Microdialysis sampling coupled to HPLC for transdermal delivery study of ondansetron hydrochloride in rats

The transdermal delivery of ondansetron hydrochloride (ON) solution in propylene glycol (PG) with a widely used penetration enhancer, oleic acid (OA), was studied in rats by a microdialysis sampling technique. Dialysate samples collected from the probe were directly injected into the HPLC system without any pre-treatment and no interference occurred in the blank sample. A good linearity between the standard concentrations and peak areas within the calibration range was achieved. In vivo recovery (32.52 +/- 1.8%) of the probe was assessed with the retrodialysis method, which was used to calculate the ON concentration in the dermis. Oleic acid at the concentrations of 2% and 5% (w/v) increased the steady-state delivery rate from 0.001 to 0.030 and 0.058 microg/h, respectively. OA proved to be an effective enhancer for transdermal delivery of ON in rats.     

Potential energy surface for linear triatomic molecules: An algebraic method

Recently, we proposed a new transformation between the angle of canonical coordinates and the bond angle to describe the bending motion in Potential Energy Surfaces (PES) of bent triatomic molecules. In this work we extend the transformation to include linear triatomic molecules. Results for the linear triatomic molecule N₂O are reported.     

Synthesis of silylcyclopropanes via arsonium ylides

Silylcyclopropanes were synthesized from trimethylsilylmethylenetriphenylarsorane and substituted chalcones.     

羧甲基纤维素钠修饰的聚氨酯泡沫制备磁性吸油材料

采用聚氨酯泡沫为模板,依次修饰羧甲基纤维素钠(CMC)、Fe~(3+),在惰性气氛中高温热处理反应,制备多孔结构的磁性吸油材料.用光学显微镜、扫描电子显微镜、红外吸收光谱、X-射线衍射、接触角等技术对材料进行表征.详细考察了加热反应温度、CMC浓度和Fe~(3+)浓度对材料吸油性能和磁性的影响规律.实验表明,当加热反应温度选择230°C,CMC浓度为0.3 wt%,FeCl_3浓度为0.1 mol/L时,材料吸油性能最佳,对正己烷、二甲苯、环己烷、甲苯、乙酸乙酯、氯仿、机油、原油等有机溶剂和油类分子的吸附容量为10倍左右.磁性多孔材料具有明显的亲油、疏水特性,水的接触角达115.9°,同时材料密度只有0.036g/cm~3,能够漂浮于水面,实现对水面有机溶剂的快速吸附.吸附后的材料在外界磁场控制下,能够通过磁分离方式从水面快速分离.该材料具有良好的循环利用性能,可重复使用20次以上,吸油性能仍然保持良好.     

基于氟代异靛蓝并[7,6-g]异靛蓝的共轭聚合物的合成及其半导体性质

采用Stille缩聚,合成了3个异靛蓝并[7,6-g]异靛蓝(DIID)和乙烯单元交替排列的共轭聚合物P0F、P2F和P4F,三者在DIID单元中分别含0、2和4个氟原子(F).3个聚合物均具有良好的平面性,前线分子轨道几乎在整个共轭骨架上离域.它们均具有宽的吸收光谱,吸收范围在400~1000 nm,光学带隙约为1.25 eV;随着氟原子数目的增加,聚合物的最高占有分子轨道(HOMO)和最低空分子轨道(LUMO)能级依次下降0.1~0.2 eV.以这3个聚合物作为活性层,制备了顶栅-底接触型有机场效应晶体管器件,随着氟原子数目的增加,聚合物的传输性质由双极传输变为n型传输.P0F和P2F是双极传输型聚合物,空穴迁移率(μ_h)分别达到0.11和0.30 cm~2 V~(-1) s~(-1),电子迁移率(me)分别达到0.22和1.19 cm~2 V~(-1) s~(-1).P4F是n型聚合物,me达到0.18 cm~2 V~(-1) s~(-1).     

