Individual differences of P300 potentials lead to that a large amount of training data must be collected to construct pattern recognition models in P300-based brain-computer interface system, which may cause subjects’ fatigue and degrade the system performance. TrAdaBoost is a method that transfers the knowledge from source area to target area, which improves learning effect in the target area. Our research purposed a TrAdaBoost-based linear discriminant analysis and a TrAdaBoost-based support vector machine to recognize the P300 potentials across multiple subjects. This method first trains two kinds of classifiers separately by using the data deriving from a small amount of data from same subject and a large amount of data from different subjects. Then it combines all the classifiers with different weights. Compared with traditional training methods that use only a small amount of data from same subject or mixed different subjects’ data to directly train, our algorithm improved the accuracies by 19.56% and 22.25% respectively, and improved the information transfer rate of 14.69 bits/min and 15.76 bits/min respectively. The results indicate that the TrAdaBoost-based method has the potential to enhance the generalization ability of brain-computer interface on the individual differences.
Objective To enhance the understanding of nonfibrotic hypersensitivity pneumonitis (nfHP) by summarizing the clinical characteristics of 32 cases of nfHP. Methods The data of 32 cases with nfHP was collected and analyzed. They were diagnosed in Beijing Friendship Hospital, Capital Medical University from Jan 1st, 2017 to Oct 31, 2021. Results The median age of the nfHP patients was 54 years, among whom 75.0% were females. The cases developed in a majority of avian exposure (22 cases, 68.8%). The main symptoms were dyspnea/shortness of breath (28 cases, 87.5%), cough (25 cases, 78.1%）and sputum production (21 cases, 65.6%). High-resolution CT (HRCT) showed diffuse ground glass opacification (25 cases, 78.1%), centrilobular ground glass nodules (20 cases, 62.5%) and air trapping (9 cases, 28.1%). Bronchoalveolar lavage fluid (BALF) featured an increase of proportion of lymphocytes (>20%, 90.6% and >40%, 50%), and a decrease of CD4+/CD8+ T cell ratio (<1.2, 65.6% and <0.8, 40.6%). Most of the cases had reduced diffusion capacity for carbon monoxide (16 cases out of 26 cases, 61.5%) and decreased total lung capacity (13 cases out of 26 cases, 50%). Few cases showed obstructive ventilatory function (6 cases out of 26 cases, 23.1%). Most cases (22 cases, 68.8%) of nfHP showed an excellent survival with short-term corticosteroid treatment. Few cases (5 cases, 15.6%) experienced spontaneous remission after antigen avoidance. Conclusions The diagnosis of nfHP includes identifying antigenic exposures, featured chest HRCT and lymocytosis in BALF. nfHP patients showed an excellent survival with short-term corticosteroid treatment as well as antigen avoidance.
ObjectiveTo explore the effectiveness of using antibiotic bone cement-coated plates internal fixation technology as a primary treatment for Gustilo type ⅢB tibiofibular open fractures. Methods The clinical data of 24 patients with Gustilo type ⅢB tibiofibular open fractures who were admitted between January 2018 and December 2021 and met the selection criteria was retrospectively analyzed. Among them, there were 18 males and 6 females, aged from 25 to 65 years with an average age of 45.8 years. There were 3 cases of proximal tibial fracture, 6 cases of middle tibial fracture, 15 cases of distal tibial fracture, and 21 cases of fibular fracture. The time from injury to emergency surgery ranged from 3 to 12 hours, with an average of 5.3 hours. All patients had soft tissue defects ranging from 10 cm×5 cm to 32 cm×15 cm. The time from injury to skin flap transplantation for wound coverage ranged from 1 to 7 days, with an average of 4.1 days, and the size of skin flap ranged from 10 cm×5 cm to 33 cm×15 cm. Ten patients had bone defects with length of 2-12 cm (mean, 7.1 cm). After emergency debridement, the tibial fracture end was fixed with antibiotic bone cement-coated plates, and the bone defect area was filled with antibiotic bone cement. Within 7 days, the wound was covered with a free flap, and the bone cement was replaced while performing definitive internal fixation of the fracture. In 10 patients with bone defect, all the bone cement was removed and the bone defect area was grafted after 7-32 weeks (mean, 11.8 weeks). The flap survival, wound healing of the affected limb, complications, and bone healing were observed after operation, and the quality of life was evaluated according to the short-form 36 health survey scale (SF-36 scale) [including physical component summary (PCS) and mental component summary (MCS) scores] at 1 month, 6 months after operation, and at last follow-up. ResultsAll 24 patients were followed up 14-38 months (mean, 21.6 months). All the affected limbs were successfully salvaged and all the transplanted flaps survived. One case had scar hyperplasia in the flap donor site, and 1 case had hypoesthesia (grade S3) of the skin around the scar. There were 2 cases of infection in the recipient area of the leg, one of which was superficial infection after primary flap transplantation and healed after debridement, and the other was sinus formation after secondary bone grafting and was debrided again 3 months later and treated with Ilizarov osteotomy, and healed 8 months later. The bone healing time of the remaining 23 patients ranged from 4 to 9 months, with an average of 6.1 months. The scores of PCS were 44.4±6.5, 68.3±8.3, 80.4±6.9, and the scores of MCS were 59.2±8.2, 79.5±7.8, 90.0±6.6 at 1 month, 6 months after operation, and at last follow-up, respectively. The differences were significant between different time points (P<0.05). ConclusionAntibiotic bone cement-coated plates internal fixation can be used in the primary treatment of Gustilo type ⅢB tibiofibular open fractures, and has the advantages of reduce the risk of infection in fracture fixation, reducing complications, and accelerating the functional recovery of patients.