Gigantic enhancement of spin Seebeck effect by phonon drag

We investigate both theoretically and experimentally a gigantic enhancement of the spin Seebeck effect in a prototypical magnet LaY$_2$Fe$_5$O$_{12}$ at low temperatures. Our theoretical analysis sheds light on the important role of phonons; the spin Seebeck effect is enormously enhanced by nonequilibrium phonons that drag the low-lying spin excitations. We further argue that this scenario gives a clue to understand the observation of the spin Seebeck effect that is unaccompanied by a global spin current, and predict that the substrate condition affects the observed signal.Comment: 5 pages, 4 figure

Fingerprinting spin liquids using spin noise spectroscopy

Spin liquids, not showing a spontaneous-symmetry-breaking order down to low temperatures, serve as a platform for unconventional spin-correlated phenomena beyond the Landau paradigm. Numerous varieties of classical and quantum spin liquids (QSL) motivate the experimental identification of different spin liquid states. However, the lack of an unambiguous signature makes the identification attempts often unsuccessful. A new experimental approach is clearly needed, and an emerging concept is to use spin noise as fingerprints of spin liquid states. In this thesis, I perform spin noise spectroscopy on spin liquid compounds whose specific states have not been established. Chapter 1 presents an introduction to different classes of spin liquid states and the difficulty in their identification, motivating a new experimental approach. Chapter 2 explains the principle of spin noise spectroscopy, together with more conventional AC susceptometry. I also introduce a spin noise spectrometer that employs a Superconducting QUantum Interference Device (SQUID). In Chapter 3, I present the SQUID spin noise spectrometers that I designed and assembled during my DPhil. They have an extreme sensitivity approaching 10⁻¹⁴ T/√Hz, broad bandwidth of DC to 100 kHz, and a temperature range of 10 mK to 6000 mK. I utilize them to study QSL candidate compounds with controversial spin liquid states. Chapter 4 presents the spin noise study of Ca₁₀Cr₇O₂₈, which has been hypothesized to be either a QSL or a spiral spin liquid (SSL). Powerful spin noise spanning a frequency range from 0.1 Hz to 50 kHz is discovered in Ca₁₀Cr₇O₂₈, and its overall correspondence with the prediction of SSL noise simulation evidences Ca₁₀Cr₇O₂₈ as an SSL. Lastly, Chapter 5 presents the spin noise study of ZnCu₃(OH)₆Cl₂, an iconic QSL candidate with a spin-1/2 kagome lattice. Spins substituted in the interlayer are discovered to generate powerful spin noise spanning from 0.1 Hz to 100 Hz and to undergo a sharp transition at 260 mK. The experimental observations are consistent with spinon-mediated interactions between the interlayer spins, via the spinon spectrum in a quantum spin liquid state within the kagome layer

Linear-response theory of spin Seebeck effect in ferromagnetic insulators

We formulate a linear response theory of the spin Seebeck effect, i.e., a spin voltage generation from heat current flowing in a ferromagnet. Our approach focuses on the collective magnetic excitation of spins, i.e., magnons. We show that the linear-response formulation provides us with a qualitative as well as quantitative understanding of the spin Seebeck effect observed in a prototypical magnet, yttrium iron garnet.Comment: 6 pages, 3 figures. Added references and revised argument on the length scales at the end of Sec.

Improvement of P Recovery Rate in an Uncultivated Non-Allophanic Andisol Using Fermented Chicken Manure Pellets and P Foraging Root Growth of Japanese Radish

Poster Sessio

Recent thirty-year trends in the frequency of summertime localized intense rainfall in and around the Tokyo Metropolis

This study analyzed the interannual trends in localized heavy rainfall (LHR) frequency using data from 228 rainfall stations from 1991 to 2020. After categorizing the LHR and widespread heavy rainfall (WHR), the target area was divided into six regions using a cluster analysis of the LHR frequency at each station over 30 years. A significant increase in LHR was observed from the northern Tama Region to the southern Saitama Prefecture (Cluster 1a) and from the southern Tama Region to the northern Kanagawa Prefecture (Cluster 1b) at the 5% significance level. Furthermore, because a discontinuous increase in the frequency of LHR was detected around 2005, the analysis was divided into two periods: 1991–2004 and 2005–2020. Changes in the frequency distribution of LHR in both periods were determined and compared with those of WHR. In the areas corresponding to Cluster 1a and Cluster 1b, the frequency of LHR increased significantly in the later period, whereas the frequency of WHR decreased in the Tama Region and eastern foothills of the Kanto Mountains.departmental bulletin pape

Effectiveness of abatacept for patients with Sjögren’s syndrome associated with rheumatoid arthritis. An open label, multicenter, one-year, prospective study: ROSE (Rheumatoid Arthritis with Orencia Trial toward Sjögren’s syndrome Endocrinopathy) trial

