gebhart/patrepeval huggingface dataset:
Sample Disturbance in the Investigation of Clay Structure (1971)

Synopsis The preparation of clay samples to allow the detailed investigation of microstructure inevitably involves some degree of disturbance, introduced by the standard preparation techniques for the electron microscope, polarizing microscope and X-ray diffractometer. The present investigation assesses the influence of such processes as impregnation, grinding, etching, etc. and the results indicate that certain procedures require modification. A simple surface peeling technique is proposed as suitable for minimizing surface disturbance in scanning electron microscope studies. With the polarizing microscope the standard method of sample preparation does not introduce significant errors. In the case of X-ray diffraction studies, surface disturbance caused by grinding does not introduce significant errors in Carbowax impregnated samples, but invalidates the results for air dried samples. La préparation des échantillons d'argiles pour l'etude détaillée des microstructures met en jeu inévitablement un certain degré de perturbation introduite par les techniques standards de préparation des échantillons pour la microscopic électronique, la microscopie en lumière polarisée, et l'étude de la diffraction des rayons X. La présente étude évalue l'influence de procédés comme le broyage, l'imprégnation, l'attaque chimique etc., et les résultats indiquent que certaines méthodes devraient être modifiées. On propose une simple technique de décapage de surface comme étant appropriée pour minimiser la perturbation de surface lors des études au microscope électronique à balayage. Pour l'emploi du microscope polarisant, la méthode standard de préparation des échantillons n'introduit pas d'erreur significative. Dans le cas des études de diffraction des rayons X, la perturbation de surface crée par le broyage n'introduit pas d'erreurs signifrcatives dans le cas des échantillons imprégnés de Carbowax, mais rend non valables les résultats obtenus avec des échantillons séchés à l'air.
Nucleotide sequence homology between the heat-labile enterotoxin gene of Escherichia coli and Vibrio cholerae deoxyribonucleic acid (1980)

Isolated deoxyribonucleic acid fragments encoding the heat-labile enterotoxin of Escherichia coli were used to probe for homologous sequences in restricted whole-cell deoxyribonucleic acid from Vibrio cholerae. Significant sequence homology between the heat-labile enterotoxin gene and V. cholerae deoxyribonucleic acid was demonstrated, and apparent differences were observed in the organization of the cholera toxin gene among different strains of V. cholerae.
Co-engagement of CD3 with LFA-1 or ICAM-1 adhesion molecules enhances the frequency of activation of single murine CD4<sup>+</sup> and CD8<sup>+</sup> T cells and induces synthesis of IL-3 and IFN-γ but not IL-4 or IL-6 (1992)

Interaction between the cell adhesion molecules lymphocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) augments T cell activation by increasing the avidity of T cell/antigen-presenting cell (APC) binding. To examine whether LFA-1 and ICAM-1 can also contribute to T cell activation in the absence of APCs, single murine CD4+ and CD8+ T cells were cultured with IL-2 and immobilized antibodies to CD3, CD4 or CD8, and LFA-1 or ICAM-1. The combination of anti-CD3, anti-CD4/CD8, and IL-2 stimulated approximately 20% of CD4+ cells and 30% of CD8+ cells to proliferate. Inclusion of anti-ICAM-1 antibody increased these frequencies to 30 and 40% respectively. Maximum activation frequencies were obtained with the combination of anti-CD3, anti-CD4/CD8, and anti-LFA-1 which stimulated cell division by approximately 40% of single CD4+ cells and at least 60% of single CD8+ cells. Under these conditions, 30-40% of the resultant CD4+ clones and greater than 90% of CD8+ clones secreted IL-3 and IFN-gamma. In addition to responding at higher frequencies that CD4+ cells, CD8+ cells formed larger clones which produced 4-fold higher levels of both cytokines. Although the expression of IL-2, IL-3, IFN-gamma, granulocyte-macrophage colony stimulating factor and tumor necrosis factor alpha could be detected in CD4+ and CD8+ clones at the mRNA level following reverse transcription and polymerase chain reaction amplification, neither the secreted nor mRNA expression of IL-4 or IL-6 was detected in any of the tested clones. It is concluded that co-stimulation of T cells via LFA-1 or ICAM-1 can enhance T cell receptor-dependent activation in the absence of accessory cells and that this mode of stimulation leads to the expression of a restricted range of cytokine genes.
Modeling of Negative Capacitance in Ferroelectric Thin Films (2019)

