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Objective: To improve the mixing efficiency and working performance of the new twin-screw extruder. Methods: A new twin-screw extruder with embedded planetary gear train and kneading block was designed. A three-dimensional model was established by SolidWorks, and the flow field analysis of the flow channel was performed by ANSYS/CFS finite element analysis software based on the finite volume method. The Macroscopic pressure diagram, velocity vector diagram, velocity flow diagram were gotten, which was compared with the traditional twin-screw extruder three-dimensional flow field. Results: Under the gradual action of the planetary gear train and the kneading block, the mixing performance and working efficiency of the stepwise acceleration twin screw extruder were significantly better than those of the traditional twin screw. By calculation, the stepwise accelerated twin screw was 20% ~ 25% higher than the traditional twin screw. Conclusion: In the process of continuous acceleration, the gradual acceleration twin screw makes the residence time of the material in the barrel shorter o increase production and reduce energy consumption, and the addition of kneading block makes the material get better shearing.

Objective: In order to improve the mixing performance and work speed of a single screw extruder increase. Methods: A coaxial gradual acceleration single screw using planetary wheel assemblies and mixing elements was designed. Using ansys/cfx to conduct the three-dimensional flow field analysis of the flow channel, the macro pressure field, speed vector diagram, speed streaming diagram and axial speed changes, were finished, which was compared to the only traditional pillar. Results: As the speed of the pillar continues to increase, the time for the material to stay in the barrel becomes shorter, and the extrusion efficiency of the gradual acceleration screw can be improved by 20% to 25%, so that the energy consumption is greatly reduced, due to the presence of the kneading block, the material is repeatedly squeezed at the kneading block, so that the gradual acceleration of the single screw in the increase in production capacity at the same time the mixing performance can be guaranteed. Conclusion: The coaxial gradual acceleration of the single screw high-speed rotation of the kneading block can make the material mix more fully, and can shorten the residence time of the material in the screw, improve the output.

Objective: This study aimed to investigate the difference of bioactivators from different flaxseed. Methods: 12 flaxseed varieties were used as study objectives, 8 kinds of bioactivators from different varieties of flaxseed were measured and analyzed by principal component and clustering. Results: The order of effect of flaxseed varieties on bioactive substances was as follows: lignan＞total cyanide＞flavone＞phytosterol＞total phenolic acid＞tocopheronic acid＞FRAP value＞DPPH value. 3 principal components were extracted by principal component analysis and their accumulative contribution rate reach to 82.925%. The first, second and third principal component were mainly determined by flavone and FRAP values, lignan and tocopheronic acid, total cyanide and total phenolic acid, respectively. 12 flaxseed varieties were divided into three groups by clustering analysis, and their comprehensive assessment value reduced successively. Group I include Baya11, Ningya17, Baya9, Longya8 and Lunxuan2, Group II include Longya10, Ningya16 and Ningya16 and Jinya7, and Group III include Lunxuan1, Jinya8, Yiya3 and Yiya4. Conclusion: Comprehensive score of Baya11 is the highest, and it has higher nutritional value.

Abstract Background Artificial induction of mutagenesis is effective for genetic resource innovation and breeding. However, the traditional mutation methods for fish breeding are not convenient or safe for daily use. Hence, development of a simple, safe and effective mutagenesis method with a high mutation rate and applicability to multiple fish species, is needed. Results We reported the first successful mutagenesis in a marine aquaculture fish species, Japanese flounder, Paralichthys olivaceus, using a novel atmosphere and room temperature plasma (ARTP) mutagenesis tool. ARTP treatment time was optimized for the fertilized eggs and sperm, respectively. Eggs fertilized for 60 min were treated by ARTP with a radio-frequency power input of 120 W, and the ARTP treatment time was 25 min. Under an ARTP radio-frequency power input of 200 W, the optimal treatment time for sperm diluted with Ringer’s solution by 1:40 v/v was 10 min. The ARTP-treated group presented differences in morphological traits such as body height, total length among individuals at day 90 after hatching. Whole-genome sequencing was used to reveal the mutation features of ARTP-treated individuals collected at day 120 after hatching. In total, 69.25Gb clean data were obtained from three controls and eight randomly selected ARTP-treated individuals, revealing 240,722 to 322,978 SNPs and 82,149 to 86,798 InDels located in 17,394~18,457 and 12,907~13,333 genes, respectively. The average mutation rate reached 0.064% at the genome level. Gene ontology clustering indicated that genes associated with cell components, binding function, catalytic activity, cellular process, metabolic process and biological regulation processes had higher mutation rates. Conclusions ARTP mutagenesis is a useful method for breeding of fish species to accelerate the selection of economically important traits that would benefit the aquaculture industry, given the variety of mutations detected.

