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Increasing the number of read/write layers and ensuring the quality of read/write signals are the key factors to enhance the optical storage capacity. However, limited by the single optical path, the structure, and the material of the disk, the existing system reads and writes up to 16 layers. In the existing optical storage system design, the optical path design and the signal model are independent of each other, so the signal quality based on the signal model can only be evaluated after the implementation of the optical path. We propose a dual-beam read/write optical path for the optical storage system, which breaks through the limitation of the single optical path and can read/write multilayers. The servo detection signals and servo margins show that the dual-beam read/write system has good error detection capability and strong robustness. The servo error signal is calculated according to the relationship between the wavefront aberration, relative coordinate system displacement difference, and servo error of the optical system, thus deriving a quantifiable signal evaluation model. The effectiveness of the model is verified by experiments. The signal evaluation model breaks through the limitations of the traditional optical design method for the optical storage system and can guide the optical design from the signal perspective. The dual-beam optical path for multilayer optical storage systems provides a broader range of ideas for enhancing optical storage capacity. [ABSTRACT FROM AUTHOR]

The PML‐RARα fusion gene, generated by the t(15;17) chromosome translocation, is regarded as the initiating factor of acute promyelocytic leukaemia (APL). In addition to the well‐known effects on blocking myeloid differentiation at the promyelocytic stage, promyelocytic leukaemia‐retinoic acid receptor α (PML‐RARα) has also been reported to interfere with multiple differentiation processes, including erythroid differentiation. However, the detailed molecular mechanism by which PML‐RARα impairs erythropoiesis has not yet been fully addressed. By chromatin immunoprecipitation‐PCR assay, we found that PML‐RARα bound to the distal promoter region of LMO2 (LIM‐only protein 2), a critical erythroid‐specific transcription factor. Luciferase reporter assays and qRT‐PCR results demonstrated that PML‐RARα down‐regulated the expression of the LMO2 distal transcript through transrepressing its promoter activity. Analysis of gene expression profiling data from large cohorts of acute myeloid leukaemia (AML) patients confirmed that LMO2 expressed at a markedly lower level in APL patients in comparison to non‐APL AML patients. Further flow cytometry analysis demonstrated that PML‐RARα inhibited erythropoietin‐induced erythroid differentiation by down‐regulating LMO2 expression. Our findings reveal a previously unidentified mechanism, by which PML‐RARα interferes with erythropoiesis through directly targeting and transrepressing LMO2 expression in the development of APL. [ABSTRACT FROM AUTHOR]