Effects of exogenous riboflavin or cytochrome addition on the cathodic reduction of Cr(VI) in microbial fuel cell with Shewanella putrefaciens.

Bioreduction of Cr(VI) is recognized as a cost-effective and environmentally friendly method, attracting widespread interest. However, the slow rate of Cr(VI) bioreduction remains a practical challenge. Additionally, the direct removal efficiency of microbes for high concentrations of Cr(VI) is not ideal due to the toxicity. Therefore, this study investigated the effects of exogenous riboflavin or cytochrome on the cathodic reduction of Cr(VI) in microbial fuel cells. The results demonstrated that the exogenous riboflavin or cytochrome effectively improved the voltage output of the cells, with riboflavin increasing the voltage by 52.08%. Within the first 24 h, the Cr(VI) removal ratio in the normal, cytochrome, and riboflavin groups was 14.3%, 29.3%, and 53.8%, respectively. And the final removal ratio was 55.1%, 69.1%, and 98.0%, respectively. These results showed different enhancement effects of riboflavin and cytochrome on Cr(VI) removal. The analysis of riboflavin and cytochrome contents revealed that the additions did not have a significant impact on the autocrine riboflavin of S. putrefaciens, but affected the autocrine cytochrome. SEM, XPS, and FTIR results confirmed the presence of reduced Cr(III) on the cathode, which formed precipitate and adhered to the cathode surface. The EDS analysis showed that the amount of Cr on the cathode in normal, cytochrome, and riboflavin groups was 4.71%, 6.37%, 7.56%, respectively, which was consistent with the voltage and Cr(VI) removal data. These findings demonstrated the significant enhancement of exogenous riboflavin or cytochrome on Cr(VI) reduction, thereby providing data reference for the future bio-assisted remediation of Cr(VI) pollution.

Long-term effect of acetate and biochar addition on enrichment and activity of denitrifying anaerobic methane oxidation microbes.

The denitrifying anaerobic methane oxidation (DAMO) process plays a crucial role in the global carbon/nitrogen cycles and methane emission control, and also has application potential in biological wastewater treatment. However, given that DAMO microbes are susceptible to external conditions such as additional carbon source in the system, it is essential to evaluate the effect of alternative carbon substance on the enrichment efficiency and metabolic activity of DAMO microbes. To this end, this study investigated the effect of acetate (0.1 mmol/L-R2, 0.5 mmol/L-R3) and biochar addition (R4) on the enrichment and activity of DAMO microbes. The long-term operation showed that the NO2--N and CH4 consumption rates in the reactors almost presented the sequence of R4>R2>R3>R1. However, the short-term activity test with isotope labelling showed the sequence of R2>R4>R1>R3. Furthermore, the addition of acetate and biochar improved the electrochemical activity and extracellular polymeric substance (EPS) secretion in the systems. In R4 reactor, the proportion of DAMO bacteria was the highest (7.20%), indicating that the addition of biochar could promote the enrichment of DAMO bacteria, and Thauera was co-enriched with the proportion increasing from 0.26% to 6.73%. While in R1, R2 and R3 reactors, DAMO bacteria were enriched with relatively low abundances (0.10%, 0.23%, 0.15%, respectively), together with methanogens and denitrifiers. This study showed that biochar and acetate with appropriate concentration could enhance the enrichment and activity of DAMO bacteria, the results can provide reference for the enrichment of DAMO microbes and its application in the biological nitrogen removal of wastewater.

Does China's Eco-Province Policy Effectively Reduce the Pollutant Emission Intensities?

