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find Author "李凡" 10 results
  • 乳腺癌诊治现状与展望

    Release date:2019-11-25 03:18 Export PDF Favorites Scan
  • Automated detection of sleep-arousal using multi-scale convolution and self-attention mechanism

    In clinical, manually scoring by technician is the major method for sleep arousal detection. This method is time-consuming and subjective. This study aimed to achieve an end-to-end sleep-arousal events detection by constructing a convolutional neural network based on multi-scale convolutional layers and self-attention mechanism, and using 1 min single-channel electroencephalogram (EEG) signals as its input. Compared with the performance of the baseline model, the results of the proposed method showed that the mean area under the precision-recall curve and area under the receiver operating characteristic were both improved by 7%. Furthermore, we also compared the effects of single modality and multi-modality on the performance of the proposed model. The results revealed the power of single-channel EEG signals in automatic sleep arousal detection. However, the simple combination of multi-modality signals may be counterproductive to the improvement of model performance. Finally, we also explored the scalability of the proposed model and transferred the model into the automated sleep staging task in the same dataset. The average accuracy of 73% also suggested the power of the proposed method in task transferring. This study provides a potential solution for the development of portable sleep monitoring and paves a way for the automatic sleep data analysis using the transfer learning method.

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  • The study on the characteristics of active force of neck muscles under rapid braking conditions

    This paper studies the active force characteristics of the neck muscles under the condition of rapid braking, which can provide theoretical support for reducing the neck injury of pilots when carrier-based aircraft blocks the landing. We carried out static loading and real vehicle braking experiments under rapid braking conditions, collected the active contraction force and electromyography (EMG) signals of neck muscles, and analyzed the response characteristics of neck muscle active force response. The results showed that the head and neck forward tilt time was delayed and the amplitude decreased during neck muscle pre-tightening. The duration of the neck in the extreme position decreased, and the recovery towards the seat direction was faster. The EMG signals of trapezius muscle was higher than sternocleidomastoid muscle. This suggests that pilots can reduce neck injury by pre-tightening the neck muscles during actual braking flight. In addition, we can consider the design of relevant fittings for pre-tightening the neck muscles.

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  • Predictive value of fibrinogen-albumin-ratio in adult hemorrhage after extracorporeal membrane oxygenation

    ObjectiveTo explore the clinical value of fibrinogen-albumin-ratio (FAR) in adult extracorporeal membrane oxygenation (ECMO) hemorrhage. MethodsThe clinical data of adult patients receiving ECMO in the West China Hospital from 2018 to 2020 were analyzed retrospectively. Patients were divided into a bleeding group and a non-bleeding group based on whether they experienced bleeding after ECMO. Logistic regression analysis was used to study the relationship between FAR and bleeding, as well as risk factors for death. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to analyze the predictive ability of FAR. According to the optimal cut-off value of FAR for predicting hemorrhage, patients were divided into a high-risk group and a low-risk group, and the occurrence of bleeding was compared between the two groups. ResultsA total of 125 patients were enrolled in this study, including 85 males and 40 females, aged 46.00 (31.50, 55.50) years. Among them, 58 patients received veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and 67 patients received veno-venous extracorporeal membrane oxygenation (VV-ECMO). There were 49 patients having bleeding, and the lactate level was higher (P=0.026), the platelet count before ECMO initiation and 24 h after ECMO initiation was lower (P=0.031, 0.020), the fibrinogen level 24 h after ECMO initiation was lower (P=0.049), and the proportion of myocarditis patients was higher (P=0.017) in the bleeding group than those of the non-bleeding group. In the subgroup analysis of ECMO mode, the higher D-Dimer, lactate level and lower FAR before and 24 h after ECMO initiation were associated with bleeding in the VA-ECMO group (P=0.017, 0.011, 0.033, 0.005). The 24 h FAR was independently correlated with bleeding (P=0.048), and AUC was 0.714. The cut-off value was 55.73. According to this optimal cut-off value, 25 patients were divided into the high-risk group (≤55.73) and 33 into the low-risk group (>55.73). There was a higher incidence of bleeding in the high-risk group compared to the low-risk group (unadjusted P=0.002; P=0.013 for multivariable adjustment). In the VV-ECMO group, the relationship between FAR and bleeding events was not significant (P>0.05). ConclusionLow 24 h FAR is an independent risk factor for bleeding in VA-ECMO patients, and the diagnostic cut-off value is 55.73.

