Gas adsorption properties of ZSM-5 zeolites heated to extreme temperatures

Zeolites are broadly useful catalysts and molecular sieve adsorbents for purification. In this work the thermal degradations of bare and platinum-loaded ZSM-5 was studied with the goal of understanding the behavior of nanoporous solids at extreme temperatures comparable to those present in nuclear fuels. Zeolites were heated in air and nitrogen at temperatures up to 1500 °C, and then characterized for thermal stability via X-ray diffraction (XRD) and for gas adsorption by the Brunauer-Emmett-Teller (BET) method. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were also employed. These results indicate zeolites are stable when heat-treated up to 800 °C and degrade slowly at higher temperatures. However, significant surface area degradation begins at 1025–1150 °C with an activation energy of 400 kJ/mole. At 1500 °C, gas adsorption measurements and SEM images show complete collapse of the porous structure. Critically for nuclear fuel applications, however, the zeolites still adsorb helium in significant quantities

Pregnancy rates following three different timings of intrauterine insemination for women with unexplained infertility: A randomised controlled trial

Objective: To compare pregnancy rates following three different timings of intrauterine insemination after human chorionic gonadotrophin administration at 24, 34 and 48h in women with unexplained infertility. Setting: Kasr El-Aini Hospital. Design: Randomized controlled trial. Participants and methods: Couples with unexplained infertility had 125 cycles of IUI divided in three groups: Group (1): 24h after hCG administration, Group (2): 34h after hCG administration and Group (3): 48h after hCG administration. Results: There was no significant difference in pregnancy rates between all groups, Group 1 vs. Group 2 OR=0.61, 95% [CI] 0.15–2.36, Group 1 vs. Group 3 OR=0.42, 95% CI 0.12–1.53 and Group 2 vs. Group 3 OR=0.729, CI 0.23–2.32. Conclusion: IUI can be done any time between 24 and 48h after hCG injection without significant differences in pregnancy rates

Audit of Maternal Mortality Ratio and Causes of Maternal Deaths in the Largest Maternity Hospital in Cairo, Egypt (Kasr Al Aini) in 2008 and 2009; Lessons Learned

This study examined maternal deaths at Cairo University Maternity Hospital between January 2008 and December 2009. The aim was to calculate Maternal Mortality Ratio (MMR) as well as identify the causes and predisposing factors to maternal deaths. Data were collected from the files of the hospitalized pregnant women in the hospital. There were 38 maternal deaths and MMR was 79 per 100,000 live births for the two years examined. The main causes of death were obstetric hemorrhage, hypertensive disorders of pregnancy and cardiac arrest. Substandard medical care and the delay in seeking of medical advice were two contributing factors to maternal deaths recorded. The need for audit and publication of all obstetric hospitals MMR to compare and identify areas of improvements is recommended.Cette étude a examiné les décès maternels au Centre Hospitalier de la maternité au Caire entre janvier 2008 et décembre 2009. L'objectif était de calculer les taux de mortalité maternelle (TMM) ainsi que d'identifier les causes et les facteurs prédisposant à la mortalité maternelle. Les données ont été recueillies à partir des dossiers des femmes enceintes hospitalisées à l'hôpital. Il y a eu 38 décès maternels et TMM était de 79 pour 100,000 naissances vivantes pour les deux années étudiées. Les principales causes de décès étaient l'hémorragie obstétricale, les troubles hypertensifs de la grossesse et l'arrêt cardiaque. Les soins médicaux de qualité inférieure et le retard dans la recherche de conseils médicaux étaient deux facteurs qui contribuent aux décès maternels enregistrés. Nous préconisons la vérification et la publication de tous les TMM des hôpitaux obstétriques pour permettre d'identifier les domaines qui méritent d’être améliorés

Clinical Application of Novel Therapies for Coronary Angiogenesis: Overview, Challenges, and Prospects

Cardiovascular diseases continue to be the leading cause of death worldwide, with ischemic heart disease as the most significant contributor. Pharmacological and surgical interventions have improved clinical outcomes, but are unable to ameliorate advanced stages of end-heart failure. Successful preclinical studies of new therapeutic modalities aimed at revascularization have shown short lasting to no effects in the clinical practice. This lack of success may be attributed to current challenges in patient selection, endpoint measurements, comorbidities, and delivery systems. Although challenges remain, the field of therapeutic angiogenesis is evolving, as novel strategies and bioengineering approaches emerge to optimize delivery and efficacy. Here, we describe the structure, vascularization, and regulation of the vascular system with particular attention to the endothelium. We proceed to discuss preclinical and clinical findings and present challenges and future prospects in the field