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Understanding sequence effect in DNA bending elasticity by molecular dynamic simulations

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Communications in Theoretical Physics 2021年第7期73卷 127-135页

作者： xiao-wei qiang Hai-Long Dong Kai-Xin Xiong Wenbing Zhang Zhi-Jie Tan Department of Physics and Key Laboratory of Artificial Micro&Nano-Structures of Ministry of Education School of Physics and TechnologyWuhan UniversityWuhan 430072China

Structural elasticity of double-strand DNAs is very important for their biological functions such as DNA-ligand binding and DNA-protein *** all-atom molecular dynamics simulations,we investigated the bending elasticity of DNA with three typical sequences including poly(A)-poly(T)(AA-TT),poly(AT)-poly(TA)(AT-TA),and a generic sequence(GENE).Our calculations indicate that,AA-TT has an apparently larger bending persistence length(P~63 nm)than GENE(P~49 nm)and AT-TA(P~48 nm)while the persistence length of AT-TA is only very slightly smaller than that of GENE,which agrees well with those from existing ***,through extensive electrostatic calculations,we found that the sequence-dependent bending elasticity is attributed to the sequence-dependent electrostatic bending energy for AA-TT,AT-TA and GENE,which is coupled to their backbone ***,the apparently stronger bending stiffness of AA-TT is attributed to its narrower minor ***,for the three DNAs,we predicted the non-electrostatic persistence length of~17 nm,thus electrostatic interaction makes the major contribution to DNA bending *** mechanism of electrostatic energy dominating sequence effect in DNA bending elasticity is furtherly illustrated through the electrostatic calculations for a grooved coarse-grained DNA model where minor groove width and other microscopic structural parameters can be artificially adjusted.

关键词： DNA elasticity molecular dynamic simulation persistence length electrostatic interaction

Red Electroluminescence and Photoluminescence from Novel Binuclear Europium Complex with Squaric Acid Ligand

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Chinese Chemical Letters 2001年第10期12卷 921-924页

作者： wei Guo ZHU xiao qiang wei Mei Xiang ZHU Zhi Yun LU Bo LIANG Ming Gui XIE De qiang ZHANG Yong QIU College of Chemistry Xiangtan UniversityXiangtan411105 Department of Chemistry Sichuan UniversityChendu610064 Department of Chemistry Tsinghua University

A novel binuclear europium P-diketone complex with squaric acid ligand was synthesized for the first time. Its structure was elucidated by IR, UV, and Elemental Analysis. Red light emitting diode (LED) was fabricated by using the novel europium complex as an emitting layer, tris(8-quinolinolate) aluminum (III) (Alq(3)) as an electron-transporting layer, N, N'-diphenyl-N, N'-(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) as a hole-transporting layer. A cell structure of indium-tin-oxide/TPD/Eu-complex/Alq(3)/Mg: Ag was employed. Red electroluminescence was observed at room temperature with dc bias voltage of 2 V in this cell. 2 Red emission peaks at about 613 nm with maximum luminance of over 106 cd/m(2). Compared with the EL luminance from those europium complexes reported before, one from the Eu-complex is best in the same cells.

关键词： europium chelate squaric acid electroluminescence (EL) photoluminescence (PL)

Synthesis and Characterization of a New Barium Aluminoborate, Ba2Al4B6O17

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Chinese Journal of Structural Chemistry 2019年第8期38卷 1380-1391页

作者： CHEN Xue-An CHEN Qian xiao wei-qiang CHANG Xin-An College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China Institute of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing 100124China

A new barium aluminoborate, Ba2Al4B6O17, has been synthesized by the hightemperature solution reaction at 780 ℃. The single-crystal XRD analysis shows that it crystallizes in triclinic space group P■ with a = 8.9601(5), b = 9.1835(6), c = 10.6574(7) ?, a = 95.050(6)°, b = 111.569(5)°, g = 90.280(6)°, V = 811.71(9) ?3, Z = 2, Mr = 719.46, Dc = 2.944 g/cm3, μ = 5.127 mm-1, F(000) = 660, R = 0.0361 and wR = 0.0855 for 3846 observed reflections and 262 variables. This compound represents a new structure that features a three-dimensional [Al4B6O17]n4n- framework constructed by AlO4 tetrahedra, BO3 triangles, and B2O54-groups composed of two corner-sharing BO3 triangles, with intersecting open channels accommodating Ba2+ cations. It melts incongruently at 849 ℃. The existence of BO3 groups is confirmed by FT-IR and Raman spectra. The insulating nature with an optical band gap of about 3.50 eV is revealed by UV-VIS diffuse reflectance spectrum. Band structure calculations indicate that it is an indirect band material.

