Enhanced bioelectricity generation by double-chamber air-cathode catalyst-free microbial fuel cells with addition of non-consumptive vanadium (V)

Improvement of microbial fuel cells (MFCs) via bioelectricity recovery is urgently needed in micro-energy devices nowadays.</p

Vanadium Contamination and Associated Health Risk of Farmland Soil near Smelters throughout China

Whereas there is broad consensus that smelting causes serious soil contamination during vanadium production, little is known about the vanadium content of soil near smelters and the associated health risk at continental scale. This study is the first to map the distribution of vanadium in farmland soil surrounding smelters throughout mainland China, and assess the associated health risk. Analysis of 76 samples indicated that the average vanadium content in such soil was 115.5 mg/kg - far higher than the 82 mg/kg background content in China (p < 0.05). Southwest China (198.0 mg/kg) and North China (158.3 mg/kg) possessed highest vanadium contents. Vanadium content was strongly related to longitude, altitude, and atmospheric temperature. The reducible fraction accounted for the largest percentages in vanadium speciation. The average Pollution Load Index for all samples was 1.51, denoting significant metal enrichment. The Children's hazard index was higher than unity, indicating elevated health risk. The relative contribution of vanadium to the total health risk ranged from 6.02% to 34.5%, while nickel and chromium were the two main contributors in most regions. This work may serve as a model providing an overview of continental vanadium contamination around smelters, and draw attention to their possible health risks

Chemical synthesis and characterization of zinc borohydride

AbstractMetal borohydrides have received increasing research interests on account of their high hydrogen storage capacities. In this paper, zinc borohydride Zn(BH4)2 was synthesized using NaBH4 and ZnCl2 in THF under room temperature for 72h, and the crystallographic constitution of the synthesized products were analyzed by XRD. The results showed that the major phase of the products was NaCl, alternatively, NaBH4 or ZnCl2 disappeared. This concluded the formation of Zn(BH4)2. Moreover, both experiment phenomena and fired products further confirmed the synthesis of Zn(BH4)2, which a XRD pattern of Zinc borohydride was obtained

Leveraging the UAV to support Chinese Antarctic expeditions: a new perspective

Recent developments in Unmanned Aerial Vehicles (UAVs) and their applications in various subjects are of interest to polar communities. Due to the harsh climate and dangerous environment, these regions pose challenges for the expedition teams. Several countries have tested the UAV technology to support Antarctic research and logistics. In this trend paper, we provide insightful reviews and discussions on such a prospective topic. Based on a comprehensive literature survey, we firstly summarize the key research progress of UAV in Antarctic studies. Then the examples of risk scenarios during the field exploration are given, after which several promising applications of the UAVs in safety guarantee are illustrated. In particular, we present a case of site-selection for the Chinese first ice sheet airfield, using the data collected in the 34th Chinese National Antarctic Research Expedition (CHINARE). In the end, we highlight the unique value of the UAVs in the popularization of polar science before concluding the advantages and limitations. Considering their excellent performance, we expect more innovations for UAV’s applications in the following Antarctic expeditions

Efficient electrochemical oxidation of thallium (I) in groundwater using boron-doped diamond anode

Thallium (Tl) is a highly toxic element whose occurrence is widespread in soil and groundwater. The present study investigates the oxidation of Tl(I) with boron-doped diamond (BDD) anode in an electrochemical system, compared with PbO2 and carbon felt materials. Under initial conditions of Tl(I) of 10 mg L−1, pH of 2.0, and current density of 5 mA cm−2, 99.2 ± 0.9% of Tl(I) is oxidized to Tl(III) within 15 min. This process is suppressed by the increase of initial Tl(I) concentration and initial pH, respectively, while it is enhanced with the increase of current density. Compared with direct electrochemical effect, indirect electrochemical oxidation with the generated oxidants mainly contribute to the excellent performance and ·OH plays a significant role. Subsequent coagulation/precipitation realizes the nearly complete removal of total Tl in the exhaust electrolyte and the quality of the effluent can meet EPA drinking water standards. Analysis of the generated precipitate further indicates that Tl(III) is the main oxidation state of Tl. This study offers a potentially attractive method for remediation of Tl-polluted groundwater

Elevated Oxidative Stress and Inflammation in Hypothalamic Paraventricular Nucleus Are Associated With Sympathetic Excitation and Hypertension in Rats Exposed to Chronic Intermittent Hypoxia

Obstructive sleep apnea (OSA), characterized by recurrent collapse of the upper airway during sleep leading to chronic intermittent hypoxia (CIH), is an independent risk factor for hypertension. Sympathetic excitation has been shown to play a major role in the pathogenesis of OSA-associated hypertension. Accumulating evidence indicates that oxidative stress and inflammation in the hypothalamic paraventricular nucleus (PVN), a critical cardiovascular and autonomic center, mediate sympathetic excitation in many cardiovascular diseases. Here we tested the hypothesis that CIH elevates oxidative stress and inflammation in the PVN, which might be associated with sympathetic excitation and increased blood pressure in a rat model of CIH that mimics the oxygen profile in patients with OSA. Sprague-Dawley rats were pretreated with intracerebroventricular (ICV) infusion of vehicle or superoxide scavenger tempol, and then exposed to control or CIH for 7 days. Compared with control+vehicle rats, CIH+vehicle rats exhibited increased blood pressure, and increased sympathetic drive as indicated by the blood pressure response to ganglionic blockade and plasma norepinephrine levels. Pretreatment with ICV tempol prevented CIH-induced increases in blood pressure and sympathetic drive. Molecular studies revealed that expression of NAD(P)H oxidase subunits, production of reactive oxygen species, expression of proinflammatory cytokines and neuronal excitation in the PVN were elevated in CIH+vehicle rats, compared with control+vehicle rats, but were normalized or reduced in CIH rat pretreated with ICV tempol. Notably, CIH+vehicle rats also had increased systemic oxidative stress and inflammation, which were not altered by ICV tempol. The results suggest that CIH induces elevated oxidative stress and inflammation in the PVN, which lead to PVN neuronal excitation and are associated with sympathetic excitation and increased blood pressure. Central oxidative stress and inflammation may be novel targets for the prevention and treatment of hypertension in patients with OSA