2015-2018年血流感染病原菌菌群分布及耐药性分析

目的:对我院血培养常见病原菌的菌群分布及耐药性进行分析,为临床血流感染治疗和合理应用抗生素提供依据。方法:对我院2015-2018年血培养阳性标本病原菌菌群分布及耐药性进行统计分析。结果:2015-2018年血培养标本分离细菌2 587株,革兰阴性菌1 243株（48.05%）,革兰阳性菌1 123株（43.41%）,真菌221株（占8.54%）;主要革兰阴性菌为大肠埃希菌（482株/18.63%）、肺炎克雷伯菌（271株/10.48%）、铜绿假单胞菌（97株/3.75%）;主要革兰阳性菌为凝固酶阴性葡萄球菌（583株/22.54%）、金黄色葡萄球菌（157株/6.07%）等;主要真菌为近平滑念珠菌（106株,4.10%）、白色念珠菌（32株,1.24%）等;4年间大肠埃希菌对头孢西丁的耐药率逐渐下降（P＜0.01）,肺炎克雷伯菌对亚胺培南的耐药率从2.00%上升至10.05%（P＜0.05）,共检出33株耐碳青霉烯肺炎克雷伯菌。结论:我院血培养标本以革兰阴性菌为主,其中大肠埃希菌检出率最高,同时肺炎克雷伯菌检出率呈逐年增长趋势。临床应根据药敏结果合理应用抗生素,及时调整治疗方案,降低血流感染的死亡率。     

加热与常温渗漉-层析提取工艺对丹参水提物的影响

分别采用渗漉层析耦合和不同温度下加热提取工艺,从同一批丹参中提取水溶性成分丹酚酸,并采用高效液相色谱分析产物,研究提取工艺和温度对丹参水提物中丹酚酸B的含量、提取率及产物色谱谱图的影响。结果表明,用渗漉层析耦合工艺得到的丹参水提物中的丹酚酸B含量最高且小分子酚酸类化合物很少;采用加热提取工艺时小分子酚酸类化合物种类及含量随温度（60~100 ℃）的升高而增加,丹酚酸B含量及提取率随提取温度的升高呈现由高到低又增高的规律、两者在100 ℃时达到最大值。研究表明应根据对丹参水提物及其制剂的质量与安全性要求选择合适的工艺及工艺条件。     

导管相关性血流感染的病原菌分析

目的分析导管相关性血流感染（CRBSI）的病原菌分布,为临床诊治提供参考。方法对本院2008年9月-2010年12月中心静脉导管培养阳性的180例病例进行回顾性分析。结果 180例中56例（31.1%）为CRBSI确诊病例。来源于重症监护病房29例,结核病区8例,肾内科6例,呼吸科4例,其他科室9例;56株病原菌中革兰阴性杆菌24株（42.8%）,主要为鲍曼不动杆菌和肺炎克雷伯菌;革兰阳性球菌22株（39.3%）,以凝固酶阴性葡萄球菌和金黄色葡萄球菌为主;假丝酵母菌属10株（17.9%）。结论多耐药鲍曼不动杆菌和真菌在CRBSI中出现,应引起临床高度重视。     

电针足三里穴对胃肠功能紊乱模型大鼠脏器微循环的影响及穴位脏腑相关性理论探讨

[目的]通过观察电针足三里穴对胃肠功能紊乱模型大鼠胃、肠、肝、脑微循环的影响,探讨足三里穴与胃之间穴位脏腑相关特异性.[方法]48只SD大鼠随机均分为正常组,模型组,足三里1、2组、三阴交1、2组.大鼠腹腔注射利血平制作胃肠功能紊乱模型.正常和模型组及三阴交1组、足三里1组束缚7天,三阴交2组、足三里2组连续电针7天,第8天三阴交和足三里1、2组采用激光多普勒微循环血流分析仪监测各组大鼠胃、肠、肝、脑等器官表面微循环.[结果]模型组胃、肠微循环血流量明显低于正常对照组（P＜0.05）,电针即刻（1min）明显高于电针前（P＜0.05）;较模型组,足三里1、2组电针即刻（1min）胃微循环血流量升高（P＜0.05）,且明显高于三阴交1、2组,有显著性差异（P＜0.05）;电针即刻（1min）三阴交2组和足三里1、2组肠微循环血流量明显高于模型对照组（P＜0.05）.针刺对各组大鼠肝及脑微循环的影响无显著性差异（P＞0.05）.[结论]电针足三里穴能有效调节胃肠功能紊乱模型大鼠胃、肠,尤其是胃微循环血流量,具有穴位特异性,为足三里穴与胃之间穴位脏腑特异性相关理论提供一定科学依据.     

Identification of distant co-evolving residues in antigen 85C from Mycobacterium tuberculosis using statistical coupling analysis of the esterase family proteins

A fundamental goal in cellular signaling is to understand allosteric communication, the process by which sig-nals originating at one site in a protein propagate reliably to affect distant functional sites. The general principles of protein structure that underlie this process remain unknown. Statistical coupling analysis (SCA) is a statistical technique that uses evolutionary data of a protein family to measure correlation between distant functional sites and suggests allosteric communication. In proteins, ...     

