| 1. |
- Leebens-Mack, James H., et al.
(författare)
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One thousand plant transcriptomes and the phylogenomics of green plants
- 2019
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 574:7780, s. 679-
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Tidskriftsartikel (refereegranskat)abstract
- Green plants (Viridiplantae) include around 450,000-500,000 species(1,2) of great diversity and have important roles in terrestrial and aquatic ecosystems. Here, as part of the One Thousand Plant Transcriptomes Initiative, we sequenced the vegetative transcriptomes of 1,124 species that span the diversity of plants in a broad sense (Archaeplastida), including green plants (Viridiplantae), glaucophytes (Glaucophyta) and red algae (Rhodophyta). Our analysis provides a robust phylogenomic framework for examining the evolution of green plants. Most inferred species relationships are well supported across multiple species tree and supermatrix analyses, but discordance among plastid and nuclear gene trees at a few important nodes highlights the complexity of plant genome evolution, including polyploidy, periods of rapid speciation, and extinction. Incomplete sorting of ancestral variation, polyploidization and massive expansions of gene families punctuate the evolutionary history of green plants. Notably, we find that large expansions of gene families preceded the origins of green plants, land plants and vascular plants, whereas whole-genome duplications are inferred to have occurred repeatedly throughout the evolution of flowering plants and ferns. The increasing availability of high-quality plant genome sequences and advances in functional genomics are enabling research on genome evolution across the green tree of life.
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| 2. |
- Ren, Wen, et al.
(författare)
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The workflows of a novel self-glazed zirconia for dental prostheses fabrication : case reports
- 2018
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Ingår i: Advances in Applied Ceramics. - : Informa UK Limited. - 1743-6753 .- 1743-6761. ; 117:7, s. 406-413
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Tidskriftsartikel (refereegranskat)abstract
- In the clinical application of ceramic prostheses, micro-leakage, porcelain chipping, low-treatment efficiency and quality uncertainty have appeared as the major problems that dentists encountered. However, the full-contour zirconia monolithic prostheses have the potentials for solving the problems. It appears that the full-contour zirconia monolithic prostheses produced through the fully digital workflow can ensure that the restorations can be closely aligned with the abutment and be easy to adjust and to wear, thus to assure the stability and accuracy of occlusal, which are crucial to the ultimate integration of the full-contour zirconia monolithic prostheses by avoiding unfavourable grinding. The newly developed full digital approach can greatly simplify the previous workflow that involved many manual operations. It improves not only the treatment efficiency but also the reliability of the prostheses by avoiding manual operational mistakes.
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| 3. |
- Yang, X., et al.
(författare)
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Colossal dielectric performance of pure barium titanate ceramics consolidated by spark plasma sintering
- 2016
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 6:79, s. 75422-75429
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Tidskriftsartikel (refereegranskat)abstract
- A facile sol-gel-hydrothermal method was developed to prepare well-dispersed BaTiO3 (BT) nanocrystals with a size of about 20 nm. By using such nanopowder, dense BT nanoceramics were densified via spark plasma sintering (SPS). Dielectric measurements reveal that pure BT nanoceramics have an extremely high permittivity up to 6 x 10(4) and a low dielectric loss. On the basis of microstructure characterization and dielectric measurement, it was proposed that the polaron dipoles configured by oxygen vacancies and Ti3+ cations within the grains could contribute to the colossal dielectric permittivity of the ceramics. By using the thermally activated polaron hopping model, a large activation energy EA has been determined (0.135 eV) below the Curie temperature, possibly due to the coupling of polaron dipoles and intrinsic ferroelectric dipoles. This simple method offers the possibility to produce pure BT nanoceramics with a colossal permittivity.
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| 4. |
- Yang, Ying, et al.
(författare)
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Design of magnetic fields for half and full type electromagnetic swirl flow generators
- 2015
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Ingår i: Steel Research International. - : John Wiley & Sons. - 1611-3683 .- 1869-344X. ; 86:4, s. 361-374
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the placement of an electromagnetic swirl flow generator (EMSFG) around a submerged entry nozzle (SEN) was proposed as a method for generating a rotating electromagnetic field in a continuous casting (CC) process of steel. First, two kinds of a full type EMSFG and a half type EMSFG were designed based on mathematical modeling. Then, distributions of magnetic flux intensity in an EMSFG as well as distributions of Lorentz force in molten steel were simulated. It was found that the EMSFG structure and electromagnetic parameters have an important effect on magnetic flux intensity and Lorentz force distributions. For both a full type and a half type EMSFG, the magnetic flux intensity and Lorentz force increases as the magnetomotive force increases. Especially, for a full type EMSFG, the magnetic flux intensity is distributed evenly in molten steel. Moreover, the Lorentz force increases along a radial direction in the molten steel in the SEN. However, for a half type EMSFG, the magnetic flux intensity and Lorentz force decreases gradually towards the region without an EMSFG. Consequently, a full type EMSFG with a 44 000 AT magnetomotive force and a 50 Hz frequency is more suitable to apply in the operation of an EMSFG under actual production conditions.
