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TiO2 photocatalyst (P-25) (50mgL−1) was tentatively introduced into pulsed high-voltage discharge process for non-thermal plasma-induced photocatalytic degradation of the representative mode organic pollutant parachlorophenol (4-CP), including other compounds phenol and methyl red in water. The experimental results showed that rate constant of 4-CP degradation, energy efficiency for 4-CP removal and TOC removal with TiO2 were obviously increased. Pulsed high-voltage discharge process with TiO2 had a promoted effect for the degradation of these pollutants under a broad range of liquid conductivity. Furthermore, the apparent formation rates of chemically active species (e.g., ozone and hydrogen peroxide) were increased, the hydrogen peroxide formation rate from 1. 10×10−6 to 1. 50×10−6 Ms−1, the ozone formation rate from 1. 99×10−8 to 2. 35×10−8 Ms−1, respectively. In addition, this process had no influence on the photocatalytic properties of TiO2. The introduction of TiO2 photocatalyst into pulsed discharge plasma process in the utilizing of ultraviolet radiation and electric field in pulsed discharge plasma process enhanced the yields of chemically active species, which were available for highly efficient removal and mineralization of organic pollutants. [Copyright &y& Elsevier]

This paper provides evidence for the degradation of organic pollutant by the photo-Fenton complex mechanism. Both the complex oxidation and HO· oxidation mechanisms were verified by p-chlorophenol degradation, UV/Vis spectra anaylsis, and quantum yield. The hydroxyl radical involved in the photo-Fenton process can also be generated from the decomposition of H_2O_2, photolysis of Fe^{3+} and degradation of hydrated Fe(VI)-complex, excepting the traditional Fenton reaction. [ABSTRACT FROM AUTHOR]

A novel metallo-organic chemical vapor deposition (MOCVD) technique has been applied to the preparation of the photocatalytic titanium dioxide supported on activated carbon. The effects of various condition parameters such as carrier gas flow rate, source temperature and deposition temperature on the deposition rate were investigated. The maximum deposition rate of 8.2 mg/(g·h) was obtained under conditions of carrier gas flow rate of 400 ml/min, source temperature of 423 K and deposition temperature of 913 K. The deposition rate followed Arrhenius behavior at temperature of 753 K to 913 K, corresponding to activation energy E a of 51.09 kJ/mol. TiO2 existed only in anatase phase when the deposition temperature was 773 K to 973 K. With increase of deposition temperature from 1073 K to 1273 K, the rutile content sharply increased from 7% to 70%. It was found that a deposition temperature of 773 K and a higher source temperature of 448 K resulted in finely dispersed TiO2 particles, which were mainly in the range of 10–20 nm. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, C22H17N3O7, the furo[2,3- d]pyrimidine ring system is essentially planar. π–π Stacking and inter­molecular C—H⋯O hydrogen-bond inter­actions stabilize the crystal structure. [ABSTRACT FROM AUTHOR]

In order to remedy the lack of research on the effect of "Grain for Green" on soil carbon （C） and nitrogen （N） distribution on slope soil in purple hilly areas of Sichuan Basin, China, a study was conducted on a long-term observation site established in the Wanan small watershed of Yanting Agro-ecological Experimental Station of Purple Soil, Chinese Academy of Sciences. The morphology, content, and storage of C and N in soil at different slope positions of farmland and the artificial forests in rehabilitated land with a history of approximately 30 years were compared. Our results showed that "Grain for Green" significantly increased soil organic carbon （SOC） content and SOC stock in all soil layers. The SOC stock of the surface layer （0-20 cm） increased by 25.86 t·hm -2 , and the annual SOC stocks ratio was 0.89 t·hm -2 . Soil total nitrogen （TN） content increased slightly but only in the 0-20 cm soil layer. Compared with those in sloping farmland, the differences in available C and N nutrients such as soil nitrate N （NO 3 - -N）, ammonia N （NH 4 + -N）, and dissolved organic C （DOC） in the whole soil profile （0-70 cm） were basically not significant （P &gt; 0.05）. In addition, our research also found that slope position had significant effects on the contents of TN, SOC, NO 3 - -N, NH 4 + -N, and DOC in farmland soil （ P < 0.05）. The variation trend of soil NO 3 - -N, NH 4 + -N, and DOC contents along the slope was as follows： upper slope < middle slope < lower slope, whereas the soil TN and SOC contents were highest in the lower slope, followed by the upper slope and middle slope. The position of the slope had a significant impact only on DOC content in forest soil, which increased along the slope. This research indicated that when evaluating the impact of land use changes on soil C and N stocks in the purple soil hilly region, the influence of topographic factors cannot be ignored.

Since the 1990s, a large area of sloping farmland in a purple soil hilly region of southwest China was converted into an orchard to prevent soil erosion, increase soil fertility, and elevate economic benefits for farmers. In order to explore the spatial distribution of soil carbon (C) and nitrogen (N) fractions on the slope of returning arable lands to citrus orchards in purple soil hilly areas, a soil sampling event was carried out in a citrus orchard at the Yanting Agro-ecological Experimental Station of Purple Soil, Chinese Academy of Sciences, to examine the differences in soil C and N fractions and their influencing factors. The results showed that the slope position had significant effects on the contents of soil total nitrogen (TN), nitrate nitrogen (NO 3 - -N), and dissolved organic carbon (DOC) ( P &lt; 0.05), but the effects were not obvious regarding the total organic carbon (SOC) and ammonia nitrogen (NH 4 + -N) of the soil ( P &gt; 0.05). For topsoil (0-30 cm), the variation trend of soil NO 3 - -N content along the slope was upper slope &lt; middle slope &lt; lower slope, whereas the TN and DOC contents along the slope exhibited the trend of upper slope &gt; middle slope &gt; lower slope. The contents of soil C and N in each slope position generally showed a downward trend with increasing soil depth (0-30 cm). The contents of soil TN, SOC, NO 3 - -N, and DOC were significantly affected by soil depth ( P &lt; 0.05). The TN storage (0-30 cm) significantly decreased from the top to the bottom within the soil slope, with a value of 2.37, 1.89, and 1.62 t·hm -2 (reported as N) for the upper slope, middle slope, and lower slope, respectively. There was no significant difference in SOC reserves along the slope, with a range from 56.12 to 58.48 t·hm -2 (reported as C). Our results provide scientific basis for understanding the spatial distribution of soil nutrients of the restored farmland in purple soil hilly areas. Our research suggests that the spatial distribution of soil carbon and nitrogen storage should not be ignored when predicting the response of soil nutrients to land use change.

