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  • Author: Bo Huang x
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Abstract

Application of 1-butyl-3-metyhlimidazaolium hexafluorophosphate ([C4mim][PF6]), in the extraction of rubidium and cesium from brine solutions using 1,4,7,10,13,16-hexaoxacyclooctadecane (18C6) as extractant was investigated. Parameters that affect the extraction including pH of aqueous phase, equilibration time, dosage of the ionic liquid, phase ratio, concentration of 18C6 were studied. Under the optimal conditions, the single extraction efficiency of rubidium ions and cesium ions were up 84.11% and 94.99%, respectively. The stripping of alkali metal ions from the loaded organic phase with different stripping agents and concentrations were also investigated. The initial value of the K/Cs and K/Rb ratios were 93.0 and 104.3, respectively, which have dropped 91.21% and 88.01%, respectively, after the extraction and stripping experiments. It was taken a big step in the separation and enrichment of cesium (rubidium) ion and potassium ion. The extraction mechanism was revealed most likely to be a cation exchange mode in this system.

Abstract

Background: Mild heat stress provides protection to cells, which is known as thermal tolerance. Various kinds of heat shock proteins have been proven to play important roles in this process. Another antiapoptotic factor induced by mild heat stress, peroxisome proliferator activated receptor beta (PPAR-β), provides a protective effect to cells against subsequent oxidant injury.

Objective: To understand the expression of PPAR-β and other proteins in human umbilical vein endothelial cells (HUVECs) during mild heat stress. H2O2-induced apoptosis of cells with mild heat pretreatment were also investigated to elucidate cell resistance to oxidant injury.

Methods: HUVECs were chosen in the current study because vascular endothelial cells in burn wounds, especially in the zone of stasis, suffer sequentially from heat stimulus and oxidant injury.

Results: The cells were subjected to 43 ☐C for 25 minutes and allowed to recover for different times (from 1 to 72 hours). The PPAR-β expression was found to be upregulated in the later recovery stage. BCL-2 also showed a similar trend, but P53 showed otherwise. Heat pretreated HUVECs were exposed to 400 μmol/L of H2O2 for 12 hours, and apoptosis rate was assessed. H2O2-induced apoptosis was attenuated by heat pretreatment and by the PPAR-β agonist GW0742 (p < 0.01 and p < 0.05 versus control group); HUVECs transfected with PPAR-β shRNA seemed much more susceptible to oxidation damage (p < 0.05 versus the control group). Mild heat stress also upregulated the BCL-2 expression relative to PPAR-β.

Conclusion: Heat-induced PPAR-β may be partly responsible for this process, which may also be one of the possible explanations of the antiapoptotic function of PPAR-β, although the specific mechanism needs further examination.

Abstract

Background: The alternative splicing of Bcl-x generates the proapoptotic Bcl-xs protein and the antiapoptotic variant Bcl-xl. Previous studies have demonstrated that some chemotherapeutic agents such as emetine, staurosporine, and epigallocatechin gallate (EGCG) in combination with ibuprofen significantly altered the ratio of the Bcl-x variants Bcl-xs/Bcl-xl in various cell lines, suggesting Bcl-x splicing might be affected by the exogenous stimuli.

Objective: We investigated the regulative role of imatinib in the alternative pre-mRNA splicing of Bcl-x in K562 cells and the related mechanism.

Methods: Cell proliferation was measured using WST assay kit. Cell apoptosis was assayed using an Annexin V-FITC Apoptosis Detection Kit. RT-PCR and western blot assay was used to analyze the mRNA and protein level of alternative splicing of exon 2 in the Bcl-x gene respectively.

Results: Imatinib regulated the alternative splicing in the Bcl-x gene in the K562 cells. In addition, we found that hydroxyurea, another agent for the therapy of CML, could enhance the effect of imatinib on the ratio of the Bcl-xl/Bcl-xs. Moreover, the induction of alternative splicing was correlated with protein phosphatase 1 (PP1). Alternatively, pretreatment with calyculin efficiently blocked imatinib-induced alternative splcing in the K562 cells compared with okadaic acid, which showed an important role of PP1 in regulating imatinib-induced splicing.

