2株苯胺降解的分离鉴定及其降解特性研究

从处理印染废水的活性污泥中分离得到2株苯胺降解菌,从菌落、细胞形态、生理生化及16S rRNA基因扩增测序等方面对2株菌进行了鉴定,并比较分析2株菌在好氧与缺氧条件下的苯胺降解、偶氮染料脱色及苯胺脱氨氧化酶基因tdnQ和黄素还原酶基因(fre)的携带情况.结果表明,2株菌属于Pseudomonas属和Shewanella属,分别命名为Pseudomonas sp.AN30和Shewanella sp.DN425.AN30菌株在振荡好氧条件下72h内对250mg/L苯胺的降解率为96.1%,DN425菌株的降解率为13.8%;在静置缺氧条件下AN30菌株的苯胺降解率为39.6%,DN425菌株的降解率仅为8.6%.DN425菌株在静置缺氧条件下4h内可将初始浓度为50 mg/L的偶氮染料酸性大红彻底脱色,而AN30菌株对酸性大红不具有脱色能力.以总DNA为模板,分别用tdnQ基因和fre基因特异性引物进行扩增,2株菌均能扩增出大小分别为380bp和630bp左右的目标条带,显示2菌株均携带有苯胺脱氨氧化酶基因和黄素还原酶基因.     

亚硝态氮胁迫下菲律宾蛤仔实时定量P CR内参基因的筛选

为了更好地从基因角度研究亚硝态氮对贝类的生态毒性,需要筛选一个合适的内参基因作为参考,对其毒性相关基因进行定量表达分析。本研究以菲律宾蛤仔(Ruditapes philippinarum)作为研究对象,以亚硝态氮胁迫的鳃组织cDNA作为模板,利用geNorm软件和NormFinder软件对6个候选内参基因进行表达稳定性分析,并对2个结果做了综合赋权分析。结果显示,geNorm分析的基因表达稳定性结果为ActinCyPAEF1αUbi18STubu,NormFinder软件分析的结果为ActinUbiCyPAEF1α18STubu,最后经加权赋值法综合分析获得6个候选基因的表达稳定性为ActinCyPAUbiEF1α18STubu,即Actin为表达最稳定的基因。因此,Actin可以作为衡量亚硝态氮胁迫后菲律宾蛤仔鳃组织中基因表达的内参基因。     

声凝并联合雾化预处理及其在过滤除尘中的应用

根据声凝并理论和雾化湿式除尘理论,建立了燃煤飞灰在声场联合雾化加湿作为预处理的过滤式除尘实验装置。分别在声场、雾化加湿、声场与雾化加湿相结合3种预处理条件下进行实验,确定合适的加湿量范围,得出不同条件下燃煤飞灰的去除效果。在声场联合雾化加湿条件下,分别研究了声压级和雾化加湿量对飞灰的去除率的影响。结果表明,声场和雾化加湿联合作用能有效提高燃煤PM2.5去除率。以声场联合雾化加湿作为预处理进行过滤除尘实验,结果表明,虽然对高效滤料的除尘效率提高作用有限,但是该预处理可减轻滤袋负荷,有效延缓压差增长,降低清灰频率。由于采用表面覆膜滤材,加湿量控制得当可避免产生"糊袋"现象。     

浮游动物DNA宏条形码标志基因比较研究

DNA宏条形码技术作为一种新型生物监测方法,在未来生态环境监测中有巨大的应用潜力。目前,浮游动物DNA宏条形码监测仍在发展阶段,需要首先对其(采样方法、引物选择和数据分析等)进行标准化和调整,然后才能用于常规流域生态监测。其中,如何选择合适的PCR扩增引物是DNA宏条形码生物监测标准化的关键问题之一。本研究比较了COI、18SV9和16S通用引物在浮游动物DNA宏条形码监测中的差异,为初步建立规范化的浮游动物DNA宏条形码监测方法提供技术支撑。结果表明,16S引物对浮游动物具有更好的特异性,其产生的操作分类单元(operational taxonomic unit, OTU)有88.1%属于浮游动物。虽然18SV9引物具有更高的物种覆盖度,不仅能扩增出浮游动物,还能扩增出大量藻类和真菌,但其物种识别敏感性较差,不适合浮游动物物种水平多样性监测。COI引物的浮游动物物种特异性、物种覆盖度和物种识别敏感性都适中,检出的浮游动物物种数量高于18SV9引物和16S引物,更加适合浮游动物DNA宏条形码监测。     

