379 results on '"Taketsugu T"'
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2. Corrigendum to “A novel pH-Dependent sensor for recognition of strontium ions in water: A hierarchically structured mesoporous architectonics” [Talanta 253 (2023) 124064]
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Alhindawy, I.G., primary, Tolan, D.A., additional, Elshehy, E.A., additional, El-Said, W.A., additional, Abdelwahab, S.M., additional, Mira, H.I., additional, Taketsugu, T., additional, Utgikar, V.P., additional, El-Nahas, A.M., additional, and Youssef, A.O., additional
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- 2024
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3. The role of nitrogen-doping and the effect of the pH on the oxygen reduction reaction on highly active nitrided carbon sphere catalysts
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Eckardt, M., Sakaushi, K., Lyalin, A., Wassner, M., Hüsing, N., Taketsugu, T., and Behm, R.J.
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- 2019
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4. Ultrafast Relaxation and Photodissociation Dynamics of 1,3-Butadiene Studied by Probing Molecular Orbitals
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Makida, A., Fujiwara, T., Harabuchi, Yu, Taketsugu, T., Sekikawa, T., Yamanouchi, Kaoru, editor, Cundiff, Steven, editor, de Vivie-Riedle, Regina, editor, Kuwata-Gonokami, Makoto, editor, and DiMauro, Louis, editor
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- 2015
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5. Catalytic Oxidative Dehydrogenation of Light Alkanes over Oxygen Functionalized Hexagonal Boron Nitride
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Kumar, S, Lyalin, A, Huang, Z, Taketsugu, T, Kumar, S, Lyalin, A, Huang, Z, and Taketsugu, T
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The catalytic activity of oxygen functionalized hexagonal boron nitride (h-BN) with >B−O−O−B< and >B−O−B< active sites at the zigzag edges for oxidative dehydrogenation (ODH) of light alkanes, specifically ethane (C2H6), propane (C3H8), butane (C4H10), and isobutane (HC(CH3)3) is explored. It has been found that the reaction pathway involves two H atom transfer steps with small activation energies. We demonstrate that the synergy of two active sites, >B−O−O−B< and >B−O−B<, is crucial for the first and second H-transfer, respectively. With the increase in molecular mass of the considered light alkanes, the ODH reaction temperature decreases. In the case of butane and isobutane, the ODH reaction occurs almost at the same temperature indicating that the reaction is independent of the shape of the isomer. The rate-limiting nature of the first H-transfer step is predicted. The charge redistribution during H-transfers and localized oxygen atomic states in the conduction band are explored to suggest possible descriptors for the rational design of new catalysts. The universal action of the >B−O−O−B< and >B−O−B< active sites for ODH of the light alkanes paves the way for metal-free BN-based materials for future catalytic applications.
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- 2022
6. Direct Confirmation of the Woodward-Hoffmann Rule by Femtosecond Transient Soft X-ray Absorption
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Sekikawa, T., primary, Saito, N., additional, Kurimoto, Y., additional, Ishii, N., additional, Mizuno, T., additional, Kanai, T., additional, Itatani, J., additional, Saita, K., additional, and Taketsugu, T., additional
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- 2022
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7. Boron nitride for enhanced oxidative dehydrogenation of ethylbenzene
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Han, R, Diao, J, Kumar, S, Lyalin, A, Taketsugu, T, Casillas, G, Richardson, C, Liu, F, Yoon, CW, Liu, H, Sun, X, and Huang, Z
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0305 Organic Chemistry ,Physical Chemistry - Abstract
It is demonstrated experimentally and confirmed theoretically that highly defective boron nitride showed outstanding performance for oxidative dehydrogenation of ethylbenzene. The catalyst is derived from carbon-doped hexagonal boron nitride nanosheets synthesized via a two-step reaction when participating the oxidative dehydrogenation reaction. The first step yields a polymeric precursor with the atomic positions of B, C, N relatively constrained, which is conducive for the formation of carbon atomic clusters uniformly dispersed throughout the BN framework. During the oxidative dehydrogenation of ethylbenzene to styrene, the nanoscale carbon clusters are removed and highly defective boron nitride (D-BN) is obtained, exposing boron-rich zigzag edges of BN that act as the catalytic sites. The catalytic performance of D-BN is therefore remarkably better than un-doped h-BN. Our results indicate that dispersed C-doping in h-BN is highly effective in terms of defect formation and resultant enhanced activity in oxidative dehydrogenation reactions.
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- 2021
8. Delayed Ring-Opening in 1,3-Cyclohexadiene upon Photoexcitation to a Higher State Probed by Time-Resolved Soft X-Ray Absorption
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Kurimoto, Y., primary, Saito, N., additional, Ishii, Y., additional, Kanai, T., additional, Itatani, J., additional, Saita, K., additional, Taketsugu, T., additional, and Sekikawa, T., additional
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- 2021
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9. Synthesis of armchair graphene nanoribbons from the 10,10 '-dibromo-9,9 '-bianthracene molecules on Ag(111) : the role of organometallic intermediates
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Simonov, Konstantin, Generalov, A. V., Vinogradov, A. S., Svirskiy, G. I., Cafolla, A. A., McGuinness, C., Taketsugu, T., Lyalin, A., Mårtensson, Nils, Preobrajenski, A. B., Simonov, Konstantin, Generalov, A. V., Vinogradov, A. S., Svirskiy, G. I., Cafolla, A. A., McGuinness, C., Taketsugu, T., Lyalin, A., Mårtensson, Nils, and Preobrajenski, A. B.
- Abstract
We investigate the bottom-up growth of N = 7 armchair graphene nanoribbons (7-AGNRs) from the 10,10'-dibromo-9,9'-bianthracene (DBBA) molecules on Ag(111) with the focus on the role of the organometallic (OM) intermediates. It is demonstrated that DBBA molecules on Ag(111) are partially debrominated at room temperature and lose all bromine atoms at elevated temperatures. Similar to DBBA on Cu(111), debrominated molecules form OM chains on Ag(111). Nevertheless, in contrast with the Cu(111) substrate, formation of polyanthracene chains from OM intermediates via an Ullmann-type reaction is feasible on Ag(111). Cleavage of C-Ag bonds occurs before the thermal threshold for the surface-catalyzed activation of C-H bonds on Ag(111) is reached, while on Cu(111) activation of C-H bonds occurs in parallel with the cleavage of the stronger C-Cu bonds. Consequently, while OM intermediates obstruct the Ullmann reaction between DBBA molecules on the Cu(111) substrate, they are required for the formation of polyanthracene chains on Ag(111). If the Ullmann-type reaction on Ag(111) is inhibited, heating of the OM chains produces nanographenes instead. Heating of the polyanthracene chains produces 7-AGNRs, while heating of nanographenes causes the formation of the disordered structures with the possible admixture of short GNRs.
