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国家自然科学基金(51204017)

作品数:6 被引量:79H指数:4
相关作者:周晓敏齐昕王长松马祥华冯雪莹更多>>
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Effects of Different Extracts of Kanggushu(抗骨疏) on Osteoporosis in Model Rats and the Underlying Mechanisms被引量:1
2013年
Objective: To investigate the preventive effects and possible underlying mechanism of different extracts of Kanggushu (抗骨疏) on osteoporosis in ovariectomized rats. Methods: One hundred and sixty- five female SD rats were divided into 11 groups: control, sham, model, Xianling Gubao Capsule (仙灵骨葆胶囊), nilestriol, Kanggushu aqueous extract high-, medium-, and low-dose and suet extract high-, medium-, and low-dose groups. The osteoporosis model was made by ovariectomizing the rats. The latter 8 groups were administered intragastricly with Xianling Gubao Capsule, nilestriol, Kanggushu aqueous extract and suet extract for 12 weeks, respectively, while the other 3 groups were administered orally saline. The whole body bone mineral density, bone mineral content, organ coefficient of uterus, serum estradiol and alkaline phosphatase contents, blood calcium, phosphorus, interleukin 6 and bone Gla-protein levels after treatment were monitored. Additionally, three-point bending test of femur, HE staining, and scanning electron microscope were performed to explore the pharmacodynamics and underlying mechanisms. Results: In comparison with ovariectomized rats of model group, Kanggushu aqueous extract high-dose resulted in an increased bone mineral density, bone mineral content and organ coefficient of uterus, improved estradiol level, and improved maximum load and structural stiffness (P〈0.05 or P〈0.01). Two-dimensional and thrae-dimensional trabecular structure was also observed under HE staining and scanning electron microscopy, and the number and thickness of trabecular bone in Kanggushu aqueous extract high-dose group was significantly increased compared to the model group, while the lipid droplets in bone marrow cavity were significantly less. However, there were no significant differences in blood calcium, total serum alkaline phosphatase and bone Gla protein among different treatment groups. Overall, the osteoprotective effects of Kanggushu aqueous extract were comparable to those
高植明杨丽黄丰熊爱华周宁周岚李孔燕邓洁丽李凯宇刘伟陈瑶罗万婷聂红
关键词:OSTEOPOROSISESTROGEN
Establishment of a Mouse Thrombocytopenia Model Induced by Cyclophosphamide被引量:10
2009年
An experiment was conducted to compare the effects of two mouse thrombocytopenia models induced by cyclophosphamide at two different administration routes to determine a proper cyclophosphamide administration route that could cause stable thrombocytopenia. A suitable drug dosage that could induce thrombocytopenia in mouse efficiently with the definite administration route was then investigated. BALB/c mice were randomly divided into Normal, Model A and Model B groups. To Model A, 200 mg/kg of cyclophosphamide was given by vena caudalis injection as first dose and 30 mg/kg as maintenance dose by intraperitoneal injection at the following 6 days. To Model B, 150 mg/kg of cyclophosphamide was given by subcutaneous injection once a day for consecutive 3 days. All groups were under investigation for 15 days. The result suggested that a decrease in the number of blood platelets of Model B at the 7th day were significantly than that of Normal. Other platelet related indices like platelet distribution width, mean platelet volume and platelet-large cell ratio of Model B increased significantly in comparison with those of Normal group. The platelets count was reduced but fluctuated greatly, and more than half of the mice died in Model A. Therefore, subcutaneous injection of cyclophosphamide for 3 days was used for the cyclophosphamide dosage test. BALB/c mice were randomly divided into Normal, cyclophosphamide low dose (100 mg/kg), medium dose (120 mg/kg) and high dose (140 mg/kg) groups. All groups were under investigation for 11 days. Though all 3 dosages successfully initiated thrombocytopenia as the platelets number dropped at the 7th day, the low dose was considered to be a suitable one that was of high efficacy and low toxicity. Thus, BALB/c mice challenged by subcutaneous injection of cyclophosphamide 100 mg/kg per day for 3 consecutive day is one simple, feasible and stable mouse thrombocytopenia model that could be used for pharmacodynamic test of the drugs which are supposed to have platelets increasi
聂红李孔燕张晓琦冯雪莹杨端容吴玉斯周玖瑶叶文才
关键词:THROMBOCYTOPENIACYCLOPHOSPHAMIDEMODEL
中高功率交流电机逆变器的低开关频率控制策略综述被引量:26
2015年
为了降低开关损耗,中高功率逆变器运行的开关频率都比较低,通常只有几千Hz有时甚至只有几百Hz,载波调制或是常规的SVPWM在降低开关频率之后会产生严重的电流畸变,需要使用特殊的开关策略控制逆变器。目前,适用于中高功率逆变器的控制策略主要有最优脉宽调制以及预测控制两大类。最优脉宽调制策略基于调制的思想,是一类较为成熟的逆变器低开关频率控制策略,应用广泛,但其计算量大、动态特性差的问题逐渐被学者们发现。预测控制虽然早在1983年就被提出,但由于当时控制器的硬件限制,一直没有引起重视,直至近年来才受到国内外学者的关注,并掀起了研究热潮。该文对最优脉宽调制以及预测控制进行了回顾,剖析了它们的设计思想,总结了近几年的研究成果,分析了各类方法的特点和局限,对待研究的问题进行了阐述,对未来的研究方向进行了展望。
齐昕周珂王长松周晓敏潘治赟马祥华
关键词:控制策略预测控制
一种低硬件资源消耗快速SVPWM算法被引量:24
2014年
常规SVPWM算法需要进行多次复杂的坐标变换并涉及大量的浮点乘法运算,增加了控制器的运算负荷且占用更多的内存空间。针对这一问题提出快速SVPWM方法,利用压缩变化将基础电压矢量转移至特殊位置,进而可以利用电压矢量变换后的两个分量的符号和大小判断其所在的扇区,无需进行其他数学运算;同时发现双边对称7段SVPWM三相占空比计算的特殊规律,将6个扇区分为3组,每组的2个扇区具有相同的运算规则,基于该发现提出简明扇区判据,只对矢量所属的组别进行判定,由判据结果可以直接获得三相占空比,进一步简化算法,减少了运算量和程序代码长度。通过仿真对算法的可行性进行了验证,同时在以DSP为控制核心的永磁电机实验平台上进行了实验。实验表明,在浮点DSP平台上快速SVPWM算法的运算速度提高了38%,同时减少了程序代码所占的存储空间,节省了45个字节的内存空间。
齐昕王冲周晓敏丛隽马祥华王长松
关键词:空间矢量脉宽调制逆变器
Morphological Characteristics of Smooth Muscle Cells Isolated from the Rat Ductus Deferens
2008年
The aim of this study was to establish a method of isolating and culturing smooth muscle cells from the ductus deferens of rats. Smooth muscle cells were prepared from ductus deferens by explanting technique after dissection of adventitia and intimae, and cultured in vitro. The identification of the smooth muscle cells were verified by using anti u-smooth muscle actin (a-SMA) immunohistochemistry studies. The result suggested that the cells are multi-morphous, showing long fusiform or star shapes. The apophysis of cells contacted and coalesced to each other, in some regions the cells overlapped in multilayer, while in the other regions they formed monolayer that fluctuated and showed a "peak-valley" shape. They presented a positive reaction through immunohistochemistry studies. The purity of the cells was more than 99% through this method. The culturing of smooth muscle cells by explanting technique is simple and stable.
聂红尹震林倩旋冯雪莹张建宇李孔燕
关键词:RAT
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