Abstract Negative Poisson’s ratio (NPR) material attracts a lot of attentions for its unique mechanical properties. However, achieving NPR is at the expense of reducing Young’s modulus. It has been observed that the composite stiffness can be enhanced when blending positive Poisson’s ratio (PPR) material into NPR material. Based on the respective interpolation of Young’s modulus and Poisson’s ratio, two concurrent topology optimization problems with different types of constraints, called Problem A and B, are respectively discussed to explore the Poisson’s ratio effect in porous microstructure. In Problem A, the volume constraints are respectively imposed on macro and micro structures; in Problem B, besides setting an upper bound on the total available base materials, the micro thermal insulation capability is considered as well. Besides considering the influence of micro thermal insulation capability on the optimized results in Problem B, the similar and dissimilar influences of Poisson’s ratios, volume fractions in Problem A and B are also investigated through several 2D and 3D numerical examples. It is observed that the concurrent structural stiffness resulting from the mixture of PPR and NPR base materials can exceed the concurrent structural stiffness composed of any individual base material.

Low carbon steel was exposed at two sites in Mauritius, namely Port Louis and Belle Mare. The site at Port Louis is basically an industrial marine one whereas the one at Belle Mare is a purely marine site. Though the corrosion loss trend at both sites follow the power law, the corrosion loss at Port Louis was found to be higher than that at Belle Mare. This study has been performed to investigate the surface characteristics of the rust layers of the samples exposed at the two sites, through Raman spectroscopy and SEM, so as to get a better insight into the mechanism of the atmospheric corrosion process. For Port Louis, it was observed that there was not much change in the corrosion products in the rust layer over the 3 years period. The structure was less compact than that at Belle Mare with the presence of lepidocrocite and akaganeite as commonly observed corrosion products. The corrosion rate at Port Louis is, therefore, expected to follow the same trend over the long term. For Belle Mare, the corrosion products changed significantly after 3 years of exposure. Though lepidocrocite and akaganeite were observed on the surface after 0.2 years of exposure, magnetite was the most probable corrosion product in the more compact rust layer after 3 years of exposure. This compactness of the rust layer is expected to have reduced the corrosion rate as compared to that of Port Louis. Significant changes in the corrosion rate at Belle Mare are, therefore, expected over the medium and the long term.

摘要 目的 评估抗逆转录病毒治疗（ART）早期进行磺胺甲基异恶唑预防疗法是否降低中国艾滋病病毒（HIV）感染成年人的死亡率。 方法 我们使用中国国家免费抗逆转录病毒数据库的数据进行回顾性观察性队列研究。对14岁以上在2010年1月1日至2012年12月31日之间开始ART治疗并且基...

Résumé Objectif Évaluer si la prophylaxie par le cotrimoxazole administrée précocement au cours de la thérapie antirétrovirale (TAR) réduit la mortalité chez les adultes infectés par le virus de l'immunodéficience humaine (VIH) en Chine. Méthodes Nous avons effectué une étude de cohorte par observation rétrospective en utilisant les données de la base de données antirétrovirale gratuite nationale chinoise. Les patients âgés de plus de 14 ans qui ont commencé une TAR entre le 1er janvier 2010 et le 31 décembre 2012 et qui avaient un nombre de lymphocytes T CD4+ (cellules CD4+) à la ligne de base inférieur à 200 cellules/µL, ont été suivis jusqu'à leur décès, jusqu'à ce qu'ils soient perdus de vue au suivi ou jusqu'au 31 ...

Резюме Цель Определить, приводит ли профилактика котримоксазолом на раннем этапе антиретровирусной терапии (АРТ) к снижению смертности среди ВИЧ-инфицирова...

