Based on the analysis of the influence of the valve pivot distance on the performance of mechanical heart valve (MHV), such as the valve opening and closing features, flow field characteristics and the valve assembly properties, value constraints of the valve pivot distance were established, and the reasonable valve was obtained by means of the finite element method. It can be shown that the central flow characteristics of the valve could be enhanced with the increasing of the ratio of pivot distance to valve inner diameter, but the plastic deformation of the ring could be liable to occur in the MHV assembly process. It is proved that the valve of specifications can be designed in similar ratio of pivot distance to valve inner diameter according to the result of the valve performance experiment.
Heart Valve Prosthesis ; Heart Valves ; Prosthesis Design

Objective To explore the clinical significance of the serum cell-free DNA on early diagnosis and prognostic value of patients with cervical carcinoma. Methods Forty-five patients with cervical carcinoma and 50 healthy women from May 2012 to February 2014 were selected from the Central Hospital of Ezhou. Serum cell-free DNA(cf-DNA),carbohydrate antigen125(CA125),carbohydrate antigen19-9(CA19-9), squamous cell carcinoma antigen( SCC ),β-human chorionic gonadotropin( β--HCG ) were detected by electrochemiluminescence analyzer. Results The levels of serum cf-DNA,SCC,β-HCG of patients in the cervical carcinoma group were(178. 8 ± 43. 4)μg/ L,(0. 7 ± 0. 3)μg/ L,(1. 3 ± 0. 4)kU/ L respectively, higher than those in health women((1 354. 7 ± 267. 2)μg/ L,(1. 4 ± 0. 4)μg/ L,(5. 2 ± 0. 6)kU/ L),and the differences were significant(t = 30. 690,9. 709,37. 614;P < 0. 001). Serum cf-DNA level of patients with Ⅱ-Ⅲperiod cervical carcinoma was(2 538. 8 ± 775. 3)μg/ L,higher than patients with Ⅰ period((1 244. 7 ± 253. 6)μg/ L;t = 8. 191,P < 0. 001). The area under the curve of ROC of serum cf-DNA,CA125,CA19-9, SCC,β-HCG were 0. 951 6,0. 638 2,0. 614 4,0. 805 7,0. 753 1 respectively and the AUC of serum cf-DNA was the largest. The sensibility,specificity,accuracy of cf-DNA were 75. 56% ,99. 13% ,93. 36% and 28. 32% , 93. 24% ,64. 26% in terms of CA125. Meanwhile,the sensibility,specificity,accuracy of CA19-9 were 19. 75% , 94. 47% ,67. 28% and 38. 87% ,88. 53% ,80. 16% in terms of SCC. The sensibility,specificity,accuracy of β-HCG were 43. 28% ,86. 21% ,77. 83% respectively. Conclusion Serum cf-DNA has high sensibility, specificity and accuracy in early diagnosis and prognostic value of patients with cervical carcinoma and it is worthy of clinical promotion.

Objective To study the applicability of ultrafiltration of tween-80 and it solubilizing schizonepeta volatile oil and paeonol of ultrafiltration. Method Taking components content as index, temperature, pressure, concentration and membrane pore size were selected as factors for orthogonal design method. The concentration was determinated in medical solution before and after ultrafiltration, and the transmittance rate (TS) was calculated to observe the content variation of tween-80 and it solubilizing solution. Results The four factors had markedly effect on TS of tween-80, concentration was statistically significant (P

Objective: To examine the causal relationships between obesity, peripheral blood lipid indicators and non-small cell lung cancer (NSCLC) using Mendelian randomization (MR) method, so as to provide the basis for developing NSCLC prevention and control strategies. Methods: Genetic variation data of three obesity evaluation indicators, including body mass index (BMI), body fat ratio (BFR) and waist-to-hip ratio (WHR), and seven peripheral blood lipid indicators, including triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB) and lipoprotein a [LP (a)] were collected through genome-wide association studies (GWAS) and related public databases. Potential causal relationships between obesity, peripheral blood lipid indicators and NSCLC were analyzed using inverse-variance weighted (IVW) method and multivariable MR analysis upon a random effect model. Heterogeneity and horizontal pleiotropy of instrumental variables were evaluated using Cochran's Q test and MR-Egger regression. Results: There was statistically association between BMI with NSCLC (OR=1.256, 95%CI: 1.087-1.451); there were no statistically associations between BFR, WHR, seven peripheral blood lipid indicators and NSCLC (all P>0.005). There was heterogeneity in the association between BMI, BFR, WHR, TG, HDL-C and NSCLC (all P<0.05); no horizontal pleiotropy of instrumental variables was found (all P>0.05). There was no statistically association between BMI and NSCLC after adjusting BFR (OR=1.367, 95%CI: 0.878-2.128); there was still statistically association between BMI and NSCLC after adjusting WHR and peripheral blood lipid indicators (both P<0.05). Conclusions The increase of BMI is associated with the increased risk of NSCLC incidence. BFR may be a potential influencing factor for the association between BMI and NSCLC.