    Release date:2024-08-22 04:25 Export PDF Favorites Scan
  • Clinical diagnosis and treatment analysis of liver metastasis of intracranial anaplastic solitary fibrous tumor/hemangiopericytoma

    ObjectiveTo investigate the clinicopathologic features of intracranial anaplastic solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) and diagnosis and treatment after liver metastasis.MethodThe clinicopathologic data of patients with intracranial anaplastic SFT/HPC who had metastasized to the liver and other organs after surgery were collected from 2003 to 2019 in the Second Hospital of Lanzhou University.ResultsAll 3 patients with intracranial anaplastic SFT/HPC underwent surgical resection and supplemented with conventional radiotherapy after operation. After the initial intervention treatment, 2 patients relapsed at 10 years and 7 years after the operation, and 3 patients had liver metastases at 11, 7, and 6 years after the initial intervention treatment. One of them was accompanied by uterus, lung, and vertebral body metastases.ConclusionsIntracranial anaplastic SFT/HPC has a high risk of recurrence and extracranial metastasis. Liver is a common target organ for metastasis of anaplastic SFT/HPC, liver metastasis is delayed after initial intervention of intracranial anaplastic SFT/HPC, it requires a long-term close follow-up.

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  • Standardized Techniques for Laparoscopic Radical Rectal Resection and Its Application Prospect: Outcomes in 433 Patients and Review of The Literature

    ObjectiveTo standardize the techniques for laparoscopic radical rectal resection and discuss its application prospect. MethodsThe clinical data of 433 patients who underwent laparoscopic radical rectal resections from July 2003 to December 2010 in our hospital were reviewed retrospectively, and the different surgery procedures and the development prospect were explored. ResultsFive cases (1.2%) underwent handassistant laparoscopic procedures, 412 cases (95.2%) were done by laparoscopic-assisted operation, and the specimens were taken out with transanal pull-through technique in 16 cases (3.7%). In all of them, conversion to open procedures occurred in 11 patients (2.5%), and 290 (67.0%) patients were followed-up in 1 to 6 years, average in 2.7 years. Local recurrence occurred in 7 (2.4%) patients, while distant metastasis were diagnosed in 22 (7.6%) cases, and the overall mortality was 15.9% (46/290). There was no port-site metastasis occurred. ConclusionsFour-port laparoscopic rectal resection technique is also the clinical mainstream. Standardized laparoscopic procedure for rectal resections enhances the transformation of laparoscopic skills, and makes the operation predictable. Single incision procedure and natural orifice transluminal endoscopic surgery are future direction to explore.

    Release date:2016-09-08 10:45 Export PDF Favorites Scan
  • Long-term effectiveness of posterior lumbar interbody fusion of retaining posterior ligamentous complex

    ObjectiveTo compare the long-term effectiveness of wheather posterior ligamentous complex (PLC) preserved between posterior fenestration decompression interbody fusion and posterior total laminectomy interbody fusion. MethodsThe clinical data of 89 patients who suffered from single segmental degenerative diseases of lower lumbar spine and followed up more than 10 years after receiving lumbar spinal fusion between January 2000 and January 2005 were retrospectively analysed. The patients were divided into two groups according to the different surgical methods, the 33 patients in group A were treated with posterior lumbar fenestration decompression, interbody fusion, and internal fixation, while 56 patients in group B were treated with posterior total laminectomy resection decompression, interbody fusion, and internal fixation. There was no significant difference in gender, age, body mass index, type of lesion, disease duration, lesion segment, and preoperative Japanese Orthopedic Association (JOA) score, visual analogue scale (VAS) score, and Cobb angle of lumbar lordosis between the two groups (P>0.05). The effectiveness was evaluated by JOA score, and the improvement of pain was evaluated by VAS score. The incidence of adjacent segment degeneration (ASD) at last follow-up was recorded. ResultsBoth groups were followed up 10-17 years (mean, 12.6 years). There were 3 cases (9.1%) in group A and 5 cases (8.9%) in group B complicated with cerebrospinal fluid leakage, showing no significant difference (χ2=0.001, P=0.979). There was no complication such as infection, nerve root injury, internal plant loosening or transposition in both groups. Intervertebral fusion was satisfactory in both groups. The fusion time in groups A and B was (3.4±1.2) months and (3.7±1.6) months respectively, and there was no significant difference between the two groups (t=0.420, P=0.676). At last follow-up, the JOA score and VAS score of the two groups were significantly improved when compared with preoperative ones (P<0.05); there was no significant difference in Cobb angle of lumbar lordosis before and after operation in group A (t=0.293, P=0.772), but the Cobb angle of lumbar lordosis in group B was significantly lost at last follow-up (t=14.920, P=0.000). At last follow-up, the VAS score and Cobb angle of lumbar lordosis in group A were significantly superior to those in group B (P<0.05); there was no significant difference in JOA score between the two groups (t=0.217, P=0.828). There were 3 cases (9.1%) in group A and 21 cases (37.5%) in group B complicated with ASD, showing significant difference between the two groups (χ2=8.509, P=0.004). ConclusionLong-term effectiveness of both groups was satisfactory, but in terms of maintaining lumbar lordosis and reducing the incidence of ASD, the lumbar fusion retaining PLC is superior to total laminectomy and lumbar fusion removing PLC.

