sensing characteristics of hematite and barium oxide doped hematite films towards ozone and nitrogen dioxide

Abstract Hematite (α-Fe2O3) and barium oxide doped hematite (BaO-Fe 2 O 3 ) thin films were investigated as ozone (O 3 ) and nitrogen dioxide (NO 2 ) sensing materials. Fe 2 O 3 and BaO-Fe 2 O 3 films were deposited by radio- frequency sputtering using pure Fe 2 O 3 , and 1-2% BaO doped Fe 2 O 3 targets. The 700 °C (1 hour) annealed films showed significant responses to O 3 at temperatures ranging from 150 °C to 300 °C. Although, hematite is an n-type semiconductor, the Fe 2 O 3 and BaO-Fe 2 O 3 films exhibit p-type behavior to O 3 and n- type behavior to NO 2 at the studied concentration ranges in this work. The response to oxidizing gases is not strictly an increase in resistance due to a conversion from n-type to p-type depending on gas concentrations. This effect is more visible with increasing Ba concentration

Synthesis of new hydroxylated mono and bis-tetrathiafulvalenes: Electrochemical behaviour, X-ray analysis and conductivity

International audienceSeries of unsymetrical and judiciously functionnalized tetrathiafulvalenes (TTFs) are elaborated by the protection-deprotection of thiolates or selenolates strategy. We have connected the physical properties of the corresponding materials to the interactions born out of the presence of selenium atoms on one side or both sides of the TTF core. The electrochemical values of the new donors are presented. Radical cation salts (RCS) and charge transfer complexes (CTC) were prepared in order to study, in particular, their electrical conductivit

Gènes de susceptibilité HLA et rétinopathie diabétique chez la population algérienne

Introduction : La rétinopathie diabétique (RD) est la complication microvasculaire la plus fréquente du diabète de type 1 (DT1). Certains sujets DT1 avec un bon équilibre glycémique peuvent développer la RD alors que d’autres sujets mal équilibrés ne développent pas de RD. Cela peut être expliqué par la présence de certains gènes de susceptibilité ou de protection. L’objectif de notre étude est de rechercher une association entre les marqueurs HLA de classe I et classe II et la RD dans la population algérienne. Patients et méthode : L’étude a été réalisée chez 52 sujets DT1 avec et sans RD et 140 témoins sains. Le typage HLA a été réalisé par la technique de « microlymphocytotoxicité ».Résultats : La fréquence des antigènes HLA-A29 et HLA-DR9 est plus élevée chez les DT1 avec RD par rapport aux DT1 sans RD et aux témoins avec comme valeurs respectives : HLA-A29 (59,26 % vs 0 %, OR=∞, pc=4,6×10−7), (59,26 % vs 5,66 %, OR=24,24, pc=7,6×10–10) et HLA-DR9 (29,63 % vs 0 %, OR=∞, pc=1,310−3), (29,63 % vs 4,29 %, OR=9,40, pc=7,010−5). Cependant, la fréquence de l’antigène HLA-B49 est plus faible chez les DT1 avec RD par rapport aux DT1 sans RD (3,7 % vs 28 %, OR=0,10, pc=8,8×10−3) et par rapport aux témoins (3,7 % vs 22,64 %, OR=0,13, pc=0,011) avec une différence statistiquement significative. Conclusion : Les antigènes HLA-A29 et DR9 sont probablement des marqueurs de susceptibilité à la RD alors que l’antigène HLA-B49 a probablement un effet protecteur dans la population algérienne.Susceptibility genes, HLA and diabetic retinopathy in the Algerian population Background: Diabetic retinopathy (DR) is the most frequent microvascular complication of type I diabetes (T1D). Some well-controlled type I diabetics may develop DR, while other poorly-controlled diabetics do not develop DR. This might be explained by certain susceptibility genes or protective genes. The purpose of our study is to search for any association between the HLA class I and II markers and DR in the Algerian population. Patients and methods: This study was carried out in 52 T1D subjects with and without DR compared to 140 healthy controls. HLA typing was performed using the " microlymphocytotoxicity" technique. Results: The frequency of HLA-A29 and HLA-DR9 antigens is higher in T1D with DR compared to T1D without DR and to controls with frequencies of HLA-A29 (59.26% vs. 0%, OR = ∞, pc = 4.6 × 10-7), (59.26% vs. 5.66%, OR = 24.24, pc = 7.6 × 10-10) and HLA-DR9 (29.63% vs. 0%, OR = ∞, pc = 1.310-3), (29.63% vs. 4.29%, OR = 9.40, pc = 7.010-5) respectively. However, the frequency of HLA-B49 antigen is significantly lower in T1D with DR than in T1D without DR (3.7% vs. 28%, OR = 0.10, pc = 8.8 × 10-3) and compared to controls (3.7% vs. 22.64%, OR = 0.13, pc = 0.011). Conclusion: HLA-A29 and HLA-DR9 antigens are probably markers of susceptibility for DR while HLA-B49 antigen is probably associated with a protective effect in the Algerian population