Effects of Antioxidant Tempol on Systematic Inflammation and Endothelial Apoptosis in Emphysematous Rats Exposed to Intermittent Hypoxia

Haiyan Zhao,Yaping Zhao,Xin Li,Leiqian Xu,Fangxin Jiang,Wanju Hou,Lixia Dong,Jie Cao 연세대학교의과대학 2018 Yonsei medical journal Vol.59 No.9

Purpose: Obstructive sleep apnea and chronic obstructive pulmonary disease are independent risk factors of cardiovascular disease(CVD), and their coexistence is known as overlap syndrome (OS). Endothelial dysfunction is the initial stage of CVD; however,underlying mechanisms linking OS and CVD are not well understood. The aim of this study was to explore whether OS canlead to more severe inflammation and endothelial apoptosis by promoting endothelial dysfunction, and to assess the interventioneffects of antioxidant tempol. Materials and Methods: Male Wistar rats (n=66) were exposed to normal oxygen [normal control (NC) group], intermittent hypoxia(IH group), cigarette smoke (CH group), as well as cigarette smoke and IH (OS group). Tempol intervention was assessed inOS group treated with tempol (OST group) or NaCl (OSN group). After an 8-week challenge, lung tissues, serum, and fresh bloodwere harvested for analysis of endothelial markers and apoptosis. Results: The levels of intracellular adhesion molecule-1, vascular cellular adhesion molecule-1, and apoptosis in circulating epithelialcells were the highest in OS group and the lowest in NC group. These levels were all greater in IH group than in CH group,and were lower in OST group than in OS and OSN groups (all p<0.001). Conclusion: Synergistic effects of IH with cigarette smoke-induced emphysema produce a greater inflammatory status and endothelialapoptosis. OS-related inflammation and endothelial cell apoptosis may play important roles in promoting cardiovasculardysfunction, and antioxidant tempol could achieve a partial protective effect.

Proteolysis Characteristics of Sarcoplasmic, Myofibrillar, and Stromal Proteins Separated from Grass Carp and Antioxidant Properties of Their Hydrolysates

Haiyan Wang,Fenglan Zhang,Jin Cao,Qingsheng Zhang,Zhirong Chen 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.2

Proteolysis of grass carp sarcoplasmic, myofibrillar,and stromal proteins by 5 commercial proteases were studied. Sarcoplasmic and myofibrillar protein could be well hydrolyzed by Alcalase 2.4 L to reach high protein recoveries (PR) (71.86±2.46 and 80.77±3.05%, respectively),while the maximum PR for stromal protein was only 42.83±2.84%. However, stromal hydrolysates, containing mostly 6-10 kDa fraction, exhibited higher ·OH scavenging activities due to its high content of antioxidant-assisting amino acids. Alcalase 2.4 L and pancreatin 6.0, which produced hydrolysates with relative high degree of hydrolysis (DH), were used for further hydrolysis of whole grass carp protein with the assistance of response surface methodology (RSM). The results showed that serine proteases (Alcalase 2.4 L and pancreatin 6.0) could produce sarcoplasmic, myofibrillar, or stromal hydrolysates with relatively high PR, DH, and strong ·OH scavenging activity, which may be used to prepare antioxidant hydrolysates from grass carp.

Granular Properties of Pteridium squilinum Starch

Qingming Cao,Haiyan Zhong,Zhonghai Li,Changbo Sun 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Surface plasmon resonance-enhanced solar-driven photocatalytic performance from Ag nanoparticles-decorated Ti3+ self-doped porous black TiO2 pillars

Guo Zhou,Haiyan Meng,Yan Cao,Xuejun Kou,Shuxiang Duan,Leilei Fan,Ming Xiao,Fangzhou Zhou,Zhenzi Li,Zipeng Xing 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.64 No.-

The tiny Ag nanoparticles-uniformly decorated Ti3+ self-doped porous black TiO2 pillars (Ag-TPBTPs) are prepared, which show obvious surface plasmon resonance (SPR) and extend the photoresponse to visible light and near-infrared region (∼1500 nm). The Ag-TPBTPs exhibit excellent solar-driven photocatalytic activities by mineralizing of high-toxic 2,4-dichlorophenol (∼99%), which is three times higher than that of the pristine TiO2. The remarkable solar-driven photocatalytic performance can be ascribed to the porous pillars structure offering more surface active sites, the self-doped Ti3+ and SPR effect of Ag nanoparticles improving the utilization of solar light, and enhancing the spatial separation efficiency of photogenerated charge carriers.

