Growth charts for children aged 6-17 years in Shanxi, China: comparison with other cities of China and WHO.

BACKGROUND: Growth charts are an important method for evaluating a child's health, growth, and nutritional status. It is essential to monitor the growth of children and adolescents using growth charts. OBJECTIVES: To present body mass index (BMI)-for-age references reflecting children's growth in Shanxi. We also compare our new data with growth references of other cities of China and World Health Organization (WHO) growth standards. METHODS: A stratified cluster random sampling method was used to recruit 5461 children and adolescents aged 6-17 years. Height and weight were measured and BMI was calculated. The LMS method was used to calculate the percentile values of body mass index by sex and age. Smoothed BMI-for-age growth curves were presented for both sexes and compared with reference data from other cities of China and WHO. RESULTS: BMI centiles increased with age but with different patterns in both boys and girls. The centile curves from the 3rd to the 50th had a slight increase, while a sharp increase was seen from 11 to 17 years in boys and from 6 to 14 years in girls in the higher centiles. In comparison with other cities of China, the values for the 50th percentile are higher than those reported for children from China 2009, Shanghai, Changsha and China 2010 in both sexes. In comparison with WHO growth references, Chinese girls and boys had higher values in all percentiles, whereas curves of girls look roughly the same. The medians for BMI in Shanxi increase linearly from 6 to 17 years in boys. CONCLUSIONS: The BMI percentiles of children aged 6-17 years in Shanxi differed significantly from the growth reference curves of other cities of China and WHO. Recommending the provision of BMI reference curves for local children and adolescents to assess their growth and development and monitor their nutritional status. Early detection of overweight and obesity in children provides a scientific basis for the prevention and control of overweight and obesity in children.

Active volatile components of the preferred hosts are potential attractants to Hyphantria cunea adults.

The extraordinary adaptability and dispersal abilities have allowed Hyphantria cunea to expand its range, posing a great threat to urban landscapes and natural ecosystems. Searching for safe, efficient, and low-cost control methods may provide new strategies for pest management in H. cunea spread areas. In this study, based on the attraction of insects by preferred hosts, it was found that the response rates of virgin H. cunea female adults to Salix matsudana, Juglans mandshurica and Ulmus pumila were 89.17%, 97.92% and 93.98%, respectively. It was further found that this significant preference was mainly related to the volatiles m-xylene, o-xylene, dodecane and tetradecane found in the three species. Even though all four compounds at 10 µL/mL and 100 µL/mL had significant attractive effects on the virgin H. cunea female adults, m-xylene and dodecane at 100 µL/mL elicited significant EAG responses and tending behaviors by stimulating the olfactory receptor neurons (ORN A) of females, with response rates of 83.13% and 84.17%, while also having significant attractive effects on virgin male adults with rates of 65.74% and 67.51%. Therefore, both m-xylene and dodecane which at concentrations of 100 µL/mL had strong attractions to adults, could be used as the first choice of attractants for both sexes of H. cunea. This has important practical significance in reducing the frequency of H. cunea generations, limiting their population, controlling their spread range, and improving the efficiency of pest management in epidemic areas.

Performance of four simplified screening methods of elevated blood pressure among children and adolescents / 中国学校卫生

Objective@#To evaluate the performance of four simplified screening methods of elevated blood pressure commonly used among children and adolescents according to Chinese guidelines for prevention and treatment of hypertension (revised in 2018), so as to provide a reference for the early detection of the elevated blood pressure among children and adolescents.@*Methods@#Stratified cluster random sampling method was used to monitor the physical fitness of 5 211 children and adolescents in a city of Shanxi Province from October to November 2021. Chinese guidelines for prevention and treatment of hypertension was considered as gold standard, and sensitivity, specificity, area under the curve (AUC) and Kappa value were calculated to evaluate the screening effectiveness of formula method, height specific method, age group specific method, sex and age specific method for screening elevated blood pressure.@*Results@#The detection rates of elevated blood pressure among children and adolescents screened by gold standard, formula method, height specific method,age group specific method, sex and age specific method were 21.9%, 24.0%, 21.1%, 24.5% and 20.2%, respectively. There was no significant difference between prevalence of elevated blood pressure screened by formula method, sex and age specific method and gold standard( χ 2=1.21, 1.41, P >0.05), whereas height specific method and age group specific method had significant differences with gold standard ( χ 2=20.39, 67.09, P <0.05). AUC was the largest for height specific method [0.94(95% CI =0.93-0.95)], and the smallest for age group specific method [0.87(95% CI = 0.86 -0.88)]. The Kappa values of height specific method (0.89) and sex and age specific method (0.89) were both greater than 0.85 , which were more consistent with the screening effectiveness of gold standard. When comparing by sex, age and body mass index (BMI), the screening effectivenesses were consistent with the overall in boys, 6-11 years and normal body weight groups, while the screening effectivenesses were different in girls, 12-17 years, overweight and obese groups. The AUC (0.87), Kappa value (0.71) and sensitivity (82.33%) of age group specific method were the lowest and the screening effectiveness was the worst.@*Conclusion@#Height specific method is more effective and can be used for early identification and self detection of blood pressure abnormalities among children and adolescents.

Study of Raman scattering enhancement method based on optical multiplexing for on-line detection of gas components in strong-impact environments.

