| 101. |
- Koo, Jun Mo, et al.
(författare)
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Biobased thermoplastic elastomer with seamless 3D-Printability and superior mechanical properties empowered by in-situ polymerization in the presence of nanocellulose
- 2020
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Ingår i: Composites Science And Technology. - : Elsevier BV. - 0266-3538 .- 1879-1050. ; 185
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Tidskriftsartikel (refereegranskat)abstract
- A biobased and biocompatible thermoplastic elastomer (TPE) with superior 3D printability was demonstrated with great potential for customized manufacturing technologies and fabrication of biointegrated devices. The inherent structural and stereochemical disadvantages of biobased monomers, such as 2,5-furandicarboxylic acid, in comparison with today used petroleum based monomers like terephthalic acid generally lead to lower mechanical performance for the biobased replacement polymers. This is additionally enhanced by poor interfacial adhesion and fusion commonly encountered during customized manufacturing technologies like 3D printing. Herein, we demonstrate that in-situ polymerization in the presence of trace amounts of cellulose nanocrystals (CNCs) can homogeneously distribute the nanofiller leading to dramatically strengthened thermally 3D-printable bio-furan-based TPE. This TPE exhibited a tensile strength of 67 MPa which is 1.5-7-fold higher than the values reported for silicone and thermoplastic urethane, which are widely used in biomedical applications. In addition, the TPE had an impressive extensibility of 860% and negligible in vivo cytotoxicity; such properties have not been reported to date for bio-based or petrochemical TPEs. While a petrochemical 3D printed TPE counterpart retained only half of the tensile strength compared to the hot-pressed analogue, the 3D-printed biobased TPE insitu modified with nanocellulose maintained 70-80% of its strength under the same experimental conditions. This is explained by inter-diffusion between interfaces facilitated by the nanocellulose and the furan rings. Using the ergonomic shape of a wrist as a 3D-printable design, we successfully manufactured a wearable thermal therapeutic device from the nanocellulose modified biobased TPE, giving promise for wide variety of future applications.
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| 102. |
- Krajnc, Luka, et al.
(författare)
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FORMATION BEHAVIOUR OF SPINEL-CaS MULTIPHASE INCLUSIONS IN Ca-TREATED RESULPHURISED STEEL DURING THE LADLE FURNACE PROCESS
- 2020
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Ingår i: Materiali in tehnologije. - : INST ZA KOVINSKE MATERIALE I IN TEHNOLOGIE. - 1580-2949 .- 1580-3414. ; 54:4, s. 559-565
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Tidskriftsartikel (refereegranskat)abstract
- The formation of multiphase inclusions was investigated in resulphurised steel. Samples were taken at different stages of the steelmaking process, from primary deoxidation through calcium modification and sulphur addition to casting. Chemical analyses were made on all the samples, from which thermodynamic calculations using thermochemical computing software were performed, to determine which phases are stable at any given stage of the steelmaking process. Inclusions were investigated using a scanning electron microscope and automatic inclusion analysis software. The presentation of the automatic inclusion analysis results in the form of ternary diagrams provides an insight into the calcium modification of inclusions and the change of the inclusions' size and chemical composition after sulphur addition. Based on the results from this study, a formation mechanism is proposed for spinel-CaS multiphase inclusions in resulphurised steel.
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| 103. |
- Krasilnikov, A., et al.
(författare)
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Evidence of 9 Be + p nuclear reactions during 2ω CH and hydrogen minority ICRH in JET-ILW hydrogen and deuterium plasmas
- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:2
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Tidskriftsartikel (refereegranskat)abstract
- The intensity of 9Be + p nuclear fusion reactions was experimentally studied during second harmonic (2ω CH) ion-cyclotron resonance heating (ICRH) and further analyzed during fundamental hydrogen minority ICRH of JET-ILW hydrogen and deuterium plasmas. In relatively low-density plasmas with a high ICRH power, a population of fast H+ ions was created and measured by neutral particle analyzers. Primary and secondary nuclear reaction products, due to 9Be + p interaction, were observed with fast ion loss detectors, γ-ray spectrometers and neutron flux monitors and spectrometers. The possibility of using 9Be(p, d)2α and 9Be(p, α)6Li nuclear reactions to create a population of fast alpha particles and study their behaviour in non-active stage of ITER operation is discussed in the paper.
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| 104. |
- Kwon, Woojin, et al.
(författare)
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B-fields in Star-forming Region Observations (BISTRO): Magnetic Fields in the Filamentary Structures of Serpens Main
- 2022
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 926:2
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Tidskriftsartikel (refereegranskat)abstract
- We present 850 mu m polarimetric observations toward the Serpens Main molecular cloud obtained using the POL-2 polarimeter on the James Clerk Maxwell Telescope as part of the B-fields In STar-forming Region Observations survey. These observations probe the magnetic field morphology of the Serpens Main molecular cloud on about 6000 au scales, which consists of cores and six filaments with different physical properties such as density and star formation activity. Using the histogram of relative orientation (HRO) technique, we find that magnetic fields are parallel to filaments in less-dense filamentary structures where NH2 < 0.93 x 10(22) cm(-2) (magnetic fields perpendicular to density gradients), while they are perpendicular to filaments (magnetic fields parallel to density gradients) in dense filamentary structures with star formation activity. Moreover, applying the HRO technique to denser core regions, we find that magnetic field orientations change to become perpendicular to density gradients again at NH2 approximate to 4.6 x 10(22) NH2 approximate to 16 x 10(22) cm(-2), magnetic fields change back to being parallel to density gradients once again, which can be understood to be due to magnetic fields being dragged in by infalling material. In addition, we estimate the magnetic field strengths of the filaments (B-POS = 60-300 mu G)) using the Davis-Chandrasekhar-Fermi method and discuss whether the filaments are gravitationally unstable based on magnetic field and turbulence energy densities.