Electrochemical properties of stacked-nanoflake Li4Ti5O12 spinel synthesized by a polymer-pyrolysis method

Xiaoming Zhu,Xiaoyu Jiang,Haiyan Lu,Xinping Ai,Hanxi Yang,Yuliang Cao 한국물리학회 2014 Current Applied Physics Vol.14 No.4

Stacked-nanoflake Li4Ti5O12 spinel was synthesized via the pyrolysis of a LieTi copolymeric precursor formed by in situ polymerization of LiOH and [Ti(OC4H9)4] and acrylic acid. XRD and SEM characterization shows that the powders calcined at 700 C for 3 h was well-crystallized particles with submicron diameter. Chargeedischarge measurement showed the Li4Ti5O12 electrode had displayed excellent rate capability and delivered reversible capacity of 171, 158, 148, 138 and 99 mAh g1 at rates of 0.1C, 0.5C, 1C, 2C and 4C, respectively. The test electrode also showed excellent cyclability as the capacity retains 96.1% after 60 cycles between 0.5 and 2.5 V.

Joule Heating Effect on Oxide Whisker Growth Induced by Current Stressing in Cu/Sn-58Bi/Cu Solder Joint

Hongwen He,Liqiang Cao,Lixi Wan,Haiyan Zhao,Guangchen Xu,Fu Guo 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.4

The electromigration test was conducted in Cu/Sn-58Bi/Cu solder joint with high current density of 104 A/cm2. Results showed that a large number of whiskers with natural weed appearance were observed at the cathode side in such a short current stressing time. Furthermore, some secondary whiskers were attached to the primary whiskers, which has never been reported before. We presumed the vapor-solid (VS) mechanism to explain the oxide whiskers growth, which was quite different from the traditional theory that the compressive stress took on the driving force. In conclusion, due to the over-Joule heating effect, the metal oxide whiskers were synthesized in bulk quantities by thermal evaporation of Sn oxide and Bi oxide.

Structural evolution of the thermal conversion products of modified coal tar pitch

Qi Li,Dongyun Han,Haiyan Qiao,Weiwei Shi,Yuqi Zhang,Zubin Cao 한국탄소학회 2023 Carbon Letters Vol.33 No.1

Coal tar pitch is a product with high carbon content and aromatic compounds. Modified coal tar pitch is a high quality raw material for the preparation of intermediate phase pitch, needle coke, carbon microspheres, et al. In this paper, modified coal tar pitch was used as raw material, nitrogen was used as protective gas, and thermal conversion was carried out at constant temperatures (370, 390, 410, 420 °C). Polarized light microscopy, SEM, elemental analysis, FTIR spectroscopy, Raman spectroscopy and XRD diffraction combined with split-peak fitting were used to characterize the microstructures of the thermal transformation products. The results showed that the Iar and CH3/ CH2 contents of the products increased with the gradual increase of the thermal conversion temperature, and the aromatic content increased. And the higher the temperature at the same heating rate, the more the ideal graphite microcrystal content, and the defective graphite microcrystals are converted into ideal graphite microcrystals during the thermal conversion process. When the reaction temperature exceeds 390 °C, the microstructure of the thermal transformation products is anisotropic spheres, and the small spheres fuse with each other and tend to be basin-like and mosaic structure as the temperature increases.

