222 research outputs found

    Structural Modification of KAISiO4 Minerals

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    Kalsilite, a polymorph of KAISiO4 is an end member of nepheline-kalsilite series and the mineral was syn-thesized by hydorhermal methods. The synthetic kalsilite is hexagonal, P63, with a=5.151(5), c=8.690(8) A. The structure was refined by full-matrix least-squares methods to a R-value 0.084, using 373 observed reflections. The obtained structure agrees well with those of the natural and the alkali-exchanged specimens reported in the previous literatures. The oxygen atoms are disordered at two mirror-equivalent sites, constructing the domain structure. The average domain structure shows P63mc symmetry and the strctural relation between the two P63 structure corresponds to the twinning by merohedry. The domain structure was considered to be caused accompanied with the high-low inversion of the kalslite structure. Heating experiments of kalsilite reveal that the X-ray powder pattern changes at 865℃, and that cell dimensions vary discontinuously at this temperature. It was confirmed that kalsilite underwent a displacive transition like those observed in quartz or tridymite. The high-form is refered as 'high-kalsilite', and a possible simulate model is proposed. The structure of the high-kalsilite at 950℃ was refined byfull-matrix least-squares methods to a R-value 0.095, using 115 observed reflections. The high-kalsilite is also hexagonal, P63mc or P63/mmc, with a=5.288(1), c=8.628(5) A at 950℃. The structure almost prefectly coincides with that of the simulated model. Based on the interatomic distances, the distribution of silicon and aluminum atoms is found to be or-dered and the space group is determined to be P63mc. Kaliophilite and the related orthorhombic from, polymorphs of KAISiO4, were synthesized by dry method. The synthetic kaliophilite (kaliophilite-H2) is hexagonal with a=5.17(1), c=8.49(3) A, and the orthorhombic KAISiO4 (kaliophilite-O1) is orthormbic with a=9.01(1), b=15.60(2), c=8.53(4) A. Detailed examina-tion of the obtained powder patterns together with that of simulated model indicates that the kaliophilite-H2 has a disorderd structure of four types of the low-kalsilite. The structure was refined by the X-ray powder pattern-fitting method (Rietvelt method) to a R-value 0.121

    Interpretation of the Crystad Structure of Synthetic Kaliophilite from the Domain Structure of Kalsilite

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    The syntheses of kaliophilite have been carried out from the starting materials of near kalsilite compotions (KAISiO4), of which the AI2O3/SiO2 ratio is greater than 1/2. The X-ray powder deffraction pattern fit well to those of previous investigators. The crystal structure of synthetic kaliophilite was proposed by using the model consisting of four different types of kalsilite structure. The positions and intensities of the X-ray powder pattern were able to be explained on the basis of these four domains, belonging to thr twinning by merohedory. As a result of the conditions of the syntheses, it may be supposed that the violation of the AI-O-AI avoidanice rule can possibly exist along the domain boundaries

    A study on the fourth q-Painlev\'e equation

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    A q-difference analogue of the fourth Painlev\'e equation is proposed. Its symmetry structure and some particular solutions are investigated.Comment: 18 page

    Association between Oral Health Status and Diabetic Nephropathy-Related Indices in Japanese Middle-Aged Men

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    Oral health status is known to be associated with lifestyle-related diseases such as diabetes and chronic kidney disease. In Japan, around 40% of hemodialysis cases are patients with diabetic nephropathy. The aim of this study was to clarify the association between oral health status and diabetic nephropathy-related indices in Japanese middle-aged men. Sixty-six men (age range: 55–64 years) with ≥20 remaining teeth and who received public medical checkups and oral examinations were enrolled. We examined correlations of age, body mass index, HbA1c, HDL-C, LDL-C, neutral fat, serum creatinine, and the estimated glomerular filtration rate (eGFR) with the number of remaining teeth or the community periodontal index (CPI) score (periodontal pocket < 4mm: 0, 4–6 mm: 1, ≥6 mm: 2). A positive correlation between the CPI score and serum creatinine and a negative correlation between CPI score and eGFR (Spearman’s rank correlation coefficient, r = 0.459, p < 0.01, and r = −0.460, p < 0.01, respectively) were observed. The mean eGFR in the CPI score 0 group was significantly higher than that in the CPI score 1/2 group (82.6 vs. 70.7, Student’s t-test, p < 0.01). Logistic regression analysis using eGFR as a dependent variable and age, CPI score, body mass index, HbA1c, and neutral fat as independent variables suggested that low eGFR (<60) could be attributed to CPI score (OR = 3.169, 95% CI: 1.031–9.742, p = 0.044). These results suggest a possible association between periodontal status and renal function in Japanese middle-aged men. Periodontal condition is controlled by oral prophylaxis, and periodontal disease and chronic kidney disease have some common risk factors. Thus, periodontal management can contribute to the prevention of severe chronic kidney disease

    An immunofluorescent study on anti-synovial tissue antibody in the body fluid from patients with rheumatoid arthritis

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    There is as yet no plausible and convincing explanation for the etiology of rheumatoid arthritis. The authors investigated anti-synovial tissue antibody in the body fluid of rheumatoid arthritis by means of indirect immunofluorescent technic using non-affected synovial tissues as antigen. As the result the anti-synovial tissue antibody was detected in 7 cases of the 15 synovial fluid samples of rheumatoid arthritis and in two out of the six serum samples. The site of the localization of this antibody was demonstrated to be in the synovial membrane, especially in synovial cells and in the small blood vessel walls situated immediately adjacent to the synovial surface, but it was found in no connective tissues other than synovial membrane. It seems that this anti-synovial tissue antibody should be considered as an independent factor from rheumatoid factor, and that rather than the rheumatoid factor it is more actively associated with the localization and progression of chronic inflammation within the rheumatoid arthritis joint.</p

    CXCL14 Deficiency in Mice Attenuates Obesity and Inhibits Feeding Behavior in a Novel Environment

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    BACKGROUND: CXCL14 is a chemoattractant for macrophages and immature dendritic cells. We recently reported that CXCL14-deficient (CXCL14(-/-)) female mice in the mixed background are protected from obesity-induced hyperglycemia and insulin resistance. The decreased macrophage infiltration into visceral adipose tissues and the increased insulin sensitivity of skeletal muscle contributed to these phenotypes. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we performed a comprehensive study for the body weight control of CXCL14(-/-) mice in the C57BL/6 background. We show that both male and female CXCL14(-/-) mice have a 7-11% lower body weight compared to CXCL14(+/-) and CXCL14(+/+) mice in adulthood. This is mainly caused by decreased food intake, and not by increased energy expenditure or locomotor activity. Reduced body weight resulting from the CXCL14 deficiency was more pronounced in double mutant CXCL14(-/-)ob/ob and CXCL14(-/-)A(y) mice. In the case of CXCL14(-/-)A(y) mice, oxygen consumption was increased compared to CXCL14(+/-)A(y) mice, in addition to the reduced food intake. In CXCL14(-/-) mice, fasting-induced up-regulation of Npy and Agrp mRNAs in the hypothalamus was blunted. As intracerebroventricular injection of recombinant CXCL14 did not change the food intake of CXCL14(-/-) mice, CXCL14 could indirectly regulate appetite. Intriguingly, the food intake of CXCL14(-/-) mice was significantly repressed when mice were transferred to a novel environment. CONCLUSIONS/SIGNIFICANCE: We demonstrated that CXCL14 is involved in the body weight control leading to the fully obese phenotype in leptin-deficient or A(y) mutant mice. In addition, we obtained evidence indicating that CXCL14 may play an important role in central nervous system regulation of feeding behavior
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