不同树脂粘结剂及硅烷偶联剂对玻璃纤维桩与牙本质粘结强度的影响

[目的]评价不同树脂粘结剂及不同组份硅烷偶联剂对玻璃纤维桩与牙本质粘结强度的影响.[方法]将24颗单根管离体牙去除牙冠经常规根管治疗和预备,粘固MATCHPOST玻璃纤维桩.将每颗牙根垂直牙长轴切割出3个3.0mm的片段作为测试样本.根据涂布硅烷偶联剂的组份不同将离体牙随机均分为A组（双组份组）和B组（单组份组）;根据...     

Electromechanical time course in frog ventricle: Manipulation of calcium level during voltage clamp

Extracellular calcium concentration was rapidly altered in the “diastolic” interval between two contractions, and also during the time course of a single 10 s clamp pulse. The results strongly suggest that contraction of frog ventricular muscle is largely determined by a continuous, voltage-dependent influx of calcium into the cell, with little or no contribution from mechanisms involving release of calcium from intracellular stores. In addition, contraction can be graded, as a rapid response to alterations in extracellular calcium concentration.     

Simulation of Granular Flows and Pile Formation in a Flat-Bottomed Hopper and Bin,and Experimental Verification

Granular flows of 200 μm particles and the pile formation in a flat-bottomed hopper and bin in the presence of air and in a vacuum were predicted based on three-dimensional numerically empirical constitutive relations using Smoothed Particle Hydrodynamics and Computational Fluid Dynamics methods. The constitutive relations for the strain rate independent stress have been obtained as the functions of the Almansi strain including the large deformation by the same method as Yuu et al. [1]. The constitutive relations cover the elastic and the plastic regions including the flow state and represent the friction mechanism of granular material. We considered the effect of air on the granular flow and pile by the two-way coupling method. The granular flow patterns, the shapes of piles and the granular flow rates in the evolution are compared with experimental data measured under the same conditions. There was good agreement between these results, which suggests that the constitutive relations and the simulation method would be applicable for predicting granular flows and pile formation with complex geometry including free surface geometry. We describe the mechanisms by which the air decreases the granular flow rate and forms the convergence granular flow below the hopper outlet.     

T-type Ca2+ current contribution to Ca2+-induced Ca2+ release in developing myocardium

In normal adult-ventricular myocardium, Ca2+-induced Ca2+ release (CICR) from the sarcoplasmic reticulum (SR) is activated via Ca2+ entry through L-type Ca2+ channels. However, embryonic-ventricular myocytes have a prominent T-type Ca2+ current (ICa,T). In this study, the contribution of ICa,T to CICR was determined in chick-ventricular development. Electrically stimulated Ca2+ transients were examined in myocytes loaded with fura-2 and Ca2+ currents with perforated patch-clamp. The results show that the magnitudes of the Ca2+ transient, L-type Ca2+ current (ICa,L) and ICa,T, decline with development with the majority of the decline of transients and ICa,L occurring between embryonic day (ED) 5 and 11. Compared to controls, the magnitude of the Ca2+ transient in the presence of nifedipine was reduced by 41% at ED5, 77% at ED11, and 78% at ED15. These results demonstrated that the overall contribution of ICa,T to the transient was greatest at ED5, while ICa,L was predominate at ED11 and 15. This indicated a decline in the contribution of ICa,T to the Ca2+ transient with development. Nifedipine plus caffeine was added to deplete the SR of Ca2+ and eliminate the occurrence of CICR due to ICa,T. Under these conditions, the transients were further reduced at all three developmental ages, which indicated that a portion of the Ca2+ transients present after just nifedipine addition was due to CICR stimulated by ICa,T. These results indicate that Ca2+ entry via T-type channels plays a significant role in excitation-contraction coupling in the developing heart that includes stimulation of CICR.     

Electromechanical effects of leukotriene D4 on ferret tracheal muscle and its muscarinic responsiveness

We investigated the possible electrophysiological processes by which leukotriene D₄ (LTD₄) affects airway smooth muscle and its responsiveness to acetylcholine (ACh). For study in vitro, preparations of ferret tracheal muscle (dissected free of overlying mucosal and submucosal layers) were used. These preparations were arranged so that force transducers and glass intracellular microelectrodes (having tip resistances of 35–60 megohm) could be used to measure isometric force generation and cell membrane potential (Em) simultaneously from muscle stimulated by LTD₄. At rest, the muscle was electrically and mechanically quiescent and had an Em of −59±0.2 mV (mean±SEM). We found that ferret tracheal muscle cells were relatively sensitive to LTD₄, and that both the resulting depolarization (beginning at 10⁻¹⁰ M LTD₄) and force generation (produced by higher concentrations) progressed in a concentration-dependent manner. Depolarization by 10⁻⁹ M LTD₄ elicited electrical oscillations. These oscillations were accompanied by phasic contractile activity at 5 × 10⁻⁹ M LTD₄. Verapamil abolished these oscillations and diminished force substantially. We also found that ACh depolarized and contracted the muscle in a concentration-dependent manner. It caused electrical oscillations at ≥ 10⁻⁶ M. Diltiazem abolished these oscillations and markedly diminished force generation without affecting Em. Preexposure of airway muscle preparations for 20 min to a concentration (10⁻¹⁰ M) of LTD₄ that, by itself, did not produce significant force, substantially augmented the voltage-tension relationship of the muscle upon ACh stimulation. We conclude that there is an electrical basis for the slow, prolonged force generation of airway muscle caused by LTD₄, and that LTD₄ potentiates the electromechanical responsiveness of the airway muscle to muscarinic stimulation.