22 research outputs found

    Imprinting spatial helicity structure of vector vortex beam on spin texture in semiconductors

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    We present the transfer of the spatially variant polarization of topologically structured light to the spatial spin texture in a semiconductor quantum well. The electron spin texture, which is a circular pattern with repeating spin-up and spin-down states whose repetition rate is determined by the topological charge, is directly excited by a vector vortex beam with a spatial helicity structure. The generated spin texture efficiently evolves into a helical spin wave pattern owing to the spin-orbit effective magnetic fields in the persistent spin helix state by controlling the spatial wave number of the excited spin mode. By tuning the repetition length and azimuthal angle, we simultaneously generate helical spin waves with opposite phases by a single beam.Comment: 6 pages, 4 figure

    Nanosecond pump-probe device for time-resolved serial femtosecond crystallography developed at SACLA

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    X-ray free-electron lasers (XFELs) have opened new opportunities for timeresolved X-ray crystallography. Here a nanosecond optical-pump XFEL-probe device developed for time-resolved serial femtosecond crystallography (TRSFX) studies of photo-induced reactions in proteins at the SPring-8 Angstrom Compact free-electron LAser (SACLA) is reported. The optical-fiber-based system is a good choice for a quick setup in a limited beam time and allows pump illumination from two directions to achieve high excitation efficiency of protein microcrystals. Two types of injectors are used: one for extruding highly viscous samples such as lipidic cubic phase (LCP) and the other for pulsed liquid droplets. Under standard sample flow conditions from the viscous-sample injector, delay times from nanoseconds to tens of milliseconds are accessible, typical time scales required to study large protein conformational changes. A first demonstration of a TR-SFX experiment on bacteriorhodopsin in bicelle using a setup with a droplet-type injector is also presented.112Ysciescopu

    Effect of anionic surfactant on dispersibility and luminescence of SiC nanotubes

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    We investigated the relationship between the dispersibility and optical properties of silicon carbide nanotubes (SiCNTs). By dissolving the aggregation of SiCNTs using sodium cholate as an anionic surfactant, the cluster size decreased and the dispersibility improved with the increasing surfactant concentration. The macroscopic and microscopic photoluminescence properties were evaluated using excitation lights with variable spot size. The emission intensity of SiCNTs increased with the decreasing cluster size, owing to the improvement of the dispersibility, and the emission intensity of the well-dispersed SiCNTs increased superlinearly with the excitation density. These results indicate the presence of SiCNTs that recombine non-radiatively in the cluster, and the effect of their NTs is suppressed as the cluster size is reduced

    Point-of-care molecular diagnosis of Mycoplasma pneumoniae including macrolide sensitivity using quenching probe polymerase chain reaction

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    Objectives Macrolides are generally considered to be the drugs of choice for treatment of patients with Mycoplasma pneumoniae infection. However, macrolide-resistant M. pneumoniae has been emerging since about 2000. The Smart Gene system (MIZUHO MEDY Co., Ltd., Tosu, Japan) is a novel fully automated system for detection of pathogens using the method of quantitative polymerase chain reaction (qPCR) with QProbe (QProbe PCR). The entire procedure is completed within 50 min and the size of the instrument is small (15 x 34 x 30 cm). The purpose of this study was to evaluate the usefulness of the Smart Gene system for detection of M. pneumoniae and detection of a point mutation at domain V of the 23S rRNA gene of M. pneumoniae. Materials Pharyngeal swab samples were collected from 154 patients who were suspected of having respiratory tract infections associated with M. pneumoniae. Results Compared with the results of qPCR, the sensitivity and specificity of the Smart Gene system were 98.7% (78/79) and 100.0% (75/75), respectively. A point mutation at domain V of the 23S rRNA gene was detected from 7 (9.0%) of 78 M. pneumoniae-positive samples by the Smart Gene system and these results were confirmed by direct sequencing. The minimum inhibitory concentrations of clarithromycin among the 5 isolates of M. pneumoniae with a point mutation at domain V of the 23S rRNA gene were >64 mu g/ml and those among the 33 isolates without a mutation in the 23S rRNA gene were Conclusion The Smart Gene system is a rapid and accurate assay for detection of the existence of M. pneumoniae and a point mutation at domain V of the 23S rRNA gene of M. pneumoniae at the same time. The Smart Gene system is suitable for point-of-care testing in both hospital and outpatient settings

