Graphene-based nanomaterials(GBNs) have attracted increasing interests of the scientific community due to their unique physicochemical properties and their applications in biotechnology, biomedicine, bioengineering, d...Graphene-based nanomaterials(GBNs) have attracted increasing interests of the scientific community due to their unique physicochemical properties and their applications in biotechnology, biomedicine, bioengineering, disease diagnosis and therapy. Although a large amount of researches have been conducted on these novel nanomaterials, limited comprehensive reviews are published on their biomedical applications and potential environmental and human health effects. The present research aimed at addressing this knowledge gap by examining and discussing:(1) the history, synthesis,structural properties and recent developments of GBNs for biomedical applications;(2) GBNs uses as therapeutics,drug/gene delivery and antibacterial materials;(3) GBNs applications in tissue engineering and in research as biosensors and bioimaging materials; and(4) GBNs potential environmental effects and human health risks. It also discussed the perspectives and challenges associated with the biomedical applications of GBNs.展开更多
Biometric inventories for 25 years,from 1983 to 2005,indicated that the Jianfengling tropical mountain rain forest in Hainan,China,was either a source or a modest sink of carbon.Overall,this forest was a small carbon ...Biometric inventories for 25 years,from 1983 to 2005,indicated that the Jianfengling tropical mountain rain forest in Hainan,China,was either a source or a modest sink of carbon.Overall,this forest was a small carbon sink with an accumulation rate of(0.56±0.22) Mg C ha-1yr-1,integrated from the long-term measurement data of two plots(P9201 and P8302).These findings were similar to those for African and American rain forests((0.62±0.23) Mg C ha-1yr-1).The carbon density varied between(201.43±29.38) Mg C ha-1 and(229.16±39.2) Mg C ha-1,and averaged(214.17±32.42) Mg C ha-1 for plot P9201.Plot P8302,however,varied between(223.95±45.92) Mg C ha-1 and(254.85±48.86) Mg C ha-1,and averaged(243.35±47.64) Mg C ha-1.Quadratic relationships were found between the strength of carbon sequestration and heavy rainstorms and dry months.Precipitation and evapotranspiration are two major factors controlling carbon sequestration in the tropical mountain rain forest.展开更多
Using the model system MM5.V3 and multi-layer grid nesting technique, we have done a multi-scale numerical simulation over the area of Beijing, Tianjin and Hebei Province to analyze the temperature and wind field ther...Using the model system MM5.V3 and multi-layer grid nesting technique, we have done a multi-scale numerical simulation over the area of Beijing, Tianjin and Hebei Province to analyze the temperature and wind field there and study its local circulations. The results show a coupling effect of Urban Heat Island Circulation (UHIC), Mountain Valley Breeze (MVB) and Sea Land Breeze (SLB) occurs in this area when the synoptic system is weak. The SLB can penetrate deep into the mainland for about 200 km when it is blooming. MVB can extend to south and cover almost the whole plain area in Beijing. Both MVB and SLB are diurnal periodical; meanwhile the phase of MVB drops behind that of SLB for about six hours. As a local circulation, the UHIC weakens the two circulations above, and it also has a diurnal period. As a result, the coupling effect of circulations reveals not only different features in spring-summer period and autumn-winter period in a year but also the difference between early morn- ing to noonday and afternoon to night in a day. We noted the diffusion of contamination over the area around Beijing, and found the steady presence of a transport routine of contamination over North-China throughout the year caused by the Coupling Effect mentioned above. This find is important for studying the environment pollution in this area.展开更多
Cytotoxicity of selected metal oxide nanoparticles（MNPs）（ZnO,CuO,Co 3 O 4 and TiO 2）was investigated in Escherichia coli both under light and dark conditions.Cytotoxicity experiments were conducted with spread pla...Cytotoxicity of selected metal oxide nanoparticles（MNPs）（ZnO,CuO,Co 3 O 4 and TiO 2）was investigated in Escherichia coli both under light and dark conditions.Cytotoxicity experiments were conducted with spread plate counting and the LC 50 values were calculated.We determined the mechanism of toxicity via measurements of oxidative stress,reduced glutathione,lipid peroxidation,and metal ions.The overall ranking of the LC 50 values was in the order of ZnO 〈 CuO 〈 Co 3 O 4 〈 TiO 2 under dark condition and ZnO 〈 CuO 〈 TiO 2 〈 Co 3 O 4 under light condition.ZnO MNPs were the most toxic among the tested nanoparticles.Our results indicate depletion of reduced glutathione level and elevation of malondialdehyde level correlated with the increase in oxidative stress.Released metal ions were found to have partial effect on the toxicity of MNPs to E.coli.In summary,the dynamic interactions of multiple mechanisms lead to the toxicity of the tested MNPs to E.coli.展开更多
In this study,the cytotoxicity of two different crystal phases of TiO2 nanoparticles,with surface modification by humic acid（HA）,to Escherichia coli,was assessed.The physicochemical properties of TiO2 nanoparticles ...In this study,the cytotoxicity of two different crystal phases of TiO2 nanoparticles,with surface modification by humic acid（HA）,to Escherichia coli,was assessed.The physicochemical properties of TiO2 nanoparticles were thoroughly characterized.Three different initial concentrations,namely 50,100,and 200 ppm,of HA were used for synthesis of HA coated TiO2 nanoparticles（denoted as A/RHA50,A/RHA100,and A/RHA200,respectively）.Results indicate that rutile（LC50（concentration that causes 50%mortality compared the control group）=6.5）was more toxic than anatase（LC50=278.8）under simulated sunlight（SSL）irradiation,possibly due to an extremely narrow band gap.It is noted that HA coating increased the toxicity of anatase,but decreased that of rutile.Additionally,AHA50 and RHA50had the biggest differences compared to uncoated anatase and rutile with LC50of 201.9 and21.6,respectively.We then investigated the formation of reactive oxygen species（ROS）by TiO2 nanoparticles in terms of hydroxyl radicals（OH）and superoxide anions（O2^-）.Data suggested that O2^- was the main ROS that accounted for the higher toxicity of rutile upon SSL irradiation.We also observed that HA coating decreased the generation of OH and O2^- on rutile,but increased O2^- formation on anatase.Results from TEM analysis also indicated that HA coated rutile tended to be attached to the surface of E.coli more than anatase.展开更多
