Profile of bordered pit aspiration in Cryptomeria japonica using confocal laser scanning microscopy: pit aspiration and heartwood color     

Junji Matsumura  Yoko Yamasaki  Kazuyuki Oda  Yoshitake Fujisawa 《Journal of Wood Science》2005,51(4):328-333

Nine trees of Cryptomeria japonica from six elite tree clones with a broad range of heartwood colors were selected. The profiles of pit aspiration percentage (ASP) of earlywood and latewood from pith to bark for green and air-dry conditions were determined to study the relationship between heartwood color and pit aspiration. Confocal laser scanning microscopy (CLSM) observations showed that the ASP of earlywood was low in sapwood and high in heartwood in the green condition. Pit aspiration increased in intermediate wood when compared with sapwood. On the other hand, latewood pits did not aspirate during heartwood formation. Comparing the air-dry condition with the green condition, sapwood pits aspirated during drying in both earlywood and latewood; however, there was no significant difference in pit aspiration of heartwood. There was no significant difference between samples with red and black heartwoods for ASP. The difference in ASP between individual trees was larger than that by heartwood color. The general advantage of CLSM over light microscopy is that serial optical sections along the Z axis can be obtained for any moisture condition, without the need for thin sectioning or embedding.  相似文献   

Low-Frequency Raman Scattering and the Fast Relaxation Process in Glycerol     

T Uchino  T Yoko 《Science (New York, N.Y.)》1996,273(5274):480-483

Ab initio molecular orbital calculations were used to determine the structure and vibrational frequencies of the cyclic glycerol trimer, which represents the region of medium-range ordering in liquid and supercooled glycerol. The calculations reproduced the experimentally observed low-frequency Raman scattering peak (or the "boson peak") at approximately50 per centimeter, which suggests that the peak results from the localized collective motions of the cooperatively hydrogen-bonded hydroxyl groups. The calculations also suggest that the fast relaxation process may result from the translational motion of each glycerol molecule in the cyclic structure. On the basis of these results, a model of the glass transition was developed.  相似文献   

Biallelic inactivation of BRCA2 in Fanconi anemia     

Howlett NG  Taniguchi T  Olson S  Cox B  Waisfisz Q  De Die-Smulders C  Persky N  Grompe M  Joenje H  Pals G  Ikeda H  Fox EA  D'Andrea AD 《Science (New York, N.Y.)》2002,297(5581):606-609

Fanconi anemia (FA) is a rare autosomal recessive cancer susceptibility disorder characterized by cellular hypersensitivity to mitomycin C (MMC). Six FA genes have been cloned, but the gene or genes corresponding to FA subtypes B and D1 remain unidentified. Here we show that cell lines derived from FA-B and FA-D1 patients have biallelic mutations in BRCA2 and express truncated BRCA2 proteins. Functional complementation of FA-D1 fibroblasts with wild-type BRCA2 complementary DNA restores MMC resistance. Our results link the six cloned FA genes with BRCA1 and BRCA2 in a common pathway. Germ-line mutation of genes in this pathway may result in cancer risks similar to those observed in families with BRCA1 or BRCA2 mutations.  相似文献   

Optical switching and image storage by means of azobenzene liquid-crystal films     

Ikeda T  Tsutsumi O 《Science (New York, N.Y.)》1995,268(5219):1873-1875

Liquid crystals are promising materials for optical switching and image storage because of their high resolution and sensitivity. Azobenzene liquid crystals (LCs) have been developed, in which azobenzene moieties play roles as both mesogens and photosensitive chromophores. Azobenzene LC films showed a nematic phase in trans isomers and no LC phase in cis isomers. Trans-cis photoisomerization of azobenzene with a laser pulse resulted in a nematic-to-isotropic phase transition with a rapid optical response of 200 microseconds.  相似文献   

Molecular structures of gellan gum imaged with atomic force microscopy in relation to the rheological behavior in aqueous systems in the presence or absence of various cations     

Funami T  Noda S  Nakauma M  Ishihara S  Takahashi R  Al-Assaf S  Ikeda S  Nishinari K  Phillips GO 《Journal of agricultural and food chemistry》2008,56(18):8609-8618

Aqueous solutions of gellan gum with comparable molecular masses but with different acyl contents were investigated by atomic force microscopy and rheological measurements in the presence or absence of various cations. For a high-acyl sample, no continuous network structures were identified microscopically, except in the presence of Ca (2+), where structural inhomogeneity was the highest in terms of the height distribution of molecular assemblies. Rheological thermal hysteresis between sol-gel transitions was detected in the presence of K (+) and Ca (2+), particularly Ca (2+). The storage modulus at 20 degrees C was larger in the order Na (+) < Ca (2+) < K (+). For a low-acyl sample, continuous network structures were identified in the presence of each cation, involving greater thermal hysteresis than the corresponding data for the high-acyl sample. Structural homogeneity was the highest in the presence of K (+). Thermal hysteresis and elasticity of the system were discussed in terms of continuousness and homogeneity of network structures.  相似文献   

Soluble starch synthase I effects differences in amylopectin structure between indica and japonica rice varieties     

Takemoto-Kuno Y  Suzuki K  Nakamura S  Satoh H  Ohtsubo K 《Journal of agricultural and food chemistry》2006,54(24):9234-9240

