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181.
Takahashi M Tsujimura N Otsuka K Yoshino T Mori T Matsunaga T Nakasono S 《Journal of Bioscience and Bioengineering》2012,113(4):529-535
Recently, humanized animals whereby a part of the animal is biologically engineered using human genes or cells have been utilized to overcome interspecific differences. Herein, we analyzed the detail of the differentiation states of various human leukocyte subpopulations in humanized mouse and evaluated comprehensively the similarity of the leukocyte lineage between humanized mice and humans. Humanized mice were established by transplanting human CD34(+) cord blood cells into irradiated severely immunodeficient NOD/Shi-scid/IL2Rγ(null) (NOG) mice, and the phenotypes of human cells contained in bone marrow, thymus, spleen and peripheral blood from the mice were analyzed at monthly intervals until 4 months after cell transplantation. The analysis revealed that transplanted human hematopoietic stem cells via the caudal vein homed and engrafted themselves successfully at the mouse bone marrow. Subsequently, the differentiated leukocytes migrated to the various tissues. Almost all of the leukocytes within the thymus were human cells. Furthermore, analysis of the differentiation states of human leukocytes in various tissues and organs indicated that it is highly likely that the human-like leukocyte lineage can be developed in mice. 相似文献
182.
Matsunaga T Akola J Kohara S Honma T Kobayashi K Ikenaga E Jones RO Yamada N Takata M Kojima R 《Nature materials》2011,10(2):129-134
Phase-change optical memories are based on the astonishingly rapid nanosecond-scale crystallization of nanosized amorphous 'marks' in a polycrystalline layer. Models of crystallization exist for the commercially used phase-change alloy Ge(2)Sb(2)Te(5) (GST), but not for the equally important class of Sb-Te-based alloys. We have combined X-ray diffraction, extended X-ray absorption fine structure and hard X-ray photoelectron spectroscopy experiments with density functional simulations to determine the crystalline and amorphous structures of Ag(3.5)In(3.8)Sb(75.0)Te(17.7) (AIST) and how they differ from GST. The structure of amorphous (a-) AIST shows a range of atomic ring sizes, whereas a-GST shows mainly small rings and cavities. The local environment of Sb in both forms of AIST is a distorted 3+3 octahedron. These structures suggest a bond-interchange model, where a sequence of small displacements of Sb atoms accompanied by interchanges of short and long bonds is the origin of the rapid crystallization of a-AIST. It differs profoundly from crystallization in a-GST. 相似文献
183.
Saravanan L Jayavel R Aldeyab SS Zaidi JS Ariga K Vinu A 《Journal of nanoscience and nanotechnology》2011,11(9):7783-7788
Europium doped cadmium sulphide (Cd(0.98)Eu(0.2)S) nanostructures were synthesised by chemical co-precipitation method using ethylene glycol (EG) and deionized water (Eu:CdS-1), and isopropyl alcohol (IPA) and deionized water (Eu:CdS-2) as mixed solvents. It has been found that the nanostructure of the europium doped CdS can be controlled by simply varying the mixed solvent system. Powder XRD pattern reveals the formation of hexagonal (wurtzite) and cubic (zinc blende) structure for Eu:CdS-1, and Eu:CdS-2, respectively. The crystallite size of the sample prepared using IPA and deionized water was measured to be 2.64 nm which is much smaller than that of the sample prepared using EG and deionized water as mixed solvent (3.65 nm). Morphology of the materials can also be changed from flower shaped crystals to paddy like structures by varying the mixed solvents. Band gap values of Eu3+ doped CdS nanocrystals synthesized from two different solvents were estimated using UV-reflectance spectra. The size and crystallinity of the samples were confirmed by HRTEM and SAED analysis. A significant change in the PL emission of the CdS nanocrystals was observed for the europium doped CdS which is mainly due to the presence of EU3+ ions which also play a significant role in the energy transfer process. It was also observed that the shift in the emission and efficiency depends on size and shape of the synthesised nanoparticles. 相似文献
184.
Thupakula U Khan AH Bal JK Ariga K Acharya S 《Journal of nanoscience and nanotechnology》2011,11(9):7709-7714
We report on the synthesis of CdSe nanocrystal quantum dots (QDs) of different radii (R). Size dependent optical properties like increase in the confinement energy with decreasing radius for different excitonic transitions are studied. Different excitonic transitions are calculated from the second derivative of UV-vis absorption spectra of as synthesized CdSe QDs. The transitions are assigned to specific states by calculating the transition energies using effective mass approximation. A close matching of the transition energies with the experiment suggesting that the second derivative of the absorption spectra could provide a direct knowledge of the electronic transition for the direct band gap semiconductor quantum dots. 相似文献
185.
Watanabe T Furukawa S Kitamoto K Takatsuki A Hirata R Ogihara H Yamasaki M 《International journal of food microbiology》2005,105(2):131-137
As a non-thermal sterilization process, high-pressure carbon dioxide treatment (HPCT) is considered to be promising. The main sterilizing effect of HPCT is thought to be acidification in cytoplasm of microorganisms. We investigated the tolerance mechanism of Saccharomyces cerevisiae to HPCT with special reference to vacuolar and plasma membrane H(+)-ATPases. HPCT was imposed at 35 degrees C, 4 to 10 MPa, for 10 min. slp1 mutant defective in vacuole morphogenesis was more sensitive to HPCT than its isogenic parent. Concanamycin A, a specific inhibitor of vacuolar H(+)-ATPase (V-ATPase), at 10 microM rendered the parent more HPCT-sensitive to the level of slp1. To confirm further the contribution of V-ATPase to the tolerance against HPCT in S. cerevisiae, we compared vma1 mutant of V-ATPase with its isogenic parent for their HPCT sensitivity. vma1 mutant was more sensitive to HPCT than its parent. Addition of 10 microM vanadate, an inhibitor of plasma membrane H(+)-ATPase (P-ATPase), to the wild type strains also increased the inactivation ratio. These results clearly show that V- and P-ATPases contribute to the tolerance against HPCT in S. cerevisiae by accumulating excess H(+) from cytoplasm to vacuole and excluding H(+) outside of the cell, respectively. 相似文献
186.
