334 research outputs found

    Palladium-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to Five-, Six-, and Seven-Membered β-Substituted Cyclic Enones: Enantioselective Construction of All-Carbon Quaternary Stereocenters

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    The first enantioselective Pd-catalyzed construction of all-carbon quaternary stereocenters via 1,4-addition of arylboronic acids to β-substituted cyclic enones is reported. Reaction of a wide range of arylboronic acids and cyclic enones using a catalyst prepared from Pd(OCOCF_3)_2 and a chiral pyridinooxazoline ligand yields enantioenriched products bearing benzylic stereocenters. Notably, this transformation is tolerant to air and moisture, providing a practical and operationally simple method of synthesizing enantioenriched all-carbon quaternary stereocenters

    Effects of nicorandil, a potassium channel opener, on idiopathic ventricular tachycardia

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    AbstractObjectives. We assessed the effects of the adenosine triphosphate (ATP)–sensitive potassium channel opener, nicorandil, on ATP- and verapamil-responsive ventricular tachycardias (VTs).Background. Adenosine- or ATP-sensitive VTs are thought to be due to a nonreentrant mechanism, presumably delayed afterdepolarization. We suggest that this potassium channel opener may suppress ATP- and verapamil-sensitive VTs.Methods. The subjects included 13 patients with idiopathic VTs, 7 of whom had sustained VT and 6 of whom had nonsustained VT. We evaluated the effects of ATP, nicorandil and verapamil on VTs.Results. Sustained VT: Verapamil had preventive effects on seven VTs. Four VTs were terminated by ATP, and of these, nicorandil terminated two and prevented exercise-induced VT in the two others. Three ATP-insensitive VTs, which were determined to be due to a reentry by an electrophysiologic study, were not terminated by nicorandil. Nonsustained VT: All six VTs were inhibited by ATP, and five of these were suppressed by nicorandil. Verapamil inhibited four of the five VTs. QT intervals and the corrected QT intervals were significantly shortened by nicorandil.Conclusions. Nicorandil suppresses ATP- and verapamil-responsive VTs. One of the mechanisms of suppression by nicorandil might be related to a reduction of calcium in the myocardium, because it reduces the action potential duration

    Detection of soluble interleukin-2 receptor and soluble intercellular adhesion molecule-1 in the effusion of otitis media with effusion

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    We measured sIL-2R, TNF-α and sICAM-1 in the sera and middle ear effusions (MEEs) of patients with otitis media with effusion (OME). Although there was no signmcant difference between the sIL-2R levels of the serous and mucoid MEEs, they were significantly higher than serum sIL-2R levels of OME patients and healthy controls. TNF-α levels of the mucoid MEEs were significantly higher than those of the serous type. However, TNF-α was rarely detected in the sera of OME patients or healthy controls. We observed significant differences between the serous and mucoid MEEs with respect to their sICAM-1 levels, which were also higher than serum slCAM-1 levels of OME patients and healthy controls. Our findings suggested that IL-2, TNF-α and ICAM-1 could be significantly involved in the pathogenesis of OME through the cytokine network

    直売型農産物流通の持続的展開に関する経済分析

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    学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 中嶋 康博, 東京大学教授 木南 章, 東京大学教授 松本 武祝, 東京大学准教授 齋藤 勝宏, 東京大学准教授 細野 ひろみUniversity of Tokyo(東京大学

    Synthesis of Diverse β-Quaternary Ketones via Palladium-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to Cyclic Enones

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    The development and optimization of a palladium-catalyzed asymmetric conjugate addition of arylboronic acids to cyclic enone conjugate acceptors is described. These reactions employ air-stable and readily-available reagents in an operationally simple and robust transformation that yields β-quaternary ketones in high yields and enantioselectivities. Notably, the reaction itself is highly tolerant of atmospheric oxygen and moisture and therefore does not require the use of dry or deoxygenated solvents, specially purified reagents, or an inert atmosphere. The ring size and β-substituent of the enone are highly variable, and a wide variety of β-quaternary ketones can be synthesized. More recently, the use of NH_4PF_6 has further expanded the substrate scope to include heteroatom-containing arylboronic acids and β-acyl enone substrates

    Coupling between dynamic 3D tissue architecture and BMP morphogen signaling during Drosophila wing morphogenesis

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    At the level of organ formation, tissue morphogenesis drives developmental processes in animals, often involving the rearrangement of two-dimensional (2D) structures into more complex three-dimensional (3D) tissues. These processes can be directed by growth factor signaling pathways. However, little is known about how such morphological changes affect the spatiotemporal distribution of growth factor signaling. Here, using the Drosophila pupal wing, we address how decapentaplegic (Dpp)/bone morphogenetic protein (BMP) signaling and 3D wing morphogenesis are coordinated. Dpp, expressed in the longitudinal veins (LVs) of the pupal wing, initially diffuses laterally within both dorsal and ventral wing epithelia during the inflation stage to regulate cell proliferation. Dpp localization is then refined to the LVs within each epithelial plane, but with active interplanar signaling for vein patterning/differentiation, as the two epithelia appose. Our data further suggest that the 3D architecture of the wing epithelia and the spatial distribution of BMP signaling are tightly coupled, revealing that 3D morphogenesis is an emergent property of the interactions between extracellular signaling and tissue shape changes.Peer reviewe

    Comparison of Nitrofen Uptake via Water and Food and its Distribution in Tissue of Common Carp, Cyprinus carpio L.

