뇌의부분 손상으로 인한 정동행동의 변화에 관한 연구

이순철,T. Yamamoto.S.Ueki 충남대학교 약학대학 의약품개발연구소 1988 藥學論文集 Vol.4 No.-

Nucleus accumbens septi (NAB), one of mesolimbic system, which anatomically related the limbic system. We an attempted to elucidated emotional changes following bilateral NAB lesions in rats. Caudal, rostral and both areas of NAB were lesioned each in separated animal groups. Furthermore, aggressive behavior induced by NAB rats was investigated in comparison with those induced by olfactory bulbectomized rats and raphe nucleus-lesioned rats. 1) At postoperative day 2, locomotor activity were increased in r-NAB rats but not in c-NAB rats. 2) All rats exhibited hyperirritability and muricide including mouse-eating behavior after NAB lesions. 3) Muricide of NAB rats was significantly supressed by L-DOPA, L-5-HTP and antidepressants, muricide of raphe rats was also significantly inhibited by L-DOPA and L-5-HTP, while that in OB rats was not suppressed. These results suggested that the NAB plays an important role in locomotor activity and aggression. The characteristics of aggressive behavior induced by NAB rats resemble to that of raphe-rats.

Raf kinase inhibitory protein is required for cerebellar long-term synaptic depression by mediating PKC-dependent MAPK activation.

Yamamoto, Yukio,Lee, Dongwon,Kim, Yoonhee,Lee, Bokyoung,Seo, Changwoo,Kawasaki, Hiroshi,Kuroda, Shinya,Tanaka-Yamamoto, Keiko The Society 2012 The Journal of neuroscience Vol.32 No.41

<P>It was demonstrated previously that a positive feedback loop, including protein kinase C (PKC) and mitogen-activated protein kinase (MAPK), is required for the gradual expression of cerebellar long-term depression (LTD). PKC and MAPK are mutually activated in this loop. MAPK-dependent PKC activation is likely to be mediated by phospholipase A2. On the other hand, it is not clear how PKC activates MAPK. Therefore, the entire picture of this loop was not fully understood. We here test the hypothesis that this loop is completed by the PKC substrate, Raf kinase inhibitory protein (RKIP). To test this hypothesis, we used a mutant form of RKIP that is not phosphorylated by PKC and thus constitutively inhibits Raf-1 and MEK, upstream kinases of MAPK. When this RKIP mutant was introduced into Purkinje cells of mouse cerebellar slices through patch-clamp electrodes, LTD was blocked, while wild-type (WT) RKIP had no effect on LTD. Physiological epistasis experiments demonstrated that RKIP works downstream of PKC and upstream of MAPK during LTD induction. Furthermore, biochemical analyses demonstrated that endogenous RKIP dissociates from Raf-1 and MEK during LTD induction in a PKC-dependent manner, suggesting that RKIP binding-dependent inhibition of Raf-1 and MEK is removed upon LTD induction. We therefore conclude that PKC-dependent regulation of RKIP leads to MAPK activation, with RKIP completing the positive feedback loop that is required for LTD.</P>

Single Molecule Visualization and Characterization of Sox2–Pax6 Complex Formation on a Regulatory DNA Element Using a DNA Origami Frame

Yamamoto, Seigi,De, Debojyoti,Hidaka, Kumi,Kim, Kyeong Kyu,Endo, Masayuki,Sugiyama, Hiroshi American Chemical Society 2014 NANO LETTERS Vol.14 No.5

<P>We report the use of atomic force microscopy (AFM) to study Sox2–Pax6 complex formation on the regulatory DNA element at a single molecule level. Using an origami DNA scaffold containing two DNA strands with different levels of tensile force, we confirmed that DNA bending is necessary for Sox2 binding. We also demonstrated that two transcription factors bind cooperatively by observing the increased occupancy of Sox2–Pax6 on the DNA element compared to that of Sox2 alone.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2014/nalefd.2014.14.issue-5/nl4044949/production/images/medium/nl-2013-044949_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl4044949'>ACS Electronic Supporting Info</A></P>

