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2. Spiral Magnetic Field and Their Role on Accretion Dynamics in the Circumnuclear Disk of Sagittarius A*: Insight from {\lambda} = 850 {\mu}m Polarization Imaging

Author

Sato, Kazuki, Shinnaga, Hiroko, Furuya, Ray S., Suzuki, Takeru K., Kakiuchi, Kensuke, and Ott, Jürgen

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We showcase a study on the physical properties of the Circumnuclear Disk surrounding the Sgr A* of the Galactic Center, emphasizing the role of magnetic field (B field) with 0.47 pc spatial resolution, based on the sensitive {\lambda} = 850 {\mu}m polarization data taken with the JCMT. The B field within the CND exhibits a coherent spiral pattern. Applying the model described by Wardle and Ko\ddot{o}nigl 1990 (WK model) to the observed B field pattern, it favors gas-pressure-dominant models without dismissing a gas-and-B field comparable model, leading us to estimate the B-field strength in the ionized cavity around Sgr A* as 0.24 + 0.05 mG. Analysis -0.04 based on the WK model further allows us to derive representative B-field strengths for the radial, azimuthal, and vertical components as (Br,B{\phi},Bz) = (0.4 \pm 0.1,-0.7 \pm 0.2,0.2 \pm 0.05) mG, respectively. A key finding is that the |{\phi}| component is dominant over Br and Bz components, consistent with the spiral morphology, indicating that the CND' s B-field is predominantly toroidal, possibly shaped by accretion dynamics. Considering the turbulent pressure, estimated plasma \{beta} values indicate the effective gas pressure should surpass the magnetic pressure. Assessing the CND of our MWG in the toroidal-and-vertical stability parameter space, we propose that such an "effective" magnetoro-tational instability (MRI) may likely be active. The estimated maximum unstable wavelength, {\lambda}max = 0.1 \pm 0.1 pc, is smaller than the CND' s scale height (0.2 \pm 0.1 pc), which indicates the potential for the effective MRI intermittent cycles of \sim 10^{6} years, which should profoundly affect the CND's evolution, considering the estimated mass accretion rate of 10^{-2}M_{\odot} yr^{-1} to the Sgr A*.

Published
2024

4. Sweat lactate sensor for detecting anaerobic threshold in heart failure: a prospective clinical trial (LacS-001)

Author

Katsumata, Yoshinori, Muramoto, Yuki, Ishida, Noriyuki, Takemura, Ryo, Nagashima, Kengo, Ikoma, Takenori, Kawamatsu, Naoto, Araki, Masaru, Goda, Ayumi, Okawara, Hiroki, Sawada, Tomonori, Ichihara, Yumiko Kawakubo, Hattori, Osamu, Yamaoka, Koki, Seki, Yuta, Ryuzaki, Toshinobu, Ikura, Hidehiko, Nakashima, Daisuke, Nagura, Takeo, Nakamura, Masaya, Sato, Kazuki, and Shiraishi, Yasuyuki

Published
2024
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7. Emergent SU(3) magnons and thermal Hall effect in the antiferromagnetic skyrmion lattice

Author

Takeda, Hikaru, Kawano, Masataka, Tamura, Kyo, Akazawa, Masatoshi, Yan, Jian, Waki, Takeshi, Nakamura, Hiroyuki, Sato, Kazuki, Narumi, Yasuo, Hagiwara, Masayuki, Yamashita, Minoru, and Hotta, Chisa

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

Complexity of quantum phases of matter is often understood by the underlying gauge structures, as was recognized by the $\mathbb{Z}_2$ and U(1) gauge theory description of spin liquid in frustrated magnets. Anomalous Hall effect of conducting electrons can intrisically arise from U(1) gauges expressing the spatial modulation of ferromagnetic moments or from SU(2) gauges representing the spin-orbit coupling effect. Similarly, in insulating ferro and antiferromagnets, the magnon excitations can contribute to anomalous transports by feeling the U(1) and SU(2) gauges arising from the features of ordered moments or interactions. In this work, we report the emergent higher rank SU(3) gauge structure in the magnon transport based on the thermal conductivity measurements of MnSc$_2$S$_4$ in an applied field up to 14\,T. The thermal Hall coefficient takes a substantial value when the material enters a three-sublattice antiferromagnetic skyrmion phase, which is confirmed by the large-scale spin wave theory. The excited magnons are dressed with SU(3) gauge field, which is a mixture of three species of U(1) gauge fields originating from the slowly varying magnetic moments on these sublattices., Comment: 16 pages, 12 figures

