Unravelling the Photoelectrochemical Water Splitting of Nanometer-Thick Carbon Nitride Layer.

Matching the thickness of the graphitic carbon nitride (CN) nanolayer with the charge diffusion length is expected to compensate for the poor intrinsic conductivity and charge recombination in CN for photoelectrochemical cells (PEC). Herein, the compact CN nanolayer with tunable thickness is in situ coated on carbon fibers. The compact packing along with good contact with the substrate improves the electron transport and alleviates the charge recombination. The PEC investigation shows CN nanolayer of 93 nm-thick yields an optimum photocurrent of 116 µA cm-2 at 1.23 V versus RHE, comparable to most micrometer-thick CN layers, with a low onset potential of 0.2 V in 1 m KOH under 1 sun illumination. This optimum performance suggests the electron diffusion length matches with the thickness of the CN nanolayer. Further deposition of NiFe-layered double hydroxide enhanced the surface water oxidation kinetics, delivering an improved photocurrent of 210 µA cm-2 with IPCE of 12.8% at 400 nm. The CN nanolayer also shows extended potential in PEC organic synthesis. This work experimentally reveals the PEC behavior of the nanometer-thick CN layer, providing new insights into CN in the application of energy and environment-related fields.

Traceability of chemicals from Tripterygium Wilfordii Hook. f. in raw honey and the potential synergistic effects of honey on acute toxicity induced by celastrol and triptolide.

The object of this study was to trace TwHf-derived toxins in raw honey and clarify their acute toxic effect related to the addition of honey or sugars. TwHf flowers, raw honey from TwHf planting base and from beekeepers in high-risk area were detected using LC-MS/MS. The results revealed five target toxins were detected in TwHf flowers; only celastrol was detected in one raw honey sample, as a food safety risk factor, celastrol had been traced back to TwHf flowers from raw honey. In a series of acute toxic tests on zebrafish, toxification effects were observed when honey, mimic honey or sugar was mixed with toxins. The degree of toxicity varied among various sugar-based solutions. At the same mass concentration, they follow this order: raw honey/mimic honey > glucose > fructose. The main toxic target organs of triptolide and celastrol with honey were the heart and liver.

MRPS23 is a novel prognostic biomarker and promotes glioma progression.

Mitochondrial ribosomal protein S23 (MRPS23), a component of the ribosome small subunit, has been reported to be overexpressed in various cancers and has been predicted to be involved in increased cell proliferation. It has been confirmed that MRPS23 was involved in the regulation of breast cancer and hepatocellular carcinoma cell proliferation. However, little is known about the function of MRPS23 in glioma. In this study, we found that MRPS23 expression was higher in gliomas than in adjacent normal tissues. Higher expression of MRPS23 in gliomas correlated with poorer prognosis, unfavorable histological features, absence of mutations in the isocitrate dehydrogenase gene (IDH), absence of chromosome 1p and 19q deletions, and responses to chemoradiotherapy. Univariate and multivariate Cox analysis demonstrated MRPS23 expression was independently prognostic of overall survival, disease-free survival, and progression-free survival in patients with glioma. KEGG enrichment analysis results indicated that high MRPS23 expression was associated with cell proliferation and immune response-related signaling pathways. We also confirmed that MRPS23 was highly expressed in glioma cells lines, and MRPS23 knockdown significantly reduced cell survival, proliferation, and migration of glioma cells lines. Collectively, these findings offer mechanistic insights into how MRPS23 during glioma progression, and identify MRPS23 as a potential therapeutic target in the future.

Effects of 12-week aerobic exercise with different frequencies on executive function in preschool children: a cluster randomized controlled trial.

