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排序方式: 共有1932条查询结果,搜索用时 15 毫秒
81.
The molecular mechanism for effects of TiN coating on NiTi alloy on endothelial cell function 总被引:1,自引:0,他引:1
The aim of this study is to systematically investigate the molecular mechanism of different effects of nickel titanium (NiTi) alloy surface and titanium nitride (TiN) coating on endothelial cell function. Release of nickel (Ni) ion from bare and TiN-coated NiTi alloys and proliferation of endothelial cells on the two materials were evaluated, and then influence of the two materials on cellular protein expression profiles was investigated by proteomic technology. Subsequently, proteomic data were analyzed with bioinformatics analyses and further validated using a series of biological experiments. Results showed that although the two materials did not affect cell proliferation, the Ni ions released from bare NiTi alloy generated inhibition on pathways associated with actin cytoskeleton, focal adhesion, energy metabolism, inflammation, and amino acid metabolism. In comparison, TiN coating not only effectively prevented release of Ni ions from NiTi alloy, but also promoted actin cytoskeleton and focal adhesion formation, increased energy metabolism, enhanced regulation of inflammation, and promoted amino acid metabolism. Furthermore, the two processes, “the initial mediation of adsorbed serum protein layer to endothelial cell adhesion and growth on the two materials” from our previous study, and “the following action of the two materials on cellular protein expression profile”, were linked up and comprehensively analyzed. It was found that in stage of cell adhesion (within 4 h), release of Ni ions from bare NiTi alloy was very low, and the activation of adsorbed proteins to cell adhesion and growth related biological pathways (such as regulation of actin cytoskeleton, and focal adhesion pathways) was almost as same as TiN-coated NiTi alloy. This indicated that the released Ni ions did not affect the mediation of adsorbed proteins to endothelial cell adhesion. However, in stage of cell growth and proliferation, the release of Ni ions from bare NiTi alloy increased with time and reached a higher level, which inhibited endothelial cell function at molecular level, whereas TiN coating improved endothelial cell function. 相似文献
82.
Pengfei Zhao Mingbin Zheng Caixia Yue Zhenyu Luo Ping Gong Guanhui Gao Zonghai Sheng Cuifang Zheng Lintao Cai 《Biomaterials》2014
A key challenge to strengthen anti-tumor efficacy is to improve drug accumulation in tumors through size control. To explore the biodistribution and tumor accumulation of nanoparticles, we developed indocyanine green (ICG) loaded poly (lactic-co-glycolic acid) (PLGA) -lecithin-polyethylene glycol (PEG) core-shell nanoparticles (INPs) with 39 nm, 68 nm and 116 nm via single-step nanoprecipitation. These INPs exhibited good monodispersity, excellent fluorescence and size stability, and enhanced temperature response after laser irradiation. Through cell uptake and photothermal efficiency in vitro, we demonstrated that 39 nm INPs were more easily be absorbed by pancreatic carcinoma tumor cells (BxPC-3) and showed better photothermal damage than that of 68 nm and 116 nm size of INPs. Simultaneously, the fluorescence of INPs offered a real-time imaging monitor for subcellular locating and in vivo metabolic distribution. Near-infrared imaging in vivo and photothermal therapy illustrated that 68 nm INPs showed the strongest efficiency to suppress tumor growth due to abundant accumulation in BxPC-3 xenograft tumor model. The findings revealed that a nontoxic, size-dependent, theranostic INPs model was built for in vivo cancer imaging and photothermal therapy without adverse effect. 相似文献
83.
目的调查深圳市某小学一起水痘疫情的流行特征,探讨其危险因素。方法按照病例定义搜索病例,描述疾病的三间分布并开展危险因素现场调查分析。结果 2012年11月30日至2013年1月9日共搜索到符合病例定义的病例22例,首例病例发病时间为11月15日,未隔离;疫情报告日期和发病高峰为11月30日;对新发病例严格执行隔离措施,末例病例为12月19日。17例病例为一年级(6)班学生,该班罹患率为33.3%(17/51),另有4例其它班级病例与该班首发病例在同一午托室休息。一年级(6)班未接种组的罹患率为100%(4/4),接种组为33.3%(13/39),水痘疫苗的4年保护率为66.7%。结论未尽早隔离首发病例、及时报告是此次疫情的主要危险因素,及时发现新发病例、严格执行隔离措施可有效控制疫情。疫苗保护效果还需深入开展评价。 相似文献
84.
