128 research outputs found
Quantitative analysis of major elements in igneous rocks with X-ray fluorescence spectrometer “ZSX primus II” using a 1:10 dilution glass bead
Detailed procedures of sample processing including preparation of a 1: 10 dilution glass bead and evaluations of calibration lines of the X-ray fluorescence spectrometer for major element compositions of igneous rock samples are presented. We used 11 igneous rock standard samples of the Geological Survey of Japan and the synthetic material for the calibration. A powdered rock sample ignited at 900 ° C for four hours and lithium tetraborate as an alkali flux ignited at 700 ° C for four hours are weighed 0.4000 ± 0.0001 g and 4.0000 ± 0.0001 g, respectively. The mixture of rock powder sample and lithium tetraborate is put into a platinum crucible and fused to a glass bead. The calibration lines for basalts and andesites named "Major12" analyze 10 major elements such as Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K and P in 10 minutes. The result of repeated analyses of six standard materials shows that the relative standard deviations are less than 3% and relative errors are less than 1.2%. Therefore, the calibration lines "Major12" are sufficient to be applied to routine measurement of igneous rocks. For analysis of ultramafic rocks, another set of calibration lines "majorOl\u27\u27 was made based on standard samples including synthesized materials of SiO, and MgO reagents, and the calibration lines cover wider Si, Mg, Ni and Cr ranges than "Major12". The calibration lines "majorOl\u27\u27 successfully reproduced concentrations of nine major element compositions (Si, Ti, Al, Fe, Mn, Mg, Ca, Ni, Cr) of the standard samples of ultramafic rocks
Serum levels of 1,25-dihydroxyvitamin D, 24,25-dihydroxyvitamin D, and 25-hydroxyvitamin D in nondialyzed patients with chronic renal failure
Serum levels of 1,25-dihydroxyvitamin D, 24,25-dihydroxyvitamin D, and 25-hydroxyvitamin D in nondialyzed patients with chronic renal failure.BackgroundIn patients with chronic renal failure (CRF), abnormalities in vitamin D metabolism are known to be present, and several factors could contribute to the abnormalities.MethodsWe measured serum levels of three vitamin D metabolites, 1,25(OH)2D, 24,25(OH)2D and 25(OH)D, and analyzed factors affecting their levels in 76 nondialyzed patients with CRF (serum creatinine> 1.6 and < 9.0 mg/dl), 37 of whom had diabetes mellitus (DM-CRF) and 39 of whom were nondiabetic (nonDM-CRF).ResultsSerum levels of 1,25(OH)2D were positively correlated with estimated creatinine clearance (CCr; r = 0.429; P < 0.0001), and levels of 24,25(OH)2D were weakly correlated with CCr (r = 0.252, P < 0.05); no correlation was noted for 25(OH)D. Serum levels of all three vitamin D metabolites were significantly and positively correlated with serum albumin. Although there were no significant differences in age, sex, estimated CCr, calcium and phosphate between DM-CRF and nonDM-CRF, all three vitamin D metabolites were significantly lower in DM-CRF than in nonDM-CRF. To analyze factors influencing vitamin D metabolite levels, we performed multiple regression analyses. Serum 25(OH)D levels were significantly and independently associated with serum albumin, presence of DM and serum phosphate (R2 = 0.599; P < 0.0001). 24,25(OH)2D levels were significantly and strongly associated with 25(OH)D (β; = 0.772; R2 = 0.446; P < 0.0001). Serum 1,25(OH)2D levels were significantly associated only with estimated CCr (R2 = 0.409; P < 0.0001).ConclusionsThese results suggest that hypoalbuminemia and the presence of DM independently affect serum 25(OH)D levels, probably via diabetic nephropathy and poor nutritional status associated with diabetes, and that 25(OH)D is actively catalyzed to 24,25(OH)2D in CRF, probably largely via extrarenal 24-hydroxylase. Serum levels of 1,25(OH)2D were significantly affected by the degree of renal failure. Thus, this study indicates that patients with CRF, particularly those with DM, should receive supplements containing the active form of vitamin D prior to dialysis