OBJECTIVE: To explore the effects of a 12-week aerobic exercise program with different frequencies on executive functions (EFs) in preschool children. METHOD: Four kindergartens, comprising 126 preschool children in Shanghai, were enrolled in this 12-week cluster randomized controlled trial with a 12-week follow-up period. Kindergartens were allocated to high-frequency (three times a week) or low-frequency (once a week) exercise groups using stratified block randomization. Three core sub-EFs, including inhibition, working memory, and cognitive flexibility, were assessed at baseline, post-intervention, and the 12-week follow-up. RESULTS: Compared to baseline, both groups showed significant improvements in inhibition and working memory after the intervention and at the 12-week follow-up. However, only the high-frequency exercise group demonstrated a significant improvement in cognitive flexibility after the follow-up period. Nonetheless, there were no significant differences in the core sub-functions of EFs between the two groups at the end of the intervention or the follow-up periods. CONCLUSION: A 12-week aerobic exercise of three times a week was insufficient to significantly improve EFs in preschool children compared to once a week. Future studies are needed to examine the dose-response relationship of aerobic exercise on EFs and to verify the effects of different exercise modalities on EFs in preschool children.

Estimation of annual soil CO2 efflux under the erosion and deposition conditions by measuring and modeling its respiration rate in southern China.

Soil respiration (Rs) is a crucial ecological process of carbon (C) cycling in the terrestrial ecosystems, and soil erosion has a significant impact on its C budget and balance. However, the variations of Rs rate and their CO2 efflux induced by erosion are currently poorly understood. To this end, four landscape positions (top, up, middle and toe) with different erosional and depositional characteristics were selected on a typical eroded slope in southern China to conduct field experiments, aiming to explore the effects of erosion and deposition on Rs among various sites. From March 2021 to February 2022, the in-situ Rs were measured using an automated soil respiration system, together with soil temperature at 5 cm depth (Ts5) and water content at 10 cm depth (SWC10). We initially constructed various Rs models across a one-year period, based on its relationships with Ts5 and SWC10. Subsequently, the seasonal changes of Rs at different erosional sites were simulated by the optimum models, and their annual CO2 fluxes were further estimated. The results showed that Rs rates at all sites displayed a bimodal seasonal pattern, with the highest values in May and August. And the measured Rs of the eroding and depositional sites were 0.05-7.71 and 1.47-13.03 µmol m-2 s-1, respectively. Also, remarkably higher Ts5 and SWC10 were observed in depositional sites versus the eroding sites (P < 0.05). Additionally, Rs rates at all sites were positively correlated with SOC and Ts5, but negatively correlated with SWC10. Herein, Rs models to single- and double-variable were established at different positions, and we found that the fitted R2 and AIC differed on various sites, primarily in erosional and depositional sites. Furthermore, through the best-fitting models (higher R2 and lowest AIC) we screened, the average Rs values of 3.03 and 4.46 µmol m-2 s-1 were quantitatively estimated for the eroding and depositional sites, respectively. Finally, it could be further assessed that the mean annual soil CO2-C efflux of eroded site (1104.14 g m-2) was significantly lower than that of depositional site (1629.46 g m-2). These findings highlighted the effect of erosion and deposition on Rs, which will facilitate a better understanding of C cycling in terrestrial ecosystems.

Hydrophobic Carbon Nitride Nanolayer Enables High-Flux Oil/Water Separation with Photocatalytic Antifouling Ability.

Efficient oil/water separation tackles various issues in occasions of oil leakage and oil discharge, such as environmental pollution, recollection of the oil, and saving the water. Herein, a compact superhydrophobic/superoleophilic graphitic carbon nitride nanolayer coated on carbon fiber networks (CNBA/CF) is designed and synthesized for efficient gravity-driven oil/water separation. The CNBA/CF shows excellent oil absorption and an impressive oil/water filtration separation performance. The flux reaches the state-of-art value of 4.29 × 105 L/m2/h for dichloromethane with separation efficiency up to 99%. Successive oil absorption tests, long-term filtration separation, and harsh conditions experiments confirm the remarkable separation and chemical structure stability of the CNBA/CF filter. Besides, the CNBA/CF demonstrates good photocatalytic antifouling ability thanks to the extended visible light absorption and improved charge separation. This work combines the material surface wettability modulation with a photocatalytic self-cleaning property in the fabrication of efficient oil/water separation materials while overcoming the filter fouling issue.

