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Biochar applied to the soil can contribute to the sustainability of agriculture by promoting ecosystem services. Tea production contributes to addressing hunger and poverty in developing countries. However, little is known about the impact of biochar amendment on ecosystem services in tea plantations. We evaluated ecosystem services from an economic assessment perspective to better understand the effects of biochar on ecosystem services and dis-services. We conducted field experiments in two subtropical tea plantations with three treatments: no fertilizer and compound fertilizers applied without and with biochar. Results showed that biochar increased the net ecosystem carbon budget by 17-fold through direct carbon addition, thus increasing regulating services. Compared to compound fertilizer alone, biochar application reduced total reactive nitrogen loss by an average of 1.8 % due to an average reduction of 16.2 % and 21.5 % in nitrous oxide and nitric oxide emissions, respectively. However, the high cost of biochar, the low environmental benefits due to the low carbon price, and the fact that biochar did not provide additional economic profit made the net ecosystem economic benefits unsatisfactory. For comparison, we set up an optimistic scenario based on the increased carbon price ($160/ton CO

Rice paddies are a significant source of atmospheric methane (CH4) threatening global warming. Methane fluxes from rice soils are mediated by both methanogens and methanotrophs, while subject to fertilization regimes. A field experiment was conducted to investigate the response of CH4 emissions, with a close link to methanogenic and methanotrophic communities, to different fertilization strategies over two consecutive rice growing seasons in a paddy field. Four fertilized treatments were established consisting of chemical phosphorous (P) and potassium (K) fertilizer (PK), chemical nitrogen (N) PK fertilizer (NPK), chemical NPK combined with organic manure (NPKM), and organic manure alone (M). Results showed that, relative to chemical PK treatment without N fertilizer input, the application of chemical NPK fertilizer, manure, and their combination significantly increased seasonal mean CH4 emissions by 67.4, 20.4 and 101.2%, respectively. Methane fluxes were significantly and positively (r2 = 0.75) related to mcrA gene copy numbers and the ratio of mcrA/pmoA, while negatively (r2 = 0.40) related to pmoA gene copy numbers, which was mainly regulated by the dynamics of water irrigation regime. The abundance of mcrA and pmoA had trade-off relationship over the rice growing season. In comparison with PK fertilization, N fertilized treatments did not alter the seasonal trend of CH4 fluxes, but enhanced the source strength of CH4 emissions through increased mcrA abundances rather than reduced pmoA-dominated methanotrophic CH4 oxidation in rice paddies. In contrast, N fertilization showed no effect on pmoA abundance and associated methanotrophic community in rice paddies. Results highlight that, given the fertilizer-driven balance between methanogenic and methanotrophic communities, fertilization options with either chemical or organic N input stimulated CH4 emissions mainly through improving soil C substrate and methanogenic activities, especially under the combination of chemical and organic N fertilization in rice paddies.

Biochar impact on soil nitrous oxide (N2O) and nitric oxide (NO) emissions from intensive greenhouse vegetable cropping systems is not well established. Annual soil N2O and NO emissions were simultaneously measured from a typical greenhouse vegetable field treated with different biochar application rates in southeast China. Both N2O and NO emissions differed greatly across the individual vegetable cropping seasons, of which being higher in green soybean and tomato growing seasons, respectively. Over the annual vegetable cropping rotation, biochar amendment decreased soil N2O and NO emissions by 10–23% and 18–19% relative to N fertilization alone, respectively. Biochar rate of 20 t ha−1 gained the lowest N2O and NO emissions over the annual cycle. The ratio of NO/N2O was negatively correlated with soil moisture and depends on biochar addition or not. On average, annual emission factor (EF) of N2O and NO combined was accounted for 2.13% with biochar amendment, which was decreased by 22% compared with N fertilization alone (EF = 2.74%). Vegetable yield was significantly enhanced under the biochar combined with N fertilizer plots relative to control, while there is no difference among the N fertilization treatments with or without biochar amendment. Therefore, biochar could be used as an effective management mitigating soil N2O and NO emissions while maintaining crop yield in greenhouse vegetable cropping systems in southeast China.

Biochar amendment has been shown to reduce nitrous oxide (N2O) emissions from acidic soils in tea plantations. Given that both soil bacterial and fungal denitrifications can produce N2O, their relative contributions to the decrease in N2O emissions following biochar amendment remain unclear. Here, we examined soils sampled from a subtropical tea plantation that had received 2 years of biochar amendment. Measurements of the relative contributions of fungi and bacteria to N2O production were taken by the substrate-induced respiration method implemented with the addition of selective inhibitors. The abundances of total fungi, bacteria, and key N2O-related bacterial genes were quantified by q-PCR, and the composition of the fungal community was analyzed by 18S rRNA amplicon sequencing. The results showed that the contribution of fungi to N2O production (52%) was greater than that of bacteria (18%) for the N-applied acidic soils. Biochar amendment significantly decreased the fungal abundances and the fungal contribution to N2O production (by 28%). In contrast, biochar amendment significantly increased the abundances of N2O-related bacteria (e.g., ammonia-oxidizing bacteria (AOB), nirS, nosZ). Structural equation models (SEMs) revealed that biochar decreased the fungal contribution to N2O production through enhancing the soil pH and shifting the fungal community composition. Our results highlight that the decreased N2O emissions could be ascribed to the stimulated N2O consumption process (driven by N2O-consuming bacteria encoded by the nosZ gene) and suppressed fungal dominance in acidic soils from tea plantations. This study presents relatively comprehensive insights into the regulatory roles of biochar on soil microbe-mediated N2O production processes.

Aquaculture ponds are of increasing worldwide concerns as critical sources of atmospheric methane (CH4) and nitrous oxide (N2O), but little is known about these gases emissions as affected by aquaculture species, stocking and water management in aquaculture ponds. Here, a two-year study was carried out to quantify CH4 and N2O emissions from freshwater crab and fish aquaculture ponds in subtropical China. We further explored how the microbial functional genes [CH4: mcrA and pmoA; N2O: archaeal and bacterial amoA (AOA + AOB), nirS, nirK, nosZ] may drive CH4 and N2O release in the crab aquaculture pond typically undergoing flooding-to-drainage alteration. Over the two-year period, annual CH4 and N2O fluxes averaged 0.95 mg m−2 h−1 and 20.94 μg m−2 h−1 in the fish aquaculture, and 0.78 mg m−2 h−1and 28.48 μg m−2 h−1 in the crab aquaculture, respectively. The direct N2O emission factors were estimated to be 0.77% and 0.36% of the total N input by feed or 1.59 g N2O-N kg−1 and 1.06 g N2O-N kg−1 aquaculture yield in the crab and fish ponds, respectively. Among three functional stocking areas, CH4 and N2O emissions were consistently the highest at the feeding area (FA) in the both aquaculture ponds, followed by at the undisturbed area (UA) and aerated area (AA). The shift in sediment soil moisture from waterlogging to drainage conditions significantly increased the abundance of AOB relative to AOA and pmoA, decreased those of denitrifying functional genes (nirS, nirK, nosZ) and mcrA, while did not alter the functional group ratio of nirS + nirK relative to nosZ. Our results highlight that a better understanding of CH4 and N2O emissions from aquaculture ponds requires taking into consideration of data sourced from more diverse aquaculture systems with different management patterns. In addition, a deep analysis of the microbial processes that drive CH4 and N2O production and consumption from aquaculture ponds remains to be addressed in future studies.

