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Application of Et_3NHCl-AlCl_3 Ionic Liquid as an Initiator in Cationic Copolymerization of 1, 3-Pentadiene with Styrene
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作者 Yuan Yuan WANG Hui SUN Juan LI Dong JIANG Li Yi DAI 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第1期117-120,共4页
The random copolymer poly (1, 3-pentadiene-co-styrene) formed through cationic copolymerization using the ~ethylamine hydrochloride and hydrous aluminium chloride (Et3NHCl-AlCl3) room temperature ionic liquid as i... The random copolymer poly (1, 3-pentadiene-co-styrene) formed through cationic copolymerization using the ~ethylamine hydrochloride and hydrous aluminium chloride (Et3NHCl-AlCl3) room temperature ionic liquid as initiating agent in toluene was analyzed using IR spectra in conjunction with gel permeation chromatography (GPC). The room temperature ionic liquid was found to have high initiatic activity for copolymerization. 展开更多
关键词 Et3NHCl-AlCl3 ionic liquid 1 3-pentadiene STYRENE cationic copolymerization.
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CATIONIC POLYMERIZATION OF 1,3—PENTADIENE INITIATED BY ORGANIC AZIDE/Et_2AlCl
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作者 赵宇行 戴汉松 +1 位作者 刘佳林 寸琳峰 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1995年第4期381-384,共4页
The cationic polymerization of 1, 3-pentadiene was initiated by the organic azide/Et_2 AlClinitiating system in CH_2Cl_2 and n-hexane. The polymerizations were also carried out in parallelwith organic chloride/Et_2AlC... The cationic polymerization of 1, 3-pentadiene was initiated by the organic azide/Et_2 AlClinitiating system in CH_2Cl_2 and n-hexane. The polymerizations were also carried out in parallelwith organic chloride/Et_2AlCl and Et_2 AlCl alone for comparison. The Et_2 AlCl- induced polymer-ization gives a low yield while the polymerization initiated by organic chloride/Et_2 AlCl producesmainly insoluble product. In contrast, the polymerization with azide/Et,AlCl has a high conver-sion and the resulting polymer having a high molecular weight is totally soluble. The SEC spectraof the polymers have clearly shown the differences between these initiating systems. 展开更多
关键词 Cationic polymerization 1 3-pentadiene initiator Azide/Et_2AlCl
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RIP3/MLKL通过激活4EBP1-eIF4E通路诱导程序性坏死 被引量:1
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作者 王树超 徐玫丽 《中南大学学报(医学版)》 CAS CSCD 北大核心 2023年第7期979-985,共7页
目的:程序性坏死是一种由受体相互作用蛋白3(receptor interacting protein 3,RIP3)和混合谱系激酶域样蛋白(mixed lineage kinase domain-like protein,MLKL)介导的细胞死亡形式,有研究指出哺乳动物雷帕霉素靶蛋白通路可能参与程序性... 目的:程序性坏死是一种由受体相互作用蛋白3(receptor interacting protein 3,RIP3)和混合谱系激酶域样蛋白(mixed lineage kinase domain-like protein,MLKL)介导的细胞死亡形式,有研究指出哺乳动物雷帕霉素靶蛋白通路可能参与程序性坏死的调控,真核细胞翻译起始因子4E结合蛋白1(eukaryotic translation initiation factor 4Ebinding protein 1,4EBP1)-真核起始因子4E(eukaryotic initiation factor 4E,eIF4E)通路是哺乳动物雷帕霉素靶蛋白最重要的下游分子通路之一,然而此通路是否参与程序性坏死的发生,目前尚无相关研究。本研究旨在探索4EBP1-eIF4E通路在程序性坏死中是否发生改变。