High spatial resolution hard X-ray microscope using X-ray refractive lens and phase contrast imaging experiments

A high spatial resolution X-ray microscope was constructed using an X-ray refractive lens as an objective. The spatial resolution was tested using 18 keV X-ray. A 0.4 mm line and 0.4 mm space tantalum test pattern was successfully resolved. Using the similar setup with the addition of a phase plate, a Zernike type phase-contrast microscopy experiment was carried out for the phase retrieval of the samples. Two-dimensional phase-contrast images were successfully taken for the first time in the hard X-ray region. Images of a gold mesh sample were analyzed and the validity of this method was indicated. An improvement of the lens, however, is required for the precise phase retrieval of the samples. # 2001 Elsevier Science B.V. All rights reserved

Nitrogen doping into titanium dioxide by the sol–gel method using nitric acid

N-doped TiO(2) has been prepared by use of sol-gel systems containing titanium alkoxide, with nitric acid as the nitrogen source. The time needed for gelation of the systems was drastically reduced by ultrasonic irradiation. The peaks assigned to the nitrate and nitrous ions were observed by FT-IR measurement during the sol-gel reaction. The N-doping was confirmed by the observation of N-O peaks in the XPS spectrum of the sample heated at 400 A degrees C. The nitrate ion acted as an oxidizer of the ethanol solvent and titanium species. The TiO(2) became doped with nitrogen oxide species as a result of reduction of nitrate ion incorporated into the dried gel samples. These results indicated that the added nitric acid was reduced during the sol-gel transition and heating process, and the resulting NO species were situated in the titania networks. The UV and visible photocatalytic activity of the samples was confirmed by the degradation of trichloroethylene.ArticleRESEARCH ON CHEMICAL INTERMEDIATES. 37(8):869-881 (2011)journal articl

Acid epimerization of 20-keto pregnane glycosides is determined by 2D-NMR spectroscopy

Carbohydrates influence many essential biological events such as apoptosis, differentiation, tumor metastasis, cancer, neurobiology, immunology, development, host-pathogen interactions, diabetes, signal transduction, protein folding, and many other contexts. We now report on the structure determination of pregnane glycosides isolated from the aerial parts of Ceropegia fusca Bolle (Asclepiadaceae). The observation of cicatrizant, vulnerary and cytostatic activities in some humans and animals of Ceropegia fusca Bolle, a species endemic to the Canary Islands, encouraged us to begin a pharmacological study to determine their exact therapeutic properties. High resolution 1H-NMR spectra of pregnane glycosides very often display well-resolved signals that can be used as starting points in several selective NMR experiments to study scalar (J coupling), and dipolar (NOE) interactions. ROESY is especially suited for molecules such that ωτc ~ 1, where τc are the motional correlation times and ω is the angular frequency. In these cases the NOE is nearly zero, while the rotating-frame Overhauser effect spectroscopy (ROESY) is always positive and increases monotonically for increasing values of τc. The ROESY shows dipolar interactions cross peaks even in medium-sized molecules which are helpful in unambiguous assignment of all the interglycosidic linkages. Selective excitation was carried out using a double pulsed-field gradient spin-echo sequence (DPFGSE) in which 180° Gaussian pulses are sandwiched between sine shaped z-gradients. Scalar interactions were studied by homonuclear DPFGSE-COSY and DPFGSE-TOCSY experiments, while DPFGSE-ROESY was used to monitor the spatial environment of the selectively excited proton. Dipolar interactions between nuclei close in space can be detected by the 1D GROESY experiment, which is a one-dimensional counterpart of the 2D ROESY method. The C-12 and C-17 configurations were determined by ROESY experiments

APASL consensus statements and recommendations for hepatitis C prevention, epidemiology, and laboratory testing

The Asian Pacific Association for the Study of the Liver (APASL) convened an international working party on “APASL consensus statements and recommendations for management of hepatitis C” in March 2015 to revise the “APASL consensus statements and management algorithms for hepatitis C virus infection” (Hepatol Int 6:409–435, 2012). The working party consisted of expert hepatologists from the Asian–Pacific region gathered at the Istanbul Congress Center, Istanbul, Turkey on 13 March 2015. New data were presented, discussed, and debated during the course of drafting a revision. Participants of the consensus meeting assessed the quality of the cited studies. The finalized recommendations for hepatitis C prevention, epidemiology, and laboratory testing are presented in this review

Hepatic STAT1-Nuclear Translocation and Interleukin 28B Polymorphisms Predict Treatment Outcomes in Hepatitis C Virus Genotype 1-Infected Patients

