Oxidative steam reforming of ethanol over M x La2-x Ce1.8Ru0.2O7-δ (M = Mg, Ca) catalysts: effect of alkaline earth metal substitution and support on stability and activity.

Alkaline earth metal substitutions on the A-site of pyrochlore oxide M x La2-x Ce1.8Ru0.2O7-δ (M = Mg, Ca) were studied as catalyst materials for oxidative/autothermal steam reforming of ethanol (OSRE/ATR). The as-prepared oxides were synthesized by a combustion method and characterized using powder X-ray diffraction (PXRD), and X-ray photoelectron and absorption spectroscopy (XPS and XAS). PXRD Rietveld analysis and elemental analysis (ICP-AES) support the formation of a pyrochlore-type structure (space group Fd3̄m) with a distorted coordination environment. The substitution of Mg2+ and Ca2+ ions affects the oxidation states of Ce4+/3+ and Ru n+ ions and creates oxygen vacancies, which leads to enhanced catalytic activity and reduced ethylene selectivity. A long-term stability test showed optimized catalysts Mg0.3La1.7Ce1.8Ru0.2O7-δ and Ca0.2La1.8Ce1.8Ru0.2O7-δ with S H2 = 101(1)% and S H2 = 91(2)% under OSRE conditions. The initial operation temperatures were lower than that of the unsubstituted catalyst La2Ce1.8Ru0.2O7-δ . Catalysts supported on La2Zr2O7 showed stable OSRE/ATR performance and low carbon deposition compared to catalysts supported on Al2O3. We ascribe the enhanced activity to well-dispersed alkaline earth metal and Ru ions in a solid solution structure, synergistic effects of (Mg, Ca)2+/Ce3+/4+/Ru n+ ions, and a strong catalyst-support interaction that optimized the ethanol conversion and hydrogen production.

Trends in prevalence and risk factors of childhood asthma in Fuzhou, a city in Southeastern China.

UNLABELLED: Abstract Objective: The prevalence of asthma in children age 0-14 years in Fuzhou, a city in Southeast China, was 1.57% in 1990 and 3.28% in 2000. The aim of this study was to investigate the asthma prevalence and risk factors in children in the same city in 2010. METHODS: This was a cross-sectional study with a two-stage, clustered, stratified random sample design. Parents of 12235 children 0-14 years of age in Fuzhou were surveyed using a questionnaire. Children with history and/or symptoms of asthma were then interviewed by pediatricians in a nearby clinic to confirm the diagnosis of asthma, and a second questionnaire listing reported risk factors of asthma was completed by the parents in the clinic. RESULTS: About 11738 questionnaires were completed with a response rate of 95.9%. Among the responders, 648 children had history and/or symptoms of asthma but only 485 (4.13%) were confirmed with asthma. The prevalence was 1.83%, 7.64% and 6.27% in the age groups of 0-1 years, 3-4 years and 13-14 years, respectively. The most significant (binary logistic regression test) factors associated with asthma were presence of atopic or allergic diseases (OR=21.5, 95% CI: 12-38.5), family history of allergy or asthma (OR=29.4, 95% CI: 12.6-68.6), use of at least one course of antibiotics in the first year of life (OR=7.61, 95% CI: 3.4-17.06), supplementary protein feedings before 6 months (OR=1.90, 95% CI: 1.23-2.95). Natural ventilation at home (versus frequent use of air-conditioning) appeared to be a protective factor (OR = 0.5, 95% CI: 0.3-0.8). CONCLUSION: The prevalence of asthma in childhood has increased significantly during the past 20 years in Fuzhou.

An exploratory study of the association between KCNB1 rs1051295 and type 2 diabetes and its related traits in Chinese Han population.

