Sex-dependent obesogenic effect of tetracycline on Drosophila melanogaster deteriorated by dysrhythmia

Antibiotics have been identified as obesogens contributing to the prevalence of obesity. Moreover, their environmental toxicity shows sex dependence, which might also explain the sex-dependent obesity observed. Yet, the direct evidence for such a connection and the underlying mechanisms remain to be explored. In this study, the effects of tetracycline, which is a representative antibiotic found in both environmental and food samples, on Drosophila melanogaster were studied with consideration of both sex and circadian rhythms (represented by the eclosion rhythm). Results showed that in morning-eclosed adults, tetracycline significantly stimulated the body weight of females (AM females) at 0.1, 1.0, 10.0 and 100.0 µg/L, while tetracycline only stimulated the body weight of males (AM males) at 1.0 µg/L. In the afternoon-eclosed adults, tetracycline significantly stimulated the body weight of females (PM females) at 0.1, 1.0 and 100.0 µg/L, while it showed more significant stimulation in males (PM males) at all concentrations. Notably, the stimulation levels were the greatest in PM males among all the adults. The results showed the clear sex dependence of the obesogenic effects, which was diminished by dysrhythmia. Further biochemical assays and clustering analysis suggested that the sex- and rhythm-dependent obesogenic effects resulted from the bias toward lipogenesis against lipolysis. Moreover, they were closely related to the preference for the energy storage forms of lactate and glucose and also to the presence of excessive insulin, with the involvement of glucolipid metabolism. Such relationships indicated potential bridges between the obesogenic effects of pollutants and other diseases, e.g., cancer and diabetes.     

N和P对锥状斯氏藻(Scrippsiellat trochoidea)生长及孢囊形成的影响

在实验室设置了5个N、P浓度梯度，研究了它们对锥状斯氏藻（Scrippsiella trochoidea）营养细胞生长和孢囊形成的综合效应。结果表明，当N、P浓度分别超过10和1．5μg／L时，就能维持锥状斯氏藻一定的种群数量，而在高N、P浓度组（N浓度为500μg／L，P浓度为74μg／L组）的生长势态明显优于其他浓度组，稳定生长期持续时间较长，且有着较高的细胞比生长速率。孢囊一般在营养细胞达到稳定生长期后开始形成，但低营养盐浓度组孢囊开始形成的时间较早。各试验组孢囊形成率相近，最终形成率为17．8％～35．6％。     

城市污水厂污泥堆肥中试实验研究

城市污水厂污泥由于产生量大且成分复杂，如何对它进行稳定化、无害化处理已越来越受到人们的关注。本研究基于好氧发酵仓式堆肥系统，研究了城市污泥处理过程中温度、含水率、pH、有机质、水溶性有机碳、总氮和发芽指数等指标参数的变化规律。研究结果表明：当物抖初始含水率控制在65％左右时，在强制通风量112．5m^3／12hr，搅拌频率30min/24hr的工艺条件下，堆肥过程可以实现顺利升温并在55℃以上维持3天，满足杀灭致病茵要求的条件；14天反应用期结束时，物抖含水率、水溶性有机碳和有机质含量显著降低，堆肥产品腐熟，卫生学指标达到了美国EPA污泥产品A类标准；得列的污泥产品成为性质优良的土壤质量调节荆。     

银硫离子选择电极测定工业废水中的硫化物

本法用Ag/S离子选择电极测定废水中的硫化物,测定浓度范围0.1～1000.0mg/l,方法精密度为4.3％,回收率为P2.5％,检出限为0.1mg/l。大多数离子不干扰测定,该法简便快速,适用于例行监测。     

Insights into reactive oxygen species formation induced by water-soluble organic compounds and transition metals using spectroscopic method