MWCNTs dispersion adopting GA and its application towards copper tailings-based cementitious materials.

Hydrophobic carbon nanotubes are hardly to disperse in water and prone to agglomerate when poured with Copper Tailing-Based Cementitious Material (CTCM). Multi-walled carbon nanotubes (MWCNTs) + Arabic Gum (GA) dispersions were prepared by a novel method of synergistic optimization of concentration, controlling low-frequency ultrasonic time and setting the ambient temperature with non-toxic anionic surfactant GA as surfactant. The results of UV-Vis spectroscopy showed that the high stability MWCNTs + GA dispersion with low aggregation area (< 1.2%) and low aggregation beam size (< 219 nm) have been prepared by using 1.7 mmol/l GA. The effects of highly stable MWCNTs dispersion on the mechanical properties, microstructure and durability of CTCM were studied. The 28 days compressive strength increased by 21.5%, and the flexural strength increased by 20.5%, almost reaching the mechanical level of the control group. The results of SEM, XRD and EDS showed that GA significantly enhanced the dispersion of MWCNT in aqueous solution at a suitable concentration (mass ratio of GA:CNTs = 1:1). The microstructure of the prepared CTCM by high stability MWCNTs dispersion was optimized obviously, and the mechanical properties and durability were improved significantly. This method solves the dual problem of MWCNTs not being fully dispersed in aqueous solution and being easily re-agglomerated in cementitious materials, as well as finding a breakthrough for the low cost and industrialization of tailings cement-based composite cementitious materials.

The performance of Miscanthus hybrids in saline-alkaline soil.

Cultivating the dedicated biomass crop Miscanthus on marginal land is a sustainable means of avoiding competition with food crops for arable land. A large proportion of global marginal land is saline-alkaline; however, little is known about the performance of Miscanthus in saline-alkaline soil. In this study, Miscanthus × giganteus and ten other Miscanthus hybrids grown in the Yellow River Delta were exposed to low and saline-alkaline soils during the 2016-2018 growing season to evaluate the agronomic traits, biomass quality and the potential productive index of eleven Miscanthus genotypes. Plant biomass, plant height, and tiller number significantly decreased in high saline-alkaline soil. In particular, the average plant biomass of ten Miscanthus hybrids in low saline-alkaline soil in 2017 and 2018 were 0.21 and 2.25 kg per plant, respectively, and in high saline-alkaline soil were 0.13 and 0.65 kg per plant, respectively. Cell wall, cellulose, and nitrogen content of all genotypes significantly decreased in high saline-alkaline soil, while hemicellulose, ash, sodium, potassium, magnesium, and calcium content significantly increased. However, high saline-alkaline soil had no observable impact on lignin content of Miscanthus biomass. The effect of high saline-alkaline on biomass quality parameters could provide important information for the application of Miscanthus biomass in saline-alkaline soil. The selected genotypes (A5) could be considered as breeding materials in saline-alkaline soil.

Synthesis of hollow mesoporous silica spheres functionalized with copper ferrocyanide and its application for Cs+ removal.

In this study, the potassium copper ferrocyanide-functionalized hollow mesoporous silica spheres was successfully prepared. SEM, FTIR, XRD, EDS, and XPS techniques were used to characterize the structure of materials before and after functionalization. The synthesized functionalized hollow mesoprous silica was applied to remove cesium from aqueous solution. The applicability of the adsorbent for the removal of cesium ions was assessed and the effective parameters such as solution pH, contacting time, initial Cs+ concentration, and competitive ions effect were evaluated systematically under the batch mode. The experimental results showed that the adsorbent exhibited high Cs+ selectivity even in the highly concentrated coexisting ions solution, which makes them to be used as potential adsorbents for the removal of cesium from nuclear wastewater or contaminated groundwater.

