Search

Objective: Improve the mechanization and automation of the pretreatment process of China's freshwater fish processing industry. Methods: The catfish head cutting simulation model is constructed by the numerical analysis software ANSYS/LS-DYNA, and the catfish head removal process is simulated and analyzed and the motion parameters are optimized by FEM. The blade speed and transportation speed are adjusted with the minimum cutting power consumption as the optimization goal, and the accuracy of the simulation results is verified by the prototype test. Results: When the speed of the blade is 850 r/min and the conveying speed is 14 cm/s, the cutting section of the fish head is smooth and smooth, the sensory of the section is good, and the cutting efficiency of the head can be guaranteed. Conclusion: The established simulation model of disc cutter cutting fish head can describe the motion process, but the accuracy needs to be improved.

Objective: In order to improve the mechanization and automation level of catfish head cutting. Methods: Through the study on the shape parameters and friction characteristics of catfish, the related parameters of catfish were obtained. Based on the machine vision technology to identify the assembly line fish, the end of the fish skull was defined as the fish head cutting track line, and an adaptive adjustment device was designed to adjust the position of the fish body, so that the disc cutter can avoid the skull for head removal. The GUI was designed in order to achieve visual control. Results: The system test results showed that the success rate of cutting track line discrimination of the image acquisition system reached 90%, with the average error of the adaptive adjustment system of 0.21 cm, which confirmed the reliability of the system. Conclusion: According to the preset processing efficiency, about 600 catfish can be processed per hour.

Bidirectional controllable propagation of waterborne sound holds significant importance in developing multifunctional underwater acoustic and mechanical devices. However, the existing waterborne acoustic metasurfaces have rarely explored the bidirectional sound modulations. Here, a class of Janus waterborne acoustic metasurface, enabling two‐faced arbitrarily asymmetric wavefront manipulations is reported. A three‐degree‐of‐freedom mechanical system facilitated by acoustic‐structure interaction underwater is proposed to introduce bianisotropic responses of unit cells. Monolayer ultrathin Janus metasurface is inversely designed by utilizing a function‐structure integrated topology optimization framework. Distinct underwater acoustic functionalities, including axial and oblique focusing, beam splitting, and sound diffusion, are successfully demonstrated. Underwater experiments are further conducted to validate the concept of Janus metasurface. The good consistency between experimental and simulated results confirms the excellent two‐faced asymmetric acoustic focusing performance. The proposed Janus metasurface opens up a new dimension for designing advanced waterborne acoustic devices with two‐faced multifunctional wavefront manipulations. [ABSTRACT FROM AUTHOR]

Objective To explore the attitude of medical students to premarital sex and its association with social ecological risk factors, so as to provide scientific basis for sex education in schools and relevant departments. Methods From September to November 2021, an anonymous survey was conducted among 1 280 students from a medical college in Shanxi Province, including general demographic characteristics, socio-ecological risk factors, and attitudes toward premarital sexual behavior. Results There was 39.75 percent of the students who had a positive attitude toward premarital sex. After adjusting for general demographic characteristics, binary logistic regression analysis showed that in the household dimension, the approving rate about premarital sex of high-risk group (OR = 1.61, 95%CI: 1.01-2.54) was 1.61 times higher than in the low-risk group. In the time dimension, the approving rate about premarital sex of medium-risk group (OR = 1.57, 95%CI: 1.14-2.17) was 1.57 times more than the low-risk group, and compared with the low-risk group of the cultural dimension, the medium-risk group (OR = 1.96, 95%CI: 1.43-2.69) and the high-risk group (OR = 4.75, 95%CI: 3.24-6.97) were positively correlated with premarital sexual attitudes, that is, the higher the approval of premarital sex is, as the risk increased. The results of WQS model analysis showed that cultural dimension had the most influence on medical students' attitudes towards premarital sexual behavior, accounting for 45.40%, meantime, time dimension and family dimension accounted for 15.60% and 14.40%, respectively. Conclusion The positive attitude of medical students towards premarital sexual behavior is the result of the comprehensive effect of social and ecological risk factors. Besides the high-risk family factors and the medium-risk time factors, the medium and high-risk cultural factors increase the approval of premarital sexual behavior of medical students. Then, the cultural factors have the most influences on the outcome. [ABSTRACT FROM AUTHOR]

C23H23AgN4O8S, monoclinic, P21/n (no. 14), a = 8.5356(4) Å, b = 27.9494(15) Å, c = 10.3796(6) Å, V = 2474.1(2) Å3, Z = 4, R gt(F) = 0.0347, wR ref(F 2) = 0.0744, T = 289 K.

The objective of this study was to evaluate the effect of empowerment education on depression level and laboratory indicators of patients treated with hemodialysis.

This meta-analysis aims to evaluate the effects of traditional Chinese medicine (TCM) nursing combined with conventional nursing in patients with chronic obstructive pulmonary disease (COPD).

