| 1. |
- Wang, Fang, et al.
(författare)
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Research on Injury Prevention Effectiveness of Cyclist Helmet in Typical Road Cycling Accident Scenarios
- 2024
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Ingår i: Jixie Gongcheng Xuebao/Journal of Mechanical Engineering. - : Chinese Mechanical Engineering Society. - 0577-6686. ; 60:8, s. 256-270
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Tidskriftsartikel (refereegranskat)abstract
- In intense and fast road cycling races, various accidents pose a great threat to cyclist safety. There is a lack of in-depth research on helmet performance and cyclist head injury in road cycling races. In this paper, based on collecting and summarizing the typical accident scenarios of road cycling races, models of road bicycle, anthropologic characteristics of cyclists and helmets are constructed with experimental and computational methods, and the head injury protection performance of helmets and cyclist's head injury response in typical accident scenarios are comprehensively analyzed and evaluated. The results show that the helmet can play a significant injury protection effect, but serious head injury may still occur in some scenarios; different helmets have significant differences in cyclist's head injury protection, and there is no direct correlation with the price. There are significant differences in the effectiveness of helmets for head injury protection among cyclists of different body sizes, with the 50th percentile adult men having the lowest peak kinematic response and injury risk, the 5th percentile adult women having the highest predicted values for all injury criteria, and at least 55% of female cyclists having a significant risk of skull fracture and severe brain injury. None of the accident boundary parameters examined in this study (accident speed, friction coefficient, and slope) had a significant effect on cyclist head injury in the accident scenarios; the Union cycliste Internationale stipulates that helmets may not be worn five kilometers from the end of the climb, while this study recommends cyclists wear safety helmets throughout the road cycling races. This study will provide a reference for the design of safety helmets for road cycling races, as well as data to support the improvement of road cycling race rules.
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| 2. |
- Xu, Huan, et al.
(författare)
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Osteoconductive and Antibacterial Poly(lactic acid) Fibrous Membranes Impregnated with Biobased Nanocarbons for Biodegradable Bone Regenerative Scaffolds
- 2021
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 0888-5885 .- 1520-5045. ; 60:32, s. 12021-12031
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Tidskriftsartikel (refereegranskat)abstract
- Carbonaceous nanostructures featuring unique structural characteristics and high cytocompatibility offer a wealth of possibilities to impart enhancements of mechanical properties and biological activities for osteogenic tissue scaffolds. Here, we unveil the fabrication of osteoconductive and antibacterial porous poly(lactic acid) (PLA) membranes by direct electrospinning of microfibers impregnated with coffee-ground-derived quantum dots (QDs). It enabled a straightforward pathway to regulate the diameter and its distribution for the electrospun PLA microfibers, as well as the improved hydrophilicity. The QDs exhibited high affinity to the PLA matrix, permitting remarkable promotion of tensile strength and elastic modulus for the QD-modified PLA membranes while maintaining comparable extensibility. More importantly, osteoblast adhesion and stretching on the electrospun membranes were significantly enhanced with the existence of QDs, as exemplified by the nearly 1.8-fold increase in cell viability cultured onto the composite membrane loaded with 1.5% QDs compared to that of pure PLA. This was accompanied by rapid biomimetic mineralization and uniform apatite formation in an osteofriendly manner. Unexpectedly, immediate and broad-spectrum antibacterial performance was achieved for the composite membranes, likely arising from the synergistic effects of QD-imparted membrane stress and oxidative stress. The unusual combination of mechanical, biomineralization, biological, and antibacterial performances makes the biodegradable membrane scaffolds promising for guided bone/tissue regeneration therapy.
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| 3. |
- Zhang, Cunzhi, et al.
(författare)
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Eco-Friendly Bioinspired Interface Design for High-Performance Cellulose Nanofibril/Carbon Nanotube Nanocomposites
- 2020
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 12:49, s. 55527-55535
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Tidskriftsartikel (refereegranskat)abstract
- Inspired by a wood-like multicomponent structure, an interface-reinforced method was developed to fabricate high-performance cellulose nanofibril (CNF)/carbon nanotube (CNT) nanocomposites. Holocellulose nanofibrils (HCNFs) with core-shell structure were first obtained from bagasse via mild delignification and mechanical defibration process. The well-preserved native hemicellulose as the amphiphilic shell of HCNFs could act as a binding agent, sizing agent, and even dispersing agent between HCNFs and CNTs. Remarkably, both the tensile strength at high relative humidity (83% RH) and electrical conductivity of the HCNF/CNT nanocomposites were significantly improved up to 121 MPa and 321 S/m, respectively, demonstrating great superiority compared to normal CNF/CNT composite films. Furthermore, these HCNF/CNT composites with outstanding integrated performances exhibited great potential in the field of flexible liquid sensing.
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