106 research outputs found
Nonreciprocal second harmonic generation in a magnetoelectric material
Nonreciprocal devices that allow the light propagation in only one direction
are indispensable in photonic circuits and emerging quantum technologies.
Contemporary optical isolators and circulators, however, require large size or
strong magnetic fields because of the general weakness of magnetic light-matter
interactions, which hinders their integration into photonic circuits. Aiming at
stronger magneto-optical couplings, a promising approach is to utilize
nonlinear optical processes. Here, we demonstrate nonreciprocal magnetoelectric
second harmonic generation (SHG) in CuB2O4. SHG transmission changes by almost
100% in a magnetic-field reversal of just 10 mT. The observed nonreciprocity
results from an interference between the magnetic-dipole- and
electric-dipole-type SHG. Even though the former is usually notoriously smaller
than the latter, it is found that a resonantly enhanced
magnetic-dipole-transition has a comparable amplitude as non-resonant
electric-dipole-transition, leading to the near-perfect nonreciprocity. This
mechanism could form one of the fundamental bases of nonreciprocity in
multiferroics, which is transferable to a plethora of magnetoelectric systems
to realize future nonreciprocal and nonlinear-optical devices.Comment: 21 pages, 4 figure
The Gateway Reflex, a Novel Neuro‐immune Interaction, is Critical for the Development of Mouse Multiple Sclerosis (MS) Models
The central nervous system (CNS) is an immune‐privileged tissue protected by the brain–blood barrier (BBB), which limits the absorption of substances and cells from blood flow. In the case of inflammatory diseases in the CNS, such as multiple sclerosis (MS), however, autoreactive T cells that attack brain autoantigens, including myelin proteins, circumvent the BBB. Despite the wide distribution of brain autoantigens, demyelination often occurs as discrete foci. This fact suggests that there might be a certain cue that guides autoreactive T cells to particular site(s) in the CNS. In other words, there exists a mechanism that facilitates a site‐specific accumulation of autoreactive T cells in the CNS. Using a murine model of MS, experimental autoimmune encephalomyelitis (EAE), we identified dorsal vessels of the fifth lumbar (L5) spinal cord as the initial entry site of immune cells. The formation of a gateway for immune cells is defined by local neural stimulations. For example, neural stimulation by gravity creates this gateway by increasing the expression of chemokines that attract autoreactive T cells. Regional neural activation by the other stimuli, such as electric pulses or pain sensation, also induces gateway formation, but at different blood vessels via chemokine expression. These neuro‐immune interactions are examples of the gateway reflex and are extensively reviewed in this chapter
Exciton-magnon splitting in van der Waals antiferromagnet MnPS unveiled by second-harmonic generation
Ultrafast and coherent generation of magnons is of great significance for
high-speed antiferromagnetic spintronics. One possible route is by
exciton-magnon pairwise optical excitation. To date, such exciton-magnon
transitions have been studied mostly by linear optical means in a limited
number of conventional three-dimensional antiferromagnets. Here we investigate
this correlated transition in van der Waals antiferromagnet MnPS by using
resonant second-harmonic generation spectroscopy, a nonlinear optical probe
sensitive to the symmetry of electronic and magnetic excitations. Two
exciton-magnon peaks are observed, in line with the exciton-induced splitting
of magnon density of states predicted by a Koster-Slater type theory,
indicating significant exciton-magnon interactions. In addition, a large linear
magnetoelectric effect of excitons is observed. These findings provide renewed
understandings on the correlation effects in two-dimensional magnets with
enhanced quasiparticle scattering cross-sections, and point to potential
coherent control among charge, spin and orbital degrees of freedom in
two-dimensional magnets by optical means
Microfluidic Device for Simple Diagnosis of Plant Growth Condition by Detecting miRNAs from Filtered Plant Extracts
植物の生育状態を野外で早期診断できる装置を開発〜ストレスに応答して生じるmiRNAを葉から検出〜.京都大学プレスリリース. 2024-04-04.Plants are exposed to a variety of environmental stress, and starvation of inorganic phosphorus can be a major constraint in crop production. In plants, in response to phosphate deficiency in soil, miR399, a type of microRNA (miRNA), is up-regulated. By detecting miR399, the early diagnosis of phosphorus deficiency stress in plants can be accomplished. However, general miRNA detection methods require complicated experimental manipulations. Therefore, simple and rapid miRNA detection methods are required for early plant nutritional diagnosis. For the simple detection of miR399, microfluidic technology is suitable for point-of-care applications because of its ability to detect target molecules in small amounts in a short time and with simple manipulation. In this study, we developed a microfluidic device to detect miRNAs from filtered plant extracts for the easy diagnosis of plant growth conditions. To fabricate the microfluidic device, verification of the amine-terminated glass as the basis of the device and the DNA probe immobilization method on the glass was conducted. In this device, the target miRNAs were detected by fluorescence of sandwich hybridization in a microfluidic channel. For plant stress diagnostics using a microfluidic device, we developed a protocol for miRNA detection by validating the sample preparation buffer, filtering, and signal amplification. Using this system, endogenous sly-miR399 in tomatoes, which is expressed in response to phosphorus deficiency, was detected before the appearance of stress symptoms. This early diagnosis system of plant growth conditions has a potential to improve food production and sustainability through cultivation management
Association of schizophrenia onset age and white matter integrity with treatment effect of D-cycloserine : a randomized placebo-controlled double-blind crossover study
Background: It has been reported that drugs which promote the N-Methyl-D-aspartate-type glutamate receptor function by stimulating the glycine modulatory site in the receptor improve negative symptoms and cognitive dysfunction in schizophrenia patients being treated with antipsychotic drugs.
