3,780 research outputs found

    Blow-up criterion of strong solutions to the Navier-Stokes equations in Besov spaces with negative indices

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    A H\"older type inequality in Besov spaces is established and applied to show that every strong solution u(t,x)u(t,x) on (0,T) of the Navier-Stokes equations can be continued beyond t>Tt>T provided that the vorticity \omega(t,x)\in L^{\frac 2{2-\alpha}}(0,T;\dot{B}^{-\alpha}_{\infty,\infty}(\mr^3))\cap L^{\frac2{1-\alpha}}(0,T;\dot{B}^{-1-\alpha}_{\infty,\infty}(\mr^3)) for 0<α<10<\alpha<1

    Crystal architectures of a layered silicate on monodisperse spherical silica particles cause the topochemical expansion of the core-shell particles

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    Anisotropic structural changes in an expandable layered silicate (directed towards the c-axis) occurring on isotropic and monodisperse microspheres were detected by measurable increases in the grain size. The hierarchical changes were observed through pursing the sophisticated growth of expandable layered silicate crystals on monodisperse spherical silica particles with diameters of 1.0 mu m; the core-shell hybrids with a quite uniform grain size were successfully produced using a rotating Teflon-lined autoclave by reacting spherical silica particles in a colloidal suspension with lithium and magnesium ions under alkaline conditions at 373 K. The size distribution of the core-shell particles tended to be uniform when the amount of lithium ions in the initial mixture decreased. The intercalation of dioctadecyldimethylammonium ions into the small crystals through cation-exchange reactions expanded the interlayer space, topochemically increasing the grain size without any change occurring in the shapes of the core-shell particles. (C) 2015 Elsevier Inc. All rights reserved.ArticleMICROPOROUS AND MESOPOROUS MATERIALS. 215:168-174 (2015)journal articl

    Photochromic Intercalation Compounds

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    Photochromism of intercalation compounds has been investigated so far. Starting from fundamental studies on the photochromic reactions of the dyes in the presence of layered materials, the precise design of the nanostructures of intercalation compounds toward controlled photochemical reactions and the creation of novel photoresponsive supramolecular systems based on layered solids have been a topic of interests. Various layered materials with different surface chemistries have been used as hosts for the controlled orientation, and aggregation of the intercalated dyes and the states of the intercalated guests affected photoresponses. Molecular design of the photochromic dyes has also been conducted in order to organize them on layered solids with the desired manner. On the other hand, layered solids with such functions as semiconducting and magnetic have been examined to host photochromic dyes for the photoresponsive changes in the materials' properties.ArticlePHOTOFUNCTIONAL LAYERED MATERIALS. 166: 177-211 (2015)journal articl

    An annotated bibliography on the biology and fishery of the skipjack tuna, Katsuwonis pelamis, of the Pacific Ocean

