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41.
Vertebrate eggs contain maternal steroid hormones in their yolks; and in avian species the concentration of these steroids vary within and among clutches. The organizational actions of these variable doses of maternal steroids in the avian egg, analogous to those regulating the development of sexually dimorphic traits, are little explored. In this study, we examined the organizational effects of yolk testosterone in the house sparrow, Passer domesticus, a sexually dichromatic passerine bird in which males are characterized by the presence of a throat patch or badge of black feathers that varies in size among males. We injected a physiological dose of testosterone or vehicle into eggs in the field, removed nestlings, and hand-raised them in the laboratory. At 5 months of age, we investigated treatment effects on plumage and behavior. Males that hatched from testosterone-injected eggs developed a larger badge than males that hatched from vehicle-injected (control) eggs. However, testosterone did not induce the expression of a badge in females. In staged dyadic encounters, both males and females hatched from testosterone-injected eggs were more successful at obtaining and defending a food source than individuals of the same sex hatched from control eggs. The results suggest that variable concentrations of maternal testosterone in the eggs of the house sparrow organize the expression of a plumage trait in males and behavior in both sexes.Communicated by J. Graves  相似文献   
42.
养殖场沼液中雌激素排放特征及去除效果研究   总被引:1,自引:0,他引:1  
为探究典型奶牛养殖场沼液中类固醇雌激素的排放特征,采用固相萃取-高效液相色谱串联质谱(SPE-HPLC-MS/MS)分析方法,对重庆市某奶牛养殖场厌氧池和好氧池出水中类固醇雌激素进行夏、秋、冬3季连续监测.结果表明:类固醇雌激素(含雌酮;17α-雌二醇;17β-雌二醇;雌三醇;硫酸雌酮)在厌氧池和好氧池出水中总浓度分别在347.28~2117.65ng/L和10.75~1070.00ng/L之间,其中厌氧池出水以雌酮(E1)、17α-雌二醇(17α-E2)和17β-雌二醇(17β-E2)为主,好氧池出水以E1和17β-E2为主.研究显示:好氧处理对E1、17β-E2、17α-E2的平均去除率达85.70%、56.82%、57.32%,厌氧处理可有效去除硫酸雌酮(E1-3S).在微生物作用下,厌氧和好氧处理均存在E1、17α-E2和17β-E2的相互转化,但雌三醇(E3)的低检出率则显示体系中雌激素转化为E3的比例较低.对雌激素活性(EEQ95th)的评估显示厌氧-好氧处理后雌激素活性平均降低70.34%,但沼液的雌激素生态环境风险仍不可忽视,需持续观察及研究.  相似文献   
43.
Dutta, Sudarshan, Shreeram Inamdar, Jerry Tso, Diana S. Aga, and J. Tom Sims, 2012. Dissolved Organic Carbon and Estrogen Transport in Surface Runoff from Agricultural Land Receiving Poultry Litter. Journal of the American Water Resources Association (JAWRA) 48(3): 558-569. DOI: 10.1111/j.1752-1688.2011.00634.x Abstract: Dissolved organic carbon (DOC) provides a reactive substrate for the transport of organic contaminants with runoff. Very few studies have investigated the export of DOC from agricultural land, especially those receiving manure applications. We investigated exports of DOC in surface runoff from agricultural fields receiving various treatments of poultry litter (raw vs. pelletized). In addition, we also investigated how estrogens in runoff were associated with DOC. Different forms of estrogens studied were: estrone, 17β-estradiol, estriol, and their conjugates. Experimental agricultural plots were 12 m × 5 m long and had reduced tillage and no-till management practices. The aromatic content of DOC was characterized using specific ultraviolet absorbance (SUVA). Flow-weighted concentrations of DOC and SUVA in surface runoff from plots with poultry litter were significantly (p ≤ 0.10) greater than the control (no litter) plots. Compared to pelletized poultry litter, reduced-tillage plots with raw litter yielded higher DOC concentrations and SUVA values. No significant differences (p ≥ 0.10) in DOC and SUVA were observed between litter treatments for plots with no-till. Total estrogen concentrations (including all forms) were positively and significantly (p ≤ 0.10) correlated with DOC. These results can help select and guide agricultural management practices that can reduce the exports of DOC and associated contaminant from agricultural land receiving manure applications.  相似文献   
44.
