162 research outputs found

    Experimental study of sulfur isotope exchange between S0(4)(2-) and H(2)S (aqueous) at 400℃ and 1000 bars water pressure

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    Experimental procedures used in this study are the same as those developed by Sakai and Dickson (1978). 0.005 M Na(2)S(2)O(3) solutions were heated to 400℃ under 1000 bar water pressure in a gold bag of Dickson gold-bag equipment (Fig. 1). At an elevated temperature Na(2)S(2)O(3) quickly and completely decomposed into 1:1 mixture of SO(4)(2-) and H(2)S (eq. (1)) and subsequent isotope exchange (eq. (2)) was monitored by consecutively withdrawing aliquots of solution for chemical and isotopic analyses at desired time intervals. For the preparation of SO(2) for isotope analyses, 2 to 5 mg BaSO(4) was thoroughly mixed with silica glass powder of 10 times the BaSO(4) in weight and heated to 1400℃ or so in sealed, evacuated silica glass tubings (see Fig. 2 and equation (4)). The technique is a modification of Holt and Engelkemeir (1971). The (18)O/(16)O ratios of SO(2) thus formed stayed constant by exchange with silica glass powder (Fig. 3). Numerical data of the three runs performed in this study are summarized in Tables 1 to 3. In runs 2 and 3, a small aliquot of (34)S- enriched H(2)SO(4) was added into the starting solution and thus equilibrium was approached from above the quilibrium value (see Fig. 4). When isotope exchange occurs between two molecules, X and Y, the reaction rate, r, is related to the extent of exchange, F, at given time, t, by equation (17), where X and Y indicate concentrations of given species, α(e), α(o) and α denote the fractionation factor at equilibrium, at time t=0 and at an arbitrary time t, and F = (α - α(o))/(α(e) - α(0)) or the extent of isotope exchange. Assuming the exchange rate is of the first order with respect to both X and Y and to the β'th power of hydrogen ion activity, a(H)(+), eq. (17) reduces to eq. (19), where k(1) denotes the rate constant. If X, Y and pH of solution stayed constant during the run, the half-time, t(1/2), of the exchange reaction can be obtained graphically as shown in Fig. 5. The t(1/2) for runs 1, 2, and 3 are determined to be 5.8, 5.5 and 6.1 hrs, respectively. Introducing F=0.5 and t=t(1/2) into eq. (19), we obtain eq. (20) which is graphically shown in Fig. 6 using the data by the present work and those by Sakai and Dickson(1978). The numerical values of log k(1) + 0.16 may be obtained by extrapolating the lines to pH=0 and, from these values, the rate constant, k(1) , may be calculated for temperatures of 300° and 400℃. From these two values of k(1) and from the Arrhenius plot, the activation energy of the exchange reaction was calculated to be 22 kcal/mole, a much smaller value than 55 kcal/mole obtained by Igumnov (1977). The value of β is found to be 0.29 at 300℃ and 0.075 at 400℃, although the physico-chemical nature of β is not clear to the present authors. Using these values, eq. (24), where C is a constant, is derived which would enable us to calculate the t(1/2) of any system of known ΣS and pH. However, as we do not know yet how β varies with different systems, eq. (24) is applicable only to limited systems in which temperature, total sulfur contents and pH are similar to those of the present study. Fig. 7 illustrates how t(1/2) varies with pH and total sulfur content at 300° and 400℃ and predicts t(1/2) for some solutions obtainable by hydrothermal reactions of seawater with various igneous rocks. The average equilibrium fractionation factor at 400℃ obtained by this study is 1.0153, in good accord with 1.0151 given by Igumnov et al. (1977). Theoretical fractionation factors between SO(4)(2-) and H(2)S have been calculated by Sakai (1968) , who gives too high values compared to the experimental data obtained by this and other researchers (Fig. 9). In the present study, the reduced partition function ratio (R.P.F.R.) of SO(4)(2-) was recalculated using two sets of the vibrational frequencies of SO(4)(2-) (shown in Table 5) and the valence force fields of Heath and Linnett (1947), which reproduces the observed frequencies of SO(4)(2-) better than Urey-Bradley force field used by Sakai (1968). The results of new calculation are shown in Table 6. This table also includes the R.P.F.R. of H(2)S which was calculated by Thode et al. (1971). Using these new R.P.F.R. of SO(4)(2-) and H(2)S, the fractionation factors between SO(4)(2-) and H(2)S were calculated and are listed in the last column of Table 6 and plotted in Fig. 9. Fig. 9 indicates that the new calculation gives values more shifted from the experimental values than before. The major sulfate ions in our solution at 300° and 400℃ exist as NaSO(4)(-) (Sakai and Dickson, 1978; see also Table 4 of this paper) and, therefore, the measured fractionation factors are those between NaSO(4)(-) and H(2)S. The discrepancy between the theory and experiments may, at least, be partially explained by this fact, although other more important reasons, which are not known to us at the moment, may also exist

