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随机环境下种群增长模型的数值模拟与最优解

系统科学与数学 2016年第11期36卷 2087-2098页

作者：余味乔韵璇中国人民大学统计学院北京100872

由于很多随机微分方程没有显式解,其数值算法是近年研究的一个热点问题.文章用Milstein高阶法对随机Logistic模型进行数值求解.随机Logistic模型以及由它衍生出的一系列模型是生物经济中常用的模型,对于研究生物资源的适度开发和控制捕... 详细信息

由于很多随机微分方程没有显式解,其数值算法是近年研究的一个热点问题.文章用Milstein高阶法对随机Logistic模型进行数值求解.随机Logistic模型以及由它衍生出的一系列模型是生物经济中常用的模型,对于研究生物资源的适度开发和控制捕获以获得最大的经济效益具有重要的意义.文章首先用数值模拟得到此模型在不同参数下的样本轨道,并且与直接用其强解的表达式得到的轨道相对比.然后考虑三种不同的捕获模式-固定捕获努力量,两点分布的捕获努力量和与种群数量变化比例相同的捕获努力量,其中后两种捕获努力量是与种群数量有关的随机过程.用模拟的方法得出这三种捕获模式的长期平均产出的变化规律,并且比较这三种捕获模式的优劣.发现设计的后两种捕获模式相比于固定捕获努力量各有其优点.最后用随机Logistic模型分析一个北冰洋鳕鱼的数据.

关键词：种群增长模型随机微分方程蒙特卡洛模拟捕获努力量最优解

The cell cycle inhibitor P21 promotes the development of pulmonary fibrosis by suppressing lung alveolar regeneration

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Acta Pharmaceutica Sinica B 2022年第2期12卷 735-746页

作者： Xiaoxi Lv Chang Liu Shanshan Liu yunxuan Li Wanyu Wang Ke Li Fang Hua Bing Cui Xiaowei Zhang Jiaojiao yu Jinmei yu ZhuoWei Hu Immunology and Cancer Pharmacology Group State Key Laboratory of Bioactive Substance and Function of Natural MedicinesInstitute of Materia MedicaChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China Drug Clinical Trial Institution Children’s HospitalCapital Institute of PediatricsBeijing 100020China Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China

The cell cycle inhibitor P21 has been implicated in cell senescence and plays an important role in the injury-repair process following lung *** fibrosis(PF)is a fibrotic lung disorder characterized by cell senescence in lung alveolar epithelial *** this study,we report that P21 expression was increased in alveolar epithelial type 2 cells(AEC2 s)in a time-dependent manner following multiple bleomycin-induced *** injury of AEC2 s resulted in telomere shortening and triggered P21-dependent cell ***2 s with elevated expression of P21 lost their self-renewal and differentiation *** particular,elevated P21 not only induced cell cycle arrest in AEC2 s but also bound to P300 andβ-catenin and inhibited AEC2 differentiation by disturbing the P300-β-catenin ***,senescent AEC2 s triggered myofibroblast activation by releasing profibrotic *** of P21 restored AEC2-mediated lung alveolar regeneration in mice with chronic *** results of our study reveal a mechanism of P21-mediated lung regeneration failure during PF development,which suggests a potential strategy for the treatment of fibrotic lung diseases.

关键词： P21 Cell senescence Alveolar epithelial type 2 cells Pulmonary fibrosis Alveolar regeneration Bleomycin Cell cycle arrest P300-β-catenin complex

F-box gene FOA2 regulates GA-and ABA-mediated seed germination in Arabidopsis

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Science China(Life Sciences) 2016年第11期59卷 1192-1194页

作者： Reqing Hei Dashi yu Xinmei Li Guifang Duan yunxuan Zhang Dongying Tang Xiaoying Zhao Xuanming Liu Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation College of BiologyHunan UniversityChangsha 410082China State Key Laboratory of Chemo/Biosensing and Chemometrics Hunan UniversityChangsha 410082China

