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Search Results: 1 - 10 of 94 matches for " Satoki Karasawa "
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A Novel Biomaterial for Cartilage Repair Generated by Self-Assembly: Creation of a Self-Organized Articular Cartilage-Like Tissue  [PDF]
Kazuo Yudoh, Rie Karasawa
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2012, DOI: 10.4236/jbnb.2012.32017
Abstract: Recently, attention has been drawn to tissue engineering and other novel techniques aimed at reconstruction of the joint. Regarding articular cartilage tissue engineering, three-dimensional materials created in vitro by cultivation of autologous chondrocytes or mesenchymal stem cells with a collagen gel have been implanted to replace defective parts of the articular cartilage in limited cases with the diseases such as trauma or arthritis. However, several passages of chondrocyte culture are required to obtain a sufficient number of cells for tissue engineering. Additionally, several other problems arise including dedifferentiation of chondrocytes during cell culture, which need to be solved from a viewpoint of cellular resources. The purpose of our study is to create a novel biomaterial possessing functions and structures comparable to native hyaline articular cartilage by utilizing the physicochemical properties of the cartilage matrix components themselves, in other words, employing a self-assembly technique instead of using chondrocytes to produce cartilage matrices eventually leading to articular cartilage tissue formation. We verified the conditions and accuracy of the self-organization process and analyzed the resulting micro structure using electron beam microscopy in order to study the technique involved in the self-organization which would be applicable to creation of cartilage-like tissue. We demonstrated that self-assembly of several cartilage components including type II collagen, proteoglycan and hyaluronic acid could construct self-assembled cartilage-like tissues characterized by nano composite structures comparable to human articular cartilage and by low friction coefficients as small as those of native cartilage.
Successful Treatment of PFAPA (Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenitis) Syndrome with Shinbuto*  [PDF]
Yuichirou Tsuji, Chitose Karasawa
International Journal of Clinical Medicine (IJCM) , 2014, DOI: 10.4236/ijcm.2014.520160
Abstract: Periodic fever with aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is an autoimmune disorder and the most common disorder characterized by periodic fever in children. A male patient has been followed up from 11 months to 10 years of age because of repeated high fever. We prescribed antifebriles and antibiotics for each febrile episode without a beneficial effect to him each time. He required several days of rest at home to recover from each episode. During his most recent febrile episode at 10 years of age, we prescribed 5.0 g of shinbuto (TJ-30; Tsumura Co., Tokyo, Japan). His fever resolved the next day and he was able to attend school. His growth and development are normal. Shinbuto had a therapeutic effect in this patient with PFAPA syndrome and may be useful in this condition.
Serum Antibody Titers of Measles and Rubella among Japanese Children  [PDF]
Yuichirou Tsuji, Chitose Karasawa
World Journal of Vaccines (WJV) , 2015, DOI: 10.4236/wjv.2015.54017
Abstract: Background: The rubella outbreak in Japan has not yet been eliminated. In particular, an outbreak of congenital rubella syndrome has recently become a public health problem in Japan. The World Health Organization has set an elimination target of 2015 for measles in Japan. However, an outbreak of measles occurred in Japan between 2007 and 2008. Starting in April 2006, the measles and rubella vaccines were administered twice, once when a child reached 1 year old and once when the child was 5 - 6 years old (just before starting elementary school). Between October of 1978 and 2006, children were vaccinated only once for measles and rubella. Design: During the study enrollment period (2011-2013), the serum antibody titers of measles and rubella were measured in pediatric patients (n = 163) in the Tokyo Takanawa Hospital. Results: The prevalence rates of the two diseases indicated that only one vaccination was insufficient to protect against infection. Conclusions: Our studies have determined that it was important to vaccinate children twice for measles and rubella during early infancy.
