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51.
52.
本文报道应用高分子右旋糖酐制成软脑膜微循环障碍的动物实验模型。软脑膜微循环障碍模型的标志;软脑膜微血管血流速度减慢,血液流态呈粒状流或絮状流,血细胞聚集。 将98只家兔分成甲、乙二组。甲组38只,静脉注射平均分子量为25万的高分子右旋糖酐,乙组60只,静脉注射平均分子量为49万的高分子右旋糖酐。实验结果发现,甲组38只家兔仅28只可复制成软脑膜微循环障碍的实验模型,模型复制成功率为73.6%;乙组60只家兔,59只可形成软脑膜微循环障碍实验模型,成功率为98.3%。本实验证明复制动物模型以49万分子量的高分子有旋糖酐为宜。 本实验模型可用于脑微循环障碍和改善脑微循环药物的研究工作。  相似文献   
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For more than two decades, antisense oligonucleotides (ODNs) have been used to modulate gene expression for the purpose of applications in cell biology and for development of novel sophisticated medical therapeutics. Conceptually, the antisense approach represents an elegant strategy, involving the targeting to and association of an ODN sequence with a specific mRNA via base-pairing, resulting in an impairment of functional and/or harmful protein expression in normal and diseased cells/tissue, respectively. Apart from ODN stability, its efficiency very much depends on intracellular delivery and release/access to the target side, issues that are still relatively poorly understood. Since free ODNs enter cells relatively poorly, appropriate carriers, often composed of polymers and cationic lipids, have been developed. Such carriers allow efficient delivery of ODNs into cells in vitro, and the mechanisms of delivery, both in terms of biophysical requirements for the carrier and cell biological features of uptake, are gradually becoming apparent. To become effective, ODNs require delivery into the nucleus, which necessitates release of internalized ODNs from endosomal compartments, an event that seems to depend on the nature of the delivery vehicle and distinct structural shape changes. Interestingly, evidence is accumulating which suggests that by modulating the surface properties of the carrier, the kinetics of such changes can be controlled, thus providing possibilities for programmable release of the carrier contents. Here, consideration will also be given to antisense design and chemistry, and the challenge of extra- and intracellular barriers to be overcome in the delivery process.  相似文献   
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Poly (3-phenylthiophene) (P3PhT) films have been electrochemically synthesized by direct oxidation of 3-phenylthiophene in the electrolyte of pure boron trifluoride diethyl etherate (BFEE). The oxidation potential of the monomer was measured to be 1.29 V (vs. SCE), and about 0.15 V lower than that measured in a neutral medium of acetonitrile. Free-standing P3PhT film with tensile strength of 32–40 MPa has been obtained for the first time. The morphology and the structure of the polymer film have been studied by scanning electron microscopy, infrared and Raman spectroscopies. Raman spectral results demonstrated that the doping level of the P3PhT film increased with film thickness during electrochemical growth process.  相似文献   
56.
目的通过动物实验观察不同骨水泥强化松质骨螺钉的生物力学和组织学变化动态,为骨质疏松骨折患者内固定提供理论基础。方法在10只杂种犬胫骨近端制作松质骨螺钉植入的动物模型,分别采用碳酸化羟基磷灰石水泥(CHC)和聚甲基丙烯酸甲酯(PMMA)强化,分别于术后5d、4、8、12和16周处死动物,观察螺钉拔出的生物力学和组织学变化。结果CHC强化的螺钉拔出力随手术后时间的延长而逐渐升高,16周时达到(512.5 14.5)N,而PMMA强化组螺钉拔出力则随手术后时间的延长而逐渐降低。CHC-骨界面结合紧密,并且随时间延长出现CHC降解和骨长入,而PMMA-骨界面形成一层纤维组织。结论CHC强化能够提高松质骨螺钉植入体内的稳定性,并且随植入时间延长而逐渐升高。  相似文献   
57.
相对于普通高校,高职高专学校中学业不良学生的比例更高,管理的难度更大。因此,分析、研究学生学业不良的成因,并采取科学有效的措施予以矫正,对于促进学生健康成长,全面提高教育教学质量,具有积极的意义。  相似文献   
58.
In vitro activation of purified rat microsomal glutathione transferase 1 (MGST1) by S-nitrosylation has been recently reported. This study was designated to explore its in vivo relevance. Unexpectedly, we failed to detect S-nitrosylated MGST1 in rat liver microsomes treated with S-nitrosoglutathione (GSNO); neither did we observe MGST1 S-nitrosylation in endotoxin challenged rats. However, by using matrix-assisted laser dissociation/ionization time-of-flight mass spectrometry (MALDI-TOF MS), we identified several other proteins which are susceptible to S-nitrosylation in liver microsomes, including retinol dehydrogenase type I (RODH I), aldolase B, cytochrome P4502C11, and peroxiredoxin 1. Our results suggest that MGST1 S-nitrosylation is unlikely to be involved in the protection mechanism against nitrosative stress caused by endotoxin challenge. Further studies on the novel S-nitrosylable microsomal proteins are also warranted.  相似文献   
59.
Stem cells and periodontal regeneration   总被引:10,自引:0,他引:10  
  相似文献   
60.
A poptosis, an evolutionarily conserved form of cell suicide, oc- curs in two physiological stages: commitment and execution.[1] It has been found that several Bcl-2 family proteins are located in the outer mitochondrial membrane, where they control relea…  相似文献   
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