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- 2018
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10. Synthesis of armchair graphene nanoribbons from the 10,10′-dibromo-9,9′-bianthracene molecules on Ag(111): the role of organometallic intermediates
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Simonov, K. A., primary, Generalov, A. V., additional, Vinogradov, A. S., additional, Svirskiy, G. I., additional, Cafolla, A. A., additional, McGuinness, C., additional, Taketsugu, T., additional, Lyalin, A., additional, Mårtensson, N., additional, and Preobrajenski, A. B., additional
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- 2018
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11. Atomically Thin Hexagonal Boron Nitride Nanofilm for Cu Protection: The Importance of Film Perfection.
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Khan, MH, Jamali, SS, Lyalin, A, Molino, PJ, Jiang, L, Liu, HK, Taketsugu, T, Huang, Z, Khan, MH, Jamali, SS, Lyalin, A, Molino, PJ, Jiang, L, Liu, HK, Taketsugu, T, and Huang, Z
- Abstract
Outstanding protection of Cu by high-quality boron nitride nanofilm (BNNF) 1-2 atomic layers thick in salt water is observed, while defective BNNF accelerates the reaction of Cu toward water. The chemical stability, insulating nature, and impermeability of ions through the BN hexagons render BNNF a great choice for atomic-scale protection.
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- 2017
12. Response to pre-dilatation with POBA can predict target lesion revascularization after DCB angioplasty for de novo small coronary artery lesions
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Taka-aki Takamura, Yasuyuki Kawai, Satori Akita, Minako Oda, Hironobu Akao, Tohru Nakagawa, Shunsuke Takama, Taketsugu Tsuchiya, Michihiko Kitayama, and Kouji Kajinami
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Medicine (General) ,R5-920 - Abstract
Objective To assess the determinants of target lesion revascularization (TLR) after drug-coated balloon (DCB) angioplasty for de novo small coronary artery lesions. Methods This retrospective study enrolled consecutive lesions from patients that were in a stable condition and had undergone successful DCB treatment for de novo small coronary artery lesions. The study endpoint was TLR and major adverse cardiac events at 12 months. Results A total of 68 patients with 83 lesions were enrolled in the study. Of these, 11 (13.3%) lesions required TLR. Mean ± SD pre-dilatation balloon diameters were similar in the non-TLR (2.33 ± 0.72 mm) and TLR (2.18 ± 0.36 mm) groups. A comparison of the two groups showed that post/pre-lumen area ratio during pre-dilatation (%) by plain old balloon angioplasty (POBA) was significantly and negatively associated with TLR and the optimal cut-off point was 170%. Cox proportional hazard and multivariate regression analyses showed that post/pre-lumen area ratio was the only independent predictor of TLR (hazard ratio 0.9318; 95% confidence interval 0.9001, 0.9645). Conclusion Greater pre-dilatation using POBA, assessed as the post/pre-lumen area ratio, may be independently associated with a lower 12-month TLR rate in patients undergoing DCB angioplasty for de novo small coronary lesions.
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- 2022
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13. Ultrafast Relaxation and Photodissociation Dynamics of 1,3-Butadiene Studied by Probing Molecular Orbitals
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Makida, A., primary, Fujiwara, T., additional, Harabuchi, Yu, additional, Taketsugu, T., additional, and Sekikawa, T., additional
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- 2014
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14. Possible effect of direct oral anti-coagulant for preventing long stenting lesion from in-stent restenosis in femoropopliteal segment: Case report with angioscopy findings
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Taketsugu Tsuchiya, Satori Akita, Minako Oda, Takaaki Takamura, Katsuhide Kitagawa, Koji Kajinami, and Michihiko Kitayama
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Medicine (General) ,R5-920 - Abstract
A 64-year-old female underwent a successful first percutaneous intervention using MISAGO stents for a de novo femoropopliteal lesion. Subsequently, three more effective procedures were done using balloon catheters for in-stent restenosis. In May 2016, a fourth procedure using Zilver PTX stent for in-stent restenosis was carried out. For this final procedure, we added direct oral anti-coagulant as she had additional problem of popliteal vein thrombosis and her femoropopliteal segment remained clear. A Zilver PTX stent, a drug-eluting stent for a peripheral artery, was expected to bring superior outcomes compared to conventional bare nitinol stents (i.e. MISAGO stent). But subsequent studies reported that Zilver PTX stent was not more effective than conventional bare nitinol stents. In our above mentioned case, her angioscopy findings suggest that her successful outcome appears to be related to the added direct oral anti-coagulant.
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- 2020
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15. Healing of femoral artery dissection after drug-coated balloon angioplasty: A case report with intravascular ultrasonography and angioscopy images
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Taketsugu Tsuchiya, Minako Oda, Takaaki Takamura, Katsuhide Kitagawa, Koji Kajinami, and Michihiko Kitayama
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Medicine (General) ,R5-920 - Abstract
Early 80s male with intermitted claudication underwent endovascular therapy for atherosclerotic stenosis at left external iliac artery and middle of superficial femoral artery. Patient also had chronic atrial fibrillation, diabetes mellitus, and hypertension. After stent deployment for external iliac artery lesion, a short superficial femoral artery lesion was performed with angioplasty using drug-coated balloon. The drug-coated balloon angioplasty resulted in 50% residual stenosis with linear dissection; however, provisional stenting was not performed as decent ante-grade blood flow allowed 10 extra minutes. Medication involved ongoing use of aspirin 100 mg and rivaroxaban 15 mg. Angiography post 3 months from index procedure showed external iliac artery and superficial femoral artery patency and healing of intimal dissection at superficial femoral artery lesion was estimated by intravascular ultrasonography. In angioscopy findings, red thrombus was seen in dissection cavity.
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- 2019
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16. Enhanced detection of lymphovascular invasion in small rectal neuroendocrine tumors using D2‐40 and Elastica van Gieson immunohistochemical analysis
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Yoshiyasu Kitagawa, Dai Ikebe, Taro Hara, Kazuki Kato, Teisuke Komatsu, Fukuo Kondo, Ryousaku Azemoto, Fumitake Komoda, Taketsugu Tanaka, Hirofumi Saito, Makiko Itami, Taketo Yamaguchi, and Takuto Suzuki
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D2‐40 ,Elastica van Gieson ,lymphovascular invasion ,rectal neuroendocrine tumors ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Rectal neuroendocrine tumor (RNET) lymphovascular invasion (LVI) is regarded as an important predictor of nodal metastasis after endoscopic resection (ER). However, little is known about the frequency of immunohistochemical detection of LVI in RNETs. This study was performed to establish the actual detection of LVI rate in RNETs ≤10 mm and to evaluate associated clinical outcomes. We retrospectively reviewed the records for 98 consecutive patients treated by ER with a total of 102 RNETs ≤10 mm. Tissue sections were labeled with hematoxylin–eosin (HE) stain, the D2‐40 monoclonal antibody to evaluate lymphatic invasion, and Elastica van Gieson (EVG) stain to detect venous invasion. LVI detection rate by HE versus immunohistochemical analysis was compared. Follow‐up findings and clinical outcomes were also evaluated for 91 patients who were followed for ≥12 months. Lymphatic and venous invasion were detected using HE staining alone in 6.9% and 3.9% of patients, respectively, whereas they were detected using D2‐40 and EVG staining in 20.6% and 47.1% of the patients, respectively. Thus, the LVI detection frequency using D2‐40 and EVG staining (56.9%) was significantly higher than with HE (8.8%). Two out of seven patients who required additional surgery had regional lymph node metastases. However, among the 84 patients who were followed up without surgery, no distant metastases or recurrences were detected. Compared with HE staining, immunohistochemical analysis significantly increased the frequency of LVI detection in RNETs ≤10 mm. However, the clinical impact of LVIs detected using immunohistochemical analysis remains unclear. Clarification of the actual role of LVI using immunohistochemical analysis requires a patient long‐term follow‐up and outcomes.