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    Carp (Cyprinus carpio L.) were exposed to nitrofen (NIP) by different routes (via water or food) to compare bioaccumulation parameters and tissue distribution. The bioconcentration factor of NIP was 5,100, and the lipid-corrected biomagnification factor was 0.137. Growth-corrected elimination half lives were 2.1–3.0 days via aqueous exposure and 2.7–2.9 days via dietary exposure. From either uptake route, the tissue distribution of NIP was highest in the head, followed by muscle, viscera, dermis, digestive tract and hepatopancreas, which was highly correlated with the tissue lipid content. We conclude that the uptake route has no influence on tissue distribution of NIP and that the accumulation potential in tissues depends on the lipid content

    Estrategia de publicidad Soy ITESO

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    En el marco del Proyecto de Aplicación Profesional (PAP) del Programa de Desarrollo de Estrategias Comerciales Nacionales e Internacionales I, el cuál se llevó a cabo en el periodo de verano 2023, se tiene como propósito crear estrategias publicitarias en redes sociales para la tienda SOY ITESO. El objetivo principal de este proyecto es mejorar sus estrategias sobre todo en el área publicitaria, para así poder crear una comunidad activa, crecer el negocio y aumentar sus ventas, sobre todo ahora que cuenta con un espacio más amplio y moderno para ofrecer a la comunidad del ITESO sus productos. También se trabajó en estrategias POP para mejorar el acomodo y aspecto de la tienda y que fuera mucho más llamativa para los clientes y finalmente se creó una propuesta de página web que pueda ser recreativa y mucho más llamativa para quienes la visitan.ITESO, A.C

    The royal food of termites shows king and queen specificity

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    シロアリの王と女王の特別食を世界初解明 --王と女王の繁殖と長寿を支えるロイヤルフード--. 京都大学プレスリリース. 2023-07-13.Society in eusocial insects is based on the reproductive division of labor, with a small number of reproductive individuals supported by a large number of non-reproductive individuals. Because inclusive fitness of all colony members depends on the survival and fertility of reproductive members, sterile members provide royals with special treatment. Here we show that termite kings and queens each receive special food of a different composition from workers. Sequential analysis of feeding processes demonstrated that workers exhibit discriminative trophallaxis, indicating their decision-making capacity in allocating food to the kings and queens. LC-MS/MS analyses of the stomodeal food and midgut contents revealed king- and queen-specific compounds including diacylglycerols and short-chain peptides. DESI-MSI analyses of ¹³C-labelled termites identified phosphatidylinositol and acetyl-L-carnitine in the royal food. Comparison of the digestive tract structure showed remarkable differences in the volume ratio of the midgut-to-hindgut among castes, indicating that digestive division of labor underlies reproductive division of labor. Our demonstration of king- and queen-specific food in termites provides insight into the nutritional system that underpins the extraordinary reproduction and longevity of royals in eusocial insects

    The motor activity of mammalian axonemal dynein studied in situ on doublet microtubules

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    Flagellar dynein generates forces that produce relative shearing between doublet microtubules in the axoneme; this drives propagated bending of flagella and cilia. To better understand dynein's role in coordinated flagellar and ciliary motion, we have developed an in situ assay in which polymerized single microtubules glide along doublet microtubules extruded from disintegrated bovine sperm flagella at a pH of 7.8. The exposed, active dynein remain attached to their respective doublet microtubules, allowing gliding of individual microtubules to be observed in an environment that allows direct control of chemical conditions. In the presence of ATP, translocation of microtubules by dynein exhibits Michaelis-Menten type kinetics, with V max = 4.7 ± 0.2 Μm/s and K m = 124 ± 11 ΜM. The character of microtubule translocation is variable, including smooth gliding, stuttered motility, oscillations, buckling, complete dissociation from the doublet microtubule, and occasionally movements reversed from the physiologic direction. The gliding velocity is independent of the number of dynein motors present along the doublet microtubule, and shows no indication of increased activity due to ADP regulation. These results reveal fundamental properties underlying cooperative dynein activity in flagella, differences between mammalian and non-mammalian flagellar dynein, and establish the use of natural tracks of dynein arranged in situ on the doublet microtubules of bovine sperm as a system to explore the mechanics of the dynein-microtubule interactions in mammalian flagella. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58643/1/20277_ftp.pd
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