Dear Editor, GA and ABA antagonize each other in controlling seed germination, but the molecular mechanism is not fully understood. The F-box proteins act as the most important SCF （SKP1, cullin/CDC53, F-box protein） complex subunit of the ubiquitin （Ub）- 26S proteasome system, mediate diverse physiological processes ranging from hormonal signaling cascades to environmental stress responses （Santner and Estelle, 2010）. We previously demonstrated that FOAl （F-box overexpressed/oppressed ABA signaling） is an ABA signaling-related gene,

关键词： and ABA mediated seed germination in Arabidopsis FOA F-box gene FOA2 regulates GA Figure gene

TRIB3 promotes pulmonary fibrosis through inhibiting SLUG degradation by physically interacting with MDM2

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Acta Pharmaceutica Sinica B 2023年第4期13卷 1631-1647页

作者： Xiaoxi Lv Shanshan Liu Chang Liu yunxuan Li Tingting Zhang Jie Qi Ke Li Fang Hua Bing Cui Xiaowei Zhang yuxin Liu Jiaojiao yu Jinmei yu Li Li Xia Li Zhigang Yao Bo Huang State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China National Clinical Research Center for Metabolic Diseases Key Laboratory of Diabetes ImmunologyMinistry of EducationAnd Department of Metabolism and EndocrinologyThe Second Xiangya Hospital of Central South UniversityChangsha 410011China Drug Clinical Trial Institution Children's HospitalCapital Institute of PediatricsBeijing 100020China Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China Shandong University Weihai 264209China Department of Respiratory Medicine Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China Institute of Basic Medicine Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100005China

Pulmonary fibrosis(PF)is the pathological structure of incurable fibroproliferative lung diseases that are attributed to the repeated lung injury-caused failure of lung alveolar regeneration(LAR).Here,we report that repetitive lung damage results in a progressive accumulation of the transcriptional repressor SLUG in alveolar epithelial type II cells(AEC2s).The abnormal increased SLUG inhibits AEC2s from self-renewal and differentiation into alveolar epithelial type I cells(AEC1s).We found that the elevated SLUG represses the expression of the phosphate transporter SLC34A2 in AEC2s,which reduces intracellular phosphate and represses the phosphorylation of JNK and P38 MAPK,two critical kinases supporting LAR,leading to LAR ***3,a stress sensor,interacts with the E3 ligase MDM2 to suppress SLUG degradation in AEC2s by impeding MDM2-catalyzed SLUG *** SLUG degradation by disturbing the TRIB3/MDM2 interaction using a new synthetic staple peptide restores LAR capacity and exhibits potent therapeutic efficacy against experimental *** study reveals a mechanism of the TRIB3—MDM2—SLUG—SLC34A2 axis causing the LAR failure in PF,which confers a potential strategy for treating patients with fibroproliferative lung diseases.

关键词： E3 ligase Lung injury MDM2 Protein—protein interaction Proteolysis Ubiquitination UPS

Effects of Maca Extract on Exercise Endurance and Ultrastructure of Mitochondria in Spinal Neurons

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Medicinal Plant 2018年第3期9卷 47-50页

作者： Farong yu Wangjun CHEN Xiuzhen LIAN Mingren XIE Denglou LI yunxuan GUO Key Laboratory of Evidence of Science and Technology Research and Application Gansu Institute of Political Science and Law

