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Abstract: SnO2–Ta2O5 based varistors doped with 0–2.0mol% of ZnO were prepared by sintering the samples at 1450°C for 2h with conventional ceramic processing method. The doping effect of ZnO on the microstructural and electrical properties of the as-prepared SnO2–Ta2O5 based varistor ceramics was investigated. The change in SnO2 lattice parameter and EDX analysis both confirmed the doping of Zn ions into SnO2 grains, although the identified phase was only SnO2 (cassiterite) by X-ray diffraction in detection limit. The microstructure observation indicated that the doped ZnO can facilitate the sintering of the varistor ceramics. The measured electric-field/current-density characteristics of the samples revealed that the nonlinear exponents and varistor voltage increased with increasing doping amount of ZnO when the ZnO content was no more than 0.5mol%; and more addition of ZnO would cause a decrease in nonlinear exponent and varistor voltage of the ceramic varistors. [Copyright &y& Elsevier]

Lead (Pb) isotopes have been widely used in isotopic dating and geochemical tracing. The rapid development in Earth sciences requires high precision and accuracy of isotopic measurements of low Pb contents or small amounts of samples. However, low ionization efficiency can significantly affect the sensitivity and precision of the measurement. Emitters, such as silicon dioxide (SiO 2) gel used in the thermal ionization mass spectrometer (TIMS) measurement of Pb isotopes, can reduce Pb loss at the low-temperature stage and improve Pb ionization efficiency at the high-temperature stage, but they inevitably introduce Pb blank and affect the quality of the results. Therefore, the emitters should possess the features of both high ionization efficiency and low Pb blank. In the present study, a SiO 2 gel solution was produced via a double-bottle method and then purified by the Sr-spec® resin. We further measured Pb blank value of this emitter using the isotopic dilution method and examined its ionization efficiency via measuring isotopic composition of standard reference materials of Pb solution and rock powders using different amounts of Pb. Analytical data show that Pb blank values of the twice-purified SiO 2 gel solution are lower than 1 pg/μL (lowest value of ∼0.3 pg/μL). Moreover, it can effectively improve Pb ionization, and maintain high and stable ion signal intensity during the measurement runs. Analytical results of Pb isotopic compositions, obtained from nano- to subnano-gram Pb amounts of reference materials, all fall in the ranges of their reference values, meeting the requirements in precision and accuracy for the measurements on micro-samples. This emitter is useful for Pb isotopic measurement of micro-samples and predictable to promote the application of Pb isotopic geochemistry. [Display omitted] • SiO 2 gel was produced by reaction of SiCl 4 and water with a double-bottle configuration. • Low Pb blank of the gel was obtained via purification of the Sr-Spec® ion exchange resin. • This gel can effectively improve Pb ionization during the TIMS measurement. • The gel emitter ensures Pb isotopic measurement of micro-sample in sub-nanogram level. [ABSTRACT FROM AUTHOR]

Objective To describe the demographics and clinical characteristics of patients with A (H7N9) infection, to test the differences in the distribution of demographics and clinical characteristics by clinical severity, and to explore potential factors associated with clinical severity. Methods This retrospective study was conducted to collect epidemiological and clinical information regarding the confirmed cases in Guangdong through field investigation and review of medical records. Results Of the 256 cases, 100 (39.0%) patients died, and 168 (65.6%) patients were admitted to ICUs. The male-to-female ratio was approximately 2.0:1, and the median age was 56 years (range, 1 to 88). Among the 215 patients accepting oseltamivir treatment, the median time from the onset of illness to oseltamivir treatment was 5 days (range, 0 to 16); 35 patients received zanamivir treatment after a median of 8 days (range, 0 to 23). The univariable logistic regression models demonstrated that time from the onset of illness to oseltamivir treatment (OR = 1.10, 95% CI = 1.01–1.10) and zanamivir treatment (OR = 1.05, 95% CI = 1.02–1.07) were associated with the death of patients. Conclusions Preventive measures should focus on high-risk populations, such as the elderly and the groups with high frequency exposure to live poultry. Earlier oseltamivir and zanamivir treatment were recommended. [ABSTRACT FROM AUTHOR]

Recent studies have shown that transcription factors (TFs) and microRNAs (miRNAs), while independently regulate their downstream targets, collaborate with each other to regulate gene expression. However, their synergistic roles in protein–protein interactions (PPIs) remain mostly unknown. In this paper, we present a novel framework (called CoRePPI) for inferring TF and miRNA co-regulation of PPIs. Particularly, CoRePPI is aimed at discovering the co-regulation specific to a condition of interest, by using heterogeneous data, including miRNA and messenger RNA (mRNA) expression profiles, putative miRNA targets, TF targets and PPIs. CoRePPI firstly finds the network motifs indicating the co-regulation of PPIs by TFs and miRNAs in tumor and normal conditions separately. Then by identifying the differential motifs found in one condition but not in the other, it builds the networks consisting of TFs, miRNAs and their co-regulated PPIs specific to different conditions respectively. To validate CoRePPI, we apply it to the Pan-Cancer dataset which includes the expression profiles of 12 cancer types from TCGA. Through network topology analysis, we found that the tumor and normal CoRePPI networks are scale-free. Furthermore, the results of differential and intersected network analysis between the tumor and normal CoRePPI networks suggest that only a small fraction of the regulatory relationships between TFs and miRNAs are conserved in both conditions but they co-regulate different downstream PPIs in tumor and normal conditions; and in different conditions the majority of the regulatory relationships between TFs and miRNAs are different although they may regulate the same PPIs in their respective conditions. The CoRePPI sub-networks constructed for the three types of cancers (breast cancer, lung cancer and ovarian cancer) are all scale-free, and the intersection of these CoRePPI sub-networks can be utilized as the biomarker CoRePPI sub-network of the three types of cancers. The PPI enrichment analyses of the tumor and normal CoRePPI networks suggest that the co-regulating TFs and miRNAs are significantly associated with the specific biological processes, diseases and pathways. In addition, comparing with the two non-condition-specific approaches, the tumor CoRePPI network is found to have the most enriched cancer-related PPIs. Altogether, the results uncover the combined regulatory patterns of TFs and miRNAs on the PPIs, and may provide new insights for research in cancer-associated TFs and miRNAs. [ABSTRACT FROM AUTHOR]

Abstract: Neutral polyfluorinated alkyl substances (PFASs) were measured in high-volume air samples collected on board the research vessel Snow Dragon during the 4th Chinese National Arctic Expedition from the Japan Sea to the Arctic Ocean in 2010. Four volatile and semi-volatile PFASs (fluorotelomer alcohols (FTOHs), fluorotelomer acids (FTAs), perfluoroalkyl sulfonamides (FASAs), and sulfonamidoethanols (FASEs)) were analyzed respectively in the gas and particle phases. FTOHs were the dominant PFASs in the gas phase (61–358pgm−3), followed by FTAs (5.2–47.9pgm−3), FASEs (1.9–15.0pgm−3), and FASAs (0.5–2.1pgm−3). In the particle phase, the dominant PFAS class was FTOHs (1.0–9.9pgm−3). The particle-associated fraction followed the general trend of FASEs>FASAs>FTOHs. Compared with other atmospheric PFAS measurements, the ranges of concentrations of ∑FTOH in this study were similar to those reported from Toronto, north America (urban), the northeast Atlantic Ocean, and northern Germany. Significant correlations between FASEs in the gas phase and ambient air temperature indicate that cold surfaces such as sea-ice, snowpack, and surface seawater influence atmospheric FASEs. [Copyright &y& Elsevier]