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The Fourier and Grover walks on the two-dimensional lattice and torus [article]

Masahiro Asano, Takashi Komatsu, Norio Konno, Akihiro Narimatsu
2018 arXiv   pre-print
In this paper, we consider discrete-time quantum walks with moving shift (MS) and flip-flop shift (FF) on two-dimensional lattice Z^2 and torus π_N^2=(Z/N)^2.  ...  In the present paper, we consider QWs on the two-dimensional lattice, Z 2 , and N × N torus, π 2 N with moving shift (MS) and flip-flop shift (FF).  ... 
arXiv:1811.05302v2 fatcat:eb7uw7hev5endkxmvqi7rqooyu

Ventilatory Failure and Successful Management for a Dog with Severe Cervical Meningioma

Kazushi ASANO, Tsuyoshi KADOSAWA, Takashi MORI, Toru MIYAMOTO, Hiroshi UENO, Kazuhiro WATANABE, Toru FUJINAGA
2005 Journal of Veterinary Medical Science  
A 12-year-old intact male mongrel dog with a weight of 22 kg was referred with a complaint of progressive tetraparesis. Cervical myelography revealed an intradural-extramedullary mass at the second cervical vertebra. After computed tomography (CT) under general anesthesia, the patient showed dyspnea and cyanosis caused by insufficient movement of the chest wall. Positive pressure ventilation was therefore initiated. Hemilaminectomy and partial mass removal were performed 12 hr after the CT. The
more » ... mass was histopathologically diagnosed as meningioma. Gradual weaning from the mechanical ventilation lasted for 80 hr after the operation. The patient eventually recovered from the ventilatory failure and the tetraparesis at approximately 6 and 14 days after the operation, respectively. KEY WORDS: canine, cervical meningioma ventilatory failure.
doi:10.1292/jvms.67.599 pmid:15997187 fatcat:zryuw4kzyvcbrlfb7cbcq4ekye

Optogenetic induction of contractile ability in immature C2C12 myotubes

Toshifumi Asano, Toru Ishizuka, Keisuke Morishima, Hiromu Yawo
2015 Scientific Reports  
Myoblasts can be differentiated into multinucleated myotubes, which provide a well-established and reproducible muscle cell model for skeletal myogenesis in vitro. However, under conventional differentiation conditions, each myotube rarely exhibits robust contraction as well as sarcomere arrangement. Here, we applied trains of optical stimulation (OS) to C2C12 myotubes, which were genetically engineered to express a channelrhodopsin variant, channelrhodopsin-green receiver (ChRGR), to
more » ... e whether membrane depolarization facilitates the maturation of myotubes. We found that light pulses induced membrane depolarization and evoked action potentials in ChRGR-expressing myotubes. Regular alignments of sarcomeric proteins were patterned periodically after OS training. In contrast, untrained control myotubes rarely exhibited the striated patterns. OS-trained and untrained myotubes also differed in terms of their resting potential. OS training significantly increased the number of contractile myotubes. Treatment with nifedipine during OS training significantly decreased the fraction of contractile myotubes, whereas tetrodotoxin was less effective. These results suggest that oscillations of membrane potential and intracellular Ca 21 accompanied by OS promoted sarcomere assembly and the development of contractility during the myogenic process. These results also suggest that optogenetic techniques could be used to manipulate the activity-dependent process during myogenic development. R epeated exercise with adequate physical activity is important for health by preventing the development of many chronic diseases such as obesity, type 2 diabetes, sarcopenia, neurodegeneration, and osteoporosis 1-3 . The expression of muscle functionality relies on the correct assembly of myofibrils, which comprise of tandem arrays of minimum contractile units, i.e., sarcomeres. Muscle activity such as excitation and contraction is known to regulate the expression and modification of a number of molecules such as acetylcholinesterase 4 , L-type Ca 21 channels 5 , and glucose transporters 5,6 . Previously, it was reported that muscle fiber stimulation with electrical 7-9 , mechanical 10,11 , or pharmacological 12,13 methods, which mimic motor neuron inputs, facilitate the maturation of developing muscles as well as the maintenance of contractility. Cultured myogenic cells subjected to electrical stimuli with a given temporal pattern in vitro exhibited accelerated sarcomere assembly, and the contractile ability was induced by facilitating the production of elongation factors and muscle proteins 14,15 . Electrical field stimulation using electrodes placed in the extracellular space is a simple method for controlling the temporal pattern of muscle activation. However, it is difficult to identify the activated cells because the electric field is generally widespread and nonuniform. In addition, the placement of metal electrodes in the extracellular space has invasive effects on cells because they generate toxic gases such as H 2 and Cl 2 and change pH due to a Faradaic reaction. Therefore, the magnitude and duration of electrical field is limited within the range of a few volts/mm and milliseconds to minimize the side effects. However, optogenetic approaches using light-sensitive ion channels, channelrhodopsins (ChRs), have attracted attention as a new method for stimulating cells and tissues [16] [17] [18] [19] , and their application is expanding in the field of neuroscience [20] [21] [22] [23] . We have previously demonstrated that muscular contraction was optically controlled in a synchronous manner using a given train of light pulses when a myotube was generated from C2C12 clonal myoblasts, which were genetically engineered to express channelrhodopsin-2 (ChR2) 24 . However, previous studies have not demonstrated whether it is possible to manipulate the developmental process in any biological tissues 25 . Thus, we hypothesized that oscillatory changes of membrane potential after manipulation by optogenetic stimulation would induce the morphological and functional acquisition of the contractile ability in immature muscle. To test this hypothesis, optical stimulation (OS) training was applied to the ChR-expressing myotubes derived from C2C12, a myoblast cell line. We found that flashing a light with a specific rhythm facilitated both OPEN SUBJECT AREAS: OPTOGENETICS DIFFERENTIATION
doi:10.1038/srep08317 pmid:25661648 pmcid:PMC4650824 fatcat:3m5cfh4uzzhglajt24pypsxkse

