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.
ObjectiveTo evaluate the medium-and long-term effectiveness of the 3rd-generation ceramic-on-ceramic total hip arthroplasty (THA) for end-stage hip disease. MethodsA retrospective analysis was made on the clinical data of 142 patients (148 hips) who underwent the 3rd-generation ceramic-on-ceramic THA between May 2001 and May 2005. There were 78 males and 64 females, aged 57.2 years on average (range, 23-81 years). Preoperative diagnosis was avascular necrosis of femoral head in 73 patients (77 hips), degenerative osteoarthritis in 35 patients (36 hips), femoral neck fracture in 18 patients (18 hips), rheumatoid arthritis in 14 patients (15 hips), and septic hip sequelae in 2 patients (2 hips). The preoperative Harris hip score was 58.3±12.9. ResultsAll incisions healed by first intention without complication. All patients were followed up 8.8 years on average (range, 7-12 years). At the last follow-up, the Harris hip score (92.5±10.2) was significantly higher than that at pre-operation (t=-25.29, P=0.00). At the last follow-up, there were 4 hips with groin pain, 6 hips with thigh pain. Complications occurred in 6 cases (6 hips), including loosening cups in 2 hips, hip dislocation in 2 hips, ceramic head fracture in 1 hip, and squeaking in 1 hip. The revision rate was 1.35% (3/148). X-ray film showed that acetabular cup loosening in 2 hips, discontinuous radiolucent line in 4 hips, and new bone formation in 88 hips; discontinuous radiolucent line around femoral component was observed in 25 hips, endosteal new bone formation in 95 hips, cortical bone hypertrophy in 2 hips, and femoral component subsidence in 9 hips (less than 2 mm). ConclusionThird-generation ceramic-on-ceramic THA is an effective treatment for end-stage hip disease, and can achieve satisfactory medium-and long-term effectiveness and a high implant survival rate.
ObjectiveTo investigate the correlation between tumor-vessel signs on 64-slice spiral CT (MSCT) and malignant change of tubulovillous adenoma in the colon and rectum. MethodsA retrospective study of the image and the clinical data of 16 patients with tubulovillous adenoma or malignant change proved by pathologies from February 2010 to October 2012 was conducted. The tumor-vessel signs were analyzed by multiplanar reformation (MPR) and maximum intensity projection (MIP) on picture archiving and communication systems workstation. ResultsAmong the 16 cases of tubulovillous adenoma or malignant change, 2 cases of tumor diameter≤2 cm had no tumor-vessel sign; and in the 14 cases of tumor diameter >2 cm, 13 were observed to bear tumor-vessel signs. The size of the tumor and tumor-vessel signs showed a certain correlation (r=0.618, P=0.002). And the manifestation of tumor-vessel signs had obvious differences between benign and malignant tumor. For the adenoma group, it showed venous blood vessel involvement, and downy and natural contour; for the adenocarcinoma group, it showed arterial blood vessel involvement, blood vessels with uneven thickness, visible expansion and irregular defect manifestations. No obvious difference was detected among tumor-vessel signs of adenocarcinoma with different malignant degree. ConclusionMSCT combined with image reconstruction techniques (such as MPR and MIP) can clearly demonstrate tumor blood supply, and tumor-vessel in the arterial phase may suggest a high risk of malignant change of tubulovillous adenoma in the colon and rectum.
ObjectiveTo systematically review the implementation status, effectiveness and existing problems of nutrition improvement measures for vulnerable populations in rural areas of China. MethodsAll studies about the implementation status, effectiveness and existing problems of nutrition improvement measures for vulnerable populations in rural areas of China were electronically searched in VIP, CNKI, WanFang Data and CBM from inception to January 1st, 2014. Two reviewers independently screened literature according to inclusion and exclusion criteria, extracted data, and assessed methodological quality of included studies, and then performed qualitative analysis in terms of implementation effectiveness and situation. ResultsA total of 79 studies were finally included. The results of qualitative analysis showed that:the earliest study was published in 1990; 38.0% of these studies were carried out in the southwest and northwest areas of China; 31.6% of these studies were financially supported, and most funds were provided by some international institutions; 90.0% of these research subjects focused on infants and children (under the age of 10); a variety of nutrition improvement measures had been taken, and 55.7% of these interventions measures were nutrition education which could be implemented easily; the implementation duration of 38.0% of these measures lasted less than half a year; 32.9% of these studies adopted the blood test to evaluate the outcomes of nutrition measures; all of the studies showed that nutrition levels of vulnerable populations in rural areas of China had been obviously improved by these measures. ConclusionThe nutrition improvement measures for vulnerable populations in rural areas of China have been implemented relatively earlier focusing on populations in West China where was less developed. However, an imbalance exists in the attention to target populations, especially to the elderly. Face to face nutrition education is most frequently taken; however, it could not directly reflect the changing of nutritional status. In addition, implementation duration is fairly short which indicates that more fund supports are needed from the government or institutions.
