The Experts below are selected from a list of 29478 Experts worldwide ranked by ideXlab platform
Kirsi Svedström - One of the best experts on this subject based on the ideXlab platform.
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Spatially-localized bench-top X-ray scattering reveals tissue-specific microfibril orientation in Moso bamboo
Plant Methods, 2017Co-Authors: Patrik Ahvenainen, Patrick G. Dixon, Aki Kallonen, Heikki Suhonen, Lorna J. Gibson, Kirsi SvedströmAbstract:Background Biological materials have a complex, hierarchical structure, with vital structural features present at all size scales, from the nanoscale to the macroscale. A method that can connect information at multiple length scales has great potential to reveal novel information. This article presents one such method with an application to the bamboo culm wall. Moso ( Phyllostachys edulis ) bamboo is a commercially important bamboo species. At the cellular level, bamboo culm wall consists of vascular bundles embedded in a parenchyma cell tissue matrix. The microfibril angle (MFA) in the bamboo cell wall is related to its macroscopic longitudinal stiffness and strength and can be determined at the nanoscale with wide-angle X-ray scattering (WAXS). Combining WAXS with X-ray microtomography (XMT) allows tissue-specific study of the bamboo culm without invasive chemical treatment. Results The scattering contribution of the Fiber and parenchyma cells were separated with spatially-localized WAXS. The Fiber Component was dominated by a high degree of orientation corresponding to small MFAs (mean MFA 11°). The parenchyma Component showed significantly lower degree of orientation with a maximum at larger angles (mean MFA 65°). The Fiber ratio, the volume of cell wall in the Fibers relative to the overall volume of cell wall, was determined by fitting the scattering intensities with these two Components. The Fiber ratio was also determined from the XMT data and similar Fiber ratios were obtained from the two methods, one connected to the cellular level and one to the nanoscale. X-ray diffraction tomography was also done to study the differences in microfibril orientation between Fibers and the parenchyma and further connect the microscale to the nanoscale. Conclusions The spatially-localized WAXS yields biologically relevant, tissue-specific information. With the custom-made bench-top set-up presented, diffraction contrast information can be obtained from plant tissue (1) from regions-of-interest, (2) as a function of distance (line scan), or (3) with two-dimensional or three-dimensional tomography. This nanoscale information is connected to the cellular level features.
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spatially localized bench top x ray scattering reveals tissue specific microfibril orientation in moso bamboo
Plant Methods, 2017Co-Authors: Patrik Ahvenainen, Patrick G. Dixon, Aki Kallonen, Heikki Suhonen, Lorna J. Gibson, Kirsi SvedströmAbstract:Biological materials have a complex, hierarchical structure, with vital structural features present at all size scales, from the nanoscale to the macroscale. A method that can connect information at multiple length scales has great potential to reveal novel information. This article presents one such method with an application to the bamboo culm wall. Moso (Phyllostachys edulis) bamboo is a commercially important bamboo species. At the cellular level, bamboo culm wall consists of vascular bundles embedded in a parenchyma cell tissue matrix. The microfibril angle (MFA) in the bamboo cell wall is related to its macroscopic longitudinal stiffness and strength and can be determined at the nanoscale with wide-angle X-ray scattering (WAXS). Combining WAXS with X-ray microtomography (XMT) allows tissue-specific study of the bamboo culm without invasive chemical treatment. The scattering contribution of the Fiber and parenchyma cells were separated with spatially-localized WAXS. The Fiber Component was dominated by a high degree of orientation corresponding to small MFAs (mean MFA 11°). The parenchyma Component showed significantly lower degree of orientation with a maximum at larger angles (mean MFA 65°). The Fiber ratio, the volume of cell wall in the Fibers relative to the overall volume of cell wall, was determined by fitting the scattering intensities with these two Components. The Fiber ratio was also determined from the XMT data and similar Fiber ratios were obtained from the two methods, one connected to the cellular level and one to the nanoscale. X-ray diffraction tomography was also done to study the differences in microfibril orientation between Fibers and the parenchyma and further connect the microscale to the nanoscale. The spatially-localized WAXS yields biologically relevant, tissue-specific information. With the custom-made bench-top set-up presented, diffraction contrast information can be obtained from plant tissue (1) from regions-of-interest, (2) as a function of distance (line scan), or (3) with two-dimensional or three-dimensional tomography. This nanoscale information is connected to the cellular level features.
Patrik Ahvenainen - One of the best experts on this subject based on the ideXlab platform.
