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  • Author or Editor: Feng Wu x
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Abstract  

Bibliographic data on ophthalmology, optometry and visual science (OOVS) literature of China drawn from the SCI-Expanded database covering the period 2000–2007 (961 publications) were analyzed to create a comprehensive overview of research output. Of 961 articles, 480 were published in 2006 and 2007. The majority of researchers worked in university hospitals (53%). 21% of the publications included one or more international co-authors. For each article, the average author number was 4.96±2.73, which increased from 3.96 in 2000 to 5.36 in 2007. The most cited references came from Investigative Ophthalmology & Visual Science and Ophthalmology. The greatest number of studies was focused on the retina.

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Abstract

The crystallization behavior of β-nucleated isotactic polypropylene (PP) composites filled with Kevlar fibers (KFs), as well as that of non-nucleated PP/KF composites for comparison, was investigated using differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The morphological observations revealed that the KF addition could induce thick α-transcrystalline layer around their surfaces in PP/KF composites, while no obvious transcrystalline layer could be detected in β-nucleated PP/KF composites. Detailed DSC investigations suggested that for the PP/KF composites, the dominant modification was α-form, and the crystallization process of matrix was promoted by KF addition, as illustrated by faster isothermal crystallization rate, shorter induction time, and higher crystallization temperature. However, for β-nucleated PP/KF composites, the main modification was β-form, and their crystallization characteristics were independent of KF addition, indicating that the α-nucleating effect of KFs was absent in this system. The DSC results were confirmed by further rheological and wide angle X-ray diffraction (WAXD) studies. The mechanism of the formation of transcrystalline layer was also discussed.

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Abstract  

Photodegradation of paracetamol in montmorillonite KSF suspension followed the Langmuir–Hinshelwood kinetic model. The influence of KSF dosage, initial paracetamol concentration, initial pH, chelating agents and a radical scavenger on the degradation of paracetamol were studied and described in detail. The degradation mechanism of paracetamol was also proposed in this work.

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Abstract  

This study of photodegradation of the antibiotic chloromycetin (Cm) in aqueous solution by direct and indirect photolysis included photolysis under UV-C light (λ = 254 nm) and photo-oxidation under UV–vis light (λ ≥ 365 nm) in the presence of iron and humic acid. The factors affecting Cm degradation were studied and are described in detail, including initial pH, ionic strength and initial concentrations of iron and humic acid. Results showed that a degradation efficiency up to 90% was achieved by direct photolysis of Cm at pH 5–7 and the calculated quantum yield was 0.084. Higher salt content (NaCl, 0.01–0.5 M) was found to benefit direct photolysis. Indirect photolysis of Cm in the presence of iron(III) formed OH radicals at pH ~ 3. Under UV–vis light, increased pH resulted in a significant decrease in the efficiency of indirect photolysis. Direct and indirect photolysis reactions both followed a pseudo first-order kinetic law. Humic acid tended to inhibit the photodegradation of Cm under the conditions of this work, implying that photosensitization of humic acid did not play any role in the photodegradation.

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Abstract  

A new method was proposed for determining the most probable mechanism function of a solid phase reaction. According to Coats-Redfern's integral equation Eβ→0 was calculated by extrapolating β to zero using a series of TG curves with different heating rates. Similarly, Eα→0 was calculated according to Ozawa's equation. The most probable mechanism function of the solid phase dehydration of manganese(II) oxalate dihydrate was confirmed to be G(α)=(1-α)1/2 by comparing Eα→0 with Eβ→0.

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Abstract

The adsorption and photodegradation behavior of tetracycline (TC), chloramphenicol (CAP) and sulfamethoxazole (SMX) in clay mineral dispersion was investigated in this work. Only TC showed significant adsorption to natural montmorillonite and rectorite, whereas CAP and SMX adsorbed to natural montmorillonite, kaolinite and rectorite to a much lower extent. The adsorption equilibrium constants (L/kg) of TC to natural montmorillonite were 332 and 108 at pH 3.0 and 7.0, respectively. The kinetic rate constant k app (min−1) for the removal of CAP in the presence of different clay minerals follows the sequence: montmorillonite KSF (1.6 × 10−2) > rectorite (4.6 × 10−3) > natural montmorillonite (3.8 × 10−3) > kaolinite (2.8 × 10−3). Removal of SMX follows the same sequence. Oxalate significantly promotes the removal of CAP and SMX in montmorillonite KSF dispersion, while penicillamine (PEN) and β-cyclodextrin retard the diminution. After 3 h of irradiation in 5 g/L KSF dispersion, the total organic carbon was reduced by 72 and 39% for CAP and SMX, respectively.