Methods: We performed a placebo-controlled double-blind crossover study involving 41 schizophrenia patients in which D-cycloserine 50 mg/day was added-on, and the influence of the onset age and association with white matter integrity on MR diffusion tensor imaging were investigated for the first time. The patients were evaluated using the Positive and Negative Syndrome Scale (PANSS), Scale for the Assessment of Negative Symptoms (SANS), Brief Assessment of Cognition in Schizophrenia (BACS), and other scales.
Results: D-cycloserine did not improve positive or negative symptoms or cognitive dysfunction in schizophrenia. The investigation in consideration of the onset age suggests that D-cycloserine may aggravate negative symptoms of early-onset schizophrenia. The better treatment effect of D-cycloserine on BACS was observed when the white matter integrity of the sagittal stratum/ cingulum/fornix stria terminalis/genu of corpus callosum/external capsule was higher, and the better treatment effect on PANSS general psychopathology (PANSS-G) was observed when the white matter integrity of the splenium of corpus callosum was higher. In contrast, the better treatment effect of D-cycloserine on PANSS-G and SANS-IV were observed when the white matter integrity of the posterior thalamic radiation (left) was lower.
Conclusion: It was suggested that response to D-cycloserine is influenced by the onset age and white matter integrity
Successful treatment of chronic lupus myocarditis with prednisolone and mizoribine
A 36-year-old female patient who was diagnosed with chronic myocarditis as an initial manifestation of systemic lupus erythematosus (SLE) was admitted to our hospital. At her third occurrence of heart failure, we performed an endomyocardial biopsy and proved chronic myocarditis with SLE. Subsequently, she was treated with prednisolone and the immunosuppressive agent mizoribine (MZR), and her cardiac function improved. We describe for the first time treatment with MZR for chronic cardiac involvement of SLE
Mild Acute Graft-Versus-Host Disease Improves Outcomes After HLA-Haploidentical-Related Donor Transplantation Using Posttransplant Cyclophosphamide and Cord Blood Transplantation
Haploidentical-related donor transplantation using posttransplant cyclophosphamide (PTCy-haplo) and cord blood transplantation (CBT) are valid alternatives for patients with hematological malignancies when HLA-matched donor transplantation (MDT) is unavailable. However, the effects of graft-versus-host disease (GVHD) on outcomes after these transplants have not been fully elucidated. Therefore, we evaluated the effects of acute and chronic GVHD on transplant outcomes after PTCy-haplo transplants and compared them with CBT and MDT. We included a total of 914 adult patients with hematological malignancies in the Kyoto Stem Cell Transplantation Group registry who received PTCy-haplo (N = 120), CBT (N = 402), and MDT (N = 392), and achieved neutrophil engraftment. A multivariate analysis revealed that grade I-II acute GVHD improved of overall survival (OS) after PTCy-haplo [hazard ratio (HR) = 0.39, P = 0.018] and CBT (HR = 0.48, P < 0.001), but not after MDT (HR = 0.80, P = 0.267) compared with patients without acute GVHD. Grade I-II acute GVHD had a trend toward reducing the risk of nonrelapse mortality (NRM) after PTCy-haplo (HR = 0.13, P = 0.060) and this positive effect was significant after CBT (HR = 0.39, P = 0.003). A negative impact of grade III-IV acute GVHD on NRM was observed after CBT and MDT, but not after PTCy-haplo. Limited chronic GVHD had a positive impact on OS after CBT and MDT, but not after PTCy-haplo. In conclusion, mild acute GVHD improved outcomes after PTCy-haplo and CBT, and limited chronic GVHD improved outcomes after CBT and MDT. These data indicated that the effects of GVHD on transplant outcomes depended on transplant platforms
Distinguishing the cerebrospinal fluid cytokine profile in neuropsychiatric systemic lupus erythematosus from other autoimmune neurological diseases
Neuropsychiatric systemic lupus erythematosus (NPSLE) is a serious complication in SLE. Although the mechanism of NPSLE remains unclear, cytokines and chemokines are considered to be involved in their pathogenesis. Here we used Bio-Plex Pro assays to examine 27 types of cytokines and chemokines in the cerebrospinal fluid (CSF) of 32 NPSLE patients. We used the CSF of 20 patients with multiple sclerosis (MS) and 22 patients with neuromyelitis optica (NMO) as a disease control group. Fourteen of 27 cytokines/chemokines were significantly higher in the NPSLE patients compared to the MS/NMO patients. We could identify six "minimum predictive markers" by using a weighted-voting algorithm that could distinguish NPSLE from MS and NMO: interleukin (IL)-17, IL-2, interferon (IFN)-γ, IL-5, basic fibroblast growth factor (FGF)-basic and IL-15. The determination of various types of CSF cytokine profiles may contribute to the diagnosis of NPSLE and may help elucidate the mechanisms underlying this disease
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