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941.
942.
This study presents the carpological heterogeneity of Tragopogon pterodes, an endemic plant species from Balkan Peninsula. The goal of this paper was to determine the variability of morphological characters of achenes and assess the degree of their morphological differentiation relative to the position they occupy in the receptacle. Analysis included four different populations of T. pterodes and examination of 18 (8 qualitative and 10 quantitative) characters of achenes in total. Data analysis employed basic statistic, univariate (ANOVA, Tukey HSD) and multivariate (CDA, CA) analyses to check the level of heterocarpy in this species. The results indicate possible morphological differentiation of three groups of achenes (outer, median and inner achenes), depending of their position on the receptacle. The members of all three types were described, illustrated and compared. The variability of investigated carpological characters in this species is providing important information prior to their further taxonomic treatment. 相似文献
943.
Global change‐driven effects on dissolved organic matter composition: Implications for food webs of northern lakes 下载免费PDF全文
Irena F. Creed Ann‐Kristin Bergström Charles G. Trick Nancy B. Grimm Dag O. Hessen Jan Karlsson Karen A. Kidd Emma Kritzberg Diane M. McKnight Erika C. Freeman Oscar E. Senar Agneta Andersson Jenny Ask Martin Berggren Mehdi Cherif Reiner Giesler Erin R. Hotchkiss Pirkko Kortelainen Monica M. Palta Tobias Vrede Gesa A. Weyhenmeyer 《Global Change Biology》2018,24(8):3692-3714
Northern ecosystems are experiencing some of the most dramatic impacts of global change on Earth. Rising temperatures, hydrological intensification, changes in atmospheric acid deposition and associated acidification recovery, and changes in vegetative cover are resulting in fundamental changes in terrestrial–aquatic biogeochemical linkages. The effects of global change are readily observed in alterations in the supply of dissolved organic matter (DOM)—the messenger between terrestrial and lake ecosystems—with potentially profound effects on the structure and function of lakes. Northern terrestrial ecosystems contain substantial stores of organic matter and filter or funnel DOM, affecting the timing and magnitude of DOM delivery to surface waters. This terrestrial DOM is processed in streams, rivers, and lakes, ultimately shifting its composition, stoichiometry, and bioavailability. Here, we explore the potential consequences of these global change‐driven effects for lake food webs at northern latitudes. Notably, we provide evidence that increased allochthonous DOM supply to lakes is overwhelming increased autochthonous DOM supply that potentially results from earlier ice‐out and a longer growing season. Furthermore, we assess the potential implications of this shift for the nutritional quality of autotrophs in terms of their stoichiometry, fatty acid composition, toxin production, and methylmercury concentration, and therefore, contaminant transfer through the food web. We conclude that global change in northern regions leads not only to reduced primary productivity but also to nutritionally poorer lake food webs, with discernible consequences for the trophic web to fish and humans. 相似文献
944.
The effect of ethoxylated oleyl–cetyl alcohol (Henkel, “Merima”, Serbia) on the growth and metabolic activity of Cladosporium cladosporioides, Geotrichum candidum and their mixed culture was in the focus of this paper. The cultures were grown in Czapek-Dox liquid nutrient medium with the addition of 0.5% pollutant and without it. The physico-chemical and biochemical changes of pH, the total biomass dry weight, the quantity of free and total organic acids, proteolytic activity and the quality of carbohydrates were evaluated from 4th to 19th day of fungal growth. The pollutant caused an inhibitory effect on biomass dry weight of C. cladosporioides and G. candidum for 10.36% and 4.65% respectively, and stimulatory effect on biomass of mixed culture for 3.80%. The pollutant had influence on the decrease in pH value of the media in the phase of culture growth, and pH changes were correlated with the amount of excreted total organic acids. The highest quantity of free and total organic acids was noted in media with pollutant of mixed culture and C. cladosporioides, respectively. The alkaline protease activities of C. cladosporioides, G. candidum and mixed culture were enhanced by addition of pollutant for 56.88%, 55.84% and 30.94% respectively. The obtained results indicate the potential of both pure and mixed cultures in mycoremediation environment contaminated by alcohol ethoxylated and detergent industry. 相似文献
945.
