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find Author "谢平" 13 results
  • 色素上皮衍生因子与视网膜疾病的研究进展

    研究表明色素上皮衍生因子( pigment epithelium-derived factor, PEDF) 能影响视网膜分化、发育和成熟,对视网膜缺血性损伤有促进修复作用,是新生血管的天然抑制剂。现将PEDF的研究历史、PEDF的结构、生理作用以及与视网膜疾病的关系研究现状综述如 下。 (中华眼底病杂志,2003,19:68-70)

    Release date:2016-09-02 06:00 Export PDF Favorites Scan
  • Surgical treatment of iatrogenic bile duct injury: a report of 27 cases

    Objective To summarize the classification, diagnosis, and treatment of iatrogenic bile duct injury. Method The clinical data of 27 cases of iatrogenic bile duct injuries who treated in Central Hospital of Huzhou City from 2008–2013 were retrospectively analyzed. Results The classification of 27 cases: 5 cases of type Ⅰ, 18 cases of type Ⅱ, 2 cases of type Ⅲ, 2 cases of type Ⅳ. Diagnosis: 11 cases were immediately discovered at the time of the initial operation, include 1 case of type Ⅰ, 8 cases of type Ⅱ, 1 case of type Ⅲ, 1 case of type Ⅳ; 10 cases were detected in early stage after the initial operation, include 2 cases of type Ⅰ, 7 cases of type Ⅱ, 1 case of type Ⅲ; 6 cases were detected in delayed stage after the initial operation, include 2 cases of type Ⅰ, 3 cases of type Ⅱ, 1 case of type Ⅳ. Treatment effect: 17 cases for excellent, 5 cases for good, 4 cases for bad, the well recover rate was 84.6% (22/26). One case died after operation. A total of 26 cases were followed up, 1 case was lost to follow up. During the follow-up period, bile leakage occurred in 3 cases, infection of incision occurred in 2 cases, cholangitis occurred in 3 cases, and bile duct stricture occurred in 2 cases. Conclusions The best time of repairing for the iatrogenic bile duct injuries is at the time of the initial operation or early stage. According to the type of injury and the time of the injury was diagnosed, timely and effective treatment by intervention and (or) surgery is the key.

    Release date:2017-04-01 08:56 Export PDF Favorites Scan
  • Effect of internal limiting membrane peeling and transplantation on vision-related quality of life in refractory macular hole

    ObjectiveTo observe the effect of internal limiting membrane peeling and transplantation on vision-related quality of life in refractory macular hole.MethodsA retrospective clinical study. Thirty patients (30 eyes) with refractory macular hole diagnosed in Ophthalmology Department of The First Affiliated Hospital of Nanjing Medical University from January to December 2016 were included in this study. There were 13 males (13 eyes) and 17 females (17 eyes), with the mean age of 57.3±6.9 years. There were 15 patients (15 eyes) with large macular diameter, 12 patients (12 eyes) with high myopia macular hole, and 3 patients (3 eyes) with secondary traumatic macular hole. The BCVA examination was performed using the Snellen visual acuity chart, which was converted into logMAR visual acuity. OCT was performed to measure the macular retinal thickness (CRT), base diameter and minimum diameter of macular hole. Then, the macular hole index (MHI) was calculated. The logMAR BCVA was 1.52±0.30, MHI was 0.51±0.19. The Chinese version of visual-related quality of life scale -25 (CVRQoL-25) was used to evaluate the vision-related quality of life of patients. The CVRQoL-25 score was 57.60±7.13. All patients underwent 23G vitrectomy combined with inner limited membrane peeling and autologous ILM transplantation. The follow-up was at least 3 months after surgery. The changes of BCVA, MHI, CRT and CVRQoL-25 score before and after surgery were comparatively analyzed. Paired t test was performed to compare the measurement data before and after surgery, and Spearman rank correlation analysis was used for the correlation analysis among the parameters.ResultsAt 3 months after surgery, the hole closure was detected in 28 eyes (93.3%), not detected in 2 eyes (6.7%). The logMAR BCVA was 1.16±0.33, CRT was 161.00±15.26, and CVRQoL-25 scores was 70.83±9.77. Compared with before surgery, the BCVA (t=4.386, P=0.000) and CVRQoL-25 score (t=-5.991, P=0.000) after surgery were improved. Spearman rank correlation analysis showed that CVRQoL-25 score was negatively correlated with preoperative and postoperative logMAR BCVA (r=−0.536, −0.796; P=0.002, 0.000); positively correlated with preoperative MHI (r=0.421, P=0.020) and postoperative CRT (r=0.589, P=0.001).ConclusionInternal limiting membrane peeling and transplantation for refractory macular hole can significantly improve the vision-related quality of life and visual acuity, while achieved a high hole closure rate (93.3%).

