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排序方式: 共有1317条查询结果,搜索用时 296 毫秒
1.
Harada Kousuke Kato Yuria Takahashi Jun Imamura Hiyoko Nakamura Natsume Nishina Atsuyoshi Phay Nyunt Tadaishi Miki Shimizu Makoto Kobayashi-Hattori Kazuo 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(1):103-109
Plant Foods for Human Nutrition - Adipose tissue is an endocrine organ and its endocrine function is closely associated with type 2 diabetes mellitus. Valeriana officinalis (Valerian) exerts some... 相似文献
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Endometrial adenocarcinoma in the uterine corpus is a malignant cancer that occurs in menopausal women and aged rodents. Because of the similarities in pathogenesis and morphology of endometrial adenocarcinoma in rodents and humans, prediction of the modes of action (MOA) in uterine carcinogenesis is important for extrapolation of rodent data to humans. Three MOAs have been accepted as major pathways for uterine carcinogenesis in rodents: 1) estrogenic activity, 2) increased serum 17beta-estradiiol (E2) to progesterone (P4) ratio and 3) modulation of estrogen metabolism to produce 4-hydroxyestradiol via P450 induction. Inhibition of estrogen excretion and increased aromatase in situ in the tumor are also a potential pathway. Here, chemicals showing uterine carcinogenicity were chosen from approximately 300 pesticides evaluated in Japan within the past decade, and their mechanisms were predicted using parameters from mechanistic and toxicity studies. Seven pesticides increased uterine tumor formation in rats, and the pathways of 4 pesticides could be predicted based on various mechanistic studies. The MOAs of cyenopyrafen and benthiavalicarb-isopropyl were predicted to be modulation of estrogen metabolism, while those of pyriminobac-methyl and spirodiclofen were predicted to be increased E2 to P4 ratio. The driven pathways of metazosulfuron and isopyrazam could not be predicted using several mechanistic studies. No mechanistic studies have been reported for sedaxane, which has a chemical structure and toxicological profile similar to isopyrazam. Our results indicated that appropriate mechanistic studies are useful for mechanism prediction in risk assessment. From this analysis, a flowchart showing a decision tree for predictive MOAs in uterine carcinogenesis was proposed. 相似文献
4.
Genotype distribution of Raffaelea quercivora in the oak galleries and its composition in the mycangia of Platypus quercivorus 下载免费PDF全文
Raffaelea quercivora is the pathogenic fungus that causes Japanese oak wilt. The female monogynous ambrosia beetle, Platypus quercivorus, carries this fungus in mycangia on the pronotum. These beetles bore galleries in oak trees with their partners to produce offspring, and they deposit fungus on the gallery walls from their mycangia. The offspring mature in the gallery, before loading the fungal pathogen and flying from the gallery to other healthy trees. To investigate the unloading and loading modes of the fungus within the gallery, we developed four polymorphic microsatellite markers for R. quercivora and identified the fungal genotypes in the galleries and mycangia of the beetles. Small wood chips were sampled at 5–10‐mm intervals from the walls of five galleries in a dead Quercus serrata tree. The pronota were also sampled from five female adult beetles. The genotypes of the R. quercivora isolates from the wood chips and pronota were identified using the microsatellite makers. The genotypic analysis showed that each gallery was inhabited patchily by 5–10 genotypes of R. quercivora, and the mycangia of each beetle contained 3–6 genotypes. These results indicate that diverse R. quercivora genotypes are unloaded repeatedly from the mycangia of female beetles onto the gallery wall, which results in their patchy distribution on the walls. When the offspring leave the host tree, the fungal clones that proliferate in the walls are also loaded repeatedly into the mycangia of the mature beetles. 相似文献
5.
