Environmental Stability of Crystals: A Greedy Screening.

Discovering materials that are environmentally stable and also exhibit the necessary collection of properties required for a particular application is a perennial challenge in materials science. Herein, we present an algorithm to rapidly screen materials for their thermodynamic stability in a given environment, using a greedy approach. The performance was tested against the standard energy above the hull stability metric for inert conditions. Using data of 126 320 crystals, the greedy algorithm was shown to estimate the driving force for decomposition with a mean absolute error of 39.5 meV/atom, giving it sufficient resolution to identify stable materials. To demonstrate the utility outside of a vacuum, the in-oxygen stability of 39 654 materials was tested. The enthalpy of oxidation was found to be largely exothermic. Further analysis showed that 1438 of these materials fall into the range required for self-passivation based on the Pilling-Bedworth ratio.

Population-Based Estimation of the Preterm Birth Rate in Lilongwe, Malawi: Making Every Birth Count.

Objective The objective of this study was to perform a population-based estimation of the preterm birth (PTB) rate in regions surrounding Lilongwe, Malawi. Study Design We partnered with obstetrician specialists, community health workers, local midwives, and clinicians in a 50 km region surrounding Lilongwe, Malawi, to perform a population-based estimation of the PTB rate during the study period from December 1, 2012 to May 19, 2015. Results Of the 14,792 births captured, 19.3% of births were preterm, including preterm early neonatal deaths. Additional PTB risk factors were similarly prevalent including domestic violence, HIV, malaria, anemia, and malnutrition. Conclusion When performing a population-based estimation of the rate of PTB, including women without antenatal care and women delivering at home, the 19.3% rate of PTB is among the highest recorded globally. This is accompanied by a high rate of risk factors and comorbid conditions.

Population-Based Estimation of Dental Caries and Periodontal Disease Rates of Gravid and Recently Postpartum Women in Lilongwe, Malawi.

Objectives The objective of this study was to determine the rate of dental caries and periodontal disease among gravid and recently postpartum women at five delivery centers within and surrounding Lilongwe, Malawi. Study Design We partnered with obstetric specialists, community health workers, and dentists to perform dental history interviews and dental examinations during the study period from December 2012 to May 2014. Dental examinations were performed according to World Health Organization standards to assess periodontal and oral health status. Results Among the 387 gravid and recently postpartum women, the rate of dental caries was 69.3% and the rate of composite dental disease (caries and periodontal disease) was 76.7%. The majority (69.5%) of women examined had a decayed-missing-filled (DMF) index greater than or equal to one; the average DMF Index was 2.48. The majority of women had never seen a dentist (62.8%). However, most did perform oral hygiene, two or more times per day (90.2%); most women reported brushing with toothpaste (88.1%). Conclusion When assessing this population for dental caries and periodontal disease, the rate of dental disease was high. Therefore, this may be an ideal setting to test for impactful interventions aimed at reducing caries and periodontal disease.