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Search Results: 1 - 10 of 1044 matches for " Yoko Murayama "
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Greater omentum gastrointestinal stromal tumor with PDGFRA-mutation and hemoperitoneum
Yoko Murayama,Masayuki Yamamoto,Ryuichiro Iwasaki,Tamana Miyazaki
World Journal of Gastrointestinal Oncology , 2012, DOI: 10.4251/wjgo.v4.i5.119
Abstract: Although gastrointestinal stromal tumor (GIST) occurs generally in the digestive tract, omental GIST is very rare. We report the first case of an adult greater omental GIST with a new platelet-derived growth factor receptor α gene (PDGFRA)-mutation with hemoperitoneum. A 43-year-old man was admitted to our hospital complaining of acute abdominal pain. Abdominal contrast-enhanced computed tomography revealed a huge mass in the right abdominal cavity, and a large accumulation of fluid in the pelvic cavity, suggesting hemoperitoneum. We diagnosed the rupture as an intra-abdominal tumor, and an emergency tumorectomy was performed with resection of the greater omentum. This tumor was located in the distal right side of the greater omentum, and showed no continuity with the gastric wall. The tumor occurred primarily in the greater omentum. The resected tumor was about 19 cm × 12 cm × 14 cm in diameter, and weighed 1529 g. Histologically, the tumor was composed of epithelioid-shaped cells with high cellularity, and was positive for CD117 and CD34, and negative for S-100, α-smooth muscle actin. The mitosis was 6/50 under high power field. This case showed exon 18 mutation of PDGFRA with 846 (Asp to Glu) substitution, 848 (Asn to Lys) substitution. This is the first report of this PDGFRA mutation in omental GIST, and this might play an important role in the tumorigenesis of this case. Based on these findings, the tumor was diagnosed as high risk GIST primarily occurring in the greater omentum. The patient was treated with imatinib at a dose of 400 mg/d as adjuvant chemotherapy, and has been followed up for 24 mo with no evidence of recurrence.
Non-Contact Stress Measurement during Tensile Testing Using an Emat for SH0-Plate Wave and Lamb Wave  [PDF]
Riichi Murayama
Journal of Sensor Technology (JST) , 2011, DOI: 10.4236/jst.2011.13009
Abstract: The stress on a test specimen during tensile testing is generally measured by a strain gauge. This method has some problems in that it would influence the measurement conditions of the tensile test and can evaluate only the position at which the strain gauge is attached. The acoustoelastic method is proposed as a method replacing the strain gauge method. However, an ultrasonic sensor with a piezoelectric oscillator requires a coupling medium to inject an ultrasonic wave into a solid material. This condition, due to the error factor of the stress measurement, makes it difficult for the ultrasonic sensor to move on the specimen. We then tried to develop a non-contact stress measurement system during tensile testing using an electromagnetic acoustic transducer (EMAT) with an SH0-plate wave and S0-Lamb wave. The EMAT can measure the propagation time in which the ultrasonic wave travels between a receiver and a transmitter without a coupling medium during the tensile testing and can move easily. The interval between the transmitter and the receiver is 10mm and can be moved along the parallel direction or the vertical direction of the tensile load. The transit time was measured by a cross-correlation method and converted into the stress on the test specimen using the acoustoelastic method. We confirmed that the stress measurement using an SH0-plate wave was superior to that with an S0-Lamb wave.
A New Guide Wave Inspection System Using Three Polarized Transverse Wave EMATs without Any Couplant  [PDF]
Riichi Murayama
Journal of Sensor Technology (JST) , 2016, DOI: 10.4236/jst.2016.64009
Abstract: A guide wave is provided with the characteristic of long range propagation in the axis direction of a pipe, so it is possible to detect many defects over a large pipe area at once. At present, there is a technique to generate a guide wave using a piezoelectric element (PZT). However, the transverse wave-transducer using PZT needs to require a high viscosity couplant because the transverse wave cannot travel into typical liquid like water or oil. A guide wave inspection system that uses an electromagnetic ultrasonic transducer (EMAT) which does not require any couplant has then been developed to solve this trouble. First, a guide wave into a pipe, L, T and F-mode, can be transmitted and received by a polarized shear horizontal transverse wave propagating to the thickness direction when the vibration direction has been adjusted to the best direction. At next stage, the three EMATs for L, T and F-mode with different polarized vibration directions were piled up to improve the performance at the same position under the permanent magnet to inspect the pipe at the same condition. Next, the system with the EMATs can be confirmed to be able to detect three guide wave modes signal with enough intensity. Finally, the detection performance using the test pipes with any artificial defects has been done by the developed pipe inspection system, and any drilled holes and any notches can be detected. It is indicated that the developed system could be useful in real industrial field.