Economic development and environmental conservation are two important challenges for China. A series of initiatives including Eco-province (EP) policies have been taken to achieve sustainable development by the Chinese government. Increasing concerns regarding policy implications on sustainable development have increased attention to the topic. However, the research on the relationship between economic development and pollutant (COD, SO2) emission intensities after the implementation of EP policy remains inadequate. We applied a Time-Varying Difference-in-Differences Model by employing Chinese provincial panel data to quantitatively study the policy effect, and further utilized the Mediating Effect Model to analyze the mechanism. The article generates several findings: (1) The EP policy had overall inhibitory effects on both COD and SO2 emission intensities, and it would reduce the emission intensity by 4.99% and 6.77% on average, respectively. However, there was a five year lag in the policy effect. (2) The policy effect was significant in the western and central provinces with high pollutant emission intensities, but not in the eastern provinces. (3) The primary inhibiting mediating effects of Eco-province policy to lower pollutant emission intensity were increased GDP per capita and inventions.

Influence of climates and materials on the moisture buffering in office buildings: a comprehensive numerical study in China.

In recent years, moisture buffering materials for interior finishing have received much attention for their ability to regulate indoor humidity passively. It is necessary to investigate the potential of such materials' moisture buffering performance before application because the effect is highly climate and material dependent. However, existing studies in China lack a comprehensive overview of the moisture buffering potential of different interior finishing materials throughout the large country with a wide spectrum of climates. This paper aims to outline the moisture buffering potential for office buildings in various climates in China through numerical methods. Specifically, simulations in 15 representative Chinese cities are conducted with five interior finishing materials under two heating, ventilation, and air conditioning (HVAC) scenarios. The results show that the moisture buffering materials hold a general potential to regulate indoor humidity conditions and reduce buildings' HVAC load. Such benefits are evident in the mild climate but weak in humid areas. The moisture buffering effect also displays significant seasonal variations and could worsen indoor humidity conditions in some cases, indicating the importance of utilizing moisture buffering materials properly. In addition, although moisture buffering materials can reduce the HVAC load, the reduction is limited, within 3 kWh/m2, in most simulated cases. The energy-saving benefits of moisture buffering materials should thus not be over-emphasized. Finally, suggestions are put forward to instruct the choice of interior finishing material according to climate and buildings' HVAC scenarios.

[Study on Hollow Brick Wall's Surface Temperature with Infrared Thermal Imaging Method].

To address the characteristic of uneven surface temperature of hollow brick wall, the present research adopts soft wares of both ThermaCAM P20 and ThermaCAM Reporter to test the application of infrared thermal image technique in measuring surface temperature of hollow brick wall, and further analyzes the thermal characteristics of hollow brick wall, and building material's impact on surface temperature distribution including hollow brick, masonry mortar, and so on. The research selects the construction site of a three-story-high residential, carries out the heat transfer experiment, and further examines the exterior wall constructed by 3 different hollow bricks including sintering shale hollow brick, masonry mortar and brick masonry. Infrared thermal image maps are collected, including 3 kinds of sintering shale hollow brick walls under indoor heating in winter; and temperature data of wall surface, and uniformity and frequency distribution are also collected for comparative analysis between 2 hollow bricks and 2 kinds of mortar masonry. The results show that improving heat preservation of hollow brick aid masonry mortar can effectively improve inner wall surface temperature and indoor thermal environment; non-uniformity of surface temperature decreases from 0. 6 to 0. 4 °C , and surface temperature frequency distribution changes from the asymmetric distribution into a normal distribution under the condition that energy-saving sintering shale hollow brick wall is constructed by thermal mortar replacing cement mortar masonry; frequency of average temperature increases as uniformity of surface temperature increases. This research provides a certain basis for promotion and optimization of hollow brick wall's thermal function.

Blockade of toll-like receptor 2 expression and membrane translocation in rat corneal epithelial cells by glucocorticoid (TobraDex) after penetrating keratoplasty.

