308 research outputs found

    Heterogeneity of LL 5-7 chondrites in relation to HAYABUSA samples.

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    第3回極域科学シンポジウム/第35回南極隕石シンポジウム 11月30日(金) 国立国語研究所 2階講

    Mineralogy, Three Dimensional Structure, and Oxygen Isotope Ratios of Four Crystalline Particles from Comet 81P/Wild 2

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    Preliminary examinations of small dust particles from comet 82P/Wild 2 revealed many expected and unexpected features. Among them the most striking feature is the presence of abundant crystalline material in the comet. Synchrotron radiation X-ray diffraction and microtomography are the most efficient methods to detect and describe bulk mineralogical features of crystalline cometary particles. In the present study, in addition to these two non-destructive techniques, electron microscopy and ion-probe mass spectrometry were carried out on the four crystalline particles

    “Dogged” Search of Fresh Nakhla Surfaces Reveals New Alteration Textures

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    Special Issue: 74th Annual Meeting of the Meteoritical Society, August 8-12, 2011, London, U.K.International audienceCarbonaceous chondrites are considered as amongst the most primitive Solar System samples available. One of their primitive characteristics is their enrichment in volatile elements.This includes hydrogen, which is present in hydrated and hydroxylated minerals. More precisely, the mineralogy is expected to be dominated by phyllosilicates in the case of CM chondrites, and by Montmorillonite type clays in the case of CI. Here, in order to characterize and quantify the abundance of lowtemperature minerals in carbonaceous chondrites, we performed thermogravimetric analysis of matrix fragments of Tagish Lake, Murchison and Orgueil

    Three Dimensional Structures of Particles Recovered from the Asteroid Itokawa by the Hayabusa Mission and a Role of X-Ray Microtomography in the Preliminary Examination

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    Particles of regolith on S-type Asteroid 25143 Itokawa were successfully recovered by the Hayabusa mission of JAXA (Japan Aerospace Exploration Agency). Near-infrared spectral study of Itokawa s surface indicates that these particles are materials similar to LL5 or LL6 chondrites. High-resolution images of Itokawa's surface suggest that they may be breccias and some impact products. At least more than 1500 particles were identified as Itokawa origin at curation facility of JAXA. Preliminary analysis with SEM/EDX at the curation facility shows that they are roughly similar to LL chondrites. Although most of them are less than 10 micron in size, some larger particles of about 100 micron or larger were also identified. A part of the sample (probably several tens particles) will be selected by Hayabusa sample curation team, and sequential examination will start from January 2011 by Hayabusa Asteroidal Sample Preliminary Examination Team (HASPET). In mainstream of the analytical flow, each particle will be examined by microtomography, XRD and XRF first as nondestructive analyses, and then the particle will be cut by an ultra-microtome and examined by TEM, SEM, EPMA, SIMS, PEEM/XANES, and TOF-SIMS sequentially. Three-dimensional structures of Itokawa particles will be obtained by microtomography sub-team of HASPET. The results together with XRD and XRF will be used for design of later destructive analyses, such as determination of cutting direction and depth, to obtain as much information as possible from small particles. Scientific results and a role of the microtomography in the preliminary examination will be presented

    Serum galectin-9 levels are elevated in the patients with type 2 diabetes and chronic kidney disease

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    Background: Galectin-9 (Gal-9) induces apoptosis in activated T helper 1 (T(H)1) cells as a ligand for T cell immunoglobulin mucin-3 (Tim-3). Gal-9 also inhibits the G1 phase cell cycle arrest and hypertrophy in db/db mice, the hallmark of early diabetic nephropathy, by reversing the high glucose-induced up-regulation of cyclin dependent kinase inhibitors such as p27(Kip1) and p21(Cip1). Methods: We investigated the serum levels of Gal-9 in the patients with type 2 diabetes and various stages of chronic kidney disease (CKD) (n = 182). Results: Serum Gal-9 levels in the patients with type 2 diabetes were 131.9 +/- 105.4 pg/ml and Log(10)Gal-9 levels significantly and positively correlated with age (r = 0.227, p = 0.002), creatinine (r = 0.175, p = 0.018), urea nitrogen (r = 0.162, p = 0.028) and osmotic pressure (r = 0.187, p = 0.014) and negatively correlated with estimated glomerular filtration rate (eGFR) (r = -0.188, p = 0.011). Log(10)Gal-9 levels increased along with the progression of GFR categories of G1 to G4, and they were statistically significant by Jonckheere-Terpstra test (p = 0.012). Log(10)Gal-9 levels remained similar levels in albuminuria stages of A1 to A3. Conclusion: The elevation of serum Gal-9 in the patients with type 2 diabetes is closely linked to GFR and they may be related to the alteration of the immune response and inflammation of the patients with type 2 diabetes and CKD