关键词： Ba2Al4B6O17 borate synthesis X-ray diffraction crystal structure

Synthesis and phosphorescent properties of two novel iridium (Ⅲ) complexes bearing bulky tert-butyl substituents

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Chinese Chemical Letters 2007年第9期18卷 1119-1123页

作者： Rong Huang xiao qiang wei Tai Ping Zhang Zhi Yun Lu Ming Gui Xie College of Chemistry Sichuan UniversityChengdu 610064China School of Optic-electronic Information University of Electronic Science and Technology of ChinaChengdu 610054China

The synthesis and phosphorescence properties of two novel Ir(Ⅲ)complexes bearing tert-butyl substituents,bis(4-tert-butyl-2- phenylbenzothiozolato-N,C^(2′))iridium(Ⅲ)(acetylacetonate)[(tbt)_2Ir(acac)]and bis(4-tert-butyl-1-phenyl-1H-benzimidazolato- N,C^(2′))iridium(Ⅲ)(acetylacetonate)[(tpbi)_2Ir(acac)],are reported,their molecular structures are confirmed by^1H NMR,ESI-MS and elementary ***(PL)studies revealed that they can emit strong green and orange phosphorescence in high quantum *** to their prototypes lacking of tert-butyl substituents,the two novel iridium(Ⅲ)complexes both have shorter lifetimes and improved or nearly similar PL quantum efficiencies,implying that the exciton quenching is inhibited effectively when molecular steric hindrance *** two chelates have great potential to be used as electrophosphorescent materials.

关键词： Synthesis tert-Butyl substituent Phosphorescence Electrophosphorescence

Synthesis of a Novel Blue- light- emitting Polymer Material Bearing Coumarin Pendants

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Chinese Chemical Letters 2002年第7期13卷 674-677页

作者： Zhi Yun LU Tong Suo YUAN Yan Lai CHEN xiao qiang wei wei Guo ZHU Ming Gui XIE Department of Chemistry Sichuan UniversityChengdu 610064

A novel blue luminescent polymer bearing coumarin pendants was prepared. Its luminescent properties were determined indicating that it had strong blue fluorescent properties and good film formation ability. This nov... 详细信息

关键词： Synthesis coumarin fluorescence polymer blue organic electroluminescent material.

Fabrication of a white organic light-emitting device with single liq:rubrence luminescent layer

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Optoelectronics Letters 2008年第2期4卷 126-129页

作者： CHEN xiao-qiang wei Wan-yin WU You-yu DONG Mao-jun ZHANG Fu-jia School of Physical Science and Technology Lanzhou University Lanzhou 730000 China

A kind of white OLED with single luminescent layer was designed, in which rubrene was doped in Liq. The structure of the devices is ITO/PVK:TPD/Liq: Rubrene/Alq3/Al. The brightness of the devices comes to 3120 cd/m2(at a driving voltage of 25 V), the CIE coordinates of the typical devices is (0.308,0.347), and the coordinates is very close to the white equi-energy point. The emitting and luminescent characteristics of the devices were discussed.

关键词：白色有机光器件发光器件冷光散射

Synthesis and Fluorescent Properties of New Binuclear Europiumβ-Diketone Chelates Eu_mY_(1-m)(TTA)_3phen as Red Electroluminescent Materials

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Chinese Chemical Letters 1999年第7期10卷 603-606页

作者： wei Guo ZHU xiao qiang wei Zhi Yun LU Qing JIANG Ming Gui XIE(Department of Chemistry. Sichuan University. Chengdu 610064) Department of Chemistry Sichuan University

A new type of binuclear europlum β-diketone chelates Eum Y1-m(TTA)3 phen (0≤m≤1) and the influence of the proportion of Y on fluorescence intensity of the Eu-complexes were studied. It was found the proportion of Y3+ could affect the fluorescence properties and the film formation seriously. only m≥0.5.Y3+ could increase the luminescent intensity and improve the film formalion. As a resull. three new binuclear europium β-diketone chelales consisted of Eu, Y1-m (TTA)3phen (m=0.9. 0.7 and 0.5) were designed and synthesized. Their structures were elucidated by IR. UV. DSC and Elementary Analysis. Their PL properties were studied. The results showed that the three binuclear europium β-diketone chelates had better PL properties and film formation than Eu(TYA)3phen. They could emit sharply red light, and fluorescenl wavelength of them was all at 613nm (half bandwidth 10nm). They can be used as red organic electroluminescent materials (OELMs) in organic electrolminescent devices (OELDS).

