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951.
Study of the binding and energy transfer of erbium ion with rhaponticin and its pharmacokinetics application 下载免费PDF全文
Binding and energy transfer of an erbium ion with rhaponticin (RH) was investigated and a simple spectrofluorimetric method was developed for determination of RH using an Er3+ probe. Results using spectra, chromatography and density functional theory (DFT) indicated that binding of Er3+ to RH occurred at the hydroxyl group of C‐11 and at the methoxy group at C‐12 of the conjugated aromatic ring through hydrogen bonding. Resonance energy transfer (RET) occurred from intramolecular charge transfers (ICT), the binding of RH to Er3+ ion induced fluorescence enhancement (FE) of the Er3+ ion. This method was applied to the pharmacokinetic detection of RH. The main advantages of the proposed method compared with previously reported ones are its simplicity and lower cost. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
952.
Two star‐shaped tetranuclear Ru(II) complexes containing uncoordinated imidazole groups: synthesis,characterization, photophysical and pH sensing properties 下载免费PDF全文
Tetrapodal ligands H4L1 and H4L2 containing imidazole groups have been synthesized by the reaction of 1,10‐phenanthroline‐5,6‐dione with 1,2,4,5‐tetrakis[(4‐formylphenoxy)methyl]benzene and 1,2,4,5‐tetrakis[(3‐formylphenoxy)methyl]benzene, respectively, in presence of NH4OAc. Two star‐shaped complexes [{Ru(bpy)2}4(μ4‐H4L1)](PF6)8 and [{Ru(bpy)2}4(μ4‐H4L2)](PF6)8 (bpy = 2,2′‐bipyridine) have been prepared by refluxing Ru(bpy)2Cl2·2H2O and each ligand in ethylene glycol. The deprotonated complexes [{Ru(bpy)2}4(μ4‐L1)](PF6)4 and [{Ru(bpy)2}4(μ4‐L2)](PF6)4 have been obtained by the reaction of sodium methoxide with [{Ru(bpy)2}4(μ4‐H4L1)](PF6)8 and [{Ru(bpy)2}4(μ4‐H4L2)](PF6)8, respectively, in methanol. The pH effects on the UV–vis light absorption and emission spectra of both complexes have been studied, and ground‐ and excited‐state ionization constants of both complexes have been derived. The photophysical properties of both complexes are strongly dependent on the solution pH. They act as proton‐induced off–on–off luminescent sensors through two successive deprotonation processes of imidazole groups, with a maximum on–off ratio of 8 in buffer solution at room temperature. Theoretical calculations for the highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LOMO) orbitals of bridging ligand are also presented for plausible explanations of the fluorescence changes. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
953.
You Li Hisato Yagi Ezenwa Obi Onuoha Rama Rao Damerla Richard Francis Yoshiyuki Furutani Muhammad Tariq Stephen M. King Gregory Hendricks Cheng Cui Manush Saydmohammed Dong Min Lee Maliha Zahid Iman Sami Linda Leatherbury Gregory J. Pazour Stephanie M. Ware Toshio Nakanishi Elizabeth Goldmuntz Michael Tsang Cecilia W. Lo 《PLoS genetics》2016,12(2)
Heterotaxy, a birth defect involving left-right patterning defects, and primary ciliary dyskinesia (PCD), a sinopulmonary disease with dyskinetic/immotile cilia in the airway are seemingly disparate diseases. However, they have an overlapping genetic etiology involving mutations in cilia genes, a reflection of the common requirement for motile cilia in left-right patterning and airway clearance. While PCD is a monogenic recessive disorder, heterotaxy has a more complex, largely non-monogenic etiology. In this study, we show mutations in the novel dynein gene DNAH6 can cause heterotaxy and ciliary dysfunction similar to PCD. We provide the first evidence that trans-heterozygous interactions between DNAH6 and other PCD genes potentially can cause heterotaxy. DNAH6 was initially identified as a candidate heterotaxy/PCD gene by filtering exome-sequencing data from 25 heterotaxy patients stratified by whether they have airway motile cilia defects. dnah6 morpholino knockdown in zebrafish disrupted motile cilia in Kupffer’s vesicle required for left-right patterning and caused heterotaxy with abnormal cardiac/gut looping. Similarly DNAH6 shRNA knockdown disrupted motile cilia in human and mouse respiratory epithelia. Notably a heterotaxy patient harboring heterozygous DNAH6 mutation was identified to also carry a rare heterozygous PCD-causing DNAI1 mutation, suggesting a DNAH6/DNAI1 trans-heterozygous interaction. Furthermore, sequencing of 149 additional heterotaxy patients showed 5 of 6 patients with heterozygous DNAH6 mutations also had heterozygous mutations in DNAH5 or other PCD genes. We functionally assayed for DNAH6/DNAH5 and DNAH6/DNAI1 trans-heterozygous interactions using subthreshold double-morpholino knockdown in zebrafish and showed this caused heterotaxy. Similarly, subthreshold siRNA knockdown of Dnah6 in heterozygous Dnah5 or Dnai1 mutant mouse respiratory epithelia disrupted motile cilia function. Together, these findings support an oligogenic disease model with broad relevance for further interrogating the genetic etiology of human ciliopathies. 相似文献
954.
