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排序方式: 共有5135条查询结果,搜索用时 15 毫秒
91.
Nexø BA Christensen T Frederiksen J Møller-Larsen A Oturai AB Villesen P Hansen B Nissen KK Laska MJ Petersen TS Bonnesen S Hedemand A Wu T Wang X Zhang X Brudek T Maric R Søndergaard HB Sellebjerg F Brusgaard K Kjeldbjerg AL Rasmussen HB Nielsen AL Nyegaard M Petersen T Børglum AD Pedersen FS 《PloS one》2011,6(2):e16652
We have investigated the role of human endogenous retroviruses in multiple sclerosis by analyzing the DNA of patients and controls in 4 cohorts for associations between multiple sclerosis and polymorphisms near viral restriction genes or near endogenous retroviral loci with one or more intact or almost-intact genes. We found that SNPs in the gene TRIM5 were inversely correlated with disease. Conversely, SNPs around one retroviral locus, HERV-Fc1, showed a highly significant association with disease. The latter association was limited to a narrow region that contains no other known genes. We conclude that HERV-Fc1 and TRIM5 play a role in the etiology of multiple sclerosis. If these results are confirmed, they point to new modes of treatment for multiple sclerosis. 相似文献
92.
Anders Telenius 《Nordic Journal of Botany》2011,29(3):378-381
Abstract To the benefit of taxonomists, systematists, ecologists, conservationists and the interested general public community GBIF (the Global Biodiversity Information Facility) now offers more than 280 million records from biological and geological collections and observation data bases worldwide. Taxonomic revisions, phylogenetic analyses, large scale ecological modelling, and decisionmaking in conservation and planning issues are simplified and may be based on better background knowledge than ever before using the central GBIF portal at http://www.gbif.org/ or regional portals hosted by the different GBIF‐nodes. 相似文献
93.
Jannik E. Jakobsen Juan Li Peter M. Kragh Brian Moldt Lin Lin Ying Liu Mette Schmidt Kjeld Dahl Winther Brian Dall Schyth Ida E. Holm G��bor Vajta Lars Bolund Henrik Callesen Arne Lund J?rgensen Anders Lade Nielsen Jacob Giehm Mikkelsen 《Transgenic research》2011,20(3):533-545
Modelling of human disease in genetically engineered pigs provides unique possibilities in biomedical research and in studies of disease intervention. Establishment of methodologies that allow efficient gene insertion by non-viral gene carriers is an important step towards development of new disease models. In this report, we present transgenic pigs created by Sleeping Beauty DNA transposition in primary porcine fibroblasts in combination with somatic cell nuclear transfer by handmade cloning. Göttingen minipigs expressing green fluorescent protein are produced by transgenesis with DNA transposon vectors carrying the transgene driven by the human ubiquitin C promoter. These animals carry multiple copies (from 8 to 13) of the transgene and show systemic transgene expression. Transgene-expressing pigs carry both transposase-catalyzed insertions and at least one copy of randomly inserted plasmid DNA. Our findings illustrate critical issues related to DNA transposon-directed transgenesis, including coincidental plasmid insertion and relatively low Sleeping Beauty transposition activity in porcine fibroblasts, but also provide a platform for future development of porcine disease models using the Sleeping Beauty gene insertion technology. 相似文献
94.
