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1.
T. Moen M. Delghandi M. S. Wesmajervi J.-I. Westgaard K. T. Fjalestad 《Animal genetics》2009,40(6):993-996
A first genetic linkage map of the Atlantic cod ( Gadus morhua ) was produced, based on segregation data from 12 full-sib families of Norwegian origin. The map contained 174 single nucleotide polymorphism markers and 33 microsatellites, distributed on 25 linkage groups and had a length of 1225 cM. A significant difference in recombination rates between sexes was found, the average ratio of female:male recombination rates being 1.78 ± 1.62 (SD). 相似文献
2.
Ana Isabell Paulino Aud Larsen Gunnar Bratbak Dale Evens Svein Rune Erga Einar Bye-Ingebrigtsen 《Marine Biology Research》2018,14(5):421-435
Changes in phytoplankton community composition potentially affect the entire marine food web. Because of seasonal cycles and inter-annual variations in species composition, long-term monitoring, covering many sequential years, is required to establish a baseline study and to reveal long-term trends. The current study describes the phytoplankton biomass variations and species composition in relation to hydrographic and meteorological conditions in the Raunefjord, western Norway, over a 6-year period from 2001 to 2006. The extent of inflow or upwelling in the fjord varied from year to year and resulted in pronounced differences in water column stability. The annual phytoplankton community succession showed some repeated seasonal patterns, but also high variability between years. Two to four diatom blooms were observed per year, and the spring blooms occurring before water column stratification in March were dominated by Skeletonema marinoi and Chaetoceros socialis, and other Chaetoceros and Thalassiosira spp. Blooms of the haptophytes Phaeocystis pouchetii and Emiliania huxleyi were irregular and in some years totally absent. Although E. huxleyi was present all year round it appeared in bloom concentrations only in 2003, when the summer was warm and the water column characterized by high surface temperatures and pronounced stratification. The annual average abundance of both diatoms and flagellates increased during the six years. Despite the high variation from year to year, our investigation provides valuable knowledge about annual phytoplankton community patterns in the region, and can be used as a reference to detect possible future changes. 相似文献
3.
Productivity-diversity relationships for plants, bryophytes, lichens, and polypore fungi in six northern forest landscapes 总被引:1,自引:0,他引:1
Ivar Gjerde Magne Stersdal Jrund Rolstad Ken Olaf Storaunet Hans H. Blom Vegard Gundersen Einar Heegaard 《Ecography》2005,28(6):705-720
We investigated the relationship between site productivity and diversity of vascular plants, bryophytes, lichens, and polypore fungi in forests based on species richness data in 0.25 ha forest plots (grain size), selected from six 150–200 ha study areas (focus), and spanning over a latitudinal distance of 1350 km (extent) in Norway. We 1) searched for prevailing productivity-diversity relationships (PDRs), 2) compared PDRs among taxonomic groups and species found in different micro-habitats, and 3) investigated the effect of increasing plot (grain) size on PDRs. Using vegetation types as a surrogate for site productivity, we found a general pattern of increasing species richness with site productivity. On average total species richness doubled with a ten-fold increase in productivity. Lichens PDRs stood out as less pronounced and more variable than for other species groups investigated. PDRs of species associated with downed logs tended to level off at high-productive sites, a pattern interpreted as an effect of disturbance. Increasing the grain size >10-fold did not change the proportional difference in species richness between sites with high and low productivity. 相似文献
4.
5.
Retroviral-mediated gene transfer into mammalian cells 总被引:2,自引:0,他引:2
D B Kohn P W Kantoff M A Eglitis J R McLachlin R C Moen E Karson J A Zwiebel A Nienhuis S Karlsson R O'Reilly 《Blood cells》1987,13(1-2):285-298
Retroviruses may be used as genetic vectors to transfer genes into mammalian cells with high efficiency. We have shown that the N2 vector will transfer a functional bacterial gene for neomycin resistance (NeoR) into more than 80% of mouse spleen foci. A derivative of the N2 vector was constructed to study transfer and expression of the human gene for adenosine deaminase (ADA) in mammalian lymphoid and hematopoietic stem cells. This vector, termed SAX, contains the human ADA cDNA with an SV40 promoter in addition to the NeoR gene. The SAX vector was found to efficiently transfer and express the ADA gene in an ADA-deficient human T-cell line. Gene transfer by SAX using an autologous nonhuman primate bone marrow transplant model resulted in expression of the human ADA gene in peripheral blood cells of treated animals. Human bone marrow treated with SAX produced 1%-2% of colonies in vitro that were expressing the vector genes. Transfer of genes into circulating hematopoietic stem cells of fetal sheep in utero was most efficient; vector gene expression was evident in 20%-40% of hematopoietic colonies. Therefore, retroviral vectors are capable of transferring functional genes into a wide variety of mammalian lymphoid and hematopoietic cells. Such vectors may be useful for clinical trials of gene therapy, that is, the correction of genetic diseases by insertion of a normal gene into a patient's defective cells. 相似文献
6.
Effects on the aquatic biota of lime (CaCO3) application in acidified lakes and streams were studied in a number of waters. After treatment, lime-sensitive species of mosses (Sphagnum spp.) decreased, but species such as Potamogeton natans and Myriophyllum alterniflorum seemed to be favoured. A few years after liming species composition and diversity of phytoplankton, zooplankton and benthic insect larvae were almost identical to that found in oligotrophic and non-acid lakes. Molluscs and benthic crustaceans may have difficulties recolonizing. Reproduction of remaining species of fish was successful as soon as pH increased. High survival of larvae and fry can result in some extremely rich year classes with slow individual growth. In most cases restocking of depleted fish stocks was successful. 相似文献
7.