方法:首先向小鼠上皮样成纤维细胞系L929细胞中加入程序性坏死诱导剂TSZ(TNF-α/SM-164/Z-VAD-FMK),在光学显微镜下观察细胞坏死情况;进一步向敲除RIP3和MLKL基因的L929细胞中加入TSZ,采用碘化丙啶(propidium iodide,PI)染色观察细胞坏死情况,实时荧光定量聚合酶链反应和蛋白质印迹法检测4EBP1和eIF4E的mRNA和蛋白质表达水平。结果:野生型L929细胞用TSZ处理后,坏死细胞增加,4EBP1的mRNA和蛋白质表达水平明显下调且磷酸化的4EBP1(phosphorylated 4EBP1,p-4EBP1)/4EBP1值增加(P<0.05或P<0.01),eIF4E的mRNA表达水平明显上调且磷酸化的eIF4E(phosphorylated eIF4E,p-eIF4E)/eIF4E值增加(均P<0.01);在敲除L929细胞中的RIP3和MLKL基因后,PI阳性坏死细胞明显减少,4EBP1的mRNA和蛋白质表达水平明显上调且p-4EBP1/4EBP1值下降(P<0.05或P<0.01),eIF4E的mRNA表达水平明显下调且p-eIF4E/eIF4E值下降(均P<0.01)。结论:4EBP1-eIF4E通路在RIP3/MLKL介导的程序性坏死中发生活化。 展开更多
关键词 程序性坏死 受体相互作用蛋白3 混合谱系激酶域样蛋白 真核细胞翻译起始因子4E结合蛋白1 真核起始因子4E
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Lateral resonances in initial stressed 1-3 piezocomposites 被引量:2
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作者 张红艳 沈亚鹏 尹冠生 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第7期873-881,共9页
A theoretical analysis of the lateral resonances in 1-3 piezocomposites with poling initial stress is conducted using the Bloch wave theory. Based on the linear piezoelectricity theory, theoretical formulations that i... A theoretical analysis of the lateral resonances in 1-3 piezocomposites with poling initial stress is conducted using the Bloch wave theory. Based on the linear piezoelectricity theory, theoretical formulations that include initial stress for the propagation of acoustic plane waves are made. Numerical calculations are performed to study the effects of the initial stress on the lateral mode frequencies and the stop band. It is found that lateral mode frequencies increase with the piezoelectricity of the piezocomposites, but decrease with the poling initial stress. The influence of the initial shear stress on the lateral mode frequencies is minimal, and can thus be neglected. 展开更多
关键词 lateral modes 1-3 piezocomposites initial stress
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ARID1A Inactivation Increases Expression of circ0008399 and Promotes Cisplatin Resistance in Bladder Cancer
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作者 Yang-kai JIANG Yu-jun SHUAI +7 位作者 Hua-min DING Hui ZHANG Chao HUANG Liang WANG Jia-yin SUN Wen-jie WEI Xing-yuan XIAO Guo-song JIANG 《Current Medical Science》 SCIE CAS 2023年第3期560-571,共12页
Objective Cisplatin(CDDP)-based chemotherapy is a first-line,drug regimen for muscle-invasive bladder cancer(BC)and metastatic bladder cancer.Clinically,resistance to CDDP restricts the clinical benefit of some bladde... Objective Cisplatin(CDDP)-based chemotherapy is a first-line,drug regimen for muscle-invasive bladder cancer(BC)and metastatic bladder cancer.Clinically,resistance to CDDP restricts the clinical benefit of some bladder cancer patients.AT-rich interaction domain 1A(ARID1A)gene mutation occurs frequently in bladder cancer;however,the role of CDDP sensitivity in BC has not been studied.Methods We established ARID1A knockout BC cell lines using CRISPR/Cas9 technology.IC50 determination,flow cytometry analysis of apoptosis,and tumor xenograft assays were performed