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111.
112.
Bachmann TT Leca B Vilatte F Marty JL Fournier D Schmid RD 《Biosensors & bioelectronics》2000,15(3-4):193-201
Engineered variants of Drosophila melanogaster acetylcholinesterase (AChE) were used as biological receptors of AChE-multisensors for the simultaneous detection and discrimination of binary mixtures of cholinesterase-inhibiting insecticides. The system was based on a combination of amperometric multielectrode biosensors with chemometric data analysis of sensor outputs using artificial neural networks (ANN). The multisensors were fully manufactured by screen-printing, including enzyme immobilisation. Two types of multisensors were produced that consisted of four AChE variants each. The AChE mutants were selected in order to obtain high resolution, enhanced sensitivity and minimal assay time. This task was successfully achieved using multisensor I equipped with wild-type Drosophila AChE and mutants Y408F, F368L, and F368H. Each of the AChE variants was selected on the basis of displaying an individual sensitivity pattern towards the target analytes. For multisensor II, the inclusion of F368W, which had an extremely diminished paraoxon sensitivity, increased the sensor's capacity even further. Multisensors I and II were both used for inhibition analysis of binary paraoxon and carbofuran mixtures in a concentration range 0-5 microg/l, followed by data analysis using feed-forward ANN. The two analytes were determined with prediction errors of 0.4 microg/l for paraoxon and 0.5 microg/l for carbofuran. A complete biosensor assay and subsequent ANN evaluation was completed within 40 min. In addition, multisensor II was also investigated for analyte discrimination in real water samples. Finally, the properties of the multisensors were confirmed by simultaneous detection of binary organophosphate mixtures. Malaoxon and paraoxon in composite solutions of 0-5 microg/l were discriminated with predication errors of 0.9 and 1.6 microg/l, respectively. 相似文献
113.
Pastor J Lafon M Travé-Massuyès L Démonet JF Doyon B Celsis P 《Biological cybernetics》2000,82(1):49-59
Today, cognitive functions are considered to be the offspring of the activity of large-scale networks of functionally interconnected
cerebral regions. The interpretation of cerebral activation data provided by functional imaging has therefore recently moved
to the search for the effective connectivity of activated regions, which aims at understanding the role of anatomical links
in the activation propagation. Our assumption is that only causal connectivity can offer a real understanding of the links
between brain and mind. Causal connectivity is based on the anatomical connection pattern, the information processing within
cerebral regions and the causal influences that connected regions exert on each other. In our approach, the information processing
within a region is implemented by a causal network of functional primitives, which are the interpretation of integrated biological
properties. Our choice of a qualitative representation of information reflects the fact that cerebral activation data are
only the approximate view, provided by imaging techniques, of the real cerebral activity. This explicit modeling approach
allows the formulation and the simulation of functional and physiological assumptions about activation data. Two alternative
models explaining results of the striate cortex activation described by Fox and Raichle (Fox PT, Raichle ME (1984) J. Neurophysiol
51:1109–1120; Fox PT, Raichle ME (1985) Ann Neurol 17:303–305) are provided as an example of our approach.
Received: 22 December 1998 / Accepted in revised form: 23 June 1999 相似文献
114.
Acetylcholinesterase is the primary target of organophosphorous and carbamate insecticides. Quantitative changes in acetylcholinesterase are suspected to confer resistance to these insecticides, but a method to estimate the amount in insect is not available. A method using irreversible inhibitors has been developed. Among the irreversible inhibitors tested, 7-(methylethoxyphosphinyloxy)-1-methylquinolinium iodide, chlorpyrifos-ethyl-oxon, and coumaphos-oxon were found to be sufficiently potent and specific. 相似文献
115.
116.
José M. Quintero José M. Fournier José Ramos Manuel Benlloch 《Physiologia plantarum》1998,102(2):279-284
Twenty‐day‐old sunflower plants ( Helianthus annuus L. cv. Sun‐Gro 380) grown in nutrient solutions with different KCl levels were used to study the effects of K+ status of the root and of abcisic acid (ABA) on the exudation rate (Jv ), the hydraulic conductivity of the root (Lp ), the fluxes of exuded K+ and Na+ (JK and JNa ), and the gradient of osmotic pressure between the xylem and the external medium. Jv and Lp increased in direct proportion to the K+ starvation of the root. Also addition of ABA (4 µ M ) at the onset of exudation in the external medium made Jv and Lp rise, and this effect also increased with the degree of K+ starvation. Similarly, K+ starvation and ABA promoted both the flux of exuded Na+ and the accumulation of Na+ in the root. We suggest that ABA acts as a regulating signal for the radial transport of water across the root, and that potassium may be an effector of this mechanism. 相似文献
117.
