| 1. |
- Arsana, Komang G.Y., et al.
(author)
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Laboratory Liquid-Jet X-ray Microscopy and X-ray Fluorescence Imaging for Biomedical Applications
- 2024
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In: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 25:2
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Journal article (peer-reviewed)abstract
- Diffraction-limited resolution and low penetration depth are fundamental constraints in optical microscopy and in vivo imaging. Recently, liquid-jet X-ray technology has enabled the generation of X-rays with high-power intensities in laboratory settings. By allowing the observation of cellular processes in their natural state, liquid-jet soft X-ray microscopy (SXM) can provide morphological information on living cells without staining. Furthermore, X-ray fluorescence imaging (XFI) permits the tracking of contrast agents in vivo with high elemental specificity, going beyond attenuation contrast. In this study, we established a methodology to investigate nanoparticle (NP) interactions in vitro and in vivo, solely based on X-ray imaging. We employed soft (0.5 keV) and hard (24 keV) X-rays for cellular studies and preclinical evaluations, respectively. Our results demonstrated the possibility of localizing NPs in the intracellular environment via SXM and evaluating their biodistribution with in vivo multiplexed XFI. We envisage that laboratory liquid-jet X-ray technology will significantly contribute to advancing our understanding of biological systems in the field of nanomedical research.
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| 2. |
- Kördel, Mikael, et al.
(author)
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Biological Laboratory X-Ray Microscopy
- 2019
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In: X-Ray Nanoimaging. - : SPIE - International Society for Optical Engineering. - 9781510629189
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Conference paper (peer-reviewed)abstract
- Zone-plate-based soft x-ray microscopes operating in the water window allow high-resolution and high-contrast imaging of intact cells in their near-native state. Laboratory-source-based x-ray microscopes are an important complement to the accelerator-based instruments, providing high accessibility and allowing close integration with other cell-biological techniques. Here we present recent biological applications using the Stockholm laboratory water-window x-ray microscope, which is based on a liquid-nitrogen-jet laser-plasma source. Technical improvements to the microscope in the last few years have resulted in increased x-ray flux at the sample and significantly improved stability and reliability. In addition to this, vibrations in key components have been measured, analyzed and reduced to improve the resolution to 25 nm half-period. The biological applications include monitoring the development of carbon-dense vesicles in starving human embryonic kidney cells (HEK293T), imaging the interaction between natural killer (NK) cells and HEK293T target cells, and most recently studying a newly discovered giant DNA virus and the process of viral replication inside a host amoeba. All biological imaging was done on cryo-frozen hydrated samples in 2D and in some cases 3D.
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| 3. |
- Kördel, Mikael, et al.
(author)
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Quantitative conversion of biomass in giant DNA virus infection
- 2021
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In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 11:1
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Journal article (peer-reviewed)abstract
- Bioconversion of organic materials is the foundation of many applications in chemical engineering, microbiology and biochemistry. Herein, we introduce a new methodology to quantitatively determine conversion of biomass in viral infections while simultaneously imaging morphological changes of the host cell. As proof of concept, the viral replication of an unidentified giant DNA virus and the cellular response of an amoebal host are studied using soft X-ray microscopy, titration dilution measurements and thermal gravimetric analysis. We find that virions produced inside the cell are visible from 18 h post infection and their numbers increase gradually to a burst size of 280-660 virions. Due to the large size of the virion and its strong X-ray absorption contrast, we estimate that the burst size corresponds to a conversion of 6-12% of carbonaceous biomass from amoebal host to virus. The occurrence of virion production correlates with the appearance of a possible viral factory and morphological changes in the phagosomes and contractile vacuole complex of the amoeba, whereas the nucleus and nucleolus appear unaffected throughout most of the replication cycle.
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| 4. |
- Pujani, N. M., et al.
(author)
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The Effectiveness Of Introduction To Astronomy Teaching Materials To Improve Problem-Solving And Generic Science Skills
- 2022
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In: Jurnal Pendidikan IPA Indonesia. - : Universitas Negeri Semarang. - 2339-1286 .- 2089-4392. ; 11:2, s. 333-340
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Journal article (peer-reviewed)abstract
- This study aims to analyze the effectiveness of introductory astronomy teaching materials with inquiry settings on students’ problem-solving and generic science skills. This study used a quasi-experimental design with the one-group pretest-posttest design. The research subjects were one class of 23 fourth-semester science education students. Data on problem-solving skills were collected using a test method with ten essay questions, and generic science skills data were collected using 30 multiple-choice questions. Data analysis was carried out descriptively, and a t-test with a significance level of 0.05. The analysis results showed that the use of inquiry-based introductory astronomy teaching materials in astronomy learning was effective in improving the problem-solving skills (p<0.05, = 0.67 medium categories) and generic science skills (p<0 .05, = 0.53 moderate type). So, it can be concluded that introductory astronomy teaching materials with inquiry settings effectively improve stu-dents’ problem-solving and generic science skills.
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