897 research outputs found

    Production and processing of Cu-Cr-Nb alloys

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    A new Cu-based alloy possessing high strength, high conductivity, and good stability at elevated temperatures was recently produced. This paper details the melting of the master alloys, production of rapidly solidified ribbon, and processing of the ribbon to sheet by hot pressing and hot rolling

    Rubrobacter spartanus sp. nov., a moderately thermophilic oligotrophic bacterium isolated from volcanic soil

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    © 2017 IUMS. Bacterial strain HPK2-2T was isolated from soil adjacent to the caldera of Kilauea Volcano in Hawaii Volcanoes National Park. HPK2-2T is a chemoorganoheterotroph that shows optimal growth at 50 °C (range 45-55 °C) and pH 8.0 (range 5.0-10.0). Sequence analysis of the 16S subunit of the rRNA gene showed that HPK2-2T is most closely related to the type strain of Rubrobactertaiwanensis (ATCC BAA-406T), with which it shared 94.5% sequence identity. The major fatty acids detected in HPK2-2T were C18:0 14-methyl and C16:0 12-methyl; internally branched fatty acids such as these are characteristic of the genus Rubrobacter. The only respiratory quinone detected was MK-8, which is the major respiratory quinone for all members of the family Rubrobacteraceae examined thus far. We propose that HPK2-2T represents a novel species of the genus Rubrobacter, for which we propose the name Rubrobacterspartanus (type strain HPK2-2T; DSM 102139T; LMG 29988T)

    Apparent Size as the Determinant of Prey Selection by Bluegill Sunfish (Lepomis Macrochirus)

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    Copyright by the Ecological Society of America. This is the publisher's version, also available electronically from http://www.jstor.org/stable/1935055.Although it is known that visual predation by planktivorous fish tends to be size selective, the mechanism by which fish select their prey has not previously been described. Experiments in which bluegill sunfish (Lepomis macrochirus) were given a binary choice between prey of different sizes presented at different distances showed the fish selected the prey that appeared largest, either because of its actual size or its proximity to the fish. This paper incorporates this mechanism of prey selection by apparent size into a model of bluegill predation. According to the model, bluegill, in choosing the apparently largest prey under all conditions, alter their diet composition depending upon the abundance of prey. When prey are abundant, bluegill predominantly select prey of the largest size class available because these have the greatest probability of appearing largest; as large prey become scarce and smaller prey have a greater chance of appearing large, the fish tend to eat more prey from smaller size classes. When the model is tested against data from published fish-feeding experiments, the predicted size ratios of prey eaten correlate accurately with the observed ratios and numbers of prey eaten

    A Chemical Alarm Releaser in Honey Bee Stings ( Apis Mellifera

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    Differential mRNA expression in ectopic germinal centers of myasthenia gravis thymus

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    Myasthenia gravis (MG) is an autoimmune neuromuscular disorder resulting in weakness of voluntary muscles. It is caused by antibodies directed against proteins present at the post-synaptic surface of neuromuscular junction (NMJ). A characteristic pathology of patients with early onset MG is thymic hyperplasia with ectopic germinal centers (GC). However, mechanisms that trigger and maintain thymic hyperplasia are poorly characterized. In order to determine the central mechanisms involved in the pathology, thymus samples from MG patients were assessed by histology and grouped based on appearance of GC compared to samples without them. We assessed the differential mRNA expression profiles between the two groups by GeneChip® Human Transcriptome Array 2.0. Partek Genomic Suite 6.6 and Transcript Analysis Console 2.0 programs were used for further analysis. Forty eight annotated mRNA transcripts were identified that were differentially expressed between the two groups with greater than 1.5 fold difference in expression (ANOVA p\u3c0.05). We verified their expression by RT-PCR. We identified Regulator of G protein Signaling 13 or RGS13 that is known to be expressed in GC B-cells and regulate responsiveness to chemokine signaling. Upregulation of RGS13 was found to be associated with specimens having GC. We verified its expression in GC by immunohistochemistry. Gene ontology (GO) enrichment analysis and Ingenuity Pathway Analysis (IPA) core analysis of differentially expressed genes indicate involvement of immune response regulation and cell proliferation pathways, indicating their importance in GC formation and regulation

    Prevalence, significance and predictive value of antiphospholipid antibodies in Crohn's disease

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    AIM To assess the prevalence and stability of different antiphospholipid antibodies (APLAs) and their association with disease phenotype and progression in inflammatory bowel diseases (IBD) patients. METHODS About 458 consecutive patients [Crohn's disease (CD): 271 and ulcerative colitis (UC): 187] were enrolled into a follow-up cohort study in a tertiary IBD referral center in Hungary. Detailed clinical phenotypes were determined at enrollment by reviewing the patients' medical charts. Disease activity, medical treatment and data about evolvement of complications or surgical interventions were determined prospectively during the follow-up. Disease course (development f complicated disease phenotype and need for surgery), occurrence of thrombotic events, actual state of disease activity according to clinical, laboratory and endoscopic scores and accurate treatment regime were recorded during the follow-up, (median, 57.4 and 61.6 mo for CD and UC). Sera of IBD patients and 103 healthy controls (HC) were tested on individual anti-β2-Glycoprotein-I (anti-β2-GPI IgA/M/G), anti-cardiolipin (ACA IgA/M/G) and anti-phosphatidylserine/prothrombin (anti-PS/PT IgA/M/G) antibodies and also anti-Saccharomyces cerevisiae antibodies (ASCA IgA/G) by enzyme-linked immunosorbent assay (ELISA). In a subgroup of CD (n = 198) and UC patients (n = 103), obtaining consecutive samples over various arbitrary time-points during the disease course, we evaluated the intraindividual stability of the APLA status. Additionally, we provide an overview of studies, performed so far, in which significance of APLAs in IBD were assessed. RESULTS Patients with CD had significantly higher prevalence of both ACA (23.4%) and anti-PS/PT (20.4%) antibodies than UC (4.8%, P < 0.0001 and 10.2%, P = 0.004) and HC (2.9%, P < 0.0001 and 15.5%, P = NS). No difference was found for the prevalence of anti-β2-GPI between different groups (7.2%-9.7%). In CD, no association was found between APLA and ASCA status of the patients. Occurrence of anti-β2-GPI, ACA and anti-PS/PT was not different between the group of patients with active vs inactive disease state according to appropriate clinical, laboratory and endoscopic scores in CD as well as in UC patients. All subtypes of anti-β2-GPI and ACA IgM status were found to be very stable over time, in contrast ACA IgG and even more ACA IgA status showed significant intraindividual changes. Changes in antibody status were more remarkable in CD than UC (ACA IgA: 49.9% vs 23.3% and ACA IgG: 21.2% vs 5.8%). Interestingly, 59.1% and 30.1% of CD patients who received anti-TNF therapy showed significant negative to positive changes in ACA IgA and IgG antibody status respectively. APLA status was not associated with the clinical phenotype at diagnosis or during follow-up, medical therapy, or thrombotic events and it was not associated with the probability of developing complicated disease phenotype or surgery in a Kaplan-Meier analysis. CONCLUSION The present study demonstrated enhanced formation of APLAs in CD patients. However, presence of different APLAs were not associated with the clinical phenotype or disease course
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