Objective: To clarify the efficacy and safety of abatacept for secondary Sjögren’s syndrome (SS) associated with rheumatoid arthritis (RA).Methods: The primary endpoint of this open-labeled, prospective, observational multicenter study for secondary SS with RA was the remission rate of Simplified Disease Activity Index (SDAI) at 52 weeks after initiation of abatacept. The secondary endpoints included Saxon’s test and Schirmer’s test. Adverse events and adherence rate during the study period were also analyzed.Results: Thirty-six patients (all females) were enrolled in this study. The mean SDAI decreased significantly from 20.6 ± 11.2 (±SD) at baseline to 10.0 ± 10.5 at 52 weeks (p < 0.05). Patients with SDAI remission increased from 0 (0 week) to 12 patients (33.3%) at 52 weeks. Saliva volume assessed by Saxon’s test increased significantly from 2136 ± 1809 (0 week) to 2397 ± 1878 (24 weeks) mg/2 min (n = 34, p < 0.05). Saliva volume increased significantly from 2945 ± 2090 (0 week) to 3419 ± 2121 (24 weeks) mg/2 min in 11 patients with Greenspan grade 1 or 2 of labial salivary gland biopsy (p < 0.05), but no change was noted in 18 patients with Greenspan grade 3 or 4. Tear volume by Schirmer’s test increased significantly from 4.2 ± 4.8 (0 week) to 6.4 ± 7.8 (24 weeks) mm/5 min (n = 30, p < 0.05). The adherence rate to abatacept was 80.6% (29/36) over the 52-week period. Twelve adverse events occurred in 10 of the 36 patients, and 7 of these events were infections.Conclusion: Abatacept seems to be effective for both RA and SS related manifestations

Intracellular stability of 2′-OMe-4′-thioribonucleoside modified siRNA leads to long-term RNAi effect

Chemically modified siRNAs are expected to have resistance toward nuclease degradation and good thermal stability in duplex formation for in vivo applications. We have recently found that 2′-OMe-4′-thioRNA, a hybrid chemical modification based on 2′-OMeRNA and 4′-thioRNA, has high hybridization affinity for complementary RNA and significant resistance toward degradation in human plasma. These results prompted us to develop chemically modified siRNAs using 2′-OMe-4′-thioribonucleosides for therapeutic application. Effective modification patterns were screened with a luciferase reporter assay. The best modification pattern of siRNA, which conferred duration of the gene-silencing effect without loss of RNAi activity, was identified. Quantification of the remaining siRNA in HeLa-luc cells using a Heat-in-Triton (HIT) qRT–PCR revealed that the intracellular stability of the siRNA modified with 2′-OMe-4′-thioribonucleosides contributed significantly to the duration of its RNAi activity

Frequency Distribution of Intense Rainfall in the Wards of Tokyo and Its Relationship with the Spatial Structure of Building Heights

This study presents the minute spatial structure of both the frequency of intense rainfall (data from the 1991 to 2002, except 1993, were used) and recent trends (15-25 years until 2002) in the special wards of the Tokyo Metropolis in summer (June to September), on the basis of hourly rainfall data from a dense rain-gauge network. As this is the first step in elucidating the relationship between the distribution of the frequency of intense rainfall and that of surface roughness in metropolitan Tokyo, the averaged number of building stories within a certain area, which is referred to as the smoothed building height (SBH), was assumed to be an alternative parameter when deciding surface roughness. The distribution of the ascending rate of SBH (hereafter, the ascending rate of SBH is referred to as ARS) for wind direction was calculated by varying the averaging area for SBH, in order to compare it to the distribution of intense rainfall frequency. The results are summarized as follows. The high-frequency areas of intense rainfall appear in the western to northern parts of the area comprising the wards and along the boundary between the Tokyo Metropolis and SaitamaPrefecture. The frequency of intense rainfall in these areas is two to three times as high as that in the eastern part of the area comprising the wards. Moreover, the maximum areas of intense rainfall frequency are localized in the western, northern to northwestern, and southern part of the area comprising the wards, corresponding to wind direction. These areas are situated 3-5 km from the leeward side of the area, where the ARS derived from the SBH at a 1-2 km scale islarge, that is, the vicinities of Shinjuku (SNJ), Ikebukuro (1KB), and Shibuya (SBY). Accordingly, we suggest that the large surface roughness due to high-rise buildings in the western part of the area comprising the wards has the effect of increasing the frequency of intense rainfall. The increasing trend of intense rainfall is clear in the western part of the area comprising the wards, whereas a decreasing trend, although not statistically significant, is seen in the eastern part of the area comprising the wards. It is noted that observational stations with large increasing trends of intense rainfall, such as Nakano (NKN) and Shinagawa (SNG), are located 3-5 km from the leeward side of SNJ and on the shore of Tokyo Bay in the southern part of the area comprising the wards, respectively, where the ARS for easterly winds derived from the SBH at a 1-2 km scale is large

Factors in glucocorticoid regimens associated with treatment response and relapses of IgG4-related disease: a multicentre study

Glucocorticoids (GC) are effective for treating IgG4-related disease (IgG4-RD); however, relapse is often observed. We conducted a retrospective multicentre study to investigate risk factors in GC regimens associated with relapses of IgG4-RD. Data on 166 patients with definitive IgG4-RD diagnosis were collected from 12 institutions. Comprehensive surveillance of clinical backgrounds and GC regimens as well as multivariate analysis of factors associated with treatment responses and relapses was performed. To determine the initial maximal GC dose, the patients were stratified into three groups depending on the initial prednisolone (PSL) dosage: 0.7 mg/kg/day. The multivariate analysis extracted the disease duration and reduction speed of initial GC dose. Patients treated with initial GC 0.7 mg/kg/day of PSL showed higher relapse rates than those treated with 0.4–0.69 mg/kg/day. The relapse rates were significantly higher in patients with fast reduction of the initial dose (>0.4 mg/day) than in patients with slow reduction (<0.4 mg/day). To avoid relapse, 0.4–0.69 mg/kg/day of initial PSL with slow reduction speed (<0.4 mg/day) is needed in the early treatment of IgG4-RD

Teacher Training and Licensing System, as well as Curriculum for Kindergarten Education in the Early Post-war Period: Ideal of “Teacher Training in Universities”

departmental bulletin pape