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排序方式: 共有253条查询结果,搜索用时 15 毫秒
1.
Specific interaction between coronavirus leader RNA and nucleocapsid protein. 总被引:24,自引:20,他引:4 下载免费PDF全文
S A Stohlman R S Baric G N Nelson L H Soe L M Welter R J Deans 《Journal of virology》1988,62(11):4288-4295
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Hardies SC; Martin SL; Voliva CF; Hutchison CA d; Edgell MH 《Molecular biology and evolution》1986,3(2):109-125
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Morphotypes of friable embryogenic maize callus 总被引:1,自引:0,他引:1
Friable, embryogenic callus cultures of maize are normally maintained as a heterogeneous mixture of various morphotypes in different stages of development (Fransz and Schel 1991). With stringent selection during subculture, three Type II callus morphotypes have been enriched and maintained. Cultured tissue segments from the three morphotypes referred to as pre-embryogenic, early embryogenic, and late embryogenic were analyzed using light and scanning electron microscopy. The results suggest a developmental relationship between the three morphotypes. Regeneration studies substantiated that all morphotypes were capable of regenerating through somatic embryogenesis.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- BAP
6-benzylaminopurine
- MS
Murashige and Skoog(1962) Medium
- SEM
Scanning Electron Microscopy
- FAA
Formalin-acetic acid-alcohol 相似文献
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André Welter Joseph Jadot Gaston Dardenne Michel Marlier Jean Casimir 《Phytochemistry》1976,15(5):747-749
A new natural imino-alcohol, 2,5-dihydroxymethyl 3,4-dihydroxypyrrolidine has been isolated from the leaves of Derris elliptica. Its structure was determined by chemical and physical methods. 相似文献
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Interstitial fluid is a solution that bathes and surrounds the human cells and provides them with nutrients and a way of waste removal. It is generally believed that elevated tumor interstitial fluid pressure (IFP) is partly responsible for the poor penetration and distribution of therapeutic agents in solid tumors, but the complex interplay of extravasation, permeabilities, vascular heterogeneities and diffusive and convective drug transport remains poorly understood. Here we consider–with the help of a theoretical model–the tumor IFP, interstitial fluid flow (IFF) and its impact upon drug delivery within tumor depending on biophysical determinants such as vessel network morphology, permeabilities and diffusive vs. convective transport. We developed a vascular tumor growth model, including vessel co-option, regression, and angiogenesis, that we extend here by the interstitium (represented by a porous medium obeying Darcy''s law) and sources (vessels) and sinks (lymphatics) for IFF. With it we compute the spatial variation of the IFP and IFF and determine its correlation with the vascular network morphology and physiological parameters like vessel wall permeability, tissue conductivity, distribution of lymphatics etc. We find that an increased vascular wall conductivity together with a reduction of lymph function leads to increased tumor IFP, but also that the latter does not necessarily imply a decreased extravasation rate: Generally the IF flow rate is positively correlated with the various conductivities in the system. The IFF field is then used to determine the drug distribution after an injection via a convection diffusion reaction equation for intra- and extracellular concentrations with parameters guided by experimental data for the drug Doxorubicin. We observe that the interplay of convective and diffusive drug transport can lead to quite unexpected effects in the presence of a heterogeneous, compartmentalized vasculature. Finally we discuss various strategies to increase drug exposure time of tumor cells. 相似文献
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EO Ogueji CD Nwani SC Iheanacho CE Mbah CO Okeke A Yaji 《African Journal of Aquatic Science》2018,43(3):293-303
Indiscriminate discharge of pharmaceutical waste into the aquatic ecosystem may pose serious health challenges to aquatic biota. The effect of acute exposure to ibuprofen was evaluated using changes in behaviour and haematological parameters under static bio-assay method in Clarias gariepinus. Test specimens were exposed to acute concentrations of ibuprofen (0.28, 0.33, 0.38, 0.43 and 0.48 mg l?1) for 24, 48, 72 and 96 h durations respectively. Behavioural and phenotypic changes were observed in surviving fish. There were significant (p < 0.05) concentration and duration-dependent increases in erythrocyte (RBC), haemoglobin (Hb), pack cell volume (PCV) and leukocytes (WBC) in treated fish compared to the control. Insignificant decreases (p > 0.05) in mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were observed in treated fish compared to the control. Ibuprofen elicited dose and duration- dependent decrease in neutrophil counts with the decreases being significant (p < 0.05) in the higher doses of 0.43 and 0.48 mg l?1. Ibuprofen did not elicit any significant changes in monocytes, basophils and eosinophils. Changes observed in this study showed that ibuprofen negatively affected the health of the fish and we recommend that discharge of ibuprofen into the aquatic environment should be monitored and controlled. 相似文献
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