981 research outputs found

    Real-time data-driven and multi-scale model-guided system for bioproccess digital twin platform

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    Quantifying gas emissions from the "Millennium Eruption" of Paektu volcano, Democratic Peoples Republic of Korea/China

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    Paektu volcano (Changbaishan) is a rhyolitic caldera that straddles the border between the Democratic People’s Republic of Korea and China. Its most recent large eruption was the Millennium Eruption (ME; 23 km3^{3} dense rock equivalent) circa 946 CE, which resulted in the release of copious magmatic volatiles (H2_{2}O, CO2_{2}, sulfur, and halogens). Accurate quantification of volatile yield and composition is critical in assessing volcanogenic climate impacts but is challenging, particularly for events before the satellite era. We use a geochemical technique to quantify volatile composition and upper bounds to yields for the ME by examining trends in incompatible trace and volatile element concentrations in crystal-hosted melt inclusions. We estimate that the ME could have emitted as much as 45 Tg of S to the atmosphere. This is greater than the quantity of S released by the 1815 eruption of Tambora, which contributed to the “year without a summer.” Our maximum gas yield estimates place the ME among the strongest emitters of climate-forcing gases in the Common Era. However, ice cores from Greenland record only a relatively weak sulfate signal attributed to the ME. We suggest that other factors came into play in minimizing the glaciochemical signature. This paradoxical case in which high S emissions do not result in a strong glacial sulfate signal may present a way forward in building more https://symplectic.admin.cam.ac.uk/objectedit.html?cid=1&oid=876954generalized models for interpreting which volcanic eruptions have produced large climate impacts.K.I. was supported by the NSF under award no. 1349486 and by AAAS. Fieldwork was supported by the Richard Lounsbery Foundation

    Effects of Hormones on the Expression of Matrix Metalloproteinases and Their Inhibitors in Bovine Spermatozoa

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    Proteases and protease inhibitors play key roles in most physiological processes, including cell migration, cell signaling, and cell surface and tissue remodeling. Among these, the matrix metalloproteinase (MMPs) pathway is one of the most efficient biosynthetic pathways for controlling the activation of enzymes responsible for protein degradation. This also indicates the association of MMPs with the maturation of spermatozoa. In an attempt to investigate the effect of MMP activation and inhibitors in cultures with various hormones during sperm capacitation, we examined and monitored the localization and expression of MMPs (MMP-2 and MMP-9), tissue inhibitors of metalloproteinases (TIMP-2 and TIMP-3), as well as their expression profiles. Matured spermatozoa were collected from cultures with follicle-stimulating hormone (FSH), luteinizing hormone (LH), and Lutalyse at 1 h, 6 h, 18 h, and 24 h. ELISA detected the expression of MMP-2, MMP-9, TIMP-2, and TIMP-3 in all culture media, regardless of medium type (FSH-supplemented fertilization Brackett-Oliphant medium (FFBO), LH-supplemented FBO (LFBO), or Lutalyse-supplemented FBO (LuFBO)). TIMP-2 and TIMP-3 expression patterns decreased in LFBO and LuFBO. MMP-2 and MMP-9 activity in FBO and FFBO progressively increased from 1 h to 24 h but was not detected in LFBO and LuFBO. The localization and expression of TIMP-2 and TIMP-3 in sperm heads was also measured by immunofluorescence analysis. However, MMPs were not detected in the sperm heads. MMP and TIMP expression patterns differed according to the effect of various hormones. These findings suggest that MMPs have a role in sperm viability during capacitation. In conjunction with hormones, MMPs play a role in maintaining capacitation and fertilization by controlling extracellular matrix inhibitors of sperm

    Iron Plays a Certain Role in Patterned Hair Loss

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    Role of iron in hair loss is not clear yet. The purpose of this study was to evaluate the relationship between iron and hair loss. Retrospective chart review was conducted on patients with female pattern hair loss (FPHL) and male pattern hair loss (MPHL). All patients underwent screening including serum ferritin, iron, and total iron binding capacity (TIBC), CBC, ESR and thyroid function test. For normal healthy controls, age-sex matched subjects who had visited the hospital for a check-up with no serious disease were selected. A total 210 patients with FPHL (n = 113) and MPHL (n = 97) with 210 healthy controls were analyzed. Serum ferritin concentration (FC) was lower in patients with FPHL (49.27 +/- 55.8 mu g/L), compared with normal healthy women (77.89 +/- 48.32 mu g/L) (P < 0.001). Premenopausal FPHL patients turned out to show much lower serum ferritin than age/sex-matched controls (P < 0.001). Among MPHL patients, 22.7% of them showed serum FC lower than 70 mu g/L, while no one had serum FC lower 70 mu g/L in healthy age matched males. These results suggest that iron may play a certain role especially in premenopausal FPHL. The initial screening of iron status could be of help for hair loss patients.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/2008000790/14SEQ:14PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:2008000790ADJUST_YN:YEMP_ID:A079501DEPT_CD:801CITE_RATE:1.249FILENAME:iron and hair loss 이종희.pdfDEPT_NM:의학과SCOPUS_YN:YCONFIRM:

    In vivo metabolism of Talosin A, new isoflavonol glycoside from Kitasatospora kifunensis, in rats

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    The isoflavonol glycoside Talosin A, genistein (GT)-7-α-L-6-deoxy talopyranose (GT-Tal), was first isolated from the culture broth of Kitasatospora kifunensis MJM341. The aim of the present study was to evaluate the oral absorption and metabolism of the newly isolated isoflavonol glycoside, GT-Tal compared to genistin (GT-7-O-β-D-glucopyranoside; GT-Glu). Free GT-Glu and GT-Tal could not be detected prior to enzymatic hydrolysis of the corresponding conjugates in rat plasma. Following oral administration of GT-Tal (15 min), GT-Tal was rapidly absorbed through the gastrointestinal tract and metabolized into GT-Tal conjugates with a mean Cmax of 2.74 µg/mL. GT-Tal was further metabolized to its aglycone, free GT and conjugated GT. After oral administration, GT-Glu was absorbed after being convereted to its aglycone and then further metabolized into its conjugate metabolites (free GT with a mean Cmax of 0.24 mg/mL at 1.25 h; conjugated GT with a mean Cmax of 1.31 mg/mL at 2.00 h). Significant differences in absorption and metabolism of GT-Tal and GT-Glu were observed. GT-Tal was metabolized into its corresponding conjugates or underwent deglycosylation to form GT, whereas GT-Glu was metabolized into its aglycone, GT
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