Tomoki Honryo Michio Kurata Tokihiko Okada Yoshifumi Sawada Yasunori Ishibashi 《Journal of the World Aquaculture Society》2014,45(5):523-531
To investigate the reason for the high mortality of cultured juvenile Pacific bluefin tuna (PBT), especially during land‐based culture, we examined the effect of the rate of light‐intensity change during the dawn period. Juvenile PBT kept in a natural light environment (control) were compared with those exposed to an artificially slowed change in light intensity during the dawn period (test group). For the test group, lamps, which were connected to automatic timers and placed above the rearing tank, were switched on from 0345 to 0515 h at 15‐min intervals. After 9 d, the survival rate of the test and control group was identical. Between Day 1 and Day 6, whole‐body cortisol levels were not different between groups. However, whole‐body glucose levels in the test group were significantly higher than those in the control group. Both groups displayed a diel rhythm in plasma cortisol concentration that peaked at 0300–0600 h. These results suggest that slowing the increase in light intensity during the dawn period did not improve survival and that low light intensity itself induces high mortality in cultured PBT juveniles. 相似文献
6.
Deep-seeding tolerance, the emergence of seedlings from deep seeded conditions, is involved in stand establishment in semi-arid
regions, where the soil surface is too dry for seed germination. Genes determining deep-seeding tolerance in barley were mapped
using two doubled haploid populations derived from the following crosses: Harrington × TR306 (H/T)and Step toe × Morex (S/M).
Significant quantitative trait loci (QTLs) for deep-seeding tolerance were found in each population. Two QTL sex plained 40%
of the phenotypic variation in the H/T population and one QTL (S/M) 8% of the total phenotypic variance. Multiple QTLs accounting
for coleoptile length and first internode length were detected in both populations. In the H/T population, there were coincident
QTLs for deep-seeding tolerance, coleoptile length and first internode length on the long arm of chromosome 5H. These QTLs
correspond with previously reported QTLs for abscisic acid and gibberellic acid response. QTL coincidence may be due to the
pleiotropic effects of alleles at a single locus. This information may be useful for breeding programs manipulating morphological
and physiological traits in order to develop varieties for semi-arid regions.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
7.
Hidenori Tozuka Michikazu Ota Hisayoshi Kofujita Kouetsu Takahashi 《Journal of Wood Science》2005,51(1):48-59
The protected structure of -oxoacteoside (tomentoside A), 2-oxo-2-(3,4-dihydroxyphenyl)ethyl 3-O-(2,3,4-tri-O-acetyl--l-rhamnopyranosyl)-4-O-caffeoyl--d-glucopyranoside 14 was synthesized in 14% overall yield in 11 steps, starting from d-glucose for biological and medicinal studies of phenylpropanoid glycosides. The first step was the preparation of a 3-O-rhamnopyranosyl disaccharide sugar core 2 from a suitably protected rhamnosyl trichloroacetimidate 10 and glucose derivative (diacetone-d-glucose 1) in 71% yield. To the glucose moiety of this sugar core, several protection/deprotection procedures were performed sequentially to obtain a fully acetylated sugar core 7 with a 4-OH group on the glucose moiety, in 57% yield in five steps. Thereafter, to the 4-OH group of the glucose moiety, selective 4-O-caffeoylation was achieved by proton-transfer esterification with 3,4-di-O-allylcaffeic acid 16 to give the caffeoyl disaccharide 11 in 97% yield. Then, it was converted to trichloroacetimidate 13 for a glycosylation donor in 90% in two steps. Finally, anomeric glycosylation was conducted with 2-oxo-2-(3,4-di-allyloxyphenyl)ethyl alcohol 19 with catalytic amounts of BF3·Et2O to give 2-oxo-2-(3,4-di-allyloxyphenyl)ethyl 2,6-di-O-acetyl-3-O-(2,3,4-tri-O-acetyl--l-rhamnopyranosyl)-4-O-(3,4-di-allyloxycaffeoyl)--d-glucopyranoside 14 in 60% yield. Deprotected intermediates of compounds 2, 11, 14, and 19 which were obtained in high yield would be useful for biological and medicinal studies of phenylpropanoid glycosides.Part of this study was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April, 2002 相似文献
8.