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- 2016
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17. Neutrophil-rich Variant of Persistent Bullous Grover’s Disease
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Sayaka Togo, Kentaro Ozawa, Asami Fujii, Tsukasa Tanii, Daisuke Tsuruta, Norito Ishii, Takashi Hashimoto, Taketsugu Tadokoro, and Taiki Isei
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bullous ,dyskeratosis ,grover’s disease ,minocycline ,neutrophils ,Dermatology ,RL1-803 - Published
- 2019
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18. A variational determination of spin-rovibronic energy levels of MgNC in the A2P state
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Taketsugu, T. and Carter, S.
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- 2001
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19. Theoretical study of nanotube growth in terms of frontier density distribution
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Kumeda, Y., Fukuhiro, Y., Taketsugu, T., and Hirano, T.
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- 2001
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20. Theoretical study on adsorption and proton exchange reaction of H~2O on H-form zeotite
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Tajima, N., Taketsugu, T., and Hirao, K.
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- 1997
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21. Detection of regional low myocardial perfusion helps predict a response to cardiac resynchronization therapy in patients with non-ischemic cardiomyopathy: Results of the Find Index by Nuclear Imaging for Dyssynchrony (FIND) study
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Takehiko Keida, Itsuro Morishima, Taketsugu Tsuchiya, Kouichi Sagara, Kaoru Okishige, Kenta Kumagai, Yoshiaki Mibiki, Kentaro Nakamura, Tamon Yamanaka, Yukihiko Yoshida, Akira Yamamoto, and Mitsuaki Takami
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Heart failure ,Cardiac resynchronization therapy ,Dyssynchrony ,Scarring ,SPECT ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Background: The aim of this study was to investigate the use of imaging techniques to predict the response to cardiac resynchronization therapy (CRT) in patients with non-ischemic cardiomyopathy (NICM) by simultaneous assessment of left ventricular (LV) dyssynchrony and myocardial perfusion in a single nuclear scan of the heart. Methods: Patients indicated for CRT device implantation underwent a resting myocardial perfusion assessment with single photon emission computed tomography (MP-SPECT) examination using technetium-99 m methoxyisobutylisonitrile prior to device implantation. CardioGRAF and cardioBull software (FUJIFILM RI Pharma, Tokyo, Japan) were used to analyze the LV mechanical dyssynchrony and myocardial viability, respectively. Patient follow-ups were performed at 6 months after device implantation. CRT response was defined as a ≥10% decrease in the LV end systolic volume. Results: A total of 43 patients with NICM were analyzed. Using the cutoff points of 6.2 for the dyssynchrony index and 66% for LV myocardial perfusion, the combined indices predicted CRT response with a sensitivity of 77.8% and specificity of 91.2%. Conclusion: Combined assessment of MP-SPECT and a measure of LV mechanical dyssynchrony showed good predictive ability in patients with non-ischemic heart failure.
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- 2013
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22. Clinical impact and risk stratification of balloon angioplasty for femoropopliteal disease in nitinol stenting era: Retrospective multicenter study using propensity score matching analysis
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Taketsugu Tsuchiya, Takaaki Takamura, Yoshimitsu Soga, Osamu Iida, Keisuke Hirano, Kenji Suzuki, Terutoshi Yamaoka, Yusuke Miyashita, Michihiko Kitayama, and Koji Kajinami
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Medicine (General) ,R5-920 - Abstract
Objective: Nitinol stenting could bring the better outcome in endovascular therapy for femoropopliteal disease. However, it might be expected that recent marked advances in both device technology and operator technique had led to improved efficacy of balloon angioplasty even in this segment. The aims of this study were to evaluate the clinical impact of balloon angioplasty for femoropopliteal disease and make risk stratification clear by propensity score matching analysis. Methods: Based on the multicenter retrospective data, 2758 patients (balloon angioplasty: 729 patients and nitinol stenting: 2029 patients), those who underwent endovascular therapy for femoropopliteal disease, were analyzed. Results: The propensity score matching procedure extracted a total of 572 cases per group, and the primary patency rate of balloon angioplasty and nitinol stenting groups after matching was significantly the same (77.2% vs 82.7% at 1 year; 62.2% vs 64.3% at 3 years; 47.8% vs 54.3% at 5 years). In multivariate Cox hazard regression analysis, significant predictors for primary patency were diabetes mellitus, regular dialysis, cilostazol use, chronic total occlusion, and intra-vascular ultra-sonography use. The strategy of balloon angioplasty was not evaluated as a significant predictor for the primary patency. After risk stratification using five items ( d iabetes mellitus, regular d ialysis, no use of i ntra-vascular ultra-sonography, c hronic total occlusion, and no use of c ilostazol: the DDICC score), the estimated primary patency rates of each group (low, DDICC score 0–2; moderate, DDICC score 3; high risk, DDICC score 4–5) were 88.6%, 78.3%, and 63.5% at 1 year; 75.2%, 60.7%, and 39.8% at 3 years; and 66.0%, 47.1%, and 26.3% at 5 years (p
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- 2016
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23. Clinical characteristics of patients with Rutherford category IV, compared with V and VI
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Taketsugu Tsuchiya, Osamu Iida, Tatsuya Shiraki, Yoshimitsu Soga, Keisuke Hirano, Kenji Suzuki, Terutoshi Yamaoka, Yusuke Miyashita, Michihiko Kitayama, and Koji Kajinami
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Medicine (General) ,R5-920 - Abstract
Objective: Patients categorized Rutherford category IV might have different characteristics compared with Rutherford category V and VI. Our study aims were to estimate the clinical differences between Rutherford category IV and Rutherford category V and VI, for those underwent endovascular therapy for isolated infrapopliteal disease, and also to find risk factors for endovascular therapy in Rutherford category IV. Methods: Based on the Japanese multi-center registry data, 1091 patients with 1332 limbs (Rutherford category IV: 226 patients with 315 limbs, Rutherford category V and VI: 865 patients with 1017 limbs) were analyzed retrospectively. Results: Patients’ backgrounds and lesions’ characteristics had significant differences. Both freedom rate from major adverse limb event with perioperative death and amputation-free survival rate at 1 year were better in Rutherford category IV than Rutherford category V and VI (93.6% vs 78.3%, 87.7% vs 66.7%) and those maintained to 3 years ( p 3.0 mg/dL), chronic obstructive pulmonary disease, and coronary artery disease in Rutherford category IV. Conclusion: From the present results, Rutherford category IV should be recognized to have quite different backgrounds and better outcome from Rutherford category V and VI.
