40 research outputs found

    Shock propagation through a bubbly liquid in a deformable tube

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    Shock propagation through a bubbly liquid contained in a deformable tube is considered. Quasi-one-dimensional mixture-averaged flow equations that include fluid–structure interaction are formulated. The steady shock relations are derived and the nonlinear effect due to the gas-phase compressibility is examined. Experiments are conducted in which a free-falling steel projectile impacts the top of an air/water mixture in a polycarbonate tube, and stress waves in the tube material and pressure on the tube wall are measured. The experimental data indicate that the linear theory is incapable of properly predicting the propagation speeds of finite-amplitude waves in a mixture-filled tube; the shock theory is found to more accurately estimate the measured wave speeds

    Lack of Association of Two Common Polymorphisms rs2910164 and rs11614913 with Susceptibility to Hepatocellular Carcinoma: A Meta-Analysis

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    BACKGROUND: Single nucleotide polymorphisms (SNPs) in microRNA-coding genes may participate in the process of carcinogenesis by altering the expression of tumor-related microRNAs. It has been suggested that two common SNPs rs2910164 in miR-146a and rs11614913 in miR-196a2 are associated with susceptibility to hepatocellular carcinoma (HCC). However, published results are inconsistent and inconclusive. In the present study, we performed a meta-analysis to systematically summarize the possible association between the two SNPs and the risk for HCC. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a search of case-control studies on the associations of SNPs rs2910164 and/or rs11614913 with susceptibility to HCC in PubMed, EMBASE, ISI Web of Science, Cochrane Central Register of Controlled Trials, ScienceDirect, Wiley Online Library and Chinese National Knowledge Infrastructure databases. Data from eligible studies were extracted for meta-analysis. HCC risk associated with the two polymorphisms was estimated by pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). 5 studies on rs2910164 and 4 studies on rs11614913 were included in our meta-analysis. Our results showed that neither allele frequency nor genotype distribution of the two polymorphisms was associated with risk for HCC in all genetic models. Similarly, subgroup analysis in Chinese population showed no association between the two SNPs and the susceptibility to HCC. CONCLUSIONS/SIGNIFICANCE: This meta-analysis suggests that two common SNPs rs2910164 and rs11614913 are not associated with the risk of HCC. Well-designed studies with larger sample size and more ethnic groups are required to further validate the results

    Annexin-A1 gene expression during liver development and post-translation modification after experimental endotoxemia

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    Objective and design: We have previously reported a role for annexin-A1 in liver proliferation and tumorogenicity as well as its action as an acute phase protein in a model of endotoxemia in interleukin-6 null mice.Material and methods: in this study, we have investigated the analysis of the gene and protein expression in annexin-A1 null mice and the wild type livers during foetal and adult life, and in the presence of a proinflammatory stimulus.Results: the data indicate a link between the expression of the annexin-A1 as serine-phosphorylated-protein during early events of the inflammatory response and as tyrosine-phosphorylated-form at later time-points, during the resolution of inflammation.Conclusions: the study of annexin-A1 post-translation modification may promote a new annexin-A1 peptide discovery programme to treat specific pathologies.Univ São Paulo, IBILCE, Dept Biol, BR-05508 São Paulo, BrazilUniv London St Bartholomews Hosp Med Coll, Coll Med, William Harvey Res Inst, Ctr Biochem Pharmacol, London EC1M 6BQ, EnglandUniv London Imperial Coll Sci Technol & Med, Div Neurosci & Mental Hlth, Dept Cellular & Mol Neurosci, London W12 ONN, EnglandUniversidade Federal de São Paulo, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, BR-04023900 São Paulo, BrazilWeb of Scienc

    Pulsed Laser Diode for Use as a Light Source for Short-Exposure, High-Frame-Rate Flow Visualization

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    A pulsed laser diode (PLD) is demonstrated as a practical light source for high-speed digital schlieren and shearing-interferometric cinematogrpahy. Frame rates of greater than 300k fps with exposure times on the order of 10 ns have been achieved with an inexpensive and user-friendly setup. The light source has primarily been used in our laboratory to study nonsteady phenomena in high-speed gas flows. Examples are presented to illustrate the usefulness of the PLD as a light source with characteristics of a narrow band of wavelength, short exposure time, high frame-rate, and long pulse train duration

    Pulsed Laser Diode for Use as a Light Source for Short-Exposure, High-Frame-Rate Flow Visualization

    No full text
    A pulsed laser diode (PLD) is demonstrated as a practical light source for high-speed digital schlieren and shearing-interferometric cinematogrpahy. Frame rates of greater than 300k fps with exposure times on the order of 10 ns have been achieved with an inexpensive and user-friendly setup. The light source has primarily been used in our laboratory to study nonsteady phenomena in high-speed gas flows. Examples are presented to illustrate the usefulness of the PLD as a light source with characteristics of a narrow band of wavelength, short exposure time, high frame-rate, and long pulse train duration

    Spatial and temporal profiles for anti-inflammatory gene expression in leukocytes during a resolving model of peritonitis

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    The recent appreciation of the role played by endogenous counterregulatory mechanisms in controlling the outcome of the host inflammatory response requires specific analysis of their spatial and temporal profiles. In this study, we have focused on the glucocorticoid-regulated anti-inflammatory mediator annexin 1. Induction of peritonitis in wild-type mice rapidly (4 h) produced the expected signs of inflammation, including marked activation of resident cells (e.g., mast cells), migration of blood-borne leukocytes, mirrored by blood neutrophilia. These changes subsided after 48-96 h. In annexin 1(null) mice, the peritonitis response was exaggerated (similar to 40% at 4 h), with increased granulocyte migration and cytokine production. In blood leukocytes, annexin I gene expression was activated at 4, but not 24, h postzymosan, whereas protein levels were increased at both time points. Locally, endothelial and mast cell annexin I gene expression was not detectable in basal conditions, whereas it was switched on during the inflammatory response. The significance of annexin 1 system plasticity in the anti-inflammatory properties of dexamethasone was assessed. Clear induction of annexin 1 gene in response to dexamethasone. treatment was evident in the circulating and migrated leukocytes, and in connective tissue mast cells; this was associated with the steroid failure to inhibit leukocyte trafficking, cytokine synthesis, and mast cell degranulation in the annexin 1(null) mouse. In conclusion, understanding how inflammation is brought under control will help clarify the complex interplay between pro- and anti-inflammatory pathways operating during the host response to injury and infection.Univ Fed Sao Paulo, Inst Biociencias Letras & Ciencias Exatas, Dept Biol, BR-15054000 Sao Paulo, BrazilBarts & London Queen Mary Sch Med & Dent, William Harvey Res Inst, Ctr Biochem Pathol, London EC1M 6BQ, EnglandUniv Fed Sao Paulo, Inst Biociencias Letras & Ciencias Exatas, Dept Biol, BR-15054000 Sao Paulo, BrazilWeb of Scienc
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