Analysis for sources of atmospheric α- and γ-HCH in gas and particle-associated phase in Dalian, China by multiple regression

Atmospheric concentrations of α- and γ-hexachlorocyclohexanes were measured once a week in Dalian throughout 2008, using a high-volume air sampler, to estimate diurnal, monthly and seasonal variations. Multiple regression analysis was used to estimate the impact of selected meteorological conditions on atmospheric concentrations of hexachlorocyclohexanes and to identify the potential source regions. Overall, α- and γ-hexachlorocyclohexanes were mainly associated with the gas phase, with an annual mean gas-phase concentration of 36±30 and 10±9.8pgm-3 respectively. On the other hand, mean particle (PM10) associated concentrations throughout the year were 1.9±2.4 and 0.46±0.43pgm-3 respectively. Gas-phase concentration of α- and γ-hexachlorocyclohexanes peaked in the autumn season whereas highest concentrations in the particle phase were measured in spring. Ratio of α-/γ-isomer ranged from 3.7 to 7.4 in the gas phase which was close to the ratio in technical hexachlorocyclohexanes (5-7). In the particle-associated phase this ratio ranged from 1.2 to 3.8, with the exception of daytime samples in spring (up to 16) and summer seasons (up to 14) and this exception could be due to the isomerization from γ- to α- in ambient air, at least partly resulted from the impact of sunlight. Regression analysis showed that, at the sampling site, concentrations of α- and γ-hexachlorocyclohexanes in the gas phase were both elevated with increasing temperature and wind speed, whereas in the particle-associated phase their concentrations tended to remain stable

Chicken IFI6 inhibits avian reovirus replication and affects related innate immune signaling pathways

Interferon-alpha inducible protein 6 (IFI6) is an important interferon-stimulated gene. To date, research on IFI6 has mainly focused on human malignant tumors, virus-related diseases and autoimmune diseases. Previous studies have shown that IFI6 plays an important role in antiviral, antiapoptotic and tumor-promoting cellular functions, but few studies have focused on the structure or function of avian IFI6. Avian reovirus (ARV) is an important virus that can exert immunosuppressive effects on poultry. Preliminary studies have shown that IFI6 expression is upregulated in various tissues and organs of specific-pathogen-free chickens infected with ARV, suggesting that IFI6 plays an important role in ARV infection. To analyze the function of avian IFI6, particularly in ARV infection, the chicken IFI6 gene was cloned, a bioinformatics analysis was conducted, and the roles of IFI6 in ARV replication and the innate immune response were investigated after the overexpression or knockdown of IFI6 in vitro. The results indicated that the molecular weight of the chicken IFI6 protein was approximately 11 kDa and that its structure was similar to that of the human IFI27L1 protein. A phylogenetic tree analysis of the IFI6 amino acid sequence revealed that the evolution of mammals and birds was clearly divided into two branches. The evolutionary history and homology of chickens are similar to those of other birds. Avian IFI6 localized to the cytoplasm and was abundantly expressed in the chicken lung, intestine, pancreas, liver, spleen, glandular stomach, thymus, bursa of Fabricius and trachea. Further studies demonstrated that IFI6 overexpression in DF-1 cells inhibited ARV replication and that the inhibition of IFI6 expression promoted ARV replication. After ARV infection, IFI6 modulated the expression of various innate immunity-related factors. Notably, the expression patterns of MAVS and IFI6 were similar, and the expression patterns of IRF1 and IFN-β were opposite to those of IFI6. The results of this study further advance the research on avian IFI6 and provide a theoretical basis for further research on the role of IFI6 in avian virus infection and innate immunity

Process Optimization on Mixed Fermentation of Pickled Radish with Lactobacillus plantarum and Leuconostoc mesenteroides

