gebhart/patrepeval huggingface dataset:
Altered Peptide Ligand–Induced Partial T Cell Activation: Molecular Mechanisms and Role in T Cell Biology (1996)

The elucidation of the phenomena of T cell antagonism and partial activation by altered peptide ligands has necessitated a revision in the traditional concepts of TCR recognition of antigen and subsequent signal transduction. Whereas previous models supported a single ligand specificity for any particular T cell, many studies using analogs of immunogenic peptides have now demonstrated a flexibility in this recognition. Moreover, interaction with such altered peptide ligands can result in dramatically different phenotypes of the T cells, ranging from inducing selective stimulatory functions to completely turning off their functional capacity. Investigations of the biochemical basis leading to these phenotypes have shown that altered peptide ligands can induce a qualitatively different pattern of signal transduction events than does any concentration of the native ligand. Such observations imply that several signaling modules are directly linked to the TCR/CD3 complex and that they can be dissociated from each other as a direct result of the nature of the ligand bound. Interestingly, many in vivo models of T cell activation are compatible with a selective signaling model, and several studies have shown that peptide analogs can play a role in various T cell biologic phenomena. These data strongly suggest that naturally occurring altered peptide ligands for any TCR exist in the repertoire of self-peptides or, in nature, derived from pathogens, and recent reports provide compelling evidence that this is indeed the case. The concept of altered peptide ligands, their effects on T cell signaling, the hypothesized mechanisms by which they exert their effects, and their possible roles in shaping the T cell immune response are the scope of this review.
Label‐Free Fluorescent Probing of G‐Quadruplex Formation and Real‐Time Monitoring of DNA Folding by a Quaternized Tetraphenylethene Salt with Aggregation‐Induced Emission Characteristics (2008)

Biosensing processes such as molecular beacons require non-trivial effort to covalently label or mark biomolecules. We report here a label-free DNA assay system with a simple dye with aggregation-induced emission (AIE) characteristics as the fluorescent bioprobe. 1,1,2,2-Tetrakis[4-(2-bromoethoxy)phenyl]ethene is nonemissive in solution but becomes highly emissive when aggregated. This AIE effect is caused by restriction of intramolecular rotation, as verified by a large increase in the emission intensity by increasing viscosity and decreasing temperature of the aqueous buffer solution of 1,1,2,2-tetrakis[4-(2-triethylammonioethoxy)phenyl]ethene tetrabromide (TTAPE). When TTAPE is bound to a guanine-rich DNA strand (G1) via electrostatic attraction, its intramolecular rotation is restricted and its emission is turned on. When a competitive cation is added to the G1 solution, TTAPE is detached and its emission is turned off. TTAPE works as a sensitive poststaining agent for poly(acrylamide) gel electrophoresis (PAGE) visualization of G1. The dye is highly affinitive to a secondary structure of G1 called the G-quadruplex. The bathochromic shift involved in the G1 folding process allows spectral discrimination of the G-quadruplex from other DNA structures. The strong affinity of TTAPE dye to the G-quadruplex structure is associated with a geometric fit aided by the electrostatic attraction. The distinct AIE feature of TTAPE enables real-time monitoring of folding process of G1 in the absence of any pre-attached fluorogenic labels on the DNA strand. TTAPE can be used as a K+ ion biosensor because of its specificity to K+-induced and -stabilized quadruplex structure.
Investigating the properties of interfacial layers in planar Schottky contacts on hydrogen-terminated diamond through direct current/small-signal characterization and radial line small-signal modelling (2015)

Large-area Schottky diodes on hydrogen-terminated diamond are investigated through DC and small-signal characterization and physics-based equivalent circuit modeling. Measured current- and capacitance-voltage characteristics suggest significant distributed resistance effects induced by the relatively low mobility of the 2D hole gas in the diamond sub-surface. A distributed equivalent circuit model of the device is proposed aimed at correlating the device physics with the observed electrical behavior. It is shown that a heterostructure-like model of H-diamond Schottky contacts, including a thin non-conductive interfacial layer that separates the 2D hole channel from the Schottky barrier, enables an accurate description of both the device DC and AC behaviour and the extraction of relevant quantitative information on the physical parameters of the interface, channel charge control, and carrier mobility.
Anesthesiology (1992)