Conclusion: Imatinib regulates the alternative splicing of Bcl-x in K562 cells, which may be associated with the activation of PP1.

Abstract

The yellow-feather broiler is a popular poultry breed in Asia, particularly in China. In this study, we performed RNA-seq analysis to identify differentially expressed genes (deGs) in the liver of yellow-feather broilers that had been subjected to acute heat stress treatment (38±1°C for 4 h, recovery 2 h) and determine the response of the liver to high temperature and its effects on yellow-feather broiler physiology. We found that the cloacal temperature and respiratory rate of yellow-feather chickens were significantly increased immediately after the initiation of acute heat stress (38°c) treatment. And after recovery for 2 h, there was no difference in the cloacal temperature and respiratory rate between the acute heat stress and control groups. A total of 834 DEGs were observed in response to heat stress by RNA-seq. Almost half of the DEGs were involved in the lipid and energy metabolism, including fatty acid metabolism (ACOX1, ACACA, ACSL1, ACSL6, ACAA1, ACAA2, HADHB, and FASN) and propanoate metabolism (ACSS2, ALDH2, ACACA, DLAT, ALDH7A1, MDH1, ME1, ABAT, SUCLG2, and ACSS3). Our findings provide the context for RNA-seq studies in the liver of yellow-feather chickens and suggest that the liver of yellow-feather broilers has the lipid and energy metabolism physiological mechanisms activated in response to heat stress.

Abstract

The Western honey bee (Apis mellifera) is a social insect characterized by caste differentiation in which the queen bee and worker bees display marked differences in morphology, behavior, reproduction, and longevity despite their identical genomes. The main causative factor in caste differentiation is the food fed to queen larvae, termed royal jelly (RJ). Alternative splicing (AS) is an important RNA-mediated post-transcriptional process in eukaryotes. Here we report AS changes in A. mellifera after being fed either A. mellifera RJ or A. cerana RJ. The results demonstrated that the RJ type affected 4 types of AS in adult A. mellifera: exon skipping, intron retention, alternative 5’ splice sites, and alternative 3’splice sites. After feeding with A. cerana RJ, AS occurred in many genes in adult A. mellifera that encode proteins involved in development, growth, the tricarboxylic acid cycle, and substance metabolism. This study provides the first evidence that heterospecific RJ can influence the AS of many genes related to honey bee development and growth.

Abstract

In this study, a total of 176 tree cores from Schrenk spruce (Picea schrenkiana) were used to establish a tree-ring chronology and a 167-year July–October normalized differential vegetation index (NDVI) for the Alatau Mountains in Central Asia was reconstructed using this newly developed chronology. The tree-ring based NDVI reconstruction tracks the observed data well (r=0.577, p<0.01, n=25) and precisely captures the drought events recorded in historical documents that occurred over a large area in 1917 and 1938. After applying a 21-year moving average, three dense (1860–1870, 1891–1907, and 1950–1974) and three sparse (1871–1890, 1908–1949, and 1975–2006) vegetation coverage periods were found in this reconstruction. Spatial correlation proves that the reconstructed NDVI series contains climatic signals representative for a large area including southern Kazakhstan. Although a comparison between this reconstruction and four climatic reconstructions for southeastern Kazakhstan, Nilka (in the Ili region), the Issyk Lake, and the Aksu region reveals similar variations, the coherence between these reconstructions become weak with the increase in spatial distance from north to south. In addition to the local representation, it was also demonstrated that the newly developed NDVI index can indicate the large-scale circulations over Eurasia, with the higher NDVI associated with stronger westerly winds from the Atlantic to the Alatau Mountains, and the lower NDVI associated with the weaker winds.