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941.
Douglas HD Kitaysky AS Kitaiskaia EV Maccormick A Kelly A 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2009,179(3):297-304
The Goymann–Wingfield model predicts that glucocorticoid levels in social animals reflect the costs of acquiring and maintaining
social status. The crested auklet is one of the few avian colonial species where a mutual ornament in males and females is
used in both sexual and aggressive displays. Previous studies of the crested auklet support the notion that the crest ornament
is a badge of status in this species. Here, we examined the relationship between the crest ornament size and the adrenocortical
function in breeding crested auklets. Crest length was negatively correlated with corticosterone at baseline in males, but
not in females. Baseline corticosterone in females (but not in males) was negatively correlated with body condition index.
Although male and female crested auklets are monomorphic in their ornamental traits, our results suggest that the socially
mediated physiological costs associated with status signaling may differ between the sexes. 相似文献
942.
K. N. S. Usha Kiranmayee P. B. Kavi Kishor C. Tom Hash Santosh P. Deshpande 《Tropical plant biology》2016,9(1):12-28
Shoot fly is a major insect pest of sorghum damaging early crop growth, establishment and productivity. Host plant resistance is an efficient approach to minimize yield losses due to shoot fly infestation. Seedling leaf blade glossiness and trichome density are morphological traits associated with shoot fly resistance. Our objective was to identify and evaluate QTLs for glossiness and trichome density using- i) 1894 F2s, ii) a sub-set of 369 F2-recombinants, and iii) their derived 369 F2:3 progenies, from a cross involving introgression lines RSG04008-6 (susceptible)?×?J2614-11 (resistant). The QTLs were mapped to a 37–72 centimorgan (cM) or 5–15 Mb interval on the long arm of sorghum chromosome 10 (SBI-10L) with flanking markers Xgap001 and Xtxp141. One QTL each for glossiness (QGls10) and trichome density (QTd10) were mapped in marker interval Xgap001-Xnhsbm1044 and Xisep0630-Xtxp141, confirming their loose linkage, for which phenotypic variation accounted for ranged from 2.29 to 11.37 % and LOD values ranged from 2.03 to 24.13, respectively. Average physical map positions for glossiness and trichome density QTLs on SBI-10 from earlier studies were 4 and 2 Mb, which in the present study were reduced to 2 Mb and 800 kb, respectively. Candidate genes Glossy15 (Sb10g025053) and ethylene zinc finger protein (Sb10g027550) falling in support intervals for glossiness and trichome density QTLs, respectively, are discussed. Also we identified a sub-set of recombinant population that will facilitate further fine mapping of the leaf blade glossiness and trichome density QTLs on SBI-10. 相似文献
943.
Approximate parameter inference in systems biology using gradient matching: a comparative evaluation
Benn Macdonald Mu Niu Simon Rogers Maurizio Filippone Dirk Husmeier 《Biomedical engineering online》2016,15(1):80
Background
A challenging problem in current systems biology is that of parameter inference in biological pathways expressed as coupled ordinary differential equations (ODEs). Conventional methods that repeatedly numerically solve the ODEs have large associated computational costs. Aimed at reducing this cost, new concepts using gradient matching have been proposed, which bypass the need for numerical integration. This paper presents a recently established adaptive gradient matching approach, using Gaussian processes (GPs), combined with a parallel tempering scheme, and conducts a comparative evaluation with current state-of-the-art methods used for parameter inference in ODEs. Among these contemporary methods is a technique based on reproducing kernel Hilbert spaces (RKHS). This has previously shown promising results for parameter estimation, but under lax experimental settings. We look at a range of scenarios to test the robustness of this method. We also change the approach of inferring the penalty parameter from AIC to cross validation to improve the stability of the method.Methods
Methodology for the recently proposed adaptive gradient matching method using GPs, upon which we build our new method, is provided. Details of a competing method using RKHS are also described here.Results
We conduct a comparative analysis for the methods described in this paper, using two benchmark ODE systems. The analyses are repeated under different experimental settings, to observe the sensitivity of the techniques.Conclusions
Our study reveals that for known noise variance, our proposed method based on GPs and parallel tempering achieves overall the best performance. When the noise variance is unknown, the RKHS method proves to be more robust.944.
