This paper investigates the control design of the hydraulic servo actuator in the railway suspension system. The control mechanism of the hydraulic servo actuator is discussed by establishing the formalized nonlinear equations. Based on the experimental data obtained from multi-operating conditions, the model identification of the hydraulic servo actuator is meticulously designed. With support from a numerical actuator model derived from experimental data, rather than relying solely on physical model knowledge, a numerical model-assisted active disturbance rejection control is proposed. In the experiment, the tracking results for the sinusoidal reference signals with various frequencies are presented, which shows the effectiveness of the proposed control design.

This paper investigates the vertical control problem of maglev train. Firstly, vertical model of maglev train is constructed, including car body, levitation bogie, suspension electromagnet and guideway. The presented vertical model considers the elastic connections between components and the external disturbances affecting at the guideway. To achieve the vertical control objective, i.e., regulating the suspension gap, a linear active disturbance rejection control (ADRC) design is proposed. The proposed ADRC can deal with the guideway disturbances and the unknown elastic information. To apply ADRC technique to vertical control of maglev train, the procedures to determine the relative degree and the nominal input gain are quantitatively discussed. To illustrate the effectiveness of the proposed ADRC, the comparison with the control design in MBB train and PID control is given.

In order to verify the accuracy of levitation chassis dynamics model of high speed maglev, the flexible vibration of the levitation chassis is explored, and the finite element model of levitation chassis is established to calculate its elastic mode; then the flexible-rigid dynamics model of the high-speed maglev vehicle is built. According to the field test data from Tongji University's maglev test line, the influence of flexible vibration of levitation chassis is analyzed on the gap of guidance and levitation electromagnet. The comparison with the simulation demonstrates that the results from the model of the levitation chassis flexibility is more close to the test results. The main frequencies of the vertical and lateral levitation chassis vibration are 10.4 and 13.2 Hz respectively, which are similar to modal frequencies of relative pitching and anti-phase yawing between the front and rear levitation frame. The flexibility of levitation chassis should be taken into account in the key issues of high-speed maglev trains, such as control parameter optimization, suspension parameter optimization, and running stability.

BackgroundThis study aims to describe a novel laparoscopic aspirator bracket (LAB) and its use in laparoscopic nephron-sparing surgery (NSS) by a simple enucleation (SE) technique.MethodsA total of 123 renal tumor cases who underwent laparoscopic NSS via LAB or laparoscopic aspirator between July 2017 and April 2021 were retrospectively analyzed. General characteristics, perioperative data and postoperative follow-up data of patients were compared.ResultsThe application of LAB in laparoscopic renal tumor SE surgery shortened the operation time (88.58 ± 38.25 vs. 102.25 ± 35.84 min, p < 0.05) and improved the zero ischemia rate (18.75% vs. 3.39%, p < 0.05), shortened warm ischemia time (16.17 ± 5.16 vs. 19.39 ± 5.62 min, p < 0.05) and decreased intraoperative blood loss (166.19 ± 111.60 vs. 209.15 ± 127.10 ml, p < 0.05). In addition, the serum creatinine and eGFR values in the LAB group also showed faster and better renal function recovery.ConclusionThe new LAB could aspirate and expose the operative field with a single instrument. In operations that need to expose and aspirate simultaneously, such as in renal tumor simple enucleation, it could shorten operation time, reduce intraoperative blood loss and improve the postoperative renal function recovery.

Background and ObjectivesLaparoscopic single-incision triangulated umbilical surgery (SITUS), which enables the extraction of intraabdominal specimens through a single umbilical incision, has yet to be used to perform adrenalectomy. We have modified SITUS to enable extraction of large (>5 cm) adrenal masses with optimal cosmetic outcomes and investigated efficacy and safety. Methods. In this retrospective study, we analyzed data of 16 patients with adrenal tumors >5 cm who had undergone adrenalectomy by SITUS between October 2015 and April 2018. Two C-shaped incisions were made around the umbilicus and sutured centripetally. After extracting the specimen, we evaluated these patients’ operative/postoperative data. Results. SITUS was performed in all 16 patients without conversion to laparoscopic or open surgery. The mean operation time was 75.31 ± 21.54 min (intraperitoneal time 41.94 ± 17.57 min; incision suturing time 33.38 ± 6.34 min). The estimated median blood loss was 57.5 mL (range 30–610 mL). Drainage time and duration of hospital stay were 55.69 ± 12.92 h and 3.94 ± 0.90 d, respectively. After surgery, all incisions were hidden under the umbilicus. Three patients developed keloid diathesis, resulting in enlargement of their scars. Conclusions. SITUS is a safe and feasible procedure for removing large adrenal tumors. In addition to its cosmetic advantages, SITUS facilitates functional recovery, particularly in patients with large adrenal tumors.