1992 marks the 150th anniversary of an important contribution of American medicine to humankind: the discovery of anesthesia. On March 30,1842, Dr Crawford Long successfully administered ether anesthesia to his patient James Venable to remove a tumor of the neck. Progress continues to be made by anesthesiologists to provide for the well-being of the anesthesized patient in a safe, cost-effective fashion. Due to concerns for hemodynamic instability, neonates have received modest, if any, anesthesia for surgical procedures. Commonly, this results in "light anesthesia" with a muscle relaxant administered for immobilization. Anand and Hickey<sup>1</sup>in a randomized, prospective study addressed the question of whether deeper levels of anesthesia, by blunting the neonatal stress response to pain, improve clinical outcome. Using neonates undergoing cardiac operations, light anesthesia (halothane-morphine) was compared to "deep anesthesia" (the opioid sufentanil). The deeply anesthetized infants had a significantly lower mortality rate than the light anesthesia group
Coandă Effect Used to Improve the Efficiency of a Rotary Wing Aircraft (2010)

The Annals of ''Dunarea de Jos'' University of Galati Fascicle XIV MECHANICAL ENGINEERING
ISSN 1224 - 5615
Distortion of Allelic Expression of Apolipoprotein E in Alzheimer's Disease (1997)

The APOE epsilon4 allele is a strong genetic susceptibility factor for Alzheimer's disease. Interaction with other biological factors may modulate the effect of the apoE isoforms. However, previous work suggested that other genetic variability within the APOE locus, influencing the effect of the epsilon4 allele, may exist. Such variability could modify the expression of the APOE gene and, in particular, the level of expression of APOE alleles could be an important determinant of disease pathogenesis. To test this hypothesis we examined the levels of expression of APOE in heterozygotes with AD and in controls, using a new method of semi-quantitation. We report that relative epsilon4 mRNA expression is increased in AD compared with controls and suggest that genetic variability in the neural expression of APOE contributes to disease risk.
A novel in vitro assay for human angiogenesis. (1996)

Angiogenesis, the development of new blood vessels, is an important process in tissue development and wound healing but becomes pathologic when associated with solid tumor growth, proliferative retinopathies, and rheumatoid arthritis. To date, there has not been a physiologically relevant in vitro model for human angiogenesis that can be used to screen for enhancers and inhibitors of human angiogenesis and allow further investigation of this process. Initially, culture conditions were established for the induction of human angiogenesis in vitro using fragments of human placental blood vessel. Once the assay was validated, it was examined for its ability to detect known inhibitors and enhancers of angiogenesis. The role of endogenous acidic fibroblast growth factor (aFGF), basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) in the angiogenic response was also assessed by performing RT-PCR on both the parent vessel and microvessel outgrowths. In addition, neutralizing antibodies against the three growth factors were used to quantify the relative importance of each growth factor in the angiogenic response. A fragment of human placental blood vessel was embedded in a fibrin gel in microculture plates and was found to give rise to a complex network of microvessels during a period of 7 to 21 days in culture. The response did not require the addition of exogenous growth factors, and thus provides a convenient system for testing substances for their ability to stimulate or inhibit a human in vitro angiogenic response. The ability of the well known angiogenesis antagonist, hydrocortisone, in the presence and absence of heparin, and suramin to significantly inhibit the angiogenic response indicated that the model could be used as an efficient in vitro assay for screening inhibitors of human angiogenesis. The presence of mRNA for aFGF, bFGF, and three isoforms of VEGF, as well as their receptors, FGFR1, FGFR2, Flt-1, and KDR, in vessel outgrowths and the parent vessel, as identified by RT-PCR, strongly implicated aFGF, bFGF, and VEGF as having an important role in this neovascularization response. This was further confirmed by the ability of neutralizing antibodies to aFGF, bFGF, and VEGF to inhibit the angiogenic response to varying extent. Furthermore, the response could be enhanced by the addition of these growth factors in serum-starved cultures. Finally, a stimulatory effect was observed when matrigel was incorporated into the fibrin gel, which indicates that components of the extracellular matrix also play an important role in governing the strength of the angiogenic response. A physiologic angiogenic response relevant to wound healing can be generated by culturing fragments of human placental blood vessels in fibrin gels. The growth factors aFGF, bFGF, and VEGF were shown to play an important role in stimulating this spontaneous angiogenic response. This assay, which can be performed in microcultures, was also shown to be an excellent method for screening for potential inhibitors and enhancers of human angiogenesis.
Transient and Stable Expression of the Firefly Luciferase Gene in Plant Cells and Transgenic Plants (1986)

