gebhart/patrepeval huggingface dataset:
Relation of monophasic action potential recorded with contact electrode to underlying transmembrane action potential properties in isolated cardiac tissues: a systematic microelectrode validation study (1988)

Monophasic action potentials, recorded with contact non-suction electrodes, have been used both clinically and experimentally. However, to date no systematic microelectrode validation studies have been done to underlying myocardial cell populations from different myocardial regions with different transmembrane potential profiles. In the present study transmembrane action potential properties, recorded with standard microelectrodes, were compared with monophasic action potentials recorded with contact electrodes in three different (endocardium, epicardium, and free running Purkinje fibre) isolated canine preparations during pacing and during spontaneous automatic activity. The mean transmembrane durations at 50% and 90% repolarisations (APD50 and APD90) of 19-30 cells at a monophasic action potential recording site was not statistically significant from monophasic action potential duration in all three tissue preparations studied. However, in endocardial preparations, composed of superficial (1-2 cell layers) Purkinje fibres with deeper ventricular muscle cells, the APD50 (139(17) ms) and APD90 (181(26) ms) of monophasic action potentials more closely reflected (but not significantly different) the underlying deeper ventricular muscle cells (APD50 134(14) ms and APD90 167(15) ms) rather than the mean transmembrane action potential durations of the underlying most superficial Purkinje fibres (166(22) ms for APD50 and 210(30) ms for APD90) (p less than 0.025). Tetrodotoxin (TTX) at 1 x 10(-6) mol.litre-1 shortened Purkinje fibre action potential duration and slightly lengthened that of ventricular muscle. Simultaneously recorded monophasic action potential showed an intermediate change in action potential duration. Incremental pacing and applied single premature stimuli resulted in similar degrees of shortening of action potential duration for both monophasic action potential and transmembrane potential in all three preparations. In endocardial preparations, barium chloride (4 mmol.litre-1) superfusion induced early afterdepolarisations, and spontaneous phase 4 depolarisations (n = 6) in both Purkinje and ventricular muscle cells giving rise to spontaneous automatic activity. These abnormal automatic activities were accurately detected by simultaneous monophasic action potential recordings. Suppression of automaticity by verapamil (0.2-0.5 micrograms.ml-1) as confirmed by transmembrane action potential recordings were similarly detected by monophasic action potential recordings (ABSTRACT TRUNCATED AT 250 WORDS)
A hierarchical network storage architecture for video-on-demand services (1997)

The advances in cable TV networks and multimedia technologies have open the possibilities for network/service/content providers to offer residential customers with video-on-demand services. However, the mass storage system used in supporting such services demands proper organization and management. We present a three-level hierarchical network storage architecture for the video-on-demand storage system. At the first-level (local service center, LSC) a limited number of programs with high viewing probabilities are stored; while at the second-level (local central service center, LCSC) a few programs with the second highest viewing probabilities are stored. The third-level (central service center, CSC) contains all programs provided in the system. Based on this architecture and the program viewing probability distribution function, we use a minimum-cost function to find out the number of programs stored in the two service centers (LSC and LCSC) and the number of links among these three service centers. We also describe two program reallocation algorithms which swap programs between service centers according to the change in user request patterns.
Piecewise linear approximation applied to nonlinear function of a neural network (1997)

An efficient piecewise linear approximation of a nonlinear function (PLAN) is proposed. This uses a simple digital gate design to perform a direct transformation from X to Y, where X is the input and Y is the approximated sigmoidal output. This PLAN is then used within the outputs of an artificial neural network to perform the nonlinear approximation. The comparison of this technique with two other sigmoidal approximation techniques for digital circuits is presented and the results show that the fast and compact digital circuit proposed produces the closest approximation to the sigmoid function. The hardware implementation of PLAN has been verified by a VHDL simulation with Mentor Graphics running under the UNIX operating system.
Formation of low-temperature self-organized nanoscale nickel metal islands (2003)

The growth and evolution of nanometre-sized Ni metal islands deposited under low-temperature non-ultra high vacuum conditions as a function of metal layer thickness, growth temperature and time is reported. The temperature of formation of the islands has been intentionally kept low for possible applications in flat panel display technology and also to act as a catalyst for carbon nanotube growth. It is shown that the size and distribution of the islands depends critically on the annealing temperature and the initial thickness of the metal layer. The mechanism of formation of the islands is described in terms of an Ostwald ripening mechanism of mass transport of either weakly bound individual Ni atoms or smaller clusters into larger more dispersed clusters.
Migration of Intradermally Injected Quantum Dots to Sentinel Organs in Mice (2007)

