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.
Brain–computer interface (BCI) technology enable humans to interact with external devices by decoding their brain signals. Despite it has made some significant breakthroughs in recent years, there are still many obstacles in its applications and extensions. The current used BCI control signals are generally derived from the brain areas involved in primary sensory- or motor-related processing. However, these signals only reflect a limited range of limb movement intention. Therefore, additional sources of brain signals for controlling BCI systems need to be explored. Brain signals derived from the cognitive brain areas are more intuitive and effective. These signals can be used for expand the brain signal sources as a new approach. This paper reviewed the research status of cognitive BCI based on the single brain area and multiple hybrid brain areas, and summarized its applications in the rehabilitation medicine. It’s believed that cognitive BCI technologies would become a possible breakthrough for future BCI rehabilitation applications.
The surface morphology of titanium metal is an important factor affecting its hydrophilicity and biocompatibility, and exploring the surface treatment strategy of titanium metal is an important way to improve its biocompatibility. In this study, titanium (TA4) was firstly treated by large particle sand blasting and acid etching (SLA) technology, and then the obtained SLA-TA4 was treated by single surface treatments such as alkali-heat, ultraviolet light and plasma bombardment. According to the experimental results, alkali-heat treatment is the best treatment method to improve and maintain surface hydrophilicity of titanium. Then, the nanowire network morphology of titanium surface and its biological property, formed by further surface treatments on the basis of alkali-heat treatment, were investigated. Through the cell adhesion experiment of mouse embryonic osteoblast cells (MC3T3-E1), the ability of titanium material to support cell adhesion and cell spreading was investigated after different surface treatments. The mechanism of biological activity difference of titanium surface formed by different surface treatments was investigated according to the contact angle, pit depth and roughness of the titanium sheet surface. The results showed that the SLA-TA4 titanium sheet after a treatment of alkali heat for 10 h and ultraviolet irradiation for 1 h has the best biological activity and stability. From the perspective of improving surface bioactivity of medical devices, this study has important reference value for relevant researches on surface treatment of titanium implantable medical devices.
ObjectiveTo study the effectiveness and safety of simply anterior approach for lower cervical spine fracture dislocation (Allen-Ferguson II or III type) without spinal cord injury. MethodsTwenty-five patients with lower cervical spine fracture dislocation (Allen-Ferguson II or III type) without spinal cord injury were treated between June 2013 and June 2015. There were 17 males and 8 females with an average age of 41.2 years (range, 31-57 years). Injury was caused by falling from height in 11 cases, by bruise in 5 cases, by crash of heavy object in 6 cases, and by traffic accident in 3 cases. There were 24 cases of fresh fractures and 1 case of old fracture. According to the Frankel grading criteria, 19 cases were rated as grade E and 6 cases as grade D. The injured levels included C4, 5 in 5 cases, C5, 6 in 14 cases, and C6, 7 in 6 cases. Unilateral locked-facet joint was observed in 9 cases, and bilateral locked-facet joint in 16 cases. The operation time, intraoperative blood loss, and surgical complications were recorded; the Odom standard was used to evaluate the effectiveness. The Cobb angle and D-value (the degree of cervical kyphosis or lordosis) were measured on the X-ray film, the bone graft fusion rate was recorded. ResultsThe operation was successfully completed in 25 patients; the operation time was 66 to 115 minutes, the intraoperative blood loss was 80 to 220 mL. The postoperative follow-up time was 12 to 36 months (mean, 19.3 months). Postoperative temporary dysphagia occurred in 1 case, and pain at donor site in 2 cases; there were no complications of spinal cord injury, hematoma, hoarse, and esophageal fistula. The nerve function was improved from preoperative grade D to postoperative grade E at 3 months. The X-ray films showed bone graft fusion; there was no loss of intervertebral height or loosening of internal fixation. At 3 months after operation, the effectiveness was excellent in 18 cases, good in 6 cases, and fair in 1 case, and the excellent and good rate was 96.0%. The postoperative Cobb angle and the D value were significantly improved when compared with preoperative ones (P < 0.05). ConclusionSimple anterior approach has the advantages of good effectiveness, small trauma, and fast recovery for treating lower cervical spine fracture dislocation (Allen-Ferguson II or III type) without spinal cord injury.
OBJECTIVE: To modify the surface of poly(D,L-lactide) film by anhydrous ammonia gaseous plasma treatment. METHODS: The changes of contact angles were measured and surface energy were calculated. Mouse 3T3 fibroblast cells were cultured on plasma modified and control poly(D,L-lactide) films. RESULTS: It was found that the hydrophilicity and surface energy of the materials have been increased after plasma treatment. Cell culture results showed that ammonia plasma treatment could promote the cell attachment and cells growth. After 4 days culture, the cells on the plasma treated films were 2-folds quantitatively compared with that of the control films. CONCLUSION: Ammonia plasma treatment can improve the cell affinity to poly(D,L-lactide).
