Design of a chattering-free integral terminal sliding mode approach for DFIG-based wind energy systems

This article proposes a Fuzzy Second Order Integral Terminal Sliding Mode (FSOITSM) control approach for DFIG-based wind turbines subject to grid faults and parameter variations. Since traditional terminal sliding mode control (SMC) suffers from singularity, a novel integral terminal sliding manifold is proposed to eliminate chattering and improve the wind turbine's performance in the presence of faults and disturbances. A fuzzy system is proposed to auto-tune the controllers' gains and ensures the invariance of the sliding surfaces even under heavy uncertainties, thus further improving the reliability and performance of the proposed controller. The performance of the proposed approach was assessed under various operating conditions. A comparison analysis with a standard SMC approach as well as the state of the art in voltage sag mitigation was also carried over. Reliability, robustness, and power availability under faulty grid conditions are among the main features of the proposed approach. In addition, the proposed approach exhibited chattering free dynamics and enabled the finite time convergence of the sliding manifold and overcame the singularity problem associated with standard TSMC.     

胸部创伤合并心功能和心肌细胞损害的早期监测与临床观察

目的:探讨血清N末端B型钠尿肽原(NT-proBNP)和心脏型脂肪酸结合蛋白(h-FABP)在胸部创伤所致心肌挫伤的早期监测价值,并观察重组人生长激素(rhGH)的治疗效果。方法:选择82例胸部创伤合并心肌挫伤患者(挫伤组)和50例健康人(对照组)为研究对象,挫伤组采用rhGH治疗。血清NT-proBNP检测采用电化学发光免疫分析(ECLIA)法,血清h-FABP检测采用双抗体夹心酶联免疫(ELISA)一步法。结果:治疗前血清h-FABP阳性率(41.4%)显著高于NT-proBNP(29.8%)及心电图(ECG)(17.7%)(P<0.01)。治疗前,胸部创伤合并心肌挫伤患者血清NT-proBNP和h-FABP水平分别与对照组比较差异有统计学意义(P<0.01);治疗后,两者水平均显著低于治疗前(P<0.01),与对照组比较,差异无统计学意义(P>0.05)。胸部创伤合并心肌挫伤患者血清NT-proBNP与h-FABP呈显著正相关(r=0.719,P<0.01),相关性良好。胸部创伤合并心肌挫伤的82例患者经rhGH治疗后,血清NT-proBNP和h-FABP水平达正常,ECG也无异常表现,无一例死亡病例。结论:rhGH对胸部创伤合并心肌挫伤具有临床治疗作用,血清NT-proBNP和h-FABP的联合检测可早期诊断胸部创伤合并心功能及心肌细胞损害,也可观察临床疗效。     

2014年中国医药市场发展蓝皮书——医疗终端部分（Ⅱ）

介绍了中国的卫生机构状况、2007—2013年中国药品医疗终端规模,以及中国医院终端化学药和中成药各大类药品市场份额状况,并分别对中国医院终端化学药和中成药各大类重点品种的销售额Top10进行了分析。     

泪点栓治疗视频终端顽固性干眼症的临床效果研究

目的：探讨泪点栓治疗视频终端顽固性干眼症的临床效果。方法选取2013年2~5月本院收治的视频终端顽固性干眼症患者59例（118只眼）,按照治疗方法不同分为两组,观察A组30例（60只眼）和观察B组29例（58只眼）,观察A组采用上下泪小点植入永久性泪点栓治疗,观察B组采用上泪小点植入临时性自溶性泪点栓,下泪小点植入永久性泪点栓治疗。结果两组治疗后3个月的BUT、Schirmer-Ⅰ明显高于治疗前,FL及主观症状评分明显低于治疗前,差异有统计学意义（P〈0.05）。两组治疗后3个月的BUT、Schirmer-Ⅰ、FL及主观症状评分比较,差异无统计学意义（P〉0.05）。观察A组的并发症发生率高于观察B组（P〈0.05）。结论采用泪点栓可显著改善视频终端顽固性干眼症患者的临床症状,上泪小点植入临时性自溶性泪点栓,下泪小点植入永久性泪点栓治疗安全性更高。     

