俄罗斯鲟胸鳍棘层状骨的纳米尺度表征：三维 FIB-SEM 研究Nanoscale Characterization of Microscopically Layered Bone in the Russian Sturgeon Pectoral Fin Spine: A 3D FIB-SEM Study
希伯来大学兽医学院团队用 Zeiss Crossbeam 540 FIB-SEM（像素约 10 nm）对俄罗斯鲟（Huso gueldenstaedtii）胸鳍棘的骨单位骨和外周骨做三维成像。图像堆栈导入 Dragonfly 3D World 2022.2 做漂移校正；随后在 Dragonfly 的 Segmentation Wizard 中训练 2D U-Net 模型分割胶原纤维与孔隙，用 Segmentation Comparator 评估（Dice 0.56–0.66），再按特征向量（Eigenvector）各向异性分析绘制钙化胶原纤维束取向图，并对孔隙做 6-连通组件、厚度网格和骨架分析。结果显示：皮质骨单位中纤维取向呈顺/逆时针“扇形”交替，符合板层骨；外周骨虽低倍下看似分层，纳米尺度却以沿棘长轴的单向纤维为主，属平行纤维骨，并伴有成群的孔隙结构。A Hebrew University veterinary team imaged osteonal and peripheral bone of the Russian sturgeon (Huso gueldenstaedtii) pectoral fin spine with a Zeiss Crossbeam 540 FIB-SEM (~10 nm pixels). Stacks were drift-corrected in Dragonfly 3D World 2022.2, then segmented with a 2D U-Net trained in Dragonfly's Segmentation Wizard (evaluated with the Segmentation Comparator, Dice 0.56–0.66); Eigenvector-based anisotropy analysis mapped calcified collagen fibril bundle orientation, and voids were analysed with 6-connected components, thickness meshes and skeleton graphs. Dermal osteons show clockwise–anticlockwise fanning consistent with lamellar bone, while the peripheral bone, layered-looking at low magnification, is mainly unidirectional parallel-fibered bone with grouped voids.