Effects of epigallocatechin-3-gallate on bovine oocytes matured in vitro

Huang, Ziqiang,Pang, Yunwei,Hao, Haisheng,Du, Weihua,Zhao, Xueming,Zhu, Huabin Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.9

Objective: Epigallocatechin-3-gallate (EGCG) is a major ingredient of catechin polyphenols and is considered one of the most promising bioactive compounds in green tea because of its strong antioxidant properties. However, the protective role of EGCG in bovine oocyte in vitro maturation (IVM) has not been investigated. Therefore, we aimed to study the effects of EGCG on IVM of bovine oocytes. Methods: Bovine oocytes were treated with different concentrations of EGCG (0, 25, 50, 100, and $200{\mu}M$), and the nuclear and cytoplasmic maturation, cumulus cell expansion, intracellular reactive oxygen species (ROS) levels, total antioxidant capacity, the early apoptosis and the developmental competence of in vitro fertilized embryos were measured. The mRNA abundances of antioxidant genes (nuclear factor erythriod-2 related factor 2 [NRF2], superoxide dismutase 1 [SOD1], catalase [CAT], and glutathione peroxidase 4 [GPX4]) in matured bovine oocytes were also quantified. Results: Nuclear maturation which is characterized by first polar body extrusion, and cytoplasmic maturation characterized by peripheral and cortical distribution of cortical granules and homogeneous mitochondrial distribution were significantly improved in the $50{\mu}M$ EGCG-treated group compared with the control group. Adding $50{\mu}M$ EGCG to the maturation medium significantly increased the cumulus cell expansion index and upregulated the mRNA levels of cumulus cell expansion-related genes (hyaluronan synthase 2, tumor necrosis factor alpha induced protein 6, pentraxin 3, and prostaglandin 2). Both the intracellular ROS level and the early apoptotic rate of matured oocytes were significantly decreased in the $50{\mu}M$ EGCG group, and the total antioxidant ability was markedly enhanced. Additionally, both the cleavage and blastocyst rates were significantly higher in the $50{\mu}M$ EGCG-treated oocytes after in vitro fertilization than in the control oocytes. The mRNA abundance of NRF2, SOD1, CAT, and GPX4 were significantly increased in the $50{\mu}M$ EGCG-treated oocytes. Conclusion: In conclusion, $50{\mu}M$ EGCG can improve the bovine oocyte maturation, and the protective role of EGCG may be correlated with its antioxidative property.

Mechanical and fracture behavior of rock mass with parallel concentrated joints with different dip angle and number based on PFC simulation

Zhao, Weihua,Huang, Runqiu,Yan, Ming Techno-Press 2015 Geomechanics & engineering Vol.8 No.6

Rock mass is an important engineering material. In hydropower engineering, rock mass of bank slope controlled the stability of an arch dam. However, mechanical characteristics of the rock mass are not only affected by lithology, but also joints. On the basis of field geological survey, this paper built rock mass material containing parallel concentrated joints with different dip angle, different number under different stress conditions by PFC (Particle Flow Code) numerical simulation. Next, we analyzed mechanical property and fracture features of this rock mass. The following achievements have been obtained through this research. (1) When dip angle of joints is $15^{\circ}$ and $30^{\circ}$, with the increase of joints number, peak strength of rock mass has not changed much. But when dip angle increase to $45^{\circ}$, especially increase to $60^{\circ}$ and $75^{\circ}$, peak strength of rock mass decreased obviously with the increase of joints number. (2) With the increase of confining stress, peak strengths of all rock mass have different degree of improvement, especially the rock mass with dip angle of $75^{\circ}$. (3) Under the condition of no confining stress, dip angle of joints is low and joint number is small, existence of joints has little influence on fracture mode of rock mass, but when joints number increase to 5, tensile deformation firstly happened at joints zone and further resulted in tension fracture of the whole rock mass. When dip angle of joints increases to $45^{\circ}$, fracture presented as shear along joints, and with increase of joints number, strength of rock mass is weakened caused by shear-tension fracture zone along joints. When dip angle of joints increases to $60^{\circ}$ and $75^{\circ}$, deformation and fracture model presented as tension fracture zone along concentrated joints. (4) Influence of increase of confining stress on fracture modes is to weaken joints' control function and to reduce the width of fracture zone. Furthermore, increase of confining stress translated deformation mode from tension to shear.

