gebhart/patrepeval huggingface dataset:
Main properties and current applications of some polysaccharides as biomaterials (2007)

Abstract This review concerns the applications of some polysaccharides in the domain of biomaterials and bioactive polymers. Natural polysaccharides from different sources have been studied for a long time, and their main properties are summarized in this paper; some of their derivatives obtained by chemical modification are also described. The main polysaccharides currently used in the biomedical and pharmaceutical domains are chitin and its derivative chitosan, hyaluronan and alginates. Alginates are well known for their property of forming a physical gel in the presence of divalent counterions (Ca, Ba, Sr) whereas carrageenans form a thermoreversible gel; these seaweed polysaccharides are mainly used to encapsulate different materials (cells, bacteria, fungi). Other promising systems are the electrostatic complexes formed when an anionic polysaccharide is mixed with a cationic polysaccharide (e.g. alginate/chitosan or hyaluronan/chitosan). An important development of the applications of polysaccharides can be predicted for the next few years in relation to their intrinsic properties such as biocompatibility and biodegradability in the human body for some of them; they are also renewable and have interesting physical properties (film‐forming, gelling and thickening properties). In addition, they are easily processed in different forms such as beads, films, capsules and fibres. Copyright © 2007 Society of Chemical Industry
InSb ∕ AlInSb quantum-well light-emitting diodes (2006)

We have investigated the room-temperature electroluminescent properties of InSb∕AlxIn1−xSb quantum-well light-emitting diodes. The maximum emission from diodes containing quantum wells occurred at significantly higher energies than the band gap of InSb. Close agreement between experimental and theoretical data confirms that recombination occurs within the quantum well.
Antigen-Dependent Intrathecal Antibody Synthesis in the Normal Rat Brain: Tissue Entry and Local Retention of Antigen-Specific B Cells (1998)

The intrathecal Ab response to Ag introduced into the normal brain has not been fully explored. Involvement of Ag-specific, peripheral B cells in an intrathecal response was studied using a normal rat model of Ag infusion through an indwelling cannula into defined brain sites, while maintaining a functionally intact blood-brain barrier. Specific Ab was detected in serum and cerebrospinal fluid. The intrathecal response is first detectable at day 14. Isoelectric focusing of cerebrospinal fluid reveals banding patterns consistent with local Ab production. To increase Ag-specific, circulating peripheral lymphocytes available for trafficking to Ag-stimulated brain and for enhancing intrathecal Ab synthesis, rats were preimmunized peripherally. Subsequently, Ag or saline (control) was infused through the cannula. Under this protocol, intrathecal synthesis is detectable earlier (day 5 postinfusion). Immunohistochemical studies at the infusion site assessed Ag-specific B cells, T cells, and activated APCs. Rats receiving peripheral preimmunization followed by Ag into caudate nucleus have far greater numbers of these cells, including plasma cells, within the infusion site compared with saline controls. Results confirm previous indirect evidence of intrathecal Ab synthesis in normal rat brain and provide the first direct evidence for B cell trafficking across normal brain barriers plus retention at the Ag deposition site. Our studies indicate that the normal brain microenvironment supports development of Ag-directed humoral immunity. We propose that immune privilege in normal brain is characterized by down-regulation of cell-mediated but not Ab immune responses within the central nervous system.
Effect of Alloying Additions on the Phase Equilibria and Oxidation in the Mo-Si-B System (2001)

The Mo-Si-B alloys containing the Mo metal phase in equilibrium with the Mo3Si and Mo5SiB2 intermetallic phases have potential as hot-section materials for jet engines. For high-pressure turbine blade application, the ternary Mo-Si-B compositions exhibit adequate oxidation resistance in the temperature range of 1000 to 1300 deg C, but below 1000 deg C, the oxidation resistance is not good. The present study was undertaken to explore the effect of a number of alloying additions to a ternary Mo-Si-B Base on improving the oxidation resistance. Microstructures and phase equilibria were determined at selected temperatures of quaternary and quinary alloys. The elements added were W, Nb, V, Cr, Re, Ge, Al, Hf and Ti + Cr. These alloys did not produce a better oxidation resistance-composition than the base ternary Mo-Si-B alloy.
Run-time evaluation of opportunities for object inlining in Java (2002)

