Hydrogen sulfide alleviates hypothyroidism-induced myocardial fibrosis in rats through stimulating autophagy and inhibiting TGF-β1/Smad2 pathway

Xiong Song,Liangui Nie,Junrong Long,Junxiong Zhao,Xing Liu,Liuyang Wang,Da Liu,Sen Wang,Shengquan Liu,Jun Yang 대한약리학회 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.1

Hypothyroidism alone can lead to myocardial fibrosis and result in heart failure, but traditional hormone replacement therapy does not improve the fibrotic situation. Hydrogen sulfide (H2S), a new gas signaling molecule, possesses antiinflammatory, antioxidant, and anti-fibrotic capabilities. Whether H2S could improve hypothyroidism-induced myocardial fibrosis are not yet studied. In our study, H2S could decrease collagen deposition in the myocardial tissue of rats caused by hypothyroidism. Furthermore, in hypothyroidism-induced rats, we found that H2S could enhance cystathionine-gamma-lyase (CSE), not cystathionine β-synthase (CBS), protein expressions. Finally, we noticed that H2S could elevate autophagy levels and inhibit the transforming growth factor-β1 (TGF-β1) signal transduction pathway. In conclusion, our experiments not only suggest that H2S could alleviate hypothyroidism- induced myocardial fibrosis by activating autophagy and suppressing TGF-β1/ SMAD family member 2 (Smad 2) signal transduction pathway, but also show that it can be used as a complementary treatment to conventional hormone therapy.

Seepage Evolution Law and Deformation Failure Characteristics of Porous Media Based on Smoothed Particle Hydrodynamics

Xiong Song,Xiaoqiang Zhang,Shunchuan Wu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.11

It is difficult to characterize the whole process of seepage movement by traditional numerical methods, which leads to the unclear mechanism of stress-strain change in soil. Therefore, the meshless method smooth particle hydrodynamics method is proposed to study the seepage law and deformation characteristics of soil. Combined with the strain softening model, a nonlinear cohesive force change model of porous media is proposed to accurately describe the evolution characteristics of soil seepage failure. Secondly, the damping coefficient and stress normalization method are used to better eliminate the defects of numerical stress noise generated by soil deformation after boundary interpolation, and improve the accuracy of SPH method in studying the internal stress of soil deformation. It is concluded that the influence of the viscosity coefficient on the unsteady head is significantly higher than that of the constant head. At the same time, the evolution characteristics of soil seepage instability under linear cohesion change are compared and analyzed. It can be seen that the proposed nonlinear cohesion change model is more in line with the actual failure mode of soil seepage. The research results can provide a new method and idea for the study of slope seepage motion range and stability analysis.

Effect of Treatment of In Vitro Matured Pig Oocytes with Calcium Ionophore on Monospermic Penetration In Vitro

Song, Xue-Xiong,Zhao, Xian-Mian,Han, Yi-Bing,Niwa, Koji Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.2

The present study examined whether treatment of in vitro matured pig oocytes with calcium ionophore (A23187) could prevent polyspermic penetration in vitro. When oocytes cultured for maturation for 33, 36 or 44 h were subsequently treated with $50{\mu}M$ A23187 in medium with fetal calf serum (FCS) for 1, 2 and 3 h and then cultured for 12 h without spermatozoa, virtually no activation occurred. In the absence of FCS, however, 31-42, 45-49 and 56-64% of oocytes were activated, respectively. When oocytes treated with $50 {\mu}M$ A23187 in medium with FCS for 3 h were inseminated in vitro, the penetration rates (14-57%) were lower (p<0.01) with a higher (p<0.01) incidence (35-67%) of monospermy compared with untreated oocytes (69-80% penetration and 15-17% monospermy). However, sperm penetration was completely blocked in all oocytes treated with A23187 in the absence of FCS. When oocytes matured for 33 h were treated with different concentrations of A23187 for 3 h and inseminated in vitro, the penetration rate did not change but there was an increased incidence (p<0.05) of monospermy at $10-20{\mu}M$ and $2.5-5{\mu}M$ A23187 in the presence and absence of FCS, respectively, compared with at $0{\mu}M$ A23187. With these lower concentrations of A23187, treatment of oocytes for at least 60 and 30 min in the presence and absence of FCS, respectively, was required to increase the incidence of monospermy without reducing penetration rate. These results indicate that a high concentration ($50{\mu}M$) of A23187 in medium without FCS, but not in medium with FCS, stimulated in vitro matured pig oocytes to induce parthenogenetic activation and a complete block to sperm penetration in vitro. However, treatment of oocytes with lower concentrations of A23187 ( $10-20{\mu}M$ and $2.5-5{\mu}M$) both in the presence and absence of FCS maintained sperm penetration in vitro and increased the incidence of monospermy.

The Pattern Indicator oa Large Screen

Song Xiong Li,Yong Gao Jin 대한전자공학회 1995 ICEIC:International Conference on Electronics, Inf Vol.1 No.1

Chopper Controller Based DC Voltage Control Strategy for Cascaded Multilevel STATCOM

Xiong, Lian-Song,Zhuo, Fang The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.2

The superiority of CMI (Cascaded Multilevel Inverter) is unparalleled in high power and high voltage STATCOM (Static Synchronous Compensator). However, the parameters and operating conditions of each individual power unit composing the cascaded STATCOM differ from unit to unit, causing unit voltage disequilibrium on the DC side. This phenomenon seriously impairs the operation performance of STATCOM, and thus maintaining the DC voltage balance and stability becomes critical for cascaded STATCOM. This paper analyzes the case of voltage disequilibrium, combines the operation characteristics of the cascaded STATCOM, and proposes a new DC voltage control scheme with the advantages of good control performance and stability. This hierarchical control method uses software to achieve the total active power control and also uses chopper controllers to enable that the imbalance power can flow among the capacitors in order to keep DC capacitor voltages balance. The operating principle of the chopper controllers is analyzed and the implementation is presented. The major advantages of the proposed control strategy are that the number of PI regulators has been decreased remarkably and accordingly the blindness of system design and debugging also reduces obviously. The simulation reveals that the proposed control scheme can achieve the satisfactory control goals.

