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By decomposing Zn(OH)42- or Zn(NH3)42+ precursor in various solvents at suitable reaction conditions, zinc oxide with a diversity of well-defined morphologies was synthesized. Flowerlike ZnO built up by nanorods was obtained by treating Zn(OH)42- precursor in water at 180 °C for 13 h. Whereas a replacement of the solvent by n-heptane yields snow flakelike ZnO. The prismlike and the prickly spherelike ZnO were also prepared, respectively, by decomposing Zn(NH3)42+ or Zn(OH)42- in ethanol at 100 °C for 13 h. The rodlike ZnO was produced at 180 °C under the same condition for preparing prickly spherelike product. Besides these typical samples, ZnO in other morphologies was studied manipulatively by changing the reaction conditions of our solution route. Systematical condition-dependent experiments were compared comprehensively to reveal the formation and detailed growth process of ZnO nanosized crystallites and aggregates. The experimental results studied by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy indicated that the solvent, precursor, solution basicity, and reaction temperature as well as time are responsible for the variations of ZnO morphologies.

Original lignin and hemicelluloses were sequentially extracted with high yield/purity, using acidic dioxane/water solution and dimethyl sulfoxide, from ball-milled wheat straw. The acidic dioxane lignin fraction is distinguished by high beta-O-4' structures and by low amounts of condensed units (beta-5', 5-5', and beta-1'). Hemicelluloses contain arabinoxylans as the major polysaccharides, which are substituted by alpha-l-arabinofuranose, 4-O-methylglucuronic acid, acetyl group (DS = 0.1), and xylose at O-3 and/or O-2 of xylans. It was found that arabinoxylans form cross-links with lignins through ferulates via ether bonds, glucuronic acid via ester bonds, and arbinose/xylose via both ether and glycosidic bonds, respectively, in the cell walls of wheat straw. Diferulates are also incorporated into cross-links between lignin and hemicelluloses as well as lignification of wheat straw cell walls. The guaiacyl unit is considered to be a significant condensed structural constructor in extracted lignin and a connector between lignin and carbohydrates.

An investigation of the acetylation of rice straw with acetic anhydride at 100 and 120 degrees C for 1-4 h with four tertiary amine catalysts (pyridine, 4-dimethylaminopyridine, N-methylpyrrolidine, and N-methylpyrrolidinone) or without catalyst in a solvent-free system was undertaken, and the extent of acetylation was measured by weight percent gain, which increased with the extent of reaction time and temperature and the amounts of catalyst used. 4-Dimethylaminopyridine was found to be the most effective catalyst of those studied. At a concentration of 7% of the catalyst in acetic anhydride, a weight percent gain of 15.4% was realized, compared with 11.2% for the noncatalyst reaction, after 0.5 h of exposure to the system at 120 degrees C. Characterization of acetylated straw was performed by FT-IR, CP MAS (13)C NMR, and thermal studies. Interestingly, the acetylated straw is significantly hydrophobic and does not get wet with water, thereby offering potential for the better utilization of cheap waste materials as natural sorbents in oil cleanup.

BACKGROUND: Exacerbations of chronic obstructive pulmonary disease (COPD) lead to significant increases in resource utilization and cost to the health care system. COPD patients with chronic bronchitis and a history of exacerbations pose an additional burden to the system. This study examined health care utilization and cost among these patients. METHODS: For this retrospective analysis, data were extracted from a large national health plan with a predominantly Medicare population. This study involved patients who were aged 40-89 years, had been enrolled continuously for 24 months or more, had at least two separate insurance claims for COPD with chronic bronchitis (International Classification of Diseases, Ninth Revision, Clinical Modification code 491.xx), and had pharmacy claims for COPD maintenance medications between January 1, 2007, and March 31, 2009. Two years of data were examined for each patient; the index date was defined as the first occurrence of COPD. Baseline characteristics were obtained from the first year of data, with health outcomes tracked in the second year. Severe exacerbation was defined by COPD-related hospitalization or death; moderate exacerbation was defined by oral or parenteral corticosteroid use. Adjusted numbers of exacerbations and COPD-related costs per patient were estimated controlling for demographic and clinical characteristics. RESULTS: The final study sample involved 8554 patients; mean age was 70.1±8.6 years and 49.8% of the overall population had exacerbation, 13.9% had a severe exacerbation only, 29.1% had a moderate exacerbation only, and 6.8% had both a severe and moderate exacerbation. COPD-related mean annual costs were $4069 (all figures given in US dollars) for the overall population and $6381 for patients with two or more exacerbations. All-cause health care costs were $18,976 for the overall population and $23,901 for patients with history of two or more exacerbations. Severity of exacerbations, presence of cardiovascular disease, diabetes, and long-term oxygen use were associated with higher adjusted costs. CONCLUSIONS: The results indicate that despite treatment with maintenance medications, COPD patients continue to have exacerbations resulting in higher costs. New medications and disease management interventions are warranted to reduce the severity and frequency of exacerbations and the related cost impact of the disease.

1-Thioglycerol-capped CdTe nanocrystals were used as core template to generate CdTe/CdS core−shell nanocrystals in aqueous solution by means of ultrasonic irradiation. The photoluminescence quantum yields of CdTe/CdS core−shell nanocrystals were up to 20%, larger than the original CdTe nanocrystals by around 10 times. The reaction conditions, such as the concentration, the molar ratio of reactants, and the pH value, were investigated, showing that ultrasonic irradiation controlled the decomposition of thiourea and the formation of a gradient CdS shell around the original CdTe core.