聚苯胺/聚合物导电材料研究进展

从制备方法着手综述了近年来聚苯胺/聚合物导电材料研制开发的最新成果，并简介了聚苯胺/聚合物导电材料的应用情况。     

氧氟沙星滴耳剂的高效液相色谱分析和稳定性研究

本文采用反相高效液相色谱法考察了氧氟沙星滴耳剂的稳定性。该法简便、迅速、专属性强、精密度好，制剂回收率为９９．９７％。经光照、高温、低温和加速试验，结果表明：本制剂对冷和热稳定，对光不稳定。建议氧氟沙星滴耳剂暂定有效期２年，使用中应注意避光保存。     

Influence of volume replacement with different HES–solutions on microcirculatory blood flow in cardiac surgery

A variety of hydroxyethyl starch (HES) preparations with different molecular weight average (Mw) and molar substitution (MS) is available for volume replacement during acute normovolemic haemodilution (ANH). Particularly with regard to microcirculation, the ideal solution for volume therapy has not been found. A 5th group without ANH served as a control (10 patients in each group). In addition to systemic haemodynamics and various laboratory parameters, skin capillary blood flow was measured by laser Doppler flowmetry. Laser Doppler flow (LDF) was monitored simultaneously at the patient's forehead and forearm. Changes in systemic haemodynamics were similar in all ANH–patients. Systemic vascular resistance (SVR) was lowest after infusion of HES 200/0.5. The most pronounced increase in plasma viscosity was in patients of group 1 (450/0.7) (P<0.05) and plasma viscosity remained highest during the entire investigation period in these patients. After ANH, skin capillary blood flow measured at the forehead decreased in all patients except in patients of group 2 (200/0.5: max. + 18%). Group 3 (200/0.62) showed the highest decrease in forehead–LDF. During CPB, forehead–LDF decreased significantly in groups 3 (200/0.62) and 4 (40/0.5). At the end of the operation, LDF was most reduced in groups 1 (– 32%) and 3 (– 33%). Forearm–LDF increased in all ANH–patients. Immediately after ANH this increase was lowest in group 3 (200/0.62). In the further course of the investigation, no more differences were seen in any HES patients. The different HES preparations showed a different microcirculatory response. 6% HES 200/0.5 seems to be overall most suitable for volume replacement in cardiac surgery patients undergoing acute normovolemic haemodilution (ANH) due to the best effects on microcirculatory skin perfusion assessed by laser Doppler flow. HES 6% 200/0.62 showed the overall least positive effects with regard to skin capillary blood flow in this situation.     

极化心脏停搏液对离体大鼠心脏的保护作用

目的探讨Na+通道阻滞剂河豚毒素(tetraodontoxin,TTX)在极化状态下对离体大鼠心脏的保护作用. 方法将20只Wistar大鼠按体重均衡原则随机分成两组,每组10只.取出心脏建立Langendorff灌注模型和左心工作灌注模型,分别用去极化心脏停搏液(St.Thomas 2号液,STH-2组)和极化心脏停搏液(22 μmol/L TTX + K-H缓冲液,TTX组)停搏,低温保存5小时后再灌注心脏.观察两组心脏缺血前、后在心功能、心肌酶漏出量、三磷酸腺苷酶(ATPase)活性、再灌注后心肌胞浆游离Ca2+浓度和心肌超微结构等方面的改变. 结果恢复灌注后,TTX组心功能恢复明显优于STH-2组(P＜0.01),心肌酶漏出量较少(P＜0.05),各种ATPase维持较高的活性(P＜0.01),胞浆游离Ca2+浓度明显低于STH-2组(P＜0.01),心肌超微结构得到很好的保护. 结论以TTX阻断Na+通道为特点的极化心脏停搏液对大鼠心肌缺血-再灌注损伤的保护作用优于去极化心脏停搏液,有希望成为新型、有效的心脏停搏液和供者心脏保存液.     

高渗盐水与甘露醇对颅脑手术患者脑氧代谢的影响

目的 比较3％高渗盐水（HTS）与20％甘露醇对颅脑手术患者脑氧代谢的影响。方法 择期大脑半球胶质瘤切除术患者40例，ASAⅠ级或Ⅱ级，随机分为2组（n=20）：3％HTS组（HTS组）和20％甘露醇组（M组）。采用静吸复合麻醉，呼气末异氟醚浓度为1 MAC、血液动力学稳定15．min后，分别于15 min内静脉输注3％HTS 5．35 ml／kg或20％，甘露醇1 g／kg。L3，4珠网膜下腔置管测脑脊液压力（CSFP），行右颈静脉球穿刺置管、采血，测定颈静脉球氧饱和度。分别于输注前（T0）、输注完即刻（T1）、输注完15min（T2）、30min（T3）、60min（T4）、120min（T5）监测CSFP;于T0、T3-T5时监测平均动脉压，采集颈静脉球部和桡动脉血，进行血气分析，计算动脉-静脉氧含量差（Da-jvO2）、脑氧摄取率（CERO2）。结果 与T0比较，2组CSFP在T2-T5时降低，Da-jvO2和CERO2在T4，5时降低（P〈0．05）;与M组比较，HTS组CSFP在T2时降低（P〈0．05）。结论 3％HTS与20%甘露醇均可有效地降低颅内压，改善颅脑手术患者的脑氧代谢。     

