Effects of heavy metal pollution on farmland soils and crops:A case study of the Xiaoqinling Gold Belt,China

This paper focuses on the heavy metal enrichment and heavy metal pollution degree associated with mining activities in some crops and the soils of different parent materials in the Xiaoqinling Gold Belt.According to the geochemical analysis results of the soils observed in the gold belt,the soils are most highly enriched in Pb,followed by Cr,Cu,and Zn.Furthermore,they are relatively poor in Hg,Cd,and As.It is also shown that the heavy metals in all kinds of soils have the same geochemical characteristics in the gold belt.As for the crops(such as corn and wheat)in the gold belt,Zn and Cu are the most abundant elements,followed by Pb and Cr.Meanwhile,Hg,Cd,and As were found to have relatively low concentrations in the crops.The heavy metals in wheat and corn have the same geochemical characteristics in the gold belt in general.Compared to the aeolian loess soils and the crops therein,heavy metals are more enriched in diluvial and alluvial soils and the crops therein.As shown by relevant studies,the Hg,Pb,Cd,Cu,and Zn pollution are mainly caused by mining activities.Corn and wheat in the gold belt have a high tendency of risk exposure to heavy metal pollution since they are mostly affected by mining activities and feature high background values of heavy metal concentrations.Furthermore,wheat is more liable to be enriched in heavy metals than corn is grown in all types of soils.The Hg pollution in soils leads to Hg accumulation,increasing the risk of Hg uptake in crops,and further affecting human health.This study will provide a scientific basis for the control and management of heavy metals in farmland soils of mining areas.

Atomic layer deposition of ultrafine Pd nanoparticles for enhancing the rate capability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode

Atomic layer deposition(ALD)technology has been adopted to obtain the ultrathin coating layer on the surface of LiNi_(x)Co_(y)Mn_(z)O_(2)(NCM)cathode materials.However,the as-reported coating materials usually form dense film layers and present low electronic conductivity,leading to poor electrochemical kinetics.Herein,the ultrafine Pd nanoparticles(~5 nm)with superior electronic conductivity are successfully deposited on the surface of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)particles by ALD technology.Benefiting from its high electrical conductivity,intrinsic electrochemical inertia to Li+and HF,unique point coating,and the interfacial Pd-O bond,the coating of ultrafine Pd nanoparticles significantly weakens the electrochemical polarization and enhances the rate capability of NCM811 cathode.The capacity retention ratio at 1 C after 100 cycles reaches 84.6%,and the capacity of 153.5 mA·h·g^(−1) is realized at 5 C.Further research finds that the battery with the coating layer of 5 deposition cycles has a better electrochemical performance than the batteries with 2 and 8 deposition cycles.This work enriches the application of ALD technology in the surface modification of electrode materials and broadens the mind of electrochemical performance enhancement.

Establishment of a predictive model for inpatient sudden cardiac death in a Chinese cardiac department population:a retrospective study

Background:Little is known about the risk factors for sudden cardiac death (SCD) in the overall hospitalized cardiac department population.This study was conducted to investigate the risk factors and develop a predictive model for SCD in a hospitalized cardiac department population.Methods:We conducted a retrospective study of patients admitted to the cardiac department of the First Affiliated Hospital of Xinjiang Medical University from June 2015 to February 2017.We collected the clinical data from medical records.Multiple stepwise logistic regression analysis was carried out to confirm the risk factors for SCD and develop a predictive risk model.The risk score was assessed by the area under receiver operating characteristic (AUROC) curve and the Hosmer-Lemeshow goodness-of-fit test.Results:A total of 262 patients with SCD and 4485 controls were enrolled in our study.Logistic regression modeling identified eight significant risk factors for in-hospital SCD:age,main admitting diagnosis,diabetes,corrected QT interval,QRS duration,ventricular premature beat burden,left ventricular ejection fraction,and estimated glomerular filtration rate.A predictive risk score including these variables showed an AUROC curve of 0.774 (95% confidence interval:0.744–0.805).The Hosmer-Lemeshow goodness-of-fit test showed the chi-square value was 2.527 (P= 0.640).The incidence of in-hospital SCD was 1.3%,4.1%,and 18.6% for scores of 0 to 2,3 to 5 and ≥6,respectively (P<0.001).Conclusions:Age,main admitting diagnosis,diabetes,QTc interval,QRS duration,ventricular premature beat burden,left ventricular ejection fraction,and estimated glomerular filtration rate are factors related to in-hospital SCD in a hospitalized cardiac department population.We developed a predictive risk score including these factors that could identify patients who are predisposed to in-hospital SCD.

Ventricular tachycardia as the initial symptom of cardiac hydatidosis

To the Editor:A 44-year-old female presented at the local hospital for repeated episodes of having palp Nations,accompanied with cold sweats,amaurosis,vomiting,and limb weakness in the previous 2 months.An electrocardiogram indicated "ventricular tachycardia" when she was not feeling well.The symptoms alleviated significantly after injections of"amiodarone"(dose unknown),after which the patient was discharged.A local physician recommended ablation,so the patient was transferred to our hospital.The patient was generally healthy and had lived in a region with pastures.According to the patient5 self-report,she had been diagnosed as having liver hydatidosis 30 years ago,but had recovered after surgical treatment at the local hospital.Furthermore,the patient claimed to have no other medical history.