Community-acquired, methicillin-resistant Staphylococcus aureus (CA-MRSA) has been associated with morbidity and mortality in various countries. In this study, we characterized the molecular and clinical features of pediatric CA-MRSA pneumonia in China. Between June 2006 and February 2008, 55 previously healthy children confined in eight hospitals countrywide were found to be afflicted with CA-MRSA pneumonia. A total of 55 strains collected from these children were analyzed by multilocus sequence typing (MLST), Staphylococcus cassette chromosome mec (SCCmec) typing, and spa typing. The Panton-Valentine leukocidin (PVL) gene was also detected. Overall, nine STs were obtained, with ST59 (40.4%) established to be the most prevalent type. We first registered the new ST1409 from a child with necrotizing pneumonia. SCCmecIVa was the most predominant type, followed by SCCmec type V. Twelve spa types were identified, of which one new spa type, t5348, was first detected and registered. One typical livestock-associated spa type, t034, was found in a 4-month-old girl living in the countryside. We also found that 40% of those isolates were PVL-positive. In addition, the median age of the children in this study was 10 months. A total of 69% (38/55) of the children with community-acquired pneumonia (CAP) had preceding influenza or influenza-like illness, and three ST910-MRSA-IV strains (PVL gene-positive) were associated with severe necrosis. The results indicated that the recent CA-MRSA found in Chinese children with CAP was largely associated with the spread of the ST59-MRSA-IV clone, and most of the PVL-positive strains in this study did not cause necrotic cases.

By using WCl6 as a precursor and absolute ethanol as a solvent, ultrafine W18O49 nanowires (UFNWs) were synthesized by a one-pot solution-phase method and used as gas sensing materials. Their crystal structure, morphology, and specific surface area can be regulated by controlling precisely the content of the WCl6 precursor in the solution. It has been found that, when the content of the precursor is 4 mg/mL, the formed products are UFNWs with a diameter of about 0.8 nm, only one crystal plane [010] is exposed, and the specific surface area is 194.72 m2/g. After the gas sensing test, we found that they have excellent selectivity to acetone. The response of 50 ppm acetone reaches 48.6, the response and recovery times are 11 and 13 s, respectively. In order to evaluate the interaction between W18O49 surfaces and different volatile organic compound (VOC) molecules, we simulated and calculated the adsorption energy (E Ads) among different W18O49 surfaces and different VOCs by DFT. The calculated results are in agreement with the experimental results, further confirming the ultrahigh selectivity of W18O49 UFNWs to acetone. The above results demonstrate that the high selectivity of W18O49 UFNWs to acetone is due to the exposure of its single crystal plane [010]. This work has practical significance for better detection of acetone.

Antibiotics are commonly prescribed in the Chinese children population. It is likely that the third-generation cephalosporins and macrolides are currently overused in Chinese children. Efforts must be made to ensure safe and appropriate antibiotic prescribing to reduce and prevent the future development of antibiotic resistance.

In recent years, bimetallic nanocrystals have attracted great interest from many researchers. Bimetallic nanocrystals are expected to exhibit improved physical and chemical properties due to the synergistic effect between the two metals, not just a combination of two monometallic properties. More importantly, the properties of bimetallic nanocrystals are significantly affected by their morphology, structure, and atomic arrangement. Reasonable regulation of these parameters of nanocrystals can effectively control their properties and enhance their practicality in a given application. This review summarizes some recent research progress in the controlled synthesis of shape, composition and structure, as well as some important applications of bimetallic nanocrystals. We first give a brief introduction to the development of bimetals, followed by the architectural diversity of bimetallic nanocrystals. The most commonly used and typical synthesis methods are also summarized, and the possible morphologies under different conditions are also discussed. Finally, we discuss the composition-dependent and shape-dependent properties of bimetals in terms of highlighting applications such as catalysis, energy conversion, gas sensing and bio-detection applications.

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