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

Cancer - malaria: hidden connections

International audienceCancer and malaria exemplify two maladies historically assigned to separated research spaces. Cancer, on the one hand, ranks among the top priorities in the research agenda of developed countries. Its rise is mostly explained by the ageing of these populations and linked to environment and lifestyle. Malaria, on the other hand, represents a major health burden for developing countries in the Southern Hemisphere. These two diseases also belong to separate fields of medicine: non-communicable diseases for cancer and communicable diseases for malaria

Serum CA125 and HE4 levels as predictors for optimal interval surgery and platinum sensitivity after neoadjuvant platinum-based chemotherapy in patients with advanced epithelial ovarian cancer

International audienceBackground: The aim of this study is to evaluate a new tumour marker, HE4, and to compare it with CA125 in predicting optimal cytoreduction and response to chemotherapy. Thirty patients with advanced epithelial ovarian cancer and multiple sera harvested during neoadjuvant chemotherapy (NAC) were included. Results: Based on ROC curves analysis, CA125 ≤ 75 UI/ml and HE4 ≤ 252 pmol/L after the 3rd cycles of NAC, with a sensitivity of 93.7 % and a specificity of 92.3 % (PPV = 93.7 % and NPV = 92.3 %), offered the best combination for predicting optimal cytoreduction. In addition, the HE4 value of 115 pmol/L is the best cut-off level for identifying platinum-sensitive patients. Conclusions: The introduction of HE4 as a new tool for predicting platinum-sensitivity and interval optimal cytoreduction is promising

A 4-days-on and 3-days-off maintenance treatment strategy for adults with HIV-1 (ANRS 170 QUATUOR): a randomised, open-label, multicentre, parallel, non-inferiority trial

International audienc