PURPOSE: To evaluate the role of Toll-like receptor (TLR) 2 and the effect of glucocorticoid on immune rejection of penetrating keratoplasty. METHODS: Allograft corneal transplantation was performed between host Sprague Dawley (SD) and Wistar donor rats. The expression of TLR2 messenger RNA (mRNA) and protein in corneas was determined by reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and immunofluorescence on days 5, 7, and 9 after operation. Three groups were included: allograft, allograft treated with TobraDex (Alcon, Rijksweg, Belgium), and isograft. Normal rat corneas were included as an additional control. RESULTS: Various degrees of congregation of inflammatory cells and neovascularization of grafts were confirmed by histopathology. Immunohistochemistry revealed that TLR2 was expressed in epithelial, stromal, and endothelial cells of normal tissue, and in all of the grafts. Immunofluorescence analysis of TLR2 showed membrane staining of epithelial cells in the allografts on days 7 and 9. This was absent in the isografts and the allografts treated with TobraDex. TLR2 mRNA was detected in normal corneas, and levels were increased in all of the grafts, as determined by quantitative reverse transcription-polymerase chain reaction. By day 9 after transplantation, a 3.6-fold increase in TLR2 mRNA was observed in the allografts compared with the isografts or the allografts treated with TobraDex, which was statistically significant, at P < 0.005. CONCLUSIONS: Expression of TLR2 in the rat cornea was significantly increased and concurred with the allograft rejection, but was effectively blocked by treatment with TobraDex.

[Effects of anti-CD25 monoclonal antibody on the level of cytokines in aqueous humour after rat penetrating keratoplasty].

OBJECTIVE: To investigate the toxicity of anti-CD25 monoclonal antibody (mAb) to rat cornea and its effects on the cytokines in the aqueous humour after penetrating keratoplasty (PKP), thereby evaluating the effect of anti-CD25 mAb in preventing corneal allograft rejection. METHODS: The corneal toxicity of anti-CD25 mAb at 50, 100 and 200 microg administered via subconjunctival injection was evaluated in 12 SD rats by histological examination and transmission electron microscopy. Another 93 SD rats were randomized into 5 groups, and transplantation of corneal allograft from Wistar rats was performed in 4 groups with the other group as the normal control. The 4 allograft groups were treated with saline, 100 microg anti-CD25 mAb, 100 microg anti-CD25 mAb with 50 microg dexamethasone, and 50 microg dexamethasone, respectively. The graft rejection was observed, the aqueous humour levels of IFN-gamma and IL-4 were measured with ELISA, and IFN-gamma mRNA expressions in the grafts detected with RT-PCR. RESULTS: anti-CD25 mAb at 50 or 100 microg did not show significant toxicity on the cornea, but at 200 microg, the mAb caused swelling of the corneal stromal cells and endothelial cells. After corneal allograft transplantation, a significant delay in allograft rejection was observed in the 3 groups with mAb or dexamethasone treatment as compared with that in saline group (P<0.05). IFN-gamma mRNA expression in the allograft on days 11 after PKP and in the aqueous humour on days 6 and 11 was markedly increased in saline group compared with that in the 3 treatment groups (P<0.05). The mean IL-4 level in the aqueous humour was significantly higher in the mAb group than in saline group (P<0.05), but markedly lower in anti-CD25 mAb+dexamethasone and dexamethasone groups than in anti-CD25 mAb group (P<0.05). CONCLUSIONS: Anti-CD25 mAb at 20 and 100 microg does not obviously affect the rat corneas. Anti-CD25 mAb inhibits IFN-gamma expression and promotes IL-4 the expression to reduce corneal allograft rejection, whereas anti-CD25 mAb with low-dose dexamethasone inhibits both IFN-gamma and IL-4 expressions to more effectively promote the graft survival.

[Recombinant type 1 adeno-associated virus-mediated transfection of ECV304 cells with enhanced green fluorescent protein gene in vitro].