Aribaud Marcel Kevers Claire Martin-Tanguy Josette Gaspar Thomas 《Plant Cell, Tissue and Organ Culture》1998,55(2):85-94
Foliar discs (8 mm diameter) from expanding leaves of the middle part of vegetative shoots of Chrysanthemum morifolium Ramat
raised in vitro were induced to form directly on specific media in vitro either roots or vegetative buds, or callus. The budding
programme, on its specific medium, was deviated to callus formation by the addition of 2 mM β-OH-E (β-OH-ethyldrazine, an
inhibitor of diamine oxidase). Conversely vegetative buds instead of callus were formed on the callus medium in the presence
of 2 mM DFMO (difluoromethylornithine, an inhibitor of ornithine decarboxylase). Callus formation was characterized by high
accumulation of free and particularly conjugated polyamines (PA), very low or undetectable activities of diamine- and polyamine
oxidases, and transglutaminase. DFMO-deviation of callus initiation in favour of bud formation lowered the accumulation of
PA and increased the activity of amine-oxidases. The high catabolism of PA in the organogenic (rooting, budding) programs
was questioned as to its role in developmental processes.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
118.
Stephane Fournier Patrick Taffé Dragana Radovanovic Erik Von Elm Beata Morawiec Jean-Christophe Stauffer Paul Erne Ahmed Beggah Pierre Monney Patrizio Pascale Juan-Fernando Iglesias Eric Eeckhout Olivier Muller 《PloS one》2015,10(3)
Background
Different studies have shown circadian variation of ischemic burden among patients with ST-Elevation Myocardial Infarction (STEMI), but with controversial results. The aim of this study was to analyze circadian variation of myocardial infarction size and in-hospital mortality in a large multicenter registry.Methods
This retrospective, registry-based study was based on data from AMIS Plus, a large multicenter Swiss registry of patients who suffered myocardial infarction between 1999 and 2013. Peak creatine kinase (CK) was used as a proxy measure for myocardial infarction size. Associations between peak CK, in-hospital mortality, and the time of day at symptom onset were modelled using polynomial-harmonic regression methods.Results
6,223 STEMI patients were admitted to 82 acute-care hospitals in Switzerland and treated with primary angioplasty within six hours of symptom onset. Only the 24-hour harmonic was significantly associated with peak CK (p = 0.0001). The maximum average peak CK value (2,315 U/L) was for patients with symptom onset at 23:00, whereas the minimum average (2,017 U/L) was for onset at 11:00. The amplitude of variation was 298 U/L. In addition, no correlation was observed between ischemic time and circadian peak CK variation. Of the 6,223 patients, 223 (3.58%) died during index hospitalization. Remarkably, only the 24-hour harmonic was significantly associated with in-hospital mortality. The risk of death from STEMI was highest for patients with symptom onset at 00:00 and lowest for those with onset at 12:00.Discussion
As a part of this first large study of STEMI patients treated with primary angioplasty in Swiss hospitals, investigations confirmed a circadian pattern to both peak CK and in-hospital mortality which were independent of total ischemic time. Accordingly, this study proposes that symptom onset time be incorporated as a prognosis factor in patients with myocardial infarction. 相似文献119.
Florent Guérin Mathilde Wagner Antoine Liné Magaly Zappa Magali Fasseu Valérie Paradis Valérie Vilgrain Bernard E. Van Beers Josette Legagneux Richard Moreau Philippe Lettéron 《PloS one》2015,10(5)
MethodsWe conducted an experimental study comparing portacaval shunt (PCS), total portal vein ligation (PVL), and sham (S) operated rats. Each group were either sacrificed at 6 weeks (early) or 6 months (late). Arterial liver perfusion was studied in vivo using CT, and histopathological changes were noted. Liver mRNA levels were quantified by RT-QPCR for markers of inflammation (Il10, Tnfa), proliferation (Il6st, Mki67, Hgf, Hnf4a), angiogenesis: (Vegfa, Vegfr 1, 2 and 3; Pgf), oxidative stress (Nos2, and 3, Hif1a), and fibrosis (Tgfb). PCS and PVL were compared to the S group.ResultsPeriportal fibrosis and arterial proliferation was observed in late PCS and PVL groups. CT imaging demonstrated increased arterial liver perfusion in the PCS group. RT-QPCR showed increased inflammatory markers in PCS and PVL early groups. Tnfa and Il10 were increased in PCS and PVL late groups respectively. All proliferative markers increased in the PCS, and Hnf4a in the PVL early groups. Mki67 and Hnf4a were increased in the PCS late group. Nos3 was increased in the early and late PCS groups, and Hif1a was decreased in the PVL groups. Markers of angiogenesis were all increased in the early PCS group, and Vegfr3 and Pgf in the late PCS group. Only Vegfr3 was increased in the PVL groups. Tgf was increased in the PCS groups.ConclusionsPortal deprivation in rats induces a sustained increase in intrahepatic markers of inflammation, angiogenesis, proliferation, and fibrosis. 相似文献
120.