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Yoshio Ando

Bio: Yoshio Ando is an academic researcher from Tokyo Institute of Technology. The author has contributed to research in topics: Finite element method & Mixed finite element method. The author has an hindex of 13, co-authored 85 publications receiving 619 citations. Previous affiliations of Yoshio Ando include Japan Atomic Energy Research Institute & University of Tokyo.


Papers
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Journal ArticleDOI
TL;DR: The aryl C-glycoside structure is, among the plenty of biologically active natural products, one of the distinct motifs embedded, and the synthetic strategies and tactics employed in the total synthesis of this class of natural products.
Abstract: The aryl C-glycoside structure is, among the plenty of biologically active natural products, one of the distinct motifs embedded. Because of the potential bioactivity as well as the synthetic challenges, these structures have attracted considerable interest, and extensive research toward the total synthesis has been performed. This Review focuses on the synthetic strategies and tactics employed in the total synthesis of this class of natural products. The Introduction describes the historical background, structural features, and synthetic problems associated with aryl C-glycoside natural products. Next the Review summarizes the methods for constructing the aryl C-glycoside bonds. Completed total syntheses—and, in some cases, selected examples of incomplete syntheses—of natural aryl C-glycosides are also summarized. Finally described are the strategies for constructing polycyclic structures, which were utilized in the total syntheses.

173 citations

Journal ArticleDOI
TL;DR: In this paper, a variational functional for the finite element method is derived by using the Lagrange multiplier method, which is a very general one and almost all the functionals ever used in finite element analysis are included as its special cases.

44 citations

Journal ArticleDOI
TL;DR: A concise, highly convergent total synthesis of saptomycin B, a member of the pluramycin class of antitumor antibiotics, is reported.
Abstract: A concise, highly convergent total synthesis of saptomycin B, a member of the pluramycin class of antitumor antibiotics, is reported. The target compound was assembled from four building blocks (a tricyclic platform, two sugars, and an alkynal) in 15% yield through 10 synthetic operations. The key steps included the regioselective installation of two amino sugars (L-vancosamine and D-angolosamine) on the tricycle and the efficient construction of the tetracyclic skeleton by an aldol reaction followed by formation of the pyranone. The unknown configuration at C14 was assigned as R.

36 citations

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TL;DR: In this paper, the simplified hybrid displacement method for plate bending is given systematically with some extension made to allow for the discontinuity of deflection field, and eight types of finite elements are developed utilizing this principle.

35 citations

Journal ArticleDOI
TL;DR: Intramolecular photoredox reactions of naphthoquinone derivatives were found to proceed in a stereospecific manner and this method was used as a basis for the enantioselective total synthesis of (-)-spiroxin C.
Abstract: Intramolecular photoredox reactions of naphthoquinone derivatives were found to proceed in a stereospecific manner. This method was used as a basis for the enantioselective total synthesis of (−)-spiroxin C.

35 citations


Cited by
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Journal ArticleDOI
01 Jan 1974
TL;DR: In this paper, the authors describe a fitting for hose end fittings that is suitable for use in conjunction with a cross-linked polyethylene hose or pipe, where a body incorporating a nipple adapted for insertion in a pipe end and a clamping ring normally retained on the body and adapted for clamping action about the outer surface of said pipe end is described.
Abstract: The present invention is concerned with hose end fittings and has particular reference to fitting suitable for use in conjunction with a cross-linked polyethylene hose or pipe. The characteristic feature of the fitting of the present invention is a body incorporating a nipple adapted for insertion in a pipe end and a clamping ring normally retained on the body and adapted for clamping action about said outer surface of said pipe end, the nipple and ring being contoured on the inner surface to effect an improved clamping action. In a preferred embodiment the nipple may incorporate an annular groove incorporating an O-ring to assist sealing between the nipple and the internal surface of the tube or pipe.