to verify changes in the CDDP sensitivity of BC cells losing ARID1A.qRT-PCR,Western blotting,RNA interference,bioinformatic analysis,and ChIP-qPCR analysis were performed to further explore the potential mechanism of ARID1A inactivation in CDDP sensitivity in BC.Results It was found that ARID1A inactivation was associated with CDDP resistance in BC cells.Mechanically,loss of ARID1A promoted the expression of eukaryotic translation initiation factor 4A3(EIF4A3)through epigenetic regulation.Increased expression of EIF4A3 promoted the expression of hsa_circ_0008399(circ0008399),a novel circular RNA(circRNA)identified in our previous study,which,to some extent,showed that ARID1A deletion caused CDDP resistance through the inhibitory effect of circ0008399 on the apoptosis of BC cells.Importantly,EIF4A3-IN-2 specifically inhibited the activity of EIF4A3 to reduce circ0008399 production and restored the sensitivity of ARID1A inactivated BC cells to CDDP.Conclusion Our research deepens the understanding of the mechanisms of CDDP resistance in BC and elucidates a potential strategy to improve the efficacy of CDDP in BC patients with ARID1A deletion through combination therapy targeting EIF4A3. 展开更多
关键词 AT-rich interaction domain 1A hsa_circ_0008399 eukaryotic translation initiation factor 4A3 cisplatin resistance bladder cancer
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NANOCRYSTALLINE STRUCTURE AND INITIAL PERMEABILITY OF ANNEALED Fe_(73.5)Cu_(1)W_(3)Si_(13.5)B_(9) Alloy
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《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1996年第3期199-205,共7页
The nanocrystalline structure of annealed Fe73.5 Cu1 W3Si13.5B9 alloy has been investigated by using the XRD and the TEM methods. The relation between the initial permeability and the microstructure of the annealed al... The nanocrystalline structure of annealed Fe73.5 Cu1 W3Si13.5B9 alloy has been investigated by using the XRD and the TEM methods. The relation between the initial permeability and the microstructure of the annealed alloy has been discussed. The crystalline phase in annealed Fe73.5 Cu1 W3Si13.5B9 alloy is the α-Fe(Si) phase with DO3 superstructure. The volume fraction, Si content and degree of order of the αFe(Si) phase increase with increasing annealing temperature. In the temperature range of 490-570℃, the α-Fe(Si) phase has a size of 13 nm, and its grain number increases as the annealing temperature is increased. The DO3 ordered region in the α-Fe(Si) grain is spherical approximately, and its size increases as the annealing temperature increases. The size of the DO3 ordered region is 12.8 nm at the temperature of 570℃,which is close to that of the α-Fe(Si) grain. There is obvious change in the structure of the residual amorphous phase during annealing, and the nearest atomic distance and the short-range order of residual amorphous phase reach maximum and minimum at 530℃, respectively. The initial permeability of annealed Fe73.5 Cu1 W3Si13.5 B9 alloy is not only dependent on the size, volume fraction and Si content of the α-Fe(Si) phase but also related to the structure state of the residual amorphous phase. 展开更多