Photocatalytic properties, mechanical strength and durability of TiO2/cement composites prepared by a spraying method for removal of organic pollutants.

TiO2/cement composites were prepared by a spraying method to degrade organic pollutants. After coated with waterproof liquid, pure cement pastes/mortars were sprayed with TiO2 suspensions with different TiO2 contents and spraying times. Photocatalytic properties, mechanical strength and durability were studied. Maximum photocatalytic activity and uniform TiO2 distribution were achieved at the optimal conditions of 10 wt% TiO2 content in suspension and 3 spraying times. The TiO2/cement pastes had better degradation performance over Rhodamine B (RhB) and methylene blue (MB) than that over methyl orange (MO). After 20 times of cycling degradation, the photocatalytic efficiencies had no significant reduction. The TiO2/cement mortars had good mechanical strengths, meeting the mechanical demands of wastewater treatment tanks. In durability, the TiO2/cement mortars had better water penetration resistance, chloride penetration resistance and anti-carbonation than pure cement mortars.

ABA-mediated regulation of leaf and root hydraulic conductance in tomato grown at elevated CO2 is associated with altered gene expression of aquaporins.

Elevated CO2 concentration in the air (e[CO2]) decreases stomatal density (SD) and stomatal conductance (g s) where abscisic acid (ABA) may play a role, yet the underlying mechanism remains largely elusive. We investigated the effects of e[CO2] (800 ppm) on leaf gas exchange and water relations of two tomato (Solanum lycopersicum) genotypes, Ailsa Craig (WT) and its ABA-deficient mutant (flacca). Compared to plants grown at ambient CO2 (400 ppm), e[CO2] stimulated photosynthetic rate in both genotypes, while depressed the g s only in WT. SD showed a similar response to e[CO2] as g s, although the change was not significant. e[CO2] increased leaf and xylem ABA concentrations and xylem sap pH, where the increases were larger in WT than in flacca. Although leaf water potential was unaffected by CO2 growth environment, e[CO2] lowered osmotic potential, hence tended to increase turgor pressure particularly for WT. e[CO2] reduced hydraulic conductance of leaf and root in WT but not in flacca, which was associated with downregulation of gene expression of aquaporins. It is concluded that ABA-mediated regulation of g s, SD, and gene expression of aquaporins coordinates the whole-plant hydraulics of tomato grown at different CO2 environments.

Dereplication and targeted isolation of bioactive sulphur compound from bacteria isolated from a hydrothermal field.

Marine micro-organisms in the deep-sea hydrothermal vent systems are considered as potential sources of bioactive natural products. Sixteen bacterial strains were isolated from a deep-sea hydrothermal field and screened for bioactive metabolism studies. After the strains were subjected to bioactive testing at different culture media, chemical dereplication by HPLC coupled to high-resolution mass spectrometer was performed to analyse or determine the main secondary metabolisms in those strains. Strain 06204 was large-scale fermented with relative optimal media, for isolating the desired sulphur compound. Butyrolactone I 3-sulphate was isolated and structurally identified from the extract, guided by dereplication and showed moderate antivirus activities against H3N2 and EV71 viruses. Our study suggests that deep-sea hydrothermal bacteria are good sources of sulphur natural products. Meanwhile, the described approach, mainly bioactive screening, dereplication and targeted isolation, is effective and efficient to discover interesting bioactive compounds in hydrothermal bacteria.

Comparative Study of Two Different TiO2 Film Sensors on Response to H2 under UV Light and Room Temperature.

