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931.
932.
The purpose of this study was to examine attitudes of medical students at a single university toward genetic testing in minors, defining attitudes as willingness to offer testing, and reasons for offering or not offering testing. A survey was distributed to all University of Arizona medical students (n = 428) during the 2003-2004 academic year. The survey consisted of three clinical vignettes concerning genetic testing for Huntington's disease (HD), BRCA1 breast cancer predisposition mutation, and cystic fibrosis (CF) carrier status. For each vignette, students responded to whether they would provide testing for a 7-year-old, a 17-year-old, and their reasons for each age and condition. One hundred thirty-five students (31.5%) responded to the survey. Medical students were significantly more likely to test a 7-year-old for CF carrier status (57%), than they were for a BRCA1 mutation (47%), and an HD mutation (40%). Students were significantly more likely to test a 17-year-old than a 7-year-old in each clinical scenario. Students who had completed a genetics course in medical school were significantly less likely to test a 7-year-old for a BRCA1 mutation than those who had not completed a formal course. Medical students' willingness to perform genetic testing in a minor is influenced by the type of condition, the age of the minor being tested, and the amount of genetics education received in medical school. 相似文献
933.
Magdalena Ietswaart Marie Johnston Chris H Dijkerman Clare L Scott Sara A Joice Steven Hamilton Ronald S MacWalter 《BMC neurology》2006,6(1):39-7
Background
The study aims to assess the therapeutic benefits of motor imagery training in stroke patients with persistent motor weakness. There is evidence to suggest that mental rehearsal of movement can produce effects normally attributed to practising the actual movements. Imagining hand movements could stimulate the redistribution of brain activity, which accompanies recovery of hand function, thus resulting in a reduced motor deficit. 相似文献934.
Cooper MH Iverson SJ Rouvinen-Watt K 《Physiological and biochemical zoology : PBZ》2006,79(4):820-829
Cetoleic acid (22:1n-11) is a good indicator of diet in marine predators and has proven to be an important fatty acid (FA) when using adipose tissue FA composition to study diet in marine mammals and seabirds. Feeding studies have shown that 22:1 isomers are predictably underrepresented in adipose tissue relative to diet, implying that metabolism within the predator strongly influences the relationship between the level of these FAs in diet and adipose tissue. Fully understanding such metabolic processes for individual FAs is important for the quantitative estimation of predator diets. We employed a dual-label radioisotope tracer technique to investigate the potential modification of 22:1n-11 and its recovery in the blubber of gray seals (Halichoerus grypus) and in the adipose tissue and liver of mink (Mustela vison), a smaller model carnivore also accustomed to fish-based diets. In both seals and mink, (3)H radioactivity was found in the chain-shortened products of 22:1n-11, with 18:1 being the dominant product. We also found (3)H radioactivity in saturated FAs. The distribution patterns of (3)H radioactivity across the FAs isolated from seal blubber and mink subcutaneous adipose tissue were comparable, indicating that mink are a good model for the investigation of lipid metabolism in marine carnivores. 相似文献
935.
Liljander M Sällström MA Andersson S Andersson A Holmdahl R Mattsson R 《Arthritis research & therapy》2006,8(2):R45-6
Collagen-induced arthritis in mice is one of the most commonly used autoimmune experimental models, with many similarities
to rheumatoid arthritis. Since collagen-induced arthritis is a complex polygenic disease there is a need for identification
of several major disease-controlling genes. Because rheumatoid arthritis particularly affects aged women, we have in the present
study identified new genetic regions critical for collagen-induced arthritis by studying aged female mice of a cross between
NFR/N and B10.Q (H-2q haplotype). The mice in the present study had different reproductive histories, which did not significantly affect the onset,
incidence or severity of the disease. A total of 200 female mice were used in a total genome-wide screening with 125 microsatellite
markers. We found one new significant quantitative trait locus affecting the arthritis incidence, severity and day of onset
on chromosome 11 (denoted Cia40), which colocalizes with a locus controlling pregnancy failure. Furthermore, a quantitative trait locus of suggestive significance
associated with the incidence, severity and day of onset was identified on chromosome 1. Finally, a suggestively significant
quantitative trait locus associated with collagen type II antibody titers was identified on chromosome 13. This study indicates
that several gene loci control arthritis in aged multiparous females, and that at least one of these loci coincides with pregnancy
failure. 相似文献
936.
