957 research outputs found
An Efficient Photoelectrochemical Hydrogen Evolution System using Silicon Nanomaterials with UltraâHigh Aspect Ratios
We fabricated ultraâhigh aspect ratio silicon nanomaterials, including a silicon nanomesh and silicon nanowire array, on a wafer scale for efficient photoelectrochemical hydrogen production. These silicon nanomaterials (feature sizeâ20â
nm) possess a high aspect ratio to increase the optical absorptivity of the cells to approximately 95â% over a broad range of wavelengths. The silicon nanomesh and Si nanowire cells achieved high photocurrent values of 13 and 28â
mAâcm â2 , respectively, which are increased by 200â% and 570â% in comparison to their bulk counterparts. In addition, these scalable Si nanomaterials remained stable for up to 100â
min of hydrogen evolution. Detailed studies on the doping and geometrical structures of the resulting hydrogen evolution cells suggest that both the n + âpp + doping and thickness of nanostructures are keys to the enhancement of the hydrogen evolution efficiency. The results obtained in this work show that these silicon nanomaterials can be used for highâperformance waterâsplitting system applications. The straight doping: Waferâscale ultraâhigh aspect ratio Si nanomesh/nanowires (feature sizeâ20â
nm) were fabricated and utilized to produce an efficient photoelectrochemical hydrogen evolution system. The Si nanomesh cell yielded extreme optical absorptivity, high external quantum efficiency, and high photocurrent. Detailed studies suggest that both the n + âpp + doping and thickness of nanostructures are keys to the enhancement of the hydrogen evolution efficiency.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109595/1/ente_201402074_sm_miscellaneous_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/109595/2/889_ftp.pd
Experimental Study on the Acellular Demal Matrix Graft for the Root Coverage in Dog
Mucogingival surgery is a plastic surgical procedure designed to correct defects in the morphology, position, and dimensions of the gingiva surrounding the teeth. Many surgical techniques have been reported in mucogingival surgery. Since these procedures also include the soft tissue esthetic approach, the term periodontal plastic surgery has been proposed to be more appropriate.1 Root coverage is a procedure that falls with this definition, and it has attracted more interest than others
The Effect of Environmental Enrichment on Glutathione-Mediated Xenobiotic Metabolism and Antioxidation in Normal Adult Mice
Olfactory bulb (OB) plays an important role in protecting against harmful substances via the secretion of antioxidant and detoxifying enzymes. Environmental enrichment (EE) is a common rehabilitation method and known to have beneficial effects in the central nervous system. However, the effects of EE in the OB still remain unclear. At 6 weeks of age, CD-1Âź (ICR) mice were assigned to standard cages or EE cages. After 2 months, we performed proteomic analysis. Forty-four up-regulated proteins were identified in EE mice compared to the control mice. Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes Pathway demonstrated that the upregulated proteins were mainly involved in metabolic pathways against xenobiotics. Among those upregulated proteins, 9 proteins, which participate in phase I or II of the xenobiotic metabolizing process and are known to be responsible for ROS detoxification, were validated by qRT-PCR. To explore the effect of ROS detoxification mediated by EE, glutathione activity was measured by an ELISA assay. The ratio of reduced glutathione to oxidized glutathione was significantly increased in EE mice. Based on a linear regression analysis, GSTM2 and UGT2A1 were found to be the most influential genes in ROS detoxification. For further analysis of neuroprotection, the level of iNOS and the ratio of Bax to Bcl-2 were significantly decreased in EE mice. While TUNEL+ cells were significantly decreased, Ki67+ cells were significantly increased in EE mice, implicating that EE creates an optimal state for xenobiotic metabolism and antioxidant activity. Taken together, our results suggested that EE protects olfactory layers via the upregulation of glutathione-related antioxidant and xenobiotic metabolizing enzymes, eventually lowering ROS-mediated inflammation and apoptosis and increasing neurogenesis. This study may provide an opportunity for a better understanding of the beneficial effects of EE in the OB
Data Assimilation of AOD and Estimation of Surface Particulate Matters over the Arctic
In this study, more accurate information on the levels of aerosol optical depth (AOD) was calculated from the assimilation of the modeled AOD based on the optimal interpolation method. Additionally, more realistic levels of surface particulate matters over the Arctic were estimated using the assimilated AOD based on the linear relationship between the particulate matters and AODs. In comparison to the MODIS observation, the assimilated AOD was much improved compared with the modeled AOD (e.g., increase in correlation coefficients from â0.15â0.26 to 0.17â0.76 over the Arctic). The newly inferred monthly averages of PM10 and PM2.5 for AprilâSeptember 2008 were 2.18â3.70 ÎŒg mâ3 and 0.85â1.68 ÎŒg mâ3 over the Arctic, respectively. These corresponded to an increase of 140â180%, compared with the modeled PMs. In comparison to in-situ observation, the inferred PMs showed better performances than those from the simulations, particularly at Hyytiala station. Therefore, combining the model simulation and data assimilation provided more accurate concentrations of AOD, PM10, and PM2.5 than those only calculated from the model simulations
Data Assimilation of AOD and Estimation of Surface Particulate Matters over the Arctic
In this study, more accurate information on the levels of aerosol optical depth (AOD) was calculated from the assimilation of the modeled AOD based on the optimal interpolation method. Additionally, more realistic levels of surface particulate matters over the Arctic were estimated using the assimilated AOD based on the linear relationship between the particulate matters and AODs. In comparison to the MODIS observation, the assimilated AOD was much improved compared with the modeled AOD (e.g., increase in correlation coefficients from â0.15â0.26 to 0.17â0.76 over the Arctic). The newly inferred monthly averages of PM10 and PM2.5 for AprilâSeptember 2008 were 2.18â3.70 ÎŒg mâ3 and 0.85â1.68 ÎŒg mâ3 over the Arctic, respectively. These corresponded to an increase of 140â180%, compared with the modeled PMs. In comparison to in-situ observation, the inferred PMs showed better performances than those from the simulations, particularly at Hyytiala station. Therefore, combining the model simulation and data assimilation provided more accurate concentrations of AOD, PM10, and PM2.5 than those only calculated from the model simulations
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