    Nanosecond pump-probe device for time-resolved serial femtosecond crystallography developed at SACLA

    Get PDF
    X-ray free-electron lasers (XFELs) have opened new opportunities for timeresolved X-ray crystallography. Here a nanosecond optical-pump XFEL-probe device developed for time-resolved serial femtosecond crystallography (TRSFX) studies of photo-induced reactions in proteins at the SPring-8 Angstrom Compact free-electron LAser (SACLA) is reported. The optical-fiber-based system is a good choice for a quick setup in a limited beam time and allows pump illumination from two directions to achieve high excitation efficiency of protein microcrystals. Two types of injectors are used: one for extruding highly viscous samples such as lipidic cubic phase (LCP) and the other for pulsed liquid droplets. Under standard sample flow conditions from the viscous-sample injector, delay times from nanoseconds to tens of milliseconds are accessible, typical time scales required to study large protein conformational changes. A first demonstration of a TR-SFX experiment on bacteriorhodopsin in bicelle using a setup with a droplet-type injector is also presented

    Anatomical Transcriptome of G Protein-Coupled Receptors Leads to the Identification of a Novel Therapeutic Candidate GPR52 for Psychiatric Disorders

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    <div><p>Many drugs of abuse and most neuropharmacological agents regulate G protein-coupled receptors (GPCRs) in the central nervous system (CNS)_ENREF_1. The striatum, in which dopamine D1 and D2 receptors are enriched, is strongly innervated by the ventral tegmental area (VTA), which is the origin of dopaminergic cell bodies of the mesocorticolimbic dopamine system_ENREF_3 and plays a central role in the development of psychiatric disorders_ENREF_4. Here we report the comprehensive and anatomical transcript profiling of 322 non-odorant GPCRs in mouse tissue by quantitative real-time PCR (qPCR), leading to the identification of neurotherapeutic receptors exclusively expressed in the CNS, especially in the striatum. Among them, GPR6, GPR52, and GPR88, known as orphan GPCRs, were shown to co-localize either with a D2 receptor alone or with both D1 and D2 receptors in neurons of the basal ganglia. Intriguingly, we found that GPR52 was well conserved among vertebrates, is Gs-coupled and responsive to the antipsychotic drug, reserpine. We used three types of transgenic (Tg) mice employing a <i>Cre-lox</i> system under the control of the GPR52 promoter, namely, GPR52-LacZ Tg, human GPR52 (hGPR52) Tg, and hGPR52-GFP Tg mice. Detailed histological investigation suggests that GPR52 may modulate dopaminergic and glutamatergic transmission in neuronal circuits responsible for cognitive function and emotion. In support of our prediction, GPR52 knockout and transgenic mice exhibited psychosis-related and antipsychotic-like behaviors, respectively. Therefore, we propose that GPR52 has the potential of being a therapeutic psychiatric receptor. This approach may help identify potential therapeutic targets for CNS diseases.</p></div

    Anatomically comprehensive profiling of mouse GPCR mRNA expression reveals the CNS specific clusters.

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    <p><b>A,</b> Six CNS specific clusters were highlighted by red square. <b>B,</b> Cluster 4, 11, and 12 indicated by red numbers in (<b>A</b>) were enlarged. Red and Green indicates orphan GPCRs of our interest and adhesion GPCRs, respectively. <b>C,</b> Pie charts of the numbers of orphan and ligand-known GPCRs in all and six CNS specific clusters.</p
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