During the 2015-2016 school year, the Florida Department of Health in Duval County hosted Teen Health Centers (TeenHC) at five high schools of Jacksonville providing HIV/STD screening and pregnancy testing. The purpose of this study was to assess the cost-effectiveness of the TeenHC chlamydia screening program and determine at what student participation level, the program can be cost-effective. We assessed the costs and effectiveness of the chlamydia screening program compared with "no TeenHC". Cost-effectiveness was measured as cost per quality-adjusted life years (QALY) gained. At a program cost of US$61,001 and 3% participation rate, the cost/QALY gained was $124,328 in the base-case analysis and $81,014-$264,271 in 95% of the simulation trials, all greater than the frequently citied $50,000/QALY benchmark. The cost/QALY gained could be <$50,000/QALY if student participation rate was >7%. The TeenHC chlamydia screening has the potential to be cost-effective. Future program efforts should focus on improving student participation.

The characteristics of phase scintillation (represented by the phase scintillation indices, σφ) from GPS and Beidou are statistically analyzed using a ground‐based receiver at Zhongshan Station, Antarctica, from 2020 to 2022 for the first time. The phase scintillation of the GPS and Beidou signals present a similar pattern of occurrence. The statistical results on the occurrence morphology of phase scintillation show that the phase scintillation predominately occurs in the magnetic pre‐noon and pre‐midnight sectors. Moreover, phase scintillation performs a dependence on solar and geomagnetic activities. Furthermore, the phase scintillation also gives a seasonal variation with the maximum occurrence happened at the autumn and the minimum occurrence during the summer. Consequently, these results improve understanding of the morphological characteristics of the phase fluctuations in the less studied Antarctic region. The study also demonstrates the use of the combined data set to improve the coverage in the Antarctic region. Key Points: Morphological characteristics of phase scintillation of GPS and Beidou signals at Zhongshan station, Antarctica, for the first timeThe occurrences of phase scintillation mainly concentrated in the prenoon and pre‐midnight sectors for both signalsThe similar behaviors of phase scintillation convey the usefulness of the combined data for irregularity studies in the polar region [ABSTRACT FROM AUTHOR]

Purpose: The Youth Risk Behavior Survey (YRBS) among high school students includes standard questions about sexual identity and sex of sexual contacts, but these questions are not consistently included in every state that conducts the survey. This study aimed to develop and apply a method to predict state-level proportions of high school students identifying as lesbian, gay, or bisexual (LGB) or reporting any same-sex sexual contacts in those states that did not include these questions in their 2017 YRBS. Methods: We used state-level high school YRBS data from 2013, 2015, and 2017. We defined two primary outcomes relating to self-reported LGB identity and reported same-sex sexual contacts. We developed machine learning models to predict the two outcomes based on other YRBS variables, and comparing different modeling approaches. We used a leave-one-out cross-validation approach and report results from best-performing models. Results: Modern ensemble models outperformed traditional linear models at predicting state-level proportions for the two outcomes, and we identified prediction methods that performed well across different years and prediction tasks. Predicted proportions of respondents reporting LGB identity in states that did not include direct measurement ranged between 9.4% and 12.9%. Predicted proportions of respondents reporting any same-sex contacts, where not directly observed, ranged between 7.0% and 10.4%. Conclusion: Comparable population estimates of sexual minority adolescents can raise awareness among state policy makers and the public about what proportion of youth may be exposed to disparate health risks and outcomes associated with sexual minority status. This information can help decision makers in public health and education agencies design, implement and evaluate community and school interventions to improve the health of LGB youth. [ABSTRACT FROM AUTHOR]