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921.
922.
The primary aim of this paper is to select an appropriate power transformation when we use ARMA models for a given time series. We propose a Bayesian procedure for estimating the power transformation as well as other parameters in time series models. The posterior distributions of interest are obtained utilizing the Gibbs sampler, a Markov Chain Monte Carlo (MCMC) method. The proposed methodology is illustrated with two real data sets. The performance of the proposed procedure is compared with other competing procedures. © 1997 John Wiley & Sons, Ltd. 相似文献
923.
924.
Eunah Kim Joon Hyun Kim Keunhee Seo Ka Young Hong Seon Woo A. An Junyoung Kwon Seung-Jae V. Lee Sung Key Jang 《Cellular and molecular life sciences : CMLS》2018,75(23):4287-4300
The initiator tRNA (Met-tRNA i Met ) at the P site of the small ribosomal subunit plays an important role in the recognition of an mRNA start codon. In bacteria, the initiator tRNA carrier, IF2, facilitates the positioning of Met-tRNA i Met on the small ribosomal subunit. Eukarya contain the Met-tRNA i Met carrier, eIF2 (unrelated to IF2), whose carrier activity is inhibited under stress conditions by the phosphorylation of its α-subunit by stress-activated eIF2α kinases. The stress-resistant initiator tRNA carrier, eIF2A, was recently uncovered and shown to load Met-tRNA i Met on the 40S ribosomal subunit associated with a stress-resistant mRNA under stress conditions. Here, we report that eIF2A interacts and functionally cooperates with eIF5B (a homolog of IF2), and we describe the functional domains of eIF2A that are required for its binding of Met-tRNA i Met , eIF5B, and a stress-resistant mRNA. The results indicate that the eukaryotic eIF5B–eIF2A complex functionally mimics the bacterial IF2 containing ribosome-, GTP-, and initiator tRNA-binding domains in a single polypeptide. 相似文献
925.
International Stroke Genetics Consortium 《Nature genetics》2012,44(3):328-333
Genetic factors have been implicated in stroke risk, but few replicated associations have been reported. We conducted a genome-wide association study (GWAS) for ischemic stroke and its subtypes in 3,548 affected individuals and 5,972 controls, all of European ancestry. Replication of potential signals was performed in 5,859 affected individuals and 6,281 controls. We replicated previous associations for cardioembolic stroke near PITX2 and ZFHX3 and for large vessel stroke at a 9p21 locus. We identified a new association for large vessel stroke within HDAC9 (encoding histone deacetylase 9) on chromosome 7p21.1 (including further replication in an additional 735 affected individuals and 28,583 controls) (rs11984041; combined P = 1.87 × 10(-11); odds ratio (OR) = 1.42, 95% confidence interval (CI) = 1.28-1.57). All four loci exhibited evidence for heterogeneity of effect across the stroke subtypes, with some and possibly all affecting risk for only one subtype. This suggests distinct genetic architectures for different stroke subtypes. 相似文献
926.
Sansone SA Rocca-Serra P Field D Maguire E Taylor C Hofmann O Fang H Neumann S Tong W Amaral-Zettler L Begley K Booth T Bougueleret L Burns G Chapman B Clark T Coleman LA Copeland J Das S de Daruvar A de Matos P Dix I Edmunds S Evelo CT Forster MJ Gaudet P Gilbert J Goble C Griffin JL Jacob D Kleinjans J Harland L Haug K Hermjakob H Ho Sui SJ Laederach A Liang S Marshall S McGrath A Merrill E Reilly D Roux M Shamu CE Shang CA Steinbeck C Trefethen A Williams-Jones B Wolstencroft K Xenarios I 《Nature genetics》2012,44(2):121-126
To make full use of research data, the bioscience community needs to adopt technologies and reward mechanisms that support interoperability and promote the growth of an open 'data commoning' culture. Here we describe the prerequisites for data commoning and present an established and growing ecosystem of solutions using the shared 'Investigation-Study-Assay' framework to support that vision. 相似文献
927.
Lee JH Huynh M Silhavy JL Kim S Dixon-Salazar T Heiberg A Scott E Bafna V Hill KJ Collazo A Funari V Russ C Gabriel SB Mathern GW Gleeson JG 《Nature genetics》2012,44(8):941-945
De novo somatic mutations in focal areas are well documented in diseases such as neoplasia but are rarely reported in malformation of the developing brain. Hemimegalencephaly (HME) is characterized by overgrowth of either one of the two cerebral hemispheres. The molecular etiology of HME remains a mystery. The intractable epilepsy that is associated with HME can be relieved by the surgical treatment hemispherectomy, allowing sampling of diseased tissue. Exome sequencing and mass spectrometry analysis in paired brain-blood samples from individuals with HME (n = 20 cases) identified de novo somatic mutations in 30% of affected individuals in the PIK3CA, AKT3 and MTOR genes. A recurrent PIK3CA c.1633G>A mutation was found in four separate cases. Identified mutations were present in 8-40% of sequenced alleles in various brain regions and were associated with increased neuronal S6 protein phosphorylation in the brains of affected individuals, indicating aberrant activation of mammalian target of rapamycin (mTOR) signaling. Thus HME is probably a genetically mosaic disease caused by gain of function in phosphatidylinositol 3-kinase (PI3K)-AKT3-mTOR signaling. 相似文献
928.