Autonomous Animated Robots

Yamamoto, Masahito,Iwadate, Kenji,Ooe, Ryosuke,Suzuki, Ikuo,Furukawa, Masashi Society for Computational Design and Engineering 2009 International Journal of CAD/CAM Vol.9 No.1

In this paper, we demonstrate an autonomous design of motion control of virtual creatures (called animated robots in this paper) and develop modeling software for animated robots. An animated robot can behave autonomously by using its own sensors and controllers on three-dimensional physically modeled environment. The developed software can enable us to execute the simulation of animated robots on physical environment at any time during the modeling process. In order to simulate more realistic world, an approximate fluid environment model with low computational costs is presented. It is shown that a combinatorial use of neural network implementation for controllers and the genetic algorithm (GA) or the particle swarm optimization (PSO) is effective for emerging more realistic autonomous behaviours of animated robots.

Influence of voxel size on cone-beam computed tomography-based detection of vertical root fractures in the presence of intracanal metallic posts

Yamamoto-Silva, Fernanda Paula,de Oliveira Siqueira, Claudeir Felipe,Silva, Maria Alves Garcia Santos,Fonseca, Rodrigo Borges,Santos, Ananda Amaral,Estrela, Carlos,de Freitas Silva, Brunno Santos Korean Academy of Oral and Maxillofacial Radiology 2018 Imaging Science in Dentistry Vol.48 No.3

Purpose: This study was performed to evaluate the influence of voxel size and the accuracy of 2 cone-beam computed tomography (CBCT) systems in the detection of vertical root fracture (VRF) in the presence of intracanal metallic posts. Materials and Methods: Thirty uniradicular extracted human teeth were selected and randomly divided into 2 groups(VRF group, n=15; and control group, n=15). The VRFs were induced by an Instron machine, and metallic posts were placed in both groups. The scans were acquired by CBCT with 4 different voxel sizes: 0.1 mm and 0.16 mm (for the Eagle 3D V-Beam system) and 0.125 mm and 0.2 mm (for the i-CAT system) (protocols 1, 2, 3, and 4, respectively). Interobserver and intraobserver agreement was assessed using the Cohen kappa test. Sensitivity and specificity were evaluated and receiver operating characteristic analysis was performed. Results: The intraobserver coefficients indicated good (0.71) to very good (0.83) agreement, and the interobserver coefficients indicated moderate (0.57) to very good (0.80) agreement. In respect to the relationship between sensitivity and specificity, a statistically significant difference was found between protocols 1 (positive predictive value: 0.710, negative predictive value: 0.724) and 3 (positive predictive value: 0.727, negative predictive value: 0.632) (P<.05). The least interference due to artifact formation was observed using protocol 2. Conclusion: Protocols with a smaller voxel size and field of view seemed to favor the detection of VRF in teeth with intracanal metallic posts.

Development of Nano-sized WC Powder for Hardmetals

Yamamoto Yoshiharu,Mizukami Masahiko 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

In order to develop the nano-sized WC powder that improved the hardness of hardmetals, carbothermal reduction of WO3 by C was examined by using the thermogravimetric analysis. At the direct carburization reaction path of , the nano-sized grain was generated at the reaction stage to and W. For trial production, the intermediate products which consists of metal and carbide phases obtained by the first heating has been carburized to the final WC powder. We succeeded in the development of the WC powder of about 70nm. In addition, the nano-sized WC powder in which the vanadium of the most effective grain growth inhibitor was uniformly dispersed was developed.