Steel slag(SS)is one of byproduct of steel manufacture industry.The environmental concerns of SS may limit their re-use in different applications.The goal of this study was to investigate the leaching behavior of meta...Steel slag(SS)is one of byproduct of steel manufacture industry.The environmental concerns of SS may limit their re-use in different applications.The goal of this study was to investigate the leaching behavior of metals from SS before and after treated by microbially induced carbonate precipitation(MICP).Toxicity characteristic leaching procedure,synthetic precipitation leaching procedure and water leaching tests were performed to evaluate the leaching behavior of major elements(Fe,Mg and Ca)and trace elements(Ba,Cu and Mn)in three scenarios.The concentrations of leaching metals increased with the content of SS.After it reached the peak concentration,the leaching concentration decreased with the content of SS.The leachability of all elements concerned in this study was below 0.5%.The carbonate generated from the MICP process contributed to the low leachability of metals.After bio-modified by MICP process,the leaching concentrations of Ba from TCLP,SPLP and WLT tests were below 2.0 mg/L,which was the limit in drinking water regulated by U.S.EPA.The concentrations of Cu leached out from MICP-treated SS-sand samples were below 1.3 mg/L which is the limit regulated by national secondary drinking water.Compared with the regulations of U.S.EPA and Mississippi Department of Environment Quality(MDEQ),MICP-treated samples were classified as non-hazardous materials with respects to the leaching of metals.Meanwhile,maximum contaminant limits regulated by U.S.EPA states that MICP-treated SS are eco-friendly materials that can be reused as construction materials.展开更多
By use of a shorehne-change numerical model （GENESIS） based on one-line theory, a preliminary modeling study on shoreline changes caused by a beach nourishment project in Beidaihe, China, is presented in this paper....By use of a shorehne-change numerical model （GENESIS） based on one-line theory, a preliminary modeling study on shoreline changes caused by a beach nourishment project in Beidaihe, China, is presented in this paper. Firstly, the GENESIS model is verified and model sensitivity to the major parameter changes is discussed by simulating a hydraulic model test. The beach nourishment project, after that the shoreline change is kept being monitored, is a small-scale emergency one carried out to use two bathing places on the west beach in the summer, 2008. In this paper the shoreline changes caused by the beach nourishment project are modeled by the GENESIS model, and the computed results fit well with the measured shorelines. With the same model and parameters, a long-term performance of the project is predicted, and the result shows that the bathing places only can be suitable for bathing in 2 to 3 years without subsequence nourishment project. Therefore, it is proposed to nourish the beaches in time to keep the service life of the beach in recent years and carry out the beach nourishment project for the whole west beach as soon as possible.展开更多
Many hybrid electrodes for supercapacitors(SCs)are a reckless combination without proper structural design that keeps them from fulfilling their potential.Herein,we design a reduced graphene oxide/poly(3,4-ethylenedio...Many hybrid electrodes for supercapacitors(SCs)are a reckless combination without proper structural design that keeps them from fulfilling their potential.Herein,we design a reduced graphene oxide/poly(3,4-ethylenedioxythiophene)/polyaniline(RGO/PEDOT/PANI)hybrid with hierarchical and porous structure for high-performance SCs,where components fully harness their advantages,forming an interconnected and conductive framework with substantial reactive sites.Thus,this hybrid achieves a high capacitance of 535 F g^−1 along with good rate capability and cyclability.The planar SC based on this hybrid deliver an energy density of 26.89 Wh kg^−1 at a power density of 800 W kg^−1.The linear SC developed via modifying a cotton yarn with the hybrid exhibits good flexibility and structural stability,which operates normally after arbitrary deformations.This work provides a beneficial reference for developing SCs.展开更多
The effect of a terrestrial humic acid （HA） and Suwannee River HA on the cytotoxicity of engineered zinc oxide nanoparticles （ZnONPs） and titanium dioxide nanoparticles （TiO2NPs） to natural aquatic bacterial ass...The effect of a terrestrial humic acid （HA） and Suwannee River HA on the cytotoxicity of engineered zinc oxide nanoparticles （ZnONPs） and titanium dioxide nanoparticles （TiO2NPs） to natural aquatic bacterial assemblages was measured with spread plate counting. The effect of HA （10 and 40 ppm） on the cytotoxicity of ZnONPs and TiO2NPs was tested factorially in the presence and absence of natural sunlight （light irradiation （LI））. The experiment was of full factorial, completely randomized design and the results were analyzed using the General Linear Model in SAS analytical software. The method of least squares means was used to separate the means or combinations of means. We determined the mechanism of toxicity via measurements of oxidative stress and metal ions. The toxicity of ZnONPs and TiO2NPs to natural aquatic bacterial assemblages appears to be concentration dependent. Moreover, the cytotoxicity of ZnONPs and TiO2NPs appeared to be affected by HA concentration, the presence of sunlight irradiation, and the dynamic multiple interactions among these factors. With respect to light versus darkness in the control group, the data indicate that bacterial viability was inhibited more in the light exposure than in the darkness exposure. The same was true in the HA treatment groups. With respect to terrestrial versus Suwanee River HA for a given nanoparticle, in light versus darkness, bacterial viability was more inhibited in the light treatment groups containing the terrestrial HA than in those containing Suwanee River HA. Differences in the extent of reactive oxygen species formation, adsorption/binding of ZnONPs/TiO2NPs by HA, and the levels of free metal ions were speculated to account for the observed cytotoxicity. TEM images indicate the attachment and binding of the tested nanoparticles to natural bacterial assemblages. Besides the individual parameter, significant effects on bacterial viability count were also observed in the following combined treatments： HA-ZnONPs, HA-LI, ZnONPs-LI展开更多
