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121.
Hiroyuki Hirayama Eiiti Kasuya 《Ethology : formerly Zeitschrift fur Tierpsychologie》2014,120(12):1228-1236
Many studies have shown the benefits of selecting suitable sites for offspring survival and growth. However, costs of selecting suitable sites have been little covered. If the female's costs associated with selecting suitable sites exceed the benefit from improvement of offspring performance, selecting such sites can have a negative effect on the ongoing reproductive success for ovipositing females. We investigate the potential costs of selecting suitable sites in the water strider Aquarius paludum insularis. Where there exists a risk of egg parasitism, the female A. paludum will submerge and select a deep site, more suitable for offspring survival, for oviposition. By forcing A. paludum underwater once a day for 10 d, we investigated the potential costs associated with oviposition at deep sites, firstly relating to the performance of submergence (latency to asphyxiation or proportion of buoyancy loss) and, secondly, in the number of eggs laid. Buoyancy became weaker and the latency to asphyxiation became shorter with the number of submergences. The number of eggs laid in the period of forced submergence was smaller than both before and after the period. Selecting deep sites can therefore increase the mortality risk of ovipositing females and also decrease the number of eggs laid in their lives. Selecting suitable sites in all the oviposition bouts can decrease ovipositing females' reproductive success. Costs, not only benefits, should be taken into consideration for understanding oviposition site selection during the lifespan of an ovipositing female. 相似文献
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124.
Masayoshi Shinjoh Norio Sugaya Yoshio Yamaguchi Yuka Tomidokoro Shinichiro Sekiguchi Keiko Mitamura Motoko Fujino Hiroyuki Shiro Osamu Komiyama Nobuhiko Taguchi Yuji Nakata Naoko Yoshida Atsushi Narabayashi Michiko Myokai Masanori Sato Munehiro Furuichi Hiroaki Baba Hisayo Fujita Akihiro Sato Ichiro Ookawara Kenichiro Tsunematsu Makoto Yoshida Mio Kono Fumie Tanaka Chiharu Kawakami Takahisa Kimiya Takao Takahashi Satoshi Iwata Keio Pediatric Influenza Research Group 《PloS one》2015,10(8)
We assessed vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza in children 6 months to 15 years of age in 22 hospitals in Japan during the 2013–14 season. Our study was conducted according to a test-negative case-control design based on influenza rapid diagnostic test (IRDT) results. Outpatients who came to our clinics with a fever of 38°C or over and had undergone an IRDT were enrolled in this study. Patients with positive IRDT results were recorded as cases, and patients with negative results were recorded as controls. Between November 2013 and March 2014, a total of 4727 pediatric patients (6 months to 15 years of age) were enrolled: 876 were positive for influenza A, 66 for A(H1N1)pdm09 and in the other 810 the subtype was unknown; 1405 were positive for influenza B; and 2445 were negative for influenza. Overall VE was 46% (95% confidence interval [CI], 39–52). Adjusted VE against influenza A, influenza A(H1N1)pdm09, and influenza B was 63% (95% CI, 56–69), 77% (95% CI, 59–87), and 26% (95% CI, 14–36), respectively. Influenza vaccine was not effective against either influenza A or influenza B in infants 6 to 11 months of age. Two doses of influenza vaccine provided better protection against influenza A infection than a single dose did. VE against hospitalization influenza A infection was 76%. Influenza vaccine was effective against influenza A, especially against influenza A(H1N1)pdm09, but was much less effective against influenza B. 相似文献
125.
Nobukatsu Horita Kiichiro Tsuchiya Ryohei Hayashi Keita Fukushima Shuji Hibiya Masayoshi Fukuda Yoshihito Kano Tomohiro Mizutani Yasuhiro Nemoto Shiro Yui Ryuichi Okamoto Tetsuya Nakamura Mamoru Watanabe 《Biochemical and biophysical research communications》2014
Background and aims
The dynamics of intestinal stem cells are crucial for regulation of intestinal function and maintenance. Although crypt stem cells have been identified in the intestine by genetic marking methods, identification of plural crypt stem cells has not yet been achieved as they are visualised in the same colour.Methods
Intestinal organoids were transferred into Matrigel® mixed with lentivirus encoding mCherry. The dynamics of mCherry-positive cells was analysed using time-lapse imaging, and the localisation of mCherry-positive cells was analysed using 3D immunofluorescence.Results
We established an original method for the introduction of a transgene into an organoid generated from mouse small intestine that resulted in continuous fluorescence of the mCherry protein in a portion of organoid cells. Three-dimensional analysis using confocal microscopy showed a single mCherry-positive cell in an organoid crypt that had been cultured for >1 year, which suggested the presence of long-lived mCherry-positive and -negative stem cells in the same crypt. Moreover, a single mCherry-positive stem cell in a crypt gave rise to both crypt base columnar cells and transit amplifying cells. Each mCherry-positive and -negative cell contributed to the generation of organoids.Conclusions
The use of our original lentiviral transgene system to mark individual organoid crypt stem cells showed that long-lived plural crypt stem cells might independently serve as intestinal epithelial cells, resulting in the formation of a completely functional villus. 相似文献126.