LEED-AES Study of Iron Film Deposited on MgO (001) Surface

1973 Shinku  
he orientation and the surface structure of the epitaxially grown iron film is studied by a four grid type LEED-AES system. The substrate of MgO (001) surface is prepared by cleaving in air and heating in ultra high vacuum (5 •~ 10-9 Torr) at 500 •Ž. No contaminant is detected by AES from this surface.
doi:10.3131/jvsj.16.22 fatcat:hif2ljnodfeehjuexv4vphxqfu


Toshiyuki Asano, Toru Yamashiro, Taro Kakinuma
2011 Coastal Engineering Proceedings  
Field observations on secondary oscillations (seiche) in Urauchi Bay of Kami-koshiki Island, Japan were conducted during October 7-21, 2008. The seiches prone bay has a unique configuration as T-shape, which may cause the inherent characteristics of the eigen oscillations. The analyzed data show that the oscillations of the bay have at least two distinct modes; mode-1 oscillation of the period around 25 minutes with forming anti-nodes at the both inward inlets and possessing a node at the bay
more » ... uth, mode-2 oscillation of the period around 12 minutes which oscillates between the both inward inlets having the node at the branching point. Next, numerical simulations were conducted to reproduce the secondary oscillations in the bay by providing input sinusoidal waves with the eigen periods of oscillations to the calculating bay geometry. The numerical results are found to show basically consistent characteristics with the field observations.
doi:10.9753/icce.v32.currents.38 fatcat:wahe6vrrivg5bkrwh673xd62pi

p53 mutations and tetraploids under r- and K-selection

Norio Chikatsu, Yukari Nakamura, Hiroyuki Sato, Toshiro Fujita, Shigetaka Asano, Toru Motokura
2002 Oncogene  
Cotransfection of rat embryo ®broblasts with c-myc and activated H-ras oncogenes is one experimental model of the multistep oncogenesis associated with p53 mutations and aneuploidy. Using the model, we found that selection processes, e.g., r-and K-selection, aect emergence of p53 mutants and tetraploids. Culture optimum for logarithmic growth (r-selection) selected p53 mutants as they proliferated rapidly, while in con¯uent culture (K-selection) tetraploids emerged regardless of the p53 status.
more » ... Transfection of the mutated p53 gene with dominant negative functions eradicated untransfected cells under both r-and K-selection. However, these p53 mutants can be eradicated under K-selection by cells with normal p53 function and that had been selected under prolonged K-selection. The presence of competitors and the type of selection should determine whether or not p53 mutants and/or tetraploids predominate. These observations strengthen the importance of selection processes in case of cancer.
doi:10.1038/sj.onc.1205413 pmid:12082535 fatcat:6sxmtom325fsxolvrkxgoiscyy