Programmable Color Pattern Controller

Song Xiong Li,Yang Gao Jin 대한전자공학회 1991 International Conference on Electronics, Informati Vol.1 No.1

Chopper Controller Based DC Voltage Control Strategy for Cascaded Multilevel STATCOM

Lian-Song Xiong,Fang Zhuo 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.2

The superiority of CMI (Cascaded Multilevel Inverter) is unparalleled in high power and high voltage STATCOM (Static Synchronous Compensator). However, the parameters and operating conditions of each individual power unit composing the cascaded STATCOM differ from unit to unit, causing unit voltage disequilibrium on the DC side. This phenomenon seriously impairs the operation performance of STATCOM, and thus maintaining the DC voltage balance and stability becomes critical for cascaded STATCOM. This paper analyzes the case of voltage disequilibrium, combines the operation characteristics of the cascaded STATCOM, and proposes a new DC voltage control scheme with the advantages of good control performance and stability. This hierarchical control method uses software to achieve the total active power control and also uses chopper controllers to enable that the imbalance power can flow among the capacitors in order to keep DC capacitor voltages balance. The operating principle of the chopper controllers is analyzed and the implementation is presented. The major advantages of the proposed control strategy are that the number of PI regulators has been decreased remarkably and accordingly the blindness of system design and debugging also reduces obviously. The simulation reveals that the proposed control scheme can achieve the satisfactory control goals.

Intersubband Transitions in Nonpolar GaN-based Resonant Phonon Depopulation Multiple-Quantum Wells for Terahertz Emissions

Ya-Feng Song,Xiong-Xiong Kong,Wei-Bin Tang,Zhong-Qiang Suo,Huan Zhang,Chen-Yang Li,Qian Jia,Cai-Xia Xue,Yan-Wu Lu,Chao-Pu Yang 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.11

We investigate the polarization effect in intersubband transitions in polar and nonpolar GaN-based multiple-quantum well (MQW) structures for terahertz (THz) emissions by using systematic comparisons and design a nonpolar GaN/Al$_{0.2}$Ga$_{0.8}$N two-well-based MQW structure with an emitting photon of 7.27 THz (30.07 meV). Its lower energy separation (92.7 meV) matches the resonant phonon depopulation condition for better population inversion. It shows a lower threshold current density $J\rm_{th}$ at all temperatures (1.548 kA/cm$^2$ at 90 K) and a higher output power of up to 86.1 mW at 5.8 K and 33.6 mW at 100 K. Our results for the polar GaN MQW are very close to the experimental data in the literature. We find that the $J\rm_{th}$ of the nonpolar GaN MQW increases more slowly than that of the polar GaN MQW as temperature increases, indicating the nonpolar GaN MQW may be a worth-trying direction for improving the operation temperature. These results can provide meaningful references for the design and fabrication of nonpolar GaN-based THz MQW or quantum cascade structures.

The Oscillation Frequency of CML-based Multipath Ring Oscillators

Song, Sanquan,Kim, Byungsub,Xiong, Wei The Institute of Electronics and Information Engin 2015 Journal of semiconductor technology and science Vol.15 No.6

A novel phase interpolator (PI) based linear model of multipath ring oscillator (MPRO) is described in this paper. By modeling each delay cell as an ideal summer followed by a single pole RC filter, the oscillation frequency is derived for a 4-stage differential MPRO. It is analytically proved that the oscillation frequency increases with the growth of the forwarding factor ${\alpha}$, which is also confirmed quantitatively through simulation. Based on the proposed model, it is shown that the power to frequency ratio keeps constant as the speed increases. Running at the same speed, a 4-stage MPRO can outperform the corresponding single-stage ring oscillator (SPRO) with 27% power saving, making MPRO with a large forwarding factor ${\alpha}$ an attractive option for lower power applications.

Fabrication, design, and optimization of hierarchical composite Kagome honeycomb sandwich structure under uniaxial compression

Song Shijun,Xiong Chao,Yin Junhui,Yang Zhaoshu,Wang Lu 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.2

In this study, a hierarchical composite Kagome honeycomb sandwich (HCKHS) structure was manufactured based on the interlocking method, and its uniaxial compression performance was explored. Through experiments, the compressive strength, stiffness, energy absorption, and failure process of HCKHS specimens of seven different sizes were determined and compared. Mechanical analytical models were established, and the variation trend in the specific strength was predicted and compared with those of other advanced sandwich structures. The size effect of the HCKHS specimens was analyzed. The influence of a single variable on the core modulus, failure strength, and failure modes was discussed, and failure mechanism maps were drawn. The structure was optimized based on the maximum specific strength and engineering application, and the optimal size design ratio was obtained. The results showed that the HCKHS specimens exhibited excellent compressive properties with a convenient manufacturing process, making them suitable for lightweight applications in engineering. The optimization ideas presented herein are also applicable to other two-dimensional hierarchical or normal composite honeycomb sandwich structures with diamond, triangular, and hexagonal shapes.