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- 2015
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24. Vibrational symmetry of a single molecule revealed by tip-enhanced Raman spectroscopy
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Jaculbia, R. B., Imada, H., Kuniyuki Miwa, Iwasa, T., Takenaka, M., Yang, B., Kazuma, E., Hayazawa, N., Taketsugu, T., and Kim, Y.
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The scanning tunneling microscope (STM) is a powerful tool for studying various nanoscale materials with atomic scale spatial resolution. Despite the atom scale spatial sensitivity however, the STM lacks the chemical sensitivity crucial to the investigation of nanomaterials. Raman spectroscopy on the other hand has a very strong chemical sensitivity but its spatial resolution is highly restricted by the diffraction limit of light allowing only about several hundreds of nanometer resolution. Combining these two powerful experiments into a technique called STM-tip enhanced Raman spectroscopy (STM-TERS) alleviates the limitation of STM and Raman allowing for simultaneous subnanometer spatial resolution and high chemical sensitivity.
25. Ultrafast relaxation and photodissociation dynamics of 1,3-butadiene studied by probing molecular orbitals.
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Makida, A., Fujiwara, T., Harabuchi, Yu, Taketsugu, T., and Sekikawa, T.
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- 2014
26. Two arc welding robots coordinated with 3-D vision sensor.
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Ishida, H., Taketsugu, T., Ishimatsu, T., Kasagami, F., and Kugai, K.
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- 1994
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27. Boron-induced transformation of ultrathin Au films into two-dimensional metallic nanostructures.
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Preobrajenski A, Vinogradov N, Duncan DA, Lee TL, Tsitsvero M, Taketsugu T, and Lyalin A
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The synthesis of large, freestanding, single-atom-thick two-dimensional (2D) metallic materials remains challenging due to the isotropic nature of metallic bonding. Here, we present a bottom-up approach for fabricating macroscopically large, nearly freestanding 2D gold (Au) monolayers, consisting of nanostructured patches. By forming Au monolayers on an Ir(111) substrate and embedding boron (B) atoms at the Au/Ir interface, we achieve suspended monoatomic Au sheets with hexagonal structures and triangular nanoscale patterns. Alternative patterns of periodic nanodots are observed in Au bilayers on the B/Ir(111) substrate. Using scanning tunneling microscopy, X-ray spectroscopies, and theoretical calculations, we reveal the role of buried B species in forming the nanostructured Au layers. Changes in the Au monolayer's band structure upon substrate decoupling indicate a transition from 3D to 2D metal bonding. The resulting Au films exhibit remarkable thermal stability, making them practical for studying the catalytic activity of 2D gold., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)
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- 2024
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28. Acceleration of Reaction Space Projector Analysis Using Combinatorial Optimization: Application to Organic Chemical Reactions.
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Qu L, Tsutsumi T, Ono Y, and Taketsugu T
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In recent years, automated reaction path search methods have established the concept of a reaction route network. The Reaction Space Projector (ReSPer) visualizes the potential energy hypersurface into a lower-dimensional subspace using principal coordinates. The main time-consuming process in ReSPer is calculating the structural distance matrix, making it impractical for complex organic reaction route networks. We implemented the Alternate Optimization (AO) algorithm, one of the combinatorial optimizations, in ReSPer to reduce computational costs. Evaluations using gold clusters and the Au
5 several reaction route networks showed that ReSPer-AO accurately computes distances with lower computational costs. Applying ReSPer-AO to the C5 H8 O reaction route network clarified dynamic conformation changes in its potential energy landscape. The ReSPer-AO method enables analysis of chemical reactions and dynamic conformations in a low-dimensional reaction space that accurately represents hydrocarbon reaction route networks.- Published
- 2024
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29. Relationship Between Swallowing Function and Low Serum Albumin Levels in Older Japanese People Aged ≥ 75 Years.
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Iwai K, Azuma T, Yonenaga T, Sasai Y, Komatsu Y, Tabata K, Nomura T, Sugiura I, Inagawa Y, Matsumoto Y, Nakashima S, Abe Y, and Tomofuji T
- Abstract
Background/objectives: This cross-sectional study aimed to investigate the relationship between swallowing function and low serum albumin levels in older Japanese people (aged ≥ 75 years)., Methods: A total of 3258 participants (1325 males, 1933 females; mean age, 80.8 years) who had a dental checkup in Gifu City, Japan, between April 2020 and March 2021 were recruited. Swallowing function was assessed using the repetitive saliva swallow test, with poor swallowing function defined as swallowing fewer than three times in 30 s. A serum albumin level < 3.6 G/dL was considered low., Results: In total, 78 participants (2%) had a low serum albumin level. Furthermore, after adjusting for age, gender, circulatory disease, support/care-need certification, number of present teeth, and tongue and lip function, a low serum albumin level was positively associated with older (odds ratio [OR]: 1.115; 95% confidence interval [CI]: 1.064-1.169), male (OR: 2.208; 95% CI: 1.360-3.584), circulatory disease (OR: 1.829; 95% CI: 1.079-3.099), support/care-need certification (OR: 2.087; 95% CI: 1.208-3.606), and poor swallowing function (OR: 2.379; CI: 1.377-4.112)., Conclusions: These results indicate that poor swallowing function was associated with a low serum albumin level in older Japanese people aged ≥ 75 years.
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- 2024
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30. Low-dimensional projection of reactivity classes in chemical reaction dynamics using supervised dimensionality reduction.
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Tanaka R, Mizuno Y, Tsutsumi T, Toda M, Taketsugu T, and Komatsuzaki T
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Transition state theory (TST) provides a framework to estimate the rate of chemical reactions. Despite its great success with many reaction systems, the underlying assumptions such as local equilibrium and nonrecrossing do not necessarily hold in all cases. Although dynamical systems theory can provide the mathematical foundation of reaction tubes existing in phase space that enables us to predict the fate of reactions free from the assumptions of TST, numerical demonstrations for large systems have been yet one of the challenges. Here, we propose a dimensionality reduction algorithm to demonstrate structures in phase space (called reactive islands) that predict reactivity in systems with many degrees of freedom. The core of this method is the application of supervised principal component analysis, where a coordinate transformation is performed to preserve the dynamical information on reactivity (i.e., to which potential basin the system moves from a region of interest) as much as possible. The reactive island structures are expected to be reflected in the transformed, low-dimensional phase space. As an illustrative example, the algorithm is scrutinized using a modified Hénon-Heiles Hamiltonian system extended to many degrees of freedom, which has three channels leading to three different products from one stable potential basin. It is shown that our algorithm can predict the reactivity in the transformed, low-dimensional coordinate system better than a naïve coordinate system and that the reactivity distribution in the transformed low-dimensional space is considered to reflect the underlying reactive islands., (© 2024 Author(s). Published under an exclusive license by AIP Publishing.)
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- 2024
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31. Optical force and torque in near-field excitation of C3H6: A first-principles study using RT-TDDFT.
