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Experimental study on the in-plane thermal conductivity of Au nanofilms

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Progress in Natural Science:Materials International 2007年第2期17卷 212-216页

作者： TAKAHASHI Koji IKUTA Tatsuya fujii Motoo Graduate School of Engineering Kyushu UniversityFukuoka 812-8581Japan Institute for Materials Chemistry and Engineering Kyushu UniversityKasuga 816-8580Japan

The in-plane thermal conductivity of Au nanofilms with thickness of 23 nm, which are fabricated by the electron beam-physical vapor deposition method and a suspension technology, is experimentally measured at 80-300 K by a one-dimensional steady-state electrical heating method. Strong size effects are found on the measured nanofilm thermal conductivity. The Au nanofilm in-plane thermal conductivity is much less than that of the bulk material. With the increasing temperature, the nanofilm thermal conductivity increases. This is opposite to the temperature dependence of the bulk property. The Lorenz number of the Au nanofilms is about three times larger than the bulk value and decreases with the increasing temperature, which indicates the invalidity of the Wiedemann-Franz law for metallic nanofilms.

关键词： nanofilm in-plane thermal conductivity size effect Wiedemann-Franz law.

Case of angina pectoris at rest and during effort due to coronary spasm and myocardial bridging

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World Journal of Cardiology 2015年第6期7卷 367-372页

作者： hiroki Teragawa Yuichi fujii Tomohiro Ueda Daiki Murata Shuichi Nomura Department of Cardiovascular Medicine Hiroshima General Hospital of West Japan Railway Company

We present a case of a 71-year-old male who hadchest symptoms at rest and during effort. He had felt chest oppression during effort for 1 year,and his chest symptoms had recently worsened. One month before admission he felt chest squeezing at rest in the early morning. He presented at our institution to evaluate his chest symptoms. Electrocardiography and echocardiography failed to show any specific changes. Because of the possibility that his chest symptoms were due to myocardial ischemia,he was admitted to our institution for coronary angiography(CAG). An initial CAG showed mild atherosclerotic changes in the proximal segment of the left anterior descending coronary artery(LAD) and mid-segment of the left circumflex coronary artery. Subsequent spasm provocation testing using acetylcholine revealed a bilateral coronary vasospasm,which was relieved after the intracoronary infusion of nitroglycerin. Finally,a CAG showed myocardial bridging(MB) of the mid-distal segments of the LAD. Fractional flow reserve using the intravenous administration of adenosine triphosphate was positive at 0.77,which jumped up to 0.90 through the myocardial bridging segments when the pressure wire was pulled back. Thus,coronary vasospasm and MB might have contributed to his chest symptoms at rest and during effort. Interventional cardiologists should consider the presence of MB as a potential cause of myocardial ischemia.

关键词： Coronary spasm Myocardial bridging Myocardial squeezing Fractional flow reserve

Effect of Gravity on Arc Shape in GTA Welding-for Low Electric Arc Current

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Journal of Materials Science & Technology 2003年第z1期19卷 209-211页

作者： Hidetoshi fujii Yosuke SUMI Manabu TANAKA Kiyoshi NOGI Joining and Welding Research Institute Osaka University 11-1 Mihogaoka Ibaraki Osaka 567-0047 Japan Joining and Welding Research Institute Osaka University 11-1 Mihogaoka Ibaraki Osaka 567-0047 Japan Joining and Welding Research Institute Osaka University 11-1 Mihogaoka Ibaraki Osaka 567-0047 Japan Joining and Welding Research Institute Osaka University 11-1 Mihogaoka Ibaraki Osaka 567-0047 Japan

Gas tungsten arc (GTA) welding was performed both in a microgravity environment and in a terrestrial environment,and the arc shapes in both environments were compared. A microgravity condition was obtained using the free fallsystem at the Japan Microgravity Center. The system can maintain a 10 s microgravity of less than 10-5 g. Awater-cooled Cu plate was used to simplify the arc phenomenon. The electric arc current was between 15 and 80 A,and the shielding and atmospheric gas was 99.9995% Ar and its flowing rate was 10 l/min. The polarity was a directcurrent electrode negative (DCEN). The arc gap was 3 mm and careful attention was also paid to the arc gap in boththe terrestrial and microgravity environments being the same. As a result, it was found that no effect of gravity onthe arc shape is observed under general welding conditions (over 60 A). When the electric arc current is lower than25 A, the arc shape is determined by the initial position of the arc root and is constant with time. Accordingly, itcan not be judged whether or not the arc shape is affected by gravity for this range. When the electric arc current isbetween 25 A and 60 A, it is estimated that the arc shape is not affected by gravity though it is occasionally affectedby other minor effects.

