碳酸钙和氧化钙脱除煤气中H_2S和COS的研究

采用热重分析法在常压下对CaCO3和CaO分别脱除H2S和COS的反应进行了研究。结果表明,脱除H2S和COS的反应初速率分别与H2S分压和COS分压成正比;CaO脱除H2S和COS的反应速度与颗粒粒度成反比,与颗粒的比表面积成正比例。与CaO脱除H2S和COS的反应相比,CaCO3脱除H2S和COS反应的初速率慢得多。

Bile-acid-activated farnesoid X receptor regulates hydrogen sulfide production and hepatic microcirculation

AIM: To investigate whether the farnesoid X receptor (FXR) regulates expression of liver cystathionase (CSE), a gene involved in hydrogen sulfi de (H2S) generation. METHODS: The regulation of CSE expression in response to FXR ligands was evaluated in HepG2 cells and in wild-type and FXR null mice treated with 6-ethyl chenodeoxycholic acid (6E-CDCA), a synthetic FXR ligand. The analysis demonstrated an FXR responsive element in the 5'-flanking region of the human CSE gene. The function of this site was investigated by luciferase reporter assays, chromatin immunoprecipitation and electrophoretic mobility shift assays. Livers obtained from rats treated with carbon tetrachloride alone, or in combination with 6-ethyl chenodeoxycholic acid, were studied for hydrogen sulphide generation and portal pressure measurement. RESULTS: Liver expression of CSE is regulated by bile acids by means of an FXR-mediated mechanism. Western blotting, qualitative and quantitative polymerase chain reaction, as well as immunohistochemical analysis, showed that expression of CSE in HepG2 cells and in mice is induced by treatment with an FXR ligand. Administration of 6E-CDCA to carbon tetrachloride treated rats protected against the down-regulation of CSE expression, increased H2S generation, reduced portal pressure and attenuated the endothelial dysfunction of isolated and perfused cirrhotic rat livers. CONCLUSION: These results demonstrate that CSE is an FXR-regulated gene and provide a new molecular explanation for the pathophysiology of portal hypertension.

α-Lipoic acid protects against cholecystokinin-induced acute pancreatitis in rats

AIM: α-Lipoic acid (ALA) has been used as an antioxidant.The aim of this study was to investigate the effect of α-lipoic acid on cholecystokinin (CCK)-octapeptide induced acute pancreatitis in rats.METHODS: ALA at 1 mg/kg was intra-peritoneally injected, followed by 75 μg/kg CCK-octapeptide injected thrice subcutaneously after 1, 3, and 5 h. This whole procedure was repeated for 5 d. We checked the pancreatic weight/body weight ratio, the secretion of pro-inflammatory cytokines and the levels of lipase,amylase of serum. Repeated CCK octapeptide treatment resulted in typical laboratory and morphological changes of experimentally induced pancreatitis.RESULTS: ALA significantly decreased the pancreatic weight/body weight ratio and serum amylase and lipase in CCK octapeptide-induced acute pancreatitis. However,the secretion of IL-1β, IL-6, and TNF-α were comparable in CCK octapeptide-induced acute pancreatitis.CONCLUSION: ALA may have a protective effect against CCK octapeptide-induced acute pancreatitis.

ALTERATION OF CHOLESTEROL SULFATE IN HUMAN SERA DURING THE COURSE OF PREGNANCY

Objective To determine the concentrations of cholesterol sulfate ( CS) in human sera and pla-cental villi during the course of pregnancy. And to analyze its inhibitory activity on thrombin and further characterize the functional significance of CS. Methods The concentrations of CS were determined by thin-layer chromatog-raphy (TLC) on 60 cases of normal pregnant women and 30 cases of normal placental villi. The effect of CS in human sera on the activity of thrombin was analyzed. Results The concentrations of CS in human sera gradually increased from the first to third trimester of gestation with a correlation coefficient of 0. 69, and a correlation between the concentration of CS and weeks of gestation (P <0. 01). CS was also contained in the placental villi, and its concentrations at the second and third trimester of gestations were 4. 7 and 6. 2-fold of that at the first trimester of gestation. CS inhibited the activity of thrombin. Conclusion Placental CS is one of the sources of CS in the serum , probably by shedding. From the observation that CS inhibited the activity of thrombin, the increased expression of CS may play an important role in the regulation of blood coagulation during the course of pregnancy.

Beneficial effect of sulphate-bicarbonate-calcium water on gallstone risk and weight control

AIM： To investigate the effect of drinking sulphate-bi- carbonate-calcium thermal water （TW） on risk factors for atherosclerosis and cholesterol gallstone disease.

The separation single-wall carbon nanotubes on length by sepharose gel

The separations of single-wall carbon nanotubes on length by sepharose gel were investigated in this work. The solutions of sodium dodecyl sulfate and sodium deoxycholate were applied as the eluent in sequence. SEM and Raman were used to characterize the length of nanotube bundles. The results show that the longer nanotubes were eluted out first, and then the shorter tubes were followed by the sodium dodecyl sulfate. However, the separated order was totally reversed by the sodium deoxycholate. By this method, the process generated nanotube fractions not only were narrower in length distributions, but also could control the separation orders by changing the eluents. Moreover, the separation principle was also discussed.

Tunable Separation of Single-Walled Carbon Nanotubes by Dual-Surfactant Density Gradient Ultracentrifugation

We present a systematic study of the effects of surfactants in the separation of single-walled carbon nanotubes （SWNTs） by density gradient ultracentrifugation （DGU）. Through analysis of the buoyant densities, layer positions, and optical absorbance spectra of SWNT separations using the bile salt sodium deoxycholate （DOC） and the anionic salt sodium dodecyl sulfate （SDS）, we clarify the roles and interactions of these two surfactants in yielding different DGU outcomes. The separation mechanism described here can also help in designing new DGU experiments by qualitatively predicting outcomes of different starting recipes, improving the efficacy of DGU and simplifying post-DGU fractionation.

改进型拟态弧菌选择性鉴别培养基的研制

旨在研究一种更适用于拟态弧茵快速筛检的改进型选择性鉴别培养基。根据拟态弧茵的特殊生态、营养、代谢、抵抗力等多方特点，并基于保留拟态弧茵选择性鉴别培养基（VmDM）的优点，改进其不足，分析研究并设计了改进型拟态弧茵选择性鉴别培养基（imVmDM）。继而对imVmDM的特异性、显色效果、阳性检出率、灵敏度和准确性进行了与VmDM和TCBS的对此评价。结果显示，培养18～24h，在imVmDM上，拟态弧茵菌落呈紫色，其他致病茵菌落呈黄色或不生长，色差对比显著；而在VmDM上，拟态孤菌茵落呈绿色，与培养基颜色相近；TCBS不能区分拟态孤茵与其余多种致病性弧菌。imVmDM与VmDM、TCBS的检出限都为101cfu／mL，但污染有非拟态弧茵时，imVmDM的特异性、准确性和显色效果更好。并且LimVmDM有效降低了检测成本，每个平板的配制价格由VmDM的5．58元降至0．33元。因此，imVmDM更适用于水产品中拟态弧菌的快速筛检，特别是大量样品的检测，能很大程度地降低检测成本，具有良好的市场应用前景。