Unrecognized States in the Former USSR and Kosovo: A Focus on Standing Armies  [PDF]
Yoko Hirose
Open Journal of Political Science (OJPS) , 2016, DOI: 10.4236/ojps.2016.61007
Abstract: The end of the Cold War and the collapse of the USSR and Yugoslavia result in a proliferation of unrecognized and weak states, which continue to exist today. This article considers the relationship between unrecognized states and the major powers, Russia and the United States, by focusing on the foreign military bases or standing armies of the latter. In addition, unrecognized states, their parent countries, and similar states have received significant merits and profits from being unrecognized states, and this situation has also helped the survival of unrecognized states. It is possible that unrecognized states can be understood as part of the global strategies of the two great powers and that these states have been maintained through a complex negotiation process that is designed to maintain the superpowers’ global influence.
Success Factors for Social Systems to Increase the Number of Organ Donations—From the Perspectives of Mechanisms and Organizational Behaviors  [PDF]
Yoko Uryuhara
International Journal of Clinical Medicine (IJCM) , 2018, DOI: 10.4236/ijcm.2018.92007
Abstract: Deceased organ donation is much less prominent in Japan than it is in Western and other Asian countries. Because a shortage of organ donation is a serious social issue in Japan, various solutions to the issue have been considered. Although it was believed that the most critical factor in the organ shortage was the absence of a well-established social system, no prior studies attempted to analyze the issue from the perspective of the mechanisms and organizational behaviors. To identify common success factors of increasing organ donation, we conducted a qualitative survey in 5 countries promoting organ donations on a national level and increasing the number of organ donations. We found several important common factors: 1) to change from an explicit consent system to a presumed consent system with establishment of an appropriate in-hospital system, 2) to increase the level of job satisfaction of healthcare professionals and help them generating better results, 3) to demonstrate managements’ leadership for all staff to realize the importance of organ donations, 4) to establish an environment where medical professionals engaged in organ donations can appreciate autonomous working styles, the recognition of the importance of the work. It is suggested that these successful factors are introduced into Japan with long-, mid-term strategy to enhance organ donation.
Plasma and Serum Lipidomics of Healthy White Adults Shows Characteristic Profiles by Subjects’ Gender and Age
Masaki Ishikawa, Keiko Maekawa, Kosuke Saito, Yuya Senoo, Masayo Urata, Mayumi Murayama, Yoko Tajima, Yuji Kumagai, Yoshiro Saito
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0091806
Abstract: Blood is a commonly used biofluid for biomarker discovery. Although blood lipid metabolites are considered to be potential biomarker candidates, their fundamental properties are not well characterized. We aimed to (1) investigate the matrix type (serum vs. plasma) that may be preferable for lipid biomarker exploration, (2) elucidate age- and gender-associated differences in lipid metabolite levels, and (3) examine the stability of lipid metabolites in matrix samples subjected to repeated freeze-thaw cycles. Using liquid chromatography-mass spectrometry, we performed lipidomic analyses for fasting plasma and serum samples for four groups (15 subjects/group) of young and elderly (25–34 and 55–64 years old, respectively) males and females and for an additional aliquot of samples from young males, which were subjected to repeated freeze-thaw cycles. Lysophosphatidylcholine and diacylglycerol levels were higher in serum than in plasma samples, suggesting that the clotting process influences serum lipid metabolite levels. Gender-associated differences highlighted that the levels of many sphingomyelin species were significantly higher in females than in males, irrespective of age and matrix (plasma and serum). Age-associated differences were more prominent in females than in males, and in both matrices, levels of many triacylglycerols were significantly higher in elderly females than in young females. Plasma and serum levels of most lipid metabolites were reduced by freeze-thawing. Our results indicate that plasma is an optimal matrix for exploring lipid biomarkers because it represents the original properties of an individual’s blood sample. In addition, the levels of some blood lipid species of healthy adults showed gender- and age-associated differences; thus, this should be considered during biomarker exploration and its application in diagnostics. Our fundamental findings on sample selection and handling procedures for measuring blood lipid metabolites is important for ensuring the quality of biomarkers identified and its qualification process.
