157 research outputs found

    Photopolymerization with high-order Bessel light beams

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    Funding: Core Research for Evolutional Science and Technology (JPMJCR1903); Japan Society for the Promotion of Science (JP16H06507, JP17K19070, JP18H03884); Engineering and Physical Sciences Research Council (EP/P030017/1).We study photopolymerization with high-order Bessel light beams with phase singularities on-axis. Self-trapping and self-focusing of propagation-invariant light beams in a photopolymer allow the fabrication of extended helical microfibers with a length scale of a centimeter, which is more than an order of magnitude larger than the propagation distance of the Bessel light beams. We show the evolution of microfibers rotating at a rate proportional to the incident optical power, while the periodicity of the helical structures remains constant, irrespective of the laser power. This suggests that optical momentum transfer plays a predominant role in the growth and rotation of such fiber structures.Publisher PDFPeer reviewe

    Twisted mass transport enabled by the angular momentum of light

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    The authors acknowledge support in the form of KAKENHI Grants-in-Aid (Grant Nos. JP 16H06507, JP 17K19070, and JP 18H03884) from the Japan Society for the Promotion of Science (JSPS), Japan Science and Technology Agency (JST) CREST Grant No. (JPMJCR1903), and the U.S. National Science Foundation Award #1809518. KD and YA thank the UK Engineering and Physical Sciences Research Council for funding (through Grant No. EP/P030017/1).Light may carry both orbital angular momentum (AM) and spin AM. The former is a consequence of its helical wavefront, and the latter is a result of its rotating transverse electric field. Intriguingly, the light–matter interaction with such fields shows that the orbital AM of light causes a physical “twist” in a range of materials, including metal, silicon, azopolymer, and even liquid-phase resin. This process may be aided by the light’s spin AM, resulting in the formation of various helical structures. The exchange between the AM of light and matter offers not only unique helical structures at the nanoscale but also entirely novel fundamental phenomena with regard to the light–matter interaction. This will lead to the future development of advanced photonics devices, including metamaterials for highly sensitive detectors as well as reactions for chiral chemical composites. Here, we focus on interactions between the AM of light and azopolymers, which exhibit some of the most diverse structures and phenomena observed. These studies result in helical surface relief structures in azopolymers and will leverage next-generation applications with light fields carrying optical AM.Publisher PDFPeer reviewe

    Regulation of P450 oxidoreductase by gonadotropins in rat ovary and its effect on estrogen production

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    <p>Abstract</p> <p>Background</p> <p>P450 oxidoreductase (POR) catalyzes electron transfer to microsomal P450 enzymes. Its deficiency causes Antley-Bixler syndrome (ABS), and about half the patients with ABS have ambiguous genitalia and/or impaired steroidogenesis. POR mRNA expression is up-regulated when mesenchymal stem cells (MSCs) differentiate into steroidogenic cells, suggesting that the regulation of POR gene expression is important for steroidogenesis. In this context we examined the regulation of POR expression in ovarian granulosa cells by gonadotropins, and its possible role in steroidogenesis.</p> <p>Methods</p> <p>Changes in gene expression in MSCs during differentiation into steroidogenic cells were examined by DNA microarray analysis. Changes in mRNA and protein expression of POR in the rat ovary or in granulosa cells induced by gonadotropin treatment were examined by reverse transcription-polymerase chain reaction and western blotting. Effects of transient expression of wild-type or mutant (R457H or V492E) POR proteins on the production of estrone in COS-7 cells were examined in vitro. Effects of POR knockdown were also examined in estrogen producing cell-line, KGN cells.</p> <p>Results</p> <p>POR mRNA was induced in MSCs following transduction with the SF-1 retrovirus, and was further increased by cAMP treatment. Expression of POR mRNA, as well as Cyp19 mRNA, in the rat ovary were induced by equine chorionic gonadotropin and human chorionic gonadotropin. POR mRNA and protein were also induced by follicle stimulating hormone in primary cultured rat granulosa cells, and the induction pattern was similar to that for aromatase. Transient expression of POR in COS-7 cells, which expressed a constant amount of aromatase protein, greatly increased the rate of conversion of androstenedione to estrone, in a dose-dependent manner. The expression of mutant POR proteins (R457H or V492E), such as those found in ABS patients, had much less effect on aromatase activity than expression of wild-type POR proteins. Knockdown of endogenous POR protein in KGN human granulosa cells led to reduced estrone production, indicating that endogenous POR affected aromatase activity.</p> <p>Conclusion</p> <p>We demonstrated that the expression of POR, together with that of aromatase, was regulated by gonadotropins, and that its induction could up-regulate aromatase activity in the ovary, resulting in a coordinated increase in estrogen production.</p

