Mercury and its derivatives are hazardous environmental pollutants and could affect the aquatic ecosystems and human health by biomagnification. Lake sediments can provide important historical information regarding ch...Mercury and its derivatives are hazardous environmental pollutants and could affect the aquatic ecosystems and human health by biomagnification. Lake sediments can provide important historical information regarding changes in pollution levels and thus trace anthropogenic or natural influences. This research investigates the 100-year history of mercury (Hg) deposition in sediments from Chao Lake, a shallow eutrophic lake in China. The results indicate that the Hg deposition history can be separated into three stages (pre-1960s, 1960s–1980s, and post-1980s) over the last 100 years. Before the 1960s, Hg concentrations in the sediment cores varied little and had no spatial difference. Since the 1960s, the concentration of Hg began to increase gradually, and showed a higher concentration of contamination in the western half of the lake region than in the eastern half of the lake region due to all kinds of centralized human-input sources. The influences of anthropogenic factors and hydrological change are revealed by analyzing correlations between Hg and heavy metals (Fe, Co, Cr, Cu, Mn, Pb, and Zn), stable carbon and nitrogen isotopes (d13C and d15N), nutrients, particle sizes, and meteorological factors. The results show that Hg pollution intensified after the 1960s, mainly due to hydrological change, rapid regional development and urbanization, and the proliferation of anthropogenic Hg sources. Furthermore, the temperature, wind speed, and evaporation are found to interactively influence the environmental behaviors and environmental fate of Hg.展开更多
Amyotrophic lateral syndrome(ALS)is a progressive degenerative disorder characterized by motor neuron death and axon degeneration.Mitochondrial dysfunction plays a key role in the pathogenesis of ALS,the mechanism of ...Amyotrophic lateral syndrome(ALS)is a progressive degenerative disorder characterized by motor neuron death and axon degeneration.Mitochondrial dysfunction plays a key role in the pathogenesis of ALS,the mechanism of which remains poorly understood.The B-cell lymphoma-2(Bcl-2)family of proteins that control and mediate mitochondrial function and apoptosis,including the pro-apoptotic members Bcl2-Associated X(Bax),are involved in ALS development.The death receptor 6(DR6)regulates motor neuron death in ALS,and DR6 antibodies can prevent axon degeneration and motor neuron damage by blocking DR6.Previous studies demonstrated that PSAP localized to mitochondria and was required for DR6-induced apoptosis.In this study,SOD1^(G93A) was transfected into the motor neuron cell line NSC-34 to serve as an ALS cell model in vitro.The data assessed the role of PSAP in SOD1^(G93A)induced apoptosis and demonstrated that the overexpression of SOD1^(G93A),but not wtSOD1,induced PARP cleavage,caspase-3 activation,cytochrome c release,and Bax translocation.PSAP,Bax,and Bak were necessary for SOD1^(G93A)induced apoptosis,as silencing PSAP inhibited SOD1^(G93A)-mediated cell death that was dependent on Bax-Bak interaction.展开更多
Groundwater is a key factor controlling the growth of vegetation in desert riparian systems. It is important to recognise how groundwater changes affect the riparian forest ecosystem. This information will not only he...Groundwater is a key factor controlling the growth of vegetation in desert riparian systems. It is important to recognise how groundwater changes affect the riparian forest ecosystem. This information will not only help us to understand the ecological and hydrological process of the riparian forest but also provide support for ecological recovery of riparian forests and water-resources management of arid inland river basins. This study aims to estimate the suitability of the Water Vegetation Energy and Solute Modelling(WAVES) model to simulate the Ejina Desert riparian forest ecosystem changes,China, to assess effects of groundwater-depth change on the canopy leaf area index(LAI) and water budgets, and to ascertain the suitable groundwater depth for preserving the stability and structure of desert riparian forest. Results demonstrated that the WAVES model can simulate changes to ecological and hydrological processes. The annual mean water consumption of a Tamarix chinensis riparian forest was less than that of a Populus euphratica riparian forest, and the canopy LAI of the desert riparian forest should increase as groundwater depth decreases. Groundwater changes could significantly influence water budgets for T. chinensis and P. euphratica riparian forests and show the positive and negative effects on vegetation growth and water budgets of riparian forests. Maintaining the annual mean groundwater depth at around 1.7-2.7 m is critical for healthy riparian forest growth. This study highlights the importance of considering groundwater-change impacts on desert riparian vegetation and water-balance applications in ecological restoration and efficient water-resource management in the Heihe River Basin.展开更多
The technique of DGT (diffusive gradients in thin films) was applied to obtain high-resolution vertical profiles of dissolved reactive phosphorus (DRP) in sediment porewater of Lake Chaohu, a shallow eutrophication la...The technique of DGT (diffusive gradients in thin films) was applied to obtain high-resolution vertical profiles of dissolved reactive phosphorus (DRP) in sediment porewater of Lake Chaohu, a shallow eutrophication lake. Three kinds of DGT probes (with three thicknesses of diffusive gel: 0.38 mm, 0.78 mm and 1.18 mm) measured vertical concentration and induced flux from solid to solution phase which had intricate variations with depth. The results indicated that higher concentrations and induced fluxes of DRP were achieved by using DGT probe with thicker diffusion layer (CDGT1.18 > CDGT0.78 > CDGT0.38) and relatively stable DRP concentration profiles using DGT probes with 0.78 mm diffusive gel were obtained in each sediment core. The DRP concentrations displayed a clear gradient from Core C1 to Core C3 in sediment porewaters due to different sources and exchange degrees of reactive phosphorus. Compared to the concentrations obtained by the centrifugation technique, the concentrations of DRP resulting from the DGT technique were higher because some dissolved reactive phosphorus compounds have always been neglected using conventional centrifugation method.展开更多