2,298 citations

Journal ArticleDOI
TL;DR: In this article, an assessment of flat triangular plate bending elements with displacement degrees-of-freedom at the three comer nodes only is presented, with the purpose of identifying the most effective for thin plate analysis.
Abstract: SUMMARY An assessment of flat triangular plate bending elements with displacement degrees-of-freedom at the three comer nodes only is presented, with the purpose of identifying the most effective for thin plate analysis. Based on a review of currently available elements, specific attention is given to the theoretical and numerical evaluation of three triangular 9 degrees-of-freedom elements; namely, a discrete Kirchhoff theory (DKT) element, a hybrid stress model (HSM) element and a selective reduced integration (SRI) element. New and efficient formulations of these elements are discussed in detail and the results of several example analyses are given. It is concluded that the most efficient and reliable three-node plate bending elements are the DKT and HSM elements.

800 citations

Journal ArticleDOI
TL;DR: The finite element method is now recognized as a general approximation process which is applicable to a variety of engineering problems and boundary solution procedures have been introduced as an independent alternative which at times is more economical and possesses certain merits as mentioned in this paper.
Abstract: The finite element method is now recognized as a general approximation process which is applicable to a variety of engineering problems—structural mechanics being only one of these. Boundary solution procedures have been introduced as an independent alternative which at times is more economical and possesses certain merits. In this survey of the field we show how such procedures can be utilized in conventional FEM context.

711 citations

Journal ArticleDOI
TL;DR: In this paper, a simple and efficient finite element is introduced for plate bending applications, where Bilinear displacement and rotation functions are employed in conjunction with selective reduced integration, and the element is surprisingly accurate.
Abstract: A simple and efficient finite element is introduced for plate bending applications. Bilinear displacement and rotation functions are employed in conjunction with selective reduced integration. Numerical examples indicate that, despite its simplicity, the element is surprisingly accurate.

647 citations

Journal ArticleDOI
TL;DR: In this review, small molecule agents are introduced, but focus primarily on macromolecular MR contrast agents, particularly those containing gadolinium (Gd 3+ ) that are assembled or based in part on these same small molecules.
Abstract: Magnetism in medicine has had a long and interesting history In the 10 th century AD, Egyptian physician and philosopher Avicenna prescribed a grain of magnetite dissolved in milk for the accidental swallowing of rust reasoning that magnetite would render the poisonous iron inert by attracting it and accelerating its excretion through the intestine1 A thousand years later on July 3, 1977, “Indomitable”, the little machine that could, labored for five hours to produce one image, an event that used magnetism to change the landscape of modern medicine 2 Looking at the homemade superconducting magnet constructed from 30 miles of niobiumtitanium wire that now resides in its rightful place at the Smithsonian Institution, it is incredible to comprehend how in a mere 30 years magnetic resonance imaging (MRI) has gone from its crude, almost ugly, human scan to where physicians can now regularly order MRIs off their menu of diagnostic tools because of its exquisite anatomical resolution, routinely down to 05 to 1 mm When the field was first reviewed in this journal in 1987, 3 only 39 papers were found in Medline with keywords “gado-“ and “MRI” 4 Today, this same search on PubMed pulls out over 250,000 records, of which a significant component has been development of MR contrast agents The human body is essentially a super-sized water bottle, with about two-thirds of its weight consisting of water Water's hydrogen atoms are able to act as microscopic compass needles that stand “at attention” when placed in a strong magnetic field When submitted to pulses of radio waves, their magnetic alignment is disrupted and the differences in how they relax to the previous state are used to generate images Contrast agents can act to catalyze the process of the return to the ground relaxed state Now commonplace in the clinic, paramagnetic or superparamagnetic metal ions are administered in 40–50% of the 7–10 million MR examinations per year 5 These image-enhancing contrast agents add significant morphological and functional information to unenhanced MR images, allowing for enhanced tissue contrast, characterization of lesions, and evaluation of perfusion and flow-related abnormalities In this review, we will introduce small molecule agents, but focus primarily on macromolecular MR contrast agents, particularly those containing gadolinium (Gd 3+ ) that are assembled or based in part on these same small molecules A brief discussion on iron oxide and manganese (Mn 2+ ) agents is also provided

568 citations