Traffic analysis and network bandwidth provisioning tools for academic information networks

Shunji Abe, Toru Hasegawa, Shoichiro Asano
2005 Progress in Informatics  
A set of traffic analysis and network bandwidth provisioning tools for support of the Science Information Network (SINET) is presented. The software structure and functionality are also described. The tools provide an estimation of tail probability based on an approximation using Fractional Brownian Motion (FBM) tail probability, and the tools also enable calculation of the average queueing buffer waiting time using the MMPP/G/1 waiting time approximation method. The estimations provided by
more » ... e tools are consistent with simulations based on observed traffic data.
doi:10.2201/niipi.2005.1.7 fatcat:bmdyp2k3njexrkdkkj2aczo2oa

Optogenetic manipulation of neural and non-neural functions

Hiromu Yawo, Toshifumi Asano, Seiichiro Sakai, Toru Ishizuka
2013 Development, Growth and Differentiation  
Asano, T., Ishizuka, T. & Yawo, H. 2012. Optically controlled contraction of photosensitive skeletal muscle cells. Biotechnol. Bioeng. 109, 199-204.  ...  satellite cells (Yaffe & Saxel 1977) , were demonstrated to be contractile with optical stimulation, showing twitch-like contractions at low frequency and tetanus-like contraction at high frequency (Asano  ... 
doi:10.1111/dgd.12053 pmid:23550617 fatcat:mhnx4iqcsbdhbgw74ds566k5dq

Organelle Optogenetics: Direct Manipulation of Intracellular Ca2+ Dynamics by Light

Toshifumi Asano, Hiroyuki Igarashi, Toru Ishizuka, Hiromu Yawo
2018 Frontiers in Neuroscience  
oscillation of membrane potential and accelerated the assembly of sarcomere, the smallest contractile unit in muscle fibers in a manner dependent on the increase of intracellular Ca 2+ ([Ca 2+ ] i ) (Asano  ...  ER -Venus was confined in the peri-nucleus region in contrast to the conventional ChRGR-Venus, which localized in the plasma membrane with the original membrane targeting property (Wen et al., 2010; Asano  ... 
doi:10.3389/fnins.2018.00561 pmid:30174581 pmcid:PMC6107701 fatcat:nzkermi4zbdw7acfg7avr65l5q

Direct conversion of osteosarcoma to adipocytes by targeting TNIK

Toru Hirozane, Mari Masuda, Teppei Sugano, Tetsuya Sekita, Naoko Goto, Toru Aoyama, Takato Sakagami, Yuko Uno, Hideki Moriyama, Masaaki Sawa, Naofumi Asano, Masaya Nakamura (+6 others)
2021 JCI Insight  
Osteosarcoma (OS) is an aggressive mesenchymal tumor for which no molecularly targeted therapies are available. We have previously identified TRAF2 and NCK-interacting protein kinase (TNIK) as an essential factor for the transactivation of Wnt signal target genes and shown that its inhibition leads to eradication of colorectal cancer stem cells. The involvement of Wnt signaling in the pathogenesis of OS has been implicated. The aim of the present study was to examine the potential of TNIK as a
more » ... herapeutic target in OS. RNA interference or pharmacological inhibition of TNIK suppressed the proliferation of OS cells. Transcriptome analysis suggested that a small-molecule inhibitor of TNIK up-regulated the expression of genes involved in OS cell metabolism and down-regulated transcription factors essential for maintaining the stem cell phenotype. Metabolome analysis revealed that this TNIK inhibitor redirected the metabolic network from carbon flux towards lipid accumulation in OS cells. Using in vitro and in vivo OS models, we confirmed that TNIK inhibition abrogated the OS stem cell phenotype, simultaneously driving conversion of OS cells to adipocyte-like cells through induction of peroxisome proliferator-activated receptor-γ. In relation to potential therapeutic targeting in clinical practice, TNIK was confirmed to be in an active state in OS cell lines and clinical specimens. From these findings, we conclude that TNIK is applicable as a potential target for treatment of OS, affecting cell fate determination.
doi:10.1172/jci.insight.137245 pmid:33400690 pmcid:PMC7934882 fatcat:2nzkztszsnhy3nwq2ddjc5lx7y