Object-oriented languages, such as Java, encourage the use of many small objects linked together by field references, instead of a few monolithic structures. While this practice is beneficial from a program design perspective, it can slow down program execution by incurring many pointer indirections. One solution to this problem is object inlining: when the compiler can safely do so, it fuses small objects together, thus removing the reads/writes to the removed field, saving the memory needed to store the field and object header, and reducing the number of object allocations.The objective of this paper is to measure the potential for object inlining by studying the run-time behaviour of a comprehensive set of Java programs. We study the traces of program executions in order to determine which fields behave like inlinable fields. Since we are using dynamic information instead of a static analysis, our results give an upper bound on what could be achieved via a static compiler-based approach. Our experimental results measure the potential improvements attainable with object inlining, including reductions in the numbers of field reads and writes, and reduced memory usage.Our study shows that some Java programs can benefit significantly from object inlining, with close to a 10% speedup. Somewhat to our surprise, our study found one case, the <tt>db</tt> benchmark, where the most important inlinable field was the result of unusual program design, and fixing this small flaw led to both better performance and clearer program design. However, the opportunities for object inlining are highly dependent on the individual program being considered, and are in many cases very limited. Furthermore, fields that are inlinable also have properties that make them potential candidates for other optimizations such as removing redundant memory accesses. The memory savings possible through object inlining are moderate.
XRR and XPS studies of SiO2 thin films formed by r.f. magnetron sputtering (1999)

Grazing-incidence x-ray reflectivity has been exploited to study as-grown SiO2 thin films deposited on Si(100) substrates by radio-frequency (r.f.) magnetron sputtering under various substrate temperatures and gas flow conditions. Results indicate that an increase of substrate temperature from room temperature to 763 K only slightly decreases the surface roughness. Comparatively, the surface morphology is strongly controlled by the gas flow conditions during deposition. The surface roughness increases almost linearly from 0.51 to 2.38 nm as the argon gas flow is increased from 8 to 50 sccm. The chemical state and composition of the films were analysed by XPS. Copyright © 1999 John Wiley & Sons, Ltd.
Acoustic impedance measurement using sine sweep excitation and known volume velocity technique (1978)

The direct determination of acoustic impedance requires the measurements of both pressure and volume velocity, but the latter in general cannot be measured directly. Thus, other means must be adopted to bypass this measurement problem. This paper presents two methods which utilize excitation of a system with known volume velocity. This, along with measured pressure response, provides both magnitude and phase of impedance as continuous functions of frequency. The first method uses a convertible acoustic horn driver for excitation. Its volume velocity is determined by measuring calibrated pressure in a fixed cavity at the back of the driver. The second method uses for excitation an electrodynamic shaker driven piston which carriers an accelerometer. This signal is integrated to yield input acoustic velocity information. The two-channel analog signal processing setup includes the following instruments: sine sweep oscillator, tracking filters, log converters, phase meter, etc. In order to establish the validity of the proposed experimental techniques, several example cases have been evaluated. Excellent agreement between theory and measurements are obtained for driving point and transfer impedances over the plane wave frequency regime. The advantages of the methods proposed here over some other established techniques are as follows: (1) our methods are easier to use, (2) continuous impedance spectra are obtained quickly, (3) excellent dynamic range is achieved, and (4) complications of digital systems are not involved.
Transcriptional regulation of the tissue‐type plasminogen‐activator gene in human endothelial cells : identification of nuclear factors that recognise functional elements in the tissue‐type plasminogen‐activator gene promoter (1998)

