To evaluate the fatigue behavior of nitinol stents, we used the finite element method to simulate the manufacture processes of nitinol stents, including expanding, annealing, crimping, and releasing procedure in applications of the clinical treatments. Meanwhile, we also studied the effect of the crown area dimension of stent on strain distribution. We then applied a fatigue diagram to investigate the fatigue characteristics of nitinol stents. The results showed that the maximum strain of all three stent structures, which had different crown area dimensions under vessel loads, located at the transition area between the crown and the strut, but comparable deformation appeared at the inner side of the crown area center. The cause, of these results was that the difference of the area moment of inertia determined by the crown dimension induced the difference of strain distribution in stent structure. Moreover, it can be drawn from the fatigue diagrams that the fatigue performance got the best result when the crown area dimension equaled to the intermediate value. The above results proved that the fatigue property of nitinol stent had a close relationship with the dimension of stent crown area, but there was no positive correlation.
Alloys ; Computer Simulation ; Equipment Failure Analysis ; Finite Element Analysis ; Stents

Objective To evaluate different treatment modaltities for limited (local) hepatic metastasis in patients of colonic carcinoma Methods We conducted a retrospective analysis on 81 cases of colonic cancer suffering from hepatic local metastasis from 1987 to 2000 Results The 1、3、5 year survival rate was 85%、 46% and 32% respectively for patients underwent resection of metastatic liver cancer, and 26%、 0 and 0, respectively for those not having the metastatic liver cancer resected ( P 0 05) Conclusion Resection or ablation therapy promises a much longer long term survival than do nothing in colonic cancer patients with local liver metastatic tumor

Objective To discuss and to compare the curative effects of interventional embolization with different embolic agents in treating giant hepatic cavernous hemangiomas. Methods From 2008 to 2010, a total of 30 cases with clinically proved hepatic cavernous hemangioma were treated with interventional embolization. According to the embolic agents used , the patients were divided into pingyangmycin-lipiodol emulsion mixed with sodium alginate microspheres group(PLE+KMG, group A, n=15) and pingyangmycin-lipiodol emulsion group (PLE, group B, n=15). CT scanning was performed one, 3, 6, 12 months after the treatment to evaluate the curative effect. Results The technical success rate was 100%in both groups. The mean PLE dose used in group A and B was (10.9 ± 5.2) ml and (11.4 ± 4.9) ml respectively, the difference between the two groups was not significant (P > 0.05). CT reexamination performed one, 3, 6 months after the treatment showed that a reduction in tumor volume over 50%in group A was seen in 9, 11 and 14 cases respectively, while in group B it was 0, 3 and 5 cases respectively (P <0.05). One week after the procedure, the degree of pain in patients of group A was more severe than that in patients of group B, the difference between the two groups was statistically significant (P < 0.05). Slight abnormal hepatic function was seen in some patients of both groups, which presented mainly as an elevation of aminotransferase, which returned to normal after symptomatic medication. Follow-up with questionnaire indicted that patients of group A were more satisfied with the treatment than the patients of group B. Conclusion Transhepatic infusion of pingyangmycin-lipiodol emulsion is a safe and effective treatment for giant cavernous hemangioma of the liver. Combination use of pingyangmycin-lipiodol emulsion and sodium alginate microspheres can obviously reduce the tumor size mainly in the first and the third month after the treatment, besides it produces instant clinical effect although the pain is more severe than in patients treated with pure pingyangmycin-lipiodol emulsion.

