437 research outputs found

    Program, Responsibilities, and Problems Concerning Water Resources in Ohio

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    Author Institution: Principal Geologist, Ohio Division of Wate

    Hydrogen penetration into titanium from environment in different states

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    In this paper, the accumulation of hydrogen in titanium from media of different aggregate states is considered, since the accumulation of hydrogen in structural and functional materials, which ultimately can lead to the destruction of structures, essentially depends on the environments in which these structures operate. Obtained: electrolytic and plasma saturation is characterized by hydrogen entrapment by low-temperature traps with weak binding energy (point defects and their complexes, vacancies and their complexes, etc. The method of Siwerst is characterized by capture of high-temperature traps (microcracks of microcracks, intergranular boundaries, etc.)

    Si-compatible candidates for high-K dielectrics with the Pbnm perovskite structure

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    We analyze both experimentally (where possible) and theoretically from first-principles the dielectric tensor components and crystal structure of five classes of Pbnm perovskites. All of these materials are believed to be stable on silicon and are therefore promising candidates for high-K dielectrics. We also analyze the structure of these materials with various simple models, decompose the lattice contribution to the dielectric tensor into force constant matrix eigenmode contributions, explore a peculiar correlation between structural and dielectric anisotropies in these compounds and give phonon frequencies and infrared activities of those modes that are infrared-active. We find that CaZrO_3, SrZrO_3, LaHoO_3, and LaYO_3 are among the most promising candidates for high-K dielectrics among the compounds we considered.Comment: 17 pages, 9 figures, 4 tables. Supplementary information: http://link.aps.org/supplemental/10.1103/PhysRevB.82.064101 or http://www.physics.rutgers.edu/~sinisa/highk/supp.pd

    CD74 deficiency ameliorates Pseudomonas aeruginosa-induced ocular infection

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    Eye trauma and contact lens wear are the main factors that predispose to the development of infectious keratitis. The existing therapies fail to control the inflammation-driven tissue damage that occurs during Pseudomonas aeruginosa infection. Antibiotic treatment reduces bacterial burdens, but better interventions are needed to alleviate tissue damage resulting from local inflammation. We have previously documented that inhibition of macrophage migration inhibitory factor (MIF) reduces the bacterial levels and the inflammatory damage during keratitis. Here, we report that mice deficient for CD74, the putative MIF receptor, developed milder Pseudomonas aeruginosa-induced disease, characterized by decreased proinflammatory mediators and reduced bacterial presence in the cornea. However, topical inhibition of MIF using antibodies applied to the cornea further promoted recovery from disease, suggesting that in addition to MIF-dependent signaling events, MIF-triggered CD74-independent signaling pathways regulate sensitization to P. aeruginosa-induced infection

    Identification of a penta- and hexapeptide of islet amyloid polypeptide (IAPP) with amyloidogenic and cytotoxic properties.

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    Pancreatic arnyloid is found in more than 95 % of type II diabetes patients. Pancreatic amyloid is formed by the aggregation of islet amyloid polypeptide (hIAPP or amylin), which is a 37-residue peptide. Because pancreatic amyloid is cytotoxic, it is believed that its formation is directly associated with the development of the disease. We recently showed that hIAPP amyloid formation follows the nucleation-dependent polymerization mechanism and proceeds via a conformational transition of soluble hIAPP into aggregated beta-sheets. Here, we report that the penta- and hexapeptide sequences, hIAPP(23-27) (FGAIL) and hIAPP(22-27) (NFGAIL) of hIAPP are sufficient for the formation of beta-sheet- containing amyloid fibrils. Although these two peptides differ by only one amino acid residue, they aggregate into completely different fibrillar assemblies. hIAPP(23-27) (FGAIL) fibrils self-assemble laterally into unusually broad ribbons, whereas hIAPP(22-27) (NFGAIL) fibrils coil around each other in a typical arnyloid fibril morphology. hIAPP(20-27) (SNNFGAIL) also aggregates into beta-sheet- containing fibrils, whereas no arnyloidogenicity is found for hIAPP(24-27) (GAIL), indicating that hIAPP(23-27) (FGAIL) is the shortest fibrillogenic sequence of hIAPP. Insoluble amyloid formation by the partial hIAPP sequences followed kinetics that were consistent with a nucleation-dependent polymerization mechanism. hIAPP(22-27) (NFGAIL), hIAPP(20-27) (SNNFGAIL), and also the known fibrillogenic sequence, hIAPP(20-29) (SNNFGAILSS) exhibited significantly lower kinetic and thermodynamic solubilities than the pentapeptide hIAPP(23-27) (FGAIL). Fibrils formed by all short peptide sequences and also by hIAPP(20-29) were cytotoxic towards the pancreatic cell line RIN5fm, whereas no cytotoxicity was observed for the soluble form of the peptides, a notion that is consistent with hIAPP cytotoxicity. Our results suggest that a penta- and hexapeptide sequence of an appropriate amino acid composition can be sufficient for beta-sheet and amyloid fibril formation and cytotoxicity and may assist in the rational design of inhibitors of pancreatic amyloid formation or other arnyloidosis-related diseases