Ambient particulate matter (PM) can cause adverse health effects via their ability to produce Reactive Oxygen Species (ROS). Water-Soluble Organic Compounds (WSOCs), a complex mixture of organic compounds which usually coexist with Transition Metals (TMs) in PM, have been found to contribute to ROS formation. However, the interaction between WSOCs and TMs and its effect on ROS generation are still unknown. In this study, we examined the ROS concentrations of V, Zn, Suwannee River Fulvic Acid (SRFA), Suwannee River Humic Acid (SRHA) and the mixtures of V/Zn and SRFA/SRHA by using a cell-free 2′,7′-Dichlorodihydrofluorescein (DCFH) assay. The results showed that V or Zn synergistically promoted ROS generated by SRFA, but had an antagonistic effect on ROS generated by SRHA. Fluorescence quenching experiments indicated that V and Zn were more prone to form stable complexes with aromatic humic acid-like component (C1) and fulvic acid-like component (C3) in SRFA and SRHA. Results suggested that the underlying mechanism involving the fulvic acid-like component in SRFA more tending to complex with TMs to facilitate ROS generation through π electron transfer. Our work showed that the complexing ability and complexing stability of atmospheric PM organics with metals could significantly affect ROS generation. It is recommended that the research deploying multiple analytical methods to quantify the impact of PM components on public health and environment is needed in the future.     

Detecting forest landcape boundary between Mountain Birch and evergreen eoniferous forest in the northern slope of Changbai Mountain

Boundaries between different forest types in Changbai Mountain Eatern China are results from complex interactions between forest ecosystems,topogrphy,and geomorphology.Detecting and quantifying the transitional zones are highly important since high environmental beterogeneity and biodiversity are ofter found within these zpmes.In this study,we used GIS and multivariate statistics techniques(PCA and MSWA) to analyze data from Landsat TM satellite imageries and quantitatively determined the positions and widths of the landscape boundary betweeen mountain birch and evergreen coniferous forests in the northern slope of Changbai Mountain.The results showed that the widths of the landscape boundary ranges from 30-50 m while using the MWW A or/and PC method.Such detected widths are consistent with field transect data that suggest a 50m tranistional zone width.The results further suggest that TM data can be used in combination with GIS and statistical techniques in determining forest landscape boundaries.MSWA is more reliable than PCA,while PCA can also be used to determine the landscape boundary when transects are properly located.     

高职电子技术课程改革探讨

本文首先分析了高等职业教育电子技术课程的传统教学方式和弊端，随后探讨了电子技术教学的改革途径：包括高职教材内容的修订和更新，通过多媒体技术与EDA技术改善电子技术的课堂教学；精选验证性实验及强化EDA技术在实验和设计环节中的比例等多方面措施。     

基于集集地震的建筑物易损性统计分析

文章收集了台湾921集集地震的强地震动和震害调查资料，利用统计分析的方法，分析了建筑物破坏的数量、震中距、地表加速度之间的关系，对集集地震做了基于地震动参数的易损性初步分析。     

Mercury consumption and contamination of environment in gold mining in China

1　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｇｏｌｄｉｎｄｕｓｔｒｙｉｎＣｈｉｎａｇｒｏｗｓｕｐｑｕｉｃｋｌｙｗｉｔｈｔｈｅｇｒｏｗｔｈｒａｔｅｏｆａｂｏｕｔ 10 %ｓｉｎｃｅ 90’ｓ.Ｉｎ 1995,ｔｈｅｐｒｏｄｕｃｔｉｏｎｏｆｇｏｌｄｗａｓｏｖｅｒ10 0ｔｏｎｓ/ａ,ａｎｄｉｎ 1996ｒｅａｃｈｅｄ 12 0ｔｏｎｓ/ａ .Ｉｔｉｓｒａｎｋｅｄｓｉｘｔｈｉｎｔｈｅｗｏｒｌｄ(Ｃｈａｎｇ ,1995) .Ｔｈｅｉｒｍａｉｎｐｒｏｃｅｄｕｒｅｓｏｆｇｏｌｄｅｘｔｒａｃｔｉｏｎａｒｅ :(1)ｃｙａｎｉｚａｔｉｏｎｉｎｔｏｔａｌｏｒｅ ｃａｒｂｏ…     

北方庭院生态系统能量分析及养分平衡研究

以基于食用菌生产的北方庭院生态系统为研究对象，通过对沈阳南郊一典型农户庭院生态系统的能量分析与养分平衡研究表明，该庭院生态系统的产品总输出能为４１８７２１４ＭＪ／ａ，其中平菇产品的生物能占６５４％；输入输出系统的Ｎ、Ｐ２Ｏ５及Ｋ２Ｏ基本上保持着养分平衡；该庭院生态系统是一个生产力高、综合效益可观的系统，对指导该地区农村庭院生态系统建设具有重要的现实意义。