    Release date:2020-01-11 10:26 Export PDF Favorites Scan
  • Analysis of Correlation between Surface Electromyography and Spasticity after Stroke

    To quantitatively evaluate the upper-limb spasticity of stroke patients in recovery stage, the relationship between surface electromyography (sEMG) characteristic indexes from biceps brachii and triceps brachii and the spasticity were explored, which provides the electrophysiological basis for clinical rehabilitation. Ten patients with spasticity after stroke were selected to be estimated by modified Ashworth (MAS) assessment and a passive elbow sinusoidal motion experiment was carried out. At the same time, the sEMG of biceps and triceps were recorded. The results shows that the reflex electromyographic threshold could reflect the physiological mechanism of spasticity and had significant correlation with MAS scale which showed that sEMG could be prosperous for the clinical quantitative evaluation of spasticity of stroke patients.

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  • Intermuscular coupling based on wavelet packet-cross frequency coherence

    Human motion control system has a high degree of nonlinear characteristics. Through quantitative evaluation of the nonlinear coupling strength between surface electromyogram (sEMG) signals, we can get the functional state of the muscles related to the movement, and then explore the mechanism of human motion control. In this paper, wavelet packet decomposition and n:m coherence analysis are combined to construct an intermuscular cross-frequency coupling analysis model based on wavelet packet-n:m coherence. In the elbow flexion and extension state with 30% maximum voluntary contraction force (MVC), sEMG signals of 20 healthy adults were collected. Firstly, the subband components were obtained based on wavelet packet decomposition, and then the n:m coherence of subband signals was calculated to analyze the coupling characteristics between muscles. The results show that the linear coupling strength (frequency ratio 1:1) of the cooperative and antagonistic pairs is higher than that of the nonlinear coupling (frequency ratio 1:2, 2:1 and 1:3, 3:1) under the elbow flexion motion of 30% MVC; the coupling strength decreases with the increase of frequency ratio for the intermuscular nonlinear coupling, and there is no significant difference between the frequency ratio n:m and m:n. The intermuscular coupling in beta and gamma bands is mainly reflected in the linear coupling (1:1), nonlinear coupling of low frequency ratio (1:2, 2:1) between synergetic pair and the linear coupling between antagonistic pairs. The results show that the wavelet packet-n:m coherence method can qualitatively describe the nonlinear coupling strength between muscles, which provides a theoretical reference for further revealing the mechanism of human motion control and the rehabilitation evaluation of patients with motor dysfunction.

    Release date:2020-06-28 07:05 Export PDF Favorites Scan
  • Analysis of Corticomuscular Coherence during Rehabilitation Exercises after Stroke

    To better evaluate neuromuscular function of patients with stroke related motor dysfunction, we proposed an effective corticomuscular coherence analysis and coherent significant judgment method. Firstly, the related functional frequency bands in the electroencephalogram (EEG) were extracted via wavelet decomposition. Secondly, coherence were analysed between surface electromyography (sEMG) and sub-bands extracted from EEG. Further more, a coherent significant indicator was defined to quantitatively describe the similarity in certain frequency domain and phase lock activity between EEG and sEMG. Through the analysis of corticomuscular coherence during knee flexion-extension of stroke patients and healthy controls, we found that the stroke patients exhibited significantly lower gamma-band corticomuscular coherence in performing the task with their affected leg, and there was no statistically significant difference between their unaffected lag and the healthy controls, but with the rehabilitation training, the bilateral difference of corticomuscular coherence in patients decreased gradually.

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  • Analysis of Abnormal Muscular Coupling During Rehabilitation after Stroke

    For the questions of deeply researching abnormal neuromuscular coupling and better evaluating motor function of stroke patients with motor dysfunction, an effective intermuscular coherence analysis method and index are studied to explore the neuromuscular oscillation and the pathomechanism of motor dysfunction, based on which an assessment standard of muscle function is established. Firstly, the contrastive analysis about the intermuscular coherence of antagonistic muscle of affected and intact upper limbs of stroke patients was conducted. Secondly, a significant indicator of Fisher's Z-transformed coherence significant indicator was defined to quantitatively describe the coupling differences in certain functional frequency domain between surface electromyogram (sEMG) of affected and intact sides. Further more, the relationship between intermuscular coherence and motor task was studied. Through the analysis of intermuscular coherence during elbow flexion-extension of affected and intact sides, we found that the intermuscular coherence was associated with motor task and the stroke patients exhibited significantly lower beta-band intermuscular coherence in performing the task with their affected upper limbs. More conclusion can be drawn that beta-band intermuscular coherence has been found concerned with Fugle-Meyer scale, which indicates that beta-band intermuscular coherence could be an index assisting in evaluating motor function of patients.