    Release date:2019-01-03 04:07 Export PDF Favorites Scan
  • Clinical study of percutaneous vertebroplasty through extreme extrapedicular approach in the treatment of osteoporotic vertebral compression fracture

    Objective To evaluate the effectiveness of percutaneous vertebroplasty (PVP) in the treatment of osteoporotic vertebral compression fracture (OVCF) through unilateral puncture of extreme extrapedicular approach and bilateral injection of bone cement. Methods The clinical data of 156 patients with OVCF who met the selection criteria between January 2014 and January 2016 were retrospectively analyzed. All patients were treated with PVP through unilateral puncture. According to different puncture methods, the patients were divided into two groups. In group A, 72 cases were performed PVP through the unilateral puncture of extreme extrapedicular approach and bilateral injection of bone cement, while in group B, 84 cases were performed PVP through the unilateral puncture of transpedicular approach. There was no significant difference in general data of gender, age, weight, bone mineral density, lesion segment, and disease duration between the two groups (P>0.05). The radiation exposure time, operation time, volume of bone cement injection, rate of bone cement leakage, pre- and post-operative visual analogue scale (VAS) score and local Cobb angle were recorded and compared between the two groups. Results There was no significant difference in radiation exposure time and operation time between the two groups (P>0.05), but the volume of bone cement injection in group A was significantly more than that in group B (t=20.024, P=0.000). Patients in both groups were followed up 24-32 months (mean, 26.7 months). There were 9 cases (12.5%) and 10 cases (11.9%) of cement leakage in group A and B, respectively. There was no significant difference in the incidence (χ2=0.013, P=0.910). No neurological symptoms and discomfort was found in the two groups. The VAS scores of the two groups were significantly improved after operation (P<0.05). There was no significant difference in local Cobb angle between before and after operation in group A (P>0.05); but the significant difference was found in local Cobb angle between at 2 years after operation and other time points in group B (P<0.05). The VAS score and local Cobb angle in group A were significantly better than those in group B at 2 years after operation (P<0.05). Conclusion It is simple, safe, and feasible to use the unilateral puncture of extreme extrapedicular approach and bilateral injection of bone cement to treat OVCF. Compared with the transpedicular approach, the bone cement can be distributed bilaterally in the vertebral body without prolonging the operation time and radiation exposure time, and has an advantage of decreasing long-term local Cobb angle losing of the fractured vertebrae.