OBJECTIVE: To assess the feasibility of recombinant type 1 adeno-associated virus (rAAV1) as a vector for gene therapy of corneal neovascularization. METHODS: The rAAV1 vector carrying enhanced green fluorescence protein (EGFP) gene (rAAV1-EGFP) was transfected into ECV304 cells at different multiplicities of infection (MOI=5 x 10(3), 5 x 10(4), 5 x 10(5)). EGFP expression in the cells was observed under inverted fluorescence microscope, and the EGFP-positive cell percentage determined by flow cytometry. MTT assay was used to assess the proliferation of the transfected cells. RESULTS: The cells with rAAV1-EGFP transfection at MOI of 5 x 10(5) began to exhibit GFP expression 2 days after transfection, and the fluorescence intensity increased with the MOI used for transfection. GFP expression reached the maximum on day 7, at the point of which the transduction efficiency of rAAV1-EGFP in ECV304 cells was 45.90%, 58.56% and 68.31% corresponding to MOIs of 5 x 10(3), 5 x 10(4), and 5 x 10(5), respectively. MTT assay did not reveal significant difference in the absorbance between the transfected cells and the control cells at 72 and 96 h after transfection. CONCLUSION: arAAV1-EGFP gene can be stably and efficiently expressed in ECV304 cells without causing cell growth inhibition, suggesting the potential of rAAV1 as a safe and efficient vector for gene therapy of corneal neovascularization.

[The oxidation degradation of great green SF by Fenton reagent].

Photo-Fenton method, the combination of Fenton reagent with light, is an efficient method for waste water treatment. In the present paper, the degradation of great green SF using this method was studied. Great green SF is a kind of permanent and nondegradable dye. Through numerous experiments, the influences of various parameters including the UV absorption curve of great green dye SF, the concentration-absorbency curve of great green dye SF, dosage of Fe2+, dosage of H2O2, initial pH, different light sources, and cation-exchange resin on the degradation were researched intensively. The optimum condition for dye SF degradation was given. Under the experiment condition, the sun light can promote this reaction apparently. The reaction time can greatly be shortened too. After the cation-exchange resin was introduced into the Fenton system, the activation of H2O2 can be enhanced to a great extent. The dosage of H2O2 will be decreased. The degradation effect of the great green SF is better. Under optimal conditions, the overall color removal is more than 96.7% within 40 min; COD can be removed effectively at the same time.

[Study on the method of producing doped nanometer thin films by microemulsion based inorganogels process and its photocatalytic capability].

In the present, the method of producing doped nanometer thin films by microemulsion based inorganogels process and its photocatalytic capability were studied. The best match of ingredients in microemulsion process was studied. On the basis of that, ME-S2 self-cleaning glass was made. The ME-S2 self-cleaning glass experienced the experiment of cleaning dirt in actual waste water, experiment of superhydrophilic property, and X-ray diffraction spectroscopy. ME-S2 has excellent photocatalytic capability. This kind of glass has a certain extent of self-cleaning function, and the transmittance of ME-S2 remains better than the ordinary glass. ME-S2 has excellent superhydrophilic property.

[Study on preparation of lanthanum-doped TiO2 nanometer thin film materials and its photocatalytic activity].

In this paper, lanthanum-doped TiO2 nanometer film materials coated on glass were prepared in Ti(OBu)4 precursor solutions by sol-gel processing. Transmittance and photocatalytic activity were respectively investigated and tested for these nanometer thin films prepared with different amount of lanthanum (La), different amount of polyethylene glycol (PEG), and different coating layer times. Some reactive mechanisms were also discussed. For one layer La-addition had little effect on the film transmissivity; but the photocatalytic activity was significantly improved due to La-addition. With increasing PEG, the transmittance of the film decreased for one layer film; but its photocatalytic activity did not rise. Increasing layer number did not affect the transmissivity of multilayer film. After coating two times, increasing layer number did not significantly improve the photocatalytic activity. The highest photocatalytic activity and best transmissivity were obtained for two layer TiO2 film when the dosage of lanthanum was 0.5 g and the dosage of polyethylene was 0.2 g in the precursor solutions. These materials will probably be used in the protection of environment, waste water treatment, and air purification.