Published
2023
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19. Anomaly Detection By Autoencoder Based On Weighted Frequency Domain Loss

Author

Nakanishi, Masaki, Sato, Kazuki, and Terada, Hideo

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition
Abstract

In image anomaly detection, Autoencoders are the popular methods that reconstruct the input image that might contain anomalies and output a clean image with no abnormalities. These Autoencoder-based methods usually calculate the anomaly score from the reconstruction error, the difference between the input image and the reconstructed image. On the other hand, the accuracy of the reconstruction is insufficient in many of these methods, so it leads to degraded accuracy of anomaly detection. To improve the accuracy of the reconstruction, we consider defining loss function in the frequency domain. In general, we know that natural images contain many low-frequency components and few high-frequency components. Hence, to improve the accuracy of the reconstruction of high-frequency components, we introduce a new loss function named weighted frequency domain loss(WFDL). WFDL provides a sharper reconstructed image, which contributes to improving the accuracy of anomaly detection. In this paper, we show our method's superiority over the conventional Autoencoder methods by comparing it with AUROC on the MVTec AD dataset.

Published
2021

20. Synthesis of New Lithium- and Monoamine-Intercalated Superconductors Li$_x$(C$_n$H$_{2n+3}$N)$_y$Fe$_{1-z}$Se ($n$ = 6, 8, 18) with the Dramatically Expanded Interlayer Spacing

Author

Sakamoto, Chika, Noji, Takashi, Sato, Kazuki, Kawamata, Takayuki, and Kato, Masatsune

Subjects
Condensed Matter - Superconductivity
Abstract

New superconductors, Li$_x$(C$_n$H$_{2n+3}$N)$_y$Fe$_{1-z}$Se ($n$ = 6, 8, 18), have been synthesized via the co-intercalation of linear monoamines together with Li into FeSe. The distance between neighboring Fe layers expands up to 55.7 {\AA} for n = 18, which is much larger than the previous record of 19 {\AA} in the FeSe-based intercalation superconductors. Tc remains saturated at $\sim$42 K., Comment: 6 pages, 3 figures, 1 table

Published
2020
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22. Decoding Emotion Dimensions Arousal and Valence Elicited on EEG Responses to Videos and Images: A Comparative Evaluation

Author

Moctezuma, Luis Alfredo, Sato, Kazuki, Molinas, Marta, Abe, Takashi, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Liu, Feng, editor, Zhang, Yu, editor, Kuai, Hongzhi, editor, Stephen, Emily P., editor, and Wang, Hongjun, editor

Published
2023
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24. FUGIN hot core survey. I. Survey method and initial results for $l = 10^\circ-20^\circ$

Author

Sato, Kazuki, Hasegawa, Tetsuo, Umemoto, Tomofumi, Saito, Hiro, Kuno, Nario, Seta, Masumichi, and Sakamoto, Seiichi

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We have developed a method to make a spectral-line-based survey of hot cores, which represent an important stage of high-mass star formation, and applied the method to the data of the FUGIN (FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope) survey. First, we select hot core candidates by searching the FUGIN data for the weak hot core tracer lines (HNCO and CH$_3$CN) by stacking, and then we conduct follow-up pointed observations on these candidates in C$^{34}$S, SO, OCS, HC$_3$N, HNCO, CH$_3$CN, and CH$_3$OH $J=2-1$ and $J=8-7$ lines to confirm and characterize them. We applied this method to the $l = 10^\circ-20^\circ$ portion of the FUGIN data and identified 22 "Hot Cores" (compact sources with more than two significant detection of the hot core tracer lines, i.e., SO, OCS, HC$_3$N, HNCO, CH$_3$CN, or CH$_3$OH $J=8-7$ lines) and 14 "Dense Clumps" (sources with more than two significant detection of C$^{34}$S, CH$_3$OH $J=2-1$, or the hot core tracer lines). The identified Hot Cores are found associated with signposts of high-mass star formation such as ATLASGAL clumps, WISE HII regions, and Class II methanol masers. For those associated with ATLASGAL clumps, their bolometric luminosity to clump mass ratios are consistent with the star formation stages centered at the hot core phase. The catalog of FUGIN Hot Cores provides a useful starting point for further statistical studies and detailed observations of high-mass star forming regions., Comment: 23 pages, 8 figures, 4 tables, submitted to PASJ

