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Operationally Simple Enantioselective Silane Reduction of Ketones by the [Ir(OMe)(cod)]₂/Azolium Catalytic System

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International Journal of Organic Chemistry 2024年第1期14卷 1-19页

作者： Satoshi sakaguchi Chika Nagao Ryo Ichihara Shogo Matsuo Department of Chemistry and Materials Engineering Faculty of Chemistry Materials and Bioengineering Kansai University Suita Japan

An operationally simple protocol was designed for the enantioselective silane reduction (ESR) of ketones using air- and moisture-stable [Ir(OMe)(cod)]2 (cod = 1,5-cyclooctadiene) (3) as a metal catalyst precursor. This reaction was driven by chiral hydroxyamide-functionalized azolium salt 2. The catalytic ESR reaction could be performed under benchtop conditions at room temperature. Treatment of 2 with 3 in THF yielded the monodentate IrCl(NHC)(cod) (NHC = N-heterocyclic carbene) complex 4 in 93% yield, herein the anionic methoxy ligand of 3 serves as an internal base that deprotonates the azolium ring of 2. The well-defined Ir complex 4 catalyzed the ESR reaction of propiophenone (6) with (EtO)2MeSiH using the pre-mixing reaction procedure. Based on this success, the catalytic ESR reaction was designed and implemented using an in situ-generated NHC/Ir catalyst derived from 2 and 3. Thus, a wide variety of aryl ketones could be reduced to the corresponding optically active alcohols in moderate to excellent stereoselectivities at room temperature without temperature control. Since the high catalytic activity of 3 was observed, we next evaluated several other transition metal catalyst precursors for the catalytic ESR reaction under the influence of 2. This evaluation revealed that Ir(acac)(cod) (acac = acetylacetonate) (28) and [IrCl(cod)]2 (5) can be successfully used as metal catalyst precursors in the ESR reaction.

关键词： Asymmetric Catalysis Enantioselective Reduction Hydrosilylation Reaction N-Heterocyclic Carbene Iridium

Unroofing Technique for Anomalous Origin of the Left Coronary Artery from the Right Sinus of Valsalva: Report of a Case

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World Journal of Cardiovascular Surgery 2024年第6期14卷 69-77页

作者： Keisuke Morimoto Futoshi Kobayashi Hiromu Horie Yuki sakaguchi Einosuke Mizuta Department of Cardiovascular Surgery Sanin Rosai Hospital Yonago Japan Department ofCardiology Sanin Rosai Hospital Yonago Japan

Anomalous origin of the left coronary artery (AOLCA) from the right sinus of Valsalva constitutes a rare congenital coronary artery anomaly. Patients with an anomalous left main coronary artery face a significantly higher risk of sudden cardiac death compared to those with an anomalous right coronary artery. The anomalous coronary artery traversing between the ascending aorta and the pulmonary artery markedly heightens the risk of myocardial ischemia, arrhythmia, and sudden death. Symptomatic patients often exhibit a longer intramural course of the coronary artery, which may necessitate earlier intervention or influence the choice of surgical repair method. Surgical intervention is advocated for patients with this anomaly, even in the absence of symptoms. For anomalous aortic origin of a coronary artery from the opposite sinus of Valsalva with an intramural course, coronary unroofing is the preferred revascularization procedure. This report presents a case of AOLCA originating from the right sinus of Valsalva, treated surgically using the unroofing technique for the aortic intramural segment of the anomalous coronary artery traversing between the great vessels. The unroofing technique is recommended for treating AOLCA with an extensive intramural course that does not involve the commissure.

关键词： Unroofing Technique Anomaly of Coronary Artery Anomalous Origin of Left Coronary Artery

Contribution of adult-born neurons to memory consolidation during rapid eye movement sleep

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Neural Regeneration Research 2022年第2期17卷 307-308页

作者： Akinobu Ohba Masanori sakaguchi International Institute for Integrative Sleep Medicine(WPI-IIIS) University of TsukubaTsukubaIbarakiJapan

Introduction: Memory consolidation stabilizes newly acquired memories by integrating them into pre-existing memory networks, which is thought to occurvia changes in synaptic strength. Sleep may influence memory consol... 详细信息

关键词： strength. sleep integrating

Fabric characteristics of in situ sand with/without liquefaction verified by anisotropy of magnetic susceptibility

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第5期15卷 1274-1283页

作者： Xueqian Ni Junnan Ma Hide sakaguchi Feng Zhang School of Civil Engineering Central South UniversityChangsha410075China Department of Civil Engineering Nagoya Institute of TechnologyNagoya466-8555Japan Ocean Policy Research Institute The Sasakawa Peace FoundationTokyo105-8524Japan