    family members and health-related behaviors

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    The aim of this study was to clarify the associations of family members living together with health-related behaviors in Japanese young workers. The participants were 300 men and women aged 20-39 years in 2015 who had a job. A web-based self-administered questionnaire on status of partnering and parenting, number of family members living together, dietary habits, drinking habit, smoking habit, self-rated health, employment status, working time and commuting time was conducted through Internet. Multiple logistic regression analysis and general linear models were used to assess the association of family members living together with health-related behaviors. The multivariate-adjusted odds ratio (95% confidence interval, p-value) for current drinking in unmarried participants living with their parents compared to unmarried participants living alone was 0.35 (0.13-0.93, p=0.036). The adjusted means of frequency of breakfast skipping and frequency of eating out showed a trend for inverse associations with the presence of a partner and children. However, those associations disappeared after adjustment for age of youngest child. The findings suggest that the presence of parents might affect drinking behavior and that age of youngest child living together might affect the frequency of breakfast skipping in young Japanese workers

    ノビレチンは17型ヘルパーT細胞の分化調節により、実験的自己免疫性脳脊髄炎の発症を抑制する

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    Multiple sclerosis is an organ-specific autoimmune disease that targets the myelin antigen in the central nervous system. Nobiletin is a dietary polymethoxylated flavonoid found in citrus fruits. In this study, we investigated how nobiletin affects the disease state and immune responses to myelin oligodendrocyte glycoprotein in experimental autoimmune encephalomyelitis mice. Nobiletin was administered orally from 14 days before immunization until the end of the experiment, and clinical scores were determined. The production levels of interleukin-17A and interferon-γ were measured in a culture supernatant of splenocytes stimulated with myelin oligodendrocyte glycoprotein. In addition, flow cytometric analysis was performed to examine the effect of nobiletin on T cell differentiation in vitro. Admin­istration of nobiletin significantly decreased the clinical score and interleukin-17A production in splenocytes. Furthermore, in vitro analysis showed that nobiletin significantly suppressed Th17 cell differentiation and interleukin-17A production in a dose-dependent manner. The results suggest that nobiletin attenuates experimental autoimmune encephalomyelitis severity through modulation of Th17 cell differentiation

    Polymethoxyflavonids and T helper 17 cells

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    We examined the effects of polymethoxyflavonoids (PMFs) on T helper (Th) 17 cell differentiation in vitro and in vivo. Five different PMFs including nobiletin (NOB), sudachitin (SUD), demethoxysudachitin, heptamethoxyflavone and natsudaidain were used for the in vitro study, and effects of those flavonoids on Th17 responses were investigated. NOB and heptamethoxyflavone significantly suppressed the proliferation response, but SUD, demethoxysudachitin and natsudaidain did not suppress the proliferation response. All of the five flavonoids decreased IL-17A production. Mice with experimentally induced autoimmune encephalomyelitis were used as an in vivo Th17 differentiation model. We focused on two flavonoids, NOB and SUD, and examined the effects of those flavonoids. NOB significantly suppressed Th17 cell proliferation and cytokine responses, but SUD only decreased proliferation responses. The results suggest that the suppressive effect of NOB on Th17 response in vivo is stronger than that of SUD

    コウリン ケッショウ ト シン ケッカン シッカン

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    Hyperphosphatemia has been known as a risk factor for cardiovascular disease particularly inchronic kidney disease patients. Hyperphosphatemia can be involved in the calcification of vascularsmooth muscle cells, resulting in M¨onkeberg medial calcific sclerosis which is a type of arteriosclerosis.However, it has not been clarified whether hyperphosphatemia can deteriorate endothelialfunction and can be a risk factor of atherosclerosis. Our recent study demonstrated that hyperphosphatemiaincreased oxidative stress and decreased nitric oxide production in endothelial cells.In addition, hyperphosphatemia attenuated endothelium-dependent vasodilation reaction. Theseobservations suggest that hyperphosphatemia may cause endothelial dysfunction, and be an importantfactor for progression of atherosclerosis as well as vascular calcification. Positive associationbetween hyperphosphatemia and cardiovascular disease may be explained by the dual harmfuleffects of phosphorus on the vessels

    エイヨウ ト メンエキ キノウ : ヒヒッス エイヨウソ テイエイヨウ ジョウタイ カエイヨウ ジョウタイ ト メンエキ

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    It is known that nutritional state crucially affects immune function. In recent years, the contributionof the diet to the optimal working of the immune system has become wildly appreciatedand the influence of different dietary components on specific aspects of immune function has beenextensively studied. Soy isoflavone genistein suppresses antigen-specific immune response inBALB/c mice and suppresses development of atopic-like dermatitis in NC/Nga mice. In other soyisoflavone equol enhances antigen-specific IgE production via IL-13-mediated pathway. Further,equol exacerbates colitis of dextran sulfate sodium-treated mice. Therefore, immune stimulatoryeffects are strikingly different among soy isoflavones. In this reviews, in addition of the isoflavone,we overview the effects of dietary nucleic acid and protein-deficiency on antigen-specific immuneresponses. Furthermore, we present hot topics researches in the field of obesity and T cellfunction

