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find Author "ZHANG Kai" 21 results
  • Research progress of the role of periosteum in distraction osteogenesis

    Objective To review the research progress of the role of periosteum in distraction osteogenesis. Methods The related domestic and foreign literature about the role of periosteum in distraction osteogenesis in recent years was extensively reviewed, summarized, and the mechanism and influencing factors of periosteum during traction and osteogenesis were analyzed. Results The periosteum is rich in all kinds of cells (mesenchymal stem cells, osteoblasts, etc.), microvessel and various growth factors, which are necessary for the formation of new bone. It can promote the formation of new bone in the process of traction osteogenesis significantly. Conclusion The periosteum plays an important role in the progress of distraction osteogenesis.

    Release date:2017-07-13 11:11 Export PDF Favorites Scan
  • Efficacy and predictive factors analysis of vagus nerve stimulation in patients with refractory MRI-negative epilepsy

    ObjectiveTo investigate the efficacy of vagus nerve stimulation (VNS) in patients with refractory magnetic resonance imaging (MRI)-negative epilepsy and to evaluate potential clinical predictors. MethodsA retrospective collection of efficacy data was conducted on 24 patients with intractable MRI-negative epilepsy treated with VNS, who were followed up for more than six months, at Beijing Tiantan Hospital and Beijing Fengtai Hospital from January 2016 to September 2023. Patients were divided into two subgroups based on their response to VNS: responders (≥50% reduction in seizure frequency) and non-responders (<50% reduction in seizure frequency). The relationship between preoperative clinical data and VNS efficacy was further analyzed to identify potential predictors of VNS efficacy. ResultsA total of 24 patients were included, with an average age of (14.26±8.39) years old. Seizure frequency was reduced by more than 50% in 37.5% of patients, and 8.3% of patients achieved seizure-free after VNS treatment. Preoperative seizure frequency and interictal epileptiform discharge type were significantly associated with VNS efficacy (P<0.05). Multivariate regression analysis showed that a monthly seizure frequency of less than 100 and focal interictal epileptiform discharges were independent predictors of VNS efficacy (P<0.05). ConclusionVNS is an effective treatment for patients with refractory MRI-negative epilepsy. Lower monthly seizure frequency and focal interictal epileptiform discharges are potential predictors of VNS efficacy. These findings provide important references for clinicians in selecting and evaluating patients for VNS treatment.

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  • APPLIED ANATOMY OF SUPERFICIAL INFERIOR EPIGASTRIC ARTERY FLAP

    Objective To provide the anatomical basis for the appl ication of the superficial inferior epigastric artery flap. Methods Ten cadavers which were immersed in formal in less than 6 months and were perfused by red latex were used in this study. There were 8 males and 2 females with an average age of 58 years (range, 35-78 years). The origin, course, branch,distribution, diameter, pedicle length, and neighbour of superficial inferior epigastric artery and vein were observed in the 2 sides of inguinal region. Results In these series of 10 cadaver (20 sides) dissections, the superficial inferior epigastric artery was identified in 18 sides, which average cal iber was 1.48 mm with a mean vascular pedicle length of 4.80 cm. In 11 sides, the superficial inferior epigastric artery arose aspart of a common trunk with one or more other vessels; in other 7, it originated from the femoral. There were 4 branch modes of superficial inperior epigastric artery: single trunks (5 sides), double ramification (3 sides), single lateral ramification (7 sides), and single medial ramification (3 sides). The superficial inferior epigastric vein was observed in 20 sides, which average cal iber was 2.33 mm with a mean sides pedicle length of 5.45 cm. In 8 sides, the venous drainage was as an individual vein; in 12 sides, both patterns were observed (a pair of venae comitantes and an individual vein). Conclusion The inferior epigastric artery flap can be appl ied to microsurgical flap transfer, potentially in breast reconstruction, phalloplasty, reconstruction of head, neck and four l imbs defects.

    Release date:2016-09-01 09:04 Export PDF Favorites Scan
  • Application of folded transverse superficial epigastric artery perforator flap for large penetrating defect after buccal carcinoma resection