Facilitation (positive inter-specific interaction) plays an important role in promoting succession in harsh environments.
To examine whether tussocks facilitate the establishment of other species, after peat mining, investigations were carried
out in a formerly Sphagnum-dominated wetland (Sarobetsu mire, northern Japan). Two tussock-forming species, Carex middendorffii and Eriophorum vaginatum, have established in sparsely vegetated areas, with a dry ground surface, since peat extraction ended. The following factors
were examined, in three microhabitats created by tussocks (center = raised tussock center, edge = tussock edge covered with
litter, and flat = flat areas without tussocks): (1) relationships between tussock microhabitats and plant distributions,
and (2) the effects of tussocks on survival, growth, flowering and seed immigration of common species. Two (1 × 10 m) plots
were established, in each of three sparsely vegetated sites, in September 2005. Tussocks were mapped in each plot, and species,
location, flowering, growth stage (seedling, juvenile and fertile) and size of all plants were recorded, during snow-free
periods from September 2005 to September 2006. Seed traps were used to investigate seed dispersal from June to October 2006.
Four native species, Drosera rotundifolia, Lobelia sessilifolia, Moliniopsis japonica, Solidago virgaurea, and an exotic species, Hypochaeris radicata, were most common. During seedling and juvenile stages, these species were distributed more densely at the tussock edge than
in the flat areas, but were less common at the center. H. radicata had a higher survival rate at the edge than in the flat during the winter. The annual growth of H. radicata, L. sessilifolia and S. virgaurea was higher at the edge. Seed traps detected that D. rotundifolia seeds accumulate more at the edge. In conclusion, tussocks facilitated plant establishment in the edge microhabitat by providing
litter cover, enhancing seed accumulation, germination and survival, and thus promoted revegetation. However, Sphagnum mosses have not established in the study sites, and the vegetation differs strongly from the areas where no peat mining had
taken place. 相似文献
127.
Osami Shoji Takashi Fujishiro Shingo Nagano Shota Tanaka Takuya Hirose Yoshitsugu Shiro Yoshihito Watanabe 《Journal of biological inorganic chemistry》2010,15(8):1331-1339
Cytochrome P450BSβ, a H2O2-dependent cytochrome P450 catalyzing the hydroxylation of long-alkyl-chain fatty acids, lacks the general acid–base residue
around the heme, which is indispensable for the efficient generation of the active species using H2O2. On the basis of the crystal structure of the palmitic acid bound form of cytochrome P450BSβ, it was suggested that the role of the general acid–base function was provided by the carboxylate group of fatty acids. The
participation of the carboxylate group of the substrate was supported by the fact that cytochrome P450BSβ can catalyze oxidations of nonnatural substrates such as styrene and ethylbenzene in the presence of a series of short-alkyl-chain
carboxylic acids as a dummy molecule of fatty acid. We refer to a series of short-alkyl-chain carboxylic acids as a “decoy
molecule”. As shown here, we have clarified the crystal structure of the decoy-molecule-bound form and elucidated that the
location of its carboxylate group is virtually the same as that of palmitic acid in the heme cavity, indicating that the carboxylate
group of the decoy molecule serves as the general acid–base catalyst. This result further confirms that the role of the acid–base
function is satisfied by the carboxylate group of the substrates. In addition, the structure analysis of the substrate-free
form has clarified that no remarkable structural change is induced by the binding of the decoy molecule as well as fatty acid.
Consequently, whether the carboxylate group is positioned in the active site provides the switching mechanism of the catalytic
cycle of cytochrome P450BSβ. 相似文献
128.
Yusuke Hirasawa Tomokazu Shoji Takashi Arai Alfarius E. Nugroho Jun Deguchi Takahiro Hosoya Nahoko Uchiyama Yukihiro Goda Khalijah Awang A. Hamid A. Hadi Motoo Shiro Hiroshi Morita 《Bioorganic & medicinal chemistry letters》2010,20(6):2021-2024
A new bisindole alkaloid, bisleuconothine A (1) consisting of an eburnane–aspidosperma type skeleton, was isolated from the bark of Leuconotis griffithii. The structure including absolute stereochemistry was elucidated on the basis of 2D NMR data and X-ray analysis. Bisleuconothine A (1) showed cell growth inhibitory activity against various human cancer cell lines. 相似文献
129.
130.