The gene encoding human tissue-type plasminogen activator (t-PA) is regulated in a cell-type-specific manner. Previous studies in non-endothelial cells have indicated that basal and phorbol ester mediated induction is controlled by a cAMP response element (CRE) referred to as the tPACRE, and an activating protein 2 (AP-2)-like site. The classification of the AP-2-like site was assigned on the basis of its sequence homology, but has been shown in some cell systems to be recognised by promoter-specific transcription factor-1 (Sp-1). Here, we have investigated the transcriptional regulation of the t-PA gene in endothelial cells and addressed the functional roles of the tPACRE and the Sp-1/AP-2-like sites. 5'-RACE experiments indicate that the t-PA gene uses two transcription initiation sites in these cells with the downstream site being preferred. Functional analyses of the t-PA promoter using reporter-gene constructs transfected into C11STH endothelial cells demonstrate that the first 410 bp of the t-PA promoter confers an increase in reporter-gene activity on treatment with 4beta-phorbol 12-myristate 13-acetate (PMA). Mutagenesis of either the tPACRE or the Sp-1/AP-2 site weakens both basal and inducible expression, while disruption of both sites renders the promoter completely unresponsive. Using supershift assays, we identify the predominant tPACRE-binding proteins in nuclear extracts prepared from both C11STH cells and primary umbilical vein endothelial cells (HUVECs) as activating transcription factor 2, CREB (cAMP-responsive-element-binding protein), CREM (cAMP response element modulator) and c-jun. Treatment of cells with PMA results in a selective recruitment of jun-D to the tPACRE, while Sp-1 was identified as the major transcription factor that recognises the AP-2-like site. Based on this data and previous reports, we have reassigned this as a Sp-1-binding site. Finally, the identification of specific endothelial-derived t-PACRE-binding proteins suggests an integral role for these factors in the regulation of t-PA gene expression in human endothelial cells.
Stealth and secured optical coherent transmission using a gain switched frequency comb and multi-homodyne coherent detection (2021)

A novel all-optical stealth and secured transmission is proposed and demonstrated. Spectral replicas of the covert signal are carried by multiple tones of a gain switched optical frequency comb, optically coded with spectral phase mask, and concealed below EDFA's noise. The secured signal's spectrum is spread far beyond the bandwidth of a coherent receiver, thus forcing real time all-optical processing. An unauthorized user, who does not possess knowledge on the phase mask, can only obtain a noisy and distorted signal, that cannot be improved by post-processing. On the other hand, the authorized user decodes the signal using an inverse spectral phase mask and achieves a substantial optical processing gain via multi-homodyne coherent detection. A transmission of 20 Gbps under negative -7.5 dB OSNR is demonstrated here, yielding error-free detection by the eligible user.
Essential Role of Ferritin Pfr in <i>Helicobacter pylori</i> Iron Metabolism and Gastric Colonization (2002)

The reactivity of the essential element iron necessitates a concerted expression of ferritins, which mediate iron storage in a nonreactive state. Here we have further established the role of the Helicobacter pylori ferritin Pfr in iron metabolism and gastric colonization. Iron stored in Pfr enabled H. pylori to multiply under severe iron starvation and protected the bacteria from acid-amplified iron toxicity, as inactivation of the pfr gene restricted growth of H. pylori under these conditions. The lowered total iron content in the pfr mutant, which is probably caused by decreased iron uptake rates, was also reflected by an increased resistance to superoxide stress. Iron induction of Pfr synthesis was clearly diminished in an H. pylori feoB mutant, which lacked high-affinity ferrous iron transport, confirming that Pfr expression is mediated by changes in the cytoplasmic iron pool and not by extracellular iron. This is well in agreement with the recent discovery that iron induces Pfr synthesis by abolishing Fur-mediated repression of pfr transcription, which was further confirmed here by the observation that iron inhibited the in vitro binding of recombinant H. pylori Fur to the pfr promoter region. The functions of H. pylori Pfr in iron metabolism are essential for survival in the gastric mucosa, as the pfr mutant was unable to colonize in a Mongolian gerbil-based animal model. In summary, the pfr phenotypes observed give new insights into prokaryotic ferritin functions and indicate that iron storage and homeostasis are of extraordinary importance for H. pylori to survive in its hostile natural environment.
An evaluation of large arteries compliance in man (1979)

Cardiac output, blood pressure, and the characteristics of diastolic pressure decay were studied in 12 normal subjects and 23 sustained hypertensive patients of the same age. In normal subjects and in hypertensives, analysis of the diastolic decay showed that i) the form of the decay approximated a simple monoexponential curve during the last two-thirds of the diastolic segment, and ii) the time constant (t) of the curve was positively correlated with the total peripheral resistance (TPR), with an intercept of nearly zero. The validity of the relationship t = K x TPR was demonstrated both in groups of patients and also in individuals. Using a simple model for the vascular system, the K value was identified as the large arteries compliance and could thus be calculated in each individual. The values of arterial compliance was 1.26 +/- 0.04 ml.mmHg-1.m-2 in normal subjects and was significantly reduced in hypertensive patients (0.88 +/- 0.02 ml.mmHg=1.m-2,. P less than 0.001).
Isolates from normal human intestinal flora but not lactic acid bacteria exhibit 7α- and 7β-hydroxysteroid dehydrogenase activities (2004)

