Enzymes involved in fruiting body senescence in L. edodes.

Yuichi Sakamoto,Keiko Nakade,Naotake Konno 한국버섯학회 2010 한국버섯학회지 Vol.8 No.4

Lentinula edodes (shiitake mushroom) is a very popular edible, cultivated mushroom in Japan. There are post-storage problems with shiitake mushrooms, such as gill browning and cell wall lysis of the fruiting body, which can result in loss of fresh food quality and consequent loss of value. Lentinan is a cell wall component of beta-1, 3-linked-D-glucan with beta-1, 6 branches, which was isolated as an anti-tumor active-substance from L. edodes. Lentinan content decreases following harvest as a result of increased glucanase activity. We isolated one exo-glucanase encoding genes, exg21) and two endo-glucanase encoding gene tlg12) and glu1 from L. edodes. Transcription level of the exg2, tlg1 and glu1 gene increased after harvesting. Enzymes encoded by the genes have lentinan degrading activity, therefore, these genes are involved in lentinan degradation after harvesting. We also identified several cell wall degradation- related enzyme-encoding genes3), such as mixed-linked glucanase (mlg1), chitinases (chi1, chi29), chitin deacetylase (chd1), and chitosanase (cho1). It is revealed that transcriptional levels of these genes increased after harvesting, by real-time PCR. Glucanase and chitinase activity increased following harvest as results of increased transcription of these cell wall degradation-related enzyme-encoding genes. Increase of these cell wall degradation- related enzyme activities would cause cell wall lysis and lentinan degradation during post-harvest preservation. We identified laccase and tyrosinase encoding genes (lcc4 and tyr, respectively) by PCR-subtraction. The lcc4 was a novel laccase-encoding gene in L. edodes. Transcription levels of lcc4 and tyr increased after harvesting, and these genes would be involved in browning of the fruiting body. 1) Sakamoto et al. (2005) Current Genetics, 48: 195-203 2) Sakamoto et al. (2006) Plant Physiology 141: 793-801 3) Sakamoto et al. (2009) Current Genetics 55: 409-423

Open-cell Stent Deployment across the Wide Neck of a Large Middle Cerebral Aneurysm Using the Stent Anchor Technique

Shigeyuki Sakamoto,Shigeyuki Sakamoto,Masaaki Shibukawa,Itaru Tani,Shuichi Oki,Kaoru Kurisu 대한뇌혈관외과학회 2016 Journal of Cerebrovascular and Endovascular Neuros Vol.18 No.1

We describe a case of successful open-cell stent deployment across the wide neck of a large middle cerebral artery aneurysm using the stent anchor technique. A microcatheter was looped through the aneurysm and navigated into a distal vessel across the aneurysm neck. Although the loop of the microcatheter in the aneurysm straightened as it was gently withdrawn, the microcatheter again protruded into the aneurysm by open-cell stent navigation. The stent was partially deployed in a vessel distal to the aneurysm neck, withdrawn slowly to straighten the loop of the microcatheter in the aneurysm, and completely deployed across the aneurysm neck. After successful stent deployment, stent-assisted coil embolization was performed without complications. The stent anchor technique was successfully used to deploy an open-cell stent across the aneurysm neck in this case of microcatheter protrusion into the aneurysm during stent navigation.

A Diesel Generator Model with Fluctuating Engine Torque Including Magnetic Saturation for Transient Analysis using XTAP

Sakamoto, Orie The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Diesel engine generators are widely used in the world, especially in remote site power systems as distributed generators. A weak distribution feeder with a small diesel engine may suffer from voltage and power fluctuations due to misfiring of the engine cylinder. In this study, new generator model with example engine torque was developed for the electromagnetic transient analysis program for power systems named XTAP. The configuration and verification results of the developed model are presented in the paper. The model is considered to be useful for analyses of small power systems with those diesel engines.

Estimation of Surface Color with Use of Subjective Feeling: On the Influence of Contrast by Complementary Color

Sakamoto, Kazuyoshi,Wada, Mitsuyoshi,Min, Byung-Chan Korean Society for Emotion and Sensibility 2002 감성과학 Vol.5 No.2

The unique colors of paper, that is, blue, green, red, and yellow were used in the estimation of color from the subjective feeling. The monochrome with unique color or the unique color surrounded with the background color was presented. subject gazed the monochrome or the unique color, which was tailed target rotor. The target and background color were the complementary color each other. The various ratios of the area of gazed color and background were taken. Subject answered the level of subjective feeling consisted of pair of adjective items for unique color presented. With the use of the subjective feeling for the target color presented, the estimation of the unique color was cai\ulcornerlied out due to Fuzzy theory and neural networks. The results of color difference between unique color presented and the estimated color gave very small value for the case without background, while the results of the case with background color depended on the ratio of area of presented color and background color till the ration of 2:1, The relation showed the Kirschman's law, The color difference saturated In the increase of area of background with the ratio more than 2:1.