    Технология подготовки попутного газа для газлифтной эксплуатации скважин на нефтяном месторождении Пильтун-Астохское (Сахалинская область)

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    Целью выпускной работы является анализ влияния технологических параметров установки подготовки на качество газа для последующего применения в газлифтной эксплуатации нефтяных скважин. В процессе исследования изучены виды газлифтной эксплуатации, технологии подготовки нефтяного газа: компримирование газа, адсорбция, адсорбция и низкотемпературная сепарация. Обоснован выбор технологии низкотемпературной сепарации, построена моделирующая схема установки подготовки газа в программной среде UniSim Design Suite R460. Установлено влияние давления и температуры в изкотемпературном сепараторе на точки росы по углеводородам и воде подготовленного газа, а также на массовый расход конденсата.The aim of this graduation work is to analyze the influence of the technological parameters of the treatment unit on the quality of gas for subsequent use in gas-lift operation of oil wells. During the study the types of gas lift operation, associated gas treatment technologies (gas compression, adsorption, adsorption and low-temperature separation) were studied. The choice of low-temperature separation technology is justified, a simulating scheme of a gas treatment unit in the UniSim Design Suite R460 software environment is built. The effect of pressure and temperature in the low-temperature separator on the mass flow of condensate and the dew points of the prepared gas (hydrocarbon and water dew point) is established

    Immunohistochemical detection of macrophage migration inhibitory factor in fetal and adult bovine epididymis: Release by the apocrine secretion mode?

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    Originally defined as a lymphokine inhibiting the random migration of macrophages, the macrophage migration inhibitory factor (MIF) is an important mediator of the host response to infection. Beyond its function as a classical cytokine, MIF is currently portrayed as a multifunctional protein with growth-regulating properties present in organ systems beyond immune cells. In previous studies, we detected substantial amounts of MIF in the rat epididymis and epididymal spermatozoa, where it appears to play a role during post-testicular sperm maturation and the acquisition of fertilization ability. To explore its presence in other species not yet examined in this respect, we extended the range of studies to the bull. Using a polyclonal antibody raised against MIF purified from bovine eye lenses, we detected MIF in the epithelium of the adult bovine epididymis with the basal cells representing a prominently stained cell type. A distinct accumulation of MIF at the apical cell pole of the epithelial cells and in membranous vesicles localized in the lumen of the epididynnal duct was obvious. In the fetal bovine epididymis, we also detected MIF in the epithelium, whereas MIF accumulation was evident at the apical cell surface and in apical protrusions. By immuno-electron microscopy of the adult bovine epididymis, we localized MIF in apical protrusions of the epithelial cells and in luminal membrane-bound vesicles that were found in close proximity to sperm cells. Although the precise origin of the MIF-containing vesicles remains to be delineated, our morphological observations support the hypothesis that they become detached from the apical surface of the epididymal epithelial cells. Additionally, an association of MIF with the outer dense fibers of luminal spermatozoa was demonstrated. Data obtained in this study suggest MIF release by an apocrine secretion mode in the bovine epididymis. Furthermore, MIF localized in the basal cells of the epithelium and in the connective tissue could be responsible for regulating the migration of macrophages in order to avoid contact of immune cells with spermatozoa that carry a wide range of potent antigens. Copyright (c) 2006 S. Karger AG, Basel
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