While various prior studies have delved into the potential consequences of climate change on crop production in specific areas, notably in southeastern Louisiana, limited investigation has been carried out concerning ...While various prior studies have delved into the potential consequences of climate change on crop production in specific areas, notably in southeastern Louisiana, limited investigation has been carried out concerning some crops within the state of Louisiana. Consequently, there exists a dearth of knowledge regarding the specific hurdles and potential benefits confronting agricultural producers in this region. Therefore, the primary aim of this study was to explore and measure the impact of climate change on the yields of corn, rice, soybeans, and cotton in Louisiana, thereby addressing this informational void. The study uses data on average high temperatures and precipitation to assess the impact of climate change on these specific food crops in Louisiana. The researchers used ArcGIS and its symbology tool to create three separate maps depicting the spatial distribution of harvested cropland in Louisiana. The graduated color option was used on each map, which represented the years 2007, 2012, and 2017. Similarly, eight separate maps were created using the graduated color option to visually present the distribution patterns of Louisiana’s corn, cotton, rice, and soybean crops. These maps provided a visual representation of the state’s total crop production between 2007 and 2017. The researchers also created six bar charts to show the distribution of corn, cotton, rice, and soybean production in Louisiana over three time periods: 2007, 2012, and 2017. These charts also included information about the average high temperature and annual precipitation in each parish. The study revealed decreasing trends in Louisiana corn and cotton yields alongside consistent increases in rice and soybean yields, with projections suggesting future temperature rises may negatively impact crop yields, highlighting the need for research into climate-smart agricultural practices to mitigate these effects and safeguard global crop production. Louisiana’s response to climate change in food crop production involves implementing a compr展开更多
This study explores the intricate relationship between population growth and water resource management in Louisiana, emphasizing the spatial distribution of water quality. Human activities, particularly urbanization, ...This study explores the intricate relationship between population growth and water resource management in Louisiana, emphasizing the spatial distribution of water quality. Human activities, particularly urbanization, have significantly impacted the state’s water resources, with population growth driving increased water withdrawals for public supply, industry, and power generation. By employing a Geographic Information System (GIS)-centered approach, this research utilizes Louisiana’s census data from 1999 to 2020 to illustrate population shifts and their effects on water resource distribution. The study also incorporated advanced remote sensing techniques, using Sentinel 2 imagery to assess the water quality through the Trophic State Index (TSI). The TSI, calculated based on the near-infrared (NIR) and Red bands of Sentinel-2 imagery, provided a nuanced understanding of the nutrient levels and clarity/ quality of water bodies across the state. The study reveals a significant correlation between population density and water withdrawals, with higher populations leading to greater extraction from both groundwater and surface water sources. For instance, densely populated parishes like East Baton Rouge and Orleans showed substantially higher water withdrawals for public supply, industry, and power generation compared to less populated areas. The water quality analysis indicated that many water bodies in Louisiana are experiencing high levels of nutrient enrichment, with rivers and streams accounting for 86% of the impaired water bodies, and lakes, reservoirs, and coastal waters showing hypereutrophic conditions in up to 96% of cases. These results underscore the significant impact of human activities on Louisiana’s water resources, highlighting the need for effective water management practices that consider both quantity and quality. The study therefore advocates for the implementation of water conservation measures, responsible consumption, and pollution prevention strategies to ensure the sustainable use of w展开更多
Louisiana possesses a bountiful groundwater reserve, an invaluable and noteworthy asset. Despite extensive literature on climate change implications in Louisiana, there is limited academic research focused on its effe...Louisiana possesses a bountiful groundwater reserve, an invaluable and noteworthy asset. Despite extensive literature on climate change implications in Louisiana, there is limited academic research focused on its effects on the state’s water resources. Therefore, this study addresses that gap by using GIS to spatially analyze water usage trends from 1960 to 2014, to examine climate-induced consequences and determine the susceptibility of water utilities’ functions and facilities. This study utilized various online sources to gather data on water withdrawals, temperature trends, and climate impacts in Louisiana. Water usage data from the Lower Mississippi Gulf-Water Science Centre and temperature trends from Meteoblue covering 2023 were also analyzed to assess the state’s water resource challenges. The