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Search Results: 1 - 10 of 325 matches for " Yuichiro Yoneoka "
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Pituitary intratumoral hemorrhage during radiation therapy following partial removal of giant pituitary adenoma: A case report  [PDF]
Junyang Liu, Yuichiro Yoneoka, Kensuke Tanaka, Hiraku Satou, Eisuke Abe, Naoto Watanabe, Yukihiko Fuji, Hitoshi Takahashi, Hidefumi Aoyama
Case Reports in Clinical Medicine (CRCM) , 2014, DOI: 10.4236/crcm.2014.31010
Abstract:


We report a rare case of intratumoral hemorrhage during postoperative radiotherapy for pituitary adenoma. A 57-year-old Asian male, complaining of long-standing eye strain, underwent a medical checkup of the brain. Magnetic resonance imaging showed a multicystic giant pituitary adenoma. The patient underwent an endoscopic endonasal transsphenoidal partial removal of the adenoma to provide optic pathway decompression and got relief from the visual symptoms. Just before completion of the postoperative radiotherapy for residual adenoma, the patient developed right hemiparesis, mild motor aphasia, and right oculomotor palsy. A cranial CT scan showed intratumoral hemorrhage into the intratumoral cyst. The patient therefore had to undergo three additional craniotomies for evacuation of cyst contents over the next 8 months. The follow-up MRI at 11 months after the initial hemorrhage showed that the new oozing of blood in the intratumoral cyst was still appearing. Intratumoral hemorrhage is a rare, albeit life-threatening, complication of pituitary adenoma. We reviewed relevant literature and suggested that the cystic component in pituitary adenoma could be a key pathogenesis of this rare complication. In conclusion, we suggest that it may be necessary to realize that cases which have cystic giant pituitary adenoma may cause hemorrhage by chance with the foreseeability.


Synchronized multiple regression of diagnostic radiation-induced rather than spontaneous: disseminated primary intracranial germinoma in a woman: a case report
Yuichiro Yoneoka, Itaru Tsumanuma, Shinya Jinguji, Manabu Natsumeda, Yukihiko Fujii
Journal of Medical Case Reports , 2011, DOI: 10.1186/1752-1947-5-39
Abstract: A 43-year-old Japanese woman presented to our hospital complaining of memory problems over a period of one year and blurred vision over a period of three months. Following magnetic resonance imaging, she was found to have a massive lesion in the third ventricle and small lesions in the pineal region, fourth ventricle, and in the anterior horn of the left lateral ventricle. Prior to an open biopsy to confirm the pathology of the lesions, she underwent a single cranial computed tomography scan and a single cranial digital subtraction angiography for a transcranial biopsy. Fourteen days after the first magnetic resonance image - 12 and eight days after the computed tomography scan and digital subtraction angiography, respectively - a pre-operative magnetic resonance image was taken, which showed a notable synchronous shrinkage of the third ventricle tumor, as well as shrinkage of the lesions in the pineal region and in the fourth ventricle. She did not undergo steroid administration until after a biopsy that confirmed the pathological diagnosis of pure germinoma. She then underwent whole craniospinal irradiation and went into a complete remission.In our case report, we state that diagnostic radiation can induce the regression of germinomas; this is the most reasonable explanation for the synchronous multiple regression observed in this case of germinoma. Clinicians should keep this non-spontaneous regression in mind and monitor germinoma lesions with minimal exposure to diagnostic radiation before diagnostic confirmation, and also before radiation treatment with or without chemotherapy begins.Spontaneous regression and remission from cancer was defined by Cole and Everson in 1956 [1]. Examples of the spontaneous regression of primary intracranial germinomas can be found in the literature [2-5]. In our case report, we present the case of a patient with disseminated lesions of primary intracranial germinoma who experienced synchronous shrinkage of disseminated lesions of
Reconciling Safety and Fairness in Global Agri-Food Standardization  [PDF]
Yuichiro Amekawa
Sociology Mind (SM) , 2013, DOI: 10.4236/sm.2013.31006
Abstract:

Private food safety standards have recently emerged as a dynamic power in the global value chan. Good agricultural practices (GAP) is one such standard currently gaining popularity as a prominent field-level food quality assurance system. Achieving private GAP certification, most notably of GlobalGAP, is a dif ficult option for low income producers in the Global South due to the high costs required for necessary investments and certification. This paper critically analyzes the ethical implications of private food safety standards in light of three theoretical perspectives from environmental sociology: ecological moderniza tion, risk society, and eco-socialism. It then examines the potential of public GAP schemes currently emerging in the Global South for reconciling safety and fairness in global agri-food standardization. It is suggested that the expansion of producer participation in public GAP program be regulated by gradual improvements in the state capacity of resource mobilization for auditing and extension institutions.

