首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   34篇
  免费   2篇
林业   2篇
农学   1篇
  12篇
综合类   1篇
农作物   6篇
水产渔业   3篇
畜牧兽医   6篇
园艺   3篇
植物保护   2篇
  2021年   2篇
  2020年   1篇
  2019年   3篇
  2018年   3篇
  2017年   3篇
  2016年   2篇
  2015年   1篇
  2013年   2篇
  2012年   3篇
  2011年   4篇
  2010年   2篇
  2009年   2篇
  2008年   2篇
  2005年   2篇
  2000年   1篇
  1986年   1篇
  1984年   2篇
排序方式: 共有36条查询结果,搜索用时 31 毫秒
21.
Laboratory tests provide essential support to the veterinary practitioner, and their use has grown exponentially. This growth is the result of several factors, such as the eradication of historical diseases, the occurrence of multifactorial diseases, and the obligation to control endemic and epidemic diseases. However, the introduction of novel techniques is counterbalanced by economic constraints, and the establishment of evidence- and consensus-based guidelines is essential to support the pathologist. Therefore, we developed standardized protocols, categorized by species, type of production, age, and syndrome at the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), a multicenter institution for animal health and food safety. We have 72 protocols in use for livestock, poultry, and pets, categorized as, for example, “bovine enteric calf”, “rabbit respiratory”, “broiler articular”. Each protocol consists of a panel of tests, divided into ‘mandatory’ and ‘ancillary’, to be selected by the pathologist in order to reach the final diagnosis. After autopsy, the case is categorized into a specific syndrome, subsequently referred to as a syndrome-specific panel of analyses. The activity of the laboratories is monitored through a web-based dynamic reporting system developed using a business intelligence product (QlikView) connected to the laboratory information management system (IZILAB). On a daily basis, reports become available at general, laboratory, and case levels, and are updated as needed. The reporting system highlights epidemiologic variations in the field and allows verification of compliance with the protocols within the organization. The diagnostic protocols are revised annually to increase system efficiency and to address stakeholder requests.  相似文献   
22.
The land use change from natural to managed ecosystems causes serious soil degradation. The main objective of this research was to assess deforestation effects on soil physical quality attributes and soil water retention curve (SWRC) parameters in the Fandoghlou region of Ardabil province, Iran. Totally 36 surface and subsurface soil samples were taken and soil water contents measured at 13 suctions. Alfa (α) and n parameters in van Genuchten (1980) model were estimated by fitting SWRC data by using RETC software. The slope of SWRC at inflection point (SP) was calculated by Dexter (2004) equation. The results indicated that with changing land use from forest (F) to range land (R) and cultivated land (C), and also with increasing soil depth from 0–25 to 75–100 cm in each land use, organic carbon, micropores, saturated and available water contents decreased and macropores and bulk density increased significantly (P < 0.05). The position of SWRC shape in F was higher than R and C lands at all soil depths. Changing F to R and C lands and also increasing soil depth in each land use significantly (P < 0.05) increased α and decreased n and SP. The average values of SP were obtained 0.093, 0.051 and 0.031 for F, R and C, respectively. As a result, deforestation reduced soil physical quality by affecting SWRC parameters.  相似文献   
23.
Phytocystatins are the plant thiol protease inhibitors involved in several reaction mechanisms of the plant system like regulation of proteolytic activity and storage of proteins. Biochemical and biophysical changes induced by fungicide SDD in phytocystatin purified from Phaseolus mungo have been investigated in terms of mass spectroscopy, Fourier transform infrared spectroscopy, and fluorescence spectroscopy, at pH 7.0, with varying fungicide concentrations (1-9 mM) and a time of incubation ranging from 2 to 8 h at 37 degrees C, with a fixed cystatin concentration (1.5 mM). Reactive oxygen species responsible for inhibitor damage were also investigated, and thiourea was found to scavenge the free radicals generated by SDD. FTIR analysis indicates a significant conformational transition from alpha-helix to beta-sheet structure; quenching of fluorescence is evident by fluorescence spectroscopy. The activity assay showed a decrease in inhibitory activity, as well as a fragmentation of the inhibitor was observed in electrophoresis. Results obtained implicate that exposure of phytocystatins to SDD involves physicochemical changes in cystatins leading to damage and a decrease in the activity of the inhibitor.  相似文献   
24.
A factorial experiment based on a completely randomized design with three replicates was conducted to evaluate effects of sixteen different mixtures of organic nitrogen sources and antibiotics which were supplemented to an Murashige and Skoog (MS) medium containing 4 mg L?1 2,4-Dichlorophenoxyacetic acid (2,4-D), 0.4 mg L?1 benzyl-aminopurine (BAP), 30 g L?1 sucrose, 8 g L?1 Agar-agar on fresh weight and dry weight (assessed after three days of drying at 70°C) of calli and in vitro callogenesis from scutellum of four indigenous Iranian Indica rice (Oryza sativa L.) cultivars, including ‘Hashemi’, ‘Gerdeh’, ‘Hasani’, and ‘Gharib’. It was found that proline at 2.8 g L?1 is the most effective source of organic nitrogen in enhancing growth, whereas asparagine at 0.75 g L?1 inhibited the calli growth. Hygromycin at 50 mg L?1, with slight differences between the cultivars, could effectively stunt the growth of untransformed calli. Mixture of cefotaxime (250 mg L?1) and vancomycin (250 mg L?1) did not have any significant effects on calli growth, although this treatment was slightly phytotoxic.  相似文献   
25.
26.