关键词： Europium β-diketone chelate synthesis photoluminescence fluorescence properties

余甘子斑点病病原菌鉴定、生物学特性及防治药剂筛选

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南方农业学报 2024年第2期55卷 479-488页

作者：赖多王德林周国昌邵雪花秦健庄庆礼蔡时可肖维强广东省农业科学院果树研究所/农业农村部南亚热带果树生物学与遗传资源利用重点实验室/广东省热带亚热带果树研究重点实验室广东广州510640 汕尾市农业科学院广东汕尾516699 广东省农业科学院作物研究所广东广州510640

【目的】明确余甘子果实斑点病的病原菌种类,了解其生物学特性,筛选有效的防治药剂,为余甘子果实斑点病的科学诊断和田间防治提供理论依据。【方法】从广东省汕尾市陆河县余甘子产业园种植基地采集发生斑点病的余甘子果实,采用组织分离... 详细信息

【目的】明确余甘子果实斑点病的病原菌种类,了解其生物学特性,筛选有效的防治药剂,为余甘子果实斑点病的科学诊断和田间防治提供理论依据。【方法】从广东省汕尾市陆河县余甘子产业园种植基地采集发生斑点病的余甘子果实,采用组织分离法对余甘子斑点病病果进行病原菌分离,通过形态学特征和基于多基因(ITS、TUB和EF1-α)的系统发育进化分析对病原菌进行鉴定;采用针刺接种法测定病原菌菌株的致病力;采用菌丝生长速率法测定不同培养条件对病原菌菌丝生长的影响;通过室内毒力测定评估12种常见杀菌剂对病原菌的抑菌活性。【结果】从余甘子病果中分离出1株病原真菌菌株PE3,致病性测定结果表明,该菌株为余甘子斑点病致病菌,其形态特征与间座壳菌Diaporthe phoenicicola相似,且其ITS、TUB和EF1-α基因系统发育进化树分析显示与***聚在同一分支。生物学特性测定结果显示,菌株PE3菌丝生长的最适温度为25℃,最适p H为7,最适生长碳源为甘油和蔗糖,最适生长氮源为酵母提取物。室内毒力测定结果显示,450 g/L咪鲜胺乳油对菌株PE3菌丝生长的抑制作用最强,抑制中浓度(EC_(50))为0.019 mg/L;其次是8%氟硅唑微乳剂、10%苯醚甲环唑微乳剂和25%吡唑醚菌酯悬浮剂,EC_(50)分别为0.023、0.124和0.194 mg/L;而2%春雷霉素水剂对菌株PE3菌丝生长的抑制效果最差,EC_(50)为402.336 mg/L。【结论】间座壳菌***是引起余甘子果实斑点病的病原菌,450 g/L咪鲜胺乳油、8%氟硅唑微乳剂、10%苯醚甲环唑微乳剂和25%吡唑醚菌酯悬浮剂能有效防治余甘子果实斑点病,可在余甘子种植中推广应用。

关键词：余甘子果实斑点病间座壳菌生物学特性毒力测定

维普期刊数据库博看期刊

Identification and functional analysis of CG3526 in spermatogenesis of Drosophila melanogaster

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Insect Science 2024年第1期31卷 79-90页

作者： Qihao Hu Yanhong xiao Runnan wei Ting Tang Liang Wen Yuzhen Lu xiao-qiang Yu Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology Guangzhou Key Laboratory of Insect Development Regulation and Application ResearchInstitute of Insect Science and TechnologySchool of Life SciencesSouth China Normal UniversityGuangzhou510631 China

Spermatogenesis is a critical part of reproduction in insects;however,its molecular mechanism is still largely *** this study,we identified a testis-specific gene CG3526 in Drosophila *** analysis showed that CG3526 contains a zinc binding domain and 2 C2H2 type zinc fingers,and it is clustered to the vertebrate really interesting new gene(RING)family E3 ubiquitin-protein *** CG3526 was knocked down by RNA interference(RNAi),the testis became much smaller in size,and the apical tip exhibited a sharp and thin end instead of the blunt and round shape in the control *** importantly,compared to the control flies,only a few mature sperm were present in the seminal vesicle of C587-Gal4>CG3526 RNAi *** staining of the testis from CG3526 RNAi flies showed that the homeostasis of testis stem cell niche was disrupted,cell distribution in the apical tip was scattered,and the process of spermatogenesis was not ***,we found that the phenotype of CG3526 RNAi flies’testis was similar to that of testis of Stat92E RNAi flies,the expression level of CG3526 was significantly downregulated in the Stat92EF06346 mutant flies,and the promoter activity of CG3526 was upregulated by *** together,our results indicated that CG3526 is a downstream effector gene in the JAK-STAT signaling pathway that plays a key role in the spermatogenesis of Drosophila.

关键词： CG3526 JAK-STAT spermatogenesis STAT92E testis