Both elevated atmospheric carbon dioxide (CO2) and rising temperature can alter soil methane (CH4) fluxes, leading to a feedback to climate change. However, predicting this feedback needs to understand the microbial mechanisms involved in CH4 emissions driven by climate change. A 3-year field measurement of CH4 fluxes from rice paddies was taken in 2012–2014 to examine their responses to elevated CO2 (enriched up to 500 μmol mol−1) and rising canopy air temperature (above ambient 1.5–2.0 °C) using a free-air CO2 enrichment (FACE) system. Using real-time PCR and Illumina MiSeq sequencing of 16S rRNA genes, we measured the abundance and composition of methanogenic community in rhizosphere soil of rice paddies in 2014. Elevated CO2 and rising temperature showed additive effects on CH4 fluxes and methanogen abundances, where CH4 fluxes were correlated with methanogen abundances. Elevated CO2, rising temperature and their combination increased seasonal CH4 emissions by 28–120%, 38–74% and 82–143%, respectively. Either elevated CO2 or rising temperature did not significantly alter the diversity of methanogenic community, and methanogenic genera Methanosaeta, Methanosarcina, Methanobacterium, Methanocella and Methanoregula dominated in rhizosphere soils for all treatments. However, elevated CO2 induced a shift from acetoclastic to hydrogenotrophic methanogens in their relative abundances. Rising temperature stimulated CH4 emissions by increasing CH4 production per individual predominant methanogen genus. Besides the enhancement of soil C substrates and rhizosphere methanogen abundances as previously reported, an additive effect of elevated CO2 and canopy warming on CH4 emissions is also associated with elevated CO2-induced changes in the composition of methanogenic archaea and warming-stimulated the activity of methanogenic archaea in rice paddies.

Elevated mercury concentrations in wheat grains pose a potential health risk to human. In this study, we selected two low-mercury-accumulating wheat cultivars (Nongda-3163, Gaocheng-8901) and two high-mercury-accumulating wheat cultivars (Jimai-21, Taishan-21) to investigate the role of rhizospheric organic acids and microorganisms in mercury accumulation and translocation to different wheat plants. The wheat grew in greenhouse with three levels of mercury treatment: control (no added mercury), low treatment (1 mg kg−1 total mercury) and high treatment (5 mg kg−1 total mercury). Under low mercury treatment condition, Jimai-21 and Taishan 21 had significantly higher mercury concentrations in roots and secreted higher amounts of oxalic acid and citric acid in the rhizosphere soil than Nongda-3163 and Gaocheng-8901. Meanwhile, abundances of gram positive bacteria, gram negative bacteria and fungi in the rhizosphere soil of Jimai-21 were significantly higher than those of Nongda-3163 and Gaocheng-8901, while abundance of protozoa in the rhizosphere soil of Jimai-21 was significantly lower than those of Gaocheng-8901. These facts may lead to higher mercury concentrations in grains of Jimai-21 and Taishan-21 than those of Nongda-3163 and Gaocheng-8901. In the current study, the oxalic acid had the largest contribution on mercury accumulation and translocation (p = .002), followed by citric acid (p = .002) and protozoa (p = .038) under low mercury treatment condition. Under high mercury treatment condition, Jimai-21 and Taishan-21 had significantly higher translocation factors from roots to leaves, glumes and grains than Nongda-3163 and Gaocheng-8901, and the significant contribution sequentially were citric acid (p = .002), fungi (p = .02) and gram positive bacteria (p = .018). Improving the beneficial relationship among rhizospheric organic acids, microorganisms and wheat cultivars was a realizable strategy to ensure wheat safety for mercury.

Inland aquaculture ponds have been documented as important sources of atmospheric methane (CH4) and nitrous oxide (N2O), while their regional or global source strength remains unclear due to lack of direct flux measurements by covering more typical habitat-specific aquaculture environments. In this study, we compared the CH4 and N2O fluxes from rice paddies and nearby inland fish aquaculture wetlands that were converted from rice paddies in southeast China. Both CH4 and N2O fluxes were positively related to water temperature and sediment dissolved organic carbon, but negatively related to water dissolved oxygen concentration. More robust response of N2O fluxes to water mineral N was observed than to sediment mineral N. Annual CH4 and N2O fluxes from inland fish aquaculture averaged 0.51 mg m−2 h−1 and 54.78 μg m−2 h−1, amounting to 42.31 kg CH4 ha−1 and 2.99 kg N2O-N ha−1, respectively. The conversion of rice paddies to conventional fish aquaculture significantly reduced CH4 and N2O emissions by 23% and 66%, respectively. The emission factor for N2O was estimated to be 0.46% of total N input in the feed or 1.23 g N2O-N kg−1 aquaculture production. The estimate of sustained-flux global warming potential of annual CH4 and N2O emissions and the net economic profit suggested that such conversion of rice paddies to inland fish aquaculture would help to reconcile the dilemma for simultaneously achieving both low climatic impacts and high economic benefits in China. More solid direct field measurements from inland aquaculture are in urgent need to direct the overall budget of national or global CH4 and N2O fluxes.

Nitrogen (N) fertilizer has shown to affect soil nitrous oxide (N2O) and nitric oxide (NO) emissions that contribute to global warming and stratospheric ozone depletion. However, soil N2O and NO emissions with a linkage to crop N use efficiency (NUE) under different fertilization strategies in winter wheat-summer rice rotation systems remain yet to be further examined. Here, we carried out a two-year field study to assess the response of soil N2O and NO emissions as an interplay with NUE to different fertilization strategies in a typical winter wheat-summer rice rotation cropland of subtropical China. Three fertilizer treatments were established consisting of phosphorus (P) and potassium (K) fertilizer application (PK), NPK fertilizer application (NPK), and NPK fertilizer application with N partially replaced with manure (NPKM). Annual N2O, NO and N2O + NO emissions averaged 0.96, 0.24 and 1.19 kg N ha−1 yr−1 for the PK plots and 6.54, 1.48 and 8.03 kg N ha−1 yr−1 for the NPK plots, respectively. Relative to the NPK plots, partially replacing chemical N fertilizer with manure decreased annual N2O and NO emissions and their combined emissions by 13–15%, while it significantly enhanced crop NUE as compared to the NPK plots. Annual mean emission factors (EFs) of N fertilizer for N2O and NO were estimated to be 1.17% and 0.26% for the NPK plots, and 0.99% and 0.22% for the NPKM plots, respectively. Both N2O and NO emissions were positively correlated with N surplus, while yield-scaled N2O + NO emissions and the fertilizer N-induced combined EF for N2O + NO were negatively related to crop NUE. Together, our results highlight that improving crop NUE while reducing soil N surplus constitutes an effective strategy to mitigate soil gaseous N loss through N2O and NO in the wheat-rice rotation cropping systems.

