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- Koga, Shigehiro, et al.
(författare)
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In vivo subcellular imaging of tumors in mouse models using a fluorophore-conjugated anti-carcinoembryonic antigen antibody in two-photon excitation microscopy
- 2014
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Ingår i: Cancer Science. - : Wiley. - 1347-9032 .- 1349-7006. ; 105:10, s. 1299-1306
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Tidskriftsartikel (refereegranskat)abstract
- Recently, there has been growing interest in applying fluorescence imaging techniques to the study of various disease processes and complex biological phenomena in vivo. To apply these methods to clinical settings, several groups have developed protocols for fluorescence imaging using antibodies against tumor markers conjugated to fluorescent substances. Although these probes have been useful in macroscopic imaging, the specificity and sensitivity of these methods must be improved to enable them to detect micro-lesions in the early phases of cancer, resulting in better treatment outcomes. To establish a sensitive and highly specific imaging method, we used a fluorophore-conjugated anti-carcinoembryonic antigen (CEA) antibody to perform macroscopic and microscopic in vivo imaging of inoculated cancer cells expressing GFP with or without CEA. Macroscopic imaging by fluorescence zoom microscopy revealed that bio-conjugation of Alexa Fluor 594 to the anti-CEA antibody allowed visualization of tumor mass consisting of CEA-expressing human cancer cells, but the background levels were unacceptably high. In contrast, microscopic imaging using a two-photon excitation microscope and the same fluorescent antibody resulted in subcellular-resolution imaging that was more specific and sensitive than conventional imaging using a fluorescence zoom microscope. These results suggest that two-photon excitation microscopy in conjunction with fluorophore-conjugated antibodies could be widely adapted to detection of cancer-specific cell-surface molecules, both in cancer research and in clinical applications.
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3. |
- Yamamoto, Kohei, et al.
(författare)
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Ultrafast demagnetization of Pt magnetic moment in L1(0)-FePt probed by magnetic circular dichroism at a hard x-ray free electron laser
- 2019
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Ingår i: New Journal of Physics. - : IOP PUBLISHING LTD. - 1367-2630. ; 21:12
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Tidskriftsartikel (refereegranskat)abstract
- Unraveling the origin of ultrafast demagnetization in multisublattice ferromagnetic materials requires femtosecond x-ray techniques to trace the magnetic moment dynamics on individual elements, but this could not yet be achieved in the hard x-ray regime. We demonstrate here the first ultrafast demagnetization dynamics in the ferromagnetic heavy 5d-transition metal Pt using circularly-polarized hard x-rays at an x-ray free electron laser (XFEL). The decay time of laser-induced demagnetization of L1(0)-FePt is determined to be tau(Pt) = 0.61 +/- 0.04 ps using time-resolved x-ray magnetic circular dichroism at the Pt L-3 edge, whereas magneto-optical Kerr measurements indicate the decay time for the total magnetization as tau(total) < 0.1 ps. A transient magnetic state with a photomodulated ratio of the 3d and 5d magnetic moments is demonstrated for pump-probe delays larger than 1 ps. We explain this distinct photo-modulated transient magnetic state by the induced-moment behavior of the Pt atom and the x-ray probing depth. Our findings pave the way for the future use of XFELs to disentangle atomic spin dynamics contributions.
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- Yamamoto, Yuki, et al.
(författare)
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Preventing Peatland Fires in Central Kalimantan, Indonesia: The Role of Economic Incentives and Social Norms
- 2020
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Ingår i: JOURNAL OF FOREST ECONOMICS. - : Now Publishers. - 1104-6899 .- 1618-1530. ; 35:2-3, s. 207-227
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Tidskriftsartikel (refereegranskat)abstract
- This study examines the role of economic incentives and social norms in farmers' fire prevention behaviors using survey and remote sensing data. We focus on Central Kalimantan, Indonesia, where large peatland fires cause environmental and social problems. Our regression results indicate that farmers' prevention behaviors are positively associated with agricultural economic returns and participation in local community mutual assistance activities. On the contrary, economic returns on non-agricultural activities are negatively associated with prevention behavior. In addition, we find no difference in fire prevention activities between villages participating in the Reducing Emissions from Deforestation and Forest Degradation scheme and non-participating villages. These results suggest that a performance-based incentive is important to improve the effectiveness of policies designed to prevent peatland fires and mitigate the risk of climate change.
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