全文获取类型
收费全文 | 71篇 |
免费 | 9篇 |
专业分类
林业 | 7篇 |
农学 | 1篇 |
14篇 | |
综合类 | 3篇 |
农作物 | 5篇 |
水产渔业 | 23篇 |
畜牧兽医 | 18篇 |
园艺 | 5篇 |
植物保护 | 4篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 6篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 6篇 |
2007年 | 2篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 2篇 |
1998年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有80条查询结果,搜索用时 15 毫秒
31.
Hornok S Edelhofer R Joachim A Farkas R Berta K Répási A Lakatos B 《Acta veterinaria Hungarica》2008,56(1):81-88
Blood samples were collected from 330 cats in Hungary in order to evaluate their seroconversion to Toxoplasma gondii and Neospora caninum using the indirect fluorescent antibody test (IFAT). The overall prevalence of toxoplasmosis was 47.6%, the prevalence being 22.4% among urban, 50% among suburban and 61.3% among rural animals. Significantly more cats had high IFAT titres (1:640 to 1:5120) in the countryside. Female cats were more frequently infected with T. gondii than males (53.3% vs. 39.3%), and seropositivity increased with the age of animals. The prevalence (0.6%) and titre (1:40) of antibodies to N. caninum was low. Sixty-two cats were also screened for seroconversion to feline infectious peritonitis (FIP) virus. Higher titres to T. gondii were more frequently detected among FIP-positive cats, but this difference was non-significant due to the small number of cats with concurrent infection. 相似文献
32.
Berta M. Jáuregui Urcesino García Koldo Osoro Rafael Celaya 《Strength and Conditioning Journal》2009,62(2):119-126
Heathlands in the northwest of Spain have been traditionally used by domestic herbivores as a food resource. However, their abandonment in the past decades has promoted a high incidence of wildfires, threatening biodiversity. Sheep and goats exhibit different grazing behavior, affecting rangelands dynamics in a different way, but the botanical and structural composition may also affect such dynamics. The aim of this article was to compare the grazing effects of sheep and goats on three different heathland types: previously burned grass- or gorse (Ulex gallii Planchon)-dominated and unburned heather (Erica spp.)-dominated shrublands. Two grazing treatments (sheep or goats) were applied in each vegetation type in a factorial design with two replicates (12 experimental plots). A small fenced area was excluded from grazing in each plot (control treatment). The experiment was carried out from 2003 to 2006, and the grazing season extended from May to October–November. Plant cover, canopy height, and phytomass amount and composition were assessed in each plot. Results showed that goats controlled shrub encroachment, phytomass accumulation, and canopy height more than sheep in either burned grass– and gorse– and unburned heather–dominated shrublands. It was accompanied by a higher increase of herbaceous species under goat grazing. Nevertheless, plant dynamics showed different trends between the three vegetation types studied. Grazing effects were more important in previously burned grass-dominated heathlands than in unburned heather-dominated shrublands. At the end of the experiment (May 2006), shrub cover, height, and woody phytomass were significantly higher in the ungrazed enclosures than in the grazed plots. Small ruminant grazing, especially with goats, is proposed as an efficient tool to reduce shrub encroachment and woody phytomass accumulation in heathlands, thus reducing fire hazard, although these grazing effects depend on heathland composition. 相似文献
33.
34.
Cesar Blanco Berta los de Santos Fernando Romero 《European journal of plant pathology / European Foundation for Plant Pathology》2006,114(4):415-425
Atmospheric concentrations of Botrytis cinerea conidia were monitored for two seasons in a strawberry crop in Moguer (Huelva, southwestern Spain). Concentrations of conidia
were estimated using a Burkard volumetric spore sampler. A diurnal pattern of conidial release was observed. Airborne conidial
concentration was significantly and positively correlated with the average solar radiation and mean temperature, and negatively
with rainfall and relative humidity. Among the weather variables considered, solar radiation showed the most consistent results
in the regression analysis, explaining over 40% of airborne conidial concentration variability. Correlation between Botrytis
fruit rot incidence and accumulated number of conidia over seven days was significant and positive. Two regression models
containing three variables explained over 62 and 52% of the fruit rot incidence variability. A positive but non-significant
correlation was established between B. cinerea incidence in flowers and airborne conidial concentration. It was not possible to fit a consistent regression model to relate
flower infection incidence to conidial concentration or weather variables. 相似文献
35.