Identification of the Bacterial Gene in Patients Who Repeatedly Develop Streptococcal Pharyngitis  [PDF]
Yuichiro Tsuji, Ichihashi Izumi
International Journal of Clinical Medicine (IJCM) , 2012, DOI: 10.4236/ijcm.2012.37121
Abstract:

Background: We aimed at determining whether the pathogenic bacteria at the onset of disease are genetically different and whether this affects future choice of the therapeutic methods against group A β-hemolytic streptococcal acute pharyngitis/tonsillitis. Methods: A pharynx swab was collected from pediatric patients who visited our hospital. The swab was cultured, and hemolytic streptococcus was detected 230 times. We isolated pathogenic bacteria of patients infected more than once and examined the bacteria using pulse-field gel electrophoresis. Results: Based on gene search results, we found that if the period of developing relapse was within 1 month from the first infection, all patients had the same gene. However, all patients in whom reinfection occurred after 6 months or later had different pertinent genes. Conclusions: The number of relapse/reinfection is significant for this disease, and considerably caution is essential for its treatment. No changes to antibacterial drug administration may be necessary for the second administration unless more than 6 months have passed since the first infection.

Method of Searching for Earthquake Disaster Evacuation Routes Using Multi-Objective GA and GIS  [PDF]
Yuichiro Shimura, Kayoko Yamamoto
Journal of Geographic Information System (JGIS) , 2014, DOI: 10.4236/jgis.2014.65042
Abstract: This study treats the determination of routes for evacuation on foot in earthquake disasters as a multi-objective optimization problem, and aims to propose a method for quantitatively searching for evacuation routes using a multi-objective genetic algorithm (multi-objective GA) and GIS. The conclusions can be summarized in the following three points. 1) A GA was used to design and create an evacuation route search algorithm which solves the problem of the optimization of earthquake disaster evacuation routes by treating it as an optimization problem with multiple objectives, such as evacuation distance and evacuation time. 2) In this method, goodness of fit is set by using a Pareto ranking method to determine the ranking of individuals based on their relative superiorities and inferiorities. 3) In this method, searching for evacuation routes based on the information on present conditions allows evacuation routes to be derived based on present building and road locations. Further, this method is based on publicly available information; therefore, obtaining geographic information similar to that of this study enables this method to be effective regardless of what region it is applied to, or whether the data regards the past or the future. Therefore, this method has high degree of spatial and temporal reproducibility.
Construction Sequence of the Koh Ker Monuments Constrained by the Chemical Composition and Magnetic Susceptibility of Its Bricks  [PDF]
Etsuo Uchida, Yuichiro Sakurai
Archaeological Discovery (AD) , 2018, DOI: 10.4236/ad.2018.62009
Abstract: Using a portable X-ray fluorescence analyzer and magnetic susceptibility meter, we measured fired bricks from nine temples (Prasat Thom, Prasat Damrei, Prasat Chamreh, Prasat Krachap, Prasat Kraham, Prasat Chen, Prasat Banteay Pir Chan, Prasat Chrap, and Prasat Pram) of the Koh Ker monuments, Cambodia. Based on cluster analysis of the chemical compositional data for Ti, Fe, Rb, Y, and Zr, as well as magnetic susceptibility data, the brick buildings could be classified into four groups (Stages A to D). Taking into consideration the five construction stages (Stages ① to ⑤) defined by Uchida et al. (2014) for laterite buildings, and using the assumption that all buildings were basically constructed outwards from the center, we define a construction sequence for these brick buildings. Thus, the following chronological relationship was obtained for construction stages of both laterite and brick buildings: Stage A → Stages B & ① → Stages C & ② → Stages D & ③ → Stage ④ → Stage ⑤. We surmise that the Northern Libraries of Prasat Pram, Prasat Chen and Prasat Damrei were added after the construction of their Inner Enclosures.
An implementation of the microphysics in full general relativity : General relativistic neutrino leakage scheme
Yuichiro Sekiguchi
Physics , 2010, DOI: 10.1088/0264-9381/27/11/114107