Jacobs KB Yeager M Zhou W Wacholder S Wang Z Rodriguez-Santiago B Hutchinson A Deng X Liu C Horner MJ Cullen M Epstein CG Burdett L Dean MC Chatterjee N Sampson J Chung CC Kovaks J Gapstur SM Stevens VL Teras LT Gaudet MM Albanes D Weinstein SJ Virtamo J Taylor PR Freedman ND Abnet CC Goldstein AM Hu N Yu K Yuan JM Liao L Ding T Qiao YL Gao YT Koh WP Xiang YB Tang ZZ Fan JH Aldrich MC Amos C Blot WJ Bock CH Gillanders EM Harris CC Haiman CA Henderson BE Kolonel LN Le Marchand L McNeill LH 《Nature genetics》2012,44(6):651-658
In an analysis of 31,717 cancer cases and 26,136 cancer-free controls from 13 genome-wide association studies, we observed large chromosomal abnormalities in a subset of clones in DNA obtained from blood or buccal samples. We observed mosaic abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of >2 Mb in size in autosomes of 517 individuals (0.89%), with abnormal cell proportions of between 7% and 95%. In cancer-free individuals, frequency increased with age, from 0.23% under 50 years to 1.91% between 75 and 79 years (P = 4.8 × 10(-8)). Mosaic abnormalities were more frequent in individuals with solid tumors (0.97% versus 0.74% in cancer-free individuals; odds ratio (OR) = 1.25; P = 0.016), with stronger association with cases who had DNA collected before diagnosis or treatment (OR = 1.45; P = 0.0005). Detectable mosaicism was also more common in individuals for whom DNA was collected at least 1 year before diagnosis with leukemia compared to cancer-free individuals (OR = 35.4; P = 3.8 × 10(-11)). These findings underscore the time-dependent nature of somatic events in the etiology of cancer and potentially other late-onset diseases. 相似文献
929.
Boros S Xi Q Dimke H van der Kemp AW Tudpor K Verkaart S Lee KP Bindels RJ Hoenderop JG 《Cellular and molecular life sciences : CMLS》2012,69(6):981-992
Tissue transglutaminase (tTG) is a multifunctional Ca2+-dependent enzyme, catalyzing protein crosslinking. The transient receptor potential vanilloid (TRPV) family of cation channels
was recently shown to contribute to the regulation of TG activities in keratinocytes and hence skin barrier formation. In
kidney, where active transcellular Ca2+ transport via TRPV5 predominates, the potential effect of tTG remains unknown. A multitude of factors regulate TRPV5, many
secreted into the pro-urine and acting from the extracellular side. We detected tTG in mouse urine and in the apical medium
of polarized cultures of rabbit connecting tubule and cortical collecting duct (CNT/CCD) cells. Extracellular application
of tTG significantly reduced TRPV5 activity in human embryonic kidney cells transiently expressing the channel. Similarly,
a strong inhibition of transepithelial Ca2+ transport was observed after apical application of purified tTG to polarized rabbit CNT/CCD cells. Furthermore, tTG promoted
the aggregation of the plasma membrane-associated fraction of TRPV5. Using patch clamp analysis, we observed a reduction in
the pore diameter after tTG treatment, suggesting distinct structural changes in TRPV5 upon crosslinking by tTG. As N-linked
glycosylation of TRPV5 is a key step in regulating channel function, we determined the effect of tTG in the N-glycosylation-deficient
TRPV5 mutant. In the absence of N-linked glycosylation, TRPV5 was insensitive to tTG. Taken together, these observations imply
that tTG is a novel extracellular enzyme inhibiting the activity of TRPV5. The inhibition of TRPV5 occurs in an N-glycosylation-dependent
manner, signifying a common final pathway by which distinct extracellular factors regulate channel activity. 相似文献
930.
<正>建立了一种用带有能谱仪的扫描电子显微镜(SEM-EDXA) 测定麦草细胞壁木素分布的方法。讨论了溴化、切片厚度和样品座对定量测定的影响。结果表明,溴对木素的化合不但是专一的,而且也是稳定的;利用薄切片背散射,吸收和荧光对定量测定的影响可以忽略,空间分辩力也可得到弥补。因此,SEM-EDXA技术以较高的准确度提供了定量测定木素分布的信息。 相似文献