On-line gas detection under strong impact such as combustion and explosion is of great significance for understanding the reaction processes. To realize simultaneous on-line detection of various gases under strong impact, an approach based on optical multiplexing for enhancing spontaneous Raman scattering is proposed. A single beam is transmitted several times using optical fibers through a specific measurement point in the reaction zone. Thus, the excitation light intensity at the measurement point is enhanced and the Raman signal intensity is substantially increased. Indeed, the signal intensity can be increased by a factor of ∼10, and the constituent gases in air can be detected with sub-second time resolution, under a 100 g impact.

Effect of Leaching Behavior on the Geometric and Hydraulic Characteristics of Concrete Fracture.

The leaching of material from concrete fracture surfaces has an impact on the structural concrete in service, but the number of studies that consider the effect of the coupling of the leaching, fracture geometry and hydraulic processes on concrete fractures is insufficient. In this study, a series of experiments was conducted, and a leaching model proposed, to investigate the mechanism of leaching behavior on the geometric and hydraulic characteristics of concrete fractures. Following the leaching experiment, the evolution of fracture geometric characteristics was observed by a three-dimensional (3D) laser scanning technique, finding that the fracture produces residual leached depth and local uneven leaching, which results in a decrease in roughness. The hydraulic characteristics were then investigated by permeability tests, and it was found that the fracture hydraulic aperture and permeability increase monotonically with leaching time. A simulation of fluid flow in a numerical fracture revealed the effect of residual leached depth and a decrease in roughness on the hydraulic characteristics. Finally, based on the analysis of the chemical composition of the leaching solution, a leaching model of concrete rough fracture surface is proposed and the mechanism of leaching behavior is discussed. These new findings are useful for the understanding of the development of leaching, local to concrete fracture surfaces.

Thermal modeling of high-power Yb-doped fiber lasers with irradiated active fibers.

With both radiation effects and thermal effects taken into consideration, a multiphysics thermal model concerning high-power Yb-doped fiber lasers operated with post-irradiated active fibers is established. Radiation-related parameters, including propagation losses, refractive indexes and lifetime, are considered. And, with the temperature profile of the active fiber, temperature-dependent parameters, including absorption and emission cross-sections, refractive indexes and lifetime, are updated every loop to simulate the output parameters. Simulation results show that radiation induces great changes to the thermal profiles of the active fiber. And severe performance degradation of high-power Yb-doped fiber lasers are recorded, featuring a remarkable drop in output power and an even steeper decline in the transverse mode instability threshold, which is a predominant limitation at high radiation doses. With a deposited radiation of 100 Gy, an output decline of about 50% and a mode instability threshold drop over 85% are observed. And it's shown that, with the exploited active fiber, it's hardly possible for the investigated fiber laser to generate stable single-mode output at kilowatt levels with accumulated radiation doses beyond 50 Gy. At low radiation doses within 20 Gy, to maintain safe and stable single-mode operation of the laser system, longer active fibers with lower absorption coefficients are preferred despite a small rollover of the output power.

High energy closed-loop cycle narrow linewidth optically pumped XeF(C-A) blue laser at a repetition rate of 10 Hz.

We report for the first time on a closed-loop cycle narrow linewidth XeF(C-A) blue laser at a repetition rate of up to 10 Hz with each pulse energy of >1 J. A FWHM linewidth of less than 1.5 nm (minimum to 1.1 nm) with a highly stable wavelength centered at 488.3 nm was achieved by employing a polarization-independent custom-designed narrowband optical filter (NBOF) into the cavity. The pulse energy, as well as the repetition rate, to the best of our knowledge, is the highest ever reported in the narrow linewidth XeF(C-A) blue lasers at repetitively-pulsed mode.

Wavelength-tunable passively mode-locked mid-infrared Er3+-doped ZBLAN fiber laser.

A passively mode-locked Er3+-doped ZBLAN fiber laser around 3 µm with a wide wavelength tuning range is proposed and demonstrated. The laser cavity was comprised of a semiconductor saturable absorber mirror and a blazed grating to provide a wavelength tunable feedback. The central wavelength of the mode-locked fiber laser can be continuously tuned from 2710 to 2820 nm. The pulse train had a maximum average power of higher than 203 mW, a repetition rate of 28.9 MHz and a pulse duration of 6.4 ps, yielding a peak power of exceeding 1.1 kW. To the best of our knowledge, this is the first demonstration of a wavelength-tunable passively mode-locked mid-infrared fiber laser at 3 µm.

Watt-level passively Q-switched heavily Er(3+)-doped ZBLAN fiber laser with a semiconductor saturable absorber mirror.

A diode-cladding pumped mid-infrared passively Q-switched Er(3+)-doped ZBLAN fiber laser with an average output power of watt-level based on a semiconductor saturable absorber mirror (SESAM) is demonstrated. Stable pulse train was produced at a slope efficiency of 17.8% with respect to launched pump power. The maximum average power of 1.01 W at a repetition rate of 146.3 kHz was achieved with a corresponding pulse energy of 6.9 µJ, from which the maximum peak power was calculated to be 21.9 W. To the best of our knowledge, the average power and the peak power are the highest in 3 µm region passively Q-switched fiber lasers. The influence of gain fiber length on the operation regime of the fiber laser has been investigated in detail.

Super-flat supercontinuum generation from a Tm-doped fiber amplifier.

Super-flat supercontinua are generated from a double clad Tm-doped fiber amplifier. Two different laser configurations are investigated and compared. In the direct-output configuration, the long-wavelength edge of the supercontinuum spectra is extended to beyond 2.65 µm with a 10 dB bandwidth of 740 nm. In the passive pigtail configuration, the generated supercontinuum features excellent flatness with an intensity difference smaller than 1 dB in the wide central spectral range from 1.98 µm to 2.41 µm.