Published
2020
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28. Transcriptomic Analysis of Resistant and Susceptible Responses in a New Model Root-Knot Nematode Infection System Using Solanum torvum and Meloidogyne arenaria

Author

Sato, Kazuki, Uehara, Taketo, Holbein, Julia, Sasaki-Sekimoto, Yuko, Gan, Pamela, Bino, Takahiro, Yamaguchi, Katsushi, Ichihashi, Yasunori, Maki, Noriko, Shigenobu, Shuji, Ohta, Hiroyuki, Franke, Rochus B, Siddique, Shahid, Grundler, Florian MW, Suzuki, Takamasa, Kadota, Yasuhiro, and Shirasu, Ken

Subjects
Agricultural, Veterinary and Food Sciences, Plant Biology, Biological Sciences, Infectious Diseases, Genetics, 2.1 Biological and endogenous factors, Aetiology, Infection, Turkey berry, plant immunity, plant-parasitic nematode, lignin deposition, comparative transcriptomics, Crop and pasture production, Plant biology
Abstract

Root-knot nematodes (RKNs) are among the most devastating pests in agriculture. Solanum torvum Sw. (Turkey berry) has been used as a rootstock for eggplant (aubergine) cultivation because of its resistance to RKNs, including Meloidogyne incognita and M. arenaria. We previously found that a pathotype of M. arenaria, A2-J, is able to infect and propagate in S. torvum. In vitro infection assays showed that S. torvum induced the accumulation of brown pigments during avirulent pathotype A2-O infection, but not during virulent A2-J infection. This experimental system is advantageous because resistant and susceptible responses can be distinguished within a few days, and because a single plant genome can yield information about both resistant and susceptible responses. Comparative RNA-sequencing analysis of S. torvum inoculated with A2-J and A2-O at early stages of infection was used to parse the specific resistance and susceptible responses. Infection with A2-J did not induce statistically significant changes in gene expression within one day post-inoculation (DPI), but afterward, A2-J specifically induced the expression of chalcone synthase, spermidine synthase, and genes related to cell wall modification and transmembrane transport. Infection with A2-O rapidly induced the expression of genes encoding class III peroxidases, sesquiterpene synthases, and fatty acid desaturases at 1 DPI, followed by genes involved in defense, hormone signaling, and the biosynthesis of lignin at 3 DPI. Both isolates induced the expression of suberin biosynthetic genes, which may be triggered by wounding during nematode infection. Histochemical analysis revealed that A2-O, but not A2-J, induced lignin accumulation at the root tip, suggesting that physical reinforcement of cell walls with lignin is an important defense response against nematodes. The S. torvum-RKN system can provide a molecular basis for understanding plant-nematode interactions.

Published
2021

30. Error Analysis of Approximate Operators for a Particle Method based on Voronoi Diagram

Author

Koba, Hajime and Sato, Kazuki

Subjects
Mathematics - Numerical Analysis, 33F05
Abstract

This paper considers several approximate operators used in a particle method based on a Voronoi diagram. We introduce and study our approximate operators on gradient and Laplace operators. We derive error estimates for these approximate operators by applying our weight functions. The key idea of deriving our error estimates is to divide the integration region into a ring-shaped area and some areas. In the Appendix, we give an example application of the main results of this paper., Comment: 1 figure. The authors changed the title of this paper, that is, we changed "Truncation Error Analysis of Approximate Operators for a Moving Particle Semi-Implicit Method" to "Error Analysis of Approximate Operators for a Particle Method based on Voronoi Diagram"

Published
2019

34. Safety and efficacy of rozanolixizumab in patients with generalised myasthenia gravis (MycarinG): a randomised, double-blind, placebo-controlled, adaptive phase 3 study

