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991.
Negrin Negrev Yuri Nyagolov Margarita Stefanova Emiliya Stancheva 《Central European Journal of Biology》2011,6(4):518-523
Effects of the hormones of the hypothalamic-pituitary-thyroid axis on some basic parameters of the activity of protein C anticoagulation
pathway in rats are studied. Thyrotropin-releasing hormone (0.06 mg/kg body mass), thyrotropin (1 IU/kg), triiodothyronine
(T3) (0.08 mg/kg), thyroxine (T4) (0.08 mg/kg), administered subcutaneously for three consecutive days on four different groups
of rats increased significantly activated protein C, free protein S and protein S activity, and reduced the soluble endothelial
protein C receptor. Protein C antigen and total protein S were significantly elevated only by thyrotropin-releasing hormone
and thyroid-stimulating hormone, but they were not affected by T3 and T4 treatment. The data indicate the hypothalamic-pituitary-thyroid
axis is involved in the regulation of the protein C anticoagulation pathway in rats by activation of this system, suggesting
a tendency of hypocoagulability. 相似文献
992.
Sergio Rico Ana Yepes Héctor Rodríguez Jorge Santamaría Sergio Antoraz Eva M. Krause Margarita Díaz Ramón I. Santamaría 《PloS one》2014,9(10)
The Two-Component System (TCS) AbrA1/A2 from Streptomyces coelicolor M145 is a negative regulator of antibiotic production and morphological differentiation. In this work we show that it is able to auto-regulate its expression, exerting a positive induction of its own operon promoter, and that its activation is dependent on the presence of iron. The overexpression of the abrA2 response regulator (RR) gene in the mutant ΔabrA1/A2 results in a toxic phenotype. The reason is an excess of phosphorylated AbrA2, as shown by phosphoablative and phosphomimetic AbrA2 mutants. Therefore, non-cognate histidine kinases (HKs) or small phospho-donors may be responsible for AbrA2 phosphorylation in vivo. The results suggest that in the parent strain S. coelicolor M145 the correct amount of phosphorylated AbrA2 is adjusted through the phosphorylation-dephosphorylation activity rate of the HK AbrA1. Furthermore, the ABC transporter system, which is part of the four-gene operon comprising AbrA1/A2, is necessary to de-repress antibiotic production in the TCS null mutant. Finally, in order to test the possible biotechnological applications of the ΔabrA1/A2 strain, we demonstrate that the production of the antitumoral antibiotic oviedomycin is duplicated in this strain as compared with the production obtained in the wild type, showing that this strain is a good host for heterologous antibiotic production. Thus, this genetically modified strain could be interesting for the biotechnology industry. 相似文献
993.
Therese Solstad Elisa Bjørgo Christian J. Koehler Margarita Strozynski Knut Martin Torgersen Kjetil Taskén Bernd Thiede 《Proteomics》2010,10(15):2758-2768
Several lines of evidence suggest that detergent‐resistant membranes (DRMs) (also known as lipid rafts and glycosphingolipid‐enriched microdomains) may have a role in signaling pathways of apoptosis. Here, we developed a method that combines DRMs isolation and methanol/chloroform extraction with stable isotope labeling with amino acids in cell culture‐based quantitative proteome analysis of DRMs from control and cisplatin‐induced apoptotic Jurkat T cells. This approach enabled us to enrich proteins with a pivotal role in cell signaling of which several were found with increased or decreased amounts in DRMs upon induction of apoptosis. Specifically, we show that three isoforms of protein kinase C (PKC) are regulated differently upon apoptosis. Although PKCα which belongs to the group of conventional PKCs is highly up‐regulated in DRMs, the levels of two novel PKCs, PKCη and PKCθ, are significantly reduced. These alterations/differences in PKC regulation are verified by immunoblotting and confocal microscopy. In addition, a specific enrichment of PKCα in apoptotic blebs and buds is shown. Furthermore, we observe an increased expression of ecto‐PKCα as a result of exposure to cisplatin using flow cytometry. Our results demonstrate that in‐depth proteomic analysis of DRMs provides a tool to study differential localization and regulation of signaling molecules important in health and disease. 相似文献
994.
Isabel Brunet-Galmés Antonio Busquets Arantxa Pe?a Margarita Gomila Balbina Nogales Elena García-Valdés Jorge Lalucat Antonio Bennasar Rafael Bosch 《Journal of bacteriology》2012,194(23):6642-6643
Pseudomonas stutzeri AN10 (CCUG 29243) can be considered a model strain for aerobic naphthalene degradation. We report the complete genome sequence of this bacterium. Its 4.71-Mb chromosome provides insights into other biodegradative capabilities of strain AN10 (i.e., benzoate catabolism) and suggests a high number of horizontal gene transfer events. 相似文献
995.