Sexual dimorphism results from sex-biased gene expression, which evolves when selection acts differently on males and females. While there is an intimate connection between sex-biased gene expression and sex-specific selection, few empirical studies have studied this relationship directly. Here we compare the two on a genome-wide scale in humans and flies. We find a distinctive “Twin Peaks” pattern in humans that relates the strength of sex-specific selection, quantified by genetic divergence between male and female adults at autosomal loci, to the degree of sex-biased expression. Genes with intermediate degrees of sex-biased expression show evidence of ongoing sex-specific selection, while genes with either little or completely sex-biased expression do not. This pattern apparently results from differential viability selection in males and females acting in the current generation. The Twin Peaks pattern is also found in Drosophila using a different measure of sex-specific selection acting on fertility. We develop a simple model that successfully recapitulates the Twin Peaks. Our results suggest that many genes with intermediate sex-biased expression experience ongoing sex-specific selection in humans and flies. 相似文献
955.
Steve C. N. Hui Jean-Philippe Pialasse Judy Y. H. Wong Tsz-ping Lam Bobby K. W. Ng Jack C. Y. Cheng Winnie C. W. Chu 《Scoliosis》2016,11(1):46
Background
Patients with adolescent idiopathic scoliosis (AIS) frequently receive x-ray imaging at diagnosis and subsequent follow monitoring. The ionizing radiation exposure has accumulated through their development stage and the effect of radiation to this young vulnerable group of patients is uncertain. To achieve the ALARA (as low as reasonably achievable) concept of radiation dose in medical imaging, a slot-scanning x-ray technique by the EOS system has been adopted and the radiation dose using micro-dose protocol was compared with the standard digital radiography on patients with AIS.Methods
Ninety-nine participants with AIS underwent micro-dose EOS and 33 underwent standard digital radiography (DR) for imaging of the whole spine. Entrance-skin dose was measured using thermoluminescent dosimeters (TLD) at three regions (i.e. dorsal sites at the level of sternal notch, nipple line, symphysis pubis). Effective dose and organ dose were calculated by simulation using PCXMC 2.0. Data from two x-ray systems were compared using independent-samples t-test and significance level at 0.05. All TLD measurements were conducted on PA projection only. Image quality was also assessed by two raters using Cobb angle measurement and a set of imaging parameters for optimization purposes.Results
Entrance-skin dose from micro-dose EOS system was 5.9–27.0 times lower at various regions compared with standard DR. The calculated effective dose was 2.6?±?0.5 (μSv) and 67.5?±?23.3 (μSv) from micro-dose and standard DR, respectively. The reduction in the micro-dose was approximately 26 times. Organ doses at thyroid, lung and gonad regions were significantly lower in micro-dose (p?<?0.001). Data were further compared within the different gender groups. Females received significantly higher (p?<?0.001) organ dose at ovaries compared to the testes in males. Patients with AIS received approximately 16–34 times lesser organ dose from micro-dose x-ray as compared with the standard DR. There was no significant difference in overall rating of imaging quality between EOS and DR. Micro-dose protocol provided enough quality to perform consistent measurement on Cobb angle.Conclusions
Entrance-skin dose, effective dose and organ dose were significantly reduced in micro-dose x-ray. The effective dose of a single micro-dose x-ray (2.6 μSv) was less than a day of background radiation. As AIS patients require periodic x-ray follow up for surveillance of curve progression, clinical use of micro-dose x-ray system is beneficial for these young patients to reduce the intake of ionizing radiation.956.
Xiaobei Wang Huaixu Cheng Mingsheng Lu Yaowei Fang Yuliang Jiao Weijuan Li 《Biofouling》2016,32(10):1223-1233
Dental plaque is a biofilm of water-soluble and water-insoluble polysaccharides, produced primarily by Streptococcus mutans. Dextranase can inhibit biofilm formation. Here, a dextranase gene from the marine microorganism Arthrobacter oxydans KQ11-1 is described, and cloned and expressed using E. coli DH5α competent cells. The recombinant enzyme was then purified and its properties were characterized. The optimal temperature and pH were determined to be 60°C and 6.5, respectively. High-performance liquid chromatography data show that the final hydrolysis products were glucose, maltose, maltotriose, and maltotetraose. Thus, dextranase can inhibit the adhesive ability of S. mutans. The minimum biofilm inhibition and reduction concentrations (MBIC50 and MBRC50) of dextranase were 2 U ml?1 and 5 U ml?1, respectively. Scanning electron microscopy and confocal laser scanning microscope (CLSM) observations confirmed that dextranase inhibited biofilm formation and removed previously formed biofilms. 相似文献
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960.
Isolation and Identification of Pathogens Causing Marigold (Tagetes erecta L.) Black Spot in Beijing,China 下载免费PDF全文
Dong‐liang Chen Xi Cheng Chang Luo Ming‐yuan Li Qian‐qian Feng Ji‐ye Yan Cong‐lin Huang 《Journal of Phytopathology》2016,164(7-8):547-553
Black spot leads to great marigold losses worldwide. The disease is characterized by black spots on leaves and stems in its early stages, and the whole plant has black rot at the advanced stage. In this report, 6 of 217 Alternaria strains isolated from lesions of marigold plants in Beijing were randomly selected. The morphological characteristics and a pathogenic tree based on two protein‐coding genes (gpd and alt a 1) indicated that Alternaria tagetica is the causal agent of marigold black spot in Beijing. All six Alternaria strains could successfully re‐infect marigold, but they could not infect carrot or zinnia by either spore spray in a greenhouse or planting experiments in the epidemic area. This is the first report of the A. tagetica pathogen being isolated from marigold in Beijing. 相似文献