Oriented Graphene Nanoribbons Embedded in Hexagonal Boron Nitride Trenches

Graphene nanoribbons (GNRs) are ultra-narrow strips of graphene that have the potential to be used in high-performance graphene-based semiconductor electronics. However, controlled growth of GNRs on dielectric substrates remains a challenge. Here, we report the successful growth of GNRs directly on hexagonal boron nitride substrates with smooth edges and controllable widths using chemical vapour deposition. The approach is based on a type of template growth that allows for the in-plane epitaxy of mono-layered GNRs in nano-trenches on hexagonal boron nitride with edges following a zigzag direction. The embedded GNR channels show excellent electronic properties, even at room temperature. Such in-plane hetero-integration of GNRs, which is compatible with integrated circuit processing, creates a gapped channel with a width of a few benzene rings, enabling the development of digital integrated circuitry based on GNRs.Comment: 32 pages, 4 figures, Supplementary informatio

CtBP1 Overexpression in Keratinocytes Perturbs Skin Homeostasis

Carboxyl-terminal–binding protein-1 (CtBP1) is a transcriptional corepressor with multiple in vitro targets, but its in vivo functions are largely unknown. We generated keratinocyte-specific CtBP1 transgenic mice with a keratin-5 promoter (K5.CtBP1) to probe the pathological roles of CtBP1. At transgene expression levels comparable to endogenous CtBP1 in acute skin wounds, the K5.CtBP1 epidermis displayed hyperproliferation, loss of E-cadherin, and failed terminal differentiation. Known CtBP1 target genes associated with these processes, e.g., p21 Brca1, and E-cadherin, were downregulated in K5.CtBP1 skin. Surprisingly, K5.CtBP1 pups also exhibited a hair loss phenotype. We found that expression of the Distal-less 3 (Dlx3), a critical regulator of hair follicle differentiation and cycling, was decreased in K5.CtBP1 mice. Molecular studies revealed that CtBP1 directly suppressed Dlx3 transcription. Consistently, K5.CtBP1 mice displayed abnormal hair follicles with decreased expression of Dlx3 downstream targets Gata3 Hoxc13, and hair keratins. In summary, this CtBP1 transgenic model provides in vivo evidence for certain CtBP1 functions predicted from in vitro studies, reveals—to our knowledge—previously unreported functions and transcriptional activities of CtBP1 in the context of epithelial–mesenchymal interplay, and suggests that CtBP1 has a pathogenic role in hair follicle morphogenesis and differentiation

Somatomotor-Visual Resting State Functional Connectivity Increases After Two Years in the UK Biobank Longitudinal Cohort

Functional magnetic resonance imaging (fMRI) and functional connectivity (FC) have been used to follow aging in both children and older adults. Robust changes have been observed in children, where high connectivity among all brain regions changes to a more modular structure with maturation. In older adults, prior work has identified changes in connectivity associated with the default mode network (DMN); other work has used brain age to predict pre-clinical Alzheimer's disease. In this work, we find an increasing connectivity between the Somatomotor (SMT) and Visual (VIS) Networks using the Power264 atlas in a longitudinal cohort of the UK Biobank (UKB). This cohort consists of 2,722 subjects, with scans being taken an average of two years apart. The average connectivity increase between SMT-VIS is 6.8% compared to the younger scan baseline (from $\rho=0.39$ to $\rho=0.42$), and occurs in male, female, older subject ($>65$ years old), and younger subject ($<55$ years old) groups. Among all inter-network connections, this average SMT-VIS connectivity is the best predictor of relative scan age, accurately predicting which scan is older 57% of the time. Using the full FC and a training set of 2,000 subjects, one is able to predict which scan is older 82.5% of the time when using the difference of FC between the two scans as input to a classifier. This previously under-reported relationship may shed light on normal changes in aging brain FC, identifies a potential confound for longitudinal studies, and proposes a new area for investigation, specifically the SMT-VIS connectivity.Comment: 12 pages, 10 figures, 3 table

Data Processing Pipeline for Pointing Observations of Lunar-based Ultraviolet Telescope

We describe the data processing pipeline developed to reduce the pointing observation data of Lunar-based Ultraviolet Telescope (LUT), which belongs to the Chang'e-3 mission of the Chinese Lunar Exploration Program. The pointing observation program of LUT is dedicated to monitor variable objects in a near-ultraviolet (245-345 nm) band. LUT works in lunar daytime for sufficient power supply, so some special data processing strategies have been developed for the pipeline. The procedures of the pipeline include stray light removing, astrometry, flat fielding employing superflat technique, source extraction and cosmic rays rejection, aperture and PSF photometry, aperture correction, and catalogues archiving, etc. It has been intensively tested and works smoothly with observation data. The photometric accuracy is typically ~0.02 mag for LUT 10 mag stars (30 s exposure), with errors come from background noises, residuals of stray light removing, and flat fielding related errors. The accuracy degrades to be ~0.2 mag for stars of 13.5 mag which is the 5{\sigma} detection limit of LUT.Comment: 10 pages, 7 figures, 4 tables. Minor changes and some expounding words added. Version accepted for publication in Astrophysics and Space Science (Ap&SS