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Genetic relationships among sympatric varieties of <Emphasis Type="Italic">Acer mono</Emphasis> in the Chichibu Mountains and Central Hokkaido,Japan     

Chunping Liu  Jian Cong  Hailong Shen  Cunxue Lin  Yoko Saito  Yuji Ide 《林业研究》2017,28(4):699-704

Acer mono Maxim. is one of the major components of cool temperate forests in Japan. Some of its many varieties are distributed sympatrically. Because of its great variability, the intraspecific taxonomy and nomenclature of the species are controversial. To understand the genetic relationships among these varieties and whether hybridization or introgression occurred among the sympatric varieties, we studied the genetic relationships among sympatric varieties of A. mono in the Chichibu Mountains (A. mono var. ambiguum, A. mono var. connivens, A. mono var. marmoratum) and Central Hokkaido (A. mono var. mayrii and A. mono var. glabrum) in Japan. Our results showed that varieties in Chichibu are genetically close, suggesting that hybridization or introgression might occur between these varieties, which could explain the higher genetic diversity of varieties in Chichibu than in Hokkaido. In contrast to the close relationships between the varieties in Chichibu, varieties in Hokkaido seemed relatively separated from each other; indeed, there may be reproductive isolation between the two varieties. The results provide new insight for the taxonomy of the varieties of A. mono, especially the sympatric varieties, in Japan.  相似文献   

Detection of an autoantibody from Pug dogs with necrotizing encephalitis (Pug dog encephalitis).     

K Uchida  T Hasegawa  M Ikeda  R Yamaguchi  S Tateyama 《Veterinary pathology》1999,36(4):301-307

An autoantibody against canine brain tissue was detected in the cerebrospinal fluid (CSF) and serum of two Pug dogs (Nos. 1 and 2) by indirect immunofluorescence assay (IFA). Dog No. 1, a 2-year-old male, exhibited severe depression, ataxia, and generalized seizures and died 2 months after the onset of symptoms. Dog No. 2, a 9-month-old male, exhibited severe generalized seizures and died 17 months after the onset of symptoms. Histopathologic examination revealed a moderate to severe multifocal accumulation of lymphocytes, plasma cells, and a few neutrophils in both the gray and white matter of the cerebrum in dog No. 1. In dog No. 2, the cellular infiltrates were mild, but there was a severe, diffuse, and multifocal necrosis in the cerebral cortex with prominent astrocytosis. With the aid of IFA using fluorescein isothiocyanate-labeled antidog IgG goat serum and a confocal imaging system, specific reactions for glial cells were detected in the CSF of these Pug dogs but not in six canine control CSF samples. Double-labeling IFA using CSF from these Pug dogs and a rabbit antiserum against glial fibrillary acidic protein (GFAP) revealed that the autoantibody recognized GFAP-positive astrocytes and their cytoplasmic projections. By immunoblot analysis, the autoantibody from CSF of these Pug dogs recognized two common positive bands at 58 and 54 kd, which corresponded to the molecular mass of human GFAP. The role of this autoantibody for astrocytes is not yet clear. However, if the presence of the autoantibody is a specific feature of Pug dog encephalitis, it will be a useful clinical diagnostic marker and a key to the pathogenesis of this unique canine neurologic disease.  相似文献   

Prebiotic effect of glycerol galactoside isolated from color-faded nori in rats     

Kenji Ishihara  Chiaki Oyamada  Yoko Sato  Toshiyuki Suzuki  Masaki Kaneniwa  Hiromi Kunitake  Toshihiko Muraoka 《Fisheries Science》2010,76(6):1015-1021

Glycerol galactoside (GG; floridoside: 2-O-glycerol-α-d-galactopyranoside, and isofloridoside: 1-O-glycerol-α-d-galactopyranoside) is known to be a component of edible red seaweed nori. Recently, we have found that low-quality nori (color-faded nori), which has a low protein content, contains a large quantity of GG. From further studies, we have also found that GG has prebiotic characteristics in vitro. In this study, we evaluated the in vivo prebiotic activity of GG in rats. Dietary GG selectively increased the cecal Bifidobacterium count in rats. Other indices of prebiotics, such as pH of cecal content, organic acid concentrations, and fecal weight, also supported the existence of prebiotic activity of GG. The present data will also contribute to the development of a new method of utilizing color-faded nori as a health-promoting foodstuff.  相似文献   

Temperature-induced momentum-dependent spectral weight transfer in Bi2Sr2CaCu2O8+delta     

Z Shen  PJ White  DL Feng  C Kim  GD Gu  H Ikeda  R Yoshizaki  N Koshizuka 《Science (New York, N.Y.)》1998,280(5361):259-262

Angle-resolved photoemission data from the cuprate superconductor Bi2Sr2CaCu2O8+delta above and below the superconducting transition temperature Tc reveal momentum-dependent changes that extend up to an energy of about 0.3 electron volt, or 40kTc (where k is the Boltzmann constant). The data suggest an anomalous transfer of spectral weight from one momentum to another, involving a sizable momentum transfer Q approximately (0.45pi, 0). The observed Q is intriguingly near the charge-order periodicity required if fluctuating charge stripes are present.  相似文献