关键词： Microgravity, Arc shape, Gas tungsten arc welding, Water-cooled Cu

Endoplasmic reticulum stress,autophagy,neuroinflammation,and sigma 1 receptors as contributors to depression and its treatment

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Neural Regeneration Research 2024年第10期19卷 2202-2211页

作者： Chika fujii Charles F.Zorumski Yukitoshi Izumi Department of Psychiatry Washington University School of MedicineSt.LouisMOUSA Taylor Family Institute for Innovative Psychiatric Research Washington University School of MedicineSt.LouisMOUSA

The etiological factors contributing to depression and other neuropsychiatric disorders are largely undefined. Endoplasmic reticulum stress pathways and autophagy are well-defined mechanisms that play critical functions in recognizing and resolving cellular stress and are possible targets for the pathophysiology and treatment of psychiatric and neurologic illnesses. An increasing number of studies indicate the involvement of endoplasmic reticulum stress and autophagy in the control of neuroinflammation, a contributing factor to multiple neuropsychiatric illnesses. Initial inflammatory triggers induce endoplasmic reticulum stress, leading to neuroinflammatory responses. Subsequently, induction of autophagy by neurosteroids and other signaling pathways that converge on autophagy induction are thought to participate in resolving neuroinflammation. The aim of this review is to summarize our current understanding of the molecular mechanisms governing the induction of endoplasmic reticulum stress, autophagy, and neuroinflammation in the central nervous system. Studies focused on innate immune factors, including neurosteroids with anti-inflammatory roles will be reviewed. In the context of depression, animal models that led to our current understanding of molecular mechanisms underlying depression will be highlighted, including the roles of sigma 1 receptors and pharmacological agents that dampen endoplasmic reticulum stress and associated neuroinflammation.

关键词： allopregnanolone fluvoxamine ketamine neurosteroids postpartum depression quercetin

Effects of 5-HT2B, 5-HT3 and 5-HT4 receptor antagonists on gastrointestinal motor activity in dogs

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World Journal of Gastroenterology 2013年第39期19卷 6604-6612页

作者： hiroki Morita Erito Mochiki Nobuyuki Takahashi Kiyoshi Kawamura Akira Watanabe Toshinaga Sutou Atsushi Ogawa Mitsuhiro Yanai Kyoichi Ogata Takaaki fujii Tetsuro Ohno Souichi Tsutsumi Takayuki Asao Hiroyuki Kuwano Department of General Surgical Science (Surgery 1) Gunma UniversityGraduate School of MedicineGunma 371-8511Japan RaQualia Pharma Inc. Research and Development5-2 TaketoyoAichi 470-2341Japan

AIM:To study the effects of 5-hydroxytryptamine(5-HT)receptor antagonists on normal colonic motor activity in conscious ***:Colonic motor activity was recorded using a strain gauge force transducer in 5 dogs before and after 5-HT2B,5-HT3 and 5-HT4 receptor antagonist *** force transducers were implanted on the serosal surfaces of the gastric antrum,terminal ileum,ileocecal sphincter and *** materials or vehicle alone was administered as an intravenous bolus injection during a quiescent period of the whole colon in the interdigestive *** effects of these receptor antagonists on normal gastrointestinal motor activity were ***:5-HT2B,5-HT3 and 5-HT4 receptor antagonists had no contractile effect on the fasting canine terminal *** 5-HT3 and 5-HT4 receptor antagonists inhibited phaseⅢof the interdigestive motor complex of the antrum and significantly inhibited colonic motor *** the proximal colon,the inhibitory effect was dose *** dependency,however,was not observed in the distal *** 5-HT2B receptor antagonist had no contractile effect on normal colonic motor ***:The 5-HT3 and 5-HT4 receptor antagonists inhibited normal colonic motor ***5-HT2B receptor antagonist had no contractile effect on normal colonic motor activity.

关键词： 5-hydroxytryptamine receptor antagonist Colonic motility Irritable bowel syndrome

Effect of Stacking Fault Energy on the Grain Structure Evolution of FCC Metals During Friction Stir Welding

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Acta Metallurgica Sinica(English Letters) 2020年第7期33卷 1001-1012页

作者： Xiaochao Liu Yufeng Sun Tomoya Nagira Kohsaku Ushioda Hidetoshi fujii Joining and Welding Research Institute Osaka University11-1 MihogaokaIbarakiOsaka 567-0047Japan School of Materials Science and Engineering Northwestern Polytechnical UniversityXi'an 710072China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China

The effect of stacking fault energy(SFE) on the grain structure evolution of face-centered cubic metals during friction stir welding was investigated by using pure aluminum,pure copper and Cu-30 Zn alloy as experiment *** "stop action" and rapid cooling were employed to "freeze" the microstructure of the flowing materials around the *** materials were used to show the streamline of the material *** microstructures of the three materials at different welding stages were contrastively studied by the electron backscatter diffraction *** results show that at the material flow stage,as the SFE decreases,the grain structure evolution changes from the continuous dynamic recrystallization to discontinuous dynamic recrystallization,and further to the dynamic equilibrium between the annealing twinning due to thermally activated grain boundary migration and the twin destruction during the plastic *** to different grain structure evolution mechanisms,the grain structure at the end of the material flow is greatly *** in copper,a lot of dislocations remain,which gives rise to the static recrystallization occurring during the subsequent cooling stage.

