Detection and enumeration of colonic mucosal cells in amniotic fluid using a colon epithelial-specific monoclonal antibody

Since its introduction, prenatal diagnosis of chromosomal and metabolic disorder by mid-trimester amniocentesis has relied upon the use of a mixture of fetal cells obtained from amniotic fluid. Little knowledge has been gained in the sorting of these cells for diagnosis of tissue-specific disorders. In an attempt to determine the contribution of fetal colonic mucosal cells to the overall amniocyte population, we used the colonic epithelial-specific monoclonal antibody (MC-Ab) 7E₁₂H₁₂, IgM isotype. Specimens of the small intestine, colon, buccal mucosa, kidney, urinary bladder, and umbilical cord were obtained from electively aborted normal fetuses of 12–28 weeks' gestation. All of these specimens were examined with 7E₁₂H₁₂ by the immunoperoxidase technique. The MC-Ab reacted with the colonic epithelial cells but not with any of the other tissues. In addition, 40 amniotic fluid samples obtained from women between 16 and 18 weeks of gestation, who underwent amniocentesis because of advanced maternal age, were tested using a fluorescent activated cell sorter. Among the amniotic fluid specimens examined, 18·4 ± 10·3 percent cells reacted with 7E₁₂H₁₂. Double immunofluorescence studies revealed that all Mc-Ab-stained cells contained secretory component, confirming that they were epithelial in origin. All fetuses whose amniotic fluid was analysed had normal karyotypes and amniotic fluid alpha-fetoprctein levels that were also normal. This study demonstrates that cell-specific Mc-Ab can be used to detect colon cells in the amniotic fluid and that colon cells contribute significant numbers in the mixture of amniotic fluid cells. This technique could be helpful in the prenatal diagnosis of disorders in which the flow of amniotic fluid through the fetal intestine is impaired, such as cystic fibrosis, imperforate anus, Hirschsprung aganglionic megacolon, and intestinal atresia.     

基于升流式厌氧污泥床反应器的微生物燃料电池的研究

构建了一种基于升流式厌氧污泥床反应器（UASB）的微生物燃料电池（MFCs）,利用UASB高效去除COD能力及连续进样方式,获得稳定电能输出。考察了水力停留时间、进液方式、电极材料、离子交换膜种类、溶液离子强度等因素对于MFCs性能的影响。实验结果表明：在水力停留时间6h、连续进液、高纯石墨板电极以及均相阳离子交换膜条件下,连续运行3个月,放电功率稳定在145mW／m^2,开路电压0．78V,放电电流最高可达321mA／m^2。     

口服二苯胂酸在小鼠小脑蒲肯野细胞诱发氧化和氮化应激

为了研究口服化学战剂降解产物二苯胂酸(DPA)导致小脑功能异常与诱发小鼠小脑蒲肯野细胞氧化和氮化应激之间的关系,利用硫代巴比妥酸反应物(TBARS)法和免疫组织化学方法检测脑组织丙二醛(MDA)和3-硝基酪氨酸(3-NT)的变化情况.同时,通过在体外合成3价DPA的模型化合物二苯胂酸碘(DPI),并用Western-blot检测3-NT的生成.研究发现,在小鼠一次口服15mg·kg-1DPA以及连续5d口服5mg·kg-1 DPA的情况下,小脑组织TBARS上升,蒲肯野细胞MDA和3-NT染色阳性.体外实验检测到DPI和NO反应可以生成3-NT,这表明DPA会导致小鼠小脑功能异常,这与其在体内代谢过程中产生的砷相关活性物质在小脑蒲肯野细胞诱发氧化和氮化应激密切有关.     

1株产电假单胞菌（Pseudomonas sp.）RE7的分离及特性研究

微生物燃料电池(microbial fuel cell,MFC)阳极微生物的种类和作用机制对MFC的产电性能有着重要的影响.从已稳定运行1 a的MFC的阳极室分离得到1株电化学活性革兰氏阴性细菌——菌株RE7,其16S rRNA基因序列与Pseudomonas aeruginosa strain CMG 587有99%同源性,属于假单胞菌属（Pseudomonas sp.）.利用菌株RE7构建的MFC的稳定产电和循环伏安曲线测定结果都表明,菌株RE7具有较强的电化学活性,利用菌株RE7构建的MFC的最大输出电压为352 mV,相应的最大面积功率密度为69.2 mW/m²,体积最大功率密度为6.2 W/m³.由不同稀释比例的MFC排出液的产电效果比较可知,菌株RE7极有可能是通过自身分泌的氧化还原类物质进行电子传递.     

