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排序方式: 共有514条查询结果,搜索用时 62 毫秒
131.
Maria Vass Iva Diblikova Eloise Kok Kamil Stastny Karla Frgalova Karel Hruska Milan Franek 《Food Additives & Contaminants》2008,25(8):930-936
An enzyme-linked immunosorbent assay (ELISA) method is described for the semi-quantitative determination of semicarbazide (SEM), the marker residue for the banned nitrofuran drug, nitrofurazone, in chicken eggs. The sample homogenate is subjected to acid hydrolysis and derivatisation with o-nitrobenzaldehyde, followed by ethyl acetate/hexane extraction and detection by ELISA. The ELISA procedure has been validated using 0.3, 1.0 and 3 microg kg(-1) of SEM in fortified samples. Detection capability (CC(ss)) was based on the acceptance of 5% false compliant results for a given concentration level according to Commission Decision 2002/657/EC and was determined to be 0.3 microg kg(-1) with a respective limit of detection of 0.13 microg kg(-1). A validated LC-MS/MS method was used for the analysis of incurred egg samples and the results compared with ELISA. A good correlation between the results obtained from ELISA and LC-MS/MS within the concentration range 0.12-20.3 microg kg(-1) was observed in samples collected from chickens fed with a medicated ration of nitrofurazone (r = 0.992, n = 14). Validated ELISA enabled reliable monitoring of SEM levels in eggs collected from incurred chickens over a 90-day period. 相似文献
132.
133.
Microstructured Multilevel Bacterial Cellulose Allows the Guided Growth of Neural Stem Cells 下载免费PDF全文
134.
Imbedded Nanocrystals of CsPbBr3 in Cs4PbBr6: Kinetics,Enhanced Oscillator Strength,and Application in Light‐Emitting Diodes 下载免费PDF全文
Junwei Xu Wenxiao Huang Peiyun Li Drew R. Onken Chaochao Dun Yang Guo Kamil B. Ucer Chang Lu Hongzhi Wang Scott M. Geyer Richard T. Williams David L. Carroll 《Advanced materials (Deerfield Beach, Fla.)》2017,29(43)
Solution‐grown films of CsPbBr3 nanocrystals imbedded in Cs4PbBr6 are incorporated as the recombination layer in light‐emitting diode (LED) structures. The kinetics at high carrier density of pure (extended) CsPbBr3 and the nanoinclusion composite are measured and analyzed, indicating second‐order kinetics in extended and mainly first‐order kinetics in the confined CsPbBr3, respectively. Analysis of absorption strength of this all‐perovskite, all‐inorganic imbedded nanocrystal composite relative to pure CsPbBr3 indicates enhanced oscillator strength consistent with earlier published attribution of the sub‐nanosecond exciton radiative lifetime in nanoprecipitates of CsPbBr3 in melt‐grown CsBr host crystals and CsPbBr3 evaporated films. 相似文献
135.
Emre Alp Emre Can Araz Ahmet Furkan Buluç Yağmur Güner Yücel Değer Halil Eşgin Kamil Burak Dermenci M. Kürşat Kazmanlı Servet Turan Aziz Genç 《Advanced Powder Technology》2018,29(12):3455-3461
Zinc oxide (ZnO) nanostructures with various morphologies have been fabricated in literature owing to their potential applications in various emerging fields. In this study, we report a facile, one-step gram-scale synthesis of nanocrystalline mesoporous ZnO microspheres by thermal decomposition of zinc acetate dihydrate in ethylene glycol at 250?°C for 12?h. The average size of the hollow microspheres is found to be 3.01?±?0.52?µm, which are formed by loosely bonded nanocrystallites with average sizes of 17?±?4?nm. We propose a formation mechanism for the mesoporous microspheres, Ostwald ripening of spherical-like nanocrystallites, on the basis of the results obtained by different synthesis durations. We also report the possibility of tuning the morphologies of the obtained ZnO by simply modifying the thermal decomposition solution, where porous ZnO nanoplates are obtained when a mixture of ethylene glycol and water is used and ZnO nanorods with aspect ratios of ~3 are synthesized by using diethylene glycol. ZnO nanowires with lengths up to several microns are fabricated when no solvent is used, i.e. thermal decomposition in air atmosphere. Microstructural and phase characterizations of the samples are conducted by using a field-emission gun scanning electron microscope and X-ray diffractometer. Performances of the obtained nanocrystalline mesoporous ZnO microspheres in photocatalytic degradation of Rhodamine B and as active anode materials in lithium-ion batteries are also presented. 相似文献
136.