The negative capacitance (NC) effect in ferroelectric thin films has attracted a great deal of attention from the material and semiconductor device communities because it could be a possible solution to the impending problems related to field-effect transistor power consumption and dynamic random-access memory charge loss. A short discussion on the fundamental premise of the NC effect is presented. A phase-field model based on the time-dependent Ginzburg-Landau (TDGL) formalism in conjunction with the Chensky-Tarasenko (C-T) formalism for multidomain configuration is then developed to reveal the subtle correlation between the domain wall motion and NC effect for different thicknesses of ferroelectric and dielectric films. When a ferroelectric film becomes thin enough, a stripe domain structure can be achieved through competition between the electrostatic energy and domain wall energy. This stripe domain structure is quite resilient to transition to a homogeneous polarization state, making it very useful for (quasi-)static NC operation. Finally, the physical implications of the numerical results are explored with analytical modeling. It is identified that the domain wall motion in the stripe domain structure remains dominated by the external field, even when the entire film is in the (quasi-)static NC state.
Linear- and nonlinear-optical properties of a new gadolinium calcium oxoborate crystal, Ca_4GdO(BO_3)_3 (1997)

Large and good-optical-quality crystals of gadolinium and calcium oxoborate, Ca4GdO(BO3)3 (GdCOB) have been grown from a melt by the Czochralski pulling method. The crystal is absolutely insensitive to moisture. Linear- and quadratic nonlinear-optical properties of this new monoclinic biaxial borate crystal are reported. The crystal is transparent in the visible and the near IR (from 0.32 to 2.7 µm), with favorable phase matching conditions for second-harmonic generation. Experimental phase-matching results, measured with a femtosecond broadband pulse parametric generator source tunable from 0.8 to 2.100 µm, are compared with theoretical predictions. The effective nonlinear coefficients are determined, leading to deff=1 pm/V for type I crystals in the ZX plane. The damage threshold is as high as 1 GW/cm2 at 0.532 µm. The second-harmonic generation conversion efficiency of a Q-switched Nd:YAG laser with a 15-mm long crystal is greater than 50%. These values together with the possibility of growing large crystals make GdCOB an excellent candidate for the next generation of crystals for frequency conversion and parametric processes.
Certifying the reliability of software (1986)

A description is given of a procedure for certifying the reliability of software before its release to users. The ingredients of this procedure are a life cycle of executable product increments, representative statistical testing, and a standard estimate of the MTTF (mean time to failure) of the product at the time of its release. The authors also discuss the development of certified software products and the derivation of a statistical model used for reliability projection. Available software test data are used to demonstrate the application of the model in certification process.
Particle Replication in Nonwetting Templates Nanoparticles with Tumor Selective Alkyl Silyl Ether Docetaxel Prodrug Reduces Toxicity (2014)

Delivery systems designed to have triggered release after passively targeting the tumor may improve small molecule chemotherapeutic delivery. Particle replication in nonwetting templates was used to prepare nanoparticles to passively target solid tumors in an A549 subcutaneous xenograft model. An acid labile prodrug was delivered to minimize systemic free docetaxel concentrations and improve tolerability without compromising efficacy.
Role of peptide structure in lipid-peptide interactions: a fluorescence study of the binding of pentagastrin-related pentapeptides to phospholipid vesicles (1984)