Objective To analyze the plaque distribution of abdominal aorta and its branches by multislice spiral CT angiography (MSCTA).Methods 145 patients recommended to abdominal enhanced CT were randomly selected in this investigation,and divided into three groups according to their age,i.e.,young,middle and old-aged group.CTA was performed with the use of multiple planar reconstruction(MPR),volume rendering (VR)and vessel probe(VP)technology.Results 124 patients with atherosclerotic plaques of abdominal aorta and all its branch-vessels,the incidences of the three groups were 9.7%(14 cases),30.3%(44 cases)and 45.5%(66 cases)respectively(P <0.005).It showed that calcified plaques were detected in a total of 1 50 in 302 plaques of all the branch-vessels.230 plaques(76.2%)were detected in abdominal branch-vessels of grade 1,of which,the incidences of superior mesenteric artery plaques was the highest(32.4%).Of the 54 plaques(1 7.9%)detected in abdominal branch-vessels of grade 2,the incidence of splenic artery plaques was the highest(13.8%).In abdominal branch-vessels of grade 3,the plaques were mainly distributed in splen-ic lobial artery.The splenic artery plaques mainly spreaded in the middle segment,while other plaques were mostly in peristome and proximal segment of vessels.The incidences of plaques in the three branches were 47.6%(69 cases),1 5.2%(22 cases),and 9.0%(13 cases)respectively(P <0.005).Conclusion The incidences of atherosclerotic plaques are higher in the middle and aged people. The plaques of the three abdominal branch-vessels mainly distribute in the peristome and proximal segment,and are much likely to be detected in abdominal branch-vessels of grade 1.

In view of gemcitabine resistance has limited clinical activity of gemcitabine as a cellulotoxic drug in pancreatic cancer patients, this study is designed to investigate the effect of emodin on the sensitivity of pancreatic cancer to gemcitabine as well as its mechanism. After gemcitabine-resistant pancreatic cancer cell line (SW1990/GZ) was established by escalating doses of gemcitabine serially in pancreatic cancer cell line (SW1990). The cellular proliferation was detected by cell counting kit-8 (CCK-8) assay. Flow cytometry (FCM) was used to determine apoptosis of pancreatic cancer cells. The activity of NF-kappaB in pancreatic cancer cells was measured by electrophoretic mobility shift assay (EMSA). Western blotting was used to detect the protein expression of Bcl-2 and Survivin in SW1990/GZ cells. Metastatic model simulating human pancreatic cancer was established by orthotopic implantation of histologically intact human tumor tissue into pancreatic wall of nude mice. Also, immunohistochemistry was used to detect the positive expression of Ki-67, NF-kappaB, Bcl-2 and Survivin in the tumors. The results show that pretreatment of cells with emodin followed by gemcitabine induced a higher percentage of growth inhibition and apoptosis of pancreatic cancer cells than that of gemcitabine alone. In addition to in vitro results, emodin in combination with gemcitabine is much more effective as an antitumor agent compared to either agent alone in the orthotopic tumor model. Further study showed that the emodin with or without gemcitabine significantly down-regulates NF-kappaB and its regulated molecules such as Bcl-2 and Survivin proteins both in vitro and in vivo. It is concluded that inactivation of NF-kappaB signaling pathway by emodin resulting in the chemosensitization of pancreatic cancer to gemcitabine, which is likely to be an important and novel strategy for the treatment of pancreatic cancer.

Flashing light effect on microalgae could significantly improve the light efficiency and biomass productivity of microalgae. In this paper, the baffles were introduced into the traditional flat plate photobioreactor so as to enhance the flashing light effect of microalgae. Making Chlorella sp. as the model microalgae, the effect of light intensity and inlet velocity on the biomass concentration of Chlorella sp. and light efficiency were evaluated. The results showed that, when the inlet velocity was 0.16 m/s, with the increase of light intensity, the cell dry weight of Chlorella sp. increased and light efficiency decreased. With increasing the inlet velocity, the cell dry weight of Chlorella sp. and light efficiency both increased under the condition of 500 μmol/(m2 x s) light intensity. The cell dry weight of Chlorella sp. cultivated in the novel flat plate photobioreactor was 39.23% higher than that of the traditional one, which showed that the flashing light effect of microalgae could be improved in the flat plate photobioreactor with inclined baffles built-in.
Biomass ; Chlorella ; growth & development ; Culture Techniques ; instrumentation ; Light ; Microalgae ; growth & development ; Photobioreactors

