Measurement and correlation of densities and viscosities of thiourea in triglycol solution using VTF equation

The densities and viscosities of thiourea in triglycol + water had been determined from 302.85 to 341.45 K. The viscosities were correlated using the VTF equation. The results showed that the model agree very well with the experimental data.     

Hydroxyl Radicals Formation in Dielectric Barrier Discharge During Decomposition of Toluene

A method based on high performance liquid chromatography (HPLC), has been developed to measure hydroxyl radical (^·OH) in plasma reactors. The determination was performed indirectly by detecting the products of the reaction of ^·OH with salicylic acid (SAL). The applicability, and effect of time, specific input energy (SIE), relative humidity (RH), catalyst were investigated. It was found that 3 h was the optimal trapping time; concentration of ^·OH was (5.9–23.6) × 10¹³ radicals/cm³ at SIE range. The highest ^·OH yield and toluene removal efficiency (η) were achieved with a RH of 20%. With MnO _x , η was two times that without catalyst, while ^·OH yield in gas stream was one-sixth that without catalyst. However, if summed with ^·OH adsorbed on catalyst surface, the total ^·OH yield was the same as without catalyst. Experiments performed with/without toluene allowed to determine the role of ^·OH on decomposition of toluene in air plasma.     

A new griseofulvin derivative from the mangrove endophytic fungus <Emphasis Type="Italic">Sporothrix</Emphasis> SP.

A new griseofulvin derivative, 7-chloro-2',5,6-trimethoxy-6'-methylspiro(benzofuran-2(3H),1'-(2) cyclohexene)3,4'-dione (1), together with the known 2-acetyl-7-methoxybenzofuran (2), was isolated from the marine-derived mangrove endophytic fungus Sporothrix sp. (No. 4335). The structure of new compound 1 was elucidated by analysis of spectroscopic data.     

Preparation and electrical properties of Nd and Mn co-doped Bi<Subscript>4</Subscript>Ti<Subscript>3</Subscript>O<Subscript>12</Subscript> thin films

Ferroelectric thin films of Nd and Mn co-doped bismuth titanate, Bi_3.15Nd_0.85Ti_3−x Mn _x O₁₂ (BNTM) (x = 0–0.1), were fabricated on Pt/TiO₂/SiO₂/Si(100) substrates by a sol–gel technique. The BNTM films had a polycrystalline perovskite structure and uniform and dense surface morphologies. A lattice distortion was observed in the BNTM films due to Mn ion doping. The ferroelectric measurement of the films indicated that the values of coercive field (E _c ) decreased gradually with the increase of the Mn content (x), however, the remanent polarization (P _r ) increase firstly and then decrease with the increase of x. The sample with x = 0.05 had optimum electrical properties and a maximum 2P _r value. The 2P _r and 2E _c values of the film at a maximum applied electric field of 400 kV/cm were 38.3 μC/cm² and 180 kV/cm, respectively. Moreover, this BNTM capacitors did not show fatigue behaviors after 1.0 × 10¹⁰ switching cycles at a frequency of 1 MHz, suggesting a fatigue-free character. The main reason for the increase of the 2P _r and the decrease of the 2E _c might be attributed to the lattice distortion in BNTM films due to Mn ion doping.     

Planar or quasi-planar octa- and ennea-coordinate aluminum and gallium in boron rings

An ab initio theoretical investigation has been performed on planar or quasi-planar octa-and ennea-coordinate Al and Ga centered in X@B8- and X@B9 (X=Al, Ga). These high symmetry molecular wheels all turned out to be true minima of the systems and σ+π double aromatic in nature, similar to the previously characterized D8h B@B8- both electronically and geometrically. Adiabatic and vertical detachment energies of the anions and the ionization potentials of the neutrals have been calculated to aid their eventua...     

Transfer Volumes of Small Peptides from Water to Aqueous Xylitol Solutions at 298.15 K

Densities have been measured by an oscillating-tube densimeter for aqueous solutions of glycylglycine and glycylglycylglycine in aqueous xylitol solutions with xylitol mass fractions ranging from 0 to 0.15 at 298.15 K. Apparent molar volumes and limiting partial molar volumes have been used to calculate the corresponding transfer volumes from water to different concentrations of xylitol + water mixtures. The results are interpreted in terms of the cosphere overlap model.     

