圆二色法研究铜离子存在下葛根素对牛血清白蛋白二级结构的影响

采用圆二色光谱法(CD)研究了Cu2+存在下葛根素(PUE)对牛血清白蛋白(BSA)二级结构的影响。结果表明,在pH 7.4的条件下,BSA的各种二级结构分别为56.3%α-螺旋,26.1%β-折叠,17.6%转角和无规则卷曲。葛根素和Cu2+-葛根素都能诱导BSA二级结构发生改变。葛根素使BSA的α-螺旋含量增加,β-折叠含量减少,这表明葛根素与BSA的相互作用,可使蛋白质分子的疏水作用增强,导致BSA的肽链结构收缩。Cu2+-葛根素使BSA的α-螺旋含量大幅度降低,β-折叠含量略有增加,这表明Cu2+-葛根素与BSA的相互作用以配位作用为主,使得BSA的肽链结构伸展,蛋白质的构象发生变化。     

高效液相色谱-四极杆串联线性离子阱质谱法测定水产品及饲料中的孔雀石绿、结晶紫及其代谢物

提出了高效液相色谱-四极杆串联线性离子阱质谱法测定水产及饲料中的孔雀石绿、结晶紫及其代谢物(隐色孔雀石绿、隐色结晶紫)的方法。样品经乙腈提取,Agilent XDB C18色谱柱分离,四极杆串联线性离子阱质谱进行检测。以氘代孔雀石绿、氘代隐色孔雀石绿、氘代结晶紫、氘代隐色结晶紫为内标物。4种化合物的线性范围均为0.05~5.0μg·L-1,检出限(3S/N)均为0.5μg·kg-1。以空白样品为基体做加标回收试验,计算得4种化合物的回收率在93.3%~120%之间,相对标准偏差(n=6)在1.4%~18%之间。另外,还采用数据相关采集模式结合增强离子扫描模式对4种化合物进行定性分析,可对试样中4种化合物在定量同时进行定性确证。     

苏丹红猝灭吖啶染料荧光的动力学研究

在体积分数95%乙醇介质中,吖啶黄、吖啶橙的荧光发射波长与苏丹红染料的吸收波长十分接近。实验数据表明,随着苏丹红I~IV用量的增加,溶液中吖啶黄、吖啶橙荧光发射强度明显降低,其荧光猝灭程度与苏丹红用量成正比。动力学研究表明苏丹红I,II与吖啶黄或吖啶橙之间可形成非共价复合物,从而发生静态荧光猝灭;而苏丹红III,IV猝灭吖啶黄或吖啶橙则表现为一种复杂的动力学特点,可能同时存在静态荧光猝灭与动态猝灭。     

新型色满酮并环己烷螺环氧化吲哚类化合物的合成

以色酮 氧化吲哚合成子与硝基苯乙烯,在催化剂DBU作用下,在二氯甲烷中发生Michael/Michael加成环化反应,合成了9个未见文献报道的新型色满酮并环己烷螺环氧化吲哚类化合物3a~3i产率72%~87%, dr值4/1~2/1, 其结构经¹H NMR, ¹³C NMR和HR-MS（ESI-TOF）表征确定。     

以氨基酸为配体的铑催化剂催化苯乙炔和2,4⁃羟基苯甲醛的氧化偶联反应

以氨基酸和1,5-环辛二烯(cod)为配体的铑催化剂催化苯乙炔和2,4-二羟基苯甲醛的氧化偶联反应,并合成了2-苯基-7-羟基-1H-色酮-4-酮.研究了以不同氨基酸为配体的铑催化剂对相同底物的催化效果,结果发现,在相同反应条件下,Rh(cod)(L-Phe)的催化效果最佳.     

一个描述Josephson振动阻尼效应的场方程

在GPE方程的基础上添加了一个耗散项-12γcψ,用来分析双势阱模型的Josephson振荡中的阻尼现象,并得出:凝聚态粒子总数及 Josephson振动的振幅随时间呈指数衰减.     

Bovine Serum Albumin Loaded Solid Lipid Nanoparticles Prepared by Double Emulsion Method

Solid lipid nanoparticles loaded with bovine serum albumin(BSA) were prepared by a double emulsion method. As the mass fraction of the model drug BSA increased from 0 to 15%, the particle size gradually increased. The physical stability of the nanoparticles was investigated by zeta potential measurement and they were shown to be quite stable. Fluorescence spectroscopy confirmed that the loaded position of BSA was on the interface between the inner aqueous phase and the solid lipid phase. Both Fourier-transf...     

The dynamics of triple-well trapped Bose-Einstein condensates with atoms feeding and loss effects

In this paper, we consider the macroscopic quantum tunnelling and self-trapping phenomena of Bose-Einstein condensates （BECs） with three-body recombination losses and atoms feeding from thermal cloud in triple-well potential. Using the three-mode approximation, three coupled Gross-Pitaevskii equations （GPEs）, which describe the dynamics of the system, are obtained. The corresponding numerical results reveal some interesting characteristics of BECs for different scattering lengths. The self-trapping and quantum tunnelling both are found in zero-phase and ：r-phase modes. Furthermore, we observe the quantum beating phenomenon and the resonance character during the self-trapping and quantum tunnelling. It is also shown that the initial phase has a significant effect on the dynamics of the system.