Eiichiro ASANO, Toru ISHIDA, Hideo TAN
1962 Tetsu to hagane  
doi:10.2355/tetsutohagane1955.48.11_1456 fatcat:5jn3hrljynhp3bmrxpowwfeap4

Automatic segmentation method of cerebral arteries in MRA images:

Tatsunori ASANO, Yoshikazu UCHIYAMA, Takahiko ASANO, Hiroki KATO, Takeshi HARA, Xiangroug Zhou, Toru IWAMA, Hiroaki HOSHI, Yasutomi KINOSADA, Hiroshi FUJITA
2010 Medical Imaging and Information Sciences  
The detection of cerebrovascular diseases such as unruptured aneurysm and stenosis is a major application of magnetic resonance angiography(MRA) . However, their accurate detection is often difficult for radiologists. Therefore, several computer-aided diagnosis(CAD)schemes have been developed in order to assist radiologists with image interpretation. The purpose of this study is to modify our segmentation method of cerebral arteries and its application to a large image database. For the
more » ... tion of cerebral arteries, we first used a gray level transformation to calibrate voxel values. To adjust for variations in the positioning of patients, image registration was subsequently employed to maximize the overlapping of the cerebral arteries in the target image and reference image. The cerebral arteries were then segmented from the background using gray-level thresholding and region growing techniques. Finally, rule-based schemes with features such as size and anatomical location were employed to distinguish between cerebral arteries and false positives. Our method was applied to 876 clinical cases, which were obtained from three different hospitals. The segmentation of cerebral arteries in 98.1%(859/876)of the MRA studies was attained as an acceptable result. Therefore, our computerized method would be useful for the segmentation of cerebral arteries in MRA images.
doi:10.11318/mii.27.55 fatcat:l5kzify7irdoxfxmxhehm2nhhe

The efficacy of 18F-fluorodeoxyglucose positron emission tomography for the evaluation of hepatocellular carcinoma treatment
肝癌治療効果判定における`18´F‐fluorodeoxyglucose Positron Emission Tomographyの有用性

Kazuo ENOMOTO, Shinichi OKAZUMI, Toru FUKUNAGA, Takehide ASANO, Toshiyuki KIKUCHI, Toru NAGASHIMA, Kaichi ISONO
1993 Kanzo  
, Takehide ASANO, Toshiyuki KIKUCHI, Toru NAGASHIMA and Kaichi ISONO* By the FDG-PET images, the necrosis region in the HCC nodules were recognized as the less FDG-accumulated region than the live region  ...  Fig. 1 Tomogr 14: 370-374, 1990 The efficacy of 18F-fluorodeoxyglucose positron emission tomography for the evaluation of hepatocellular carcinoma treatment Kazuo ENOMOTO, Shinichi OKAZUMI, Toru FUKUNAGA  ... 
doi:10.2957/kanzo.34.464 fatcat:46ua4wba7zaidnshkeici3tb7y

Lateral Approach to the Upper Cervical Lesions

Tadashi Morimoto, Eiharu Morilkawa, Toru Matsui, Takao Asano
2000 Spinal Surgery  
脳外23:301 − 309, 1995 18.Tsuzuki N , Asano T , Tanaka H . Adachi Y : Posterolateral apProach to the atlas and the axis .  ... 
doi:10.2531/spinalsurg.14.95 fatcat:wu6cpmzambg2blccd2q7fnbjve

Immunohistochemical localization of Na+,K+-ATPase in human liver

1988 Acta Histochemica et Cytochemica  
doi:10.1267/ahc.21.593 fatcat:jwyo4aizufbefagsoo5lz7kl4i
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