    Extracts of citrus Sudachi peel attenuate body weight gain in C57BL/6 mice fed a high-fat diet

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    Citrus Sudachi is the special local product of Tokushima Prefecture, and over 98% of Sudachi consumed in Japan every year is produced in Tokushima Prefecture. In this study, we evaluated the function of sudachi peel extract (SPE) using an animal model of obesity. C57BL/6 mice were fed a high-fat diet containing 1% SPE powder. Treatment with SPE significantly decreased body weight compared to that of mice fed a high-fat diet. A significant difference in body weight was observed between the control and SPE groups from 7 weeks after the start of the experiment, the significant difference continued until the end of the 14-week experiment. Reduction of blood glucose levels following insulin administration in SPE-treated mice was grater than that in control mice. Determination of mRNA expression in adipose tissue showed that the expression level of TNF-α in the SPE group was significantly decreased compared to that on the control group. These results suggest that SPE potentially has the ability to attenuate body weight gain

    Efficient generation of vesicular stomatitis virus (VSV)-pseudotypes bearing morbilliviral glycoproteins and their use in quantifying virus neutralising antibodies

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    Morbillivirus neutralising antibodies are traditionally measured using either plaque reduction neutralisation tests (PRNTs) or live virus microneutralisation tests (micro-NTs). While both test formats provide a reliable assessment of the strength and specificity of the humoral response, they are restricted by the limited number of viral strains that can be studied and often present significant biological safety concerns to the operator. In this study, we describe the adaptation of a replication-defective vesicular stomatitis virus (VSVΔG) based pseudotyping system for the measurement of morbillivirus neutralising antibodies. By expressing the haemagglutinin (H) and fusion (F) proteins of canine distemper virus (CDV) on VSVΔG pseudotypes bearing a luciferase marker gene, neutralising antibody titres could be measured rapidly and with high sensitivity. Further, by exchanging the glycoprotein expression construct, responses against distinct viral strains or species may be measured. Using this technique, we demonstrate cross neutralisation between CDV and peste des petits ruminants virus (PPRV). As an example of the value of the technique, we demonstrate that UK dogs vary in the breadth of immunity induced by CDV vaccination; in some dogs the neutralising response is CDV-specific while, in others, the neutralising response extends to the ruminant morbillivirus PPRV. This technique will facilitate a comprehensive comparison of cross-neutralisation to be conducted across the morbilliviruses

    Dietary diversity and healthy lifestyle

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    The aim of this study was to clarify the characteristics of lifestyle and health awareness according to dietary diversity in a Japanese worksite population. The participants were 1,312 men and women aged 20 to 63 years who were living in Tokushima Prefecture, Japan during the period 2012-2013. We obtained anthropometric data and information on lifestyle characteristics using a self-administered questionnaire. Dietary intake was assessed using a food frequency questionnaire, and dietary diversity was determined using the Quantitative Index for Dietary Diversity (QUANTIDD). The characteristics of lifestyle and health awareness according to quartiles of the QUANTIDD score were assessed using the chi-square test and a general linear model. The higher the QUANTIDD score was, the larger were the proportions of participants who knew the appropriate amount of dietary intake and participants who referred to nutritional component information when choosing and / or buying food. Among participants with higher QUANTIDD scores, the proportion of participants who considered their current diet was good was high in women, whereas the proportion of participants who wanted to improve their diet in the future was high in men. Those results indicate that higher dietary diversity was related to better characteristics of lifestyle and awareness of health

    A Rare Case Oesophageal Perforation by a Fish Bone, Leading to Pericardial Penetration and Cardiac Tamponade

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    An 82-year-old woman swallowed a fish bone and presented to our hospital 3 days later when she had breathing difficulty and became hypotensive. Chest computed tomography (CT) showed a linear structure with high bone density extending from the oesophagus into the pericardium, along with pericardial effusion, air, and a left pleural effusion. We diagnosed the patient with oesophageal perforation by a foreign body (a fish bone) leading to pericardial penetration, cardiac tamponade, and left empyema. The patient underwent emergency surgery. Pericardial fenestration and drainage of the pericardial and thoracic cavities were performed. Chest CT showed a recurrent abscess cavity in the pericardium on day 6. A pigtail catheter was placed in the recurrent abscess cavity under CT guidance for drainage. The patient gradually improved and was discharged after 5 months
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