Optimization of the Near-Infrared Fluorescence Labeling for In Vivo Monitoring of a Protein Drug Distribution in Animal Model

The objective of this study is to optimize the parameters in labeling near-infrared (NIR)fluorescent dye cypate to protein drugs for in vivo optical imaging of drug distributions in animal model. l-ASparaginase (l-ASNase) was used as a protein drug model for the study. To achieve this goal, various labeling conditions, including different catalysts, feed ratios of all components, pH conditions, temperatures, and reacting durations, were investigated. The dye-to-protein (D/P) ratio and enzymatic activity were designated as the metric to evaluate the labeling process. The stability of the cypate–protein conjugate in blood serum and its distribution in small animals were subsequently inspected. Results showed that feed ratio of l-ASNase and the pH value played the most important role in adjusting the labeling efficiency. Reaction duration and temperature had less effect on the dye-to-protein labeling properties. The optimal condition for the labeling of cypate to l-ASNase was 4 h reaction duration at 4 °C and pH 8.5 under catalysis by HOBt/HBTU. The dynamic distribution in animal model displayed that the labeled l-ASNase firstly accumulated in liver and cleared from the enteron system. This study demonstrated that the NIR image system combined with NIR probe has the capability to trace the dynamics of protein drugs in animals for drug development.     

F-P半导体激光放大器弱信号机制下的增益特性研究

利用直接耦合的激光器放大器对,观察了弱信号机制下Fabry-Perot的半导体激光放大器的光放大.测量了放大器增益随放大器注入电流的变化关系,并将实验结果同理论模型相比较,发现理论和实验是一致的.把F-P放大器看作是一个光电探测器,通过测量放大器的短路光电流,得到了激光器同放大器之间的耦合效率.     

稀土元素镧对锌阳极带电化学性能的影响

研究了镧的加入对牺牲锌阳极带电化学性能的影响。结果表明，稀土元素镧对锌阳极带的电位和电流效率影响很小，实验结果符合相关标准。证明在纯锌中添加微量稀土元素镧改善锌阳极带机械性能，同时保持必要的电化学性能的工艺方法是有效、可行的。     

Sunlight-activated AlFeO_3/TiO_2 photocatalyst

The photocatalytic oxidation of organic contami-nants(i.e.aromatic hydrocarbons,chlorinated aromat-ics,surfactants and pesticides,etc.)by using TiO2-based semiconductors as photocatalysts in the pres-ence of ultraviolet(UV)or natural sunlight illumina-tio…     

Determination of antioxidants in cosmetics by micellar electrokinetic capillary chromatography with electrochemical detection

A new and efficient method for the determination of antioxidants [Propyl gallate (PG), tert-butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT)] in cosmetics has been established by using micellar electrokinetic capillary chromatography with electrochemical detection (MECC-ED). Under the optimum conditions of the method, all analytes were successfully separated within 13 min at the separation voltage of 18 kV in a 20 mmol/L borate running buffer (pH 7.4) containing 25 mmol/L sodium dodecyl sulfate. The excellent linearity was obtained in the concentration range from 5.0 x 10(-4) to 2.0 x 10(-6) mol/L and the detection limits (S/N = 3) of PG, TBHQ, BHA, and BHT range from 3 x 10(-7) to 3 x 10(-6) mol/L.     

Ethanol‐promoted reductive homocoupling reactions of aryl halides catalyzed by palladium on carbon (Pd/C)

Homocoupling reactions of aryl bromides or iodides proceeded smoothly with palladium on carbon (Pd/C) catalyst, ethanol and base in dimethyl sulfoxide (DMSO) to afford exclusively symmetric biaryls in good to excellent yields. Ethanol was first used as a reducing agent in situ to reduce the Pd²⁺/C species into Pd⁰/C active species to complete the catalytic redox cycle. It was found that ethanol can promote the Pd/C‐catalyzed reductive homocoupling of aryl iodides and bromides efficiently in the presence of base. A reaction mechanism has been put forward and discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

Forming highly fluorescent near-infrared emitting PbS quantum dots in water using glutathione as surface-modifying molecule

We present a new facile procedure for transferring oil-soluble oleic acid-capped NIR-emitting PbS quantum dots (QDs) into water, using hydrophilic thiol ligands as the surface-modifying agents of the primary capping molecules (oleic acid). The influence of exchange of the primary capping molecules with five different types of thiol molecules is investigated. The results show that highly fluorescent water-soluble PbS QDs are obtained using glutathione as a surface-modifying agent (photoluminescence quantum yield (PL QY), >30%); significantly less fluorescent water-soluble QDs were obtained using l-cysteine (PL QY, ~5%); with other three thiol molecules, PbS QDs lose almost completely their fluorescence in aqueous solution. This striking difference among the five thiol molecules may be attributed to the difference in the molecular structure. Next, we explored systematically the conditions of QD water solubilization, storage stability, photostability and cytotoxicity and tested further the resulting water-soluble PbS QDs for the imaging of living animals. The preliminary results from these studies illustrate that our synthesis procedure is very facile and that the as-prepared water-soluble PbS QDs are stable and low-cytotoxic and will be an important potential probe in the imaging of living animals due to free carboxyl and amino groups on the external surface of the QDs.     

Molecular and Mesoscopic Dynamics Simulations on the Compatibility of PLA/Plasticizer Blends

The compatibility of the blend systems for olyactic acid (PLA)/tributyl citrate (TBC) and PLA/glycerol has been studied by molecule and mesoscopic dynamics methods. The results from glass transition temperature simulations showed that the compatibility of PLA/TBC system was better than that of PLA/glycerol, which were consistent with the conclusion obtained from the pair correlation functions. Besides, the behaviors of phase state distribution and evolution process were investigated by mesoscopic dynamics method as well. The results indicated that citrate ester was a better plasticizer than glycerol for PLA.     

Preparation of Hierarchical Cube‐on‐plate Metal Phosphides as Bifunctional Electrocatalysts for Overall Water Splitting

To rationally design efficient and cost‐effective electrocatalysts, a simple but efficient strategy has been developed to directly anchor prussian blue analogue (PBA) nanocubes on cobalt hydroxide nanoplates (PBA@Co(OH)₂) via the in‐situ interfacial precipitation process. Subsequently, the thermal treatment in the presence of sodium hydrogen phosphite enabled the successful transition into metal phosphides with the hierarchical cube‐on‐plate structure. When used as electrocatalytsts, the obtained bimetal phosphides exhibited good bifunctional electrocatalytic activities for hydrogen and oxygen evolution reactions with good long‐term stability. Thus, an enhanced performance for overall water splitting can be achieved, which could be ascribed to the hierarchical structure and favorable composition of as‐prepared bimetal phosphide for rapid electron and mass transfer. The present study demonstrates a favorable approach to modulate the composition and structure of metal phosphide for enhancing the electrocatalytic ability toward water splitting.