New designed DNA light switch Ruthenium complexes as DNA photocleavers and Topoisomerase I inhibitors

Two ruthenium complexes containing a new ligand phipz (phipz = 2‐(1,10‐phenanthroline)‐1H‐imidazo[4,5‐b]phenazine) were designed and synthesized. These complexes were found to inhibit the DNA supercoiled relaxation mediated by topoisomerase I (topo I), cleave DNA under irradiation and bind to calf thymus DNA through intercalative mode. Furthermore, complex 2 shows higher photocleavage activity, topo I inhibition activity and DNA affinity than complex 1 . Additionally, introduction of phenazine unit may be the reason that two complexes exhibit DNA ‘light switch’ behavior. The present work shows that two complexes might be potential as new DNA ‘light switches’, DNA photocleavers and topo I inhibitors.     

基于SSCVD方法的a-b轴取向ZnO薄膜制备

以Zn₄(OH)₂(O₂CCH₃)₆·2H₂O为单一固相有机源,采用单源化学气相沉积法(Single sour cechem icalvapor deposition,SSCVD)在Si(100)衬底上制备ZnO薄膜,用X射线衍射(XRD)、原子力显微镜(AFM)分析ZnO薄膜样品的晶体结构和微观形貌,并用X射线光电子能谱(XPS)对薄膜的锌氧化学计量比进行了分析。研究结果表明:在非平衡条件下所得到的ZnO薄膜沿a-b轴取向生长,基片温度对ZnO薄膜生长过程影响较大,随着基片温度的升高,薄膜呈现c轴生长趋势;晶粒成柱状、尺寸均匀、膜层结构致密;薄膜样品中n_Zn:n_O=0.985。     

Josephson junction through a thin ferromagnetic layer: negative coupling

We investigate Josephson coupling through a ferromagnetic thin film using superconductor-insulator-ferromagnet-superconductor planar junctions. Damped oscillations of the critical current are observed as a function of the ferromagnetic layer thickness. We show that they result from the exchange energy gained or lost by a quasiparticle Andreev-reflected at the ferromagnet-superconductor interface. The critical current cancels out at the transition from positive ("0") to negative ("pi") coupling, in agreement with theoretical calculations.     

零阶贝塞尔函数组成的两个正交系

给出了在常见的函数内积下任意两个零阶贝塞尔函数的内积公式，进而证明了由第一类和第二类零阶贝塞尔函数的线性函数族的正交性以及长度的表达式．     

2-(diphenylphosphinoyl) pyrrolidines; versatile reagents for the synthesis of heterocyclic enamines and enamides.

A method is described for the preparation of N-substituted 2-(diphenylphosphinoyl) pyrrolidines. Application of these phosphine oxides in the Horner-Wittig reaction affords heterocyclic enamines and enamides in good yields.     

Selective absorption

Summary Some organic acids, alcohol and amine which have an asymmetric carbon atom were used for an investigation of asymmetric absorption on wool. Racemic mixture of hydratropic acid, mandelic acid andα-phenethylamine have shown the selective absorption on wool from their aqueous and alcoholic aqueous solutions and S-form of their diastereoisomers preferentially absorbed on wool. According to the results we obtained so far, it is concluded that the preferential absorption strongly depends on the configuration of the substance of which wool is composed.     

Photon statistics of laser light scattered by motile spermatozoa

The intensity of laser light scattered by swimming spermatozoa is experimentally determined to obey a gaussian distribution. This is due to the fact that the fluctuations of the electric susceptabilities of the sperm system accord with gaussian statistics. The result is obtained from the light intensity correlation data and the photoelectron counting distribution with a photoelectron counting technique. It also gives us the justification of the usual process in light intensity correlation spectroscopy of swimming spermatozoa when we get the susceptibility correlation function from the experimentally obtainable intensity correlation function.     

Inclusion complexes of ketoconazole with beta-cyclodextrin: physicochemical characterization and in vitro dissolution behaviour of its vaginal suppositories

Ketoconazole (KZ) is an imidazole antifungal agent which is administered topically and also orally. KZ is practically insoluble in water. Vaginal candidiasis is a common condition and up to 75% of all women have at least one episode of this infection during their lifetime. The aim of study was to prepare KZ/β-cyclodextrin (β-CD) complex to improve the physicochemical properties of KZ and to investigate the possibility of preparing vaginal suppositories with the complexes. A linear increase in KZ solubility as a function of β-CD concentration was verified using the phase-solubility diagram. The resulting diagram was classified as A_L-type, is generally related to the formation of a soluble complex. Complexes were prepared in a 1:1 molar ratio by different methods, namely freeze-drying, spray-drying, co-evaporation and kneading. Characterization of the complexes prepared was performed by practical yield %, aqueous solubility, active agent amount analyses, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffractometry (PXRD) and ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy. Characterization studies provided additional evidences of complexation. The paddle method defined in USP31 was used in in vitro dissolution experiments on the prepared vaginal suppositories. It was found that solubility enhancement by preparing KZ/β-CD complexes depends on the type of the preparation method. Dissolution of KZ from complexes was found to be faster than the active agent and the commercial suppositories. This result may be attributed to the interactions between β-CD and active agent, high energetic amorphous state and decrease in the interfacial tension between insoluble active agent and dissolution media.