Affective brain-computer interfaces (aBCIs) has important application value in the field of human-computer interaction. Electroencephalogram (EEG) has been widely concerned in the field of emotion recognition due to its advantages in time resolution, reliability and accuracy. However, the non-stationary characteristics and individual differences of EEG limit the generalization of emotion recognition model in different time and different subjects. In this paper, in order to realize the recognition of emotional states across different subjects and sessions, we proposed a new domain adaptation method, the maximum classifier difference for domain adversarial neural networks (MCD_DA). By establishing a neural network emotion recognition model, the shallow feature extractor was used to resist the domain classifier and the emotion classifier, respectively, so that the feature extractor could produce domain invariant expression, and train the decision boundary of classifier learning task specificity while realizing approximate joint distribution adaptation. The experimental results showed that the average classification accuracy of this method was 88.33% compared with 58.23% of the traditional general classifier. It improves the generalization ability of emotion brain-computer interface in practical application, and provides a new method for aBCIs to be used in practice.
Twenty one cases of hepatocholelithiasis treated through hepatic round ligament approach for hepaticojejunostomy is reported. Of them 5 were introgenic injury to the biliary tract， 8 were left hepatolithiasis (7 complicated with bile duct stricture), 2 were intrahepatic sandy stone with acute suppurative cholangeitis, and 3 were residual stone in left hepatic duct with cystlike dilatation after T-tube drainage; while traumatic injury to the biliary passages, previous multiple biliary tract operations and left hepatic duct stone with acute hemorrhage were present in one of case individually 75.9% each. The ages of the patients were between 32 to 50 years. Clinical follw-up in this series was satisfactory. The authors consider that this approach gives good exposure with little injury to the liver and no liver resection needed. The indication for this approach mode of anastomosis and some operative details are discussed.
ObjectivesTo systematically review the risk factors of hepatocellular carcinoma (HCC) in patients with hepatic B surface antigen (HBsAg).MethodsScopus, EMbase, PubMed, and The Cochrane Library databases were systematically searched for relevant studies on HCC after HBsAg seroclearance from inception to October 31st, 2017. Two reviewers independently screened literature, extracted the data, and evaluated the risk of bias in the included studies. Meta-analysis was then conducted using R 3.5.3 software.ResultsA total of 28 studies involving 105 411 patients were included. Among 105 411 patients with chronic hepatitis B (CHB), 7 656 patients occurred spontaneously HBsAg seroclearance, while 1 248 patients had HBsAg seroclearance after interferon or nucleoside analogue therapy. The rate of HBsAg seroclearance was 6.77%. Meta-analysis showed that risk factors for HCC after serum HBsAg conversion included cirrhosis (OR=6.43, 95%CI 3.56 to 11.60, P<0.001), male (OR=2.72, 95%CI 1.66 to 4.46,P<0.001), and age ≥50 years at HBsAg seroclearance (OR=3.71, 95%CI 2.17 to 6.35,P<0.001).ConclusionsPatients with CHB after HBsAg seroclearance are still at risk of developing HCC. Therefore, periodic surveillance is recommended, especially for male patients, patients with cirrhosis, and patients who experience HBsAg seroclearance when over 50.
Due to the high complexity and subject variability of motor imagery electroencephalogram, its decoding is limited by the inadequate accuracy of traditional recognition models. To resolve this problem, a recognition model for motor imagery electroencephalogram based on flicker noise spectrum (FNS) and weighted filter bank common spatial pattern (wFBCSP) was proposed. First, the FNS method was used to analyze the motor imagery electroencephalogram. Using the second derivative moment as structure function, the ensued precursor time series were generated by using a sliding window strategy, so that hidden dynamic information of transition phase could be captured. Then, based on the characteristic of signal frequency band, the feature of the transition phase precursor time series and reaction phase series were extracted by wFBCSP, generating features representing relevant transition and reaction phase. To make the selected features adapt to subject variability and realize better generalization, algorithm of minimum redundancy maximum relevance was further used to select features. Finally, support vector machine as the classifier was used for the classification. In the motor imagery electroencephalogram recognition, the method proposed in this study yielded an average accuracy of 86.34%, which is higher than the comparison methods. Thus, our proposed method provides a new idea for decoding motor imagery electroencephalogram.