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91.
Elsa Léger Gwenaël Vourc’h Laurence Vial Christine Chevillon Karen D. McCoy 《Experimental & applied acarology》2013,59(1-2):219-244
Today, we are witnessing changes in the spatial distribution and abundance of many species, including ticks and their associated pathogens. Evidence that these changes are primarily due to climate change, habitat modifications, and the globalisation of human activities are accumulating. Changes in the distribution of ticks and their invasion into new regions can have numerous consequences including modifications in their ecological characteristics and those of endemic species, impacts on the dynamics of local host populations and the emergence of human and livestock disease. Here, we review the principal causes for distributional shifts in tick populations and their consequences in terms of the ecological attributes of the species in question (i.e. phenotypic and genetic responses), pathogen transmission and disease epidemiology. We also describe different methodological approaches currently used to assess and predict such changes and their consequences. We finish with a discussion of new research avenues to develop in order to improve our understanding of these host–vector–pathogen interactions in the context of a changing world. 相似文献
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Molecular Biology - Neuroinflammation plays a key role in the pathogenesis of neurodegenerative diseases. Microglial cells are the main immune cells of the central nervous system. On exposure to... 相似文献
94.
In neurons of the rat dorsal root ganglia (DRG), using a patch-clamp technique in the whole-cell configuration, we studied
the characteristics of calcium channels activated by depletion of the ryanodine-sensitive calcium stores of the endoplasmic
reticulum. Current-voltage (I-V) relationships of these store-operated calcium channels were obtained by subtraction of the
integral I-V characteristics after application of caffeine from the integral I-V characteristics of calcium channels in the
control. Currents through store-operated calcium channels could be induced by application of a series of hyperpolarization
current pulses to the cell under conditions of replacement of a calcium-free solution containing caffeine by a caffeine-free
solution containing 2 mM Ca2+. In this case, the following two main conditions were abserved: Voltage-operated calcium channels were inactivated, while
a gradient of the electrochemical potential for calcium ions was increased, which made easier passing of these currents through
store-operated calcium channels. Therefore, we found that in DRG neurons, despite the presence of great numbers of both voltage-operated
and receptor-dependent calcium channels, one more mechanism underlying the entry of calcium through store-operated channels
does exist.
Neirofiziologiya/Neurophysiology, Vol. 39, No. 3, pp. 195–200, May–June, 2007. 相似文献
95.
A. R. Kotovskaya M. I. Koloteva V. Yu. Luk’yanuk G. P. Stepanova L. M. Filatova S. P. Builov A. F. Zhernavkov L. L. Kondratuk 《Human physiology》2010,36(7):871-876
Analysis of alterations in the cardiac activity on the basis of electrocardiographic (ECG) findings in 29 cosmonauts of flight
and ground professions aged from 29 to 61 years after 34 short (8–30 days) space flights (SFs) between 1982 and 2006 has been
carried out. The ECG data at the stage of clinical selection, clinical-physiological examination (CPE) before a SF, at the
stage of the launch of a spacecraft (SC) into orbit and its landing on Earth and at the stage of postflight CPE have been
analyzed. The analysis of cardiac activity parameters on the basis of ECG data at different stages of observations has led
to the identification of three groups of cosmonauts. There were no significant changes or negative tendencies in the alteration
of ECG data in the first group (55.2% of the total number of cosmonauts) during the observation period from selection to the
end of the SF. The changes that later became more pronounced during the landing on Earth and were retained during postflight
CPE have been found in the second group of cosmonauts (in 34.5% cases) at the time of selection and preflight CPE. Considerable
disturbances in cardiac activity that are dangerous for human health have been found in ECGs in the third group (10.3%) during
the descent from orbit. The data from the study are the first step in the investigation of possible medical risks for the
development and improvement of requirements for the medical selection of crews and the admission of subjects with partial
health insufficiency on SFs. 相似文献
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Paola Barraja Virginia Spanò Diana Patrizia Anna Carbone Girolamo Cirrincione Daniela Vedaldi Alessia Salvador Giampietro Viola Francesco Dall’Acqua 《Bioorganic & medicinal chemistry letters》2009,19(6):1711-1714
A convenient synthesis of the pyrano[2,3-e]isoindol-2-one ring system, an heteroanalogue of angelicin, is reported. Our synthetic approach consists of the annelation of the pyran ring on the isoindole moiety using 5-dialkylamino- or 5-hydroxymethylene intermediates as building blocks. The photoantiproliferative activity of the new derivatives was studied. Some of them bearing the benzyl group at the 8 position were active with IC50 in the micromolar range. Cell cytotoxicity involves apoptosis, alteration of cell cycle profile and membrane photodamage. 相似文献
99.
The activity of glutathione-S-transferase (GST), a key phase II enzyme catalyzing the biotrans-formation of organic electrophilic compounds, was studied in the bivalve Crenomytilus grayanus, the mysid shrimp Neomysis mirabilis, and the flounder Liopsetta pinnifasciata from Peter the Great Bay, Sea of Japan. GST activity was increased in fish and mollusks from polluted areas of the bay, compared to background areas. In mysid shrimps, pollution caused inhibition of the activity of this enzyme. The role of GST in adaptation processes of different species to the current level of pollution is discussed. 相似文献
100.
Osamu Katano Yoshimasa Aonuma Kei’ichiroh Iguchi Taiga Yodo Naoto Matsubara 《Ichthyological Research》2003,50(4):349-357
Response to predators may not be identical between different prey species with different life histories and body sizes, particularly when the threat of predation is not great. To clarify this hypothesis, we introduced two prey species (10 Japanese dace, Tribolodon hakonensis, and 10 pale chub, Zacco platypus) into each experimental pond (in total, 8 ponds×4 trials) in which benthic algae had been allowed to grow. The presence or absence of Far Eastern catfish, Silurus asotus, and a refuge for prey fish was used to produce four treatments. The presence of catfish and/or a refuge did not affect either the feeding behavior or growth rate of Japanese dace. In contrast, when catfish were present and no refuge was available, the incidence of bottom feeding for pale chub greatly decreased. Pale chub growth rate was low when catfish were present and a refuge was available, indicating that pale chub spent more of their time in the refuge and lost opportunities of acquiring food. Japanese dace can reach a threshold size at which the prey are safe from predation, but pale chub cannot, and this may explain the differences in response to predators of the two species. 相似文献