Effects of copper mining on heavy metal contamination in a rice agrosystem in the Xiaojiang River Basin, southwest China

Metallic ore mining causes heavy metal pollution worldwide.However,the fate of heavy metals in agrosystems with long-term contamination has been poorly studied.Dongchuan District(Yunnan,southwest China),located at the middle reaches of the Xiaojiang River,is a well-known 2000-year-old copper mining site.In this work,a survey on soil heavy metal contents was conducted using a handheld X-ray fluorescence instrument to understand the general contamination of heavy metals in the Xiaojiang River Basin.Furthermore,river water,soil,and rice samples at six sites along the fluvial/alluvial fans of the river were collected and analyzed to implement an environmental assessment and an evaluation of irrigated agrosystem.V,Zn,and Cu soil levels(1724,1047,and 696mg·kg-1,respectively)far exceeded background levels.The geo-accumulation indexes(Igeo)showed that cultivated soils near the mining sites were polluted by Cd and Cu,followed by Zn,V,Pb,Cr,Ni,and U.The pollution index(Pi)indicated that rice in the area was heavily polluted with Pb,Cr,Cd,Ni,Zn,and Cu.The difference in orders of metal concentrations between the soil and rice heavy metal contamination was related to the proportion of bioavailable heavy metals in the soil.The crop consumption risk assessment showed that the hazard quotient exceeded the safe threshold,indicating a potential carcinogenic risk to consumers.The Nemerow integrated pollution index and health index indicated that the middle of the river(near the mining area)was the heaviest polluted site.

Influence of two inlets of the Luzon overflow on the deep circulation in the northern South China Sea

An inverse reduced-gravity model is used to simulate the deep South China Sea(SCS)circulation.A set of experiments are conducted using this model to study the influence of the Luzon overflow through the two inlets on the deep circulation in the northern SCS.Model results suggest that the relative contribution of these inlets largely depends on the magnitude of the input transport of the overflow,but the northern inlet is more efficient than the southern inlet in driving the deep circulation in the northern SCS.When all of the Luzon overflow occurs through the northern inlet the deep circulation in the northern SCS is enhanced.Conversely,when all of the Luzon overflow occurs through the southern inlet the circulation in the northern SCS is weakened.A Lagrangian trajectory model is also developed and applied to these cases.The Lagrangian results indicate that the location of the Luzon overflow likely has impacts upon the sediment transport into the northern SCS.

Darbepoetin alfa injection versus epoetin alfa injection for treating anemia of Chinese hemodialysis patients with chronic kidney failure:A randomized,open-label,parallel-group,non-inferiority Phase III trail

Background:Erythropoietin is a glycoprotein that mainly regulates erythropoiesis.In patients with chronic renal failure with anemia,darbepoetin alfa can stimulate erythropoiesis,correct anemia,and maintain hemoglobin levels.This study was designed to demonstrate the efficacy and safety of darbepoetin alfa injections as being not inferior to epoetin alfa injections(Recombinant Human Erythropoietin injection,rHuEPO)when maintaining hemoglobin(Hb)levels within the target range(10.0-12.0 g/dL)for the treatment of renal anemia.Methods:Ninety-five patients were enrolled in this study from April 15,2013 to April 10,2014 at 25 sites.In this study,patients(n=95)aged 18-70 years were randomized into a once per week intravenous darbepoetin alfa group(n=56)and a twice or three times per week intravenous epoetin alfa group(n=39)for 28 weeks,who had anemia with hemoglobin levels between 6 g/dL and 10 g/dL due to chronic kidney disease(CKD)and were undergoing hemodialysis or hemofiltration with ESA-naive(erythropoiesis stimulating agent-naive).The primary efficacy profile was the mean Hb level(the non-inferiority margin was-1.0 g/dL,week 21-28);the secondary efficacy profiles were the Hb increase rate(week 0-4),the target Hb achievement cumulative rate and time,the change trends of the Hb levels,and the target Hb maintenance ratio.Adverse events(AEs)were observed and compared,and the efficacy and safety were analyzed between the two treatment groups.Additionally,the frequencies of dose adjustments between the darbepoetin alfa and epoetin alfa groups were compared during the treatment period.SAS?software version 9.2 was used to perform all statistical analyses.Descriptive statistics were used for all efficacy,safety,and demographic variable analyses,including for the primary efficacy indicators.Results:The mean Hb level was 11.3 g/dL in the darbepoetin alfa group and 10.7 g/dL in the epoetin alfa group,respectively;the difference of the lower limits of the 95%confidence intervals(CI)between the two groups was 0.1 g/dL(>-1.0 g/dL),and non-inferiority was proven;the Hb levels started to increase in the first four weeks at a similar increase rate;no obvious differences were observed between the groups in the target Hb achievement cumulative rates,and the Hb levels as well as the target Hb level maintenance rate changed over time.The incidence of AEs was 62.5%in the darbepoetin alfa group and 76.9%in the epoetin alfa group.All the adverse events observed in the study were those commonly associated with hemodialysis.Conclusion:Darbepoetin alfa intravenously once per week can effectively increase Hb levels and maintain the target Hb levels well,which makes it not inferior to epoetin alfa intravenously twice or three times per week.Darbepoetin alfa shows an efficacy and safety comparable to epoetin alfa for the treatment of renal anemia.