Yolanda Salda?a-Alvarez María Guadalupe Salas-Martínez Humberto García-Ortiz Angélica Luckie-Duque Gustavo García-Cárdenas Hermenegildo Vicente?o-Ayala Emilio J. Cordova Marcelino Esparza-Aguilar Cecilia Contreras-Cubas Alessandra Carnevale Margarita Chávez-Salda?a Lorena Orozco 《PloS one》2016,11(1)
To evaluate the associations between six single-nucleotide polymorphisms (SNPs) in intron 1 of FTO and body mass index (BMI), a case-control association study of 2314 unrelated Mexican-Mestizo adult subjects was performed. The association between each SNP and BMI was tested using logistic and linear regression adjusted for age, gender, and ancestry and assuming additive, recessive, and dominant effects of the minor allele. Association analysis after BMI stratification showed that all five FTO SNPs (rs1121980, rs17817449, rs3751812, rs9930506, and rs17817449), were significantly associated with obesity class II/III under an additive model (P<0.05). Interestingly, we also documented a genetic model-dependent influence of gender on the effect of FTO variants on increased BMI. Two SNPs were specifically associated in males under a dominant model, while the remainder were associated with females under additive and recessive models (P<0.05). The SNP rs9930506 showed the highest increased in obesity risk in females (odds ratio = 4.4). Linear regression using BMI as a continuous trait also revealed differential FTO SNP contributions. Homozygous individuals for the risk alleles of rs17817449, rs3751812, and rs9930506 were on average 2.18 kg/m2 heavier than homozygous for the wild-type alleles; rs1121980 and rs8044769 showed significant but less-strong effects on BMI (1.54 kg/m2 and 0.9 kg/m2, respectively). Remarkably, rs9930506 also exhibited positive interactions with age and BMI in a gender-dependent manner. Women carrying the minor allele of this variant have a significant increase in BMI by year (0.42 kg/m2, P = 1.17 x 10−10). Linear regression haplotype analysis under an additive model, confirmed that the TGTGC haplotype harboring all five minor alleles, increased the BMI of carriers by 2.36 kg/m2 (P = 1.15 x 10−5). Our data suggest that FTO SNPs make differential contributions to obesity risk and support the hypothesis that gender differences in the mechanisms involving these variants may contribute to disease development. 相似文献
996.
997.
Jesús Aranda Margarita Poza Belén G Pardo Soraya Rumbo Carlos Rumbo José R Parreira Patricia Rodríguez-Velo Germán Bou 《BMC microbiology》2010,10(1):279
Background
Acinetobacter baumannii is a multidrug-resistant bacterium responsible for nosocomial infections in hospitals worldwide. Study of mutant phenotypes is fundamental for understanding gene function. The methodologies developed to inactivate A. baumannii genes are complicated and time-consuming; sometimes result in unstable mutants, and do not enable construction of double (or more) gene knockout mutant strains of A. baumannii. 相似文献998.
Sobol MA Philimonenko VV Philimonenko AA Hozák P 《Histochemistry and cell biology》2012,138(1):167-177
Using quantitative evaluation of immuno-gold labeling and antigen content, we evaluated various automated freeze-substitution protocols used in preparation of biological samples for immunoelectron microscopy. Protein extraction from cryoimmobilized cells was identified as a critical point during the freeze-substitution. The loss of antigens (potentially available for subsequent immuno-gold labeling) was not significantly affected by freezing, while the cryosubstitution with an organic solvent caused a significant loss of antigens. While addition of water can improve visibility of some cell structures, it strengthened the negative effect of cryosubstitution on antigen loss by extraction. This was, however, significantly reversed in the presence of 0.5% glutaraldehyde in the substitution medium. Furthermore, we showed that the level of these changes was antigen-dependent. In conclusion, low concentrations of glutaraldehyde can be generally recommended for cryosubstitution rather than the use of pure solvent, but the exact conditions need to be elaborated individually for certain antigens. 相似文献
999.
1000.
Wu Z Yang C Xiong Y Feng Z Lombardo M Verras A Chabin RM Xu S Tong X Xie D Lassman ME Bhatt UR Garcia-Calvo MM Geissler W Shen Z Chen Q Sinharoy R Hale JJ Tata JR Pinto S Shen DM Colletti SL 《Bioorganic & medicinal chemistry letters》2012,22(4):1774-1778
Efforts to modify the central proline portion of lead compound 4 lead to the discovery of novel prolylcarboxypeptidase (PrCP) inhibitors. Especially, replacement with alanine afforded compound 19 displaying more potent human and mouse PrCP inhibitory activity than 4 and an overall comparable profile. 相似文献