Diagnosis, Differential ; Humans ; Hyponatremia ; diagnosis ; etiology ; therapy ; Inappropriate ADH Syndrome ; diagnosis ; etiology ; therapy

Objective To investigate the clinical effect of long-term home non-invasive assisted ventilation in stable chronic obstructive pulmonary disease (COPD) combined with type Ⅱ respiratory failure.Methods Seventy-eight patients with stable COPD combined with type Ⅱ respiratory failure were divided into treatment group (26 cases) and control group (52 cases).Patients in control group were given conventional treatment,including inhaled salmeterol/fluticasone plus long-term home oxygen therapy (LTOT).Patients in treatment group on the basis of conventional treatment were given non-invasive assisted ventilation therapy for 6-8 hours a day,and the course was 12 months.Blood gas analysis index [pH,arterial blood carbon dioxide partial pressure (PaCO2),arterial blood oxygen partial pressure (PaO2)],pulmonary function index [forced expiratory volume in 1 second (FEV1),FEV1 percentage of expected value (FEV1％)],6 min walk test (6-MWT) distance,St George's respiratory questionnaire (SGRQ) and acute episodes.Results After 12 months'follow-up,there was no endotracheal intubation and dead patients in treatment group.Five patients had acute trachea intubation and invasive mechanical ventilation,and 1 case died in the control group.The index of pulmonary function (FEV1,FEV1％) in two groups after treatment was improved compared with that before treatment (P＜ 0.05).But FEV1 and FEV1％ over the same period in treatment group after treatment was higher than that in control group (P ＜ 0.05).The blood gas analysis indicators (pH,PaCO2,PaO2) in treatment group after treatment were improved compared with that before treatment (P ＜0.05).PaO2 in control group after treatment was improved,compared with that before treatment (P＜ 0.05),but there was no significant difference in control group in pH and PaCO2 levels before and after treatment (P ＞0.05).After treatment 6-MWT distance,and SGRQ scores were improved,compared with that before treatment (P ＜ 0.05),6-MWT from the same period in treatment group after treatment was higher than that in control group,and SGRQ scores was lower than that in control group during this period (P ＜ 0.05).There was significant difference in average acute episodes between treatment group and control group [(0.84 ± 0.16) times vs.(1.49 ± 0.78) times,t =-3.65,P ＜ 0.05].Conclusion Home non-invasive assisted ventilation treatment can improve blood gas analysis and pulmonary function in patients of COPD combined with type Ⅱ respiratory failure of stationary phase,increase exercise tolerance,improve the quality of life,and reduce the number of acute episodes and intubation rate.

Objective To compare the values of 3D-SPACE sequence and 2D-TSE sequence for displaying the anatomical details of the sinus tarsi ligament of the ankle.Methods 1.5T Siemens Auanto MRI scanner and 8-channel skull phased array coil were used for the examination of 26 healthy volunteers with 3D-SPACE three-dimensional isotropic sectional scanning as well as 2D-T1WI-TSE transverse and 2D-T2WI-TSE coronal sagittal two-dimensional fast spin echo scan.Two senior MRI radiologists evaluated the display rates of the two sequences for the cervical ligament of sinus tarsi and talus ligament so as to determine the values of the two sequences for displaying the cervical ligament of sinus tarsi.Results 3D-SPACE sequence behaved significantly better than 2D sequence when used to display the sinus tarsi ligament (P＜0.05),and the display rates were statistically different at different positions (P＜0.05).3D-SPACE sequence gained obvious advantages over 2D conventional TSE sequence when used to display the cervical ligament of sinus tarsi and talus ligament,and the highest display rate occurred in case of the cervical ligament of sinus tarsi scanned with 3D-SPACE coronal view and in case of the talus ligament scanned at coronal and sagittal positions.Conclusion 3D-SPACE sequence can display clearly the anatomical details of the sinus tarsi ligament with multiplanar reconstruction,curved planar reformation and etc,and thus is worthy promoting clinically.