以吡啶和葡萄糖为燃料的MFC产电特性研究

不同类型的有机物对MFC的产电性能有不同的影响,通过构建填料型MFC,以吡啶和葡萄糖为混合燃料,以铁氰化钾为电子受体,对有机物在MFC中的降解以及产电性进行研究.结果表明,外阻为1 000Ω的条件下,MFC的最大输出电压随着葡萄糖浓度的降低而降低,当吡啶初始浓度为500 mg/L,葡萄糖浓度分别为500、250、100 mg/L时,运行周期逐渐缩短,分别为49.5、25.7、25.2 h;最大体积功率密度为48.5、36.2、15.2 W/m3,最高电压为623 mV.MFC可实现对吡啶的高效降解,24h内吡啶去除率高达95%,但葡萄糖的浓度对吡啶的降解速率影响不大;高浓度吡啶存在的条件下对MFC利用葡萄糖产电的性能影响不大.利用500 mg/L单一吡啶作为MFC的燃料时,无明显产电现象.MFC利用吡啶和葡萄糖作为混合燃料时,可以在实现吡啶降解的同时稳定地向外输出电能.     

Degradation of MTBE and TBA by a new isolate from MTBE-contaminated soil

Methyl ten-butyl ether （MTBE）, a gasoline additive, possesses serious problems to the environmental health. In the present study, a bacterial culture named A-3 which could effectively degrade MTBE was isolated from the MTBE contaminated soil. The isolate was identified as Chryseobacterium sp., a new species capable of degrading MTBE. In order to enhance its degradation ability, selected environment factors were investigated. The results showed that the optimal temperature was in the range of 25-30℃, the pH was 7.0, the inoculum size was 2 × 10^8 CFU/ml and the optimal concentration of MTBE was from 50 to 100 mg/L. The maximum MTBE utilization rate （Vmax） was 102 nmol MTBE/（mg cell protein.h）. Furthermore, it was found that the isolate could also degrade tert-butyl alcohol （TBA）. The degradation rates of TBA were much faster than those of MTBE. The additional TBA would lead to the decrease of the initial MTBE degradation rate and the inhibitory effect of TBA increased with the increase of TBA concentration. Similar protein profiles at least seven peptides were demonstrated after SDS-PAGE analysis of crude extracts obtained from the cells growing in MTBE and TBA culture.     

串联微生物燃料电池的电压反转行为

微生物燃料电池是一种处理废水同时产电的具有广阔应用前景的新型水处理技术,其串联是产生更高电压的有效方法之一,但是会产生电压反转现象降低串联微生物燃料电池的性能.文章将二极管引入串联微生物燃料电池中以考察电压反转的行为.结果表明,不同的串联微生物燃料电池中均会发生电压反转.串联正向二极管的微生物燃料电池的电压反转行为与没...     

LCA study of photovoltaic systems based on different technologies

This work deals with the application of a Life Cycle Assessment approach for evaluating the environmental and energy impacts ascribed to the production of photovoltaic (PV) cells of first and second generations. PV technologies based on silicon and CuInSe₂ (CIS) thin films were taken into account herein. PV systems prepared with amorphous silicon (a-Si) showed a low environmental impact and short energy payback time when compared to those ones obtained using crystalline silicon (c-Si). PV technologies associated with mono-crystal (mono-Si) and polycrystalline silicon (multi-Si) showed large emissions of CO₂, nitrogen oxides, non-methane volatile organic compounds, particulates, and SO₂ into air per square meter of PV panel processed. In addition, these technologies displayed a significant fossil fuel demand, biological oxygen demand, and global warming potential, which make them eco-unfriendly. Ribbon silicon (ribbon-Si) and CIS thin films showed intermediate impact scores, but further improvements in their production chain are needed before these devices are commercially used. The technologies examined herein were categorized in first- and second-generation technologies in order to compare their environmental impact and conversion efficiency. Much attention was also paid to the development of third-generation PV cells with improved conversion efficiencies and lower environmental impacts.