The growth plate’s response to load is partially mediated by mechano-sensing via the chondrocytic primary cilium

Mechanical load plays a significant role in bone and growth-plate development. Chondrocytes sense and respond to mechanical stimulation; however, the mechanisms by which those signals exert their effects are not fully understood. The primary cilium has been identified as a mechano-sensor in several cell types, including renal epithelial cells and endothelium, and accumulating evidence connects it to mechano-transduction in chondrocytes. In the growth plate, the primary cilium is involved in several regulatory pathways, such as the non-canonical Wnt and Indian Hedgehog. Moreover, it mediates cell shape, orientation, growth, and differentiation in the growth plate. In this work, we show that mechanical load enhances ciliogenesis in the growth plate. This leads to alterations in the expression and localization of key members of the Ihh-PTHrP loop resulting in decreased proliferation and an abnormal switch from proliferation to differentiation, together with abnormal chondrocyte morphology and organization. Moreover, we use the chondrogenic cell line ATDC5, a model for growth-plate chondrocytes, to understand the mechanisms mediating the participation of the primary cilium, and in particular KIF3A, in the cell’s response to mechanical stimulation. We show that this key component of the cilium mediates gene expression in response to mechanical stimulation.     

关于Sauer引理的一个推广

Sauer引理是统计学习理论中的基本结论．在许多实际问题中，需要研究N类模式识别问题．本文将Sauer引理推广到N类分类问题．     

乙醇三维内微肋热管的传热性能

采用实验研究的方法对三维内微肋热管的强化传热特性进行研究，首次报道了以乙醇为工质的三维内微肋热管的传热性能。在实验范围内，与光管相比，竖直放置时，沸腾换热系数可以提高98％—190％，凝结换热系数可以提高76％—178％。三维内微肋结构能够同时明显地强化热管的沸腾换热与凝结换热，可以有效地减小热管的内热阻。