Robin A. James Andrew J. Stapleton Adam Hughes Eric Charrault Kamil Zuber Eliza Switalska Drew Evans Peter Murphy Marta Llusca 《Advanced Engineering Materials》2018,20(7)
137.
Present study has produced first detailed land‐cover map of Socotra Island. A Landsat 7 ETM+ dataset was used as a main source of remotely sensed data. From numerous reference points (more than 250) coming from the ground data verification the set of training fields and the set of evaluation fields were digitised. As a classification method the supervised maximum likelihood classification without prior probabilities was used in combination with rule‐based post‐classification sorting, providing results of sufficient accuracy and subject resolution. Estimates of the area and degree of coverage of particular land‐cover classes within Socotra Island have brought excellent overview on state of island biotopes. Overall accuracy of the map achieved is more than 80%, 19 terrestrial land‐cover classes (including three types of Shrublands, three types of Woodlands, two types of Forests and Mangroves) have been distinguished. It consequently allows estimates of the current and potential occurrence of endemic plant populations, proposals of management and conservation plans and agro‐forestry planning. 相似文献
138.
139.
A model-driven traceability framework for software product lines 总被引:1,自引:0,他引:1
Nicolas Anquetil Uirá Kulesza Ralf Mitschke Ana Moreira Jean-Claude Royer Andreas Rummler André Sousa 《Software and Systems Modeling》2010,9(4):427-451
Software product line (SPL) engineering is a recent approach to software development where a set of software products are
derived for a well defined target application domain, from a common set of core assets using analogous means of production
(for instance, through Model Driven Engineering). Therefore, such family of products are built from reuse, instead of developed
individually from scratch. SPL promise to lower the costs of development, increase the quality of software, give clients more
flexibility and reduce time to market. These benefits come with a set of new problems and turn some older problems possibly
more complex. One of these problems is traceability management. In the European AMPLE project we are creating a common traceability
framework across the various activities of the SPL development. We identified four orthogonal traceability dimensions in SPL
development, one of which is an extension of what is often considered as “traceability of variability”. This constitutes one
of the two contributions of this paper. The second contribution is the specification of a metamodel for a repository of traceability
links in the context of SPL and the implementation of a respective traceability framework. This framework enables fundamental
traceability management operations, such as trace import and export, modification, query and visualization. The power of our
framework is highlighted with an example scenario. 相似文献
140.
Changes in zinc content and dysregulated zinc homeostatic mechanisms have been recognized in several solid malignancies such as prostate cancer, breast cancer, or pancreatic cancer. Moreover, it has been shown that zinc serum and/or tissue levels are altered in melanoma with varying effects on melanoma development and biology. This study was conducted to explore the effects of acute increases of intracellular zinc in a set of melanoma tissue explants obtained from clinical samples. Measurements of their zinc content showed an extant heterogeneity in total and free intracellular zinc pools associated with varying biological behavior of individual cells, e.g., autophagy levels and propensity to cell death. Use of zinc pyrithione elevated intracellular zinc in a short time frame which resulted in marked changes in mitochondrial activity and lysosomes. These alterations were accompanied by significantly enhanced autophagy flux and subsequent cell demise in the absence of typical apoptotic cell death markers. The present results show for the first time that acutely increased intracellular zinc in melanoma cells specifically enhances their autophagic activity via mitochondria and lysosomes which leads to autophagic cell death. While biologically relevant, this discovery may contribute to our understanding and exploration of zinc in relation to autophagy as a means of controlling melanoma growth and survival. 相似文献