Supercurrent flow between two superconductors with different order parameters, a phenomenon known as the Josephson effect, can be achieved by inserting a non-superconducting material between two superconductors to decouple their wavefunctions. These Josephson junctions have been employed in fields ranging from digital to quantum electronics, yet their functionality is limited by the interface quality and use of non-superconducting material. Here we show that by exfoliating a layered dichalcogenide (NbSe2) superconductor, the van der Waals (vdW) contact between the cleaved surfaces can instead be used to construct a Josephson junction. This is made possible by recent advances in vdW heterostructure technology, with an atomically flat vdW interface free of oxidation and inter-diffusion achieved by eliminating all heat treatment during junction preparation. Here we demonstrate that this artificially created vdW interface provides sufficient decoupling of the wavefunctions of the two NbSe2 crystals, with the vdW Josephson junction exhibiting a high supercurrent transparency.

We have fabricated graphene/graphene oxide/graphene (G/GO/G) junctions by local anodic oxidation lithography using atomic force microscopy (AFM). The conductance of the G/GO/G junction decreased with the bias voltage applied to the AFM cantilever V(tip). For G/GO/G junctions fabricated with large and small |V(tip)|. GO was semi-insulating and semiconducting, respectively. AFM-based LAO lithography can be used to locally oxidize graphene with various oxidation levels and achieve tunability from semiconducting to semi-insulating GO.

These results suggest that autologous platelet-rich plasma can enhance ACL cell viability and function in vitro.

We report magnetotransport measurements in ballistic graphene mesoscopic wires where the charge carrier mean free path is comparable to the wire width W. Magnetoresistance curves show characteristic peak structures where the peak field scales with the ratio of cyclotron radius R(c) and wire width W as W/R(c)=0.9±0.1, due to diffusive boundary scattering. The obtained proportionality constant between R(c) and W differs from that of a classical semiconductor two-dimensional electron system in which W/R(c)=0.55.

SUMMARYIn plant organelles, RNA editing alters specific cytidine residues to uridine in transcripts. Target cytidines are specifically recognized by pentatricopeptide repeat (PPR) proteins of the PLS subfamily, which have additional C-terminal E or E-DYW motifs. Recent in silico analysis proposed a model for site recognition by PLS-subfamily PPR proteins, with a correspondence of one PPR motif to one nucleotide, and with the C-terminal last S motif aligning with the nucleotide at position -4 with respect to the editing site. Here, we present quantitative biochemical data on site recognition by four PLS-subfamily proteins: CRR28 and OTP85 are DYW-class members, whereas CRR21 and OTP80 are E-class members. The minimal RNA segments required for high-affinity binding by these PPR proteins were experimentally determined. The results were generally consistent with the in silico-based model; however, we clarified that several PPR motifs, including the C-terminal L2 and S motifs of CRR21 and OTP80, are dispensable for the RNA binding, suggesting distinct contributions of each PPR motif to site recognition. We also demonstrate that the DYW motif interacts with the target C and its 5 0 proximal region (from À3 to 0), whereas the E motif is not involved in binding.

