AIM:To assess the feasibility,safety,and advantages of minimally invasive laparoscopic-endoscopic cooperative surgery(LECS)for gastric submucosal tumors(SMT).METHODS:We retrospectively analyzed 101 consecutive patient...AIM:To assess the feasibility,safety,and advantages of minimally invasive laparoscopic-endoscopic cooperative surgery(LECS)for gastric submucosal tumors(SMT).METHODS:We retrospectively analyzed 101 consecutive patients,who had undergone partial,proximal,or distal gastrectomy using LECS for gastric SMT at Peking Union Medical College Hospital from June 2006to April 2013.All patients were followed up by visit or telephone.Clinical data,surgical approach,pathological features such as the size,location,and pathological type of each tumor;and follow-up results were analyzed.The feasibility,safety and effectiveness of LECS for gastric SMT were evaluated,especially for patients with tumors located near the cardia or pylorus.RESULTS:The 101 patients included 43(42.6%)menand 58(57.4%)women,with mean age of 51.2±13.1 years(range,14-76 years).The most common symptom was belching.Almost all(n=97)patients underwent surgery with preservation of the cardia and pylorus,with the other four patients undergoing proximal or distal gastrectomy.The mean distance from the lesion to the cardia or pylorus was 3.4±1.3 cm,and the minimum distance from the tumor edge to the cardia was 1.5 cm.Tumor pathology included gastrointestinal stromal tumor in 78 patients,leiomyoma in 13,carcinoid tumors in three,ectopic pancreas in three,lipoma in two,glomus tumor in one,and inflammatory pseudotumor in one.Tumor size ranged from 1 to8.2 cm,with 65(64.4%)lesions<2 cm,32(31.7%)>2 cm,and four>5 cm.Sixty-six lesions(65.3%)were located in the fundus,21(20.8%)in the body,10(9.9%)in the antrum,three(3.0%)in the cardia,and one(1.0%)in the pylorus.During a median follow-up of 28 mo(range,1-69 mo),none of these patients experienced recurrence or metastasis.The three patients who underwent proximal gastrectomy experienced symptoms of regurgitation and belching.CONCLUSION:Laparoscopic-endoscopic cooperative surgery is feasible and safe for patients with gastric submucosal tumor.Endoscopic intraoperative localization and support can help preserve the cardia and pylorus during surgery.展开更多
We present the design, fabrication, and characterization of two new types of terahertz photoconductive emitters. One has an asymmetric four-contact electrode structure and the other has an arc-shaped electrode structu...We present the design, fabrication, and characterization of two new types of terahertz photoconductive emitters. One has an asymmetric four-contact electrode structure and the other has an arc-shaped electrode structure, which are all modified from a traditional strip line antenna. Numerical simulations and real experiments confirm the good performance of the proposed antennas. An amplitude increase of about 40% is experimentally observed for the terahertz signals generated from the new structures. The special electrode structure and its induced local bias field enhancement are responsible for this radiation efficiency improvement. Our work demonstrates the feasibility of developing highly efficient terahertz photoconductive emitters by optimizing the electrode structure.展开更多
基金Supported by Wu Jieping Medical Foundation Special Grant for Clinical Research,No.320.6752.1206Beijing Municipal Natural Science Foundation of China,No.7132209the Innovation Fund from Chinese Academy of Medical Sciences and Peking Union Medical College,No.2011-1002-017
文摘AIM:To assess the feasibility,safety,and advantages of minimally invasive laparoscopic-endoscopic cooperative surgery(LECS)for gastric submucosal tumors(SMT).METHODS:We retrospectively analyzed 101 consecutive patients,who had undergone partial,proximal,or distal gastrectomy using LECS for gastric SMT at Peking Union Medical College Hospital from June 2006to April 2013.All patients were followed up by visit or telephone.Clinical data,surgical approach,pathological features such as the size,location,and pathological type of each tumor;and follow-up results were analyzed.The feasibility,safety and effectiveness of LECS for gastric SMT were evaluated,especially for patients with tumors located near the cardia or pylorus.RESULTS:The 101 patients included 43(42.6%)menand 58(57.4%)women,with mean age of 51.2±13.1 years(range,14-76 years).The most common symptom was belching.Almost all(n=97)patients underwent surgery with preservation of the cardia and pylorus,with the other four patients undergoing proximal or distal gastrectomy.The mean distance from the lesion to the cardia or pylorus was 3.4±1.3 cm,and the minimum distance from the tumor edge to the cardia was 1.5 cm.Tumor pathology included gastrointestinal stromal tumor in 78 patients,leiomyoma in 13,carcinoid tumors in three,ectopic pancreas in three,lipoma in two,glomus tumor in one,and inflammatory pseudotumor in one.Tumor size ranged from 1 to8.2 cm,with 65(64.4%)lesions<2 cm,32(31.7%)>2 cm,and four>5 cm.Sixty-six lesions(65.3%)were located in the fundus,21(20.8%)in the body,10(9.9%)in the antrum,three(3.0%)in the cardia,and one(1.0%)in the pylorus.During a median follow-up of 28 mo(range,1-69 mo),none of these patients experienced recurrence or metastasis.The three patients who underwent proximal gastrectomy experienced symptoms of regurgitation and belching.CONCLUSION:Laparoscopic-endoscopic cooperative surgery is feasible and safe for patients with gastric submucosal tumor.Endoscopic intraoperative localization and support can help preserve the cardia and pylorus during surgery.
基金supported by the National Science and Technology Support Program of China under Grant No.2013BAK14B03
文摘We present the design, fabrication, and characterization of two new types of terahertz photoconductive emitters. One has an asymmetric four-contact electrode structure and the other has an arc-shaped electrode structure, which are all modified from a traditional strip line antenna. Numerical simulations and real experiments confirm the good performance of the proposed antennas. An amplitude increase of about 40% is experimentally observed for the terahertz signals generated from the new structures. The special electrode structure and its induced local bias field enhancement are responsible for this radiation efficiency improvement. Our work demonstrates the feasibility of developing highly efficient terahertz photoconductive emitters by optimizing the electrode structure.
