The research on the characteristics of the online game market and development——based on the analysis of the network externality

网络游戏产业在我国的发展不足十年，但已经是IT业内的一个主力产业，成为社会关注的焦点。它不仅带来了巨大的经济效益，而且推动了我国宽带业、通信业以及其他相关产业的发展。任何一个新兴的产业，在刚开始的几年人们对它的认识往往不足。对于一个发展速度快，并且产品成功商业运营后短期内回报高的产业，很多企业未做好充分准备，在对产业认知甚少的情况下就一味的投身到市场竞争中。虽然不乏成功者，但更多的是品尝失败的滋味。究其原因，最主要的还是缺乏对网络游戏产业内在经济规律的理解，特别是在产品特性、市场结构以及竞争策略等方面。 因此，本文从网络经济学中网络外部性的视角对我国网络游戏产业的市场特性进行研究。首先介绍了...Chinese online games industry has been developing for less than a decade, but it has been one of main industries in IT industry, and become the focus of social attention. Online game has not only brought the huge economic benefit, also promoted many industries, such as the Wide Band industry, the communication industry, and some other related industries. People are often insufficient to understand...学位：经济学硕士院系专业：经济学院财政金融系_财政学(含税收学)学号：2005130087

间充质干细胞在器官移植中发挥免疫抑制作用及机制探讨的研究进展

器官移植是终末期器官衰竭患者最有效的治疗手段。将间充质干细胞(MSC)用于器官移植已成为细胞疗法的重要组成部分。然而,MSC发挥免疫抑制作用的机制还有待进一步地挖掘,且影响MSC发挥免疫抑制作用的因素很多,这些原因导致MSC难以达到预期疗效。在本综述中将通过介绍MSC的免疫抑制作用及机制、影响MSC发挥免疫抑制作用的因素以及MSC的临床应用等方面来阐述MSC在器官移植领域的研究进展。国家重点研发项目(2018YFA0108304)国家自然科学基金(81771721、81671583

Video-assisted Thoracoscopic 3D Mode Operation for Solitary Pulmonary Nodules

目的探讨三维胸腔镜手术(3d VIdEO-ASSISTEd THOrACIC SurgEry,3d-VATS治疗孤立性肺结节(SOlITAry PulMOnAry nOdulE,SPn)的效果。方法回顾性分析2013年3月~2014年3月50例SPn的资料,采用3d-VATS手术模式楔形切除结节,根据快速病理结果决定是否行肺叶切除加淋巴结清扫术。统计手术时间(去除快速冰冻时间)、术后24 H引流量、总引流量、引流管拔除时间、淋巴结清扫数及术后并发症等。结果 3d-VATS模式下,50例均行肺结节楔形切除,其中23例病理为恶性,继续行肺癌根治术,手术顺利。肺癌根治术手术时间(62±12)MIn,术中出血量(35±5)Ml,清扫淋巴结(19±3)个,术后24 H引流量(120±20)Ml,术后胸管引流时间(4±1)d,术后住院时间(7±2)d。并发症3例,其中术后肺炎2例,阵发性心房纤颤1例,均治愈。无围手术期死亡。随访2~12个月,平均6.3月。1例术后3个月脑转移,1例术后5个月肺癌复发。结论胸腔镜3d模式下治疗SPn是一种新的选择方式,安全可行,值得推广应用。Objective To evaluate the effects of surgical treatment for solitary pulmonary nodules under thoracoscopic 3D mode(3D-VATS).Methods A total of 50 cases of solitary pulmonary nodules from March 2013 to March 2014 were retrospectively analyzed.Intraoperative wedge pulmonary resection with 3D-VATS was utilized.According to intraoperative pathological findings,lobectomy plus lymph node dissection was given or not.Intraoperative time( minus fast freezing time),drainage volume for 24 h,total drainage volume,drainage tube removal time,number of lymph node dissected,and postoperative complications were recorded.Results Under 3D-VATS mode,50 cases of solitary pulmonary nodules were treated with wedge resection,including 23 cases of malignant pathology receiving radical resection, which was smoothly.The radical resection time( lung lobectomy plus lymphadenectomy) was(62 ± 12) min,the bleeding volume was(35 ± 5) ml,the lymphadenectomy number was 19 ± 3,the drainage volume for 24 h was(120 ± 20) ml,the postoperative chest tube removal time was(4 ± 1) days,and the postoperative hospital stay was(7 ± 2) days.Postoperative complications occurred in 3 cases,including 2 cases of pneumonia and 1 case of paroxysmal atrial fibrillation.No perioperative deaths were observed.All the cases were followed up for 2- 12 months,with an average of 6.3 months.Brain metastases was found in 1 case at the third postoperative month and recurrence of lung cancer was noted in 1 case at the fifth postoperative month.Conclusion Thoracoscopic 3D mode treatment for solitary pulmonary nodules is a new,safe,and feasible alternative and should be widely applied

Combined Use of Thoracoscopy and Laparoscopy in Total Laryngectomy for Cervical Esophageal Carcinoma