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    ENGLISH: The skipjack tuna, Katsuwonus pelamis is an important resource of the tropical and subtropical waters of the world ocean. Fishermen of many countries exploit this resource; at the present time, the annual world catch is approximately 200 thousand metric tons. Many fishery experts believe that the skipjack is not being fully utilized while stocks of other tunas are being fished, in some areas, at levels exceeding their maximum sustainable yields. In addition to the importance of skipjack as a commercial fish and as a source of food, there is a small but expanding recreational fishery in some countries bordering the Pacific. This bibliography provides a list of publications pertaining to the biology and fishery of the Pacific skipjack tuna. Papers concerned with food technology, food chemistry, radio-chemistry, and certain other subjects are excluded. The main sources for our publication have been the existing bibliographies of tunas, which are listed and indexed accordingly. In addition, reports of various marine laboratories and other scientific organizations have been checked; these are too numerous to list. We are fairly confident that all major works pertaining to skipjack tuna in the Pacific, printed prior to the end of 1966, appear in this bibliography. Only reports considered to be in permanent form are included. Annotations are based on actual examination of each of the entries listed here. The annotations do not evaluate a paper but serve rather to give a more precise idea of its contents if not revealed by the title alone. If the title sufficed in this respect, no annotation was prepared. A relatively small number of works believed to contain information pertinent to our bibliography could not be examined, but a list of such papers is provided. SPANISH: El atĂșn barrilete, Katsuwonus pelamis, es un recurso importante de las aguas tropicales y subtropicales del ocĂ©ano mundial. Los pescadores de varios paĂ­ses explotan este recurso; actualmente, la captura mundial anual es aproximadamente de 200,000 toneladas mĂ©tricas. Muchos expertos en la pesquerĂ­a creen que el barrilete no es utilizado completamente, mientras los stocks de otros atunes son pescados en algunas ĂĄreas a niveles que exceden su rendimiento mĂĄximo sostenible. AdemĂĄs de la importancia del barrilete como pez comercial y como fuente de alimento, existe una pesquerĂ­a pequeña recreativa que se estĂĄ desarrollando en algunos paĂ­ses colindantes con el PacĂ­fico. Esta bibliografĂ­a suministra una lista de publicaciones correspondientes a la biologĂ­a y pesquerĂ­a del atĂșn barrilete en el PacĂ­fico. Estudios referentes a la tecnologĂ­a alimenticia, quĂ­mica alimenticia, radioquĂ­mica y ciertos otros sujetos son excluĂ­dos. Las fuentes principales correspondientes a nuestra publicaciĂłn han sido las bibliografĂ­as existentes sobre atunes, las cuales estĂĄn enumeradas y catalogadas de acuerdo. AdemĂĄs, se han examinado los informes de varios laboratorios marĂ­timos y los de otras organizaciones cientĂ­ficas; Ă©stos son demasiado numerosos para enumerar. Estamos bastante seguros de que todos los trabajos principales correspondientes al atĂșn barrilete del PacĂ­fico, editados antes de terminar el año de 1966, aparecen en esta bibliografĂ­a. Se incluyen Ășnicamente los informes que se consideran permanentes. Las anotaciones se basan en el examen actual de cada una de las entradas aquĂ­ referidas. Las anotaciones no evaluan un estudio, pero sirven mĂĄs bien para dar una idea mĂĄs precisa de su contenido si el tĂ­tulo por sĂ­ mismo no lo explica. No se preparĂł ninguna anotaciĂłn si el tĂ­tulo a este respecto era suficiente. Un nĂșmero relativamente pequeño de trabajos que se cree tengan informaciĂłn pertinente a nuestra bibliografĂ­a no pudo ser examinado, pero se suministra una lista de tales estudios. (PDF contains 227 pages.

    Theoretical Investigation by Quantum Mechanics on the Tunnel Diode Effect of Electric Conductive Characteristics and Haptic Sensing in MCF Rubber

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    By applying our developed intelligent fluid, magnetic compound fluid (MCF), to silicon oil rubber, we have made the MCF rubber highly sensitive to temperature and electric conduction. MCF is useful as the element material in haptic robot sensors and other related devices. In the present paper, we clarified the relationship between the electric current and the voltage under a tensile strain by utilizing the quantum mechanics theory on the multibarrier potential problem. The experimental results could be qualitatively explained by our proposed theory. The electrons can be moved between the solid materials by the tunnel effect. The relation between voltage and electric current is affected by the formation of the clusters, and it is changed by the application of heat. We also clarified experimentally the present MCF rubber useful in haptic sensors. Because the motions of humans and robots are different, the sensing of the rubber is different, depending on the placement. However, as for both motions of human and robot, there is no quantitative difference in the electric resistance among kinetic energy, momentum, and force. The sensing is also different based on the stiffness of the surface to which the sensor is adhered

    The Three-Dimensional Microstructure of the Liver A Review by Scanning Electron Microscopy

