Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 5 )

2018 ( 19 )

2017 ( 29 )

2016 ( 26 )

Custom range...

Search Results: 1 - 10 of 3637 matches for " Takayuki Saito "
All listed articles are free for downloading (OA Articles)
Page 1 /3637
Display every page Item
Study of the High Energy Gamma-ray Emission from the Crab Pulsar with the MAGIC telescope and Fermi-LAT
Takayuki Saito
Physics , 2011,
Abstract: My thesis deals with a fundamental question of high energy gamma-ray astronomy. Namely, I studied the cut-off shape of the Crab pulsar spectrum to distinguish between the leading scenarios for the pulsar models. Pulsars are celestial objects, which emit periodic pulsed electromagnetic radiation (pulsation) from radio to high energy gamma-rays. Two major scenarios evolved in past 40 years to explain the pulsation mechanism: the inner magnetosphere scenario and the outer magnetosphere scenario. Both scenarios predict a high energy cut-off in the gamma-ray energy spectrum, but with different cut-off sharpness. An exponential cut-off is expected for the outer magnetosphere scenario while a super-exponential cut-off is predicted for the inner magnetosphere scenario. Therefore, one of the best ways to confirm or rule out these scenarios is to measure the energy spectrum of a pulsar at around the cut-off energy, i.e., at energies between a few GeV and a few tens of GeV. All past attempts (>10) to measure pulsars with ground-based instruments have failed while satellite-borne detectors had a too small area to study detailed spectra in the GeV domain. In this thesis, the gamma-ray emission at around the cut-off energy from the Crab pulsar is studied with the MAGIC telescope. The public data of the satellite-borne gamma-ray detector, Fermi-LAT, are also analyzed in order to discuss the MAGIC observation results in comparison with the adjacent energy band.
Aeolian Tone from a Semi-Circular Cylinder in a Stream  [PDF]
Takayuki Yamagata, Nozomi Saito, Nobuyuki Fujisawa
Journal of Flow Control, Measurement & Visualization (JFCMV) , 2016, DOI: 10.4236/jfcmv.2016.41003
Abstract: Aeolian tone from a semi-circular cylinder in a uniform flow is studied experimentally for various angles of attack. It is found that the peak sound spectrum of the Aeolian tone from the semi-circular cylinder is smaller than that from the circular cylinder and the lowest sound is observed around the zero angle of attack. This is due to the reduction in the fluctuating lift force on the semi-circular cylinder compared to that of the circular cylinder. This result suggests the validity of the analogy between the sound pressure level and the fluctuating lift force on a semi-circular cylinder in a stream. The flow visualization study also supports these results.
Effect of Fucoidan Dietary Supplement on the Chemotherapy Treatment of Patients with Unresectable Advanced Gastric Cancer  [PDF]
Masahide Ikeguchi, Hiroaki Saito, Yasunari Miki, Takayuki Kimura
Journal of Cancer Therapy (JCT) , 2015, DOI: 10.4236/jct.2015.611111
Abstract: In Japan, S-1 plus cisplatin has become a standard regimen for the treatment of unresectable advanced gastric cancer; however, many patients are unable to continue effective chemotherapy because of the regimen’s severe side effects. Thus, control of drug toxicity is key to prolonging patient survival. Fucoidan is a major sulfated polysaccharide found in brown seaweeds and has a wide range of biological activities. In the present study, we analyzed the effect of fucoidan on suppressing the toxicity of chemotherapy drugs. Twenty-four patients with unresectable advanced gastric cancer underwent treatment with S-1 plus cisplatin and were randomly allocated into a fucoidan treatment group (n = 12) or a control group without fucoidan treatment (n = 12). The study results demonstrated that fucoidan controlled the occurrence of fatigue during chemotherapy and patients could continue chemotherapy for longer time periods by maintaining the patients’ favorable nourishment status. As a result, the survival of patients with fucoidan treatment was longer than that of patients without fucoidan. Thus, fucoidan should be included as a key food supplement for patients with gastrointestinal carcinomas who are suffering from the adverse side effects of chemotherapy.
Connection between rotation and miscibility in a two-component Bose-Einstein condensate
Takayuki Shimodaira,Tetsuo Kishimoto,Hiroki Saito
Physics , 2010, DOI: 10.1103/PhysRevA.82.013647
Abstract: A two-component Bose-Einstein condensate rotating in a toroidal trap is investigated. The topological constraint depends on the density distribution of each component along the circumference of the torus, and therefore the quantization condition on the circulation can be controlled by changing the miscibility using the Feshbach resonance. We find that the system exhibits a variety of dynamics depending on the initial angular momentum when the miscibility is changed.
Comparison between 0.06% and 0.1% Levobupivacaine Combined with 2 μg/mL of Fentanyl for Epidural Labor Analgesia  [PDF]
Takako Hamada, Mariko Baba, Masaki Sato, Takayuki Saito, Keisuke Murakami, Hiroyuki Sumikura
Open Journal of Anesthesiology (OJAnes) , 2013, DOI: 10.4236/ojanes.2013.39080