The luciferase gene from the firefly, Photinus pyralis, was used as a reporter of gene expression by light production in transfected plant cells and transgenic plants. A complementary DNA clone of the firefly luciferase gene under the control of a plant virus promoter (cauliflower mosaic virus 35S RNA promoter) was introduced into plant protoplast cells (Daucus carota) by electroporation and into plants (Nicotiana tabacum) by use of the Agrobacterium tumefaciens tumor-inducing plasmid. Extracts from electroporated cells (24 hours after the introduction of DNA) and from transgenic plants produce light when mixed with the substrates luciferin and adenosine triphosphate. Light produced by the action of luciferase was also detected in undisrupted leaves or cells in culture from transgenic plants incubated in luciferin and in whole transgenic plants "watered" with luciferin. Although light was detected in most organs in intact, transgenic plants (leaves, stems, and roots), the pattern of luminescence appeared to reflect both the organ-specific distribution of luciferase and the pathway for uptake of luciferin through the vasculature of the plant.
Nonlinear Robust Tracking Control of a QuadrotorUAVonSE(3) (2012)

Abstract This paper provides nonlinear tracking control systems for a quadrotor unmanned aerial vehicle ( UAV ) that are robust to bounded uncertainties. A mathematical model of a quadrotor UAV is defined on the special E uclidean group, and nonlinear output‐tracking controllers are developed to follow (i) an attitude command, and (ii) a position command for the vehicle center of mass. The controlled system has the desirable properties that the tracking errors are uniformly ultimately bounded, and the size of the ultimate bound can be reduced arbitrarily by control system parameters. Numerical examples illustrating complex maneuvers are provided.
Propagation of Femtosecond Surface Plasmon Polariton Pulses on the Surface of a Nanostructured Metallic Film: Space-Time Complex Amplitude Characterization (2005)

Ultrashort surface plasmon polariton (SPP) pulses, propagating on the surface of a nanostructured metallic film, are characterized in space and time using time-resolved spatial-heterodyne imaging. Optical pulses are coupled from free space into various surface modes using a 2D array of circular nanoholes, and spatial amplitude and phase characteristics of the scattered surface field are measured with femtosecond-scale time resolution. Demonstrated in-plane focusing of SPP pulse provides additional electromagnetic field localization with possible applications in SPP nanophotonics, nonlinear surface dynamics, biochemical sensing, and ultrafast surface studies.
Methods for Expansion of Human Embryonic Stem Cells (2005)

The manipulation of human embryonic stem cells (hESCs) requires refined skills. Here we introduce both mechanical and enzymatic transfer methods for hESCs depending on experimental purpose. We use the mechanical transfer method for maintenance of hESC lines. Although the method is laborious and time-consuming, the technique permits efficient transfer of undifferentiated hESCs and results in similar clump sizes. We implement the enzymatic transfer method when we need the bulk production of cells for various experiments. The enzyme-treated expansion rapidly produces greater amounts of hESCs within a limited time frame. However, the cell clumps vary in size, and there is a probability that both the differentiated and undifferentiated cells will be transferred. In cases in which there are differentiated colonies, the combination of two methods allows mass production of hESCs by excluding differentiated colonies from passage by manual selection before enzyme treatment.
Skeletal muscle features in myotonic dystrophy and sarcopenia: do similar nuclear mechanisms lead to skeletal muscle wasting? (2012)

