oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 3 )

2018 ( 51 )

2017 ( 64 )

2016 ( 64 )

Custom range...

Search Results: 1 - 10 of 5616 matches for " Hiroyuki Nakamura "
All listed articles are free for downloading (OA Articles)
Page 1 /5616
Display every page Item
Profit-Sharing and the Endogenous Order of Moves in Oligopoly  [PDF]
Hiroyuki Takami, Tamotsu Nakamura
Theoretical Economics Letters (TEL) , 2012, DOI: 10.4236/tel.2012.22023
Abstract: Whether firms move sequentially or simultaneously is one of the most important questions in the oligopoly theory. Forms of firms and/or their remuneration systems influence the decisions. This paper analyzes the effect of profit-sharing on the endogenous order of moves in a wage-setting stage of a unionized duopoly where one adopts profit-sharing while the other does not. It is shown that the two firms do not move simultaneously. In addition, if a fraction of profits going to the union is large, the Stackelberg equilibrium with the profit sharing firm moving first emerges endogenously.
Effects of air sac compliances on flow in the parabronchi: Computational fluid dynamics using an anatomically simplified model of an avian respiratory system  [PDF]
Akira Urushikubo, Masanori Nakamura, Hiroyuki Hirahara
Journal of Biomedical Science and Engineering (JBiSE) , 2013, DOI: 10.4236/jbise.2013.64061
Abstract:

Air flow in an avian lung was studied numerically to determine the effects of air sac compliance on flow in the parabronchi. In this preliminary study, the geometry of the avian respiratory system was simplified to capture the characteristics of respiratory flow. The pressure fluctuation within air sacs caused by inflation and deflation was expressed by a lumped parameter model. The results demonstrate that the flow direction in the parabronchi varied, depending upon the compliance of the air sacs. A unidirectional flow in the parabronchi was achieved for compliances where pressure fluctuations in all air sacs were in phase. Air sac compliance significantly affected the pressures in the anterior and posterior air sacs and thus the pressure difference over the parabronchi that drove the flow in the parabronchi. These results address the importance of air sac compliance in the avian respiratory system and suggest that the compliance of air sacs would be optimized to accomplish unidirectional flow in the parabronchi.

