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971.
Perspectives addressing either “local” or “routing” control over ecological form and function alternatively emphasize ambient conditions or recognize that form and processes at one location may be heavily influenced by other points in space. In their natural state, floodplains of montane gravel-bed rivers are organized laterally into parafluvial zones, where scour occurs annually, and orthofluvial environments, within which active (that is, early successional) and passive (that is, late successional) zones differ in regard to flooding influences. Vertically, these rivers interact with extensive alluvial aquifers throughout the length of their floodplains. We addressed how local and routing controls organize riverscape structure and function by investigating seasonal dynamics of interstitial dissolved oxygen (DO) vertically within the alluvial aquifer, longitudinally along flowpaths, and laterally across active and passive orthofluvial (PO) zones in the Nyack floodplain, Middle Fork Flathead River, MT. Groundwater DO was positively correlated to pH and negatively correlated electrical conductivity (EC) across all seasons. In some wells (7 of 19), DO was significantly lower and EC greater at shallow depths, and the magnitudes of vertical zonation were related to dissolved organic carbon concentrations. Longitudinal declines in DO were always and exclusively observed along flowpaths of the PO zone. At the same time, persistent hypoxic patches within the active orthofluvial environment suggest metabolic hotspots that contribute to local control of physicochemistry. In ecosystems heavily influenced by material transport, local and routing controls may be manifested simultaneously as distinct patterns of organization, which are expressed at different spatial and temporal scales. 相似文献
972.
973.
Thamara Hesselink Gerard J. A. Rouwendal Maurice G. L. Henquet Dion E. A. Florack Johannes P. F. G. Helsper Dirk Bosch 《Transgenic research》2014,23(5):717-728
β1,4-Galactosylation of plant N-glycans is a prerequisite for commercial production of certain biopharmaceuticals in plants. Two different types of galactosylated N-glycans have initially been reported in plants as the result of expression of human β1,4-galactosyltransferase 1 (GalT). Here we show that these differences are associated with differences at its N-terminus: the natural short variant of human GalT results in hybrid type N-glycans, whereas the long form generates bi-antennary complex type N-glycans. Furthermore, expression of non-mammalian, chicken and zebrafish GalT homologues with N-termini resembling the short human GalT N-terminus also induce hybrid type N-glycans. Providing both non-mammalian GalTs with a 13 amino acid N-terminal extension that distinguishes the two naturally occurring forms of human GalT, acted to increase the levels of bi-antennary galactosylated N-glycans when expressed in tobacco leaves. Replacement of the cytosolic tail and transmembrane domain of chicken and zebrafish GalTs with the corresponding region of rat α2,6-sialyltransferase yielded a gene whose expression enhanced the level of bi-antennary galactosylation even further. 相似文献
974.
Tjinta Brinkhuizen Chantal A. H. Weijzen Jonathan Eben Monique R. Thissen Ari?nne M. van Marion Bj?rn G. Lohman Véronique J. L. Winnepenninckx Patty J. Nelemans Maurice A. M. van Steensel 《PloS one》2014,9(9)
Background
Basal cell carcinoma (BCC) is the most common cancer in Caucasians. Trichoepithelioma (TE) is a benign neoplasm that strongly resembles BCC. Both are hair follicle (HF) tumours. HFs are hypoxic microenvironments, therefore we hypothesized that hypoxia-induced signalling pathways could be involved in BCC and TE as they are in other human malignancies. Hypoxia-inducible factor 1 (HIF1) and mechanistic/mammalian target of rapamycin (mTOR) are key players in these pathways.Objectives
To determine whether HIF1/mTOR signalling is involved in BCC and TE.Methods
We used immunohistochemical staining of formalin-fixed paraffin-embedded BCC (n = 45) and TE (n = 35) samples to assess activity of HIF1, mTORC1 and their most important target genes. The percentage positive tumour cells was assessed manually in a semi-quantitative manner and categorized (0%, <30%, 30–80% and >80%).Results
Among 45 BCC and 35 TE examined, expression levels were respectively 81% and 57% (BNIP3), 73% and 75% (CAIX), 79% and 86% (GLUT1), 50% and 19% (HIF1α), 89% and 88% (pAKT), 55% and 61% (pS6), 15% and 25% (pMTOR), 44% and 63% (PHD2) and 44% and 49% (VEGF-A). CAIX, Glut1 and PHD2 expression levels were significantly higher in TE when only samples with at least 80% expression were included.Conclusions
HIF and mTORC1 signalling seems active in both BCC and TE. There are no appreciable differences between the two with respect to pathway activity. At this moment immunohistochemical analyses of HIF, mTORC1 and their target genes does not provide a reliable diagnostic tool for the discrimination of BCC and TE. 相似文献975.
