gebhart/patrepeval huggingface dataset:
Giant tunnel magnetoresistance in magnetic tunnel junctions with a crystalline MgO(0 0 1) barrier (2007)

A magnetic tunnel junction (MTJ), which consists of a thin insulating layer (a tunnel barrier) sandwiched between two ferromagnetic electrode layers, exhibits tunnel magnetoresistance (TMR) due to spin-dependent electron tunnelling. Since the 1995 discovery of room-temperature TMR, MTJs with an amorphous aluminium oxide (Al–O) tunnel barrier have been studied extensively. Al–O-based MTJs exhibit magnetoresistance (MR) ratios up to about 70% at room temperature (RT) and are currently used in magnetoresistive random access memory (MRAM) and the read heads of hard disk drives. MTJs with MR ratios significantly higher than 70% at RT, however, are needed for next-generation spintronic devices. In 2001 first-principle theories predicted that the MR ratios of epitaxial Fe/MgO/Fe MTJs with a crystalline MgO(0 0 1) barrier would be over 1000% because of the coherent tunnelling of fully spin-polarized Δ1 electrons. In 2004 MR ratios of about 200% were obtained in MTJs with a single-crystal MgO(0 0 1) barrier or a textured MgO(0 0 1) barrier. CoFeB/MgO/CoFeB MTJs for practical applications were also developed and found to have MR ratios up to 500% at RT. MgO-based MTJs are of great importance not only for device applications but also for clarifying the physics of spin-dependent tunnelling. In this article we introduce recent studies on physics and applications of the giant TMR in MgO-based MTJs.
Growth hormone regulates the balance between bone formation and bone marrow adiposity (2009)

Cancellous bone decreases and bone marrow fat content increases with age. Osteoblasts and adipocytes are derived from a common precursor, and growth hormone (GH), a key hormone in integration of energy metabolism, regulates the differentiation and function of both cell lineages. Since an age-related decline in GH is associated with bone loss, we investigated the relationship between GH and bone marrow adiposity in hypophysectomized (HYPOX) rats and in mice with defects in GH signaling. HYPOX dramatically reduced body weight gain, bone growth and mineralizing perimeter, serum insulin-like growth factor 1 (IGF-1) levels, and mRNA levels for IGF-1 in liver and bone. Despite reduced body mass and adipocyte precursor pool size, HYPOX resulted in a dramatic increase in bone lipid levels, as reflected by increased bone marrow adiposity and bone triglyceride and cholesterol content. GH replacement normalized bone marrow adiposity and precursor pool size, as well as mineralizing perimeter in HYPOX rats. In contrast, 17beta -estradiol, IGF-1, thyroxine, and cortisone were ineffective. Parathyroid hormone (PTH) reversed the inhibitory effects of HYPOX on mineralizing perimeter but had no effect on adiposity. Finally, bone marrow adiposity was increased in mice deficient in GH and IGF-1 but not in mice deficient in serum IGF-1. Taken together, our findings indicate that the reciprocal changes in bone and fat mass in GH signaling-deficient rodents are not directly coupled with one another. Rather, GH enhances adipocyte as well as osteoblast precursor pool size. However, GH increases osteoblast differentiation while suppressing bone marrow lipid accumulation.
Fluorescence resonance energy transfer imaging of cell signaling from in vitro to in vivo: Basis of biosensor construction, live imaging, and image processing (2013)

The progress in imaging technology with fluorescent proteins has uncovered a wide range of biological processes in developmental biology. In particular, genetically-encoded biosensors based on the principle of fluorescence resonance energy transfer (FRET) have been used to visualize spatial and temporal dynamics of intracellular signaling in living cells. However, development of sensitive FRET biosensors and their application to developmental biology remain challenging tasks, which has prevented their widespread use in developmental biology. In this review, we first overview general procedures and tips of imaging with FRET biosensors. We then describe recent advances in FRET imaging - namely, the use of optimized backbones for intramolecular FRET biosensors and transposon-mediated gene transfer to generate stable cell lines and transgenic mice expressing FRET biosensors. Finally, we discuss future perspectives of FRET imaging in developmental biology.
Chemical Synthesis of Peptides and Proteins (1970)