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| 5. |
- Yang, Ying, et al.
(författare)
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The Influence of Swirl Flow on the Flow Field, Temperature Field and Inclusion Behavior When Using a Half Type Electromagnetic Swirl Flow Generator in a Submerged Entry Nozzle and Mold
- 2015
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Ingår i: Steel Research International. - : Wiley-VCH Verlagsgesellschaft. - 1611-3683 .- 1869-344X. ; 86:11, s. 1312-1327
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Tidskriftsartikel (refereegranskat)abstract
- In the preceding work, the inclusion behavior in a submerged entry nozzle (SEN) and mold induced by using a swirl flow has been investigated. The results showed that a swirl flow can effectively promote the inclusions removal to the meniscus as well as reduce the inclusions entrapment at the solidified shell wall. Moreover, that the swirl flow was generated by using a full type electromagnetic swirl flow generator (EMSFG). In the present work, a kind of a half type EMSFG was investigated, since it is easier to implement in a production scale. The influence of the stirrer on the fluid flow, heat transfer, and inclusion behavior in the SEN and mold was studied. Furthermore, a comparison between these two types of EMSFG from the aspects of flow field, temperature field, and inclusion behavior was done. In addition, the effect of different magnetomotive forces, inclusion sizes, densities as well as boundary conditions on the inclusion behavior was studied. The results show that the effect of a half type EMSFG (88000 AT) on the molten steel is very close to a full type case (44000 AT). More specifically, the flow pattern, temperature distribution as well as inclusion behavior in the SEN and mold look very similar. Also, it was found that from the viewpoints of the inclusions separation to the mold meniscus and the inclusions trapping at the solidified shell wall, better results could be obtained for a “Trap” boundary condition when using half type EMSFGs.
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| 6. |
- Zhang, Ranran, et al.
(författare)
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A dual-layer macro/mesoporous structured TiO2 surface improves the initial adhesion of osteoblast-like cells
- 2017
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Ingår i: Materials science & engineering. C, biomimetic materials, sensors and systems. - : Elsevier BV. - 0928-4931 .- 1873-0191. ; 78, s. 443-451
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Tidskriftsartikel (refereegranskat)abstract
- A dual-layer TiO2 surface with hierarchical macro and mesoporous structure was prepared by a combinational approach of micro-arc oxidation followed by evaporation-induced self-assembly of nano-crystallites. The mesoporous layer contains pores with an average size of <10 nm and consists of anatase TiO2 nanocrystallites. The dual-layer hierarchical macro/mesoporous structured TiO2 surface improves the hydrophilicity and fibronectin adsorption ability in comparison with the sole macroporous or smooth TiO2 surface. With the formation of an additional mesoporous layer on macroporous TiO2 surface, the attached number of human osteogenic sarcoma cells (SaOS-2) increases in the initial incubation of 4 h but it does not show significant difference after 24 h compared to that attached on the macroporous or smooth surfaces. Whereas, it was noticed that SaOS-2 cells have larger spread area and more stress fibers on the macro/mesoporous structured surface than those on the other surfaces. To understand the intracellular mechanism of the initial cell adhesion on the macro/mesoporous surface, the Rho/ROCK pathway was investigated to reveal the topography-induced biological functions by introducing the ROCK inhibitor Y-27632 during cell culture. In the presence of Y-27632, cells on the macroporous surface and macro/mesoporous surface both show stellate appearance, with poor assembly stress fibers and long cell membrane protrusions. Cells on the smooth surface have larger spread areas compared to the former two surfaces. And the attached cells significantly reduced but there are no differences among the three surfaces. It reveals that the ROCK inhibitor invalidates the promotion of initial cell adhesion on the macro/mesoporous structure. This study may shed light on the mechanism behind the enhancement effect of macro/mesoporous structure for initial cell adhesion.
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| 7. |
- Zhang, Ranran, et al.
(författare)
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Effects of the hierarchical macro/mesoporous structure on the osteoblast-like cell response
- 2018
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Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 106:7, s. 1896-1902
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Tidskriftsartikel (refereegranskat)abstract
- To improve the success of medical devices, implants with strong surface bioactivity are urgently required. Coatings with a macroporous structure produced by micro-arc oxidation possess advantages, such as strong adhesion to substrate and excellent resistance to wear and corrosion. Mesoporous structures contain pores with sizes of 2-50 nm, which can endow the biomaterials with the ability to enhance osteogenesis and to be loaded with diverse drugs. Thus, in this study, we aimed to evaluate the effects of both macroporous and mesoporous structures using a hierarchical macro/mesoporous structure to modify the titanium implant surface. The behaviors of SaOS-2 human osteosarcoma cells on the macro/mesoporous structure, including initial adhesion, proliferation, alkaline phosphatase (ALP) activity, and collagen secretion, were investigated. Cells that attached on the macro/mesoporous surface showed the highest cell numbers and greatest spreading area after incubation for 1, 2, and 4 h compared with the polished smooth substrate and macroporous surface in the presence of fetal bovine serum (FBS). However, in the absence of FBS, cell adhesion on the polished substrate, macroporous structure, and macro/mesoporous structure did not differ significantly. Cell proliferation on the macroporous and macro/mesoporous surfaces increased compared with that on the smooth substrate surface. Furthermore, ALP activity and collagen secretion were enhanced on the macro/mesoporous structure. Our findings provided important insights into the cellular responses to macro/mesoporous structures in the field of implant surface modification.
