gebhart/patrepeval huggingface dataset:
Tissue-Type Plasminogen Activator Domain-Deletion Mutant BM 06.022: Modular Stability, Inhibitor Binding, and Activation Cleavage (1994)

Recombinant BM 06.022 (M(r) 39,589) is a domain-deletion mutant of the human tissue-type plasminogen activator (tPA) structured by the kringle 2 and protease modules. Unfolding under various conditions was investigated via 1H-NMR spectroscopy by monitoring the well-resolved high-field methyl resonances at approximately -0.97 ppm (kringle 2) and approximately -0.29 and -0.54 ppm (protease). Reversible acid/base unfolding is manifest under low pH (< 4.8) conditions. It is observed that, relative to the protease, the kringle exhibits higher overall stability at low pH. At pH 4.6, BM 06.022 undergoes two distinct thermal melting transitions, at approximately 334 and approximately 352 K, assigned to an irreversible denaturation of the protease and a reversible unfolding of the kringle 2, respectively. Under the same conditions, the protease reacted with the active site inhibitor 1,5 dansyl-L-glutamylglycyl-L-arginine chloromethyl ketone (EGRck) exhibits a higher (approximately 10 K) thermal stability than the inhibitor-free protease. Upon acidification, the EGRck-modified protease unfolds irreversibly around pH 3.4. As exemplified by BM 06.022, a single-chain protein, as defined by continuity of the polypeptide backbone, can exhibit simultaneous folding reversibility and irreversibility for autonomous segments of the sequence. Conversion of the isolated (single-chain) protease or intact BM 06.022 to their catalytically active two-chain forms via plasminolytic cleavage of the Arg275-Ile276 peptide bond leaves the kringle 2 spectrum unaffected while perturbing the resolved high-field methyl resonances stemming from the protease. The latter also shift when the protease is reacted with EGRck, indicating that these signals are sensitive to events at the binding pocket.(ABSTRACT TRUNCATED AT 250 WORDS)
Superconducting implementation of neural networks using fluxon pulses (1993)

The authors fabricated neural-based superconducting integrated circuits by using Nb/AlO/sub x//Nb Josephson junctions, and demonstrated the operation of a 2-b neural-based A/D converter. Fluxon pulses were used as neural impulses, and a Josephson junction was used as a threshold element. The conductance values of resistors by which Josephson transmission lines are connected represent fixed synaptic strengths. The preliminary experimental result suggests that variable critical currents of DC-SQUIDs (superconducting quantum interference devices) may provide synapses with variable strength.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Activation of the alpha 4 beta 1 integrin through the beta 1 subunit induces recognition of the RGDS sequence in fibronectin. (1994)

Lymphocyte attachment to fibronectin is mainly mediated by the interaction of alpha 5 beta 1 and alpha 4 beta 1 integrins with the RGD and CS-1/Hep II sites, respectively. We have recently shown that the anti-beta 1 mAb TS2/16 can convert the partly active alpha 4 beta 1 present on certain hemopoietic cells that recognizes CS-1 but not Hep II, to a high avidity form that binds both ligands. In this report we have studied whether mAb TS2/16 also affects alpha 4 beta 1 ligand specificity. Incubation of the B cell lines Ramos and Daudi (which lack alpha 5 beta 1) with mAb TS2/16 induced specific attachment to an 80-kD fragment which lacks CS-1 and Hep II and contains the RGD sequence. mAbs anti-alpha 4 and the synthetic peptides CS-1 and IDAPS inhibited adhesion to the 80-kD fragment thus implying alpha 4 beta 1 as the receptor for this fragment. Interestingly, the synthetic peptide GRGDSPC and a 15-kD peptic fibronectin fragment containing the RGD sequence also inhibited B cell adhesion to the 80-kD fragment. Because we have previously shown that RGD peptides do not affect the constitutive function of alpha 4 beta 1, we tested whether TS2/16-activated alpha 4 beta 1 acquired the capacity to recognize RGD. Indeed RGD peptides inhibited TS2/16-treated B cell adhesion to a 38-kD fragment containing CS-1 and Hep II but did not affect binding of untreated cells to this fragment. An anti-fibronectin mAb reactive with an epitope on or near the RGD sequence also efficiently inhibited cell adhesion to the 80-kD fragment, indicating that the RGD sequence is a novel adhesive ligand for activated alpha 4 beta 1. These results emphasize the role of alpha 4 beta 1 as a receptor with different ligand specificities according to the activation state, a fact that may be important for lymphocyte migration, localization, and function.
Recent progress in nonpolar and semi-polar GaN light emitters on patterned Si substrates (2018)