Eleftheria Polychronidou Ilias Kalamaras Andreas Agathangelidis Lesley-Ann Sutton Xiao-Jie Yan Vasilis Bikos Anna Vardi Konstantinos Mochament Nicholas Chiorazzi Chrysoula Belessi Richard Rosenquist Paolo Ghia Kostas Stamatopoulos Panayiotis Vlamos Anna Chailyan Nanna Overby Paolo Marcatili Anastasia Hatzidimitriou Dimitrios Tzovaras 《BMC bioinformatics》2018,19(14):414
946.
To evaluate the acoustic behavior of blue whales (Balaenoptera musculus) located inshore and offshore of southern California, singular A and B calls, D calls, and AB phrases were analyzed from 12 mo of passive acoustic data collected at four locations within the Southern California Bight. The relative proportions of singular calls and phrases were used to evaluate spatial and temporal patterns in sound and song type usage, and singular call and phrase production rates were calculated to investigate spatial and temporal variability in call abundance. Blue whale sounds were recorded from spring through early winter, with the majority of all detections occurring between September and December. The proportions and production rates of singular calls and phrases varied between the inshore and offshore sites. In addition, the percentage of A units within repetitive song phrases was greater inshore than offshore, resulting from a higher proportion of AB song type inshore, in which A and B phrase units were alternating. The ABB song type, in which a single A unit was followed by multiple B units, was more common offshore. The observed differences in calling and singing behaviors may identify distinct and variable acoustic behavioral settings for blue whales off southern California. 相似文献
947.
Emilia Wilmowicz Agata Kućko Maciej Ostrowski Katarzyna Panek 《Plant Growth Regulation》2018,85(1):91-100
Abscission is a natural process that occurs to facilitate shedding of no longer needed organs, but on the other hand, can be triggered by certain environmental conditions, e.g. biotic or abiotic stresses. Regardless of the stimuli, organ shedding takes place specifically at the abscission zone (AZ). A signaling pathway that controls this process in Arabidopsis thaliana from ligand to receptors has been proposed. However, knowledge concerning the influence of plant hormones on these molecular elements still remains enigmatic. Excessive and premature flower abscission in the crop species Lupinus luteus L. is a process of substantial interest to the agricultural industry, as it can affect yield. Our strategy combined molecular studies, comprehensive ultrastructural and histological analysis, as well as exogenous hormone treatment to describe the contribution of the Lupinus IDA-like gene in flower abscission. In the AZ of the naturally abscised flowers, the differentiation of morphologically distinct cells characterized by progressive degradation processes was accompanied by LlIDL mRNA accumulation. A similar effect was observed following early steps of AZ activation and after abscisic acid or ethylene treatments. These phytohormones, previously pointed out as key stimulators of flower separation, altered the temporal expression pattern of LlIDL. Exogenous EPIP peptide synthesized on the basis of LlIDL sequence, significantly increased flower abortion rate, which indicates that this motif governs protein activity. In conclusion, our data provide new evidence for LlIDA involvement in both the early and late events of flower abscission supported by detailed spatiotemporal characterization of AZ cell structure and ultrastructure. 相似文献
948.