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| 8. |
- Zhang, Ranran, et al.
(författare)
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Micro/nanostructured TiO2/ZnO coating enhances osteogenic activity of SaOS-2 cells
- 2019
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Ingår i: Artificial cells nanomedicine and biotechnology. - : Informa UK Limited. - 2169-1401 .- 2169-141X. ; 47:1, s. 2838-2845
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Tidskriftsartikel (refereegranskat)abstract
- Although titanium implants account for a large proportion of the commercial dental market, their bioactivity are inadequate in many applications. A micro- and nano- scale hierarchical surface topography of the implant is suggested for rapid osseointegration from the biomimetic perspective. Moreover, Zinc (Zn) is an essential element in the skeletal system. Thus, a micro/nanostructured TiO2/ZnO coating, produced by micro-arc oxidation, and hydrothermal treatment, and heat treatment, was designed to endow the implant surface with enhanced osteogenic capacity. Physiochemical properties and biological effects of this coating were investigated in our study. The annealed micro/nanostructured TiO2/ZnO coating exhibited higher hydrophilicity and fibronectin adsorption ability compared to the micro-arc oxidation modified TiO2 coating. SaOS-2 cells grown on the annealed micro/nanostructured TiO2/ZnO coating showed increased alkaline phosphatase activity and collagen secretion, and immunofluorescence labeling revealed an upregulation of osteopontin, collagen type iota and osteocalcin. The micro/nanostructure and incorporation of Zn were considered to perform positive effect on the enhanced osteogenic activity of SaOS-2 cells. In conclusion, the micro/nanostructured TiO2/ZnO structure is simple, stable, and easy to produce and scale up, has promising applications in the surface modification of titanium implants.
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| 9. |
- Zhang, Ranran, et al.
(författare)
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Novel micro/nanostructured TiO2/ZnO coating with antibacterial capacity and cytocompatibility
- 2018
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Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 44:8, s. 9711-9719
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Tidskriftsartikel (refereegranskat)abstract
- Insufficient osseointegration between implants and bone, and peri-implant infection are the two most common factors contributing to implantation failure. As such, implant materials should ideally be designed with antibacterial capacity while maintaining cytocompatibility. Combining Zn, a known antibacterial agent, with micro/nanostructures on the implant surface to promote osseointegration, potentially reduces peri-implant infection. To this end, in the present study, we developed novel bifunctional micro/nanostructured titanium oxide/zinc oxide (TiO2/ZnO) coating by micro-arc oxidation (MAO) followed by hydrothermal treatment. The release rate of the Zn2+ ions was reduced by heat treatment which established a balance between antibacterial capacity and cytocompatibility. The results demonstrate a simple approach for developing a Zn-based material that balances antibacterial capacity and cytocompatibility as a promising coating material for Ti implants.
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| 10. |
- Zhang, Ranran, et al.
(författare)
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The immunomodulatory effects of Zn-incorporated micro/nanostructured coating in inducing osteogenesis
- 2018
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Ingår i: Artificial cells nanomedicine and biotechnology. - : Informa UK Limited. - 2169-1401 .- 2169-141X. ; 46, s. S1123-S1130
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Tidskriftsartikel (refereegranskat)abstract
- Micro/nanostructured TiO2/ZnO coating has been shown to possess multiple functions, including antibacterial activity and bioactivity. Osteoblast-like SaOS-2 cells were employed for evaluating the in vitro osteogenic capacity of this coating and positive results were obtained. However, traditional principles of osseointegration focus only on the osteogenic differentiation alone. The effects of immunomodulation on the osteogenic activity have been largely ignored. In this study, the inflammatory responses of macrophages on the micro/nanostructured TiO2/ZnO coating were investigated. The extract media of macrophage cell line RAW264.7 cultured on the TiO2/ZnO coating were collected as indirect co-culture conditioned media. The osteogenic activity of SaOS-2 cells in the conditioned media was investigated. Adhesion, ALP activity and extracellular mineralization of cells grown in the conditioned media extracted from the micro/nanostructured TiO2/ZnO coating were found to be enhanced, compared to those grown in the conditioned media extracted from the macroporous TiO2 coating. The immune microenvironment produced by the micro/nanostructured TiO2/ZnO coating showed excellent capacity to promote osteogenesis, indicating that this coating could be a promising candidate for implant surface modification in orthopaedic and dental applications. Furthermore, this work could help us understand the interplay between the host immune system and the osteoimmunomodulatory properties of the biomaterials, and optimize the design for coating biomaterials.
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