Jurgen Vercauteren Gertjan Beheydt Mattia Prosperi Pieter Libin Stijn Imbrechts Ricardo Camacho Bonaventura Clotet Andrea De Luca Zehava Grossman Rolf Kaiser Anders S?nnerborg Carlo Torti Eric Van Wijngaerden Jean-Claude Schmit Maurizio Zazzi Anna-Maria Geretti Anne-Mieke Vandamme Kristel Van Laethem 《PloS one》2013,8(4)
Introduction
Clinically evaluating genotypic interpretation systems is essential to provide optimal guidance in designing potent individualized HIV-regimens. This study aimed at investigating the ability of the latest Rega algorithm to predict virological response on a short and longer period.Materials & Methods
9231 treatment changes episodes were extracted from an integrated patient database. The virological response after 8, 24 and 48 weeks was dichotomized to success and failure. Success was defined as a viral load below 50 copies/ml or alternatively, a 2 log decrease from the baseline viral load at 8 weeks. The predictive ability of Rega version 8 was analysed in comparison with that of previous evaluated version Rega 5 and two other algorithms (ANRS v2011.05 and Stanford HIVdb v6.0.11). A logistic model based on the genotypic susceptibility score was used to predict virological response, and additionally, confounding factors were added to the model. Performance of the models was compared using the area under the ROC curve (AUC) and a Wilcoxon signed-rank test.Results
Per unit increase of the GSS reported by Rega 8, the odds on having a successful therapy response on week 8 increased significantly by 81% (OR = 1.81, CI = [1.76–1.86]), on week 24 by 73% (OR = 1.73, CI = [1.69–1.78]) and on week 48 by 85% (OR = 1.85, CI = [1.80–1.91]). No significant differences in AUC were found between the performance of Rega 8 and Rega 5, ANRS v2011.05 and Stanford HIVdb v6.0.11, however Rega 8 had the highest sensitivity: 76.9%, 76.5% and 77.2% on 8, 24 and 48 weeks respectively. Inclusion of additional factors increased the performance significantly.Conclusion
Rega 8 is a significant predictor for virological response with a better sensitivity than previously, and with rules for recently approved drugs. Additional variables should be taken into account to ensure an effective regimen. 相似文献95.
Drought signal transduction in plants 总被引:5,自引:0,他引:5
Anders B. Jensen Peter K. Busk Mercé Figueras M. Mar Albà Giovanna Peracchia Ramon Messeguer Adela Goday Montserrat Pagès 《Plant Growth Regulation》1996,20(2):105-110
Water deficit is one of the most common environmental limitations of crop productivity by affecting growth through alterations in metabolism and gene expression. The mechanisms involved in drought perception and signal transduction pathways are poorly understood. The participation of the plant hormone abscisic acid (ABA) has been well established. ABA levels increase when there are changes in the environment that result in cellular dehydration. Different approaches have been taken to understanding the molecular responses to desiccation and how ABA regulates gene expression. Recent efforts have identified particular topics of importance in the dissection of the signal transduction pathway which are summarized as follows: physiological approaches: identification of signalling molecules. Genetic approaches: the use of mutants, and Molecular approaches: promoter analysis. 相似文献
96.
Lysosomes and microsomes were isolated from rat liver and microinjected into the cytoplasm of HeLa cells. The fate of the transplanted organelles and their effects on the recipient cells were followed in the electron microscope at various time intervals after administration. Needle injection with buffer or sucrose did not seem to evoke any ultrastructural alterations, such as induced autophagy or other signs of sublethal cell injury. Recipients of microinjected cell organelles elicited a rapid and conspicuous increase in membrane-bounded cytoplasmic vacuoles, concomitant with the disappearance of the injected material. Golgi complexes became abundant with many small vesicles clustering around their cisternae. The volume density of the lysosomal compartment increased 2-3-fold after organelle injection as compared with control-injected (0.3 M sucrose) or noninjected cells. Our preliminary results show that isolated cell organelles can be microinjected into cells n culture and indicate that the microinjected organelles were segregated from the cytoplasm into membrane-bounded vacuoles probably through autophagolysosome formation. Thus, this technique offers an additional approach for studies on the segregation and degradation of cell organelles in somatic cells and may enable more detailed analyses on the mechanisms of autophagic sequestration of specific cell organelles. 相似文献
97.
