Fluorescence detection of guanine-adenine transition by a hydrogen bond forming small compound

In combination with abasic site-containing oligodeoxynucleotides, 2-amino-4-oxopteridine (pterin) can selectively recognize guanine base over other nucleobases accompanied by fluorescence quenching, which allows clear detection of a guanine-adenine transition with the naked eye.     

Furan-containing oligoaryl cyclophanene

[structure: see text] Furan-containing oligoaryl cyclophanene 1 and the corresponding cyclophane 2 were synthesized from propargylic dithioacetal 3. The electrochemical and photophysical properties and the fluxional behavior of these molecules have been examined. The emission of 1 appeared at 499 nm whereas that of 2 appeared at 389 nm.     

以混合表面活性剂为模板可控合成MCM-48和MCM-41分子筛

利用阳离子和三嵌段共聚物混合表面活性剂为模板,在水热条件、碱性介质中可控合成出MCM-48和MCM-41分子筛。在固定P123(聚氧乙烯-聚氧丙烯-聚氧乙烯三嵌段共聚物):TEOS(正硅酸乙酯)(物质的量的比)为0.01875的体系中,调节CTAB(十六烷基三甲基溴化铵)∶TEOS(正硅酸乙酯)物质的量比值m,当m在0.12~0.13范围合成出MCM-48分子筛;当m在0.04~0.08范围合成出MCM-41分子筛。通过XRD,TEM,N2物理吸附,IR等方法进行了表征。结果表明:聚氧乙烯-聚氧丙烯-聚氧乙烯三嵌段共聚物(P123)的加入可以更大程度地降低合成介孔材料所需阳离子表面活性剂的用量;可控合成的介孔材料具有高比表面积、高度有序的孔道结构、较集中的孔径分布。     

Preparation of a silicon micro-strip nuclear radiation detector by a two-step annealing process

The annealing process for boron implantation is a crucial step during large size nuclear radiation detector fabrication. It can reduce the lattice defects and the projection straggling. A two-step annealing process for boron implantation was developed instead of a one-step annealing process, and the reverse body resistance of a silicon micro-strip detector was significantly increased, which means that the performance of the detector was improved.     

Selective aerobic oxidation of sulfides to sulfoxides catalyzed by coenzyme NAD models

Coenzyme NAD⁺ models can be applied in the photooxygenation of sulfides to sulfoxides as organocatalysts at room temperature. A series of sulfoxides are synthesized easily with this protocol and the possible mechanism is discussed. This procedure provides a reliable approach to the clean production of useful sulfoxides in synthetic chemistry.     

Hydrothermal Synthesis,Crystal Structure and Luminescent Property of a New Cd(Ⅱ) Coordination Polymer with Four-fold Interpenetrated dia Topology

A new Cd(ΙΙ) coordination polymer with 2-nitroterephthalic acid(H2npa) and 1,4-bis(2-methyl-imidazol-1-yl) butane(bib) has been prepared by hydrothermal synthesis and characterized by single-crystal X-ray diffraction, IR and EA. Complex [Cd(npa)(bib)]n(1) is of orthorhombic system, space group Pcca with a = 16.1750(5), b = 9.8764(5), c = 15.5890(3) A, V =2490.4(2) A3, Z = 4, Mr = 539.82, Dc = 1.440 g/cm3, F(000) = 1088, μ = 0.918 mm-1, the final R =0.0320 and w R = 0.0775 for 2253 reflections with I 2σ(I). X-ray diffraction analysis reveals that complex 1 displays a four-fold interpenetrated dia topology. Furthermore, the luminescent property for complex 1 is also investigated in solid state at room temperature.     

Resolution of ketoconazole enantiomers by high-performance liquid chromatography and inclusion complex formation between selector and enantiomerss

The analytical resolution of ketoconazole (KTZ) enantiomers was performed by high-performance liquid chromatography with sulphobutylether-β-cyclodextrin (SBE-β-CD) as a chiral mobile phase additive (chiral selector). Some important factors affecting the resolution of KTZ enantiomers were investigated. In addition, the molecular interaction between KTZ and SBE-β-CD was studied using the UV absorption spectrum and HPLC for an understanding of the resolution process. The results show that the type and concentration of the chiral mobile phase additive, the pH of the mobile phase and the volume fraction of methanol (?_MeOH) in the mobile phase all have a clear influence on the resolution of KTZ enantiomers. Under optimal conditions, namely the use of 0.5 mmol L^?1 SBE-β-CD as the chiral mobile phase additive, pH of 4.0 and ?_MeOH in the mobile phase of 0.6, KTZ enantiomers are resolved with a resolution of 3.74. SBE-β-CD can bind to KTZ with a stability constant of 1157. The chromatographic method can provide the complexation stability constants of (+)-KTZ with SBE-β-CD (K₍₊₎) and (?)-KTZ with SBE-β-CD (K_(?)). The intrinsic enantioselectivity was calculated from the K₍₊₎ to (K_(?)) ratio as 1.34.     

两个dpa类配体的铜(Ⅱ)配合物的合成、结构、核酸酶活性及细胞毒性

以dpa衍生配体4-methyl-N,N-bis（pyridin-2-ylmethyl）aniline（L）合成2个单核铜配合物[CuL（NO₃）₂]（1）和[CuL（OAc）（H₂O）]ClO₄（2）,并对其进行了表征。单晶结构显示,配合物1中的Cu中心可以描述为畸变的五角双锥构型,而2的Cu中心为畸变的八面体构型。运用电子吸收和发射光谱法研究了配合物与CT-DNA的键合作用,结果表明2个配合物与DNA的相互作用均为部分插入模式。通过改变浓度、时间进一步检测配合物切割DNA的能力,以及验证其切割机理,结果表明在外界诱导剂存在下,2个配合物均表现出强的切割DNA的能力,其作用机理为氧化切割机理,其中活性氧可能为·OH和¹O₂。利用MTT法测定了配合物对体外HeLa、HepG-2和SGC-7901肿瘤细胞增殖的抑制能力。     

The phase equilibriums in the NH4Cl-CaCl2-H2O system at 50 and 75°C and their Pitzer model representations

The solubilities and refractive indexes in the NH₄Cl-CaCl₂-H₂O system were measured at 50 and 75°C and the phase diagrams were constructed on the basis of the experimental data. The mixing parameters and equilibrium constant K _sp were evaluated using the Pitzer ion-interaction model representations. The results obtained were in good agreement with the experimental data. The mixed parameters of Pitzer ion-interaction model and equilibrium constant obtained in the work can furthermore be applied to solubility predictions of more complicated systems containing NH₄Cl and CaCl₂.     

AuNPs/Sol-gel复合膜法固定乙酰胆碱酯酶生物传感器检测有机磷农药

基于有机磷农药对乙酰胆碱酯酶(Acetylcholinesterase,AChE)的抑制作用,用金纳米粒子(Au nanoparticles,AuNPs)与壳聚糖/SiO2杂化溶胶-凝胶构成复合固酶基质,将AChE固定于玻碳电极表面,制备了电流型AChE生物传感器选用久效磷进行实验,以氯化硫代乙酰胆碱为底物,建立了电化...