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261.
George P. Malanson 《西北部美国博物学家》2011,40(2)
Hanging gardens are insular plant communities of the Colorado Plateau. This study examines hanging gardens in the Narrows, Zion National Park, Utah. The floristic similarity of gardens and the presence of species in classes of variables which characterize the habitat are disclosed. Although the gardens are isolated and dissimilar, the individual species are not restricted in the range of habitat found. Floristic dissimilarity cannot be attributed to differences in habitat. These results are compared to studies of hanging gardens in eastern Utah. 相似文献
262.
Cranio-lenticulo-sutural dysplasia is caused by a SEC23A mutation leading to abnormal endoplasmic-reticulum-to-Golgi trafficking 总被引:1,自引:0,他引:1
Boyadjiev SA Fromme JC Ben J Chong SS Nauta C Hur DJ Zhang G Hamamoto S Schekman R Ravazzola M Orci L Eyaid W 《Nature genetics》2006,38(10):1192-1197
Cranio-lenticulo-sutural dysplasia (CLSD) is an autosomal recessive syndrome characterized by late-closing fontanels, sutural cataracts, facial dysmorphisms and skeletal defects mapped to chromosome 14q13-q21 (ref. 1). Here we show, using a positional cloning approach, that an F382L amino acid substitution in SEC23A segregates with this syndrome. SEC23A is an essential component of the COPII-coated vesicles that transport secretory proteins from the endoplasmic reticulum to the Golgi complex. Electron microscopy and immunofluorescence show that there is gross dilatation of the endoplasmic reticulum in fibroblasts from individuals affected with CLSD. These cells also exhibit cytoplasmic mislocalization of SEC31. Cell-free vesicle budding assays show that the F382L substitution results in loss of SEC23A function. A phenotype reminiscent of CLSD is observed in zebrafish embryos injected with sec23a-blocking morpholinos. Our observations suggest that disrupted endoplasmic reticulum export of the secretory proteins required for normal morphogenesis accounts for CLSD. 相似文献
263.
Hes-1 regulates the excitatory fate of neural progenitors through modulation of <Emphasis Type="Italic">Tlx3 (HOX11L2)</Emphasis> expression 总被引:1,自引:1,他引:0
Indulekha CL Divya TS Divya MS Sanalkumar R Rasheed VA Dhanesh SB Sebin A George A James J 《Cellular and molecular life sciences : CMLS》2012,69(4):611-627
Tlx3 (HOX11L2) is regarded as one of the selector genes in excitatory versus inhibitory fate specification of neurons in distinct regions
of the nervous system. Expression of Tlx3 in a post-mitotic immature neuron favors a glutamatergic over GABAergic fate. The
factors that regulate Tlx3 have immense importance in the fate specification of glutamatergic neurons. Here, we have shown that Notch target gene, Hes-1, negatively regulates Tlx3 expression, resulting in decreased generation of glutamatergic neurons. Down-regulation of Hes-1 removed the inhibition on Tlx3 promoter, thus promoting glutamatergic differentiation. Promoter–protein interaction studies
with truncated/mutated Hes-1 protein suggested that the co-repressor recruitment mediated through WRPW domain of Hes-1 has
contributed to the repressive effect. Our results clearly demonstrate a new and unique role for canonical Notch signaling
through Hes-1, in neurotransmitter/subtype fate specification of neurons in addition to its known functional role in proliferation/maintenance
of neural progenitors. 相似文献
264.
