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find Author "LIU Dong" 18 results
  • Research progress on collateral circulation scores of CT angiography and prognosis of ischemic stroke

    Good collateral circulation can effectively improve the prognosis of patients with severe stenosis or occlusion of cerebral blood supply artery. Studies have shown that CT angiography (CTA) can non-invasively and intuitively evaluate the degree of stenosis and collateral blood flow in diseased vessels. Rapid and accurate CTA collateral circulation score is of great significance for clinical decision-making and judging the prognosis of ischemic stroke. At present, there are many scoring scales based on CTA collateral circulation. This article will review the existing 7 CTA collateral circulation scoring scales, the advantages and disadvantages of clinical application and related research progress in predicting prognosis, aiming to provide a reference for clinicians to choose the collateral circulation score scale and the best treatment plan according to different situations.

    Release date:2022-10-19 05:32 Export PDF Favorites Scan
  • Treatment Strategy for Patients with Subacute Myocardial Infarction and Severe Ischemic and Functional Mitral Regurgitation

    Objective To investigate appropriate treatment strategy and timing for patients with subacute myocardial infarction and severe ischemic mitral regurgitation (IMR). Methods A total of 89 patients with subacute myocardial infarction and severe IMR underwent surgical treatment from January 2005 to December 2011 in Beijing Anzhen Hospital. There were 66 male patients and 23 female patients with their mean age of 64 (55-73) years. All the patients received only coronary artery bypass grafting (CABG) after 3 months of medication treatment without specific management for their IMR. Echocardiography was examined before medication treatment,preoperatively and 6 months after CABG to analyze their IMR degree and measure left ventricular end-systolic dimension (LVESD),left ventricular end diastolic dimension (LVEDD) and left ventricular ejection fraction (LVEF). Results There was no surgery-related death,perioperative myocardial ischemia or other severe postoperative complication. Eighty-one patients (91.0%) were followed up for 6-60 months. At 6 months after CABG,mitral regurgitation area (3.1±1.3 cm2 vs. 5.6±2.3 cm2),LVEDD (51.3±4.2 mm vs. 54.3±5.5 mm) and LVESD (31.7±3.9 mm vs. 34.6±4.3 mm) were significantly decreased than preoperative values (P<0.05),but LVEF was not statistically different from preoperative value (59.1%±3.9% vs. 58.9%±5.6%,P>0.05). From the third year during follow-up,all the patients received annual CT examination of their coronary artery,and no significant graft stenosis (graft stenosis>50%) was found. Conclusion With appropriately delayed CABG and right medication treatment,patients with subacute myocardial infarction and severe IMR may no longer need concomitant surgical management for their IMR, which can decrease surgical risks and reduce treatment cost.

    Release date:2016-08-30 05:45 Export PDF Favorites Scan
  • Stress analysis of the molar with the all-ceramic crown prosthesis based on centric occlusal optimization

    Stress distribution of denture is an important criterion to evaluate the reasonableness of technological parameters, and the bite force derived from the antagonist is the critical load condition for the calculation of stress distribution. In order to improve the accuracy of stress distribution as much as possible, all-ceramic crown of the mandibular first molar with centric occlusion was taken as the research object, and a bite force loading method reflecting the actual occlusal situation was adopted. Firstly, raster scanning and three dimensional reconstruction of the occlusal surface of molars in the standard dental model were carried out. Meanwhile, the surface modeling of the bonding surface was carried out according to the preparation process. Secondly, the parametric occlusal analysis program was developed with the help of OFA function library, and the genetic algorithm was used to optimize the mandibular centric position. Finally, both the optimized case of the mesh model based on the results of occlusal optimization and the referenced case according to the cusp-fossa contact characteristics were designed. The stress distribution was analyzed and compared by using Abaqus software. The results showed that the genetic algorithm was suitable for solving the occlusal optimization problem. Compared with the reference case, the optimized case had smaller maximum stress and more uniform stress distribution characteristics. The proposed method further improves the stress accuracy of the prosthesis in the finite element model. Also, it provides a new idea for stress analysis of other joints in human body.

