Electrodeposition Combination with Hydrothermal Preparation of ZnO Films and Their Application in Dye-Sensitized Solar Cell

A suitable method is necessary for the high performance of dyes-sensitized solar cells (DSSCs). In this paper, photoanodes of DSSCs have been fabricated through electrodeposition and combination with hydrothermal method. The results of mix method showed better performance than the single one. After the second step electrodeposition, the ZnO films formed flack finally. With the increase of hydrothermal time, ZnO films become thicker and bigger, which can offer large surface area to absorb much more dyes. The short-circuit current (2.4 mA/cm2) and open-circuit voltage (0.67 V) were greater than the single one, alternating current impedance indicating that electrodeposition and hydrothermal mix are a more suitable method for high performance DSSCs. We expected to obtain higher conversion efficiency of DSSCs by this method

Cellular FLICE-like inhibitory protein (cFLIP) critically maintains apoptotic resistance in human lens epithelial cells

The present study aims to understand the mechanism of the lens epithelial cell’s strong anti-apoptotic capacity and survival in the mature human lens that, on the one hand, maintains lens transparency over several decades, while on the other hand, increases the risk of posterior capsule opacification (PCO). Here we compared FHL124 cells and HeLa cells, spontaneously immortalized epithelial cell lines derived from the human lens and cervical cancer cells, respectively, of their resistance to TNFα-mediated cell death. TNFα plus cycloheximide (CHX) triggered almost all of HeLa cell death. FHL124 cells, however, were unaffected and able to block caspase-8 activation as well as prevent caspase-3 and PARP-1 cleavage. Interestingly, despite spontaneous NFκB and AP-1 activation and upregulation of multiple cell survival/anti-apoptotic genes in both cell types, only FHL124 cells were able to survive the TNFα challenge. After screening and comparing the cell survival genes, cFLIP was found to be highly expressed in FHL124 cells and substantially upregulated by TNFα stimulation. FHL124 cells with a mild cFLIP knockdown manifested a profound apoptotic response to TNFα stimulus similar to HeLa cells. Most importantly, we confirmed these findings in an ex vivo lens capsular bag culture system. In conclusion, our results show that cFLIP is a critical gene that is regulating lens epithelial cell survival

An interlaboratory comparison of aerosol inorganic ion measurements by ion chromatography : Implications for aerosol pH estimate

Water-soluble inorganic ions such as ammonium, nitrate and sulfate are major components of fine aerosols in the atmosphere and are widely used in the estimation of aerosol acidity. However, different experimental practices and instrumentation may lead to uncertainties in ion concentrations. Here, an intercomparison experiment was conducted in 10 different laboratories (labs) to investigate the consistency of inorganic ion concentrations and resultant aerosol acidity estimates using the same set of aerosol filter samples. The results mostly exhibited good agreement for major ions Cl-, SO2-4, NO-3, NHC4 and KC. However, F-, Mg2C and Ca2C were observed with more variations across the different labs. The Aerosol Chemical Speciation Monitor (ACSM) data of nonrefractory SO2-4, NO-3 and NHC4 generally correlated very well with the filter-analysis-based data in our study, but the absolute concentrations differ by up to 42 %. Cl-from the two methods are correlated, but the concentration differ by more than a factor of 3. The analyses of certified reference materials (CRMs) generally showed a good detection accuracy (DA) of all ions in all the labs, the majority of which ranged between 90 % and 110 %. The DA was also used to correct the ion concentrations to showcase the importance of using CRMs for calibration check and quality control. Better agreements were found for Cl-, SO2-4, NO-3, NHC4 and KC across the labs after their concentrations were corrected with DA; the coefficient of variation (CV) of Cl-, SO2-4, NO-3, NHC4 and KC decreased by 1.7 %, 3.4 %, 3.4 %, 1.2 % and 2.6 %, respectively, after DA correction. We found that the ratio of anion to cation equivalent concentrations (AE/CE) and ion balance (anions-cations) are not good indicators for aerosol acidity estimates, as the results in different labs did not agree well with each other. In situ aerosol pH calculated from the ISORROPIA II thermodynamic equilibrium model with measured ion and ammonia concentrations showed a similar trend and good agreement across the 10 labs. Our results indicate that although there are important uncertainties in aerosol ion concentration measurements, the estimated aerosol pH from the ISORROPIA II model is more consistent

