Eigenmode excitation of Alfven ion cyclotron instability

科研費報告書収録論文(課題番号:07558072・基盤研究(A)(2)・H7～H9/研究代表者:犬竹, 正明/高密度プラズマ源を用いた電磁流体工学試験装置の開発

Giant Negative Thermal Expansion Induced by the Synergistic Effects of Ferroelectrostriction and Spin-Crossover in PbTiO3-Based Perovskites

The discovery of unusual negative thermal expansion (NTE) provides the opportunity to control the common but much desired property of thermal expansion, which is valuable not only in scientific interests but also in practical applications. However, most of the available NTE materials are limited to a narrow temperature range, and the NTE effect is generally weakened by means of various modifications. Here, we report an enhanced NTE effect that occurs over a wide temperature range (\alpha V = -5.24 * 10-5 {\deg}C^-1, 25-575 {\deg} C), and this NTE effect is accompanied by an abnormal enhanced tetragonality, a large spontaneous polarization, and a G-type antiferromagnetic ordering in the present perovskite-type ferroelectric of (1-x)PbTiO3-xBiCoO3. Specifically, for the composition of 0.5PbTiO3-0.5BiCoO3, an extensive volumetric contraction of ~4.8 % has been observed near the Curie temperature of 700 {\deg}C, which represents the highest level in PbTiO3-based ferroelectrics. According to our experimental and theoretical results, the giant NTE originates from a synergistic effect of the ferroelectrostriction and spin-crossover of cobalt on the crystal lattice. The actual NTE mechanism is contrasted with previous functional NTE materials, in which the NTE is simply coupled with one ordering such as electronic, magnetic, or ferroelectric ordering. The present study sheds light on the understanding of NTE mechanisms and it attests that NTE could be simultaneouslycoupled with different orderings, which will pave a new way toward the design of large NTE materials.Comment: 30 page

Desempenho do capim-tanzânia cultivado em solução nutritiva com a omissão de macronutrientes

The effects of nutritional disorder depends on the plant nutrient and the crop species. The experiment was carried out to evaluate the effect of nutrients on the nutrition and plant growth of Panicum maximum cv. Tanzania, grown in nutrient solution. Plants of Tanzania grass were grown in pots containing nutrient solution corresponding to seven treatments, one complete and the others with individual absence of N, P, K, Ca, Mg and S, arranged in a randomized  design with three replications. After describing the symptoms of the nutrients not applied, the plants were harvested 45 days after transplantation and divided into roots and shoots, and the levels of macronutrients were determined. The removal of nutrients in Tanzania grass resulted in a decrease both of dry matter production, with emphasis on nitrogen, and nutrient uptake, producing typical visual symptoms for each nutrient. Macronutrient levels in the shoots of grass in nutrient solution and omitting the nutrients were, respectively: N = 23.6 to 11.4, P = 1.7 to 0.3, K = 15.2 to 2.0 , Ca = 3.8 to 0.7, Mg = 3.0 to 0.3 S = 1.0 to 0.6 g kg-1Os efeitos da  desordem nutricional na planta depende do nutriente e da espécie cultivada. O experimento foi desenvolvido com o objetivo de avaliar o efeito dos macronutrientes sobre a nutrição e o crescimento de plantas de Panicum maximum cv. Tanzânia, cultivado em solução nutritiva. As plantas do capim-Tanzânia foram cultivadas em vasos contendo solução nutritiva correspondendo a sete tratamentos sendo a completa e com ausência individual N, P, K, Ca, Mg e S, dispostos em delineamento inteiramente  casualizado e três repetições. Após a descrição da sintomatologia dos nutrientes não aplicados, as plantas foram colhidas, 45 dias após o transplante, divididas em raiz e parte aérea e determinado os teores de macronutrientes. A supressão dos macronutrientes em capim-tanzânia provocou diminuição na produção de matéria seca destacando-se o nitrogênio, e na absorção de nutrientes,  promovendo sintomas visuais característica para cada nutriente. Os teores dos macronutrientes na parte aérea do capim da solução nutritiva completa e com omissão dos nutrientes foram respectivamente: N = 23,6-11,4; P = 1,7-0,3; K = 15,2-2,0; Ca = 3,8-0,7; Mg = 3,0-0,3; S = 1,0-0,6 g kg-1

Desempenho do capim-tanzânia cultivado em solução nutritiva com à omissão de macronutrientes

