Interface engineering of NiMoSx heterostructure nanorods for efficient oxygen evolution reaction.

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.

Transcription enhancer factor 1 binds multiple muscle MEF2 and A/T-rich elements during fast-to-slow skeletal muscle fiber type transitions.

In adult mouse skeletal muscle, beta-myosin heavy chain (betaMyHC) gene expression is primarily restricted to slow type I fibers; however, its expression can be induced in fast type II fibers in response to a sustained increase in load-bearing work (mechanical overload [MOV]). Our previous betaMyHC transgenic and protein-DNA interaction studies have identified an A/T-rich element (betaA/T-rich -269/-258) that is required for slow muscle expression and which potentiates MOV responsiveness of a 293-bp betaMyHC promoter (beta293wt). Despite the GATA/MEF2-like homology of this element, we found binding of two unknown proteins that were antigenically distinct from GATA and MEF2 isoforms. By using the betaA/T-rich element as bait in a yeast one-hybrid screen of an MOV-plantaris cDNA library, we identified nominal transcription enhancer factor 1 (NTEF-1) as the specific betaA/T-rich binding factor. Electrophoretic mobility shift assay analysis confirmed that NTEF-1 represents the enriched binding activity obtained only when the betaA/T-rich element is reacted with MOV-plantaris nuclear extract. Moreover, we show that TEF proteins bind MEF2 elements located in the control region of a select set of muscle genes. In transient-coexpression assays using mouse C2C12 myotubes, TEF proteins transcriptionally activated a 293-bp betaMyHC promoter devoid of any muscle CAT (MCAT) sites, as well as a minimal thymidine kinase promoter-luciferase reporter gene driven by three tandem copies of the desmin MEF2 or palindromic Mt elements or four tandem betaA/T-rich elements. These novel findings suggest that in addition to exerting a regulatory effect by binding MCAT elements, TEF proteins likely contribute to regulation of skeletal, cardiac, and smooth muscle gene networks by binding select A/T-rich and MEF2 elements under basal and hypertrophic conditions.

Hydrothermal Synthesis of Znx Ni1-x S Nanosheets for Hybrid Supercapacitor Applications.

Nickel-foam-supported Znx Ni1-x S nanosheets are synthesized by a two-step hydrothermal method. The Znx Ni1-x S nanosheets can be considered as the product of the partial substitution of Zn2+ ions by Ni2+ ions in the ZnS lattice. The resulting Znx Ni1-x S/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 Znx Ni1-x S 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 Znx Ni1-x S 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.

Long-term trend of O3 in a mega City (Shanghai), China: Characteristics, causes, and interactions with precursors.

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 Δ[O3]/Δ[NOx] was as large as -1.5. In contrast, under low O3 concentrations, the ratio of Δ[O3]/Δ[NOx] 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.

The Clinical Impact of Ventilator-Associated Events: A Prospective Multi-Center Surveillance Study.

OBJECTIVE: 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. DESIGN: A 4-month, prospective multicenter surveillance study between April and July 2013. SETTING: Our study included 15 adult intensive care units (ICUs) of 15 hospitals in China. PATIENTS: Patients admitted to ICUs during the study period METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

[Optimization of culture conditions for recombinant dextransucrase expression].

We optimized the medium for recombinant dextransucrase expression in engineering strain Escherichia coli BL21 (DE3)/pET28-dexYG by an Orthogonal experiment. After the medium had been decided, we studied the effect of temperature, sucrose concentration and pH value on the yield. The results indicated that optimal conditions were adding IPTG of 0.25 mmol/L when OD600 reached 2.0 and cultivation lasted for 4 h at 25 degrees C. Under the selected medium and these conditions, the dextransucrase activity expressed by the engineering strain was high activity. Maximal activity reached 110.16 U/mL sucrose concentration effects the dextran yield grately. The results for dextransucrase expression would provide foundation for industrial application of dextransucrase.

A histidine-rich cluster mediates the ubiquitination and degradation of the human zinc transporter, hZIP4, and protects against zinc cytotoxicity.

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.