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    The improvement in scanning electron microscopy (SEM) techniques has permitted us to describe the microstructure of the liver. By SEM, the liver peritoneal surface is composed of flat mesothelial cells possessing microvilli and cilia. Hepatic sinusoids connect the portal vessels with the terminal branches of the hepatic vein (central veins). Endothelial cells of the portal space arteries are elongated and arranged longitudinally, while those of the central and portal veins are polygonal and flattened, possessing microvilli. The sinusoidal endothelial cells show both small fenestrations (sieve plates), up to 200 nm in diameter, and large ones, up to 1 m. Within the sinusoids are seen bridging structures, covered by fenestrated endothelium, seeming to have a fibrillar core. Kupffer cells resemble macrophages, showing microvilli, blebs, lamellipodia and filopodia. Within the Space of Disse are seen the fat-storing cells, having laminar dendritic projections. The polyhedral liver cell faces the Space of Disse (vascular pole) or faces an adjacent hepatocyte (biliary pole). Vascular facets are evenly covered by microvilli. Biliary facets show a central longitudinal depression, bordered by microvilli (bile hemicanaliculi). Canaliculoductular junction and bile duct epithelia show blebs, microvilli and cilia. Up to now, fetal liver and liver pathology have been scarcely investigated by SEM: in the future, they can be successfully approached by three-dimensional studies

    Hormone-like (endocrine) Fgfs: their evolutionary history and roles in development, metabolism, and disease

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    Fibroblast growth factors (Fgfs) are proteins with diverse functions in development, repair, and metabolism. The human Fgf gene family with 22 members can be classified into three groups, canonical, intracellular, and hormone-like Fgf genes. In contrast to canonical and intracellular Fgfs identified in invertebrates and vertebrates, hormone-like Fgfs, Fgf15/19, Fgf21, and Fgf23, are vertebrate-specific. The ancestral gene of hormone-like Fgfs was generated from the ancestral gene of canonical Fgfs by gene duplication early in vertebrate evolution. Later, Fgf15/19, Fgf21, and Fgf23 were generated from the ancestral gene by genome duplication events. Canonical Fgfs act as autocrine/paracrine factors in an Fgf receptor (Fgfr)-dependent manner. In contrast, hormone-like Fgfs act as endocrine factors in an Fgfr-dependent manner. Canonical Fgfs have a heparin-binding site necessary for the stable binding of Fgfrs and local signaling. In contrast, hormone-like Fgfs acquired endocrine functions by reducing their heparin-binding affinity during their evolution. Fgf15/19 and Fgf23 require ÎČKlotho and αKlotho as cofactors, respectively. However, Fgf21 might physiologically require neither. Hormone-like Fgfs play roles in metabolism at postnatal stages, although they also play roles in development at embryonic stages. Fgf15/19 regulates bile acid metabolism in the liver. Fgf21 regulates lipid metabolism in the white adipose tissue. Fgf23 regulates serum phosphate and active vitamin D levels. Fgf23 signaling disorders caused by hereditary diseases or tumors result in metabolic disorders. In addition, serum Fgf19 or Fgf21 levels are significantly increased by metabolic disorders. Hormone-like Fgfs are newly emerging and quite unique in their evolution and function

    The role of perineural invasion in predicting survival in patients with primary operable colorectal cancer: a systematic review

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    Perineural invasion is a clear route for cancer cell spread however, the role of nerves in cancer progression is relatively unknown. Recent work would suggest that nerves can actively infiltrate the tumour microenvironment and stimulate cancer cell growth. Therefore, the aim of the present study was to systematically review the identification and associations of perineural invasion and survival in patients with primary operable colorectal cancer. From initial search results of 912 articles, 38 studies were selected. Using H&#38;E stains; five studies including 1835 patients reported on survival stratified by perineural invasion in colon cancer with weighted average detection rates of 26%; eleven studies including 3837 patients reported on rectal cancer with weighted average detection rates of 25% and; sixteen studies including 9145 patients reported on survival stratified by perineural invasion in colorectal cancer with weighted average detection rates of 17%. Using special techniques (S100), six studies including 1458 patients reported on the identification of perineural invasion in colorectal cancer. In comparison to H&#38;E staining alone, the use of immunohistochemistry with S100 increased the detection of perineural invasion to approximately 70%. However, those studies did not examine the relationship with outcomes, so further research is required to establish the clinical significance of perineural invasion detected by immunohistochemistry. In conclusion, perineural invasion deserves special attention for improved prognostic stratification in patients with colorectal cancer. Further work is required to standardise pathology assessment and reporting of perineural invasion, in particular its definition, use of special stains and routine inclusion in pathology practice. Reliable assessment is required for investigations into mechanisms of perineural invasion, its role tumour spread and prognostic value
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