Progression of Hepatic Adenoma to Carcinoma in Ogg1
The carcinogenic potential of phenobarbital (PB) was assessed in a mouse line carrying a mutant Mmh allele of the Mmh/Ogg1 gene encoding the enzyme oxoguanine DNA glycosylase (Ogg1) responsible for the repair of 8-hydroxy-2′-deoxyguanosine (8-OHdG). Mmh homozygous mutant (Ogg1−/−) and wild-type (Ogg1+/+) male and female, 10-week-old, mice were treated with 500 ppm PB in diet for 78 weeks. Hepatocellular carcinomas (HCCs) were found in PB-treated Ogg1−/− mice, while Ogg1+/+ animals developed only hepatocellular adenomas (HCAs) at the same rate. This was coordinated with PB-induced significant elevation of 8-OHdG formation in DNA and cell proliferation in adjacent liver of Ogg1−/− mice. Proteome analysis predicted activation of transcriptional factor Nrf2 in the livers and HCAs of PB-administered Ogg1+/+ mice; however, its activation was insufficient or absent in the livers and HCCs of Ogg1−/− mice, respectively. Significant elevation of phase I and II metabolizing enzymes was demonstrated in both Ogg1−/− and Ogg1+/+ animals. Treatment of Ogg1−/− mice with PB resulted in significant elevation of cell proliferation in the liver. These results indicate that PB induced progression from HCA to HCC in Ogg1−/− mice, due to persistent accumulation of DNA oxidative base modifications and suppression of Nrf2-mediated oxidative stress response, resulting in significant elevation of cell proliferation
Analysis of Methoxymethylbenzoguanamine Resins Using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry and Electrospray Ionization Mass Spectrometry
Methoxymethylbenzoguanamine resins were analyzed by matrix-assisted laser desorption/ionization timeof-flight mass spectrometry (MALDI-TOF-MS) and electrospray ionization mass spectrometry (ESI-MS). In the case of MALDI-TOF-MS measurements, they could not be characterized because fragmentation occurred considerably. On the ESI-MS measurement, optimization of needle voltage, cone voltage, and cationizing agent made their molecular-related ions intense with little fragmentation. Cluster ions were formed owing to hydrogen bond among their complex components. Gel permeation chromatography (GPC) was used to fractionate the resins. As a result, different oligomer components could be characterized in detail
Structural analysis of crystalline R(+)-α-lipoic acid-α-cyclodextrin complex based on microscopic and spectroscopic studies
R(+)-α-lipoic acid (RALA) is a naturally-occurring substance, and its protein-bound form plays significant role in the energy metabolism in the mitochondria. RALA is vulnerable to a variety of physical stimuli, including heat and UV light, which prompted us to study the stability of its complexes with cyclodextrins (CDs). In this study, we have prepared and purified a crystalline RALA-αCD complex and evaluated its properties in the solid state. The results of 1H NMR and PXRD analyses indicated that the crystalline RALA-αCD complex is a channel type complex with a molar ratio of 2:3 (RALA:α-CD). Attenuated total reflection/Fourier transform infrared analysis of the complex showed the shift of the C=O stretching vibration of RALA due to the formation of the RALA-αCD complex. Raman spectroscopic analysis revealed the significant weakness of the S–S and C–S stretching vibrations of RALA in the RALA-αCD complex implying that the dithiolane ring of RALA is almost enclosed in glucose ring of α-CD. Extent of this effect was dependent on the direction of the excitation laser to the hexagonal morphology of the crystal. Solid-state NMR analysis allowed for the chemical shift of the C=O peak to be precisely determined. These results suggested that RALA was positioned in the α-CD cavity with its 1,2-dithiolane ring orientated perpendicular to the plane of the α-CD ring. © 2015 by the authors; licensee MDPI, Basel, Switzerland
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