Analysis of Land Subsidence Using the HES  [PDF]
Witsarut Sriratana, Riichi Murayama
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2012, DOI: 10.4236/jemaa.2012.47043
Abstract: This study presents a methodology for analysis of the industrial machine alignment in the production line. The level of land subsidence in the area of the industrial machine location was assessed by adopting Hall Effect Sensor (HES). A computer was used for real-time data collecting and displaying the angle of subsidence over operational period. The measurement module consists of two flat-curve permanent magnets mounted parallelly and the magnetic poles which were placed in position that can be generating the magnetic tension force. The center between two permanent magnets was the sensor namely HES placed perpendicularly to the magnetic fluxes. The permanent magnets were the moving parts which can be displaced depending on the inclined angle of land subsidence. Analysis of the relationship between the incline angle of the measurement module and the output voltage from the HES was considered from the function of subsidence angle and magnetic density on X-axis and perpendicular angle (Y-axis) with the resolution of 100 mV per degree. There were two ranges of measurement according to the angle resolution, –20 to 20 degree at 1 degree of resolution per step and –6 to 6 degree at 0.01 degree of resolution per step.
Elimination of Oil Residual inside the Copper Pipe Using Ladder Technique  [PDF]
Witsarut Sriratana, Riichi Murayama
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.51002

This study presents the methodology to eliminate oil residual in copper pipe due to rolling process for manufacturing coil used in air conditioner. The pressure caused by Nitrogen flow rate was applied starting from 0, 5, 10, and 15 bar, respectively which was depending on time delay and pipe length. The developed system was divided into 2 modules: Parallel pressure ladder module (PPLM) [1] and Serial pressure ladder module (SPLM) which were experimented with 2 sizes of copper pipe: diameter 7.29 mm, thickness 0.25 mm, and length 10 km, and diameter 8 mm, thickness 0.25 mm, and length 10 km. From experiment, it can be noted that PPLM would perform better in elimination of oil residual compared to SPLM. About 97.44% (0.04 mg/m) and 97.59% (0.05 mg/m) of oil residual can be respectively eliminated from diameter 7.29 mm pipe and diameter 8 mm pipe which exceeded the standard allowance of 30% or 0.1 mg/m. Moreover, the cost of Nitrogen can be reduced by 6.25% per month.

Measurement of the Lubricant Properties Using Hall Effect Sensor: A Study on Contamination and Viscosity  [PDF]
Witsarut Sriratana, Riichi Murayama
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.54051

This study proposes the development of contamination measurement for industrial machines based on magnetic field method. A permanent magnet was used to generate the 0.17 T magnetic fields and Hall Effect sensor was applied to measure the contamination level of metal particles in industrial machine lubricant during operation time and to predict the replacement period if the lubricant condition does not meet the standard (NAS 1638). Contamination level of metal particles was directly related to the output voltage of Hall Effect sensor. When there was any movement of metal particles to the permanent magnet, the measured result was then transferred to a computer for analysis. This methodology could be applied to experiment the conditions of used lubricant for assessing the contamination and the metal particle remaining in the tank or inside the pipe of the machine as well as the conditions of car lubricant and other lubricants used in industrial processes.

Study of an Omnidirectional Guide Wave Sensor Using an EMAT  [PDF]
Riichi Murayama, Kazuki Iwaya
Journal of Sensor Technology (JST) , 2017, DOI: 10.4236/jst.2017.72002
Abstract: Nondestructive inspection of structures is important for ensuring the safety of the social infrastructure. Among them, the ultrasonic inspection method plays a role as a major technology. However, when examining a huge structure, the inspection time tends to be very long. Therefore, a system for transmitting and receiving ultrasonic waves in all directions from the ultrasonic sensor has been constructed. Several types of ultrasonic sensors using this concept have already been devised, but since the ultrasonic energy is dispersed in all directions, there is a problem that a sufficient detection performance cannot be ensured, especially when the thickness of the material to be inspected becomes thick. Therefore, we developed a highly sensitive omnidirectional ultrasonic sensor utilizing the resonance phenomenon of the ultrasonic wave propa-gating in the thickness direction. The omnidirectional ultrasonic system also consists of an electromagnetic ultrasonic transducer (EMAT) using a circular magnet. It is possible to inspect the plate thickness from 0.3 mm to 10 mm and the inspection range of the diameter of 300 mm around the sensor by the developed system. It is indicated that the developed system allows the high-speed inspection of huge structures.
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