In the cell nucleus, the gene primary transcripts undergo molecular processing to generate mature RNAs, which are finally exported to the cytoplasm. These mRNA maturation events are chronologically and spatially ordered, and mostly occur on distinct ribonucleoprotein (RNP)-containing structures. Defects in the mRNA maturation pathways have been demonstrated in myotonic dystrophy type 1 (DM1) and type 2 (DM2) whose characteristic multisystemic features are caused by the expansion of two distinct nucleotide sequences: (CTG)n in the DMPK gene on chromosome 19q13 in DM1, and (CCTG)n in the ZNF9 gene on chromosome 3q21 in DM2. By combining biomolecular and cytochemical techniques, it has been shown that the basic mechanisms of DMs reside in the accumulation of CUG- or CCUG-containing transcripts in intranuclear foci where several RNA-binding proteins necessary for the physiological processing of pre-mRNA are sequestered. Moreover, a nucleoplasmic accumulation of splicing and cleavage factors has been found in DMs. This suggests that the dystrophic phenotype could depend on a general alteration of the pre-mRNA post-transcriptional pathway. Interestingly, the accumulation of pre-mRNA processing factors in the myonuclei of DM1 and DM2 patients is reminiscent of the nuclear alterations typical of sarcopenia, i.e., the loss of muscle mass and function which physiologically occurs during ageing. Consistently, in an in vitro study, we observed that satellite-cell-derived DM2 myoblasts show cell senescence alterations and impairment of the pre-mRNA maturation pathways earlier than the myoblasts from healthy patient. These results suggest possible common cellular mechanisms responsible for skeletal muscle wasting in sarcopenia and in myotonic dystrophy.
Low programming voltages and long retention time in metal nanocrystal EEPROM devices (2002)

Conventional Si/Ge nanocrystal EEPROM devices have several advantages over conventional EEPROM with continuous floating gate. However, to maintain good retention characteristics the programming voltages (write and erase) cannot be scaled down easily. Interface and dopant fluctuations at the Si/Ge nanocrystal interface also cause device design difficulty. We demonstrate for the first time that metal nanocrystal EEPROMs can have much lower programming voltages by careful choice of the metal floating-gate workfunction. The interface fluctuations are at a minimum due to the metal density of states. The retention characteristic for metal nanocrystals is similar to that of Si nanocrystals in view of the Coulomb blockade. Process integration of the metal floating gate on thin tunneling oxide is greatly improved by the self-assembly step of nanocrystal formation. Energy minimization during self assembly will relax the interface stress and stabilize the metal structure to avoid penetration and contamination. Together with Schottky contact injection improvement, the introduction of metal nanocrystals can push deep submicron CMOS and EEPROM scaling for more technology generations.
Diffusion and transport coefficients in synthetic opals (2000)

Opals are structures composed of close-packed spheres in the size range of nano to micrometers. They are sintered to create small necks at the points of contact. We have solved the diffusion problem in such structures. The relation between the diffusion coefficient and the thermal and electrical conductivity is used to estimate the transport coefficients of opal structures as a function of the neck size and the mean free path of the carriers. The theory presented is also applicable to the diffusion problem in other periodic structures.
Electrodynamic tethers for reboost of the International Space Station and spacecraft propulsion (1996)

The International Space Station (ISS) will require periodic reboost due to atmospheric aerodynamic drag. This is nominally achieved through the use of thruster firings by the attached Progress M spacecraft. Many Progress flights to the ISS are required annually. Electrodynamic tethers provide an attractive alternative in that they can provide periodic reboost or continuous drag cancellation using no consumables, propellant, nor conventional propulsion elements. The system could also serve as an emergency backup reboost system used only in the event resupply and reboost are delayed for some reason. The system also has direct application to spacecraft and upper stage propulsion. Electrodynamic tethers have been demonstrated in space previously with the Plasma Motor Generator (PMG) experiment and the Tethered Satellite System (TSS-IR). The advanced electrodynamic tether proposed for this application has significant advantages over previous systems in that higher thrust is achievable with significantly shorter tethers and without the need for an active current collection device, hence making the
Computation of electromagnetic field inside a tissue at mobile communications frequencies (2003)