Automatic detection of wakefulness and rest intervals in actigraphic signals: A data-driven approach
《Medical engineering & physics》2014,36(12):1585-1592
Actigraphy is an useful tool for evaluating the activity pattern of a subject; activity registries are usually processed by first splitting the signal into its wakefulness and rest intervals and then analyzing each one in isolation. Consequently, a preprocessing stage for such a splitting is needed. Several methods have been reported to this end but they rely on parameters and thresholds which are manually set based on previous knowledge of the signals or learned from training. This compromises the general applicability of this methods. In this paper we propose a new method in which thresholds are automatically set based solely on the specific registry to be analyzed. The method consists of two stages: (1) estimation of an initial classification mask by means of the expectation maximization algorithm and (2) estimation of a final refined mask through an iterative method which re-estimates both the mask and the classifier parameters at each iteration step. Results on real data show that our methodology outperforms those so far proposed and can be more effectively used to obtain derived sleep quality parameters from actigraphy registries. 相似文献
85.
86.
This study systematically investigated the ferrate(vi)–ozone combination process for TBBPA degradation. Firstly, the advantages of a ferrate(vi)–ozone combination process were assessed as compared with a sole ozone and ferrate(vi) oxidation process. Then, the performance of the ferrate(vi)–ozone combination process was investigated under different experimental conditions, including the dosing orders of oxidants, dosing concentrations of oxidants, and the initial solution pH. At the same time, toxicity control (including the acute and chronic toxicity) and mineralization were analyzed after optimization. Finally, a mechanism was proposed about the synergetic effects of the ferrate(vi)–ozone combination process for decontamination. The ferrate(vi)–ozone combination process proved to be an efficient and promising technology for removing TBBPA from water. After being pre-oxidized by ferrate(vi) for 3 min and then co-oxidized by the two oxidants, TBBPA of 1.84 μmol L−1 could be completely degraded by dosing only 0.51 μmol L−1 of ferrate(vi) and 10.42 μmol L−1 of ozone within 10 min in wide ranges of pH (5.0–11.0). Up to 91.3% of debromination rate and 80.5% of mineralization rate were obtained, respectively. In addition, no bromate was detected and the acute and chronic toxicity were effectively controlled. The analysis of the proposed mechanism showed that there might exist a superposition effect of the oxidation pathways. In addition, the interactions between the two oxidants were beneficial for the oxidation efficiency of ferrate(vi) and ozone, including the catalytic effect of ferrate(vi) intermediates on ozone and the oxidation of low-valent iron compounds by ozone and the generated ·OH radical.This study systematically investigated the ferrate(vi)–ozone combination process for TBBPA degradation. 相似文献
87.
88.
The Lyme borreliosis (LB) group of spirochaetes currently comprises 18 named species that vary in their geographic distribution, host specificity and ability to cause disease in humans. In Europe three species are most abundant, Borrelia afzelii, Borrelia garinii and Borrelia valaisiana but only two of these (B. garinii and B. afzelii) are regularly found in Asia as well. A recently published study has shown that Borrelia species associated with birds, such as B. garinii, showed limited geographic structuring between European countries while, the rodent associated species, B. afzelii, showed extensive spatial structuring in Europe. Here, we use multilocus sequence analysis to show that when the wider, inter-continental, distribution is considered, there is evidence of spatial structuring even in the bird-associated species B. garinii. Furthermore, our investigations into historical LB populations provided evidence for range expansions of B. garinii and B. afzelii populations in Europe in the distant past. We propose that the expansion of B. afzelii in Europe may be linked to rodent population expansions after the last glacial maximum. 相似文献
89.
目的了解鲍氏不动杆菌医院感染耐药性变化趋势。方法分析2006~2008年分离本院感染患者标本的鲍氏不动杆菌及其耐药率资料。结果3年间共分离到鲍氏不动杆菌92株,主要以患者痰标本为主,分布率为72.26%;科室分布主要是重症监护病房(ICU)居首位,合计分布率为25.97%;鲍氏不动杆菌总体耐药普遍较高,但耐药率较为稳定。结论临床医生应根据耐药率变化选择敏感药物或采取联合用药,既可有效治疗鲍氏不动杆菌感染又能有效防止或减慢耐药菌株的形成。 相似文献
90.
Inflammopharmacology - Imrecoxib is a novel cyclooxygenase-2 inhibitor independently developed in China, which exhibits a good efficacy and tolerance in orthopedic disorders. The current study... 相似文献