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81.
Possible mutagenic activity of captan was investigated by in vitro and in vivo cytogenetic studies and by the dominant lethal study in mice. In vitro cytogenetic study with cultured human diploid cells revealed a significant increase in the frequency of cells showing stickiness and a severe mitotic inhibition at concentrations of 3.0 and 4.0 microgram of captan per ml. although no chromosomal aberrations were observed. In in vivo cytogenetic study, no chromosomal aberrations were induced in the bone marrow cells of rats treated orally with captan at a single dose of 500, 1000 or 2000 mg/kg or at five consecutive doses of 200, 400 or 800 mg/kg/day. Dominant lethal study also failed to show any mutation induction after treatment of male mice with daily oral dose of 200 or 600 mg of captan per kg bw for five days. 相似文献
82.
Yusuke Nakatsu Yasuka Matsunaga Takeshi Yamamotoya Koji Ueda Masa-ki Inoue Yu Mizuno Mikako Nakanishi Tomomi Sano Yosuke Yamawaki Akifumi Kushiyama Hideyuki Sakoda Midori Fujishiro Akihide Ryo Hiraku Ono Tohru Minamino Shin-Ichiro Takahashi Haruya Ohno Masayasu Yoneda Tomoichiro Asano 《Cell reports》2019,26(12):3221-3230.e3
83.
Nuclear sequence markers are useful tool for the study of the history of populations and adaptation. However, it is not easy to obtain multiple nuclear primers for organisms with poor or no genomic sequence information. Here we used the genomes of organisms that have been fully sequenced to design comprehensive sets of primers to amplify polymorphic genomic fragments of multiple nuclear genes in non-sequenced organisms. First, we identified a large number of candidate polymorphic regions that were flanked on each side by conserved regions in the reference genomes. We then designed primers based on these conserved sequences and examined whether the primers could be used to amplify sequences in target species, montane brown frog (Rana ornativentris), anole lizard (Anolis sagrei), guppy (Poecilia reticulata), and fruit fly (Drosophila melanogaster), for population genetic analysis. We successfully obtained polymorphic markers for all target species studied. In addition, we found that sequence identities of the regions between the primer sites in the reference genomes affected the experimental success of DNA amplification and identification of polymorphic loci in the target genomes, and that exonic primers had a higher success rate than intronic primers in amplifying readable sequences. We conclude that this comparative genomic approach is a time- and cost-effective way to obtain polymorphic markers for non-sequenced organisms, and that it will contribute to the further development of evolutionary ecology and population genetics for non-sequenced organisms, aiding in the understanding of the genetic basis of adaptation. 相似文献
84.
The mechanism of self incompatibility in pistils of Lilium longiflorum Thunb. cv. Hinomoto, which is overcome by heat treatment, was analyzed. Immersing detached pistils in a distilled water bath
held at 45°C for 5 min suppressed levels of ethylene and activities of 1-aminocyclopropane-1-carboxylate (ACC) oxidase at
6 h after self- and cross-incompatible pollination. However, the levels and activities showed no significant difference 48
h after pollination. Levels of ACC and activities of ACC synthase at 6 h after self-incompatible pollination were lower in
pistils with heat treatment. Moreover, the heat treatment suppressed the activity of superoxide dismutase and enhanced the
activity of catalase, ascorbate peroxidase, dehydroascorbate reductase, and glutathione reductase. In addition, the amount
of hydrogen peroxide (H2O2) was reduced by heat treatment. In summary, heat treatment suppressed the ethylene-forming system and also enhanced the hydrogen
peroxide-scavenging system in self-pollinated pistils associated with self incompatibility. A possible correlation between
self incompatibility and stress in pistils after self-incompatible pollination is discussed based on the results obtained
using heated pistils.
Received: 12 April 2000 / Revision accepted: 19 September 2000 相似文献
85.