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Amano R, Nishizawa D, Taketsugu T, and Iwasa T
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Optical trapping is an effective tool for manipulating micrometer-sized particles, although its application to nanometer-sized particles remains difficult. The field of optical trapping has advanced significantly, incorporating more advanced techniques such as plasmonic structures. However, single-molecule trapping remains a challenge. To achieve a deeper understanding of optical forces acting on molecular systems, a first-principles approach to analyze the optical force on molecules interacting with a plasmonic field is crucial. In our study, the optical force and torque induced by the near-field excitation of C3H6 were investigated using real-time time-dependent density functional theory calculations on real-space grids. The near field from the scanning tunneling probe was adopted as the excitation source for the molecule. The optical force was calculated using the polarization charges induced in the molecule based on Lorentz force. While the optical force and torque calculated as functions of the light energy were in moderate agreement with the oscillator strengths obtained from the far-field excitation of C3H6, a closer correspondence was achieved with the power spectrum of the induced dipole moment using near-field excitation. Time-domain analysis of the optical force suggests that the simultaneous excitation of multiple excited states generally weakens the force because of mismatches between the directions of the induced polarization and the electric field. This study revealed a subtle damping mechanism for the optical force arising from intrinsic electronic states and the influence of beating., (© 2024 Author(s). Published under an exclusive license by AIP Publishing.)
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- 2024
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32. An Atypical Spindle Cell/Pleomorphic Lipomatous Tumor of the Thigh With a Difficult Imaging Diagnosis That Mimicked a Malignant Lipomatous Tumor.
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Fujibuchi T, Ichikawa J, Kawasaki T, Onohara K, and Aoki K
- Subjects
- Humans, Diagnosis, Differential, Positron Emission Tomography Computed Tomography, Male, Liposarcoma diagnostic imaging, Liposarcoma pathology, Middle Aged, Tomography, X-Ray Computed, Thigh diagnostic imaging, Thigh pathology, Lipoma diagnostic imaging, Lipoma pathology, Magnetic Resonance Imaging
- Abstract
Abstract: Atypical spindle cell/pleomorphic lipomatous tumor is categorized as a benign lipomatous tumor, but various MRI findings pose accurate diagnostic challenges. In our case, both MRI and PET/CT scans indicated the possibility of atypical lipomatous tumor/well-differentiated liposarcoma or dedifferentiated liposarcoma. Needle biopsy suggested benign to low-grade malignancy; hence, we opted for the wide resection. The final diagnosis of atypical spindle cell/pleomorphic lipomatous tumor was confirmed through histopathology analysis, including immunohistochemistry and fluorescence in situ hybridization. Since achieving an accurate diagnosis solely through imaging can be challenging, histopathology remains essential., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)
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- 2024
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33. Unveiling the Nature of Chemical Bonds in Real Space.
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Hara T, Hasebe M, Tsuneda T, Naito T, Nakamura Y, Katayama N, Taketsugu T, and Sawa H
- Abstract
Recent advent of diverse chemical entities necessitates a re-evaluation of chemical bond concepts, underscoring the importance of experimental evidence. Our prior study introduced a general methodology, termed Core Differential Fourier Synthesis (CDFS), for mapping the distribution of valence electron density (VED) in crystalline substances within real space. In this study, we directly compare the VED distributions obtained through CDFS with those derived from high-accuracy theoretical calculation using long-range corrected density functional theory, which quantitatively reproduces accurate orbital energies. This comparison serves to demonstrate the precision of the CDFS in replicating complex details. The VED patterns observed experimentally exhibited detailed structures and phases of wave functions indicative of sp
3 hybrid orbitals, closely aligning with theoretical predictions. This alignment underscores the utility of our approach in gathering quantum chemical data experimentally, a crucial step for discussing the chemical properties, such as reaction mechanisms.- Published
- 2024
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34. Chiral Tetrakis Eu(III) Complexes with Ammonium Cations for Improved Circularly Polarized Luminescence.
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Tsurui M, Takizawa R, Kitagawa Y, Wang M, Kobayashi M, Taketsugu T, and Hasegawa Y
- Abstract
Large dissymmetry factor of the circularly polarized luminescence (g
CPL ) was observed in ligand and coordination tuned chiral tetrakis europium (Eu(III)) complexes with ammonium cations. The gCPL value was estimated to be -1.54, which is the largest among chiral luminescent molecules. Through photophysical measurements, single crystal X-ray structural analyses and quantum chemical calculations, changes in the geometric and electronic structures were observed for a series of chiral tetrakis Eu(III) complexes which enhanced the gCPL value. The emission quantum yield and photosensitized energy transfer efficiencies of chiral Eu(III) complexes with ammonium cations were also larger than those of chiral Eu(III) complex with Cs+ . Based on the systematic modifications and analyses for chiral tetrakis Eu(III) complex, effect of the ammonium cation on enhanced CPL brightness is reported., (© 2024 Wiley-VCH GmbH.)- Published
- 2024
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35. Near-field induced local excitation dynamics of Na10 and Na10-N2 from real-time TDDFT.
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Nishizawa D, Amano R, Taketsugu T, and Iwasa T
- Abstract
Electron dynamics of the Na10 chain and the Na10-N2 complex locally excited by an atomistic optical near-field are investigated using real-time time-dependent density functional theory calculations on real-space grids. Ultrafast laser pulses were used to simulate the near-field excitation under on- and off-resonance conditions. Off-resonance excitation did not lead to the propagation of the excitation through the Na10 chain. In contrast, under the resonance conditions, the excited state is delocalized over the entire Na chain. Analysis of the local dipole moment of each atom in Na10 indicates that this behavior is consistent with the transition density. Adding an N2 molecule to the opposite end of the local excitation region results in energy transfer via the Na10 chain. The energy transfer efficiency of the N2 molecule is well correlated with the absorption spectrum of Na10. The present study paves the way for realizing remote excitation and photonic devices at the atomic scale., (© 2024 Author(s). Published under an exclusive license by AIP Publishing.)
- Published
- 2024
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36. Singlet Fission as the Gateway to Triplet Generation in Heavy Atom-Free Organic Molecules.
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Tsuneda T and Taketsugu T
- Abstract
Triplet generations in heavy atom-free organic molecules are primarily revealed to proceed through singlet fissions (SFs) by investigating the contributions of SFs and intersystem crossings to the generation rates. The spin-flip long-range corrected time-dependent density functional theory calculations on 11 organic molecules known for triplet generation under photoirradiation are performed. The correlation between the descriptors for SF and the experimental singlet-to-triplet conversion rates strongly supports the predominance of SF progressions in all these molecules, corroborated by experimental observations of their triplet-triplet annihilations. Based on these findings, we propose updated conditions for SF progression: There is a high-absorption singlet state just above the triplet-triplet excitation of the chromophore dimer, or the singlet (triplet-triplet) excitation itself is responsible for photoabsorption. To the best of our knowledge, all organic molecules known for rapid triplet state generation fulfill these conditions.
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- 2024
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37. Guest-Responsive Near-Infrared-Luminescent Metal-Organic Cage Organized by Porphyrin Dyes and Yb(III) Complexes.