Growth of nonpolar and semi-polar GaN and GaN-based structures offers the opportunity to reduce quantum confined Stark effect and possibly increase indium incorporation, as compared to polar structures, for enhanced performance in green and longer wavelength light emitters. However, the development of the nonpolar and semi-polar GaN growth is hampered by the lack of suitable substrates. Silicon, despite its large thermal-expansion and lattice mismatch with GaN, provides the advantages of the availability of large-size wafers with high crystalline quality at low cost, good electrical conductivity, and feasibility of its removal through chemical etching for better light extraction and heat transfer. In this article, we overview the recent progress in epitaxial growth of nonpolar and semi-polar GaN-based structures on patterned Si substrates. Also discussed are structural and optical properties of the resulting material.
Digital angiographic impulse response analysis of regional myocardial perfusion: linearity, reproducibility, accuracy, and comparison with conventional indicator dilution curve parameters in phantom and canine models. (1989)

The system mean transit time (Tsys) of the impulse response function describing contrast material transit through the coronary circulation was determined from serial digital angiographic images. The linearity, reproducibility, and relations with regional myocardial perfusion and conventional time-density curve parameters, time to peak concentration (TPC), and exponential washout rate (k) were assessed in a dynamic flow x-ray phantom (n = 46) and in six open-chest dogs (n = 102) while coronary flow was altered by stenosis and/or hyperemic stimuli. In the phantom studies, the inverse of the system mean transit time (Tsys-1) closely predicted flow/volume (r = 0.99, slope = 0.99). In dogs, Tsys-1 was independent of the shape of the contrast bolus injection (single or double-peaked), class of contrast agent (ionic or nonionic), the type of hyperemic stimulus (dipyridamole, dipyridamole plus norepinephrine, transient total occlusion, or ionic contrast media), and was highly reproducible between adjacent myocardial regions served by the same artery (r = 0.98 +/- 0.01). There was a strong correlation between Tsys-1 and regional coronary flow for stenotic and/or hyperemic vessels (r = 0.94, distribution volume = 14.9 ml/100 g) over a wide range (0-514 ml/min/100 g). Tsys-1 performed better than conventional time-density curve parameters TPC-1 and k for predicting phantom flow/volume ratios and regional myocardial blood flow in the dog. These data suggest that both digital coronary angiography and coronary contrast transit can be modeled as linear systems and that impulse response analysis may provide accurate and reproducible estimates of regional myocardial blood flow.
Experimental study of nuclear fragmentation of 200 and 400 MeV/<i>u</i><sup>12</sup>C ions in water for applications in particle therapy (2013)

Carbon ion beams in the energy range of about 100-450 MeV/u offer excellent conditions for tumour therapy, in particular for the treatment of deep-seated radio-resistant tumours. Their depth-dose distribution is characterized by a low dose in the entrance channel, small lateral beam spread and an elevated biological effectiveness in the Bragg peak region. In comparison to protons the radiation field of heavier ions stopping in tissue is however more complex due to nuclear fragmentation reactions occurring along their stopping path. This results in an attenuation of the primary beam flux and a build-up of lower-Z fragments with longer ranges causing the characteristic dose tail beyond the Bragg peak. In the present work the characteristics of secondary charged particles at various depths of water were investigated experimentally using (12)C ion beams of 200 and 400 MeV/u delivered by the heavy-ion synchrotron SIS-18 at GSI Darmstadt. The nuclear charge Zf of secondary fragments was identified by combining energy loss and time-of-flight (TOF) measurements. Energy spectra and yields were recorded at lab angles of 0° - 10° and at seven different water depths corresponding to the entrance channel, the Bragg peak region and the tail of the Bragg curve.
Muscle immobilization and remobilization downregulates PGC-1α signaling and the mitochondrial biogenesis pathway (2013)