F.?Ishiguri S.?Maruyama K.?Takahashi Z.?Abe S.?Yokota M.?Andoh N.?YoshizawaEmail author 《Journal of Wood Science》2003,49(2):135-139
Sugi green logs with red or black heartwood were smoke-heated, and the changes in the color of the heartwood after ultraviolet
(UV) (λ = 365 nm) radiation exposure were then observed. After UV radiation exposure, the redness and yellowness increased in both
the red and black heartwoods, whereas the brightness decreased. In the black heartwood, the resulting color turned from yellowish
white to reddish brown. Reddening in black heartwood after exposure to a combination of smoke heating and UV radiation is
thought to be due to a decrease in brightness and an increase in both redness and yellowness. However, the degree of change
in heartwood color by UV radiation exposure was not greatly affected by smoke-heating treatments of various lengths. When
methanol extracts were fractionated and exposed to UV radiation, the yellowness increased in the n-hexane-soluble portion and the redness increased in the acetone-soluble fractions from the n-hexane-insoluble portion. These results suggest that the n-hexane-soluble fraction contains the substances that allow heartwood color to change to yellow after UV radiation exposure,
and the acetone-soluble-fraction from the n-hexane-insoluble portion contains the substances that allow it to change to red.
Received: November 14, 2001 / Accepted: June 3, 2002
Acknowledgment This research was supported in part by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of
Science.
This study was presented in part at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001
Correspondence to:N. Yoshizawa 相似文献
9.
Kazumasa Yoshida Mitsuru Nishiguchi Shojiro Hishiyama Atsushi Kato Koetsu Takahashi 《Journal of Wood Science》2006,52(4):372-375
Sugi (Cryptomeria japonica D. Don) produces secondary metabolite norlignans in xylem. Several norlignans are involved in the coloration of heartwood
and defense of sapwood against microbial invasion. Their biosynthetic process should be well understood so that their properties
can be exploited to improve the quality and utility of C. japonica wood. Unfortunately, information on the norlignan biosynthesis is limited because norlignans are mainly synthesized in a
particular season in the transition zone (TZ) along with the heartwood formation, and is difficult to study. Although the
generation of two norlignans of C. japonica, agatharesinol and (E)-hinokiresinol, has been reported, systems for producing other norlignans are not yet known. To establish a novel norlignan
generating system, we examined the changes occurring in norlignans in a TZ during the process of drying a C. japonica log. On the day of felling, the TZ contained agatharesinol and (E)-hinokiresinol, which increased until they reached a maximum on day 40 after felling. Sequirin-C appeared on day 40 and increased
to day 70. The generation of sequirin-C in the TZ can be used to investigate the biosynthetic process of heartwood norlignans.
This study describes for the first time the changes that occur in the composition of norlignan during the drying of the TZ. 相似文献
10.
Kyotaro Noguchi Tadashi Sakata Takeo Mizoguchi Masamichi Takahashi 《Journal of Forest Research》2005,10(6):435-441
Fine roots are a key component of forested ecosystems, but available information is still limited. This study examined the
production and mortality of fine roots less than 1 mm in diameter in a Japanese cedar (Cryptomeria japonica D. Don) plantation located on the Kanto Plain in central Japan. We used a minirhizotron technique in combination with soil
coring, and collected data for 1 year (May 2002–May 2003). Fine root production and mortality were determined from changes
in the lengths of individual fine roots on minirhizotron tubes. Both fine root production and mortality rates were greater
in the upper soil than in lower soil levels. Both rates were seasonal, with higher values in summer than in winter; this trend
was more pronounced in upper soil levels. These results suggest that environmental conditions, such as temperature or soil
properties, affect the production and mortality rates of fine roots. Fine root production and mortality occurred simultaneously,
and their rates were similar, which may have led to unclear seasonal changes in fine root standing crop estimates. Soil coring
indicated that the fine root biomass of this stand was about 120 g m−2, of which 40% was from Japanese cedar. The estimated rates of dry matter production and mortality of total fine roots, including
understory plants, were both approximately 300 g m−2 year−1. 相似文献