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| 105. |
- Lagerwall, Jan P. F., et al.
(författare)
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Cellulose nanocrystal-based materials : from liquid crystal self-assembly and glass formation to multifunctional thin films
- 2014
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Ingår i: NPG Asia materials. - : Springer Science and Business Media LLC. - 1884-4049 .- 1884-4057. ; 6
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Forskningsöversikt (refereegranskat)abstract
- Cellulose nanocrystals (CNCs), produced by the acid hydrolysis of wood, cotton or other cellulose-rich sources, constitute a renewable nanosized raw material with a broad range of envisaged uses: for example, in composites, cosmetics and medical devices. The intriguing ability of CNCs to self-organize into a chiral nematic (cholesteric) liquid crystal phase with a helical arrangement has attracted significant interest, resulting in much research effort, as this arrangement gives dried CNC films a photonic band gap. The films thus acquire attractive optical properties, creating possibilities for use in applications such as security papers and mirrorless lasing. In this critical review, we discuss the sensitive balance between glass formation and liquid crystal self-assembly that governs the formation of the desired helical structure. We show that several as yet unclarified observations-some constituting severe obstacles for applications of CNCs-may result from competition between the two phenomena. Moreover, by comparison with the corresponding self-assembly processes of other rod-like nanoparticles, for example, carbon nanotubes and fd virus particles, we outline how further liquid crystal ordering phenomena may be expected from CNCs if the suspension parameters can be better controlled. Alternative interpretations of some unexpected phenomena are provided, and topics for future research are identified, as are new potential application strategies.
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| 106. |
- Lango Allen, Hana, et al.
(författare)
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Hundreds of variants clustered in genomic loci and biological pathways affect human height.
- 2010
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 467:7317, s. 832-8
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Tidskriftsartikel (refereegranskat)abstract
- Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P<0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.
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| 107. |
- Larsen, Dennis, et al.
(författare)
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Exceptionally rapid oxime and hydrazone formation promoted by catalytic amine buffers with low toxicity
- 2018
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Ingår i: Chemical Science. - : Royal Society of Chemistry (RSC). - 2041-6539 .- 2041-6520. ; 9:23, s. 5252-5259
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Tidskriftsartikel (refereegranskat)abstract
- Hydrazone and oxime bond formation between α-nucleophiles (e.g. hydrazines, alkoxy-amines) and carbonyl compounds (aldehydes and ketones) is convenient and is widely applied in multiple fields of research. While the reactants are simple, a substantial drawback is the relatively slow reaction at neutral pH. Here we describe a novel molecular strategy for accelerating these reactions, using bifunctional buffer compounds that not only control pH but also catalyze the reaction. The buffers can be employed at pH 5-9 (5-50 mM) and accelerate reactions by several orders of magnitude, yielding second-order rate constants of >10 M-1s-1. Effective bifunctional amines include 2-(aminomethyl)imidazoles and N,N-dimethylethylenediamine. Unlike previous diaminobenzene catalysts, the new buffer amines are found to have low toxicity to human cells, and can be used to promote reactions in cellular applications.
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| 108. |
- Lewin, Harris A., et al.
(författare)
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The Earth BioGenome Project 2020 : Starting the clock
- 2022
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences (PNAS). - 0027-8424 .- 1091-6490. ; 119:4
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 109. |
- Li, You, et al.
(författare)
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Preinvasion Assessment of Exotic Bark Beetle-Vectored Fungi to Detect Tree-Killing Pathogens
- 2022
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Ingår i: Phytopathology. - 0031-949X. ; 112:2, s. 261-270
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Tidskriftsartikel (refereegranskat)abstract
- Exotic diseases and pests of trees have caused continental-scale disturbances in forest ecosystems and industries, and their invasions are considered largely unpredictable. We tested the concept of preinvasion assessment of not yet invasive organisms, which enables empirical risk assessment of potential invasion and impact. Our example assesses fungi associated with Old World bark and ambrosia beetles and their potential to impact North American trees. We selected 55 Asian and European scolytine beetle species using host use, economic, and regulatory criteria. We isolated 111 of their most consistent fungal associates and tested their effect on four important southeastern American pine and oak species. Our test dataset found no highly virulent pathogens that should be classified as an imminent threat. Twenty-two fungal species were minor pathogens, which may require context-dependent response for their vectors at North American borders, while most of the tested fungi displayed no significant impact. Our results are significant in three ways; they ease the concerns over multiple overseas fungus vectors suspected of heightened potential risk, they provide a basis for the focus on the prevention of introduction and establishment of species that may be of consequence, and they demonstrate that preinvasion assessment, if scaled up, can support practical risk assessment of exotic pathogens.
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| 110. |
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