Impacts of high-quality coal mine drainage recycling for replenishment of aquatic ecosystems in arid regions of China: Bacterial community responses.

Coal mine water is usually recycled as supplementary water for aquatic ecosystems in arid and semiarid mining regions of China. To ensure ecosystem health, the coal mine water is rigorously treated using several processes, including reverse osmosis, to meet surface water quality standards. However, the potential environmental impacts of this management pattern on the ecological function of receiving water bodies are unclear. In this study, we built several microcosm water ecosystems to simulate the receiving water bodies. High-quality treated coal mine drainage was mixed into the model water bodies at different concentrations, and the sediment bacterial community response and functional changes were systematically investigated. The results showed that the high-quality coal mine drainage could still shape bacterial taxonomic diversity, community composition and structure, with a concentration threshold of approximately 50%. Moreover, both the Mantel test and the structural equation model indicated that the salinity fluctuation caused by the receiving of coal mine drainage was the primary factor shaping the bacterial communities. 10 core taxa in the molecular ecological network influenced by coal mine drainage were identified, with the most critical taxa being patescibacteria and g_Geothermobacter. Furthermore, the pathway of carbohydrate metabolism as well as signaling molecules and interactions was up-regulated, whereas amino acid metabolism showed the opposite trend. All results suggested that the complex physical-chemical and biochemical processes in water ecosystems may be affected by the coal mine drainage. The bacterial community response and underlying functional changes may accelerate internal nutrient cycling, which may have a potential impact on algal bloom outbreaks.

Structural basis for Ca2+ activation of the heteromeric PKD1L3/PKD2L1 channel.

The heteromeric complex between PKD1L3, a member of the polycystic kidney disease (PKD) protein family, and PKD2L1, also known as TRPP2 or TRPP3, has been a prototype for mechanistic characterization of heterotetrametric TRP-like channels. Here we show that a truncated PKD1L3/PKD2L1 complex with the C-terminal TRP-fold fragment of PKD1L3 retains both Ca2+ and acid-induced channel activities. Cryo-EM structures of this core heterocomplex with or without supplemented Ca2+ were determined at resolutions of 3.1 Å and 3.4 Å, respectively. The heterotetramer, with a pseudo-symmetric TRP architecture of 1:3 stoichiometry, has an asymmetric selectivity filter (SF) guarded by Lys2069 from PKD1L3 and Asp523 from the three PKD2L1 subunits. Ca2+-entrance to the SF vestibule is accompanied by a swing motion of Lys2069 on PKD1L3. The S6 of PKD1L3 is pushed inward by the S4-S5 linker of the nearby PKD2L1 (PKD2L1-III), resulting in an elongated intracellular gate which seals the pore domain. Comparison of the apo and Ca2+-loaded complexes unveils an unprecedented Ca2+ binding site in the extracellular cleft of the voltage-sensing domain (VSD) of PKD2L1-III, but not the other three VSDs. Structure-guided mutagenic studies support this unconventional site to be responsible for Ca2+-induced channel activation through an allosteric mechanism.

Vitamin D deficiency in hepatitis C virus infection: what is old? what is new?

In the past few years, a growing body of clinical evidence has highlighted the risk of vitamin D deficiency in patients with chronic hepatitis C and that vitamin D levels are associated with the course of hepatitis C virus (HCV) infection, adverse effects, and treatment response to peginterferon/ribavirin. Recently, studies have found that vitamin D status is related to drug resistance and increased risk of infection in patients with liver cirrhosis. Vitamin D-related gene polymorphisms have been found to explain the interactions between vitamin D deficiency and HCV infection, offering a new perspective toward understanding the current problems such as the development of insulin resistance and racial differences in sustained virological response. Studies have been conducted to determine whether vitamin D supplementation as an adjuvant yields a better result compared with traditional HCV treatment. Here, we provide a brief review of the past and present knowledge of vitamin D in HCV infection.

Temporal and spatial variations of contaminant removal, enzyme activities, and microbial community structure in a pilot horizontal subsurface flow constructed wetland purifying industrial runoff.