Grafting is a commonly used method for citrus propagation and transmitting'Candidatus Liberibacter asiaticus'(CLas),the putative causing agent of citrus Huanglongbing(HLB).Optimization of the grafting inoculat...Grafting is a commonly used method for citrus propagation and transmitting'Candidatus Liberibacter asiaticus'(CLas),the putative causing agent of citrus Huanglongbing(HLB).Optimization of the grafting inoculation methods facilitates the material preparation in HLB research.Citrus buds with CLas were grafted onto healthy sour tangerine(Citrus sunki Hort.ex Tanaka)seedlings by different methods such as top grafting(‘T'grafting and‘V'grafting)and side grafting(abdominal grafting).Along with the symptom observation,titers of CLas in the leaves were detected by RTqPCR monthly.The correlation between the growth status of buds or different grafting methods and the success rate of HLB transmission were analyzed.Our results suggest that sufficient DNA could be extracted to accurately detect the CLas from even only 0.0125 g leaf midrib or branch bark.The probability of CLas transmission was higher in plants inoculated with buds in better growth conditions.The success rate of‘T'grafting was significantly higher than that of side grafting and‘V'grafting.Additionally,in terms of HLB transmission efficiency,the two-bud grafting scheme was superior to the single-bud and three-bud grafting schemes.In conclusion,the grafting combinations with the highest HLB transmission efficiency were screened to provide a methodological reference for the practice or research of grafting to obtain plant material.展开更多
Recent sediments from Lake Chenghai, China, were investigated at high temporal resolution to trace both natural and anthropogenic effects on the lake using total organic carbon （TOC）, total nitrogen （TN）, total ph...Recent sediments from Lake Chenghai, China, were investigated at high temporal resolution to trace both natural and anthropogenic effects on the lake using total organic carbon （TOC）, total nitrogen （TN）, total phosphorus （TP）, organic phosphorus （Po）, inorganic phosphorus （Pi） and organic carbon and nitrogen stable isotopes （~13Corg and 615N） in a 137Cs-dated sediment core. The results indicated that the sedimentary record covers the last 60 years, during which the lake had undergone apparent changes in nutrient sources and productivity in response to nutrient loading. Prior to the late 1980s, the nutrient contents in sediments mainly originated from algae and lake productivity was relatively stable. Since the late 1980s, increasing TOC, TN and TP concentrations together with the change of 613Corg and 615N suggested anthropogenic perturbations in nutrient loading and lake productivity. Endogenic nutrients derived from algae and anthropogenic inputs were two important sources of sedimentary nutrients. The anthropogenic nutrients mainly originated from the discharge of industrial wastewater and artificial cultivation of Spirulina after the middle 1980s, and domestic wastewater discharged from Yongsheng County since 1993.展开更多
Characterization, treatment and releases of eight polybrominated diphenyl ethers （PBDEs） congeners and sixteen polycyclic aromatic hydrocarbons （PAHs） in wastewater were evaluated along the treatment processes of ...Characterization, treatment and releases of eight polybrominated diphenyl ethers （PBDEs） congeners and sixteen polycyclic aromatic hydrocarbons （PAHs） in wastewater were evaluated along the treatment processes of a typical secondary treatment municipal sewage treatment plant （STP） （in Hefei City） situated the beside Nanfei River, East China. The findings showed that the average concentrations of the total PBDEs in raw wastewater and treated effluent were 188.578 and 36.884 ng/L respectively. Brominated diphenyl ether （BDE） 209 congener, the predominant PBDE in the STP and Nanfei River, could be related to the discharge of car-industry-derived wastes. For PAHs, the average concentrations in raw wastewater and treated effluent were 5758.8 and 2240.4 ng/L respectively, with naphthalene, benzo[a]pyrene and indeno[1,2,3-c,d]pyrene being detected at the highest concentrations. PAHs mainly originate from the combustion of biomass/coal and petroleum. The STP reduced about 80% of the PBDEs and 61% of the PAHs, which were eliminated mainly by sedimentation processes. The removal rates of PBDEs/PAHs increased with the increase of their solid-water partitioning coefficients. Accordingly, the STP＇s effluent, containing some PBDE congeners （e.g., BDE 47, 99 and 209, etc.） and low-molecular-weight PAHs, could be an important contributor of these contaminants＇ input to Nanfei River. It resulted in a significant increase of PBDE/PAH concentrations and PAH toxicological risk in the river water downstream. About 4.040 kg/yr of PBDEs and 245.324 kg/yr of PAHs could be released into the Nanfei River. The current conventional wastewater treatment processes should be improved to remove the relatively low-molecular-weight PBDEs/PAHs more effectively.展开更多
