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By mining and analyzing the published 16S rRNA amplification data of activated-sludge from 32 sewage and waste-water treatment facilities, at home and abroad, this study examines the microbial structure of sludge and its response to inflow water quality, temperature, and treatment type. Activated sludge generally shows high species diversity and community richness. Many activated sludge samples contain different microbial community structures. In these samples, the dominant bacteria included Thauera , Nitrospira , Comamonas , Dechloromonas , Rhodoferax , Aquihabitans , and Acidovorax . Temperature was negatively correlated with several key denitrifying microorganisms, such as Nitrospira , Aquihabitans , Terrimonas , and Dechloromona . When temperatures were lower than 15℃, the corresponding removal rates of TN and NH 4 + -N in the 32 sewage treatment plants only reached 49.67% and 63.19%, respectively. With higher BOD 5 /COD values, these sewage treatment systems exhibited improved biodegradability performances. With higher relative abundances of advantageous functional bacteria, such as Zoogloea , Arcobacter , Acidovorax , and Acinetobacter , pollutant-removal rates would increase accordingly. As for domestic-sewage treatments, the performance of the A 2 O process is superior to that of the OD, CAS, and CMAS processes. Additionally, the relative abundances of multiple functional dominant bacteria, including Comamonas , Rhodoferax , Nitrospira , and Novosphingobium , were significantly higher in sludge treated with the A 2 O process than in sludge treated with the other three processes.

Objective: To investigate the awareness and use of banned pesticides among vegetable greenhouse farmers in a town of Ledu County, Qinghai Province, China and to provide a basis for the management and control of banned pesticides., Methods: Local residents who lived in a town of Ledu County for more than 5 years were selected as subjects in August 2012. A questionnaire survey was conducted in 267 vegetable greenhouse farmers who were selected from five villages of the town by cluster random sampling., Results: Of the 267 subjects, 249 (93.26%) completed and returned the questionnaires. Eighty-seven (34.9%) of the 249 subjects were aware of banned pesticides, and the banned pesticide awareness rate varied significantly among the subjects with different education levels (χ(2) = 11.061, P = 0.011). Only education level entered the regression equation in non-conditional logistic regression analysis. Only five (2.0%) of the 249 subjects knew the banned pesticides as well as the details. All the 249 subjects used banned pesticides to varying degrees in the past 5 years. Only 9.0% (17/189) of the vegetable greenhouse farmers knew the time pesticides were initially banned in China., Conclusion: The banned pesticide awareness rate is relatively low in the town of Ledu County, and this rate is influenced by education level. It is needed to spread the knowledge and hazards of banned pesticides.

To check feasibility and effectiveness of the α-amylase reporter system, two vectors were designed and tested using hepatitis B virus surface antigen (HBsAg) and Homo sapiens granulocyte-macrophage colony stimulating factor 2 (hGM-CSF2) as a model. By integrating the vector containing two independent cassettes into the same genome locus, high-producing clones of HBsAg (or hGM-CSF2) were screened using the α-amylase as a reporter. Results show there was a positive correlation (Correlation coefficient, R (2) > 0.95) between the yield of recombinant proteins and the α-amylase activity of corresponding transformants, which was independent of the gene dosage.

Nudix hydrolases are a superfamily of pyrophosphatases, most of which are involved in clearing the cell of potentially deleterious metabolites and in preventing the accumulation of metabolic intermediates. We determined that the product of the orf17 gene of Escherichia coli, a Nudix NTP hydrolase, catalyzes the hydrolytic release of pyrophosphate from dihydroneopterin triphosphate, the committed step of folate synthesis in bacteria. That this dihydroneopterin hydrolase (DHNTPase) is indeed a key enzyme in the folate pathway was confirmed in vivo: knockout of this gene in E. coli leads to a marked reduction in folate synthesis that is completely restored by a plasmid carrying the gene. We also determined the crystal structure of this enzyme using data to 1.8 A resolution and studied the kinetics of the reaction. These results provide insight into the structural bases for catalysis and substrate specificity in this enzyme and allow the definition of the dihydroneopterin triphosphate pyrophosphatase family of Nudix enzymes.

A growing number of research results demonstrate that copper is an important trace element to life. In this study, whole-cell recording made from acutely dissociated rat hippocampal CA1 neurons was employed to investigate the actions of copper (Cu(2+)) on the delayed rectifier K(+) currents (I(K)). External application of various concentrations of Cu(2+) (1-1000microM) reduced the amplitude of I(K) in a dose-dependent manner with an IC(50) value of 100microM and a Hill coefficient of 0.4. 300microM of Cu(2+) depolarized the I(K) activation curves by 12.5mV and hyperpolarized the I(K) state-inactivation curves by 17.4mV, respectively. At this concentration, Cu(2+) also significantly increased the value of the fast decay time constant (tau(1)), but had no effect on the I(K) recovery from inactivation. These results suggest that relevant concentrations of copper at physiological and pathological level can influence the neuronal excitability of rat hippocampal CA1 neurons by voltage-gated delayed rectifier K(+) channels, and such actions are likely involved in the pathophysiology of Cu-related Wilson's disease.

Lead exposure is known to be associated with cognitive dysfunction in children. Impairment of the induction of long-term potentiation (LTP) has been reported in area CA1 of rat hippocampus following lead exposure in vivo and in vitro. The present study was carried out to investigate whether the alterations of N-methyl-d-aspartate (NMDA) receptor-independent LTP following lead exposure involve internal calcium stores in hippocampus CA1 synapses. Monosynaptic field excitatory postsynaptic potentials in hippocampal slice area CA1 were recorded using the whole-cell patch-clamp upon acute lead treatment, and these studies were coupled with calcium imaging experiments to observe internal calcium changes in cultured hippocampal neurons. Inhibiting calcium release by ryanodine significantly reduced NMDA receptor-independent LTP, and depletion of internal calcium stores with thapsigargin blocked this form of LTP. Caffeine, an agonist of ryanodine receptors, enhanced this form of LTP. However, caffeine-enhanced NMDA receptor-independent LTP was depressed after bath application of lead. Moreover, lead further decreased ryanodine- and thapsigargin-reduced NMDA receptor-independent LTP. Calcium imaging also confirmed that lead had an effect on internal calcium release and uptake. Taken together, these results demonstrated that lead inhibited NMDA receptor-independent LTP by action on calcium release and uptake by ryanodine-sensitive stores in rat hippocampal area CA1.

The effects of copper on voltage-gated A-type potassium currents were investigated in acutely dissociated rat hippocampal CA1 neurons using the whole-cell patch-clamp technique. Extracellular application of various concentrations of copper (1-1000 microM) reversibly reduced the amplitude of voltage-gated A-type potassium currents in a dose-dependent manner with a 50% inhibitory concentration value of 130 microM. Copper (300 microM) increased the V1/2 of the activation curve and state-inactivation curve by 17.2 and 9.0 mV, respectively. Thus, copper slowed down the activation and inactivation process of voltage-gated A-type potassium currents. This study indicated that copper reversibly inhibits the hippocampal CA1 neuronal voltage-gated A-type potassium current in a dose-dependent and voltage-dependent manner, and such actions are likely involved in the regulation of the neuronal excitability and the pathophysiology of Wilson's disease.