    Release date:2020-12-14 05:08 Export PDF Favorites Scan
  • Equivalent modeling and evaluation of molars using point-contact higher kinematic pair based on occlusal dynamic analysis

    As a representative part of the oral system and masticatory robot system, the modeling method of the dental model is an important factor influencing the accuracy of the multi-body dynamic model. Taking the right first molars of the masticatory robot as the research object, an equivalent model, point-contact higher kinematic pair composed of v-shaped surface and sphere surface, was proposed. Firstly, the finite element method was used to analyze the occlusal dynamics of the original model in three static contact cases (intrusive contact, centric occlusion, and extrusive contact) and one dynamic chewing case, and the expected bite force was obtained. Secondly, the Hertz contact model was adopted to establish the analytical expression of the bite force of the equivalent model in three static contact cases. The normal vectors and contact stiffness in the expression were designed according to the expected bite force. Finally, the bite force performance of the equivalent model in three static contact cases and one dynamic chewing case was evaluated. The results showed that the equivalent model could achieve the equivalent bite force of 8 expected items in the static contact cases. Meanwhile, the bite force in the early and late stages of the dynamic chewing case coincides well with the original model. In the middle stage, a certain degree of impact is introduced, but it can be weakened by subsequent trajectory planning. The equivalent modeling scheme of the dental model proposed in this paper further improves the accuracy of the dynamic model of the multi-body system. It provides a new idea for the dynamic modeling of other complex human contacts.

    Release date:2020-10-20 05:56 Export PDF Favorites Scan
  • Design and performance analysis of elastic temporomandibular joint structure of biomimetic masticatory robot

    Masticatory robots have a broad application prospect in the field of denture material tests and mandible rehabilitation. Mechanism type of temporomandibular joint structure is an important factor influencing the performance of the masticatory robot. In view of the wide application of elastic components in the field of the biomimetic robot, an elastic component was adopted to simulate the buffering characteristics of the temporomandibular joint disc and formed the elastic temporomandibular joint structure on the basis of point-contact high pair. Secondly, the influences of the elastic temporomandibular joint structure (on mechanism degree, kinematics, dynamics, etc.) were discussed. The position and velocity of the temporomandibular joint were analyzed based on geometric constraints of the joint surface, and the dynamic analysis based on the Lagrange equation was carried out. Finally, the influence of the preload and stiffness of the elastic component was analyzed by the response surface method. The results showed that the elastic temporomandibular joint structure could effectively guarantee the flexible movement and stable force of the joint. The elastic joint structure proposed in this paper further improves the biomimetic behavior of masticatory robots. It provides new ideas for the biomimetic design of viscoelastic joint discs.

    Release date:2020-08-21 07:07 Export PDF Favorites Scan
  • EFFECTIVENESS OF ARTHROSCOPY AND/OR ARTHROTOMY THERAPY FOR DIFFUSE PIGMENTED VILLONODULAR SYNOVITIS OF THE KNEE

    Objective To investigate the method and the effectiveness of arthroscopy and/or arthrotomy combinedwith postoperative radiotherapy for diffuse pigmented villonodular synovitis (PVNS) of the knee. Methods BetweenSeptember 2000 and August 2010, 97 patients with diffuse PVNS of the knee were treated. There were 38 males and 59 femaleswith a median age of 33 years (range, 8-75 years). The disease duration ranged from 1 week to 30 years, including 52 left kneesand 45 right knees. There were 10 recurrent cases. The extention and flexion of the knee joint were (1.9 ± 2.3)° and (122.9 ± 5.6)°,respectively; the Lysholm score was 43.2 ± 6.7; and the International Knee Documentation Committee (IKDC) score was53.2 ± 5.7, preoperatively. According to the scope and degree of the knee joint lesions, simultaneous anterior and posteriorsynovectomy was performed under arthroscopy in 82 cases, synovectomy under arthroscopy and removal of posterior extraarticularlesion by arthrotomy in 3 cases, synovectomy and the soft tissue lesions resection under arthroscopy in 9 cases, andstaging resection and bone graft in 3 cases. After operation, 76 patients received postoperative radiotherapy. Results Poplitealartery was injuryed in 1 case and the branch of popl iteal veins were injuryed in 3 cases during operation. Intra-articularhemorrhage occurred in 1 case at 3 days after operation. The other patients achieved heal ing of incision by first intentionwithout nerve damage and other complications. All patients were followed up 1 year and 3 months to 11 years and 2 months(median, 61 months) postoperatively. During follow-up, 89 cases had no relapse. At 15 months after operation, the extentionand flexion of the knee joint were (0.2 ± 1.3)° and (135.9 ± 6.6)°, respectively; the Lysholm score was 89.8 ± 5.8; and the IKDCscore was 87.8 ± 5.8. All indexes were significantly improved when compared with the preoperative ones (P lt; 0.05). At 6 monthsto 8 years postoperatively, 8 cases had occurrence, and they had sl ight limitation of the range of motion but had no pain andswelling of the knees after reoperation. Conclusion According to the scope and degree of the knee joint lesions, arthroscopyand/or arthrotomy combined with postoperative radiotherapy should be chosen for diffuse PVNS of the knee so as to obtain good effectiveness. Radiotherapy and enough total radiation dose are important factors to insure no recurrence.