Climate change and anthropogenic activities are expected to impact the environmental behaviors and fates of persistent organic pollutants(POPs), however, quantitative studies on these combined factors are scarce. In t...Climate change and anthropogenic activities are expected to impact the environmental behaviors and fates of persistent organic pollutants(POPs), however, quantitative studies on these combined factors are scarce. In this study, dichlorodiphenyltrichloroethane(DDTs), polycyclic aromatic hydrocarbons(PAHs), and polychlorinated biphenyls(PCBs)were used as examples to identify how and when those factors may be related to the deposition of POPs in the sediment of Lake Chaohu, China, using generalized additive models(GAMs). Three historical trends of DDT, PAH, and PCB deposition were delineated in a dated sediment core encompassing ~100 years of historical record: a steady state or gradually increasing stage, a rapidly increasing stage, and a declining stage. The GAM results showed that aquatic total phosphorus(TP) concentrations and regional GDP(anthropogenic factors) were dominant contributors to POP accumulation rates in the lake sediment. The fitted relationships between air temperature and sedimentary DDT and PAH concentrations were linear and negative, while a positive linear relationship was found for PCBs, suggesting that Lake Chaohu may have become a net source for DDTs and PAHs, and a sink for PCBs, under a progressively warming climate.展开更多
The technique of DGT（diffusive gradients in thin films） using three diffusive gel thicknesses was applied to estimate the mobility and bioavailability of heavy metals in sediments and porewater of Lake Taihu, China....The technique of DGT（diffusive gradients in thin films） using three diffusive gel thicknesses was applied to estimate the mobility and bioavailability of heavy metals in sediments and porewater of Lake Taihu, China. The DGT results showed significantly positive correlations between Co, Pb, Cd and Mn, and Ni and Fe concentrations in porewater. Cu and Zn showed a significantly negative correlation with Mn, due to Cu combination with carbonates and Zn derived from agricultural pollution, respectively. The rank order of average concentrations of Co, Ni and Cd at each station was DGT1.92〉DGT0.78〉 DGT0.39, suggesting stronger resupply from sediments to porewater when using thicker diffusive gels. Comparing centrifugation and DGT measurements, Co, Ni and Cd are highly labile; Mn and Fe are moderately labile; and Cu, Zn and Pb are slightly labile. The variations of AVS concentrations in sediment cores indicate that metal sulfides in deeper layers are easily diffused into surface sediments.展开更多
Receptor models have been proved as useful tools to identify source categories and quantitatively calculate the contributions of extracted sources.In this study,sixty surface sediment samples were collected from fourt...Receptor models have been proved as useful tools to identify source categories and quantitatively calculate the contributions of extracted sources.In this study,sixty surface sediment samples were collected from fourteen lakes in Jiangsu Province,China.The total concentrations of C_4–C_（14）-perfluoroalkyl carboxylic acids and perfluorooctane sulfonic acid（∑_（12）PFASs） in sediments ranged from 0.264 to 4.44 ng/g dw（dry weight）,with an average of 1.76 ng/g dw.Three commonly-applied receptor models,namely principal component analysis-multiple linear regression（PCA-MLR）,positive matrix factorization（PMF） and Unmix models,were employed to apportion PFAS sources in sediments.Overall,these three models all could well track the ∑_（12） PFASs concentrations as well as the concentrations explained in sediments.These three models identified consistently four PFAS sources：the textile treatment sources,the fluoropolymer processing aid/fluororesin coating sources,the textile treatment/metal plating sources and the precious metal sources,contributing 28.1%,37.0%,29.7% and 5.3% by PCA-MLR model,30.60%,39.3%,22.4% and 7.7% by PMF model,and 20.6%,52.4%,20.2% and 6.8% by Unmix model to the ∑_（12） PFASs,respectively.Comparative statistics of multiple analytical methods could minimize individual-method weaknesses and provide convergent results to enhance the persuasiveness of the conclusions.The findings could give us a better knowledge of PFAS sources in aquatic environments.展开更多
Arsenic（As） fractions in the sediments of seven lakes from East Plain Ecoregion and six lakes from Yungui Plateau Ecoregion, China, were investigated. Results indicated that the total As concentrations in sediment s...Arsenic（As） fractions in the sediments of seven lakes from East Plain Ecoregion and six lakes from Yungui Plateau Ecoregion, China, were investigated. Results indicated that the total As concentrations in sediment samples of lakes of the East Plain Lake Ecoregion are higher than those of Yungui Plateau Lake Ecoregion. Residual As is the main fraction in sediment samples of lakes from both ecoregions, followed by reducible As and soluble or oxidizable As. The total As is correlated to oxidizable As and residual As in sediment samples from both lake ecoregions. As distribution in sediment samples of lakes of the East Plain Ecoregion appears to be affected by human activity, while the As origin mainly comes from natural sources in sediment samples of lakes in the Yungui Plateau Ecoregion. The potential ecological risk index and geoaccumulation index values suggest ＂low to moderate＂ risk degree and ＂unpolluted to moderately polluted＂ for As in the studied lake sediments.展开更多