The cubic phase WO3−x with two-dimensional nanosheet structure is prepared at a relative low temperature through thermal decomposition method. The starting material and decomposition environment are the key factors to obtain the cubic phase WO3−x. The cubic crystal structure is stabilized by the large amounts of oxygen vacancies. The dark blue cubic WO3−x exhibits electrocatalysis performance for hydrogen evolution reaction (HER) in acidic solution (an overpotential −294 mV at the current density of 10 mA/cm2). The cubic phase WO3−x shows good photothermal stability with eminent photothermal conversion effect (photothermal conversion efficiency is 48.7% at 808 nm).

Indirect nitrous oxide (N2O) emissions from rivers draining agricultural watersheds are of increasing concerns due to riverine abundant sources of nitrogen loaded through leaching and runoff. However, the seasonal variation of N2O emissions from agricultural drainage rivers is poorly explored, especially the uncertainty in quantifying indirect N2O emission factors (EFs) from these aquatic environments. Here, a two-year study (2014-2016) was conducted to quantify indirect N2O emissions from a river draining a rice paddy watershed in subtropical China. Indirect N2O fluxes were simultaneously determined using the floating chamber method (chamber-based) and the gas exchange modeling approach (model-based) based on the measurement of dissolved N2O concentration. Results showed that seasonal dissolved N2O concentration and N2O fluxes had a similar variation pattern, with the highest and the lowest levels in summer and winter, respectively. The annual mean of model-based N2O fluxes (20.24 ± 3.34 μmol m−2 d−1) was generally in agreement with chamber-based N2O fluxes (18.70 ± 3.56 μmol m−2 d−1). The indirect emission factor of N2O was highly dependent on the surface water NO3−-N concentration. Annual mean indirect EF of N2O from the drainage river was estimated to be 0.00051, which was significantly lower than the default EF5r value (0.0025) proposed by the Intergovernmental Panel on Climate Change (IPCC). These results suggest that the use of IPCC default value might have overestimated indirect N2O emissions from agricultural impacted riverine systems. Our study also highlights that more extensive in-situ measurements are required for monitoring indirect N2O emissions from agricultural impacted waters with different drainage characteristics, which would benefit for refining the IPCC EF5r default value to further constrain global N2O budget.

Subtropical agricultural soils are hotspots of nitrogen(N)-oxide emissions, whereas the spatiotemporal variability and driving factors of their emissions in different cultivation systems are poorly understood. Here, to assess the magnitude and pattern of soil N-oxide emissions, we conducted measurements of nitrous oxide (N2O) and nitric oxide (NO) fluxes from the soil between rows and under the canopy of tea plants in two subtropical tea plantations over a one-year period. Results showed that N2O and NO emissions from the soil between rows were 32.6 and 9.1 kg N ha−1 for the Yixing (YX) site and 33.9 and 9.9 kg N ha−1 for the Jurong (JR) site, respectively. Across both sites, N2O and NO emissions from the soil between rows were 2.8–5.2 and 1.4–4.0 times, respectively, larger than those from the soil under the canopy. We attributed greater N-oxide emissions from the soil between rows mainly to increased soil mineral N and water contents as compared to the soil under the canopy. On average, N2O and NO emissions from the soil under the canopy accounted for 36% and 44% of the total losses from the entire field, respectively. For the entire tea field, N2O emissions were 12.6 and 15.7 kg N ha−1 for the YX and JR sites, respectively, but the difference was not statistically different. In contrast, NO emissions from the YX and JR sites were 3.8 and 5.7 kg N ha−1 and differed significantly between the two sites, which was due to higher NO emissions from the soil under the canopy in the JR site. The greatest N-oxide fluxes occurred in the spring and summer seasons after topdressing when soil conditions were conducive to microbial N-oxide production. The structural equation modeling analyses suggested that the variables explaining the variances of soil N-oxide emissions were different between the two tea plantations. Our results indicated that microbial nitrification and abiotic chemodenitrification processes were likely the major pathways leading to N-oxide emissions in the soil under the canopy. Our findings highlight the importance of N-oxide fluxes simultaneously taken from the soil between rows and under the canopy and implementing mitigation practices in subtropical tea plantations.

Mercury pollution in fields has become a potential threat to human health. Planting wheat cultivars with low mercury accumulation in slight or medium mercury-polluted fields is an efficient solution to ensure food safety. Therefore, this study evaluated the mercury resistance and accumulation characteristics of 30 generalized wheat cultivars in major wheat-producing areas of China. A modified membership function that considers the weight of each trait was used. Results demonstrated that the plant height of wheat significantly increased under both low mercury and high mercury stresses. The uppermost internode length significantly increased while the spikelet number significantly decreased under low mercury stress. Yield-related traits, including total grain number, fresh grain yield, and dry grain yield, significantly decreased under high mercury stress. The mercury concentrations in wheat grains presented a significant negative correlation with the mercury resistance coefficients of plant height (−0.38*), spike length (−0.39*), and fresh grain yield (−0.38*) under high mercury stress. The heritability of all traits reached medium to high levels, ranging from 0.31 to 0.68. This finding suggested that the investigated traits are stable and suitable for the assessment system. Selection criteria for wheat mercury resistance were established using discriminant analysis, which integrated the mercury resistance coefficients of effective tiller number, fresh grain yield, and dry biomass into the discriminant function under low mercury stress and the mercury resistance coefficients of dry grain yield and dry biomass under high mercury stress. Ultimately, Liangxing-99, Nongda-3163, and Gaocheng-8901 were screened for high mercury resistance and low mercury accumulation. These wheat cultivars could be planted in fields with low or medium mercury pollution to obtain safe grains.

