Optimal tracking control for non-zero-sum games of linear discrete-time systems via off-policy reinforcement learning

In this article, a model-free off-policy reinforcement learning algorithm is applied to address the optimal tracking problem based on multiplayer non-zero-sum games for discrete-time linear systems. In contrast to the traditional method and the policy iteration method for solving the optimal tracking problems, the proposed algorithm operates with the system data rather than the knowledge of the system dynamics. For performing the proposed algorithm, an auxiliary augmented system is constructed via assembling the original system and the reference trajectory while a discount factor is introduced into the performance indexes. It is analyzed that the solutions of the proposed algorithm converge to the Nash equilibrium and the result is not influenced by the probing noise. Two simulations are presented to verify the feasibility and effectiveness of the proposed algorithm.     

Evaluation of Degenerative Lumbar Scoliosis After Short Segment Decompression and Fusion

The objective of this study was to investigate short segment decompression of degenerative lumbar scoliosis (DLS) and the efficiency of fusion treatment.After DLS surgery, the patients were retrospectively reviewed using the VAS (visual analog scale) and ODI (Oswestry Disability Index) to assess clinical outcomes. All patients underwent posterior lumbar decompressive laminectomy, pedicle screw internal fixation, and posterolateral bone graft fusion surgery. Radiographic measurements included the scoliotic Cobb angle, the fused Cobb angle, the anterior intervertebral angle (AIA), the sagittal intervertebral angle (SIA), and lumbar lordosis angle. The relationships between these parameters were examined by bivariate Pearson analysis and linear regression analysis.Preoperatively, the Cobb angle at the scoliotic segment was 15.4°, which decreased to 10.2° immediately following surgery (P < 0.05). The AIA significantly increased by the last follow-up (4.4 ± 3.4) compared with pre- and postoperative values (2.5 ± 2.8 and 2.2 ± 2.4, respectively; P < 0.05). However, the scoliotic Cobb angle and the AIA did not correlate with the VAS or ODI scores. At the final follow-up, no patients had pseudoarthrosis or internal instrumentation-related complications.Short fusion surgical treatment results in limited DLS correction, with correction loss over time. The AIA between the upper adjacent segment and proximal fused vertebra continues to increase postoperatively, which does not exacerbate clinical symptoms, as reflected by the low reoperation rates for repairing degeneration at adjacent levels.     

益心舒胶囊联合常规疗法治疗非瓣膜性心房颤动临床研究

目的：观察益心舒胶囊联合常规疗法治疗非瓣膜性心房颤动的疗效。方法：纳入96 例气阴亏虚兼瘀血内阻型非瓣膜性心房颤动患者，采用随机数字表法分为对照组和观察组各48 例。2 组患者均予常规降压、降糖、调脂以及调整心态、饮食等治疗措施，并服用华法林钠片治疗，观察组加予益心舒胶囊治疗。2 组疗程均为3 个月。观察2 组治疗前及治疗3 个月后凝血功能指标、心房颤动发作情况、血浆N 末端B 型利钠肽原（NT-proBNP） 以及血液流变学水平的变化。结果：治疗后，2 组凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）、凝血酶时间（TT）、国际标准化比值（INR） 均较治疗前增加（P＜0.01），观察组PT、APTT、TT、INR 均长于或高于对照组（P＜0.01）。2 组心房颤动发作时间与发作频率均较治疗前缩短或降低（P＜0.01），观察组心房颤动发作时间与发作频率均短于或低于对照组（P＜0.01）。2 组血浆NT-proBNP 水平均较治疗前降低（P＜0.01），观察组血浆NT-proBNP 水平均低于对照组（P＜0.01）。2 组红细胞比容（HCT）、纤维蛋白原（Fb）、全血黏度、血浆比黏度均较治疗前降低（P＜0.01），观察组4 项指标值均低于对照组（P＜0.01）。结论：在常规治疗基础上加服益心舒胶囊治疗气阴亏虚兼瘀血内阻型非瓣膜性心房颤动，在改善患者的凝血功能、心功能以及缓解临床症状方面疗效明显，且可有效改善血液流变学水平。     

科研评价导向的改变对中文科技期刊的机遇与挑战

【目的】 值此《中国科技期刊研究》创刊30周年之际,思考科研评价体系的改变给中文科技期刊带来的影响,为中文期刊探寻发展路径。【方法】 结合对中文科技期刊困境的研究,提出应对策略。【结果】 近期国家陆续出台的纠偏评价导向的政策文件,为中文科技期刊既带来了发展机遇,也提出了挑战。【结论】 在重构符合中文科技期刊发展特点的评价体系的基础上,中文科技期刊应明确目标定位,面向国家需求,提升知识服务能力,建立品牌特色。     

足趾移植长手指全形再造术的临床应用

目的探讨足趾移植长手指全形再造手术的临床疗效。方法自2015年6月至2019年6月,对16例因外伤致手指缺损患者采用足趾移植长手指全形再造术,术后评估供区及受区的感觉功能、运动功能及外观形态,分析指甲畸形及增生性瘢痕的发生情况,并记录术后发生感染、血肿、皮片坏死及供区愈合不良等情况;通过调查问卷的方式分析患者的满意度。结果所有患者术后获随访1~12个月,其中2例受区发生感染,1例受区皮片边缘发生坏死,经换药后予以缓解;其余患者的供、受区均未出现长时间的痛疼感觉,受区感觉功能恢复达87.50%,受区运动功能恢复均较满意,手指外形基本满意。供区感觉受影响者2例,运动功能受限者1例,外形一般者2例。所有患者无指甲畸形及增生性瘢痕发生;满意者1例,基本满意者14例,不满意者1例。结论采用足趾移植长手指全形再造手术,基本可以满足患者及医师对于缺损手指进行完美修复的目标。     

层面递进法激光腔内剜除高危前列腺增生的治疗体会

目的探讨1 470 nm激光剜除治疗高危前列腺增生的手术技巧及临床效果。 方法回顾分析2018年6月至2018年9月中山大学附属第三医院泌尿外科采用1 470 nm激光治疗共89例高危前列腺增生患者的临床资料，年龄平均（68±3）岁，前列腺体积（57.4±2.6）ml。所有患者均采用"寻找层面，先易后难，剜切结合"的层面递进法思路行激光腔内前列腺剜除术，比较患者术中及术后情况。 结果89例均顺利完成手术，与术前相比，术后3个月患者最大尿流率明显增加，[（6.9±2.1） ml/s vs（19.8±3.6） ml/s]。国际前列腺症状评分显著好转，[（24.6±1.7） vs（8.0±1.2）]。术中无输血、无电切综合征、无直肠和膀胱穿孔病例，无输尿管损伤、大出血、心脑血管意外等严重并发症发生。 结论层面递进法激光剜除技术构想对于高危前列腺增生外科包膜层面的寻找、减少术后并发症有独到优势，且易于掌握，或可为业界同行提供一个新的思路。