876 research outputs found

    Spin Oscillations in Antiferromagnetic NiO Triggered by Circularly Polarized Light

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    Coherent spin oscillations were non-thermally induced by circularly polarized pulses in fully compensated antiferromagnetic NiO. This effect is attributed to an entirely new mechanism of the action, on the spins, of the effective magnetic field generated by an inverse Faraday effect. The novelty of this mechanism is that spin oscillations are driven by the time derivative of the effective magnetic field acting even on "pure" antiferromagnets with zero net magnetic moment in the ground state. The measured frequencies (1.07 THz and 140 GHz) of the spin oscillations correspond to the out-of-plane and in-plane modes of antiferromagnetic magnons.Comment: 4 pages, 2 figures. Submitted to Physical Review Letter

    Immunoregulatory effects triggered by immunobiotic Lactobacillus jensenii TL2937 strain involve efficient phagocytosis in porcine antigen presenting cells

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    Background: Immunobiotic Lactobacillus jensenii TL2937 modulates porcine mononuclear phagocytes from Peyer?s patches (PPMPs) and induces a differential production of pro- and anti-inflammatory cytokines in response to Toll-like receptor (TLR)-4 activation. Objective: In view of the important role played by phagocytosis in the activation of antigen presenting cells (APCs), the aim of the present work was to examine the interaction of TL2937 with porcine PPMPs focusing on phagocytosis. In addition, this study aimed to investigate whether the effects of L. jensenii TL2937 in porcine blood monocyte-derived dendritic cells (MoDCs) are similar to those found in PPMPs considering that MoDCs do not recapitulate all functions of mucosal APCs. Results: studies showed a high ability of porcine CD172a+ PPMPs to phagocytose L. jensenii TL2937. Interestingly, our results also revealed a reduced capacity of the non-immunomodulatory L. plantarum TL2766 to be phagocytosed by those immune cells. Phagocytosis of L. jensenii TL2937 by porcine PPMPs was partially dependent on TLR2. In addition, we demonstrated that TL2937 strain was able to improve the expression of IL-1, IL-12 and IL-10 in immature MoDCs resembling the effect of this immunobiotic bacterium on PPMPs. Moreover, similarly to PPMPs those immunomodulatory effects were related to the higher capacity of TL2937 to be phagocytosed by immature MoDCs. Conclusions: Microbial recognition in APCs could be effectively mediated through ligand-receptor interactions that then mediate phagocytosis and signaling. For the immunobiotic strain TL2937, TLR2 has a partial role for its interaction with porcine APCs and it is necessary to investigate the role of other receptors. A challenge for future research will be advance in the full understanding of the molecular interactions of immunobiotic L. jensenii TL2937 with porcine APCs that will be crucial for the successful development of functional feeds for the porcine host. This study is a step in that direction.Fil: Tsukida, Kohichiro. Tohoku University; JapónFil: Takahashi, Takuya. Tohoku University; JapónFil: Iida, Hikaru. Tohoku University; JapónFil: Kanmani, Paulraj. Tohoku University; JapónFil: Suda, Yoshihito. Miyagi University; JapónFil: Nochi, Tomonori. Tohoku University; JapónFil: Ohwada, Shuichi. Tohoku University; JapónFil: Aso, Hisashi. Tohoku University; JapónFil: Ohkawara, Sou. Meiji Seika Pharma Co., Ltd. Agricultural & Veterinary Division; JapónFil: Makino, Seiya. Meiji Co., Ltd. Division of Research and Development; JapónFil: Kano, Hiroshi. Meiji Co., Ltd. Division of Research and Development; JapónFil: Saito, Tadao. Tohoku University; JapónFil: Villena, Julio Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Kitazawa, Haruki. Tohoku University; Japó

    Current Status and Future of Reconstructive Surgery: Development of Novel and Artificial Flaps

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    Recent advances in reconstructive surgery, such as microvascular free flap transfer, have contributed to the development of other surgical specialties to achieve improved performance of surgery. Although microvascular free flap transfer is one of the most frequently used methods, it has several limitations and shortcomings, such as donor-site morbidity and insufficient flap function. We refined conventional methods of free flap transfer and developed various types of novel flaps to overcome these shortcomings. However, although many technical refinements are being developed, the restoration of complex organs to their original status remains difficult. We believe that there are two solutions for reconstruction of complex organs: 1) vascularized composite allotransplantation and 2) artificial flaps using regenerative medicine. In this article, we aimed to present the current status of reconstructive surgery and discuss its future.journal articl

    Spectral dependence of photoinduced spin precession in DyFeO3

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    Spin precession was nonthermally induced by an ultrashort laser pulse in orthoferrite DyFeO3 with a pump-probe technique. Both circularly and linearly polarized pulses led to spin precessions; these phenomena are interpreted as the inverse Faraday effect and the inverse Cotton-Mouton effect, respectively. For both cases, the same mode of spin precession was excited; the precession frequencies and polarization were the same, but the phases of oscillations were different. We have shown theoretically and experimentally that the analysis of phases can distinguish between these two mechanisms. We have demonstrated experimentally that in the visible region, the inverse Faraday effect was dominant, whereas the inverse Cotton-Mouton effect became relatively prominent in the near-infrared region.Comment: 27 pages, 8 figure

    Ca2+-permeable mechanosensitive channels MCA1 and MCA2 mediate cold-induced cytosolic Ca2+ increase and cold tolerance in Arabidopsis

