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31.
Fabrication of porous hollow silica nanoparticles and their applications in drug release control. 总被引:11,自引:0,他引:11
Preparation and characterization of porous hollow silica nanoparticles (PHSN) for controlled release applications were investigated. Through orthogonally designed experiments, the optimal synthesis conditions for the preparation of PHSN were obtained and the produced PHSN were characterized by BET, SEM, TEM and IR. Scanning and transmission electron microscopy images revealed their hollow shell-core structure and also demonstrated that the size and shape of PHSN are determined by the templating CaCO3 nanoparticles. The produced PHSN were applied as a carrier to study the controlled release behaviors of Brilliant Blue F (BB), which was used as a model drug. Being loaded into the inner core and on the surfaces of the nanoparticles, BB was released slowly into a bulk solution for about 1140 min as compared to only 10 min for the normal SiO2 nanoparticles, thus exhibited a typical sustained release pattern without any burst effect. In addition, higher BET of the carriers, lower pH value and lower temperature prolonged BB release from PHSN, while stirring speed showed little influence on the release behavior. It showed that PHSN have a promising future in controlled drug delivery applications. 相似文献
32.
体重指数、腰围、腰臀比与血压、血糖、血脂关系的探讨 总被引:1,自引:1,他引:0
目的 探讨体重指数(BMI)、腰围(WC)、腰臀比(WHR)与代谢性因素的关系.方法 对镇江市居民基线资料的1108例对象按BMI、WC、WHR分组.在正常体重、超重、肥胖;腰围正常、腰围过大;腰臀比正常、腰臀比过大各组中,比较收缩压(SBP)、舒张压(DBP)、血糖(FBG)、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)的水平.结果 不论男性女性组,超重肥胖、腰围过大组,血压、血糖、血脂水平与正常组比较均明显升高;腰臀比过大组与正常组比较,男性组TG、FBG明显升高;HDL-C明显降低;女性组TG、FBG、SBP明显升高,HDL-C明显降低.结论 BMI、WC、WHR指标与代谢性因素密切相关;BMI、WC在提示肥胖程度方面优于WHR指标. 相似文献
33.
食管癌三维适形后程加速超分割放射治疗的疗效分析 总被引:3,自引:0,他引:3
目的评价三维适形后程加速超分割放射治疗食管癌的疗效及放疗反应、并发症。方法2002年2月至2004年5月,71例食管鳞癌随机分成两组,三维适形后程加速超分割组36例,食管病变上下外约4cm,前后、左右外约0.5~1cm作为PTV1,每次2GY,每周5次,DT40GY后,病变上下外约2cm,前后、左右外约0.5~1cm作为PTV2,每日2次,每次1.5GY,间隔4~6小时,总疗程6周,总剂量67GY/38次。非三维适形后程加速超分割组35例,时间、剂量、分割方式同适形组。所有病例均采用8MV-X外照射。结果1、2、3年的生存率和原发肿瘤的局控率,与非适形后程加速超分割比较,适形组明显提高,分别为88.9%、75%、63.9%比68.6%、51.4%、40%和86.1%、72.2%、58.3%比65.7%、48.5%、34.3%。适形组的急性放射反应明显低于非适形后程加速超分割组,两组有显著差别。结论本研究的初步结果表明食管癌适形后程加速超分割放射治疗的疗效优于非适形后程加速超分割组。 相似文献
34.
移情对建立新型医患关系伦理模式的利与弊 总被引:1,自引:0,他引:1
在现代社会这样一个转轨时期,医患矛盾越来越突出,如何缓和医患关系、建立新型医患关系伦理模式成为大家共同关心的课题。作者从移情的角度入手,阐述了新型医患关系伦理模式的内涵,分析了移情对于缓和医患关系有哪些有利之处与不利之处,并提出了如何适度利用移情的方法,使其发挥最大作用。 相似文献
35.
