Water and sanitation in schools: a systematic review of the health and educational outcomes.

A systematic review of the literature on the effects of water and sanitation in schools was performed. The goal was to characterize the impacts of water and sanitation inadequacies in the academic environment. Published peer reviewed literature was screened and articles that documented the provision of water and sanitation at schools were considered. Forty-one peer-reviewed papers met the criteria of exploring the effects of the availability of water and/or sanitation facilities in educational establishments. Chosen studies were divided into six fields based on their specific foci: water for drinking, water for handwashing, water for drinking and handwashing, water for sanitation, sanitation for menstruation and combined water and sanitation. The studies provide evidence for an increase in water intake with increased provision of water and increased access to water facilities. Articles also report an increase in absenteeism from schools in developing countries during menses due to inadequate sanitation facilities. Lastly, there is a reported decrease in diarrheal and gastrointestinal diseases with increased access to adequate sanitation facilities in schools. Ensuring ready access to safe drinking water, and hygienic toilets that offer privacy to users has great potential to beneficially impact children's health. Additional studies that examine the relationship between sanitation provisions in schools are needed to more adequately characterize the impact of water and sanitation on educational achievements.

Total synthesis of cyclic diterpene tonantzitlolone based on a highly stereoselective substrate-controlled aldol reaction and ring-closing metathesis.

The total synthesis of the cyclic diterpene ent-tonantzitlolone (ent-1) is presented. Key steps for assembling the macrocyclic core structure of 1 are a highly selective aldol reaction and an E selective ring-closing metathesis reaction. A detailed investigation of these two steps and the final transformations towards the completion of the synthesis is disclosed.

Total synthesis and elucidation of the absolute configuration of the diterpene tonantzitlolone.

[structure: see text] The first enantioselective total synthesis of tonantzitlolone, a novel 15-membered macrocyclic diterpene, utilized a Julia olefination, a highly selective, potassium enolate-based anti-Felkin aldol reaction, and an E-selective ring-closing metathesis as key C-C bond-forming steps. The absolute configuration of tonantzitlolone is established.

Selective complexation of N-alkylpyridinium salts: binding of NAD+ in water.

A new class of receptor molecules is presented that is highly selective for N-alkylpyridinium ions and electron-poor aromatics. Its key feature is the combination of a well-preorganized molecular clip with an electron-rich inner cavity and strategically placed, flanking bis-phosphonate monoester anions. This shape and arrangement of binding sites attracts predominantly flat electron-poor aromatics in water, binds them mainly by pi-cation, pi-pi, CH-pi, and hydrophobic interactions, and leads to their highly efficient desolvation. NAD(+) and NADP, the important cofactors of many redox enzymes, are recognized by the new receptor molecule, which embraces the catalytically active nicotinamide site and the adenine unit. Even nucleosides such as adenosine are likewise drawn into the clip's cavity. Complex formation and structures were examined by one- and two-dimensional NMR spectroscopy, Job plot analyses, and isothermal titration microcalorimetric (ITC) measurements, as well as quantum chemical calculations of (1)H NMR shifts. The new receptor molecule is a promising tool for controlling enzymatic oxidation processes and for DNA chemistry.