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Hosoya S, Shoji S, Nakanishi T, Kobayashi M, Wang M, Fushimi K, Taketsugu T, Kitagawa Y, and Hasegawa Y
- Abstract
Metal-organic cages (MOCs) with luminophores have significant advantages for the facile detection of specific molecules based on turn-on or turn-off luminescence changes induced by host-guest complexation. One important challenge is the development of turn-on-type near-infrared (NIR)-luminescent MOCs. In this study, we synthesized a novel MOC consisting of two porphyrin dyes linked by four Yb(III) complexes, which exhibit bimodal red and NIR fluorescence signals upon photoexcitation of the porphyrin π system. Single-crystal X-ray structural analysis and computational molecular modeling revealed that planar aromatic perfluorocarbons were intercalated into the MOC. The tight packing between the MOC and guests enhanced the NIR fluorescence of Yb(III) by suppressing energy transfer from the photoexcited porphyrin to oxygen molecules. Guest-responsive turn-on NIR fluorescence changes in an MOC were successfully demonstrated.
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- 2024
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38. Advanced theoretical design of light-driven molecular rotary motors: enhancing thermal helix inversion and visible-light activation.
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Shi W, Ma J, Jiang C, and Taketsugu T
- Abstract
In this study, we have advanced the field of light-driven molecular rotary motors (LDMRMs) by achieving two pivotal goals: lowering the thermal helix inversion (THI) barrier and extending the absorption wavelength into the visible spectrum. This study involves the structural reengineering of a second-generation visible LDMRM, resulting in the synthesis of a novel class, specifically, 2-((2 S )-5-methoxy-2-methyl-2,3-dihydro-1 H -cyclopenta[ a ]naphthalen-1-yl)-3-oxo-2,3-dihydro-1 H -dibenzo[ e , g ]indole-6,9-dicarbonitrile. This redesigned motor stands out with its two photoisomerization stages and two thermal helix inversions, featuring exceptionally low THI barriers (4.00 and 2.05 kcal mol
-1 at the OM2/MRCI level for the EM → EP and ZM → ZP processes, respectively). Moreover, it displays absorption wavelengths in the visible light range (482.98 and 465.76 nm for the EP and ZP isomers, respectively, at the TD-PBE0-D3/6-31G(d,p) level), surpassing its predecessors in efficiency, as indicated by the narrow HOMO-LUMO energy gap. Ultrafast photoisomerization kinetics (approximately 0.8-1.6 ps) and high quantum yields (around 0.3-0.6) were observed through trajectory surface hopping simulations. Additionally, the simulated time-resolved fluorescence emission spectrum indicates a significantly reduced "dark state" duration (0.09-0.26 ps) in these newly designed LDMRMs compared to the original ones, marking a substantial leap forward in the design and efficiency of LDMRMs.- Published
- 2024
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39. Predictive Factors Associated with Future Decline in Swallowing Function among Japanese Older People Aged ≥ 75 Years.
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Iwai K, Azuma T, Yonenaga T, Sasai Y, Komatsu Y, Tabata K, Nomura T, Sugiura I, Inagawa Y, Matsumoto Y, Nakashima S, Abe Y, and Tomofuji T
- Subjects
- Humans, Aged, Male, Female, Japan, Aged, 80 and over, Deglutition Disorders, Risk Factors, East Asian People, Deglutition physiology
- Abstract
Predictive factors associated with a decline in swallowing function after 2 years were examined in 3409 Japanese older people aged ≥ 75 years who had undergone a dental checkup in Gifu Prefecture, Japan. Participants with normal swallowing function in a baseline survey in April 2018 were followed for 2 years. Swallowing function was assessed using a repetitive saliva swallowing test. In our study, 429 participants (13%) who were swallowing less than three times in 30 s based on a repetitive saliva swallowing test after 2 years were diagnosed as those with decline in swallowing function. Multivariate logistic regression analyses showed the decline in swallowing function after 2 years was associated with the male gender (odds ratio [ORs]: 0.772; 95% confidence interval [CIs]: 0.615-0.969), age ≥ 81 years (presence; ORs: 1.523; 95% CIs: 1.224-1.895), support/care-need certification (presence; ORs: 1.815; 95% CIs: 1.361-2.394), periodontal pocket depth (PPD) ≥ 4 mm (presence; ORs: 1.469; 95% CIs: 1.163-1.856), difficulty in biting hard food (yes; ORs: 1.439; 95% CIs: 1.145-1.808), choking on tea and water (yes; ORs: 2.543; 95% CIs: 2.025-3.193), and dry mouth (yes; ORs: 1.316; 95% CIs: 1.052-1.646) at baseline. Therefore, the dental checkup items associated with a decline in swallowing function after 2 years were a PPD ≥ 4 mm, difficulty in biting hard food, choking on tea and water, and dry mouth. PPD status and confirming to the self-administered questionnaire about biting, choking, and dry mouth may be useful in predicting future decline in swallowing function.
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- 2024
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40. An encompassed representation of timescale hierarchies in first-order reaction network.
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Nagahata Y, Kobayashi M, Toda M, Maeda S, Taketsugu T, and Komatsuzaki T
- Abstract
Complex networks are pervasive in various fields such as chemistry, biology, and sociology. In chemistry, first-order reaction networks are represented by a set of first-order differential equations, which can be constructed from the underlying energy landscape. However, as the number of nodes increases, it becomes more challenging to understand complex kinetics across different timescales. Hence, how to construct an interpretable, coarse-graining scheme that preserves the underlying timescales of overall reactions is of crucial importance. Here, we develop a scheme to capture the underlying hierarchical subsets of nodes, and a series of coarse-grained (reduced-dimensional) rate equations between the subsets as a function of time resolution from the original reaction network. Each of the coarse-grained representations guarantees to preserve the underlying slow characteristic timescales in the original network. The crux is the construction of a lumping scheme incorporating a similarity measure in deciphering the underlying timescale hierarchy, which does not rely on the assumption of equilibrium. As an illustrative example, we apply the scheme to four-state Markovian models and Claisen rearrangement of allyl vinyl ether (AVE), and demonstrate that the reduced-dimensional representation accurately reproduces not only the slowest but also the faster timescales of overall reactions although other reduction schemes based on equilibrium assumption well reproduce the slowest timescale but fail to reproduce the second-to-fourth slowest timescales with the same accuracy. Our scheme can be applied not only to the reaction networks but also to networks in other fields, which helps us encompass their hierarchical structures of the complex kinetics over timescales., Competing Interests: Competing interests statement:The authors declare no competing interest.
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- 2024
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41. Ab initio molecular dynamics study of intersystem crossing dynamics for MH 2 (M = Si, Ge, Sn, Pb) on spin-pure and spin-mixed potential energy surfaces.