Tomoko Naganuma Mii Tanaka Shiori Tezuka Sam M.J.G. Steyaert Kahoko Tochigi Akino Inagaki Hiroaki Myojo Koji Yamazaki Shinsuke Koike 《Ecology and evolution》2021,11(14):9182
Previous studies on the mating system of the Asian black bear (Ursus thibetanus) have been limited to observations of captive populations and estimations of multiple paternities. Hence, the mating system of wild bears remains poorly understood. Animal‐borne camera systems (i.e., cameras mounted on animals) provide novel tools to study the behavior of elusive animals. Here, we used an animal‐borne video system to record the activities of wild bears during the mating season. Video camera collars were attached to four adult Asian black bears (male “A” and “B,” and female “A” and “B”) captured in Tokyo, central Japan, in May and June 2018. The collars were retrieved in July 2018, after which the video data were downloaded and analyzed in terms of bear activity and mating behavior. All the bears were found to interact with other uniquely identifiable bears for some of the time (range 9–22 days) during the deployment period (range 36–45 days), and multiple mating in males was documented. Both males and females exhibited different behaviors on social days (i.e., days when the bear interacted with conspecifics) compared with solitary days (i.e., days with no observed interactions with conspecifics). Compared with solitary days, the bears spent a lower proportion of time on foraging activities and higher proportion of time on resting activities on social days. Our results suggest that Asian black bears have a polygamous mating system, as both sexes consort and potentially mate with multiple partners during a given mating season. Furthermore, bears appeared to reduce their foraging activities on social days and engaged more in social interactions. 相似文献
86.
87.
E Osaki Y Nishina J Inazawa N G Copeland D J Gilbert N A Jenkins M Ohsugi T Tezuka M Yoshida K Semba 《Nucleic acids research》1999,27(12):2503-2510
88.
An enzyme (S-1) which catalyzes the splitting of carbon-mercury linkages of organomercury compounds was purified about 24-fold from the cell-free extract of mercury-resistant Pseudomonas K-62 strain by treatment with streptomycin, precipitation with ammonium sulfate, and successive chromatography on Sephadex G-150, DEAE-Sephadex, and DEAE-cellulose. A purified preparation of the enzyme showed a single band on polyacrylamide gel electrophoresis, and was colorless. The molecular weight of the enzyme was estimated to be 19,000, and Km was 5.3 X 10(-5) M for p-chloromercuribenzoic acid (PCMB). The temperature and pH optimum for the reaction were 50degrees and 7.0, respectively. The enzyme was capable of catalyzing the decomposition of methylmercuric chloride (MMC), ethylmercuric chloride (EMC), phenylmercuric acetate (PMA), and PCMB in the presence of a sulfhydryl compound to form a mercuric ion plus methane, ethane, benzene, or benzoic acid, respectively. The mercuric ion thus formed was reduced to metallic mercury by metallic mercury-releasing enzyme (MMR-enzyme). 相似文献
89.
Takeuchi Yuichi; Nihira Junko; Kondo Noriaki; Tezuka Takafumi 《Plant & cell physiology》1985,26(6):1027-1035
Nitrogen dioxide (NO2) fumigation inhibited nitrate reductase(NR, EC 1.6.6.1
[EC]
) activity assayed by an in vivo system in thecotyledons, but not in the first leaves, of squash (Cucurbitamaxima Duch.) seedlings. The inhibition was recovered when theseedlings were transferred to NO2-free conditions, indicatingthat the effect of NO2 was reversible. The NADH content in thecotyledons, photosynthetic O2 evolution and respiratory O2 uptakedid not change notably under NO2 fumigation. Nitrate contentsin the cotyledons and first leaves did not change with NO2 fumigation,but nitrite, ammonium and rapidly-metabolized amino acids contentsincreased. The inhibitory effect of NO2 was also observed inthe in vitro assay, though the inhibition rate was smaller thanthat in the in vivo assay. These results indicate that the inhibitoryeffect of NO2 on NR activity in squash cotyledons was derivedin part from the decrease in the amount of active NR due toammonium and/or amino acids accumulated in the tissue underNO2 fumigation. (Received February 12, 1985; Accepted May 27, 1985) 相似文献
90.
The elongation of pollen tubes in Lilium longiflorum cv. Hinomoto after self-incompatible pollination stopped halfway, but that after cross-compatible pollination (cross with cv. Georgia) did not. The elongation of pollen tubes after self-pollination was enhanced by exogenous cAMP and by pertussis toxin or cholera toxin, which activates adenylate cyclase. The level of endogenous cAMP in pistils after self-pollination was approximately one half of that after cross-pollination. Furthermore, the activity of adenylate cyclase in pistils after self-pollination was also approximately one half of that after cross-pollination. By contrast, cAMP phosphodiesterase in pistils after self-pollination was approximately 2 times as high as that after cross-pollination. A possible correlation between self-incompatibility and the low level of endogenous cAMP in lily pistils is discussed on the basis of these results. 相似文献