibited a single saturable high-affinity carrier with a Michaelis constant of 152 +/- 26 microm and 203 +/- 36 microm and a maximal transport velocity of 960 +/- 165 and 1096 +/- 208 nmol/10(9)cells/min, respectively. Glutamate uptake was less than one-tenth of glutamine and alanine, and linearly increased with glutamate concentration which was mediated by diffusion. 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid (SITS), known as anion channel blockers, inhibited the sodium-dependent glutamine and alanine transport by 40% at 10 microm. Cellular contents of these amino acids in MOLT4 cells revealed glutamate to be the highest among them despite low glutamate influx. A glutamine metabolism study using whole cells indicated this high conversion rate from glutamine to glutamate, but no conversion to another amino acid. Based on these results, the high glutamate concentration in MOLT4 was speculated to be synthesized from transported glutamine by active glutaminase.