Estimation of bioaccessibility and potential human health risk of mercury in Chinese patent medicines

Mercury(Hg), mainly in cinnabar species, has been used in medicine for thousands of years in China, and worldwide concern has been raised on its toxicity. In this work, the amount of bioaccessible mercury in 16 Chinese patent medicines(CPMs) was measured by using an in vitro simulated digestion system, consisting of simulated gastric and intestinal fluid, to investigate the bioavailability of mercury in CPMs and evaluate its potential risk to human health. Total mercury and mercury in the gastrointestinal extracts were measured by inductively coupled plasma mass spectrometry(ICP-MS). The levels of total Hg in 16 CPMs ranged from not detected to 11.89 mg/g, with a mean value of 1.13 mg/g, while the extractable Hg ranged from not detected to 4.37 μg/g, with a mean value of 0.42 μg/g.Mercury bioaccessibility varied significantly in the investigated CPMs, depending on the ingredient. Compared to the CPMs without cinnabar(2.5%–30.9%), the percentage of mercury in the gastrointestinal supernatants for CPMs with cinnabar was quite a bit lower(0.037%). By comparing with the Food and Agricultural Organization/World Health Organization Joint Expert Committee on Food Additives(FAO/WHO) safety guideline, the average daily intake dose(ADD) of Hg in the medicines was then calculated to access the risk of mercury to human health from taking CPMs.     

Fungal diversity in major oil-shale mines in China

As an insufficiently utilized energy resource,oil shale is conducive to the formation of characteristic microbial communities due to its special geological origins.However,little is known about fungal diversity in oil shale.Polymerase chain reaction cloning was used to construct the fungal ribosomal deoxyribonucleic acid internal transcribed spacer(r DNA ITS)clone libraries of Huadian Mine in Jilin Province,Maoming Mine in Guangdong Province,and Fushun Mine in Liaoning Province.Pure culture and molecular identification were applied for the isolation of cultivable fungi in fresh oil shale of each mine.Results of clone libraries indicated that each mine had over 50% Ascomycota(58.4%–98.9%)and 1.1%–13.5%unidentified fungi.Fushun Mine and Huadian Mine had 5.9% and 28.1% Basidiomycota,respectively.Huadian Mine showed the highest fungal diversity,followed by Fushun Mine and Maoming Mine.Jaccard indexes showed that the similarities between any two of three fungal communities at the genus level were very low,indicating that fungi in each mine developed independently during the long geological adaptation and formed a community composition fitting the environment.In the fresh oil-shale samples of the three mines,cultivable fungal phyla were consistent with the results of clone libraries.Fifteen genera and several unidentified fungi were identified as Ascomycota and Basidiomycota using pure culture.Penicillium was the only genus found in all three mines.These findings contributed to gaining a clear understanding of current fungal resources in major oil-shale mines in China and provided useful information for relevant studies on isolation of indigenous fungi carrying functional genes from oil shale.     

Growth inhibition and oxidative damage of Microcystis aeruginosa induced by crude extract of Sagittaria trifolia tubers

Aquatic macrophytes are considered to be promising in controlling harmful cyanobacterial blooms. In this research, an aqueous extract of Sagittaria trifolia tubers was prepared to study its inhibitory effect on Microcystis aeruginosa in the laboratory. Several physiological indices of M. aeruginosa, in response to the environmental stress, were analyzed. Results showed that S. trifolia tuber aqueous extract significantly inhibited the growth of M. aeruginosa in a concentration-dependent way. The highest inhibition rate reached 90% after 6 day treatment. The Chlorophyll-a concentration of M. aeruginosa cells decreased from 343.1 to314.2 μg/L in the treatment group. The activities of superoxide dismutase and peroxidase and the content of reduced glutathione in M. aeruginosa cells initially increased as a response to the oxidative stress posed by S. trifolia tuber aqueous extract, but then decreased as time prolonged. The lipid peroxidation damage of the cyanobacterial cell membranes was reflected by the malondialdehyde level, which was notably higher in the treatment group compared with the controls. It was concluded that the oxidative damage of M. aeruginosa induced by S.trifolia tuber aqueous extract might be one of the mechanisms for the inhibitory effects.     