RIS Selection and Energy Efficiency Optimization for Irregular Distributed RIS-assisted Communication Systems

Xu Fangmin,Fu Jinzhao,Cao HaiYan,Hu ZhiRui 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.7

In order to improve spectral efficiency and reduce power consumption for reconfigurable intelligent surface (RIS) assisted wireless communication systems, a joint design considering irregular RIS topology, RIS on-off switch, power allocation and phase adjustment is investigated in this paper. Firstly, a multi-dimensional variable joint optimization problem is established under multiple constraints, such as the minimum data requirement and power constraints, with the goal of maximizing the system energy efficiency. However, the proposed optimization problem is hard to be resolved due to its property of nonlinear nonconvex integer programming. Then, to tackle this issue, the problem is decomposed into four sub-problems: topology design, phase shift adjustment, power allocation and switch selection. In terms of topology design, Tabu search algorithm is introduced to select the components that play the main role. For RIS switch selection, greedy algorithm is used to turn off the RISs that play the secondary role. Finally, an iterative optimization algorithm with high data-rate and low power consumption is proposed. The simulation results show that the performance of the irregular RIS aided system with topology design and RIS selection is better than that of the fixed topology and the fix number of RISs. In addition, the proposed joint optimization algorithm can effectively improve the data rate and energy efficiency by changing the propagation environment.

Resource Allocation for D2D Communication in Cellular Networks Based on Stochastic Geometry and Graph-coloring Theory

( Fangmin Xu ),( Pengkai Zou ),( Haiquan Wang ),( Haiyan Cao ),( Xin Fang ),( Zhirui Hu ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.12

In a device-to-device (D2D) underlaid cellular network, there exist two types of co-channel interference. One type is inter-layer interference caused by spectrum reuse between D2D transmitters and cellular users (CUEs). Another type is intra-layer interference caused by spectrum sharing among D2D pairs. To mitigate the inter-layer interference, we first derive the interference limited area (ILA) to protect the coverage probability of cellular users by modeling D2D users’ location as a Poisson point process, where a D2D transmitter is allowed to reuse the spectrum of the CUE only if the D2D transmitter is outside the ILA of the CUE. To coordinate the intra-layer interference, the spectrum sharing criterion of D2D pairs is derived based on the (signal-to-interference ratio) SIR requirement of D2D communication. Based on this criterion, D2D pairs are allowed to share the spectrum when one D2D pair is far from another sufficiently. Furthermore, to maximize the energy efficiency of the system, a resource allocation scheme is proposed according to weighted graph coloring theory and the proposed ILA restriction. Simulation results show that our proposed scheme provides significant performance gains over the conventional scheme and the random allocation scheme.

Polarization Error Analysis of an All-Optical Fibre Small Current Sensor for Partial Discharge

Gaifang Xin,Jun Zhu,Chengming Luo,Jing Tang,Wei Li,Yuxin Cao,Haiyan Xu 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.5

In view of the characteristics of the small amplitude of a current signal, an all-optical fi bre small-current sensor for partial discharge is devised. A novel type of sensor head with electric winding light is proposed. A complete optical model of the optical fi bre current sensor is developed under the eff ect of polarization error factors. In addition, the eff ect of polarization error factors on the optical fi bre sensing system is simulated. The simulation results show that as the extinction ratio increases, the output relative error of the optical fi bre small-current sensor decreases. The eff ect of the fast and slow axis misalignment errors of a polarizing beam splitter is similar to the eff ect of the alignment angle error of an optical fi bre polarizer. It is observed that the relative error curve follows a sine function. Meanwhile, the output relative error increases fi rst and then oscillates with an increase in the linear birefringence. We conclude that the linear birefringence of the sensing optical fi bre is the main error source for the measurement accuracy of the sensing system. Finally, an experimental system for the optical fi bre small-current sensor is implemented. The experimental results show that the eff ect of linear birefringence on the fi bre current sensing system can be suppressed by introducing a large amount of circular birefringence into the sensing optical fi bre. The theoretical mechanism of these errors is analysed, which can be applied to implement corresponding measures to reduce the eff ect of error factors on the sensing system and further improve the measurement accuracy of the optical fi bre small-current sensor.