water withdrawal data was linked to a shapefile within ArcMap, using graduated color symbology to visualize regional variations in water usage. This method highlighted significant water withdrawals across Louisiana from 1960 to 2014, clearly illustrating the differences between regions. Based on the data sources, the results show that groundwater levels in Louisiana have steadily declined over time. For instance, water levels in the Jasper Aquifer in St. Tammany dropped from approximately 125 feet to 50 feet, while levels in the Sparta Aquifer in Lincoln fell from 30 feet to −25 feet. Similarly, the Chicot Aquifer in Acadia experienced a decline from −25 feet to −50 feet. These reductions indicate a concerning trend of groundwater depletion, exacerbated by high temperatures and current drought conditions affecting roughly 73% of the state. To ensure sustainable water management in Louisiana, investing in water storage, transfer infrastructure, and conservation practices are needed to protect surface and groundwater sources. More so, the state’s Reservoir Priority and Development Program (RPDP), which includes the construction of reservoirs, is a key initiative that can address water scarcity, improve w展开更多
Titanium dioxide nanoparticles （TiO2 NPs） are among the most widely manufactured nanomaterials on a global scale. However, prudent and vigilant surveillance, incumbent upon the scientific community with the advent o...Titanium dioxide nanoparticles （TiO2 NPs） are among the most widely manufactured nanomaterials on a global scale. However, prudent and vigilant surveillance, incumbent upon the scientific community with the advent of new technologies, has revealed potentially undesirable effects of TiO2 NPs on biological systems and the natural environment during their application and discharge. Such effects are likely best evaluated by first assessing the fate of the TiO2 NPs in natural environments. In this study, the effects of terrestrial humic acid （HA） and tannic acid （TA）, two major members of the collective： dissolved organic matter （DOM）, on the cytotoxicity of TiO2 NPs to Escherichia coli were investigated in the presence and absence of natural sunlight. Qualitative （transmission electron microscopy （TEM）） and quantitative （LCso） analyses were employed in this study. In addition, the production of reactive oxygen species （ROS） in the form of .OH was further assessed-as HA or TA increased the production of ROS decreased. The inhibition of bacterial viability in the light treatment groups, with respective treatment organics at concentrations of 10 ppm, was less in TA than in terrestrial HA. SAS was used to analyze the treatment effect of individual factors of light irradiation, DOM, and concentration of TiO2 NPs.展开更多
BACKGROUND Patients with acute pancreatitis(AP)frequently experience hospital readmissions,posing a significant burden to healthcare systems.Acute peripancreatic fluid collection(APFC)may negatively impact the clinica...BACKGROUND Patients with acute pancreatitis(AP)frequently experience hospital readmissions,posing a significant burden to healthcare systems.Acute peripancreatic fluid collection(APFC)may negatively impact the clinical course of AP.It could worsen symptoms and potentially lead to additional complications.However,clinical evidence regarding the specific association between APFC and early readmission in AP remains scarce.Understanding the link between APFC and readmission may help improve clinical care for AP patients and reduce healthcare costs.AIM To evaluate the association between APFC and 30-day readmission in patients with AP.METHODS This retrospective cohort study is based on the Nationwide Readmission Database for 2016-2019.Patients with a primary diagnosis of AP were identified.Participants were categorized into those with and without APFC.A 1:1 propensity score matching for age,gender,and Elixhauser comorbidities was performed.The primary outcome was early readmission rates.Secondary outcomes included the incidence of inpatient complications and healthcare utilization.Unadjusted analyses used Mann-Whitney U andχ2 tests,while Cox regression models assessed 30-day readmission risks and reported them as adjusted hazard ratios(aHR).Kaplan-Meier curves and log-rank tests verified readmission risks.RESULTS A total of 673059 patients with the principal diagnosis of AP were included.Of these,5.1%had APFC on initial admission.After propensity score matching,each cohort consisted of 33914 patients.Those with APFC showed a higher incidence of inpatient complications,including septic shock(3.1%vs 1.3%,P<0.001),portal venous thrombosis(4.4%vs 0.8%,P<0.001),and mechanical ventilation(1.8%vs 0.9%,P<0.001).The length of stay(LOS)was longer for APFC patients[4(3-7)vs 3(2-5)days,P<0.001],as were hospital charges($29451 vs$24418,P<0.001).For 30-day readmissions,APFC patients had a higher rate(15.7%vs 6.5%,P<0.001)and a longer median readmission LOS(4 vs 3 days,P<0.001).The APFC group also had higher readmission charges($28展开更多
基金supported by National Institutes of Heath NIMHD Grant # G12MD007581 through the RCMI Center for Environmental HealthNational Science Foundation Grant # HRD-1547754 through the CREST Center for Nanotoxicity Studies at Jackson State University
文摘Graphene-based nanomaterials(GBNs) have attracted increasing interests of the scientific community due to their unique physicochemical properties and their applications in biotechnology, biomedicine, bioengineering, disease diagnosis and therapy. Although a large amount of researches have been conducted on these novel nanomaterials, limited comprehensive reviews are published on their biomedical applications and potential environmental and human health effects. The present research aimed at addressing this knowledge gap by examining and discussing:(1) the history, synthesis,structural properties and recent developments of GBNs for biomedical applications;(2) GBNs uses as therapeutics,drug/gene delivery and antibacterial materials;(3) GBNs applications in tissue engineering and in research as biosensors and bioimaging materials; and(4) GBNs potential environmental effects and human health risks. It also discussed the perspectives and challenges associated with the biomedical applications of GBNs.
