In order to quickly and accurately identify the onset and offset of the QRS complex in electrocardiogram (ECG) signal with different forms, a triple local transform method was employed in the present study to detect the suspected onset and offset points of QRS. The accurate onset and offset points of QRS complexes were selected according to the rules drawn by the trial process based on the characteristics of angle and amplitude constituted within these suspected points. The method makes full advantage of the angle and amplitude characteristics of the QRS complex, by which the results can be acquired with some simple arithmetic quickly, accurately and adaptively. The method was investigated with data from the MIT-BIH arrhythmia database and satisfactory results were obtained.
Nowadays, for gait instability phenomenon, many researches have been carried out at home and abroad. However, the relationship between plantar pressure and gait parameters in the process of balance adjustment is still unclear. This study describes the human body adaptive balance reaction during slip events on slippery level walk by plantar pressure and gait analysis. Ten healthy male subjects walked on a level path wearing shoes with two contrastive contaminants (dry, oil). The study collected and analyzed the change rule of spatiotemporal parameters, plantar pressure parameters, vertical ground reaction force (VGRF), etc. The results showed that the human body adaptive balance reaction during slip events on slippery level walk mainly included lighter touch at the heel strikes, tighter grip at the toe offs, a lower velocity, a shorter stride length and longer support time. These changes are used to maintain or recover body balance. These results would be able to explore new ideas and provide reference value for slip injury prevention, walking rehabilitation training design, research and development of walking assistive equipments, etc.
ObjectiveTo review the current situation of total knee arthroplasty (TKA) used in young patients with osteoarthritis. MethodsThe recent literature in the treatment of osteoarthritis with TKA in young patients was extensively reviewed. The characteristics, curative effect, and postoperative satisfaction degree of TKA in young patients were analyzed and summarized. ResultsYoung patients have longer life expectancy and higher activity, which may lead to much higher expectation of the TKA. Comparing with elderly patients, young patients obtain equal or better effectiveness after TKA, but they are likely to not be satisfied with the effects because of low survival rate of the prosthesis. At present, continuous development of implant design, prosthesis material, and operation technique are in progress to reduce wear, hence to prolong the implant survivorship so as to meet the desire of young patients. However, the studies of the big samples and long-term follow-up are required to confirm the clinical advantages of such developments. ConclusionWith the trend of TKA in young patients, surgeons should have a good understanding of the patients' demands, select suitable prosthesis and give appropriate preoperative counseling to build up an objective expectation of curative effect, which will lead to a better doctor-patient relationship.
Based on the application of finite element analysis in spine biomechanics, the research progress of finite element method applied in lumbar spine mechanics is reviewed and the prospect is forecasted. The related works, including lumbar ontology modeling, clinical application research, and occupational injury and protection, are summarized. The main research areas of finite element method are as follows: new accurate modeling process, the optimized simulation method, diversified clinical effect evaluation, and the clinical application of artificial lumbar disc. According to the recent research progress, the application prospects of finite element method, such as automation and individuation of modeling process, evaluation and analysis of new operation methods and simulation of mechanical damage and dynamic response, are discussed. The purpose of this paper is to provide the theoretical reference and practical guidance for the clinical lumbar problems by reviewing the application of finite element method in the field of the lumbar spine biomechanics.