对老年患者临终前气管插管的回顾性调查

目的 比较缓和医疗理念推广前后老年患者临终前气管插管率有无显著变化。方法 回顾性调查2008年1月至2017年12月于中国人民解放军总医院第二医学中心年龄≥65岁的死亡患者,分为肿瘤组和非肿瘤组,逐年统计气管插管率,并比较2014年前后有无变化及2组患者临终前插管率和插管后生存期有无差异。采用SPSS 21.0软件进行数据分析。根据数据类型,组间比较分别采用t检验及χ²检验。结果 共收集死亡患者1233例,男性1150例(93.27%),女性83例(6.73%);肿瘤患者456例(36.98%),非肿瘤患者777例(63.02%)。肿瘤组的平均年龄明显低于非肿瘤组,肿瘤低龄组的比例显著高于非肿瘤组,差异均有统计学意义(均P<0.05)。965例(78.26%)接受临终前气管插管,其中肿瘤组占29.22%(282/965),非肿瘤组占70.78%(683/965)。肿瘤组的整体插管率为61.84%(282/456),非肿瘤组的整体插管率为87.90%(683/777),2组插管率差异有统计学意义(P<0.01)。2014年前后对比,无论是整体插管率、肿瘤组还是非肿瘤组,自身前后对比都存在显著差异[557(82.76%)和408(72.86%),194(69.04%)和88(50.29%),363(92.60%)和320(83.12%);P<0.01]。肿瘤组插管后平均生存期(108.09±16.40)d,非肿瘤组为(273.93±20.20)d,差异有统计学意义(P<0.01)。插管后1个月以内死亡的患者,肿瘤组为56例(54.96%),非肿瘤组为100例(42.90%)。肿瘤患者插管后生存1年以上的比例为19例(6.74%),非肿瘤患者为146例(21.38%),差异有统计学意义(P<0.01)。结论 我中心临终前老年患者的整体气管插管率较高。自2014年缓和医疗理念普及后,无论肿瘤还是非肿瘤患者,临终前的气管插管率都显著降低。非肿瘤患者插管后的生存期明显长于肿瘤患者。要建立科学的评价体系,严格评估插管的必要性。     

Patients’ perceptions of physicians’ recommendations for comfort care differ by patient age and gender

OBJECTIVE: To determine patient characteristics associated with patient and proxy perceptions of physicians’ recommendations for life-prolonging care versus comfort care, and with acceptance of such recommendations. DESIGN: Cross-sectional. SETTING: Five teaching hospitals in Denver, Colo. PATIENTS: We studied 239 hospitalized adults believed by physicians to have a high likelihood of dying within 6 months. MEASUREMENTS AND MAIN RESULTS: Interviews with patients or proxies were conducted to determine perceptions of physicians’ recommended goal of care and roles in decision making. RESULTS: Patients’ mean age was 66.6 years; 44% were women. In adjusted analysis, age greater than 70 years and female gender were associated with a higher likelihood of believing that comfort care had been recommended by the physician (odds ratio [OR], 3.70; 95% confidence interval [CI], 1.89 to 7.24; OR, 1.99; 95% CI, 1.04 to 3.84, respectively). Patients and proxies gave substantial decision-making authority to physicians: 29% responded that physicians dominate decision making, 55% that decision making is equally shared by physicians and patients, and only 16% that patients make decisions, Increasing age was associated with an increased likelihood of believing that physicians should dominate decision making (P<.005). CONCLUSIONS: Among patients with advanced illness, perceived comfort care recommendations were related to patient age and gender, raising concern about possible gender and age bias in physicians’ recommendations. Although all patients and proxies gave significant decision-making authority to physicians, older individuals were more likely to give physicians decision-making authority, making them more vulnerable to possible physician bias. Presented at the annual meeting of the American Geriatrics Society, May 19, 1999. Financial support for this work was received from the Hartford/Jahnigen Center of Excellence in Geriatrics at the University of Colorado and the Colorado Collective for Medical Decisions, a nonprofit organization to improve care of the dying in the state of Colorado.     

NT-proBNP in heart failure: therapy decisions and monitoring

With increasing cardiac dysfunction, a complex neurohormonal response results in increasing circulating levels of an array of plasma hormones. Increments in plasma levels of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) and their amino-terminal congeners are more closely related to cardiac structure and function and to cardiovascular prognosis than changes in other plasma neurohormones. Reports suggest that changes in plasma BNP levels in the course of treatment of acutely decompensated heart failure provide a more powerful prognostic indicator of the likelihood of survival or recurrent decompensation than symptomatic assessment. This observation requires a randomised controlled trial in which changes in peptide levels determine aggression and duration of in-patient therapy in order to establish whether this indicator can improve results from management of acute in-patient heart failure. Plasma BNP or NT-proBNP is a powerful independent predictor of mortality and morbidity in long-term follow-up of heart failure cohorts. In addition, it appears likely to be a good predictor of beneficial response to the addition of beta blockade to anti-heart failure pharmacotherapy. Finally, adjustment of therapy for heart failure according to serial measurements of NT-proBNP promises to improve outcomes in comparison with adjusting therapy according to unassisted clinical acumen.