Dbh+ catecholaminergic cardiomyocytes contribute to the structure and function of the cardiac conduction system in murine heart

The heterogeneity of functional cardiomyocytes arises during heart development, which is essential to the complex and highly coordinated cardiac physiological function. Yet the biological and physiological identities and the origin of the specialized cardiomyocyte populations have not been fully comprehended. Here we report a previously unrecognised population of cardiomyocytes expressing Dbhgene encoding dopamine beta-hydroxylase in murine heart. We determined how these myocytes are distributed across the heart by utilising advanced single-cell and spatial transcriptomic analyses, genetic fate mapping and molecular imaging with computational reconstruction. We demonstrated that they form the key functional components of the cardiac conduction system by using optogenetic electrophysiology and conditional cardiomyocyte Dbh gene deletion models. We revealed their close relationship with sympathetic innervation during cardiac conduction system formation. Our study thus provides new insights into the development and heterogeneity of the mammalian cardiac conduction system by revealing a new cardiomyocyte population with potential catecholaminergic endocrine function

IBEWMS: Individual Band Spectral Feature Enhancement-Based Waterfront Environment AAV Multispectral Image Stitching

As the use of autonomous aerial vehicles (AAVs) for waterfront monitoring increases, combining multiple AAV multispectral (MS) images into a single, seamless panoramic image has become crucial. This process ensures the accuracy and effectiveness of waterfront monitoring. However, the varying reflective properties of different wavelengths bring challenges for existing single-band MS image stitching frameworks, especially in complex waterfront areas. To address this challenge, we developed the individual band enhanced waterfront multispectral stitching (IBEWMS) framework. Central to this framework is the individual band spectral feature enhancement (IBSFE) module, which enhances each spectral band based on varying reflectance of different land covers, yielding clearer and more reliable features. Using IBSFE, we designed a detector-free framework to effectively extract and match feature points in waterfront MS images. In addition, we implemented an image fusion technique to address issues, such as ghosting and global reflectance inconsistency, in panoramic images. To support this work, we provided the Wuhan AAV Waterfront Environment MS Dataset, comprising 12 315 high-resolution 5-band MS images. Experiments show that IBEWMS outperforms both deep learning and traditional stitching frameworks, offering valuable support for downstream applications

A Hierarchical Blockchain-Assisted Conditional Privacy-Preserving Authentication Scheme for Vehicular Ad Hoc Networks

Through information sharing, vehicles can know the surrounding road condition information timely in Vehicular Adhoc Networks. To ensure the validity of these messages and the security of vehicles, the message authentication, privacy-preserving, and delay problems are three important issues. Although many conditional privacy-preserving authentication schemes have been proposed to ensure secure communication, there still exist some imperfections such as frequent interactions or unlinkability. From this, our paper proposes a novel hierarchical blockchain-assisted authentication scheme to solve these existing issues comprehensively. First, unlinkability is achieved by a dynamic key derivation algorithm. Second, the proposed scheme can reduce correlation processing delay, queuing delay, and deployment costs by adopting hierarchical Vehicle Fog Computing. Third, cross-region authentication is achieved by taking advantage of the properties of blockchain. In addition, we demonstrate our scheme can fulfill the security criteria of the Vehicular Adhoc Network by security analysis. Furthermore, the simulations are carried out to show its availability by using JAVA and NS-3. The findings reveal that the suggested method outperforms earlier schemes in terms of computation cost and communication cost. All in all, making the authentication scheme more efficient and concise is the focus of our future research

Effects of aluminium content on the molecular structure and properties of polyaluminocarbosilane for SiC fibre fabrication

Effects of aluminium content on the molecular structure and properties of polyaluminocarbosilane for SiC fibre fabricatio

Synthesis of polyaluminocarbosilane with low branched molecular structure using liquid polysilacarbosilane and aluminum acetylacetonate by high-pressure method

Synthesis of polyaluminocarbosilane with low branched molecular structure using liquid polysilacarbosilane and aluminum acetylacetonate by high-pressure metho

Integrated transcriptome and lineage analyses reveal novel catecholaminergic cardiomyocytes contributing to the cardiac conduction system in murine heart

Summary Cardiac conduction system (CCS) morphogenesis is essential for correct heart function yet is incompletely understood. Here we established the transcriptional landscape of cell types populating the developing heart by integrating single-cell RNA sequencing and spatial enhanced resolution omics-sequencing (Stereo-seq). Stereo-seq provided a spatiotemporal transcriptomic cell fate map of the murine heart with a panoramic field of view and in situ cellular resolution of the CCS. This led to the identification of a previously unrecognized cardiomyocyte population expressing dopamine beta-hydroxylase ( Dbh + -CMs), which is closely associated with the CCS in transcriptomic analyses. To confirm this finding, genetic fate mapping by using Dbh Cre /Rosa26-tdTomato reporter mouse line was performed with Stereo-seq, RNAscope, and immunohistology. We revealed that Dbh + -derived CMs first emerged in the sinus venosus at E12.5, then populated the atrial and ventricular CCS components at E14.5, with increasing abundance towards perinatal stages. Further tracing by using Dbh CFP reporter and Dbh CreERT /Rosa26-tdTomato inducible reporter, we confirmed that Dbh + -CMs are mostly abundant in the AVN and ventricular CCS and this persists in the adult heart. By using Dbh Cre /Rosa26-tdTomato/Cx40-eGFP compound reporter line, we validated a clear co-localization of tdTomato and eGFP signals in both left and right ventricular Purkinje fibre networks. Finally, electrophysiological optogenetic study using cell-type specific Channelrhodopsin2 (ChR2) expression further elucidated that Dbh + -derived CMs form a functional part of the ventricular CCS and display similar photostimulation-induced electrophysiological characteristics to Cx40 CreERT /ChR2-tdTomato CCS components. Thus, by utilizing advanced transcriptomic, mouse genetic, and optogenetic functional analyses, our study provides new insights into mammalian CCS development and heterogeneity by revealing novel Dbh + -CMs. Highlights Stereo-seq provided a spatiotemporal transcriptomic cell fate map of the murine heart with a panoramic field of view and in situ cellular resolution of the CCS. Established the transcriptional landscape of cell types populating the developing murine heart. Revealed previously unreported catecholaminergic cardiomyocyte populations contributing to the developing and mature murine cardiac conduction system

Dbh+ catecholaminergic cardiomyocytes contribute to the structure and function of the cardiac conduction system in murine heart

The heterogeneity of functional cardiomyocytes arises during heart development, which is essential to the complex and highly coordinated cardiac physiological function. Yet the biological and physiological identities and the origin of the specialized cardiomyocyte populations have not been fully comprehended. Here we report a previously unrecognised population of cardiomyocytes expressing Dbh gene encoding dopamine beta-hydroxylase in murine heart. We determined how these myocytes are distributed across the heart by utilising advanced single-cell and spatial transcriptomic analyses, genetic fate mapping and molecular imaging with computational reconstruction. We demonstrated that they form the key functional components of the cardiac conduction system by using optogenetic electrophysiology and conditional cardiomyocyte Dbh gene deletion models. We revealed their close relationship with sympathetic innervation during cardiac conduction system formation. Our study thus provides new insights into the development and heterogeneity of the mammalian cardiac conduction system by revealing a new cardiomyocyte population with potential catecholaminergic endocrine function