两种菁类染料复合敏化TiO_2纳米晶电极的光电化学研究

应用光电化学方法研究了两种菁类染料Cy3和Cy5复合敏化TiO2纳米晶电极的光电化学行为.结合两种染料的紫外-可见光谱和循环伏安曲线,确定了Cy3和Cy5的电子基态和激发态能级位置.结果表明两种染料的激发态能级位置能与TiO2纳米粒子导带边位置相匹配,复合敏化可以显著提高TiO2纳米晶的光电流,使TiO2纳米晶电极吸收波长由紫外光区红移至可见光区和近红外区.复合敏化降低了染料Cy3 在电极吸附时的聚集程度,使其单色光的转换效率(IPCE)提高了169%,复合敏化电极总的光电转换效率η为2.09%,分别是Cy3和Cy5单独敏化时光电转换效率的2.069 和1.229倍.     

The Relationship of Phthalocyanine 4 (Pc 4) Concentrations Measured Noninvasively to Outcome of Pc 4 Photodynamic Therapy in Mice

The ability to noninvasively measure photosensitizer concentration at target tissues will allow optimization of photodynamic therapy (PDT) and could improve outcome. In this study, we evaluated whether preirradiation tumor phthalocyanine 4 (Pc 4) concentrations, measured noninvasively by the optical pharmacokinetic system (OPS), correlated with tumor response to PDT. Mice bearing human breast cancer xenografts were treated with 2 mg kg⁻¹ Pc 4 iv only, laser irradiation (150 J cm⁻²) only, Pc 4 followed by fractionated irradiation or Pc 4 followed by continuous irradiation. Laser irradiation treatment was initiated when the tumor to skin ratio of Pc 4 concentration reached a maximum of 2.1 at 48 h after administration. Pc 4 concentrations in tumor, as well as in Intralipid in vitro , decreased monoexponentially with laser fluence. Pc 4-PDT resulted in significant tumor regression, and tumor response was similar in the groups receiving either fractionated or continuous irradiation treatment after Pc 4. Tumor growth delay following Pc 4-PDT correlated with OPS-measured tumor Pc 4 concentrations at 24 h prior to PDT ( R ² = 0.86). In excised tumors, OPS-measured Pc 4 concentrations were similar to the HPLC-measured concentrations. Thus, OPS measurements of photosensitizer concentrations can be used to assist in the scheduling of Pc 4-PDT.     

Synthesis of micron-sized hollow silica spheres with a novel mesoporous shell of MCF

Micron-sized hollow silica spheres whose shells are made up of mesocellular silica foams(MCFs) have been synthesized by one-pot sol-gel method in benzene/water/P123 emulsion.The material is characterized with SEM,TEM,BET and ~(29)Si MAS NMR. The results show that the MCFs of the unique shell of hollow silica spheres were connected by large windows with a narrow distribution of～10 nm in diameter,the inner space of the hollow sphere is accessible.And the formation mechanism of the hollow silica spheres is ...     

Synthesis, Electrochemical Characteristics of [Ni(phen)(H2O)4]SO4⋅2H2O and Its Interaction Mechanism with DNA

A polypyridyl nickel complex of [Ni(phen)(H₂O)₄]SO₄?2H₂O (phen = 1,10-phenanthroline) was synthesized and characterized by X-ray diffraction and IR spectroscopy. The results indicated that the central nickel ion is in a distorted octahedral geometry coordinated by two nitrogen atoms from 1,10-phenanthroline and four water molecules. The crystal data for this complex are: a=8.8797(18) Å, b=18.468(4) Å, c=22.081(4) Å, α=90°, β=90°, γ=90°, R ₁=0.0533, and wR ₂=0.2095. Electrochemical experiments showed that the complex could be reoxidized at a gold electrode under the precondition of electrolysis stripping. According to the results of cyclic voltammetry and coulometry, an electrochemical reaction mechanism was proposed. The DNA binding properties of the complex were further investigated by electronic absorption spectrophotometry and electrochemistry. The binding constant and the binding mode between the two species were estimated based on the spectroscopic and electrochemical results.