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1.
Three objectives were included in this research work. The first objective compared different immune components in healthy mature males, mature females, and female kids of local and imported Saanen goats, reared under a sub-tropical environment. The significantly differing immune components were the blood monocyte percent, blood CD8 count, and the total white blood cell count. The second objective compared the performance of Saanen versus local does. The means of the milk yield and prolificacy of the imported Saanen does were significantly higher than those of the local does (p < 0.05). The third objective compared the immune responses (hemagglutination-HA titers) and complement fixation (CF) titers in mature does of the two breeds to chicken red blood cells (c-RBC). The HA titers showed a significant seroconversion only in imported Saanen (p < 0.05) but not in local does; however, the CF titers increased significantly at 4 weeks following priming with c-RBC in local (p < 0.05) but not in the imported Saanen does. The impact of the differences in blood immune components and responses to antigens in the compared goats on protection potential against prevalent diseases in the sub-tropical zone of the eastern Mediterranean countries is discussed.  相似文献   
2.
Concept maps have become a ubiquitous tool in education in the last 20 years and are used extensively to teach scientific concepts. A concept map is a tool learners can use to organize information about a topic in terms of key concepts and the relationships among them. As a graphical representation, the map provides an overall picture of a particular concept or topic. This article describes how we have used concept maps to teach physiology to veterinary medical and veterinary technician students enrolled in our on-campus and distance-learning programs.  相似文献   
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This study took place in a mixed deciduous forest located in Northern Iran to investigate the effects of two types of silvicultural methods, specifically the single-selection method and the group-selection method. The study also included the observation of skid trails in terms of runoff, sediment yield, and the loss of NO3-N and PO4-P. The process of recovery was studied by the assessment of these characteristics after the completion of forest operations for a period of 3 years. Although there is a considerable amount of literature on the topic of soil erosion caused by forest harvesting, there is little information regarding the medium-term effects of different sizes of gaps in the forest canopy. The attempt to gather data was done by designating hillslope plots on the soil directly affected by machinery passage on skid trails, as well as on the felling gaps in correlation with the two types of silvicultural methods. Plots were also marked on an unharvested area as a control. The results confirmed the suitability of retention forestry within the framework of sustainable forest management. A majority of the data gathered showed no difference between the single selection and the control area. What is more, the values obtained from the felling gaps correlated to the group selection resulted to be the same as the control values 2 years after harvesting. However, the disturbance caused by machinery passage on skid trails showed a significantly higher level of impact, and the recovery time needed was at least 3 years.  相似文献   
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Mass flux assessment can provide information that is essential for a sustainable management of elements in agricultural soils. In this article, we present an assessment of regional-scale averages of zinc (Zn) fluxes into agricultural soils and crops of central Iran for the period 1997–2011, using available databases such as regional agricultural statistics. The basic units of the balances were 15 townships of the provinces Qom, Isfahan and Fars. Averaged over the entire study region, the net Zn input into arable soil resulting from all fertilizer inputs – Zn removal with harvested crops was 1515 g ha?1 yr?1 across the entire region, with a range of 438–3009 g ha?1 yr?1 among townships. Estimated average Zn inputs with manure, mineral fertilizers, sewage sludge and compost were 1254, 531, 19 and 7 g ha?1 yr?1, respectively. The input-to-output ratio of these fluxes ranged from 1.8 to 12.9 among townships and averaged 6.1 for the entire study area. Considering that outputs other than with crop harvests are minor, Zn stocks are rapidly building up in the soils of the study region. Uncertainties in the manure and crop removal data were the main sources of estimation uncertainty in this study.  相似文献   
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Background: Acrylamide (ACR) is a well-known industrial toxic chemical that produces neurotoxicity, which is characterized by progressive central and peripheral neuronal degeneration. Chrysin is a natural, biologically active flavonoid compound, which is commonly found in many plants. The antioxidant and neuroprotective properties of chrysin have been demonstrated. Methods: In this study, the possible effect of chrysin on ACR-induced toxicity was evaluated in both in vitro and in vivo experiments. PC12 cells were used as a suitable in vitro model. Cells were exposed to chrysin (0.5-5 µM) for 12 and 24 h, and then ACR in IC50 concentration was added to the cells. Finally, cell viability was determined using (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay. For in vivo assay, Wistar rats were treated with ACR (50 mg/kg i.p. for 11 days) alone or in combination with chrysin (12.5, 25, and 50 mg/kg). At the end of treatment, behavioral index was evaluated. Results: ACR decreased cell viability and pre-treatment with chrysin (0.5-5 µM) significantly decreased ACR-induced cytotoxicity in the time- and dose-dependent manner. In Wistar rats, exposure to ACR significantly induced severe gait abnormalities, but treatment with chrysin (50 mg/kg) reduced ACR-induced neurotoxicity in animals. Conclusion: In the current study, chrysin exhibited neuroprotective effect on PC12 cells as an in vitro model and also on Wistar rats. Iran. Key Words: Acrylamide, Chrysin, Neurotoxicity, Antioxidant  相似文献   
8.