关键词 Fe_(73.5)Cu_1 W_3Si_(13.5)B_9 alloy NANOCRYSTALLINE degree of order amorphous phase initial permeability
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具有初应力的1-3型压电复合材料的横向共振分析 被引量:3
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作者 张红艳 沈亚鹏 尹冠生 《应用数学和力学》 CSCD 北大核心 2007年第7期780-788,共9页
1-3型压电复合材料在极化处理过程中会出现极化残余应力,基于线性压电理论,采用解析方法研究了极化残余应力对1-3型压电复合材料的横向共振模态的影响·首先建立含有初始应力的平面波波动方程,基于Bloch波函数理论构建了位移和电势... 1-3型压电复合材料在极化处理过程中会出现极化残余应力,基于线性压电理论,采用解析方法研究了极化残余应力对1-3型压电复合材料的横向共振模态的影响·首先建立含有初始应力的平面波波动方程,基于Bloch波函数理论构建了位移和电势函数,从而最终得到方程的解·数值结果表明初始残余应力的出现降低了复合材料的横向振动频率,而材料的压电性则使得横向振动频率提高·初始剪应力对对横向振动的频率影响较小,可以忽略·第一阶及第二阶振动频率将随着初始应力的大小呈线性变化·得出的结论对超声换能器的制作和研究将提供有意义的指导作用· 展开更多
关键词 横向共振 1-3型压电复合材料 初始应力
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Control Efficacy of Validamycin A·(0.2 Billion Spores/ml) Paenibacillus polymyxa DN-1 3% AS for Rice Sheath Blight
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作者 胡飞 苏卫华 +4 位作者 李昌春 周子燕 胡本进 徐丽娜 郑进国 《Agricultural Science & Technology》 CAS 2016年第11期2615-2618,共4页
With validamycin A.(0.2 billion spores/ml) Paenibacillus polymyxa DN-1 3% AS as the test agent, the effects of different dosage and different application time on the control efficacy for' rich sheath blight were in... With validamycin A.(0.2 billion spores/ml) Paenibacillus polymyxa DN-1 3% AS as the test agent, the effects of different dosage and different application time on the control efficacy for' rich sheath blight were investigated. The results of two- year test showed that when the application amount was in the range of 45-90 g.a.i/ hm^2, the field efficacy of validamycin A-(0.2 billion spores/ml) P. polymyxa DN-1 3% AS in the initial infection stage of rich sheath blight (Le., the diseased plant rate was below 5%) reached 80.38%-89.06%, and that in the peak infection stage (i.e., the diseased plant rate was higher than 10%) reached only 41.12%-53.26%. The field efficacy of validamycin A.(0.2 billion spores/ml) P. polymyxa DN-1 3% AS at the early onset of rich sheath blight was significantly better than that at the onset, so that the application time of validamycin A .(0.2 billion spores/ml) P. polymyxa DN-1 3% AS should be appropriately brought forward in the prevention and control of rice sheath blight. 展开更多
关键词 Validamycin A-(0.2 billion spores/roll P. polymyxa DN-1 3% AS Rice sheath blight initial infection stage Peak infection stage Control efficacy
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Cationic polymerization of 1,3-pentadiene initiated by allyl chloride/AlCl_3/ether systems
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作者 PENG Yuxing, ZHANG Jiawei, LIU Jialin and CUN LinfengChengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China 《Chinese Science Bulletin》 SCIE EI CAS 1997年第18期1544-1549,共6页
RECENT progress made in cationic polymerization is characterized by developments of