    Release date:2016-08-31 04:23 Export PDF Favorites Scan
  • Correlation analysis of red blood cell distribution width and disease severity of adult patients with community-acquired pneumonia

    Objective To investigate the relationship between the red blood cell distribution width (RDW) and the severity of community-acquired pneumonia (CAP). Methods The clinical data of 285 adult patients with CAP admitted from November 2014 to August of 2017 were analyzed retrospectively. The severity of CAP was evaluated by pneumonia severity index (PSI) score. Meanwhile, 60 cases with qualified medical examination were collected as a healthy control group. The distributions of PSI score, RDW, procalcitonin (PCT), C-reactive protein (CRP) and neutrophil percentage (NEU%) were described in the patients with different risk degree. The correlation analysis of various indicators were analyzed by Spearman correlation. The threshold of RDW(%) was calculated through the construction of the general linear regression equation. The risk factors of PSI score were analyzed with multiple linear regression. Results The higher the risk stratification, the higher the distribution of PSI scores, RDW, PCT, CRP and NEU% were. RDW was positively correlated with PCT, CRP, and NEU% (r values were 0.417, 0.252, 0.318, respectively, P<0.05). PSI score was positively correlated with RDW, PCT, CRP, and NEU% (r values were 0.537,0.598, 0.557, 0.482, respectively, P<0.05). RDW was positively correlated with PSI score (r=0.537, P<0.05). The thresholds of RDW(%) were 14.514 and 19.041. Multiple linear regression showed that RDW, PCT, CRP and NEU% were all influential factors of PSI scores and explained 46.9% of the total mutation rate. Conclusion RDW is correlated with the severity of CAP, and can predict the severity of CAP.

    Release date:2018-03-29 03:32 Export PDF Favorites Scan
  • Uniportal versus three-port subxiphoid video-assisted thoracoscopic extended thymectomy: A retrospective cohort study

    ObjectiveTo investigate the clinical characteristics of uniportal and three-port subxiphoid video-assisted thoracoscopic surgery (XVATS) extended thymectomy.MethodsThe clinical data of 60 consecutive patients of XVATS thymectomy in Xuzhou Central Hospital from January 2017 to May 2019 were retrospectively analyzed. There were 29 males and 31 females, with an average age of 53.1 (27.0-76.0) years. The patients were divided into an uniportal XVATS group (30 patients) and a three-port XVATS group (30 patients). The clinical effectiveness was compared between the two groups.ResultsThere was no significant difference in age, sex, body mass index, tumor size, intraoperative blood loss, postoperative time of thoracic tube indwelling and thoracic drainage, or postoperative hospitalization time between the two groups (P>0.05). There was no perioperative mortality, conversion to thoracotomy, thrombosis or mediastinal infection. The operation time of the uniportal XVATS group was significantly longer than that of the three-port group (87.5±19.0 min vs. 75.8±15.7 min, P=0.012). Besides, patients in the uniportal group had significantly lower pain score during 3-14 postoperative days than that of the three-port group (P=0.001).ConclusionUniportal XVATS extended thymectomy is feasible with less pain as compared with the patients using three-port XVATS, but it needs longer operation time at initial stage.

    Release date:2020-05-28 10:21 Export PDF Favorites Scan
  • Uniportal versus three-port single-direction thoracoscopic lobectomy: A retrospective cohort study

    ObjectiveTo explore the feasibility and short-term efficacy of uniportal and three-port single-direction video-assisted thoracoscopic surgery (S-VATS) anatomical lobectomy for lung cancer.MethodsClinical data of 60 lung cancer patients, including 40 males and 20 females with an average age of 62.2±9.0 years, who received S-VATS anatomic lobectomy and systematic lymph nodes dissection by the same surgeon in our hospital between July 2016 and January 2019 were retrospectively analyzed. These patients were divided into a uniportal S-VATS group and a three-port S-VATS group according to surgical procedures, with 30 patients in each group. The clinical data of the two groups were compared.ResultsThere was no conversion to thoracotomy, surgical port addition, or mortality in this cohort, with tumor-negative surgical margin. There was no statistical difference in the operation time between the two groups (70.8±16.4 min vs. 73.7±14.3 min, P>0.05). Meanwhile, both groups showed similar intraoperative blood loss, stations and numbers of dissected lymph nodes, incidence of operation-related complications, duration and volume of chest tube drainage, as well as postoperative hospital stay (P>0.05). Besides, pain score of the patients in the uniportal S-VATS group was significantly lower than that of the three-port S-VATS group on postoperative 3-14 d (P<0.05). The mean duration of follow-up was 10 months, and all the patients were survived without tumor recurrence or metastasis.ConclusionThe transition from three-port S-VATS to uniportal S-VATS anatomical lobectomy for treatment of lung cancer is feasible. However, further studies are needed to elucidate the optimal resection sequence of pulmonary vessels.

