Estrogenic activities of two synthetic pyrethroids and their metabolites

Synthetic pyrethroids(SPs) are among the most common pesticides in current use,and so far,several SPs have been assessed for their potential estrogenicities by various methods.Previous studies have shown that the estrogenicities partly come from their metabolites.Although considerable information is available with respect to the metabolism and environmental degradation of SPs,little is known about the estrogenicities of the metabolites.In this study,permethrin(PM) and β-cypermethrin(CP),as well as their metabolites(3-phenoxybenzoic alcohol(PBCOH),3-phenoxybenzaldehyde(PBCHO) and 3-phenoxybenzoic acid(PBCOOH) were evaluated for their estrogenic activities in the MCF-7 human breast carcinoma cell line.In the MCF-7 cell proliferation assay,PM and CP exhibited significant estrogenic activities at 10-7 mol/L,comparable to 17β-estradiol(E2 ) of 10-9 mol/L,with the relative proliferative effect ratios of 55.4% and 56.3%,respectively.The real-time quantitative polymerase chain reaction(qRT-PCR) results confirmed the estrogenicities of PM and CP with significant alteration of pS2 and ERα mRNA levels observed at 10-6 mol/L.For the three major metabolites,PBCOH and PBCOOH exhibited estrogenic activities in all assays,while no significant estrogenic responses was observed for PBCHO compared to the vehicle control.In particular,PBCOH had even slightly stronger estrogenic activity than its parent compounds,indicating that metabolism may be one of the reasons for the estrogenicities of the SPs.Given the widespread use of SPs,the toxicological effects of parent compounds and their metabolites should be taken into consideration in the risk assessment of SPs.     

以苯酚为燃料的微生物燃料电池产电特性

选取城市污水处理厂的好氧和厌氧混合污泥作为接种液,构建了双极室微生物燃料电池(Microbial fuel cell, MFC),对以葡萄糖、葡萄糖和苯酚、苯酚为不同燃料的MFC进行了有机物降解和产能效果的研究.试验结果表明,以葡萄糖为单一燃料时MFC的启动时间最短,以苯酚为单一燃料时MFC启动时间最长.MFC在不同燃料来源条件下对苯酚去除率均大于85%,COD去除率超过80%.MFC的连续运行试验结果表明,在1000Ω外电阻条件下,以葡萄糖为单一燃料的MFC运行周期最长,可达400h,最大输出电压为551mV,功率密度为 121 mW·m-2(阳极);以葡萄糖和苯酚为混合燃料的MFC运行周期约200h,最大输出电压为208mV,功率密度为 16mW·m-2(阳极);而以苯酚为单一燃料的MFC运行周期仅约为100h,最大输出电压为121mV,功率密度为 6 mW·m-2(阳极).试验结果最终表明,MFC能够利用苯酚作为燃料,在实现高效降解的同时可稳定地向外输出电能,这为酚类难降解有机物的高效低耗处理提供了新的研究思路.     

大气污染物多时间分辨率的小波分析

利用Modet小波函数进行小波变换,利用Daubechies小波函数进行分解及滤波,以乌鲁木齐市的大气污染物时间序列为例,分析了当地单个大气监测站点NO2的多分辨率的演变特性,并对NO2的时间序列进行了滤波消噪.研究结果显示,NO2年际变化和季节性变化的时间尺度在尺度空间中分布不均匀,具有较明显的局部化特征;除了季节性变化的时间尺度和变化趋势之外,还存在大气污染物中、长期变化趋势.基于滤波消噪后的时间序列建立的预测模型可用于有效地提高大气污染物的预测预报精度.     