    Objective To explore the effectiveness of folded transverse superficial epigastric artery perforator flap in repairing the large penetrating defect after buccal carcinoma resection. Methods Between January 2019 and June 2021, 12 patients with buccal squamous cell carcinoma were treated. There were 6 males and 6 females with an average of 66.9 years (range, 53-79 years). The pathological stage was T3a-T4b, and the preoperative mouth opening was (3.08±0.46) cm. The disease duration ranged from 6 to 24 months, with an average of 15 months. After buccal carcinoma radical resection and neck lymph node dissection, the penetrating defects in size of 8 cm×6 cm to 16 cm×8 cm and in depth of 0.5-1.5 cm were remained. The transverse superficial epigastric artery perforator flap in size of 8 cm×6 cm to 14 cm×8 cm were harvested and folded to repair the penetrating defects. The donor site was sutured directly. Results All 12 skin flaps survived after operation, and the wounds healed by first intention. No internal or external fistula complications occurred. All incisions at the recipient site healed by first intention. All patients were followed up 12-18 months (mean, 14 months). There was no obvious abnormality in the color and texture of the flap, the oral and facial appearances were symmetrical, and there was no obvious swelling in the cheek. At last follow-up, the patient’s mouth opening was (2.89±0.33) cm, which was not significantly different from that before operation (t=1.879, P=0.087). The subjective satisfaction scores of 12 patients were 6-8 points, with an average of 7.3 points. Significant scars remained at the donor site but concealed in location. Conclusion The folded transverse superficial epigastric artery perforator flap can be used as a surgical method for repairing large penetrating defects after the buccal carcinoma resection, with a good recovery of facial appearance and oral function.

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  • Research advance in polyaryletherketones for biomedical applications

    With high thermal stability, excellent mechanical properties, suitable biocompatibility and radiolucency, polyaryletherketones (PAEKs) have been widely used in biomedical field such as trauma, spinal implants, craniomaxillofacial repair and so on. However, PAEKs are bio-inert in nature and often show weak osteointegration with host bone, limiting their further utilization in biomedical application. Therefore, how to improve the bioactivity and osteointegration of PAEK implants has become the focus in biomedical field. This paper reviews the current research advance and some existed problems in bioactive PAEKs, and outlooks the possible solution.

    Release date:2018-09-25 02:22 Export PDF Favorites Scan
  • EARLY EFFECTIVENESS OF COMBINING RADIAL FOREARM FREE FLAP AND ADJACENT TISSUE FLAP IN RECONSTRUCTION OF PALATOMAXILLARY DEFECTS

    Objective To investigate the method of combining radial forearm free flap and adjacent tissue flap in reconstruction of palatomaxillary defects and its effectiveness. Methods Between March 2005 and May 2010, 17 patients with palatomaxillary defects were treated. There were 11 males and 6 females with an age range of 45-74 years (mean, 62.5 years), including 1 case of benign tumor and 16 cases of malignant tumors (7 cases of squamous cell carcinoma of palate, 1 case of recurring squamous cell carcinoma of palate, 1 case of malignant melanoma of palate, 1 case of adenoid cystic carcinoma of palate, 1 case of malignant melanoma of maxilla, 1 case of ductal carcinoma of maxilla, and 4 cases of squamous cell carcinoma of maxilla). The maxillectomy defect ranged from 7.0 cm × 5.5 cm to 10.0 cm × 7.5 cm. According to Brown’s classification for the maxillectomy defect, there were type II in 15 cases, type III in 2 cases. Palatomaxillary defects were repaired with radial forearm free flap and buccal fat pad in 11 cases, and with radial forearm free flap, buccal fat pad, and mandibular osteomuscular flap pedicled with temporal muscle in 6 cases. The effectiveness was evaluated after operation by observing the vitality of the flap, the functions of speech, swallowing, breath, and the facial appearance. Results All cases were followed up 6-12 months without tumor recurrence. All flaps and skin grafts at donor sites survived. The functions of seech, swallowing, and breath were normal without obvious opening limitation. The facial appearance was satisfactory without obvious maxillofacial deformity. No enophthalmos occurred in patients with orbital floor and infraorbital rim defects. The patients had no oronasal fistula with satisfactory oral and nasal functions. Conclusion According to the type of palatomaxillary defects, it can have good early effectiveness to select combining radial forearm free flap and buccal fat pad or combining radial forearm free flap, buccal fat pad, and mandibular osteomuscular flap for repairing defects.

    Release date:2016-08-31 05:45 Export PDF Favorites Scan
  • Quantitative experiment and analysis of gradient-induced eddy currents on magnetic resonance imaging

    Pulsed magnetic field gradients generated by gradient coils are widely used in signal location in magnetic resonance imaging (MRI). However, gradient coils can also induce eddy currents in final magnetic field in the nearby conducting structures which lead to distortion and artifact in images, misguiding clinical diagnosis. We tried in our laboratory to measure the magnetic field of gradient-induced eddy current in 1.5 T superconducting magnetic resonance imaging device; and extracted key parameters including amplitude and time constant of exponential terms according to inductance-resistance series mathematical module. These parameters of both self-induced component and crossing component are useful to design digital filters to implement pulse pre-emphasize to reshape the waveform. A measure device that is a basement equipped with phantoms and receiving coils was designed and placed in the isocenter of the magnetic field. By applying testing sequence, contrast experiments were carried out in a superconducting magnet before and after eddy current compensation. Sets of one dimension signal were obtained as raw data to calculate gradient-induced eddy currents. Curve fitting by least squares method was also done to match inductance-resistance series module. The results also illustrated that pulse pre-emphasize measurement with digital filter was correct and effective in reducing eddy current effect. Pre-emphasize waveform was developed based on system function. The usefulness of pre-emphasize measurement in reducing eddy current was confirmed and the improvement was also presented. All these are valuable for reducing artifact in magnetic resonance imaging device.

