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41.
Dennis W. H. Müller Jean-Michel Gaillard Laurie Bingaman Lackey Jean-Michel Hatt Marcus Clauss 《European Journal of Wildlife Research》2010,56(2):205-208
Life in zoological gardens provides a number of benefits to captive animals, resulting in an artificial reduction of the “struggle
for life” compared to their free-ranging counterparts. These advantages should result in a higher chance of surviving from
1 year to the next, and thus in longer average life expectancies for captive animals, given that the biological requirements
of the species are adequately met. Here, we compare the life expectancy of captive and free-ranging populations of three deer
species (reindeer Rangifer tarandus, red deer Cervus elaphus, and roe deer Capreolus capreolus). Whereas captive reindeer and red deer had life expectancies equal to or longer than free-ranging individuals, the life
expectancy of captive roe deer was shorter than that of free-ranging animals. These results support the impression that roe
deer are difficult to keep in zoos, whereas reindeer and red deer perform well under human care. We suggest that the mean
life expectancy of captive populations relative to that of corresponding free-ranging populations is a reliable indicator
to evaluate the husbandry success of a species in captivity. 相似文献
42.
Particulate adenylate cyclase plays a key role in human sperm olfactory receptor-mediated chemotaxis
Spehr M Schwane K Riffell JA Barbour J Zimmer RK Neuhaus EM Hatt H 《The Journal of biological chemistry》2004,279(38):40194-40203
Human sperm chemotaxis is a critical component of the fertilization process, but the molecular basis for this behavior remains unclear. Recent evidence shows that chemotactic responses depend on activation of the sperm olfactory receptor, hOR17-4. Certain floral scents, including bourgeonal, activate hOR17-4, trigger pronounced Ca(2+) fluxes, and evoke chemotaxis. Here, we provide evidence that hOR17-4 activation is coupled to a cAMP-mediated signaling cascade. Multidimensional protein identification technology was used to identify potential components of a G-protein-coupled cAMP transduction pathway in human sperm. These products included various membrane-associated adenylate cyclase (mAC) isoforms and the G(olf)-subunit. Using immunocytochemistry, specific mAC isoforms were localized to particular cell regions. Whereas mAC III occurred in the sperm head and midpiece, mAC VIII was distributed predominantly in the flagellum. In contrast, G(olf) was found mostly in the flagellum and midpiece. The observed spatial distribution patterns largely correspond to the spatiotemporal character of hOR17-4-induced Ca(2+) changes. Behavioral and Ca(2+) signaling responses of human sperm to bourgeonal were bioassayed in the presence, or absence, of the adenylate cyclase antagonist SQ22536. This specific agent inhibits particulate AC, but not soluble AC, activation. Upon incubation with SQ22536, cells ceased to exhibit Ca(2+) signaling, chemotaxis, and hyperactivation (faster swim speed and flagellar beat rate) in response to bourgeonal. Particulate AC is therefore required for induction of hOR17-4-mediated human sperm behavior and represents a promising target for future design of contraceptive drugs. 相似文献
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Selected aspects of digestion in captive giraffes were investigated in two trials with a type of marker that is new for digestive studies in non-domestic species. N-Alkanes were used as internal and external markers. In Trial 1, diet composition, intake, and digestibility were directly measured and estimated with the marker. Six giraffes were dosed once daily for 3 weeks with labeled pellets containing 3,800 ppm of each C28, C32, and C36 alkanes at ˜100 mg/100 kg bodyweight. Intake of cabbage, browse, and a cattle pellet could accurately be estimated with the alkane method. For an oat/wheat mix and clover hay, however, there were large differences between directly measured intakes and those obtained using the alkane method, with the alkane method substantially underestimating. In Trial 2 mean retention times (MRTs) of fluid and particle phase were estimated. Three subadult giraffes were dosed once with cobalt-ethylenediamine tetraacetic acid (Co-EDTA) (260 mg) and alkanes C29 (140 mg) and C36 (370 mg). The average MRT for the fluid phase (Co-EDTA) was 31 hr and for the particle phase (alkanes) was 41 hr (C36) and 43 h (C29). This study showed that n-alkanes have potential as markers for investigating digestive strategies in non-domestic herbivores. Zoo Biol 17:295–309, 1998. © 1998 Wiley-Liss, Inc. 相似文献
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Digestive physiology of the plains viscacha (Lagostomus maximus): A large herbivorous hystricomorph rodent 下载免费PDF全文
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Plant and Soil - Plant-parasitic nematodes are able to sense and respond to gradients of chemical signals. How pH and inorganic salts in the rhizosphere affect nematode accumulation and... 相似文献