The Tuojiang River and Fujiang River, two important tributaries of the upper reaches of the Yangtze River, have serious water pollution problems, among which nitrogen (N) and phosphorus (P) are the most important pollutants. Therefore, the aim of this study was to identify the influencing factors of water quality in different spaces and provide a scientific basis for the prevention and control of surface water pollution in the upper reaches of the Yangtze River and its tributaries. Water samples of trunk and tributaries in the Tuojiang River and Fujiang River were collected, and the spatial distribution characteristics of water N and P were analyzed. The results showed that the Tuojiang River and Fujiang River showed serious pollution of total nitrogen (TN), with a water quality worse Ⅴ-section proportion as high as 94% and 50%, respectively. Both rivers showed that TN and TP concentrations in the tributaries were higher than those in the main stream. For both rivers, total phosphorus (TP), with moderate pollution, was mainly concentrated in Ⅱ, Ⅲ, and Ⅳ class water quality, whereas the P pollution was more serious for the Fujiang River compared to that of the Fujiang River. For the Tuojiang River, nitrate nitrogen (NN) concentration from upstream to downstream showed a trend of decreasing after the first increase, with the maximum concentration of ammonium nitrogen (AN) exhibiting at the upstream site. In particular, TP concentration increased significantly after rivers flowed through a city. For the Fujiang River trunk stream, TN and NN concentration exhibited a gradually increasing trend from the middle to lower reaches. Generally, our study revealed that TN, TP, and NN in the rivers were affected by water pH and water temperature ( T ). Therefore, the control of N and P pollution in rivers should pay attention to the influence of water environmental factors.

Shallow groundwater is the main drinking water supply for the mountainous area in the upper reaches of the Yangtze River, while its quality is often degraded by nitrate (NO 3 - -N) pollution due to intensive agricultural production activities. In the present study, we selected a mountainous agricultural watershed in the upper reaches of the Yangtze River to investigate the land use, management, and hydrogeological conditions, aiming to clarify the spatial-temporal variations in NO 3 - -N concentration of shallow groundwater, thereby exploring the key regulators. The results showed that the NO 3 - -N concentrations of the groundwater ranged from 0.40 to 12.51 mg ·L -1 in the study area, and the exceeding ratio was nearly 30%. On an average, NO 3 - -N concentrations for the wet season were higher than that for the dry season, indicating great variations in NO 3 - -N concentration across different seasons. In addition, the spatial variations of NO 3 - -N concentration in groundwater were also significant among different sub-catchment, which was mainly due to variations in the groundwater table depth and land uses. Furthermore, the significant correlations between the NO 3 - -N concentrations and concentrations of Cl - , NH 4 + -N, DOC, and SO 4 2- in the shallow groundwater were also explored in this study, suggesting that the NO 3 - -N concentrations were likely to depend on the chemical factors of the shallow groundwater in the study area. Overall, our current study highlights that the characterization of spatial-temporal variations of NO 3 - -N status in shallow groundwater and illustration of key regulators are essential to mitigate NO 3 - -N pollution and prevent quality degradation of shallow groundwater in mountainous rural areas of the upper Yangtze River watershed.

To study the effect of ginseng saponin Rh₂ in inducing apoptosis of human leukemia K562 cells, and explore its mechanism from the aspect of autophagy pathway. CCK-8 assay was used to examine the growth inhibition of human leukemia cell lines K562 treated with ginsenoside Rh₂; flow cytometry (FCM) was used to detect cell apoptosis; Hoechst staining was used to observe the changes of cell morphological apoptosis; Acridine and MDC staining were used to detect the effects of the Rh₂ on autophagy; Western blot and RT-PCR were used to detect the expression levels of the proteins closely associated with autophagy and apoptosis. In order to study the effect of autophagy in proliferation and apoptosis, we used the autophagy inhibitor (3-MA).CCK-8 indicated that Rh₂ at low concentration could effectively inhibit the proliferation of leukemia cellsin dose- and time-dependent manners in K562 cells; FCM indicated that Rh₂ induced apoptosis; Hoechest staining showed that K562 cells had typical apoptotic morphological changes by treated Rh₂; Acridine and MDC staining showed that Rh₂ enhanced the green fluorescence and a large number of acidic autophagy vesicles were present; Western blot and RT-PCR results showed that Rh₂ increased the expression levels of Beclin-1, LC3A, LC3B, activated Caspase-3 and p-p38 in K562 cells; application of autophagy inhibitors(3-MA) could weaken the inhibition effect of Rh₂ on proliferation and induction effect on apoptosis in K562 cells. Ginsenoside Rh₂ inhibited the proliferation and induced apoptosis probably through activating p-p38, and inducing cell autophagy signaling pathway in K562 cells., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)