检索结果-南通市图书馆

Effects of hypoxia on the biological behavior of MSCs seeded in demineralized bone scaffolds with different stiffness

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2019年第2期35卷 309-320页

作者： yuanyuan sun Guobao Chen Yonggang Lv Key Laboratory of Biorheological Science and Technology (Chongqing University) Ministry of Education Bioengineering College Chongqing University Chongqing 400044 China Mechanobiology and Regenerative Medicine Laboratory Bioengineering College Chongqing University Chongqing 400044 China

Matrix stiffness has been demonstrated in many studies to adjust the biological behaviors of mesenchymal stem cells (MSCs). However, in the initial phase of bone restore, MSCs will encounter a hypoxic microenvironment. Studying the connection existing between the matrix stiffness and biological behavior of MSCs under hypoxic condition can better simulate the microenvironment at the prime period of bone repairment. In this work, three-dimensional (3D) decalcified bone scaffolds with diverse stiffness (high stiffness (66.06 ± 27.83) MPa, medium stiffness (26.90 ± 13.16) MPa, and low stiffness (0.67 ± 0.14) MPa) but same microstructure have been prepared by controlling decalcification time. In addition, the decellularized bone scaffold was regard as control group and its stiffness was (230.93 ± 72.65) MPa. The viability, proliferation, infiltration, and osteogenic differentiation of MSCs seeded into these 3D demineralized bone scaffolds were systematically investigated under 100 μM CoCl2-simulated hypoxic and normoxic environments. The results showed that the viability, proliferation, and extracellular matrix (ECM) secretion of MSCs had no significant difference on scaffolds with diverse stiffness but the degree of collagen deposition of MSCs gradually increased with the increase of scaffold stiffness both under normoxia and hypoxia. Compared to normoxia, the viability, proliferation, ECM secretion, vascular endothelial growth factor (VEGF) expression, and osteogenis of MSCs on the scaffolds with the same stiffness were evidently inhibited by hypoxia. Additionally, under hypoxic condition, the expression of VEGF and hypoxia inducible factor 1α(HIF-1α) in MSCs on the low stiffness scaffold was markedly increased comparing to those on other groups. In summary, we found that the low stiffness scaffold can improved the proliferation and osteoginic differentiation of MSCs under hypoxic environment, which may help to explore efficient methods for bone defect repairing.

关键词： Mesenchymal stem cells Hypoxia Matrix stiffness Demineralized bone scaffold Osteogenic differentiation

In situ synthesis of FeS/Carbon fibers for the effective removal of Cr(Ⅵ)in aqueous solution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2020年第4期14卷 147-158页

作者： Rongrong Zhang Daohao Li Jin sun Yuqian Cui yuanyuan sun School of Environmental Science and Engineering Collaborative Innovation Center for Marine Biomass FiberMaterials and Textiles of Shandong ProvinceQingdao UniversityQingdao 266071China

Iron sulfide(FeS)nanoparticles(termed FSNs)have attracted much attention for the removal of pollutants due to their high efficiency and low cost,and because they are environmentally ***,issues of agglomeration,transformation,and the loss of active components limit their ***,this study investigates in situ synthesized FeS/carbon fibers with an Fecarrageenan biomass as a precursor and nontoxic sulfur source to ascertain the removal efficiency of the *** enrichment of sulfate groups as well as the double-helix structure in i-carrageenan-Fe could effectively avoid the aggregation and loss of FSNs in practical *** obtained FeS/carbon fibers were used to control a Cr(Ⅵ)polluted solution,and exhibited a relatively high removal capacity(81.62 mg/g).T he main mechanisms included the reduction of FeS,electrostatic adsorption of carbon fibers,and Cr(Ⅲ)-Fe(Ⅲ)complexation *** pseudo-second-order kinetic model and Langmuir adsorption model both provided a good fit of the reaction process;hence,the removal process was mainly controlled by chemical adsorption,specifically monolayer adsorption on a uniform ***,co-existing anions,column,and regeneration experiments indicated that the FeS/carbon fibers are a promising remediation material for practical application.