Efficacy and safety of darbepoetin alfa injection replacing epoetin alfa injection for the treatment of renal anemia in Chinese hemodialysis patients:A randomized,open-label,parallel-group,noninferiority phase III trial

Background:This study was to explore the clinical efficacy and safety of darbepoetin alfa injection replacing epoetin alfa injection(recombinant human erythropoietin injection,rHuEPO)for the treatment of anemia associated with chronic kidney failure in Chinese patients undergoing hemodialysis.Method:This study was a multicenter,randomized,open-label,intergroup parallel control phase III noninferiority trial from April 19,2013 to September 9,2014 at 25 sites.In this study,the members of the darbepoetin alfa group underwent intravenous administration once per week or once every two weeks.The members of the control drug epoetin alfa group underwent intravenous administration two or three times per week.All subjects underwent epoetin alfa administration during the 8-week baseline period.After that,subjects were randomly assigned to the darbepoetin alfa group or epoetin alfa group.The noninferiority in the changes of the average Hb concentrations from the baseline to the end of the evaluation period(noninferiority threshold:-1.0 g/dl)was tested between the two treatments.The time-dependent hemoglobin(Hb)concentration and the maintenance rate of the target Hb concentration(the proportion of subjects with Hb concentrations between 10.0 and 12.0 g/dl)were also evaluated.Iron metabolism,including changes in the serum iron,total iron-binding capacity,ferritin,transferrin saturation,and comparisons of the dose adjustments between the two groups during the treatment period were analyzed further.Adverse events(AEs)were also observed and compared,and the safety was analyzed between the two treatment groups.The conversion rate switching from epoetin alfa to darbepoetin alfa was also discussed.SAS?software version 9.2 was used to perform all statistical analyses.Descriptive statistics were used for all efficacy,safety,and demographic variable analyses,including for the primary efficacy indicators.Results:Four hundred and sixty-six patients were enrolled in this study,and ultimately 384 cases were analyzed for safety,including 267 cases in the darbepoetin alfa group and 117 cases in the epoetin alfa group.There were 211 cases in the per-protocol set,including 152 cases in the darbepoetin alfa group and 59 cases in the epoetin alfa group.The changes in the average Hb concentrations from the baseline to the end of the evaluation period were-0.07 and-0.15 g/dl in the darbepoetin alfa group and epoetin alfa group respectively.The difference between the two groups was 0.08 g/dl(95%confidence interval[CI]:-0.22 to 0.39),and the lower limit of the 95%CI was-0.22>-1.0 g/dl.The average Hb concentrations of the two groups were 10.88-11.43 g/dl(darbepoetin alfa)and 10.91-11.38 g/dl(epoetin alfa)during the study period of Weeks 0-28,with the maintenance rates of the target Hb concentration ranging within 71%-87%and 78%-95%in the darbepoetin alfa group and epoetin alfa group respectively.During the period of comparison between the two groups,the incidence of AEs in the darbepoetin alfa group was 61.42%,while in the epoetin alfa group it was 56.41%.All of the adverse events and reactions in the study were those commonly associated with hemodialysis.Conclusion:The overall efficacy and safety of darbepoetin alfa for the treatment of Chinese renal anemia patients undergoing hemodialysis are consistent with those of epoetin alfa.

