AI 中文总结
该研究提出URA-SIM算法，通过相位域补全将减帧SIM测量转为兼容经典流程的原始堆栈，实现活细胞成像的稳定重建，兼具保真度、轻量计算与兼容性，可适配多种SIM模态。
AI 中文摘要
减帧结构光照明显微镜（SIM）因可提升时间吞吐量并减少光漂白，在活细胞成像中颇具吸引力，但不完整的相位采样会导致重建不稳定且计算需求高。本文提出URA-SIM，一种统一的减采框架，通过模型一致的相位域补全，将固定减帧测量转换为可兼容流程的原始堆栈。URA-SIM不求解大型物体级逆问题，也不替代已建立的SIM重建，而是估计目标模态所需的低维相位谐波流形上的缺失相位内容，再将阶数分离与图像形成任务委托给经典重建流程。该设计兼具三项实用优势：SIM正向结构带来的保真度、轻量型在线计算能力、与现有重建工作流的直接兼容性。对于2D-SIM，URA-SIM利用三相SIM的一次谐波相位结构估计共享零阶场，并通过方向谐波拟合补全缺失相位样本。在校准数据与生物2D-SIM数据上，减帧重建保留可分辨结构，且在COS7线粒体对比数据中仍具竞争力；在活细胞COS7线粒体成像中，URA-SIM从5帧采集的原始帧重建每个时间点，可分辨不同时间采样 regime 下的线粒体嵴。针对3D-SIM与非线性SIM的实验进一步表明，当相位模型与重建流程接口适配目标模态时，该设计原则可迁移。这些结果支持URA-SIM作为一种透明、模型一致且计算轻量的途径，从固定减帧采集通向经典SIM重建工作流。
英文摘要
Reduced-frame structured illumination microscopy (SIM) is attractive for live-cell imaging because it can improve temporal throughput and reduce photobleaching, but incomplete phase sampling makes reconstruction unstable and computationally demanding. Here we present URA-SIM, a unified reduced-acquisition framework that turns fixed reduced-frame measurements into pipeline- compatible raw stacks through model-consistent phase-domain completion. Instead of solving a large object-level inverse problem or replacing established SIM reconstruction, URA-SIM estimates the missing phase content on the low-dimensional phase-harmonic manifold required by the target modality and then delegates order separation and image formation to classical reconstruction pipeline. This design combines three practical advantages: fidelity from the SIM forward structure, lightweight online computation, and direct compatibility with existing reconstruction workflows. For 2D-SIM, URA-SIM uses the first-harmonic phase structure of three-phase SIM to estimate a shared zero-order field and complete missing phase samples by direction-wise harmonic fitting. On calibration and biological 2D-SIM data, reduced-frame reconstructions preserve resolvable structures and remain competitive on COS7 mitochondria comparison data. In live-cell COS7 mitochondria imaging, URA-SIM reconstructs each time point from five acquired raw frames and resolves mitochondrial cristae across different temporal sampling regimes. Experiments on 3D-SIM and nonlinear SIM further show that the same design principle can be transferred when the phase model and reconstruction-pipeline interface are adapted to the target modality. These results support URA-SIM as a transparent, model-consistent and computationally lightweight route from fixed reduced-frame acquisition to classical SIM reconstruction workflows.