Utilizing the third-order polynomial curve fitted to the experimental data, which represents the relationship between cerebral blood flow (CBF) and mean artery blood pressure (MABP), we constructed a lumped-parameter dynamic model with 5 elements. In this model; the resistance is not constants it is determined by the fitted curve. We simulated the process of CBF autoregulation numerically by solving the govern equation of this model and got quite accurate results. Furthermore, we studied the influence of hemodynamic parameters on the CBF autoregulation by this model and proved that the characteristic resistance is the most important factor.
Blood Flow Velocity ; Blood Pressure ; physiology ; Cerebrovascular Circulation ; physiology ; Homeostasis ; Humans ; Hypotension ; physiopathology ; Models, Biological ; Oxygen ; metabolism ; Regional Blood Flow

Objective To investigate the relationship between carotid arteriostenosis and atheromatous plaques with cerebral in-farction.Methods Cervical spiral CT angiography of 56 cases with cerebral infarction and 49 cases without cerebral infarction were retrospectively analysed .The difference between the two groups was compared with regard to the distribution ,nature of plaques and the degree of carotid artery stenosis.Results Of 56 patients with cerebral infarction,126 atheromatous plaques were detected in 42 patients,of which 39 were soft,34 were calcified,53 exhibited a combined nature of both calcified and soft plaque and 7 cases were plaque ulcerations (soft plaque and mixed plaque accounted for about 73%).Plaque location for carotid artery was in the bifurcation. 102 carotid arteries stenosis were found in 38 patients,which included mild stenosis in 29,moderate in 40,severe in 27 and occlusion in 6(moderate and severe stenosis accounted for about 65.7%).In the control group,28 plaques were detected in 1 1 cases,of which 6 were soft,13 were calcified and 9 exhibited a combined nature of both calcified and soft plaque.1 1 carotid arteries stenosis were found in 7 patients,included mild stenosis in 10,moderate in 1.A significant difference (P <0.05)in carotid arteriostenosis and ath-eromatous plaques between the two groups was found.Conclusion Carotid plaques and stenosis are important risk factors of cerebral infarction.Multi-slice spiral CT angiography(MSCTA)has important value in analysis of carotid artery stenosis and atheroderotic plaques.

Objectives To enhance the diagnosis of cervical epithelial neoplasia and cervical cancer at the early stage and to prevent cervical invasive carcinoma by analyzing the cervical/vaginal cytology or histopathologic results of Atypical squamous cells of undetermined significance (ASCUS).Methods From January 2014 to June 2015,a total of 4579 cases were selected in the census of gynecological diseases in Qiannan Hospital.TBS classification (the bethesda system) showed that 164 cases of ASCUS or above were found using cervical/vaginal cytology with live tissue under colposcopy.Results Among 164 cases,75 was cervical intraepithelial neoplasia level 3 (CINⅢ) accounting for 54.7％.Sixty-three cases of ASCUS and 16 of CINⅡ or above were found among patients at the age of 39 or younger (25.4％).A hundred and one cases of ASCUS and 59 of CINⅡ or above were found among women older than 40 (58.41％).Among patients with liquid-based cervical cytology positive,those older than 40 had higher risk.Liquid-based cervical cytology examination was divided into 5 levels.Spearman rank correlation analysis was applied with correlation coefficient (r =1) and positive correlation was shown (P =0.000,P＜0.01).The difference was statistically significant.The higher level of liquid-based cervical cytology examination level was required,the higher risk of cervical cancer was seen among women.Corclusion The use of liquid-based cervical cytology examination can help grassroots doctors improve CIN diagnosis rate and prevent cervical invasive carcinoma among women in the countryside.

Objective To explore the prevention and treatment of lymphorrhagia due to lymph node dissection in gastric carcinoma. MethodsClinical data of 743 patients undergoing radical gastrectomy plus lymphadenectomy from January 1997 to March 2004 were analyzed retrospectively. ResultsThe patients in D3 or D4 lymphadenectomy suffered from a higher lymphorrhagia rate than those in D2 lymphadenectomy(P