Hedvig E. L?fdahl Juan Du Anders N?sman Emilia Andersson Carlos A. Rubio Yunxia Lu Torbj?rn Ramqvist Tina Dalianis Jesper Lagergren Hanna Dahlstrand 《PloS one》2012,7(10)
Background
The prevalence and role of human papillomavirus (HPV) in the aetiology of oesophageal squamous cell carcinoma is uncertain. Based on the presence of HPV in the oral cavity and its causal association with squamous cell carcinoma of the oropharynx, we hypothesised that HPV is more strongly associated with proximal than distal oesophageal squamous cell carcinoma.Methods
A population-based study comparing HPV infection in relation to tumour site in patients diagnosed with oesophageal squamous cell carcinomas in the Stockholm County in 1999–2006. Multiplex polymerase chain reaction genotyping (PCR) with Luminex was conducted on pre-treatment endoscopic biopsies to identify type specify HPV. Carcinogenic activity of HPV was assessed by p16INK4a expression. Multivariable logistic regression was used to calculate odds ratios and 95% confidence intervals.Results
Among 204 patients, 20 (10%) had tumours harbouring HPV DNA, almost all (90%) of HPV high-risk type, mainly HPV16. Tumours containing HPV were not overrepresented in the upper compared to the middle or lower third of the oesophagus (odds ratio 0.6, 95% confidence interval 0.2–1.9). P16INK4a expression was similarly common (24% and 16%) in the HPV-positive and HPV-negative groups.Conclusion
This study found a limited presence of HPV in oesophageal squamous cell carcinoma of uncertain oncogenic relevance and did not demonstrate that HPV was more strongly associated with proximal than distal tumours. 相似文献98.
Andersson M Andersson J Sellborn A Berglin M Nilsson B Elwing H 《Biosensors & bioelectronics》2005,21(1):79-86
A recently developed variant of quartz crystal microbalance (QCM) called QCM-with dissipation monitoring (QCM-D) allows simultaneous and simple measurements of changes in adsorbed mass as well as the viscoelastic property (D-factor) of deposited protein layers on the sensor surface. We have taken the QCM-D technology a step further and demonstrated its advantages in the study of protein assembly as a consequence of surface induced immune complement activation, or contact activated blood coagulation. In the present study we have continued our QCM-D investigations of surface assembly of fibrin clot formation and complement activation and incubated differently modified quartz sensor surfaces in blood plasma and sera. Polymer surfaces used were spin-coated polyethylene, poly(ethylene terephtalate), poly(methylmetacrylate) and poly(dimethylsiloxane). Also used were sputtered titanium and heparin grafted surfaces. In this investigation we found that we could describe the surface induced coagulation with four independent parameters: (1) Time of onset of coagulation, (2) fibrin deposition rate, (3) total frequency shift at stable plateau, and (4) fibrin clot density. The most important finding was that the blood plasma clot density can be assessed with the use of D determinations and that the clot density varied significantly with the chemical composition of the surface. However, the D-factor did not give any new analytical information about the possible complement activation mechanisms. Nevertheless, the QCM-D was found to be a reliable tool for the analysis of surface induced complement activation. We also compared the QCM-D technique with traditional enzyme immuno assay (EIA) measurements of soluble products from the surface activation of the complement and coagulation systems. We found that the results from EIA and QCM-D measurements corresponded well for the complement activation but not for the coagulation, probably due to the biological complexity of the coagulation system. 相似文献
99.
Direct action of endocrine disrupting chemicals on human sperm 总被引:1,自引:0,他引:1
Dorte L Egeberg Luis Alvarez Christoph Brenker Anders Rehfeld Hanne Frederiksen Benjamin Wäschle U Benjamin Kaupp Melanie Balbach Dagmar Wachten Niels E Skakkebaek Kristian Almstrup Timo Strünker 《EMBO reports》2014,15(7):758-765
Synthetic endocrine disrupting chemicals (EDCs), omnipresent in food, household, and personal care products, have been implicated in adverse trends in human reproduction, including infertility and increasing demand for assisted reproduction. Here, we study the action of 96 ubiquitous EDCs on human sperm. We show that structurally diverse EDCs activate the sperm‐specific CatSper channel and, thereby, evoke an intracellular Ca2+ increase, a motility response, and acrosomal exocytosis. Moreover, EDCs desensitize sperm for physiological CatSper ligands and cooperate in low‐dose mixtures to elevate Ca2+ levels in sperm. We conclude that EDCs interfere with various sperm functions and, thereby, might impair human fertilization. 相似文献
100.