目的探讨胸、腹腔镜联合全喉切除治疗颈段食管的可行性和疗效。方法 2009年1月~2014年7月胸、腹腔镜联合全喉切除治疗33例颈段食管癌。胸腔镜下分离食管、腹腔镜下管胃成形、全喉切除、气管永久造口、胃咽吻合术。结果胸部手术时间40~66 MIn,平均53 MIn;腹部手术时间35~51 MIn,平均44 MIn;颈部手术时间128~150 MIn,平均139 MIn。术中出血量130~270 Ml,平均150 Ml。术后住院时间8~14 d,平均12 d。病理均为鳞状细胞癌,其中高分化2例,中分化19例,中-低分化7例,低分化5例。切缘病理学检查无癌组织残留。31例淋巴结转移。并发症:吻合口漏2例,喉返神经损伤3例,肺部感染6例,胃排空障碍2例,吻合口狭窄1例,无死亡病例。33例随访1个月~5年,术后1、3、5年生存率分别为87.9%、54.5%、45.5%。结论颈段食管癌应采取积极的手术治疗,胃咽吻合术是颈段食管癌切除后较为理想的修复手段。Objective To investigate clinical feasibility and efficacy of combined use of thoracoscopy and laparoscopy in total laryngectomy for cervical esophageal carcinoma.Methods Clinical data of 33 patients with cervical esophageal carcinoma undergoing surgical treatment in our department from January 2009 to July 2014 were analyzed retrospectively.The esophagus was separated under thoracoscopy.And laparoscopic gastroplasty,total laryngectomy,tracheal permanent colostomy,and gastric pharyngeal anastomosis were performed.Results The thoracoscopic operation time was 40- 66 min( mean,53 min),the laparoscopic operation time was 35- 51 min( mean,44 min),and the cervical operation time was 128- 150 min( mean,139 min).The blood loss was 130- 270 ml( mean,150 ml).The postoperative hospital stay was 8- 14 d( mean,12 d).Pathological examinations showed squamous cell carcinoma in all the cases,including 2 cases of highly differentiated carcinoma,19 cases of moderately differentiated carcinoma,7 cases of moderately or lowly differentiated carcinoma,and 5 cases of lowly differentiated carcinoma.No residual cancer was found at cutting edges pathologically.Among the 33 cases,lymph node metastasis was found in 31 cases.Complications included 2 cases of anastomotic fistula,3 cases of recurrent laryngeal nerve injury,6 cases of pulmonary infection,2cases of delayed gastric emptying,and 1 case of anastomotic stenosis.There was no death.All the patients were followed up for 1months to 5 years.The survival rates at 1,3,and 5 postoperative year were 87.9%,54.5%,and 45.5%,respectively.Conclusions Cervical esophageal carcinoma should be surgically treated actively.Gastric pharyngeal anastomosis is an ideal option for the repair of cervical esophageal cancer resection

完全经腋窝腔镜下治疗小儿先天性肌性斜颈

【目的】探讨完全经腋窝腔镜下治疗小儿先天性肌性斜颈的手术方法。【方法】自2015年1月至2016 年11月，在中山大学附属第一医院小儿外科完全经腋窝腔镜下治疗的小儿先天性肌性斜颈患儿共12例。在患 侧腋窝做两个小切口，分别置入5mm和3mmTrocar，经5mmTrocar置入镜头，经3mmTrocar置入分离钳或电凝 钩。皮下腔内持续充入CO2气体，压力维持在6mmHg。在颈阔肌筋膜下间隙分离胸锁乳突肌胸骨头和锁骨头， 予电灼切断。【结果】12例患儿均完全经腋窝腔镜下完成手术，颈部无切口，术后恢复好。随访16～22个月，斜 颈均获矫正，腋下切口瘢痕不明显。【结论】完全经腋窝腔镜下治疗小儿先天性肌性斜颈，是安全可行的，效果确 切，外观满意

饲料中棉粕替代鱼粉蛋白对草鱼的生长、血液生理指标和鱼体组成的影响

以初始体重（100.0±0.29） g的草鱼为研究对象，通过8周的生长实验，研究饲料中棉粕替代鱼粉蛋白对草鱼的生长、饲料利用，血液生理指标和鱼体生化组成的影响。实验设置7种等氮等能饲料，对照组（C）以鱼粉为唯一蛋白源，其余6组分别以棉粕替代饲料中鱼粉蛋白的20%（R20）、40%（R40）、60%（R60）、80%（R80）、90%（R90）、100%（R100）。研究结果表明：随着饲料中棉粕含量的升高，草鱼特定生长率呈下降的趋势，当替代比例达到60%，显著低于对照组（P〈0.05）；饲料效率、蛋白质贮积率和能量贮积率随着饲料中棉粕含量升高而显著降低（P〈0.05）。通过折线法分析，在实验条件下，棉粕可以替代鱼粉蛋白的43.3%而不影响草鱼的生长。各组草鱼之间血清谷丙转氨酶、谷草转氨酶和甘油三酯含量无显著差异（P〉0.05）；总胆固醇、高密脂蛋白胆固醇和低密胆固醇呈现下降趋势，当替代水平达到40%显著低于对照组（P〈0.05）。棉粕替代鱼粉蛋白显著影响鱼体的水分含量（P〈0.05），当替代比例达到80%，鱼体的水分含量显著高于对照组（P〈0.05）；各组之间鱼体的蛋白质和灰分含量无显著性差异（P＆gt;0.05）。R20组的鱼体脂肪和能量含量显著高于对照组（P〈0.05）， R100组的鱼体脂肪和能量含量显著低于对照组（P〈0.05），其他各组之间和对照组无显著性差异（P＆gt;0.05）