The Hippo pathway was initially discovered in Drosophila melanogaster as a key regulator of tissue growth. It is an evolutionarily conserved signaling cascade regulating numerous biological processes, including cell growth and fate decision, organ size ...Read More
Antimicrobial susceptibility of bifidobacteria (2000)

Eighteen Bifidobacterium strains were tested for their susceptibility to a range of antimicrobial agents. All the strains tested, including the reference culture Lactobacillus acidophilus CH2, were susceptible to several groups of antimicrobial agents, they were cephalosporin (cefamandole, cefazolin, cefaperazone, cefoxitin), polypeptide (bacitracin), macrolide (erythromycin), penicillin (amoxicillin), phenicol (chloramphenicol) and beta-lactam (imipenem). Fourteen strains were resistant to more than 10 antibiotics. The reference culture was resistant to only three antibiotics. The results showed that bifidobacteria are resistant to a wide range of antimicrobial agents.
Long tomato microsatellites are predominantly associated with centromeric regions (1999)

Microsatellites as genetic markers are used in many crop plants. Major criteria for their usability as molecular markers include that they are highly polymorphic and evenly spread throughout a genome. In tomato, it has been reported that long arrays of tetranucleotide microsatellites containing the motif GATA are highly clustered around the centromeres of all chromosomes. In this study, we have isolated tomato microsatellites containing long arrays (> 20 repeats) of the dinucleotide motifs GA, GT, AT, as well as GATA, assessed their variability within Lycopersicon esculentum varieties and mapped them onto a genetic map of tomato. The investigated microsatellite markers exhibited between 1 and 5 alleles in a diverse set of L. esculentum lines. Mapping of the microsatellites onto the genetic map of tomato demonstrates that, as previously shown, GATA microsatellites are highly clustered in the regions of the tomato centromeres. Interestingly, the same centromeric location was now found for long dinucleotide microsatellite markers. Because of this uneven distribution, genetic mapping of the entire tomato genome using long dinucleotide microsatellites will be very difficult to achieve and microsatellite markers with shorter arrays of microsatellites could be more suitable for mapping experiments albeit their lower level of polymorphism. Some microsatellite markers described in this study might provide a useful tool to study the molecular structure of tomato centromeric regions and for variety identification.
Randomised trial of endoscopy with testing for Helicobacter pylori compared with non-invasive H pylori testing alone in the management of dyspepsia (2002)

In this patient group, non-invasive testing for H pylori is as effective and safe as endoscopy and less uncomfortable and distressing for the patient. Non-invasive H pylori testing should be the preferred mode of investigation.
Cancer‐associated fibroblasts predict poor outcome and promote periostin‐dependent invasion in oesophageal adenocarcinoma (2014)

Interactions between cancer cells and cancer-associated fibroblasts (CAFs) play an important role in tumour development and progression. In this study we investigated the functional role of CAFs in oesophageal adenocarcinoma (EAC). We used immunochemistry to analyse a cohort of 183 EAC patients for CAF markers related to disease mortality. We characterized CAFs and normal oesophageal fibroblasts (NOFs) using western blotting, immunofluorescence and gel contraction. Transwell assays, 3D organotypic culture and xenograft models were used to examine the effects on EAC cell function and to dissect molecular mechanisms regulating invasion. Most EACs (93%) contained CAFs with a myofibroblastic (α-SMA-positive) phenotype, which correlated significantly with poor survival [p = 0.016; HR 7. 1 (1.7-29.4)]. Primary CAFs isolated from EACs have a contractile, myofibroblastic phenotype and promote EAC cell invasion in vitro (Transwell assays, p ≤ 0.05; organotypic culture, p < 0.001) and in vivo (p ≤ 0.05). In vitro, this pro-invasive effect is modulated through the matricellular protein periostin. Periostin is secreted by CAFs and acts as a ligand for EAC cell integrins αvβ3 and αvβ5, promoting activation of the PI3kinase-Akt pathway. In patient samples, periostin expression at the tumour cell-stromal interface correlates with poor overall and disease-free survival. Our study highlights the importance of the tumour stroma in EAC progression. Paracrine interaction between CAF-secreted periostin and EAC-expressed integrins results in PI3 kinase-Akt activation and increased tumour cell invasion. Most EACs contain a myofibroblastic CAF-rich stroma; this may explain the aggressive, highly infiltrative nature of the disease, and suggests that stromal targeting may produce therapeutic benefit in EAC patients.
Comparative Analysis Report: The Benefits of Using Intelligent Transportation Systems in Work Zones (2008)