极性有机物一体化采样器(POCIS)作为富集水体中有机物的新型采样技术,可以反映目标物在被测水体中的时间权重浓度,因此在环境监测中是对主动采样方式的重要补充.本研究采用POCIS进行了4种固醇类雌激素化合物(雌酮、雌二醇、雌三醇及雌炔醇)的富集动力学,以及温度和目标物浓度对POCIS富集雌激素影响的实验室模拟研究.结果表明,POCIS对目标化合物的富集放置时间7 d内呈现显著的线性关系(r2≥0.988 1,P<0.001).温度对目标物在POCIS上富集的影响比较显著(RSD>12%),随着温度的升高,目标化合物在POCIS上的采样速率减小.而目标物浓度对POCIS富集没有显著的影响(RSD<5%).将所建立的POCIS采样装置应用于九龙江流域的现场环境中,发现利用POCIS估算出的目标物时间权重浓度与主动采样测定的浓度具有显著的相关性(r2=0.720 9,P<0.001),验证了POCIS在实际环境中的可应用性.  相似文献   
45.
磁性分子印迹材料对双酚A的识别与选择性吸附   总被引:2,自引:2,他引:0  
通过简单的溶胶-凝胶法制备了以Fe3O4@SiO2为载体的磁性分子印迹材料(MMIPs),通过TG、FT-IR、VSM和TEM等方法对其物理化学性质进行了表征,并研究了其对双酚A(BPA)的识别与选择性吸附性能.研究发现印迹材料对BPA有特殊的吸附能力,即能够与BPA上的酚羟基发生键合形成氢键,其对BPA的吸附符合Langmuir吸附模型和拟二级吸附动力学;且在pH=6时,其对BPA的吸附能力达到最强,为18.37 mg·g-1(温度为25℃,时间为60 min).与其它结构相似的酚类化合物相比,MMIPs对BPA的吸附最强,具有选择识别性;可利用良好的磁性(15.4 emu·g-1)使BPA从溶液中分离去除;并且MMIPs可以循环使用6次;此材料在微量BPA的提取、分离与吸附等领域具有应用价值.  相似文献   
46.
47.
以雌酮(E1)和17α-乙炔基雌二醇(EE2)2种典型类固醇雌激素为研究对象,考察了不同硝化负荷好氧MBR对其的去除特性.结果表明,硝化负荷为6.19,0.35,10.58mg/(gMLSS·d)的MBR对E1平均去除率分别为72.33%、64.06%和71.77%,去除负荷分别为29.98,23.06,27.66mg/(gMLSS·d);对EE2平均去除率分别为55.40%、42.87%和58.90%,去除负荷分别为22.39,16.54,23.58mg/(gMLSS·d).E1去除效果均优于EE2.MBR硝化负荷与氨氧化细菌之间有较好的线性关系;而SEs去除负荷与氨氧化细菌及硝化负荷之间不满足线性关系.硝化负荷为0.35mg/(gMLSS·d)时,SEs去除负荷较低,硝化负荷达到6.19mg/(gMLSS·d)时,SEs的去除负荷显著提高,而当硝化负荷增加到10.58mg/(gMLSS·d)时,SEs去除负荷不再有效提高.  相似文献   
48.