Since the KCNB1 encoding Kv2.1 channel accounts for the majority of Kv currents modulating insulin secretion by pancreatic islet beta-cells, we postulated that KCNB1 is a plausible candidate gene for genetic variation contributing to the variable compensatory secretory function of beta-cells in type-2 diabetes (T2D). We conducted two studies, a case-control study and a cross-section study, to investigate the association of common single-nucleotide polymorphisms (SNPs) in KCNB1 with T2D and its linking traits. In the case-control study, we first examined the association of 20 tag SNPs of KCNB1 with T2D in a population with 226 T2D patients and non-diabetic subjects (screening study). We then identified the association in an enlarged population of 412 T2D patients and non-diabetic subjects (replication study). In the cross-sectional study, we investigated the linkage between the candidate SNP rs1051295 and T2D by comparing beta-cell function and insulin sensitivity among rs1051295 genotypes in a general population of 1051 subjects at fasting and after glucose loading (oral glucose tolerance tests, OGTT) in 84 fasting glucose impaired subjects, and several T2D-related traits. We found that among the 19 available tag SNPs, only the KCNB1 rs1051295 was associated with T2D (P = 0.027), with the rs1051295 TT genotype associated with an increased risk of T2D compared with genotypes CC (P = 0.009). At fasting, rs1051295 genotype TT was associated with a 9.8% reduction in insulin sensitivity compared to CC (P = 0.008); along with increased plasma triglycerides (TG) levels (TT/CC: P = 0.046) and increased waist/hip (W/H) ratio (TT/CC: P = 0.013; TT/TC: P = 0.002). OGTT confirmed that genotype TT exhibited reduced insulin sensitivity by 16.3% (P = 0.030) compared with genotype TC+CC in a fasting glucose impaired population. The KCNB1 rs1051295 genotype TT in the Chinese Han population is associated with decreased insulin sensitivity and increased plasma TG and W/H ratio, which together contribute to an increased risk for T2D.

Enhanced catalytic activity of Ce(1-x)M(x)O2 (M = Ti, Zr, and Hf) solid solution with controlled morphologies.

Ce(1-x)M(x)O(2) (M = Ti, Zr, and Hf) nanomaterials with controlled morphology and composition were synthesized by a two-step route for the first time. These nanomaterials exhibit high activities for hydrogen reduction and ethanol reforming reactions, and therefore, they may be useful for applications in catalysis and solid oxide fuel cells.

A quaternary germanium(II) phosphate, Na[Ge(4)(PO(4))(3)].

A new germanium(II) phosphate, sodium tetra-germanium tris-(phosphate), Na[Ge(4)(PO(4))(3)], has been synthesized by a solid-state reaction. The compound is isotypic with A[Sn(4)(PO(4))(3)] (A = Na, K, NH(4)). It features a [Ge(4)(PO(4))(3)](-) framework made up of GeO(3) pyramids and PO(4) tetra-hedra, which are linked by shared corners, yielding a three-dimensional structure. The crystal studied showed partial inversion twinning.

Immunohistochemical localization of tissue-type plasminogen activator and type I plasminogen activator inhibitor in radicular cysts.

BACKGROUND: The plasminogen/plasmin proteolytic system participates in a wide variety of extracellular matrix degradation. Detailed knowledge of plasminogen activators (PAs) and their inhibitors may be important for understanding the pathogenesis of radicular cysts. The purpose of this study was to investigate the in situ localization of tissue-type PA (t-PA) and type I PA inhibitor (PAI-1) in radicular cysts. METHODS: Thirty formalin-fixed, paraffin-embedded specimens of radicular cysts were examined using immunohistochemistry. In addition, another section from each radicular cyst specimen was stained with hematoxylin and eosin to assess the presence of inflammatory infiltrates. Differences in t-PA and PAI-1 expression between tissues with low and high levels of inflammation were subsequently analyzed using Fisher's exact test. RESULTS: Both t-PA- and PAI-1-positive cells were detected in the lining epithelium, connective tissue, inflammatory infiltrates, and endothelium. In addition, the t-PA signal was mainly expressed in epithelial cells. However, the PAI-1 signal was mainly expressed in fibroblasts. Moreover, significantly greater t-PA as well as PAI-1 expression was noted in radicular cysts with high levels of inflammation as compared to tissues with low levels of inflammatory cell infiltrates (P < 0.05). CONCLUSIONS: The present study confirms earlier indications of local production of PA and its inhibitor in radicular cysts. In addition, this study further shows the tissue localization of the antigens for t-PA as well as PAI-1, and demonstrates that the expression of both t-PA and PAI-1 increases with the grade of inflammation in radicular cysts.