关键词 CATIONIC POLYMERIZATION 1 3-pentadiene CARBOCATION initiATION crosslinking.
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以α型氢氧化物前驱体制备LiNi_(0.8)Co_(0.15)Al_(0.05)O_2及其电化学性能 被引量:17
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作者 陈勃涛 《无机化学学报》 SCIE CAS CSCD 北大核心 2010年第2期190-196,共7页
本文采用球形Al/Co部分取代α型Ni(OH)2为前驱体成功制备了锂离子电池正极材料LiNi0.8Co0.15Al0.05O2。首先采用氢氧化钠与碳酸钠为沉淀剂合成出Al/Co部分取代α型Ni(OH)2,然后将之与LiOH·H2O混合,最后在氧气气氛中不同温度下热处... 本文采用球形Al/Co部分取代α型Ni(OH)2为前驱体成功制备了锂离子电池正极材料LiNi0.8Co0.15Al0.05O2。首先采用氢氧化钠与碳酸钠为沉淀剂合成出Al/Co部分取代α型Ni(OH)2,然后将之与LiOH·H2O混合,最后在氧气气氛中不同温度下热处理8h,即可得到球形LiNi0.8Co0.15Al0.05O2材料。X射线衍射结果表明,LiNi0.8Co0.15Al0.05O2材料为α-NaFeO2相。扫描电镜结果表明,材料颗粒形貌为球形。热重分析结果表明合成LiNi0.8Co0.15Al0.05O2的主反应温度在700~750℃之间。振实密度测试结果表明,750℃下制备的LiNi0.8Co0.15Al0.05O2材料可达2.2g·cm-3。恒流充放电结果表明,该材料在0.5mA·cm-2电流密度下,在3.0~4.3V间的首次充电容量可达210.3mAh·g-1,首次放电容量为179.7mAh·g-1,充放电效率为85.4%。与采用以β-Ni0.85Co0.15(OH)2为前驱体合成的LiNi0.85Co0.15O2和Al掺杂的LiNi0.8Co0.15Al0.05O2相比,尽管其首次放电容量与放电效率都有所降低,但循环性能有所提高,50周期后容量仍为初始容量的89.5%。研究表明,以球形Al/Co部分取代α型Ni(OH)2作为前驱体为球形氧化镍钴铝锂材料的制备提供了一条新的途径。 展开更多
关键词 锂离子电池 LiNi0.8Co0.15Al0.05O2正极材料 球形α型氢氧化物 前驱体 电化学性能
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Crosslinking reaction in the cationic polymerization of 1, 3-pentadiene
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作者 彭宇行 张文传 +6 位作者 肖潮萍 刘佳林 寸琳锋 郑朝辉 邓建国 关英 刘莉 《Science China Chemistry》 SCIE EI CAS 1999年第2期204-209,共6页
The eationic polymerization of 1, 3-pentadiene (PD) initiated by A1C13 inn-hexane was carried out. Effects of arenes, alkyl halides and ethers on the gel formation resulting from crosslinking reaction were investigate... The eationic polymerization of 1, 3-pentadiene (PD) initiated by A1C13 inn-hexane was carried out. Effects of arenes, alkyl halides and ethers on the gel formation resulting from crosslinking reaction were investigated. The crosslinking was reduced by various arenes through a chain transfer mechanism. Alkyl halides such asrert-butyl chloride and allyl chloride could complex with AlCl3 to generate an initiating system giving rise to a gel-free polymerization, while benzyl chloride reduced the formation of gel by chain transfer. Ethers exerted two effects on the polymerization system: giving a complex initiating system with AlCl3 to produce a relatively high molecular weight polymer, or reducing crosslinking by lowering activity of carbocations. 展开更多
关键词 CATIONIC POLYMERIZATION 1 3-pentadiene CROSSLINKING initiation.
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Cellular Caspase-3 Contributes to EV-A71 2Apro-Mediated Down-Regulation of IFNAR1 at the Translation Level 被引量:6
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作者 Bangtao Chen Yuya Wang +3 位作者 Xinyi Pei Sanyuan Wang Hao Zhang Yihong Peng 《Virologica Sinica》 SCIE CAS CSCD 2020年第1期64-72,共9页