Prolonged immobilization (IM) results in skeletal muscle atrophy accompanied by increased reactive oxygen species (ROS) generation, inflammation, and protein degradation. However, the biological consequence of remobilizing such muscle has been studied only sparsely. In this study, we examined the peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α)-controlled mitochondrial biogenesis pathway and inflammatory response in mice subjected to 2 wk of hindlimb IM followed by 5 days of remobilization (RM). We hypothesized that ROS generation and activation of redox-sensitive signaling pathways play important roles in the etiology of muscle injury. FVB/N mice (age 2 mo) were randomly assigned to either 14 days of IM by casting one of the hindlimbs (n = 7), IM followed by 5 days of RM with casting removed (n = 7), or to a control group (Con; n = 7). Muscle to body weight ratios of three major leg muscles were significantly decreased as a result of IM. Two ubiquitin-proteasome pathway enzymes, muscle atrophy F-box (MAFb or atrogin-1) and muscle ring finger-1 (MuRF-1), were upregulated with IM and maintained at high levels during RM. Protein contents of PGC-1α and nuclear respiratory factors 1 and 2 in tibialis anterior (TA) muscle were reduced by 50% (P < 0.01) in IM vs. Con, with no recovery observed during RM. IM suppressed mitochondrial transcription factor A and cytochrome-c content by 57% and 63% (P < 0.01), respectively, and cytochrome-c oxidase activity by 58% (P < 0.05). Furthermore, mitochondrial DNA content was reduced by 71% (P < 0.01) with IM. None of these changes were reversed after RM. With RM, TA muscle showed a 2.3-fold (P < 0.05) higher H2O2 content and a 4-fold (P < 0.01) higher 8-isoprostane content compared with Con, indicating oxidative stress. Tumor necrosis factor-α and interleukin-6 levels in TA muscle were 4- and 3-fold higher (P < 0.05), respectively, in IM and RM vs. CON. The nuclear factor-κB (NF-κB) pathway activation was observed only after RM, but not after IM alone. These data indicate an increase in ROS generation during the initial phase of muscle RM that could activate the NF-κB pathway, and elicit inflammation and oxidative stress. These events may hinder muscle recovery from IM-induced mitochondrial deterioration and protein loss.
Basestation modulation diversity for digital simulcast (2002)

A base station modulation diversity scheme is proposed for simulcast systems which use linear QAM (quadrature amplitude modulation) type modulation. With this method the bandwidth efficiency is fully preserved because each base station uses the same base pulse. Modulation diversity is achieved by filtering the input symbols with a symbol-spaced finite impulse response (FIR) filter prior to QAM modulation. The tap weights of the FIR filters at different base stations are different. They are chosen such that a necessary condition for optimum diversity gain in time-selective fading is satisfied. Examples for simulcast with two base stations are given. They demonstrate the impact of the choice of tap weights on the energy efficiency, the system complexity, and the performance in the presence of a propagation delay difference between the signals of different base stations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Comment on the preparation of the ionic liquid 1-ethyl-3-methylimidazolium ethanoate: a unique monomeric, homoleptic pentacoordinate lead ethanoate complex (2000)

Atomic absorption spectroscopy of the ionic liquid 1-ethyl-3-methylimidazolium ethanoate ([emim]2[O2CMe]), prepared according to International Patent WO 96/18459, showed it to contain large amounts of lead impurity: (ca. 0.5 M): [emim]2[Pb(O2CMe)4] was isolated and shown crystallographically to contain the first known example of a monomeric, homoleptic pentacoordinate lead(II) carboxylate complex, with a stereochemically active lone-pair.
Equibiaxial Extension of Two Polymer Melts: Polystyrene and Low Density Polyethylene (1985)