关键词： Carrageenan FeS Double-helix structure Hexavalent chromium

Multi-stage Provincial Power Expansion Planning and Multi-market Trading Equilibrium

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2024年第5期12卷 1652-1665页

作者： Guangsheng Pan Zhongfan Gu yuanyuan sun Kaiqi sun Wei Gu the School of Electrical Engineering Southeast UniversityNanjingChina Key Laboratory of Power System Intelligent Dispatch and Control of the Ministry of Education School of Electrical EngineeringShandong UniversityJinanChina

Decarbonization in the power sector is one of the critical factors in achieving carbon neutrality,and the top-level design needs to be carried out from the perspective of power planning.A multi-stage provincial power expansion planning(PPEP)model is proposed to simulate the power expansion planning at different stages of the power systems rich in renewable energy *** model covers 16 types of power supply,considering macro-policy demands and micro-operation *** stand-alone capacity aggregation model for coal-based units within the PPEP model allows for accurate construction and retirement with different stand-alone ***,the soft dynamic time warping(soft-DTW)based K-medoids technique is adopted to generate typical scenarios for balancing the model accuracy and solution ***,a multi-market trading equilibrium(MMTE)mechanism is proposed to address the differences in the levelized cost of energy between the coal-based and renewable-based units by participating in energy and ancillary service *** the coalbased units take on the task of providing ancillary services from renewable-based units in the ancillary service market,the MMTE mechanism can effectively equalize the profits of both by having renewable-based units purchase ancillary services from coal-based units and pay for them,thus improving the motivation of coal-based units.A case study in Xinjiang province,China,verifies the effectiveness of the planning results of the PPEP model and the profit equilibrium realization of the MMTE mechanism.

关键词： Power expansion planning market design ancillary service market renewable energy generation energy market

维普期刊数据库

Input-to-state stability analysis of stochastic delayed switching systems

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2023年第11期66卷 204-221页

作者： Peilin YU Feiqi DENG Xueyan ZHAO yuanyuan sun School of Automation Science and Engineering South China University of Technology

In this paper, the issues regarding the input-to-state stability(ISS) and integral input-to-state stability(iISS) of the stochastic delayed switching systems with Lévy noise and input control(SDSS-LN-IC)are proposed by employing the comparison theorem approach, mode-dependent average dwell time(MDADT)method, delay integral inequality(DII), and Lyapunov-Razumikhin(L-R) technique. Two switching situations, namely, synchronous switching and asynchronous switching, are considered. Applying integral inequalities, sufficient stability conditions in both cases are given. Moreover, the sequences of this paper allow for the coefficients for the upper-bound expectation estimation of the infinitesimal operator to be mode-dependent,regardless of the sign and time-varying function rather than a constant, as is the case in certain existing results, which manifests the condition of the Lyapunov-Razumikhin technique in this paper is looser and less conservative. Finally, the validity and correctness of the theoretical results are verified by two examples and some simulations.

关键词： input-to-state stability synchronous switching asynchronous switching Lyapunov-Razumikhin technique mode-dependent average dwell time comparison theorem approach

同方期刊数据库

Dose-dependent effects of lead on cell-cycle arrest, DNA damage, and cyclin D1 expression in primary cultured rat hippocampal neurons

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2010年第3期5卷 221-225页

作者： Shuang Gao Liguang sun yuanyuan You China Medical University Shenyang 110001 Liaoning Province China