Dissolved organic nitrogen（DON）extracted from Lake Shankou sediments using KCl was isolated into hydrophobic and hydrophilic fractions.The bioavailabilities of the hydrophobic and hydrophilic fractions to three type...Dissolved organic nitrogen（DON）extracted from Lake Shankou sediments using KCl was isolated into hydrophobic and hydrophilic fractions.The bioavailabilities of the hydrophobic and hydrophilic fractions to three types of bacterial communities collected from sediments,activated sludge and compost products were examined.The DON recoveries obtained by DAX-8 and cation exchange resins treatment were 96.17% ± 1.58% and 98.14% ±0% for the samples obtained from N4 and N14 stations,respectively.After 25 days of incubation at 25℃,most DON（59% to 96%）was degraded.Hydrophilic DON exhibited a higher reduction rate than hydrophobic DON during the growth phase.Untreated wastewater from Changshuihe town was the main degradable DON source to station N4,and 93% of hydrophilic DON and 80% of hydrophobic DON were degraded.Station N14 received a large amount of refractory DON from forest soils and exhibited DON degradation rates of 82% and 71% for the hydrophilic and hydrophobic fractions,respectively.Amino acid contents and fluorescence intensities were also analyzed.Approximately 27% to 74% of amino acids were taken up by day 5,and their concentration gradually increased in the following days due to the decomposition of dissolved proteins.Parallel factor analysis resulted in identification of tryptophan-like proteins,tyrosine-like proteins and FA-like substances.During the growth phase,40%–51% of the tryptophan-like proteins were taken up by bacteria,and the accumulation of tyrosine-like proteins was attributed to the release of biotic substances.The concentration of the FA-like substances decreased due to microbial decomposition.展开更多
In recent years,Cylindrospermopsis raciborskii blooms have been widely found worldwide.Topics dealing with the mitigation of C.raciborskii bloom is of great importance for toxins produced could threaten public health....In recent years,Cylindrospermopsis raciborskii blooms have been widely found worldwide.Topics dealing with the mitigation of C.raciborskii bloom is of great importance for toxins produced could threaten public health.The paper first investigated C.raciborskii dynamics over three years following sediment dredging in a shallow eutrophic Lake Dongqian(China).Based on rpoC1 gene copies,C.raciborskii bloom formed with average density of 1.30×10^(6) cells/L on July 2009.One year later after sediment dredging,C.raciborskii cell density decreased below 1.17×10^(5) cells/L or under detected limits during summer days on 2010.While two years later,the C.raciborskii bloom period was returned with markedly increased cell density reaching up to 4.15×10^(7) cells/L on October 2011,and the maximum peak density was shown at 20.3C that was much lower than reported optimal growth temperature.Inferred from Spearman correlation analysis,linear regression showed C.raciborskii density was significant and positive with pH and SD,whereas they were significant and negative with TP and DO.Multiple regression analysis further demonstrated that TN,TP,SRP,pH and DO provided the best model and explained 53.1% of the variance in C.raciborskii dynamics.The approaches managing nutrients reduction might not control C.raciborskii bloom as extremely low TN(avg.0.18 mg/L)and TP concentrations(avg.0.05 mg/L)resulted in the highest C.raciborskii cell density after sediment dredging.展开更多
The algal uptake of dissolved organic nitrogen （DON） in the anaerobic-anoxic-oxic （A20） process was investigated in this study. Anaerobic, aerobic and effluent DON samples from two wastewater treatment plants （WW...The algal uptake of dissolved organic nitrogen （DON） in the anaerobic-anoxic-oxic （A20） process was investigated in this study. Anaerobic, aerobic and effluent DON samples from two wastewater treatment plants （WWTPs） were separated into hydrophilic and hydrophobic fractions using a DAX-8 resin coupled with an anion exchange resin and a nanofiltration （NF） pretreatment Hydrophilic DON accounted for 66.66%-88.74% of the entire DON for the two plants evaluated. After a 1S-day incubation, 16.95%-91.75% DON was bioavailable for algal growth, and untreated samples exhibited higher DON bioavailability, with 52.83% DON average uptake rates, compared with the hydrophilic and hydrophobic fractions （45.53% and 44.40%, respectively） because the pretreatment caused the inorganic salt to be resistant to algae. Anaerobic untreated samples, hydrophilic fractions and hydrophobic fractions showed higher DON reduction rates and higher biomass accumulation compared with the other DON fractions due to the decomposition of resistant organics by anaerobic and anoxic bacteria. DON in aerobic and effluent samples of plant A was more bioavailable than that of plant B with usages of 27.49%-55.26% DON. DON bioavailability in the anaerobic-anoxic-oxic process decreased in the following order： anaerobic 〉 effluent 〉 aerobic. The DON contents were reduced after anaerobic treatment in the two plants. The EEM-PARAFAC model identified three DON components, including two humic acid-like substances and one protein-like substance in plant A and two protein-like substances and one humic acid-like substance in plant B.展开更多
Multiple myeloma(MM)is an incurable malignancy of clonal plasma cells,characterized by high relapse rates and rapid development of drug resistance.The emergence of proteasome inhibitors has dramatically improved the t...Multiple myeloma(MM)is an incurable malignancy of clonal plasma cells,characterized by high relapse rates and rapid development of drug resistance.The emergence of proteasome inhibitors has dramatically improved the therapeutic effect of MM;however,side effects and drug resistance still negatively affect the survival rate of MM.Nano-medicine has become a promising field for therapeutic innovation owing to its biodegradability and biocompatibility.Nanoparticles(NPs),when combined with MM therapeutic drugs,can reduce side effects,increase treatment efficacy,and alleviate drug resistance,providing a new direction for the treatment of MM.Restructuring drugs with NPs presents an ideal strategy for ongoing studies aimed at more effective therapies.Additionally,clinical nanomedicine research has yielded new opportunities for MM treatment.This review,guided by the development of MM therapeutic drugs,summarizes the past 20 years of research progress and breakthroughs in NP-based systems for treating MM and improving drug targeting ability.展开更多
基金The National Key Research and Development Program of China (2017YFA0605003)the National Natural Science Foundation of China (91751114 and 41521003).