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  • Synchronous analysis of corticomuscular coherence based on Gabor wavelet-transfer entropy

    Synchronization analysis of electroencephalogram (EEG) and electromyogram (EMG) could reveal the functional corticomuscular coupling (FCMC) during the motor task in human. A novel method combining Gabor wavelet and transfer entropy (Gabor-TE) is proposed to quantitatively analyze the nonlinearly synchronous corticomuscular function coupling and direction characteristics under different steady-state force. Firstly, the Gabor wavelet transform method was used to acquire the local frequency-band signals of the EEG and EMG signals recorded from nine healthy controls simultaneously during performing grip task with four different steady-state forces. Secondly, the TE of local frequency-band was calculated and the unit area index of the transfer (ATE) was defined to quantitatively analyze the synchronous corticomuscular function coupling and direction characteristics under steady-state force. Lastly, the effect of EEG and EMG signal power spectrum on Gabor-TE analysis was explored. The results showed that the coupling strength in the beta band was stronger in EEG→EMG direction than in EMG→EEG direction, and the ATE values in the beta band in EEG→EMG direction decreased with the force increasing. It is also shown that the difference in TE values of gamma band present a varying regularity as the increase of force in both directions. In addition, EMG power spectrum was significantly correlated with the result of Gabor-TE inspecific frequency band. The results of our study confirmed that Gabor-TE can quantitatively describe the nonlinearly synchronous corticomuscular function coupling in both local frequency band and information transmission. The analysis of FCMC provides basic information for exploring the motor control and the evaluation of clinical rehabilitation.

    Release date:2017-12-21 05:21 Export PDF Favorites Scan
  • Analysis of multichannel intermuscular coupling characteristics during rehabilitation after stroke

    To better analyze the problem of abnormal neuromuscular coupling related to motor dysfunction for stroke patients, the functional coupling of the multichannel electromyography (EMG) were studied and the difference between stroke patients and healthy subjects were further analyzed to explore the pathological mechanism of motor dysfunction after stroke. Firstly, the cross-frequency coherence (CFC) analysis and non-negative matrix factorization (NMF) were combined to construct a CFC-NMF model to study the linear coupling relationship in bands and the nonlinear coupling characteristics in different frequency ratios during elbow flexion and extension movement. Furthermore, the significant coherent area and sum of cross-frequency coherence were respectively calculated to quantitatively describe the intermuscular linear and nonlinear coupling characteristics. The results showed that the linear coupling relationship between multichannel muscles was different in frequency bands and the overall coupling was stronger in low frequency band. The linear coupling strength of the stroke patients was lower than that of the healthy subjects in different frequency bands especially in beta and gamma bands. For the nonlinear coupling, the intermuscular coupling strength of stroke patients in different frequency ratios was significantly lower than that of the healthy subjects, and the coupling strength in the frequency ratio 1∶2 was higher than that in the frequency ratio 1∶3. This method can provide a theoretical basis for exploring the intermuscular coupling mechanism of patients with motor dysfunction.

    Release date:2019-12-17 10:44 Export PDF Favorites Scan
  • A study on the application of cross-frequency coupling characteristics of neural oscillation in the diagnosis of mild cognitive impairment

    In order to fully explore the neural oscillatory coupling characteristics of patients with mild cognitive impairment (MCI), this paper analyzed and compared the strength of the coupling characteristics for 28 MCI patients and 21 normal subjects under six different-frequency combinations. The results showed that the difference in the global phase synchronization index of cross-frequency coupling under δ-θ rhythm combination was statistically significant in the MCI group compared with the normal control group (P = 0.025, d = 0.398). To further validate this coupling feature, this paper proposed an optimized convolutional neural network model that incorporated a time-frequency data enhancement module and batch normalization layers to prevent overfitting while enhancing the robustness of the model. Based on this optimized model, with the phase locking value matrix of δ-θ rhythm combination as the single input feature, the diagnostic accuracy of MCI patients was (95.49 ± 4.15)%, sensitivity and specificity were (93.71 ± 7.21)% and (97.50 ± 5.34)%, respectively. The results showed that the characteristics of the phase locking value matrix under the combination of δ-θ rhythms can adequately reflect the cognitive status of MCI patients, which is helpful to assist the diagnosis of MCI.

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