Time-dependent morphological alterations of cold-stored small bowel in Euro-Collins and Ringer's lactate solutions

Small bowel is one of the organs that can in principle be transplanted. Optimum preservation of the organ is essential for the success of transplantation. The aim of the present study is the investigation of time-related morphological changes of rat small bowel during preservation in hypothermic Euro-Collins (EC) and Ringer's lactate (RL) solution using light microscopy and transmission electron microscopy to evaluate the integrity of intercellular complexes of mucosal epithelium, one of the tissues of the intestine that is most susceptible to ischemia. Small bowels were perfused with either EC, RL solution or physiological saline solution and were placed in the different preservation solutions at 4 degrees C for 0, 3, 6 and 12 h. The results of our study suggest that both preservation solutions are suitable for short-term preservation of the small bowel although RL solution is more effective than EC solution. However, we conclude that further improvement of preservation solutions and/or techniques are needed to perform long-term preservation.     

Secretion of a chemotactic factor for neutrophils and eosinophils by alveolar macrophages from asthmatic patients

The studies presented in this article demonstrate the release of an IgE-dependent chemotactic factor for polymorphonuclear neutrophils (PMN) and eosinophils by alveolar macrophages (AMs) from normal subjects (n = 15) and allergic asthmatic patients (n = 15). A 60-minute incubation of normal AMs previously sensitized by 20% nonheated allergic sera with anti-human IgE antibody or the related allergen induced the release of a chemotactic activity (CA) for PMN and eosinophils in culture supernatants. When AMs were obtained from asthmatic patients, direct incubation with anti-IgE or the related allergen induced the same CA, whereas incubation with an unrelated allergen failed to produce CA (neutrophil CA after addition of anti-IgE, 22.5 +/- 3.5 cells per high power field; with related allergen, 15.8 +/- 3.6; with unrelated allergen, 0.7 +/- 1.8; p less than 0.0001). A partial characterization of the neutrophil chemotactic factor was carried out. Enzymatic treatment by trypsin or carboxypeptidase or by heating (56 degrees C for 3 hr) failed to abolish the neutrophil CA. After gel filtration the greater part of the neutrophil CA (80%) was recovered among low-molecular-weight components (300 to 1300 daltons). A preliminary deactivation of PMN by leukotriene B4 suppressed the CA of AM supernatants. These results indicate that IgE-dependent stimulation of AMs produces a neutrophil and eosinophil CA, present in a low-molecular-weight fraction possibly related to leukotrienes, and emphasizes the role of AMs in inflammatory lung processes during allergic asthma.     

Sputum induction as a research tool for the study of human respiratory mucus

The study objectives were to compare in vitro transportability and physical properties of respiratory mucus, obtained invasively by direct collection (DC) right after endotracheal intubation and non-invasively by sputum induction with 3% hypertonic saline solution inhalation (SI) 24 h before the anesthesia. Twenty-two patients with no pulmonary disease scheduled for elective abdominal surgical procedures were studied. The parameters analyzed and the main results are as follows. (1) Transportability by cilia (MCT), SI was higher than DC (0.94+/-0.25 and 0.62+/-0.25; P<0.001). There was a significant correlation between the two methods and DC could be estimated by: DC=0.21+(0.44 SI) (r=0.44; P<0.001). (2) Transportability by cough (CC), SI was higher than DC (68.23+/-32.1 and 33.58+/-19.04 mm; P=0.002). (3) Contact angle (CA), SI was lower than DC (10+/-3 degrees and 22+/-14 degrees ; P=0.025). (4) Rheological properties (no significant difference obtained between SI and DC). These results indicated that SI changes mucus physical properties and transportability in non-expectorators.     

Vortex Shaped Current Sources in a Physical Torso Phantom

Recent studies reported differential information in human magnetocardiogram and in electrocardiogram. Vortex currents have been discussed as a possible source of this divergence. With the help of physical phantom experiments, we quantified the influence of active vortex currents on the strength of electric and magnetic signals, and we tested the ability of standard source localization algorithms to reconstruct vortex currents. The active vortex currents were modeled by a set of twelve single current dipoles arranged in a circle and mounted inside a phantom that resembles a human torso. Magnetic and electric data were recorded simultaneously while the dipoles were switched on stepwise one after the other. The magnetic signal strength increased continuously for an increasing number of dipoles switched on. The electric signal strength increased up to a semicircle and decreased thereafter. Source reconstruction with unconstrained focal source models performed well for a single dipole only (less than 3-mm localization error). Minimum norm source reconstruction yielded reasonable results only for a few of the dipole configurations. In conclusion active vortex currents might explain, at least in part, the difference between magnetically and electrically acquired data, but improved source models are required for their reconstruction.     

肝细胞培养过程中酸碱度和溶解氧的关联控制

目的在生物型人工肝支持系统(BAL)中,设计一种能够精确控制溶解氧(D0)与酸碱度(pH)的控制方案.方法根据肝细胞培养过程中所需要的物料衡算,采用比例积分(PI)算法结合开关量控制、预测控制等方案,通过工控机构建关联控制系统,使得D0与pH的值相互关联.结果DO控制范围0%～200%,精度达到±5%;pH控制范围6～8,精度达到±0.05.结论经实验证实,本控制方案工作稳定,无静态误差,解决了培养过程中DO与pH相互影响的问题,可用于BAL中对肝细胞培养环境的控制.