Microstructure and Mechanical Properties of Mg-Zn-Y-Yb Alloys Produced by Consolidation of Rapidly Solidified Ribbons

Sakamoto Yoshihito,Yamasaki Michiaki,Kawamura Yoshihito 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

Fabrication of bulk alloy has been performed through the consolidation of rapidly solidified ribbons. The bulk alloy exhibited excellent mechanical properties, high tensile yield strength of 530 MPa, and large elongation of 3 %. Microstructure of the alloy was characterized by equiaxed fine grains that consist of -Mg, long period ordered (LPO) structure phase, and -type cubic compound. The strengthening of the alloys may be due to fine grains with LPO structure phase and -type compound.

A Synchronization Method for Synchronous CDMA Systems with GEO Satellites

Sakamoto, Takuya,Umehara, Daisuke,Kawai, Makoto 통신위성우주산업연구회 2001 Joint Conference on Satellite Communications Vol.2001 No.-

High-speed core networks with optical fibers are globally being installed. However, it is very difficult to access these core networks from rural districts such as remote places among mountains and solitary islands. Synchronous CDMA systems with GEO satellite links are very attractive to solve this problem, since such systems have wide service areas and are suitable for packet-based networks due to their statistically multiplexing effect. Furthermore, their statistically multiplexing effect leads to effective frequency and power efficiency. In synchronous CDMA systems, each transmitted signal from a fixed earth station must be controlled to be synchronized with each other. However, the broadband systems require extremely precise timing control. In this paper, we discuss synchronization methods and evaluate their timing accuracy for the broadband systems quantitatively. First, we point out defects of two fixed filter methods and a Kalman filter method. Then, we propose a new synchronization method, which is robust to random noise and trend components. As a result, we conclude that the proposed synchronization method can make it possible to synchronize lGchip/sec CDMA systems with GEO satellites.

Physiological Changes and Clinical Implications of Syndromic Craniosynostosis

Sakamoto, Hiroaki,Matsusaka, Yasuhiro,Kunihiro, Noritsugu,Imai, Keisuke The Korean Neurosurgical Society 2016 Journal of Korean neurosurgical society Vol.59 No.3

Syndromic craniosynostosis has severe cranial stenosis and deformity, combined with hypoplastic maxillary bone and other developmental skeletal lesions. Among these various lesions, upper air way obstruction by hypoplastic maxillary bone could be the first life-threatening condition after birth. Aggressive cranial vault expansion for severely deformed cranial vaults due to multiple synostoses is necessary even in infancy, to normalize the intracranial pressure. Fronto-orbital advancement (FOA) is recommended for patients with hypoplastic anterior part of cranium induced by bicoronal and/or metopic synostoses, and posterior cranial vault expansion is recommended for those with flattening of the posterior part of the cranium by lambdoid synostosis. Although sufficient spontaneous reshaping of the cranium can be expected by expansive cranioplasty, keeping the cranial bone flap expanded sufficiently is often difficult when the initial expansion is performed during infancy. So far distraction osteogenesis (DO) is the only method to make it possible and to provide low rates of re-expansion of the cranial vault. DO is quite beneficial for both FOA and posterior cranial vault expansion, compared with the conventional methods. Associated hydrocephalus and chronic tonsillar herniation due to lambdoid synostosis can be surgically treatable. Abnormal venous drainages from the intracranial space and air way obstruction should be always considered at any surgical procedures. Neurosurgeons have to know well about the managements not only of the deformed cranial vault and the associated brain lesions but also of other multiple skeletal lesions associated with syndromic craniosynostosis, to improve treatment outcome.

Abundance of an Arbuscular Mycorrhizal Fungus, Gigaspora rosea, Colonizing Soybean Root Determined by the Specific Fatty Acids

Sakamoto, K.,Kaji, T. 한국토양비료학회 2009 한국토양비료학회 학술발표회 초록집 Vol.2009 No.10

Different tolerance of zooplankton communities to insecticide application depending on the species composition

Sakamoto, Masaki,Tanaka, Yoshinari The Ecological Society of Korea 2013 Journal of Ecology and Environment Vol.36 No.2

Natural zooplankton communities are composed of many different species at different trophic levels in the aquatic food web. Several researchers have reported that in mesocosm/enclosure experiments, larger cladocerans tend to be more sensitive to carbamate insecticides than smaller ones (Daphnia > Moina, Diaphanosoma > Bosmina). In contrast, results from individual-level laboratory tests have suggested that large cladoceran species are more tolerant than small species. To clarify this inconsistency, we conducted a microcosm experiment using model zooplankton communities with different species compositions, where animals were exposed to lethal (near to the 24 h LC50, concentration estimated to kill 50% of individuals within 24-h for the small cladoceran Bosmina) and lower, sublethal concentrations of carbaryl. In the experiment, population densities of the small cladocerans (Bosmina and Bosminopsis) decreased subsequent to the applications of chemical, but no impacts were observed on the large cladoceran Daphnia. Our results supported the reports of previous individual level toxicity tests, and indicated that the sensitivity of zooplankton to the insecticide was unchanged by biological interactions but the response of population can be modified by compensation of population through hatching from resting eggs and/or the persistence of insecticide in the systems.

Bio-innovation design using bone shape and its application

Sakamoto, J.,Kitayama, S.,Kinari, T.,Chihara, T.,Azuma, T. 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.4