Topical exposure to nanoscale materials is likely from a variety of sources including sunscreens and cosmetics. Because the in vivo disposition of nanoscale materials is not well understood, we have evaluated the distribution of quantum dots (QDs) following intradermal injection into female SKH-1 hairless mice as a model system for determining tissue localization following intradermal infiltration. The QD (CdSe core, CdS capped, poly[ethylene glycol] coated, 37 nm diameter, 621 nm fluorescence emission) were injected intradermally (ID) on the right dorsal flank. Within minutes following intradermal injection, the highly UV fluorescent QD could be observed moving from the injection sites apparently through the lymphatic duct system to regional lymph nodes. Residual fluorescent QD remained at the site of injection until necropsy at 24 h. Quantification of cadmium and selenium levels after 0, 4, 8, 12, or 24 h in multiple tissues, using inductively coupled plasma mass spectrometry (ICP-MS), showed a time-dependent loss of cadmium from the injection site, and accumulation in the liver, regional draining lymph nodes, kidney, spleen, and hepatic lymph node. Fluorescence microscopy corroborated the ICP-MS results regarding the tissue distribution of QD. The results indicated that (1) ID injected nanoscale QD remained as a deposit in skin and penetrated the surrounding viable subcutis, (2) QD were distributed to draining lymph nodes through the sc lymphatics and to the liver and other organs, and (3) sentinel organs are effective locations for monitoring transdermal penetration of nanoscale materials into animals.
Silicon Epitaxial Layer Lifetime Characterization (2001)

Surface photovoltage (SPV) measurements are traditionally carried out under steady-state conditions to determine the minority carrier diffusion length. While this technique is very convenient for bulk wafer defect characterization, especially the detection of iron in boron-doped silicon wafers, it is poorly suited to characterize epitaxial layers that are typically much thinner than the minority carrier diffusion length. We have developed the theory for frequency-dependent SPV measurements and have verified this theory with experimental data. We consider the various recombination/generation components in the semiconductor and determine the dependence on photon flux density, optical absorption coefficient, doping density, recombination lifetime, and temperature. Epitaxial layers are usually measured with techniques that are sensitive to generation parameters confined to the reverse-biased space-charge region (scr). We show that optical excitation can be used for scr confined recombination measurements, but the resultant lifetime is an effective lifetime incorporating both scr and surface recombination, heavily influenced by surface recombination. © 2001 The Electrochemical Society. All rights reserved.
Prognostic Significance of Progesterone Receptor–Positive Tumor Cells Within Immunohistochemically Defined Luminal A Breast Cancer (2012)

Semiquantitative IHC expression of PR adds prognostic value within the current IHC-based luminal A definition by improving the identification of good outcome breast cancers. The new proposed IHC-based definition of luminal A tumors is HR positive/HER2 negative/Ki-67 less than 14%, and PR more than 20%.
Deep Learning Parametrization for B-Spline Curve Approximation (2018)

In this paper we present a method using deep learning to compute parametrizations for B-spline curve approximation. Existing methods consider the computation of parametric values and a knot vector as separate problems. We propose to train interdependent deep neural networks to predict parametric values and knots. We show that it is possible to include B-spline curve approximation directly into the neural network architecture. The resulting parametrizations yield tight approximations and are able to outperform state-of-the-art methods.
ChemInform Abstract: Self‐Assembly and Application of Diphenylalanine‐Based Nanostructures (2010)

Abstract Review: 66 refs.
A Kinetic Model for the Isomerization of n-Butene to Isobutene (1975)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA Kinetic Model for the Isomerization of n-Butene to IsobuteneVasant R. Choudhary and L. K. DoraiswamyCite this: Ind. Eng. Chem. Process Des. Dev. 1975, 14, 3, 227–235Publication Date (Print):July 1, 1975Publication History Published online1 May 2002Published inissue 1 July 1975https://pubs.acs.org/doi/10.1021/i260055a006https://doi.org/10.1021/i260055a006research-articleACS PublicationsRequest reuse permissionsArticle Views294Altmetric-Citations15LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts
Clinical utility of leukemia cell terminal transferase measurements. (1981)

Interest in the DNA-synthetic enzyme terminal deoxynucleotidyl transferase (TdT) has developed from two sets of observations: first, in normal animals, it occurs only in immature thymic lymphocytes and in a subpopulation of bone marrow lymphocytes; second, it is present in the blast cells of almost all patients with acute lymphoblastic leukemia. A prospective trial to evaluate blast cell TdT as a predictor of responsiveness to vincristine and prednisone in 30 Philadelphia chromosome-positive patients with blastic chronic myelogenous leukemia was undertaken. Eleven of 16 TdT-positive patients responded, whereas only one of 14 TdT-negative patients showed improvement. Among TdT-positive patients under the age of 50 years, the response rate was 78%. Enzyme-negative patients under the age of 50 had an 11% response rate. Blast cell morphology (i.e., lymphoblastic versus myeloblastic) had no significant correlation with either responsiveness or TdT activity. These results suggest that blast cell TdT activity may identify leukemic patients who are likely to respond to vincristine and prednisone irrespective of their conventional classification.
An efficient and scalable key management mechanism for Wireless Sensor Networks (2015)