Objective To analyze the consistency between 1.5T MRI and arthroscope when used to diagnose anterior cruciate ligament (ACL) injuries.Methods Totally 162 ACL injury patients underwent MRI examination,and the results by arthroscope were used as the diagnosis standard.The curve of receiver operating characteristic (ROC) was applied to evaluating the ACL injuries diagnosis by MRI,and the consistency was analyzed between 1.5T MRI and arthroscope.Results MRI had the sensitivity,specificity and accuracy being 98.69％,81.82％ and 98.77％ respectively when used to diagnose ACL injuries,and there was high consistency between MRI and arthroscope (Kappa=0.909,P＞0.05).Conclusion MRI gains high sensitivity and specificity when used to diagnose ACL injuries as well as high consistency with arthroscope,and thus can be a preferred non-invasive way to diagnose ACL injuries.

Objective To investigate the influence of different timing of surgery on patients with poor-grade intracranial aneurysm. Methods The clinical data of 86 patients with aneurysmal subarachnoid hemorrhage (Hunt-Hess gradeⅣ toⅤ)were analyzed retrospectively. The patients were divided into an ultra-early treatment group (the operative time within 24 h after onset;n=40),an early treatment group, (24 to 72 h after onset;n=27),and middle and late treatment group (>72 h after onset;n=19)according to the different timing of surgery. The prognosis of patients at 6 months after procedure was evaluated with the modified Rankin Scale (mRS)scores. The differences of the rate of good prognosis (mRS 0 to 2)and mortality in patients of the 3 groups were compared. Results (1 )The ratios of good prognosis in the ultra-early treatment group,early treatment group,and middle and late treatment group were 55. 0%(n=22),33. 3%(n=9),and 21. 1%(n=4),respectively. There were significant differences (P<0. 05). The mortality rate of the ultra-early treatment group (7. 5%)was lower than that of the early treatment group (25. 9%) or middle and late treatment group (42. 1%). There were significant differences (P<0. 05). (2)There were significant differences in the rate of good prognosis in different timing of surgery in patients with gradeⅣ(P<0. 05);there was no significant difference in the rate of good prognosis in patients with grade Ⅴ(P>0. 05). The mortality ratios in patients of the 3 groups were 2/18,4/11,and 6/11,respectively. There were significant differences (P<0. 05). Conclusion Ultra-early operation may benefit part of the patients with poor-grade aneurysm,particularly in patients with gradeⅣ. As for the patients with grade Ⅴ, ultra-early operation may help to reduce short-term mortality rate,however,the rate of vegetative state is high.

Objective To investigate the cognitive function of patients with prostate cancer after maximal androgen blockade therapy and its influenced factors,and to provide a new way for early prevention strategy.Methods Montreal cognitive assessment (MoCA),hospital anxiety depression scale (HAD),social support rating scale (SSRS) and self-designed questionnaire were used in 56 cases treated with maximum androgen blockade therapy for more than six months and 37 cases who underwent radical prostatectomy treatment to evaluate their cognitive function and collect the observation indexes between January 2013 and October 2015.Based on MoCA score,all patients were divided into cognitive dysfunction group (n =40) and normal cognitive function group (n =53).The observation indexes in two groups were compared and cognitive function with different treatment in two groups were analyzed.The changes on the influencing factors of cognitive function in patients were filtered using multivariable logistic regression analysis.Results In the cognitive dysfunction group and normal group,the proportion of MAB treatment was 80.0％ (32/40) vs.45.3％ (24/53),the age was 73.7 vs.73.7 years,the proportion of solitary was 32.5％ (13/40) vs.13.2％ (7/53),the proportion of depressive symptoms was 87.5％ (35/40) vs.62.3％ (33/53),the social support level was 32.5 vs.41.1 and the proportion of testosterone decreased was 95.0％ (38/40) vs.45.3％ (24/53).All events showed statistically significant differences (P ＜0.05).Compared MAB treatment group with radical surgical treatment group,the testosterone level was (0.27-±O.15) vs.(12.14 ± 1.86) nmol/L,visual space and executive function score was 4.18 ±0.79 vs.4.54 ±0.56,attention score was 4.73 ±0.99 vs.5.16 ±0.79,delayed memory score was 3.75 ± 1.21 vs.4.30 ± 1.05 and MoCA score was 26.13 ± 1.48 vs.27.27 ± 1.39,which all showed the statistically significant difference (P ＜ 0.05).The results of multiple regression analysis showed that age (OR =1.183,95％ CI 1.135-1.223),depressive symptoms (OR =1.092,95％ CI 1.047-1.149),social support (OR =0.897,95％ CI O.838-0.956),testosterone (OR =2.105,95％ CI 1.369-4.083) were the influenced factors of cognitive dysfunction.Conclusions The incidence of cognitive dysfunction in patients with prostate cancer after maximal androgen blockade therapy more than six months was higher than others.Age,depression,social support level and testosterone levels were related to the occurrence of cognitive dysfunction.