氯化钾及聚乙二醇对聚脯氨酸-精氨酸液-液相分离的协同影响

由脯氨酸（Proline,P）和精氨酸（Arginine,R）构成的双重复肽是人体内C9ORF72基因异常扩增产生的富含毒性的多肽,其异常扩增及液-液相分离（liquid-liquid phase separation,LLPS）行为是神经退行性疾病发病的重要原因,因此研究多肽的调控行为可以为治疗相关疾病提供帮助. 主要利用光学显微成像以及紫外分光光度计技术,研究35个脯氨酸-精氨酸重复多肽（PR₃₅）的LLPS现象及其调控,并对机制进行分析. 发现PR₃₅的LLPS的发生依赖溶液中氯化钾的浓度,当氯化钾浓度低于2 700 mmol/L时,LLPS不会出现,而其浓度高于2 700 mmol/L时,LLPS会发生. 同时在此临界浓度（2 700 mmol/L）溶液中,加入不同质量分数的分子拥挤剂聚乙二醇（PEG1000）后,发现PEG对LLPS具有促进作用,并且随着PEG质量分数升高,促进作用增强. 同时通过紫外分光光度计对吸光度进行了分析,得到的结论与显微镜的观察结果一致.     

Investigation of the Cr:LiSrAlF6 crystal by high-temperature Raman spectroscopy

In this paper, Cr-doped LiSrAlF₆ crystals are investigated using high-temperature Raman spectroscopy and the single-crystal Raman spectra of Cr:LiSrAlF₆ are analysed by factor group theory and comparison with other fluorides. The results indicate that Cr:LiSrAlF₆ is stable below its melting point; Raman peaks located at 561, 322 and 250 cm^-1 are assigned to the A_1g modes of AlF₆, SrF₆ and LiF₆ octachdra, respectively; with temperature increasing, Raman peaks associated with AlF₆ octahedra shift towards low frequencies, while LiF₆ and SrF₆ octahedra are temperature-insensitive; around the crystal melting point, three new Raman peaks occur, which are associated with the AlF₆ octahedral chain structure. Finally, the microstructural evolution of Cr:LiSrAlF₆ from room temperature to its melting point is discussed based on its Raman spectra.     

配位聚合物{[Zn(CF3COO)2(C5H5ON)]·H2O}n的合成、晶体结构及表征

new coordination polymer {[Zn(CF₃COO)₂(C₅H₅ON)]·H₂O}_n was synthesized based on the reaction of zinc(Ⅱ) trifluoroacetate and 3-hydroxypyridine(C₅H₅ON) in methanol medium for the first time. The structure of the coordination polymer was confirmed by IR, ¹H NMR, elemental analysis and thermal analysis. The crystal structure of the coordination polymer was also determined by X-ray single crystal diffraction. The crystal belongs to monoclinic system with space group P2₁/m, and crystallographic data of the coordination polymer are: a= 0.863 1(4) nm, b=0.717 7(3) nm, c=1.116 4(5) nm, α=γ=90°, β=107.542(6)°, V=0.659 4(5) nm³; D_c=2.037 g·cm^-3; Z=2; F(000)=400; μ=1.969 mm^-1. Zinc(Ⅱ) atom lies at the center of an octahedron formed by the coordination of zinc atom and six O atoms which come from four different trifluoroacetate ions and two different 3-hydroxypyridine molecules where each trifluoroacetate ion and 3-hydroxypyridine are coordinated to two different zinc ions to form coordination polymer. CCDC: 253909.     

微波固相合成5-亚烃基巴比妥酸

在微波固相反应条件下,由巴比妥酸与芳香醛发生缩合反应制备5-亚烃基巴比妥酸,该法操作简便、收率高。经1^HNMR、13^CNMR、IR、UV确证了产物的结构。     

一秩算子和三角代数

Abstract, In this paper, a necessary condition for a maximal triangular algebra to be closed is given, A necessary and sufficient condition for a maxima] triangular algebra to he strongly reducible is obtained,     

基于分子转-振光谱精细结构的火焰温度遥测方法

燃烧火焰温度是固体推进剂等重要参数,本文研究了基于分子转-振光谱精细结构的火焰温度遥测方法.根据分子转-振光谱线的展宽机制,研究了分子谱线线型.结合朗伯-比耳吸收定律,去除谱线中心受大气低温气体吸收影响较大的数据点后,利用谱线两翼的数据点进行谱线线型拟合,利用分子转-振光谱精细结构温度遥测方法将经拟合修正后数据反演火焰...     

高自旋介子和宇宙线中的多光子事例

1954年以来,宇宙线中发现过若干例没有得到解释的多光子事例.他们的共同特点是:总能量高((?)5×10~(10)—10~(11)eV).光子数多(十余个)、光子动量所张的角度小(≤10~(-3)—10~(-4)弧度),并且在其周围邻近没有发现任何带电粒子.显然,这些事件不可能由多重π~o产生所引起;再考虑到在乳胶的第一辐射长度内光子数分布和能量分布的特点,它们也无法用单光子的电磁簇射来解释.     

Synthesis and Crystal Structure of aNovel Polymer Copper（ Ⅱ） Complex

1 INTRODUCTION One-dimensional coordination polymers of metal complexes have been extensively studied for many years owing to their unusual properties, and many efforts have been made to prepare these kinds of complexes. Study on these polymer complexes has an active field of coordination chemistry in recent years[1～5]. In this study we obtained a com- plex C14H9CuNO3CH3OH, of which the carboxy- late oxygen atom acts as the bridging ligands to coordinate to the second metal atom, fo…     

Analytic solutions of the double ring-shaped Coulomb potential in quantum mechanics

The exact solutions of the Schr6dinger equation with the double ring-shaped Coulomb potential are presented, including the bound states, continuous states on the ＂k/2π scale＂, and the calculation formula of the phase shifts. The polar angular wave functions are expressed by constructing the so-called super-universal associated Legendre polynomials. Some special cases are discussed in detail.     

光子晶体光纤中高效的反斯托克斯信号产生

基于四波混频的反斯托克斯变换, 被广泛应用于短波辐射高分辨率成像以及直接激发分子的电子跃迁等方面. 为了实现更加高效的反斯托克斯变换, 利用中心波长为810 nm脉冲宽度为120 fs的钛蓝宝石(Ti: sapphire)飞秒激光器作为抽运光源, 在长度为0.5 m和3 m的光子晶体光纤中分别实现了高阶模和基膜的简并四波混频. 实验中, 采用的光子晶体光纤的零色散波长在820 nm附近. 在基模相位匹配条件下, 在560 nm附近实现了高效地反斯托克斯信号的产生, 反斯托克斯信号与残余抽运信号的最大功率比为33:1; 反斯托克斯信号和斯托克斯信号的最大功率比25:1; 反斯托克斯信号最大功率转换效率P_a/P_p0为34%. 抽运波长从790 nm逐渐增加到810 nm过程中, 在长为3 m的光子晶体光纤中相位从不匹配状态转化为高阶模匹配状态后, 再转化为基模匹配状态. 通过实验研究得出了相位匹配程度随抽运功率、波长和光纤长度的变化规律, 同时分析了造成理论计算与实验结果存在差异的主要因素. 本文为研究在光子晶体光纤基模中实现相位匹配和产生高效反斯托克斯信号提供了理论和实验依据.