The binding of pentagastrin and three other structurally related pentapeptides to phospholipid vesicles has been studied by fluorescence spectroscopy. The fluorescence of the tryptophan residues of these peptides exhibits an increased quantum yield upon binding to phospholipid vesicles. This is accompanied by a blue shift of the maximum emission, indicative of the incorporation of the tryptophan residue into a more hydrophobic environment. The affinity of the peptides for a zwitterionic phospholipid, dimyristoylphosphatidylcholine (DMPC), increases in the following order: N-t-Boc-beta-Ala-Trp-Met-Gly-Phe-NH2 greater than N-t-Boc-beta-Ala-Trp-Met-Arg-Phe-NH2 greater than N-t-Boc-beta-Ala-Trp-Met-Asp-Phe-NH2 greater than N-t-Boc-beta-Ala-Trp-Met-Phe-Asp-NH2. Comparison of the interaction of these various peptides with this phospholipid indicates that although the interaction is largely of hydrophobic nature, the structure of the polar amino acids and their electrostatic charge have significant influence on the nature of the bindings. In addition, the sequence of polar and apolar amino acids appears to be of importance. The higher affinity for DMPC of N-t-Boc-beta-Ala-Trp-Met-Asp-Phe-NH2 as compared to its "reversed" analogue N-t-Boc-beta-Ala-Trp-Met-Phe-Asp-NH2 suggests that the ability of the peptides to fold into amphiphatic structures can enhance their lipid binding affinity. For all peptides the interaction with DMPC is greater at 8 degrees C, i.e., below the lipid phase transition temperature, than at 40 degrees C, i.e., above the lipid phase transition temperature.(ABSTRACT TRUNCATED AT 250 WORDS)
Protective effect of a purified flavonoid fraction against reactive oxygen radicals. In vivo and in vitro study. (1989)

S 5682 is a purified flavonoid fraction containing 90% diosmin (flavone derivative) and 10% hesperidin (flavanone derivative). In this study the scavenging properties of S 5682 on active oxygen radicals were demonstrated in vivo and in vitro. The activity of intravenous S 5682 was evaluated in the rat by measuring the degree of hyperglycemia provoked by an intravenous injection of alloxan, the metabolism of which produces active oxygen radicals which are toxic to B cells of the pancreas. S 5682 produced a decrease in the hyperglycemia in a dose-dependent manner (25 mg/kg and 50 mg/kg). The production in vitro of active oxygen radicals during phagocytosis by polymorphonuclear cells and macrophages is accompanied by emission of photons which can be amplified in the presence of luminol. Measurement of this chemiluminescence is a way of determining the quantity of active oxygen radicals generated in the medium, this may be reduced either by a decrease in production or by an increase in neutralisation through a reducing effect. Results demonstrated that S 5682 had a scavenging effect on active oxygen radicals for concentrations between 2 x 10(-8) mol/l and 2 x 10(-4) mol/l. The concentration of S 5682 reducing the chemiluminescence by 50% was 1.6 x 10(-5) mol/l. These scavenging properties imply that S 5682 has a pharmacological action on capillary hyperpermeability as well as an anti-inflammatory and anti-oedematous action.
Cultural Imperialism - Carl Schneider: Kulturgeschichte des Hellenismus. Band i. Pp. xxxi+977. Munich: Beck, 1967. Cloth, DM.65 (after publication of Band ii, DM.74). (1969)

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Plateletpheresis concentrates produced in 30 minutes along with plasma and packed red cells: Preliminary results (1988)

Centrifugal devices for donor plasmapheresis that collect platelets as a by-product have recently been introduced. The platelet yield ranges from 1.2 to 2 X 10(11) per collection, and the collection time exceeds 50 minutes. An attempt to increase yields and to reduce the procedure time was carried out at our center, taking advantage of the Dideco Eccentriplate (Dideco spa, Mirandola, Italy). Within 30 minutes, 510 ml of plasma were collected along with 3.3 X 10(11) platelets. The shift of donors from whole blood to plasma and platelet donation generated a progressive decrease in red-cell availability. In order to maintain plasma and platelet production without affecting the erythrocyte production, a technique was developed that allows the collection of 3.68 X 10(11) platelets, 250 ml of plasma, and 225 ml of packed red blood cells with a hematocrit of 66.5%. The mean procedure time was 31.6 minutes; 2,671 ml of blood were processed at flow rates of 85-100 ml/minute. The cellular cross contamination of the platelet concentrates was 1.76 X 10(8) (leukocytes) and 2.23 X 10(8) (erythrocytes). Although the procedure was carried out in a selected group of donors, the technical experience has strongly modified our procedure for platelet and plasma collection.
Transistor count-rate systems (1958)

Use of transistors in nuclear counting systems results in increased reliability, reduced space and power requirements, and lower initial cost. All-transistor systems have been built for use with boron trifluoride counters, Geiger counters, and scintillation probes.
Regulation of Tumor-Stromal Fibroblast Interactions: Implications in Anticancer Therapy (2008)

