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A F Abdel-Fattah L A Sallam A H El-Refai A Zeinel-Abdin 《Acta biologica Academiae Scientiarum Hungaricae》1975,26(1-2):43-49
The formation of progesterone hydroxylases by Aspergillus niger 173 was investigated. The constitution of the fermentation medium influenced both the yield and the type of enzymes catalyzing the transformation of progesterone. The enzyme yield also varied with the pH value at which induction was performed as well as with the buffer used. The transformation activity of progesterone was more pronounced with mycelia induced in citrate-phosphate than in phosphate buffer. The results demonstrated that induction of 6beta-hydroxylase was favoured at pH values near neutrality while that of 11alpha-hydroxylase in the presence of citrate ions. The transformation activity of progesterone was optimal at pH 5.0. The action of 11alpha-hydroxylase was also optimal at pH 5.0, but other hydroxylase showed pH optima between 2.2 and 4.0. Progesterone concentrations higher than 6 mg in 50 ml reaction mixture was a limiting factor for the rate of transformation activity. 相似文献
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Mohamed F. Sallam Azzam M. Al Ahmed Mahmoud S. Abdel-Dayem Mohamed A. R. Abdullah 《PloS one》2013,8(6)
BackgroundThe mosquito, Culex tritaeniorhynchus Giles is a prevalent and confirmed Rift Valley Fever virus (RVFV) vector. This vector, in association with Aedimorphus arabiensis (Patton), was responsible for causing the outbreak of 2000 in Jazan Province, Saudi Arabia.Conclusion/SignificanceThis model is a first step in understanding the spatial distribution of Cx. tritaeniorhynchus and consequently the risk of RVFV in Saudi Arabia and to assist in planning effective mosquito surveillance and control programs by public health personnel and researchers. 相似文献
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Sallam AA Ramasahayam S Meyer SA El Sayed KA 《Bioorganic & medicinal chemistry》2010,18(21):7446-7457
Bioactive secondary metabolites originating from dibromotyrosine are common in marine sponges, such as sponges of the Aplysina species. Verongiaquinol (1), 3,5-dibromo-1-hydroxy-4-oxocyclohexa-2,5-diene-1-acetamide, and aeroplysinin-1 are examples of such bioactive metabolites. Previous studies have shown the potent antimicrobial as well as cytotoxic properties of verongiaquinol and the anti-angiogenic activity of aeroplysinin-1. The work presented herein shows the design and synthesis of dibromotyrosine-inspired phenolic ester and ether analogues with anti-angiogenic, anti-proliferative and anti-migratory properties and negligible cytotoxicity. Several analogues were synthesized based on docking experiments in the ATP binding site of VEGFR2 and their anti-angiogenic potential and ability to inhibit angiogenesis and prostate cancer proliferation, migration and invasion were evaluated using the chick chorioallantoic membrane (CAM) assay, MTT, wound-healing, and Cultrex® BME cell invasion assay models, respectively. Analogues with high docking scores showed promising anti-angiogenic activity in the CAM assay. In general, ester analogues (5, 6, and 8–10) proved to be of higher anti-migratory activity whereas ether analogues (11–14) showed better anti-proliferative activity. These results demonstrate the potential of dibromotyrosines as promising inhibitory scaffolds for the control of metastatic prostate cancer proliferation and migration. 相似文献
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Horsfield A Sallam MN Drummond FA Williams DJ Schultz RJ 《Journal of economic entomology》2008,101(2):334-340
Inconsistent control of Dermolepida albohirtum (Waterhouse) (Coleoptera: Scarabaeidae) in the period after the removal of organochlorines allowed us to study the impact of climatic variables and insecticide application on subsequent damage in sugarcane (Saccharum spp.). D. albohirtum damage records from the Invicta and Inkerman mill areas of the Burdekin district of North Queensland were compared with climatic averages during spring from 1989 to 2003. D. albohirtum damage demonstrated autocorrelation, indicating that the area of damage will increase from one year to the next if the grub is not effectively controlled. Insecticide use did not significantly impact on the area of damage between 1989 and 2003. Of the climatic variables evaluated, only pan evaporation was significant, and it was inversely related to the subsequent area of grub damage. Therefore, we suggest that weather conditions in spring impact on beetle emergence, feeding, and oviposition. Hot and dry spring weather may reduce beetle activity and ultimately the severity of crop damage, whereas wet and mild spring weather may favor beetle activity and an increase in the area of potential crop damage. 相似文献