    Release date:2017-04-13 10:03 Export PDF Favorites Scan
  • Simple pulmonary artery approach in subarterial ventricular septal defect repair in 102 patients: A clinical analysis

    ObjectiveTo summarize and analyze the experience of subarterial ventricular septal defect (VSD) repaired with simple pulmonary artery approach.MethodsWe retrospectively anlyzed the clinical data of 102 patients with subarterial VSD repaired with simple pulmonary artery approach in our hospital from August 2015 to October 2018. There were 67 males and 35 females at median age of 3 years (ranging 4 months to 49 years).ResultsThe median operation time was 82 (54-136) min. Median cardiopulmonary bypass time was 36 (21-62) min. The median aortic cross-clamping time was 13 (7-32) min. Thirty two patients of tracheal intubation were removed from the fast-track operating room immediately after surgery. Of the 102 patients, 67 patients underwent a small incision in the lower sternum. The median postoperative ICU stay time was 26 (13-36) h. There was no planned reoperations and no early death.ConclusionSimple pulmonary artery approach for subarterial ventricular septal defect repair with less intracardiac procedures, short operation time, less trauma, quick postoperative recovery has certain advantages in the application of specific groups.

    Release date:2020-01-17 05:18 Export PDF Favorites Scan
  • Research and application of orthotopic DR chest radiograph quality control system based on artificial intelligence

    With the change of medical diagnosis and treatment mode, the quality of medical image directly affects the diagnosis and treatment of the disease for doctors. Therefore, realization of intelligent image quality control by computer will have a greater auxiliary effect on the radiographer’s filming work. In this paper, the research methods and applications of image segmentation model and image classification model in the field of deep learning and traditional image processing algorithm applied to medical image quality evaluation are described. The results demonstrate that deep learning algorithm is more accurate and efficient than the traditional image processing algorithm in the effective training of medical image big data, which explains the broad application prospect of deep learning in the medical field. This paper developed a set of intelligent quality control system for auxiliary filming, and successfully applied it to the Radiology Department of West China Hospital and other city and county hospitals, which effectively verified the feasibility and stability of the quality control system.

    Release date:2020-04-18 10:01 Export PDF Favorites Scan
  • A comparative study on effectiveness of closed reduction and internal fixation of intertrochanteric fracture assisted with skeletal tractor and traction table

    ObjectiveTo investigate the effectiveness and advantages of skeletal tractor in closed reduction and proximal femoral nail antirotation (PFNA) internal fixation of intertrochanteric fracture compared with traction table.MethodsThe clinical data of 86 patients with intertrochanteric fractures, who were treated with closed reduction and PFNA internal fixation between October 2016 and March 2018 and met the selection criteria, was retrospectively analysed. Among them, 44 cases were treated with skeletal tractor (trial group) and 42 cases were treated with traction table (control group). There was no significant difference between the two groups in gender, age, cause of injury, fracture side, AO classification, and degree of osteoporosis (P>0.05). The preoperative position time, operation time, intraoperative fluoroscopy times, intraoperative blood loss, fracture healing time, intraoperative and postoperative complications, and postoperative Harris score were compared between the two groups.ResultsThe operation was successfully completed in both groups. Compared with the control group, the patients in the trial group had shorter preoperative position time and operation time, fewer intraoperative fluoroscopy times, and less intraoperative blood loss (P<0.05). The patients were followed up 12-21 months in trial group (mean, 14.2 months) and 12-22 months in control group (mean, 14.3 months). Venous thrombosis of lower extremity occurred in 8 patients (3 cases of trial group and 5 cases of control group) after operation. Internal fixation failure occurred in 5 patients (2 cases of trial group and 3 cases of control group) during 1 year after operation. All fractures healed except for those with internal fixation failure, the fracture healing time was (11.6±2.9) weeks in trial group and (12.4±3.6) weeks in control group; and there was no significant difference between the two groups (t=1.250, P=0.214). At 1 year after operation, Harris score of the trial group was 86.2±5.9 and that of the control group was 84.1±6.1. There was no significant difference between the two groups (t=1.768, P=0.080).ConclusionCompared with traction table, skeletal tractor in closed reduction and PFNA internal fixation of intertrochanteric fracture can significantly shorten the preoperative position time and operation time, reduce the intraoperative fluoroscopy times, improve the operation efficiency, and have similar effectiveness.

    Release date:2020-04-29 03:03 Export PDF Favorites Scan
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