Yanke Yu Wen Zhu Huiling Diao Chunxian Zhou Fanqing F Chen Jun Yang 《Toxicology in vitro》2006,20(6):959-965
Comet assay is a useful technique in the detection of DNA damages, particularly DNA strand breaks; and it has been utilized to show that a potent carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), can induce such damages. Recently, gammaH2AX foci formation has been suggested as another sensitive way to detect DNA double strand breaks (DSBs). However, there is no systematic comparison being conducted to evaluate the consistency of these two methods. Using MNNG as a model chemical, the sensitivity of neutral comet assay and gammaH2AX foci formation in detecting MNNG-induced damage was studied. It was found that at concentrations of 0.1 and 1 microg/ml, both methods can detect MNNG-induced damage in human amnion FL cells. However, at 0.1 microg/ml, comet assay revealed more percentage of cells with DNA damage than gammaH2AX fluorescence revealed. On the other hand, while gammaH2AX foci were readily formed at very early times by 10 microg/ml MNNG treatment, neutral comet assay did not detect any significant DNA damage at the same time points. In addition, 10 microg/ml MNNG induced a distinct whole nuclei staining pattern of gammaH2AX, a type of DNA damage which was not detected by neutral comet assay but could be detected by alkaline comet assay. Therefore, gammaH2AX may be used as a sensitive indicator for DNA damage. 相似文献
36.
Disseminating tumor cells and their interactions with leukocytes visualized in the brain. 总被引:3,自引:0,他引:3
Brain tumors are increasingly prevalent. Recent advances focus attention on individual, disseminated tumor cells that cannot be imaged or eliminated. Cells of the immune system may be ideally suited to attack individual tumor cells, but more basic understanding is needed. We describe a rat model, using the lacZ reporter gene, that allows identification of individual tumor cells, and tumor-leukocyte interactions in vivo. The model demonstrates how widely tumor can disseminate, without secondary tumorigenesis or recruitment of nonneoplastic cells. It demonstrates that leukocytes have access to disseminating tumor. Among its many applications, this work lays a foundation for developing cell-mediated immunotherapy against individual brain tumor cells. 相似文献
37.
目的 近年来产生了一些用于分析基因表达数据的聚类算法,却很少有关于评价聚类算法方法的研究。本研究的目的是尝试建立一个定量的评价基因表达数据聚类结果的方法。方法 本研究提供了一个系统的评价聚类结果的方法,利用我们提出的实验均方误差F值对几个常见的聚类算法进行比较。结果 利用F值对类质量的评价和利用已有的生物学知识对类进行分析的结果一致。结论 实验均方误差F值可以定量地评判用于基因表达数据的聚类算法。 相似文献
38.
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40.
You M. Lu Bu F. Lu Yu L. Yan Tin H. Yan Xiaon P. Ho Wen J. Wang 《The European journal of neuroscience》1993,5(10):1334-1338
The activation of membrane-associated phospholipase C is rapidly and transiently induced in the central nervous system by a variety of stimuli. Ischaemic brain injury is one of the situations that leads to a dramatic increase in polyphosphoinositide (PPI) turnover. In this study, stimulation of PPI hydrolysis by glutamate (500 μM) was measured in hippocampal slices from rats up to 21 days after an ischaemic insult of 30 min. Ischaemia was induced using the four-vessel occlusion method. PPI hydrolysis elicited by glutamate was significantly increased in the slices prepared from ischaemic rats 24 h after reperfusion, the accumulation of inositol phosphates (InsPs ) and inositol 1,4,5-trisphosphate (InsP3 ) was 614±74% ( n = 8) and 182±11% ( n = 9) of the basal level respectively. This potentiation was also observed 21 days after ischaemia. Hyper-responsiveness to glutamate was also accompanied by an increase in AIF− 4 -stimulated formation of [3 H]inositol phosphates. In addition, global ischaemia did not change either high-affinity [3 H]glutamate binding in hippocampal membranes or the stimulation of PPI hydrolysis by carbachol or noradrenaline in hippocampal slices. The present results suggest that the increased responsiveness to glutamate is the result, at least in part, of functional changes at the G-protein level, and may contribute to the pathophysiology of ischaemic brain injury or to the regenerative phenomena that accompany ischaemic damage. 相似文献