Recent advances in tumor biology have identified the stroma as an important regulator of carcinogenesis and potentially a valuable therapeutic target. While however the fact that by targeting the stromal component of a tumor represents a potential therapeutic strategy has been established, the knowledge for specific regulators for such interactions remains poor. The latter is largely due to the fact that appropriate methodological approaches that permit the screening for such regulators are lacking. In the present review we will summarize some of the literature underlining the central role of stromal factors, and essentially that of the fibroblasts in tumorigenesis. Furthermore, we will review the experimental evidence that suggest that by interfering with tumor-stroma interactions may represent a therapeutic approach. Finally, based on various experimental evidence and theoretical considerations we will suggest a biological experimental system which might facilitate the screening of such regulators.
Determination of Silencing Potency of Synthetic and Rnase III-Generated Sirna Using a Secreted Luciferase Assay (2007)

RNA interference (RNAi) is an established tool for functional genomics studies that is also showing great potential for medical applications. Currently, one of the main goals in RNAi technology is the design and discovery of potent small interfering RNAs (siRNAs). Using a secreted luciferase from Gaussia princeps (GLuc), we developed a reporter assay, which allows for rapid potency assessment of siRNAs, by measuring luminescence activity in cell culture supernatants. The method was applied in microtiter plate format and validated by comparison to quantitative reverse transcription PCR (RT-PCR) and Western blot analysis. This reporter assay was used to evaluate in HeLa cells the potency of different siRNA mixtures generated by RNase III, or several synthetic siRNAs, all directed against human p53. The results show that all four siRNA mixtures generated by RNase III induce 50%-75% decrease of the reporter activity at less than 10 nM transfected concentration. In contrast, only one out of the five commercially available synthetic siRNAs showed comparable potency. These results suggest that one advantage of using enzymatic complex siRNA mixtures for RNAi is that, unlike single synthetic siRNAs, selecting a target region is not important to ensure potency.
Performance issues with general packet radio service (2002)

The General Packet Radio Service (GPRS) is being deployed by GSM network operators world-wide, and promises to provide users with “always-on” data access at bandwidths comparable to that of conventional fixed-wire telephone modems. However, many users have found the reality to be rather different, experiencing very disappointing performance when, for example, browsing the web over GPRS. In this paper, we examine the causes, and show how unfortunate interactions between the GPRS link characteristics and TCP/IP protocols lead to poor performance. A performance characterization of the GPRS link-layer is presented, determined through extensive measurements taken over production networks. We present measurements of packet loss rates, bandwidth availability, link stability, and roundtrip time. The effect these characteristics have on TCP behavior are examined, demonstrating how they can result in poor link utilization, excessive packet queueing, and slow recovery from packet losses. Further, we show that the HTTP protocol can compound these issues, leading to dire WWW performance. We go on to show how the use of a transparent proxy interposed near the wired-wireless border can be used to alleviate many of these performance issues without requiring changes to either client or server end systems.
Advances in the Chemistry of Azaindoles (1980)

The results of research into the chemistry of azaindoles during the last ten years are examined and the advances in the development of new methods for the synthesis and the study of the chemical and physicochemical characteristics of the behaviour of azaindole systems containing condensed rings with an excess and a deficiency of π-electrons are discussed. The studies on the nature of the biological activity of various derivatives of isomeric azaindoles are summarised. The bibliography includes 267 references.
Using machine learning to predict learner emotional state from brainwaves (2007)

Intelligent Tutoring Systems (ITS) learner model has progressively evolved. Initially composed of a cognitive module it was extended with a psychological module and an emotional module. The learner model still remains non-exhaustive. Methods of data collection on the cognitive and emotional state of the learner often lack precision and objectivity. In this paper we introduce an emomental agent. It interacts with an ITS to communicate the emotional state of the learner based upon his mental state. The mental state is obtained from the learner's brainwaves. The agent learns to predict the learner's emotions by using machine learning techniques.
An Effective Bail-out Test for RANSAC Consensus Scoring (2005)