Impact of HO2 aerosol uptake on radical levels and O3 production during summertime in Beijing

The impact of heterogeneous uptake of HO2 on aerosol surfaces on radical concentrations and the O3 production regime in Beijing in summertime was investigated. The uptake coefficient of HO2 onto aerosol surfaces, γHO2 , was calculated for the AIRPRO campaign in Beijing, in summer 2017, as a function of measured aerosol soluble copper concentration, [Cu2+]eff, aerosol liquid water content, [ALWC], and particulate matter concentration, [PM]. An average γHO2 across the entire campaign of 0.070 ± 0.035 was calculated, with values ranging from 0.002 to 0.15, and found to be significantly lower than the value of γHO2 = 0.2, commonly used in modelling studies. Using the calculated γHO2 values for the summer AIRPRO campaign, OH, HO2 and RO2 radical concentrations were modelled using a box model incorporating the Master Chemical Mechanism (v3.3.1), with and without the addition of γHO2 , and compared to the measured radical concentrations. The rate of destruction analysis showed the dominant HO2 loss pathway to be HO2 + NO for all NO concentrations across the summer Beijing campaign, with HO2 uptake contributing < 0.3 % to the total loss of HO2 on average. This result for Beijing summertime would suggest that under most conditions encountered, HO2 uptake onto aerosol surfaces is not important to consider when investigating increasing O3 production with decreasing [PM] across the North China Plain. At low [NO], however, i.e. < 0.1 ppb, which was often encountered in the afternoons, up to 29 % of modelled HO2 loss was due to HO2 uptake on aerosols when calculated γHO2 was included, even with the much lower γHO2 values compared to γHO2 = 0.2, a result which agrees with the aerosol-inhibited O3 regime recently proposed by Ivatt et al. (2022). As such it can be concluded that in cleaner environments, away from polluted urban centres where HO2 loss chemistry is not dominated by NO but where aerosol surface area is high still, changes in PM concentration and hence aerosol surface area could still have a significant effect on both overall HO2 concentration and the O3 production regime. Using modelled radical concentrations, the absolute O3 sensitivity to NOx and volatile organic compounds (VOCs) showed that, on average across the summer AIRPRO campaign, the O3 production regime remained VOC-limited, with the exception of a few days in the afternoon when the NO mixing ratio dropped low enough for the O3 regime to shift towards being NOx -limited. The O3 sensitivity to VOCs, the dominant regime during the summer AIRPRO campaign, was observed to decrease and shift towards a NOx -sensitive regime both when NO mixing ratio decreased and with the addition of aerosol uptake. This suggests that if [NOx ] continues to decrease in the future, ozone reduction policies focussing solely on NOx reductions may not be as efficient as expected if [PM] and, hence, HO2 uptake to aerosol surfaces continue to decrease. The addition of aerosol uptake into the model, for both the γHO2 calculated from measured data and when using a fixed value of γHO2 = 0.2, did not have a significant effect on the overall O3 production regime across the campaign. While not important for this campaign, aerosol uptake could be important for areas of lower NO concentration that are already in a NOx -sensitive regime

TiCl4 Pretreatment and Electrodeposition Time Investigations of ZnO Photoelectrodes Preparation for Dye Sensitized Solar Cells

TiCl4 pretreatment is used in the fabrication of high performance photoanodes for dyes-sensitized solar cells (DSSCs). In this paper, TiCl4 pretreatment was used on fluorine doped tin oxide (FTO) before fabricating ZnO films by electrochemical method. The effects of TiCl4 pretreatment on some important parameters of solar cells, such as short-circuit current (Jsc) and filling factor, were investigated. The morphology of ZnO films was changed after TiCl4 pretreatment, which can offer large surface area to absorb much more dyes. When the time of electrodeposition was 3 min, the dyes-sensitized solar cells (DSSCs) based on TiCl4 pretreatment ZnO films showed more superior photoelectrochemical performance. The parameters of DSSCs are greatly improved. The DSSC based on ZnO films after TiCl4 pretreatment has a very promising value for fabricating high performance solar cells

