1,019 research outputs found
High Efficiency CVD Graphene-lead (Pb) Cooper Pair Splitter
This is the final version of the article. Available from the publisher via the DOI in this record.We demonstrate high efficiency Cooper pair splitting in a graphene-based device. We utilize a true Y-shape design effectively placing the splitting channels closer together: graphene is used as the central superconducting electrode as well as QD output channels, unlike previous designs where a conventional superconductor was used with tunnel barriers to the quantum dots (QD) of a different material. Superconductivity in graphene is induced via the proximity effect, thus resulting in both a large measured superconducting gap meV, and a long coherence length nm. The graphene-graphene, flat, two dimensional, superconductor-QD interface lowers the capacitance of the quantum dots, thus increasing the charging energy (in contrast to previous devices). As a result we measure a visibility of up to 96% and a splitting efficiency of up to 62%. Finally, the devices utilize graphene grown by chemical vapor deposition allowing for a standardized device design with potential for increased complexity.I. V. B. acknowledges the JSPS International Research Fellowship. M. Y. and S. T. acknowledge financial support by Grant-in-Aid for Scientific Research S (No. 26220710) and Grant-in-Aid for Scientific Research A (No. 26247050). M. Y. acknowledges financial support by Grant-in-Aid for Scientific Research on Innovative Areas ”Science of Atomic Layers” and Canon foundation. S. T. acknowledges financial support by MEXT project for Developing Innovation Systems and JST Strategic International Cooperative Program. S. R. and M. F. C. acknowledge financial support from EPSRC (Grant EP/J000396/1, EP/K017160, EP/K010050/1, EP/G036101/1, EP/M002438/1, EP/M001024/1), from the Royal Society Travel Exchange Grants 2012 and 2013 and from the Leverhulme Trust
Janus monolayers of transition metal dichalcogenides.
Structural symmetry-breaking plays a crucial role in determining the electronic band structures of two-dimensional materials. Tremendous efforts have been devoted to breaking the in-plane symmetry of graphene with electric fields on AB-stacked bilayers or stacked van der Waals heterostructures. In contrast, transition metal dichalcogenide monolayers are semiconductors with intrinsic in-plane asymmetry, leading to direct electronic bandgaps, distinctive optical properties and great potential in optoelectronics. Apart from their in-plane inversion asymmetry, an additional degree of freedom allowing spin manipulation can be induced by breaking the out-of-plane mirror symmetry with external electric fields or, as theoretically proposed, with an asymmetric out-of-plane structural configuration. Here, we report a synthetic strategy to grow Janus monolayers of transition metal dichalcogenides breaking the out-of-plane structural symmetry. In particular, based on a MoS2 monolayer, we fully replace the top-layer S with Se atoms. We confirm the Janus structure of MoSSe directly by means of scanning transmission electron microscopy and energy-dependent X-ray photoelectron spectroscopy, and prove the existence of vertical dipoles by second harmonic generation and piezoresponse force microscopy measurements
The predictability of graft thickness for Descemet's stripping automated endothelial keratoplasty using a mechanical microkeratome system
Descemet's stripping automated endothelial keratoplasty (DSAEK) is used for treating corneal endothelial dysfunction, and the postoperative visual acuity outcome depends on the thickness of the graft. We created a simple nomogram using factors affecting the cutting thickness during graft preparation via a mechanical microkeratome system for DSAEK. This retrospective study was conducted from May 2018 through October 2022 and included donor eyes cut by automatic methods. We measured the graft thickness, cutting accuracy, and assessed ten variables with donor/cornea-related factors potentially affecting the cutting thickness. Subsequently, we created a simple nomogram. We analyzed 81 donor tissues, and the donor median age was 76 years. The mean central graft thickness was 122.2 μm, with 62% of the grafts that could be cut within the target central graft thickness range. Comparatively, donor corneas from those with cardiac diseases were cut deeper (P = 0.007). The developed nomogram provided a 83% probability of estimating the post-cutting graft thickness within 25 µm. Our nomogram, which considers cause of death, enables reproducible production of graft of a desired thickness. A detailed analysis of donor tissues, including the cause of donor death and the characteristics from pressurization to cutting, will enable more precise DSAEK graft preparation
The Effects of 3% Diquafosol Sodium Eye Drops on Tear Function and the Ocular Surface of Cu, Zn-Superoxide Dismutase-1 (Sod1) Knockout Mice Treated with Antiglaucoma Eye Medications.
Anti-glaucoma eye drop treatment often induces dry eyes and can lead to poor medication adherence. This study aimed to investigate the effects of 3% diquafosol sodium eye drops on tear function and the ocular surface epithelium in Sod1−/− mice after treatment with anti-glaucoma eye drops. The mice were divided into four groups: group 1, control group; group 2, anti-glaucoma eye drop; group 3, anti-glaucoma eye drops followed by a secretagogue eye drop (3% diquafosol); and group 4, simultaneous anti-glaucoma and secretagogue eye drop. Mice underwent assessments of tear quantity, tear film breakup time, and vital staining score. Mice in groups 3 and 4 showed significantly better tear stability and lower corneal staining scores than mice in group 2 after eye drop instillations (p < 0.05). Mice in group 4 showed significantly better tear stability, lower corneal staining scores, and higher goblet cell densities than those in group 1 after eye drop instillations (p < 0.05). The conjunctival epithelium showed stratification and abundance of Muc5AC-positive goblet cells in group 4, whereas thinning with desquamation was observed with a few goblet cells in group 2. Thus, simultaneous administration of 3% diquafosol sodium eye drops with topical anti-glaucoma drops showed favorable effects on tear stability and the corneal epithelium against the ocular surface toxicity inflicted by the anti-glaucoma eye drops
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