Poly(<Emphasis Type="Italic">β</Emphasis>-cyclodextrin)-mediated polylactide-cholesterol stereocomplex micelles for controlled drug delivery

A series of host-guest interaction-adjusted polylactide stereocomplex micelles was prepared via the self-assembly of 4-armed poly(ethylene glycol)-block-poly(L-lactide/D-lactide)-cholesterol (4-armed PEG-b-PLLA/PDLA-CHOL) and poly(β-cyclodextrin) (PCD) with the molar ratios of CHOL/β-CD at 1:0.5, 1:1, and 1:2 in an aqueous environment. The hydrodynamic diameters of the micelles ranged from 84.1 nm to 107 nm depending on the molar ratio of CHOL/β-CD. It was shown that the micelle with the largest proportion of PCD possessed excellent abilities in drug release, cell internalization as well as proliferation inhibitory effect toward human A549 lung cancer cells. The results demonstrated that the stereocomplex and host-guest interactions-mediated PLA micelles exhibited great potential in sustained drug delivery.     

Enhancement of SrTiO<Subscript>3</Subscript>/BiPO<Subscript>4</Subscript> heterostructure for simulated organic wastewater degradation under UV light irradiation

A novel SrTiO₃/BiPO₄ heterostructure with different amounts of SrTiO₃ have been successfully prepared through the hydrothermal process. The photocatalysts were characterized by X-ray powder diffraction, UV–Vis diffuse reflectance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The photocatalytic performance was evaluated by degrading the methylene blue dye solution under UV light. Results showed that the samples displayed excellent photocatalytic degradation efficiency due to the highly efficient suppression of the recombination of electron–hole pairs. A possible mechanism of SrTiO₃/BiPO₄ heterojunctions was discussed. The research indicated that the as-prepared SrTiO₃/BiPO₄ heterogeneous photocatalyst can be used as an effective material for degrading industrial organic wastewater.     

Phosphonium and arsonium ylides. XVII. A facile synthesis of methyl 2,6-bisperfluoroalkylbenzoates via acyclic precursors

The title compounds 6a—6f were prepared with high yield via intramolecular Wittig reaction of methyl 3-perfluoroalkyl-6-peifluoroacyl-2-triphenylphosphoranylidenchex-3,5-dienoates (5a—5i) which were obtained from the reaction of 3-perfluoroacylprop-2-enylidenetriphenylphosphoranes (3a—3c) with methyl perfluoroalkynoates (4a—4c).     

电镀液和电镀层中钯和钴的分光光度法同时测定

在ＰＨ＝４．５的ＨＡｃ－ＮａＡｃ介质中,钴和钯都能与２－「２－（６－甲基苯并噻唑）偶氮」－５－「Ｎ－甲基－Ｎ－乙羧基」苯甲酸（简称ＭＣＢ）形成络合物。在λ＝７１０ｎｍ处Ｃｏ－ＭＣＢ不吸收;在６１０．５ｎｍ处Ｃｏ－ＭＣＢ有最大吸收,而Ｐｄ－ＭＣＢ也有一定的吸收值。利用这一差异,在可６１０．５ｎｍ处测定Ｐｄ和Ｃｏ的合量,而在７１０ｎｍ处测定Ｐｄ的含量学与化学传感再利用系数法算出Ｃｏ的含量。测定了纯性范     

Thermodynamics of porphyrin binding to human serum albumin using affinity capillary electrophoresis

Summary The interaction thermodynamics of heptacarboxylporphyrin (HCP) and protoporhyrin (PP) with human serum albumin (HSA) was studied by affinity capillary electrophoresis (ACE) over the temperature range of 25–50°C, where HCP and PP bound to HSAvia 1:1 molecular association. The binding equilibrium constants (pH 7.4, phosphate buffer) for the binding of HCP with HSA were found to decrease with an increase in temperature, whereas the binding constants of the PP/HSA system appeared to be independent of temperature changes over the range studied. The van’t Hoff relationship (25–50°C) was found to be linear for the interaction of either HCP or PP with HSA. However, the interaction thermodynamics for both of these porphyrins with HSA were found to be quite different. In particular, the interaction of HCP (a hydrophilic porphyrin) with HSA appeared to be based on an enthalpy-driven process, whereas the binding between PP (a hydrophobic porphyrin) and HSA driven by a favorable change in entropy. The ability of using ACE to evaluate the interaction thermodynamics of serum proteins (e.g., HSA) with ligands (e.g., porphyrins and related compounds) should aid in the development of new and more effective photosensitizers in the photodynamic therapy of cancer.