| 1. |
- Grünewald, Tilman A., et al.
(författare)
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Mapping the 3D orientation of nanocrystals and nanostructures in human bone: Indications of novel structural features
- 2020
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Ingår i: Science advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 6:24
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Tidskriftsartikel (refereegranskat)abstract
- Bone is built from collagen fibrils and biomineral nanoparticles. In humans, they are organized in lamellar twisting patterns on the microscale. It has been a central tenet that the biomineral nanoparticles are co-aligned with the bone nanostructure. Here, we reconstruct the three-dimensional orientation in human lamellar bone of both the nanoscale features and the biomineral crystal lattice from small-angle x-ray scattering and wide-angle x-ray scattering, respectively. While most of the investigated regions show well-aligned nanostructure and crystal structure, consistent with current bone models, we report a localized difference in orientation distribution between the nanostructure and the biomineral crystals in specific bands. Our results show a robust and systematic, but localized, variation in the alignment of the two signals, which can be interpreted as either an additional mineral fraction in bone, a preferentially aligned extrafibrillar fraction, or the result of transverse stacking of mineral particles over several fibrils.
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| 2. |
- Liu, Jiliang, et al.
(författare)
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Variation in the hierarchical structure of lignin-blended cellulose precursor fibers
- 2023
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Ingår i: International Journal of Biological Macromolecules. - : Elsevier B.V.. - 0141-8130 .- 1879-0003. ; 225, s. 1555-
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Tidskriftsartikel (refereegranskat)abstract
- Regenerated cellulose fibers have been considered as potential precursor fibers for carbon fibers because of their balanced cost and performance. Increased attention has been paid to blending lignin with the regenerated cellulose to generate precursor fibers which render good mechanical properties and higher carbon yield. The mechanical properties of carbon fibers have been found closely correlated to the structure of precursor fibers. However, the effects of lignin blending on molecular- and morphological structure of the precursor are still unclear. This study aims at clarifying the structural information of lignin–cellulose precursor fibers from molecular level to mesoscale by scanning X-ray microdiffraction. We present the existence of a skin–core morphology for all the precursor fibers. Increase of lignin content in precursor fiber could reduce the portion of skin and cause obvious disorder of the meso- and molecular structure. By correlating structural variations with lignin blending, 30% lignin blending has been found as a potential balance point to obtain precursor fibers maintaining structural order together with high yield rate.
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| 3. |
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| 4. |
- Saldanha, Oliva, et al.
(författare)
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Rapid Acquisition of X-Ray Scattering Data from Droplet-Encapsulated Protein Systems
- 2017
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Ingår i: ChemPhysChem. - : Wiley. - 1439-4235. ; 18:10, s. 1220-1223
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Tidskriftsartikel (refereegranskat)abstract
- Encapsulating reacting biological or chemical samples in microfluidic droplets has the great advantage over single-phase flows of providing separate reaction compartments. These compartments can be filled in a combinatoric way and prevent the sample from adsorbing to the channel walls. In recent years, small-angle X-ray scattering (SAXS) in combination with microfluidics has evolved as a nanoscale method of such systems. Here, we approach two major challenges associated with combining droplet microfluidics and SAXS. First, we present a simple, versatile, and reliable device, which is both suitable for stable droplet formation and compatible with in situ X-ray measurements. Second, we solve the problem of “diluting” the sample signal by the signal from the oil separating the emulsion droplets by multiple fast acquisitions per droplet and data thresholding. We show that using our method, even the weakly scattering protein vimentin provides high signal-to-noise ratio data.
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