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This study aims to explore the effect of aortic sinus diameter on aortic valve opening and closing performance in the case of no obvious disease of aortic valve and annulus and continuous dilation of aortic root. A total of 25 three-dimensional aortic root models with different aortic sinus and root diameters were constructed according to the size of clinical surgical guidance. The valve sinus diameter S is set to 32, 36, 40, 44 and 48 mm, respectively, and the aortic root diameter is set to 26, 27, 28, 29 and 30 mm, respectively. Through the structural mechanics calculation with the finite element software, the maximum stress, valve orifice area, contact force and other parameters of the model are analyzed to evaluate the valve opening and closing performance under the dilated state. The study found that aortic valve stenosis occurs when the = 32 mm, = 26, 27 mm and = 36 mm, = 26 mm. Aortic regurgitation occurs when the = 32, 36 and 40 mm, = 30 mm and = 44, 48 mm, = 29, 30 mm. The other 15 models had normal valve movement. The results showed that the size of the aortic sinus affected the opening and closing performance of the aortic valve. The smaller sinus diameter adapted with the larger root diameter and the larger sinus diameter adapted with the smaller root diameter. When the sinus diameter is 40 mm, the mechanical performance of the valve are good and it can well adapt with the relatively large range of aortic root dilation.
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Humans , Aorta , Aortic Valve , Physiology , Aortic Valve Insufficiency , Aortic Valve StenosisABSTRACT
Objective To explore the effect of different initial state setting on a valve simulation. Methods Two-dimensional structural models were established with the initial state of the aortic valve being partially closed in one model and fully opened in the other. The time-dependent load was applied to the valve and the vessel wall of the aortic and the ventricle sides. The finite element method was used to study the maximum stress, the length of the joint, and the contact force of the closed aortic valve under two different initial states. Results The stress and contact force of the aortic valve were relatively large at the closed position when the initial state was fully opened. The closure degree of the valve was low, and the variations in stress and closure degree were large during the periodic cycle. The stress and contact force of the valve were relatively small when the aortic valve was partially closed. The closure degree was high, and the variations in stress and closure degree of the aortic valve were small during the periodic cycle. Conclusions In the case of the aortic valve partially closed in the initial state, the stability of the calculation process and the closure degree of the valve were relatively high, which should be given more consideration in numerical simulation. The results can be used to study the mechanical behavior of the valve and the biomechanical mechanism of the aortic root.
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Objective:To investigate the impact on the level of serum IL-8 and IL-18 by Helicobacter pylori eradication therapy in patients with rheumatoid arthritis.Methods:Helicobacter pylori were assessed by 14-Curea breath test in patients with rheumatoid arthritis.All patients were divided into Hp positive group and Hp negative group on the basis of 14-C urea breath test results.The Hp positive group were divided into anti-helicobacter pylori group and control group.The level of ESR,serum C reactive protein (CRP), RF,IL-8 and IL-18 were measured in all patients before and after 12 weeks of treament.And the number of joint swelling,joint pain/tenderness,morning stiffness time, hands grip strength were recorded before and after 12 weeks treatment.Results: 12 weeks after treatment,the effective rate in the Hp negative group and the anti-helicobacter pylori group was higher than that in the control group (84.09%vs 62.50%,χ2=5.41,81.25% vs 62.50%,χ2=4.17,P<0.05).The clinical symptoms significantly improved and the levels of ESR, C-reactive protein, RF, IL-8 and IL-18 significantly reduced in the three groups ( P<0.05 ) .The clinical symptoms improved more obviously in the Hp negative group and the anti-helicobacter pylori group than that in the control group.The levels of ESR,C-reactive protein,IL-8 and IL-18 in the Hp negative group and the anti-helicobacter pylori group was lower than that in the control group.While there was no significantly difference in the level of RF in the three groups.Conclusion:From a certain extent ,Hp eradication therapy can improve the clinical curative effect of rheumatoid arthritis.
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Objective To investigate the expression of glucose-regulated protein 78(GRP78)and cysteine aspartic acid protease 12(Caspase-12) and evaluate the endoplasmic reticulum stress (ERS) in rats with contrast-induced nephropathy (CIN),and observe the protective effects of hydroxytyrosol on CIN rats.Methods Eighty-four Wistar rats,(220±20) g,were randomly divided into control group,CIN group,hydroxytyrosol treated group (group C+H).At 12th,24th,48th,72th day after the rats model were established,BUN and Scr were detected.ELISA were used to detect the expression of methane dicarboxylic aldehyde (MDA),superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px).HE staining were used to evaluate the pathological change of kidney.TUNEL were used to detect the apoptosis of tubular ceils.Real-time PCR were used to detect the expression of GRP78 mRNA and Caspase-12 mRNA in tubular cells.Immunohistochemistry and Western blotting were used to detect the expression of GRP78 and Caspase-12 protein in tubular cells.Results BUN,Scr,the mRNA and protein expression of GRP78,Caspase-12 in hydroxytyrosol treated group were higher than that in control group(P ＜ 0.05),but were significantly lower than that in CIN group (P ＜ 0.05).Pathological changes and the apoptosis of tubular cells in CIN group were more serious than that in hydroxytyrosol treated group (P ＜ 0.05).Conclusions Endoplasmic reticulum stress may be associated with contrast-induced nephropathy.Hydroxytyrosol can protect kidney from contrast medium via reducing the endoplasmic reticulum stress.
