Enhancing sulfate reduction and hydrogen sulfide removal through gas stripping in the acidogenesis phase of a two-phase anaerobic process.

This study aims at evaluating two-phase and single-phase reactors for treating sulfate wastewater with low COD/SO42- ratios. Additionally, a new process of gas stripping in an acidogenesis phase is proposed to reduce hydrogen sulfide (H2S) inhibition and enhance biomethanation. The two-phase performed better than the single-phase in terms of COD removal, CH4 production and H2S resistance. After 30 days of stripping, the COD and sulfate degradation rates increased from 85.16% to 91.09% and from 49.39% to 63.07% in the two-phase, respectively. In contrast, without stripping, they were from 79.21% to 64.37% and from 50.26% to 53.15% in the single-phase, respectively. The microbial biodiversity was augmented via stripping, including norank_f__Spirochaetaceae, Petrimonas, Desulfurella and Blvii28_wastewater-sludge_group. Stripping operation enhanced the dissimilatory sulfate reduction, amino acid metabolism and possibly sulfate-dependent anaerobic ammonia oxidation (S-ANAMMOX). This study provides a promising strategy to improve sulfate reduction and reduce H2S inhibition under a low COD/SO42- ratio.

Alleviation of Reverse Salt Leakage across Nanofiber Supported Thin-Film Composite Forward Osmosis Membrane via Heat-Curing in Hot Water.

Electrospun nanofiber with interconnected porous structure has been studied as a promising support layer of polyamide (PA) thin-film composite (TFC) forward osmosis (FO) membrane. However, its rough surface with irregular pores is prone to the formation of a defective PA active layer after interfacial polymerization, which shows high reverse salt leakage in FO desalination. Heat-curing is beneficial for crosslinking and stabilization of the PA layer. In this work, a nanofiber-supported PA TFC membrane was conceived to be cured on a hot water surface with preserved phase interface for potential "defect repair", which could be realized by supplementary interfacial polymerization of residual monomers during heat-curing. The resultant hot-water-curing FO membrane with a more uniform superhydrophilic and highly crosslinked PA layer exhibited much lower reverse salt flux (FO: 0.3 gMH, PRO: 0.8 gMH) than that of oven-curing FO membrane (FO: 2.3 gMH, PRO: 2.2 gMH) and achieved ∼4 times higher separation efficiency. It showed superior stability owing to mitigated reverse salt leakage and osmotic pressure loss, with its water flux decline lower than a quarter that of the oven-curing membrane. This study could provide new insight into the fine-tuning of nanofiber-supported TFC FO membrane for high-quality desalination via a proper selection of heat-curing methods.

Flexible and porous TiO2/SiO2/carbon composite electrospun nanofiber mat with enhanced interfacial charge separation for photocatalytic degradation of organic pollutants in water.

Semiconductor photocatalysis has long been considered as a promising approach for remediation of polluted water. However, the high recombination rate of electrons and holes, as well as a low reaction rate, have impeded its large-scale applications. Therefore, it is of great importance to develop appropriate photocatalysts for promoting its practical application. In this study, a novel TiO2/SiO2/carbon electrospun nanofiber mat (TSC NFM) with flexibility and porous hierarchy has been successfully designed and fabricated by a facile method of electrospinning and carbonization. Characterization results show that the TSC NFM consists of closely-packed and well-distributed anatase (TiO2) nanocrystals, amorphous SiO2 nanoparticles, and carbon with interconnected meso- and macro-pores. The photocatalytic performance of the TSC NFM was evaluated by degrading rhodamine B and 4-nitrophenol in batch systems. The results show that TSC NFM exhibits a higher photocatalytic activity than TiO2/SiO2 nanofiber mat, which does not contain carbon. The enhanced performance of the TSC NFM can be attributed to the improved adsorption capacity toward the organic pollutants due to the presence of carbon and to the enhanced interfacial charge separation between TiO2 nanoparticles and carbon. Besides, the as-prepared TSC NFM displays good stability and reusability. Notably, the flexible TSC NFM can be used in a continuous-flow reactor to efficiently treat wastewater. Our work provides new insights into the fabrication of carbon-based inorganic nanofiber mats, which have great potential in water treatment.

Expression of vimentin and glial fibrillary acidic protein in central nervous system development of rats.