Abstract: Performing fully general relativistic simulations taking account of microphysical processes is one of long standing problems in numerical relativity. One of main difficulties in implementation of weak interactions in the general relativistic framework lies on the fact that the characteristic timescale of weak interaction processes (the WP timescale) in hot dense matters is much shorter than the dynamical timescale. Numerically this means that stiff source terms appears in the equations so that an implicit scheme is in general necessary to stably solve the relevant equations. Otherwise a very short timestep will be required to solve them explicitly. Furthermore, in the relativistic framework, the Lorentz factor is coupled with the rest mass density and the energy density. The specific enthalpy is also coupled with the momentum. Due to these couplings, it is very complicated to recover the primitive variables and the Lorentz factor from conserved quantities. At the current status, no implicit procedure have been proposed except for the case of the spherical symmetry. Therefore, an approximate, explicit procedure is developed in the fully general relativistic framework in this paper as an first implementation of the microphysics toward a more realistic sophisticated model. The procedure is based on the so-called neutrino leakage schemes which is based on the property that the characteristic timescale in which neutrinos leak out of the system (the leakage timescale) is much longer than the WP timescale. In this paper, I present a detailed neutrino leakage scheme and a simple and stable method for solving the equations explicitly in the fully general relativistic framework. I also perform a test simulation to check the validity of the present method, showing that it works fairly well.
Stellar core collapse in full general relativity with microphysics - Formulation and Spherical collapse test -
Yuichiro Sekiguchi
Physics , 2010, DOI: 10.1143/PTP.124.331
Abstract: One of the longstanding issues in numerical relativity is to enable a simulation taking account of microphysical processes (e.g., weak interactions and neutrino cooling). We develop an approximate and explicit scheme in the fully general relativistic framework as a first implementation of the microphysics toward a more realistic and sophisticated modeling. In this paper, we describe in detail a method for implementation of a realistic equation of state, the electron capture and the neutrino cooling in a multidimensional, fully general relativistic code. The procedure is based on the so-called neutrino leakage scheme. To check the validity of the code, we perform a two dimensional (2D) simulation of spherical stellar core collapse. Until the convective activities set in, our results approximately agree, or at least are consistent, with those in the previous so-called state-of-the-art simulations. In particular, the radial profiles of thermodynamical quantities and the time evolution of the neutrino luminosities agree quantitatively. The convection is driven by negative gradients of the entropy per baryon and the electron fraction as in the previous 2D Newtonian simulations. We clarify which gradient is more responsible for the convection. Gravitational waves from the convection are also calculated. We find that the characteristic frequencies of the gravitational-wave spectra are distributed for higher frequencies than those in Newtonian simulations due to the general relativistic effects.
Parsing a sequence of qubits
Yuichiro Fujiwara
Mathematics , 2012, DOI: 10.1109/TIT.2013.2272695
Abstract: We develop a theoretical framework for frame synchronization, also known as block synchronization, in the quantum domain which makes it possible to attach classical and quantum metadata to quantum information over a noisy channel even when the information source and sink are frame-wise asynchronous. This eliminates the need of frame synchronization at the hardware level and allows for parsing qubit sequences during quantum information processing. Our framework exploits binary constant-weight codes that are self-synchronizing. Possible applications may include asynchronous quantum communication such as a self-synchronizing quantum network where one can hop into the channel at any time, catch the next coming quantum information with a label indicating the sender, and reply by routing her quantum information with control qubits for quantum switches all without assuming prior frame synchronization between users.
Even-freeness of cyclic 2-designs
Yuichiro Fujiwara
Mathematics , 2012,
Abstract: A Steiner 2-design of block size k is an ordered pair (V, B) of finite sets such that B is a family of k-subsets of V in which each pair of elements of V appears exactly once. A Steiner 2-design is said to be r-even-free if for every positive integer i =< r it contains no set of i elements of B in which each element of V appears exactly even times. We study the even-freeness of a Steiner 2-design when the cyclic group acts regularly on V. We prove the existence of infinitely many nontrivial Steiner 2-designs of large block size which have the cyclic automorphisms and higher even-freeness than the trivial lower bound but are not the points and lines of projective geometry.
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