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排序方式: 共有417条查询结果,搜索用时 46 毫秒
81.
Our previous results in a murine model indicated that the GVL effect against radiation-induced leukemias could be induced in not only MHC-incompatible but also MHC-compatible allogeneic BMT, and that the intensity of the GVL effect induced in MHC-compatible allogeneic BMT varied among different leukemias and the donor/host strain combinations used. With the use of a radiation-induced T cell leukemia which followed the induction of the GVL effect in both MHC-compatible and -incompatible, allogeneic BMT, the role of T cell subsets in the development of the GVL effect and GVHD was studied. The results indicated that Lyt2+ T cells contaminating donor BM were consistently critical for the induction of the GVL effect in MHC-incompatible (B10) and -compatible (B10.BR and AKR) allogeneic BMT of leukemia-bearing C3H mice, but the depletion of L3T4+ T cells had no effect. In contrast, lethal GVHD induced by AKR donor lymph node cells was totally dependent on L3T4+ T cells, but the depletion of Lyt2+ T cells had no effect. On the other hand, both T cell subsets could cause lethal GVHD induced by MHC-incompatible (B10) and -compatible (B10.BR) allogeneic donors. The distinct roles of T cell subsets of AKR donors were confirmed by the preferential induction of the GVL effect with the AKR donor bone marrow mixed with lymph node cells which had been depleted of L3T4+ T cells.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
82.
Downregulation of the Klotho gene in the kidney under sustained circulatory stress in rats 总被引:1,自引:0,他引:1
H Aizawa Y Saito T Nakamura M Inoue T Imanari Y Ohyama Y Matsumura H Masuda S Oba N Mise K Kimura A Hasegawa M Kurabayashi M Kuro-o Y Nabeshima R Nagai 《Canadian Metallurgical Quarterly》1998,249(3):865-871
We recently reported the isolation of the klotho gene, which in predominantly expressed in the kidney and involved in human aging phenotypes. In our previous studies, we demonstrated that the Klotho protein or its metabolites may possibly function as humoral factor(s) and protect against endothelial dysfunction because acetylcholine-mediated NO production in arteries was impaired in heterozygous klotho deficient mice (kl/+). However, the pathophysiological significance of the Klotho protein has not been clarified yet. In the present study, we examined expression of the klotho gene in the kidney of the following rat models for human diseases: (1) spontaneously hypertensive rat, (2) deoxycorticosterone acetate-salt hypertensive rat, (3) 5/6 nephrectomized rat, (4) non-insulin-dependent diabetes mellitus rat (the Otsuka Long-Evans Tokushima Fatty rat), and (5) rat with acute myocardial infarction. The expression levels of klotho mRNA in the kidney in these models were significantly lower than controls except for MI rats. This is the first report showing the expression of the klotho gene in the kidney is regulated under sustained circulatory stress such as long-term hypertension, diabetes mellitus, and chronic renal failure. 相似文献
83.
M. Aizawa K. Itatani F. S. Howell A. Kishioka M. Kinoshita 《Journal of Materials Science》1995,30(19):4936-4945
Porous calcium phosphate films could be formed on partially stabilized zirconia (3YZ) substrates by a spray-pyrolysis technique. The use of calcium metaphosphate as a binder was effective to enhance the binding strengths of these films to the substrates. The crystalline phase in the resulting films was mainly -calcium orthophosphate. This phase was thermally stabilized by solid solution with Y3+. The thickness of the film (30–150 m) was dependent upon the spraying time; the pore size was about 15 m. The films were still present on the substrate after Scotch tape (810) was adhered to the film side and then taken off from the substrate. The films prepared in this study were found to bind strongly to the substrate. 相似文献
84.
Litian Sun Toshihiko Yamasaki Kiyoharu Aizawa 《Multimedia Tools and Applications》2018,77(5):5189-5213
The amount of visual data available on the Web is growing explosively and it is becoming increasingly important to explore methods for automatically estimating the quality of this content in a manner that is consistent with the aesthetic perceptions of humans. The key to this challenging problem is to design an appropriate set of features to extract the aesthetic properties from content. Most previous studies designed a set of aesthetic features based on photographic criteria, which were unavoidably limited to specific examples and they lacked an interpretation based on the mechanism of human aesthetic perception. According to psychological theory, visual complexity is an important property of the stimuli, because it directly influences the viewer’s arousal level, which is believed to be closely related to aesthetic perception. In this study, we propose an alternative set of features for aesthetic estimation based on a visual complexity principle. We extracted the visual complexity properties from an input image in terms of their composition, shape, and distribution. In addition, we demonstrated that the proposed features are consistent with human perception on the complexity in our visual complexity dataset. Next, we employed these features for photo-aesthetic quality estimation using a large-scale dataset. Various experiments were conducted under different conditions and comparisons with state-of-the-art methods shows that the proposed visual complexity feature outperforms photography rule-based features and even better than deep features. 相似文献
85.
Takaya Arita Michał Joachimczak Takashi Ito Atsushi Asakura Reiji Suzuki 《Artificial Life and Robotics》2016,21(2):141-148
Evolutionary developmental biology, evo-devo, emerged to integrate evolution and development in the 1980s, in which evolution is conceptualized as heritable changes in development. Recently, the field is moving to a new synthesis: ecological evolutionary developmental biology, eco-evo-devo. We believe that artificial life (ALife) approach will provide new insights into the field, and also contribute to the field of robotics through the emergence perspective and the constructive methodology. This paper explores the potential of such an artificial life approach based on the evolution of virtual creatures by presenting our ongoing studies with three models: (1) metamorphosis model, (2) exaptation model and (3) Prey-predator model. 相似文献
86.
87.
88.
Weilan Luo Toshihiko Yamasaki Kiyoharu Aizawa 《Computer Vision and Image Understanding》2013,117(11):1560-1574
We propose a human motion tracking method that not only captures the motion of the skeleton model but also generates a sequence of surfaces using images acquired by multiple synchronized cameras. Our method extracts articulated postures with 42 degrees of freedom through a sequence of visual hulls. We seek a globally optimized solution for likelihood using local memorization of the “fitness” of each body segment. Our method efficiently avoids problems of local minima by using a mean combination and an articulated combination of particles selected according to the weights of the different body segments. The surface is produced by deforming the template and the details are recovered by fitting the deformed surface to 2D silhouette rims. The extracted posture and estimated surface are cooperatively refined by registering the corresponding body segments. In our experiments, the mean error between the samples of the deformed reference model and the target is about 2 cm and the mean matching difference between the images projected by the estimated surfaces and the original images is about 6%. 相似文献
89.
90.
Birds do not always vocalize at random, but may rather divide up soundspace in such a manner that they avoid overlap with the songs of other bird species. In effect, a high degree of communication efficiency can be achieved by many simultaneously active vocalists that finely integrate songs with minimal overlap. We describe this phenomenon from several recordings at our principal study location, near Volcano, California. The most-studied models for conceptualizing and studying such de-synchronized systems come from scheduling algorithms in computer science, where internet protocols involve packets of information that are broadcast widely; any collisions between them will corrupt the colliding packets so that they need to be resent. We have simulated some of these methods that might be appropriate for the soundspace of bird communities. Some features of these de-synchronized depend on specifics of the algorithms used. 相似文献