Andrew W Legan Christopher M Jernigan Sara E Miller Matthieu F Fuchs Michael J Sheehan 《Molecular biology and evolution》2021,38(9):3832
Independent origins of sociality in bees and ants are associated with independent expansions of particular odorant receptor (OR) gene subfamilies. In ants, one clade within the OR gene family, the 9-exon subfamily, has dramatically expanded. These receptors detect cuticular hydrocarbons (CHCs), key social signaling molecules in insects. It is unclear to what extent 9-exon OR subfamily expansion is associated with the independent evolution of sociality across Hymenoptera, warranting studies of taxa with independently derived social behavior. Here, we describe OR gene family evolution in the northern paper wasp, Polistes fuscatus, and compare it to four additional paper wasp species spanning ∼40 million years of evolutionary divergence. We find 200 putatively functional OR genes in P. fuscatus, matching predictions from neuroanatomy, and more than half of these are in the 9-exon subfamily. Most OR gene expansions are tandemly arrayed at orthologous loci in Polistes genomes, and microsynteny analysis shows species-specific gain and loss of 9-exon ORs within tandem arrays. There is evidence of episodic positive diversifying selection shaping ORs in expanded subfamilies. Values of omega (dN/dS) are higher among 9-exon ORs compared to other OR subfamilies. Within the Polistes OR gene tree, branches in the 9-exon OR clade experience relaxed negative (relaxed purifying) selection relative to other branches in the tree. Patterns of OR evolution within Polistes are consistent with 9-exon OR function in CHC perception by combinatorial coding, with both natural selection and neutral drift contributing to interspecies differences in gene copy number and sequence. 相似文献
937.
Chiara?GambardellaEmail author Laura?Ghigliotti Lorenzo?Gallus Eva?Pisano Grazia?Tagliafierro Sara?Ferrando 《Polar Biology》2012,35(5):795-799
Serotonin is a signal molecule with a wide range of functions in vertebrates. In Antarctic fishes, the serotonergic system
has been studied in the brain, revealing differences from temperate fishes related to the long-term cold adaptation. To date,
little is known regarding the peripheral nervous system, and no information is available for the stomach. In the present work,
we contribute to fill the gaps by investigating the presence and the immunohistochemical distribution of serotonin in the
stomach of the Antarctic silverfish Pleuragramma antarcticum, a cold-adapted key species of the Southern Ocean shelf food web. The main aim was to investigate the serotonergic system
at the gastric level, in order to reveal possible peculiarities related to long-term cold adaptation, similar to the ones
seen in the central nervous system of Antarctic fishes. Serotonin immunoreactivity was detected in the pyloric and cardiac
mucosa of P. antarcticum stomach with immunopositive cells in the pyloric and cardiac surface epithelia and in the tubular glands. No immunopositive
fibers and neuronal cell bodies were found. Our results highlight that the serotonin distribution pattern at the gastric level
is similar to that described in temperate teleosts. This finding suggests that in P. antarcticum, long-term adaptations to the Antarctic condition do not affect the serotonergic system at the gastric level. In addition,
our data constitute the baseline information for further investigations aimed at clarifying the effects of short-term temperature
variations on the gastric serotonergic system of Antarctic species in the frame of the global climate change. 相似文献
938.