Enterovirus A71(EV-A71) is the major pathogen responsible for the severe hand, foot and mouth disease worldwide, for which few effective antiviral drugs are presently available. Interferon-a(IFN-a) has been used in an... Enterovirus A71(EV-A71) is the major pathogen responsible for the severe hand, foot and mouth disease worldwide, for which few effective antiviral drugs are presently available. Interferon-a(IFN-a) has been used in antiviral therapy for decades;it has been reported that EV-A71 antagonizes the antiviral activity of IFN-a based on viral 2 Apro-mediated reduction of the interferon-alpha receptor 1(IFNAR1);however, the mechanism remains unknown. Here, we showed a significant increase in IFNAR1 protein induced by IFN-a in RD cells, whereas EV-A71 infection caused obvious downregulation of the IFNAR1 protein and blockage of IFN-a signaling. Subsequently, we observed that EV-A71 2 Apro inhibited IFNAR1 translation by cleavage of the eukaryotic initiation factor 4 GI(eIF4GI), without affecting IFNAR1 m RNA levels induced by IFN-a. The inhibition of IFNAR1 translation also occurred in puromycin-induced apoptotic cells when caspase-3 cleaved e IF4 GI. Importantly, we verified that 2 Aprocould activate cellular caspase-3, which was subsequently involved in e IF4 GI cleavage mediated by 2 Apro. Furthermore, inhibition of caspase-3 activation resulted in the partial restoration of IFNAR1 in cells transfected with 2 A or infected with EV-A71, suggesting the pivotal role of both viral 2 Aproand caspase-3 activation in the disturbance of IFN-a signaling. Collectively, we elucidate a novel mechanism by which cellular caspase-3 contributes to viral 2 Apro-mediated down-regulation of IFNAR1 at the translation level during EV-A71 infection, indicating that caspase-3 inhibition could be a potential complementary strategy to improve clinical anti-EV-A71 therapy with IFN-a. 展开更多
关键词 ENTEROVIRUS A71(EV-A71) Interferon alpha receptor 1(IFNAR1) 2A protease(2Apro) CASPASE-3 EUKARYOTIC initiation factor 4GI(eIF4GI)
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China-Saudi Arabia Relations Through the‘1+2+3’Cooperation Pattern 被引量:1
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作者 Jonathan Fulton 《Asian Journal of Middle Eastern and Islamic Studies》 2020年第4期516-527,I0003,共13页
2020 marks the 30th anniversary of China-Saudi Arabia diplomatic relations,and over this time the relationship has evolved from one of marginal significance to a comprehensive strategic partnership.As China’s role in... 2020 marks the 30th anniversary of China-Saudi Arabia diplomatic relations,and over this time the relationship has evolved from one of marginal significance to a comprehensive strategic partnership.As China’s role in the Middle East expands,the partnership with Saudi Arabia will increase in importance.This article analyses the bilateral relationship by using the ‘1+2+3’cooperation pattern as a framework.Introduced during the 2014 China-Arab States Cooperation Forum,this pattern articulates the cooperation priorities Beijing will focus on while engaging with Arab states:energy,trade and investment,infrastructure,nuclear energy,space satellite,and renewable energy.By analysing levels of China-Saudi cooperation through the‘1+2+3’we can determine the relative success of the initiative,anticipate the near-term trajectory of the bilateral relationship,and develop a framework for measuring China’s relations with other key states in the Middle East. 展开更多