BACKGROUND： Previous studies have suggested that the hippocampus is one of the neurotoxic target sites for lead. However, the molecular mechanisms of action, including the effect of lead on cell-cycle arrest, remain poorly understood. OBJECTIVE： To investigate the effects of different lead concentrations on cell-cycle arrest, DNA damage, and cyclin D1 expression in primary cultured rat hippocampal neurons. DESIGN, TIME AND SETTING： A randomized, controlled, in vitro experiment was performed at the China Medical University between July 2008 and May 2009. MATERIALS： Antibodies specific to cyclin D1 and actin were synthesized and purified by Santa Cruz Biotechnology, USA. FACStar flow cytometer was purchased from Becton Dickinson, San Jose, California, USA. METHODS： Wistar rat hippocampal neurons were primary cultured for 7 days. Neurons in the control group were treated with 0.01 mol/L phosphate buffered saline. Neurons in the 0.2, 1.0, and 10 umol/L lead acetate groups were subjected to 0.2, 1.0, and 10 umol/L lead acetate. Subsequently hippocampal neurons in each group were cultured for 24 hours. MAIN OUTCOME MEASURES： The effects of lead on cell cycle were measured by flow cytometry, DNA damage was measured using the comet assay, and cyclin D1 expression was measured using Western blot analysis. RESULTS： Treatment of hippocampal neurons with 0.2 umol/L lead acetate did not significantly alter cell cycle phase distribution, i.e., sub-G1, S, G0/G1, G2/M, whereas treatment with 1.0 and 10 umol/L lead acetate significantly increased the percentage of S and sub-G1 phase cells （P 〈 0.05）. Olive tail moment in all lead-treated groups and the percentage of DNA in the tail in 1.0 umol/L and 10 umol/L lead acetate groups were significantly greater compared with the control group （P 〈 0.05）. In addition, the percentage of tail DNA was greater in the 0.2 umol/L lead acetate group compared with the control group （P 〉 0.05）. Following incubation with 0.2, 1.0, and 10 umol/L lead

关键词： lead cell-cycle arrest DNA damage cyclin D1 hippocampal neurons nerve factor neural regeneration

维普期刊数据库

A review on nanoconfinement engineering of red phosphorus for enhanced Li/Na/K-ion storage performances

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第10期30卷 531-552,I0014页

作者： yuanyuan sun Fanyou Zeng Yukun Zhu Ping Lu Dongjiang Yang School of Environmental Science and Engineering State Key Laboratory of Bio-fibers and Eco-textilesShandong Collaborative Innovation Center of Marine Biobased Fibers and Ecological TextilesQingdao UniversityQingdao 266071ShandongChina Nanomaterial&Electrocatalysis Laboratory College of Materials Science and EngineeringQingdao University of Science and TechnologyQingdao 266042ShandongChina Queensland Micro-and Nanotechnology Centre(QMNC) Griffith UniversityNathanBrisbaneQueensland 4111Australia

Secondary batteries are widely used in energy storage *** obtain high-performance batteries,the development and utilization of electrode materials with cheap price and ideal theoretical gravimetric and volumetric specific capacities have become particularly *** abundant and low-cost red phosphorus(RP)is recognized as an anode material with great promise because it has a theoretical capacity of 2596 mA h g^(-1) in lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs).However,owing to the inferior discharging,the capacity of pure RP has a fast *** of RP nanoparticles within porous carbon framework is one of the efficient methods to overcome these *** this review,we introduce the recent progress of RP confinement into carbon matrix as an energy storage anode material in LIBs,SIBs and potassium-ion batteries(PIBs).The synthetic strategies,lithiation/sodia tion/potassiation mechanism,and the electrochemical performances of RP/carbon composites(RP/C)with kinds of designed structures and P-C and P-O-C bond by kinds of methods are ***,the challenges and perspectives of RP faced in the application development as anodes for LIBs/SIBs/PIBs are *** review will strengthen the understanding of composites of RP nanoparticles in porous carbon materials and aid researchers to carry out future work rationally.

关键词： Red phosphorus Anodes Nanoconfinement Carbon materials Energy storage

维普期刊数据库

Rapid diagnosis of nitrogen nutrition status in rice based on static scanning and extraction of leaf and sheath characteristics

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2017年第3期10卷 158-164页

作者： Chen Lisu sun yuanyuan Wang Ke College of Ocean Science and Engineering Shanghai Maritime UniversityShanghai 201306China Institute of Applied Remote Sensing&Information Technology Zhejiang UniversityHangzhou 300058China