    上皮成長因子受容体を標的とした結腸直腸腫瘍の分子イメージング : 動物モデルにおける腫瘍の検出と治療評価

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    To overcome the problem of overlooking colorectal tumors, a new and highly sensitive modality of colonoscopy is needed. Moreover, it is also important to establish a new modality to evaluate viable tumor volume in primary lesions of colorectal cancer (CRC) during chemotherapy. Therefore, we carried out molecular imaging of colorectal tumors targeting epidermal growth factor receptor (EGFR), which is highly expressed on tumor cells, for evaluating chemotherapeutic efficacy and for endoscopic detection of colorectal adenomas. We first attempted to image five CRC cell lines with various levels of EGFR expression using an Alexa Fluor‐labeled anti‐EGFR monoclonal antibody (AF‐EGFR‐Ab). A strong fluorescence signal was observed in the cells depending on the level of EGFR expression. When nude mice xenografted with LIM1215 CRC cells, which highly express EGFR, were i.v. injected with AF‐EGFR‐Ab, a strong fluorescence signal appeared in the tumor with a high signal to noise ratio, peaking at 48 hours after injection and then gradually decreasing, as shown using an IVIS Spectrum system. When the xenografted mice were treated with 5‐fluorouracil, fluorescence intensity in the tumor decreased in proportion to the viable tumor cell volume. Moreover, when the colorectum of azoxymethane‐treated rats was observed using a thin fluorescent endoscope with AF‐EGFR‐Ab, all 10 small colorectal adenomas (≤3 mm) were detected with a clear fluorescence signal. These preliminary results of animal experiments suggest that EGFR‐targeted fluorescent molecular imaging may be useful for quantitatively evaluating cell viability in CRC during chemotherapy, and also for detecting small adenomas using a fluorescent endoscope

    Chemo-dynamical evolution of Globular Cluster Systems

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    We studied the relation between the ratio of rotational velocity to velocity dispersion and the metallicity (/\sigma_{v}-metallicity relation) of globular cluster systems (GCS) of disk galaxies by comparing the relation predicted from simple chemo-dynamical models for the formation and evolution of disk galaxies with the observed kinematical and chemical properties of their GCSs. We conclude that proto disk galaxies underwent a slow initial collapse that was followed by a rapid contraction and derive that the ratio of the initial collapse time scale to the active star formation time scale is \sim 6 for our Galaxy and \sim 15 for M31. The fundamental formation process of disk galaxies was simulated based on simple chemo-dynamical models assuming the conservation of their angular momentum. We suggest that there is a typical universal pattern in the /\sigma_{v}-metallicity relation of the GCS of disk galaxies. This picture is supported by the observed properties of GCSs in the Galaxy and in M31. This relation would deviate from the universal pattern, however, if large-scale merging events took major role in chemo-dynamical evolution of galaxies and will reflect the epoch of such merging events. We discuss the properties of the GCS of M81 and suggest the presence of past major merging event.Comment: 25 pages, 8 figures, Accepted for publication in the Astrophysical Journa

    c-KITを標的としたGastrointestinal stromal tumorsに対する近赤外蛍光イメージングとレーザー照射の新しいセラノスティクス

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    It is difficult to distinguish gastrointestinal stromal tumors (GISTs) from other types of submucosal tumors under conventional gastrointestinal endoscopy. We aimed to detect GISTs by molecular fluorescence imaging using a near-infrared (NIR) photosensitizer (IR700)-conjugated anti-c-KIT antibody and to treat GISTs by photoimmunotherapy with NIR irradiation as a non-invasive theranostic procedure. We also investigated the therapeutic mechanisms. Methods: Human GIST cell lines GIST-T1 and GIST-882M were incubated with IR700-conjugated anti-c-KIT antibody, IR700-12A8, and observed by confocal laser microscopy. Mice with GIST-T1 xenografts or rats with orthotopic xenografts were injected with IR700-12A8 or AF488-conjugated antibody, and observed under IVIS or autofluorescence imaging (AFI) endoscopy. GIST cells were treated with IR700-12A8 and NIR light in vitro and vivo, and cell viability, histology and apoptosis were evaluated. Results: Strong red fluorescence of IR700-12A8 was observed on the cell membrane of GIST cells and was gradually internalized into the cytoplasm. Tumor-specific accumulation of IR700-12A8 was observed in GIST-T1 xenografts in mice. Under AFI endoscopy, a strong fluorescence signal was observed in orthotopic GIST xenografts in rats through the normal mucosa covering the tumor. The percentage of dead cells significantly increased in a light-dose-dependent manner and both acute necrotic and late apoptotic cell death was observed with annexin/PI staining. Cleaved PARP expression was significantly increased after IR700-12A8-mediated NIR irradiation, which was almost completely reversed by NaN3. All xenograft tumors (7/7) immediately regressed and 4/7 tumors completely disappeared after IR700-12A8-mediated NIR irradiation. Histologic assessment and TUNEL staining revealed apoptosis in the tumors. Conclusion: NIR fluorescence imaging using IR700-12A8 and subsequent NIR irradiation could be a very effective theranostic technology for GIST, the underlying mechanism of which appears to involve acute necrosis and supposedly late apoptosis induced by singlet oxygen