基金supported by the National Natural Science Foundation of China (Grant No. 40601009),the A3 Foresight Programthe Special Research Program of Research Institute for Tropical Forestry,Chinese Academy of Forestry (Grant No. 2007-1, RITFYWZX200902)+2 种基金 the Special Research Program for Public-welfare Forestry (Grant No. 200804001) the Eleventh-Five-Year Scientific Support Program of the State Forestry Administration of China (Grant Nos. 2006BAD03A07 and 2006BAD03A04)the "948" Program of State Forestry Administration of China (Grant No. 2007-4-18)
文摘Biometric inventories for 25 years,from 1983 to 2005,indicated that the Jianfengling tropical mountain rain forest in Hainan,China,was either a source or a modest sink of carbon.Overall,this forest was a small carbon sink with an accumulation rate of(0.56±0.22) Mg C ha-1yr-1,integrated from the long-term measurement data of two plots(P9201 and P8302).These findings were similar to those for African and American rain forests((0.62±0.23) Mg C ha-1yr-1).The carbon density varied between(201.43±29.38) Mg C ha-1 and(229.16±39.2) Mg C ha-1,and averaged(214.17±32.42) Mg C ha-1 for plot P9201.Plot P8302,however,varied between(223.95±45.92) Mg C ha-1 and(254.85±48.86) Mg C ha-1,and averaged(243.35±47.64) Mg C ha-1.Quadratic relationships were found between the strength of carbon sequestration and heavy rainstorms and dry months.Precipitation and evapotranspiration are two major factors controlling carbon sequestration in the tropical mountain rain forest.
基金Supported by Central Public Welfare Special Fund Program for the Institute and Higher Education (Grant No. IUMKY200701)Public Welfare Special Fund Pro-gram (Meteorology) of China Scientific and Technological Ministry (Grant Nos. CYHY20080620, CYHY200706004)+1 种基金Spread New Technology Program of China Meteorological Administration (Grant No. CMATG2007M15)Urban Meteorol-ogy Scientific Research Fund Program of the Institute of Beijing Urban Meteorology, China Meteorological Administration (Grant No. UMRF200702)
文摘Using the model system MM5.V3 and multi-layer grid nesting technique, we have done a multi-scale numerical simulation over the area of Beijing, Tianjin and Hebei Province to analyze the temperature and wind field there and study its local circulations. The results show a coupling effect of Urban Heat Island Circulation (UHIC), Mountain Valley Breeze (MVB) and Sea Land Breeze (SLB) occurs in this area when the synoptic system is weak. The SLB can penetrate deep into the mainland for about 200 km when it is blooming. MVB can extend to south and cover almost the whole plain area in Beijing. Both MVB and SLB are diurnal periodical; meanwhile the phase of MVB drops behind that of SLB for about six hours. As a local circulation, the UHIC weakens the two circulations above, and it also has a diurnal period. As a result, the coupling effect of circulations reveals not only different features in spring-summer period and autumn-winter period in a year but also the difference between early morn- ing to noonday and afternoon to night in a day. We noted the diffusion of contamination over the area around Beijing, and found the steady presence of a transport routine of contamination over North-China throughout the year caused by the Coupling Effect mentioned above. This find is important for studying the environment pollution in this area.
基金NSF-SBIR grant # IIP-0823040NSF-CREST program with grant # HRD-0833178Strengthening the Environmental Science Ph.D program in instruction,grant # P031B090210-11
文摘Cytotoxicity of selected metal oxide nanoparticles（MNPs）（ZnO,CuO,Co 3 O 4 and TiO 2）was investigated in Escherichia coli both under light and dark conditions.Cytotoxicity experiments were conducted with spread plate counting and the LC 50 values were calculated.We determined the mechanism of toxicity via measurements of oxidative stress,reduced glutathione,lipid peroxidation,and metal ions.The overall ranking of the LC 50 values was in the order of ZnO 〈 CuO 〈 Co 3 O 4 〈 TiO 2 under dark condition and ZnO 〈 CuO 〈 TiO 2 〈 Co 3 O 4 under light condition.ZnO MNPs were the most toxic among the tested nanoparticles.Our results indicate depletion of reduced glutathione level and elevation of malondialdehyde level correlated with the increase in oxidative stress.Released metal ions were found to have partial effect on the toxicity of MNPs to E.coli.In summary,the dynamic interactions of multiple mechanisms lead to the toxicity of the tested MNPs to E.coli.