    MicroRNA-375 plays a dual role in prostate carcinogenesis

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    Background: Prostate cancer (PCa), a highly incident and heterogeneous malignancy, mostly affects men from developed countries. Increased knowledge of the biological mechanisms underlying PCa onset and progression are critical for improved clinical management. MicroRNAs (miRNAs) deregulation is common in human cancers, and understanding how it impacts in PCa is of major importance. MiRNAs are mostly downregulated in cancer, although some are overexpressed, playing a critical role in tumor initiation and progression. We aimed to identify miRNAs overexpressed in PCa and subsequently determine its impact in tumorigenesis. Results: MicroRNA expression profiling in primary PCa and morphological normal prostate (MNPT) tissues identified 17 miRNAs significantly overexpressed in PCa. Expression of three miRNAs, not previously associated with PCa, was subsequently assessed in large independent sets of primary tumors, in which miR-182 and miR-375 were validated, but not miR-32. Significantly higher expression levels of miR-375 were depicted in patients with higher Gleason score and more advanced pathological stage, aswellaswithregionallymph nodesmetastases. Forced expression of miR-375 in PC-3 cells, which display the lowest miR-375 levels among PCa cell lines, increased apoptosis and reduced invasion ability and cell viability. Intriguingly, in 22Rv1 cells, which displayed the highest miR-375 expression, knockdown experiments also attenuated the malignant phenotype. Gene ontology analysis implicated miR-375 in several key pathways deregulated in PCa, including cell cycle and cell differentiation. Moreover, CCND2 was identified as putative miR-375 target in PCa, confirmed by luciferase assay. Conclusions: A dual role for miR-375 in prostate cancer progression is suggested, highlighting the importance of cellular context on microRNA targeting.Research Center of Portuguese Oncology Institute - Porto (CI-IPOP 4–2012) and by the Federal funds through Programa Operacional Temático Factores de Competitividade (COMPETE) with co-participation from the European Community Fund (FEDER) and by the National funds through Fundação para a Ciência e Tecnología (FCT) under the projects EXPL/BIM-ONC/0556/2012. FQV and JRC were or are supported by FCT-Fundação para a Ciência e a Tecnologia grants (SFRH/BD/70564/2010 and SFRH/BD/71293/2010, respectively)

    S-allylmercaptocysteine reduces carbon tetrachloride-induced hepatic oxidative stress and necroinflammation via nuclear factor kappa B-dependent pathways in mice

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    Purpose To study the protective effects and underlying molecular mechanisms of SAMC on carbon tetrachloride (CCl4)-induced acute hepatotoxicity in the mouse model. Methods Mice were intraperitoneally injected with CCl4 (50 μl/kg; single dose) to induce acute hepatotoxicity with or without a 2-h pre-treatment of SAMC intraperitoneal injection (200 mg/kg; single dose). After 8 h, the blood serum and liver samples of mice were collected and subjected to measurements of histological and molecular parameters of hepatotoxicity. Results SAMC reduced CCl4-triggered cellular necrosis and inflammation in the liver under histological analysis. Since co-treatment of SAMC and CCl4 enhanced the expressions of antioxidant enzymes, reduced the nitric oxide (NO)-dependent oxidative stress, and inhibited lipid peroxidation induced by CCl4. SAMC played an essential antioxidative role during CCl4-induced hepatotoxicity. Administration of SAMC also ameliorated hepatic inflammation induced by CCl4 via inhibiting the activity of NF-κB subunits p50 and p65, thus reducing the expressions of pro-inflammatory cytokines, mediators, and chemokines, as well as promoting pro-regenerative factors at both transcriptional and translational levels. Conclusions Our results indicate that SAMC mitigates cellular damage, oxidative stress, and inflammation in CCl4-induced acute hepatotoxicity mouse model through regulation of NF-κB. Garlic or garlic derivatives may therefore be a potential food supplement in the prevention of liver damage
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