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101.
Adriana Fernanda K. Vizuete Matheus Mittmann Hennemann Carlos Alberto Gonçalves Diogo Losch de Oliveira 《Neurochemical research》2017,42(10):2730-2742
Epilepsy prevalence is high in infancy and in the elderly population. Lithium–pilocarpine is widely used to induce experimental animal models of epilepsy, leading to similar neurochemical and morphological alterations to those observed in temporal lobe epilepsy. As astrocytes have been implicated in epileptic disorders, we hypothesized that specific astroglial changes accompany and contribute to epileptogenesis. Herein, we evaluated time-dependent astroglial alterations in the hippocampus of young (27-day-old) rats at 1, 14 and 56 days after Li–pilocarpine-induced status epilepticus (SE), corresponding to different phases in this model of epilepsy. We determined specific markers of astroglial activation: GFAP, S100B, glutamine synthetase (GS), glutathione (GSH) content, aquaporin-4 (AQP-4) and potassium channel Kir 4.1; as well as epileptic behavioral, inflammatory and neurodegenerative changes. Phase-dependent signs of hippocampal astrogliosis were observed, as demonstrated by increments in GFAP, S100B and GS. Astrocyte dysfunction in the hippocampus was characterized, based on the decrease in GSH content, AQP-4 and Kir 4.1 channels. Degenerating neurons were identified by Fluoro-Jade C staining. We found a clear, early (at SE1) and persistent (at SE56) increase in cerebrospinal fluid (CSF) S100B levels. Additionally, serum S100B was found to decrease soon after SE induction, implicating a rapid-onset increase in the CSF/serum S100B ratio. However, serum S100B increased at SE14, possibly reflecting astroglial activation and/or long-term increase in cerebrovascular permeability. Moreover, we suggest that peripheral S100B levels may represent a useful marker for SE in young rats and for follow up during the chronic phases of this model of epilepsy. Together, results reinforce and extend the idea of astroglial involvement in epileptic disorders. 相似文献
102.
Manihot alterniflora and M. elongata spp. nov. (Euphorbiaceae) and the rediscovery of M. quinquefolia in Caatinga (semiarid) vegetation in Brazil 下载免费PDF全文
Márcio Lacerda Lopes Martins Paulo Cezar Lemos de Carvalho Carlos Alberto da Silva Ledo André Márcio Amorim 《Nordic Journal of Botany》2018,36(3)
We describe and illustrate two species of Manihot that occur in Caatinga (semiarid) vegetation in Brazil and redescribe and lectotypify M. quinquefolia Pohl, which was only known from a single collection made by J. E. B. Pohl in 1827. Manihot elongata P.Carvalho & M.Martins is widely distributed and Manihot alterniflora P.Carvalho & M.Martins is endangered because of its small populations and restricted area of occurrence. We establish M. quinquefolia as the only species of Manihot in the Caatinga with compound leaves. An identification key is provided for the 13 species of Manihot present in the Caatinga. 相似文献
103.
Influence of the margin vegetation on the conservation of aphid biological control in apple orchards
Luan Alberto Odorizzi Santos Marlice Botelho Costa Claire Lavigne Odair Aparecido Fernandes Armin Bischoff Pierre Franck 《Journal of Insect Conservation》2018,22(3-4):465-474
The influence of three margin strip treatments (wildflower strips, grass strips and spontaneous vegetation) adjacent to apple orchards on the biological control of Dysaphis plantaginea Passerini (Hemiptera: Aphididae) was compared during two consecutive years. The wildflower strips provided the highest amount of floral resources. Within the margin strips, hoverflies responded positively to higher resource provisioning whereas ladybird abundance did not differ between strip treatments. Within the orchards, the presence of parasitoids, hoverflies, and ladybirds in aphid colonies and the predation of sentinel aphids were not significantly affected by the adjacent strip treatments. The number of natural enemies observed in aphid colonies was mainly driven by aphid number. Aphid numbers were higher close to the margin strips suggesting that aphid colonization from orchard edges may counteract the positive effect of wildflower strips on natural enemy abundance and on a reduction of aphid infestation. The results confirm the positive influence of floral resource provisioning by wildflower strips on the conservation of aphid natural enemies, but also suggest that effects of wildflower strips on aphid regulation inside orchards are not very strong compared with spontaneous vegetation naturally occurring in the margins. 相似文献
104.
Kallyne A. Barros Alberto A. Esteves-Ferreira Masami Inaba Helena Meally John Finnan Susanne Barth Seth J. Davis Ronan Sulpice 《Plant, cell & environment》2020,43(6):1404-1420
Barley is described to mostly use sucrose for night carbon requirements. To understand how the transient carbon is accumulated and utilized in response to cold, barley plants were grown in a combination of cold days and/or nights. Both daytime and night cold reduced growth. Sucrose was the main carbohydrate supplying growth at night, representing 50–60% of the carbon consumed. Under warm days and nights, starch was the second contributor with 26% and malate the third with 15%. Under cold nights, the contribution of starch was severely reduced, due to an inhibition of its synthesis, including under warm days, and malate was the second contributor to C requirements with 24–28% of the total amount of carbon consumed. We propose that malate plays a critical role as an alternative carbon source to sucrose and starch in barley. Hexoses, malate, and sucrose mobilization and starch accumulation were affected in barley elf3 clock mutants, suggesting a clock regulation of their metabolism, without affecting growth and photosynthesis however. Altogether, our data suggest that the mobilization of sucrose and malate and/or barley growth machinery are sensitive to cold. 相似文献
105.
106.