개인통신시스템

Yamamoto Heiichi 한국정보통신기술협회 1991 국제전기통신표준화소식 Vol.19 No.-

Effect of Ba Stearate Addition on Magnetic Properties of Ba-system W-type Ferrite Magnets

Yamamoto Hiroshi,Nishio Hiroaki,Sawayama Yoshihito 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

An experiment was carried out to investigate the effect of Ba Stearate as a reducing agent on the magnetic and physical properties of anisotropic type ferrite magnets. It was found that the magnetic properties of were improved by adding 0.3 wt% of Ba Stearate, 0.5 wt% of , and 0.5 wt% of CaO together. The optimum conditions for making magnets were as follows; semisintering condition: h in nitrogen gas atmosphere, drying condition: h in air, sintering condition: h in nitrogen gas atmosphere. Magnetic and physical properties of a typical sample were = 0.46 T, = 0.43 T, = 182.3 kA/m, = 177.2 kA/m, = 33.8 kJ/, = and = and = 1332 kA/m.

Temperature-Resistant Bicelles for Structural Studies by Solid-State NMR Spectroscopy

Yamamoto, Kazutoshi,Pearcy, Paige,Lee, Dong-Kuk,Yu, Changsu,Im, Sang-Choul,Waskell, Lucy,Ramamoorthy, Ayyalusamy American Chemical Society 2015 Langmuir Vol.31 No.4

<P>Three-dimensional structure determination of membrane proteins is important to fully understand their biological functions. However, obtaining a high-resolution structure has been a major challenge mainly due to the difficulties in retaining the native folding and function of membrane proteins outside of the cellular membrane environment. These challenges are acute if the protein contains a large soluble domain, as it needs bulk water unlike the transmembrane domains of an integral membrane protein. For structural studies on such proteins either by nuclear magnetic resonance (NMR) spectroscopy or X-ray crystallography, bicelles have been demonstrated to be superior to conventional micelles, yet their temperature restrictions attributed to their thermal instabilities are a major disadvantage. Here, we report an approach to overcome this drawback through searching for an optimum combination of bicellar compositions. We demonstrate that bicelles composed of 1,2-didecanoyl-<I>sn</I>-glycero-3-phosphocholine (DDPC) and 1,2-diheptanoyl-<I>sn</I>-glycero-3-phosphocholin (DHepPC), without utilizing additional stabilizing chemicals, are quite stable and are resistant to temperature variations. These <I>temperature-resistant bicelles</I> have a robust bicellar phase and magnetic alignment over a broad range of temperatures, between −15 and 80 °C, retain the native structure of a membrane protein, and increase the sensitivity of solid-state NMR experiments performed at low temperatures. Advantages of two-dimensional separated-local field (SLF) solid-state NMR experiments at a low temperature are demonstrated on magnetically aligned bicelles containing an electron carrier membrane protein, cytochrome <I>b</I><SUB>5</SUB>. Morphological information on different DDPC-based bicellar compositions, varying <I>q</I> ratio/size, and hydration levels obtained from <SUP>31</SUP>P NMR experiments in this study is also beneficial for a variety of biophysical and spectroscopic techniques, including solution NMR and magic-angle-spinning (MAS) NMR for a wide range of temperatures.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/langd5/2015/langd5.2015.31.issue-4/la5043876/production/images/medium/la-2014-043876_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/la5043876'>ACS Electronic Supporting Info</A></P>

The Logic of Japan's Free Trade Agreements (FTA) with ASEAN

Yamamoto, Chika World Association for Triple Helix and Future Stra 2012 Journal of Contemporary Eastern Asia Vol.11 No.2

Among political scientists, Japan's free trade agreements (FTA) with member nations of the Association of Southeast Asian Nations (ASEAN) has been considered to be a political tool that can compete against China for regional leadership in East Asia. However, this paper demonstrates that Japan's so-called FTA diplomacy towards ASEAN nations serves the broad interests of Japanese actors in both the political and economic sectors. Given the attention to Japanese domestic political issues, it is argued that diplomacy primarily facilitates a need for free trade with ASEAN and ASEAN markets for Japanese corporations to compete in the global economy and for the government to nurture Japan's stagnant economy by assisting these corporations. This work also contends that the unclear function of FTA as an economic good is due to the lack of the government capacity to effectively manage FTA diplomacy. This partly results from the conventional view with regard to Sino-Japanese rivalry.