Advances and applications in spatial transcriptomics

Spatial transcriptomics is an organizational study done on tissue sections that preserves the spatial information of the sample.Spatial transcriptomics aims to combine spatial information with gene expression data to quantify the mRNA expression of a large number of genes in the spatial context of tissues and cells.As a paradigm shift in biological research,spatial transcriptomics can provide both spatial location information and transcriptome-level cellular gene expression data,elucidating the interactions between cells and the microenvironment.From the understanding of the entire functional life cycle of RNA to the characterization of molecular mechanisms to the mapping of gene expression in various tissue regions,by choosing the appropriate spatial transcriptome technology,researchers can achieve a deeper exploration of biological developmental processes,disease pathogenesis,etc.In recent years,the field of spatial transcriptomics has ushered in several challenges along with its rapid development,such as the dependence on sample types,the resolution of visualized genes,the difficulty of commercialization,and the ability to obtain detailed single-cell information.In this paper,we summarize and review the four major categories of spatial transcriptome technologies and compare and analyze the technical advantages and major challenges of multiple research strategies to assist current experimental design and research analysis.Finally,the importance of spatial transcriptomics in the integration of multi-omics analysis and disease modeling as well as the future development prospects are summarized and outlined.

Single-crystalline hole-transporting layers for efficient and stable organic light-emitting devices

Efficient charge-carrier injection and transport in organic light-emitting devices(OLEDs)are essential to simultaneously achieving their high efficiency and long-term stability.However,the charge-transporting layers(CTLs)deposited by various vapor or solution processes are usually in amorphous forms,and their low charge-carrier mobilities,defectinduced high trap densities and inhomogeneous thickness with rough surface morphologies have been obstacles towards high-performance devices.Here,organic single-crystalline(SC)films were employed as the hole-transporting layers(HTLs)instead of the conventional amorphous films to fabricate highly efficient and stable OLEDs.The highmobility and ultrasmooth morphology of the SC-HTLs facilitate superior interfacial characteristics of both HTL/electrode and HTL/emissive layer interfaces,resulting in a high Haacke’s figure of merit(FoM)of the ultrathin top electrode and low series-resistance joule-heat loss ratio of the SC-OLEDs.Moreover,the thick and compact SC-HTL can function as a barrier layer against moisture and oxygen permeation.As a result,the SC-OLEDs show much improved efficiency and stability compared to the OLEDs based on amorphous or polycrystalline HTLs,suggesting a new strategy to developing advanced OLEDs with high efficiency and high stability.