    Release date:2019-05-06 04:48 Export PDF Favorites Scan
  • Treatment of benign tumors in thoracic spinal canal by modified replanting posterior ligament complex applying piezoelectric osteotomy

    ObjectiveTo investigate the feasibility and effectiveness of modified replanting posterior ligament complex (PLC) applying piezoelectric osteotomy in the treatment of primary benign tumors in thoracic spinal canal.MethodsThe clinical data of 38 patients with primary benign tumors in thoracic spinal canal between March 2014 and March 2016 were retrospectively analyzed. There were 16 males and 22 females, aged from 21 to 72 years (mean, 47.1 years). The disease duration ranged from 6 to 57 months (mean, 32.6 months). Pathological examination showed 24 cases of schwannoma, 6 cases of meningioma, 4 cases of ependymoma, 2 cases of lipoma, and 2 cases of dermoid cyst. The lesions located in 18 cases of single segment, 15 cases of double segments, and 5 cases of three segments. The length of the tumors ranged from 0.7 to 6.5 cm. There were boundaries between the tumors and the spinal cord, cauda equina, and nerve roots. The preoperative Japanese Orthopaedic Association (JOA) score was 12.2±2.3 and the thoracic Cobb angle was (11.7±2.7)°. Modified PLC replantation and microsurgical resection were performed with piezoelectric osteotomy. Continuity of uniside supraspinal and interspinous ligaments were preserved during the operation. The PLC was exposed laterally. After removing the tumors under the microscope, the pedicled PLC was replanted in situ and fixed with bilateral micro-reconstruction titanium plate. X-ray film, CT, and MRI examinations were performed to observe spinal stability, spinal canal plasty, and tumor resection after operation. The effectiveness was evaluated by JOA score.ResultsThe operation time was 56-142 minutes (mean, 77.1 minutes). The intraoperative blood loss was 110-370 mL (mean, 217.2 mL). The tumors were removed completely and the incisions healed well. Three cases complicated with cerebrospinal fluid leakage, and there was no complications such as spinal cord injury and infection. All the 38 patients were followed up 24-28 months (mean, 27.2 months). There was no internal fixation loosening, malposition, or other related complications. At last follow-up, X-ray films showed no sign of kyphosis and instability. CT showed no displacement of vertebral lamina and reduction of secondary spinal canal volume, and vertebral lamina healed well. MRI showed no recurrence of tumors. At last follow-up, the thoracic Cobb angle was (12.3±4.1)°, showing no significant difference when compared with preoperative value (t=0.753, P=0.456). JOA score increased to 23.7±3.8, showing significant difference when compared with preoperative value (t=15.960, P=0.000). Among them, 14 cases were excellent, 18 were good, 6 were fair, and the excellent and good rate was 84.2%.ConclusionModified replanting PLC applying piezoelectric osteotomy and micro-reconstruction with titanium plate for the primary benign tumors in thoracic spinal canal can reconstruct the anatomy of the spinal canal, enable patients to recover daily activities quickly. It is an effective and safe treatment.

    Release date:2019-07-23 09:50 Export PDF Favorites Scan
  • Evaluation of surgical effectiveness for slow transit constipation in functional outcomes and quality of life

    ObjectiveTo evaluate the functional outcomes and quality of life in patients with surgery for slow transit constipation (STC).MethodsFrom March 2013 to July 2017, 29 patients undergoing total or subtotal colectomy for STC in our department were analyzed prospectively. Their preoperative and postoperative 1-year follow-up details were analyzed. Evacuation function of all patients was assessed by bowel movements, abdominal pain, bloating, straining, laxative, enema use and the Wexner constipation scales. Quality of life was evaluated by the Gastrointestinal Quality of Life Index (GIQLI) and the short-form (SF)-36 survey.ResultsA high number of patients (93.1%, 27/29) in STC stated that surgery received benefits to their health. Compared with that before operation, the number of bowel movements per week during a 1-year follow-up increased significantly (31.6±19.9 vs. 1.21±0.6, P<0.05). Significant trends toward improvement of bloating, straining, laxative and enema use were noted 1-year following surgery (P<0.05). The Wexner constipation scales scores during a 1-year follow-up decreased significantly (5.69±3.4 vs. 20.34±0.6, P<0.05). The GIQLI scores during a 1-year follow-up increased significantly (120.7±20.4 vs. 78.6±17.3, P<0.05). Moreover, results of SF-36 showed significant improvements in 7 spheres (role physical, role emotional, physical pain, vitality, mental health, social function and general health) during a 1-year follow-up compared with those before operation (P<0.05).ConclusionTotal or subtotal colectomy for STC did not only alleviate constipation symptoms dramatically, but also received significant improvements in the patients’ quality of life.

    Release date:2019-09-26 01:05 Export PDF Favorites Scan
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