Validation of Bacteroidales-based microbial source tracking markers for pig fecal pollution and their application in two rivers of North China

• Pig feces is the predominant excrement produced by animal husbandry in China. • The PF, Pig-1-Bac^TaqMan, and Pig-2-Bac^TaqMan MST assays showed better performance. • The pig-specific MST assays can contribute to managing the pig fecal pollution. In China, pig feces is the predominant source of excrement produced by animal husbandry. Improper use or direct discharge of pig feces can result in contamination of natural water systems. Microbial source tracking (MST) technology can identify the sources of fecal pollution in environmental water, and contribute to the management of pig fecal pollution by local environmental protection agencies. However, the accuracy of such assays can be context-dependent, and they have not been comprehensively evaluated under Chinese conditions. We aimed to compare the performance of five previously reported pig-specific MST assays (PF, Pig-Bac1^SYBR, Pig-Bac2^SYBR, Pig-1-Bac^TaqMan, and Pig-2-Bac^TaqMan, which are based on Bacteroidales 16S rRNA gene markers) and apply them in two rivers of North China. We collected a total of 173 fecal samples from pigs, cows, goats, chickens, humans, and horses across China. The PF assay optimized in this study showed outstanding qualitative performance and achieved 100% specificity and sensitivity. However, the two SYBR green qPCR assays (Pig-Bac1^SYBR and Pig-Bac2^SYBR) cross-reacted with most non-pig fecal samples. In contrast, both the Pig-1-Bac^TaqMan and Pig-2-Bac^TaqMan assays gave 100% specificity and sensitivity. Of these, the Pig-2-Bac^TaqMan assay showed higher reproducibility. Our results regarding the specificity of these pig-specific MST assays differ from those reported in Thailand, Japan, and America. Using the PF and Pig-2-Bac^TaqMan assays, a field test comparing the levels of pig fecal pollution in rivers near a pig farm before and after comprehensive environmental pollution governance indicated that pig fecal pollution was effectively controlled at this location.     

Gender and career success: A typology and analysis of dual paradigms

Despite women's advancements in the workplace, gender inequality persists. We classify and test two frameworks used to explain gender differences in career success: unequal attributes and unequal effects. The unequal attributes framework suggests that gender is related to other attributes, which result in unequal career outcomes for men and women (i.e., a mediated effect). The unequal effects framework suggests that even when men and women share the same attribute or circumstances, they are rewarded differently, such that individual attributes have unequal effects on career outcomes for men and women (i.e., a moderated effect). We collected survey data from a gender‐balanced sample of 394 business school alumni. Using structural equation modeling to test the unequal attributes framework, we found that work hours, career orientation, having a nonemployed spouse, and working in a predominantly female job were unequal attributes that explained gender differences in career success. Using multigroup path analysis to examine unequal effects, we found that being agentic, married, having children at home, and working in a predominantly female workplace had unequal effects in relation to career success for men and women. We find support for both models across three categories of career success antecedents (i.e., personal, family, and job attributes).     

辣椒倍半萜环化酶基因在几种非生物诱发因子作用下的表达

报道了在CuCl2,HgCl2及NaCl、紫外线等几种诱发因子作用下辣椒倍半萜环化酶活性表达，并利用从辣椒中克隆出来的2个倍半萜环化酶等位基因cDNA的特异性片段，研究这两个等位基因在上述诱发因子作用下的表达情况，结果表明：在CuCl2,HgCl2,NaCl2、紫外线诱发作用下，离体辣椒叶片均能表现一定的倍半萜环化酶活性，而CK中几乎检测不出倍半萜环化酶活性，Northern Blot分析表明，辣椒倍半萜环化酶基因在逆境下被诱转导，两个cDNA在不同的诱发因子在相同的逆境胁迫下的表达有一定的特异性，推测该基因家族的不同成员在辣椒适应不同逆境的防御反应中有一定的意义，图5参6。     

城市生活垃圾的DSC和TGA分析与热值估算

利用微分扫描量热仪（ＤＳＣ）准确地测定了城市生活垃圾的含水率；热重分析仪（ＴＧＡ）测定了垃圾的水和低温下有机物总含量、难挥发性有机物和灼烧残渣的含量。根据量热和热量分析结果，可方便地计算垃圾的水和低温条件下易挥发性有机物含量，结合６０９种有机物的燃烧热，估算了垃圾的热值。