Abstract Background Laparoscopic nephron-sparing surgery (NSS) is the standard of care for small renal masses whenever feasible. This study aims to describe a novel laparoscopic aspirator bracket (LAB) and its use in laparoscopic NSS by a simple enucleation technique. Methods Between July 2017 and July 2019, we performed 54 laparoscopic NSS due to renal tumour using an SE technique by either LAB (n = 26) or laparoscopic aspirator (LA, n = 28) in 3 independent medical centres by 6 experienced surgeons. The novel aspirator could aspirate liquid and expose the operative field simultaneously. The details of operative technique are provided in the accompanying video. General characteristics and perioperative data of all patients were collected and retrospectively. Patients were followed up for 12 months after laparoscopic renal tumor simple enucleation (SE) operation. Renal function outcomes and perioperative complications were assessed. Results All 54 patients were successfully operated without conversion to open surgery. The use of the LAB in laparoscopic renal tumor SE operation can shorten the warm ischemia time ([WIT], LAB 12.92 ± 8.38 min vs. LA 17.89 ± 6.73 min) and increase the zero ischemia (ZI) rate (LAB 23.08% vs. LA 3.57%). In the one-year follow-up, the LAB group showed quicker renal function recovery (ipsilateral renal function 3 months after the surgery, LAB 41.67 ± 10.11% vs. LA 36.75 ± 10.30%). The limitations of this study were limited number of patients and retrospective attribute. Conclusion The new LAB could aspirate and expose the operative field with a single instrument. In operations that need to expose and aspirate simultaneously, such as in renal tumor simple enucleation, it could shorten WIT and improve the postoperative renal function recovery.

为对高速列车减振器开展低沉本、高精度的试验研究,开展了高速列车抗蛇行减振器实时混合试验方法研究.取抗蛇行减振器为试件并物理加载,取车辆动力学系统其余部分来数值模拟,通过实时计算、实时加载来共同完成动力试验.研究了加载系统时滞对试验结果的影响,比较了常速度时滞补偿方法和自适应时滞补偿方法的补偿效果.结果表明,对该方法而言,时滞补偿很有必要;相较于常速度的时滞补偿方法,自适应时滞补偿方法具有更好的补偿效果.该研究可为高速列车减振器动态性能分析以及列车抗蛇行性能评估提供试验方法支撑.

以某型号高速列车为原型,利用多体动力学仿真软件SIMPACK,考虑列车的轮轨非线性关系,建立完整车辆模型.通过SIMPACK软件中与MATLAB/Simulink对接的SIMAT接口,建立SIMPACK-Simulink混合试验仿真模型,其中SIMPACK车辆模型作为数值部分,采用Simulink建立时滞补偿、作动器及试验子结构模型.在该混合试验仿真系统的基础上,采用最小二乘多项式外插时滞补偿方法,分别开展直线工况和曲线工况仿真模拟,验证基于该模型开展混合试验的可行性,对比列车蛇行失稳非线性临界速度模拟精度.

文章建立了开关型天棚控制策略、连续型天棚控制策略、改进型天棚控制策略的 Simulink 模型，将三种控制模型分别应用于轨道车辆的一系垂向减振器和二系横向减振器，从而计算车辆动力学性能。结果表明，在文章中建立的三种半主动控制模型中，一系垂向减振器采用开关型天棚控制策略时转向架振动性能最优，二系横向减振器采用连续型天棚控制策略时车体振动性能最优，但同时会增大转向架蛇行失稳风险。