ObjectiveTo explore the effects of cytoskeleton depolymerizing agent and stabilizer on the clathrin/caveolae-mediated endocytosis, the expression of membrane vascular endothelial cadherin (VE-cad), and the vascular permeability by the transformation of cytoskeleton structure after lipopolysaccharide (LPS) treatment. MethodsCRL-2922 cells were used in the experiments. Indexes were tested at corresponding time point according to name of group, but in blank control group indexes could be tested at any time point. CRL-2922 cells were divided into blank control group, LPS-1 h group, and LPS-4 h group to observe cytoskeleton structure; CRL-2922 cells were divided into LPS-1 h group, Cyt D+LPS-1 h group, LPS-4 h group, and Jasp+LPS-4 h group to determine the expression of membrane VE-cad, and to determine the expression of its co-immunoprecipitation with clathrin and caveolin-1 (Cav1); besides, CRL-2922 cells were divided into blank control group, LPS-1 h group, Cyt D+LPS-1 h group, LPS-4 h group, and Jasp+LPS-4 h group to detect the cumulative infiltration rate. Results①The cytoskeleton showed a dynamic change after LPS treat-ment, the F-actin polymerized and stress fibers formed at 1 hour after LPS treatment, but depolymerized at 4 hours after LPS treatment. ②Compared with LPS-1 h group, the level of co-immunoprecipitation of VE-cad with clathrin in Cyt D+ LPS-1 h group decreased (P<0.05), the level of co-immunoprecipitation of VE-cad with Cav1 increased (P<0.05), and expression level of VE-cad in plasma membrane decreased (P<0.05); compared with LPS-4 h group, there was no significant difference in the level of co-immunoprecipitation of VE-cad with clathrin of Jasp+LPS-4 h group (P>0.05), but the level of co-immunoprecipitation of VE-cad with Cav1 decreased in Jasp+LPS-4 h group (P<0.05), and expression level of VE-cad in plasma membrane increased (P<0.05). ③Compared with blank control group, the cumulative infiltration rates of LPS-1 h group and LPS-4 h group were both higher (P<0.05); compared with LPS-1 h group, the cumulative infiltration rate of Cyt D+LPS-1 h group was higher (P<0.05); compared with LPS-4 h group, the cumulative infiltration rate of Jasp+LPS-4 h group was lower (P<0.05). ConclusionActin cytoskeleton shifts from polymerization to depoly-merization after LPS treatment, the structural change of actin cytoskeleton is an important reason for the transformation of VE-cad endocytosis pathway from clathrin-mediated to caveolae-mediated after LPS treatment.
ObjectiveTo analyze the clinical characteristics and surgical treatment of bicuspid aortic valve combined with thoracic aortic dilation. MethodsWe retrospectively analyzed the clinical data of 68 patients of bicuspid aortic valve combined with thoracic aortic dilation underwent surgical treatment in our hospital between January 2010 and June 2014. There were 47 males and 21 females at age of 26-77(44.5±16.3) years. Different surgical treatments including Wheat procedure(n=22), aortic valve replacement+ascending aortoplasty(n=10), Bentall procedure(n=13), aortic valve replacement+ascending aortic replacement+right hemi aortic arch replacement(n=13), Bentall procedure+ascending aortic replacement+right hemi aortic arch replacement(n=8), Bentall procedure+ascending aortic replacement+total arch replacement+stented elephant trunk(n=2) were carried out according to the type. ResultsAll 68 patients underwent surgical treatment. The mortality in hospital is at 4.4%(3/68). The postoperative complications were neurological and mental complications(n=3), pneumonia(n=2), and exploratory thoracotomy(n=2). We followed up 63 patients for 6 months to 4 years. A total of 62 patients were well without reoperation except one death at the end of following-up 2 years. ConclusionBicuspid aortic valve combined with thoracic aortic dilation has diversiform clinical characteristics. The surgical treatment should be chosen according to the aortic valve and thoracic aortic lesion characteristics.
The purpose of this study is to determine how restricting inversion-eversion and pronation-supination motions of the ankle joint complex influences the stability of human gait. The experiment was carried out on a slippery level ground walkway. Spatiotemporal gait parameter, kinematics and kinetics data as well as utilized coefficient of friction (UCOF) were compared between two conditions, i.e. with restriction of the ankle joint complex inversion-eversion and pronation-supination motions (FIXED) and without restriction (FREE). The results showed that FIXED could lead to a significant increase in velocity and stride length and an obvious decrease in double support time. Furthermore, FIXED might affect the motion angle range of knee joint and ankle joint in the sagittal plane. In FIXED condition, UCOF was significantly increased, which could lead to an increase of slip probability and a decrease of gait stability. Hence, in the design of a walker, bipedal robot or prosthetic, the structure design which is used to achieve the ankle joint complex inversion-eversion and pronation-supination motions should be implemented.
ObjectiveTo analyze the MR findings of primary gallbladder carcinoma so as to improve the diagnostic accuracy. MethodsA retrospective study was developed involving 15 primary gallbladder carcinoma patients identified by postoperative pathology between January 2010 and March 2013. Imaging findings were analyzed including lesions location, enhancement characteristics, the dilatation of bile ducts and gallstones. ResultsAmong the 15 gallbladder carcinoma patients, 5 were misdiagnosed as neoplasms in the porta hepatis combined with dilation of intrahepatic bile ducts. Intra- and extrahepatic bile ducts dilated in 7 patients, which were misdiagnosed as tumors or inflammation. Two cases of gallbladder carcinoma with right lobe mass were misdiagnosed as gallbladder polyps. One patient was misdiagnosed as cholecystitis. The retrospective analysis revealed that the gallbladder wall thickened in 12 cases, with focal thickening in 9 and diffuse thickening in 3 cases. Enhanced scanning demonstrated that gallbladder wall enhanced in varying degrees, and 11 cases had delayed enhancement features. There were 8 patients with gallstones and 2 with gallbladder wall nodules. ConclusionPrimary gallbladder carcinoma can easily cause bile duct dilatation, and manifests as focal or diffuse mural thickening, often accompanied by gallstones.