Fertilization has been shown to affect nitrogen (N) cycling and its related functional microbes in agricultural soils. However, the linkage between soil N2O emissions and N-related functional genes under different fertilization strategies from wheat in a wheat-rice double cropping system is rarely examined. Here, we carried out a two-year field study to examine the response of soil N2O emissions driven by N cycling functional genes [archaeal and bacterial amoA (AOA + AOB), nirS, nirK and nosZ] to different fertilization strategies in a wheat cropland of subtropical China. Three fertilizer treatments were established consisting of chemical phosphorus (P) and potassium (K) fertilizer application (PK), chemical N (urea) and PK fertilizer application (NPK), and chemical NPK fertilizer application with chemical N partially replaced with manure (composted pig manure) (NPKM). Over the two wheat seasons, seasonal total N2O emissions averaged 0.66, 3.60 and 3.11 kg N ha−1 for PK, NPK and NPKM plots, respectively. Relative to the NPK treatment, the NPKM treatment significantly decreased N2O emissions by 14 % without compromising grain yield, with a lowered combined fertilizer-induced emission factor (EF) of 1.02 %. Compared with the PK treatment, N fertilization consistently and significantly increased the abundance of ammonium-oxidation bacteria (AOB), nirS, nirK and nosZ genes. The nosZ gene, which drives N2O reduction during denitrification, showed a greater extent under NPKM with manure N combination. The AOB had a more sensitive response than ammonium-oxidation archaea (AOA) to chemical N fertilization. Seasonal N2O emissions showed significant positive correlations with AOB gene abundance and the ratio of (nirK+nirS)/nosZ, while had a negative correlation with nosZ gene abundance across N fertilized treatments. The N2O-related microbial composition of functional genes was significantly changed by N fertilizer application and also showed contrasting patterns between treatments of chemical N fertilizer with and without manure N substitution. Together, partially replacing chemical N fertilizer with manure reduced N2O emissions from wheat in a wheat-rice double cropping system, mainly through decreasing AOB associated-nitrifying potential, and particularly stimulating N2O reduction.

The optimization of fertilization management has the potential to improve crop yield, reduce greenhouse gas (GHG) emissions and enhance nitrogen agronomy efficiency (NAE). However, less is known about whether these benefits can be simultaneously achieved by optimizing fertilization regimes in Chinese croplands. We carried out a year-round field experiment to measure methane (CH4) and nitrous oxide (N2O) fluxes, crop yield and NAE under different fertilization regimes in a subtropical double-rice cropping system. Relative to the conventional chemical N fertilizer application (F), alternative fertilization strategies significantly decreased N2O emissions by 26–78% when averaged across the options of chemical N fertilizer application with reduced rates (RF, 30% off), chemical N fertilizer fully replaced by organic N fertilizer with reduced rates (OF, 30% off) and chemical N fertilizer fully replaced by controlled-release N fertilizer with reduced rates (CF, 30% off), with the largest mitigation potential occurring in OF-treated plots, but comparable extents between the early- and late-rice seasons. Soil CH4 emissions had no consistent response to alternative fertilization regimes, showing contrasting seasonal patterns between in the early- and late-rice seasons. Alternative fertilization options consistently increased NAE by 7–36% and 30–38% in the early- and late-rice seasons, respectively, and this benefit was maximized in OF-treated plots. Direct emission factors of N fertilizer for N2O and the combined greenhouse gas intensity (GHGI) of N2O and CH4 were negatively related to NAE while rice yield was positively related to NAE. Our findings suggest that optimized fertilization strategies especially through the option of chemical N fertilizer fully substituted by organic N fertilizer can reconcile low climatic impact and high NAE, but without compromising yield in double-rice cropping systems.

Mordenite molecular sieves were employed for the isomerization of α-pinene to produce limonene and camphene. To decrease diffusion resistance of α-pinene molecules, nanocrystalline cellulose (NCC) was employed as the mesoporous filler to prepare hierarchical mordenite within 6 h under microwave radiation. NCC crystals present as a rod-like morphology twining around crystals and interact with Al(OH)xOy and Si(OH)xOy species. Stronger interaction with Al(OH)xOy species inhibits the incorporation of aluminum into zeolitic framework. The acidity decreases due to a lower surface Si/Al ratio. Besides creating mesopores and macropores, NCC inhibits the growth or assembly of crystals in the short transverse direction of particles. Compared to mordenite without NCC, conversion increases by ∼50 % and the total yields of camphene and limonene are ∼52 % using mordenite catalysts with NCC. It indicates that macro/mesopores enhance the diffusion of α-pinene in mordenites, increase the accessibility of α-pinene with acid sites. After 5-times cycle tests, the conversion decreases from 63 % to 43 % due to the destruction of zeolitic structure during thermal treatment. In this study, a green synthesis route templated with NCC and green application in isomerization of α-pinene are proposed. These results are important for the synthesis of zeolites using biomass templates rapidly for biomass conversion process.

While water management has been documented to regulate CH4 emissions from rice paddies, the mechanisms behind the association between CH4 emissions and functional microbes remain unclear under water-saving ground cover rice production systems (GCRPS). In GCRPS, the soil is kept aerobic by maintaining 80 %–90 % of the water holding capacity but without standing water over the entire rice-growing season, and the soil surface is covered with rice straw or plastic film to reduce water evaporation. A split-plot field experiment was conducted to examine the effects of various GCRPS-related water-saving regimes on CH4 emissions by linking to CH4-related microbes over the 2015 and 2016 rice growing seasons in a typical Chinese rice field. Methane fluxes and related functional genes [methanogens (mcrA and methanogenic archaeal 16S rRNA) and methanotrophs (pmoA)] abundances were simultaneously measured using the closed chamber method and molecular techniques, respectively. The results showed that relative to the conventional waterlogged control (WRPS), GCRPS-related water-saving practices consistently reduced CH4 emissions, which was largely attributed to the decreased relative abundance of the methanogenic functional gene mcrA while the methanotrophic functional gene pmoA increased. When averaged over the two rice seasons, the grain yield was 17.38 % and 12.22 % greater under the GCRPS-straw and GCRPS-film water-saving systems relative to WRPS, respectively. Water-saving regimes decreased the yield-scaled CH4 emissions as compared with the WRPS, especially under GCRPS-film. The CH4 fluxes showed a positive correlation with the relative abundance of mcrA and its ratio to pmoA, but a negative correlation with the relative abundance of pmoA. The performance of CH4-simulated models could be improved by incorporating microbial parameters to predict CH4 emissions from rice fields. Overall, this study updates our understanding of the microbial mechanisms underlying CH4 emissions from water-saving GCRPSs. We proposed the GCRPS regime with biodegradable film mulching as a desirable water-saving strategy to reconcile high yields and low CH4 emissions in rice production.

The growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis plays an important role in normal brain development, and GH deficiency inevitably affects the growth of the cerebral cortex. This study was designed to analyze morphological differences in gray matter volume, cortical surface area, and gray matter thickness between children with isolated growth hormone deficiency (IGHD) and children with idiopathic short stature (ISS). Twenty-four children with IGHD (mean age 9.42 years, peak GH 5 μg/l) and 24 controls with ISS (mean age 9.21 years, peak GH 10 μg/l) were included. High-resolution three-dimensional T1-weighted MRIs were acquired at participants' first visit. Measurements of gray matter volume, cortical surface area and gray matter thickness were obtained using FreeSurfer. The total and regional differences between groups were statistically analyzed. Correlations between the FreeSurfer results and GH and IGF-I levels were also obtained. The gray matter volume, cortical surface area and gray matter thickness of the total brain and of the bilateral hemispheres of children with IGHD were significantly smaller than those of children with ISS (all P values 0.05). All the measurements had similar cortical distributions between groups but varied across regions. Cortical regions with significant differences in the mean gray matter volume and surface area were mainly distributed around the bilateral central sulci and the lateral and basal parts of the temporal lobes (all P values 0.05). There were negative correlations between gray matter volume, cortical surface area and GH levels, and the right hemispheric and total cortical surface area correlated significantly with GH levels (all P values 0.05) in children with IGHD. There were significant positive correlations between gray matter volume, cortical surface area and IGF-I levels (all P values 0.05) in both groups, except for in left hemispheric gray matter volume in children with ISS. Children with IGHD have significant morphological changes in the cerebral cortex, which were partially influenced by GH and IGF-I levels. These cortical changes may be related to deficits in their relatively slower development in intelligence, motor performance, and other functions.