OBJECTIVE: To investigate the distribution and contents of vimentin (Vim) and glial fibrillary acidic protein (GFAP) immunoreactivities in the central nervous system (CNS) of normal newborn, adult and aged rats. METHODS: In this study, thirty healthy and normal Sprague-Dawley rats were simply classified into three groups: Newborn (7 days aged), adult (5 months aged) and aged (24 months aged) rats. Brains and spinal cord were dissected and cut into frozen sections. The expression of Vim and GFAP in CNS were detected by confocal immunofluorescence. RESULTS: In each group, Vim was expressed in all the regions of CNS including the hippocampal, cerebral cortex, the third ventricle and spinal cord, and the expression was highest in neuron-like cell of newborn rats, while Vim was mainly expressed in cell bodies in adult and aged rats. GFAP was expressed in all the regions of CNS including the hippocampal, cerebral cortex, the third ventricle and spinal cord, and the expression was in astrocytes of aged rats. In the third ventricle, Vim was detected in all groups, and only observed in neuron-like cells of newborn. Meanwhile, the GFAP expression showed no significant differences between adult and aged rats in this region. The co-localization of Vim and GFAP were mainly observed in hippocampus and cerebral cortex of newborn, but this co-localization was found in the third ventricle of the rats in all groups. CONCLUSION: Our data demonstrate for the first time that the expression of Vim and GFAP in the rat's CNS during development. This data may provide a foundation for the further mechanistic studies of these two main intermediate filaments during development of CNS.

[Indirect study of zinc-cystine complex reaction by FAAS].

Each state of cystine and zinc ion in aqueous solution under different pH conditions was calculated by computer, and the scatter diagram was given. Under the influence of solution pH, the mechanism of complex reaction in indirectly determining cystine by flame atomic absorption spectrometry with ZnS was studied. The soluble complex ion is composed of 0 valence cystine Cys-Cys+/-, -1 valence cystine Cys-Cys+/- and -2 valence cystine Cys-Cys(2-) with Zn(OH)2. The theoretical analysis from computing and scatter diagram dovetail very well with the data determined from the experiments. The structure of soluble zinc-cystine complex ion is, [(COO-) CH (NH3+) CH2S-SCH2 CH (NH3+) COO-] Zn (OH)2, [(COO-) CH (NH3+) CH2S-SCH2CH(NH2)COO-]Zn(OH)2 and [(COO-)CH(NH2)CH2S-SCH2CH(NH2)COO-]Zn(OH)2.

[Effect of precursor of brain-derived neurotrophic factor on hippocampal neuron survival and its mechanism].

OBJECTIVE: To explore the effect of precursor of brain-derived neurotrophic factor (proBDNF) on cultured hippocampal neuron and its intracellular mechanism. METHODS: The hippocampal neurons were dissociated from E18 rats and cultured in neurobasal medium, and then the cells were treated with proBDNF, preBDNF(propeptide of proBDNF) and proBDNF antiserum,respectively. Thirty minutes, 1 hour or 48 hours later, the cells were stained with Nissl solution, and the immunocytochemistry methods of ELK-p (Ets domain protein), ErK2(extracellular signal regulated kinase) and c-fos were performed. RESULTS: The expressions of ELK-p, ErK and c-fos were significantly upregulated in the cultured hippocampal neurons after they were treated with proBDNF protein,and the immuno-positive staining was also obvious in some nuclei. While the endogenous proBDNF was neutralized by proBDNF antiserum treatment, the expressions of ELK-p, ErK and c-fos were downregulated and many cells showed swelling and vasoculation. The immunoreactivity in preBDNF treated cells was similar to that in normal cultured cells. CONCLUSION: proBDNF plays an important role in sustaining the hippocampal neuron survival through upregulating the ELK and ErK pathways.

[Quantitative determination of glucose by internal standard laser Raman spectra].

In the present paper we report quantitative analysis of glucose using internal standard laser Raman spectra. A good linear correlation was observed between the intensities of the -COO band at 1 125 cm(-1) using excition wavelength of 632.81 nm (r = 0.998 8) and the glucose concentration over the range 0-1.8 mol x L(-1). Band intensities were normalized against an internal standard (water band at 1 643 cm(-1)), and the limit of detection (L. O. D.) of glucose is 0.022 7 mol x L(-1). The interference ions would not influence the quantitative analysis. When this method was used to determine 5% glucose NaCl, 5% glucose, and 10% glucose injections, the result showed that the recoveries are 71.88%-126.31%, 81.02%-124.89% and 74.87%-121.32%, and the RSDs are 5.44%, 4.34% and 0.94%, respectively. The non destructive, non intrusive nature of the method makes internal standard laser Raman spectra a convenient, accurate, and green quantitative analysis method.

[Indirect studies of zinc-histidine complex reaction by FAAS].