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Psoralidin has a variety of pharmacological activities, such as anti-tumor, anti-depressant, and anti-inflammatory activities. This study aims at developing a rapid ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method to determine psoralidin in rat plasma and studying the pharmacokinetic characteristic of psoralidin after intragastric administration of 20 and 40 mg/kg. Alpinetin was used as an internal standard (IS), and the plasma samples were precipitated with acetonitrile. The calibration curves were linear over the range of 0.2–250 ng/mL (R 2 = 0.993). The pharmacokinetic parameters were calculated by DAS 3.0. Half-life (t 1/2) was 7.2 ± 0.97 h and 7.1 ± 0.27 h for different dosages, respectively. T max was 4.2 ± 1.1 h and 4.0 ± 1.1 h for different dosages, respectively. Apparent volume of distribution (V d) for different dosages was 630.1 ± 168.8 and 600.1 ± 138.8 L/kg, respectively. Clearance (CL) was 105.6 ± 29.2 and 100.6 ± 22.2 L/h/kg for different dosages, indicating that psoralidin was mainly distributed in rat tissues. The pharmacokinetic study provided important information for further clinical application in the treatment of cancer and osteoporosis.

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Abstract

The purpose of this study is to simulate the early age concrete behaviors and evaluate the cracking risk with the thermal and thermal stress analysis. A new finite element method program associated with ANSYS program is developed for the computation of thermal field and thermal stress field for early age concrete considering the following characters: degree of hydration, thermal properties (such as specific heat, thermal diffusivity), thermal boundary conditions, and mechanical properties (such as shrinkage, creep) which occur at early age. The results from simulation compared with experimental values found in the literature show a good agreement. Finally, based on this user-developed subroutine, the effects of hydration heat, ambient temperature, wind velocity, shrinkage, and length-height ratio on cracking risk were analyzed for a concrete wall which is one part of the structure of Maridal culvert in Norway. By which, the measures to control the cracking were provided for the engineering application.

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Abstract  

This work reports the synthesis and preliminary biodistribution results of [131I]SIB-PEG4-CHC in tumor-bearing mice. The tributylstannyl precursor ATE-PEG4-CHC was synthesized by conjugation of ATE to amino pegylated colchicine NH2-PEG4-CHC. [131I]SIB-PEG4-CHC was radiosynthesized by electrophilic destannylation of the precursor with a yield of ~44%. The radiochemical purity (RCP) appeared to be >95% by a Sep-Pak cartridge purification. [131I]SIB-PEG4-CHC was lipophilic and was stable at room temperature. Biodistribution studies in tumor-bearing mice showed that [131I]SIB-PEG4-CHC cleared from background rapidly, and didn’t deiodinate in vivo. However, the poor tumor localization excluded it from further investigations as a tumor-targeted radiopharmaceuticals.

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Abstract  

The sorption of Co(II) on Na-attapulgite as a function of contact time, solid content, pH, ionic strength, foreign ions, fulvic acid (FA) and temperature under ambient conditions was studied. The kinetic of Co(II) sorption on Na-attapulgite was described well by pseudo-second-order model. The sorption of Co(II) on Na-attapulgite was strongly dependent on pH and ionic strength. The sorption of Co(II) was mainly dominated by outer-sphere surface complexation and/or ion exchange at low pH, whereas inner-sphere surface complexation or surface precipitation was the main sorption mechanism at high pH values. The presence of FA did not affect Co(II) sorption obviously at pH <7, and a negative effect was observed at pH >7. The Langmuir and Freundlich models were used to simulate the sorption data at different temperatures, and the results indicated that the Langmuir model simulated the data better than the Freundlich isotherm model. The thermodynamic parameters (∆G°, ∆S°, ∆H°) calculated from the temperature-dependent sorption isotherms indicated that the sorption of Co(II) on Na-attapulgite was an endothermic and spontaneous process. The results suggest that the attapulgite sample is a suitable material in the preconcentration and solidification of radiocobalt from large volumes of aqueous solutions.

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