Nanodevices for multimodal tumor theranostics have shown great potentials for noninvasive tumor diagnosis and therapy, but the libraries of multimodal theranostic building blocks should be further stretched. In this work, Cu(II) ions are doped into polyaniline (Pani) nanoshuttles (NSs) to produce Cu-doped Pani (CuPani) NSs, which are demonstrated as new multimodal building blocks to perform tumor theranostics. The CuPani NSs are capable of shortening the longitudinal relaxation (T1) of protons under magnetic fields and can help light up tumors in T1-weighted magnetic resonance imaging. In addition, the released Cu(II) ions from CuPani NSs lead to cytotoxicity, showing the behavior of chemotherapeutic agent. The good photothermal performance of CuPani NSs also makes them as photothermal agents to perform thermochemotherapy. By combining near-infrared laser irradiation, a complete tumor ablation is achieved and no tumor recurrence is observed.

Exotic plant invasions may alter ecosystem carbon processes, especially when native plants are displaced by plants of a different functional group. Forb invasions into grasslands are common, yet little is known about how they impact carbon cycling. We conducted a field study over 2 years from April 2010 to March 2012 in China to examine changes in soil respiration (Rsoil) following invasion of exotic perennial forb species (Alternanthera philoxeroides or Solidago canadensis) into an annual grassland dominated by a native annual graminoid (Eragrostis pilosa). Measurements of Rsoil were taken once a week in stands of the native annual graminoid or one of the forb species using static chamber-gas chromatograph method. Aboveground litterfall of each of the three focal species was collected biweekly and litter decomposition rates were measured in a 6-month litterbag experiment. The monthly average and annual cumulative Rsoil increased following invasion by either forb species. The increases in cumulative Rsoil were smaller with invasion of Solidago (36%) than Alternanthera (65%). Both invasive forbs were associated with higher litter quantity and quality (e.g., C:N ratio) than the native annual graminoid. Compared to the native annual graminoid, the invasive forbs Alternanthera (155%) and Solidago (361%) produced larger amounts of more rapidly decomposing litter, with the litter decay constant k being 3.8, 2.0 and 1.0 for Alternanthera, Solidago and Eragrostis, respectively. Functional groups of the invasive plants and the native plants they replaced appear to be useful predictors of directions of changes in Rsoil, but the magnitude of changes in Rsoil seems to be sensitive to variations in invader functional traits.

The potential of biochar for mitigating climatic impacts of coastal saline bioenergy production is not well established. A full accounting of net greenhouse gas balance (NGHGB) and greenhouse gas intensity (GHGI) affected by biochar amendment combined with or without nitrogen (N) fertilizer application was examined in an annual coastal reclaimed Jerusalem artichoke bioenergy cropping system. The net ecosystem exchange of CO 2 (NEE) was determined by the difference between soil heterotrophic respiration ( R H ) and net primary production (NPP) using static chamber method. Biochar amendment raised the seasonal R H but without suppressing the NPP during the Jerusalem artichoke cropping season. Soil CH 4 emissions were 72% and 80% lower in the biochar amended than unamended plots when combined with N fertilizer application during the Jerusalem artichoke cropping and non-cropping seasons, respectively. The biochar-induced soil N 2 O mitigation efficiency was weakened by N fertilizer input over the annual cycle. Annual NGHGB and GHGI were negative for all the field treatments and were significantly lower in biochar amended than in unamended soils, suggesting that Jerusalem artichoke cropping system served as a net sink of GHGs due to net ecosystem CO 2 and biochar-induced C sequestration exceeding CO 2 -equivalents released as CH 4 and N 2 O emissions. On average, biochar amendment significantly enhanced GHGs sink capacity by resulting in almost 4–5 folds decrease in annual NGHGB or GHGI when combined with N fertilizer application or not. Therefore, higher biomass gain as potential alternative source of biofuels but lower climatic impacts of bioenergy production would be reconciled by biochar use in southeast coastal China.

The short lifetime in blood circulation and unspecific uptake of positively charged nanocarriers shed doubt on in vivo applications. Herein, positive charged polyaniline nanoshuttles (Pani NSs) are modified with cancerous cell membranes (CCMs). The Pani NSs/CCMs composites maintain the magnetic resonance imaging (MRI) contrasting and photothermal converting performance in vivo. The CCMs modulation could mainly improve following aspects: 1) Improve the biocompatibility by depressing toxic release of Cu2+. 2) Increase the immune invisibility and the half-life (t1/2) is prolonged from 4.0 to 13.8 h in blood circulation. 3) The homologous KB tumor targeting efficiency is dramatically enhanced from 3.2 to 11.5 %ID/g. However, elongated t1/2 also reserves the non-homologous tumor uptake rate as 5.6 %ID/g, indicating insufficient targeting specificity of CCMs modulating strategy. This work gives deep understanding for the fundamental necessity of long lifetime in tumor uptake, which is prior to homologous targeting, and it signifies for the functional design and surface modification of nanoagents with enhanced theranostic performance.

Organ carbon are often used to enhance denitrification in wastewater treatment. However, their possible effects on microbial interactions are very limited. In this work, an anaerobic ammonium oxidation (anammox) coupled with sulfur autotrophic/mixotrophic denitrification (SAD/SMD) system was used to investigate the changes in microbial interactions among the microbial communities under different nutrient condition. The removal efficiency of total nitrogen increased from 70% (SAD) to 97% (SMD). The Illumina sequencing analysis indicated that Planctomycetes was the most dominant bacterial phylum in anammox system. Thiobacillus and Sulfurimonas, two typical autotrophic denitrifiers, decreased significantly from 31.9% to 17.7%-12.2% and 9.3%, when the nutrient condition changed from SAD to SMD (P 0.05). Meanwhile, some heterotrophic or mixotrophic denitrifying bacteria, including Gemmobacter, Pseudomonas and Thauera increased significantly (P 0.05). Molecular ecological network (MEN) analysis showed that the addition of organic carbon substantially altered the overall architecture of the network. Compared with SAD, the SMD had shorter path lengths, indicating higher transfer efficiencies of information and materials among different microorganism. The addition of organic carbon increased the microbial interaction complexity of Proteobacteria. The links of Thiobacillus, which was a typical sulfur-oxidizing autotrophic denitrifying bacteria, significantly reduced (P 0.05) with the addition of organic carbon, while the links of the heterotrophic bacteria Geobacter significantly increased (P 0.05). This study provided new insights into our understanding of the shifts in the bacteria community and their microbial interactions under different nutrient conditions (SAD and SMD) in sulfur-supported denitrification system.

