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排序方式: 共有203条查询结果,搜索用时 187 毫秒
51.
Thor Allan Stenberg Anders Benjamin Kildal Espen Sanden Ole-Jakob How Martin Hagve Kirsti Ytrehus Terje S. Larsen Truls Myrmel 《PloS one》2014,9(9)
The mechanisms contributing to multiorgan dysfunction during cardiogenic shock are poorly understood. Our goal was to characterize the microcirculatory and mitochondrial responses following ≥10 hours of severe left ventricular failure and cardiogenic shock. We employed a closed-chest porcine model of cardiogenic shock induced by left coronary microembolization (n = 12) and a time-matched control group (n = 6). Hemodynamics and metabolism were measured hourly by intravascular pressure catheters, thermodilution, arterial and organ specific blood gases. Echocardiography and assessment of the sublingual microcirculation by sidestream darkfield imaging were performed at baseline, 2±1 and 13±3 (mean±SD) hours after coronary microembolization. Upon hemodynamic decompensation, cardiac, renal and hepatic mitochondria were isolated and evaluated by high-resolution respirometry. Low cardiac output, hypotension, oliguria and severe reductions in mixed-venous and hepatic O2 saturations were evident in cardiogenic shock. The sublingual total and perfused vessel densities were fully preserved throughout the experiments. Cardiac mitochondrial respiration was unaltered, whereas state 2, 3 and 4 respiration of renal and hepatic mitochondria were increased in cardiogenic shock. Mitochondrial viability (RCR; state 3/state 4) and efficiency (ADP/O ratio) were unaffected. Our study demonstrates that the microcirculation is preserved in a porcine model of untreated cardiogenic shock despite vital organ hypoperfusion. Renal and hepatic mitochondrial respiration is upregulated, possibly through demand-related adaptations, and the endogenous shock response is thus compensatory and protective, even after several hours of global hypoperfusion. 相似文献
52.
Sigrid N?ss Benedicte A. Lie Espen Melum Marita Olsson Johannes R. Hov Peter J. P. Croucher Jochen Hampe Erik Thorsby Annika Bergquist James A. Traherne Erik Schrumpf Kirsten Muri Boberg Stefan Schreiber Andre Franke Tom H. Karlsen 《PloS one》2014,9(12)
Background
Genetic variants within the major histocompatibility complex (MHC) represent the strongest genetic susceptibility factors for primary sclerosing cholangitis (PSC). Identifying the causal variants within this genetic complex represents a major challenge due to strong linkage disequilibrium and an overall high physical density of candidate variants. We aimed to refine the MHC association in a geographically restricted PSC patient panel.Methodology/Principal Findings
A total of 365 PSC cases and 368 healthy controls of Scandinavian ancestry were included in the study. We incorporated data from HLA typing (HLA-A, -B, -C, -DRB3, -DRB1, -DQB1) and single nucleotide polymorphisms across the MHC (n = 18,644; genotyped and imputed) alongside previously suggested PSC risk determinants in the MHC, i.e. amino acid variation of DRβ, a MICA microsatellite polymorphism and HLA-C and HLA-B according to their ligand properties for killer immunoglobulin-like receptors. Breakdowns of the association signal by unconditional and conditional logistic regression analyses demarcated multiple PSC associated MHC haplotypes, and for eight of these classical HLA class I and II alleles represented the strongest association. A novel independent risk locus was detected near NOTCH4 in the HLA class III region, tagged by rs116212904 (odds ratio [95% confidence interval] = 2.32 [1.80, 3.00], P = 1.35×10−11).Conclusions/Significance
Our study shows that classical HLA class I and II alleles, predominantly at HLA-B and HLA-DRB1, are the main risk factors for PSC in the MHC. In addition, the present assessments demonstrated for the first time an association near NOTCH4 in the HLA class III region. 相似文献53.
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Luca Espen Silvia Morgutti Chiara Alisi Livia Pirovano Enzio Ragg Sergio M. Cocucci 《Physiologia plantarum》1995,93(4):577-583
57.
Richard Bischof Espen R. Gregersen Henrik Brøseth Hans Ellegren Øystein Flagstad 《Ecology and evolution》2016,6(5):1527-1536
Due to its conspicuous manifestations and its capacity to shape the configuration and dynamics of wild populations, territorial behavior has long intrigued ecologists. Territoriality and other animal interactions in situ have traditionally been studied via direct observations and telemetry. Here, we explore whether noninvasive genetic sampling, which is increasingly supplementing traditional field methods in ecological research, can reveal territorial behavior in an elusive carnivore, the wolverine (Gulo gulo). Using the locations of genotyped wolverine scat samples collected annually over a period of 12 years in central Norway, we test three predictions: (1) male home ranges constructed from noninvasive genetic sampling data are larger than those of females, (2) individuals avoid areas used by other conspecifics of the same sex (intrasexual territoriality), and (3) avoidance of same‐sex territories diminishes or disappears after the territory owner's death. Each of these predictions is substantiated by our results: sex‐specific differences in home range size and intrasexual territoriality in wolverine are patently reflected in the spatial and temporal configuration of noninvasively collected genetic samples. Our study confirms that wildlife monitoring programs can utilize the spatial information in noninvasive genetic sampling data to detect and quantify home ranges and social organization. 相似文献
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Implementing behaviour in individual-based models using neural networks and genetic algorithms 总被引:1,自引:1,他引:0
Even though individual-based models (IBMs) have become very popular in ecology during the last decade, there have been few
attempts to implement behavioural aspects in IBMs. This is partly due to lack of appropriate techniques. Behavioural and life
history aspects can be implemented in IBMs through adaptive models based on genetic algorithms and neural networks (individual-based-neural
network-genetic algorithm, ING). To investigate the precision of the adaptation process, we present three cases where solutions
can be found by optimisation. These cases include a state-dependent patch selection problem, a simple game between predators
and prey, and a more complex vertical migration scenario for a planktivorous fish. In all cases, the optimal solution is calculated
and compared with the solution achieved using ING. The results show that the ING method finds optimal or close to optimal
solutions for the problems presented. In addition it has a wider range of potential application areas than conventional techniques
in behavioural modelling. Especially the method is well suited for complex problems where other methods fail to provide answers.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
60.
Pulg Ulrich Lennox Robert J. Stranzl Sebastian Espedal Espen O. Gabrielsen Sven Erik Wiers Tore Velle Gaute Hauer Christoph Dønnum Bjørn Otto Barlaup Bjørn T. 《Hydrobiologia》2022,849(2):485-507
Hydrobiologia - River regulation alters flow and sediment regime, habitat availability, and ultimately the ecological functioning of rivers. Various restoration and mitigation measures... 相似文献