关键词： recrystallization grain welding

Principle for obtaining high joint quality in dissimilar friction welding of Ti-6Al-4V alloy and SUS316L stainless steel

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Journal of Materials Science & Technology 2020年第11期42卷 211-224页

作者： Huihong Liu Yo Aoki Yasuhiro Aoki Kohsaku Ushioda Hidetoshi fujii Joining and Welding Research Institute Osaka UniversityIbarakiOsaka 567-0047Japan

Ti-6Al-4V alloy(Ti64)and SUS316 L stainless steel rods were dissimilarly friction *** focusing on the detailed observation of interface microstructural evolution during the friction welding(FW),the relationship between the processing conditions,weld interface microstructure,and mechanical properties of the obtained joints were systematically investigated to elucidate the principle for obtaining a high joint quality in the FW of Ti64 and SUS316L.A higher friction pressure produced a lower welding temperature in the FW,hence suppressing the thick intermetallic compound layer ***,hard and brittle Ti64/SUS316L mechanically mixed layers generally formed especially at the weld interface periphery due to the high temperature increasing rate,high rotation linear velocity and high outward flow velocity of the *** harmful layers tended to induce the cracks/voids formation at the weld interfaces hence deteriorating the joints’mechanical *** rotation speed reduction and liquid CO2 cooling during the entire processing decreased the temperature increasing rate,rotation linear velocity and outward flow velocity of the Ti64 at the weld interface ***,they suppressed the formation of the harmful mechanically mixed layers,facilitated the homogeneous and sound interface microstructure generation,and finally produced a high-quality dissimilar joint in the FW of Ti64 and SUS316L.

关键词： Friction welding Titanium alloy Stainless steel Microstructure formation mechanism Mechanically mixed layers

Increased frequency of angina attacks caused by switching a brand-name vasodilator to a generic vasodilator in patients with vasospastic angina:Two case reports

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World Journal of Cardiology 2018年第3期10卷 15-20页

作者： Remi Goto-Semba Yuichi fujii Tomohiro Ueda Chikage Oshita hiroki Teragawa Department of Education and Training JR Hiroshima Hospital Department of Cardiovascular Medicine JR Hiroshima Hospital

It is well known that calcium channel blockers(CCBs) are the first line of therapy for vasospastic angina(VSA). Here, we report two cases of VSA with an increase in the frequency of angina attacks after switching from a brand-name to a generic CCB. In both cases, angina recurred upon switching from a brand-name CCB to a generic CCB during follow-up. The patients' condition improved upon switching back to the original CCB. Both cases involved a high severity of VSA, based on the results of spasm provocation testing. These findings suggest that, in some patients with severe VSA, the frequency of angina attacks increases when switching from a brand-name CCB to a generic CCB. Cardiologists should consider this factor when prescribing drugs for angina.

关键词： Vasospastic angina Acetylcholine Brandname drugs Generic drugs Refractory chest pain

Time Dependant Weld Shape in Ar-O_2 Shielded Stationary GTA Welding

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Journal of Materials Science & Technology 2007年第5期23卷 650-654页

作者： Shanping L U Dianzhong LI Hidetoshi fujii Kiyoshi Nogi Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 Chian Joining and Welding Research Institute Osaka University Osaka567-0047 Japan

The stationary gas tungsten arc welding （GTA） is carried out on SUS304 stainless steel under Ar-0.1%O2 and Ar-0.3%O2 mixed shielding to observe the evolution of the molten pool and investigate the role of Marangoni convection on the weld shape. After welding, the oxygen content in the weld metal was measured by using an oxygen/nitrogen analyzer. Small addition of oxygen to the argon based shielding gas can effectively adjust the weld pool oxygen content. Oxygen plays an important role as an surface active element in determining the pattern of Marangoni convection in the stainless steel weld pool. When the weld metal oxygen content is over the critical value, 0.01 wt pct, corresponding to the Ar-0.3%O2 mixed shielding gas, the Marangoni convection changes from outward to inward direction and the weld shape dramatically changes from wide shallow shape to narrow deep shape.

关键词： Marangoni convection Oxygen Weld shape