We investigate the micromechanical exfoliation and van der Waals (vdW) assembly of ferromagnetic layered dichalcogenide Fe 0.25 TaS 2 . The vdW interlayer coupling at the Fe-intercalated plane of Fe 0.25 TaS 2 allows exfoliation of flakes. A vdW junction between the cleaved crystal surfaces is constructed by dry transfer method. We observe tunnel magnetoresistance in the resulting junction under an external magnetic field applied perpendicular to the plane, demonstrating spin-polarized tunneling between the ferromagnetic layered material through the vdW junction.*E-mail: moriyar@iis.u-tokyo.ac.jp; tmachida@iis.u-tokyo.ac.jp 2 Recently, studies on two-dimensional (2D) materials such as graphene, hexagonal boron nitride (h-BN), and transition metal dichalcogenides (TMDs) have received considerable attention [1,2]. These materials exhibit layered structure in the bulk form, and the van der Waals (vdW) force connects each of the layers. Thus, these crystals can easily be exfoliated down to monolayer and used to construct heterostructures of different 2D materials connected by vdW force [3]. Metal, semiconductor, and insulator 2D materials have been studied, and various functional electronics and opto-electronics devices have been demonstrated with these materials [4][5][6][7]. Further, these 2D materials could be potentially applied in the field of spintronics [8]; for example, long-distance spin transport has been demonstrated in graphene/h-BN heterostructures [9], and spin polarized tunneling has been demonstrated through graphene [10] and h-BN [11,12]. In these experiments, the source for the spin-polarized electrons is a ferromagnetic metal fabricated by the evaporation technique; thus, the interface between the ferromagnetic and non-magnetic materials involves chemical bonding. On the other hand, the vdW interface does not require any chemical bonding at the junction, in principle. Therefore, layered ferromagnetic 2D materials could possibly be used for constructing vdW heterostructures with spintronic functions. Moreover, the vdW hetrostructure could provide another degree of freedom that has not been possible in the conventional spintronics device; such as controlling the interlayer twist [13,14] In Fig. 1(c), optical micrographs of the exfoliated flake and their vdW junction are shown. The area of vdW junction is 67.8 µm 2 . The quality of the vdW interface is analyzed using cross-sectional transmission electron microscopy (TEM), as shown in Fig. 1(d). The TEM image revealed the layered structure of each Fe 0.25 TaS 2 flake with a stacking period of 0.61 nm; this period is close to the reported value for the bulk material [18]. The vdW contact between the flakes is clearly visible in the TEM image [ Fig. 1(d)].The TEM reveals that vdW junction displays different TEM contrast from the flake; this behavior is attributed to the presence of a native oxide layer existing at the surface of cleaved Fe 0.25 TaS 2 . The presence of Ta 2 O 5 oxide layer in the topmost layer of the exfoliated Fe 0.25 TaS 2 surface i...

The effect of the inspiratory flow rate during deep inspiration on the regulation of bronchomotor tone was studied in nine normal and 22 asthmatic subjects. Changes in bronchial tone were assessed by respiratory resistance measured by an oscillation method. In normal subjects with bronchoconstriction induced by methacholine a rapid deep inspiration reduced respiratory resistance more than a slow deep inspiration. Asthmatic subjects with spontaneous airway narrowing showed an increase in respiratory resistance after deep inspiration that was greater after rapid than after slow deep inspiration. On the other hand, in asthmatics with methacholine induced bronchoconstriction, bronchodilatation occurred after deep inspiration and this was also greater after rapid than after slow deep inspiration. Lignocaine inhalation attenuated both bronchoconstriction and bronchodilatation induced by both slow and rapid deep inspiration. These results suggest that the effects of deep inspiration are mediated at least in part via receptors in the airways. It is suggested that in asthmatic patients with spontaneous bronchoconstriction irritant receptor activity will be increased in proportion to the speed of inspiration. After methacholine induced bronchoconstriction stretch receptor activity is likely to behave in a similar fashion, leading to an opposite effect. A carbachol induced bronchoconstriction, and they suggested that this might have been due to greater stimulation of stretch receptors at higher flows.The inspiratory flow has not been controlled in previous studies reporting bronchoconstriction induced by deep inspiration.' 2 We therefore examined whether the flow rate during a deep inspiration affects bronchomotor tone in asthmatic patients with drug induced bronchoconstriction and with spontaneous bronchomotor tone. In addition, we examined the effects of rate of deep inspiration in asthmatic and normal subjects after pretreatment with lignocaine, which is known to block both irritant and stretch receptors.8 We also examined whether any bronchoconstrictor effect of the speed of inspiratory flow was related to the degree of airway hypersensitivity as assessed by sensitivity to methacholine. MethodsWe studied nine normal men (mean age

Hexagonal boron nitride (h-BN) crystals grown under ultrahigh pressures and ultrahigh temperatures exhibit a high crystallinity and are used throughout the world as ideal substrates and insulating layers in van der Waals heterostructures. However, in their central region, these crystals have domains which contain a significant density of carbon impurities. In this study, we utilized cathodoluminescence and far-ultraviolet photoluminescence to reveal that the carbon (C)-rich domain can exist even after exfoliation. Then, we studied the carrier transport of graphene in h-BN/ graphene/h-BN van der Waals heterostructures, precisely arranging the graphene to straddle the border of the C-rich domain in h-BN. We found that the carrier mobility of graphene on the C-rich h-BN domain was significantly suppressed. In addition, characteristic bending of the Landau fan diagram was observed on the electron-doped side. These results suggest that the C-rich domain in h-BN forms an impurity level and induces extrinsic carrier scattering into adjacent graphene.