The separation of beta-BBO phase in alpha-BBO crystal by the irradiation of femtosecond laser

We observed and described some phenomena, which were that when a alpha-BBO crystal was irradiated by a focused femtosecond laser beam, the temperature effect happened in a minute area of focus, then the induced beta-BBO phase was separated within the minute area in the alpha-BBO crystal. (C) 2007 Elsevier B.V. All rights reserved.

Growth of alpha-Al2O3:C crystal with highly sensitive optically stimulated luminescence

In this work. an alpha-Al2O3:C crystal was directly grown by the temperature gradient technique (TGT) using Al2O3 and graphite powders as the raw materials. The optical, optically stimulated luminescence (OSL) properties and dosimetric characteristics of as-grown crystal were investigated. As-grown alpha-Al2O3:C crystal shows strong absorption band at 205, 230 and 256 nm. Three-dimensional thermoluminescence (TL) emission spectrum of the crystal shows a single emission peak at similar to 415 nm. The OSL decay curve can be fitted to two exponentials, the faster component and the slower component. The OSL response of the crystal shows a linear-sublinear-saturation characteristic. As-grown alpha-Al2O3:C crystal shows excellent linearity in the dose range from 5 x 10(-6) to 50 Gy. For doses higher than the saturation dose (100 Gy). the OSL sensitivity decreases as the dose increases. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.

Differential activity of GSK-3 isoforms regulates NF-kappa B and TRAIL- or TNF alpha induced apoptosis in pancreatic cancer cells

While TRAIL is a promising anticancer agent due to its ability to selectively induce apoptosis in neoplastic cells, many tumors, including pancreatic ductal adenocarcinoma (PDA), display intrinsic resistance, highlighting the need for TRAIL-sensitizing agents. Here we report that TRAIL-induced apoptosis in PDA cell lines is enhanced by pharmacological inhibition of glycogen synthase kinase-3 (GSK-3) or by shRNA-mediated depletion of either GSK-3 alpha or GSK-3 beta. In contrast, depletion of GSK-3 beta, but not GSK-3 alpha, sensitized PDA cell lines to TNF alpha-induced cell death. Further experiments demonstrated that TNF alpha-stimulated I kappa B alpha phosphorylation and degradation as well as p65 nuclear translocation were normal in GSK-3 beta-deficient MEFs. Nonetheless, inhibition of GSK-3 beta function in MEFs or PDA cell lines impaired the expression of the NF-kappa B target genes Bcl-xL and cIAP2, but not I kappa B alpha. Significantly, the expression of Bcl-xL and cIAP2 could be reestablished by expression of GSK-3 beta targeted to the nucleus but not GSK-3 beta targeted to the cytoplasm, suggesting that GSK-3 beta regulates NF-kappa B function within the nucleus. Consistent with this notion, chromatin immunoprecipitation demonstrated that GSK-3 inhibition resulted in either decreased p65 binding to the promoter of BIR3, which encodes cIAP2, or increased p50 binding as well as recruitment of SIRT1 and HDAC3 to the promoter of BCL2L1, which encodes Bcl-xL. Importantly, depletion of Bcl-xL but not cIAP2, mimicked the sensitizing effect of GSK-3 inhibition on TRAIL-induced apoptosis, whereas Bcl-xL overexpression ameliorated the sensitization by GSK-3 inhibition. These results not only suggest that GSK-3 beta overexpression and nuclear localization contribute to TNF alpha and TRAIL resistance via anti-apoptotic NF-kappa B genes such as Bcl-xL, but also provide a rationale for further exploration of GSK-3 inhibitors combined with TRAIL for the treatment of PDA.

Effects of process on microstructure and properties of translucent Dy-alpha-SiAlON sintered at lower temperatures

Hot pressing (HP) at higher sintering temperature has been a traditional and prevalent technique for the fabrication of alpha-SiAlON. In order to prepare translucent SiAlON more easily, LiF was used as a non-oxide sintering additive to lower the sintering temperature to <= 1650 degrees C. As a result, all of the samples possessed a good hardness and fracture toughness. At the same time, the lower temperature sintered samples showed a higher optical transmittance in the range of 2.5-5.5 mu m wavelength (0.5 mm in thickness). The maximum infrared transmission reached 68% at a wavelength of 3.3 mu m. The present work shows that the sintering process has a strong effect on microstructure and property of alpha-SiAlON. To be exact, a lower sintering temperature and longer holding time can produce some fully-developed microstrcture, which is beneficial for the optical transmittance. (C) 2008 The Ceramic Society of Japan. All rights reserved.

