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51.
Abstract In this paper we report the results of extensive Monte Carlo simulations of a pure fluid of Buckingham modified exponential-six molecules. Data are presented for the configurational energy and pressure covering a wide range of temperatures and densities. These data are interpreted using the generalized van der Waals partition function with a novel separation into free volume and mean potential terms. We find, surprisingly, that the Buckingham fluid is described by a simple van der Waals-like equation of state provided that the b parameter is temperature dependent and chosen in a theoretically correct manner. 相似文献
52.
Cynthia C. M. Deaton Kristen Dodd Katherine Drennon Jack Nagle 《Science activities》2013,50(4):128-137
“Prey Play” is an interactive role-play activity that provides fifth-grade students with opportunities to examine predator–prey interactions. This four-part, role-play activity allows students to take on the role of a predator and prey as they reflect on the behaviors animals exhibit as they collect food and interact with one another, as well as limiting factors. Through this activity, students will enhance their communication and observation skills and showcase their creativity. 相似文献
53.
Elisabeth C. Charman Ken W. Smith Ian A. Dillon Steve Dodd Derek J. Gruar Andrew Cristinacce 《Bird Study》2013,60(3):255-265
Capsule The breeding success of Lesser Spotted Woodpeckers Dendrocopos minor is now lower in England than previously reported and also lower than found in studies elsewhere in Europe. Aims To quantify the breeding success and identify the causes of nest failure. To test the hypotheses that breeding success is related to aspects of food limitation and parental care, and inclement weather during the nesting period, or to interactions with Great Spotted Woodpeckers. Methods Nests were monitored in three regions of England, recording survival and causes of failure. We measured aspects of food limitation and parental care, rainfall and Great Spotted Woodpecker interactions at nests, to explore whether there was any evidence that these factors were related to breeding success. We compared results to other studies from the UK and continental Europe. Results Nest survival was 52%. The average number of chicks produced from successful nests was 2.8. Chick-stage daily nest survival was positively related to provisioning rates, indicating that food supply may be limiting. The most common cause of nest failure was presumed starvation of chicks after the disappearance of an adult. Some females ceased visiting nests, leaving provisioning solely to the male. This behaviour has been reported elsewhere in Europe, but in the present study males were unable to compensate fully by increasing their provisioning rates, leading to poor nest survival. Provisioning rates and chick-stage daily nest survival were negatively associated with rainfall. Nest predation by Great Spotted Woodpeckers occurred but was a less frequent cause of failure. Aggressive interactions were recorded between the two woodpecker species but these were unrelated to breeding parameters. Conclusions Low breeding success is most probably related to food shortages in the breeding period. Simple population modelling using parameters from the present study and from published work shows that if the low productivity that we have observed is replicated throughout Britain, it would be sufficient to account for the observed population decline. However, the possibility that survival rates are also low cannot be ruled out. 相似文献
54.
Chunjian Liu James Lin Gerry Everlof Christoph Gesenberg Hongjian Zhang Punit H. Marathe Mary Malley Michael A. Galella Murray Mckinnon John H. Dodd Joel C. Barrish Gary L. Schieven Katerina Leftheris 《Bioorganic & medicinal chemistry letters》2013,23(10):3028-3033
A series of carbamoylmethylene linked prodrugs of 1 (BMS-582949), a clinical p38α inhibitor, were synthesized and evaluated. Though the phosphoryloxymethylene carbamates (3, 4, and 5) and α-aminoacyloxymethylene carbamates (22, 23, and 26) were found unstable at neutral pH values, fumaric acid derived acyloxymethylene carbamates (2, 28, and 31) were highly stable under both acidic and neutral conditions. Prodrugs 2 and 31 were also highly soluble at both acidic and neutral pH values. At a solution dose of 14.2 mpk (equivalent to 10 mpk of 1), 2 gave essentially the same exposure of 1 compared to dosing 10 mpk of 1 itself. At a suspension dose of 142 mpk (equivalent to 100 mpk of 1), 2 demonstrated that it could overcome the solubility issue associated with 1 and provide a much higher exposure of 1. To our knowledge, the unique type of prodrugs like 2, 28, and 31 was not reported in the past and could represent a novel prodrug approach for secondary amides, a class of molecules frequently identified as drug candidates. 相似文献
55.