关键词 China Saudi Arabia Belt and Road initiative Saudi‘Vision 2030’ 1+2+3’cooperation pattern
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胰岛素强化治疗的大型临床研究 被引量:10
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作者 张饰 李玉秀 《药品评价》 CAS 2008年第3期113-115,共3页
糖尿病控制和并发症试验(DCCT)和英国前瞻性糖尿病研究(UKPDS)的结果一致表明,强化血糖控制可以减少1型和2型糖尿病微血管并发症的发生率,在大血管并发症方面尚未得出肯定的结论。然而UKPDS在其2000年发表的观察性研究中证实,高... 糖尿病控制和并发症试验(DCCT)和英国前瞻性糖尿病研究(UKPDS)的结果一致表明,强化血糖控制可以减少1型和2型糖尿病微血管并发症的发生率,在大血管并发症方面尚未得出肯定的结论。然而UKPDS在其2000年发表的观察性研究中证实,高血糖和发生心血管疾病的危险性呈连续性相关,糖化血红蛋白(HbA1c)每降低1%,发生急性心肌梗死的危险下降12%,出现任何糖尿病相关的终点事件或死亡的危险降低21%。DCCT的后续研究——糖尿病干预治疗和并发症的流行病学研究(EDIC)以及UKPDS的后续研究均表明, 展开更多
关键词 胰岛素 糖尿病 Treat—to—Target LANMET AT LANTUS initiATE 1—2-3研究
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基于培养特征的援外硕士课程体系优化研究--以商务部“旅游与酒店管理硕士”项目为例
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作者 赵阳 田园 赵慧敏 《林区教学》 2024年第11期47-51,共5页
合理的课程设置是研究生培养的核心,更是人才培养质量达到培养目标要求的重要保障。以哈尔滨商业大学旅游烹饪学院承办的商务部援助“一带一路”沿线国家“旅游与酒店管理硕士”项目为例,针对援外硕士培养特征,依托培养目标,优化课程设... 合理的课程设置是研究生培养的核心,更是人才培养质量达到培养目标要求的重要保障。以哈尔滨商业大学旅游烹饪学院承办的商务部援助“一带一路”沿线国家“旅游与酒店管理硕士”项目为例,针对援外硕士培养特征,依托培养目标,优化课程设置,构建“3+1”模块式课程体系,在理论学习、科学研究和综合实践三大核心模块基础上,建立智能辅助教学平台,通过多元途径和多种方式有效拓展专业知识、开展科研实践与实习实训项目及相互间的深度融合,进而提升旅游管理援外硕士人才培养质量,更好地落实“一带一路”倡议。 展开更多
关键词 一带一路 “旅游与酒店管理硕士”项目 课程体系 3+1”模块
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小檗碱对糖尿病db/db小鼠骨骼肌蛋白质代谢的影响及机制研究 被引量:1
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作者 王会玲 丁婷婷 +1 位作者 胡兆永 张金元 《中华内分泌代谢杂志》 CAS CSCD 北大核心 2012年第4期319-324,共6页
目的探讨小檗碱对糖尿病/胰岛素抵抗模型db/db小鼠骨骼肌蛋白质代谢及肌萎缩蛋白Fbox-1(Atrogin-1)表达的影响。方法db/db小鼠为研究对象,以野生型为对照组。予小檗碱(5mg·kg-1·d-1)腹腔注射3周,观察体重和食量;3... 目的探讨小檗碱对糖尿病/胰岛素抵抗模型db/db小鼠骨骼肌蛋白质代谢及肌萎缩蛋白Fbox-1(Atrogin-1)表达的影响。方法db/db小鼠为研究对象,以野生型为对照组。予小檗碱(5mg·kg-1·d-1)腹腔注射3周,观察体重和食量;3周末处死,分离胫骨前肌和腓肠肌。胫骨前肌冰冻切片行层黏连蛋白免疫组化染色,荧光显微镜下观察并拍照,测量肌纤维横截面积并计算肌纤维面积分布图;同位素[14C].苯丙氨酸掺入法检测肌肉蛋白合成,[3H]-酪氨酸释放率分析检测肌肉分解代谢;Northern印迹检测腓肠肌Atrogin-1和肌环指蛋白1(MurF-1)转录水平,Western印迹检测蛋白翻译水平。结果小檗碱能明显降低db/db小鼠血糖水平[(18.55±3.79对26.32±4.02)mmol/L,P〈O.01],降低脂肪重量[(2.75±0.30对3.77±0.52)g,P〈O.05],使胫骨前肌的肌重/胫骨长度比值及肌纤维横截面积下降,肌纤维面积分布图明显左移;小檗碱使野生型小鼠和db/db小鼠的蛋白质合成率下降18%~22%;蛋白质分解率升高24%~26%,使肌肉特异性的Atrogin-1、MurF-1转录和翻译水平增高,同时使真核转录因子3调节亚基(eIF3-f)蛋白水平降低。结论小檗碱具有降糖降脂作用,但可引起骨骼肌蛋白质合成下降,促进蛋白质分解代谢,加剧糖尿病的骨骼肌消耗,其机制与上调Atrogin-1和MurF-1表达,同时下调eIF3-f有关。 展开更多
关键词 糖尿病 实验性 小檗碱 骨骼 ATROGIN-1 肌环指蛋白1 真核转录因子3调节亚基
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具有初挠度夹层圆板的亚谐波共振
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作者 刘小蛮 杜国君 田冀锋 《钢铁研究》 CAS 2010年第6期31-34,共4页
利用Galerkin法和L-P摄动法得出了具有初挠度夹层圆板的三阶亚谐解,用多尺度法讨论了解的稳定性。研究表明,大挠度软夹心夹层圆板会产生与材料非线性圆板类似的非线性亚谐振动现象,只有当激振力频率的1/3与圆板系统的固有频率之差即微... 利用Galerkin法和L-P摄动法得出了具有初挠度夹层圆板的三阶亚谐解,用多尺度法讨论了解的稳定性。研究表明,大挠度软夹心夹层圆板会产生与材料非线性圆板类似的非线性亚谐振动现象,只有当激振力频率的1/3与圆板系统的固有频率之差即微小参量εδ增大到一定值时才会激发亚谐波共振,当夹层板系统的刚度减小,初挠度增大时,更容易激发其三阶亚谐波共振,出现多值与跳跃现象。稳定状态与初始条件和外激励有关。 展开更多
关键词 夹层圆板 非线性 1/3亚谐解 初挠度 刚度
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