[Objectives] To study the effects of maca extract on the exercise endurance and ultrastructure of mitochondria in spinal neurons.[Methods]First,50 Wistar rats were randomly divided into 5 groups. The control group: no swimming,administered intragastrically the same volume of distilled water; simple swimming group: free swimming,administered intragastrically the same volume of distilled water; maca extract groups: free swimming,and treated with 4. 0,5. 3,and 8. 0 g/kg dose of maca extracts. Swimming rats swam freely in the circulating water flow of swimming pool and administered for 15 d. On the 16 th d,after the swimming endurance test,the rats were killed painlessly. The ultrastructure of the mitochondria in the spinal neurons was observed with a projection electron microscope,muscle glycogen,malondialdehyde( MDA),superoxide dismutase( SOD),glutathione peroxidase( GSH-Px) and free calcium in muscle were measured by radioimmunoassay.[Results] Compared with the simple swimming group,the swimming time before sinking and total swimming time extended 19. 83%,60. 28%,77. 55% and 55. 34%,73. 91% and 94. 47% respectively,and the differences were statistically significant( P < 0. 01). The sinking times decreased by 34. 35%,51. 18% and 57. 96% respectively,the differences were statistically significant( P < 0. 01). MDA and free calcium decreased by 20. 10%,31. 49% and 38. 72%,respectively with statistically significant differences( P < 0. 01) and 6. 42%,17. 58%and 26. 35% respectively. The levels of SOD,GSH-Px and muscle glycogen increased by 5. 12%,22. 74%,52. 53%,44. 22%,77. 79%and 98. 45% respectively,with statistically significant differences( P < 0. 01) and 35. 08%,47. 83% and 81. 88%,respectively,with statistically significant differences( P < 0. 01). The volume density( Vd),surface density( Sd) and number density( Nd) of mitochondria of spinal neurons decreased by 7. 79%,18. 18%,31. 17%,16. 95%,27. 34%,43. 31% and 13. 51%,23. 19% and 43. 15% respectively.[Conclusions]

关键词： Maca extract Exercise endurance Mitochondria Wistar rats

酵母菌的致孔作用对PVA/CMC水凝胶性能的影响

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化工学报 2020年第4期71卷 1828-1835页

作者：万豫张敏翁云宣李成涛陕西科技大学环境科学与工程学院陕西西安710021 北京工商大学塑料卫生与安全质量评价技术北京市重点实验室北京100048

利用酵母菌发泡制备了聚乙烯醇/羧甲基纤维素多孔水凝胶(D-PC),采用FTIR对其化学结构进行了表征和Zeta电位分析共同证明了酵母菌和材料之间的相互作用;利用SEM和BET分别对其三维网络结构进行了观察以及比表面积、孔径进行了测定;研究了D... 详细信息

利用酵母菌发泡制备了聚乙烯醇/羧甲基纤维素多孔水凝胶(D-PC),采用FTIR对其化学结构进行了表征和Zeta电位分析共同证明了酵母菌和材料之间的相互作用;利用SEM和BET分别对其三维网络结构进行了观察以及比表面积、孔径进行了测定;研究了D-PC在不同条件下对亚甲基蓝(MB)的去除,通过纤维素降解酶实验测试了D-PC的降解性。研究结果表明:酵母菌通过静电作用包覆在D-PC内;随着酵母菌量的增加,D-PC的比表面积增大、平均孔径减小;D-PC对MB的去除机制以化学吸附为主,且吸附动力学符合伪二级动力学方程;去除效率随着酵母菌的增加而增大,随着pH、温度的增加先增大后减小;一定条件下D-PC能降解水凝胶中的聚乙烯醇。

关键词：凝胶酵母菌致孔吸附作用降解多功能性

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生物降解聚酯降解性能调控研究进展

中国塑料 2023年第3期37卷 103-112页

作者：管羽付烨翁云宣北京工商大学化学与材料工程学院北京100048

综述了聚合物分子结构设计、聚合物共混改性以及复合材料配方设计等生物降解聚酯降解速率调控方法,分析了生物降解聚酯降解性能调控面临的问题并展望其前景,以期为制备具有高性能、时控性和完全降解性的生物降解聚合物材料提供理论基础。

关键词：生物降解聚酯降解速率调控分子结构设计共混改性复合材料

Pyrrolic N or pyridinic N: The active center of N-doped carbon for CO_(2) reduction

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Chinese Journal of Catalysis 2022年第9期43卷 2405-2413页