Author

Genge, Angela, Massie, Rami, Berube, Maxime, Bril, Vera, Daniyal, Lubna, Mannan, Shabber, Ng, Eduardo, Raman, Ritesh Rohan Raghu, Sarpong, Evelyn, Alcantara, Monica, Dionne, Annie, Siddiqi, Zaeem, Blackmore, Derrick, Hussain, Faraz, Matte, Genevieve, Botez, Stephan, Tyblova, Michaela, Jakubikova, Michala, Junkerova, Jana, Vissing, John, Witting, Nanna, Holm-Yildiz, Sonja, Stemmerik, Mads, Andersen, Henning, Obál, Izabella, Solé, Guilhem, Mathis, Stéphane, Violleau, Marie-Hélène, Tranchant, Christine, Messai, Sihame, Chanson, Jean-Baptiste, Nadaj-Pakleza, Aleksandra, Verloes, Arnaud, Zaidi, Leila, Sacconi, Sabrina, Gambella, Manuela, Cavalli, Michele, Stojkovic, Tanya, Demeret, Sophie, Le Guennec, Loic, Querin, Giorgia, Weiss, Nicolas, Masingue, Marion, Magy, Laurent, Ghorab, Karima, Rukhadze, Ia, Tsiskaridze, Alexander, Janelidze, Marina, Margania, Temur, Then Bergh, Florian, Hänsel, Eike, Kalb, Andrea, Meilick, Bianca, Reuschel, Mandy, Teußer, Lars-Malte, Unterlauft, Astrid, Goedel, Clemens, Hagenacker, Tim, Totzeck, Andreas, Stolte, Benjamin, Blaes, Franz, Bindler, Christine, Tsoutsikas, Vasilios, Roediger, Annekathrin, Geis, Christian, Schmidt, Jens, Zschüntzsch, Jana, Schwarz, Margret, Meyer, Stefanie, Kummer, Karsten, Glaubitz, Stefanie, Zeng, Rachel, Wiendl, Heinz, Klotz, Luisa, Lammerskitten, Anna, Lünemann, Jan, Diószeghy, Péter, Mantegazza, Renato, Maggi, Lorenzo, Rinaldi, Elena, Gastaldi, Matteo, Mazzacane, Federico, Businaro, Pietro, Iorio, Raffaele, Antonini, Giovanni, Fionda, Laura, Rinaldi, Rita, Rossi, Simone, Habetswallner, Francesco, Tuccillo, Francesco, Umehara, Haruna, Uenaka, Eiko, Takahashi, Masanori, Higashi, Keiko, Kinoshita, Makoto, Yoneda, Emika, Nakamura, Noriko, Fujita, Saeka, Kubota, Tomoya, Ono, Masami, Yamamoto, Sana, Hatano, Taku, Oikoshi, Kazuki, Yokoyama, Kazumasa, Oji, Yutaka, Tomizawa, Yuji, Uzawa, Akiyuki, Yasuda, Manato, Akita, Sachiko, Ozawa, Yukiko, Onishi, Yosuke, Takaki, Miki, Yamada, Hiromi, Minemoto, Kanako, Sanko, Miki, Izawa, Nanae, Nakayama, Mayumi, Masuda, Masayuki, Tsuji, Rune, Ido, Nobuhiro, Hyodo, Yumi, Okubo, Yoshihiko, Minohara, Akiko, Haraguchi, Nana, Naito, Makiko, Yoshida, Seiko, Fukushige, Yuri, Tsujino, Akira, Nagaoka, Atsushi, Miyazaki, Teiichiro, Yoshimura, Shunsuke, Hirayama, Takuro, Shima, Tomoaki, Okamoto, Naoko, Matsumoto, Riki, Sekiguchi, Kenji, Ueda, Takehiro, Chihara, Norio, Kirimura, Mari, Sunagawa, Emi, Suzuki, Ayaka, Suzuki, Shigeaki, Wada, Aozora, Ishizuchi, Kei, Suzuki, Yasushi, Yata, Mitsuo, Komatsu, Yuka, Tsukita, Kenichi, Watanabe, Genya, Sato, Kazuki, Kawasaki, Emiko, Yamamoto, Naoki, Ono, Hirohiko, Tsuda, Tomoko, Ohashi, Shigeki, Utsugisawa, Kimiaki, Fujisawa, Yuka, Yokota, Yumiko, Nagane, Yuriko, Ayumi, Kameda, Takematsu, Yuka, Naito, Hiroyuki, Sugimoto, Takamichi, Kuwada, Kumiko, Rejdak, Konrad, Szklener, Sebastian, Kitowska, Monika, Derkacz, Kandyda, Druzdz, Artur, Berkowicz, Tomasz, Budzinska, Paulina, Halas, Marek, Zaslavskiy, Leonid, Skornyakova, Evgeniya, Kotov, Sergey, Novikova, Ekaterina, Sidorova, Olga, Goldobin, Vitalii, Alekseeva, Tatiana, Isabekova, Patimat, Malkova, Nadezhda, Korobko, Denis, Djordjevic, Gordana, Stojanov, Aleksandar, Peric, Stojan, Lavrnic, Dragana, Bozovic, Ivo, Palibrk, Aleksa, Casasnovas, Carlos, Nedkova-Hristova, Velina, Vidal Fernández, Nuria, Cortés Vicente, Elena, Querol Gutiérrez, Luis, Salvadó Figueras, Maria, Canovas Segura, Anna, Juntas Morales, Raúl, Sanchez Tejerina, Daniel, Saiz, Albert, Blanco Morgado, Yolanda, Llufriú Durán, Sara, Sepúlveda Gázquez, María, Martínez Hernández, Eugenia María, Gutiérrez Gutiérrez, Gerardo, Iniesta, Paqui, Meca Lallana, José, Guo, Yuh-Cherng, Chiu, Hou-Chang, Yeh, Jiann-Horng, Chen, Ya Hui, Lee, Mei Fen, Lee, Yi-Chung, Lai, Kuan Lin, Beydoun, Said, Akhter, Salma, Vu, Tuan, Lam, Lucy, Thomas, Alisha, Rivner, Michael, Quarles, Brandy, Lange, Dale, Holzberg, Shara, Pavlakis, Pantelis, Goutham, Ashwathy, Kaminski, Henry, Aly, Radwa, Ashworth, Lisa, Bender, Kathryn, Bond, Karie, Buckner, Joanne, Byerly, Sara, Caress, James, Clemons, Jessyca, Farmer, Asha, Franklin, Catherine, Harris, Summer, Hiatt, Meredith, Gandhi Mehta, Rachana, Miller, Gina, Smith, Lynn, Smith, Rose, Strittmatter, Brian, Mozaffar, Tahseen, Habib, Ali A, Hernandez, Isela, Moulton, Kelsey, Karam, Chafic, Ravikumar, Pranali, Lomen-Hoerth, Catherine, Rosow, Laura, George, Hannah, Irodenko, Viktoriya, Kang, Min, Denny, Carol, Hanson, Bart, Klein, Sara, Martinez-Thompson, Jennifer, Naddaf, Elie, Padgett, Denny, Sorenson, Eric, L Sultze, Jane, Weis, Delena, Rezania, Kourosh, Thonhoff, Jason, Shroff, Sheetal, Pascuzzi, Robert, Micheels, Angela, Bodkin, Cynthia, Comer, Adam, Baras, Gelasio, Wagner, Renee, Mahuwala, Zabeen, Ryan, Stephen, Su, Kai, Sharma, Khema, Brown, Andrew, Liow, Kore, Drużdż, Artur, Grosskreutz, Julian, Boehnlein, Marion, Bozorg, Ali, Gayfieva, Maryam, Greve, Bernhard, Woltering, Franz, and Kaminski, Henry J

