Zinc is an essential nutrient. Genetic evidence for this nutritional requirement in humans is the zinc deficiency disease, acrodermatitis enteropathica. This disorder is caused by mutations in hZIP4 ...(SLC39A4), a zinc importer required for zinc uptake in enterocytes and other cell types. Studies in mice have demonstrated that levels of the mZIP4 mRNA are reduced by elevated dietary zinc, resulting in a decreased abundance of the ZIP4 protein at the plasma membrane. Moreover, studies in cultured cells have demonstrated that low micromolar concentrations of zinc stimulate the endocytosis of the mZIP4 protein resulting in a reduction in cellular zinc uptake. In this study, we demonstrate an additional level of hZIP4 regulation involving ubiquitination and degradation of this transporter in elevated zinc concentrations. Mutational analysis identified a cytoplasmic histidine-rich domain that was essential for ubiquitin-dependent degradation of ZIP4 and protection against zinc toxicity. However, this motif was dispensable for zinc-induced endocytosis. These findings indicate that ubiquitin-mediated degradation of the ZIP4 protein is critical for regulating zinc homeostasis in response to the upper tier of physiological zinc concentrations, via a process that is distinct from zinc-stimulated endocytosis.
Display omitted
•NiMoSx heterostructure nanorods are prepared by a two-step hydrothermal method.•NiMoSx interface promotes charge transfer through strong electron interaction.•NiMoSx nanorods exhibit ...outstanding performance towards oxygen evolution reaction.•The NiMoSx||PS-MoNi couple can reach 10 mA cm−2 at 1.48 V in 1 M KOH.
The development of electrocatalyst with efficient and stability for water oxidation is the key to enhance the efficiency of water electrolysis. Interface engineering can modify the local electronic structure of active sites, which is one of the important strategy to enhance catalytic activity. Herein, we synthesized NiMoSx heterostructure nanorods by simple hydrothermal method. The self supporting electrode of NiMoSx heterostructure nanorods grown in situ on nickel foam can reduce the indirect contact resistance between the substrate and the catalyst, and promote the timely release of bubbles produced by the oxygen evolution reaction. The heterogeneous interface in NiMoSx can provide abundant electroactive centers and optimize the adsorption energy of active intermediates. NiMoSx heterostructure nanorods showed excellent oxygen evolution catalytic activity (η100 = 279 mV, η1000 = 436 mV, Tafel slope b = 72.3 mV dec−1) and more than 200 hours of sustainable durability in 1 M KOH. When NiMoSx heterostructure nanorods are used as anode materials for water electrolysis, the electrolytic cell could obtain 10 mA cm−2 at 1.48 V. The current research results not only show that NiMoSx nanostructure is an excellent oxygen evolution electrocatalyst, At the same time, it also provides a valuable interface regulation method for the design of high-performance heterostructure electrocatalyst.
The Centers for Disease Control and Prevention (CDC) has developed an approach to ventilator-associated events (VAE) surveillance. Using these methods, this study was performed to investigate VAE ...incidences and to test whether VAEs are associated with poorer outcomes in China.
A 4-month, prospective multicenter surveillance study between April and July 2013.
Our study included 15 adult intensive care units (ICUs) of 15 hospitals in China.
Patients admitted to ICUs during the study period
Patients on mechanical ventilation (MV) were monitored for VAEs: ventilator-associated conditions (VACs), infection-related ventilator-associated complications (IVACs), and possible or probable ventilator-associated pneumonia (VAP). Patients with and without VACs were compared with regard to duration of MV, ICU length of stay (LOS), overall hospital LOS, and mortality rate.
During the study period, 2,356 of the 5,256 patients admitted to ICUs received MV for 8,438 ventilator days. Of these patients, 636 were on MV >2 days. VACs were identified in 94 cases (4.0%; 11.1 cases per 1,000 ventilator days), including 31 patients with IVACs and 16 with possible VAP but none with probable VAP. Compared with patients without VACs, patients with VACs had longer ICU LOS (by 6.2 days), longer duration on MV (by 7.7 days), and higher hospital mortality rate (50.0% vs 27.3%). The mortality rate attributable to VACs was 11.7%. Compared with those with VACs alone, patients with IVACs had longer duration on MV and increased ICU LOS but no higher mortality rates.
In China, surveillance of VACs and IVACs is able to identify MV patients with poorer outcomes. However, surveillance of possible and probable VAP can be problematic.
•Fe and Co dual doped Ni3S4 exhibits efficient catalytic performance for OER.•Dual doping induce the interaction of electrons and expose more active sites.•High content of Ni3+ is beneficial to the ...electron transfer during the OER.•The FeCo-Ni3S4//MoNi4 couple can reach 10 mA cm−2 at 1.47 V in1.0 M KOH.
