BackgroundThere is growing scientific evidence supports a link between increased childhood adiposity and early onset of puberty in girls worldwide in recent decades. However, the data from Chinese girls remain ambiguous. The aims of this study were to estimate the puberty milestones and examine attainment of puberty associated with obesity and central obesity in Chinese Han schoolgirls.MethodsThe cross-sectional school-based study examined 2996 Han schoolgirls aged 9 to 19 years from 6 provinces in China. Trained clinicians assessed  the girls for height, weight, waist circumference, Tanner stages of breast and pubic hair development, and menarcheal status. We classified girls as normal weight, overweight, or obese based on BMI, and as normal weight or central obese based on the waist-height ratio, then estimated and compared median age at a given Tanner stage or greater by weight class using Probit models.ResultsThe median age at menarche was 12.36 years. The median ages at breast stages(B) 2 through 5 were 10.03, 11.38, 13.39, and 15.79 years, respectively, and at pubic hair stages(PH) 2 through 5 were 11.62, 12.70, 14.38, and 16.92 years, respectively. Girls from urban areas experienced menarche, B3 and B4 stages, and PH3 through PH5 stages earlier. Girls with central obesity and overweight/obesity reached puberty earlier at almost every Tanner stage of breast and pubic hair than normal girls. Girls with obesity developed PH2 and PH3 earlier than their overweight peers. However, we did not find any significant differences between girls with overweight and obesity at all stages of breast development.ConclusionsChildhood obesity, including both overweight/obesity and central obesity, is associated with earlier attainment of puberty in Chinese Han schoolgirls.

Molybdenum disulfide (MoS 2 ) with excellent properties has been widely reported in recent years. However, it is a great challenge to achieve p-type conductivity in MoS 2 because of its native stubborn n-type conductivity. Substitutional transition metal doping has been proved to be an effective approach to tune their intrinsic properties and enhance device performance. Herein, we report the growth of Nb-doping large-area monolayer MoS 2 by a one-step salt-assisted chemical vapor deposition method. Electrical measurements indicate that Nb doping suppresses ntype conductivity in MoS 2 and shows an ambipolar transport behavior after annealing under the sulfur atmosphere, which highlights the p-type doping effect via Nb, corresponding to the density functional theory calculations with Fermi-level shifting to valence band maximum. This work provides a promising approach of two-dimensional materials in electronic and optoelectronic applications.

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We introduce a metal-assisted exfoliation method to produce few-layer black phosphorus with the lateral size larger than 50 μm and the area 100 times larger than those exfoliated using the normal "scotch-tape" technique. Using a field effect transistor it was found the hole mobility is 68.6 cm V s and the current on/off ratio can reach about 2 × 10.

BackgroundDrug allergy (DA) is one of the most important contributors to iatrogenic morbidity and mortality. Currently DA remains a major challenge for healthcare practitioners (HCPs).ObjectiveTo assess the knowledge, attitudes and practices of DA among HCPs in Central China.MethodsA 25-item self-administered DA questionnaire were developed and applied in our study. The questionnaire covered 3 domains: knowledge, attitudes, and practice patterns. From July 2015 to October 2015, HCPs in 7 cities of Central China anonymously participated in the cross-sectional study.ResultsA total of 350 HCPs participated the study, 91 questionnaires uncompleted and 259 were analyzed. Among the respondents, 166 (64.1%) were doctors, 55 (21.2%) were nurses and 38 (14.7%) were medical students. The mean knowledge precision was 59.8%. HCPs agreed that drug induced immediate allergic reactions were IgE mediated (83.4%) and happened within 6 hours after drug administration (89.6%), and epinephrine was the first choice for drug induced anaphylaxis (79.5%). They also agreed that penicillin skin test was valuable to predict allergic reaction (88.4%). However, high proportion of HCPs (66.0%) believed glucocorticoids had an impact on drug skin test rather than antihistamines (4.2%), 47.1% never performed positive and negative control during skin test. More than 90% of the respondents would take patients' allergic history before drug administration, 98.8% agreed that they should receive advanced training of DA knowledge and practice.ConclusionThe HCPs demonstrated a low level of knowledge regarding DA. Advanced education is urgently needed for better understanding and filling the gaps exist in knowledge and clinical practice of DA.

We report the genetic and biological characterisation of a novel pantropic canine coronavirus (CCoV), strain 450/07, which caused the death of a 60-day-old miniature pinscher. At the genetic level, this virus was strictly related to the prototype strain CB/05, but displayed some unique features. After experimental infection with the new pantropic isolate, most inoculated dogs showed diarrhoea and acute lymphopenia. Gross lesions and histological changes were mainly evident in the gut and lymphoid tissues, although some animals showed remarkable changed also in parenchymatous organs. The viral RNA was detected in the faeces and/or internal organs of most pups. These findings seem to indicate that strain 450/07 is able to spread to internal organs (mainly lymphoid tissues), causing lymphopenia but inducing a mild disease.

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This study is not a clinical trial.