Each state of histidine and zinc ion in aqueous solution with different pH was calculated by computer, producing the scatter diagram. Under the influence of solution pH, the mechanism of complex reaction in indirectly determining histidine by flame atomic absorption spectrometry with ZnS was studied. In different state of histidine and zinc ion in aqueous solution at differential pH, the response peak with pH in giving conditions was obtained. The soluble complex ion is composed of 0 valence histidine His+- and -1 valence histidine His+- and Zn(OH)2. The theoretical analysis from computing and scatter diagram agrees very well with the data determined from the experiments. The structures of complex ion are Zn(OH)2 x (C6N3O2H9)2, H8) Zn(OH)2 x [(C6N3O2H8)-]2 and Zn(OH)2 x (C6N3O2H9) x [(C6N3O2H8)-].

[Studies of laser Raman spectra of sodium glutamic acid solution effected with environmental light].

The laser Raman spectra influenced by environmental light have been studied in the determination of sodium glutamic acid solution. The environmental light included natural light from outdoors and the light from indoor fluorescents. The results show that different influences on laser Raman spectra of sodium glutamic acid solution can be produced in different environmental light. There were some characteristic spectral lines, minus peaks or sharpened peaks. These influences cannot be ignored. The determinations of laser Raman spectra must be performed in darkroom or in the sheathing or mantle etc.

[Influence of different light source on the laser Raman spectra in determination of sodium glutamic acid].

The influences of different laser source and different light power on laser Raman spectra were studied for the sodium glutamic acid. The results show that some influences existed using different wavelength and power of light source the peak shifting 6 cm(-1). As UV laser has great light power, the samples were destroyed, making the Raman spectra- reduce or disappear. The attenuation of light was needed. The linear relation existed between the Raman intensity and the power of laser light source, and the correlation coefficient was more then 0.999. The Raman intensity per light power unit was related to the wavelength, and was not related to the power of laser source.

[Effect of polygonum multiflorum thunb on BDNF expression in rat hippocampus induced by amyloid beta-protein (Abeta) 1-40].

OBJECTIVE: To explore the effect of polygonum multiflorum thunb (PMT) on the expression of brain-drived neurtrophic factor (BDNF) in hippocampus CA1 in rats induced by Abeta1-40. METHODS: The rat model was established by injecting Abeta1-40 into the right dorsal hippocampus in rats, and their behavior was observed by Y-maze. The morphological changes of rat hippocampus were examined by the Nissl staining. The expression of BDNF in hippocampus CA1 neurons was also examined by immunohistochemistry and Western blot. RESULTS: After the administration of Abeta1-40, the times of rats learning how to elude electric stimulation were significantly increased, and the expression of BDNF in hippocampus CA1 were obviously reduced. The aggregation of Abeta1-40 in hippocampus and the morphological changes of CA1 hippocampus were found. After the treatment with PMT for 30 days, the times learning how to elude electric stimulation were obviously reduced, while the expression of BDNF in hippocampus CA1 was also increased. CONCLUSION: PMT can reverse the down-regulation of BDNF expression in hippocampus CA1 induced by Abeta1-40.

[Expression of eNOS in the endothelial cells during the arteriogenesis of pig hind-limbs].

OBJECTIVE: To detect the expression and activity of eNOS during the arteriogenesis of hind-limbs of pigs. METHODS: The right femoral artery was ligated, and the left femoral artery shamly operated under routine surgical procedures. Animals were sacrificed after two weeks. The expression and activity of eNOS in collateral vessels were studied by confocal immunofluorescence with antibodies against eNOS and phosphorylated eNOS (P-eNOS) respectively. RESULTS: In normal small arteries, the expression of eNOS was very low, and the staining was very weak. In growing collateral vessels, the expression of eNOS was significantly up-regulated, showing very strong positive staining. The expression of P-eNOS was also high. Dural immunostaining showed that eNOS and P-eNOS were colocalized in the endothelial cells. CONCLUSION: eNOS is up-regulated and activated during arteriogenesis, suggesting that eNOS can exert the possible role in mediating the proliferation of endothelial cells and the inflammation, and contribute to the collateral vessel growth.

[Studies of influences of environmental light on near-infrared laser raman spectra of sodium glutamic acid solution].

The near-infrared laser Raman spectra influenced by environmental light were studied in the determination of sodium glutamic acid solution. The environmental lights included natural light from outdoors and light from room fluorescent lamp. The results show that different influences on near infrared laser Raman spectra of sodium glutamic acid solution can be produced in different environmental light. There were some characteristic spectral lines, down peaks or sharpened peaks. These influences cannot be ignored. It is suggested that the determination of solution by near-infrared laser Raman spectra is carried out in dark-room or in dark cover to completely isolates the influences of the environment lights.

[Studies of laser Raman spectra of ZnCl2 solution effected by environmental light].