基金supported in part by the NSF-REU program(National Science Foundation-Research Experiences for Undergraduates,No.#CHE-1156111)the NSF-CREST program(National Science Foundation-Centers of Research Excellencein Science and Technology,No.#HRD-0833178)
文摘In this study,the cytotoxicity of two different crystal phases of TiO2 nanoparticles,with surface modification by humic acid（HA）,to Escherichia coli,was assessed.The physicochemical properties of TiO2 nanoparticles were thoroughly characterized.Three different initial concentrations,namely 50,100,and 200 ppm,of HA were used for synthesis of HA coated TiO2 nanoparticles（denoted as A/RHA50,A/RHA100,and A/RHA200,respectively）.Results indicate that rutile（LC50（concentration that causes 50%mortality compared the control group）=6.5）was more toxic than anatase（LC50=278.8）under simulated sunlight（SSL）irradiation,possibly due to an extremely narrow band gap.It is noted that HA coating increased the toxicity of anatase,but decreased that of rutile.Additionally,AHA50 and RHA50had the biggest differences compared to uncoated anatase and rutile with LC50of 201.9 and21.6,respectively.We then investigated the formation of reactive oxygen species（ROS）by TiO2 nanoparticles in terms of hydroxyl radicals（OH）and superoxide anions（O2^-）.Data suggested that O2^- was the main ROS that accounted for the higher toxicity of rutile upon SSL irradiation.We also observed that HA coating decreased the generation of OH and O2^- on rutile,but increased O2^- formation on anatase.Results from TEM analysis also indicated that HA coated rutile tended to be attached to the surface of E.coli more than anatase.
基金supported by the US National Science Foundation(No.1924241)。
文摘Steel slag(SS)is one of byproduct of steel manufacture industry.The environmental concerns of SS may limit their re-use in different applications.The goal of this study was to investigate the leaching behavior of metals from SS before and after treated by microbially induced carbonate precipitation(MICP).Toxicity characteristic leaching procedure,synthetic precipitation leaching procedure and water leaching tests were performed to evaluate the leaching behavior of major elements(Fe,Mg and Ca)and trace elements(Ba,Cu and Mn)in three scenarios.The concentrations of leaching metals increased with the content of SS.After it reached the peak concentration,the leaching concentration decreased with the content of SS.The leachability of all elements concerned in this study was below 0.5%.The carbonate generated from the MICP process contributed to the low leachability of metals.After bio-modified by MICP process,the leaching concentrations of Ba from TCLP,SPLP and WLT tests were below 2.0 mg/L,which was the limit in drinking water regulated by U.S.EPA.The concentrations of Cu leached out from MICP-treated SS-sand samples were below 1.3 mg/L which is the limit regulated by national secondary drinking water.Compared with the regulations of U.S.EPA and Mississippi Department of Environment Quality(MDEQ),MICP-treated samples were classified as non-hazardous materials with respects to the leaching of metals.Meanwhile,maximum contaminant limits regulated by U.S.EPA states that MICP-treated SS are eco-friendly materials that can be reused as construction materials.
基金supported by two funds from the Department of Land and Resources of Hebei Province,China(Grant Nos.HEBEIGT2006ZT and HEBEIGT2008-2903)two grants from the Ministry of Science and Technology,China(Grant Nos.2008BAJ08B14 and 2007FY110300-03)
文摘By use of a shorehne-change numerical model （GENESIS） based on one-line theory, a preliminary modeling study on shoreline changes caused by a beach nourishment project in Beidaihe, China, is presented in this paper. Firstly, the GENESIS model is verified and model sensitivity to the major parameter changes is discussed by simulating a hydraulic model test. The beach nourishment project, after that the shoreline change is kept being monitored, is a small-scale emergency one carried out to use two bathing places on the west beach in the summer, 2008. In this paper the shoreline changes caused by the beach nourishment project are modeled by the GENESIS model, and the computed results fit well with the measured shorelines. With the same model and parameters, a long-term performance of the project is predicted, and the result shows that the bathing places only can be suitable for bathing in 2 to 3 years without subsequence nourishment project. Therefore, it is proposed to nourish the beaches in time to keep the service life of the beach in recent years and carry out the beach nourishment project for the whole west beach as soon as possible.
基金financial support from Natural Science Foundation of Shenzhen University(Grant No.2017004)Shenzhen Science and Technology Research Grant(Grant No.JCYJ20170818142354137)+2 种基金Natural Science Foundation of Guangdong Province(Grant No.2018A030310420)Guangdong Research Center for Interfacial Engineering of Functional MaterialsNational Natural Science Foundation of China(Grant Nos.51773118,51202150,and 51272161)
文摘Many hybrid electrodes for supercapacitors(SCs)are a reckless combination without proper structural design that keeps them from fulfilling their potential.Herein,we design a reduced graphene oxide/poly(3,4-ethylenedioxythiophene)/polyaniline(RGO/PEDOT/PANI)hybrid with hierarchical and porous structure for high-performance SCs,where components fully harness their advantages,forming an interconnected and conductive framework with substantial reactive sites.Thus,this hybrid achieves a high capacitance of 535 F g^−1 along with good rate capability and cyclability.The planar SC based on this hybrid deliver an energy density of 26.89 Wh kg^−1 at a power density of 800 W kg^−1.The linear SC developed via modifying a cotton yarn with the hybrid exhibits good flexibility and structural stability,which operates normally after arbitrary deformations.This work provides a beneficial reference for developing SCs.