Acidic soils are hotspots of nitrous oxide (N2O) and nitric oxide (NO) and biochar is documented to have the potential for mitigating N2O and NO. The N2O and NO emissions associated with soil functional genes and physicochemical properties under biochar amendment remains unclear in acidic soils. Here, we carried out a two-year field study to examine the responses of soil N2O and NO emissions to biochar amendment in a subtropical tea plantation in China. Measurements of N2O and NO fluxes were taken from inter-row soils using the static chamber method. We also measured the seasonal changes in soil key nitrogen (N)-cycling functional genes and physicochemical properties. Annual N2O and NO emissions averaged 27.31 kg N2O-N ha−1 yr−1 and 8.75 kg NO-N ha−1 yr−1 for the N fertilizer applied plots, which were decreased by 24% and 16% due to biochar application, respectively. In addition, both potential nitrification (PNR) and denitrification (PDR) rates were stimulated by biochar amendment, which significantly increased the abundances of bacterial amoA (AOB), nirK and nosZ genes. Changes in the composition of the N2O-related microbial functional community were closely associated with soil PNR, pH, DOC, and NO3−-N contents. The ratios of NO/N2O were mainly lower than 1, suggesting that N2O was produced mostly through denitrification rather than nitrification. There were negative correlations between soil N2O and NO emissions and soil PDR and pH, and soil N2O emissions were negatively correlated with nosZ gene abundances. Together, the decrease in N2O and NO emissions following biochar application could be largely attributed to the enhanced denitrification process, in which biochar enriched the nirK and nosZ genes abundance, resulting from the enhancement of soil DOC and pH in acidic soils.

Efforts to advance our knowledge on the potential of bioenergy instead of fossil fuels in terms of mitigating climatic impact are in urgent need. No data is currently available on the use of urease and nitrification inhibitors in costal saline bioenergy cropping systems. An overall accounting of net greenhouse gas balance (NGHGB) and greenhouse gas intensity (GHGI) affected by combined effects of urease inhibitor hydroquinone (HQ) and nitrification inhibitor dicyandiamide (DCD) amendment was examined in a coastal saline Jerusalem artichoke bioenergy cropping system. The net ecosystem exchange of CO2 (NEE) was determined by the difference between soil heterotrophic respiration (RH) and net primary production (NPP) using static chamber method. Urease and nitrification inhibitors amendment increased the NPP but exerted a suppression effect on soil RH over the Jerusalem artichoke cropping system. A trade-off relationship was observed by decreasing soil N2O but stimulating soil CH4 emissions following HQ+DCD amendment. The plots combined urea with HQ+DCD application increased soil CH4 by 167% while decreased N2O by 16% as compared to with urea only in the bioenergy cropping system. On average, the fertilizer N-induced emission factor of N2O was estimated to be 0.25% across the fertilized plots. Compared with urea, the plots with urea and HQ+DCD resulted in a further decrease by 37% and 15% in estimated NGHGB and GHGI over the Jerusalem artichoke cropping system, respectively. Overall, Jerusalem artichoke production would achieve higher biomass as source of biofuels but lower climatic impacts, particularly when together with urease and nitrification inhibitors amendment in coastal saline soils.

Ground cover rice production system (GCRPS)-related water-saving practices have been proposed to alleviate the challenge of increasing water resource scarcity. While water irrigation regime can directly affect nitrous oxide (N2O) emissions in the rice-growing season, it may also have the post-seasonal effects on N2O emissions in the barley-growing season within an annual rice-barley rotation system. A split-plot experiment was conducted to examine the effects of various water-saving rice production regimes on N2O emissions during the following barley-growing season. The abundances of soil N2O-related functional genes (AOA and AOB, and nirS, nirK and nosZ) were simultaneously determined using qPCR. The results showed that, relative to the waterlogged control, GCRPS-film and moisture irrigated rice production system (MRPS) consistently stimulated N2O emissions and associated yield-scaled N2O emissions in the barley-growing season, while they were decreased by 10% and 15% under the GCRPS-straw water-saving system, respectively. Compared with the waterlogged control, the water-saving rice practices increased the abundances of AOA and nosZ genes in the barley-growing season. The abundances of AOA and nirS genes had significant positive correlations with N2O fluxes, as a contrary to the negative correlation of nosZ gene abundances with N2O fluxes. The barley grain yields were slightly increased following water-saving practices but showed no statistical significance among different irrigation systems. Overall, the water-saving ground cover rice production system with rice straw mulching can be encouraged to reconcile high grain yields and low N2O emissions in the following upland cropping seasons.

In this paper, a color- and brightness-tunable organic light-emitting diode (OLED) is reported. This OLED was realized by inserting a charge generation layer into an electron only device to form an n-i-p-i-n structure. It is shown that, by changing the polarity of applied voltage, only the p-i-n junction operated under positive bias can emit light and, by applying an AC voltage, emission from both junctions was realized. It is also shown that, by using a combination of blue- and red-emiting layers in two p-i-n junctions, both the color and brightness of the resulting white OLED can be tuned independently by changing the positive and negative amplitudes of the AC voltage. NRF (Natl Research Foundation, S’pore) ASTAR (Agency for Sci., Tech. and Research, S’pore)

During the second trimester, the human fetal brain undergoes numerous changes that lead to substantial variation in the neonatal in terms of its morphology and tissue types. As fetal MRI is more and more widely used for studying the human brain development during this period, a spatiotemporal atlas becomes necessary for characterizing the dynamic structural changes. In this study, 34 postmortem human fetal brains with gestational ages ranging from 15 to 22 weeks were scanned using 7.0 T MR. We used automated morphometrics, tensor-based morphometry and surface modeling techniques to analyze the data. Spatiotemporal atlases of each week and the overall atlas covering the whole period with high resolution and contrast were created. These atlases were used for the analysis of age-specific shape changes during this period, including development of the cerebral wall, lateral ventricles, Sylvian fissure, and growth direction based on local surface measurements. Our findings indicate that growth of the subplate zone is especially striking and is the main cause for the lamination pattern changes. Changes in the cortex around Sylvian fissure demonstrate that cortical growth may be one of the mechanisms for gyration. Surface deformation mapping, revealed by local shape analysis, indicates that there is global anterior–posterior growth pattern, with frontal and temporal lobes developing relatively quickly during this period. Our results are valuable for understanding the normal brain development trajectories and anatomical characteristics. These week-by-week fetal brain atlases can be used as reference in in vivo studies, and may facilitate the quantification of fetal brain development across space and time.