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 Paul R. Soskey, H. Henning Winter; Equibiaxial Extension of Two Polymer Melts: Polystyrene and Low Density Polyethylene. Journal of Rheology 1 October 1985; 29 (5): 493–517. https://doi.org/10.1122/1.549799 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 ContentThe Society of RheologyJournal of Rheology Search Advanced Search |Citation Search
Perfusion MRI of the human brain with dynamic susceptibility contrast: Gradient-echo versus spin-echo techniques (2000)

In this study, spin-echo and gradient-echo-based perfusion magnetic resonance imaging (MRI) techniques are systematically compared with respect to their application in the human brain. Six healthy subjects were evaluated with both techniques consecutively and injected twice with a gadolinium-based contrast agent. In accordance with theoretical predictions and with previous animal experiments, the spin-echo-based technique shows a markedly reduced appearance of large vessels. The intersubject standard deviations of the two methods are similar but smaller for the spin-echo technique in small regions adjacent to large vessels. Therefore, the sensitivity of the two acquisition methods for evaluating pathologic abnormalities may be similar despite the higher contrast-to-noise ratio of the gradient-echo-based technique. The gray-to-white matter ratio of the regional cerebral blood flow of the spin-echo method is closer to previous nuclear medicine measurements than that of the gradient-echo method. Our measurements indicate that spin-echo-based perfusion MRI is more representative of capillary perfusion than gradient-echo measurements. J. Magn. Reson. Imaging 2000;12:381-387.
A WIDEBAND QUADRATURE POWER DIVIDER/COMBINER AND ITS APPLICATION TO AN IMPROVED BALANCED AMPLIFIER (2013)

In this paper, a novel broadband quadrature power divider and its robust design method are presented. The QPD consists of a two-section power divider in combination with a 90-degree difierential phase shifter. The two-section power divider is calculated to provide equal power split, high output port isolation, and good return loss at all three ports. The difierential phase shifter consists of a composed right/left handed transmission line and pure-right handed transmission line named CRLHu-TL and PRHd-TL, respectively. The CRLHu-TL is divided into two parts; one of them consists of a pure-left handed section whose parasitic pad efiects are represented by means of a pure right handed section named PRHp. On the other hand, the PRHd- TL is composed by a microstrip transmission line of characteristic impedance 50› and electrical length 50 - and two sections equivalents to PRHp. The proposed circuit is applied to develop a broadband balanced amplifler with measured fractional bandwidth (FBW) of 124.4% at the center frequency of 2GHz.
Antigenic relationships of common rhinovirus types from disabling upper respiratory illnesses. (1975)

The frequency of the common cold has been though to be due to the existence of more than 89 different serologic types of rhinoviruses. However, in the civilian and military population studied in this area from 1962 through 1970, types 1A, 1B, 2, 23, 29, 30 and 31 accounted for 81 percent of 487 rhinoviruses isolated from individuals with respiratory illnesses. Antigenic relationships between these types and others have been demonstrated by neutralization in WI-38 cell cultures and by immunodiffusion. Types 1A and 1b, 2 and 49, 23 and 30, 29 and 44 and others are related. With specific animal antisera, heterotypic antibody titers are minimal. However, following natural infection in man with one of these related types, antibody responses to the other was almost equal to the homotype and could predictably provide cross-protection. Even with inactive T13 rhinovirus vaccine in man, protective levels of neutralizing antibody to T41 were produced. It is clear that the rates of rhinovirus colds would be greatly increased if more than 89 immunologic distinct types actually existed. An effective vaccine could be easily prepared by selection of a few appropriate types, such as 1A, 2, 23, 29 and 31.
Automatic Control of Hydroelectric Generating Stations (1947)

