Scanning Electron Microscopic Study of the Three-Dimensional Structure of the Collagen Networks of Gastric Cancer

The three-dimensional structure of the collagen networks in human gastric carcinoma was examined by scanning electron microscopy (SEM) after treatment with the cell-maceration method using a low temperature NaOH solution. Based on stromal content, the poorly differentiated adenocarcinoma can be divided into the medullary carcinoma area and the scirrhous carcinoma area. In the medullary carcinoma, the collagen sheath around the small tumor cell acinus formed spherical chambers (20-30 μm in diameter) with fenestrations (about 5 μm in diameter) connecting the chambers. The collagen sheath was composed of fine collagen fibrils (about 50 nm in diameter). In the scirrhous area, there was abundant fibrous stroma composed of thicker collagen fibrils (about 100 nm in diameter). Tiny tumor cell nests were sporadically seen in the fibrous stroma. These tumor nests were surrounded by collagen fibrils (about 50 nm in diameter). In the moderately differentiated tubular adenocarcinoma, the tumors were surrounded by spherical, ovoid or irregular shaped thick collagen sheaths (50-200 μm in diameter), which were composed of loosely packed 50 nm collagen fibrils. In well differentiated tubular adenocarcinoma, tumor glands were surrounded by spherical, ovoid or irregularly-shaped thick collagen sheaths (50-200 μm in diameter), composed of densely arranged fine collagen fibrils. In papillary carcinoma, the collagen sheaths were nipple-shaped. They were composed of very densely arranged fine collagen fibrils (about 50 nm in diameter)

水及びアルコールを作動媒体とする吸収式冷凍機及びヒートポンプに関する研究

関西大

Measurement of radon emanation and impurity adsorption from argon gas using ultralow radioactive zeolite

The amount of radioactive impurities contaminated in the detector gases is required to be kept at a very low level for rare event particle physics such as dark matter and neutrino observation experiments. Zeolite is a well-known adsorbent material and is one of the possible candidates for removing impurities from these gases. At the same time, the amount of radioactive impurities released from the adsorbent material needs to be sufficiently small. In this paper, a development of a new ultralow radioactive zeolite as a product of the selection of ultralow radioactive materials is reported. Results on the radon emanation and impurity adsorption from argon gas measurements are also described.Comment: 8 pages, 7 figure

種結晶添加法による有機構造規定剤を用いないゼオライト合成

学位の種別:課程博士University of Tokyo(東京大学

Inorganic molecular sieves: Preparation, modification and industrial application in catalytic processes

[EN] The increasing environmental concern and promotion of “green processes” are forcing the substitution of traditional acid and base homogeneous catalysts by solid ones. Among these heterogeneous catalysts, zeolites and zeotypes can be considered as real “green” catalysts, due to their benign nature from an environmental point of view. The importance of these inorganic molecular sieves within the field of heterogeneous catalysis relies not only on their microporous structure and the related shape selectivity, but also on the flexibility of their chemical composition. Modification of the zeolite framework composition results in materials with acidic, basic or redox properties, whereas multifunctional catalysts can be obtained by introducing metals by ion exchange or impregnation procedures, that can catalyze hydrogenation–dehydrogenation reactions, and the number of commercial applications of zeolite based catalysts is continuously expanding. In this review we discuss determinant issues for the development of zeolite based catalysts, going from zeolite catalyst preparation up to their industrial application. Concerning the synthesis of microporous materials we present some of the new trends moving into larger pore structures or into organic free synthesis media procedures, thanks to the incorporation of novel organic templates or alternative framework elements, and to the use of high-throughput synthesis methods. Post-synthesis zeolite modification and final catalyst conformation for industrial use are briefly discussed. In a last section we give a thorough overview on the application of zeolites in industrial processes. Some of them are well established mature technologies, such as fluid catalytic cracking, hydrocracking or aromatics alkylation. Although the number of zeolite structures commercially used as heterogeneous catalysts in these fields is limited, the development of new catalysts is a continuous challenge due to the need for processing heavier feeds or for increasing the quality of the products. The application of zeolite based catalysts in the production of chemicals and fine chemicals is an emerging field, and will greatly depend on the discovery of new or known structures by alternative, lower cost, synthesis routes, and the fine tuning of their textural properties. Finally, biomass conversion and selective catalytic reduction for conversion of NOx are two active research fields, highlighting the interest in these potential industrial applications.The authors acknowledge financial support from Ministerio de Ciencia e Innovacion (project Consolider-Ingenio 2010 MULTICAT).Martínez Sánchez, MC.; Corma Canós, A. (2011). Inorganic molecular sieves: Preparation, modification and industrial application in catalytic processes. Coordination Chemistry Reviews. 255(13-14):1558-1580. doi:10.1016/j.ccr.2011.03.014S1558158025513-1

Multipore zeolites: synthesis and catalytic applications

[EN] In the last few years, important efforts have been made to synthesize so-called "multipore" zeolites, which contain channels of different dimensions within the same crystalline structure. This is a very attractive subject, since the presence of pores of different sizes would favor the preferential diffusion of reactants and products through those different channel systems, allowing unique catalytic activities for specific chemical processes. In this Review we describe the most attractive achievements in the rational synthesis of multipore zeolites, containing small to extra-large pores, and the improvements reported for relevant chemical processes when these multipore zeolites have been used as catalysts.Financial support by the Spanish Government-MINECO through “Severo Ochoa” (SEV 2012-0267), Consolider Ingenio 2010-Multicat, MAT2012-37160, MAT2012-31657 and Intramural-201480I015 is acknowledged.Moliner Marin, M.; Martínez, C.; Corma Canós, A. (2015). Multipore zeolites: synthesis and catalytic applications. Angewandte Chemie International Edition. 54(12):3560-3579. https://doi.org/10.1002/anie.201406344S35603579541