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Objective To investigate the expression of 4-hydroxynonenal (4-HNE) in the kidney of diabetic rats and the effect of probucol.Methods The rats were being intraperitoneal injected with STZ (60 mg/kg) to establish diabetic models.Then diabetic rats were randomly divided into diabetic group (group D,n =24),probucol treated group (group P,n =24).Normal rats were taken as control group (group C,n =24).Rats in group P were treated by probucol (110 mg·kg-1·d-1); rats in group D and group C were given equal volume water instead.Scr,BUN,triglyceride (TG),total cholesterol (TC) and 24-hour urinary proteinin were measured at the 4th,8th and 12th week.PAS staining and HE staining were used to evaluate the pathological changes of the kidney.The immunohistochemistry and Western blotting were used to detect the expression of 4-HNE in renal tissue.Results Levels of Scr,BUN,TG,TC and 24-hour urinary protein in group D were higher than those in group C at the 4th,8th and 12th week(all P ＜ 0.05); Levels of Scr,BUN,TG,TC and 24-huor urinary protein in group P were lower than those in group D at 4th,8th and 12th week (all P ＜ 0.05).The pathological changes of the kidney in group D were more serious than that in group P.The expression of 4-HNE in group D were higher than group C at the 4th,8th and 12th week (all P ＜ 0.05);The expression of 4-HNE in the kidneys of group P decreased significantly compared to that of group D at the same time (P ＜ 0.05).Conclusions As an indicator of lipid peroxidation,the expression of 4-HNE significantly increases in the kidney of diabetic rat.Probucol may protect the diabetic kidney through decreasing the expression of 4-HNE and the level of lipid peroxidation.
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Objective To explore the measures and methods to cope with the early stage epidemic struck of H7N9 avian influenza,as the head nurses of the department of infectious diseases.Methods The main work focus of the head nurses of the department of infectious diseases were analyzed during the early stage of H7N9 epidemic struck systematically by reference to the domestic literatures.Results At the early stage of H7N9 epidemic struck,the main work focus of the head nurses of the department of infectious diseases was to draw up every emergency plans,prepare necessary protective medical supplies,train medical staff,and be ready to the preview and triage.Conclusions The head nurses of the department of infectious diseases should pay close attention to the progress of H7N9 epidemic struck,and get ready for all related work in order to ensure smooth treatment during early stage of the epidemic struck.
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Objective To analyze the therapeutic effect of three-dimensional conformal involvedfield radiotherapy (3D-CRT)combined with chemotherapy on limited disease stage small cell lung cancer (LD-SCLC).Methods The clinical data of 85 patients of LD-SCLC treated with 3D-CRT at the dose of 2 Gy/fraction,5 fractions per week for 5 - 7 weeks,with the median dose of 50 Gy ( 46 - 66 Gy),combined with 4 -8 cycles chemotherapy,64 males and 21 females,aged 29 -76,were collected and analyzed.Results The complete remission rate,partial remission rate,stability rate,and total effective rate were 36.5％,52.9％,10.6％,and 89.4％,respectively.The median survival time was 18 months,with the 1-,2-,and 3-year overall survival rates of 65.9％,33.8％,and 15.9％,respectively.The local recurrence rate,distant metastasis rate,and local recurrence + distant metastasis rate were 15.2％ (9/85),49.2％ (29/85),and 35.6％ (21/85),respectively.Body weight,response to therapy,cycles for chemotherapy,and concurrent chemo-radiotherapy were all independent prognostic factors for LD-SCLC.Cox muhivariable regression was used to analyze the prognostic factors.Conclusions Involved-field radiotherapy is effective for LD-SCLC.Distance metastasis is the main cause of treatment failure.
