Objective To discuss the practicability of application of fault tree analysis in innovation to electrical system of SL-IE radiotherapy simulator.Methods The structure and principle of the electrical system were analyzed,the fault tree for the electrical system was built,and the qualitative analysis and quantitative analysis to the fault tree were made.The electrical system was innovated with effective redundant method,and the qualitative analysis and quantitative analysis were made after innovation.Theoretical analysis and the actual validation were made for the fault tree of electrical system after innovation.Finally,several notes were provided for the innovation to the similar medical equipments.Results The fault tree analysis method was applied to innovating the electrical system,and theoretical analysis indicated that the failure probability to total system reduced obviously.Actually,the actual effect after innovation also validated the correctness of the theoretical analysis.Conclusion Application of fault tree analysis in innovation to electrical system of SL-IE radiotherapy simulator is practical.But,the selection to the innovation event,the change to maintainence after innovation and the event to innovate carefully should be paid attention to.

Brain ischemic tolerance refers to endogenous brain protective mechanism during severe ischemic injury of the body. Ischemia preconditioning is an effective mean to induce brain ischemic tolerance. However, the invasive and ethical limitation made the application of ischemic preconditioning difficult in the clinical practice. Studies found that extracellular signal regulated kinase (ERK) signaling pathway played an important role in the formation of brain ischemic tolerance. Meanwhile, brain ischemic tolerance induced by traditional Chinese medicine (TCM) had its unique advantages. This article reviewed effects of ERK signaling pathway in the inducing of brain ischemic tolerance and TCM intervention in recent years.

Adult albino rats were exposed to simulated high altitude of 5000 m for 72 hours. Mild degree of interstitial pulmonary edema was observed under light microscope. Rats with the left lung excised were subjected to hypoxice of the same degree for 48 hours. On histologic examinations interstitial edema of the right lung was more obvious than that of the previous group. In isolated alveolus or in small groups of alveoli, edematous fluid could he seen.There were perivascular and peribronchial "Cuffs". The former were supposedto be accumulation of edema fluid leaking from the capillaries at the level of alveoli. The latter might be the result of extension of perivascular fluid to the peribrochial space.Excision of the left lung may result in a rise in pulmonary arterial pressure and over perfusion in certain areas remaining lung. Hypoxia may intensify the above changes. Pulmonary hypertension and overperfusion may in force promote the genesis of pulmonary edema.

Objective To explore the changes of human mitochondrial COXI,ND1 and ND6 genes expression induced by ionizing irradiation.Methods Changes of human COXI,ND1 and ND6 gene expression were detected by RT-PCR and Real-time PCR 8 h after the irradiation in human lymphoblastoid cell lines,which were exposed to 1-10 Gy 60Co γ-rays.And the dose-effect relationships between expression changes of the genes and the doses were analyzed.The changes of these three genes expression were also analyzed at different post-radiation time-points between 0.5 h and 72 h after irradiation of 5 Gy in order to explore the time-effect.Results The expression of three genes COXI,ND1 and ND6,showed either the dose-effect or the time-effect after irradiation.The gene expression levels of three genes up-regulated generally and the peak change time-point was 4 h after irradiation.Conclusion Ionizing radiation,msht induce the changes of mitochondrial gene expression,and the gene expression level is up-regulated.

Objective To establish the analysis criteria of nucleoplasmic bridges (NPB) and a dose-response curve of NPB frequencies in human peripheral blood lymphocytes irradiated by 60Co γ-rays.Methods Human peripheral blood samples were collected from three healthy males,and were irradiated with 0,1,2,3,4,5 and 6 Gy of 60Co γ-rays.A cytokinesis-block micronucleus assay was carried out to analyze NPBs and micronuclei (MN) in binucleated cells.Results NPBs in binucleated cells at each dose level of γ-ray was conformed to the Poisson distribution.The dose-response curve of the γ-ray-induced NPB frequencies in human peripheral lymphocytes followed the linear-quadratic model y =(1.39 × 10-3)x2 + (4.94 × 10-3)x (R2 =0.981,P ＜ 0.05).Conclusions The dose-response curve of NPB frequencies in human peripheral blood lymphocytes induced by 0-6 Gy 60Co γ-rays was established.