The basolateral amygdala complex (BLA), including the lateral (LA), basal (BA) and accessory basal (AB) nuclei, is involved in acquisition of contextual and auditory fear conditioning. The BA is one of the main targets for hippocampal information, a brain structure critical for contextual learning, which integrates several discrete stimuli into a single configural representation. Congruent with the hodology, selective neurotoxic damage to the BA results in impairments in contextual, but not auditory, fear conditioning, similarly to the behavioral impairments found after hippocampal damage. This study evaluated the effects of muscimol-induced reversible inactivation of the BA during a simultaneous contextual and auditory fear conditioning training on later fear responses to both the context and the tone, tested separately, without muscimol administration. As compared to control rats micro-infused with vehicle, subjects micro-infused with muscimol before training exhibited, during testing without muscimol, significant reduction of freezing responses to the conditioned context, but not to the conditioned tone. Therefore, reversible inactivation of the BA during training impaired contextual, but not auditory fear conditioning, thus confirming and extending similar behavioral observations following selective neurotoxic damage to the BA and, in addition, revealing that this effect is not related to the lack of a functional BA during testing. 相似文献
945.
Burda K 《Cell biochemistry and biophysics》2007,47(2):271-284
Photosystem II, being a constituent of light driven photosynthetic apparatus, is a highly organized pigment-protein-lipid
complex. The arrangement of PSII active redox cofactors insures efficiency of electron transfer within it. Donation of electrons
extracted from water by the oxygen evolving complex to plastoquinones requires an additional activation energy. In this paper
we present theoretical discussion of the anharmonic fluctuations of the protein-lipid matrix of PSII and an experimental evidence
showing that the fluctuations are responsible for coupling of its donor and acceptor side. We argue that the fast collective
motions liberated at temperatures higher that 200 K are crucial for the two final steps of the water splitting cycle and that
one can distinguish three different dynamic regimes of PSII action which are controlled by the timescales of forward electron
transfer, which vary with temperature. The three regimes of the dynamical behavior are related to different spatial domains
of PSII. 相似文献
946.
Pantolestinae is a eutherian subfamily of mammals whose members are known from the middle early Paleocene through at least
the beginning of the Oligocene of North America. They are also known from Europe, and possibly Africa. A lack of information
on pantolestine skulls has prevented the use of cranial anatomy in evaluation of this group’s enigmatic higher-level phylogenetic
relationships. Conversely, postcranial skeletons are well known and locomotor interpretations based on them are robust. The
most complete known skull of a pantolestine, Pantolestes longicaudus (YPM 13525), is described here and compared to potential close fossil relatives and extant mammals. Semicircular canal morphology
is used to test locomotor hypotheses.
YPM 13525 lacks an ossified bulla. It has a mediolaterally broad basioccipital, a large entoglenoid process, and a deeply
incised glaserian fissure of the squamosal, caudal and rostral tympanic processes on the petrosal, a foramen for an internal
carotid artery (ICA) that entered the tympanic cavity from a posteromedial position, bony tubes enclosing the main stem and
transpromontorial branch of the ICA, a large anterior carotid foramen formed within the basisphenoid, evidence of a stapedial
artery ramus superior, a groove on the dorsal aspect of the basisphenoid leading to the piriform fenestra possibly for drainage
of the cavernous sinus to an extracranial inferior petrosal sinus, a dorsum sellae with well-developed posterior clinoid processes,
a foramen rotundum within the alisphenoid, and a sphenorbital fissure between the alisphenoid and orbitosphenoid. Overall,
the morphology is not strikingly similar to any potential close relative and the phylogenetic position of Pantolestinae cannot
be estimated without cladistic analysis of a character matrix that includes this new morphology and broadly samples extant
and extinct eutherian taxa. Semicircular canal morphology differs from that of two likely terrestrial Paleocene mammals, Aphronorus (another pantolestid) and Eoryctes (a palaeoryctid), suggesting a different, possibly semi-aquatic, lifestyle for Pantolestes. 相似文献
947.