Gas-particle partitioning process contributes more to nitrate dominated air pollution than oxidation process in northern China

Nitrate has been recognized as a key aerosol component in regional haze formation in China. However, reducing nitrate aerosol concentration remains a major challenge. Generally, the formation of particulate nitrate (NO3-) is mainly affected by two processes: oxidation (to generate gaseous HNO3 or particulate NO3-) and gas-particle partitioning (HNO3-NO3- partition). Here, we proposed a new method to explore the contributions of above two processes (CobsOxi (%) and CobsG/P (%)) to nitrate formation based on field observation, and combined theoretical calculation and modeling to verify it. Quantitative results showed that gas-particle partitioning process (average CobsG/P (%) was 64.90%) always contributed more than oxidation process (average CobsOxi (%) was 35.10%) for particulate nitrate formation under different pollution scenarios in the ambient environment. We argued that this phenomenon was mainly caused by high aerosol pH (&gt;4.5). Nevertheless, as pollution level rose, the CobsOxi (%) will also increase (contributing to 32%, 38%, 40% and 41% under clean, light, medium and heavy pollution levels) which may be attributed to the increased HNO3 production rate and relatively enhanced heterogeneous reaction pathway. The results indicate future strategies for prevention and control of nitrate pollution should both consider reducing precursors emission and regulating aerosol acidity, in order to increase the effectiveness of reducing nitrate dominated pollution.</p

Effect and Mechanism of Pivot Meridian Massage on TLR8/ERK Signaling Pathway and LncRNA-GAS5 in Rats with Neuropathic Pain

