ABSTRACT
The fabrication and experimental test results were presented for a micro-electro-mechanical systems (MEMS)-based gas chromatography column. Compared with conventional column, this micro-gas chromatography column is suitable for on-line analysis and monitoring because of the small size, rapid analysis and other characteristics. These 0.5, 1 and 3 m GC columns were fabricated using a deep reactive-ion etching (DRIE) and were coated the stationary phase via a dynamic coating procedure. These GC columns perfectly separated the mixture of benzene, toluene and o-xylene in less than 200 s, where, the 3.0 m of the GC column achieved) a high resolution of 14.3 between toluene and o-xylene and yielded approximately 6160 plates. Moreover, the effect of separation performance for different column length were examined and compared. These GC columns are suitable for the application of a variety of disciplines, including environmental analysis, methane gas probes and homeland security.
ABSTRACT
The interaction between the anti-Ractopamine (Rac) monoclonal antibody and the Rac derivation immobilized on the sensor chip surface was studied with surface plasmon resonance (SPR) biosensor. A continuous detection method based on the linear response during the association phase was developed. The sensor chip surface was regenerated after several tests performed continuously, thus the detection step was simplified and the life span of the chip was prospected to be prolonged. The detection was performed as an inhibitive immunoassay. The mixture of anti-Rac monoclonal antibody and the sample flowed over the surface with Rac derivation was immobilized. The relative response was in inversely proportion to the concentration of Rac. The detection limit was less than 4 μg/L with a detection time of 15 min.
ABSTRACT
Objective To evaluate the effects of the synthetic osteogenic growth peptide (sOGP) on the healing of tibial fractures in rabbits. Methods Fifty two tibial fracture models were produced in the tibiae of New Zealand white rabbits and immobilized with a 2 mm diameter Kirschner wire as intramedullary nail and grouped by random. sOGP was administered to experimental animals by intravenous injection (0.5 ?g?kg-1 ?d-1) from the first day after surgery until the day before sacrifice, while the control animals were injected with saline solution. 3-5 rabbits from each group were killed at 1, 2, 3, 4, 6 weeks after fracture. The serum was obtained to determine the level of ALP and BGP by biochemistry and RIA respectively. The bone mineral density at fracture healing site was detected by DXA, the anteroposterior and lateral radiographs were taken, the histological examination was done and quantitative analysis of the callus area and the relative amounts of bone, cartilage, and fibrous tissue in the callus of each section were calculated by computer program. The 6 weeks tibial sample were tested biomechanically by universal material test machine. Results The serum ALP, BGP level were higher in sOGP injected groups than those in the controls. All tibia osteotomies healed uneventfully on radiograph. The area of the external callus was larger in the experimental groups than that in controls at 3,4 weeks after fracture; the average area was 265.44 mm2 at 3 weeks, 233.10 mm2 at 4 weeks in the experimental groups compared with that of 209.95 mm2 at 3 weeks and 209.21 mm2 at 4 weeks in the controls. The average bone mineral density at fracture healing site was slightly greater in the experimental group at 3,4,6 weeks, and the difference of the bone mineral density at 4 weeks has statistical significance (P