Purpose: Levobupivacaine is thought to be a good alternative to bupivacaine for epidural labor analgesia because of its pharmacologic profile. However, the optimal concentration of levobupivacaine for labor analgesia has not been adequately studied. The objective of this retrospective study was to compare the analgesic effect of levobupivacaine between 0.06% and 0.1% both combined with 2 μg/mL of fentanyl. Methods: Primiparous women (ASA I, II) who delivered their babies to our hospital using combined spinal epidural analgesia and patient-controlled epidural analgesia between August 1, 2011 and September 30, 2011 were included into this retrospective study. The analgesic solution for epidural administration was 0.06% levobupivacaine with 2 μg/mL of fentanyl between August 1 and 31, and 0.1% levobupivacaine with 2 μg/mL of fentanyl between September 1 and 30. Their anesthetic and obstetric charts were reviewed to compare obstetric outcome, anesthetic intervention, and patients’ satisfaction. Results: There were 46 women fulfilling the inclusion criteria: 23 women in 0.06% group, and 23 women in 0.1% group. The number of patients who needed more than 3 requests for one actual bolus was significantly higher in the 0.06% group (P < 0.05). Conclusion: Our results revealed that 0.06% levobupivacaine combined with 2 μg/mL fentanyl does

The Effects of Glucose Load on Catabolism during Remifentanil-Based Anesthesia in Patients with Diabetes Mellitus: A Prospective Randomized Trial  [PDF]
Maiko Hasegawa-Moriyama, Mayumi Nakahara, Takayuki Saito, Tomotsugu Yamada, Keika Mukaihara, Mina Masuda, Akira Matsunaga, Yuichi Kanmura
Open Journal of Anesthesiology (OJAnes) , 2015, DOI: 10.4236/ojanes.2015.57028
Abstract: Background: General anesthesia using remifentanil may suppress the unwanted metabolic changes caused by surgical stress including hyperglycemia and ketogenesis. Surgery-related changes in catabolism can be attenuated with low-dose glucose load, without causing hyperglycemia. However, the impact of glucose load in diabetic patients during surgery is unknown. In this study, we investigated the effect of glucose load on catabolism during remifentanil-based anesthesia in patients with diabetes mellitus. Methods: Twenty-nine patients with diabetes mellitus undergoing elective surgery were randomly assigned to receive a glucose load (1.5 mg/kg/min) or not. Plasma levels of glucose, insulin, cortisol, dopamine, adrenaline, noradrenaline, acetoacetic acid, free fatty acid, ketone bodies, 3-hydroxybutyric acid, and 3-methylhistidine/creatinine, a marker of protein catabolism were measured at the start of surgery and 3 h after the start of surgery. Results: Glucose and insulin levels were significantly higher in patients who received a glucose load than in those who did not. Cortisol levels decreased at 3 h after the start of surgery in both groups whereas the levels of catecholamines were unchanged. Acetoacetic acid and total ketone body levels were significantly lower in patients given a glucose load than in those who were not 3 h after the start of surgery. The difference in the 3 methylhistidine/creatinine ratio between the two groups was not significant. Conclusions: The infusion of glucose suppressed lipid catabolism in diabetic patients under remifentanil-based anesthesia during surgery. Our study also suggests that in patients with diabetes mellitus, protein sparing is inhibited by remifentanil-based anesthesia, regardless of the glucose load. Trial registration: the University Hospital Medical Information Network identifier: UMIN000010914.
Characteristic market behaviors caused by intervention in a foreign exchange market
Takayuki Mizuno,Yukiko Umeno Saito,Tsutomu Watanabe,Hideki Takayasu
Physics , 2005,