Doxepin hydrochloride is an antidepressant drug commonly used to treat mild to moderate depression. However, this drug has poor oral bioavailability, with the percentage of drug that can enter the bloodstream being weak and variable. The present study seeks to investigate the ZIF-8 nanoparticles for doxepin delivery and to assess this drug uptake and release in ZIF-8 frameworks using the Gibbs-ensemble Monte Carlo method in the Simulated Materials Studio. This study also adopted a model for showing surface adsorbent (ZIF-8S) capabilities. ZIF-8 nano-frameworks have many advantages such as easy flowing through capillaries leading to a satisfactory drug release into the systemic circulation and preventing high plasma concentration. Additionally, the study examined the diffusion of drug molecules using the simulated molecular dynamics with regard to the structural flexibility of the MOF. Proper loading of 8.6% and slow diffusion of 7.353 x 10(-6) cm(2)/s doxepin molecules from ZIF-8 pores confirmed that this material could be recommended as an effective carrier for doxepin. Furthermore, the fixed ZIF-8S model is also used by keeping the opening of cavities fixed, thereby attaining a higher loading amount 12%. Moreover, since ethanol has been applied as a suitable solvent in many biological systems, of adsorption, diffusion processes are also repeated in this solvent. Thus, presence of such adsorption sites as zinc ions may facilitate the interaction of the framework with large molecules to provide desirable loading and diffusion amounts. Furthermore, more adsorption can be reached with less energy at the surface of the ZIF-8 in the presence of ethanol, which is due to the greater adsorption of solvent molecules. Finally, to ascertain the in vitro cellular toxicity and viability of the prepared nanoparticles, they are treated with PC3 human prostate cancer cells and the average growth curves are monitored via MTT assay. This study confirmed a decrease in the MTT signal compared to the untreated cells, so ZIF-8 can reduce the metabolic activity of the performed cancer cells. This study shows that this nanomaterial can be achieved as a vehicle for delivery of doxepin. (C) 2021 Elsevier B.V. All rights reserved.

以轨道车辆地板组合断面为研究对象,为了获得精确的振动响应计算模型,采用基于模态特征的有限元修正方法,对结构较为复杂的复合材料客室地板进行了有限元模型修正,使用修正后的模型进行模态参数、频响函数的试验和仿真验证,结果表明,在50 Hz以内试验与仿真结果匹配性较好.基于修正后的地板组合断面有限元模型,研究了不同座椅安装方式对地板断面振动响应及传递规律的影响,研究结果与现车的振动规律一致,从理论上验证了现车座椅安装改善方案的合理性.

以一艘2000 TEU支线集装箱船为研究对象,采用CFD软件模拟船舶在不同工况下遭遇尾风时,烟囱排出的高温烟气对桅杆设备工作环境温度的影响.计算结果表明,气流从烟囱围壁后端起形成高/低流速区分界面,排烟口和桅杆几乎均处于低流速区域中,增加围壁高度可增加分界面与桅杆的距离,同时烟气出口速度越大,烟气对桅杆温度影响越小.

Increasing evidence shows that hypoxia is a cause of male infertility, and hypoxia may be related to oxidative stress (OS). Cistanoside (Cis) is a phenylethanoid glycoside compound that can be extracted from Cistanches Herba and possesses various biological functions. This study aimed to investigate the protective effects of Cis on reproductive damage induced by hypoxia and explore the specific underlying mechanisms. Cell and animal hypoxia experimental models were constructed, and the protective effects of different subtypes of Cis on the male reproductive system were assessed both in vitro and in vivo. The results indicated that hypoxia significantly reduced the viability of GC-1 cells through cell cycle arrest and apoptosis activation, which were associated with increased OS. Moreover, Cis showed strong antioxidative effects both in vitro and in vivo, significantly restoring antioxidant enzyme activities and downregulating reactive oxygen species (ROS) levels while increasing cell viability and decreasing apoptosis. Importantly, the Cis subtypes (Cis-A, Cis-B, Cis-C and Cis-H) studied herein all showed certain antioxidant effects, among which the effects of Cis-B were the most significant. This study demonstrates that Cis markedly attenuates the harmful effects of hypoxia-induced OS by affecting antioxidant enzyme activities in testes and GC-1 cells.

目的 探讨临床执业医师考试真题与研究生入学考试(西医综合)真题在泌尿外科教学中的应用价值.方法 通过分析历年临床执业医师考试与研究生入学考试(西医综合)真题中的泌尿外科相关内容命题情况,提炼重点考点,分析命题变化趋势,进而分析以往泌尿外科教学中存在的问题及今后教学的改进方法.结果执业医师考试每年均有9～22道泌尿外科相关试题出现,平均每年命题13.95题,其中肿瘤、结核、梗阻、结石、创伤相关命题较多,外阴疾病、感染、总论相关命题相对较少.西医综合考试平均每年泌尿外科相关试题仅1.28题,且命题范围集中于感染、肿瘤、概论和结核四部分,未出现梗阻及外阴疾病相关命题.根据考试命题情况,今后教学可通过增加教学内容的覆盖面、适当调整教学课时、区别教学的方法进行改进.结论 根据临床执业医师考试与研究生入学考试的命题分布情况适当调整泌尿外科教学内容,可优化教学方法,提升学生课堂专注度.