The effects of nutritional disorder depend on the plant nutrient and crop species. The experiment aimed to evaluate the effect of macronutrients on nutrition and  growth of Panicum maximum cv. Tanzania, grown in nutrient solution. Plants of Tanzania guinea grass were grown in pots containing nutrient solution corresponding to seven treatments, with the complete solution and with absence of nutrients N, P, K, Ca, Mg and S, arranged in a randomized block design with three replications. After describing the symptoms of the nutrients not applied, the plants were harvested 45 days after transplantation and divided into roots and shoots, and then the macronutrients levels were determined. The suppression of macronutrients in Tanzania guinea grass resulted in lower dry matter production, with emphasis on nitrogen, and lower nutrient uptake, causing typical visible symptoms according to each nutrient. Macronutrient levels in the plant shoot in nutrient solution and omitting the nutrients were, respectively: N = 23.6 to 11.4, P = 1.7 to 0.3, K = 15.2 to 2.0 , Ca = 3.8 to 0.7, Mg = 3.0 to 0.3 S = 1.0 to 0.6 g kg-1.Os efeitos da desordem nutricional na planta depende do nutriente e da espécie cultivada. O experimento foi desenvolvido com o objetivo de avaliar o efeito dos macronutrientes sobre a nutrição e o crescimento de plantas de Panicum maximum cv. Tanzânia, cultivado em solução nutritiva. As plantas do capim-Tanzânia foram cultivadas em vasos contendo solução nutritiva correspondendo a sete tratamentos sendo a completa e com ausência individual N, P, K, Ca, Mg e S, dispostos em delineamento inteiramente casualizado e três repetições. Após a descrição da sintomatologia dos nutrientes não aplicados, as plantas foram colhidas, 45 dias após o transplante, divididas em raiz e parte aérea e determinado os teores de macronutrientes. A supressão dos macronutrientes em capim-tanzânia provocou diminuição na produção de matéria seca destacando-se o nitrogênio, e na absorção de nutrientes,  promovendo sintomas visuais característica para cada nutriente. Os teores dos macronutrientes na parte aérea do capim da solução nutritiva completa e com omissão dos nutrientes foram respectivamente: N = 23,6-11,4; P = 1,7-0,3; K = 15,2-2,0; Ca = 3,8-0,7; Mg = 3,0-0,3; S = 1,0-0,6 g kg-1

Promiscuous Gene Expression in the Thymus: The Root of Central Tolerance

The thymus is a complex organ with an epithelium formed by two main cell types, the cortical thymic epithelial (cTECs) and medullary thymic epithelial cells (mTECs), referred to as stroma. Immature thymocytes arising from the bone marrow, macrophages and dendritic cells also populate the thymus. Thymocytes evolve to mature T cells featuring cell differentiation antigens (CDs), which characterize the phenotypically distinct stages, defined as double-negative (DN), double positive (DP) and single positive (SP), based on expression of the coreceptors CD4 and CD8. The thymus is therefore implicated in T cell differentiation and during development into T cells thymocytes are in close association with the stroma. Recent evidence showed that mTECs express a diverse set of genes coding for parenchymal organ specific proteins. This phenomenon has been termed promiscuous gene expression (PGE) and has led to the reconsideration of the role of the thymus in central T cell tolerance to self-antigens, which prevents autoimmunity. The evidence of PGE is causing a reanalysis in the scope of central tolerance understanding. We summarize the evidence of PGE in the thymus, focusing particularly the use of cDNA microarray technology for the broad characterization of gene expression and demarcation of PGE emergence during thymus ontogeny

Synthetic emmprin peptides with chitobiose substitution stimulate MMP-2 production by fibroblasts

<p>Abstract</p> <p>Background</p> <p>Emmprin, a glycoprotein containing two Ig domains, is enriched on tumor cell surfaces and stimulates matrix metalloproteinase (MMP) production by adjacent stromal cells. Its first Ig domain (ECI) contains the biologically active site. The dependence of emmprin activity on N-glycosylation is controversial. We investigated whether synthetic ECI with the shortest sugar is functionally active.</p> <p>Methods</p> <p>The whole ECI peptides carrying sugar chains, a chitobiose unit or N-linked core pentasaccharide, were synthesized by the thioester method and added to fibroblasts to examine whether they stimulate MMP-2 production.</p> <p>Results</p> <p>ECI carrying a chitobiose unit, ECI-(GlcNAc) ₂, but not ECI without a chitobiose unit or the chitobiose unit alone, dose-dependently stimulated MMP-2 production by fibroblasts. ECI with longer chitobiose units, ECI-[(Man)₃(GlcNAc)₂], also stimulated MMP-2 production, but the extent of its stimulation was lower than that of ECI-(GlcNAc)₂.</p> <p>Conclusions</p> <p>Our results indicate that ECI can mimic emmprin activity when substituted with chitobiose, the disaccharide with which N-glycosylation starts.</p