Understanding and engineering the domain boundaries in chemically vapor deposited monolayer graphene will be critical for improving its properties. In this study, a combination of transmission electron microscopy (TEM) techniques including selected area electron diffraction, high resolution transmission electron microscopy (HR-TEM), and dark field (DF) TEM was used to study the boundary orientation angle distribution and the nature of the carbon bonds at the domain boundaries. This report provides an important first step toward a fundamental understanding of these domain boundaries. The results show that, for the graphene grown in this study, the 46 measured misorientation angles are all between 11° and 30° (with the exception of one at 7°). HR-TEM images show the presence of adsorbates in almost all of the boundary areas. When a boundary was imaged, defects were seen (dangling bonds) at the boundaries that likely contribute to adsorbates binding at these boundaries. DF-TEM images also showed the presence of a "twinlike" boundary.
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Nucleic Acids Res
December 2024
NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, 55 Zhongguancun East Road, Haidian District, Beijing 100190, China.
Topologically associating domains (TADs) are essential components of three-dimensional (3D) genome organization and significantly influence gene transcription regulation. However, accurately identifying TADs from sparse chromatin contact maps and exploring the structural and functional elements within TADs remain challenging. To this end, we develop TADGATE, a graph attention auto-encoder that can generate imputed maps from sparse Hi-C contact maps while adaptively preserving or enhancing the underlying topological structures, thereby facilitating TAD identification.
View Article and Find Full Text PDFCongenit Anom (Kyoto)
December 2024
Department of Molecular Craniofacial Embryology and Oral Histology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
Sonic hedgehog (Shh) is expressed in the oropharyngeal epithelium, including the frontonasal ectodermal zone (FEZ), which is defined as the boundary between Shh and Fgf8 expression domains in the frontonasal epithelium. To investigate the role of SHH signaling from the oropharyngeal epithelium, we generated mice in which Shh expression is specifically deleted in the oropharyngeal epithelium (Isl1-Cre; Shh). In the mutant mouse, Shh expression was excised in the oropharyngeal epithelium as well as FEZ and ventral forebrain, consistent with the expression pattern of Isl1.
View Article and Find Full Text PDFComput Math Appl
August 2024
Department of Mathematics, Texas State, 78666 TX, San Marcos, USA.
The utilization of nonlinear differential equations has resulted in remarkable progress across various scientific domains, including physics, biology, ecology, and quantum mechanics. Nonetheless, obtaining multiple solutions for nonlinear differential equations can pose considerable challenges, particularly when it is difficult to find suitable initial guesses. To address this issue, we propose a pioneering approach known as the Companion-Based Multilevel Finite Element Method (CBMFEM).
View Article and Find Full Text PDFACS Nano
December 2024
Center for Advanced Quantum Studies, School of Physics and Astronomy, Beijing Normal University, Beijing 100875, China.
Introducing quantum confinement has shown promise to enable control of charge carriers. Although recent advances make it possible to realize confinement from semiclassical regime to quantum regime, achieving control of electronic potentials in individual nanoscale quantum dots (QDs) has remained challenging. Here, we demonstrate the ability to tune quantum confined states in individual nanoscale graphene QDs, which are realized by inserting nanoscale monolayer WSe islands in graphene/WSe heterostructures via interfacial engineering.
View Article and Find Full Text PDFPLoS One
December 2024
Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy.
A high-resolution record of central Mediterranean Sea Surface Temperatures (SSTs) based on the alkenone UK'37 index and planktic δ18O values for the surface-dweller G. ruber has been reconstructed across the Pliocene/Pleistocene transition at Monte San Nicola (Sicily), reference area for the GSSP (Global Boundary Stratotype Section and Point) of the Gelasian Stage. Spectral analyses indicate that the SST record is predominantly paced by a cyclicity in the ~47 kyr time domain, consistent with the obliquity driven glacial-interglacial variability that is expected to dominate in the interval of relevance.
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