This document provides quantitative benefits of using Intelligent Transportation Systems (ITS) in highway construction and maintenance work zones. The technical report covers case study sites in the District of Columbia, Texas, Michigan, Arkansas, and North Carolina. The document provides insights into the mobility and safety benefits of ITS for work zone traffic management.
HLA-DR Gene Expression in a Proliferating Human Thyroid Cell Clone (12S)* (1988)

We have used a retroviral vector carrying the adenovirus E1A oncogene and the neomycin phosphotransferase gene to establish a human thyroid-derived cell line that exhibits TSH-mediated cAMP generation as well as the differential expression of HLA class II antigens in response to recombinant gamma-interferon. Twenty-two-week gestation, histologically confirmed, human fetal thyroid was collagenase digested, cultured as a monolayer, and infected directly with 12S or 13S E1A-containing retrovirus constructs. Infected clones (n = 30) were selected in a hormone-supplemented medium containing bovine TSH (bTSH; 1 mU/ml), 10% fetal bovine serum, and 0.5 mg/ml G418 antibiotic. A rapidly growing clone (designated 12S) was chosen for detailed analysis over 18 months of continuous culture. The 12S clone was sensitive to less than 10 microU/ml bTSH when assessed by extracellular accumulation of cAMP, but TSH had no influence on 72-h incorporation of [3H]thymidine. Clone 12S responded to recombinant human gamma-interferon (1-10(4) U/ml) by induction of HLA DR alpha-chain-specific mRNA and the surface expression of HLA-DR antigen detected by fluorescein isothiocyanate-labeled monoclonal antibody to nonpolymorphic HLA-DR regions using flow cytometry. These studies indicate the potential for immortalizing human thyroid cells for use as targets of anti-TSH receptor immune responses and for long term studies of human throcyte HLA gene regulation.
Limitations and Possibilities for Improvement of Photovoltaic Solar Energy Converters: Part I: Considerations for Earth's Surface Operation (1960)

Seven factors limiting the performance of photovoltaic solar energy converters are listed and explained. They can be classified into basic and technology determined limitations. Possibilities for improvement on technology determined limitations are investigated for the silicon solar cell. Such possibilities are: heavier p-layer doping; change of geometry, possibly by application of grid structures; improvement of the material constants; and utilization of drift fields for improved collection. Discussed are materials other than silicon in regard to their potential for better performance than that obtainable from the silicon solar cell; and finally, new methods of approach, such as the multilayer and the multiple transition solar cell. Both of these methods yield theoretically large improvements, but realization depends on further advances in compound semiconductor technology and in knowledge about localized centers in the forbidden gap. Limit conversion efficiencies of 38.2 per cent for a 3-layer cell and of 51 per cent for a 3-transition cell, compared to 23.6 per cent for a single p-n junction, single transition cell, are obtained. Also discussed are the possible merits of the application of the graded energy gap to photovoltaic energy converters, and potential improvement in collection efficiency is found for certain cases.
Cholecystokinin and Gastrin Receptors (2006)

Cholecystokinin and gastrin receptors (CCK1R and CCK2R) are G protein-coupled receptors that have been the subject of intensive research in the last 10 years with corresponding advances in the understanding of their functioning and physiology. In this review, we first describe general properties of the receptors, such as the different signaling pathways used to exert short- and long-term effects and the structural data that explain their binding properties, activation, and regulation. We then focus on peripheral cholecystokinin receptors by describing their tissue distribution and physiological actions. Finally, pathophysiological peripheral actions of cholecystokinin receptors and their relevance in clinical disorders are reviewed.
Corynebacterium glutamicum DNA is subjected to methylation-restriction in Escherichia coli (1994)

Efficient electroporation of Escherichia coli with plasmid DNA isolated from Corynebacterium glutamicum depends on the use of Mcr-deficient E. coli strains. The transformation frequency increased nearly 800-fold when the Mcr-deficient E. coli DH5αMCR was used instead of E. coli DH5α. We used E. coli strains with different mutations in the methyl-specific restriction systems to show that McrBC-deficiency is sufficient to generate this effect. The results imply that C. glutamicum DNA contains methylcytosine in specific sequences recognized by the E. coli McrBC system.
Cyanide Formation by Chromobacterium violaceum (1965)