This paper discusses hydroelectric station equipment, operating procedures and the factors involved in applying automatic control. Hydraulic governors and the types of water wheels (impulse, reaction, fixed propeller, and adjustable propeller) are described from the electrical engineer's viewpoint. A typical automatic control diagram is shown for each of the two methods commonly employed for accelerating the generator and synchronizing it with the system. In one method, termed self-synchronizing, the machine circuit breaker is closed at less than synchronous speed, and the machine synchronizes after its field is applied. In the other method, automatic speed matching and synchronizing equipment bring the machine on the line at correct voltage and phase angle. Considerations involved in applying supervisory control to automatic hydroelectric stations are presented.
Reactor Design for Partial Upgrading of Bitumen via Aquaprocessing (2018)

Alberta oil industry is facing a major challenge because of the widening price differentials between West Texas Intermediate and Western Canadian Select. The Western Canadian Select is trading at low of US$ 16.71 /bbl. because of its high viscosity, density, total acid number, and sulfur content and lack of access to market outside North America. Under these circumstances, partial upgrading processes such as Aquaprocessing are envisioned as a potential solution. The synthetic crude oil produced from Aquaprocessing of bitumen requires 50 vol.% less diluents than the Athabasca bitumen to meet the pipeline specifications. This thesis is focused on evaluating the reactor design parameters required for scale-up of this technology. The kinetic parameters for hydrocracking reaction were calculated using first-order rate law expression for the packed bed reactor. Diffusivity of steam in bitumen, dimensionless numbers and hydrodynamic properties of the fluid inside the reactor were calculated using experimental and simulated data. The experimental results indicate that the effect of catalyst particle size depends on the catalyst preparation techniques. The steam diffusivity in bitumen was found to increase linearly with increase in reaction temperature. 0.05 psi/m pressure drop and 39 vol.% liquid holdups are predicted for the two-phase flow regime.
The rapid hydration of the acetyl radical. A pulse radiolysis study of acetaldehyde in aqueous solution. (1988)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe rapid hydration of the acetyl radical. A pulse radiolysis study of acetaldehyde in aqueous solution.Man Nien. Schuchmann and Clemens. Von SonntagCite this: J. Am. Chem. Soc. 1988, 110, 17, 5698–5701Publication Date (Print):August 1, 1988Publication History Published online1 May 2002Published inissue 1 August 1988https://pubs.acs.org/doi/10.1021/ja00225a019https://doi.org/10.1021/ja00225a019research-articleACS PublicationsRequest reuse permissionsArticle Views543Altmetric-Citations93LEARN 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 optionsGet e-Alertsclose Get e-Alerts
Electrical Stimulation of Cerebellar Fastigial Nucleus Reduces Ischemic Infarction Elicited by Middle Cerebral Artery Occlusion in Rat (1991)

Electrical stimulation of the cerebellar fastigial nucleus (FN) globally and profoundly increases cerebral blood flow via a cholinergic mechanism. In cerebral cortex, the vasodilation is unassociated with alterations in cerebral glucose utilization, a condition favoring protection against cerebral ischemia. We sought to determine whether FN stimulation would modify the size of the focal ischemic infarction resulting from occlusion of the middle cerebral artery (MCA). The MCA was occluded in anesthetized rats of the spontaneously hypertensive (SHR) or Sprague-Dawley (SD) strains with or without 1 h of electrical stimulation of the FN. Twenty-four hours later, rats were killed and the volume of the infarction established in thionin-stained sections. In SHRs, FN stimulation reduced by 40% the well-established cortical and partially subcortical infarctions elicited by occlusion of the MCA (from 186 ± 35.2 to 113 ± 47.1 mm 3 , mean ± SD, n = 15; p < 0.001). The zone of retrieval was anatomically constant, consisting of a rim of cortex dorsal and ventral to the infarction and medially within the thalamus and striatum corresponding to the penumbral zone described by others. The effect was comparable in rats of the SD strain having smaller infarctions. The effect of FN stimulation appears to be selective for the FN system in that it is not evoked by stimulation of the dentate nucleus and is blocked by systemic administration of atropine (1.0 mg/kg). We conclude that excitation of an intrinsic system in brain represented in the rostral FN has the capacity to reduce substantially an ischemic infarction. Whether the result is a consequence of an action of the FN upon cerebral blood flow and/or results from protective actions of released transmitter is yet unknown.