Interaction between mycorrhizal fungi and herbicide application and their effects on plant growth are issues around which there is little information. Therefore, to determine the effect of arbuscular mycorrhizal (AM) fungus in alleviating the effects of herbicide stress on growth of maize and barley, two pot experiments were conducted in Shahrood University of Technology in 2009 and 2010. Factorial experiments were arranged in completely randomized design with three replications. Experimental factors were a combination of two factors: (1) non-mycorrhiza (control) and Glommusmosseae, Glommusintraradices and Glommusfasciculatum as mycorrhizal inoculums; (2) herbicide treatments, which included three levels of metribuzin (0, 175 and 350 g a.i. ha?1). In the second experiment, factors examined were inoculated soil with mycorrhiza fungi at two levels (with and without Glommusintraradices) and four rates of metribuzin (0, 175, 350 and 525 g a.i. ha?1) and two levels of iron (0 (control) and 20 mg pot?1). The results showed that soil inoculated with mycorrhiza had significantly increased dry weight, height and chlorophyll content of maize and barley in the low herbicide concentrations (175 g a.i. ha?1) compared to non-inoculated treatments. Based on our results, mycorrhiza fungi can alleviate crop stress due to low doses of metribuzin injury through increase in plant growth.  相似文献   
27.
Some studies have shown that catecholamines and the changes in their levels during and after head trauma can be useful in predicting the outcome in head trauma patients. The goal of this study is to search for a probable relation between urine levels of catecholamines and prognosis in patients with severe head trauma. Fifty four patients with severe head trauma Glasgow Coma Scale (GCS < or = 8) on admission time were recruited in Imam Reza Hospital within one. These patients were included when having no major accompanying trauma in other organs. Twenty four hour urine was collected after admission and levels of metanephrine and nor-metanephrine were measured. The relation between urine levels of these metabolites with final outcome and also with GCS at admission, 24, 48 h and 1 week after admission and discharge time and Glasgow Outcome Scale (GOS) were studied. Fifty two patients, 48 males and 4 females with a mean age of 32.3 +/- 14.7 (3-72) years were included. The main underlying etiologies were motorcycle (46.2%) and car accidents (25%). Diffuse axonal injury, brain contusion and subdural hematoma were three main diagnoses (28.8, 17.3 and 15.4% of the cases, respectively). 19 (36.5%) of the patients expired within the study period. The mean level of metanephrine and normetanephrine in urine were 207.9 +/- 200.5 and 330.2 +/- 218.4 microg in 24 h, respectively. There was no meaningful relation between urine levels of these metabolites and any of GCS and GOS. There was also no meaningful relation between these parameters and final prognosis in patients.  相似文献   
28.
A 60-day feeding experiment was carried out on juvenile Iranian sturgeon (Acipenser persicus) to evaluate the effects of different percentages of canola oil and fish oil containing n-3 highly unsaturated fatty acids (n-3 HUFA) on fish growth and fatty acid composition. The requirement for n-3 HUFA of juvenile Iranian sturgeon (48.4 ± 1.98 g) was studied by feeding the fish with various diets containing six different percentage of n-3 HUFA ranging from 1.56 to 17.25 (% of total fatty acids). Neither the weight gain, feed conversion ratio, condition factor, specific growth rate nor the protein efficiency ratio showed any significant differences between the dietary treatments nor in the body composition of juvenile Iranian sturgeon (P > 0.05); also there were no significant difference with respect to the effect of the dietary treatment (P > 0.05) on the blood parameters, for the content of plasma protein, glucose, cholesterol, and triglyceride. The fatty acid composition of the carcass of the Iranian sturgeon fed with the diets containing various levels of n-3 HUFA was reflected by the dietary fatty acid composition. The content of n-3 HUFA in the fish increased with an increase in dietary n-3 HUFA levels. The results indicate that the dietary n-3 HUFA had no effect on the growth of juvenile Iranian sturgeon.  相似文献   
29.
In this study, the effects of livestock overgrazing on vegetation of the critical area around livestock watering points in a traditional grazing ecosystem was investigated on a semi-arid rangeland in North-East of Iran. Transects were placed in 8 geographical directions around watering points and samples were taken systematically. In each experimental plot, 4 m2, percentage of canopy cover, abundance, density and species richness of vegetation were calculated. The results of this study showed that the percentage of canopy cover, density and species richness were changed with distance from watering points. Critical area immediately adjacent to watering points was dominated by unpalatable Peganum harmala and contained of ruderal species such as Sophora sp. Adjacent to this was a zone dominated by species of low palatability such as Acantholimon sp. and Hulthemia persica. In areas most distant from watering points relative importance of moderately palatable species such as Artemisia herba-alba increased. These results show the negative impacts of overgrazing on vegetation and palatability in a traditional grazing ecosystem, which may indicate the necessity of a monitoring programme, to manage livestock grazing and watering points in North-East of Iran.  相似文献   
30.
The effects of different applications of 24-epi-brassinolideon the physiology and yield of ‘Owhadi’ pistachio trees was investigated in Iran over an off and on year. Plants were treated by 24-epi-brassinolide at 0, 0.25, 0.5, 0.75 and 1mgl?1at green tip and tight cluster of bud stage. Brassinolide decreased the incidence nut physiological disorders and increased yield. The sprays decreased the incidence of inflorescence bud abscission, fruit abscission, misshapen nuts, blank, early splitting and indehisced shell compared with the controls. In both on and off years, the effect of brassinolide was dependent on the time of application and concentration used. Application of this compound, especially at tight cluster stage of buds, increased indehisced shell and yield in both on and off years. Brassinolides appear to play a key role in the growth and development of pistachio.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号