An anatase TiO2 film sensor was prepared by a facile in-situ method on the interdigitated Au electrode deposited on the alumina substrate. The structure, morphology and the optical properties of the in-situ TiO2 film sensor were characterized by X-ray diffraction, Scanning Electron Microscopy, and UV-vis diffuse reflectance spectra. The photo-assisted gas sensitivities of the prepared film towards H2 gas were evaluated at room temperature in N2 and synthetic air atmospheres. As compared to TiO2 film sensor prepared by drop-coating method, this in-situ TiO2 film sensor exhibited a more compact structure composed of uniform TiO2 microspheres as well as a better gas sensitivity towards H2 under UV irradiation, especially in synthetic air. The photo-electrochemical measurements suggest that these improvements may be associated with the efficient charge transfer in the TiO2 interface induced by the TiO2 microsphere structure. This study might offer a feasible approach to develop photo-assisted gas sensors at ambient temperature.

Effect of temperature on phytoextraction of hexavalent and trivalent chromium by hybrid willows.

The removal of hexavalent and trivalent chromium from hydroponic solution by plants to changes in temperature was investigated. Pre-rooted hybrid willows (Salix matsudana Koidz x alba L.) were exposed to a nutrient solution spiked with potassium chromate (K(2)CrO(4)) or chromium chloride (CrCl(3)) for 4 days. Ten different temperatures were tested ranging from 11 to 32 degrees C. Total Cr in solutions and in plant materials were all analyzed quantitatively. The results revealed that large amounts of the applied Cr were removed from the hydroponic solution in the presence of the plants. Significantly faster removal of Cr(III) than Cr(VI) was achieved by hybrid willows from the hydroponic solutions at all temperatures (P < 0.01). The removal rates of both chemical forms of Cr by plants increased linearly with the increase of temperatures. The highest removal rate of Cr(VI) was found at 32 degrees C with a value of 1.99 microg Cr/g day, whereas the highest value of Cr(III) was 3.55 microg Cr/g day at the same temperature. Roots were the main sink for Cr accumulation in plants at all temperatures. Translocation of both chemical forms of Cr from roots to lower stems was only found at temperatures > or = 24 degrees C. The temperature coefficient values (Q(10)) were 2.41 and 1.42 for Cr(VI) and Cr(III), respectively, indicating that the removal of Cr(VI) by hybrid willows was much more susceptible to changes in temperature than that of Cr(III). This information suggests that changes in temperature have a substantial influence on the uptake and accumulation of both chemical forms of Cr by plants.

[Correlation of delta18O in precipitation and moisture sources at Yunfu, Western Guangdong Province, China].

Fifty-nine samples of atmospheric precipitation were collected at Yunfu, Western Guangdong province during the period of April 5, 2005 to April 1, 2006 and their oxygen isotopic compositions were analyzed. Results show that delta18O values range from -12.47 per thousand to -0.18 per thousand with an average of -4.91 per thousand; the delta18O values of summer and autumn (from May to September) are relatively lower, ranging from -10.00 per thousand to -5.00 per thousand with an average of -6.30 per thousand; the delta18O values of winter and spring (from October to next April) are relatively higher, ranging from - 3.00 per thousand to - 1.00 per thousand with an average of - 2.20 per thousand. These delta18O values have relatively marked negative correlation with the corresponding temperatures and water vapour pressure and their coefficients are both -0.60; but they have had negative correlation with the precipitation amount, the coefficient is -0.33. Comparing with the monthly delta18O value of Guangzhou atmospheric precipitation, those of Yunfu City is relatively lower, maybe the reason is that Yunfu City is influenced by stronger South-West Asian Monsoon. The results of HYSPLIT back trajectory analysis indicated that the differences of delta18O values are determined by different water vapour sources during the pre-rainy season (from April to June), post-rainy season (from July to September) and non-rainy season (from October to next April), so the delta18O values can be considered as an indicator of denoting their water vapour sources, relatively higher delta18O values denote the water vapour sources are denaturalized tropical hot air mass located in the subtropical sea areas (including the South China Sea), western Pacific Ocean; relatively lower delta18O values indicate denaturalized tropical hot air mass from the India Ocean and Bengal Gulf.

