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排序方式: 共有843条查询结果,搜索用时 15 毫秒
831.
832.
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834.
Aqueous extract of the root of P. vulgare (PV) produced CNS depressant effect. It decreased the spontaneous motor activity, prolonged the pentobarbitone induced hypnosis, reduced body temperature and increased the reaction time to pain stimuli. PV also caused prevention against supramaximal electroshock and pentylenetetrazol induced seizures. PV showed a positive inotropic and chronotropic effect on perfused frog heart and caused hypotension and tachycardia in anaesthetised dogs. The effects were blocked by propranolol. PV produced dose dependent inhibition of contractions of rabbit small intestine and the effect was blocked by propranolol. PV appears to possess CNS depressant and beta-adrenoceptor agonistic activities. 相似文献
835.
Russian Journal of Bioorganic Chemistry - The abuse of antibiotics in therapy has lead to the development of resistance in the target organisms. The failure of presented antibiotics to control... 相似文献
836.
O. Zethner Bashir M. Khan M. Ismail Chaudhry B. Bolet Sharfuddin Khan Habibullah Khan Hanif Gul L. Øgaard M. Zaman Gul Nawaz 《BioControl》1987,32(5):449-455
Agrotis segetum Schiff granulosis virus (AsGV) propagated in Denmark was supplied against naturally occurring cutworm populations (A. ipsilon and to a less extentA. segetum) in experimental field plots of tobacco, okra, potato and sugar beet in northern Pakistan. AsGV doses varied between 4 ×
107 and 4 × 1011 capsules per m2 plot, and no. of applications between 1 and 3.
One treatment with AsGV did not reduce cutworm damage significantly to tobacco seedlings and potato plants.
Two treatments with AsGV reduced cutworm damage significantly. In tobacco, reduction was 64–82%, in okra and potato 85% and
77% respectively. Damage in sugar beet was reduced 78%.
Three treatments with AsGV dis not reduce damage significantly better than two treatments.
AsGV and the chemical insecticides Tamaran and Dieldrin, andBacillus thuringiensis (Thuricide) were about equally effective, reducing damage by 85%, 79%, 87% and 69%, respectively. No difference was found
between the efficiency of highly purified AsGV to which activated charcoal was added and partially purified AsGV without charcoal.
相似文献
837.
838.
Mir Zaman Hussain Stephen K. Hamilton G. Philip Robertson 《Global Change Biology Bioenergy》2023,15(2):254-263
Without fertilization, harvest of perennial bioenergy cropping systems diminishes soil nutrient stocks, yet the time course of nutrient drawdown has not often been investigated. We analyzed phosphorus (P) inputs (fertilization and atmospheric deposition) and outputs (harvest and leaching losses) over 7 years in three representative biomass crops—switchgrass (Panicum virgatum L.), miscanthus (Miscanthus × giganteus) and hybrid poplar trees (Populus nigra × P. maximowiczii)—as well as in no-till corn (maize; Zea mays L.) for comparison, all planted on former cropland in SW Michigan, USA. Only corn received P fertilizer. Corn (grain and stover), switchgrass, and miscanthus were harvested annually, while poplar was harvested after 6 years. Soil test P (STP; Bray-1 method) was measured in the upper 25 cm of soil annually. Harvest P removal was calculated from tissue P concentration and harvest yield (or annual woody biomass accrual in poplar). Leaching was estimated as total dissolved P concentration in soil solutions sampled beneath the rooting depth (1.25 m), combined with hydrological modeling. Fertilization and harvest were by far the dominant P budget terms for corn, and harvest P removal dominated the P budgets in switchgrass, miscanthus, and poplar, while atmospheric deposition and leaching losses were comparatively insignificant. Because of significant P removal by harvest, the P balances of switchgrass, miscanthus, and poplar were negative and corresponded with decreasing STP, whereas P fertilization compensated for the harvest P removal in corn, resulting in a positive P balance. Results indicate that perennial crop harvest without P fertilization removed legacy P from soils, and continued harvest will soon draw P down to limiting levels, even in soils once heavily P-fertilized. Widespread cultivation of bioenergy crops may, therefore, alter P balances in agricultural landscapes, eventually requiring P fertilization, which could be supplied by P recovery from harvested biomass. 相似文献
839.
840.
Changfu Yao Stephanie A. Bora Tanyalak Parimon Tanzira Zaman Oren A. Friedman Joseph A. Palatinus Nirmala S. Surapaneni Yuri P. Matusov Giuliana Cerro Chiang Alexander G. Kassar Nayan Patel Chelsi E.R. Green Adam W. Aziz Harshpreet Suri Jo Suda Andres A. Lopez Gislâine A. Martins Barry R. Stripp Peter Chen 《Cell reports》2021,34(1):108590