中华医学会泌尿外科分会膀胱癌指南摘要自2014年后尚无更新,但国外指南更新迅速.目前最新的2020版欧洲膀胱癌诊疗指南[1 ]有许多更新之处 ,现总结如下.

目的 探讨经脐单切口三角位腹腔镜手术(SITUS)在腹膜外入路膀胱部分切除术中的应用体会.方法 2017年7月至2019年4月,对13例平均年龄(68.00±5.22)岁、肿瘤最大径平均(3.2±0.8)cm的T2～T3期膀胱癌患者行SITUS腹膜外入路膀胱部分切除术.改进的手术操作包括切口的开关技术、腹膜外入路膀胱部分切除及膀胱缝合方法.记录术中出血量、手术时间、术后住院时间、切缘和组织病理及术后并发症.术后定期随访行CT扫描及膀胱镜检查监测有无肿瘤复发及转移.结果 13例手术均取得成功,无中转开放病例,1例增加1个辅助Trocar.平均手术时间(180.00±22.31)min,术中估计平均出血量(53.85±10.91)m L,术后平均住院时间(6.00±1.91)d,留置导尿管时间平均(7.60±0.96)d.围手术期无严重并发症发生.术后病理诊断尿路上皮癌9例,乳头状腺癌1例,脐尿管癌2例,副神经节瘤1例.所有病例切缘病例均为阴性.术后中位随访15个月,11例未发现肿瘤局部复发或远处转移,2例出现膀胱内局部肿瘤复发.结论 SITUS腹膜外入路膀胱部分切除术安全可行,并且具有创伤小、恢复快、安全性高、美容效果好等优点,是不能耐受或拒绝行膀胱根治性切除术患者较为理想的手术方法.

中华医学会泌尿外科分会前列腺癌(prostate cancer,PCa)诊疗指南自2014年后尚无更新,但国外指南更新迅速.目前,最新的2019版欧洲泌尿学学会(European Association of Urologists,EAU)前列腺癌诊疗指南出现了许多更新之处,现总结摘要如下. 1 介绍 指南是一定范围内的专家共识,但不是强制性的,也不是法定的医疗标准.

目前最新的2020 版欧洲膀胱癌诊疗指南[1 ] 相对于我国现行的2014 版中华医学会泌尿外科分会(Chinese Urological Association ,CUA)指南有许多更新之处,现摘要如下.

The aim of this study was to explore the predictive value of serum micro-RNA (miRNA)-205 in the diagnosis and prognosis of prostate cancer, and analyze miRNA-205 target genes and functions. Eight patients diagnosed with prostate cancer or benign prostatic hyperplasia (BPH) that were treated in January 2011 were selected. The serum samples between the two groups were analyzed for miRNA expression profiling, and the differentially expressed miRNA-205 was selected for further analysis. The serum samples of 64 patients with prostate cancer and 20 patients with BPH from March 2011 to March 2013 were collected for qPCR verification. We evaluated the correlation between miRNA-205 expression level and clinicopathological data of 64 patients with prostate cancer and its prognostic value. Finally, through bioinformatic analysis, target genes of miRNA-205 were predicted, and gene ontology (GO) analysis and signal pathway analysis were performed. A total of 657 differential miRNAs were screened from miRNA expression profiling. Compared with patients with BPH, miRNA-205 showed lower expression in the serum of patients with prostate cancer. Serum miRNA-205 + PSA combined had the strongest predictive ability, 0.805. The expression level of miRNA-205 in the patients with a Gleason score ≥7 was lower than that in patients with a Gleason score <7, Low miRNA-205 expression was associated with bone metastasis and higher T stage ratings, and the 5-year overall survival rate of the low miRNA-205 expression group was lower than the high miRNA-205 expression group. A total of 27 miRNA-205 target genes were predicted. The target genes of miRNA-205 are mainly enriched in biological functions such as cell adhesion and GTP kinase activity. The target genes of miRNA-205 are mainly enriched in Axon guidance and signal transduction by L1 and other signal pathways. In this study, serum miRNA-205 was successfully identified as a potential noninvasive serum marker for diagnosis and prognosis of prostate cancer, which will be helpful for future clinical research and prostate cancer drug target design.

中华医学会泌尿外科分会(Chinese Urological Association ,CUA)肾癌诊断和治疗指南摘要自2014年后尚无更新 ,但国外指南更新迅速.目前最新的2020 版欧洲泌尿协会 (European Association of Urology ,EAU)肾癌诊疗指南(2020年3月26日发布)相对2014版C U A指南有许多更新之处 ,现总结如下[1 ] .