Electrophysiological and behavioral responses of Asian and European honeybees to pear flower volatiles

Ma Weihua,Long Denglong,Wang Yi,Li Xinyu,Huang Jiaxing,Shen Jinshan,Su Wenting,Jiang Yusuo,Li Jie 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

Honeybee pollination behavior is influenced by flower volatiles, which honeybees sense via olfactory receptors. Honeybees are only weakly attracted to pear flowers. To investigate the potential reasons, we extracted and determined the floral volatile compounds from three pear cultivars (Su, Ya, and Xuehua) using headspace solidphase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC–MS). The effects of pear flower volatiles on the Asian honeybee (Apis cerana cerana Fabricius) and the European honeybee (Apis mellifera ligustica Spinola) were determined by electroantennogram (EAG) assays and behavioral tests in a three-arm olfactometer. Among the 76 flower volatiles detected with GC–MS, 21 were found in all three pear cultivars, accounting for approximately 70% of the total volatile content. 3-Methyl-1-butanol and (+)-limonene volatiles had the highest relative content. Five compounds elicited strong EAG responses in both bee species: 2-methylbu tyraldehyde, 1-nonanal, 6-methyl-5-hepten-2-one, 3-methyl-1-butanol, and (+)-limonene. Neither bee species showed positive taxis to these volatiles. In behavioral tests, A. mellifera ligustica showed a low preference for 6-methyl-5-hepten-2-one (20%, 400 µg/µL) and 2-phenethyl alcohol (16.7%, 400 µg/µL). Apis cerana cerana showed a low preference for 6-methyl-5-hepten-2-one (6.7%, 400 µg/µL) and 1-nonanal (10%, 400 µg/µL), whereas its preferences for 3-methyl-1-butanol (43.3%, 400 µg/µL) and α-farnesene (40%, 400 µg/µL) were similar to that for the control. Therefore, a lack of attractive volatile compounds could explain why honeybees are only weakly attracted to pear flowers. Therefore, to achieve acceptable pollination in pear orchards, we suggest using flower-scent sugar syrup feeding and a saturation pollination strategy.

Interactive Effects of Ultraviolet Radiation and Dissolved Organic Carbon on Phytoplankton Growth and Photosynthesis in Sanya Bay, Northern South China Sea

Jianzu Liao,Weihua Zhou,Jie Xu,Xiangcheng Yuan,Yuxian Liang,Yajuan Guo,Hui Huang,Sheng Liu,Aimin Long 한국해양과학기술원 2019 Ocean science journal Vol.54 No.4

The effects of a simulated climate change scenario, i.e., increased ultraviolet radiation (UVR) and dissolved organic carbon (DOC), on the growth and photosynthesis of tropical coastal phytoplankton were evaluated in Sanya Bay, northern South China Sea, in summer. Microcosm experiments were conducted at two contrasting stations (Stns S1 and S2) with three different UVR treatments and two DOC addition treatments. Our results showed that natural sunlight UVR or increased UV-B did not affect phytoplankton biomass and primary production. However, increased UV-B significantly decreased the proportion of picophytoplankton and the efficiency of carbon fixation at Stn S2. DOC enhancement caused negative effects on primary production under natural sunlight UVR only at Stn S1. Interactive effects of UVR and DOC addition on phytoplankton biomass and primary production were detected at Stn S1, due to the negative effects of DOC being eliminated under the increased UV-B condition. The lack of interactive effects at Stn S2 were likely due to the differences with Stn S1 in terms of light acclimation and biological interaction. In summary, this future climate change scenario will probably not affect the photosynthetic CO2 fixation and biomass of natural phytoplankton in Sanya Bay.

Driver Preview Model with Dual Far-near Points for Autonomous Vehicles

Rongrong Xu,Zezheng Huang,Weihua Li,Jianfeng Wang,Dianbo Ren,Xuewen Geng 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.11

This paper proposes a driver preview-based path-following controller to control both the lateral and longitudinal movements of a vehicle. First, a lateral tracking controller with two preview points is established by considering the displacement and heading errors of the two preview points: the far point, determined by the vehicle speed and fixed preview time, and the near point located at the center of the front axle. Depending on different parameters of the road input, the steering wheel angle is calculated, and different weights are assigned to the steering wheel angles corresponding to different road inputs. Next, a longitudinal tracking controller is established, which controls the vehicle velocity based on the road information of the far point. The control objects are the brake and accelerator pedals. Subsequently, the coupling of the lateral and longitudinal motion of the vehicle is analyzed, and an integrated longitudinal and lateral tracking controller is established. To verify the performance of the controller, the controller and vehicle model are established in Simulink and CarSim, respectively, to enable joint simulation. It is observed that the coupling is solved, and the near-point control makes the tracking error converge to zero and enhances the control effect. It demonstrates high adaptability and control accuracy of the proposed controller.

Research of the Influence of Single-Flow and Dual-Flow Patterns on Fuel Tank Washing Inerting Process

Wenyi Liu,Xuefei Huang,Weihua Liu 한국항공우주학회 2024 International Journal of Aeronautical and Space Sc Vol.25 No.2

