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83.
用1HNMR、荧光光谱和红外光谱方法研究阿德福韦双L-苯丙氨酸丙酯(FH-1)与改性六元葫芦脲(TMeQ[6])、七元葫芦脲(Q[7])以及八元葫芦脲(Q[8])的相互作用,探讨主客体作用位点及其识别机制.1HNMR图谱表明FH-1中苯丙氨酸残基部分进入葫芦脲的空腔内部受到屏蔽作用,而FH-1其它部分则位于葫芦脲端口外侧.荧光图谱表明FH-1与TMeQ[6],Q[7]与Q[8]分别形成1∶1或2∶1,1∶1或3∶1与2∶1的主客体包结配合物.红外光谱表明Q[7]与FH-1固体包合物发生了主客体相互作用,FH-1特征峰消失.吸湿性考察发现FH-1与Q[7]形成的固体包合物的吸湿稳定性明显提高,室温放置90d后仍然为白色固体.抗乙型肝炎病毒研究提示葫芦脲具有明显降低化合物细胞毒性,增加其抗病毒活性与作用选择性的效果. 相似文献
84.
用三氯化铝催化六氯三聚膦腈开环聚合制得线性聚二氯膦腈(PDCP), 通过PDCP磷原子上的亲核取代反应, 合成了新的水溶性高分子聚[(甲氧基乙氧基乙氧基)1.0(乙氧基吡咯烷酮)1.0]膦腈(P3), 用31P NMR, 1H NMR, 13C NMR和IR对其结构进行了确证, 用DSC测定了其玻璃化转变温度Tg和熔融温度Tm, 用蒸汽压渗透法(VPO)测定了其数均分子量. 改进了聚二(乙氧基吡咯烷酮)膦腈(P2)的合成方法. 体外降解实验表明, P3具有和P2类似的pH响应性降解行为, 降解速率在pH=5.0时最快, 而在pH=7.4和8.0时较慢. P3在所测试的3个pH缓冲溶液中均比P2降解慢. 用31P NMR、薄层色谱(TLC)和滴定法对降解产物进行了检测, 初步推断了P3在不同pH介质中的水解机理, 其在pH=5.0的缓冲溶液中的降解, 除侧链断裂外, 聚膦腈的骨架也裂解; 而在pH=7.4和8.0时的降解仅为侧链的断裂. 用噻唑蓝(MTT)比色法进行的体外细胞毒性评价实验表明, P3及其在pH=5.0的缓冲溶液中降解49 d后的产物均对细胞表现出了很好的生物相容性, 而且其降解产物在浓度为800 μg/mL时还表现出一定的促进细胞增殖作用. 相似文献
85.
Simple-structured, well-functioned disposable poly(dimethylsiloxane) (PDMS) microchips were developed for capillary isoelectric focusing with whole column imaging detection (CIEF-WCID). Side-by-side comparison of the developed microchips with well-established commercial capillary cartridges demonstrated that the disposable microchips have comparable performance as well as advantages such as absence of lens effect and possibility of high-aspect-ratio accompanied with a dramatic reduction in cost. 相似文献
86.
A series of gem-difluoroolefin derivatives were synthesized in moderate to good yields by the reaction of α,α-difluoro-β-carbonyl benzothiazol-2-yl sulfones (DFBTs) with various carbon nucleophiles. Using dl-proline as organocatalyst, the reaction of DFBT with acetone gave a tertiary alcohol, which could be further converted to the corresponding difluoroolefin by LDA. 相似文献
87.
Xufeng Dong Jinping Ou Xinchun Guan 《Journal of magnetism and magnetic materials》2010,322(22):3648-3652
Magnetostrictive properties have relationship with the applied orientation field during the preparation of giant magnetostrictive composites. To understand the dependence of the optimal orientation field on particle volume fraction, composites with 20%, 30% and 50% particles by volume were fabricated by distributing Terfenol-D particles in an unsaturated polyester resin under various orientation fields. Their magnetostrictive properties were tested without pre-stress at room temperature. The results indicate that as the particle volume fraction increases, the optimal orientation field increases. The main reason for this phenomenon is the packing density for the composites with higher particle volume fraction is larger than that for those with lower particle content. 相似文献
88.
A. El Allati M. El Baz Y. Hassouni A. Kassou Ou Ali F. Saif 《Journal of Russian Laser Research》2011,32(2):177-187
We suggest a model where the influence of an environment on the atom interference is associated with a random phase. The model
consists of sending a two-level state atom through two cavities, both containing a standing wave field in the Bragg regime
and Raman–Nath regime, respectively. In view of this model, we can visualize the loss of interference fringes if the randomness
of the phase increases, and the restoration of the pattern when it decreases, as which-path information. Then, the controllable
random noise acts as a decoherence that would destroy the quantum features. 相似文献
89.
Chunxia Ou 《Nonlinear Analysis: Real World Applications》2009,10(5):2652-2658
In this paper, shunting inhibitory cellular neural networks with continuously distributed delays are considered. Without assuming the global Lipschitz conditions of activation functions, some new sufficient conditions for the existence and exponential stability of the almost periodic solutions are established. 相似文献
90.
Considering for the potential application in tissue engineering, polyaniline (PANi) film was fabricated via a two-step route: a self-assembled monolayer of C6H5NHC3H6Si(OMe)3 was firstly formed on the single-crystal Si substrate; the conducting PANi film was then prepared through electroless surface polymerization of the aniline molecules on the aniline monolayer-bearing silane surface in an acidic aqueous solution. The formation of PANi film on Si surface was confirmed by characterizations of X-ray photoelectron spectroscope (XPS) and specular reflectance Fourier transform infrared (SR-FTIR) spectrum, etc. At last, the proliferation behaviors of PC-12 cells on the PANi film surface were studied by the [3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) colorimetric assays, acridine orange fluorometric staining, and scanning electron microscope (SEM) observation, etc. The results demonstrate that the as-prepared PANi film provides high ability for cell proliferation, exhibiting promising potentials as surface coating to cultivate neuronal cells for applications in the tissue engineering. 相似文献