Taal HR St Pourcain B Thiering E Das S Mook-Kanamori DO Warrington NM Kaakinen M Kreiner-Møller E Bradfield JP Freathy RM Geller F Guxens M Cousminer DL Kerkhof M Timpson NJ Ikram MA Beilin LJ Bønnelykke K Buxton JL Charoen P Chawes BL Eriksson J Evans DM Hofman A Kemp JP Kim CE Klopp N Lahti J Lye SJ McMahon G Mentch FD Müller-Nurasyid M O'Reilly PF Prokopenko I Rivadeneira F Steegers EA Sunyer J Tiesler C Yaghootkar H;Cohorts for Heart Aging Research in Genetic Epidemiology Consortium 《Nature genetics》2012,44(5):532-538
To identify genetic variants associated with head circumference in infancy, we performed a meta-analysis of seven genome-wide association studies (GWAS) (N = 10,768 individuals of European ancestry enrolled in pregnancy and/or birth cohorts) and followed up three lead signals in six replication studies (combined N = 19,089). rs7980687 on chromosome 12q24 (P = 8.1 × 10(-9)) and rs1042725 on chromosome 12q15 (P = 2.8 × 10(-10)) were robustly associated with head circumference in infancy. Although these loci have previously been associated with adult height, their effects on infant head circumference were largely independent of height (P = 3.8 × 10(-7) for rs7980687 and P = 1.3 × 10(-7) for rs1042725 after adjustment for infant height). A third signal, rs11655470 on chromosome 17q21, showed suggestive evidence of association with head circumference (P = 3.9 × 10(-6)). SNPs correlated to the 17q21 signal have shown genome-wide association with adult intracranial volume, Parkinson's disease and other neurodegenerative diseases, indicating that a common genetic variant in this region might link early brain growth with neurological disease in later life. 相似文献
265.
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268.
Perry GH Dominy NJ Claw KG Lee AS Fiegler H Redon R Werner J Villanea FA Mountain JL Misra R Carter NP Lee C Stone AC 《Nature genetics》2007,39(10):1256-1260
Starch consumption is a prominent characteristic of agricultural societies and hunter-gatherers in arid environments. In contrast, rainforest and circum-arctic hunter-gatherers and some pastoralists consume much less starch. This behavioral variation raises the possibility that different selective pressures have acted on amylase, the enzyme responsible for starch hydrolysis. We found that copy number of the salivary amylase gene (AMY1) is correlated positively with salivary amylase protein level and that individuals from populations with high-starch diets have, on average, more AMY1 copies than those with traditionally low-starch diets. Comparisons with other loci in a subset of these populations suggest that the extent of AMY1 copy number differentiation is highly unusual. This example of positive selection on a copy number-variable gene is, to our knowledge, one of the first discovered in the human genome. Higher AMY1 copy numbers and protein levels probably improve the digestion of starchy foods and may buffer against the fitness-reducing effects of intestinal disease. 相似文献
269.
Heid IM Jackson AU Randall JC Winkler TW Qi L Steinthorsdottir V Thorleifsson G Zillikens MC Speliotes EK Mägi R Workalemahu T White CC Bouatia-Naji N Harris TB Berndt SI Ingelsson E Willer CJ Weedon MN Luan J Vedantam S Esko T Kilpeläinen TO Kutalik Z Li S Monda KL Dixon AL Holmes CC Kaplan LM Liang L Min JL Moffatt MF Molony C Nicholson G Schadt EE Zondervan KT Feitosa MF Ferreira T Lango Allen H Weyant RJ Wheeler E Wood AR;MAGIC Estrada K Goddard ME Lettre G Mangino M Nyholt DR Purcell S 《Nature genetics》2010,42(11):949-960
Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10?? to P = 1.8 × 10???) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10?3 to P = 1.2 × 10?13). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions. 相似文献
270.
During spatial exploration, hippocampal neurons show a sequential firing pattern in which individual neurons fire specifically at particular locations along the animal's trajectory (place cells). According to the dominant model of hippocampal cell assembly activity, place cell firing order is established for the first time during exploration, to encode the spatial experience, and is subsequently replayed during rest or slow-wave sleep for consolidation of the encoded experience. Here we report that temporal sequences of firing of place cells expressed during a novel spatial experience occurred on a significant number of occasions during the resting or sleeping period preceding the experience. This phenomenon, which is called preplay, occurred in disjunction with sequences of replay of a familiar experience. These results suggest that internal neuronal dynamics during resting or sleep organize hippocampal cellular assemblies into temporal sequences that contribute to the encoding of a related novel experience occurring in the future. 相似文献