Jogchum Plat Tim Hendrikx Veerle Bieghs Mike L. J. Jeurissen Sofie M. A. Walenbergh Patrick J. van Gorp Els De Smet Maurice Konings Anita C. E. Vreugdenhil Yasmin Dias Guichot Sander S. Rensen Wim A. Buurman Jan Willem M. Greve Dieter Lütjohann Ronald P. Mensink Ronit Shiri-Sverdlov 《PloS one》2014,9(10)
The inflammatory component of non–alcoholic steatohepatitis (NASH) can lead to irreversible liver damage. Therefore there is an urgent need to identify novel interventions to combat hepatic inflammation. In mice, omitting cholesterol from the diet reduced hepatic inflammation. Considering the effects of plant sterol/stanol esters on cholesterol metabolism, we hypothesized that plant sterol/stanol esters reduces hepatic inflammation. Indeed, adding plant sterol/stanol esters to a high-fat-diet reduced hepatic inflammation as indicated by immunohistochemical stainings and gene expression for inflammatory markers. Finally, adding sterol/stanol esters lowered hepatic concentrations of cholesterol precursors lathosterol and desmosterol in mice, which were highly elevated in the HFD group similarly as observed in severely obese patients with NASH. In vitro, in isolated LPS stimulated bone marrow derived macrophages desmosterol activated cholesterol efflux whereas sitostanol reduced inflammation. This highly interesting observation that plant sterol/stanol ester consumption leads to complete inhibition of HFD-induced liver inflammation opens new venues in the treatment and prevention of hepatic inflammation. 相似文献
976.
There is now ample evidence that blind individuals outperform sighted individuals in various tasks involving the non-visual senses. In line with these results, we recently showed that visual deprivation from birth leads to an increased sensitivity to pain. As many studies have shown that congenitally and late blind individuals show differences in their degree of compensatory plasticity, we here address the question whether late blind individuals also show hypersensitivity to nociceptive stimulation. We therefore compared pain thresholds and responses to supra-threshold nociceptive stimuli in congenitally blind, late blind and normally sighted volunteers. Participants also filled in questionnaires measuring attention and anxiety towards pain in everyday life. Results show that late blind participants have pain thresholds and ratings of supra-threshold heat nociceptive stimuli similar to the normally sighted, whereas congenitally blind participants are hypersensitive to nociceptive thermal stimuli. Furthermore, results of the pain questionnaires did not allow to discriminate late blind from normal sighted participants, whereas congenitally blind individuals had a different pattern of responses. Taken together, these results suggest that enhanced sensitivity to pain following visual deprivation is likely due to neuroplastic changes related to the early loss of vision. 相似文献
977.
A series of substituted isoquinolinones were synthesized and their binding affinities and functional activities towards human melatonin MT1 and MT2 receptors were evaluated. Structure-activity relationship analysis revealed that substituted isoquinolinones bearing a 3-methoxybenzyloxyl group at C5, C6 or C7 position respectively (C5>C6>C7 in terms of their potency) conferred effective binding and selectivity toward the MT2 receptor, with 15b as the most potent compound. Most of the tested compounds were MT2-selective agonists as revealed in receptor-mediated cAMP inhibition, intracellular Ca2+ mobilization and phosphorylation of extracellular signal-regulated protein kinases. Intriguingly, compounds 7e and 7f bearing a 4-methoxybenzyloxyl group or 4-methylbenzyloxyl at C6 behaved as weak MT2-selective antagonists. These results suggest that substituted isoquinolinones represent a novel family of MT2-selective melatonin ligands. The position of the substituted benzyloxyl group, and the substituents on the benzyl ring appeared to dictate the functional characteristics of these compounds. 相似文献
978.
