The role of C-type natriuretic peptide in rat testes during spermatogenesis

C-type natriuretic peptide （CNP） is a 22-amino acid peptide and act as a local paracrine or autocrine regulator. There is growing evidence that ChIP is involved in male reproductive processes. To investigate the role of CNPduring spermatogenesis, we measured the mRNA expression of CNPand its specific membrane-bound natriuretic peptide receptor-B （NPR-B） using real-time RT-PCR in the testes of normal rats on different postnatal days. After that spermatogenesis dysfunction model induced by ornidazole was established with the aim to study the correlation of CNPwith spermatogenic dysfunction. Then, Sertoli cells from 18- to 22-day-old healthy male rats were cultured in the presence of different CNPconcentrations （1 ×10-6, 1×10-7 and1×10-8 mol l-1）, and the mRNA expression levels of androgen.binding protein, inhibin B and transferrin were examined at 0 min, 30 min, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h and 48 h. During the postnatal development of rat testes, the highest mRNA expression levels of CNPand NPR-B were found at postnatal Do, and the levels then declined gradually, with a second ChIPpeak at postnatal D35. In the ornidazole-induced infertile rat testes, CIVPgene expression was lower than in the uninduced rats （P〈0.05）, while IVPR-Bgene expression was greater （P〈0.05）. In cultured Sertoli cells, supplementation with CNP stimulated the gene expression of androgen-binding pmteirginhibin B/transferrin, particularly at 12 h, and 1× 10-7 mol l-1 CNP had the highest upregulation effect. The gene expression levels of CNPIIVPR-B in rat testes at different postnatal stages and in infertile rat testes indicated that CNP may participate in the physiology and/or pathology related to spermatogenesis. Moreover, ChIP regulated endocrine function in Sertoli cells. Taken together, these results showed that CNP is closely tied to spermatogenesis.

Association of the Common Genetic Variant Upstream of INSIG2 Gene with Obesity Related Phenotypes in Chinese Children and Adolescents

Objective To study the association between the rs7566605 variant of INSIG2 and obesity-related phenotypes in Chinese children and adolescents. Methods The study sample consisted of two independent cohorts of Chinese children and adolescents. Anthropometric indices, lipids, blood pressure, fasting glucose, insulin and percentage of fat mass were determined. PCR with restriction fragment length polymorphism analysis was performed for genotyping the rs7566605 variant. Results In each of the two independent cohorts, no significant association was observed between rs7566605 and obesity under additive, dominant or recessive model. We also did not detect any difference in the genotype frequency between all the obese children and controls. Furthermore, we did not find evidence of an association between body composition indices and metabolic phenotypes in all children. However, the triglyceride level of CC homozygotes was significantly higher than that of GG＋GC genotypes in obese children （P=0.022）. Additionally, we observed a non-significant trend of severe obesity in a post-hoc test. Conclusion INSIG2 rs7566605 variant is not associated Chinese childhood obesity in two independent cohorts. Further study is needed to verify the effect of rs7566605 on triglyceride in obese children.

Comparison of Changes in Body Composition during Puberty Development of Obese and Normal-weight Children in China

Objective To compare the changes in body composition, including fat mass index （FMI） and fat free mass index （FFMI） during puberty development of obese and normal-weight children in China, and to explore the effect of age and gender on body composition. Methods A total of 356 children at the age of 7-15 years were enrolled in this study. Body composition of 10 normal-weight and obese children in each age group was measured by dual-energy x-ray absorptiometry （DEXA）. FFMI and FMI were calculated according to the following formula： FFMI （kg·m^-2）=FFM（kg）/ height^2（m^2） and FMI（kg·m^-2）=FM （kg）/ height^2（m^2）. Results The fat mass and fat free mass of obese children were significantly higher than those of normal-weight children （P〈0.05）. The FMI and FFMI of obese children increased significantly with age and were higher than those of the same sex, gender, and age normal-weight children （P〈0.05）. Conclusion The levels of fat mass, fat free mass, FMI, and FFMI are different in obese and normal-weight children, and gender effects are significant in boys having higher levels of these indicators than in girls. FFMI and FMI can be used as monitoring indexes in weight control of obese children.

A novel variable topology design for a multi-flexible ejection mechanism

The airborne missile launch mechanism often subjects to significant deformations induced by the large ejection force during high-speed actuations in missile ejection process,leading to a substantial deviation of separation parameters from designed values that threats safety of the carrier.This study proposes a novel variable topology design for launch mechanism,achieved via a Prsmatic-Revolute-Revolute pair(PR-R)motion formed by the structural gap with a specific direction.It enables launch mechanism variability during missile ejection process and optimizes the ejection force given by the front and back ejection arms,and greatly optimizes the separation parameters during missile ejection.The kinetics simulation analysis is conducted under working conditions of the original ejection mechanism and the novel mechanism with variable topology design,respectively.The results show that the novel variable topology design is more befitting for the launch process in terms of system safety and controllability,effectively improving the separation posture,restraining the flexible effect of the mechanism,and fulfilling the effectiveness of the design value of multi-rigid body.

MDA-JITL model for on-line mechanical property prediction

Mechanical performance prediction is the key to the transformation and upgrading of steel enterprises to intelligent manufacturing.Due to time-varying manufacturing data,the traditional prediction model of mechanical properties of hotrolled strip may cause performance degradation or even failure in its use.An MDA-JITL model was thus proposed to handle the modeling problem of complex time-varying data.Relevant parameters were first chosen and normalized.Then,a distance measurement method combining the importance of data attributes and time characteristics was designed to select the most suitable samples for on-line local modeling.After that,using the chosen dataset,a linear local model was created to predict target sample.Finally,an uncertainty evaluation method was designed to evaluate the uncertainty of prediction results.Furthermore,the appropriate dataset partition and off-line simulation experiment scheme were created based on the peculiarities of hot-rolling production.The suggested model performs much better than the classic global model when applied to actual production data from a steel plant.The stability of its prediction accuracy is demonstrated in a simulation prediction for up to five months.Moreover,there is a high link between the uncertainty evaluation metrics and the prediction error of the model,reducing the field sampling rate by 30%in industrial applications in the latest year.

Na_(3)Zr_(2)Si_(2)PO_(12) solid-state electrolyte with glass-like morphology for enhanced dendrite suppression

Rechargeable batteries based on solid-state electrolytes are of great interest and importance for the next-generation energy storage due to their high energy output and improved safety.For building the solid-state batteries,Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)represents a promising candidate as it features high chemical stability against air exposure and a high Na^(+)conductivity.NZSP pellets were usually calcined at a high temperature,and the high volatility of Na and P elements easily led to the formation of impurity phase.In this work,the effects of calcination temperature and stoichiometry on the phase purity and ionic conductivity of the NZSP electrolyte were studied.At an elevated sintering temperature,the NZSP electrolyte showed a high ionic conductivity owing to decreased porosity,and the highest ionic conductivity at 30℃was observed to be 2.75×10^(-5)S·cm^(-1)with an activation energy of 0.41 eV.For the stoichiometry,the introduction of 5 mol%excessive P results in formation of more Na_(3)PO_(4) and glass-like phase at the grain boundary,which caused the blurred grain boundary and reduced grain barrier,and effectively suppressed Na dendrite growth,then accounted for improved cycling performance of a Na‖Na symmetric cell.Our work provided insights on reasonable design and preparation of NZSP electrolyte towards practical realization of solid-state Na-metal batteries.