A prospective study of the use of antibiotics in the Emergency Department of a Chinese University Hospital

Background: Antibiotics are one of the most widely misused group of medicines. The aim of this study was to investigate the use of antibiotics in one of the paediatric emergency departments in China. Methods: We performed a prospective, cross-sectional study of antibiotic use in the paediatric emergency room of West China Second University Hospital. A total of 500 consecutive patients from March 25 to April 3 2013 were included. Clinical details of the patients were also collected in order to analyse antibiotic use. Key findings: The median age of patients was 2 years 2 months. The five most common conditions seen in the emergency department were wheezy bronchitis, upper respiratory tract infections, tonsillitis, pneumonia and diarrhoea. A total of 311 children (62%) received antibiotics. The antibiotics prescribed were predominantly cephalosporins and penicillins. More than one antibiotic was used in 51 patients. In total, 75% of the antibiotics prescribed were cephalosporins. More than three-quarters of the young children with wheezy bronchitis received antibiotics. Antibiotic use for children with an upper respiratory tract infections or tonsillitis was greater than the 20% maximum recommended by the European Surveillance of Antimicrobial Consumption. Conclusions: The majority of children attending the emergency department received antibiotics. For many of the conditions, the use of antibiotics was inappropriate

3D printing of gradient-doped Yb: YAG laser ceramics by leveraging active mixing

Gradient-doped laser ceramics by 3D printing method have great potentials for high-power laser applications. However, it is challenging for fabricating such type of gain media since different component slurries, as prepared offline, are inconvenient to be precisely fabricated by traditional methods. To address these issues, a facile approach for additive manufacturing of high-power laser ceramics has been proposed for the gradient structure fabrication. First, a material extrusion-based 3D printing device with a home-made active mixing module has been developed to fabricate gradient-doped Yb: YAG(Y3Al5O12) laser ceramics using only two slurries with different doping concentrations. Following that, the active mixing module has been systematically investigated to obtain different Yb doped concentrations of printing slurries with uniform element distribution. By measuring the switching delay volume between different components, the proper volume adjustment has enabled the Yb concentration distribution of green bodies to be consistent with the designed profile in the 3D process. Finally, multi-component (0-5-10-5-0 at. % Yb: YAG) green bodies have been printed, and experimental tests have been conducted to evaluate the performances of these gradient-doped laser ceramics. Results have shown that the gradient-doped ceramic has obtained 82.1% in-line transmittance at 1100 nm (4.6 mm thickness, along with the doping concentration gradient) and the average Yb ions diffusion distance across the interface has been fitted in the range of 20 to 30 μm. Finally, a 1030 nm laser output with an output power of 4.5 W with a slope efficiency of 41.3% has been achieved pumped with 940 nm laser diode. This study has provided useful insights into developing various types of gradient rare earth doped laser ceramics for high-power laser applications