Suppression of Methotrexate-Induced Elevations in the Serum Alanine Aminotransferase Level of Patients with Rheumatoid Arthritis Who Had Prior Hepatitis B Infection  [PDF]
Osamu Noguchi, Yukio Nakamura, Hiroyuki Kato
Health (Health) , 2018, DOI: 10.4236/health.2018.105042
Abstract: Background: Hepatitis after the reactivation of hepatitis B virus (HBV) has been recognized serious in the patients with rheumatoid arthritis (RA) treated with biologics. Objectives: The objective of the present study was to search some common background which might be relevant to the host factors that provoke such a serious hepatitis. Methods: We retrospectively collected and analyzed all data of serum alanine aminotransferase (ALT) levels in selected patients with RA at random. Results: A significant association (P < 0.001) between methotrexate (MTX) therapy and elevated serum ALT level was found only in the anti-HBcAb-negative RA group. The mean serum ALT level was significantly higher (P < 0.001) in patients with than without MTX therapy in the anti-HBcAb-negative RA group, although no significant difference was found (P = 0.73) in the anti-HBcAb-positive RA group. In addition, the anti-HBcAb-positive RA patients showed significantly lower mean serum level of ALT (P < 0.01) than anti-HBcAb-negatives provided they are na?ve with biologics. But no significant difference between anti-HBcAb-positives and -negatives in the mean serum level of ALT was found among patients experienced with biologics (P < 0.8). Conclusions: The anti-HBcAb-positive RA group showed the suppression of MTX-induced elevations in serum ALT level. However, this suppression was not found in patients experienced in the treatment with biologics, although it was preserved in those who had not experienced biologics. Failure of this suppressive mechanism of ALT in anti-HBcAb-positive RA patients treated with biologics could be possibly associated with serious hepatitis after the reactivation of HBV infection.
Production and Peripheral Roles of 5-HTP, a Precursor of Serotonin
Kazuhiro Nakamura and Hiroyuki Hasegawa
International Journal of Tryptophan Research , 2012,
Abstract: Serotonin (5-hydroxytryptamine [5-HT]) has been implicated in a variety of physiological and pathological functions. Multiple steps of enzyme reactions enable biosynthesis of 5-HT. The first and rate-limiting step of the reaction is the synthesis of 5-hydroxy-L-tryptophan (5-HTP) from L-tryptophan. This step is dictated by an enzyme, tryptophan hydroxylase (TPH). TPH requires 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4) as a co-substrate of TPH. 5-HTP has been simply regarded as a precursor of 5-HT and it is believed that the biological significance of 5-HTP is essentially ascribed to the production of 5-HT. However, recent works shed light on the specific functions of 5-HTP in the periphery. In this review article, we focus on the specific roles of exogenous 5-HTP as well as the endogenous 5-HTP in the gut epithelial cells. Since systemic treatment with 5-HTP is applied to patients with lower 5-HT levels, the studies on the specific role of 5-HTP might create an opportunity to explore the effects of exogenously-applied 5-HTP in the gut in man.
An efficient spatio-temporal data structure for multi version managemeng of engineering drawings
DEKIHARA Hiroyuki,NAKAMURA Yasuaki
重庆邮电大学学报(自然科学版) , 2004,
Abstract:
Production and Peripheral Roles of 5-HTP, a Precursor of Serotonin
Kazuhiro Nakamura,Hiroyuki Hasegawa
International Journal of Tryptophan Research , 2009,
Abstract: Serotonin (5-hydroxytryptamine [5-HT]) has been implicated in a variety of physiological and pathological functions. Multiple steps of enzyme reactions enable biosynthesis of 5-HT. The first and rate-limiting step of the reaction is the synthesis of 5-hydroxy-L-tryptophan (5-HTP) from L-tryptophan. This step is dictated by an enzyme, tryptophan hydroxylase (TPH). TPH requires 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4) as a co-substrate of TPH. 5-HTP has been simply regarded as a precursor of 5-HT and it is believed that the biological significance of 5-HTP is essentially ascribed to the production of 5-HT. However, recent works shed light on the specific functions of 5-HTP in the periphery. In this review article, we focus on the specific roles of exogenous 5-HTP as well as the endogenous 5-HTP in the gut epithelial cells. Since systemic treatment with 5-HTP is applied to patients with lower 5-HT levels, the studies on the specific role of 5-HTP might create an opportunity to explore the effects of exogenously-applied 5-HTP in the gut in man.
Production and Peripheral Roles of 5-HTP, a Precursor of Serotonin
Kazuhiro Nakamura,Hiroyuki Hasegawa
International Journal of Tryptophan Research , 2009,
Abstract:
Efficient Spatial Data Structure for Multiversion Management of Engineering Drawings
Yasuaki Nakamura,Hiroyuki Dekihara
Journal of Systemics, Cybernetics and Informatics , 2004,
Abstract: In the engineering database system, multiple versions of a design including engineering drawings should be managed efficiently. The paper proposes an extended spatial data structure for efficient management of multiversion engineering drawings. The R-tree is adapted as a basic data structure. The efficient mechanism to manage the difference between drawings is introduced to the R-tree to eliminate redundant duplications and to reduce the amount of storage required for the data structure. The extended data structures of the R-tree, MVR and MVR* trees, are developed and the performances of these trees are evaluated. A series of simulation tests shows that, compared with the basic R-tree, the amounts of storage required for the MVR and MVR* trees are reduced to 50% and 30%, respectively. The search efficiencies of the R, MVR, and MVR* trees are almost the same.
Effect of pulmonary rehabilitation on oxidative stress in patients with pulmonary diseases  [PDF]
Masayuki Itoh, Kenji Nemoto, Takao Tsuji, Hiroyuki Nakamura, Kazutetsu Aoshiba
Advances in Bioscience and Biotechnology (ABB) , 2012, DOI: 10.4236/abb.2012.327125
Abstract: Exercise-training-based pulmonary rehabilitation has been confirmed to be effective in improving the activities of daily living (ADL) and relieving the dyspnea of chronic obstructive pulmonary disease (COPD) patients. Exercise training increases the antioxidant capacity of COPD patients, but since strenuous exercise and acute exercise loading have the opposite effect and increase oxidative stress, it is important to establish exercise training conditions that efficiently raise antioxidant capacity without increasing oxidative stress. Research on oxidative stress during exercise training by COPD patients has been pursued from that standpoint, but in recent years the targets of research on respirator diseases other than COPD have been expanding. In this article we will therefore review the results of research that has been conducted thus far on the effect of pulmonary rehabilitation on oxidative stress, including the results obtained at our own institution.
Veno-Venous Extracorporeal Membrane Oxygenation for Acute Lung Injury after Surgery for Aortic Dissection: A Case Report  [PDF]
Takanori Kono, Takeshi Oda, Keiichi Akaiwa, Katsuhiko Nakamura, Hiroyuki Tanaka
World Journal of Cardiovascular Surgery (WJCS) , 2017, DOI: 10.4236/wjcs.2017.712018
Abstract: Acute respiratory failure after surgery for aortic dissection is a serious complication that has been associated with increased mortality and morbidity. Veno-venous (VV) extracorporeal membrane oxygenation (ECMO) is reported as one of the treatments for this life-threatening complication. A 78-year-old male patient was admitted to our hospital for Stanford type A acute aortic dissection. He underwent emergency replacement of the ascending aorta, after which he developed acute lung injury. It was difficult to maintain oxygenation with a respirator mask. Therefore, VV-ECMO was initiated on postoperative day 1. The oxygenation gradually improved, and VV-ECMO was continued until postoperative day 13. On postoperative day 25, mechanical ventilation was withdrawn. The patient was discharged from the hospital on postoperative day 149. We report a case of successful treatment of acute lung injury with VV-ECMO initiated after surgery for aortic dissection. VV-ECMO can be considered as a treatment option for severe acute lung injury after surgery for aortic dissection.
Page 1 /5616
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.