文摘Mercury and its derivatives are hazardous environmental pollutants and could affect the aquatic ecosystems and human health by biomagnification. Lake sediments can provide important historical information regarding changes in pollution levels and thus trace anthropogenic or natural influences. This research investigates the 100-year history of mercury (Hg) deposition in sediments from Chao Lake, a shallow eutrophic lake in China. The results indicate that the Hg deposition history can be separated into three stages (pre-1960s, 1960s–1980s, and post-1980s) over the last 100 years. Before the 1960s, Hg concentrations in the sediment cores varied little and had no spatial difference. Since the 1960s, the concentration of Hg began to increase gradually, and showed a higher concentration of contamination in the western half of the lake region than in the eastern half of the lake region due to all kinds of centralized human-input sources. The influences of anthropogenic factors and hydrological change are revealed by analyzing correlations between Hg and heavy metals (Fe, Co, Cr, Cu, Mn, Pb, and Zn), stable carbon and nitrogen isotopes (d13C and d15N), nutrients, particle sizes, and meteorological factors. The results show that Hg pollution intensified after the 1960s, mainly due to hydrological change, rapid regional development and urbanization, and the proliferation of anthropogenic Hg sources. Furthermore, the temperature, wind speed, and evaporation are found to interactively influence the environmental behaviors and environmental fate of Hg.
基金supported by grants from the National Natural Science Foundation of China[Grant No.81701076,Linlin Zeng]the Science and Technology Department of Jilin Province[Grant No.20190701037GH,Fuqiang Zhang+2 种基金Grant No.20190701036GH,Linlin Zengand Grant No.20200201386JC,Guodong Li]the Education Department of Jilin Province[Grant No.JJKH20200948KJ,Linlin Zeng]。
文摘Amyotrophic lateral syndrome(ALS)is a progressive degenerative disorder characterized by motor neuron death and axon degeneration.Mitochondrial dysfunction plays a key role in the pathogenesis of ALS,the mechanism of which remains poorly understood.The B-cell lymphoma-2(Bcl-2)family of proteins that control and mediate mitochondrial function and apoptosis,including the pro-apoptotic members Bcl2-Associated X(Bax),are involved in ALS development.The death receptor 6(DR6)regulates motor neuron death in ALS,and DR6 antibodies can prevent axon degeneration and motor neuron damage by blocking DR6.Previous studies demonstrated that PSAP localized to mitochondria and was required for DR6-induced apoptosis.In this study,SOD1^(G93A) was transfected into the motor neuron cell line NSC-34 to serve as an ALS cell model in vitro.The data assessed the role of PSAP in SOD1^(G93A)induced apoptosis and demonstrated that the overexpression of SOD1^(G93A),but not wtSOD1,induced PARP cleavage,caspase-3 activation,cytochrome c release,and Bax translocation.PSAP,Bax,and Bak were necessary for SOD1^(G93A)induced apoptosis,as silencing PSAP inhibited SOD1^(G93A)-mediated cell death that was dependent on Bax-Bak interaction.
基金supported by the National Key Research and Development program (2016YFC0400908)the National Natural Science Foundation of China (Nos. 41101026, 31370466)the STS project of Chinese academy of sciences (29Y829731)
文摘Groundwater is a key factor controlling the growth of vegetation in desert riparian systems. It is important to recognise how groundwater changes affect the riparian forest ecosystem. This information will not only help us to understand the ecological and hydrological process of the riparian forest but also provide support for ecological recovery of riparian forests and water-resources management of arid inland river basins. This study aims to estimate the suitability of the Water Vegetation Energy and Solute Modelling(WAVES) model to simulate the Ejina Desert riparian forest ecosystem changes,China, to assess effects of groundwater-depth change on the canopy leaf area index(LAI) and water budgets, and to ascertain the suitable groundwater depth for preserving the stability and structure of desert riparian forest. Results demonstrated that the WAVES model can simulate changes to ecological and hydrological processes. The annual mean water consumption of a Tamarix chinensis riparian forest was less than that of a Populus euphratica riparian forest, and the canopy LAI of the desert riparian forest should increase as groundwater depth decreases. Groundwater changes could significantly influence water budgets for T. chinensis and P. euphratica riparian forests and show the positive and negative effects on vegetation growth and water budgets of riparian forests. Maintaining the annual mean groundwater depth at around 1.7-2.7 m is critical for healthy riparian forest growth. This study highlights the importance of considering groundwater-change impacts on desert riparian vegetation and water-balance applications in ecological restoration and efficient water-resource management in the Heihe River Basin.
文摘The technique of DGT (diffusive gradients in thin films) was applied to obtain high-resolution vertical profiles of dissolved reactive phosphorus (DRP) in sediment porewater of Lake Chaohu, a shallow eutrophication lake. Three kinds of DGT probes (with three thicknesses of diffusive gel: 0.38 mm, 0.78 mm and 1.18 mm) measured vertical concentration and induced flux from solid to solution phase which had intricate variations with depth. The results indicated that higher concentrations and induced fluxes of DRP were achieved by using DGT probe with thicker diffusion layer (CDGT1.18 > CDGT0.78 > CDGT0.38) and relatively stable DRP concentration profiles using DGT probes with 0.78 mm diffusive gel were obtained in each sediment core. The DRP concentrations displayed a clear gradient from Core C1 to Core C3 in sediment porewaters due to different sources and exchange degrees of reactive phosphorus. Compared to the concentrations obtained by the centrifugation technique, the concentrations of DRP resulting from the DGT technique were higher because some dissolved reactive phosphorus compounds have always been neglected using conventional centrifugation method.