ObjectiveTo reveal the true value of plasma detection of epidermal growth factor receptor (EGFR) mutation for early-stage non-small cell lung cancer (NSCLC) gene diagnosis and to predict survival prognosis. MethodsTissue samples of positive EGFR mutations by using amplification refractory mutation system (ARMS) method were surgically resected from 198 patients with stage I-IV NSCLC between February 2014 and June 2015 in Tangdu hospital. Paired blood samples were collected before surgery. And the cellfree DNA (cfDNA) in plasma was extracted, plasma EGFR mutations were detected by real-time polymerase chain reaction (PCR). Concentration of cfDNA was measured by ultraviolet spectrophotometry. Follow-up observation for stage ⅢA patients was put into force after surgery. Kaplan-Meire was used in survival analysis. ResultsThe sensitivity of EGFR mutation for the 198 paired tissues and plasma samples was 17.2%.The sensitivity was positively correlated with TNM stage and negatively correlated with tumor differentiation. The sensitivity of sage ⅢA was 33.3%, significantly higher than that of the patients at stage ⅠA (1.6%, P=0.000) and stage ⅠB (7.9%, P=0.004). The sensitivity of poor differentiation was 36.8%, significantly higher than that of high differentiation (0.0%, P=0.000) and moderate differentiation (15.7%, P=0.010). There was no correlation between plasma cfDNA concentration and patient characteristics. Survival analysis showed that plasma detection was a vital factor for predicting postoperative survival prognosis of stage ⅢA patients (P=0.014). ConclusionTissue samples cannot be replaced by plasma samples for epidermal growth factor receptor (EGFR) mutation test in early-stage NSCLC patients, currently. When the sensitivity increases dramatically in the plasma samples of stage ⅢA NSCLC and poor differentiation tumor, we recommend using plasma detection for gene diagnosis, dynamic monitoring of EGFR mutations in stage ⅢA or poorly differentiated tumors, especially in NSCLC patients whose tissue samples cannot be obtained by surgery. And plasma EGFR detection is a valuable method of forecasting survival prognosis for locally advanced NSCLC patients.
Objective To investigate the alternatives of different endoscopic drainages for acute cholangitis of severe type (ACST) in elderly patients with chronic respiratory disease. Methods The clinical data of 74 cases of ACST in elderly patients with chronic respiratory disease undergoing 3 kinds of drainages, endoscopic retrograde double biliary stent drainage (D-ERBD), endoscopic retrograde single biliary stent drainage (S-ERBD), or endoscopic nasobiliary drainage (ENBD) in the First Hospital of Lanzhou University from October 2005 to October 2015 were collected to analyze prospectively. Results Compared with preoperative, the white blood cell (WBC), direct bilirubin (DBIL), temperature, and abdominal pain NRS evaluation in 48 h after operation in 3 groups all decreased, the difference was statistically significant (P＜0.05). Compared among 3 groups, there were no significant difference among the incidences of postoperative hyperamylasemia, pancreatitis and gastrointestinal hemorrhage (P＞0.05). The group of ENBD was more likely to develop pulmonary infection and achieve a secondary treatment than other 2 groups (P＜0.05). Totally 5 patients died in 3 groups, with a mortality of 6.76%, but the mortality rates were similar among the 3 groups (P＞0.05). The deaths were predominantly caused by multiple organ failure (MOF), 4 cases of which were caused by respiratory failure related to respiratory infection. Conclusion The alternative of endoscopic retrograde double biliary stent drainage (D-ERBD) can not only alleviate cholangitis rapidly, but it can reduce the incidence of aspiration pneumonia.