ABSTRACT
Objective To establish the model of goat intervertebral disc degeneration （IDD） induced by controllable axial compressive stress and evaluate its imaging and pathological characteristics. Methods Twenty goats were randomly divided into 4 groups (control group, 4-week pressure group, 8-week pressure group, 12-week pressure group, n=5, 40 N pressure). Disc height index (DHI) was used to evaluate the change of intervertebral disc height by X-ray, Pfirrmann classification method was used to observe the degree of intervertebral disc degeneration by magnetic resonance imaging (MRI), and histopathological observation and evaluation for intervertebral disc were conducted by HE staining and immunohistochemistry. Results DHI in control group showed no significant changes with the extension of pressure time, while DHI in the experimental group gradually decreased. There was no significant change in Pfirrmann classification in control group. In experimental group, with the extension of time, the higher the degeneration aggravated with the Pfirrmann classification increasing. In experimental group, HE staining showed that the disc nucleus pulposus decreased in volume and nucleus pulposus cells, which were gradually replaced by fibrous tissues. Immunohistochemical staining showed that type I collagen in the nucleus pulposus gradually increased, type Ⅱ collagen gradually decreased, and intervertebral disc degeneration occurred. Conclusions A certain axial compressive stress can lead to degeneration of goat lumbar intervertebral disc, and the degree of degeneration is gradually increased with the extension of time.
ABSTRACT
The transportation of electron is inseparable from vacuum environment. The maintenance of the vacuum system of Elekta linear accelerator depends on two sputtering ionic pumps at the gun end and the target end. The traveling wave acceleration were used in Elekta linear accelerators. And the design of the electron gun filament is detachable. Because of these two reasons, the vacuum stability is relatively weak. Only two vacuum values are used to reflect the operation state of the whole vacuum system, which causes a few failures but will not trigger a the machine interlock. Considering the complexity of whole vacuum system, the problem of vacuum caused by the failure of various components in vacuum system is analyzed in this paper. It is hoped that some useful repairing experience and suggestions for the maintenance engineers of linear accelerator to solve the vacuum fault and rebuild the vacuum can be provided quickly.
Subject(s)
Electrons , Particle Accelerators , Radiotherapy Dosage , VacuumABSTRACT
BACKGROUND: In the investigation of promoting fracture healing, exogenous growth factor is very instable, expensive and inaptitude to extend generally, so how to promote the expression of endogenous growth factor effectively is worthy of further studies. OBJECTIVE: To study the effects of Shenggu injection(SGI) on the expression of basic fibroblast growth factor(bFGF) and vascular endothelial growth factor(VEGF) in fracture healing. DESIGN, TIME AND SETTING: The randomized controlled animal experiment was performed at the Orthopaedic laborary, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology between July 2007 and August 2008. MATERIALS: Sixty clean male SD rats aged 3 months were enrolled. The components of 1 g/L SGI were angelica sinensis, ground beetle, barrenwort, etc., provided by Hubei TCM hospital. METHODS: After the tibial bone fracture model was established, the SD rats were divided into two groups with 30 rats in each group, experimental group and control group. The experimental group was injected with SGI at the bone stumps, the other group was injected with the same volume of saline. This was carried once every 2 days with 0.2 mL once. Five SD rats of each group were executed to get bony callus at the 1st, 2nd, 3rd, 4th, 5th and 6th weeks after operation. MAIN OUTCOME MEASURES: The methods of immunohistochemistry were used to detect the protein expression level and differences of bFGF and VEGF in the callus tissue during different periods of fracture healing. RESULTS: The immunohistochemistry findings showed that the expression levels of bFGF and VEGF in the experimental group were higher than those in the control group in each period. CONCLUSION: SGI can improve the expression levels of bFGF and VEGF in callus tissue during fracture healing, which is maybe one of the mechanisms of SGI to promote the healing of fracture.
ABSTRACT
Object To investigate the process of flocculation impurity removal for the Anti-flu Nose Drops (AND). Methods Five kind of effective factors on flocculation impurity removal with the index of clarifying results were studied. Comparative tests for Shandong Yaosheng 1 + 1 (Ⅲ) clarificant, 50% alcohol precipitation, and 75% alcohol precipitation were performed with the quantitative index of gardenoside contents, the qualitative index of magnolin and gardenoside TLC chromatograms. The optimum process condition was selected out. Results Under the optimum process condition of flocculation impurity removal, gardenoside contents in the flocculation group is higher than those in 50% , 75% alcohol groups. TLC chromatograms showed that the spots of flocculation group are the same as those in the original liquid group. Conclusion Shandong Yaosheng 1 + 1 (Ⅲ) clarificant has following advantages; high reserved rate of active components, simple operation, cheap cost, stable process, which is a ideal method for the impurity removal.