基金supported by the Natural Science Foundation of Guangdong Province(2022A1515010889)China Agriculture Research System of MOF and MARA.
文摘Grafting is a commonly used method for citrus propagation and transmitting'Candidatus Liberibacter asiaticus'(CLas),the putative causing agent of citrus Huanglongbing(HLB).Optimization of the grafting inoculation methods facilitates the material preparation in HLB research.Citrus buds with CLas were grafted onto healthy sour tangerine(Citrus sunki Hort.ex Tanaka)seedlings by different methods such as top grafting(‘T'grafting and‘V'grafting)and side grafting(abdominal grafting).Along with the symptom observation,titers of CLas in the leaves were detected by RTqPCR monthly.The correlation between the growth status of buds or different grafting methods and the success rate of HLB transmission were analyzed.Our results suggest that sufficient DNA could be extracted to accurately detect the CLas from even only 0.0125 g leaf midrib or branch bark.The probability of CLas transmission was higher in plants inoculated with buds in better growth conditions.The success rate of‘T'grafting was significantly higher than that of side grafting and‘V'grafting.Additionally,in terms of HLB transmission efficiency,the two-bud grafting scheme was superior to the single-bud and three-bud grafting schemes.In conclusion,the grafting combinations with the highest HLB transmission efficiency were screened to provide a methodological reference for the practice or research of grafting to obtain plant material.
基金supported by the Mega-projects of Science Research for Water Environment Improvement (No.2009ZX07106-001)the National Natural Science Foundation of China (No. 40901248)the National Basic Research Program (973) of China (No. 2008CB418206)
文摘Recent sediments from Lake Chenghai, China, were investigated at high temporal resolution to trace both natural and anthropogenic effects on the lake using total organic carbon （TOC）, total nitrogen （TN）, total phosphorus （TP）, organic phosphorus （Po）, inorganic phosphorus （Pi） and organic carbon and nitrogen stable isotopes （~13Corg and 615N） in a 137Cs-dated sediment core. The results indicated that the sedimentary record covers the last 60 years, during which the lake had undergone apparent changes in nutrient sources and productivity in response to nutrient loading. Prior to the late 1980s, the nutrient contents in sediments mainly originated from algae and lake productivity was relatively stable. Since the late 1980s, increasing TOC, TN and TP concentrations together with the change of 613Corg and 615N suggested anthropogenic perturbations in nutrient loading and lake productivity. Endogenic nutrients derived from algae and anthropogenic inputs were two important sources of sedimentary nutrients. The anthropogenic nutrients mainly originated from the discharge of industrial wastewater and artificial cultivation of Spirulina after the middle 1980s, and domestic wastewater discharged from Yongsheng County since 1993.
基金supported by the Mega-projects of Science Research for Water Environment Improvement(No.2009ZX07106-001,2012ZX07101-002)the National Natural Science Foundation of China(No.40901248)the China Basic Research Program(No.2008CB418206)
文摘Characterization, treatment and releases of eight polybrominated diphenyl ethers （PBDEs） congeners and sixteen polycyclic aromatic hydrocarbons （PAHs） in wastewater were evaluated along the treatment processes of a typical secondary treatment municipal sewage treatment plant （STP） （in Hefei City） situated the beside Nanfei River, East China. The findings showed that the average concentrations of the total PBDEs in raw wastewater and treated effluent were 188.578 and 36.884 ng/L respectively. Brominated diphenyl ether （BDE） 209 congener, the predominant PBDE in the STP and Nanfei River, could be related to the discharge of car-industry-derived wastes. For PAHs, the average concentrations in raw wastewater and treated effluent were 5758.8 and 2240.4 ng/L respectively, with naphthalene, benzo[a]pyrene and indeno[1,2,3-c,d]pyrene being detected at the highest concentrations. PAHs mainly originate from the combustion of biomass/coal and petroleum. The STP reduced about 80% of the PBDEs and 61% of the PAHs, which were eliminated mainly by sedimentation processes. The removal rates of PBDEs/PAHs increased with the increase of their solid-water partitioning coefficients. Accordingly, the STP＇s effluent, containing some PBDE congeners （e.g., BDE 47, 99 and 209, etc.） and low-molecular-weight PAHs, could be an important contributor of these contaminants＇ input to Nanfei River. It resulted in a significant increase of PBDE/PAH concentrations and PAH toxicological risk in the river water downstream. About 4.040 kg/yr of PBDEs and 245.324 kg/yr of PAHs could be released into the Nanfei River. The current conventional wastewater treatment processes should be improved to remove the relatively low-molecular-weight PBDEs/PAHs more effectively.