Ursodeoxycholic acid (UDCA)-producing bacteria are of clinical and industrial interest due to the multiple beneficial effects of this bile acid on human health. UDCA is the 7β-OH epimer of the primary (i.e. synthesized by the liver) bile acid chenodeoxycholic acid (CDCA). Epimerization proceeds in two subsequent and reversible steps, catalysed by a 7α- and a 7β-hydroxysteroid dehydrogenase (7α- and 7β-HSDH), with 7oxo-lithocholic acid (7oxo-LCA) as the intermediate product. The aim of this study was to test the 7α- and 7β-HSDH activities of anaerobic whole cell cultures of a number of lactic acid bacteria and human intestinal isolates, using CDCA, UDCA and 7oxo-LCA as the substrates. Among 140 strains tested, 21 exhibited at least one of both 7-HSDH activities. 7α-HSDH activity was detected in six strains, 7β-HSDH in nine strains, and both activities in six other strains. All active strains were isolated from normal human and infant faeces. They belonged to the genera Clostridium, Eubacterium and Ruminococcus, whereas no strain of Lactobacillus, Bifidobacterium or Streptococcus was found to be active under our study conditions. The present study therefore revealed, for the first time, a number of normal human intestinal isolates supporting the epimerization of CDCA to UDCA, and further extended our knowledge of those intestinal bacteria which are responsible for 7α- or 7β-HSDH activity. Key words: screening, bile acids, epimerization, intestinal microflora, lactic acid bacteria, probiotics.
Amphiphilic cationic peptides mediate cell adhesion to plastic surfaces (1985)

Four amphiphilic peptides, each with net charges of +2 or more at neutrality and molecular weights under 4 kilodaltons, were found to mediate the adhesion of normal rat kidney fibroblasts to polystyrene surfaces. Two of these peptides, a model for calcitonin (peptide 1, MCT) and melittin (peptide 2, MEL), form amphiphilic alpha-helical structures at aqueous/nonpolar interfaces. The other two, a luteinizing hormone-releasing hormone model (peptide 3, LHM) and a platelet factor model (peptide 4, MPF) form beta-strand structures in amphiphilic environments. Although it contains only 10 residues, LHM mediated adhesion to surfaces coated with solutions containing as little as 10 pmoles/ml of peptide. All four of these peptides were capable of forming monolayers at air-buffer interfaces with collapse pressures greater than 20 dynes/cm. None of these four peptides contains the tetrapeptide sequence Arg-Gly-Asp-Ser, which has been associated with fibronectin-mediated cell adhesion. Ten polypeptides that also lacked the sequence Arg-Gly-Asp-Ser but were nonamphiphilic and/or had net charges less than +2 at neutrality were all incapable of mediating cell adhesion (Pierschbacher and Ruoslahti, 1984). The morphologies of NRK cells spread on polystyrene coated with peptide LHM resemble the morphologies on fibronectin-coated surfaces, whereas cells spread on surfaces coated with MCT or MEL exhibit strikingly different morphologies. The adhesiveness of MCT, MEL, LHM, and MPF implies that many amphiphilic cationic peptides could prove useful as well defined adhesive substrata for cell culture and for studies of the mechanism of cell adhesion.
Evaluation of an Attenuated, Cold-Recombinant Influenza B Virus Vaccine (1982)