In order to improve the quality of pickled radish, Lactobacillus plantarum and Leuconostoc mesenteroides were mixedly used as fermentation strains. The nitrite content, pH value, total acid content, total sugar content, texture character-istics and sensory score of pickled radish during fermentation were used as evaluation index to study the effects of strain ratio, inoculation amount, salt type and addition amount, calcium chloride and sucrose addition amount on the quality of pickled radish, and the contrastive analysis of taste was used by electronic tongue. Through the response surface test, the optimum fermentation parameters of pickled radish was as follows: The ratio of Lactobacillus plantarum and Leuconostoc mesenterica was 1.6:1, the inoculation amount was 5.7%, the addition amount of low sodium salt was 4.5%, the addition amount of calcium chloride was 0.3%, and the addition amount of sucrose was 2%. Under these conditions, compared with the natural fermentation group, the total acid content, brittleness and sensory score of inoculated radish after 6 days of fermentation increased significantly, which were 0.59 g/100 g, 108.8 N and 38.9 points, respectively, and the nitrite content was 0.41 mg/kg. The results of electronic tongue test showed that the mixed fermentation could effectively reduce the bitter-ness and aftertaste of pickled radish and enhance the acidity, sweetness and freshness. In conclusion, this study showed that mixed fermentation was beneficial to improve the texture, flavor and safety of pickled radish

Design of Bacteria Bottle Clamping Elements Based on Regression Models

The fixture design of the bacteria bottle plays a vital role in designing a bottled fungus picking robot to save labor cost in the picking process of bottled fungus. This paper proposed a kind of clamping element design method based on regression models. Several sets of clamping elements were designed according to the appearance data of bacteria bottle. A single-factor test was conducted by using these clamping elements, and three levels of every factor were selected to obtain the desired values of clamping elements. Then, a Box–Behnken test was performed by selected levels. The established regression models described a numeric relationship between the variation of vital measurement points and all variation sources under a precise clamping element layout. To solve the problems in obtaining the direct parameters, a response surface method was presented based on the regression models. Finally, a test was used to demonstrate the effect of the optimized clamping elements when clamping a bacteria bottle. Through the related analysis and optimization, it was demonstrated that the holding effect of the clamping elements was the best under these conditions: the inner arc area was 4948 mm2; the downward displacement was 1.48 mm; and the rubber thickness was 3.69 mm. It showed that the proposed method was feasible, and the assembly quality after optimizing had been greatly improved. It can provide a reference for designing the bottle fixture of a picking machine

Optimization and Experiment on Key Parameters of Harvester for Auricularia auricula

The Auricularia auricula harvester has low harvesting productivity, low qualification rate, and high breakage rate, and the lack of research on key operating parameters has become a bottleneck restricting the large-scale development industry. In view of the difficulty of industrialization and promotion of Auricularia auricula harvesting equipment, this paper combines the research on the physical properties of Auricularia auricula, adopts a quadratic orthogonal rotation combination design test and response surface analysis method to carry out the optimization and test of the key parameters of the harvesting equipment of Auricularia auricula, including the speed of the tray fungus stick (A), the frequency of the harvesting knife (B), and the distance of the harvesting knife (C). Design-Expert software was used to analyse the data and investigate the influence of each parameter and its interaction on the harvesting productivity, qualified rate, and breakage rate. The test results show that the factors affecting the harvesting productivity are in order: (A) > (B) > (C); the factors affecting the harvest qualification rate are in order: (C) > (B) > (A); and the factors affecting the harvesting damage rate are in order: (C) > (B) > (A). The multi-objective optimization results show that the optimal parameter combination of the key parameters of the Auricularia auricula harvesting equipment operation is that the tray speed is 308.17 r/min, the harvesting knife frequency is 10.78 Hz, the spacing between the harvesting knives is 84.67 mm, the productivity is 363 bags/h, the pass rate is 94.26%, and the breakage rate is 2.40%. The field production application under this optimized parameter combination shows that the productivity of the Auricularia auricula mechanized harvester is 346 bars/h, the qualified rate is 91.43%, and the breakage rate is 3.19%. This study can provide a reference for improving the quality of Auricularia auricula harvesting equipment

