模拟诊疗在留学生心血管内科实习带教中的应用研究

目的　探讨模拟诊疗在留学生心血管内科实习带教中的应用效果。方法　将35名留学生随机编号，分成试验组和对照组。试验组18名学生分成3组（每组6名）进行模拟诊疗教学，对照组17名学生进行常规实习。通过填写评价单和相关的临床能力测试对两组教学效果进行评价。选用SPSS 19.0软件进行t检验。结果　参与模拟诊疗教学的留学生均希望在各科实习中多采用此方法。在临床能力测试方面，试验组学生在病史采集[（22.16±2.17）vs.（20.33±2.03）]、体格检查[（23.05±1.79）vs.（19.78±2.05）]及回答问题[（23.50±1.47）vs.（19.56±1.92）]方面均优于对照组，差异有统计学意义（P<0.05）。但是在病历书写方面，两组差异无统计学意义（P>0.05）。结论　利用高仿真的模拟诊疗教学手段，弥补了留学生在实习期间不能充分接触患者的缺陷，有助于提高其临床操作技能、增强医患沟通能力等医学职业素养。     

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.     

健脾消积颗粒对脾胃湿热型功能性消化不良患儿的临床疗效及对脑肠肽水平的影响＊

目的 探讨健脾消积颗粒治疗脾胃湿热型功能性消化不良的临床疗效及其对脑肠肽的影响。方法 按照随机数字表法将2018年2月-2019年2月我院收治的80例功能性消化不良患儿均分为对照组和观察组，对照组给予多潘立酮片治疗，观察组在对照组基础上加用健脾消积颗粒治疗，比较2组治疗效果。结果 治疗后2组主要临床症状积分均显著下降，观察组下降更为明显。观察组总有效率为95%，显著高于对照组的79.5%。观察组治疗后胃电节律异常例数明显低于对照组，治疗后2组胃动素(MTL)显著上升，神经肽Y（NPY）、神经降压素（NT）显著下降，且观察组和对照组相比，差异有统计学意义。2组治疗期间均未发生不良反应及肝肾功能异常。结论 健脾消积颗粒能够明显改善脾胃湿热型功能性消化不良患儿临床症状，改善胃动力水平，调节脑肠肽分泌水平。     

Exosomes from miRNA‐126‐modified endothelial progenitor cells alleviate brain injury and promote functional recovery after stroke

AimsWe previously showed that the protective effects of endothelial progenitor cells (EPCs)‐released exosomes (EPC‐EXs) on endothelium in diabetes. However, whether EPC‐EXs are protective in diabetic ischemic stroke is unknown. Here, we investigated the effects of EPC‐EXs on diabetic stroke mice and tested whether miR‐126 enriched EPC‐EXs (EPC‐EXs^miR126) have enhanced efficacy.MethodsThe db/db mice subjected to ischemic stroke were intravenously administrated with EPC‐EXs 2 hours after ischemic stroke. The infarct volume, cerebral microvascular density (MVD), cerebral blood flow (CBF), neurological function, angiogenesis and neurogenesis, and levels of cleaved caspase‐3, miR‐126, and VEGFR2 were measured on day 2 and 14.ResultsWe found that (a) injected EPC‐EXs merged with brain endothelial cells, neurons, astrocytes, and microglia in the peri‐infarct area; (b) EPC‐EXs^miR126 were more effective than EPC‐EXs in decreasing infarct size and increasing CBF and MVD, and in promoting angiogenesis and neurogenesis as well as neurological functional recovery; (c) These effects were accompanied with downregulated cleaved caspase‐3 on day 2 and vascular endothelial growth factor receptor 2 (VEGFR2) upregulation till day 14.ConclusionOur results indicate that enrichment of miR126 enhanced the therapeutic efficacy of EPC‐EXs on diabetic ischemic stroke by attenuating acute injury and promoting neurological function recovery.     

Hypocholesterolaemic mechanism of bitter melon aqueous extracts via inhibition of pancreatic cholesterol esterase and reduction of cholesterol micellar solubility

This study investigated the hypocholesterolaemic effects of bitter melon aqueous extracts (BMAE) in vitro, the inhibitory effects of BMAE on pancreatic cholesterol esterase (CEase) and incorporation of cholesterol into micelles were investigated. BMAE decreased the in vitro micellar solubility of cholesterol in a dose-dependent manner. The conformation of CEase was investigated by means of circular dichroism (CD) and fluorescence. The result revealed the decrease of α-helix contents, increase of β-sheet and exposure of aromatic amino acid residuals. The incorporation of cholesterol into micelles was inhibited by BMAE. A complex was observed by transmission electron microscopy (TEM), which indicated interaction between cholesterol and BMAE. The result revealed that BMAE can play a role in decreased intestinal cholesterol absorption via inhibition of CEase, and of micelle formation.