HPLC测定山梨醇水溶液中山梨醇和甘露醇含量

采用HPLC法,以超纯水为流动相,用Sugar-pakⅡ(Waters)色谱柱和示差拆光检测器,准确地分离和测定了山梨醇水溶液中山梨醇和甘露醇的含量,变异系数1.42%,回收率99.89%。     

Docetaxel‐Loaded Nanoparticles of Dendritic Amphiphilic Block Copolymer H40‐PLA‐b‐TPGS for Cancer Treatment

A dendritic amphiphilic block copolymer H40‐poly(d,l ‐lactide)‐block‐d‐α‐tocopheryl polyethylene glycol 1000 succinate (H40‐PLA‐b‐TPGS) is synthesized, which is then employed to develop a system of nanoparticles (NPs) loaded with docetaxel (DTX) as a model drug for cancer treatment due to its higher drug‐loading content and drug encapsulation efficiency, smaller particle size, faster drug release, and higher cellular uptake in comparison to the linear PLA polymer NPs and PLA‐b‐TPGS copolymer NPs. The drug‐loaded NPs are prepared by a modified nanoprecipitation method and characterized in terms of size and size distribution, surface morphology, drug release profile, and physical state of DTX. Cellular uptake of coumarin 6‐loaded NPs by MCF‐7 cancer cells is determined by flow cytometry and confocal laser scanning microscopy. The antitumor efficacy of the drug‐loaded NPs is investigated in vitro by MTT assay and in vivo by xenograft tumor model. The 72 h IC50 of the drug formulated in the PLA, PLA‐b‐TPGS, and H40‐PLA‐b‐TPGS NPs is found to be, 1.5 ± 0.3, 0.9 ± 0.1, and 0.15 ± 0.06 μg mL^?1, which are 7.3, 12.2, and 73.3‐fold effective than 11.0 ± 1.2 μg mL^?1 for Taxotere, respectively. Such advantages are further confirmed by the measurement of the tumor size and weight.     

A novel label-free electrochemical aptasensor for thrombin based on the {nano-Au/thionine}n multilayer films as redox probes

Herein, a novel label-free electrochemical aptasensor based on direct immobilization of the redox probes on an electrode surface was reported. Gold electrode coated Nafion was firstly modified with redox probe-thionine (Thi) through ion exchange adsorption. Then, with the help of chemisorption and electrostatic adsorption, negatively charged nano-Au and positively charged Thi were layer-by-layer (LBL) self-assembled onto the modified electrode surface, which formed {nano-Au/Thi⁺}_n multilayer films for improving the amount of redox probes and immobilizing thiolated thrombin aptamers (TBA). In the presence of target thrombin (TB), the TBA on the multilayer film could catch the TB onto the electrode surface, which resulted in a barrier for electro-transfer, leading to decrease of the current. The proposed method avoided the cubsome redox probe labeling process, increased the amount of redox probe and reduced the distance between the redox probe and electrode surface. Thus, the approach showed a high sensitivity and a wider linearity to TB in the range from 0.12 nM to 46 nM with a detection limit of 40 pM.     

A new class of versatile chiral-bridged atropisomeric diphosphine ligands: remarkably efficient ligand syntheses and their applications in highly enantioselective hydrogenation reactions

A series of chiral diphosphine ligands denoted as PQ-Phos was prepared by atropdiastereoselective Ullmann coupling and ring-closure reactions. The Ullmann coupling reaction of the biaryl diphosphine dioxides is featured by highly efficient central-to-axial chirality transfer with diastereomeric excess >99%. This substrate-directed diastereomeric biaryl coupling reaction is unprecedented for the preparation of chiral diphosphine dioxides, and our method precludes the tedious resolution procedures usually required for preparing enantiomerically pure diphosphine ligands. The effect of chiral recognition was also revealed in a relevant asymmetric ring-closure reaction. The chiral tether bridging the two aryl units creates a conformationally rigid scaffold essential for enantiofacial differentiation; fine-tuning of the ligand scaffold (e.g., dihedral angles) can be achieved by varying the chain length of the chiral tether. The enantiomerically pure Ru- and Ir-PQ-Phos complexes have been prepared and applied to the catalytic enantioselective hydrogenations of alpha- and beta-ketoesters (C=O bond reduction), 2-(6'-methoxy-2'-naphthyl)propenoic acid, alkyl-substituted beta-dehydroamino acids (C=C bond reduction), and N-heteroaromatic compounds (C=N bond reduction). An excellent level of enantioselection (up to 99.9% ee) has been attained for the catalytic reactions. In addition, the significant ligand dihedral angle effects on the Ir-catalyzed asymmetric hydrogenation of N-heteroaromatic compounds were also revealed.     

Supercapacitor based on graphene and ionic liquid electrolyte

A new kind of supercapacitor by using chemical reduced graphene (CRG) as electrode material and ionic liquid with addition of acetonitrile as electrolyte is assembled and investigated. CRG materials with high surface area are prepared by chemical reduction of graphene oxide. The capacitive properties of the supercapacitor composed of the CRG and ionic liquid electrolyte are studied by electrical impedance spectroscopy, cyclic voltammetry and galvanostatic charge–discharge. With the combined advantages of graphene and ionic liquid, the supercapacitor shows perfect performance. The supercapacitor possesses wide cell voltage and good stability. The specific capacitance, energy density, and specific power density of the present supercapacitor are 132 Fg⁻¹, 143.7 Wh kg⁻¹, and 2.8 kW kg⁻¹, respectively. The results demonstrate the potential application of electrical energy storage devices with high performance based on this new kind of supercapacitor.

     

Formation and properties of high density Si nanodots

Laser induced crystallization of ultrathin hydrogenated amorphous Si films or amorphous Si-based multilayered structures were used to get high density Si nanodots. The present technique can get size controllable Si nanodots embedded in various dielectric materials with uniform distribution which was revealed by cross-section transmission electron microscopy. Room temperature photoluminescence and electroluminescence were achieved with the emission wavelength in a visible light region both from a-SiN/Si nanodots/a-SiN sandwiched and Si nanodots/SiO₂ multilayered structures. The luminescence was associated with the radiative recombination of generated electron-hole pairs in Si nanodots or the luminescent surface states. The electroluminescence intensity is increased with increasing the injection current implying the bipolar carrier injection plays an important role in enhancing the luminescence efficiency. The formed Si nanodots by the present approach can be applied for many kinds of devices such as high efficient light emitting diodes and solar cells.     

新工科背景下湖南大学应用化学专业的改革与建设

It is necessary to develop new engineering-directed applied chemistry major on the basis of chemistry major and to remodel the current applied chemistry education according to the concept of emerging engineering. Herein, emendation in 2020 version of applied chemistry education plan and researches on teaching renovations for applied chemistry major in Hunan University is introduced. Through the adjustments of education goals, course systems, teaching contents and teaching models, we wish to highlight the central status of the educations that integrates morality and ability. In addition to the inheritance of the specialty in corrosion and protection, it is expected to further satisfy the need of graduates for the industries such as new materials, new energy, high-tech production, environmental protection, and new generation of information technique. At last, future trends and perspectives in emerging engineering applied chemistry is proposed.