Christine Miaskowski Marylin Dodd Steven M. Paul Claudia West Deborah Hamolsky Gary Abrams Bruce A. Cooper Charles Elboim John Neuhaus Brian L. Schmidt Betty Smoot Bradley E. Aouizerat 《PloS one》2013,8(4)
The purposes of this study were to evaluate for differences in phenotypic and genotypic characteristics in women who did and did not develop lymphedema (LE) following breast cancer treatment. Breast cancer patients completed a number of self-report questionnaires. LE was evaluated using bioimpedance spectroscopy. Genotyping was done using a custom genotyping array. No differences were found between patients with (n = 155) and without LE (n = 387) for the majority of the demographic and clinical characteristics. Patients with LE had a significantly higher body mass index, more advanced disease and a higher number of lymph nodes removed. Genetic associations were identified for four genes (i.e., lymphocyte cytosolic protein 2 (rs315721), neuropilin-2 (rs849530), protein tyrosine kinase (rs158689), vascular cell adhesion molecule 1 (rs3176861)) and three haplotypes (i.e., Forkhead box protein C2 (haplotype A03), neuropilin-2 (haplotype F03), vascular endothelial growth factor-C (haplotype B03)) involved in lymphangiogensis and angiogenesis. These genetic associations suggest a role for a number of lymphatic and angiogenic genes in the development of LE following breast cancer treatment. 相似文献
56.
Joanna F. Dipnall Julie A. Pasco Michael Berk Lana J. Williams Seetal Dodd Felice N. Jacka Denny Meyer 《PloS one》2016,11(2)
Background
Atheoretical large-scale data mining techniques using machine learning algorithms have promise in the analysis of large epidemiological datasets. This study illustrates the use of a hybrid methodology for variable selection that took account of missing data and complex survey design to identify key biomarkers associated with depression from a large epidemiological study.Methods
The study used a three-step methodology amalgamating multiple imputation, a machine learning boosted regression algorithm and logistic regression, to identify key biomarkers associated with depression in the National Health and Nutrition Examination Study (2009–2010). Depression was measured using the Patient Health Questionnaire-9 and 67 biomarkers were analysed. Covariates in this study included gender, age, race, smoking, food security, Poverty Income Ratio, Body Mass Index, physical activity, alcohol use, medical conditions and medications. The final imputed weighted multiple logistic regression model included possible confounders and moderators.Results
After the creation of 20 imputation data sets from multiple chained regression sequences, machine learning boosted regression initially identified 21 biomarkers associated with depression. Using traditional logistic regression methods, including controlling for possible confounders and moderators, a final set of three biomarkers were selected. The final three biomarkers from the novel hybrid variable selection methodology were red cell distribution width (OR 1.15; 95% CI 1.01, 1.30), serum glucose (OR 1.01; 95% CI 1.00, 1.01) and total bilirubin (OR 0.12; 95% CI 0.05, 0.28). Significant interactions were found between total bilirubin with Mexican American/Hispanic group (p = 0.016), and current smokers (p<0.001).Conclusion
The systematic use of a hybrid methodology for variable selection, fusing data mining techniques using a machine learning algorithm with traditional statistical modelling, accounted for missing data and complex survey sampling methodology and was demonstrated to be a useful tool for detecting three biomarkers associated with depression for future hypothesis generation: red cell distribution width, serum glucose and total bilirubin. 相似文献57.
58.
59.
Validation of Zebrafish (Danio redo) Reference Genes for Quantitative Real-time RT-PCR Normalization 总被引:2,自引:0,他引:2
The normalization of quantitative real time RT-PCR (qRT-PCR) is important to obtain accurate gene expression data. The most common method for qRT-PCR normalization is to use reference, or housekeeping genes. However, there is emerging evidence that even reference genes can be regulated under different conditions, qRT-PCR has only recently been used in terms of zebrafish gene expression studies and there is no validated set of reference genes. This study characterizes the expression of nine possible reference genes during zebrafish embryonic development and in a zebrafish tissue panel. All nine reference genes exhibited variable expression. The fl-actin, EFlot and Rpll3ot genes comprise a validated reference gene panel for zebrafish developmental time course studies, and the EF1 or, Rpll3α and 18S rRNA genes are more suitable as a reference gene panel for zebrafish tissue analysis. Importantly, the zebrafish GAPDH gene appears unsuitable as reference gene for both types of studies. 相似文献
60.
Nicky HGM Peters Inne HM Borel Rinkes Willem PTM Mali Maurice AAJ van den Bosch Remmert K Storm Peter W Plaisier Erwin de Boer Adriaan J van Overbeeke Petra HM Peeters 《Trials》2007,8(1):1-7