Advances in Utilization of Agricultural Waste Based on Production of Edible Fungi

Along with the rapid development of edible fungus industry in China, the traditional mode of production giving priority to wood chips will be severely limited, and using agricultural waste distributed widely, having large yield, and containing high content of organic matter to produce edible fungus has good economic and ecological benefit. In this paper, based on the analysis of characteristics of agricultural waste in China, the present situation of application of agricultural waste in the production of edible fungi at home and abroad was introduced, and the main problems existing in production of edible fungi by using agricultural waste in China at the present stage were pointed out. Finally, the development direction of using agricultural waste to cultivate edible fungi was discussed, and some suggestions were put forward, such as improving the theoretical system for using agricultural waste to produce edible fungi, and establishing the standardized technical system for using agricultural waste to produce edible fungi

Application of Flow Field Analysis in Ion Beam Figuring for Ultra-Smooth Machining of Monocrystalline Silicon Mirror

X-ray free-electron lasers are large modern scientific devices that play an important role in fields such as frontier physics and biomedicine. In this study, a light source is connected to an experimental station through beam lines, which requires numerous ultra-smooth and high-precision X-ray mirrors. Monocrystalline silicon is an ideal substrate material where ion-beam figuring is required. However, the ultra-smooth surface is damaged after the ion-beam figuring. Through an analysis of the machined surface, it is found that in the process of vacuum pumping, the impurities in the cavity adhere to the machined surface and increase the roughness after processing. Therefore, an optimized vacuum-pumping scheme is proposed. The experiment demonstrates that the original value of the processed surface roughness remains unchanged

Needs and Associated Factors of Contracted Family Doctor Services in Young and Middle-aged Office Building Occupants

Background For building a healthy China, it is essential to expand the coverage of family doctor services. In young and middle-aged office building occupants, the rate of contracting family doctor services is low. Shanghai has taken the lead in exploring building-based family doctor services, and providing on-demand health management services. So it is particularly meaningful to study the health needs in young and middle-aged office building occupants. Objective To investigate the needs and associated factors of contracted family doctor services among young and middle-aged office building occupants in Shanghai. Methods A questionnaire survey was conducted from December 2019 to December 2020 with a cluster random sample of young and middle-aged office building occupants (aged 18-59 years) selected from representative office buildings in Shanghai's Hongkou District, Pudong New District, and Jing'an District of Shanghai for understanding their sociodemographic characteristics, health and healthcare-seeking conditions, knowledge of family doctor services, and needs of essential and personalized family doctor services. Multiple Logistic regression analysis was used to analyze the factors affecting the needs of family doctor services. Results In all, 2 366 cases attended the survey, and 2 272 of them (96.03%) who completed the survey effectively were included for analysis. Among them, 87.65% (1 874/2 138) had general, moderate or strong needs for essential family doctor services, and 70.59% (1 452/2 057) had needs for personalized family doctor services. Multiple Logistic regression analysis indicated that age, education level, self-assessed social class, understanding of one's own health, self-assessed health status, chronic disease prevalence, mental health status, preferred healthcare setting for treating common diseases, treatment experience in a community health institution, understanding of and degree of trust in a family doctor, and understanding of building-based family doctor services and the specific scope of the services were associated with the needs of essential family doctor services (P<0.05). Education level, social health insurance, commonly used drugs, chronic disease prevalence, preferred healthcare setting for treating common diseases, treatment experience in a community health institution, understanding of building-based family doctor services, and understanding of the scope of building-based family doctor services were associated with the needs of personalized family doctor services (P<0.05) . Conclusion The contracted family doctor services were in high demand in young and middle-aged office building occupants. Improving health literacy in this population, modifying publicity strategies regarding the services, and improving the capabilities of the family doctor team and primary medical institutions, may be conducive to increasing the rate of contracting family doctor services in this group