A live, attenuated influenza B virus vaccine was evaluated in a group of students. The virus, cold-recombinant (CR) 7, was produced by recombining the attenuated cold-adapted parent, B/Ann Arbor/1/66, with a wild strain, B/Hong Kong/8/73. In ferrets, the wild strain produced histopathologic lesions in the lungs, whereas the CR strain and the attenuated parent did not. A total of 306 individuals was inoculated intranasally with either the CR virus or a placebo. After inoculation, only one symptom was significantly more common in the vaccinees than in the control subjects. That symptom, sore throat, occurred briefly in 26% of the vaccine recipients and in 10.5% of the placebo recipients. An outbreak of influenza B occurred three months after vaccination. When serologic infection rates in the two groups were compared, it was found that the vaccine had been significantly effective (P less than 0.01) in preventing infection.
Effects of Early Cholesterol Intake on Cholesterol Biosynthesis and Plasma Lipids Among Infants Until 18 Months of Age (2005)

Although cholesterol intake before weaning affects FSRs and plasma lipid profiles at 4 months, these differences do not persist after weaning to an unrestricted diet at 18 months. This provides additional evidence that there is no imprinting of FSR in infancy with differing dietary levels of cholesterol.
Differential Restriction of Human Immunodeficiency Virus Type 2 and Simian Immunodeficiency Virus SIVmac by TRIM5α Alleles (2005)

Primate lentiviruses have narrow host ranges, due in part to their sensitivities to mammalian intracellular antiviral factors such as APOBEC3G and TRIM5alpha. Despite the protection provided by this innate immune system, retroviruses are able to transfer between species where they can cause disease. This is true for sooty mangabey simian immunodeficiency virus, which has transferred to humans as HIV-2 and to rhesus macaques as SIVmac, where it causes AIDS. Here we examine the sensitivities of the closely related HIV-2 and SIVmac to restriction by TRIM5alpha. We show that rhesus TRIM5alpha can restrict HIV-2 but not the closely related SIVmac. SIVmac has not completely escaped TRIM5alpha, as shown by its sensitivity to distantly related TRIM5alpha from the New World squirrel monkey. Squirrel monkey TRIM5alpha blocks SIVmac infection after DNA synthesis and is not saturable with restriction-sensitive virus-like particles. We map the determinant for TRIM5alpha sensitivity to the structure in the capsid protein that recruits CypA into HIV-1 virions. We also make an SIV, mutated at this site, which bypasses restriction in all cells tested.
CHARACTERIZATION OF HEAVY HYDROCARBON CUTS BY MASS SPECTROMETRY ROUTINE AND QUANTITATIVE MEASUREMENTS (1990)

ABSTRACT Routine mode and quantitative measurements of main hydrocarbon families in petroleum cuts have managed the settinq-up of our methodology, spread over the ten last years in our lab on a high resolution MS 50 Kratos spectrometer. The technique is devoted to petroleum cuts ranging from 250 to 650°C, without any previous separation, and provides thirty three data on the whole sample, in relation with the hydrocarbon families composition, balancing From “saturates” (paraffins, cyclanes, …) to “sulfur compounds” (benzo, dibenzo, naphtalenobenzothiophenes, etc.) and including “aroroatics” scattered From mono to hepta fused structures. Checkings of the method and examples are illustrated with the help of applications picked up on petroleum processing and hydra-carbon product research topics.
Activity testing of fine-particle size, iron catalysts for coal liquefaction (1993)

The use of fine-particle size (< 40 nm) unsupported catalysts in direct coal liquefaction may result in improved economics due to possible enhanced yields of desired products, the potential for decreasing reaction severity, and the possibility of using less catalyst. Sandia has developed a standard testing procedure for evaluating and comparing the fine-particle catalysts. The test procedure uses phenanthrene as the reaction solvent, the DECS-17 Blind Canyon Coal, and a statistical experimental design to enable evaluation of the catalysts over ranges of temperature (350 to 400{degrees}C), time (20 to 60 minutes), and catalyst loading (0 to 1 wt % on a dmmf coal basis). Product analyses include tetrahydrofuran (THF) conversion, heptane conversion, solvent recovery, and gas analyses. Phenanthrene as the solvent in the testing procedure yielded significant differences between thermal and catalytic reactions, whereas using a good hydrogen donor such as 9,10-dihydrophenanthrene (DHP) showed no catalytic effects.
Gene expression changes reflect clinical response in a placebo-controlled randomized trial of abatacept in patients with diffuse cutaneous systemic sclerosis (2015)

ClinicalTrials.gov NCT00442611. Registered 1 March 2007.