Objective The computerized freezing milling technique is derived from the virtual human project. It has been widely used in three-dimensional (3D) reconstruction of the human body and organs. With this technique, the study was undertaken to explore the 3D features and adjacent anatomic relationships of the sellar region for skull base surgery. Methods Continuous thin sections on the coronary plane were performed with the computerized freezing milling technique using a human head specimen. The related structures were described in six sections. After segmenting, labeling, and extracting in serial sections, the 3D reconstruction of the sellar region was finished with Amira 4.1 software. Results A total of 390 thin coronary sections were obtained. In six sections, the anatomic relationships of the pituitary gland, carotid artery, sphenoid sinus, and nerves are displayed. Three-dimensional images of the sellar region are video films that continuously and dynamically display anatomic structures in 3D space at different velocities. It can show that the cavernous segment of the internal carotid artery is located anterolateral to the sphenoid sinus and lateral to the pituitary gland. The optic nerve protrudes into the superolateral portion of the sphenoid sinus. Conclusions The combination of coronary sectional anatomy and 3D reconstruction can display the anatomic characteristics of the sellar region. The 3D models are video films that continuously and dynamically display anatomic structures in 3D space at different velocities.

Measurements of methane (CH(4)) and nitrous oxide (N(2)O) fluxes have been extensively taken following rice seedlings transplanted into paddy fields, while little is known about CH(4) and N(2)O fluxes from rice seedling nurseries. Fluxes of CH(4) and N(2)O were simultaneously measured in rice seedling nurseries under the water regimes of continuous flooding and moist irrigation without waterlogging in Southeast China in 2010. Fluxes of CH(4) and N(2)O from continuously flooded nurseries averaged 10.33-14.84 mg m(-2) h(-1) and 28.64-34.35 μg N(2)O-Nm(-2) h(-1) for the different fertilizer applied plots, respectively. Relative to continuous flooding, moist irrigation decreased total CH(4) by 14-50% but increased N(2)O by 72-186%, dependent on the fertilizer types. Compared with inorganic N fertilizer, organic manure application increased CH(4) by 44% and 148% in the continuously flooded and moist irrigation nurseries, respectively. Rice seedling growth parameters were the greatest in moist irrigation nurseries with inorganic N fertilizer application. Moist irrigation instead of continuous waterlogging and shifts from organic manure to combined organic/inorganic N fertilizer inputs have been increasingly experienced in Chinese rice seedling nurseries, which would benefit for mitigating the combined global warming potentials of CH(4) and N(2)O from rice seedling nurseries in China.

A complete accounting of net greenhouse gas balance (NGHGB) and greenhouse gas intensity (GHGI) affected by Fe(III) fertilizer application was examined in typical annual paddy rice-winter wheat rotation cropping systems in southeast China. Annual fluxes of soil carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) were measured using static chamber method, and the net ecosystem exchange of CO 2 (NEE) was determined by the difference between soil CO 2 emissions ( R H ) and net primary production (NPP). Fe(III) fertilizer application significantly decreased R H without adverse effects on NPP of rice and winter wheat. Fe(III) fertilizer application decreased seasonal CH 4 by 27–44%, but increased annual N 2 O by 65–100%. Overall, Fe(III) fertilizer application decreased the annual NGHGB and GHGI by 35–47% and 30–36%, respectively. High grain yield and low greenhouse gas intensity can be reconciled by Fe(III) fertilizer applied at the local recommendation rate in rice-based cropping systems.

article i nfo Mammalian target of rapamycin (mTOR) pathway is a serine/threonine protein kinase that plays a vital role in regulating growth, proliferation, survival, and protein synthesis among cells. In the present study, we in- vestigated the role of the mTOR pathway following subarachnoid hemorrhage brain injury — specifically in- vestigating its ability to mediate the activation of cerebral vasospasm. Additionally, we investigated whether key signaling pathway molecules such as the mTOR, P70S6K1, and 4E-BP1 play a role in the process. Thirty dogs were randomly divided into 5 groups: sham, SAH (subarachnoid hemorrhage), SAH+DMSO (dimethyl sulfoxide), SAH+Rapamycin and SAH+AZD8055. An established canine double-hemorrhage model of SAH was used by injecting autologous arterial blood into the cisterna magna on days 0 and 2. Angiography was performed at days 0 and 7. Clinical behavior, histology, immunohistochemistry, and Western blot of mTOR, P70S6K1, 4E-BP1 and PCNA (proliferating cell nuclear antigen) in the basilar arteries were examined. In the SAH and SAH+DMSO groups, severe angiographic vasospasm was obtained (34.3±19.8%, 38.4±10.3) compared with that in Sham (93.9±5.0%) respectively. mTOR, P70S6K1, 4E-BP1 and PCNA increased in the sample of spastic basilar arteries (pb0.05). In the SAH+RAPA and SAH+AZD8055 groups, Rapamycin and AZD8055 attenuated angiographic vasospasm (62.3±15.9% and 65.2±10.3%) while improving appetite and activity scores (pb0.05) on days 5 through 7. Rapamycin and AZD8055 significantly reduced the level and expression of mTOR, P70S6K1, 4E-BP1 and PCNA (pb0.05). In conclusion, our study suggests that the mTOR molecular signaling pathway plays a significant role in cerebral vasospasm following SAH, and that in- hibition of the mTOR pathway has the potential to become an attractive strategy to treat vasospasm following SAH.

Background The 20th week gestational age (GA) is at mid-gestation and corresponds to the age at which the termination of pregnancy in several countries and the first Magnetic Resonance Imaging (MRI) can be performed, and at which the premature babies may survive. However, at present, very little is known about the exact anatomical character at this GA. Objective To delineate the developing fetal brain of 20 weeks GA and obtain the three dimensional visualization model. Materials and methods 20 fetal specimens were scanned by 3.0 T and 7.0 T post-mortem MRI, and the three dimensional visualization model was obtained with Amira 4.1. Results Most of the sulci or their anlage, except the postcentral sulcus and intraparietal sulcus, were present. The laminar organization, described as layers with different signal intensities, was most clearly distinguished at the parieto-occipital lobe and peripheral regions of the hippocampus. The basal nuclei could be clearly visualized, and the brain stem and cerebellum had formed their common shape. On the visualization model, the shape and relative relationship of the structures could be appropriately delineated. The ranges of normal values of the brain structures were obtained, but no sexual dimorphisms or cerebral asymmetries were found. Conclusions The developing fetal brain of 20 weeks GA can be clearly delineated on 3.0 T and 7.0 T post-mortem MRIs, and the three dimensional visualization model supplies great help in precise cognition of the immature brain. These results may have positive influences on the evaluation of the fetal brain in the uterus.

We reported a highly efficient white organic light-emitting diode (WOLED) with a multilayer emission region made of sequentially evaporated host and guest layers. The singlet and triplet excitons were harvested in two separate channels. An external quantum efficiency of 16.3% photons/electron (∼41 cd/A) was achieved with a good color rendering index (CRI) of 76, and a Commission Internationale de l’eclairage (CIE) coordinate of (x = 0.38, y = 0.46). At brightness of 100 and 500 cd/m2, the external quantum efficiencies reached 11% and 10%, respectively. The performance of the WOLED is better than that fabricated by co-evaporation method due to an improved exciton capture and emission efficiencies. This work presents an alternative way of fabricating WOLED.