A pilot-scale horizontal subsurface flow constructed wetland (HSSFCW) was operated to purify industrial runoff containing polycyclic aromatic hydrocarbons (PAHs) in Guangzhou, China. Synthetic industrial runoff was fed into the HSSFCW with continuous flow at an average loading rate of 0.128 m(3)/(m(2)/day) for about 2 years. Pollutants such as chemical oxygen demand (COD), total phosphorus (TP), and phenanthrene were mainly removed in the front quarter of the HSSFCW, and in the vertical direction, the average removal rates of COD, TP, total nitrogen (TN), ammonia, and phenanthrene of the upper layer were 64.23, 71.16, 50.81, 65.38, and 92.47 %, which were 1.23, 2.08, 1.48, 1.72, and 1.17 times higher than those of the bottom, respectively. Correlations among pollutant removal, soil environmental indexes, enzyme activities, and soil microbial community structure were evaluated. Enzyme assays (dehydrogenase, catalase, nitrate reductase, and polyphenol oxidase) showed significant associations between enzyme activities and pollutant removal (p < 0.01 and p < 0.05). Soil microbial community structure was assessed with denaturing gradient gel electrophoresis (DGGE) fingerprinting method, and results demonstrated that bacterial communities remained relatively stable in different seasons. Proteobacteria and Bacteroidetes were found to be the dominant phyla of the bacteria communities, and three clones which might be related to the biodegradation of phenanthrene were also detected. Results of the present work would broaden the knowledge of the purification mechanism of contaminants in the constructed wetlands (CWs), and identification of the treatment performances and temporal and spatial variations of biological activities of subsurface flow constructed wetlands (SSFCWs) would help to improve the operations of CWs for surface water protection.

[Effects of electroacupuncture on expression of calmodulin in the hippocampus of rats with cerebral ischemia-reperfusion injury].

OBJECTIVE: To investigate the protective effect of electroacupuncture (EA) on injured neurons and the signal transduction mechanism of calmodulin (CaM) in rats with cerebral ischemia-reperfusion injury (CIRI). METHODS: A total of 25 SD rats were randomly divided into a sham-operation group, a model group, an EA. group, a TFP group and an EA+TFP group. The rat model of middle cerebral artery occlusion (MCAO) was established by the modified Longa thread occlusion method. The EA group was treated with EA at "Dazhui" (GV 14) and "Baihui" (GV 20) for 30 minutes. The TFP group was treated with lumbar intrathecal injection of Trinuoperazine (TFP) at a dose of 40 microL/kg, the inhibitor of CaM. The EA + TFP group was treated with EA combined with TFP, and the sham-operation group and the model group without any treatment. The neurology deficit score was evaluated by the Julio's neuroethology score methods in all rats, and the expression of CaM in cerebral hippocampus tissue was detected with immunohistochemical method in different intervention condition. RESULTS: (1) In comparison with the model group of 6.90 +/- 1.66, the neuroethology score in the EA group of 14.50 +/- 1.08, the TFP group of 11.70 +/- 1.06 and the EA + TFP group of 14.30 +/- 1.06 were all significantly increased (all P < 0.01), while those still were all lower than the sham group of 17.60 +/- 0.52 (all P < 0.01), and the EA group was better than the TFP group (P < 0.01). (2) In comparison with the sham group of 0.080 +/- 0.045, the immune positive expression score of CaM protein in hippocampus in the model group of 1.680 +/- 0.268 was sig nificantly increased (P < 0.01). In comparison with the model group, the expression score of CaM protein in the EA group of 0.880 +/- 0.179, the TFP group of 0.720 +/- 0.179 and the EA + TFP group of 0.420 +/- 0.249 were all significantly reduced (all P < 0.01), and the expression score of CaM in the EA + TFP group was lower than that in the TFP group (P < 0.05). CONCLUSION: EA can reduce the injury of cerebral neurons induced by CIRI in rats and promote the recovery, which may be related to its effect in regulating CaM signaling pathway after the ischemia-reperfusion injury.

[High performance liquid chromatographic determination of cinnamic acid in rabbit plasma and application in study of pharmacokinetics].

A high performance liquid chromatographic method was developed to determine the content of cinnamic acid in rabbit plasma and the method was utilized for the study of pharmacokinetics. Cinnamic acid was separated by employing a column of Kromasil C18 (250 mm x 4.6 mm i.d., 5 microm) and a mobile phase of methanol-acetonitrile-water-glacial acetic acid (10:22:55:0.5, v/v) at a flow rate of 0.8 mL/min and room temperature with UV detection at 270 nm and phenylpropionic acid as internal standard. The extraction recoveries of the spiked samples at low, middle and high levels were 84.9%, 84.4% and 87.7%, respectively, while the method recoveries were 98.4% with relative standard deviation (RSD) of 5.5%, 99.2% with RSD of 3.6%, 100.1% with RSD of 3.7% in turn. The RSDs of intra-day and inter-day were both lower than 6%. Finally, the metabolism of cinnamic acid in rabbit plasma after medication of Guanxin Suhe Wan and Guanxin Suhe Capsule fitted in a first order absorption of two-compartment model. The method was found to be sensitive, accurate and precise, and is appropriate for the determination of cinnamic acid.