Identification of DNA-Dependent Protein Kinase Catalytic Subunit (DNA-PKcs) as a Novel Target of Bisphenol A
Yuki Ito, Takumi Ito, Satoki Karasawa, Teruya Enomoto, Akihiro Nashimoto, Yasuyoshi Hase, Satoshi Sakamoto, Tsuneyo Mimori, Yoshihisa Matsumoto, Yuki Yamaguchi, Hiroshi Handa
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0050481
Abstract: Bisphenol A (BPA) forms the backbone of plastics and epoxy resins used to produce packaging for various foods and beverages. BPA is also an estrogenic disruptor, interacting with human estrogen receptors (ER) and other related nuclear receptors. Nevertheless, the effects of BPA on human health remain unclear. The present study identified DNA-dependent protein kinase catalytic subunit (DNA-PKcs) as a novel BPA-binding protein. DNA-PKcs, in association with the Ku heterodimer (Ku70/80), is a critical enzyme involved in the repair of DNA double-strand breaks. Low levels of DNA-PK activity are previously reported to be associated with an increased risk of certain types of cancer. Although the Kd for the interaction between BPA and a drug-binding mutant of DNA-PKcs was comparatively low (137 nM), high doses of BPA were required before cellular effects were observed (100–300 μM). The results of an in vitro kinase assay showed that BPA inhibited DNA-PK kinase activity in a concentration-dependent manner. In M059K cells, BPA inhibited the phosphorylation of DNA-PKcs at Ser2056 and H2AX at Ser139 in response to ionizing radiation (IR)-irradiation. BPA also disrupted DNA-PKcs binding to Ku70/80 and increased the radiosensitivity of M059K cells, but not M059J cells (which are DNA-PKcs-deficient). Taken together, these results provide new evidence of the effects of BPA on DNA repair in mammalian cells, which are mediated via inhibition of DNA-PK activity. This study may warrant the consideration of the possible carcinogenic effects of high doses of BPA, which are mediated through its action on DNA-PK.
10 pc Scale Circumnuclear Molecular Gas Imaging of Nearby AGNs
Satoki Matsushita
Physics , 2012, DOI: 10.1088/1742-6596/372/1/012043
Abstract: We present the images and kinematics of circumnuclear molecular gas from 100 pc scale down to 10 pc scale in nearby active galactic nuclei (AGNs) using the Submillimeter Array (SMA) and the Plateau de Bure Interferometer (PdBI). We have observed several nearby galaxies that host AGNs, such as the nearest radio galaxy Centaurus A (NGC 5128), the Seyfert 2 galaxy M51 (NGC 5194), the Seyfert 2 galaxy NGC 1068, the Seyfert 1 galaxy NGC 1097, and the Seyfert 2 / starburst composite galaxy NGC 4945, in CO lines to see whether the molecular gas distribution, kinematics, and physical conditions at 10 - 100 pc scale follows the AGN unified model or not. In 100 pc scale, most of the circumnuclear molecular gas shows smooth velocity gradient, suggesting a regular rotating feature, and also shows abnormal line ratios, suggesting the existence of active sources to make the circumnuclear molecular gas dense and/or warm conditions or abnormal chemical compositions. In 10 pc scale, on the other hand, the molecular gas kinematics shows various characteristics, some shows very disturbed kinematics such as a jet-entrained feature in the galaxies that have jets, but some still shows regular rotation feature in a galaxy that does not have obvious jets. These results indicate that the kinematics and physical/chemical conditions of the circumnuclear molecular gas at the scale less than 100 pc is highly affected by the AGN activities, and at this scale, there is no clear evidence of any unified feature seen in the circumnuclear molecular gas.
Possibility of Terahertz Observations at the ALMA site
Satoki Matsushita
Physics , 2011,
Abstract: Observational rates under terahertz (THz) opacities less than 3.0 and 2.0 at the Atacama Large Millimeter/submillimeter Array (ALMA) site have been calculated using the 225 GHz tipping radiometer monitoring data and the opacity correlation between 225 GHz and THz opacities. The observational rate with THz opacity condition less than 3.0 is 12.4% in a year, and in winter (November - April) it is about twice higher than in summer (May - October). This observational rate shows a large sinusoidal annual variation, and it seems to have relation with the El Ni\~no and La Ni\~na phenomena; the La Ni\~na years tend to have high observational rates, but the El Ni\~no years show low rates. On the other hand, the observational rate with the THz opacity condition less than 2.0 is only 1.9%, and no obvious annual and seasonal variations are observed. This indicates that THz observations under low opacity condition of less than 2.0 at the ALMA site are very difficult to be performed.