It is well known that fabric of sand may significantly affect mechanical behaviors and liquefaction resistance of *** optical techniques are currently utilized to visualize the fabric,especially the distribution of the long axis of soil ***,none of these methods provides an ideal solution in laboratory tests and in situ *** this study,anisotropy of magnetic susceptibility(AMS)was first proposed as a convenient and efficient way to evaluate the liquefaction of clean *** first,investigations with scanning electron microscopy(SEM)and AMS were simultaneously conducted on two groups of soil specimens with different initial fabrics to verify the feasibility of the AMS ***,80 in situ samples were collected to analyze the feature of liquefied and non-liquefied sand layers through AMS *** is clearly known from the test results that the natural sedimentary fabric was destroyed during liquefaction and the fabric anisotropy was greatly changed after *** feasibility of evaluating soil fabric using the AMS survey was verified by the laboratory ***,the applicability of AMS in detecting liquefied layer in situ was confirmed for the first time.

关键词： Sand liquefaction Soil fabric Anisotropy of magnetic susceptibility(AMS) Geotechnical seismic engineering

Physical activity lowers the risk for acute respiratory infections:Time for recognition

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Journal of Sport and Health Science 2022年第6期11卷 648-655,F0003页

作者： David C.Nieman Camila A.sakaguchi Human Performance Laboratory Appalachian State UniversityNorth Carolina Research CampusKannapolisNC 28081USA

Physical inactivity is a well-established risk factor for chronic diseases,such as cardiovascular disease,cancer,and diabetes *** is a growing awareness that physical inactivity should also be regarded as a risk factor for acute respiratory infections(ARIs).ARIs,such as the common cold,influenza,pneumonia,and coronavirus disease 2019(COVID-19),are among the most pervasive diseases on earth and cause widespread morbidity and *** in support of the linkage between ARIs and physical inactivity has been strengthened during the COVID-19 pandemic because of increased scientific ***-scale studies have consistently reported that the risk for severe COVID-19 outcomes is elevated in cohorts with low physical activity and/or physical fitness,even after adjusting for other risk *** lowered risk for severe COVID-19 and other ARIs in physically active groups is attributed to exercise-induced immunoprotective effects,including enhanced surveillance of key immune cells and reduced chronic *** consensus groups,including those who submitted the Physical Activity Guidelines for Americans,have not yet given this area of research the respect that is *** is time to add“reduced risk for ARIs”to the“Exercise is Medicine”list of physical activity-related health benefits.

关键词： Acute respiratory infections COVID-19 Immune system Physical activity Pneumonia

Spatio-temporal deposition profile of an experimentally produced turbidity current with a continuous suspension supply

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International Journal of Sediment Research 2022年第3期37卷 299-306页

作者： Shun Nomura Giovanni De Cesare Mikito Furuichi Yasushi Takeda Hide sakaguchi Mathematical Science and Advanced Technology JAMSTEC Plateforme de Constructions Hydrauliques EPFL Laboratory of Food Process Engineering ETH Headquarters JAMSTEC

A turbidity current is a turbulent, particle-laden gravity current that is driven by density differences resulting from the presence of suspended sediment particles. The current travels downslope, bearing a large amount of sediment over a great distance, and forms fluvial and submarine bedforms. Knowledge of the spatio-temporal deposition profile of turbidity-deposited sediment is important for a better understanding of sediment transport by turbidity currents. In the current study, the depositional process of experimentally produced quasi-steady turbidity currents in an inclined flume was investigated using an electrical-resistance-based depositmeter. It was found that the amount of sediment deposited along the flume bottom increases linearly with time at a specific rate, and decreases exponentially in the downstream direction. Inspired by this observation, the mass conservation law was modified for the suspension layer and a simple theoretical model was proposed involving two parameters, the initial sedimentation rate and the decay constant. The proposed model reproduces the observed data from the flume experiment with high accuracy, and is consistent with the sediment transport distance of a natural example, the Bengal Fan. It was concluded that the two parameters that govern the sedimentation process are the key to estimating the deposition profile of fluvial systems.