We investigated associations between signal transducer and activator of transcription (STAT) 1 in pretreated liver tissues, interleukin (IL) 28B polymorphism and treatment response in hepatitis C virus (HCV)-infected patients treated with peginterferon and ribavirin.We performed immunostaining analysis of STAT1 in liver tissues and determined IL28B polymorphism at rs8099917. We then compared the results with treatment outcomes in HCV genotype 1 patients with high viral load who were receiving peginterferon plus ribavirin. In univariate analysis, younger age, white blood cell counts, virological responder, early virological responder (EVR), mild activity (A1) of liver inflammation grading, and lower STAT1 nuclear-stain of hepatocytes in zone 1, zone 2 and total zones of liver were associated with sustained virological responder (SVR). Multivariate analysis showed that EVR, age and hepatic STAT1 nuclear-stain in zone 2 of liver were independent predictors of SVR. It was also revealed that IL28B and STAT1-nuclear translocation in hepatocytes are independent predictors of response to treatment with peginterferon and ribavirin in chronic hepatitis C patients.Concomitant assessment of lower STAT1 nuclear-stain of hepatocytes and IL28B polymorphism is useful for prediction of SVR in HCV genotype 1 patients

Decreases in the Serum VLDL-TG/Non-VLDL-TG Ratio from Early Stages of Chronic Hepatitis C: Alterations in TG-Rich Lipoprotein Levels

BACKGROUND: The liver secretes very-low-density lipoproteins (VLDLs) and plays a key role in lipid metabolism. Plasma total triglyceride (TG) level variations have been studied in patients with hepatitis C virus (HCV)-related chronic hepatitis (CH-C). However, the results of these studies are variable. A homogenous assay protocol was recently proposed to directly measure the TG content in VLDL (VLDL-TG) and VLDL remnants. METHODOLOGY/PRINCIPAL FINDINGS: Using the assay protocol, we determined serum VLDL-TG levels in 69 fasting patients with biopsy-proven HCV-related chronic liver disease and 50 healthy subjects. Patients were classified into stages F0-F4 using the 5-point Desmet scale. Serum total TG levels in patients with non-cirrhotic (F1-F3) CH-C did not demonstrate significant differences compared with healthy subjects, but serum VLDL-TG levels did demonstrate significant differences. Mean serum VLDL-TG levels tended to decrease with disease progression from F1 to F4 (cirrhosis). Compared with healthy subjects, serum non-VLDL-TG levels significantly increased in patients with stages F2 and F3 CH-C; however, we observed no significant difference in patients with liver cirrhosis. Furthermore, the serum VLDL-TG/non-VLDL-TG ratio, when taken, demonstrated a significant decrease in patients with CH-C from the mildest stage F1 onward. CONCLUSIONS/SIGNIFICANCE: The decrease in serum VLDL-TG levels was attenuated by increase in non-VLDL-TG levels in patients with non-cirrhotic CH-C, resulting in comparable total TG levels. Results of previous studies though variable, were confirmed to have a logical basis. The decrease in the serum VLDL-TG/non-VLDL-TG ratio as early as stage F1 demonstrated TG metabolic alterations in early stages of CH-C for the first time. The involvement of TG metabolism in CH-C pathogenesis has been established in experimental animals, while conventional TG measurements are generally considered as poor indicators of CH-C progression in clinical practice. The serum VLDL-TG/non-VLDL-TG ratio, which focuses on TG metabolic alterations, may be an early indicator of CH-C

Genome-Wide Association Study Confirming Association of HLA-DP with Protection against Chronic Hepatitis B and Viral Clearance in Japanese and Korean

Hepatitis B virus (HBV) infection can lead to serious liver diseases, including liver cirrhosis (LC) and hepatocellular carcinoma (HCC); however, about 85–90% of infected individuals become inactive carriers with sustained biochemical remission and very low risk of LC or HCC. To identify host genetic factors contributing to HBV clearance, we conducted genome-wide association studies (GWAS) and replication analysis using samples from HBV carriers and spontaneously HBV-resolved Japanese and Korean individuals. Association analysis in the Japanese and Korean data identified the HLA-DPA1 and HLA-DPB1 genes with Pmeta = 1.89×10−12 for rs3077 and Pmeta = 9.69×10−10 for rs9277542. We also found that the HLA-DPA1 and HLA-DPB1 genes were significantly associated with protective effects against chronic hepatitis B (CHB) in Japanese, Korean and other Asian populations, including Chinese and Thai individuals (Pmeta = 4.40×10−19 for rs3077 and Pmeta = 1.28×10−15 for rs9277542). These results suggest that the associations between the HLA-DP locus and the protective effects against persistent HBV infection and with clearance of HBV were replicated widely in East Asian populations; however, there are no reports of GWAS in Caucasian or African populations. Based on the GWAS in this study, there were no significant SNPs associated with HCC development. To clarify the pathogenesis of CHB and the mechanisms of HBV clearance, further studies are necessary, including functional analyses of the HLA-DP molecule