Adaptive evolution of primate TRIM5 alpha, a gene restricting HIV-1 infection

Recent studies showed that nonhuman primate TRIM5 alpha can efficiently block HIV-1 infection in human cell lines. It can also restrict other retroviruses, therefore, suggested as a general defender against retrovirus infection. Here, we present an evolutionary analysis of TRIM5 alpha in primates. Our results demonstrated that TRIM5a has been evolving rapidly in primates, which is likely caused by Darwinian positive selection. The SPRY domain of TRM5 alpha, which may be responsible for recognition of incoming viral capsids showed higher nonsynonymous/synonymous substitution ratios than the non-SPRY domain, indicating that the adaptive evolution of TRIM5a ill primates might be an innate strategy developed in defending retrovirus infection during primate evolution. In addition, the comparative protein sequence analysis suggested that the amino acid substitution pattern at a single site (344R/Q/P) located in the SPRY domain may explain the differences in Susceptibilities of HIV-1 infection in diverse primate species. (c) 2005 Elsevier B.V. All rights reserved.

Cloning and purification of alpha-neurotoxins from king cobra (Ophiophagus hannah)

Thirteen complete and three partial cDNA sequences were cloned from the constructed king cobra (Ophiophagus hannah) venom gland cDNA library. Phylogenetic analysis of nucleotide sequences of king cobra with those from other snake venoms revealed that obta

Enhanced poisson sum representation for alpha-stable processes

In this paper we present Poisson sum series representations for α-stable (αS) random variables and a-stable processes, in particular concentrating on continuous-time autoregressive (CAR) models driven by α-stable Lévy processes. Our representations aim to provide a conditionally Gaussian framework, which will allow parameter estimation using Rao-Blackwellised versions of state of the art Bayesian computational methods such as particle filters and Markov chain Monte Carlo (MCMC). To overcome the issues due to truncation of the series, novel residual approximations are developed. Simulations demonstrate the potential of these Poisson sum representations for inference in otherwise intractable α-stable models. © 2011 IEEE.

The free alpha amino acid nitrogen contents of some common food fishes of Kakinada region, Andhra Pradesh

The moisture and free alpha amino nitrogen contents of some important food fishes and shell fishes of Kakinada region have been studied. Crustaceans and molluscs contain free alpha amino acids in quantities several times higher than all other aquatic animals examined in this study. Their probable role in the physiological activities of these animals has been discussed.

Polymorphisms of the estrogen receptor alpha (ESR1) gene and the risk of Alzheimer's disease in a southern Chinese community

Background: Alzheimer's disease (AD) is a neurodegenerative disease with a higher prevalence in women. Expression of estrogen receptor 1 (ESR1) gene has been identified throughout the brain. Owing to the putative neuroprotective effects of estrogen, estro

Natural selection on EPAS1 (HIF2 alpha) associated with low hemoglobin concentration in Tibetan highlanders

By impairing both function and survival, the severe reduction in oxygen availability associated with high-altitude environments is likely to act as an agent of natural selection. We used genomic and candidate gene approaches to search for evidence of such genetic selection. First, a genome-wide allelic differentiation scan (GWADS) comparing indigenous highlanders of the Tibetan Plateau (3,200 3,500 m) with closely related lowland Han revealed a genome-wide significant divergence across eight SNPs located near EPAS1. This gene encodes the transcription factor HIF2 alpha, which stimulates production of red blood cells and thus increases the concentration of hemoglobin in blood. Second, in a separate cohort of Tibetans residing at 4,200 m, we identified 31 EPAS1 SNPs in high linkage disequilibrium that correlated significantly with hemoglobin concentration. The sex-adjusted hemoglobin concentration was, on average, 0.8 g/dL lower in the major allele homozygotes compared with the heterozygotes. These findings were replicated in a third cohort of Tibetans residing at 4,300 m. The alleles associating with lower hemoglobin concentrations were correlated with the signal from the GWADS study and were observed at greatly elevated frequencies in the Tibetan cohorts compared with the Han. High hemoglobin concentrations are a cardinal feature of chronic mountain sickness offering one plausible mechanism for selection. Alternatively, as EPAS1 is pleiotropic in its effects, selection may have operated on some other aspect of the phenotype. Whichever of these explanations is correct, the evidence for genetic selection at the EPAS1 locus from the GWADS study is supported by the replicated studies associating function with the allelic variants.