The authors examined the thermal change in the aroma profile of myrrh. The fresh odor of raw myrrh and its hexane extract depended on the amount of (E)-13-ocimene. Myrrh was extracted with hexane to avoid inducing changes in the constituents and odor. The main constituent, (E)-L3-ocimene (group A; low boiling point), and the other constituents (group B; high boiling point) of the hexane extract were separated by bulb-to-bulb distillation. The constituents of groups A and B were analyzed over time by nuclear magnetic resonance analysis and the odors were evaluated. Myrrh's odor depended on both the amount of thermally unstable (E)-[3-ocimene, which contributed to the fresh odor, and the constituents of group B (thermally stable), which contributed to the myrrh-like odor. Six compounds (c~-santalene, (Z)-a-bisabolene, c~-bergamotene, (E)-ct-santalal, c~-photosantalol and campherenol) were isolated from group B. No individual group B component had a myrrh-like odor, although the combined odor of group B was myrrh like. The authors demonstrated that the aroma profile of myrrh depends on the thermal instability of (E)-~-ocimene and a combination of six thermally stable terpenes with similar molecular structures. 相似文献
187.
Kawamura A Ooyama K Kojima K Kachi H Abe T Amano K Aoyama T 《Journal of oleo science》2011,60(12):597-607
Disruption of the skin barrier function caused by epidermal hyper-proliferation, results in the skin becoming dry and showing high transepidermal water loss (TEWL). Gamma linolenic acid (GLA) is reportedly efficacious for treating TEWL and epidermal hyper-proliferation. In this study, to elucidate the effect of GLA-rich oil on skin function, GLA-containing food was given to adults with dry skin or mild atopic dermatitis and skin parameters were evaluated. In the results, we recognized beneficial effects on the TEWL index. The efficacy of GLA was also demonstrated to be statistically significant especially in subjects with pro-inflammatory features. The results suggest that the mechanism of improvement of skin barrier has been associated with possible generation of anti-inflammatory metabolites from GLA. The clinical physician also confirmed that none of the subjects showed any noteworthy side effects. GLA-enriched food appears to be safe and to improve skin barrier function in subjects with dry skin conditions and mild atopic dermatitis. 相似文献
188.
189.
Kenta Adachi Kensuke Honda Suzuko Yamazaki Tomoyuki Hirano Hiroshi Kurokawa Akinobu Wakabayashi Paul H. Kasai Katsuhiko Nakamae Hitoshi Iwabuki Koji Murakami 《Polymer Engineering and Science》2011,51(4):632-640
The vinyltrimethoxysilane‐grafted ethylene‐propylene copolymer/trifunctional methoxysilane (EPR‐g‐VTMS/RTMS) composites were prepared via in situ silica sol–gel reactions. Five trifunctional methoxysilane compounds (n‐hexyltrimethoxysilane, n‐decyltrimethoxysilane, n‐tetradecyltrimethoxysilane, n‐octadecyltrimethoxysilane, and phenyltrimethoxysilane) have been selected for this study. The water‐cross‐linked EPR‐g‐VTMS/RTMS composites were characterized by attenuated total reflectance‐Fourier transform infrared spectroscopy, gel content, solid‐state 29Si CP/MAS NMR, wide‐angle x‐ray scattering, tensile strength, and field emission scanning electron microscopy measurements. The type of RTMS additive has a substantial influence on the nature of siloxane band networks and eventually the mechanical tensile properties. This finding suggests that the interaction and/or entanglement between the EPR‐g‐VTMS matrix and the substituent of the RTMS additives are crucial for the modifying mechanical properties. Moreover, for the water‐cross‐linked EPR‐g‐VTMS/CnTMS (n = 6, 10, 14, and 18) composites, the joint evidence provided by attenuated total reflectance‐Fourier transform infrared spectroscopy, 29Si CP/MAS NMR, and wide‐angle x‐ray scattering results suggested the formation of ladder‐type poly(n‐alkyl silsesquioxane)s and the presence of the highly ordered structure with a thickness equal to the length of two n‐alkyl groups in all‐trans conformation. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers. 相似文献
190.
Yusaku Nomoto Takuro Matsunaga Takamasa Sakai Masatoshi Tosaka Mitsuhiro Shibayama 《Polymer》2011,52(18):4123-4128
We investigated crystal structure, and thermal, swelling, and deformation behaviors of dried tetrafunctional (polyethylene glycol) gel, Tetra-PEG gel, with narrow molecular distribution. Tetra-PEG gel consists of two kinds of symmetrical tetrahedron-like PEG macromonomers with a fixed molecular weight. In spite of network structure with rather small molecular weight between cross-links (Mc) (≈5000), the dried Tetra-PEG gels were found to be capable of crystallization. The crystalline melting temperature (Tm) and the degree of crystallinity (Xc) of dried Tetra-PEG gels obtained by differential scanning calorimetry (DSC) were substantially constant against the polymer volume fraction at preparation (?0). Furthermore, the corrected elastic modulus (G) of dried Tetra-PEG gels did not depend on ?0. These experimental results indicate that the there exist negligible entanglements in the dried Tetra-PEG network irrespective of ?0. In other words, Tetra-PEG gels do not have significant topological inhomogeneities. 相似文献