The Influence of Family Cultural Capital on the Subject Selection Behavior of High School Students Under the New College Entrance Examination in Mainland China: The Mediating Role of Learning Efficacy

The “New College Entrance Examination” reform has become the most difficult part of mainland China’ s current education reform. This study investigates the influence of family cultural capital on the subject selection behavior of Chinese high school students with learning efficacy included as an intermediary variable. Altogether 1258 high school students in Chongqing were surveyed. We find that (1) high school students showed active participation in selecting subjects, and there were significant differences in their selection behavior in terms of grade, parents’ educational background, parents’ occupational level, and family per capita monthly income. Furthermore, (2) the effect of learning efficacy on family cultural capital was significant. The positive influences on high school students’ subject selection behavior were also reflected in the intermediary role of learning efficacy. We also found that (3) the influence of family cultural capital on the selection behavior of high school students is affected by individual and family background variables. Based on these results, countermeasures and suggestions are put forward to help high school students choose courses reasonably

The Influences of Combined Distortions on Fan Performance

Combined distortions negatively affect the aerodynamic stability of fans, but previous studies have limitations. The 3D CFD method was used to calculate the aerodynamic stability of fans under the total pressure and swirl distortion, total temperature and swirl distortion, and total pressure and total temperature distortion in the work. Rotor 67 was taken as the research object. According to the calculation results, the influences of variable distortion parameters on fan performance under combined distortions were summarized to establish the functional relationship between stability margin losses and distortion parameters

Deep Segmentation of OCTA for Evaluation and Association of Changes of Retinal Microvasculature with Alzheimer’s Disease and Mild Cognitive Impairment

BackgroundOptical coherence tomography angiography (OCTA) enables fast and non-invasive high-resolution imaging of retinal microvasculature and is suggested as a potential tool in the early detection of retinal microvascular changes in Alzheimer's Disease (AD). We developed a standardised OCTA analysis framework and compared their extracted parameters among controls and AD/mild cognitive impairment (MCI) in a cross-section study.MethodsWe defined and extracted geometrical parameters of retinal microvasculature at different retinal layers and in the foveal avascular zone (FAZ) from segmented OCTA images obtained using well-validated state-of-the-art deep learning models. We studied these parameters in 158 subjects (62 healthy control, 55 AD and 41 MCI) using logistic regression to determine their potential in predicting the status of our subjects.ResultsIn the AD group, there was a significant decrease in vessel area and length densities in the inner vascular complexes (IVC) compared with controls. The number of vascular bifurcations in AD is also significantly lower than that of healthy people. The MCI group demonstrated a decrease in vascular area, length densities, vascular fractal dimension and the number of bifurcations in both the superficial vascular complexes (SVC) and the IVC compared with controls. A larger vascular tortuosity in the IVC, and a larger roundness of FAZ in the SVC, can also be observed in MCI compared with controls.ConclusionOur study demonstrates the applicability of OCTA for the diagnosis of AD and MCI, and provides a standard tool for future clinical service and research. Biomarkers from retinal OCTA images can provide useful information for clinical decision-making and diagnosis of AD and MCI

Recent Advances in Synthetic Bioelastomers

This article reviews the degradability of chemically synthesized bioelastomers, mainly designed for soft tissue repair. These bioelastomers involve biodegradable polyurethanes, polyphosphazenes, linear and crosslinked poly(ether/ester)s, poly(ε-caprolactone) copolymers, poly(1,3-trimethylene carbonate) and their copolymers, poly(polyol sebacate)s, poly(diol-citrates) and poly(ester amide)s. The in vitro and in vivo degradation mechanisms and impact factors influencing degradation behaviors are discussed. In addition, the molecular designs, synthesis methods, structure properties, mechanical properties, biocompatibility and potential applications of these bioelastomers were also presented

Reynolds stress constrained large eddy simulation of separation flows in a U-duct

AbstractThis paper presents Reynolds stress constrained large eddy simulation (RSC-LES) method applied to a U-duct flow. Different from traditional Reynolds-averaged Navier-Stokes/detached eddy simulation (RANS/DES) hybrid method (including DES method), the RSC-LES method solves the LES equations in the whole computation domain with the near-wall regions being constrained by a prescribed Reynolds stress. By doing so it is possible to overcome the log-law mismatch (LLM) problem in hybrid method. The RSC-LES results show better agreement with experiment result. Compared with RANS and DES, RSC-LES gives more accurate pressure coefficients and friction coefficients on the wall, because the RSC-LES method captures the separation point and reattachment point on the inner wall. The computation results show that the RSC-LES method has the potential to solve the log-law mismatch problem of RANS/DES hybrid method and predict complex phenomena of internal flow field

Association between GCKR gene rs780094 (C＞T) polymorphism and non-alcoholic fatty liver disease in Han population in Qingdao, China

Objective To investigate the association between glucokinase regulatory protein (GCKR) gene rs780094 (C＞T) polymorphism and non-alcoholic fatty liver disease (NAFLD) in the Han population in Qingdao, China. Methods A case-control study was conducted in 180 patients with NAFLD and 172 healthy controls. Blood samples were collected from all the subjects and were genotyped for rs780094 by polymerase chain reaction and DNA sequencing method. Genotype and allele frequencies were compared between the control and case groups. Results No significant differences between the two groups were observed in both genotype and allele frequencies (both P＞0.05). The variant GCKR rs780094 T allele did not significantly increase the risk of NAFLD (OR=1.068, 95% CI: 0.748-1.525, P=0.719) compared with the C allele. Logistic regression model analysis adjusted for confounding factors exhibited that the TT + CT genotype of GCKR rs780094 did not significantly increase the risk of NAFLD relative to the CC genotype (P＞0.05). Conclusion GCKR rs780094 T allele may be not associated with the increased risk of NAFLD in the Han population in Qingdao

Sand Discharge Simulation and Flow Path Optimization of a Particle Separator

A numerical simulation method is used to optimize the removal of sand from a helicopter engine particle separator. First, the classic configuration of a particle separator based on the literature is simulated using two boundary conditions. The results show that the boundary conditions for the total pressure inlet and mass flow outlet are much more closely aligned with the experimental environment. By modifying the material at the front of the shroud, the separation efficiencies of coarse Arizona road dust (AC-Coarse) and MIL-E-5007C (C-Spec) can be improved to 93.3% and 97.6%, respectively. Configuration modifications of the particle separator with dual protection can increase the separation efficiencies of AC-Coarse and C-Spec to 91.7% and 97.7%