Seasonal,diurnal and nocturnal variations of carbonyl compounds in the semi-urban environment of Orléans,France

Atmospheric carbonyls were measured at a semi-urban site in Orléans, France, from October 2010to July2011. Formaldehyde, acetaldehyde and acetone were found to be the most abundant carbonyls, with average concentrations of 3.1, 1.0, 2.0 ppb, respectively in summer, 2.3, 0.7, 2.2 ppb, respectively in autumn, 2.2, 1.0, 2.1 ppb, respectively in spring,and 1.5, 0.7, 1.1 ppb, respectively in winter. Photo-oxidation of volatile organic compounds(VOCs) was found to make a remarkable contribution to atmospheric carbonyls in the semi-urban site based on the distinct seasonal and diurnal variations of the carbonyls, as well as the significantly positive correlations between the carbonyls and ozone. The significantly negative correlations between NO x and O_3 as well as the carbonyls and the positive correlations between wind speed and O_3 as well as the carbonyls implied that the carbonyls and O_3 at the semi-urban site were probably formed during air mass transport from neighboring cities.     

乌梁素海和岱海沉积物有机碳的形态特征

以富营养化类型不同的乌梁素海和岱海为对象,开展湖泊沉积物中有机碳的形态特征研究,对比分析了2个湖泊沉积物有机碳的形态特征及其差异性.结果表明,乌梁素海沉积物中总有机碳(TOC)含量范围为4.50～22.83 g·kg-1,平均11.80g·kg-1;重组碳(HFOC)含量范围为3.38～21.67 g·kg-1,平均1...     

基于功能安全标准的安全仪表系统可靠性评估软件

介绍了以功能安全国际标准IEC61508和IEC61511工程应用要求为依据,集安全仪表系统的安全仪表功能安全完整性等级(SIL)分配、安全要求规范(SRS)制定、SIL验证、可靠性数据管理等多功能为一体的安全仪表系统可靠性专用评估软件。     

离子选择电极法与离子色谱法测定生活饮用水中氟化物的比较

为比较离子选择电极法和离子色谱法测定水中氟化物是否存在显著性差异,分别使用两种方法测定了永州市两个集中式生活饮用水水源地的地表水中含氟量。并采用SPSS13.0软件对两种方法测定结果进行了统计检验。其检验结果显示,两种方法的精密度、准确度和测定结果无显著性差异,均可作为测定生活饮用水中氟含量的方法。     

冷冻分离法处理难降解有机废水的研究

以无机水样、溴氨酸溶液、U llm ann缩合反应生产废水及垃圾渗滤液为研究对象,考察了在人工条件下冷冻法处理无机离子和有机污染物的效果和差别。结果表明:在人工冷冻条件下,无机离子、溴氨酸的去除率均可达到80%~90%以上,并受冷冻时间、初始浓度、污染物自身结构特性等因素影响;而对于无机离子和有机污染物混合的实际有机废水,其去除率相对较低,为70%~80%左右,需要与其他工艺组合,以提高废水的处理效率。     

7-ACA清洁生产的潜力研究

7-ACA是头孢菌素关键性中间体。近年来,头袍菌素类抗生素使用越来越多,临床应用证明它是一类抗菌谱广、抗菌活性强,疗效高和毒性低的抗生素。然而,中国在7-ACA生产过程中普遍面临着污染重、废弃物成分复杂、治理难度大的发展"瓶颈"。本文从清洁生产源头消减的角度,分析了7-ACA清洁生产的潜力与机会,并在国内7-ACA生产现状下,提出了化学法清洁生产方案的建议。