Objective To investigate the effect of surface propertyof different polyether-ester block copolymers［poly(ethylene glycol-terephthalate)/poly(butylene terephthalate), PEGT/PBT］ on the growth of smooth muscle cells (SMCs) and endothelial cells(ECs). Methods Three kinds of copolymers were synthesized, which were 1000-T20 (group A), 1000PEGT70/PBT30 (group B) and 600PEGT70/PBT30 (group C). The water-uptake and contact angle of three polyether-ester membranes were determined. The canine aorta smooth muscle cells and external jugular vein endothelial cells were primarily harvested, subcultured, and then identified. The proliferation of SMCs and ECs on the different polyether-ester membranes were investigated. Results The water-uptake of three copolymers arranged as the sequence of group C＜group A＜group B, and contact angle as the sequence of group C＞group A＞group B, indicating group B being more hydrophilic. However, smooth musclecells andendothelial cells grew poorly on the membrane of group B after low density seeding, but proliferated well on the membranes of group A and group C. Conclusion In contrast with more hydrophilic 1000PEGT70/PBT30, moderately hydrophilic 1000-T20 and 600PEGT70/PBT30 has better compatibility with vascular cells. The above results indicate that the vascular cells can grow well on moderately hydrophilic PEGT/PBT and that PEGT/PBT can be used in vascular tissue engineering.
Objective To explore an improved method of surgical operation for reposition of the articular surface with Type Ⅲ Pilon fractures. Methods From January 1999 to December 2005, 20 patients (22 sides) with Type Ⅲ Pilon fractures were treated with the delayed open reduction and the internal fixation, which took the superior articular surface of the talus as a templet so as to reposition the lower articular surface of the tibia, strengthen the bone transplantation, fasten the internal fixation, and make an early functional exercise possible. Complete data were obtained from 16 of the patients with 18 sides (13 males,15 sides; 3 females, 3 sides; age, 14-48 years). The injury due to a fallingaccident was found in 12 patients (14 sides), and due to a traffic accident in 4patients (4 sides). Results The healing of the first intention was achieved in 14 sides, the delayed healing in 3 sides, and the infection in 1 side. The follow-up of all the 16 patients for 971 months (average, 22 months) including the X-ray examinations revealed that no screw for the internal fixation entering the articular cavity. According to the Teeny’s judging standards of radiology evaluating the result of the surgery for Pilon fractures, the anatomical reduction of the related articular surface was found in 77.8% of the sides (14/18) and thehealing of the first intention (stage Ⅰ) in 94.4% (17/18). According to the Mazur’s criteria, an excellent result was obtained in 5 sides, good in 7, fair in 5, and poor in 1. The excellent and good result was 66.7%. Conclusion Propermanagement of the injured soft tissues, prompt recovery of the tibial distant plateau height, and accurate reposition of the articular surface, enough transplant bone for the solid support, b internal fixation for the distant tibial anatomical structure, and early functional exercise are the key points to the successful operation.
Objective To observe the effect of biological fixation of femoral stem prosthesis with multilayer macropores coating by combined use of autologousbone grafting. Methods The reconstructing femoral stem prostheses were designed personally, proximal 2/3 surfaces of which were reformed by thick multilayer stereo pore structure. Twentyfour adult mongrel canines underwent right femoralhead replacement and were divided randomly into two groups. The autogenous bonemud of femoral head and neck were not used in the control group. The histologicexamination, roentgenograms and biomechanical test were carried out in the 1st,3rd and 6th month after operation to observe the bone formation and fixation inthe exterior and interior sides of the prostheses. Results Onthe whole view,bone reconstruction occurred in experimental group in the 3rd and 6th month. Roentgenograms also proved to be superior to the control group. Histological examinationshowed that both the maximum bone inserting depth（μm） and average engorging ratio(%) of newly formed bone in experimental group surpassed those in the control group. The maximum shear strength of prosthesisbone interface in experimental group was significantly higher than that in the control group（Plt;0.01）. Conclusion Intensity of biological fixation can be strengthened remarkably by using femoral stem prothesis with multilayer macropores coating by combined use of autologous bone grafting.