Published
2023
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38. New Lithium- and Diamine-Intercalated Superconductors Lix(CnH2n+4N2)yMoSe2 (n = 2, 6)

Author

Sato, Kazuki, Noji, Takashi, Hatakeda, Takehiro, Kawamata, Takayuki, Kato, Masatsune, and Koike, Yoji

Subjects
Condensed Matter - Superconductivity
Abstract

We have succeeded in synthesizing new intercalation superconductors Lix(C2H8N2)yMoSe2 and Lix(C6H16N2)yMoSe2 with Tc = 4.2 and 3.8-6.0 K, respectively, via the co-intercalation of lithium and ethylenediamine or hexamethylenediamine into semiconducting 2H-MoSe2. It has been found that the Tc values are related not to the interlayer spacing between MoSe2 layers so much but to the electronic density of states (EDOS) at the Fermi level. Moreover, only Li-intercalated LixMoSe2 with a small interlayer spacing has been found to be non-superconducting. Accordingly, it has been concluded that not only a sufficient amount of EDOS at the Fermi level due to the charge transfer from intercalated Li to MoSe2 layers but also the enhancement of the two-dimensionality of the crystal structure and/or electronic structure due to the expansion of the interlayer spacing between MoSe2 layers is necessary for the appearance of superconductivity in MoSe2-based intercalation superconductors. The pairing mechanism and the analogy to the superconductivity in the electric double-layer transistors of 2H-MoX2 (X = S, Se, Te) are discussed., Comment: 17 pages, 8 figures, 1 tabele. arXiv admin note: substantial text overlap with arXiv:1709.03779

Published
2018
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39. Intestinal Permeability and IgA Provoke Immune Vasculitis Linked to Cardiovascular Inflammation

Author

Noval Rivas, Magali, Wakita, Daiko, Franklin, Michael K, Carvalho, Thacyana T, Abolhesn, Amanda, Gomez, Angela C, Fishbein, Michael C, Chen, Shuang, Lehman, Thomas J, Sato, Kazuki, Shibuya, Akira, Fasano, Alessio, Kiyono, Hiroshi, Abe, Masanori, Tatsumoto, Narihito, Yamashita, Michifumi, Crother, Timothy R, Shimada, Kenichi, and Arditi, Moshe

Subjects
Biomedical and Clinical Sciences, Immunology, Cardiovascular, Autoimmune Disease, Digestive Diseases, Heart Disease, Aetiology, 2.1 Biological and endogenous factors, Animals, Cardiovascular Diseases, Disease Models, Animal, Humans, Immunoglobulin A, Inflammation, Interleukin-1beta, Intestines, Mice, Mice, Inbred C57BL, Mucocutaneous Lymph Node Syndrome, Permeability, Signal Transduction, Vasculitis, IgA, Kawasaki disease, complement, coronary arteritis, interleukin-1β, intestinal permeability, vasculitis
Abstract

Recent experimental data and clinical, genetic, and transcriptome evidence from patients converge to suggest a key role of interleukin-1β (IL-1β) in the pathogenesis of Kawasaki disease (KD). However, the molecular mechanisms involved in the development of cardiovascular lesions during KD vasculitis are still unknown. Here, we investigated intestinal barrier function in KD vasculitis and observed evidence of intestinal permeability and elevated circulating secretory immunoglobulin A (sIgA) in KD patients, as well as elevated sIgA and IgA deposition in vascular tissues in a mouse model of KD vasculitis. Targeting intestinal permeability corrected gut permeability, prevented IgA deposition and ameliorated cardiovascular pathology in the mouse model. Using genetic and pharmacologic inhibition of IL-1β signaling, we demonstrate that IL-1β lies upstream of disrupted intestinal barrier function, subsequent IgA vasculitis development, and cardiac inflammation. Targeting mucosal barrier dysfunction and the IL-1β pathway may also be applicable to other IgA-related diseases, including IgA vasculitis and IgA nephropathy.

Published
2019

42. Impact of end-of-life respiratory modalities on quality of dying and death and symptom relief in patients with interstitial lung disease: a multicenter descriptive cross-sectional study

Author

Koyauchi, Takafumi, Suzuki, Yuzo, Sato, Kazuki, Hozumi, Hironao, Karayama, Masato, Furuhashi, Kazuki, Fujisawa, Tomoyuki, Enomoto, Noriyuki, Nakamura, Yutaro, Inui, Naoki, Yokomura, Koshi, Imokawa, Shiro, Nakamura, Hidenori, Morita, Tatsuya, and Suda, Takafumi

Published
2022
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46. New Lithium- and Diamines-Intercalated Superconductors Li$_x$(C$_2$H$_8$N$_2$)$_y$TiSe$_2$ and Li$_x$(C$_6$H$_{16}$N$_2$)$_y$TiSe$_2$

