Natural astaxanthin enhanced antioxidant capacity and improved semen quality through the MAPK/Nrf2 pathway in aging layer breeder roosters

Background:Natural astaxanthin(ASTA)has strong antioxidant properties and has been widely used as a health product to improve human health.However,the effects of ASTA on the reproductive performance of aging roosters have been poorly studied.We aimed to investigate the effects of dietary ASTA on semen quality and antioxidant capacity in aging roosters and to explore the potential mechanism of semen quality change via antioxidation defense system.Methods:In the present study,9653-week-old Jinghong No.1 layer breeder roosters were fed a corn-soybean meal basal diet containing 0,25,50,or 100 mg/kg ASTA for 6 weeks.Results:Semen quality in the ASTA groups remarkably improved than that in the control group,and antioxidant activities,the abilities to scavenge hydroxyl radicals and superoxide anions,increased gradually with ASTA addition(P<0.05).In addition,the mRNA levels of antioxidant enzymes as well as the mRNA and protein levels of the mitogen-activated protein kinase(MAPK)and nuclear factor-erythroid 2-related factor 2(Nrf2)were markedly increased in the 50-100 mg/kg ASTA group(P<0.05).Conclusions:Collectively,these results demonstrate that dietary ASTA may improve semen quality by increasing antioxidant enzyme activities and the ability to scavenge hydroxyl radicals,which may be related to upregulation of the MAPK/Nrf2 pathway.

An Optimization Approach of Rotor Contour for Variable Reluctance Resolver

An effective approach for optimizing the rotor contour for variable reluctance(VR)resolver is presented.Using this approach,the procedure for optimizing the rotor is divided into two parts:the establishment of initial shape curve,and then computation for the optimization.In order to simplify the process of the former,a shape function is constructed.And the latter is carried out by Taguchi optimization method and finite element method(FEM).An example of a 3-10 VR resolver is used to present the procedure of the optimization,and the testing results confirmed the effectivity of the approach.

Exosomal miR-218 regulates the development of endometritis in dairy cows by targeting TGIF2/TGF-βpathway

Endometritis affects the reproductive capacity of dairy cows and leads to serious economic losses in dairy farming.Clarification of the pathogenesis of endometritis is necessary to improve the reproductive efficiency of dairy cows.Exosomes and their miRNAs have been proven to play an important role in inflammatory regulation.Exosomal miR-218 is a differentially expressed miRNA found in endometrial epithelial cells(EECs)under endometrial inflammation.Therefore,we investigated the expression of miR-218 in the uterine tissue of dairy cows,lipopolysaccharide(LPS)treated EECs,exosomal vesicles,and regulation of exosomal miR-218 by targeting TGIF-2 inducible factor homology frame 2(TGIF2)/transforming growth factor-beta(TGF-β).The expression of miR-218 was suppressed in inflammatory uterine tissues and LPS treated EECs.The expression of TGIF2 and TGF-βin inflammatory uterine tissues and LPS treated EECs was significantly higher than those in healthy uterine tissues and EECs(p<0.01).Interestingly,miR-218 derived from donor cells was found to regulate the expression of the target gene TGIF2 in recipient cells through the fusion of exosomes.Concurrently,the expression of its target gene TGIF2 was also suppressed by miR-218 in donor cells resulting in fewer TGIF2 being transported into recipient cells with exosomal fusion.This may be a novel mechanism of miRNAs-mediated regulation and provides a new reference for analyzing the pathogenesis of endometritis in dairy cows.

Research progress of large size SiC single crystal materials and devices

SiC semiconductor is the focus of recent international research.It is also an important raw material for China to achieve carbon emission peak and carbon neutrality.After nearly 20 years of research and development,we focus on the three types SiC crystals,n-type,p-type and semi-insulating,indicating the development of Shandong University for crystal growth.And defects control,electrical property,atomic polishing,and corresponding device authentication all obtain great progress.Total dislocation density of 6-inch n-type substrates decreases to 2307 cm^(-2),where BPD(Basal Plane Dislocation)lowers to 333 cm^(-2) and TSD(Threading Screw Dislocation)19 cm^(-2).The full width at half maximum(FWHM)(0004)rocking curves is only 14.4 arcsec.The resistivity reaches more than 1E+12Ω·cm for semi-insulating SiC and lower than 20 mΩ·cm for n-type SiC.The impurity concentrations in 6-inch high-purity semi-insulating(HPSI)SiC crystals reach extreme low levels.The devices made of various substrate materials have good performance.

Benchmark experimental study on wave run-ups of fixed four-rounded-square-column array in regular waves

Wave run-up on surface-piercing columns is an important phenomenon in offshore engineering.Previous studies have mainly focused on a single column and circular column arrays.This study is concerned with the wave run-up ratio and the wave force on a fixed array of four rounded square columns.A series of regular wave tests were conducted,and the effects of wave periods and steepness were investigated.The nonlinearity of the wave run-up under incident waves with a small period is more sensitive to wave steepness.Utilizing empirical mode decomposition(EMD)and fast Fourier transform(FFT)methods,the measured signals were separated into three components representing characteristics of the incident wave component(IMF1),near-field interference(IMF2),and far-field low frequency reflected wave(IMF3),respectively.The proposed methods are helpful for studying the mechanism of near-field interference,and the experimental data are essential benchmarks for validating further numerical simulations of wave runups on rounded square columns.

Parametric study on power capture performance of an adaptive bistable point absorber wave energy converter in irregular waves

The power capture performance of an adaptive bistable point absorber wave energy converter(WEC)in irregular waves is investigated in this paper.Based on the linear potential flow theory and Cummins equations,the equation of motion for the WEC is established in time domain.Then a parametric study is performed on the power capture performance of the WEC by considering the influences of different wave and system parameters such as the spring combination parameter,the stiffness of auxiliary springs and main springs,the original length value of the main spring,damping coefficient of the PTO systems and the significant wave height.The results show that in an irregular wave,each parameter will have a certain impact on the performance of the device.Appropriate device parameters need to be selected according to actual environmental parameters to ensure that the adaptive bistable WEC has better power capture performance than its linear and conventional bistable counterparts.