    Photopolymerization with light fields possessing orbital angular momentum: Generation of helical microfibers

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    Funding: UK Engineering and Physical Sciences Research Council (grant EP/P030017/1).Photopolymerization is a powerful technique to create arbitrary micro-objects with a high spatial resolution. Importantly, to date all photopolymerization studies have been performed with incident light fields with planar wavefronts and have solely exploited the intensity profile of the incident beam. We investigate photopolymerization with light fields possessing orbital angular momentum, characterized by the topological charge . We show both experimentally and theoretically that, as a consequence of nonlinear self-focusing of the optical field, photopolymerization creates an annular-shaped vortex-soliton and an associated optical fiber, which breaks up into solitons or microfibers. These microfibers exhibit helical trajectories with a chirality determined by the sign of due to the orbital angular momentum of the light field and form a bundle of helical-microfibers. This research opens up a new application for light fields with orbital angular momentum, and our generated microfibers may have applications in optical communications and micromanipulation.Publisher PDFPeer reviewe

    A case report of bimaxillary protrusion with Angle Class I usingtemporary anchorage device (TAD)

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    The report describes orthodontic treatment of a 37 years 7 months old female patientwith Angle Class I and bimaxillary protrusion using temporary anchorage device (TAD).The antero–posterior skeletal relationship was skeletal Class II. The upper and lower incisorswere labially inclined and molar relationship was Angle Class I. The treatment objectives were correction of labial inclination of upper and lower incisors with extraction of theupper and lower first bicuspid using TAD. The upper arch wire with molar tip back bend was fixed at the upper second bicuspid from TAD during the retraction of canine and anteriorteeth. As a results of the treatment for 2 years and 10 months, upper and lower anteriorteeth showed lingual bodily movement and mandible rotated counterclockwise with the depress of upper anterior and molar teeth. On the other hand, the upper molar showed moderate anchorage with the mesial movement and depress of upper molar teeth due to tip back bend.In summary, orthodontic treatment using TAD and arch wire with tip back bend at molar make it possible for the lingual bodily movement of anterior teeth and the depression of upper anterior and molar teeth

    病床あたりの循環器内科医数が急性心不全の院内死亡に与える影響

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    Background Little evidence is available about the number of cardiologists required for appropriate treatment of heart failure (HF). Our objective was to determine the association between the number of cardiologists per cardiology beds for treating patients with acute HF and in-hospital mortality. Methods and Results This was a cross-sectional study, and we used the Japanese Registry of All Cardiac and Vascular Diseases Diagnosis Procedure Combination discharge database. The data of patients with HF on emergency admission from April 1, 2012, to March 31, 2014, were extracted. The patients were categorized into 4 groups by the quartiles of the numbers of cardiologists per 50 cardiovascular beds (first group: median, 4.4 [interquartile range, 3.5-5.0]; second group: median, 6.7 [interquartile range, 6.5-7.5]; third group: median, 9.7 [interquartile range, 8.8-10.1]; and fourth group: median, 16.7 [interquartile range, 14.0-23.8]). Using multilevel mixed-effect logistics regression, we determined adjusted odds ratios for in-hospital mortality. We identified 154 290 patients with HF on emergency admissions. There were 29 626, 36 587, 46 451, and 41 626 patients in the first, second, third, and fourth groups, respectively. HF severity, on the basis of New York Heart Association classification, was similar in the 3 groups. Adjusted odds ratios (95% CIs) for in-hospital mortality were 0.92 (0.82-1.04; P=0.20), 0.82 (0.72-0.92; P<0.001), and 0.70 (0.61-0.80; P<0.001) for the second, third, and fourth groups, respectively. The proportion of medication used, including angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, β blockers, and mineralocorticoid receptor antagonists, was positively correlated to the number of cardiologists. Conclusions Patients hospitalized for HF in hospitals with larger numbers of cardiologists per cardiovascular beds had lower 30-day mortality.博士(医学)・甲第776号・令和3年3月15日Copyright © 2019 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial License(https://creativecommons.org/licenses/by-nc/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes
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