- Author
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Wada S, Tsutsumi T, Saita K, and Taketsugu T
- Abstract
Recently, surface-hopping ab initio molecular dynamics (SH-AIMD) simulations have come to be used to discuss the mechanisms and dynamics of excited-state chemical reactions, including internal conversion and intersystem crossing. In dynamics simulations involving intersystem crossing, there are two potential energy surfaces (PESs) governing the motion of nuclei: PES in a spin-pure state and PES in a spin-mixed state. The former gives wrong results for molecular systems with large spin-orbit coupling (SOC), while the latter requires a potential gradient that includes a change in SOC at each point, making the computational cost very high. In this study, we systematically investigate the extent to which the magnitude of SOC affects the results of the spin-pure state-based dynamics simulations for the hydride MH
2 (M = Si, Ge, Sn, Pb) by performing SH-AIMD simulations based on spin-pure and spin-mixed states. It is clearly shown that spin-mixed state PESs are indispensable for the dynamics simulation of intersystem crossing in systems containing elements Sn and Pb from the fifth period onward. Furthermore, in addition to the widely used Tully's fewest switches (TFS) algorithm, the Zhu-Nakamura (ZN) global switching algorithm, which is computationally less expensive, is applied to SH for comparison. The results from TFS- and ZN-SH-AIMD methods are in qualitative agreement, suggesting that the less expensive ZN-SH-AIMD can be successfully utilized to investigate the dynamics of photochemical reactions based on quantum chemical calculations., (© 2023 Wiley Periodicals LLC.)- Published
- 2024
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42. Longitudinal association of oral functions and dementia in Japanese older adults.
- Author
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Iwai K, Azuma T, Yonenaga T, Sasai Y, Nomura T, Sugiura I, Inagawa Y, Matsumoto Y, Nakashima S, Abe Y, and Tomofuji T
- Subjects
- Humans, Female, Aged, Japan epidemiology, Deglutition, Toothbrushing, Oral Health, Deglutition Disorders, Dementia epidemiology
- Abstract
The relationship between oral functions and dementia was examined in 7384 older adults (age ≥ 75 years) who visited a dental clinic in Gifu, Japan. Participants without dementia in a baseline survey in April 2018 were followed until March 2021. As oral functions, chewing function, tongue and lip function, and swallowing function were assessed by self-administered questionnaire, by oral diadochokinesis test, and by repetitive saliva swallowing test, respectively. The presence of systemic diseases was based on data obtained from the National Database of Health Insurance of Japan. At follow-up, 415 (6%) participants were diagnosed with dementia. Multivariate logistic regression analyses showed the presence of dementia at follow-up was associated with female (odds ratio [OR] 1.386; 95% confidence interval [CI] 1.117-1.719), age (OR 1.078; CI 1.056-1.101), regular dental checkups (absence; OR 1.452; CI 1.180-1.788), brushing frequency ≥ twice/day (absence; OR 1.510; CI 1.194-1.911), decayed teeth (presence; OR 1.328; CI 1.071-1.648), swallowing function (poor; OR 1.484; CI 1.135-1.939) at baseline. It was found that poor swallowing function was associated with the future onset of dementia., (© 2024. The Author(s).)
- Published
- 2024
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43. Theoretical Design and Synthesis of Caged Compounds Using X-Ray-Triggered Azo Bond Cleavage.
- Author
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Ogawara K, Inanami O, Takakura H, Saita K, Nakajima K, Kumar S, Ieda N, Kobayashi M, Taketsugu T, and Ogawa M
- Abstract
Caged compounds are frequently used in life science research. However, the light used to activate them is commonly absorbed and scattered by biological materials, limiting their use to basic research in cells or small animals. In contrast, hard X-rays exhibit high bio-permeability due to the difficulty of interacting with biological molecules. With the main goal of developing X-ray activatable caged compounds, azo compounds are designed and synthesized with a positive charge and long π-conjugated system to increase the reaction efficiency with hydrated electrons. The azo bonds in the designed compounds are selectively cleaved by X-ray, and the fluorescent substance Diethyl Rhodamine is released. Based on the results of experiments and quantum chemical calculations, azo bond cleavage is assumed to occur via a two-step process: a two-electron reduction of the azo bond followed by N─N bond cleavage. Cellular experiments also demonstrate that the azo bonds can be cleaved intracellularly. Thus, caged compounds that can be activated by an azo bond cleavage reaction promoted by X-ray are successfully generated., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)
- Published
- 2024
- Full Text
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44. Treatments and prognostic factors for bone and soft tissue sarcoma in non-urban areas in Japan.
- Author
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Nakamura N, Hasebe S, Yamanaka S, Fujii T, Fujibuchi T, Kitani T, Takeuchi K, Sato Y, Shindo Y, Ozaki T, Nishisho T, Tabata M, and Yakushijin Y
- Subjects
- Humans, Male, Female, Aged, Prognosis, Japan epidemiology, Retrospective Studies, Bone Neoplasms epidemiology, Bone Neoplasms therapy, Sarcoma epidemiology, Sarcoma therapy, Soft Tissue Neoplasms epidemiology, Soft Tissue Neoplasms therapy
- Abstract
Background: Although bone and soft tissue sarcoma is recognized as a rare cancer that originates throughout the body, few comprehensive reports regarding it have been published in Japan., Patients and Methods: Bone and soft tissue sarcomas were tabulated from the Cancer Registries at eight university hospitals in the Chugoku-Shikoku region. Prognostic factors in cases were extracted in a single facility and have been analyzed., Results: From 2016 to 2019, 3.4 patients with bone and soft tissue sarcomas per a general population of 100,000 were treated at eight university hospitals. The number of patients who underwent multidisciplinary treatment involving collaboration among multiple clinical departments has been increasing recently. In the analysis carried out at a single institute (Ehime University Hospital), a total of 127 patients (male/female: 54/73) with an average age of 67.0 y (median 69.5) were treated for four years, with a 5-year survival rate of 55.0%. In the analysis of prognostic factors by multivariate, disease stage and its relative treatment, renal function (creatinine), and a patient's ability of self-judgment, and a patient's mobility and physical capability were associated with patient prognosis regarding bone and soft tissue sarcomas. Interestingly, age did not affect the patient's prognosis (> 70 vs ≦ 70)., Conclusions: Physical and social factors may affect the prognosis of patients with bone and soft tissue sarcomas, especially those living in non-urban areas., (© 2023. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)
- Published
- 2024
- Full Text
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45. Suitable Patient Selection and Optimal Timing of Treatment for Persistent Air Leak after Lung Resection.
- Author
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Yamauchi Y, Adachi H, Takahashi N, Morohoshi T, Yamamoto T, Endo M, Ueno T, Woo T, Saito Y, and Sawabata N
- Abstract
Objectives: The choice of therapeutic intervention for postoperative air leak varies between institutions. We aimed to identify the optimal timing and patient criteria for therapeutic intervention in cases of postoperative air leaks after lung resection., Methods: This study utilized data from a prospective multicenter observational study conducted in 2019. Among the 2187 cases in the database, 420 cases with air leaks on postoperative day 1 were identified. The intervention group underwent therapeutic interventions, such as pleurodesis or surgery, while the observation group was monitored without intervention. A comparison between the intervention group and the observation group were analyzed using the cumulative distribution and hazard functions., Results: Forty-six patients (11.0%) were included in the intervention group. The multivariate analysis revealed that low body mass index ( p = 0.019), partial resection ( p = 0.010), intraoperative use of fibrin glue ( p = 0.008), severe air leak on postoperative day 1 ( p < 0.001), and high forced expiratory volume in 1 s ( p = 0.021) were significant predictors of the requirement for intervention. The proportion of patients with persistent air leak in the observation group was 20% on postoperative day 5 and 94% on postoperative day 7. The hazard of air leak cessation peaked from postoperative day 3 to postoperative day 7., Conclusions: This research contributes valuable insights into predicting therapeutic interventions for postoperative air leaks and identifies scenarios where spontaneous cessation is probable. A validation through prospective studies is warranted to affirm these findings.