Moreno-Sánchez R Marín-Hernández A Gallardo-Pérez JC Quezada H Encalada R Rodríguez-Enríquez S Saavedra E 《Journal of cellular biochemistry》2012,113(5):1692-1703
Kinetic analysis of PFK-1 from rodent AS-30D, and human HeLa and MCF-7 carcinomas revealed sigmoidal [fructose 6-phosphate, Fru6P]-rate curves with different V(m) values when varying the allosteric activator fructose 2,6 bisphosphate (Fru2,6BP), AMP, Pi, NH(4)(+), or K(+). The rate equation that accurately predicted this behavior was the exclusive ligand binding concerted transition model together with non-essential hyperbolic activation. PFK-1 from rat liver and heart also exhibited the mixed cooperative-hyperbolic kinetic behavior regarding activators. Lowering pH induced decreased affinity for Fru6P, Fru2,6BP, citrate, and ATP (as inhibitor); as well as decreased V(m) and increased content of inactive (T) enzyme forms. High K(+) prompted increased (Fru6P) or decreased (activators) affinities; increased V(m); and increased content of active (R) enzyme forms. mRNA expression analysis and nucleotide sequencing showed that the three PFK-1 isoforms L, M, and C are transcribed in the three carcinomas. However, proteomic analysis indicated the predominant expression of L in liver, of M in heart and MCF-7 cells, of L>M in AS-30D cells, and of C in HeLa cells. PFK-1M showed the highest affinities for F6P and citrate and the lowest for ATP (substrate) and F2,6BP; PFK-1L showed the lowest affinity for F6P and the highest for F2,6BP; and PFK-1C exhibited the highest affinity for ATP (substrate) and the lowest for citrate. Thus, the present work documents the kinetic signature of each PFK-1 isoform, and facilitates the understanding of why this enzyme exerts significant or negligible glycolysis flux-control in normal or cancer cells, respectively, and how it regulates the onset of the Pasteur effect. 相似文献
939.
Loughran NB Hinde S McCormick-Hill S Leidal KG Bloomberg S Loughran ST O'Connor B O'Fágáin C Nauseef WM O'Connell MJ 《Molecular biology and evolution》2012,29(8):2039-2046
Myeloperoxidase (MPO) is a member of the mammalian heme peroxidase (MHP) multigene family. Whereas all MHPs oxidize specific halides to generate the corresponding hypohalous acid, MPO is unique in its capacity to oxidize chloride at physiologic pH to produce hypochlorous acid (HOCl), a potent microbicide that contributes to neutrophil-mediated host defense against infection. We have previously resolved the evolutionary relationships in this functionally diverse multigene family and predicted in silico that positive Darwinian selection played a major role in the observed functional diversities (Loughran NB, O'Connor B, O'Fagain C, O'Connell MJ. 2008. The phylogeny of the mammalian heme peroxidases and the evolution of their diverse functions. BMC Evol Biol. 8:101). In this work, we have replaced positively selected residues asparagine 496 (N496), tyrosine 500 (Y500), and leucine 504 (L504) with the amino acids present in the ancestral MHP and have examined the effects on the structure, biosynthesis, and activity of MPO. Analysis in silico predicted that N496F, Y500F, or L504T would perturb hydrogen bonding in the heme pocket of MPO and thus disrupt the structural integrity of the enzyme. Biosynthesis of the mutants stably expressed in human embryonic kidney 293 cells yielded apoproMPO, the heme-free, enzymatically inactive precursor of MPO, that failed to undergo normal maturation or proteolytic processing. As a consequence of the maturational arrest at the apoproMPO stage of development, cells expressing MPO with mutations N496F, Y500F, L504T, individually or in combination, lacked normal peroxidase or chlorinating activity. Taken together, our data provide further support for the in silico predictions of positive selection and highlight the correlation between positive selection and functional divergence. Our data demonstrate that directly probing the functional importance of positive selection can provide important insights into understanding protein evolution. 相似文献
940.
Debbie Cavers Belinda Hacking Sara E. Erridge Marilyn Kendall Paul G. Morris Scott A. Murray 《CMAJ》2012,184(7):E373-E382