Effects of operational factors on soluble microbial products in a carrier anaerobic baffled reactor treating dilute wastewater

The effects of feed strength,hydraulic residence time(HRT),and operational temperatures on soluble microbial product(SMP) production were investigated,to gain insights into the production mechanism.A carrier anaerobic batfled reactor (CABR) treating dilute wastewater was operated under a wide range of operational conditions,namely,feed strengths of 300-600 mg/L,HRTs of 9-18 h,and temperatures of 10-28℃.Generally, SMP production increased with increasing feed strength and decreasing temperature.At high temperature (28℃),SMP production increased with decreasing HRT. As the temperature Was decreased to 18 and 10℃.the SMP production was at its peak for 12 h HRT Therefore,temperature could be an important determinant of SMP production along with HRT. A higher SMP to soluble chemical oxygen demand (SCOD) ratio Was found at high temperature and long HRT because of complete volatile fatty acid degradation.SMP accounted for 50%-75% of the SCOD in the last chamber of the CABR.As a secondary metabolite.some SMP could be consumed at lower feed strength.     

关于显色时间对磷工作曲线影响的分析

本文利用钼锑抗分光光度法测定水中磷的监测方法,通过简要的理论、实验分析,得出采用该方法的最佳显色时间为15分钟至30分钟等经验性结论。     

中国第1个天线时域近场测量系统

介绍了天线近场测量的历史以及中国第1个天线时域近场测量系统的建立过程和系统组成.指出时基修正和幅度修正技术是天线近场测量由理论向工程实际转化的关键技术,介绍了修正系统的构成和基本计算方法,并给出了修正前后测量结果的对比.在频域近场技术的背景下对时域近场的技术特点进行了分析,指出了天线时域近场测量技术的独到之处和应用前景.     

射频连续电磁波对某数字电路的辐照效应研究

在GTEM室中用射频连续波对某导弹装备上的一块数字控制电路进行电磁辐照,在一定的场强下,引入的电磁干扰还未导致被监测的与非门产生错误反转时,产生控制信号的自激多谐振荡器却首先受到了电磁干扰,主要表现为产生的方波控制信号的占空比增大.分别研究了波源频率在245MHz和330MHz的情况下电路受干扰的情况,辐照实验分别对待测设备按水平横向放置、水平纵向放置和竖直放置3种放置方位分别进行了辐照.最后对水平横向放置的两个频点,将方波控制信号的占空比随场强的变化进行了相关性拟合,建立了数学模型.     

含油污泥调质影响因素研究

针对某炼油污水处理厂产生的含油污泥,采用调质-机械分离方法进行处理。考察温度、pH值和搅拌时间对含油污泥调质效果的影响。结果表明,以PR—A复合药剂为调质剂,在温度为70℃-80℃,pH值为4．0—5．0,搅拌时间为30min条件下,经55kPa（绝压）抽滤后,含油污泥的处理效果最好,滤饼含水率可达到70．3％,进一步方便含油污泥的后续处理,有利于污泥的资源化利用和无害化处理。     

Factors affecting the sex ratio in the honeybee mite <Emphasis Type="Italic">Varroa jacobsoni</Emphasis>

Study of the seasonal variation of the sex ratio in the honeybee mite Varroa jacobsoni demonstrated that sex determination was affected by temperature, order of reproductive cycles, and population densities in the host’s brood cell and the honeybee nest. The mechanism of reproduction ensuring adaptation of the mite to parasitism and reproduction on honeybees are discussed.     

阳极初始电势对微生物燃料电池产电的影响

在微生物燃料电池中,阳极电势会对产电菌的富集和生长产生影响.为进一步明确阳极电势的作用,确定适合微生物生长的最佳阳极电势,在微生物燃料电池的阳极室中设置附加电路以改变阳极的初始电势,考察阳极初始电势对产电微生物的影响.将阳极初始电势设为350 mV时,产电微生物的生长明显变慢.而阳极初始电势为-200 mV和200 mV时,微生物的生长速度基本相同.稳定运行后,阳极初始电势分别为350、200和-200 mV的微生物燃料电池,阳极内阻分别为71、43和80 Ω.通过变性梯度凝胶电泳(DGGE)分析微生物燃料电池稳定产电前后阳极微生物群落结构,虽然3个微生物燃料电池的阳极初始电势不同,但稳定后微生物群落结构相似,Clostridium sticklandii、Pseudomonas mendocina、Paenibacillus taejonensis在阳极的富集量最多,MFC对这3种细菌的强化富集作用最明显.