基金supported by the National Key Research and Development Program of China(No.2017YFA0605003)the National Natural Science Foundation of China(No.91751114,41521003)
文摘Climate change and anthropogenic activities are expected to impact the environmental behaviors and fates of persistent organic pollutants(POPs), however, quantitative studies on these combined factors are scarce. In this study, dichlorodiphenyltrichloroethane(DDTs), polycyclic aromatic hydrocarbons(PAHs), and polychlorinated biphenyls(PCBs)were used as examples to identify how and when those factors may be related to the deposition of POPs in the sediment of Lake Chaohu, China, using generalized additive models(GAMs). Three historical trends of DDT, PAH, and PCB deposition were delineated in a dated sediment core encompassing ~100 years of historical record: a steady state or gradually increasing stage, a rapidly increasing stage, and a declining stage. The GAM results showed that aquatic total phosphorus(TP) concentrations and regional GDP(anthropogenic factors) were dominant contributors to POP accumulation rates in the lake sediment. The fitted relationships between air temperature and sedimentary DDT and PAH concentrations were linear and negative, while a positive linear relationship was found for PCBs, suggesting that Lake Chaohu may have become a net source for DDTs and PAHs, and a sink for PCBs, under a progressively warming climate.
基金supported by the Mega-projects of Science Research for Water Environment Improvement (No. 2012ZX07101-002)the National Natural Science Foundation of China (No. 41303085)
文摘The technique of DGT（diffusive gradients in thin films） using three diffusive gel thicknesses was applied to estimate the mobility and bioavailability of heavy metals in sediments and porewater of Lake Taihu, China. The DGT results showed significantly positive correlations between Co, Pb, Cd and Mn, and Ni and Fe concentrations in porewater. Cu and Zn showed a significantly negative correlation with Mn, due to Cu combination with carbonates and Zn derived from agricultural pollution, respectively. The rank order of average concentrations of Co, Ni and Cd at each station was DGT1.92〉DGT0.78〉 DGT0.39, suggesting stronger resupply from sediments to porewater when using thicker diffusive gels. Comparing centrifugation and DGT measurements, Co, Ni and Cd are highly labile; Mn and Fe are moderately labile; and Cu, Zn and Pb are slightly labile. The variations of AVS concentrations in sediment cores indicate that metal sulfides in deeper layers are easily diffused into surface sediments.
基金supported by the Mega-projects of Science Research for Water Environmental Improvement(No.2012ZX07101-002)the National Natural Science Foundation of China(No.41521003)
文摘Receptor models have been proved as useful tools to identify source categories and quantitatively calculate the contributions of extracted sources.In this study,sixty surface sediment samples were collected from fourteen lakes in Jiangsu Province,China.The total concentrations of C_4–C_（14）-perfluoroalkyl carboxylic acids and perfluorooctane sulfonic acid（∑_（12）PFASs） in sediments ranged from 0.264 to 4.44 ng/g dw（dry weight）,with an average of 1.76 ng/g dw.Three commonly-applied receptor models,namely principal component analysis-multiple linear regression（PCA-MLR）,positive matrix factorization（PMF） and Unmix models,were employed to apportion PFAS sources in sediments.Overall,these three models all could well track the ∑_（12） PFASs concentrations as well as the concentrations explained in sediments.These three models identified consistently four PFAS sources：the textile treatment sources,the fluoropolymer processing aid/fluororesin coating sources,the textile treatment/metal plating sources and the precious metal sources,contributing 28.1%,37.0%,29.7% and 5.3% by PCA-MLR model,30.60%,39.3%,22.4% and 7.7% by PMF model,and 20.6%,52.4%,20.2% and 6.8% by Unmix model to the ∑_（12） PFASs,respectively.Comparative statistics of multiple analytical methods could minimize individual-method weaknesses and provide convergent results to enhance the persuasiveness of the conclusions.The findings could give us a better knowledge of PFAS sources in aquatic environments.
基金supported by the Mega-projects of Science Research for Water Environment Improvement (Nos. 2009ZX07106-001, 2012ZX07101-002)the National Natural Science Foundation of China (No. 41303085)
文摘Arsenic（As） fractions in the sediments of seven lakes from East Plain Ecoregion and six lakes from Yungui Plateau Ecoregion, China, were investigated. Results indicated that the total As concentrations in sediment samples of lakes of the East Plain Lake Ecoregion are higher than those of Yungui Plateau Lake Ecoregion. Residual As is the main fraction in sediment samples of lakes from both ecoregions, followed by reducible As and soluble or oxidizable As. The total As is correlated to oxidizable As and residual As in sediment samples from both lake ecoregions. As distribution in sediment samples of lakes of the East Plain Ecoregion appears to be affected by human activity, while the As origin mainly comes from natural sources in sediment samples of lakes in the Yungui Plateau Ecoregion. The potential ecological risk index and geoaccumulation index values suggest ＂low to moderate＂ risk degree and ＂unpolluted to moderately polluted＂ for As in the studied lake sediments.
基金supported by the Mega-projects of Science Research for Water Environment Improvement(No.2012ZX07101-002)the National Natural Science Foundation of China(No.41303085)
文摘Dissolved organic nitrogen（DON）extracted from Lake Shankou sediments using KCl was isolated into hydrophobic and hydrophilic fractions.The bioavailabilities of the hydrophobic and hydrophilic fractions to three types of bacterial communities collected from sediments,activated sludge and compost products were examined.The DON recoveries obtained by DAX-8 and cation exchange resins treatment were 96.17% ± 1.58% and 98.14% ±0% for the samples obtained from N4 and N14 stations,respectively.After 25 days of incubation at 25℃,most DON（59% to 96%）was degraded.Hydrophilic DON exhibited a higher reduction rate than hydrophobic DON during the growth phase.Untreated wastewater from Changshuihe town was the main degradable DON source to station N4,and 93% of hydrophilic DON and 80% of hydrophobic DON were degraded.Station N14 received a large amount of refractory DON from forest soils and exhibited DON degradation rates of 82% and 71% for the hydrophilic and hydrophobic fractions,respectively.Amino acid contents and fluorescence intensities were also analyzed.Approximately 27% to 74% of amino acids were taken up by day 5,and their concentration gradually increased in the following days due to the decomposition of dissolved proteins.Parallel factor analysis resulted in identification of tryptophan-like proteins,tyrosine-like proteins and FA-like substances.During the growth phase,40%–51% of the tryptophan-like proteins were taken up by bacteria,and the accumulation of tyrosine-like proteins was attributed to the release of biotic substances.The concentration of the FA-like substances decreased due to microbial decomposition.