基金supported by NSF-SBIR grant # IIP-0823040NSF-CREST Program with grant # HRD-0833178Strengthening the Environmental Science Ph.D Program in instruction, grant # P031B090210-11
文摘The effect of a terrestrial humic acid （HA） and Suwannee River HA on the cytotoxicity of engineered zinc oxide nanoparticles （ZnONPs） and titanium dioxide nanoparticles （TiO2NPs） to natural aquatic bacterial assemblages was measured with spread plate counting. The effect of HA （10 and 40 ppm） on the cytotoxicity of ZnONPs and TiO2NPs was tested factorially in the presence and absence of natural sunlight （light irradiation （LI））. The experiment was of full factorial, completely randomized design and the results were analyzed using the General Linear Model in SAS analytical software. The method of least squares means was used to separate the means or combinations of means. We determined the mechanism of toxicity via measurements of oxidative stress and metal ions. The toxicity of ZnONPs and TiO2NPs to natural aquatic bacterial assemblages appears to be concentration dependent. Moreover, the cytotoxicity of ZnONPs and TiO2NPs appeared to be affected by HA concentration, the presence of sunlight irradiation, and the dynamic multiple interactions among these factors. With respect to light versus darkness in the control group, the data indicate that bacterial viability was inhibited more in the light exposure than in the darkness exposure. The same was true in the HA treatment groups. With respect to terrestrial versus Suwanee River HA for a given nanoparticle, in light versus darkness, bacterial viability was more inhibited in the light treatment groups containing the terrestrial HA than in those containing Suwanee River HA. Differences in the extent of reactive oxygen species formation, adsorption/binding of ZnONPs/TiO2NPs by HA, and the levels of free metal ions were speculated to account for the observed cytotoxicity. TEM images indicate the attachment and binding of the tested nanoparticles to natural bacterial assemblages. Besides the individual parameter, significant effects on bacterial viability count were also observed in the following combined treatments： HA-ZnONPs, HA-LI, ZnONPs-LI
文摘While various prior studies have delved into the potential consequences of climate change on crop production in specific areas, notably in southeastern Louisiana, limited investigation has been carried out concerning some crops within the state of Louisiana. Consequently, there exists a dearth of knowledge regarding the specific hurdles and potential benefits confronting agricultural producers in this region. Therefore, the primary aim of this study was to explore and measure the impact of climate change on the yields of corn, rice, soybeans, and cotton in Louisiana, thereby addressing this informational void. The study uses data on average high temperatures and precipitation to assess the impact of climate change on these specific food crops in Louisiana. The researchers used ArcGIS and its symbology tool to create three separate maps depicting the spatial distribution of harvested cropland in Louisiana. The graduated color option was used on each map, which represented the years 2007, 2012, and 2017. Similarly, eight separate maps were created using the graduated color option to visually present the distribution patterns of Louisiana’s corn, cotton, rice, and soybean crops. These maps provided a visual representation of the state’s total crop production between 2007 and 2017. The researchers also created six bar charts to show the distribution of corn, cotton, rice, and soybean production in Louisiana over three time periods: 2007, 2012, and 2017. These charts also included information about the average high temperature and annual precipitation in each parish. The study revealed decreasing trends in Louisiana corn and cotton yields alongside consistent increases in rice and soybean yields, with projections suggesting future temperature rises may negatively impact crop yields, highlighting the need for research into climate-smart agricultural practices to mitigate these effects and safeguard global crop production. Louisiana’s response to climate change in food crop production involves implementing a compr
文摘This study explores the intricate relationship between population growth and water resource management in Louisiana, emphasizing the spatial distribution of water quality. Human activities, particularly urbanization, have significantly impacted the state’s water resources, with population growth driving increased water withdrawals for public supply, industry, and power generation. By employing a Geographic Information System (GIS)-centered approach, this research utilizes Louisiana’s census data from 1999 to 2020 to illustrate population shifts and their effects on water resource distribution. The study also incorporated advanced remote sensing techniques, using Sentinel 2 imagery to assess the water quality through the Trophic State Index (TSI). The TSI, calculated based on the near-infrared (NIR) and Red bands of Sentinel-2 imagery, provided a nuanced understanding of the nutrient levels and clarity/ quality of water bodies across the state. The study reveals a significant correlation between population density and water withdrawals, with higher populations leading to greater extraction from both groundwater and surface water sources. For instance, densely populated parishes like East Baton Rouge and Orleans showed substantially higher water withdrawals for public supply, industry, and power generation compared to less populated areas. The water quality analysis indicated that many water bodies in Louisiana are experiencing high levels of nutrient enrichment, with rivers and streams accounting for 86% of the impaired water bodies, and lakes, reservoirs, and coastal waters showing hypereutrophic conditions in up to 96% of cases. These results underscore the significant impact of human activities on Louisiana’s water resources, highlighting the need for effective water management practices that consider both quantity and quality. The study therefore advocates for the implementation of water conservation measures, responsible consumption, and pollution prevention strategies to ensure the sustainable use of w
