Selective Hydrodeoxygenation of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran over Heterogeneous Iron Catalysts.

This work provided the first example of selective hydrodeoxygenation of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) over heterogeneous Fe catalysts. A catalyst prepared by the pyrolysis of an Fe-phenanthroline complex on activated carbon at 800 °C was demonstrated to be the most active heterogeneous Fe catalyst. Under the optimal reaction conditions, complete conversion of HMF was achieved with 86.2 % selectivity to DMF. The reaction pathway was investigated thoroughly, and the hydrogenation of the C=O bond in HMF was demonstrated to be the rate-determining step during the hydrodeoxygenation, which could be accelerated greatly by using alcohol solvents as additional H-donors. The excellent stability of the Fe catalyst, which was probably a result of the well-preserved active species and the pore structure of the Fe catalyst in the presence of H2 , was demonstrated in batch and continuous flow fixed-bed reactors.

Recent advances of chitosan nanoparticles as drug carriers.

Chitosan nanoparticles are good drug carriers because of their good biocompatibility and biodegradability, and can be readily modified. As a new drug delivery system, they have attracted increasing attention for their wide applications in, for example, loading protein drugs, gene drugs, and anticancer chemical drugs, and via various routes of administration including oral, nasal, intravenous, and ocular. This paper reviews published research on chitosan nanoparticles, including its preparation methods, characteristics, modification, in vivo metabolic processes, and applications.

Recent advances in PEG-PLA block copolymer nanoparticles.

Due to their small particle size and large and modifiable surface, nanoparticles have unique advantages compared with other drug carriers. As a research focus in recent years, polyethylene glycol-polylactic acid (PEG-PLA) block copolymer and its end-group derivative nanoparticles can enhance the drug loading of hydrophobic drugs, reduce the burst effect, avoid being engulfed by phagocytes, increase the circulation time of drugs in blood, and improve bioavailability. Additionally, due to their smaller particle size and modified surface, these nanoparticles can accumulate in inflammation or target locations to enhance drug efficacy and reduce toxicity. Recent advances in PEG-PLA block copolymer nanoparticles, including the synthesis of PEG-PLA and the preparation of PEG-PLA nanoparticles, were introduced in this study, in particular the drug release and modifiable characteristics of PEG-PLA nanoparticles and their application in pharmaceutical preparations.

[Repair of the soft tissue defect of the fifth finger with a reversed ulnar fasciocutaneous flap from the fifth metacarpal side].

OBJECTIVE: To introduce a method by reversed ulnar fasciocutaneous flap incised form the ulnar side of the fifth metacarpal area for repairing the soft tissue defect of the fifth finger. METHODS: From May 2001 to September 2001, ten patients with the soft tissue defects of the thenar side, dorsal side or ulnar side of the fifth finger were treated with the reversed ulnar fasciocutaneous flap incised from the fifth metacarpal area. The axial line of the flap was the line from ulnar side of the head of the fifth metacarpal bone to the pisiform level. The revolving point of the flap pedicle was 0.5-1 cm near the proximal end of the metacarpal-phalangeal joint.The area of the flap was form 5.0 cm x 3.5 cm to 1.5 cm x 1.0 cm. RESULTS: All flaps of the ten cases were alive. 5-7 months followed-up show that, after operation, the flap present sensation in 6-12 mm, with soft texture and good appearances. CONCLUSIONS: The advantages of this operative method were as follows: the reversed ulnar fasciocutaneous flap of the fifth metacarpal area have reliable blood supply, it was easily dissected and with good texture. So far this kind of flap is a good choice in repairing the soft tissue of the fifth finger.