关键词： Turbidity current Deposition process Mass conservation law Electrical-resistance-based depositmeter Spatio-temporal investigation Flume experiment

Best mix of primary energy resources by renewable energy and fossil fuel with CCS in view of security,stability and sustainability——A vision on hydrogen supply chain by organic chemical hydride method

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Science China(Technological Sciences) 2010年第1期53卷 62-68页

作者： Junichi sakaguchi Research Institute of Technology Innovation & Strategy of Chiyoda Corporation 2-12-1TsurumichuoTsurumi-kuYokohama230-8601Japan

The best mix scenario by renewable energy and fossil fuel with or without CCS(Carbon Dioxide Capture and Storage) would be a solution to compromise Greenhouse Gases emission issue caused by carbon dioxide(CO2),and depletion of crude oil and natural gas *** fossil fuel with pre-combustion CCS means hydrogen manufacturing and also hydrogen can be produced via electrolysis with renewable energy,it is desirable to establish transportation and storage systems of hydrogen as a clean *** this paper a vision on Hydrogen Supply Chain by Organic Chemical Hydride(OCH) Method as well as comparison of CCS configuration are discussed.

关键词： pre-combustion CCS compressors and pumps for CCS Hydrogen Supply Chain Organic Chemical Hydride Method

Involvement of A5/A7 noradrenergic neurons and B2 serotonergic neurons in nociceptive processing:a fiber photometry study

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Neural Regeneration Research 2022年第4期17卷 881-886页

作者： Shunpei Moriya Akira Yamashita Daiki Masukawa Junichi sakaguchi Yoko Ikoma Yoshimune Sameshima Yuki Kambe Akihiro Yamanaka Tomoyuki Kuwaki Department of Physiology Kagoshima University Graduate School of Medical and Dental ScienceKagoshimaJapan Department of Molecular Pharmacologyand Neurobiology Yokohama City University Graduate School of MedicineYokohamaJapan Department of Pharmacology Kagoshima University Graduate School of Medical and Dental ScienceKagoshimaJapan Research Institute of Environmental Medicine Nagoya UniversityNagoyaJapan

In the central nervous system,the A6 noradrenaline(NA)and the B3 serotonin(5-HT)cell groups are well-recognized players in the descending antinociceptive system,while other NA/5-HT cell groups are not well characterized.A5/A7 NA and B25-HT cells project to the spinal horn and form descending *** recorded G-Ca MP6 green fluorescence signal intensities in the A5/A7 NA and the B25-HT cell groups of awake mice in response to acute tail pinch stimuli,acute heat stimuli,and in the context of a non-noxious control test,using fiber photometry with a calcium imaging *** first introduced G-Ca MP6 in the A5/A7 NA or B25-HT neuronal soma,using transgenic mice carrying the tetracycline-controlled transactivator transgene under the control of either a dopamineβ-hydroxylase or a tryptophan hydroxylase-2 promoters and by the site-specific injection of adeno-associated virus(AAV-Tet O(3 G)-G-Ca MP6).After confirming the specific expression patterns of G-Ca MP6,we recorded G-Ca MP6 green fluorescence signals in these sites in awake mice in response to acute nociceptive stimuli.G-Ca MP6 fluorescence intensity in the A5,A7,and B2 cell groups was rapidly increased in response to acute nociceptive stimuli and soon after,it returned to baseline fluorescence *** was not observed in the non-noxious control *** results indicate that acute nociceptive stimuli rapidly increase the activities of A5/A7 NA or B25-HT neurons but the non-noxious stimuli do *** present study suggests that A5/A7 NA or B25-HT neurons play important roles in nociceptive processing in the central nervous *** suggest that A5/A7/B2 neurons may be new therapeutic *** performed procedures were approved by the Institutional Animal Use Committee of Kagoshima University(MD17105)on February 22,2018.

关键词： A5 NA neurons A7 NA neurons B25-HT neurons DBH-tTA mice fiber photometry G-CaMP6 mCherry monoaminergic signaling nociception TPH-t TA mice

Multi-point Optimization of Recirculation Flow Type Casing Treatment in Centrifugal Compressors

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Journal of Thermal Science 2016年第3期25卷 231-241页

作者： Min Thaw Tun Daisaku sakaguchi Nagasaki University 1-14 Bunkyo-machi 852-8521 Nagasaki Japan

High-pressure ratio and wide operating range are highly required for a turbocharger in diesel engines.A recirculation flow type casing treatment is effective for flow range enhancement of centrifugal *** ring grooves on a suction pipe and a shroud casing wall are connected by means of an annular passage and stable recirculation flow is formed at small flow rates from the downstream groove toward the upstream groove through the annular *** shape of baseline recirculation flow type casing is modified and optimized by using a multi-point optimization code with a metamodel assisted evolutionary algorithm embedding a commercial CFD code CFX from *** numerical optimization results give the optimized design of casing with improving adiabatic efficiency in wide operating flow rate *** analysis of design parameters as a function of efficiency has been *** is found that the optimized casing design provides optimized recirculation flow rate,in which an increment of entropy rise is minimized at grooves and passages of the rotating impeller.

关键词：离心式压缩机优化设计环流式壳体环形通道流量范围循环流率外壳设计