作者： yu Shang yunxuan Ding Peili Zhang Mei Wang yufei Jia yunlong Xu Yaqing Li Ke Fan Licheng Sun State Key Laboratory of Fine Chemicals Institute of Artificial PhotosynthesisDUT‐KTH Joint Education and Research Centre on Molecular DevicesInstitute for Energy Science and TechnologyDalian University of TechnologyDalian 116024LiaoningChina Center of Artificial Photosynthesis for Solar Fuels School of ScienceWestlake UniversityHangzhou 310024ZhejiangChina Department of Chemistry KTH Royal Institute of TechnologyStockholm 10044Sweden

Pyridinic N is widely regarded as the active center while pyrrolic N has low‐activity in metal‐free N‐doped carbon for electrocatalytic CO_(2) reduction reaction(CO_(2)RR)to CO,but this viewpoint remains open to *** this study,through density functional theoretical calculations,we first illustrate that the intrinsic activity of pyrrolic N is high enough for effectively catalyzing CO_(2)RR,however,due to the interplay with the neighboring pyridinic N sites,the activity of pyrrolic N is dramatically ***,experimentally,metal‐free N‐doped carbon spheres(NCS)electrocatalysts without significant pyridinic N content are prepared for CO_(2)*** pyrrolic N in NCS shows a direct‐positive correlation with the performance for CO_(2)RR,representing the active center with high *** optimum NCS could produce syngas with a wide range of CO/H_(2) ratio(0.09 to 12)in CO_(2)RR depending on the applied potential,meanwhile,the best selectivity of 71%for CO can be *** adding a small amount of pyridinic N to the optimum NCS dramatically decreases the activity for CO_(2)RR,further verifying the suppressed activity of pyrrolic N sites by the neighboring pyridinic N *** work reveals the interaction between a variety of N species in N‐doped carbon,and the potential of pyrrolic N as the new type of active site for electrocatalysts,which can improve our understanding of the electrocatalysis mechanism and be helpful for the rational design of high‐efficient electrocatalysts.

关键词： CO_(2)reduction reaction Tunable syngas Carbon sphere Pyrrolic N Metal-free catalysts

基于Sentinel-1A雷达影像的崇明东滩芦苇盐沼植被识别提取

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吉林大学学报（地球科学版） 2018年第4期48卷 1192-1200页

作者：胥为周云轩沈芳田波于鹏华东师范大学河口海岸学重点实验室上海200062

为研究芦苇盐沼植物在一个生长周期不同生长季节的雷达后向散射系数变化特征,对芦苇分布信息进行提取,探究Sentinel-1A卫星数据在长江口湿地植被监测中的应用前景。以对长江河口崇明东滩南部为研究区域,利用2016年11个时相的Sentinel-1... 详细信息

为研究芦苇盐沼植物在一个生长周期不同生长季节的雷达后向散射系数变化特征,对芦苇分布信息进行提取,探究Sentinel-1A卫星数据在长江口湿地植被监测中的应用前景。以对长江河口崇明东滩南部为研究区域,利用2016年11个时相的Sentinel-1A雷达卫星影像VV(vertical transmit/vertical receive)+VH(vertical transmit/horizontal receive)双极化数据,分析潮滩地带芦苇、白茅、海三棱藨草、水体和光滩在植被生长周期内的雷达后向散射强度变化特征,对芦苇盐沼植被进行识别提取。结果表明:相较于VH极化方式,VV极化方式下不同地物的后向散射强度差异更为明显,芦苇的后向散射强度在枯叶期下显著高于其他地物;进行芦苇植被提取时,需要对植被枯萎期不同潮位状况下的雷达影像进行组合运算,芦苇提取精度可达到88.7%;对芦苇植被雷达后向散射强度和临近时相的光学遥感归一化植被指数(normalized difference vegetation index,INDV)进行相关性分析,发现两者呈良好的正相关关系,相关系数为0.78。

关键词： Sentinel-1A卫星合成孔径雷达盐沼植被芦苇海岸带