ObjectiveTo explore the safety, effectiveness, and cosmetic advantage of endoscopic thyroidectomy for differentiated thyroid cancer in the cT1N0 stage. MethodsThe clinical data of 148 patients underwent thyroidectomy for the cT1N0 differentiated thyroid cancer in the First Affiliated Hospital of PLA General Hospital and the PLA General Hospital from September 2010 to September 2013 were analyzed retrospectively, including 36 patients by total endoscopic thyroidectomy (TET group), 41 patients by endoscopic-assisted thyroidectomy (EAT group), and 71 patients by open thyroidectomy (OT group). The intraoperative status, early complications, late complications, and cosmetic result were compared among these three groups. ResultsAll the procedures were accomplished successfully.①In the intraoperative status: The operation time of the TET group was significantly longer than that of the EAT group(P < 0.05)or OT group (P < 0.05), drainage on the first day after operation in the TET group was significantly more than that in the EAT(P < 0.05)or OT group (P < 0.05), the intraoperative bleeding of the TET group or EAT group was significantly less than that of the OT group (P < 0.05), there were no statistical significances in the total number of lymph nodes dissection and number of positive lymph nodes among three groups (P > 0.05).②In the early complications: The postoperative pain score of the TET group was significantly lower than that of the EAT group (P < 0.05)or OT group (P < 0.05), there were no statistical significances in the postoperative bleeding, seroma, infection, transient recurrent laryngeal nerve paralysis, or transient hypoparathyroidism among three groups (P > 0.05).③In the late complications: there was no statistical significance in the perpetual recurrent laryngeal nerve paralysis, perpetual hypoparathyroidism, or thyroid cancer relapse among three groups (P > 0.05).④The best cosmetic result was obtained by the patients underwent TET as compared with the patients underwent EAT(P < 0.05)or OT (P < 0.05). ConclusionsEndoscopic procedure has the same effectiveness and safety with open procedure for differentiated thyroid cancer in the cT1N0 stage, but endoscopic procedure has a better cosmetic result than that open procedure. Compared with EAT, TET has more advantages in the cosmetic result.
ObjectiveTo evaluate the characteristics, treatment, and effectiveness of grade Ⅲ spoke heel injury in children. MethodsBetween January 2007 and June 2013, 31 children with grade Ⅲ spoke heel injuries were treated. There were 19 boys and 12 girls, aged from 3 to 12 years (mean, 5.2 years). The time from trauma to operation was 2 hours to 26 days (mean, 4.4 days). The soft tissue defects of the heels ranged from 3.5 cm×2.5 cm to 8.0 cm×4.5 cm, which all complicated with Achilles tendon and calcaneus tuberosity defects. In 16 cases of large Achilles tendon defects which can not be stretched straightly to calcaneus tuberosities, repair with sl iding gastrocnemius musculocutaneous flaps (16 cm×5 cm to 21 cm×10 cm ) and insertion reconstruction of the tendon were performed. In 15 cases of Achilles tendon defects which can be stretched straightly to calcaneus tuberosities, repair with reversed pedicled flap (4.0 cm×2.5 cm to 8.0 cm×4.5 cm) and insertion reconstruction of the tendon were given. Nerve anastomosis was not performed. The donor site was covered with spl it-thickness skin graft. ResultsAll children were followed up 6 months to 4 years (mean, 13 months). The other flaps survived except 3 cases having partial necrosis. The color and appearance of the flaps were satisfactory, with no impact on wearing shoes and walking. The flaps recovered sensory function. As more follow-up time, the angle of dorsal flexion was gradually improved. Heel raising on one leg was restored. The bone amount of calcaneus tuberosity increased slowly based on X-ray films. ConclusionGrade Ⅲ spoke heel injury in children possesses pecul iar features, surgical methods should be based on defects of Achilles tendon and soft tissue. Dorsal flexion of the ankle is obviously l imited; as follow-up time goes on, the ankle function is progressively improved. However, long-term follow-up is needed.