Lipid Peroxidation by the Manganese Peroxidase of Phanerochaete chrysosporium Is the Basis for Phenanthrene Oxidation by the Intact Fungus 总被引:11,自引:10,他引:1
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The manganese peroxidase (MnP) of Phanerochaete chrysosporium supported Mn(II)-dependent, H2O2-independent lipid peroxidation, as shown by two findings: linolenic acid was peroxidized to give products that reacted with thiobarbituric acid, and linoleic acid was peroxidized to give hexanal. MnP also supported the slow oxidation of phenanthrene to 2,2′-diphenic acid in a reaction that required Mn(II), oxygen, and unsaturated lipids. Phenanthrene oxidation to diphenic acid by intact cultures of P. chrysosporium occurred to the same extent that oxidation in vitro did and was stimulated by Mn. These results support a role for MnP-mediated lipid peroxidation in phenanthrene oxidation by P. chrysosporium. 相似文献
8.
Prey preferences and dietary differences between sex and age categories of Eurasian otters were studied in coastal Norwegian habitats Relative to their trapping frequency potential prey species with hard, spiny exoskeletons (crabs and sea urchins) or otherwise tough, spiny integuments (Labridae) were much less frequently found in spraints than fish species with soft integuments Spines did not protect fish with otherwise soft integuments from otter predation The number of non-fish taxa per otter stomach did not vary significantly between otter age categories despite presumed differences in hunting abilities (small cubs large cubs and subadults, adults) Relative frequency of occurrence of crabs and sea urchins was < 5% in the stomachs in each of these otter categories Anadromous, katadromous and freshwater fish species were infrequently eaten The coastal otter population during the study period probably had access to an adequate, and preferred, supply of marine fish prey
At the otter population level no prey size selection was conclusively demonstrated within the range of fish sizes sampled However, fish sizes eaten differed significantly between otter sex and age categories The fish sizes per stomach were on average larger in males than in females, regardless of age Adult males tended to eat the largest fishes Among the self provisioning age categories (subadult and adult otters) fish lengths differed significantly between otter males and females, but not between the otter age categories, and did not covary significantly with otter body length Fish eaten by females with old placental scars (potential mothers of fisheating cubs) were significantly smaller than those eaten by small cubs, provisioned by their mothers 相似文献
At the otter population level no prey size selection was conclusively demonstrated within the range of fish sizes sampled However, fish sizes eaten differed significantly between otter sex and age categories The fish sizes per stomach were on average larger in males than in females, regardless of age Adult males tended to eat the largest fishes Among the self provisioning age categories (subadult and adult otters) fish lengths differed significantly between otter males and females, but not between the otter age categories, and did not covary significantly with otter body length Fish eaten by females with old placental scars (potential mothers of fisheating cubs) were significantly smaller than those eaten by small cubs, provisioned by their mothers 相似文献
9.
Einar Lystad Arne T. Høstmark Cecilie Kiserud Aage Haugen 《In vitro cellular & developmental biology. Animal》1994,30(9):568-573
Summary The protective influence of bovine serum albumin against growth inhibition caused by fatty acids was studied in human hepatoma
(HepG2) and immortalized human kidney epithelial (IHKE) cells. In general, growth inhibition by unsaturated fatty acids (0.15
mmol/liter) increased with increasing number of double bonds. For HepG2 cells crude albumin (1g/100 ml) did not greatly modify growth inhibition by arachidonic, eicosapentaenoic, and docosahexaenoic acid. With oleic,
linoleic, and linolenic acids, crude and defatted albumin stimulated cell growth. In contrast, for IHKE cells both albumins
counteracted growth inhibition by unsaturated fatty acids to approximately the same extent. When HepG2 cells were cultured
in the presence of saturated fatty acids (0.3 mmol/liter), C2, C6, and C8 had no or little inhibitory effect. C10 and C12
inhibited cell growth appreciably, whereas C14, and especially C16, had poor inhibitory effects. Crude albumin counteracted
growth inhibition by all these fatty acids. In contrast, defatted albumin had little or no effect (except against C10 and
C12), and even increased the growth inhibition by C14 and C16. With unsaturated fatty acids there seemed to be an inverse
relationship between cell growth and the concentration of thiobarbituric acid reactive substances (TBARS) in media. Vitamin
E abolished growth inhibition (and the increase in TBARS concentration) by unsaturated fatty acids. The complex interaction
between fatty acids and albumins calls for great caution when interpreting data on growth effects. 相似文献
10.
Olavi Junttila Einar Jensen David W. Pearce Richard P. Pharis 《Physiologia plantarum》1992,84(1):113-120
Cessation of shoot elongation in seedlings of Salix pentandra L. is induced by short photoperiod. Gibbereliin A9 (GA9 ) applied either to the apical bud or injected into a mature leaf, induced shoot elongation under a short photoperiod of 12 h, and GA9 could completely substitute for a transfer to a long photoperiod. When [3 H]GA9 or [2 H2 ]GA9 was injected into a leaf, no [3 H]GA9 was detected in the elongating apex and only traces of [3 H]GA9 were found in the shoot above the treated leaf. By the use of gas chromatography-mass spectrometry (GC-MS), [2 H2 ]GA20 was identified as the main metabolite of [2 H2 ]GA9 in both the shoot and the treated leaf. In addition, [2 H2 ]GA1 and [2 H2 ]GA29 were also identified as metabolites of [2 H2 ]GA9 . These results are consistent with the hypothesis that exogenous GA, promotes shoot elongation in Salix through its metabolism to GA20 and GA,. 相似文献