Ponotus shirahamensis, a new genus and species of raninid crab (Decapoda, Brachyura) from the Miocene Tanabe Group of Japan
Karasawa, Hiroaki;Ohara, Masaaki;
Boletín de la Sociedad Geológica Mexicana , 2009,
Abstract: ponotus shirahamensis, a new genus and species of the crab family raninidae (decapoda: brachyura) is described from the lowermost middle miocene tanabe group in wakayama prefecture of central japan. ponotus shirahamensis represents the second record for the family raninidae from the miocene deposits of japan. ponotus is most similar to notopus, an extant monotypic genus of the notopodinae, but is characterized by the absence of a spinose transverse ridge between the hepatic spines on the dorsal carapace.
New nephropid and glypheid lobsters from the Mesozoic of Japan
Hisayoshi, Kato;Hiroaki, Karasawa;
Revista mexicana de ciencias geológicas , 2006,
Abstract: a new nephropid lobster, hoploparia kamimurai new species is described from the lower cretaceous ishido formation (barremian), gunma prefecture, central japan. two species of glypheid lobsters, glyphea yoshiakii new species and glyphea sp. were obtained from the lower cretaceous arida formation (barremian), wakayama prefecture, southwest japan and the uppermost jurassic to lowermost cretaceous mitarai formation (tithonian-berriasian), gifu prefecture, central japan, respectively. these species are the first records of the fossil glypheidae from japan.
Conservation-Law-Induced Quantum Limits for Physical Realizations of the Quantum NOT Gate
Tokishiro Karasawa,Masanao Ozawa
Physics , 2007, DOI: 10.1103/PhysRevA.75.032324
Abstract: In recent investigations, it has been found that conservation laws generally lead to precision limits on quantum computing. Lower bounds of the error probability have been obtained for various logic operations from the commutation relation between the noise operator and the conserved quantity or from the recently developed universal uncertainty principle for the noise-disturbance trade-off in general measurements. However, the problem of obtaining the precision limit to realizing the quantum NOT gate has eluded a solution from these approaches. Here, we develop a new method for this problem based on analyzing the trace distance between the output state from the realization under consideration and the one from the ideal gate. Using the mathematical apparatus of orthogonal polynomials, we obtain a general lower bound on the error probability for the realization of the quantum NOT gate in terms of the number of qubits in the control system under the conservation of the total angular momentum of the computational qubit plus the the control system along the direction used to encode the computational basis. The lower bound turns out to be more stringent than one might expect from previous results. The new method is expected to lead to more accurate estimates for physical realizations of various types of quantum computations under conservation laws, and to contribute to related problems such as the accuracy of programmable quantum processors.
Channel Estimation Theory of Low-Noise Multiple Parameters:Attainablity Problem of the Cram{é}r-Rao Bounds
Masahiro Hotta,Tokishiro Karasawa
Physics , 2008, DOI: 10.1103/PhysRevA.78.012332
Abstract: For decoherence processes induced by weak interactions with the environment, a general quantum channel with one noise parameter has been formulated. This channel is called low-noise channel and very useful for investigating the parameter estimation in the leading order. In this paper, we formulate the low-noise channel with multiple unknown parameters in order to address the simultaneous achievability of the Cram{\'e}r-Rao bound for the parameters estimation. In general, the simultaneous achievement of the Cram{\'e}r-Rao bound for multi-parameter estimations suffers from non-commutativity of optimal measurements for respective parameters. However, with certain exceptions, we show that the Cram{\'e}r-Rao bound for output states of dissipative low-noise channels can be always attained in the first order of the parameters as long as D \leq N-1, where D and N denote the number of the parameters and the dimension of the system, respectively. This condition is replaced by D \leq N^{2}-1 if it is allowed to set the entanglement with ancilla systems in its input state and to perform the non-local measurement on the composite system.
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