The purpose of this study is that safety issues of modern aircraft always attract extensive attention worldwide. The combustion and explosion of fuel tank system is one of the main causes of aircraft accident. This paper builds a general mathematical model for a multi-compartment fuel tank and provides the initial conditions for a solution using the Runge–Kutta method according to mass conservation, the equation of nitrogen–oxygen dissolution and evolution, and the equation of gas flowing through the orifice. Nitrogen-enriched air (NEA) flow is usually used to decrease the oxygen concentration inside fuel tank to keep it below the oxygen concentration required to support combustion. With a four-compartment fuel tank as the research objective and adopting a domestic separation membrane to generate NEA, single-flow and dual-flow patterns are designed, respectively. Also, a washing inerting simulation is performed and the variation in the average oxygen concentration in the fuel tank and each compartment with the flight envelope is analyzed. The research results indicate that these two patterns can both meet the requirement that the average oxygen concentration of the upper ullage in the fuel tank should be lower than 12%. Although the single-flow pattern is simpler than the dual-flow pattern, it cannot avoid external air entering the fuel tank, which will cause the oxygen concentration in some compartments to be higher than 12% during the diving phase, while the dual-flow pattern can guarantee that the oxygen concentration of compartments does not exceed the limits during the entire flight. With the comparison between single-flow and dual-flow patterns, this study may provide some reference for the further design and study of washing inerting process for fuel inerting system.

Push-out tests on stud shear connectors with constrained structure of steel-concrete composite beams

Jingjing Qi,Zuwei Xie,Hua Cao,Zhi Huang,Weirong Lv,Weihua Shi 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.6

The stud shear connector is the main force transfer member in the steel-concrete composite member, and the mechanical behavior is very complicated in the concrete. The concrete around the stud is subjected to the pry-out local pressure concentration of the stud, which can easily produce splitting mirco-cracks. In order to solve the problem of pry-out local splitting of stud shear connector, a kind of stud shear connector with constraint measure is proposed in this paper. Through the push-out test, the interface shear behavior of the new stud shear connector between steel and concrete flange plate was studied, and the difference between the new stud shear connector and the traditional stud connector was compared. The results show that the stud shear connector with constraint measure can effectively avoid the adverse effect of local pressure splitting by relying on its own constraint measure. The shear stiffness of the interface between steel and concrete flange plates is greatly improved, which provides a theoretical basis for the design of strong connection coefficient of steel-concrete composite structures.

Numerical simulation of magnetic fluid hyperthermia based on multiphysics coupling and recommendation on preferable treatment conditions

Jing Li,Huan Yao,Yan Lei,Weihua Huang,Zhe Wang 한국물리학회 2019 Current Applied Physics Vol.19 No.9

In this study, we established a multiphysics coupling model of magnetic fluid hyperthermia (MFH), using complex magnetic permeability to solve the magnetic losses of magnetic nanoparticles (MNPs). The experiments were performed to verify the validity of numerical coupling method. The optimal treatment time (OTT) was regarded as the time required for the lowest temperature point of the tumor to attain the damage criteria. The OTT increased by about 42 s as the tumor radius increased by 1 cm, and decreased by 10 s for the increase in MNP dose per gram of tumor by 1 mg. To achieve cost-effective therapies under moderate treatment conditions, the preferable ranges of external magnetic field intensity H0 and frequency f, MNP radius R and volume fraction ϕ are 3–11 kA/m, 200–500 kHz, 8–10 nm, and 5%–10%, respectively. It is greatly encouraged to adopt the combination of higher H0 (8–11 kA/m) and lower f (200–300 kHz), and the conjunction of higher R and ϕ. There was a slight thermal damage to normal tissues due to eddy current loss. In conclusion, MFH can provide an excellent therapeutic effect for deep tumors.

A reduced time-varying model for a long beam on elastic foundation under moving loads

Guiming Mei,Caijin Yang,Shulin Liang,Jiangwen Wang,Dong Zou,Weihua Zhang,Yunshi Zhao,Zhong Huang,Shuqi Song,Mengying Tan,Yao Cheng,Bingrong Miao 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.9

Dynamics of a long beam on the elastic foundation subjected to moving loads is studied in the present paper. The sliding window technique is used to dynamically truncate the long beam and a reduced time-varying beam system is obtained. The Hamilton’s principle is employed to establish the equations of motion of the reduced system. The variable separation method is adopted to solve dynamical responses of the reduced system. Examples of a long simply supported Timoshenko beam on the nonlinear foundation subjected to a single moving load and multiple loads are included. Numerical results of the reduced model compared with the ones obtained from the moving element model adapted in literature are carried out to show the validity and the good efficiency of the method proposed in the present paper.

Performance Evaluation of the Regional Knowledge Innovation System in China

Sheng-Hsiung CHIU,Tzu-Yu LIN,Hong CHEN,Weihua HUANG 한국유통과학회 2018 KODISA ICBE (International Conference on Business Vol.2018 No.-

This paper investigates the effect of gender leadership with political connection on CSR performance using annual data of Chinese firms who listed in China A-share stock market and had CSR rating assessed by Rankins from 2009 to 2015. In addition, we also examine whether the foregoing question is under the influence of particular ownership structure in China. Our empirical results suggest that female chairman or CEO would not perform well in CSR activities, while leader’s political capital acts an exacerbating force. Specifically, the negative and statistically significant of interaction term female leadership with political capital is obviously identified for the Non-SOEs. The mandatory CSR reporting would not encourage firms to make more effort on CSR activities to the purpose on generating positive social externalities, while the advantages of CSR rating in firms are not obviously experience to coordinate the conflict of interest between stakeholders.