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Objective To investigate the value of CT perfusion imaging in evaluation of therapeutic effect and prognosis in radiotherapy for lung cancer.Methods Fifty-one cases of lung cancer who were unable or refused to be operated on,36 males and 15 females,aged 37 - 80,underwent CT perfusion imaging,29 of which only before radiotherapy and 22 before and after radiotherapy twice.The images were collected by cine dynamic scanning (5 mm/4 slices ) and input into the GE AW4.0workstation for data processing.The slice positions of CT imaging were determined according to the largest tumor size in CT scan.Regions of interest of tumor were drawn at the region corresponding to the original images of CT perfusion.Radiotherapy was performed after CT perfusion imaging.Relevant parameters,including blood flow ( BF),blood volume ( BV),mean transit time ( MTT),and permeability surface (PS) were calculated.The treatment response after radiotherapy was evaluated by RECIST.At 2 -4 weeks after the treatment,CT examination was conducted once more.Results The tests of the 51 patients showed that the BV was 13.6 ml·100 g-1,the BF was 129.5 ml·min-1 ·100 g-1,the MTT was 9.1 s,and the PS was 10.0 ml· min- 1· 100 g-1 before radiotherapy.The tests of the 22 of the 51 patients showed that the values of BV and BF after radiotherapy were 7.6 ml· 100 g-1 and 97.8 ml·min-1· 100 g-1,respectively,both lower than those before radiotherapy (11.2 and 108.7 ml·min-1·100g-1,respectively),however,both not significantly ( t =1.28,0.40,P ＞ 0.05 ) ; and the values of MTT and PS after radiotherapy were 8.9 s and 7.8 ml·min-1· 100 g-1,respectively,both not significantly higher than those before radiotherapy ( 7.2 s and 6.8 ml· min -1· 100 g-1,respectively,t =- 1.15,- 0.57,P ＞0.05 ).The mean area of tumor after radiotherapy was 1189.6 mm2,significantly less than that before radiotherapy ( 1920.3 mm2,t =3.98,P ＜0.05).The MTT of the SCLC patients was 12.9 s,significantly longer than that of the NSCLC patients (6.5 s,t =2.54,P ＜0.05).The MTT of the tumor with the area ≤ 10 cm2 was 11.2 s,significantly longer than that of the tumors with an area ＞ 10 cm2(5.8 s,t =2.59,P ＜ 0.05 ).The BV of the responder group was 19.2 ml· 100 g- 1,significantly higher than that of the nonresponder group (4.6 ml· 100 g - 1,t =3.62,P ＜ 0.05 ).There were not significant differences in all the perfusion characteristics between the cases with the disease-free advanced survival time ≤ 10 months and those with disease-free advanced survival time ＞ 10 months.Conclusions CT perfusion imaging helps in diagnosis and radiotherapy of lung cancer to a certain degree.
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Objective To discuss the effect of self- care education at the early time of postoperation and the use of nursing packages during the later period on non- throat patients. Methods 40 patients having un-dergone total laryngectomy were divided into the control group and the experimental group according to the surgery date with 20 cases in each group. The control group received conventional nursing, while the experi-mental group was given the system intervention by specialized nurses. The intervention content included self-care education at the early time of postoperation and the use of nursing packages during the later period. The questionnaire survey was carried out 15 days and 3 months after operation.The coping style,self-care ability and survival quality were compared between the two groups. Results The comparison of coping style showed re-markable difference in the two groups. The comparison of self- care ability and level of health knowledge showed significant difference 15 days after operation except two other items,but the four items demonstrated significant difference 3 months after operation. Difference also existed in the total scorn of survival quality. Conclusions Early system serf- care education after operation and the use of nursing package during the later period can impel the patients to cope positively, enhance self-care ability and survival quality.
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Objective To review the treatment effect of limited disease small cell lung cancer (LD-SCLC) and to evaluate the prognosis factors for SCLC. Methods From Aug. 2002 to Feb. 2006, 212 patients of SCLC confirmed with pathology and cytology were. Treated by combined modality. All patients were treated with chemotherapy 2-6 cycles, 59 patients of which were treated with only chemotherapy, 108 patients of which were treated with chemotherapy plus radiotherapy, 45 patients of which were treated with surgery plus chemotherapy with or without radiotherapy. The patients of radiotherapy were exposed to 6 or 10 MV X-ray with a total dose of 40-66 Gy in 4-7 weeks. Results The overall median survival time was 15 months. The 1-,2- and 3-year overall survival rate were 58.0%, 33.2% and 22.1%, respectively. Univariate analysis indicated that weight loss, age, LDH, ECOG performance status, operation, response to radio-chemotherapy, cycles for chemotherapy, radiotherapy irflueoced survival significantly in LD-SCLC. Multivariate analysis suggested that ECOG performance status, response to therapy, cycles for chemotherapy were the independent prognostic factors for LD-SCLC. Conclusions For LD-SCLC patients, ECOG performance ≤ 1, good response to radio-chemotherapy, and ≥ 4 cycles chemotherapy show encouraging survival rate, Distance metastasis is still the mainstay of treatment failure.
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Objective:We clarify the relationship between dysfunction of gastric motility and the plasma motilin,in order to study the pathogenesis,diagnosis and therapy of the hepatocirrhosis with dyspepsia.Methods:The liquid gastric emptying (GE),electrogastrograpgy(EGG) and plasma motilin were examined in 51 patients with hepatocirrhosis.Results:The dysfunction of gastric motility is associated with the liver function,gastric rhythm and upper gastrointestinal symptom.The plasma motilin concentration increased significantly in patients with hepatocirrhosis as compared with that of controls (P<0.01).The sorbefacient prokinetic drug (prepulsid) can improve the function of gastric power,but the lever of motilin no change.Conclusion:The patients with hepatocirrhosis have the dysfunction of gastric motility,and gastric emptying delayed,and there is a relation between GE and the liver function.We evaluate that this disorder is associated with the low sensitivity about stomach to the plasma molitin in this case.We can judge the degree of the liver damage,gastric emptying delayed.gastric rhythm by testing the gastric motilin.Drug can deal it.