- Published
- 2024
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46. Defect passivation in methylammonium/bromine free inverted perovskite solar cells using charge-modulated molecular bonding.
- Author
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Khadka DB, Shirai Y, Yanagida M, Ota H, Lyalin A, Taketsugu T, and Miyano K
- Abstract
Molecular passivation is a prominent approach for improving the performance and operation stability of halide perovskite solar cells (HPSCs). Herein, we reveal discernible effects of diammonium molecules with either an aryl or alkyl core onto Methylammonium-free perovskites. Piperazine dihydriodide (PZDI), characterized by an alkyl core-electron cloud-rich-NH terminal, proves effective in mitigating surface and bulk defects and modifying surface chemistry or interfacial energy band, ultimately leading to improved carrier extraction. Benefiting from superior PZDI passivation, the device achieves an impressive efficiency of 23.17% (area ~1 cm
2 ) (low open circuit voltage deficit ~0.327 V) along with superior operational stability. We achieve a certified efficiency of ~21.47% (area ~1.024 cm2 ) for inverted HPSC. PZDI strengthens adhesion to the perovskite via -NH2 I and Mulliken charge distribution. Device analysis corroborates that stronger bonding interaction attenuates the defect densities and suppresses ion migration. This work underscores the crucial role of bifunctional molecules with stronger surface adsorption in defect mitigation, setting the stage for the design of charge-regulated molecular passivation to enhance the performance and stability of HPSC., (© 2024. The Author(s).)- Published
- 2024
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- View/download PDF
47. Singlet fission initiating organic photosensitizations.
- Author
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Tsuneda T and Taketsugu T
- Abstract
The feasibility of singlet fission (SF) in organic photosensitizers is investigated through spin-flip long-range corrected time-dependent density functional theory. This study focuses on four major organic photosensitizer molecules: benzophenone, boron-dipyrromethene, methylene blue, and rose bengal. Calculations demonstrate that all these molecules possess moderate [Formula: see text]-stacking energies and closely-lying singlet (S) and quintet (triplet-triplet, TT) excitations, satisfying the essential conditions for SF: (1) Near-degenerate low-lying S and (TT) excitations with a significant S-T energy gap, and (2) Moderate [Formula: see text]-stacking energy of chromophores, slightly higher than solvation energy, enabling dissociation for triplet-state chromophore generation. Moreover, based on the El-Sayed rule, intersystem crossing is found to simultaneously proceed at very slow rates in all these photosensitizers. This is attributed to the fact that the lowest singlet excitation of the monomers partly involves [Formula: see text] transitions alongside the main [Formula: see text] transitions. The proposed mechanisms are strongly substantiated by comparisons with experimental studies., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
48. Ultrafast Raman observation of the perpendicular intermediate phantom state of stilbene photoisomerization.
- Author
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Kuramochi H, Tsutsumi T, Saita K, Wei Z, Osawa M, Kumar P, Liu L, Takeuchi S, Taketsugu T, and Tahara T
- Abstract
Trans-cis photoisomerization is generally described by a model in which the reaction proceeds via a common intermediate having a perpendicular conformation around the rotating bond, irrespective of from which isomer the reaction starts. Nevertheless, such an intermediate has yet to be identified unambiguously, and it is often called the 'phantom' state. Here we present the structural identification of the common, perpendicular intermediate of stilbene photoisomerization using ultrafast Raman spectroscopy. Our results reveal ultrafast birth and decay of an identical, short-lived transient that exhibits a vibrational signature characteristic of the perpendicular state upon photoexcitation of the trans and cis forms. In combination with ab initio molecular dynamics simulations, it is shown that the photoexcited trans and cis forms are funnelled off to the ground state through the same, perpendicular intermediate., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
- Published
- 2024
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49. Roles of Singlet Fission in the Photosensitization of Silicon Phthalocyanine.
- Author
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Tsuneda T and Taketsugu T
- Abstract
The roles of singlet fission in the triplet generation of silicon phthalocyanine (SiPc), a compound analogous to the IRDye700DX photosensitizer used in near-infrared photoimmunotherapy, are investigated by considering the energetical relation between the excitations of this compound. These excitations are obtained through spin-flip long-range corrected time-dependent density functional theory calculations. To initiate singlet fission, chromophores must meet two conditions: (1) near-degenerate low-lying singlet and quintet (triplet-triplet) excitations with a considerable energy gap of the lowest singlet and triplet excited states and (2) moderate π-stacking energy of chromophores, which is higher than but not far from the solvation energy, to facilitate the dissociation and generation of triplet-state chromophores. The present calculations demonstrate that SiPc satisfies both of these conditions after the formation of π-stacking irrespective of the presence of an axial ligand(s), suggesting that singlet fission plays a crucial role in the triplet generation process, although intersystem crossing occurs simultaneously at a very slow rate.
- Published
- 2023
- Full Text
- View/download PDF
50. A Steric-Repulsion-Driven Clutch Stack of Triaryltriazines: Correlated Molecular Rotations and a Thermoresponsive Gearshift in the Crystalline Solid.
- Author
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Jin M, Kitsu R, Hammyo N, Sato-Tomita A, Mizuno M, Mikherdov AS, Tsitsvero M, Lyalin A, Taketsugu T, and Ito H
- Abstract
We report that a newly developed type of triaryltriazine rotor, which bears bulky silyl moieties on the para position of its peripheral phenylene groups, forms a columnar stacked clutch structure in the crystalline phase. The phenylene units of the crystalline rotors display two different and interconvertible correlated molecular motions. It is possible to switch between these intermolecular geared rotational motions via a thermally induced crystal-to-crystal phase transition. Variable-temperature solid-state
2 H NMR measurements and X-ray diffraction studies revealed that the crystalline rotor is characterized by a vertically stacked columnar structure upon introducing a bulky Si moiety with bent geometry as the stator. The structure exhibits correlated flapping motions via a combination of 85° and ca. 95° rotations between 295 and 348 K, concurrent with a negative entropy change (Δ S‡ = -23 ± 0.3 cal mol-1 K-1 ). Interestingly, heating the crystal beyond 348 K induces an anisotropic expansion of the column and lowers the steric congestion between the adjacent rotators, thus altering the correlated motions from a flapping motion to a correlated 2-fold 180° rotation with a lower entropic penalty (Δ S‡ = -14 ± 0.5 cal mol-1 K-1 ). The obtained results of our study suggest that the intermolecular stacking of the C3 -symmetric rotator driven by the steric repulsion of the bulky stator represents a promising strategy for producing various correlated molecular motions in the crystalline phase. Moreover, direct and reversible modulation of the intermolecularly correlated rotation is achieved via a thermally induced crystal-to-crystal phase transition, which operates as a gearshift function at the molecular level.- Published
- 2023
- Full Text
- View/download PDF
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