Michaels, Ruth (Columbia University, New York, N.Y.), and W. A. Corpe. Cyanide formation by Chromobacterium violaceum. J. Bacteriol. 89:106-112. 1965.-The formation of cyanide by a Chromobacterium violaceum strain was studied with growing cultures and with nonproliferating cells grown in complex and chemically defined media. Most of the cyanide was produced during the log-phase growth of the organism, and accumulated in the culture supernatant fluid. A synergistic effect of glycine and methionine on cyanide formation in a chemically defined medium was observed, and the amount of cyanide formed was found to be dependent on the concentrations of the two substances. Cyanide formation by nonproliferating cells was stimulated by preincubation with glycine and methionine. Cyanide formation by adapted cells in the presence of glycine and methionine was stimulated by succinate, malate, or fumarate, and depressed by azide and 2,4-dinitrophenol. Methionine could be replaced by betaine, dimethylglycine, and choline.
Conducting nanowires built by controlled self-assembly of amyloid fibers and selective metal deposition (2003)

Recent research in the field of nanometer-scale electronics has focused on the operating principles of small-scale devices and schemes to realize useful circuits. In contrast to established "top-down" fabrication techniques, molecular self-assembly is emerging as a "bottom-up" approach for fabricating nanostructured materials. Biological macromolecules, especially proteins, provide many valuable properties, but poor physical stability and poor electrical characteristics have prevented their direct use in electrical circuits. Here we describe the use of self-assembling amyloid protein fibers to construct nanowire elements. Self-assembly of a prion determinant from Saccharomyces cerevisiae, the N-terminal and middle region (NM) of Sup35p, produced 10-nm-wide protein fibers that were stable under a wide variety of harsh physical conditions. Their lengths could be roughly controlled by assembly conditions in the range of 60 nm to several hundred micrometers. A genetically modified NM variant that presents reactive, surface-accessible cysteine residues was used to covalently link NM fibers to colloidal gold particles. These fibers were placed across gold electrodes, and additional metal was deposited by highly specific chemical enhancement of the colloidal gold by reductive deposition of metallic silver and gold from salts. The resulting silver and gold wires were approximately 100 nm wide. These biotemplated metal wires demonstrated the conductive properties of a solid metal wire, such as low resistance and ohmic behavior. With such materials it should be possible to harness the extraordinary diversity and specificity of protein functions to nanoscale electrical circuitry.
Aporphines as antagonists of dopamine D-1 receptors (1990)

The aporphine alkaloids are a class of compounds known to possess activity at both D-1 and D-2 dopamine receptors. (R)-Apomorphine and (S)-bulbocapnine are examples of compounds which have agonist and antagonist activity, respectively, at D-1 receptors. A series of optically pure aporphines was synthesized and their activity at D-1 and D-2 dopamine receptors was studied. The (R)-aporphines uniformly had greater affinity for both D-1 and D-2 receptors than their S antipodes. Dihydroxy compound (R)-apomorphine, in accord with previous studies, was found to be a D-1 agonist. Aporphines possessing a single hydroxy group at C-11 are antagonists at the D-1 receptor. The corresponding methoxy compounds are virtually inactive at dopamine receptors. The most potent compounds, (R)-11-hydroxyaporphine (R-14) and (R)-10-bromo-11-hydroxyaporphine (R-26), are more potent than bulbocapnine as D-1 antagonists but are not as selective. A model for binding of aporphines to the D-1 receptor was formulated in which binding interactions between the receptor and the basic nitrogen and the C-11 hydroxy group of the aporphine are required for high-affinity binding to the receptor. The absolute configuration at C-6a determines the orientation of the N-6 lone pair and binding is optimal for the 6aR series. The agonist or antagonist activity of an aporphine is determined by the presence or absence, respectively, of a hydroxy group at C-10. A hydrophobic binding site may be present and may account for the high antagonist activity of (S)-bulbocapnine.
Content based image retrieval systems (1995)