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Spatially-localized bench-top X-ray scattering reveals tissue-specific microfibril orientation in Moso bamboo
Plant Methods, 2017Co-Authors: Patrik Ahvenainen, Patrick G. Dixon, Aki Kallonen, Heikki Suhonen, Lorna J. Gibson, Kirsi SvedströmAbstract:Background Biological materials have a complex, hierarchical structure, with vital structural features present at all size scales, from the nanoscale to the macroscale. A method that can connect information at multiple length scales has great potential to reveal novel information. This article presents one such method with an application to the bamboo culm wall. Moso ( Phyllostachys edulis ) bamboo is a commercially important bamboo species. At the cellular level, bamboo culm wall consists of vascular bundles embedded in a parenchyma cell tissue matrix. The microfibril angle (MFA) in the bamboo cell wall is related to its macroscopic longitudinal stiffness and strength and can be determined at the nanoscale with wide-angle X-ray scattering (WAXS). Combining WAXS with X-ray microtomography (XMT) allows tissue-specific study of the bamboo culm without invasive chemical treatment. Results The scattering contribution of the Fiber and parenchyma cells were separated with spatially-localized WAXS. The Fiber Component was dominated by a high degree of orientation corresponding to small MFAs (mean MFA 11°). The parenchyma Component showed significantly lower degree of orientation with a maximum at larger angles (mean MFA 65°). The Fiber ratio, the volume of cell wall in the Fibers relative to the overall volume of cell wall, was determined by fitting the scattering intensities with these two Components. The Fiber ratio was also determined from the XMT data and similar Fiber ratios were obtained from the two methods, one connected to the cellular level and one to the nanoscale. X-ray diffraction tomography was also done to study the differences in microfibril orientation between Fibers and the parenchyma and further connect the microscale to the nanoscale. Conclusions The spatially-localized WAXS yields biologically relevant, tissue-specific information. With the custom-made bench-top set-up presented, diffraction contrast information can be obtained from plant tissue (1) from regions-of-interest, (2) as a function of distance (line scan), or (3) with two-dimensional or three-dimensional tomography. This nanoscale information is connected to the cellular level features.
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spatially localized bench top x ray scattering reveals tissue specific microfibril orientation in moso bamboo
Plant Methods, 2017Co-Authors: Patrik Ahvenainen, Patrick G. Dixon, Aki Kallonen, Heikki Suhonen, Lorna J. Gibson, Kirsi SvedströmAbstract:Biological materials have a complex, hierarchical structure, with vital structural features present at all size scales, from the nanoscale to the macroscale. A method that can connect information at multiple length scales has great potential to reveal novel information. This article presents one such method with an application to the bamboo culm wall. Moso (Phyllostachys edulis) bamboo is a commercially important bamboo species. At the cellular level, bamboo culm wall consists of vascular bundles embedded in a parenchyma cell tissue matrix. The microfibril angle (MFA) in the bamboo cell wall is related to its macroscopic longitudinal stiffness and strength and can be determined at the nanoscale with wide-angle X-ray scattering (WAXS). Combining WAXS with X-ray microtomography (XMT) allows tissue-specific study of the bamboo culm without invasive chemical treatment. The scattering contribution of the Fiber and parenchyma cells were separated with spatially-localized WAXS. The Fiber Component was dominated by a high degree of orientation corresponding to small MFAs (mean MFA 11°). The parenchyma Component showed significantly lower degree of orientation with a maximum at larger angles (mean MFA 65°). The Fiber ratio, the volume of cell wall in the Fibers relative to the overall volume of cell wall, was determined by fitting the scattering intensities with these two Components. The Fiber ratio was also determined from the XMT data and similar Fiber ratios were obtained from the two methods, one connected to the cellular level and one to the nanoscale. X-ray diffraction tomography was also done to study the differences in microfibril orientation between Fibers and the parenchyma and further connect the microscale to the nanoscale. The spatially-localized WAXS yields biologically relevant, tissue-specific information. With the custom-made bench-top set-up presented, diffraction contrast information can be obtained from plant tissue (1) from regions-of-interest, (2) as a function of distance (line scan), or (3) with two-dimensional or three-dimensional tomography. This nanoscale information is connected to the cellular level features.
Ryan Hensleigh - One of the best experts on this subject based on the ideXlab platform.
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3d printing of meso structurally ordered carbon Fiber polymer composites with unprecedented orthotropic physical properties
Scientific Reports, 2017Co-Authors: James P. Lewicki, Amanda S Wu, Jennifer N. Rodriguez, Yuliya Kanarska, John Horn, Jason M. Ortega, William Elmer, Marcus Andre Worsley, Ryan HensleighAbstract:Here we report the first example of a class of additively manufactured carbon Fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon Fiber composites, which allow the Fiber Component of a resin and carbon Fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of Fiber alignment within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon Fiber and polymer composites. Furthermore, our AM carbon Fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon Fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon Fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response.