The laser Raman spectra influenced by environmental light were studied in the determination of ZnCl2 solution. The environmental light included the natural light from outdoors and the light from indoor fluorescent. The results show that different influences on the laser Raman spectra of ZnCl2 solution can be produced in different environmental light. There were some characteristic spectral lines, minus peaks or sharpened peaks. These influences cannot be ignored. The determinations of laser Raman spectra must be made in darkroom or in the sheathing or mantle etc.

[Pathway for macrophage invasion into the tunica media and the intima in vein graft].

OBJECTIVE: To test whether the macrophages in vein grafts may invade into the vascular wall from the adventitia apart from the lumen. METHODS: Expression of CD68 (a marker of macrophage) and CD31 (a marker of endothelial cells) in 30 vein grafts were detected by confocal immunofluroscence. Images were processed with Silicon Graphics Octane. RESULTS: In normal veins, there were a few CD68 positive cells in the adventitia, but few CD68 positive cells were found in the media and the intima. In the diseased vein, CD68 positive cells were significantly increased and present in all layers of the vascular wall, the adventitia, media and intima, extending from the adventitia to the media. There was a close relationship between the penetration of CD68 positive cells into the media from the adventitia and the angiogenesis in the media. CONCLUSION: The adventitia may be an important pathway for macrophage invasion.

[Studies of complexing action mechanism in indirect determination of cysteine by FAAS with ZnS].

Each state of cysteine and zinc ion in aqueous solution at different pH conditions was calculated by computer, giving out the distribution curve. The mechanism of complexing action in indirectly determining cysteine by flame atomic absorption spectrometry with ZnS, and the influence of solution pH were studied. The state of cysteine and zinc ion in aqueous solution at different pH is different. The reason for forming the peak is the change of concentration of cysteine and zinc ion at different pH. The soluble complexing ion of -1 is composed valence cysteine Cys- and Zn(OH)2. The theoretical analysis is well conformable with the data determined from the experiments. The structure of complexing ion is [HS-CH2CH(NH2)-COO]2Zn(OH)2.

[Differentiation of rat bone marrow stromal cells into neuron like cells].

OBJECTIVE: To investigate the differentiation of the rat bone marrow stromal cells (BMSCs) into neuron like cells which express glutamic acid decarboxylase (GAD) and choline acetyltransferase (ChAT). METHODS: BMSCs of rats were flushed out with DMEM from femurs marrow and separated, and then planted in plastic flask. After being expanded and purified, the BMSCs were differentiated into neuron-like cells. Neurofilament (NF-200), microassociate protein-2 (MAP-2), neuron-specific nuclear protein (NeuN), nestin, gial fibrillary acidic protein (GFAP), GAD and ChAT were detected by immunohisitochemistry. RESULTS: The induced BMSCs exhibited neuronal morphological characteristics, and the expressions of NF-200, MAP-2, NeuN and nestin were positive, but the expression of GFAP was negative. About (3 +/- 0.8)% of the induced BMSCs expressed GAD, and (5 +/- 0.3)% expressed ChAT. CONCLUSION: BMSCs can differentiate into neuron like cells, and express GAD and ChAT partially.

[Distribution of NMDAR1 and subunits (alpha1 and alpha3) of GABAA receptor in the cerebellar cortex of adult rhesus macaques].

OBJECTIVE: To investigate the distribution of NMDAR1 and subunits (alpha1 and alpha3) of Immunohistochemistry and GABAA receptors in the cerebellar cortex of adult rhesus macaques. METHODS: Nissl staining were used. RESULTS: (1) NMDAR1 immunoreactivity was prevalent in the endoplasma of Purkinje and dendrites of molecular layer, and moderate in glia, but was very weak in the stellate cells in the molecular layer and granule cells. In addition, cerebellar nuclei were also strongly stained; (2) The immunostaining pattern of subunit of GABAA alpha1 receptor was similar to that of NMDAR1, but more distinctive than NMDAR1 in stellate cells; (3) Immunoreactivity of subunit (alpha3) of GABAA receptor was also prevalent in the endoplasma of Purkinje cells and dendrites. The glia and the neurons of the cerebellar nucli were intensively stained. (4) The rates of Purkinje cells containing NMDAR1, and subunits of GABAA alpha1 and alpha3 were (90.0 +/- 2.1)%, (83.0 +/- 2.3)%, and (78.0 +/- 1.8)%, respectively. Conclusion NMDAR1 and subunits (alpha1 and alpha3) of GABAA receptors are widely distributed in the cerebellum of adult rhesus macaques. These receptors may play an important role in maintaining the complicated function of the cerebellar.