Objective To assess if cotrimoxazole prophylaxis administered early during antiretroviral therapy (ART) reduces mortality in Chinese adults who are infected with human immunodeficiency virus (HIV). Methods We did a retrospective observational cohort study using data from the Chinese national free antiretroviral database. Patients older than 14 years who started ART between 1 January 2010 and 31 December 2012 and had baseline CD4+ T-lymphocyte (CD4+ cell) count less than 200 cells/µL were followed until death, loss to follow-up or 31 December 2013. Hazard ratios (HRs) for several variables were calculated using multivariate analyses. Findings The analysis involved 23 816 HIV-infected patients, 2706 of whom died during the follow-up. Mortality in patients who did and did not start cotrimoxazole during the first 6 months of ART was 5.3 and 7.0 per 100 person–years, respectively. Cotrimoxazole was associated with a 37% reduction in mortality (hazard ratio, HR: 0.63; 95% confidence interval, CI: 0.56–0.70). Cotrimoxazole in addition to ART reduced mortality significantly over follow-up lasting 6 months (HR: 0.65; 95% CI: 0.59–0.73), 12 months (HR: 0.58; 95% CI: 0.49–0.70), 18 months (HR: 0.49; 95% CI: 0.38–0.63) and 24 months (HR: 0.66; 95% CI: 0.48–0.90). The mortality reduction was evident in patients with baseline CD4+ cell counts less than 50 cells/µL (HR: 0.60; 95% CI: 0.54–0.67), 50–99 cells/µL (HR: 0.66; 95% CI: 0.56–0.78) and 100–199 cells/µL (HR: 0.78; 95% CI: 0.62–0.98). Conclusion Cotrimoxazole prophylaxis started early during ART reduced mortality and should be offered to HIV-infected patients in low- and middle-income countries.

ملخص الغرض تقييم ما إذا كانت الوقاية باستخدام الكوتريموكسازول في مرحلة مبكرة خلال العلاج بمضادات الفيروسات القهقرية يقلل معدل الوفيات بين البالغين المصابين ب...

Resumen Objetivo Evaluar si la profilaxis con cotrimoxazol en una etapa temprana de la terapia antirretroviral (TAR) reduce la mortalidad en adultos de origen chino infectados por el virus de la inmunodeficiencia humana (VIH). Métodos Se llevó a cabo un estudio de cohorte observacional retrospectivo utilizando los datos de la base de datos nacional de China de antirretrovirales de uso gratuito. Por otro lado, se realizó un seguimiento a pacientes mayores de 14 años que iniciaron el tratamiento con TAR entre el 1 de enero de 2010 y el 31 de diciembre de 2012 y con recuento basal de linfocitos T CD4+ (célula CD4+) inferior a 200 células/µl hasta su muerte, la pérdida de seguimiento o el 31 de diciembre de 2013. Se calcularon los cocientes de riesgos (CR) para diversas variables mediante análisis multivariados. Resultados En el análisis participaron 23 816 pacientes infectados por el VIH, 2706 de los cuales fallecieron durante el seguimiento. La mortalidad entre los pacientes que iniciaron y no iniciaron el tratamiento con cotrimoxazol durante los primeros 6 meses de la TAR fue de 5,3 y 7,0 por 100 personas/años, respectivamente. Cotrimoxazol se asoció a una reducción del 37 % en la mortalidad (cociente de riesgos, CR: 0,63, intervalo de confianza del 95 %, IC: 0,56 – 0,70). Además de la TAR, cotrimoxazol redujo la mortalidad considerablemente durante el seguimiento de 6 meses (CR: 0,65; IC del 95 %: 0,59 – 0,73), 12 meses (CR: 0,58; IC del 95 %: 0,49 – 0,70), 18 meses (CR: 0,49; IC del 95 %: 0,38 – 0,63) y 24 meses (CR: 0,66; IC del 95 %: 0,48 – 0,90). La reducción de la mortalidad resultó evidente en pacientes con recuento basal de células CD4+ inferior a 50 células/µl (CR: 0,60; IC del 95 %: 0,54 – 0,67), 50 – 99 células/µl (CR: 0,66; IC del 95 %: 0,56 – 0,78) y 100 – 199 células/µl (CR: 0,78; IC del 95 %: 0,62 – 0,98). Conclusión La profilaxis con cotrimoxazol iniciada en una etapa temprana de la TAR redujo la mortalidad y debe ofrecerse a los pacientes infectados por el VIH en países de ingresos bajos y medios.