The random sample consensus (RANSAC) algorithm, along with its many cousins such as MSAC and MLESAC, has become a standard choice for robust estimation in many computer vision problems. Recently, a raft of modifications to the basic RANSAC algorithm have been proposed aimed at improving its efficiency. Many of these optimizations work by reducing the number of hypotheses that need to be evaluated. This paper proposes a complementary strategy that aims to reduce the average amount of time spent computing the consensus score for each hypothesis. A simple statistical test is proposed that permits the scoring process be terminated early, potentially yielding large computational savings. The proposed test is simple to implement, imposes negligible computational overhead, and is effective for any given size of data set. The approach is evaluated by estimation of the fundamental matrix for a large number of image pairs and is shown to offer a significant reduction in computational cost compared to recently proposed RANSAC modifications.
A highly efficient directional molecular white-light emitter driven by a continuous-wave laser diode (2016)

Tailored light sources have greatly advanced technological and scientific progress by optimizing the emission spectrum or color and the emission characteristics. We demonstrate an efficient spectrally broadband and highly directional warm-white-light emitter based on a nonlinear process driven by a cheap, low-power continuous-wave infrared laser diode. The nonlinear medium is a specially designed amorphous material composed of symmetry-free, diamondoid-like cluster molecules that are readily obtained from ubiquitous resources. The visible part of the spectrum resembles the color of a tungsten-halogen lamp at 2900 kelvin while retaining the superior beam divergence of the driving laser. This approach of functionalizing energy-efficient state-of-the-art semiconductor lasers enables a technology complementary to light-emitting diodes for replacing incandescent white-light emitters in high-brilliance applications.
Photochemical Elimination of Leaving Groups from Zwitterionic Intermediates Generated via Electrocyclic Ring Closure of α,β-Unsaturated Anilides (2008)

Methacrylanilides, ArN(CH3)COC(CH2LG)=CH2, with allylic leaving groups (LG(-) = BocAla, PhCO2(-), PhCH2CO2(-), PhO(-)) undergo photochemical electrocyclic ring closure to produce a zwitterionic intermediate. Further reaction of the intermediate results in expulsion of the leaving group to give an alpha-methylene lactam as the major product. In addition, a lactam product that retains the leaving group is formed via a 1,5-H shift in the intermediate. Elimination of the leaving group is generally preferred, even for LG(-) = PhO(-), although in benzene as the solvent the lactam retaining the phenolate group becomes the sole photoproduct. The electrocyclic ring closure occurs in the singlet excited-state for the para-COPh-substituted anilide derivative and is not quenched by 0.15 M piperylene or 0.01 M sodium 2-naphthalenesulfonate (2-NPS) as triplet quenchers. Comparable concentrations of 2-NPS strongly quench the transient absorption of the triplet excited state observed at 450-700 nm according to laser flash photolysis experiments. In aqueous media, quantum yields for total products are insensitive to leaving group ability, and Phi(tot)(para-CO2CH3) = 0.04-0.06 at 310 nm and Phi(tot)(para-COPh) = 0.08-0.1 at 365 nm, for which Phi(isc) = 0.15.
Effect of long-term diltiazem treatment on central haemodynamics and exercise endurance in essential hypertension (1990)

The effects of long-term treatment with diltiazem on blood pressure, central haemodynamics and exercise endurance were studied in 16 men (mean age 52 years) with essential hypertension. Intra-arterial pressure and heart rate (HR) were monitored continuously. Cardiac output (CO) was measured by Cardiogreen at rest (supine and sitting) and during 50 W, 100 W and 150 W bicycle exercise. Haemodynamic measurements were repeated after continuous bicycling at 150 W for 20 min or until exhaustion. After 1 year on diltiazem (mean daily dose 278 mg) intra-arterial pressure was reduced (P less than 0.001) in all situations (at rest sitting from 183/108 mmHg to 157/92 mmHg (14%] due to reduction in total peripheral resistance. HR was reduced at rest (7%) and during exercise (10%). Stroke volume tended to increase while CO was unchanged. Exercise time at constant workload increased by 25%. After a peak level, intra-arterial pressure fell by 3% to 5% (P less than 0.05) due to a decrease in total peripheral resistance both before and during diltiazem treatment. Stroke volume and CO remained unchanged during endurance exercise while HR showed a small increase. Thus, there was no reduction in the overall cardiac pump function after long-term diltiazem treatment, and blood flow during exercise was maintained.