Association between actual weight status, perceived weight and depressive, anxious symptoms in Chinese adolescents: a cross-sectional study

<p>Abstract</p> <p>Backgroud</p> <p>The purpose of this study was to describe actual measured weight and perceived weight and to explore associations with depressive, anxiety symptoms in school adolescents in China.</p> <p>Methods</p> <p>A sample of 1144 Chinese adolescents was randomly selected from four schools in Wuhan, China, including 665 boys and 479 girls with ages ranging between 10 and 17 years. Actual measured weight and height and perceived weight status were compared to anxiety and depressive symptoms measured using the revised Self-Rating Anxiety Scale and Children's Depression Inventory. A general linear model was used to compare differences in psychological symptoms among the teenagers with different measured and perceived weights.</p> <p>Results</p> <p>When compared with standardized weight tables (WHO age- and gender-specific body mass index (BMI) cutoffs (2007 reference)), girls were more likely to misperceive themselves as overweight, whereas more boys misclassified their weight status as underweight. The adolescents who perceived themselves as overweight were more likely to experience depressive and anxiety symptoms (except girls) than those who perceived themselves as normal and/or underweight. However, no significant association was found between depressive and anxiety symptoms actual measured weight status.</p> <p>Conclusions</p> <p>Perceived weight status, but not the actual weight status, was associated with psychological symptoms.</p

Well spacing optimization for Sulige tight sand gas field, NW China

Reasonable well spacing has been studied and assessed to increase the reserves and improve the recovery factor of the Sulige gas field, where the reserves controlled by single well are small. An evaluation methodology for optimizing well spacing in a tight sandstone gas field was established from five aspects including geologic model, drainage radius, interference testing, numerical simulation and economic benefits. The well spacing has been optimized using this method. Through geological modeling, the rational inter-well distance is estimated to be less than 600 m and rational well array distance should be less than 1 000 m. Results of drainage areas estimation reveal that the rational inter-well distance should be ranged from 400 m to 600 m. Analysis of interference well test shows that the low limit for inter-well distance is 400 m and the favorable well array distance is 600 m. Numerical simulation and economic evaluation shows that an inter-well distance of 500 m and well array distance of 700 m are favorable. It is concluded from the above five aspects that, in current economic and technological conditions, the well pattern with inter-well distance at 500 m and well array distance at 700 m is rational in the Sulige gas field, and it can improve the recovery factor to 45%. Key words: tight sand gas field, well spacing optimization, sand body scale, drainage area, economic evaluation, recovery facto

Heritability of serum dehydroepiandrosterone sulphate levels and pubertal development in 6∼18-year-old girls: a twin study

Background: Dehydroepiandrosterone sulphate (DHEAS), the most plentiful circulating adrenal hormone, may be considered as a marker of the onset of adrenarche and is involved in pubertal development and metabolic disorders.Aim: The objective of this study is to determine the genetic and environmental influences on the variation of basal DHEAS levels and pubertal development in pubertal girls.Subjects and methods: Three hundred and sixty twin girls aged 6-18-years were enrolled, consisting of 132 monozygotic pairs and 48 dizygotic pairs. Anthropometric and sexual characteristics were examined. Serum DHEAS was measured by RIA. Estimates of genetic and environmental components of variance were based on the theory of normal maximum likelihood in Mx package.Results: Serum DHEAS concentrations of PH-II and PH-III were significantly higher than Tanner stage PH-I (p&lt;.05) and maintained higher levels in PH-IV approximate to V. Heritability of serum DHEAS estimated by model-fitting on data from 180-pairs of twins is 0.61 (0.52-0.70), the rest of the variance in DHEAS levels could be explained by unique environmental influences and age. The heritabilities of DHEAS in two pubertal sub-groups (PH-I and PH-II-V) are 0.82 (0.71-0.90) and 0.63 (0.52-0.74), respectively. The heritability index of menarche, breast development and pube development are 0.71, 0.35 and 0.45, respectively.Conclusions: Serum DHEAS concentrations of pubertal girls are mainly influenced by genetic factors, especially during the period of adrenarche. The results stress the importance of research into the genetic regulation of the endocrine regulators involved in adrenarche and related metabolic disorders in girls.Chinese National Natural Science Fund [C030104-30371223]; Fundamental Research Funds for the Central Universities [2016YB036]; National Science and Technology Infrastructure Program of China [2009BAK62B04]SCI(E)PubMedSSCIARTICLE4325-3314

Impact of 2D–3D Heterointerface on Remote Epitaxial Interaction through Graphene

Remote epitaxy has drawn attention as it offers epitaxy of functional materials that can be released from the substrates with atomic precision, thus enabling production and heterointegration of flexible, transferrable, and stackable freestanding single-crystalline membranes. In addition, the remote interaction of atoms and adatoms through two-dimensional (2D) materials in remote epitaxy allows investigation and utilization of electrical/chemical/physical coupling of bulk (3D) materials via 2D materials (3D-2D-3D coupling). Here, we unveil the respective roles and impacts of the substrate material, graphene, substrate-graphene interface, and epitaxial material for electrostatic coupling of these materials, which governs cohesive ordering and can lead to single-crystal epitaxy in the overlying film. We show that simply coating a graphene layer on wafers does not guarantee successful implementation of remote epitaxy, since atomically precise control of the graphene-coated interface is required, and provides key considerations for maximizing the remote electrostatic interaction between the substrate and adatoms. This was enabled by exploring various material systems and processing conditions, and we demonstrate that the rules of remote epitaxy vary significantly depending on the ionicity of material systems as well as the graphene-substrate interface and the epitaxy environment. The general rule of thumb discovered here enables expanding 3D material libraries that can be stacked in freestanding form