An Electrically Modulated Drug Delivery Device. III. Factors Affecting Drug Stability During Electrophoresis

A number of factors affecting the stability of propranolol HC1 during electrophoretic control were investigated. It was found that significant degradation of propranolol HC1 and hydrolysis of water occurred when a current of 15 mA was used with platinized electrodes. This degradation was thought to be due to decomposition of propranolol HC1 at the electrodes. Degradation could be significantly reduced by using uncoated platinum electrodes and currents in the range of 0 to 2.5 mA, while still allowing control of drug delivery rates. Electrode reaction processes were found at high ionic strengths and high drug concentrations but were not thought to be associated with drug decomposition.     

荔枝壳红色素的提取及稳定性观察

以荔枝壳为原料，在酸性条件下浸提荔枝壳红色素，并对其稳定性进行了研究，结果表明，该色素在酸性条件下对光、热、常用食品添加剂均具有较好的稳定性。     

甘蓝复合果蔬汁的稳定性

单一的稳定剂并不能解决甘蓝复合果蔬汁的稳定性问题,而多种稳定剂的稳定效果较好,为此挑选出较好的3种稳定剂,对其进行不同比例的复配,观察一段时间的相对粘度及浊度变化,发现两种稳定剂的复配就能达到稳定的效果,最佳添加量(质量分数)为果胶0.07%,黄原胶0 03%.     

Stability of the original Hoffmann and AO tubular external fixation devices

Detailed data of the stability of external fixation devices are needed by the orthopaedic surgeon to predict successful healing of a fracture. The stability (rigidity, yield and failure criteria) of four half-frame configurations (single, stacked, double and delta) of the original Hoffmann and AO tubular frame have been analysed under four loading conditions: axial compression, torsion, and both AP- and ML-bending. Overall the two systems' rigidities were the same between similar configurations. Both systems' single half-frames were particularly weak; however, as the number of components (rods, pins, clamps, couplings) on the frame increased, the rigidity of the frame increased. The difference in performance between the two systems lies in their yield and failure characteristics. The AO system exhibited excellent failure criteria in all modes of loading, i.e. no configuration failed within the test limits, whereas most Hoffman frames yielded and failed at low loads.     

生物伯德图用于血压稳定性的分析和计算

本文用生物伯德图分析了血压稳定性。按照经典的控制理论,讨论了生物系统的稳定性,提出了血压控制的数学模型。根据生物特点,建立了生物伯德图的表达式。作为系统稳定性的指标,增益裕量和相位裕量可以用作图法求得,也可以用计算机求解。实验结果与理论分析能很好地符合。     

妊娠相关血浆蛋白A水平与不稳定心绞痛患者冠状动脉狭窄病变形态的关系

[目的]探讨不稳定型心绞痛患者妊娠相关血浆蛋白(PAPP-A)水平与高敏C-反应蛋白(hs-CRP)及动脉粥样硬化斑块稳定性的关系.[方法]不稳定型心绞痛组患者42例,稳定型心绞痛组38例.冠状动脉造影前检测PAPP-A和hs-CRP,根据造影结果将冠状动脉病变分为复杂狭窄和光滑狭窄.[结果]稳定型心绞痛组有28例(74%)患者至少有1支血管狭窄≥70%,多于不稳定型心绞痛组的24例(57%),P＜0.05;不稳定型心绞痛组中33例(79%)有1处以上的复杂狭窄,多于稳定型心绞痛组(22例,58%,P＜0.05);PAPP-A与hs-CRP正相关(r=0.44,P＜0.001);不稳定型心绞痛组与稳定型心绞痛组相比,hs-CRP(4.40 mg/L±0.003 mg/L vs 0.48 mg/L±0.016mg/L,P＜0.001)和PAPP-A(18.40×10-3 U/L±0.002×10-3U/Lvs 7.79×10-3 U/L±0.001×10-3 U/L,P＜0.001),差异均有统计学意义;两组中有复杂狭窄者的PAPP-A和hs-CRP水平显著高于无复杂狭窄者.[结论]PAPP-A可作为评估冠状动脉斑块稳定性的血清学指标之一.     

人工关节假体植入后骨溶解的研究进展

假体植入后松动是许多行关节置换术病人面临的严重问题,解决这一问题对于提高人工关节置换的疗效有重要意义.目前认为导致假体植入后松动的主要原因是关节活动使得假体表面之间长期摩擦,因此产生大量磨损微粒,微粒在骨-假体界面之间迁移,诱发局部环境中细胞分泌各种细胞因子导致假体周围的骨溶解.为此,本文主要研究磨损微粒的产生过程以及微粒的产生对关节假体使用寿命的重要影响,在此基础上探讨如何减少微粒的产生以及限制其在假体周围的迁移,以此来预防骨溶解发生.……     

Temporomandibular Joint Air in Fractures of the Skull Base

Basilar skull fractures involving the temporal bone extend through the tympanic part of the temporal bone in two-thirds of cases. The anatomical relationship of this part of the temporal bone and the temporomandibular joint enables air to pass from the auditory canal into the joint. Air in the temporomandibular joint is demonstrated on CT scans as an indirect sign of temporal bone fracture.