Images are being generated at an ever-increasing rate by sources such as defence and civilian satellites, military reconnaissance and surveillance flights, fingerprinting and mug-shot-capturing devices, scientific experiments, biomedical imaging, and home entertainment systems. For example, NASA's Earth Observing System will generate about 1 terabyte of image data per day when fully operational. A content-based image retrieval (CBIR) system is required to effectively and efficiently use information from these image repositories. Such a system helps users (even those unfamiliar with the database) retrieve relevant images based on their contents. Application areas in which CBIR is a principal activity are numerous and diverse. With the recent interest in multimedia systems, CBIR has attracted the attention of researchers across several disciplines.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Temperature Effect of Electrical Resistivity of Carbon Black Filled Polymers (1981)

Abstract Very large positive temperature coefficients of resistivity (PTC) found in a narrow temperature range with dispersions of carbon blacks in noncrystallizing polymers are caused by an increase in average particle or aggregate distances of the dispersed black. This effect is the result of their deagglomeration upon temperature increase, induced by the increased Brownian motion, predominantly caused by the large reduction in vehicle viscosity and aided by the increase in segmental motion of the polymeric molecules. Highest PTC effects are found in the range of the steepest resistivity-concentration curves for the carbon black dispersion, differing markedly for each black and each polymer. The range itself is determined by particle size, density, degree of aggregation and agglomeration, and by the presence of surface oxides. In crystalline polymers high PTC effects are predominantly caused by the large volume expansion of the polymer in the melting range, as well as by the formation of a uniform melt from a two phase system of amorphous and crystalline components. Carbon black particles are mostly restricted to the amorphous phase in the solid, but are able to disperse into the entire volume of the melt. The effects of crosslinking the polymer as well as the influence of strain on PTC effects are considered. The decline in PTC effects above the peak temperature is discussed.
YB-1 as a Cell Cycle-regulated Transcription Factor Facilitating Cyclin A and Cyclin B1 Gene Expression (2003)

Expression of the Y-box protein YB-1 is increased in proliferating normal and cancer cells, but its role in cell proliferation and cell cycle progression is unclear. We have identified a cell cycle-dependent relocalization of YB-1 from the cytoplasm to the nucleus at the G1/S phase transition and demonstrate that both the charged zipper and the cold shock domain are involved in regulating this process. Using cell lines that constitutively overexpress YB-1, we show that nuclear accumulation of YB-1 is associated with increased cyclin A and cyclin B1 mRNA and protein expression. We provide evidence that deregulated YB-1 expression is linked to adhesion-independent cell proliferation through the induction of cyclin A. Thus, we have identified YB-1 as a cell cycle stage-specific transcription factor important for cell proliferation.
Cardiac effects induced by chemically activated neurons in canine intrathoracic ganglia (1990)

Regional or global cardiac responses were elicited when various chemicals were injected into discrete loci within acutely decentralized stellate and middle cervical ganglia. Nicotine (100 micrograms), acetylcholine (100 micrograms), or isoproterenol (1, 2, or 5 micrograms) in 1 microliters of normal saline was administered individually into 30 discrete loci within each stellate ganglion and 25 within each middle cervical ganglion. Cardiac augmentation was elicited when approximately 1 site per ganglion was injected with nicotine or acetylcholine. Similar injections into sites approximately 1-2 mm away from an active site usually failed to elicit cardiac responses. Isoproterenol elicited cardiac augmentations when injected into, on average, 3 different loci per ganglion. The responses elicited by isoproterenol injections were eliminated when the efferent sympathetic nerves arising from an injected ganglion were divided or when timolol maleate (0.1 mg/microliters normal saline) was previously injected into the same locus. These data indicate that the effects elicited by injecting isoproterenol into an intrathoracic ganglion locus were not due to leakage of this agent into the blood in sufficient quantities to directly activate cardiac myocytes. When L-glutamic acid (100 microliters of 1 M solution in normal saline) or L-aspartic acid (100 microliters of 1 M solution in normal saline) was injected into a stellate ganglion or middle cervical ganglion, positive chronotropic and/or inotropic responses were elicited. When DL-homocysteic acid (100 microliters of 1 M solution in normal saline) was administered no augmentation occurred. It is concluded that intrathoracic ganglion cardiac neurons can be activated by nicotinic or beta-adrenergic agonists, as well as by specific amino acids. These neurons are located throughout the stellate and middle cervical ganglia, cardiac neurons in one ganglionic locus being capable of activation by more than one of these chemicals.