The Ave River flows through the most urbanized and industrialized Porto district areas. Despite ovotestis was recently reported in male fish from the estuary, no data exist on the water levels of natural and pharmaceutical estrogens (17β-estradiol, estrone, and 17α-ethynylestradiol), xenoestrogenic industrial pollutants (4-octylphenol, 4-nonylphenol and their mono and diethoxylates, and bisphenol A), phytoestrogens (formononetin, biochanin A, daidzein, and genistein), and sitosterol. Absence of analyses applies to the river, estuary, and nearby coastline. Those compounds mimic the action of endogenous estradiol, being well-recognized endocrine disrupters (EDCs). To conclude about suspected influxes of estrogenic EDCs into the river and coastline, water samples were taken at eight sites every two months, during one year (2010), at low tide. Data showed ubiquitous presence of potentially hazardous amounts of estrogens (particularly ethynylestradiol, up to 10 ng L?1), nonylphenol (up to 250 ng L?1), and sitosterol (up to 6 μg L?1), which helps explaining the ovotestis emergence in local fish. Also, because physicochemical parameters used in water quality evaluation, such as pH, dissolved oxygen, nitrates, and nitrites levels, were within legal limits – suggesting good quality – our study supports that assessment of human and environmental risks by targeting surface waters requires integrating EDCs monitoring in routine analyses.  相似文献   
49.
利用唐鱼雌激素受体基因片段构建重组酵母,用以筛选环境雌激素类化学物质.实验先将唐鱼雌激素受体terα基因片段插入载体pGADT7中构建表达质粒p GADT7/TERα,同时将雌激素效应元件(ere)片段插入pMP206载体中构建报告质粒pMP206/ERE-Lac Z;然后把表达质粒和报告质粒共转化到酵母AH109中,经筛选成功构建了由唐鱼雌激素受体调控的表达lac Z基因的重组酵母AHpTERα/ERE.结果表明,所构建的重组酵母AHpTERα/ERE在不同浓度17β-雌二醇(E2)的诱导下,β-半乳糖苷酶的活性呈现出明显的剂量-效应关系,其EC50为(0.521±0.700)nmol·L-1.与DMSO对照组相比,重组酵母在17β-雌二醇诱导下有明显的β-半乳糖苷酶活性增强的现象.在不同浓度17α-乙炔基雌二醇(EE2)、壬基酚(NP)及其混合物、双酚A(BPA)、17β-雌二醇(E2)(阳性对照)的诱导下,重组酵母均呈现出剂量-效应关系,且灵敏度大小为E2EE2NPBPA.结果表明,本研究成功构建了重组基因酵母测评系统,初步判定该重组酵母可应用于环境雌激素的筛选.  相似文献   
50.
为探究孕期全氟辛烷磺酸(PFOS)暴露与母源糖皮质激素(GC)水平、胎鼠生长发育之间的关系,将孕期为12 d(GD12)的24只SD雌性大鼠,随机分为4组给予不同剂量的PFOS(0,5,10,20 mg·kg-1),连续灌胃7 d,在GD19时对孕鼠和胎鼠的体重、胎鼠肝脏系数和肝脏生化指标、孕鼠血清的生化指标和GC水平、胎盘11β-羟基类固醇脱氢酶2(11β-HSD2)的酶学活性和胰岛素样生长因子-1(IGF-1)的mRNA表达水平分别进行检测。结果表明,与对照组相比:PFOS 20 mg·kg-1组,母鼠体重、胎鼠体重和体长显著下降(P0.001);PFOS 20 mg·kg-1组,胎鼠肝脏脏器系数低于对照组(P0.001);PFOS 10 mg·kg-1组,胎鼠肝脏中的酶活性(ALT、AST和ALP等)显著升高(P0.001);PFOS 20 mg·kg-1组,孕鼠血清GC水平升高(P0.05);胎盘IGF-1的mRNA表达水平随PFOS剂量升高而降低;胎盘11β-HSD2的活性随PFOS剂量升高而降低。研究表明,孕期暴露PFOS可以导致胎鼠肝脏毒性,降低胎盘11β-HSD2氧化活性导致GC浓度升高,进而影响胎鼠的生长发育。  相似文献   
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