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    Cold shock triggers an immediate rise in the cytosolic free calcium concentration ([Ca2+]cyt) in Arabidopsis thaliana and this cold-induced elevation of [Ca2+]cyt is inhibited by lanthanum or EGTA. It is suggested that intracellular calcium mainly contributes to the cold-induced [Ca2+]cyt response by entering into the cytosol. Two calcium-permeable mechanosensitive channels, MCA1 and MCA2 (mid1-complementing activity), have been identified in Arabidopsis. Here, we demonstrate that MCA1 and MCA2 are involved in a cold-induced increase in [Ca2+]cyt. The cold-induced [Ca2+]cyt increase in mca1 and mca2 mutants was markedly lower than that in wild types. The mca1 mca2 double mutant exhibited chilling and freezing sensitivity, compared to wild-type plants. Expression of At5g61820, At3g51660, and At4g15490, which are not regulated by the CBF/DREB1s transcription factor, was down-regulated in mca1 mca2. These results suggest that MCA1 and MCA2 are involved in the cold-induced elevation of [Ca2+]cyt, cold tolerance, and CBF/DREB1-independent cold signaling

    Generalizing the Tomboulis-Yaffe Inequality to SU(N) Lattice Gauge Theories and General Classical Spin Systems

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    We extend the inequality of Tomboulis and Yaffe in SU(2) lattice gauge theory (LGT) to SU(N) LGT and to general classical spin systems, by use of reflection positivity. Basically the inequalities guarantee that a system in a box that is sufficiently insensitive to boundary conditions has a non-zero mass gap. We explicitly illustrate the theorem in some solvable models. Strong coupling expansion is then utilized to discuss some aspects of the theorem. Finally a conjecture for exact expression to the off-axis mass gap of the triangular Ising model is presented. The validity of the conjecture is tested in multiple ways.Comment: 37 pages, 17 figures. v2: comment on an earlier work included after conclusion, figure 2 corrected. v3: the latter half revised significantly with new results and new discussions, the version to appear in Ann. Phys

    Machine-learning approach for operating electron beam at KEK e/e+e^-/e^+ injector Linac

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    In current accelerators, numerous parameters and monitored values are to be adjusted and evaluated, respectively. In addition, fine adjustments are required to achieve the target performance. Therefore, the conventional accelerator-operation method, in which experts manually adjust the parameters, is reaching its limits. We are currently investigating the use of machine learning for accelerator tuning as an alternative to expert-based tuning. In recent years, machine-learning algorithms have progressed significantly in terms of speed, sensitivity, and application range. In addition, various libraries are available from different vendors and are relatively easy to use. Herein, we report the results of electron-beam tuning experiments using Bayesian optimization, a tree-structured Parzen estimator, and a covariance matrix-adaptation evolution strategy. Beam-tuning experiments are performed at the KEK ee^-/e+e^+ injector Linac to maximize the electron-beam charge and reduce the energy-dispersion function. In each case, the performance achieved is comparable to that of a skilled expert

    Cutting edge of endoscopic ultrasound-guided fine-needle aspiration for solid pancreatic lesions

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    This article provides an extensive review of the advancements and future perspectives related to endoscopic ultrasound-guided tissue acquisition (EUS-TA) for the diagnosis of solid pancreatic lesions (SPLs). EUS-TA, including fine-needle aspiration (EUS-FNA) and fine-needle biopsy (EUS-FNB), has revolutionized the collection of specimens from intra-abdominal organs, including the pancreas. Improvements in the design of needles, collection methods, and specimen processing techniques have improved the diagnostic performance. This review highlights the latest findings regarding needle evolution, actuation number, sampling methods, specimen evaluation techniques, application of artificial intelligence (AI) for diagnostic purposes, and use of comprehensive genomic profiling (CGP). It acknowledges the rising use of Franseen and fork-tip needles for EUS-FNB and emphasizes that the optimal number of actuations requires further study. Methods such as the door-knocking and fanning techniques have shown promise for increasing diagnostic performance. Macroscopic on-site evaluation (MOSE) is presented as a practical rapid specimen evaluation method, and the integration of AI is identified as a potentially impactful development. The study also underscores the importance of optimal sampling for CGP, which can enhance the precision of cancer treatment. Ongoing research and technological innovations will further improve the accuracy and efficacy of EUS-TA.Online Published: 01 November 2023journal articl

    Driving Micro-Objects Using Optical Force due to Fluorescence Emission From Molecules

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    Ito S., Nanno T., Kaji T., et al. Driving Micro-Objects Using Optical Force due to Fluorescence Emission From Molecules. Advanced Optical Materials (2025); https://doi.org/10.1002/adom.202403546.Emission of fluorescence in a specific direction generates an optical force in the opposite direction of the emission by the momentum conservation raw. This “emission force” can induce the directional transportation of small objects anisotropically emitting fluorescence from molecules in the objects only by photo-irradiation without any spatio-temporal control of light field. To demonstrate the movement by the emission force, we fabricated dye-doped cylinder-shaped polymer micro-objects (PMOs) with gold thin films on their top surfaces. The single PMOs in water on a glass substrate, the side surfaces of which were facing to the substrate, were photoexcited with a continuous wave visible (532 nm) laser. The dyes in a PMO emitted strong fluorescence toward the non-coated end (bottom) of the micro-cylinder due to the reflection by the gold thin film on the top. The individual motions of the PMOs under photoexcitation are detected with fluorescence microscopy. Analysis of the trajectories of the PMOs confirmed that the anisotropic fluorescence emission led to the transportation of the PMOs in the opposite direction of the fluorescence. The emission force acting on the PMO is quantitatively evaluated through computational simulation considering the emission force and Brownian motion
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