Background Pivotal meridian massage for neuropathic pain obtained favorable results in recent years, however, its specific mechanism of action has not been fully elucidated. Objective To observe the analgesic effect of pivotal meridian massage on rats according to the research indexes taking rat model of neuropathic pain induced by L5 spinal nerve ligation as the object of observation, to further investigate whether the analgesic effect is achieved by affecting LncRNA-GAS5 and then regulating the apoptosis of neurons in the dorsal horn of the spinal cord. Methods The experiment was conducted from January to June 2021 at the Experimental Center for Animal Medicine of Guangxi University of Chinese Medicine and Guangxi University. A total of 120 healthy female SD rats were randomly divided into the normal group, model group, sham-operated group, sham-manipulation group, and meridian manipulation group, with 24 rats in each group. Rat model of neuropathic pain was prepared by ligating the L5 spinal nerve in the model, sham-operated, sham-manipulation and meridian manipulation groups. After modeling for 24 hours, the L5 spinal nerve was exposed for a few minutes without ligation, and the wound was closed layer by layer in the sham-operated group; hind limbs of the rats in the sham-manipulation group were gently stroked for 18 minutes; a self-made massager was used to sequentially stimulate the three acupoints on the bilateral Foot Shaoyang Gallbladder Meridian of Huan Tiao, Yang Ling Quan, and Xuan Zhong, with a stimulation force of 5 N, frequency of 2 Hz, intervention of 1 minute for each acupoint and technique, totaling 18 minutes in the meridian manipulation group. The normal group and model group were fed and observed normally without any intervention. Behavioral tests (mechanical withdrawal threshold and thermal withdrawal latency) were performed before modeling and on days 1, 3, 7, and 14 after modeling. On days 7 and 14 of the intervention, 12 rats were randomly selected for tissue sampling to detect the expression of TLR8/ERK signaling pathway-related proteins (Bcl-2, Caspase-3, ERK, TLR8 protein levels) and the expression levels of LncRNA-GAS5 and miR-21 genes in the spinal cord tissue. Results (1) In terms of behavioral observations, the mechanical withdrawal threshold of the model group, sham-manipulation group, and meridian manipulation group was lower than the normal group on days 1, 3, 7, and 14 after modeling (P&lt;0.05) . The mechanical withdrawal threshold of the sham-operated group, sham-manipulation group and meridian manipulation group was higher than the model group on day 14 after modeling (P&lt;0.05) . The mechanical withdrawal threshold of the sham-operated group, meridian manipulation group was higher than the sham-manipulation group on days 7 and 14 after modeling (P&lt;0.05) . The thermal withdrawal latency in the sham-manipulation group and meridian manipulation group was shorter than the normal group on days 1, 3, and 7 after modeling (P&lt;0.05) . The thermal withdrawal latency in the sham-operated group, sham-manipulation group and meridian manipulation group was longer than the model group on days 7 and 14 after modeling (P&lt;0.05) . The sham-operated group, meridian manipulation group had longer thermal withdrawal latency than the sham-manipulation group on day 14 after modeling (P&lt;0.05) . (2) In terms of protein and gene expression levels related to the signaling pathway, on day 7 after modeling, the Bcl-2 protein expression level in the normal group was lower than the other groups (P&lt;0.05) . The Bcl-2 protein expression level in the meridian manipulation group was higher than the model group, while the Caspase-3, ERK, and TLR8 protein expression levels were lower than the model group (P&lt;0.05) . The Bcl-2, Caspase-3, ERK, and TLR8 protein expression levels in the meridian manipulation group were lower than the sham-operated group, sham-manipulation group (P&lt;0.05) . On day 14 after modeling, the Bcl-2 protein expression level in the meridian manipulation group remained higher than the model group, while the Caspase-3 and TLR8 protein expression levels remained lower than the model group, and the ERK protein expression level was higher than the model group (P&lt;0.05) . After 7 days of modeling, the expression level of LncRNA-GAS5 gene in the sham-manipulation group and meridian manipulation group was higher than the model group, while the expression level of miR-21 gene was lower than the model group (P&lt;0.05) . The expression level of LncRNA-GAS5 gene in the meridian manipulation group was higher than the sham-manipulation group, while the expression level of miR-21 gene was lower than the sham-manipulation group (P&lt;0.05) . After 14 days of modeling, the expression level of LncRNA-GAS5 gene in the model group was lower than the normal group, while the expression level of LncRNA-GAS5 gene in the meridian manipulation group and sham-manipulation group was higher than the model group (P&lt;0.05) . The expression level of miR-21 gene in the meridian manipulation group and sham-manipulation group was higher than the model group (P&lt;0.05) . Conclusion The meridian manipulation technique has a certain analgesic effect on rats with neuropathic pain. It is initially hypothesized that the analgesic mechanism may be achieved by upregulating the expression level of LncRNA-GAS5 to inhibit neuronal apoptosis by adsorbing miR-21 to mediate TLR8/ERK pathway-related proteins. Although the specific mechanism has not been conclusively confirmed, LncRNA-GAS5 is expected to be a new target for future treatment of neuropathic pain in the future

Gas-particle partitioning process contributes more to nitrate dominated air pollution than oxidation process in northern China

Nitrate has been recognized as a key aerosol component in regional haze formation in China. However, reducing nitrate aerosol concentration remains a major challenge. Generally, the formation of particulate nitrate (NO3-) is mainly affected by two processes: oxidation (to generate gaseous HNO3 or particulate NO3-) and gas-particle partitioning (HNO3-NO3- partition). Here, we proposed a new method to explore the contributions of above two processes (CobsOxi (%) and CobsG/P (%)) to nitrate formation based on field observation, and combined theoretical calculation and modeling to verify it. Quantitative results showed that gas-particle partitioning process (average CobsG/P (%) was 64.90%) always contributed more than oxidation process (average CobsOxi (%) was 35.10%) for particulate nitrate formation under different pollution scenarios in the ambient environment. We argued that this phenomenon was mainly caused by high aerosol pH (&gt;4.5). Nevertheless, as pollution level rose, the CobsOxi (%) will also increase (contributing to 32%, 38%, 40% and 41% under clean, light, medium and heavy pollution levels) which may be attributed to the increased HNO3 production rate and relatively enhanced heterogeneous reaction pathway. The results indicate future strategies for prevention and control of nitrate pollution should both consider reducing precursors emission and regulating aerosol acidity, in order to increase the effectiveness of reducing nitrate dominated pollution.</p