Chemical composition of nanoporous layer formed by electrochemical etching of p-type GaAs

Abstract : We have performed a detailed characterization study of electrochemically etched p-type GaAs in a hydrofluoric acid-based electrolyte. The samples were investigated and characterized through cathodoluminescence (CL), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). It was found that after electrochemical etching, the porous layer showed a major decrease in the CL intensity and a change in chemical composition and in the crystalline phase. Contrary to previous reports on p-GaAs porosification, which stated that the formed layer is composed of porous GaAs, we report evidence that the porous layer is in fact mainly constituted of porous As2O3. Finally, a qualitative model is proposed to explain the porous As2O3 layer formation on p-GaAs substrate

High-resolution X-ray diffraction and electron microscopy study of porous GaAs substrates

As liver fibrosis is the result of persistent necroinflammation in the liver, pro-inflammatory cytokines secreted in response to cell injury have a central role in the pathogenesis of liver fibrosis. We aimed to investigate the association of cytokine gene polymorphism and liver fibrosis among Chinese patients with chronic hepatitis B.Polymorphisms at interleukin-10 (IL-10-627, -1117), interleukin-1-beta (IL-1beta-511, -31, -3964), interleukin-1 receptor antagonist (IL-1RN), and tumor necrosis factor-alpha (TNF-alpha-308, -238) among Chinese chronic hepatitis B patients were determined. Severe liver fibrosis was defined as Ishak fibrosis score = 4 (of 6).Fifty-nine of 273 (22%) patients had severe fibrosis. The distribution of genotypes for IL-10-627 was CC (11%), CA (41%), and AA (48%). The CC genotype at IL-10-627 was protective against severe fibrosis (odds ratio (OR) 0.11; 95% CI 0.014-0.82; P = 0.032). After adjusted for baseline variables, the adjusted OR of CC genotypes at IL-10-627 for severe fibrosis was 0.063 (95% CI 0.06-0.64; P = 0.063). Other gene polymorphisms at IL-1beta, IL-1RN, TNF-alpha, and IL-10 had no significant association with severe fibrosis. Weak linkage disequilibrium was observed between IL-10-627 and IL-10-1117 with linkage disequilibrium coefficient of 0.12 (P < 0.001). The distribution of haplotypes of IL-10-1117 and IL-10-627 was A-A (69%), A-C (26%), and G-C (5%). High and intermediate IL-10 production (A-C and G-C) haplotypes were protective against severe fibrosis (OR 0.62; 95% CI 0.39-0.99; P = 0.046).High production genotype and haplotypes of IL-10 were associated with less severe liver fibrosis in chronic hepatitis B in Chinese

High-resolution X-ray diffraction and electron microscopy study of porous GaAs substrates

As liver fibrosis is the result of persistent necroinflammation in the liver, pro-inflammatory cytokines secreted in response to cell injury have a central role in the pathogenesis of liver fibrosis. We aimed to investigate the association of cytokine gene polymorphism and liver fibrosis among Chinese patients with chronic hepatitis B.Polymorphisms at interleukin-10 (IL-10-627, -1117), interleukin-1-beta (IL-1beta-511, -31, -3964), interleukin-1 receptor antagonist (IL-1RN), and tumor necrosis factor-alpha (TNF-alpha-308, -238) among Chinese chronic hepatitis B patients were determined. Severe liver fibrosis was defined as Ishak fibrosis score = 4 (of 6).Fifty-nine of 273 (22%) patients had severe fibrosis. The distribution of genotypes for IL-10-627 was CC (11%), CA (41%), and AA (48%). The CC genotype at IL-10-627 was protective against severe fibrosis (odds ratio (OR) 0.11; 95% CI 0.014-0.82; P = 0.032). After adjusted for baseline variables, the adjusted OR of CC genotypes at IL-10-627 for severe fibrosis was 0.063 (95% CI 0.06-0.64; P = 0.063). Other gene polymorphisms at IL-1beta, IL-1RN, TNF-alpha, and IL-10 had no significant association with severe fibrosis. Weak linkage disequilibrium was observed between IL-10-627 and IL-10-1117 with linkage disequilibrium coefficient of 0.12 (P < 0.001). The distribution of haplotypes of IL-10-1117 and IL-10-627 was A-A (69%), A-C (26%), and G-C (5%). High and intermediate IL-10 production (A-C and G-C) haplotypes were protective against severe fibrosis (OR 0.62; 95% CI 0.39-0.99; P = 0.046).High production genotype and haplotypes of IL-10 were associated with less severe liver fibrosis in chronic hepatitis B in Chinese