Irena Trbojević-Akmačić Frano Vučković Marija Vilaj Andrea Skelin Lennart C. Karssen Jasminka Krištić Julija Jurić Ana Momčilović Jelena Šimunović Massimo Mangino Manuela De Gregori Maurizio Marchesini Concetta Dagostino Jerko Štambuk Mislav Novokmet Richard Rauck Yurii S. Aulchenko Dragan Primorac Gordan Lauc 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(10):2124-2133
Background
Low back pain (LBP) is the symptom of a group of syndromes with heterogeneous underlying mechanisms and molecular pathologies, making treatment selection and patient prognosis very challenging. Moreover, symptoms and prognosis of LBP are influenced by age, gender, occupation, habits, and psychological factors. LBP may be characterized by an underlying inflammatory process. Previous studies indicated a connection between inflammatory response and total plasma N-glycosylation. We wanted to identify potential changes in total plasma N-glycosylation pattern connected with chronic low back pain (CLBP), which could give an insight into the pathogenic mechanisms of the disease.Methods
Plasma samples of 1128 CLBP patients and 760 healthy controls were collected in clinical centers in Italy, Belgium and Croatia and used for N-glycosylation profiling by hydrophilic interaction ultra-performance liquid chromatography (HILIC-UPLC) after N-glycans release, fluorescent labeling and clean-up. Observed N-glycosylation profiles have been compared with a cohort of 126 patients with acute inflammation that underwent abdominal surgery.Results
We have found a statistically significant increase in the relative amount of high-branched (tri-antennary and tetra-antennary) N-glycan structures on CLBP patients' plasma glycoproteins compared to healthy controls. Furthermore, relative amounts of disialylated and trisialylated glycan structures were increased, while high-mannose and glycans containing bisecting N-acetylglucosamine decreased in CLBP.Conclusions
Observed changes in CLBP on the plasma N-glycome level are consistent with N-glycosylation changes usually seen in chronic inflammation.General significance
To our knowledge, this is a first large clinical study on CLBP patients and plasma N-glycome providing a new glycomics perspective on potential disease pathology. 相似文献949.
Iva Bozic Katarina Tesovic Danijela Laketa Marija Adzic Marija Jakovljevic Ivana Bjelobaba Danijela Savic Nadezda Nedeljkovic Sanja Pekovic Irena Lavrnja 《Neurochemical research》2018,43(5):1020-1034
Kv1.3 is a voltage gated potassium channel that has been implicated in pathophysiology of multiple sclerosis (MS). In the present study we investigated temporal and cellular expression pattern of this channel in the lumbar part of spinal cords of animals with experimental autoimmune encephalomyelitis (EAE), animal model of MS. EAE was actively induced in female Dark Agouti rats. Expression of Kv1.3 was analyzed at different time points of disease progression, at the onset, peak and end of EAE. We here show that Kv1.3 increased by several folds at the peak of EAE at both gene and protein level. Double immunofluorescence analyses demonstrated localization of Kv1.3 on activated microglia, macrophages, and reactive astrocytes around inflammatory lesions. In vitro experiments showed that pharmacological block of Kv1.3 in activated astrocytes suppresses the expression of proinflammatory mediators, suggesting a role of this channel in inflammation. Our results support the hypothesis that Kv1.3 may be a therapeutic target of interest for MS and add astrocytes to the list of cells whose activation would be suppressed by inhibiting Kv1.3 in inflammatory conditions. 相似文献
950.
Joseph Kuć 《Acta Physiologiae Plantarum》1997,19(4):551-559
Plants respond to infection by accumulating many compounds some of which may function in disease resistance. These include:
phytoalexins, antifungal proteins, chitinases, glucanases, esterases, proteaes, phospholipases, lipoxygenases, ribonucleases,
peroxidases, phenoloxidases, lignin, callose, hydroxyproline and glycine-rich glycoproteins, phenolic cross-linked polysachcarides,
melanin-like pigments, salicylic acid, jasmonic acid, ethylene, peptides, oligosaccharides, hydrogen peroxide and active oxygen
species. Though specific avirulence genes, elicitors and elicitor receptors have been reported, the production of defense-related
compounds is nonspecific and can be elicited by pathogens, pathogen products and many organics and inorganics. The molecular
implications of this specificity/nonspecificity and their significance to disease resistance and practical disease control
will be discussed. 相似文献