Distribution characteristics and source tracing of petroleum hydrocarbons in the northeastern South China Sea

In recent years,oil spills caused by human activities have occurred frequently,and the resultant oil pollution has received extensive attention worldwide.In this paper,a total of 50 water samples were collected from the northeastern part of the South China Sea,and total petroleum hydrocarbons(TPHs)and n-alkane content in the samples were analyzed by gas chromatography-flame ionization detector(GC-FID)technology.The petroleum hydrocarbon characteristic indices,such as carbon predominance index(CPI)and terrigenous/aquatic ratio(TAR),were calculated to trace the source of petroleum hydrocarbons.The measured value of TPHs ranged from 121.31-603.02μg/L.For surface waters,the TPHs in the no rthern coastal waters and the central waters were higher than that in the far shore.For ve rtical waters,the TPHs sharply decreased at first,and then increased slowly and finally reached a steady state.The n-alkanes in the water samples were concentrated in C10-C38,and they were mainly from terrestrial higher plant.The waters in the near shore,mid-layer and deep sea showed a strong reducing terrestrial characteristic,while the surface waters in the open sea showed an obvious oxidizing endogenous characteristic.

Prospective study of the short-term effect of 1.75 mmol/L calcium concentration dialysate on hemodialysis patients

Objective:The purpose of the current study was to determine the influence of a 1.75 mmol/L calcium(Ca)concentration dialysate(DCa 1.75)during maintenance hemodialysis(MHD)therapy for patients with chronic kidney disease,mineral,and bone disorders(CKD-MBD)on biochemical indices and clinical prognosis.Methods:Four hundred eighty-three MHD patients from three hemodialysis centers were en-rolled.During 24 months of follow-up(January 2011 to December 2012),289 patients from Center 1 who used 1.50 mmol/L Ca concentration dialysate(Dca 1.50)between January and December 2011 and DCa 1.75 between January and December 2012 were included in the high Ca group.The remaining 194 patients from the other centers who used DCa 1.50 for hemodialysis between January 2011 and December 2012 were included in the ordinary Ca group.The following CKD-MBD biochemical indices were monitored:blood Ca;blood phosphorus(P);intact parathyroid hormone(iPTH);and bone-specific alkaline phosphatase(BAP).The metastatic calcification index included calcification of aortic arch scoring(AoACS),abdominal aorta calcification(AAC),and cardiac valve calcification(CVC).The study end points included all-cause mortality(ACM),car-diovascular and cerebrovascular diseases(CCVDs),fractures,and new metastatic calcifications.The changes between the two groups in the observed indices were compared.Results:Two hundred eighty-four patients in the high Ca group(98.3%)and 194 patients in the ordinary Ca group(100.0%)completed an average follow-up of 21.3±5.6 months.After DCa 1.75 was used,the blood Ca in the high Ca group increased[(2.39±0.22)mmol/L vs.(2.34±0.21)mmol/L,t=-2.910,P=0.004]compared to the previous year,and increased[(2.39±0.22)mmol/L vs.(2.30±0.16)mmol/L,t=5.187,P<0.001]compared to the ordinary Ca group in the same year.The blood P and iPTH decreased[(1.78±0.39)mmol/L vs.(1.89±0.42)mmol/L,t=2.909,P=0.004 and(306.5±298.6)pg/ml vs.(425.7±365.1)pg/ml,t=8.377,P<0.001,respectively]compared with the previous year,and decreased[(1.78±0.39)mmol/L vs(1.86±0.39)mmol/L,t=-2.016,P=0.044 and(306.5±298.6)pg/ml vs.(366.6±341.0)pg/ml,t=-2.113,P=0.035,respectively]compared with the ordinary Ca group in the same year.There was no difference in AoACS between the two groups before and after the change in DCa in the high Ca group(P>0.05).In 2011,there was 13 CCVDs,2 fractures,and 13 new metastatic calcifications in the ordinary Ca group compared to 8 CCVDs,3 fractures,and 16 new metastatic calcifications in the high Ca group;there were no statistically significant differences in the incidence of end point events between the two groups(χ^(2)=2.747,P=0.098).In 2012,the values for the ordinary Ca group were 13,2,and 15,respec-tively,while the values for the high Ca group were 8,1,and 19,respectively,which indicated a statistically significant difference in the incidence of end point events between the two groups(χ^(2)=4.391,P=0.036).Conclusion:Short-term use of DCa 1.75 significantly reduced the blood P and iPTH levels in MHD patients,significantly increased the blood Ca level,did not increase the proportion of new cardiovascular calcifications,and decreased the overall inci-dence of end point events.