Transition metal compound catalysts with high efficient and stable performance have attracted extensive attention of researchers. In this study, dual cation doped Ni3S4 nanosheets loaded on nickel foam were prepared by two step hydrothermal method. Co and Fe dual doping can induce the internal electronic interaction of the catalyst, thus exposing more active sites. Meanwhile, high Ni3+ content enhances the chemisorption of OH−, which is conducive to the transfer of electrons in the reaction process. The electrochemical test results show that Co and Fe doped Ni3S4 have better electrocatalytic performance for oxygen evolution than single cation doped and pure Ni3S4. In 1.0 M KOH solution, the FeCo-Ni3S4 electrode exhibits a remarkable oxygen evolution reaction activity with low overpotentials of 230 mV at 20 mA cm−2 and 279 mV at 100 mA cm−2. The water-alkali electrolyzer using FeCo-Ni3S4 as anode achieves stable overall water splitting with a low potential of 1.47 V at 10 mA cm−2. This work will provide a new direction and guidance for the synthesis and application of transition metal sulfide catalysts.
In recent years, ozone (O3) is often the major pollutant during summertime in China. In order to better understand this problem, a long-term measurement of ozone (from 2006 to 2015) and its ...precursors (NOx and VOCs) as well as the photochemical parameter (UV radiation) in a mega city of China (Shanghai) is analyzed. The focus of this study is to investigate the trend of O3 and the causes of the O3 trend in large cities in China. In order to understand the relationship between the O3 precursors and O3 formation, two distinguished different sites of measurements are selected in the study, including an urbanization site (XJH-Xujiahui) and a remote site (DT-Dongtan). At the XJH site, there are high local emissions of ozone precursors (such as VOCs and NOx), which is suitable to study the effect of O3 precursors on O3 formation. In contrast, at the DT site, where there are low local emissions, the measured result can be used to analyze the background conditions nearby the city of Shanghai. The analysis shows that there were long-term trends of O3 and NOx concentrations at the urban site (XJH) from 2006 to 2015 (O3 increasing 67% and NOx decreasing 38%), while there were very small trends of O3 and NOx concentrations at the background site (DT). The analysis for causing the O3 trend suggests that (1) the large O3 increase at the urban area (XJH) was not due to the regional transport of O3; (2) the measurement of solar radiation had not significant trend during the period, and was not the major cause for the long-term O3 trend; (3) the measurement of VOCs had small change during the same period, suggesting that the trend in NOx concentrations at the urban site (XJH) was a major factor for causing the long-term change of O3 at the urban area of Shanghai. As a result, the O3 and NOx concentrations from 2006 to 2015 at the urban area of Shanghai were strongly anti-correlated, suggesting that the extremely high NOx concentration in the urban area depressed the O3 concentrations. It is interesting to note that the anti-correlation between O3 and NOx was in an un-linearly relationship. Under high O3 concentration condition, the ratio of ΔO3/ΔNOx was as large as −1.5. In contrast, under low O3 concentrations, the ratio of ΔO3/ΔNOx was only −0.2. This result suggested that when O3 concentration was high, it was more sensitive to NOx concentration, while when O3 concentration was low, it was less sensitive to NOx concentration. This study provides useful insights for better understanding the causes of the long-term-trend of regional O3 pollution nearby Shanghai, and has important implication for air pollution control in large cities in China. Due to the fact that NOx and VOCs are not only precursors for O3, but also are important precursors for particular matter (PM). If reduction of NOx leads to decrease in PM, but increase in O3, the NOx emission control become a very complicated issue and need to carefully design a comprehensive control method.
Display omitted
•There are insignificant trends of O3 and NOx from 2006 to 2015 in a mega city (Shanghai).•The trends between O3 and NOx are strongly anti-correlated, indicating that the O3 is strongly depressed by high NOx.•The study suggests that the reduction of NOx can reduce PM2.5, while causes O3 to increase.•The NOx emission control becomes a very complicated issue and needs to carefully design a comprehensive control method.