    Release date:2020-06-29 08:13 Export PDF Favorites Scan
  • Arthroscopic Treatment for Synovial Chondromatosis

    【摘要】 目的 探讨关节镜治疗膝关节滑膜软骨瘤病的疗效。 方法 2005年1月—2009年10月,对23例(28膝)滑膜软骨瘤病患者入院行X线片、关节活动度检查、视觉模拟评分以及Lysholm膝关节功能评分。根据镜下所见分为表浅型6例,游离体型17例。结合病理学检查行Milgram 分期,Ⅱ期16例,Ⅲ期7例。所有患者均行关节镜下病变滑膜切除及游离体取出治疗。 结果 所有患者均随访13~57个月,平均(32.3±6.7)个月,术后伤口均甲级愈合。术后(5.05±2.43) d恢复正常生活或工作。症状明显改善21例(91.30%),部分改善2例(8.70%),对疗效满意23例(100%)。膝关节关节活动度由术前的伸膝(14.29±16.34)°以及屈膝(106.07±35.83)°提高到术后的伸膝(1.79±2.79)°及屈膝(132.64±35.64)°,差异具有统计学意义(Plt;0.05)。负重行走时疼痛视觉模拟评分由术前的(3.81±2.02)分降低到术后的(0.37±0.65)分(Plt;0.05)。Lysholm评分由术前的(43.20±8.24)分升至术后6个月的(86.72±5.40)分(Plt;0.05);术后1年复诊并检查膝关节正侧位X线片,均未见滑膜软骨瘤体,所有患者无复发。 结论 关节镜下游离体取出术联合病变滑膜切除术疗效满意,关节疼痛明显减轻,功能恢复,是一种治疗膝关节滑膜软骨瘤病确切有效的方法。【Abstract】 Objective To investigate the therapeutic effect of arthroscopic treatment on synovial chondromatosis.  Methods A total of 23 patients (28 knees) with synovial chondromatosis were diagnosed and treated in our hospital from January 2005 to October 2009. All of the patients underwent radiographic imaging examination, knee joint range of motion (ROM), visual analogue scale (VAS) and Lysholm score. According to distinct arthroscopic appearance, superficial pattern was found in 6 patients and loose body lesion pattern was in 17. Additionally, combined with pathological examination, according to the Milgram staging,Stage Ⅱ was in 6 patients and Stage Ⅲ was in 7. Arthroscopic limited synovectomy and removal of loose bodies were performed on all the patients.  Results The patients were followed up for 13-57 months with the mean of (32.3±6.7) months. The wound of all patients healed up. The time of returning to normal work and life was (5.05±2.43) days for average. The postoperative symptom was markedly alleviated in 21 patietns and partly alleviated in 2. All patients were satisfied with the therapeutic effect. The mean activity of knee joint was significantly different befoe and after the surgery (Plt;0.05) preoperative extension and flexion degrees were (14.29±16.34) and (106.07±35.83) degrees, respectively; postoperative extension and flexion degrees were (1.79±2.79) and (132.64±35.64) degrees (flexion) , respectively. The mean VAS score of weight bearing walking was 0.37±0.65 after theoperation and 3.81±2.02 before the peration; the difference was significantly different (Plt;0.05). The preoperative Lysholm knee score was 34-67 with the mean of 43.20±8.24, and the post-operative score was 71-99 with the mean of 86.72±5.40. There were differences in preoperative and post-operative scores (Plt;0.05) . Radiographic imaging examination of knee joint was performed 1 year after the opertation, no loose bodies was seen and no patients recurred.  Conclusion The therapeutic effect of arthroscopic limited synovectomy and removal of loose bodies is good on synovial chondromatosis.

    Release date:2016-09-08 09:26 Export PDF Favorites Scan
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