Carrier transport in quantum dot quantum well microstructures of the self-assembled CdTe/CdS/ligand core-shell system.

The study on the quantum dot quantum well (QDQW) microstructure modified by choosing different ligands containing a sulfhydryl group is of significance because it enables one to regulate photoexcited free charge carriers' (FCCs') transport behaviours in high-quality CdTe/ligand QDs via a self-assembled way. The photoelectron characteristics of ligand-capped CdTe nanoparticles were probed by a combination of surface photovoltaic (SPV) and photoacoustic technologies, supplemented by a computer simulation method of the CASTEP module. The experiment reveals that the D-value ΔEWi obtained by the associated two parameters of the SPV spectroscopy was closely related to the quantum confinement energy in the self-assembled CdTe/CdS/ligand core-shell system. In the paper the D-value was termed the depth of QWs, which were buried in the space charge regions located in the graded-band-gap and on either side of the shell-CdS. Obvious resonance quantum tunnelling may occur in the energy band structure with deep QWs on using certain ligands, resulting in an extended diffusion length of the FCCs on illumination of the photon energy hν ≥ Eg, core-CdTe, and in a strong SPV response at a specific wavelength region. In addition, the carrier-longitudinal optical phonon interaction is the reciprocal of the carriers' lifetime. The d-frontier orbital in the graded-band-gap plays an important role in both the microstructure and the resonance quantum tunnelling of the QDQW system according to the CASTEP calculations.

Study of human acellular amniotic membrane loading bone marrow mesenchymal stem cells in repair of articular cartilage defect in rabbits.

The aim of this study was to investigate the repair effect of human acellular amniotic membrane (HAAM) loading bone marrow mesenchymal stem cells (BMSCs) on articular cartilage defect in rabbits. Rabbit BMSCs were isolated and cultured, and they were then inoculated on HAAM to prepare the complex of HAAM and BMSCs. Twenty-four rabbits were randomly divided into groups A and B, with 12 animals in each group. The left and right sides were used as the experimental and control sides, respectively. The models of bilateral articular cartilage defect were established. The defect areas on the experimental side in groups A and B were implanted with the complex of HAAM and BMSCs and HAAM alone, respectively. The control sides of the two groups were not implanted with any material. In the 8th and 12th week after surgery, gross observation, histological examination and cartilage defect scoring were performed. In the 8th and 12th postoperative week, gross observation and histological observation showed that dense cartilage-like cells appeared in group A but not in group B, indicating preferable cartilage repair. The cartilage defect score on the experimental side in group A was 5.31 ± 0.68 in the 8th week and 3.23 ± 0.52 in the 12th week, and that in group A was significantly lower than in group B (P < 0.05). HAAM loading BMSCs has a good repair effect on articular cartilage defect under an in vitro environment.

[Detection and significance of HBV antigen in gallbladder tissue].

In order to know whether HBV antigen exists in extrahepatic tissue, we detected HBV antigen in liver and gallbladder tissue obtained from 31 cases with HBV chronic liver disease (17 active cirrhosis, 14 chronic hepatitis) by using polyclonal antibody and ABC method. All cases were diagnosed by biopsy (n = 12) or autopsy (n = 19), 25 were males and 6 females, the average age was 45.6 years. The results showed that in the liver tissue 30 cases were (96.77%) HBsAg positive and 15 cases (48.39%) HBcAg positive. In the gallbladder tissue 18 cases (58.06%) were HBsAg positive and 8 cases (25.81%) HBcAg positive. Although 26 cases had pathological changes in the gallbladder, the changes had no relation with the existence of HBV antigen. Their symptoms and signs were also not related with the existence of HBV antigen in the gallbladder. Among the 31 cases, 19 died. The cause of death was severe hepatic complication, but not the pathological change of the gallbladder. The results suggest that pathogenesis of HBV in extrahepatic tissue needs to be elucidated.

[Fetal hepatocellular suspension transfusion in the treatment of chronic active hepatitis B].

Using the paired method and the same observation standard, 35 pairs of patients (70 patients) suffering from chronic active hepatitis B were treated with FHST or glucose in 5 hospitals. After three months of treatment a significant decrease in ALT, TTT and a significant increase in PTA were observed in FHST group as compared with the control group (p less than 0.05-0.01). There was no significant change in HBVM in both groups. No side effect was observed during the period of treatment.