Protective effect of triterpenoid fractions from the rhizomes of Astilbe chinensis on cyclophosphamide-induced toxicity in tumor-bearing mice.

AIM OF THE STUDY: The objectives of this study were to investigate the protective effect of the triterpenoid fractions from the rhizomes of Astilbe chinensis (Saxifragaceae) (ATF) on cyclophosphamide (CTX)-induced toxicity in tumor-bearing mice. MATERIALS AND METHODS: The mice inoculated with mouse sarcoma S180 cells were treated with saline or CTX alone, or co-treated with CTX and ATF. The blood, femur bone, and serum samples were collected for determination of the haematological and biochemical parameters and splenocytes were for assay of proliferation, the activity of natural killer (NK) cells, and production of interleukin-2 (IL-2). RESULTS: ATF significantly increased the peripheral white blood cell (WBC) count and bone marrow cellularity (BMC) in CTX-treated S180-bearing mice. Increase of aspartate transanimase (AST), alanine transaminase (ALT), urea nitrogen (BUN), and creatinine in the serum of CTX-treated mice was significantly reversed by ATF. The lowered levels of splenocytes proliferation, NK cells activity, and IL-2 production from splenocytes in S180-bearing mice after CTX treatment were also increased by ATF administration. CONCLUSIONS: ATF provides significant protection against CTX-induced hematotoxicity, hepatotoxicity, nephrotoxicity, and immunotoxicity, and might be helpful in abrogation of CTX-induced toxicity during the chemotherapy.

A new cytotoxic, apoptosis-inducing triterpenoid from the rhizomes of Astilbe chinensis.

A new ursane-based compound, astilbotriterpenic acid (1), was isolated from the rhizomes of Astilbe chinensis. Its structure was determined on the basis of chemical evidence and extensive spectroscopic methods, including 1D- and 2D-NMR. The pentacyclic triterpenoid 1 was assayed for its in vitro cytotoxicity against Bcap37, HeLa, HepG2, HO-8910, K562, PAA, SGC7901, and P388 cancer cells, as well as for its apoptosis-inducing activity in HeLa cells. Compound 1 was found to strongly inhibit tumor-cell growth through induction of apoptosis and may, thus, be further evaluated as a novel chemotherapeutic agent.

Response of weeping willows to linear alkylbenzene sulfonate.

Linear alkylbenzene sulfonate (LAS) is the most commonly used anionic surfactant in laundry detergents and cleaning agents. LAS compounds are found in surface waters and soils. The short-term acute toxicity of LAS to weeping willows (Salix babylonica L.) was investigated. Willow cuttings were grown in hydroponic solution spiked with LAS at 24.0+/-1 degrees C for 192 h. The normalized relative transpiration of plants was used to determine toxicity. Severe reduction of the transpiration was only found for high doses of LAS (240 mgl(-1)). Chlorophyll contents in leaves of treated plants varied with the dose of LAS, but there was no significant linear correlation. The activities of the enzymes superoxide dismutases (SOD), catalase (CAT), and peroxidase (POD) were quantified at the end of experiments. At higher concentrations of LAS (240 mgl(-1)), the activities of SOD and CAT were decreased. The correlation between the dose of LAS and the POD activity in leaf cells was the highest of all enzyme assays (R(2)=0.5). EC(50) values for a 50% inhibition of the transpiration of the trees were estimated to 374 mgl(-1) (72 h) and 166 mgl(-1) (192 h). Results from this experiment indicated that phytotoxic effects of LAS on willow trees are not expected for normal environmental conditions.

[Analysis of the constituents of essential oils from Sambucus chinensis].

26 chemical constituents of the essential oil from Sambucus chinensis Lindl. were separated and identified by GC/MS. The relative contents of them were determined by area nomalization.