Marco Camanni Luca Bonino Elena Maria Delpiano Paola Berchialla Giuseppe Migliaretti Alberto Revelli Francesco Deltetto 《Reproductive biology and endocrinology : RB&E》2009,7(1):109-7
Background
this study aims to evaluate the effectiveness and safety of laparoscopic conservative management of ureteral endometriosis. 相似文献107.
Cervellati C Franzoni L Squerzanti M Bergamini CM Spinozzi F Mariani P Lanzara V Spisni A 《Amino acids》2009,36(4):633-641
Activation of tissue transglutaminase by calcium involves a conformational change which allows exposition of the active site
to the substrate via movements of domains 3 and 4 that lead to an increase of the inter-domain distance. The inhibitor GTP
counteracts these changes. Here we investigate the possible existence of non-native conformational states still compatible
with the enzyme activity produced by chemical and thermal perturbations. The results indicate that chemical denaturation is
reversible at low guanidine concentrations but irreversible at high concentrations of guanidine. Indeed, at low guanidine
concentrations tissue TG-ase exists in a non-native state which is still affected by the ligands as in the native form. In
contrast, thermal unfolding is always irreversible, with aggregation and protein self-crosslinkage in the presence of calcium.
DSC thermograms of the native protein in the absence of ligands consist of two partly overlapped transitions, which weaken
in the presence of calcium and merge together and strengthen in the presence of GTP. Overall, the present work shows, for
the first time, the reversible denaturation of a TG-ase isoenzyme and suggests the possibility that also in in vivo, the enzyme
may acquire non-native conformations relevant to its patho-physiological functions. 相似文献
108.
Carlos Rafael Borges Mendes Raul Rodrigo Costa Afonso Ferreira Bruno Jesus Virginia Maria Tavano Tiago Segabinazzi Dotto Miguel Costa Leal Rodrigo Kerr Carolina Antuarte Islabão Andréa de Oliveira da Rocha Franco Mauricio M. Mata Carlos Alberto Eiras Garcia Eduardo Resende Secchi 《Global Change Biology》2023,29(7):1791-1808
The western Antarctic Peninsula (WAP) is a climatically sensitive region where foundational changes at the basis of the food web have been recorded; cryptophytes are gradually outgrowing diatoms together with a decreased size spectrum of the phytoplankton community. Based on a 11-year (2008–2018) in-situ dataset, we demonstrate a strong coupling between biomass accumulation of cryptophytes, summer upper ocean stability, and the mixed layer depth. Our results shed light on the environmental conditions favoring the cryptophyte success in coastal regions of the WAP, especially during situations of shallower mixed layers associated with lower diatom biomass, which evidences a clear competition or niche segregation between diatoms and cryptophytes. We also unravel the cryptophyte photo-physiological niche by exploring its capacity to thrive under high light stress normally found in confined stratified upper layers. Such conditions are becoming more frequent in the Antarctic coastal waters and will likely have significant future implications at various levels of the marine food web. The competitive advantage of cryptophytes in environments with significant light level fluctuations was supported by laboratory experiments that revealed a high flexibility of cryptophytes to grow in different light conditions driven by a fast photo-regulating response. All tested physiological parameters support the hypothesis that cryptophytes are highly flexible regarding their growing light conditions and extremely efficient in rapidly photo-regulating changes to environmental light levels. This plasticity would give them a competitive advantage in exploiting an ecological niche where light levels fluctuate quickly. These findings provide new insights on niche separation between diatoms and cryptophytes, which is vital for a thorough understanding of the WAP marine ecosystem. 相似文献
109.
Peroxygenase is an enzyme that can convert a double bond to an epoxide. Peroxygenase activity from oat (Avena sativa) seeds was immobilized on synthetic membranes. The immobilized preparation was tested on oleic acid in aqueous and heptane media. The order of oxidant activity was tert-butyl hydroperoxide>cumene hydroperoxide>H2O2–Urea-H2O2. The immobilized preparation could be reused. Oleic acid was a preferred substrate compared to its trans analogue, elaidic acid. 相似文献
110.
Sequence and diversity of DRB genes of Aotus nancymaae, a primate model for human malaria parasites 总被引:3,自引:0,他引:3
Nino-Vasquez JJ Vogel D Rodriguez R Moreno A Patarroyo ME Pluschke G Daubenberger CA 《Immunogenetics》2000,51(3):219-230
The New World primate Aotus nancymaae is susceptible to infection with the human malaria parasite Plasmodium falciparum and Plasmodium vivax and has therefore been recommended by the World Health Organization as a model for evaluation of malaria vaccine candidates.
We present here a first step in the molecular characterization of the major histocompatibility complex (MHC) class II DRB genes of Aotus nancymaae (owl monkey or night monkey) by nucleotide sequence analysis of the polymorphic exon 2 segments. In a group of 15 nonrelated
animals captivated in the wild, 34 MHC DRB alleles could be identified. Six allelic lineages were detected, two of them having human counterparts, while two other lineages
have not been described in any other New World monkey species studied. As in the common marmoset, the diversity of DRB alleles appears to have arisen largely by point mutations in the β-pleated sheets and by frequent exchange of fixed sequence
motifs in the α-helical portion. Pairs of alleles differing only at amino acid position b86 by an exchange of valine to glycine
are present in Aotus, as in humans. Essential amino acid residues contributing to MHC DR peptide binding pockets number 1 and 4 are conserved
or semiconserved between HLA-DR and Aona-DRB molecules, indicating a capacity to bind similar peptide repertoires. These results support fully our using Aotus monkeys as an animal model for evaluation of future subunit vaccine candidates.
Received: 10 August 1999 / Revised: 11 October 1999 相似文献