Common spatial pattern (CSP) is a very popular method for spatial filtering to extract the features from electroencephalogram (EEG) signals, but it may cause serious over-fitting issue. In this paper, after the extraction and recognition of feature, we present a new way in which the recognition results are fused to overcome the over-fitting and improve recognition accuracy. And then a new framework for EEG recognition is proposed by using CSP to extract features from EEG signals, using linear discriminant analysis (LDA) classifiers to identify the user's mental state from such features, and using Choquet fuzzy integral to fuse classifiers results. Brain-computer interface (BCI) competition 2005 data setsⅣa was used to validate the framework. The results demonstrated that it effectively improved recognition and to some extent overcome the over-fitting problem of CSP. It showed the effectiveness of this framework for dealing with EEG.
Surface electromyography (sEMG) has been widely used in the study of clinical medicine, rehabilitation medicine, sports, etc., and its endpoints should be detected accurately before analyzing. However, endpoint detection is vulnerable to electrocardiogram (ECG) interference when the sEMG recorders are placed near the heart. In this paper, an endpoint-detection algorithm which is insensitive to ECG interference is proposed. In the algorithm, endpoints of sEMG are detected based on the short-time energy and short-time zero-crossing rates of sEMG. The thresholds of short-time energy and short-time zero-crossing rate are set according to the statistical difference of short-time zero-crossing rate between sEMG and ECG, and the statistical difference of short-time energy between sEMG and the background noise. Experiment results on the sEMG of rectus abdominis muscle demonstrate that the algorithm detects the endpoints of the sEMG with a high accuracy rate of 95.6%.
ObjectiveTo compare the strength difference between the interfacial screw and the interfacial screw combined with bone tunnel crossing technology to fix the tibial end of ligament during anterior cruciate ligament (ACL) reconstruction through the biomechanical test.MethodsTwenty fresh frozen pig tibia were randomly divided into two groups (n=10) to prepare ACL reconstruction models. The graft tendons in the experimental group were fixed with interfacial screw combined with bone tunnel crossing technology, and the graft tendons in the control group were fixed with interfacial screw. The two groups of specimens were fixed in the high-frequency dynamic mechanics test system M-3000, and the length change (displacement), ultimate load, and stiffness of graft tendons were measured through the reciprocating test and load-failure test.ResultsThe results of reciprocating test showed that the displacement of the experimental group was (3.06±0.58) mm, and that of the control group was (2.82±0.46) mm, and there was no significant difference between the two groups (t=0.641, P=0.529). The load-failure test results showed that the stiffness of the experimental group and the control group were (95.39±13.63) and (91.38±14.28) N/mm, respectively, with no significant difference (t=1.021, P=0.321). The ultimate load of the experimental group was (743.15±173.96) N, which was significantly higher than that of the control group (574.70±74.43) N (t=2.648, P=0.016).ConclusionIn ACL reconstruction, the fixation strength of tibial end with interface screw combined with bone tunnel crossing technology is obviously better than that of interface screw alone.
Objective To explore the effect of membrane surface nucleolin （NCL） on activation of epidermal growth factor receptor （EGFR） signaling. Methods Immunohistochemistry was used to identify the expressions of membrane surface NCL or EGFR in pallilary thyroid carcinoma （PTC） tissues. The level of phosphorlated EGFR in TPC-1 cells was observed by Western blot. TPC-1 cells invasion capacity was detected by Transwell assay. Results The posi-tive expression rates of membrane surface NCL and EGFR in PTC tissues were 100% （56/56） and 80.4% （45/56） respe-ctively， while the expressions of NCL and EGFR were related with lymph node metastasis （P＜0.05）. There was posi-tive correlation between the expressions of NCL and EGFR （r=0.635， P＜0.01）. Western blot showed that anti-NCL or anti-EGFR of TPC-1 cells could inhibit the expression of phosphorlation EGFR （P＜0.01）. Transwell assay showed the number of membrane-invading cells were reduced significantly in anti-NCL group anti-EGFR group （P＜0.01）. Conclusions Membrane surface NCL may be a kind of indispensable component in activation of EGFR signaling， by which EGFR can participate in growth and invasion of tumors. NCL can be used as a target for developing a new field of tumor treatment.