A major issue in many applications of Wireless Sensor Networks (WSNs) is ensuring security. Particularly, in military applications, sensors are usually deployed in hostile areas where they can be easily captured and operated by an adversary. Most of security attacks in WSNs are due to the lack of security guaranties in terms of authentication, integrity, and confidentiality. These services are often provided using cryptographic primitives where sensor nodes need to agree on a set of secret keys. Current key distribution schemes are not fully adapted to the tiny, low-cost, and fragile nature of sensors that are equipped with limited computation capability, reduced memory size, and battery-based power supply. This paper investigates the design of an efficient key distribution and management scheme for wireless sensor networks. The proposed scheme can ensure the generation and distribution of different encryption keys intended to secure individual and group communications. This is performed based on elliptic curve public key encryption using Diffie-Hellman like key exchange that is applied at different levels of the network topology. In addition, a re-keying procedure is performed using secret sharing techniques. This scheme is more efficient and less complex than existing approaches, due to the reduced number of messages and the less processing overhead required to accomplish key exchange. Furthermore, few number of encryption keys with reduced sizes are managed in sensor nodes, which optimizes memory usage and enhances scalability to large size networks.
A rectangular-cavity-backed cloverleaf slot antenna for circular polarization (2004)

Characteristics of a rectangular-cavity-backed cloverleaf slot antenna are investigated numerically and experimentally. The method of moments is used to calculate the antenna characteristics where the effects of the cavity are taken into account. The minimum axial ratio of 1.11 dB and the maximum gain of 10.6 dBi are obtained at 2.19 GHz. The frequency bandwidth for the axial ratio (AR) (< 3 dB) and VSWR (< 2) is 2.7%. The symmetrical radiation pattern is obtained with respect to the vertical. The calculated results on AR, VSWR, and radiation patterns are agree well with measured data
Vulnerability/Lethality Modeling of Armored Combat Vehicles - Status and Recommendations (1993)

The Survivability/Lethality Analysis Directorate of the U.S. Army Research Laboratory has a hierarchy of vulnerability/lethality models including a compartment model, point-burst model, and stochastic point-burst model. The compartment model assesses the vulnerability of armored fighting vehicles by empirically-based damage correlation curves to evaluate probabilities of kill (P sub ks) and losses of function (LoFs). The point-burst model considers a burst of behind-armor debris whenever perforation by the main penetrator occurs. Vehicle damage from the main penetrator and behind-armor debris is evaluated and combined using subjective damage-assessment lists to assess P sub ks and LoFs. The stochastic point-burst generates distributions of P sub ks and LoFs to estimate the probability of occurrence of any particular empirical test result. Recent concepts, such as vulnerability spaces; new methodologies, such as degraded states; and live-fire testing have significant implications for future modeling efforts. For instance, the historically nebulous distinction between P sub k and LoF is being addressed. Introductory studies and results using live- fire data suggest promising avenues to develop a more elementary low-level model. This report compares and contrasts the advantages, disadvantages, and applications of the existing vulnerability/lethality models. Alternative modeling approaches are identified; and the impact of ongoing research is assessed. Long-term recommendations for vulnerability modeling are specified.
Microwave Measurements of the Loss in Low Loss Dielectrics (1970)

A technique has been developed which offers a significant improvement in the measurement of the loss in low loss materials having dielectric constants ≥4. The device consists of a cutoff section of circular waveguide concentrically loaded with a rod of the dielectric to be measured. The principal advantage of the technique is that by proper choice of sample and waveguide dimensions one can minimize the effect of resistive losses due to the metal walls. This is achieved by using the sample rod essentially as a section of dielectric waveguide in which the major fraction of the energy is confined to the rod. Both the reduction in wall losses and the simplicity of the design make the use of the waveguides fabricated from lower conductivity, high melting point metals much more attractive for measurement of low loss ceramic dielectrics at high temperatures. Results are reported for single crystal sapphire.
Gradational power control in multi-channel multi-radio wireless ad hoc networks (2010)

