Akumulacija i specijacija kadmija, cinka i olova u tlu na području rudarenja olova i cinka

An exploratory study on soil contamination of Cd, Zn, Pb was carried out in the surroundings of a historical, abandoned Pb-Zn mining area in Hunan Province, China. The accumulation in soils and representative plants of Cd, Zn, Pb and their chemical speciation were investigated. The obtained results indicated that Cd, Zn and Pb presented a significant contamination compared with Environmental Quality Standards for Soils in China (GB 15618-1995). The geoaccumulation index suggested the degree of contamination: Pb > Cd > Zn. The modified BCR sequential extraction results showed that Cd, Zn, and Pb exist in soil in a relatively unstable form, and will exert a bad effect on the plants grown in the soil. Heavy metals in oranges collected in the sampling area were tested to identify the extent of pollution. The results confirmed that the sampled oranges were polluted with Pb, which exceeded the national food safety standard by 3.4 – 6.3 times. Heavy metals in branches and leaves showed different accumulation characteristics than the fruits. This work is licensed under a Creative Commons Attribution 4.0 International License.Istražena je kontaminacija kadmijem, cinkom i olovom oko napuštenog područja rudarenja olova i cinka u kineskoj pokrajini Hunan. Proučena je akumulacija u tlu i reprezentativnim biljkama te kemijska specijacija teških metala. U usporedbi sa standardima GB15618-1995 zabilježena je značajna kontaminacija kadmijem, cinkom i olovom. Prema geokemijskom indeksu razina kontaminacije slijedi niz Pb > Cd > Zn. Modificirana sekvencijska ekstrakcija prema BCR-u pokazuje da se teški metali u tlu nalaze u obliku relativno nestabilnih oblika i da će nepovoljno utjecati na biljni svijet. Zagađenje je ispitano na uzorcima naranči iz istraživanog područja. Naranče su kontaminirane olovom, a sadržaj olova veći je od 3,4 do 6,3 puta od razine koju dopuštaju nacionalni standardi za sigurnost hrane. Akumulacija teških metala u lišću i granama pokazuje drugačije karakteristike. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Contemporary survival and anticoagulation of patients with atrial fibrillation: A community based cohort study in China

BackgroundsThe understanding of death in patients with atrial fibrillation (AF) in China is limited. This study aimed to assess the contemporary survival of AF patients in China and to explore risk factors for deaths.MethodsThis was a prospective community-based cohort study including 559 AF patients, who were followed-up from July 2015 to December 2020.ResultsDuring 66-month follow-up, there were 200 deaths (56.5% cardiovascular, 40.0% non-cardiovascular, and 3.5% unknown causes) among 559 AF patients with the median age of 76 years. The top three causes of death were heart failure (33.0%), ischemic stroke (17.0%) and cancer (16.5%). Multivariate Cox regression analysis indicated baseline variables positively associated with all-cause death were age (HR: 1.10, 95% CI: 1.08–1.13), AF subtype (HR: 1.37, 95% CI: 1.08–1.73), prior myocardial infarction (HR: 3.40, 95% CI: 1.48–7.78), previous tumor (HR: 2.61, 95% CI: 1.37–4.98), hypoglycemic therapy at baseline (HR: 1.81, 95% CI: 1.13–2.91), but body weight (HR: 0.98, 95% CI: 0.97–1.00) and use of calcium channel blocker (CCB) (HR: 0.62, 95% CI: 0.41–0.95) played a protective role to all-cause death. Of patients who were alive at the end of follow-up, 24.0% were on oral anticoagulants (OAC) alone, 4.5% on dual antithrombotic therapy, 33.1% on antiplatelet agents alone and 38.4% weren't on any antithrombotic medication.ConclusionIschemic stroke still remains one of the leading causes of death and OAC is seriously underused in AF patients in China. Independent risk factors for death are age, AF subtype, previous tumor, prior myocardial infarction, hypoglycemic therapy, low body weight and no CCB use.Clinical Trial Registrationhttp://www.chictr.org.cn/ (ChiCTR-ICR-15007036)

Risk Assessment of Heavy Metals in Soils of a Lead-Zinc Mining Area in Hunan Province (China)

Eighty-two soil samples were collected, and As, Pb, Cd, Zn, Cu and Ni were analysed for their concentrations, potential ecological risks and human health risks. The average concentrations of As, Pb, Cd and Zn exceeded their corresponding limits prescribed by the Chinese National Soil Environmental Quality Standard III, while Cu and Ni were far less than prescribed. The potential ecological risk index results indicated that Cd showed severe potential ecological risk. The human health risk assessment indicated that 80.49 % of the soil samples expressed acceptable non-carcinogenic risks, while 19.51 % of the soil samples expressed unacceptable non-carcinogenic risks. The research area represents unacceptable carcinogenic risks, the major contributor of the risk being As. Of the soil samples, 34.15 % posed acceptable carcinogenic risks, and 65.85 % posed unacceptable carcinogenic risks

Superimposed features and deformation mechanism of Early Mesozoic folds in the Sangzhi-Shimen area, northern Hunan

A series of Jurassic-type folds have continuously developed in the Mesozoic from the Sangzhi-Shimen area in northern Hunan. The analysis of the fold superimposition characteristics is of great significance to explore the deformation period and deformation mechanism of the Sangzhi-Shimen complex oblique folds, and also for the theoretical study of fold deformation controlled by faults. Based on the measurement of geological structure section and analysis of fold superimposition characteristics in Sangzhi-Shimen area, two fold structures in Indosinian and early Yanshanian were identified. The low-angle unconformity contact between the Jurassic and the Middle Triassic in the study area, and the high-angle unconformity contact between the Cretaceous and the Pre-Cretaceous reflect two deformation events of Indosinian and Early Yanshanian movement. It can be further inferred that the folds in the Sangzhi-Shimen area can be divided into two phases: the Indosinian movement and the early Yanshanian movement.The Indosinian fold axial trace mainly showed NEE to near EW; the early Yanshanian fold axial trace can be divided into two groups, one is NEE-near EW, the other is NNE. Two groups of early Yanshanian folds and pre Indosinian folds are superimposed to form two types of superposed folds, the enhanced type and the oblique limited type. The former is controlled by the inherited activities of the Indosinian NEE-near EW reverse fault; the latter is controlled by NNE trending reverse fault, which formed by NWW trending regional compressive stress in early Yanshanian, and it is limited by the pre NEE-near EW trending structure.This deformation mechanism well explains that the fold axis and thrust fault in the study area have no east or Southeast inclined polarity