Henry Mbah Olubunmi Ruth Negedu-Momoh Oluwasanmi Adedokun Patrick Anibbe Ikani Oluseyi Balogun Olusola Sanwo Kingsley Ochei Maurice Ekanem Kwasi Torpey 《PloS one》2014,9(9)
Background
The surge of donor funds to fight HIV&AIDS epidemic inadvertently resulted in the setup of laboratories as parallel structures to rapidly respond to the identified need. However these parallel structures are a threat to the existing fragile laboratory systems. Laboratory service integration is critical to remedy this situation. This paper describes an approach to quantitatively measure and track integration of HIV-related laboratory services into the mainstream laboratory services and highlight some key intervention steps taken, to enhance service integration.Method
A quantitative before-and-after study conducted in 122 Family Health International (FHI360) supported health facilities across Nigeria. A minimum service package was identified including management structure; trainings; equipment utilization and maintenance; information, commodity and quality management for laboratory integration. A check list was used to assess facilities at baseline and 3 months follow-up. Level of integration was assessed on an ordinal scale (0 = no integration, 1 = partial integration, 2 = full integration) for each service package. A composite score grading expressed as a percentage of total obtainable score of 14 was defined and used to classify facilities (≤80% FULL, 25% to 79% PARTIAL and <25% NO integration). Weaknesses were noted and addressed.Results
We analyzed 9 (7.4%) primary, 104 (85.2%) secondary and 9 (7.4%) tertiary level facilities. There were statistically significant differences in integration levels between baseline and 3 months follow-up period (p<0.01). Baseline median total integration score was 4 (IQR 3 to 5) compared to 7 (IQR 4 to 9) at 3 months follow-up (p = 0.000). Partial and fully integrated laboratory systems were 64 (52.5%) and 0 (0.0%) at baseline, compared to 100 (82.0%) and 3 (2.4%) respectively at 3 months follow-up (p = 0.000).Discussion
This project showcases our novel approach to measure the status of each laboratory on the integration continuum. 相似文献979.
Joseph Bouskila Pasha Javadi Roberta M. Palmour Jean-Fran?ois Bouchard Maurice Ptito 《PloS one》2014,9(10)
Full-field electroretinography is an objective measure of retinal function, serving as an important diagnostic clinical tool in ophthalmology for evaluating the integrity of the retina. Given the similarity between the anatomy and physiology of the human and Green Monkey eyes, this species has increasingly become a favorable non-human primate model for assessing ocular defects in humans. To test this model, we obtained full-field electroretinographic recordings (ERG) and normal values for standard responses required by the International Society for Clinical Electrophysiology of Vision (ISCEV). Photopic and scotopic ERG recordings were obtained by full-field stimulation over a range of 6 log units of intensity in dark-adapted or light-adapted eyes of adult Green Monkeys (Chlorocebus sabaeus). Intensity, duration, and interval of light stimuli were varied separately. Reproducible values of amplitude and latency were obtained for the a- and b-waves, under well-controlled adaptation and stimulus conditions; the i-wave was also easily identifiable and separated from the a-b-wave complex in the photopic ERG. The recordings obtained in the healthy Green Monkey matched very well with those in humans and other non-human primate species (Macaca mulatta and Macaca fascicularis). These results validate the Green Monkey as an excellent non-human primate model, with potential to serve for testing retinal function following various manipulations such as visual deprivation or drug evaluation. 相似文献
980.
Maurice Demanou Régis Pouillot Marc Grandadam Pascal Boisier Basile Kamgang Jean Pierre Hervé Christophe Rogier Dominique Rousset Christophe Paupy 《PLoS neglected tropical diseases》2014,8(7)