基金The National Key Research and Development Program of China(2017YFA0605003)the National Natural Science Foundation of China(51922010,91751114,41521003,31700404),supported this study.
文摘In recent years,Cylindrospermopsis raciborskii blooms have been widely found worldwide.Topics dealing with the mitigation of C.raciborskii bloom is of great importance for toxins produced could threaten public health.The paper first investigated C.raciborskii dynamics over three years following sediment dredging in a shallow eutrophic Lake Dongqian(China).Based on rpoC1 gene copies,C.raciborskii bloom formed with average density of 1.30×10^(6) cells/L on July 2009.One year later after sediment dredging,C.raciborskii cell density decreased below 1.17×10^(5) cells/L or under detected limits during summer days on 2010.While two years later,the C.raciborskii bloom period was returned with markedly increased cell density reaching up to 4.15×10^(7) cells/L on October 2011,and the maximum peak density was shown at 20.3C that was much lower than reported optimal growth temperature.Inferred from Spearman correlation analysis,linear regression showed C.raciborskii density was significant and positive with pH and SD,whereas they were significant and negative with TP and DO.Multiple regression analysis further demonstrated that TN,TP,SRP,pH and DO provided the best model and explained 53.1% of the variance in C.raciborskii dynamics.The approaches managing nutrients reduction might not control C.raciborskii bloom as extremely low TN(avg.0.18 mg/L)and TP concentrations(avg.0.05 mg/L)resulted in the highest C.raciborskii cell density after sediment dredging.
基金supported by the Mega-projects of the Science Research for Water Environment Improvement (no. 2012ZX07101-002)the National Natural Science Foundation of China (nos. 41521003, 41303085)
文摘The algal uptake of dissolved organic nitrogen （DON） in the anaerobic-anoxic-oxic （A20） process was investigated in this study. Anaerobic, aerobic and effluent DON samples from two wastewater treatment plants （WWTPs） were separated into hydrophilic and hydrophobic fractions using a DAX-8 resin coupled with an anion exchange resin and a nanofiltration （NF） pretreatment Hydrophilic DON accounted for 66.66%-88.74% of the entire DON for the two plants evaluated. After a 1S-day incubation, 16.95%-91.75% DON was bioavailable for algal growth, and untreated samples exhibited higher DON bioavailability, with 52.83% DON average uptake rates, compared with the hydrophilic and hydrophobic fractions （45.53% and 44.40%, respectively） because the pretreatment caused the inorganic salt to be resistant to algae. Anaerobic untreated samples, hydrophilic fractions and hydrophobic fractions showed higher DON reduction rates and higher biomass accumulation compared with the other DON fractions due to the decomposition of resistant organics by anaerobic and anoxic bacteria. DON in aerobic and effluent samples of plant A was more bioavailable than that of plant B with usages of 27.49%-55.26% DON. DON bioavailability in the anaerobic-anoxic-oxic process decreased in the following order： anaerobic 〉 effluent 〉 aerobic. The DON contents were reduced after anaerobic treatment in the two plants. The EEM-PARAFAC model identified three DON components, including two humic acid-like substances and one protein-like substance in plant A and two protein-like substances and one humic acid-like substance in plant B.
基金supported by the National Natural Science Foundation of China Youth Project(81900131)Tianjin Municipal Natural Science Foundation(18JCQNJC80400)+6 种基金Tianjin Education Commission Research Project(2018KJ043)Tianjin Education Commission Research Project(2018KJ045)Tianjin Science and Technology Planning Project(20YFZCSY00060)Tianjin Municipal Health Commission Youth Project(TJWJ2021QN001)the Medjaden Academy&Research Foundation for Young Scientists(MJR20221011)Tianjin Key Medical Discipline(Specialty)Construction project(XZDXK-028A)Tianjin Municipal Health Health Science and Technology Project(TJWJ2023XK003).
文摘Multiple myeloma(MM)is an incurable malignancy of clonal plasma cells,characterized by high relapse rates and rapid development of drug resistance.The emergence of proteasome inhibitors has dramatically improved the therapeutic effect of MM;however,side effects and drug resistance still negatively affect the survival rate of MM.Nano-medicine has become a promising field for therapeutic innovation owing to its biodegradability and biocompatibility.Nanoparticles(NPs),when combined with MM therapeutic drugs,can reduce side effects,increase treatment efficacy,and alleviate drug resistance,providing a new direction for the treatment of MM.Restructuring drugs with NPs presents an ideal strategy for ongoing studies aimed at more effective therapies.Additionally,clinical nanomedicine research has yielded new opportunities for MM treatment.This review,guided by the development of MM therapeutic drugs,summarizes the past 20 years of research progress and breakthroughs in NP-based systems for treating MM and improving drug targeting ability.