This study aimed to evaluate the efficacy of semi fermented and non fermented Camellia sinensis extracts (Black and Green tea) and comparison between them against Streptococcus mutans ATCC 25175, S. mitis ATCC 9811 and S. sanguis ATCC 10556 that are responsible for dental caries and bacteremias following dental manipulations. Minimum inhibitory concentrations of both tea extracts were assessed by Well diffusion and Broth dilution methods and examination of cell adherence (Biofilm inhibitory concentrations) was observed on glass slides under phase contrast microscope and colony counts from glass beads. Concentration of 1 mg mL(-1) of semi fermented tea extract was completely biofilm inhibitor but biofilm formation by these bacteria was seen 7 days after treatment with 1 mg mL(-1) of non fermented Camellia sinensis on glass beads and BIC for oral streptococci treated with this extract was 1.5, 2.5 mg mL(-1) of semi fermented and 3 mg mL(-1) of non fermented extracts had bactericidal effect on these bacteria. Semi fermented and non fermented Camellia sinensis extracts were able to prevent growth of oral streptococci. Therefore dental caries significantly reduce and the efficiency of semi fermented tea was higher due to rich content of volatile components rather than non fermented extracts.  相似文献   
9.
Triploid African catfish (Clarias gariepinus) produced through cold shock 3 min post fertilization were compared to diploid offspring of the same parentage at 66 days of age. Triploid fish were significantly shorter (11%) and weighed less (18%) than diploids but showed no significant difference in mortality or cannibalism, which can be an important source of losses under aquaculture conditions. Erythrocytes of triploid fish were more oval shaped than the normal spherical shape of diploid erythrocytes, were significantly larger (38%) and had nuclei that were significantly larger (25%) than observed in diploid fish. Erythrocyte morphological characteristics show potential as an indicator for the detection of triploidy in African catfish.  相似文献   
10.
A 14 week experiment was carried out to study the effects of replacing three different levels (33%, 66%; and 100%;) of berseem leaf meal (BLM) by leucaena leaf meal (LLM) treated in four different ways (drying for 48 h at 60 C, autoclaved for 15 min, sprayed with 1% sodium hydroxide and incubated with rumen liquor for 24 h). Groups of Nile tilapia, Oreochromis niloticus (L.), fingerlings (5.07 g mean weight) were fed one of 13 isonitrogenous (30% crude protein) and isocaloric (19.67 kJ per g dry matter) diets, with two replicates (10 fish per aquarium) for each treatment. The results indicated that weight gain, specific growth rate, feed conversion ratio and protein utilization parameters were significantly (p < 0.05) increased by the higher percentage of dried or cooked LLM in tilapia diets. On the other hand, the lowest growth performance and feed utilization parameters were observed in the groups fed LLM diets treated with sodium hydroxide or incubated with rumen liquor. Carcass protein and fat increased significantly (p < 0.05) with increasing levels of LLM and simultaneously decreasing ash content.  相似文献   
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