Cross-sectional scanning tunneling microscopy of InAs/GaAs(001) submonolayer quantum dots

Cross-sectional scanning tunneling microscopy (X-STM) was employed to characterize the InAs submonolayer quantum dots (SMLQDs) grown on top of a Si-doped GaAs(001) substrate in the presence of (2X4) and c(4X4) surface reconstructions. Multiple layers were grown under different conditions to study their effects on the formation, morphology and local composition of the SMLQDs. The morphological and compositional variations in SMLQDs were observed by both filled and emptystate imaging. A detailed analysis of indium segregation in the SMLQDs layers was described by fitting local indium concentration profile with a standard segregation model. A strong influence of arsenic flux over the formation of the SMLQDs and indium incorporation was observed and reported. We investigated the well-width fluctuations of the InGaAs quantum well (QW) in which SMLQDs were formed . The monolayer fluctuations of the well width were negligible compared to the more pronounced compositional fluctuations in all the layers. Keywords: Submonolayer quantum dots, Surface reconstruction, X-STM, Indium segregatio

26. Cardiovascular risk assessment for Saudi university employees and their families: developing a framework for provision of an evidence-based cardiovascular disease preventative programme.

In the Kingdom of Saudi Arabia (KSA), cardiovascular diseases (CVDs) are the primary cause of death among adults, representing 46% of total mortality in 2014. This study’s objectives were to assess the prevalence of cardiovascular risk factors (CVRFs), and calculate the cardiovascular risk (CVR) among King Saud University employees and their families. Moreover, it aimed at assessing the possible effects of living in KSA on the heart health of expatriate employees and their families.A cross-sectional study was conducted on 4500 university employees and their families aged ⩾18 years old, using the World Health Organization STEPwise approach to surveillance of CVRFs. CVR was then calculated for participants using the Framingham Coronary Heart Risk Score calculator. The mean age of participants was 39.3±13.4 years. The prevalence of CVRFs was as follows: low fruit/vegetable consumption of 10% risk to develop CVD within the following 10-years. Furthermore, this study showed that expatriates had significant negative effects on behavioural risk factors after residing in KSA, namely: high rate of physical inactivity, high consumption of fast food, low consumption of fruit and vegetable. However, there was no effect on the pattern of tobacco use. The prevalence of CVRFs is substantially high among the study population. To combat the future expected burden of CVDs, a proposed prevention programme for employees’ cardiovascular wellness is designed and recommended to be implemented and institutionalized within the university

Preconception care for diabetic women for improving maternal and fetal outcomes : a systematic review and meta-analysis

Background Preexisting diabetes mellitus is associated with increased risk for maternal and fetal adverse outcomes. Despite improvement in the access and quality of antenatal care recent population based studies demonstrating increased congenital abnormalities and perinatal mortality in diabetic mothers as compared to the background population. This systematic review was carried out to evaluate the effectiveness and safety of preconception care in improving maternal and fetal outcomes for women with preexisting diabetes mellitus. Methods We searched the following databases, MEDLINE, EMBASE, WEB OF SCIENCE, Cochrane Library, including the CENTRAL register of controlled trials and CINAHL up to December 2009, without language restriction, for any preconception care aiming at health promotion, glycemic control and screening and treatment of diabetes complications in women of reproductive age group with type I or type II diabetes. Study design were trials (randomized and non-randomized), cohort and case-control studies. Of the 1612 title scanned 44 full papers were retrieved of those 24 were included in this review. Twelve cohort studies at low and medium risk of bias, with 2502 women, were included in the meta-analysis. Results Meta-analysis suggested that preconception care is effective in reducing congenital malformation, RR 0.25 (95% CI 0.15-0.42), NNT17 (95% CI 14-24), preterm delivery, RR 0.70 (95% CI 0.55-0.90), NNT = 8 (95% CI 5-23) and perinatal mortality RR 0.35 (95% CI 0.15-0.82), NNT = 32 (95% CI 19-109). Preconception care lowers HbA1c in the first trimester of pregnancy by an average of 2.43% (95% CI 2.27-2.58). Women who received preconception care booked earlier for antenatal care by an average of 1.32 weeks (95% CI 1.23-1.40). Conclusion Preconception care is effective in reducing diabetes related congenital malformations, preterm delivery and maternal hyperglycemia in the first trimester of pregnancy