According to the mechanism of rice growth,if nitrogen deficiency occurs,not only rice leaf but also sheath shows special symptoms:sheaths become short,stems appear light green,older sheath become *** nutrition status of rice could be identified based on the differences of color and shape of leaf and sheath under different levels of nitrogen *** vision technology can be used to non-destructively and rapidly identify rice nutrition status,but image acquisition via digital camera is susceptible to external conditions,and the images are of poor *** this research,static scanning technology was used to collect images of rice leaf and *** those images,14 color and shape characteristic parameters of leaf and sheath were extracted by R,G,B mean value function and region props function in *** on the relationship between nitrogen content and the characteristics extracted from the images,the leaf R,leaf length,leaf area,leaf tip R,sheath G,and sheath length were chosen to identify nitrogen status of rice by using Support Vector Machine(SVM).The results showed that the overall identification accuracies of different nitrogen nutrition were 94%,98%,96%and 100%for the four growth stages,*** years of data were used for validation,identification accuracies were 88%,98%,90%and 100%,*** results showed that additional sheath characteristics can effectively increase the identification accuracy of nitrogen nutrition status and the methodology developed in the study is capable of identifying nitrogen deficiency accurately in the rice.

关键词： N deficiency static scanning leaf sheath support vector machine(SVM) identification

Fabrication of three-dimensional porous La-doped SrTiO3 microspheres with enhanced visible light catalytic activity for Cr（VI） reduction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2018年第3期12卷 440-449页

作者： Dong Yang Xiaoyan Zou yuanyuan sun Zhenwei Tong Zhongyi Jiang Key Laboratory of Systems Bioengineering of Ministry of Education School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China School of Environmental Science and Engineering Tianjin University Tianjin 300072 China Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China

In recent years, much effort has been focused on the development of the photocatalysts with high performance under visible light irradiation. In this paper, three-dimensional porous La-doped SrTiO3 （LST） micro- spheres were prepared by a modified sol-gel method, in which the agarose gel/SrCO3 microsphere and La2O3 were employed as the template and the La resource, respectively. The as-prepared LST microspheres exhibit a porous structure with a diameter of about 10 μm and a surface pore size of about 100 nm. The La element was doped into the crystal lattice of SrTiO3 by the substitution of La^3＋ for Sr^2＋. Therefore, the absorption edge of LST samples shifts toward the visible light region, and their photocatalytic activity for the Cr（VI） reduction is enhanced under visible light. Among all LST samples, LST-0.5 （the La^3＋ doping content is 0.5 wt-%） exhibited the highest visible-light photocatalytic activity, which can reduce 84% Cr（VI） within 100 rain. This LST materials may become a promising photocatalyst for the facile treatment of waste- water containing poisonous heavy metal ions.

关键词： SrTiO3 La^3+ doping porous microsphere visible-light photocatalysis Cr(VI) reduction

Halogen Bond Catalysis on Carbonyl-Olefin Ring-Closing Metathesis Reaction:Comparison with Lewis Acid Catalysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2022年第11期40卷 1275-1284页

作者： Ying Li yuanyuan sun Lingpeng Meng Qingzhong Li Yanli Zeng College of Chemistry and Materials Science Hebei Key Laboratory of Inorganic Nano-materialsHebei Normal UniversityShijiazhuangHebei 050024China The Laboratory of Theoretical and Computational Chemistry College of Chemistry&Chemical EngineeringYantai UniversityYantaiShandong 264005China

The carbonyl-olefin ring-closing metathesis reactions have become a powerful tool for carbon-carbon bond *** this work,the halogen bond catalysis and classical Lewis acid catalysis on the carbonyl-olefin ring-closing metathesis reaction were investigated by density function *** both the halogen bond catalysis and classical Lewis acid catalysis,the carbonyl-olefin ring-closing me-tathesis reaction occurs by[2+2]-cycloaddition process and[2+2]-cycloreversion process,the reaction energy barriers are low,there-fore,it can be performed easily at room *** essential difference of the two kinds of catalysts is that the catalytic mecha-nism of halogen bond catalysis is mainly contribution of electrostatic interaction,while that of classical Lewis acid catalysis is mainly catalyzed by orbital *** halogen bond donor catalysts(ICI_(3),IF_(3))are expected to be efficient catalysts for the reaction and further promote the chemical synthesis of carbonyl-olefin ring-closing metathesis reaction.

关键词： Halogen bond donors Lewis acids Electrostatic interactions Orbital interaction Carbonyl-olefin ring-closing metathesis