Energetics, electronic structure and electric polarization of basal stacking faults in wurtzite GaN and ZnO

We investigate the effect of basal-plane stacking faults on the structural, electronic, and polarization properties of wurtzite GaN and ZnO. This theoretical study is performed within density-functional theory (DFT) using periodic hexagonal supercells. Both formation energies and band structures are obtained by means of total-energy calculations. The type-I stacking fault is observed to have the lowest formation energy, followed by type-II and finally the extrinsic stacking fault. In order to overcome the inherent shortcoming of DFT in reproducing band gaps, the generalized-gradient approximation is used in combination with the modified Becke-Johnson functional. It is shown that all stacking faults studied maintain a direct gap whose value is lower than that in the ideal defect-free crystals. The lowering in the band gap allows the creation of quantum-well regions at wurtzite/zincblende interfaces. In addition, we provide a consistent set of polarization parameters derived from the Berry-phase method. We find a trend of decreasing (increasing) spontaneous polarization and piezoelectric coefficient (polarization charge) in going from type-I to type-II to extrinsic stacking faults. We compare our results to experimental and theoretical data available from the literature and explain the observed trends in terms of the properties of the wurtzite and zincblende polytypes of both materials

Gender discrimination for women with diabetes mellitus in Algeria

Background: Nowadays diabetes mellitus (DM) is one of the greatest global challenges. Its expansion varies from an area to another according to genetic, traditions, socio-economic conditions, and stress. In Algeria, as in other emerging countries undergoing an epidemiological transition, noncommunicable diseases are sharply increasing. After high blood pressure, DM is now the second metabolic disease. But are women more concerned by DM since obesity frequency is higher in females? Can we assert that there is a sort of sex discrimination for DM complications? Materials and Methods: To answer these questions we took into account published documents carried in Algerian population. But, as those were very scarce, we also considered newspapers articles, some documents published by health minister department, posters and oral communications of the Algerian Society of Endocrinology and Diabetology, and our clinical experience. We also have done a small survey to get our patients′ opinions. Results and Conclusion : At the first sight, it seems gender discrimination between men and women cannot exist since most epidemiological studies showed that both sexes are broadly and equally affected by DM, except for old aged females who are the most affected. When we reconsidered the problem, and when we compared past results to those obtained after the terrorism period, many studies showed a sort of gender difference. Apart from gestational DM, which is increasing sharply, some complications and death related to DM are prevailing in women. Coronary diseases and cerebral vascular accidents are more frequent in women too, especially the young ones and those suffering from DM. These complications are probably due to the recent and rapid modification in women′s lifestyle with a strong reduction in physical activity, eating disorders, hormonal contraception, and high sensitivity to perceived stress secondary to the near past stressing life and/or to numerous responsibilities taken by women in the modern society

Gender discrimination for women with diabetes mellitus in Algeria

Background: Nowadays diabetes mellitus (DM) is one of the greatest global challenges. Its expansion varies from an area to another according to genetic, traditions, socio-economic conditions, and stress. In Algeria, as in other emerging countries undergoing an epidemiological transition, noncommunicable diseases are sharply increasing. After high blood pressure, DM is now the second metabolic disease. But are women more concerned by DM since obesity frequency is higher in females? Can we assert that there is a sort of sex discrimination for DM complications? Materials and Methods: To answer these questions we took into account published documents carried in Algerian population. But, as those were very scarce, we also considered newspapers articles, some documents published by health minister department, posters and oral communications of the Algerian Society of Endocrinology and Diabetology, and our clinical experience. We also have done a small survey to get our patients′ opinions. Results and Conclusion : At the first sight, it seems gender discrimination between men and women cannot exist since most epidemiological studies showed that both sexes are broadly and equally affected by DM, except for old aged females who are the most affected. When we reconsidered the problem, and when we compared past results to those obtained after the terrorism period, many studies showed a sort of gender difference. Apart from gestational DM, which is increasing sharply, some complications and death related to DM are prevailing in women. Coronary diseases and cerebral vascular accidents are more frequent in women too, especially the young ones and those suffering from DM. These complications are probably due to the recent and rapid modification in women′s lifestyle with a strong reduction in physical activity, eating disorders, hormonal contraception, and high sensitivity to perceived stress secondary to the near past stressing life and/or to numerous responsibilities taken by women in the modern society

Gonadal Function in Men with Cushing Syndrome

Cushing syndrome (CS) is scarcely observed in males. Because of this rarity, the real prevalence of gonadal dysfunction in men with hypercortisolism is unknown. Our aim was to analyze gonadal abnormalities in 37 males with CS (median age=28.9±11years) comparatively to age matched healthy men (n=10). For the homogeneity of the study men over 50, children, patients taking medications and those with pituitary deficits were systematically excluded. For the remaining group, we took into account medical history, clinical examination, and hormonal assessment, by radio immunoassay, for testosterone (T), prolactin (PRL), follicle stimulating hormone (FSH), and luteinizing stimulating hormone (LH).Results: 21% consulted for impotency and/or gynecomastia. When questioned, 65.7% complained about decreased libido and erectile dysfunction. Except for 3, body hair growth and repartition, and testicular volume were normal. Gynecomastia was observed in 18.9%.Testosterone was equal to 2.79±1.62ng/ml vs 6.69±3.87ng/ml (p<0.0005). Low testosterone (<3ng/ml) was observed in 67.5%. PRL =9.8 ± 4.2ng/ml vs 4.9 ± 2.6ng/ml (p<0.01). FSH = 3.87 ± 1.9mu/ml vs 3.75 ± 2.25mU/ml (p<0.30). LH = 2.7 ± 2.2mU/ml vs 3.66 ± 0.86 (p<0.30). We have not found any correlation between cortisol and T, PRL or LH, but there was a positive and significant one with FSH (r=0.57, p<0.005).Conclusion: CS causes a franc hypogonadism in 65%. According to FSH and LH results glucocorticoids excess acts probably at hypothalamic pituitary level, but an increase in testosterone degradation and/or inhibition of testis receptors cannot be ruled out. So men with hypogonadism and/or gynecomastia should be systematically checked for CS