In recent years, ozone (O
) is often the major pollutant during summertime in China. In order to better understand this problem, a long-term measurement of ozone (from 2006 to 2015) and its ...precursors (NO
and VOCs) as well as the photochemical parameter (UV radiation) in a mega city of China (Shanghai) is analyzed. The focus of this study is to investigate the trend of O
and the causes of the O
trend in large cities in China. In order to understand the relationship between the O
precursors and O
formation, two distinguished different sites of measurements are selected in the study, including an urbanization site (XJH-Xujiahui) and a remote site (DT-Dongtan). At the XJH site, there are high local emissions of ozone precursors (such as VOCs and NO
), which is suitable to study the effect of O
precursors on O
formation. In contrast, at the DT site, where there are low local emissions, the measured result can be used to analyze the background conditions nearby the city of Shanghai. The analysis shows that there were long-term trends of O
and NO
concentrations at the urban site (XJH) from 2006 to 2015 (O
increasing 67% and NO
decreasing 38%), while there were very small trends of O
and NO
concentrations at the background site (DT). The analysis for causing the O
trend suggests that (1) the large O
increase at the urban area (XJH) was not due to the regional transport of O
; (2) the measurement of solar radiation had not significant trend during the period, and was not the major cause for the long-term O
trend; (3) the measurement of VOCs had small change during the same period, suggesting that the trend in NO
concentrations at the urban site (XJH) was a major factor for causing the long-term change of O
at the urban area of Shanghai. As a result, the O
and NO
concentrations from 2006 to 2015 at the urban area of Shanghai were strongly anti-correlated, suggesting that the extremely high NO
concentration in the urban area depressed the O
concentrations. It is interesting to note that the anti-correlation between O
and NO
was in an un-linearly relationship. Under high O
concentration condition, the ratio of ΔO
/ΔNO
was as large as -1.5. In contrast, under low O
concentrations, the ratio of ΔO
/ΔNO
was only -0.2. This result suggested that when O
concentration was high, it was more sensitive to NO
concentration, while when O
concentration was low, it was less sensitive to NO
concentration. This study provides useful insights for better understanding the causes of the long-term-trend of regional O
pollution nearby Shanghai, and has important implication for air pollution control in large cities in China. Due to the fact that NO
and VOCs are not only precursors for O
, but also are important precursors for particular matter (PM). If reduction of NO
leads to decrease in PM, but increase in O
, the NO
emission control become a very complicated issue and need to carefully design a comprehensive control method.
Nickel‐foam‐supported ZnxNi1−xS nanosheets are synthesized by a two‐step hydrothermal method. The ZnxNi1−xS nanosheets can be considered as the product of the partial substitution of Zn2+ ions by ...Ni2+ ions in the ZnS lattice. The resulting ZnxNi1−xS/Ni foam can be directly used as an electrode for supercapacitors. It can reach a specific capacitance of 1412 F g−1 at a current density of 1 Ag−1 with 68.0 % capacitance retention at 16 Ag−1. Control experiments show that the electrochemical performances of ZnxNi1−xS nanosheets are much better than those of ZnS and NiS prepared under the same conditions. Furthermore, a hybrid supercapacitor device was assembled by using the ZnxNi1−xS nanosheets as the positive electrode and porous carbon as the negative electrode; the device exhibited high power and energy densities. This study demonstrates that the construction of bimetal sulfides is a strategy to develop high‐performance supercapacitor electrode materials.
Mixing metals: ZnxNi1−xS nanosheets on nickel foam were prepared by a two‐step hydrothermal process and applied as the positive electrode for hybrid supercapacitors. The ZnxNi1−xS nanosheet electrode exhibits enhanced specific capacitance and its stability is superior to that of ZnS and NiS (see figure).
Display omitted
•FeS2-NC precursor is prepared by microwave-assisted Schiff base condensation.•FeS2 has been applied to the separator coating of LSBs for the first report.•FeS2-NC coating delivers an ...ultrahigh initial capacity of 1613.6 mAh g−1 at 0.1C.•The advantaged yolk-pleat-shell structure for enhanced adsorption of polysulfides.•FeS2-NC achieves enhanced kinetic of polysulfides in Li-S batteries.
Shuttling behavior and sluggish redox kinetics of lithium polysulfides (LiPSs) are fundamental reasons that impede the practical application of lithium-sulfur batteries (LSBs). Herein, a novel FeS2-embedded N-doped carbon (FeS2-NC) nanocage is reported as a separator coating material to alleviate these problems. It is also for the first time that FeS2 is applied to the separator coating of LSBs. The yolk-pleat-shell structure of FeS2-NC was synthesized via the pyrolysis of iron complexes prepared by Schiff base condensation and subsequent sulfurization treatment. The large internal space of FeS2-NC not only physically confines LiPSs but also forms a high-speed electron–ion transport network in cooperation with the highly polar compound FeS2, providing abundant chemical adsorption and catalytic sites for fast conversions of LiPSs. Theoretical calculation further confirms that FeS2 has strong adsorption energy for both Li2S6 and Li2S8, while in-situ Raman analysis also reveals the interaction between FeS2 and LiPSs. In addition, coin cells with the light functional separator (coating loading: 0.2 mg cm−2) have a ultrahigh initial capacity of 1613.6 mAh g−1 at 0.1C and a satisfactory cyclability of 652.3 mAh g−1 at 1C over 600 cycles with an attenuation rate of 0.049% per cycle. Even the high-sulfur-loaded (2.73 mg cm−2) pouch cell release a lasting high areal capacity of 2.38 mAh cm−2 at 0.4C. These results demonstrate that FeS2-NC has the efficient capability as polysulfide trapping-catalyzing nanoreactor for LSBs application.
PDF