Koen B. Tanghe 《Journal of the history of biology》2017,50(4):927-987
Historians tend to speak of the problem of the origin of species or the species question, as if it were a monolithic problem. In reality, the phrase (or similar variants) refers to a, historically, surprisingly fluid and pluriform scientific issue. It has, in the course of the past five centuries, been used in no less than ten different ways or contexts. A clear taxonomy of these separate problems is useful or relevant in two ways. It certainly helps to disentangle confusions that have inevitably emerged in the literature in its absence. It may, secondly, also help us to gain a more thorough understanding, or sharper view, of the (pre)history of evolutionary thought. A consequent problem-centric look at that (pre)history through the lens of various origin of species problems certainly yields intriguing results, including and particularly for our understanding of the genesis of the Wallace–Darwin theory of evolution through natural selection. 相似文献
948.
Synapse-associated protein 102 (SAP102) is a scaffolding protein highly expressed early in development and plays a critical role in mediating glutamate receptor trafficking during synaptogenesis. Mutations in human SAP102 have been reported to cause intellectual disability, which is thought to be due to mislocalization of the mutant protein. However, little is known about the regulation of SAP102 synaptic targeting. Here, we investigate the role of phosphorylation of SAP102 in regulating its synaptic targeting. Previous studies have shown that synaptic targeting of SAP102 is regulated by C-terminal splicing. We now identify a phosphorylation site, serine 632, within the C-terminal alternatively spliced region, which is phosphorylated by casein kinase II (CK2). We show that Ser632 on SAP102 is phosphorylated in vitro, in heterologous cells, and in neurons. Moreover, we demonstrate that synaptic enrichment of SAP102 is increased by Ser632 phosphorylation. Consistently, elevation of synaptic activity that suppresses Ser632 phosphorylation reduces synaptic enrichment of SAP102. Furthermore, the mobility of SAP102 is decreased by Ser632 phosphorylation. Therefore, not only SAP102 synaptic targeting but also its mobility is regulated by Ser632 phosphorylation. These data provide evidence for a novel mechanism in regulating SAP102 function and glutamate receptor trafficking. 相似文献
949.
Marcelo H Ratto Louis TJ Delbaere Yvonne A Leduc Roger A Pierson Gregg P Adams 《Reproductive biology and endocrinology : RB&E》2011,9(1):24
Background
The objective of the present study was to isolate and purify the protein fraction(s) of llama seminal plasma responsible for the ovulation-inducing effect of the ejaculate. 相似文献950.
Severe acute pancreatitis (SAP) is a common disease with a poor prognosis. Heart failure is one cause of SAP patient death.
Intermedin (IMD) is a potent endogenous cardio-protective substance. Administration of exogenous IMD showed beneficial effects
in cardiovascular diseases. The aim of this study was to investigate the myocardial damage in SAP and to determine the therapeutic
potential of IMD for SAP. Using an SAP rat model, we examined endogenous IMD expression following SAP induction, and determined
the effect of IMD on myocardial function, histological morphology, apoptosis-related gene expression, and prognosis. Our results
indicated that the cardiac function and histological structure were significantly disrupted in SAP rats. Infusion of exogenous
IMD significantly preserved cardiac function and ameliorated myocardial damage. Terminal deoxynucleotidyl transferase-mediated
dUTP nick end labeling (TUNEL) revealed that myocardial apoptosis was extensively present in SAP rats, and IMD infusion led
to increased expression of the prosurvival factor Bcl-2, but decreased pro-apoptotic factors Bax and caspase-3. In addition,
IMD infusion also reversed the change of IMD receptor systems in SAP rat heart tissue. Furthermore, we found that IMD infusion
greatly decreased mortality of SAP rats. In conclusion, administration of SAP produced therapeutic effects in SAP through
modulating apoptotic and pro-survival gene expression, inhibiting myocardial apoptosis, preserving cardiac function, and a
useful therapeutic agent for SAP, and provides us an insight for a clinical trial of IMD for treating human severe acute pancreatitis. 相似文献