Author

Sato, Kazuki, Noji, Takashi, Hatakeda, Takehiro, Kawamata, Takayuki, Kato, Masatsune, and Koike, Yoji

Subjects
Condensed Matter - Superconductivity
Abstract

New intercalation superconductors of Li$_x$(C$_2$H$_8$N$_2$)$_y$TiSe$_2$ and Li$_x$(C$_6$H$_{16}$N$_2$)$_y$TiSe$_2$ with $T_{\rm c}$ = 4.2 K have successfully been synthesized via the co-intercalation of lithium and ethylenediamine or hexamethylenediamine into 1T-TiSe$_2$. Moreover, it has been found that both intercalation compounds of Li$_x$TiSe$_2$ and (C$_2$H$_8$N$_2$)$_y$TiSe$_2$ also show superconductivity with $T_{\rm c}$ = 2.4 K and 2.8 K, respectively. These results indicate that both the electron doping due to the intercalation of lithium and the expansion of the interlayer spacing between TiSe2 layers due to the intercalation of diamines suppress the charge density wave in 1T-TiSe$_2$, leading to the appearance of superconductivity., Comment: 17 pages, 8 figures, 1 table

Published
2017
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47. Energetic variational approaches for non-Newtonian fluid systems

Author

Koba, Hajime and Sato, Kazuki

Subjects
Mathematical Physics
Abstract

We consider the dominant equations for the motion of the non-Newtonian fluid in a domain from an energetic point of view. We apply our energetic variational approaches and the first law of thermodynamics to derive the generalized compressible non-Newtonian fluid system. We also derive the generalized incompressible non-Newtonian fluid system by using our energetic variational approaches.

Published
2017
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48. Aggressive End-of-Life Treatments Among Inpatients With Cancer and Non-cancer Diseases Using a Japanese National Claims Database.

Author

Togashi, Shintaro, Masukawa, Kento, Aoyama, Maho, Sato, Kazuki, and Miyashita, Mitsunori

Abstract

To describe aggressive treatments at end‐of‐life among inpatients with cancer and non-cancer diseases and to evaluate factors associated with these treatments using the Japanese national database (NDB). We conducted a retrospective cohort study among inpatients aged ≥ 20 years who died between 2012 and 2015 using a sampling dataset of NDB. The outcome was the proportion of aggressive treatments in the last 14 days of life. We considered the underlying causes of death as cancer, dementia/senility, and heart, cerebrovascular, renal, liver, respiratory, and neurodegenerative diseases. We analyzed 54,105 inpatients, with underlying cause of death distributed as follows: cancer, 24.9%; heart disease, 16.5%; respiratory disease, 12.3%; and cerebrovascular disease, 9.7%. The proportion of intensive care unit (ICU) admission was 9.7%, being the highest in heart disease (20.5%), followed by cerebrovascular diseases (12.6%), and least in dementia/senility (.6%). The proportion of cardiopulmonary resuscitation was 19.6%, being the highest in heart disease (38.1%), followed by renal diseases (19.5%), and least in cancer (6.2%). Multivariate logistic regression analysis revealed that having heart diseases, cerebrovascular diseases, younger age, less comorbidities, and shorter length of stay were associated with an increasing risk of aggressive treatments in the last 14 days of life. The proportion of aggressive treatments at the end-of-life varies depending on the disease; additionally, these treatments were associated with having heart diseases, younger age, less comorbidity, and shorter length of stay. Our findings may help develop and set benchmarks for quality indicators at the end‐of‐life for patients with non-cancer diseases. [ABSTRACT FROM AUTHOR]

Published
2024
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49. α‐Selective Solid‐Phase Synthesis of Glycosyl Phosphate Repeating Structure Via the Phosphoramidite Method.

