| 1. |
- Liu, Kehong, et al.
(författare)
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Conditioned medium of human mesenchymal stem cells affects stem cell senescence in osteoporosis
- 2024
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Ingår i: Biochemical and Biophysical Research Communications. - 0006-291X. ; 711
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Tidskriftsartikel (refereegranskat)abstract
- Systemic transplantation of mesenchymal stem cells (MSCs) and conditioned medium derived from MSCs have been reported to recover bone loss in animal models of osteoporosis; however, the underlying mechanisms remain unclear. We recently reported that extracellular vesicles released from human mesenchymal stem cells (hMSCs) prevent senescence of stem cells in bisphosphonate-related osteonecrosis of the jaw model. In this study, we aimed to compare the effects of conditioned medium (hMSCs-CM) from early and late passage hMSCs on cellular senescence and to verify the benefits of CM from early passage hMSCs in mitigating the progression of osteoporosis through the prevention of cellular senescence. We investigated the distinct endocrine effects of early (P5) and late (P17) passage hMSCs in vitro, as well as the preventive benefits of early passage hMSCs-CM in osteoporosis model triggered by ovariectomy. Our results indicate that long-term cultured hMSCs contributed to the progression of inflammatory transcriptional programs in P5 hMSCs, ultimately impairing their functionality and enhancing senescence-related characteristics. Conversely, early passage hMSCs reversed these alterations. Moreover, early passage hMSCs-CM infused intravenously in a postmenopausal osteoporosis mouse model suppressed bone degeneration and prevented osteoporosis by reducing ovariectomy-induced senescence in bone marrow MSCs and reducing the expression of senescence-associated secretory phenotype-related cytokines. Our findings highlight the high translational value of early passage hMSCs-CM in antiaging intervention and osteoporosis prevention.
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| 2. |
- Pan, Zhidong, et al.
(författare)
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Mechanically activated slag cement
- 2005
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Ingår i: Journal of the Chinese Ceramic Society. - 0454-5648. ; 33:10, s. 1248-1254
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Tidskriftsartikel (refereegranskat)abstract
- Mechanical activation of cement blended with metallurgical wastes (blast furnace slag and silica fume) in a high energy vibrating mill was investigated. The results show that the mechanical activation of the solids led to a reduction of the ground product fineness and an effective dispersion/interaction of ultra-fine silica particles within cement particles, resulting in an increased rate of the hydration reactions of the slag cement. The hardened paste samples after activation possess higher bending and compressive strengths. Fourier transform infrared spectroscopy and nuclear magnetic resonance studies indicate the mechanism of the mechanical activation on the slag cement.
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| 3. |
- Wang, Yanmin, et al.
(författare)
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Centrifugal classification of ultrafine calcium carbonate
- 2006
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Ingår i: Journal of the Chinese Ceramic Society. - 0454-5648. ; 34:8, s. 927-931
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Tidskriftsartikel (refereegranskat)abstract
- The experimental results on wet classification of ultra-fine calcium carbonate below 8 μm using an industrial scale disc-stack nozzle centrifuge system are presented. The parameters such as G-force, disc geometry, nozzle size, split, feed rate have been analysed by a statistical approach. The results show that the centrifuge is capable to efficiently classify the micron-sized material at 40% in mass. The product size distribution becomes finer and steeper after removing the undesired coarser particles from the feed. In addition, the centrifugal classification performance is empirically correlated to the parameters used.
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