Search

The experiment was to study the effect of dietary folic acid on content of folic acid in egg yolk, egg quality and egg yield of Huabei Chai chickens. A total of 315 47-week-old Huabei Chai chickens were randomly divided into seven groups with three replicates in each group. The chickens in control group (group 1) were fed with basal diet. Group 2 to group 7 were experimental groups, the diets were supplemented with 300, 600, 1 200, 1 800, 2 400 and 3 600 mg/kg folic acid, respectively. The pre-experiment lasted for 7 d, and the formal experiment lasted for 28 d. On the 7th, 14th and 28th day of the formal test, 35 eggs were randomly selected in each group, 15 eggs were used for the determination of egg quality and 20 eggs were used for the determination of folic acid content. The results showed that folic acid content reached saturation, the highest was 1.58 μg/g, and decreased with the increase of folic acid supplemental concentration and feeding time. Folic acid had no significant effect on egg yolk weight, egg yolk color and egg shape index. Dietary folic acid only had a fluctuating effect on egg production. The experiment indicates that the addition of folic acid to diet can significantly increased the content of folic acid in egg yolk, which has a certain impact on egg weight, egg white weight, eggshell weight, eggshell color, eggshell thickness, relative density and Hartmann unit, but has little impact on egg yield. [ABSTRACT FROM AUTHOR]

Background Knowledge of COVID-19 epidemiology remains incomplete and crucial questions persist. We aimed to examine risk factors for COVID-19 death. Methods A total of 80 543 COVID-19 cases reported in China, nationwide, through 8 April 2020 were included. Risk factors for death were investigated by Cox proportional hazards regression and stratified analyses. Results Overall national case-fatality ratio (CFR) was 5.64%. Risk factors for death were older age (≥80: adjusted hazard ratio, 12.58; 95% confidence interval, 6.78–23.33), presence of underlying disease (1.33; 1.19–1.49), worse case severity (severe: 3.86; 3.15–4.73; critical: 11.34; 9.22–13.95), and near-epicenter region (Hubei: 2.64; 2.11–3.30; Wuhan: 6.35; 5.04–8.00). CFR increased from 0.35% (30–39 years) to 18.21% (≥70 years) without underlying disease. Regardless of age, CFR increased from 2.50% for no underlying disease to 7.72% for 1, 13.99% for 2, and 21.99% for ≥3 underlying diseases. CFR increased with worse case severity from 2.80% (mild) to 12.51% (severe) and 48.60% (critical), regardless of region. Compared with other regions, CFR was much higher in Wuhan regardless of case severity (mild: 3.83% vs 0.14% in Hubei and 0.03% elsewhere; moderate: 4.60% vs 0.21% and 0.06%; severe: 15.92% vs 5.84% and 1.86%; and critical: 58.57% vs 49.80% and 18.39%). Conclusions Older patients regardless of underlying disease and patients with underlying disease regardless of age were at elevated risk of death. Higher death rates near the outbreak epicenter and during the surge of cases reflect the deleterious effects of allowing health systems to become overwhelmed. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus (DM) patients surviving myocardial infarction (MI) have substantially higher mortality due to the more frequent development of subsequent pathological myocardial remodelling and concomitant functional deterioration. This study investigates the molecular pathways underlying accelerated cardiac remodelling in a well‐established mouse model of diabetes exposed to MI. Methods and results: Myocardial infarction in DM mice was established by ligating the left anterior descending coronary artery. Cardiac function was assessed by echocardiography. Myocardial hypertrophy and cardiac fibrosis were determined histologically 6 weeks post‐MI or sham operation. Autophagy, the NLRP3 inflammasome, and caspase‐1 were evaluated by western blotting or immunofluorescence. Echocardiographic imaging revealed significantly increased left ventricular dilation in parallel with increased mortality after MI in DM mice (53.33%) compared with control mice (26.67%, P < 0.05). Immunoblotting, electron microscopy, and immunofluorescence staining for LC3 and p62 indicated impaired autophagy in DM + MI mice compared with control mice (P < 0.05). Furthermore, defective autophagy was associated with increased NLRP3 inflammasome and caspase‐1 hyperactivation in DM + MI mouse cardiomyocytes (P < 0.05). Consistent with NLRP3 inflammasome and caspase‐I hyperactivation, cardiomyocyte death and IL‐1β and IL‐18 secretion were increased in DM + MI mice (P < 0.05). Importantly, the autophagy inducer and the NLRP3 inhibitor attenuated the cardiac remodelling of DM mice after MI. Conclusion: In summary, our results indicate that DM aggravates cardiac remodelling after MI through defective autophagy and associated exaggerated NLRP3 inflammasome activation, proinflammatory cytokine secretion, suggesting that restoring autophagy and inhibiting NLRP3 inflammasome activation may serve as novel targets for the prevention and treatment of post‐infarct remodelling in DM. [ABSTRACT FROM AUTHOR]

In order to improve the flashover voltage of the disc insulator in gas insulated transmission line under DC voltage, this paper considers reducing the electric field intensity on the surface by adjusting the surface conductivity distribution. Based on the joint simulation of improved particle swarm optimization algorithm and finite element, the surface conductivity gradient partition optimization model is constructed to obtain the optimal surface conductivity distribution sequence. The relationship between conductivity and treatment time is obtained by plasma fluorination, and the gradient distribution of the surface conductivity of the sample is realized by adding different ring polytetrafluoroethylene baffles. Microscopic tests are used to characterize the differences between different regions of the sample surface. The two-dimensional (2D) electric potential distribution, 2D charge density distribution, electric field intensity distribution and flashover voltage on the sample surface under pre-charging conditions are studied and compared with the simulation results. The results show that the maximum field strength of the sample with gradient treatment can be reduced by 71% and the flashover voltage can be increased by 45%. The research in this paper provides a good reference and theoretical support for the surface modification of disc insulators, such as the surface parameters with gradient distribution. [ABSTRACT FROM AUTHOR]