Markus Tietjen - One of the best experts on this subject based on the ideXlab platform.
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content and molecular weight distribution of dietary Fiber Components in whole grain rye flour and bread
Journal of Agricultural and Food Chemistry, 2009Co-Authors: Roger Andersson, Gunnel Fransson, Markus TietjenAbstract:Content of dietary Fiber and dietary Fiber Components in whole-grain rye (n = 18) were analyzed. The average total content, when fructan was included, was for dietary Fiber 19.9% (range of 18.7−22.2%) and for extractable dietary Fiber 7.4% (range of 6.9−7.9%). Arabinoxylan was the main dietary Fiber Component, with an average total content of 8.6%, followed by fructan (4.1%). During baking of whole-grain rye bread, only small changes in total content of arabinoxylan, arabinogalactan, and β-glucan occurred, while the content of resistant starch increased and the content of fructan decreased in a baking-method-dependent manner. The molecular-weight distribution of extractable arabinoxylan in the flour was analyzed with a new method and ranged from 4 × 104 to 9 × 106 g/mol, with a weight average molecular weight of about 2 × 106 g/mol. During crisp bread making, only a limited degradation of arabinoxylan molecular weight was detected, while a notable degradation was observed in sour-dough bread. The molecula...
L Claes - One of the best experts on this subject based on the ideXlab platform.
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control of material stiffness during degradation for constructs made of absorbable polymer Fibers
Journal of Biomedical Materials Research Part B, 2003Co-Authors: Lutz Durselen, Martin Dauner, Helmut Hierlemann, Heinrich Planck, Anita Ignatius, L ClaesAbstract:Augmentation devices for cruciate ligament surgery should provide gradually decreasing mechanical properties with a half-time strength of at least 6 months to temporarily protect healing tendon grafts or sutured ligaments against high tensile loads during the postoperative healing period. The absorbable material of choice that shows such slow degradation kinetics is poly(L-lactide). However, previous studies have shown that poly(L-lactide) fulfills the requirement of a long half-time strength, while the corresponding stiffness decreases at a much slower rate. An augmentation stiffness that does not change much versus time cannot provide a gradual increase in graft load, which is important to stimulate the orientation of the collagenous tissue. Therefore a new augmentation device was designed, which should decrease both in strength and stiffness during degradation. The cord was braided out of two Fibers made of poly(L-lactide) and poly(L-lactide-co-glycolide), which degrade at different rates. The cord prototype was degraded in vitro and the rupture force and stiffness was tested at eight different time points up to 60 weeks. The initial rupture force and stiffness was 522.7 ± 2.8 N and 104.1 ± 3.8 N/%, respectively. Both strength and stiffness decreased continuously with a half-time strength of 18 weeks and a half-time stiffness of 39 weeks. The gradually decreasing stiffness was achieved by the breakdown of the faster-degrading Fiber Component made of poly(L-lactide-co-glycolide). Thus the new augmentation device can provide a continuous increase of forces in a tendon graft or in a healing ligament. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 67B: 697–701, 2003
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control of material stiffness during degradation for constructs made of absorbable polymer Fibers
Journal of Biomedical Materials Research, 2003Co-Authors: Lutz Durselen, Martin Dauner, Helmut Hierlemann, Heinrich Planck, Anita Ignatius, L ClaesAbstract:Augmentation devices for cruciate ligament surgery should provide gradually decreasing mechanical properties with a half-time strength of at least 6 months to temporarily protect healing tendon grafts or sutured ligaments against high tensile loads during the postoperative healing period. The absorbable material of choice that shows such slow degradation kinetics is poly(L-lactide). However, previous studies have shown that poly(L-lactide) fulfills the requirement of a long half-time strength, while the corresponding stiffness decreases at a much slower rate. An augmentation stiffness that does not change much versus time cannot provide a gradual increase in graft load, which is important to stimulate the orientation of the collagenous tissue. Therefore a new augmentation device was designed, which should decrease both in strength and stiffness during degradation. The cord was braided out of two Fibers made of poly(L-lactide) and poly(L-lactide-co-glycolide), which degrade at different rates. The cord prototype was degraded in vitro and the rupture force and stiffness was tested at eight different time points up to 60 weeks. The initial rupture force and stiffness was 522.7 ± 2.8 N and 104.1 ± 3.8 N/%, respectively. Both strength and stiffness decreased continuously with a half-time strength of 18 weeks and a half-time stiffness of 39 weeks. The gradually decreasing stiffness was achieved by the breakdown of the faster-degrading Fiber Component made of poly(L-lactide-co-glycolide). Thus the new augmentation device can provide a continuous increase of forces in a tendon graft or in a healing ligament.