Objective To compare the proximal femoral locking plate (LPFP) and proximal femoral intramedullary nail-spiral blade (PFNA) in minimally invasive internal fixation for elderly patients with intertrochanteric fractures.Methods One hundred and thirty patients aged over 60 years with intertrochanteric fractures were treated with minimally invasive internal fixation from January 2010 to June 2013,among them LPFP was applied in 69 cases and PFNA in 61 cases.The operation time,the numbers of intraoperative X-ray fluoroscopy,intraoperative blood loss,postoperative flow and decreased postoperative hemoglobin,postoperative complications,medical expenses,fracture healing time,postoperative hip Hariss function score were documented and compared between two groups.Results There were no significant differences in intraoperative blood loss [(132 ± 95) and (110 ± 79) ml],postoperative draining [(44 ± 16) and (41 ± 17) ml],decreased postoperative hemoglobin,fracture healing time [(10.5 ± 1.0) and (10.4 ± 1.5) weeks] and postoperative hip Hariss function score (87 ± 10 and 90 ± 8) between two groups.In LPFP group the number of intraoperative X-ray fluoroscopy (8.1 ±0.8 and 8.6 ± 0.9),hospitalization expenses,postoperative complications (7/69 and 16/61) were less than those in PFNA group (P＜0.05 or 0.01),however,the operation time was longer (P＜0.01).Conclusion LPFP may be a better choice in internal fixation for elderly patients with intertrochanteric fractures.

Objective For developing safe and effective anti-radiation new drugs,the effects of different lipoic acid amino acid salts on radiosensitivity were investigated.Methods The free radical scavenging ability of the above salts was evaluated in Fenton system.CCK-8 assay and flow cytometry assay were performed to evaluate the survival rate of L02 and apoptosis of AHH-1 after γ-ray irradiation,respectively.Results The lipoic acid arginine salt had the best ability of scavenging free radicals in Fenton system with an IC50 of 8.40 μ moL/ml.The survival assay showed that lipoic acid amino acid salts had better stability and equal ability in radioprotection (P ＞ 0.05) compared with lipoic acid.The apoptosis assay indicated that all lipoic acid amino acid salts could inhibit radiation-induced apoptosis,where lipoic acid arginine salt was more effective (t =-6.67,P ＜ 0.01).Conclusions Lipoic acid arginine salt has good radioprotection effect on L02 and AHH-1 cells by scavenging free radicals.

Objective To explore if the occupational exposure to low dose thorium could induce adaptive response in peripheral lymphocytes.Methods 40 individuals.who exposed to thorium and rare earth mixed dust(exposure group) or control in Baotou Steel Plant, were selected, and chromosome aberrations were analyzed.Then the peripheral blood samples were irradiated in vitro with 2 Gy60Co γ-rays,and unstable chromosome aberration or DNA stand breakage analysis using single cell gel electrophoresis was performed. Results The dicentrics before 2 Gy exposure in exposure group was higher than that in control(P>0.05). But the dicentries after 2 Gy exposure in exposure group was lower than that in control,but not significantly (P>0.05).The tricentrics in exposure group was significantly lower than that in control(U=3.1622, 0.0ol

Objective To explore the influences of the final concentration and adding time of Cytochalasin-B (Cyt-B) on radiation-induced nucleoplasmic bridges (NPB) in cytokinesis-block assay.Methods Hunan peripheral blood samples were divided into 5 final concentration groups (group 2,4,6,8,10 μg/ml) according to different final concentrations of Cyt-B.Moreover,blood samples were divided into 4 adding time groups (group 0,28,40,44 h) according to different adding times of Cyt-B.Blood samples were irradiated with 0 (sham irradiation) and 2 Gy 60Co-rays in vitro,at a dose rate of 1 Gy/min.A cytokinesis-block assay was carried out to prepare NPB samples.The percentages of mononucleated,binucleated and multinucleated cells,as well as the frequencies of NPB and micronucleus (MN) in binucleated cells were analyzed using an optical microscope.Results Nuclear division index (NDI) and the percentages of binucleated cells increased with increased concentration of Cyt-B,and decreased with delayed adding time of Cyt-B (except group 0 h) in both final concentration groups and adding time groups.After exposed to 2 Gy,NPB frequencies were no significant difference (except group 0 h).MN frequencies had the trend of decreased with the increased concentration of Cyt-B,but no significant difference with adding time of Cyt-B.Conclusions In cytokinesis-block assay,different final concentration and adding time of Cyt-B may induce to the variation of NPB frequencies,but there was no significant difference.Appropriate increased final concentration or ahead adding time of Cyt-B can increase the percentage of binucleated cells that help to improve the efficiency of analysis.

Objective To investigate the dose response of S100A4 gene expression in the irradiated lymphoblastoid cells AHH-1 at different time points post irradiation.Methods AHH-1 cells was exposed to different doses(0,1,3,5,8,10,15 and 18 Gy)of 60Co γ-rays,and its mRNA levels of S100A4 was detected by reverse transcription PCR and real-time PCR at 4,8,12,24,48 and 72 h after irradiation.Results Within the range of applied doses,the level of S100A4 gene expression was upregulated with a good dose-response (R2 =0.79-0.93,P ＜ 0.05) and had obvious difference at different time points (F =8.91,P ＜ 0.01).Conclusion S100A4 gene expression at transcriptional level could be detected easily and had optimum dose-responses at certain time points after irradiation,and hence is applicable as a dosimeter.