The impeller profile, which is one of the most important factors, determines the creation of shear stress which leads to blood hemolysis in the internal flow of centrifugal blood pump. The investigation of the internal flow field in centrifugal blood pump and the estimation of the hemolysis within different impeller profiles will provide information to improve the performance of centrifugal blood pump. The SST kappa-omega with low Reynolds correction was used in our laboratory to study the internal flow fields for four kinds of impellers of centrifugal blood pump. The flow fields included distributions of pressure field, velocity field and shear stress field. In addition, a fast numerical hemolysis approximation was adopted to calculate the normalized index of hemolysis (NIH). The results indicated that the pressure field distribution in all kinds of blood pump were reasonable, but for the log spiral impeller pump, the vortex and backflow were much lower than those of the other pumps, and the high shear stress zone was just about 0.004%, and the NIH was 0.0089.
Assisted Circulation ; Heart-Assist Devices ; Hemolysis ; Humans ; Models, Theoretical ; Stress, Mechanical

Objective To investigate the value of mammography (MAM),ultrasound (US)and MRI in the diagnosis of breast tumors using a Meta-analysis.Methods A systematic search of relevant literatures was done from CNKI,CBM,VIP,EMBASE OvidSP,PubMed and The Cochrane Library databases.Some related literatures about MAM,US and MRI in the diagnosis of breast tumors and the quality was evaluated,and the available information was extracted.The Meta-analysis was then performed by a Meta-disc 1.4 software,and a Review Manager 5.3 software was used to calculate the summary receiver operating characteristic curves and the area under the curve.Results The diagnostic effect of the MAM+US+MRI was significantly higher than that of mammography or ultrasound (P <0.05).The MAM study heterogeneity among sources was affected by whether it based on BI-RADS diagnostic criteria,and US study heterogeneity was affected by average age of patients.However,the MRI heterogeneity between studies displayed by regression analysis was not affected by each covariate.The diagnostic sensitivity and specificity were 76% (95%CI:0.73-0.79)and 72% (95%CI:0.69-0.75)for MAM,85% (95%CI:0.82-0.87)and 70% (95%CI:0.67-0.73)for US,and 95% (95%CI:0.93-0.96)and 72% (95%CI:0.69-0.75)for MRI,respectively.And the area under curve (AUC)of summary receiver operating characteristic (SROC)curve was 82.0%,88.5% or 97.4%, respectively.Moreover,the AUC of combined three methods together was 98.3%.Conclusion The value of MAM,US and MRI in diagnosis of breast tumor is higher,and the highest one exists when the combined three methods together are used.

Abstract A method for determination of trace mercury in water was established. The trace mercury in water was adsorbed quantitatively by activated carbon, and then determined by electrical pyrolysis atomic absorption spectrometry. In comparison with the detection methods of total mercury in water at present, the method avoids the steps of digestion, reduces the mercury pollution and the loss of the mercury, and is simple in operation. The effects of particle size of activated carbon, acid treatment method, acid medium and enrichment time on the enrichment efficiency were investigated. The effect of the pyrolysis temperature and the interfering ions on the determination results was investigated. Three standard addition procedures including activated carbon blank addition, solution blank addition and environmental water samples addition were studied. Regression correlation coefficients of three standard curves drawn by the three methods reached 0 . 9999 . The slope of the three standard curves had no difference by statistical test, indicating that the determination of mercury in environmental water samples under the experiment conditions was not interfered by the coexistent elements, which showed that the activated carbon blank addition method could be directly used for preparing standard curve of the method. The water samples containing 5 ng/L and 50 ng/L mercury were determined by the method, and the relative standard deviation were 7. 2% and 4. 2% (n=11), respectively, with a detection limit of 1. 2 ng/L. The recovery experiment was carried out after adding 10 ng/L mercury to the surface water and tap water samples, and the recoveries were between 92. 0% and 103. 0%. Analysis results were compared with ICP-MS as control and the deviation of the two methods were between 2 . 9% and 3 . 4%, indicating that the method was accurate and reliable, and had good precision.

ThevolatilecompositionsofDuchesneaindicawerestudiedbyheadspacesolid-phase microextraction ( HS-SPME ) , soxhlet extraction ( SE ) , ultrasonic assistant extraction ( UAE ) and steam distillation ( SD) coupled with gas chromatography-mass spectrometry ( GC-MS) . The experimental parameters of HS-SPME, including fiber type, extraction temperature, extraction time and desorption time were investigated. 47, 32, 16 and 16 compounds were identified by HS-SPME, SD, SE and UAE extracting methods, respectively. 66 compounds were obtained in total, among which 47 compounds were first reported in Duchesnea indica. The experimental results showed that terpenoids were the most abundant compositions in HS-SPME and SD, but acids accounted for 61. 44% and 69. 54% of the total content obtained by SE and UAE.

Objective To study the possibility and effects of fixed TH glue embolization through gastroesophageal and percutanenous. Methods Forty-six patients of bleeding esophageal varices were divided randomly into two groups: in treatment group:twenty-five patients treated with TH glue (?-cyanoacrylate) embolization PTVE+PSE. Absolute alcohol-cilia steel ring-TH glue ,but in control group, 21 patients of esophageal varices by variceal ligation. Analysis the percentage of rebleeding, death rate and improvement rate of liver functions. Results In the treatment group,the rebleeding of gastroesophageal varices was 8.7%, the percentage of death was 4.3%, the function of liver improved by 87.0% . In the control group, the percentage of rebleeding was 28.6%, death rate was in 19.1% and liver function improved by 48.0%. Conclusion PTVE+PSE fixed TH glue embolization is safe, less destroyed. Compared with dense edoscopic ligation, DEVL, the advantage is lessre bleeding, less death rate and higher liver function improvement rate. It is an effective method for gastroesophageal varices.

Objective To investigate the surgical methods and the differences of postoperative complications in esophageal canccr patients aged 60 years and over undergoing different operation models.Methods A total of 542 elderly esophageal cancer patients who underwent thoracic surgery at our hospital between January 2010 and December 2016 were enrolled.Patients were divided into 4 groups:left thoracic incision operation group (n =202),lvor-Lewis two incisions operation group (right chest posterolateral and upper abdomen median) (n=251),three incision operation group (left neckright chest-abdominal midian (n =29),and McKneown under-endoscope minimally invasive operation group (n=60).Clinical data,including the postoperative days,numbers of lymph nodes dissection,pulmonary infection,serous membrane fluid,arrhythmia,chylous fistula,gastric emptying dysfunction and anastomotic leakage,were retrospectively compared between the four groups.Results There was no significant difference in the postoperative days,serous membrane fluid,arrhythmia,chylous fistula,gastric emptying dysfunction and anastomotic leakage (P ＞ 0.05).The number of lymph nodes dissection in Sweet group,Ivor-Lewis group,Mckeown operation group and minimally invasive Mckneown group were (12.9±7.4)、(19.3±8.6)、(14.3±6.9)and(15.4±7.3)respectively.The number of lymph nodes dissection was more in the Ivor-Lewis group than in the other three groups (F =23.915,P =0.000).Sweet group,Ivor-Lewis group,Mckeown group and minimally invasive Mckneown group were 31.7％、40.2％、24.1％ and 50.0％ respectively.The incidence of pulmonary infection was higher in the minimally invasive surgery group than in the other three groups (x2 =9.941,P =0.019).Conclusions Ivor-Lewis surgery is more effective in lymph nodes dissection and has a lower incidence of complications in elderly esophageal cancer patients.The minimally invasive surgery group has a higher incidence of pulmonary infection than in the other surgical groups,which may be related with the immaturity of endoscopic technique.