Various power control techniques have been proposed to boost aggregate network throughput by reducing the interference impact and encouraging more concurrent transmissions in medium-shared wireless systems. In this paper, we do not intend to devise new power control mechanisms. Rather, we investigate an interesting problem of how to apply power control techniques in a multichannel networking environment, where every wireless node is equipped with multiple radio transceivers, each statically binding to a dedicated channel. For a single radio transceiver, more reduction on transmit power generally results in lower network connectivity, leading to a longer route (if path exists) for multi-hop communication (bad for end-to-end throughput). On the other hand, small transmit power helps accommodate more concurrent transmitters (good for aggregate throughput). For wireless ad hoc networks with multi-hop communication as the major behavior, how to take both route length and medium utilization into consideration to improve system capacity is thus important. Motivated by this, we propose to apply power control with different connectivity degrees on radio interfaces. Imagine several superposed network topologies having gradational connectivity levels over multiple non-interfering channels, hence the name, gradational power control (abbreviated as GradPC), is given. In our proposed GradPC protocol, a base channel is designated to use default transmit power (no power control on this radio). For other non-base radios, we adopt neighbor-based power control mechanisms to tailor the connectivity degree for each radio channel. After GradPC has successfully configured transmit power for all radios, our other corresponding protocols run in the following two phases: (i) a variant DSR is performed over the base channel to discover a multi-hop route, and (ii) once the route is ready, a radio selection procedure is activated to judiciously schedule the next link-layer packet sent over an appropriate channel. Simulation results demonstrate that the proposed GradPC along with its corresponding protocols outperform strategies with no power control and the same connected topology, by imposing gradational power levels on radios to balance the requirements for short route and high medium utilization.
Automatic Pharmaceutical Inspection (1993)

This article reviews automatic inspection within the pharmaceutical industry and deals, in particular, with the application of machine vision to these tasks. Although taking some time to be established within this industry, caused, in part perhaps, by unrealistic expectations of the performance available, machine vision systems are now available in a robust and reliable format, ideally suited to the demanding and security‐conscious needs of this sector. Such systems are now addressing a wide variety of applications, often aimed at the packaging, labelling and coding of products where the ever‐more‐stringent requirements of the regulatory bodies provide a considerable impetus to the improvement cycle. Given that effective quality management should recognize that improvements in products and processes should be sought continually, however good they are, all aspects of packaging, labelling and coding should come under scrutiny when the demanding standards of product security are considered. It is perhaps easy to understand why, when the implications of the accidental misuse of a drug could be severe, both in human terms and in the cost of any remedial action necessary. Therefore, in order to assure product security, inspection at strategic points in the manufacturing process will normally be required. However, the drawbacks of human inspectors being used to carry out repetitive inspection are numerous (and probably well known!) but include the maximum concentration span and the unavoidable subjectivity involved.
Functions of the Membrane-Associated and Cytoplasmic Malate Dehydrogenases in the Citric Acid Cycle of <i>Corynebacterium glutamicum</i> (2000)

Like many other bacteria, Corynebacterium glutamicum possesses two types of L-malate dehydrogenase, a membrane-associated malate:quinone oxidoreductase (MQO; EC 1.1.99.16) and a cytoplasmic malate dehydrogenase (MDH; EC 1.1.1.37) The regulation of MDH and of the three membrane-associated dehydrogenases MQO, succinate dehydrogenase (SDH), and NADH dehydrogenase was investigated. MQO, MDH, and SDH activities are regulated coordinately in response to the carbon and energy source for growth. Compared to growth on glucose, these activities are increased during growth on lactate, pyruvate, or acetate, substrates which require high citric acid cycle activity to sustain growth. The simultaneous presence of high activities of both malate dehydrogenases is puzzling. MQO is the most important malate dehydrogenase in the physiology of C. glutamicum. A mutant with a site-directed deletion in the mqo gene does not grow on minimal medium. Growth can be partially restored in this mutant by addition of the vitamin nicotinamide. In contrast, a double mutant lacking MQO and MDH does not grow even in the presence of nicotinamide. Apparently, MDH is able to take over the function of MQO in an mqo mutant, but this requires the presence of nicotinamide in the growth medium. It is shown that addition of nicotinamide leads to a higher intracellular pyridine nucleotide concentration, which probably enables MDH to catalyze malate oxidation. Purified MDH from C. glutamicum catalyzes oxaloacetate reduction much more readily than malate oxidation at physiological pH. In a reconstituted system with isolated membranes and purified MDH, MQO and MDH catalyze the cyclic conversion of malate and oxaloacetate, leading to a net oxidation of NADH. Evidence is presented that this cyclic reaction also takes place in vivo. As yet, no phenotype of an mdh deletion alone was observed, which leaves a physiological function for MDH in C. glutamicum obscure.