文摘Louisiana possesses a bountiful groundwater reserve, an invaluable and noteworthy asset. Despite extensive literature on climate change implications in Louisiana, there is limited academic research focused on its effects on the state’s water resources. Therefore, this study addresses that gap by using GIS to spatially analyze water usage trends from 1960 to 2014, to examine climate-induced consequences and determine the susceptibility of water utilities’ functions and facilities. This study utilized various online sources to gather data on water withdrawals, temperature trends, and climate impacts in Louisiana. Water usage data from the Lower Mississippi Gulf-Water Science Centre and temperature trends from Meteoblue covering 2023 were also analyzed to assess the state’s water resource challenges. The water withdrawal data was linked to a shapefile within ArcMap, using graduated color symbology to visualize regional variations in water usage. This method highlighted significant water withdrawals across Louisiana from 1960 to 2014, clearly illustrating the differences between regions. Based on the data sources, the results show that groundwater levels in Louisiana have steadily declined over time. For instance, water levels in the Jasper Aquifer in St. Tammany dropped from approximately 125 feet to 50 feet, while levels in the Sparta Aquifer in Lincoln fell from 30 feet to −25 feet. Similarly, the Chicot Aquifer in Acadia experienced a decline from −25 feet to −50 feet. These reductions indicate a concerning trend of groundwater depletion, exacerbated by high temperatures and current drought conditions affecting roughly 73% of the state. To ensure sustainable water management in Louisiana, investing in water storage, transfer infrastructure, and conservation practices are needed to protect surface and groundwater sources. More so, the state’s Reservoir Priority and Development Program (RPDP), which includes the construction of reservoirs, is a key initiative that can address water scarcity, improve w
基金supported by the National Science Foundation-Centers of Research Excellence in Science and Technology (NSF-CREST) (No. HRD-0833178)the National Institutes of Health (NIH) Research Initiative for Scientific Enhancement (RISE) Program (No. 5R25GM067122)
文摘Titanium dioxide nanoparticles （TiO2 NPs） are among the most widely manufactured nanomaterials on a global scale. However, prudent and vigilant surveillance, incumbent upon the scientific community with the advent of new technologies, has revealed potentially undesirable effects of TiO2 NPs on biological systems and the natural environment during their application and discharge. Such effects are likely best evaluated by first assessing the fate of the TiO2 NPs in natural environments. In this study, the effects of terrestrial humic acid （HA） and tannic acid （TA）, two major members of the collective： dissolved organic matter （DOM）, on the cytotoxicity of TiO2 NPs to Escherichia coli were investigated in the presence and absence of natural sunlight. Qualitative （transmission electron microscopy （TEM）） and quantitative （LCso） analyses were employed in this study. In addition, the production of reactive oxygen species （ROS） in the form of .OH was further assessed-as HA or TA increased the production of ROS decreased. The inhibition of bacterial viability in the light treatment groups, with respective treatment organics at concentrations of 10 ppm, was less in TA than in terrestrial HA. SAS was used to analyze the treatment effect of individual factors of light irradiation, DOM, and concentration of TiO2 NPs.
文摘BACKGROUND Patients with acute pancreatitis(AP)frequently experience hospital readmissions,posing a significant burden to healthcare systems.Acute peripancreatic fluid collection(APFC)may negatively impact the clinical course of AP.It could worsen symptoms and potentially lead to additional complications.However,clinical evidence regarding the specific association between APFC and early readmission in AP remains scarce.Understanding the link between APFC and readmission may help improve clinical care for AP patients and reduce healthcare costs.AIM To evaluate the association between APFC and 30-day readmission in patients with AP.METHODS This retrospective cohort study is based on the Nationwide Readmission Database for 2016-2019.Patients with a primary diagnosis of AP were identified.Participants were categorized into those with and without APFC.A 1:1 propensity score matching for age,gender,and Elixhauser comorbidities was performed.The primary outcome was early readmission rates.Secondary outcomes included the incidence of inpatient complications and healthcare utilization.Unadjusted analyses used Mann-Whitney U andχ2 tests,while Cox regression models assessed 30-day readmission risks and reported them as adjusted hazard ratios(aHR).Kaplan-Meier curves and log-rank tests verified readmission risks.RESULTS A total of 673059 patients with the principal diagnosis of AP were included.Of these,5.1%had APFC on initial admission.After propensity score matching,each cohort consisted of 33914 patients.Those with APFC showed a higher incidence of inpatient complications,including septic shock(3.1%vs 1.3%,P<0.001),portal venous thrombosis(4.4%vs 0.8%,P<0.001),and mechanical ventilation(1.8%vs 0.9%,P<0.001).The length of stay(LOS)was longer for APFC patients[4(3-7)vs 3(2-5)days,P<0.001],as were hospital charges($29451 vs$24418,P<0.001).For 30-day readmissions,APFC patients had a higher rate(15.7%vs 6.5%,P<0.001)and a longer median readmission LOS(4 vs 3 days,P<0.001).The APFC group also had higher readmission charges($28