Author

Kawato, Kazuki, Sato, Kazuki, and Wada, Takeshi

Subjects
*SOLID-phase synthesis, *DISACCHARIDES, *SACCHARIDES, *PHOSPHODIESTERS, *CARBOHYDRATES
Abstract

Lipophosphoglycans (LPGs) are found on the surface of Leishmania, a protozoan parasite, and are immunologically important. Herein, disaccharide 1‐phosphate repeating units of LPGs were successfully synthesized on a solid support with high anomeric purity using a disaccharide α‐1‐phosphoramidite building block. To enhance solubility in the reaction solvent, hydroxy‐protecting groups in the form of para‐t‐butylbenzoyl were introduced to the building block. The saccharide chain was elongated via stable glycosyl boranophosphate linkages, followed by the conversion of inter‐sugar linkages to phosphodiester counterparts using an oxaziridine derivative. The addition of a silylating reagent post‐reaction with the oxaziridine derivative efficiently facilitated the conversion of boranophosohodiesters to phosphodiesters. This method enabled the α‐selective synthesis of up to 15 repeating units, marking the longest homogeneous repeating units of LPGs synthesized chemically. Given the chain length equivalence to native LPGs, the method developed herein holds promise for advancing anti‐Leishmanial pharmaceuticals and vaccines. [ABSTRACT FROM AUTHOR]

Published
2024
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50. Spiral magnetic fields and their role on accretion dynamics in the circumnuclear disk of Sagittarius A*: Insight from λ = 850 μm polarization imaging.

Author

Sato, Kazuki, Shinnaga, Hiroko, Furuya, Ray S, Suzuki, Takeru K, Kakiuchi, Kensuke, and Ott, Jürgen

Subjects
*INFRARED astronomy, *GALACTIC center, *ACCRETION disks, *MAGNETIC fields, *PSEUDOPOTENTIAL method
Abstract

We showcase a study on the physical properties of the circumnuclear disk (CND) surrounding the supermassive black hole (SMBH) Sgr A* of the Galactic Center, emphasizing the role of magnetic field (⁠|$\boldsymbol {B}$| field) with |$0.50\,$| pc spatial resolution. Based on the sensitive |$\lambda = 850\, \mu$| m polarization data taken with the JCMT SCUBA2/POL2 (James Clerk Maxwell Telescope Submillimetre Common-User Bolometer Array 2), we analyzed ancillary datasets: CS |$J = 2$| –1 emission taken with ALMA (Atacama Large Millimeter/submillimeter Array), continuum emissions taken at |$\lambda = 6\,$| cm and at |$\lambda = 37\, \mu$| m taken with the VLA (Very Large Array) and SOFIA (the Stratospheric Observatory for Infrared Astronomy telescope). The |$\boldsymbol {B}$| field within the CND exhibits a coherent spiral pattern. Applying the model described by Wardle and Königl (1990, ApJ, 362, 12; the WK model) to the observed |$\boldsymbol {B}$| field pattern, it favors gas-pressure-dominant models without dismissing a gas-and- |$\boldsymbol {B}$| field comparable model, leading us to estimate the |$\boldsymbol {B}$| -field strength in the ionized cavity around Sgr A* as |$0.24^{+0.06}_{-0.04}\,$| mG. Analysis based on the WK model further allows us to derive representative |$\boldsymbol {B}$| -field strengths for the radial, azimuthal, and vertical components as |$(B_r, B_\phi , B_z) = (0.4 \pm 0.1, -0.7 \pm 0.2, 0.2 \pm 0.05)\,$| mG, respectively. A key finding is that the |$|B_\phi |$| component is dominant over |$B_r$| and |$B_z$| components, consistent with the spiral morphology, indicating that the CND's |$\boldsymbol {B}$| -field is predominantly toroidal, possibly shaped by accretion dynamics. Considering the turbulent pressure, estimated plasma |$\beta$| values indicate that the effective gas pressure should surpass the magnetic pressure. Assessing the CND of our MWG in the toroidal-and-vertical stability parameter space, we propose that such an "effective" magneto-rotational instability (MRI) may likely be active. The estimated maximum unstable wavelength, |$\lambda _{\rm max} = 0.1 \pm 0.1\,$| pc, is smaller than the CND's scale height (⁠|$0.2 \pm 0.1\,$| pc), which indicates the potential for the effective MRI intermittent cycles of |$\sim 10^6\,$| yr, which should profoundly affect the CND's evolution, considering the estimated mass accretion rate of |$10^{-2} M_{\odot }\,$| yr |$^{-1}$| to the SMBH. [ABSTRACT FROM AUTHOR]

Published
2024
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