Zinc is widely used as an anode in zinc‐ion batteries (ZIBs) due to its nontoxicity, favorable theoretical specific capacity, and low oxidation–reduction potential. Nevertheless, irreversible Zn dendritic growth and unavoidable side reactions limit its cyclic stability and high‐rate capability. This research puts forward a surface protection strategy by introducing a hydrophobic polyvinylidene fluoride and carborundum nanocoating (PVDF‐SiC) coating on the surface of Zn anode to synergistically restrain side reactions and Zn dendrites. PVDF improves the hydrophobicity of Zn anode at the solid–liquid interface, which can avoid side reactions between Zn anode and water. SiC nanoparticles with high porosity and small size pore can also homogenize the Zn2+ flux, which can cause uniform Zn deposition and inhibit Zn dendrite growth. The hydrophobic PVDF‐SiC@Zn symmetric battery accordingly exhibits an invariable overvoltage (<40 mV) after 780 h at 1 mA cm−2 with 0.25 mAh cm−2. Simultaneously, constant and convertible Zn deposition in PVDF‐SiC@Zn//Ti asymmetric battery is implemented. The PVDF‐SiC@Zn//V2O5 full battery exhibits 68% capacity retention after 400 cycles. The porous/hydrophobic PVDF‐SiC composite modification efficiently restrains the side reactions and Zn dendrite growth on the Zn anode, providing an innovative idea for achieving long‐life ZIBs. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to evaluate serum zinc status of pregnant women in the China Adult Chronic Disease and Nutrition Surveillance (CACDNS) in 2015–2016. Methods: A total of 7147 apparently healthy pregnant women were randomly selected in 302 national monitoring sites. Information on age, race, residence region, education, pregnancy, and family income per annum was collected, and the concentration of serum zinc was determined. The evaluation of serum zinc status was further performed according to the recommendations by the International Zinc Nutrition Consultative Group (IZiNCG). Results: The median concentration of serum zinc was 858.9 μg/L with an interquartile range (IQR) of 712.9 μg/L and 1048.9 μg/L, while the overall prevalence of zinc deficiency was 3.5% with a 95% confidence interval (CI) of 3.0% and 3.9%. Serum zinc status of pregnant women changed greatly in the different categories, particular in pregnancy and family income per annum (p < 0.05), but no significant difference was observed in the prevalence of zinc deficiency (p > 0.05). Conclusions: The lower prevalence of zinc deficiency generally indicated a better zinc status for pregnant women in the CACDNS in 2015–2016. However, a well-designed evaluation system of zinc status for pregnant women should be continually optimized and improved by inducing more parameters such as biochemical, dietary, or functional indicators.

Potassium (K) metal batteries are attracting considerable attention due to their low cost and high energy density. However, the practical application of K metal batteries is hampered by severe K dendrite growth and enormous volume variation during cycling on the K anode. Herein, a 3D-CTZ@K anode was fabricated by infusing molten K into a near-perfect scaffold (3D-CTZ), which was constructed by adsorbing K nucleation "seeds" (Ti3C2 MXene encapsulated ZnO nanoparticles, denoted as TZ hybrids) inside a 3D inter-connected porous carbon foam (3D-CF). Because of high potassiophilicity, large void space, extraordinary mechanical stability, and electron conductivity, the 3D-CTZ scaffold not only provides abundant K nucleation sites and rapid electron transfer paths but also physically confines the K deposition, suppressing volume variation during K plating/stripping processes. Consequently, 3D-CTZ@K achieves a dendrite-free K behavior and alleviates volume variation, realizing extraordinary cycle stability and high rate capability. The 3D-CTZ@K//PB full battery also delivers excellent long-cycle stability with an enhanced capacity retention of 75.1% and an ultrahigh energy density of 352.5 W h kg−1 at a power density of 7548.2 W kg−1. Such a sustainable K anode design sheds light on the design of dendrite-free K metal batteries and also other alkali metal batteries. [ABSTRACT FROM AUTHOR]

Four compounds (1, 5, 7, and 8) were first isolated from the genus Belamcanda Adans. nom. conserv., and six known compounds (2–4, 6, 9, and 10) were isolated from the rhizome of Belamcanda chinensis (L.) DC. Their structures were confirmed by spectroscopic data. Herein, compounds 1–10 were rhapontigenin, trans-resveratrol, 5,7,4′-trihydroxy-6,3′,5′-trimethoxy-isoflavone, irisflorentin, 6-hydroxybiochannin A, iridin S, pinoresinol, 31-norsysloartanol, isoiridogermanal, and iristectorene B, respectively. All compounds were evaluated for their antiproliferative effects against five tumor cell lines (BT549, 4T1, MCF7, MDA-MB-231, and MDA-MB-468). Among them, compound 9 (an iridal-type triterpenoid) showed the highest activity against 4T1 and MDA-MB-468 cells. Further studies displayed that compound 9 inhibited cell metastasis, induced cells cycle arrest in the G1 phase, exhibited significant mitochondrial damage in 4T1 and MDA-MB-468 cells including excess reactive oxygen species, decreased mitochondrial membrane potential, and induced 4T1 and MDA-MB-468 cell apoptosis for the first time. In summary, these findings demonstrate that compound 9 exerts promising potential for triple-negative breast cancer treatment and deserves further evaluation. [ABSTRACT FROM AUTHOR]