A total of 12 cases of old facet dislocations of cervical spine treated between december 1988 and 1993 were analyzed in order to evaluate the efficacy of various surgical modalities. In this series, there were 8 males and 4 females, with ages ranged from 16 to 50 years old (averaged 37.8 years old). The duration from injury to admission to our hospital was ranged from 1 to 8 months (averaged 3.7 months). Dislocation levels were as follows: C3,4 in 1 case, C4,5 in 4 cases, C5,6 in 4 cases and C6,7 in 3 cases. Unilateral facet dislocation was in 7 cases and bilateral facet dislocation in 5 cases. Neurological status on admission was as follows: spinal cord and nerve root lesion in 5 cases, nerve root lesion alone in 5 cases and neurologically intact in 2 cases. Besides all facets receiving facetectomy and iliac bone graft, other four kinds of adjuvant treatments were used, including internal fixation by stainless wires laminae or spinous processes in 4 cases, Luque rod in 1 cases, anterior fibrolysis combined with posterior laminoplasty in 1 cases and sustained skull traction without internal fixation in 6 cases. The reduction efficacy from postoperative stustained skull traction was better and the stainless wires fixation ranked the next. The patients only suffering from the nerve root lesion recovered better, but those who had spinal cord combined with nerve root lesion recovered badly. In conclusion, for the treatment of old facet dislocation, it is necessary to resect the facet and graft with iliac bone.
In order to improve the accuracy of classification with small amount of motor imagery training data on the development of brain-computer interface (BCI) systems, we proposed an analyzing method to automatically select the characteristic parameters based on correlation coefficient analysis. Throughout the five sample data of dataset Ⅳa from 2005 BCI Competition, we utilized short-time Fourier transform (STFT) and correlation coefficient calculation to reduce the number of primitive electroencephalogram dimension, then introduced feature extraction based on common spatial pattern (CSP) and classified by linear discriminant analysis (LDA). Simulation results showed that the average rate of classification accuracy could be improved by using correlation coefficient feature selection method than those without using this algorithm. Comparing with support vector machine (SVM) optimization features algorithm, the correlation coefficient analysis can lead better selection parameters to improve the accuracy of classification.
In this study, surface electromyography (sEMG) of the lower limbs of cerebral-palsy (CP) subjects in gait cycle was recorded and its parameters of gait cycle characters were analyzed to assess their clinical severity. Three algorithms, including integrated profile (IP), sample-entropy (SampEN) and smooth nonlinear energy operator (SNEO) algorithm, were applied to calculate the duration of walking sEMG segments in simulated SEMG signals. After that, the efficiency and accuracy were compared among these three algorithms. SNEO was then selected as the optimal algorithm among the three algorithms and employed for real sEMG signal processing of CP subjects. The results indicated that there was no significant difference in the accuracy of sEMG segement detection for the three algorithms. However, the computation speed of SNEO algorithm was much faster than those of the others and thus it was a suitable algorithm for detecting walking sEMG segments of CP subjects. In addition, the positive correlation was found between the clinical severity and the mean duration of walking sEMG segments in CP subjects. The results indicated that there was a significant difference in the three groups of CP subjects with different levels of severity. Our findings showed that the mean duration of walking sEMG segments could be considered as an assistant index to evaluate the clinical severity of CP subjects.