In recent years, investigations of the pathologic mechanism of Parkinson's disease (PD) have mainly concentrated on the basal ganglia. However, recent studies have confirmed that pathological changes in PD are accompanied by functional motor changes of the cerebral cortex. Rats were injected with 6-hydroxydopamine and ascorbic acid in the right substantia nigra. In this rat model of PD, magnetic resonance spectroscopy showed the ratio of N-acetyl-aspartic acid to creatine in a lesion in the right frontal cortex was significantly lower than the same ratio in a control group of rats. The ratio of choline to creatine in a lesion in the right frontal cortex was not significantly different between the PD-model rats and control rats. In addition, the optical densities of neurofilament protein and synaptophysin positive sites decreased significantly on the side of the brain with the injury compared with the side without the injury, and with both sides in the control rats. The density of synapses in the frontal cortex on the lesioned side was decreased compared with the unlesioned side. There were abnormal changes in the presynaptic membrane. postsynaptic membrane and synaptic vesicles, and the typical synaptic structure was no longer apparent on the lesioned side. We hypothesized loss of neurons and synapses, abnormal synaptic structure and neuron and synaptic dysfunction of the frontal cortex with a lesion in the injury side of the frontal cortex in PD-model rats. These changes might have an important role in the pathologic mechanism of PD. (C) 2009 Elsevier Ltd. All rights reserved.

Annual paddy rice-winter wheat rotation constitutes one of the typical cropping systems in southeast China, in which various water regimes are currently practiced during the rice-growing season, including continuous flooding (F), flooding-midseason drainage-reflooding (F-D-F), and flooding-midseason drainage-reflooding and moisture but without waterlogging (F-D-F-M). We conducted a field experiment in a rice-winter wheat rotation system to gain an insight into the water regime-specific emission factors and background emissions of nitrous oxide (N(2)O) over the whole annual cycle. While flooding led to an unpronounced N(2)O emission during the rice-growing season, it incurred substantial N(2)O emission during the following non-rice season. During the non-rice season, N(2)O fluxes were, on average, 2.61 and 2.48 mg N(2)O-Nm(-)(2) day(-1) for the 250 kg N ha(-1) applied plots preceded by the F and F-D-F water regimes, which are 56% and 49% higher than those by the F-D-F-M water regime, respectively. For the annual rotation system experienced by continuous flooding during the rice-growing season, the relationship between N(2)O emission and nitrogen input predicted the emission factor and background emission of N(2)O to be 0.87% and 1.77 kg N(2)O-Nha(-1), respectively. For the plots experienced by the water regimes of F-D-F and F-D-F-M, the emission factors of N(2)O averaged 0.97% and 0.85%, with background N(2)O emissions of 2.00 kg N(2)O-Nha(-1) and 1.61 kg N(2)O-Nha(-1) for the annual rotation system, respectively. Annual direct N(2)O-N emission was estimated to be 98.1 Gg yr(-1) in Chinese rice-based cropping systems in the 1990s, consisting of 32.3 Gg during the rice-growing season and 65.8 Gg during the non-rice season, which accounts for 25-35% of the annual total emission from croplands in China.

Alpha-synuclein is one of the main constituents of Lewy bodies and plays an important role in the pathology of Parkinson's disease. Mutation or overexpression of alpha-synuclein causes Parkinson's disease, and downregulation of alpha-synuclein resists MPP(+)-induced cell death, but the mechanism remains elusive. In this study, we attempted to explore the effect of alpha-synuclein knockdown on mitochondrial function in MPP(+)-treated SH-SY5Y cells. We reconstructed the short hairpin RNA expression vector, pGenesil-2, specially targeting alpha-synuclein mRNA, and it was stably transfected into SH-SY5Y cells. Cell viability, nuclear morphology, and mitochondrial membrane potential were then detected, and the expression of alpha-synuclein, cytochrome c, Bcl-2 and Bax were analyzed by Western blotting. The results showed that after exposure to 500 microM MPP(+) for 24 h, about 41.0+/-1.5% control cells showed low mitochondrial membrane potential. However, the percentage was 13.6+/-1.2% in MPP(+) treated alpha-synuclein knockdown cells. MPP(+) induced cytochrome c release significantly, which was about 3.1-fold compared with that of control. However, in alpha-synuclein knockdown cells, the release of cytochrome c was blocked, which was about 1.4-fold compared with that of control. The Bcl-2/Bax ratio of SH-SY5Y cells reduced to 35.5+/-3.8% after MPP(+) treatment, and this ratio was 85.2+/-3.0% in MPP(+) treated alpha-synuclein knockdown cells. These data suggest that knockdown of alpha- synuclein might be an effective means in rescuing MPP(+)-induced mitochondrial dysfunction of SH-SY5Y cells.

The high-fat ketogenic diet (KD) leads to an increase of blood ketone bodies (KB) level and has been used to treat refractory childhood seizures for over 80 years. Recent reports show that KD, KB and their components (d-beta-hydroxybutyrate, acetoacetate and acetone) have neuroprotective for acute and chronic neurological disorders. In our present work, we examined whether KD protected dopaminergic neurons of substantia nigra (SN) against 6-hydroxydopamine (6-OHDA) neurotoxicity in a rat model of Parkinson's disease (PD) using Nissl staining and tyrosine hydroxylase (TH) immunohistochemistry. At the same time we measured dopamine (DA) and its metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striatum. To elucidate the mechanism, we also measured the level of glutathione (GSH) of striatum. Our data showed that Nissl and TH-positive neurons increased in rats fed with KD compared to rats with normal diet (ND) after intrastriatal 6-OHDA injection, so did DA and its metabolite DOPAC. While HVA had not changed significantly. The change of GSH was significantly similar to DA. We concluded that KD had neuroprotective against 6-OHDA neurotoxicity and in this period GSH played an important role.

Purpose: To prospectively assess the relationship between the time to peak enhancement of hepatocellular carcinomas (HCC) and that of the aorta at 64-detector computed tomography (CT). Materials and methods: The study prospectively included 43 patients with known HCC. All underwent abdominal CT imaging by using BodyPerfusion CT model. The CT data acquisition was initiated with a delay of 8–15 s from the beginning of the contrast material administered. The time–density curves (TDC) of the HCC and the aorta were drawn. The times to peak enhancement of the HCC and the aorta were recorded and the correlation between the time to peak enhancement of the HCC and that of the aorta was analyzed. Results: There were three tendencies of TDC of the HCC enhancement, only 23.3% of them were similar to that of the aorta. The mean time to peak enhancement of the aorta and the HCC (86.1%) was 23.38 s and 30.04 s, respectively. The time to peak enhancement of most HCC was positively and linearly correlated with the time to peak aortic enhancement (r = 0.662, P < 0.05). Conclusion: The result may potentially allow scan delay optimization at contrast material-enhanced CT image in the detection of HCC according to interindividual variability.