Abstract: In foreign exchange markets monotonic rate changes can be observed in time scale of order of an hour on the days that governmental interventions took place. We estimate the starting time of an intervention using this characteristic behavior of the exchange rates. We find that big amount of interventions can shift the averaged rate about 1 yen per 1 dollar in an hour, and the rate change distribution becomes asymmetric for a few hours.
1H-NMR Study on the Magnetic Order in the Mixture of Two Spin Gap Systems (CH3)2CHNH3CuCl3 and (CH3)2CHNH3CuBr3
Keishi Kanada,Takehiro Saito,Akira Oosawa,Takayuki Goto,Takao Suzuki
Physics , 2007, DOI: 10.1143/JPSJ.76.064706
Abstract: The antiferromagnetic ordering in the solid-solution of the two spin-gap systems (CH3)2CHNH3CuCl3 and (CH3)2CHNH3CuBr3 has been investigated by 1H-NMR. The sample with the Cl-content ratio x=0.85 showed a clear splitting in spectra below TN=13.5 K, where the spin-lattice relaxation rate T1-1 showed a diverging behavior. The critical exponent of the temperature dependence of the hyperfine field is found to be 0.33.
Development of Non-sequential Ray-tracing Software for Cosmic-ray Telescopes
Akira Okumura,Masaaki Hayashida,Hideaki Katagiri,Takayuki Saito,Vladimir Vassiliev
Physics , 2011, DOI: 10.7529/ICRC2011/V09/1192
Abstract: We have developed non-sequential ray-tracing software which is aimed to be widely used, along with air- shower simulations, in the design of optical systems for cosmic-ray experiments. The code is based on the ROOT geometry library to provide a non-sequential photon tracking system, which is valuable when simulating refraction and multiple reflections. In addition to the basic ROOT classes, we have implemented new geometry ROOT classes so that users can flexibly define various geometries such as aspherical or Winston-cone type surfaces. We demonstrate the capabilities and performance of the software with examples of optical systems used in current and future experiments.
Historical Cohort Study of the Efficacy and Safety of Piperacillin/Tazobactam Versus Fourth-Generation Cephalosporins for Empirical Treatment of Febrile Neutropenia in Patients with Hematological Malignancies  [PDF]
Takashi Saito, Tatsuo Ichinohe, Junya Kanda, Miki Nagao, Shunji Takakura, Yutaka Ito, Yoshitsugu Iinuma, Kouhei Yamashita, Tadakazu Kondo, Takayuki Ishikawa, Takashi Uchiyama, Satoshi Ichiyama
International Journal of Clinical Medicine (IJCM) , 2011, DOI: 10.4236/ijcm.2011.21005
Abstract: We retrospectively evaluated the efficacy and safety of the combination drug piperacillin/tazobactam (PIPC/TAZ) in comparison with those of fourth-generation cephalosporins (4th Cephs) as initial empirical treatment in hematological malignancies patients with febrile neutropenia (FN). Among 200 patients assessed in this study, 49 had received PIPC/TAZ and 151 4th Cephs. Patient background characteristics were comparable between the two treatment groups. The overall efficacy rate in those receiving 4th Cephs and PIPC/TAZ was 57.0% (86/151 patients) and 59.2% (29/49 patients), respectively, with no significant difference detected between the two treatment regimens (P = 0.78). Treat-ment did not need to be discontinued or interrupted due to development of adverse drug reactions in any of the patients. Therefore in this study the efficacy and safety of PIPC/TAZ as initial antimicrobial treatment for FN in patients with hematological malignancies were not inferior to those of 4th Cephs. Based on the preliminary data obtained in this study, we propose to conduct a multicenter, prospective, controlled study to compare PIPC/TAZ versus CFPM given as empirical antimicrobial treatment against FN in patients with hematological malignancies.
Page 1 /3637
Display every page Item

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