The increasing diffusion of mobile communications is stimulating the study of the interaction mechanisms between electromagnetic (EM) fields and biological systems at radio frequencies. This paper is devoted to the modeling of the interaction between EM fields and a tissue, represented with spherical cells. Different EM approaches have been used to analyze the problem and, in particular, the lumped-element finite-difference time-domain (FDTD) technique has been used to model the cell's membrane represented with the Hodgkin-Huxley (HH) model, and the Floquet theorem to study a tissue by analyzing only few cells. The EM problem has been solved by using the FDTD technique to be independent from the geometry. Computations have been performed at GSM900 and GSM1800 frequencies overcoming the problem relevant to the computation time by using the quasi-static FDTD technique. The results show the field distribution inside the tissue at GSM frequencies; the effect of the application of the HH model to the membrane is also shown.
Iterative quantization: A procrustean approach to learning binary codes (2011)

This paper addresses the problem of learning similarity-preserving binary codes for efficient retrieval in large-scale image collections. We propose a simple and efficient alternating minimization scheme for finding a rotation of zero-centered data so as to minimize the quantization error of mapping this data to the vertices of a zero-centered binary hypercube. This method, dubbed iterative quantization (ITQ), has connections to multi-class spectral clustering and to the orthogonal Procrustes problem, and it can be used both with unsupervised data embeddings such as PCA and supervised embeddings such as canonical correlation analysis (CCA). Our experiments show that the resulting binary coding schemes decisively outperform several other state-of-the-art methods.
Efeito da salinidade sobre o desequilíbrio nutricional em genótipos diploides de bananeira (2016)

Dez genotipos diploides de bananeira, provenientes de cultura de tecidos vegetais, foram cultivados em solucao nutritiva, acrescida ou nao de NaCl (0 e 100 mol.m-3). O experimento foi conduzido em casa de vegetacao em delineamento inteiramente casualizado com 3 repeticoes, em um arranjo fatorial 10 x 2. O objetivo do trabalho foi verificar o efeito da salinidade sobre o desequilibrio nutricional em genotipos diploides de bananeira. A adicao do NaCl a solucao nutritiva provocou na maioria dos genotipos estudados um incremento nos teores de Na+ e Cl- nos diferentes orgaos das plantas, acarretando reducao no teor de Ca+2, principalmente, nas raizes + rizoma e consequente alteracao na biomassa seca total (BST), area foliar (AF) e taxas de crescimento absoluto (TCA) e relativo (TCR). Por outro lado, ocorreu incremento no teor de Mg+2 apenas no pseudocaule e raizes + rizoma e no teor de K+ apenas neste ultimo orgao. Considerando-se os nutrientes minerais avaliados nao foi observada uma desordem nutricional em grande escala, exceto para o Ca+2 em que o seu teor foi reduzido a metade nas plantas submetidas a salinidade.
Evidence for the Involvement of CD44 in Endothelial Cell Injury and Induction of Vascular Leak Syndrome by IL-2 (1999)

At sites of chronic inflammation seen during infections, autoimmunity, graft-vs-host response, and cytokine therapy, endothelial cell injury is known to occur, the exact mechanism of which is unknown. In the current study we used IL-2-induced vascular leak syndrome (VLS) as a model to investigate whether cytotoxic lymphocytes use CD44 in mediating endothelial cell injury. Administration of IL-2 to wild-type mice triggered significant VLS in the lungs and liver. In contrast, in CD44 knockout (KO) mice, IL-2-induced VLS was markedly reduced in the lungs and liver. IL-2-treated wild-type and CD44 KO mice had similar levels of perivascular infiltration with lymphocytes in the lungs and liver. This suggested that the decrease in VLS seen in CD44 KO mice was not due to the inability of lymphocytes to migrate to these organs. Ultrastructural studies demonstrated extensive endothelial cell damage in the lungs and liver of IL-2-treated wild-type, but not CD44 KO, mice. Moreover, CD44-KO mice exhibited a marked decrease in IL-2-induced lymphokine-activated killer cell activity. The induction of VLS was dependent on the expression of CD44 on immune cells rather than endothelial cells because adoptive transfer of CD44+, but not CD44- spleen cells along with IL-2 into CD44 KO mice triggered VLS. The IL-2-induced VLS was blocked by administration of F(ab')2 of Abs against CD44. The current study demonstrates that CD44 plays a key role in endothelial cell injury. Blocking CD44 in vivo may offer a novel therapeutic approach to prevent endothelial cell injury by cytotoxic lymphocytes in a variety of clinical disease models.