Karen L. Lang Izabella T. Silva Lara A. Zimmermann Cíntia Lhullier Maria V. Ma?alich Arana Jorge A. Palermo Miriam Falkenberg Cláudia M. O. Sim?es Eloir P. Schenkel Fernando J. Durán 《Marine drugs》2012,10(10):2254-2264
In the present study, the in vitro cytotoxic effects of six semi-synthetic derivatives of elatol (1) and isoobtusol (2) were investigated. Chemical modifications were performed on the hydroxyl groups aiming to get derivatives of different polarity, namely the hemisuccinate, carbamate and sulfamate. The structural elucidation of the new derivatives was based on detailed NMR and MS spectroscopic analyses. The in vitro cytotoxicity of compounds 1 to 8 was evaluated against A459 and RD tumor cell lines with CC50 values ranging from 4.93 to 41.53 µM. These results suggest that the structural modifications performed on both compounds could be considered a good strategy to obtain more active derivatives. 相似文献
36.
Luana Cagol Bernardo Baldisserotto Alexssandro Geferson Becker Carine de Freitas Souza Berta Maria Heinzmann Braulio Otomar Caron Francisco Assis Leone Lilian Dena dos Santos Eduardo Luis Cupertino Ballester 《Aquaculture Research》2020,51(6):2243-2251
The juveniles of Macrobrachium rosenbergii (0.060 ± 0.004 g and 2.018 ± 0.071 cm) were fed during 60 days with diets containing different doses of Lippia alba essential oil (EOLA) (0.0—control, 1.0, or 2.0 ml EOLA/kg diet; in triplicate, with 20 prawns/replicate). After the experimental period, were verified the survival, growth parameters and the antioxidant enzymes, lipid peroxidation and Na/K‐ATPase activities in hepatopancreas and gills, respectively, of the animals. There were no significant differences on survival, growth parameters and gill Na/K‐ATPase activity. However, glutathione peroxidase and glutathione‐S‐transferase activities were lower in hepatopancreas of prawns fed with 1.0 ml EOLA/kg diet compared to the control. Moreover, the activity of the enzyme superoxide dismutase was higher in hepatopancreas of prawns that received 2.0 ml EOLA/kg diet compared to those fed with 1.0 ml EOLA/kg diet. Although the addition of both EOLA doses has not improved the survival and growth parameters of M. rosenbergii, these doses contributed to decrease lipid peroxidation. Additionally, the dose of 2.0 ml EOLA/kg diet contributed for increasing the antioxidant enzymes activities in the hepatopancreas, improving antioxidant status, and therefore, it can be recommended as diet supplementation for M. rosenbergii. 相似文献
37.
Olga Borges Fernando Raimundo João Coutinho Berta Gonçalves Ivo Oliveira Afonso Martins Manuel Madeira 《Agroforestry Systems》2018,92(2):301-310
Several studies have emphasized the negative impact of the conventional soil management (CT) system on productivity and sustainability of chestnut orchards (Castanea sativa Mill.) when compared to no-tillage with grass cover (NT). However, scarce information is available regarding the effects of these soil management systems on soil organic matter (SOM) dynamics and soil quality. SOM or soil organic carbon is a key component of soil quality and has different fractions with different lability, namely, organic C (POC), active C (AC) and hot-water extractable carbon (HWC). These are considered as indicators of changes in management-induced soil quality. Thus, a study was carried out to evaluate the effects of NT and CT systems applied in the chestnut orchards on: (i) total amount of soil organic C (TOC), including C from both organic and mineral layers; (ii) soil organic C concentration of mineral horizons (OC); (iii) labile soil organic fractions (POC, AC, HWC); (iv) and soil mineral-associated C. The study was developed in two 30-year old chestnut orchards located in Northeast Portugal, that were kept under different soil management systems (NT or CT) during the preceding 17 years. Soil samples were taken at 0–10 and 10–20 cm soil depth. No significant differences in OC concentration were observed between NT and CT, while TOC was significantly higher in NT than in CT (22.54 and 12.17 Mg/ha or 34.16 and 22.90 Mg/ha, considering the organic layer plus mineral layers at 0–10 and 0–20 cm depth (set of two depths). The NT practice led to significantly higher concentration of labile C fractions (POC, AC and HWC) than CT at 0–10 cm soil depth. These results indicate that measurement of labile soil organic C fractions, such as POC, AC and HWC, may provide a sensitive and consistent indication of changes in soil C and SOM dynamics in response to soil management practices. Overall, NT seems to ensure better soil quality than CT in chestnut orchards under Mediterranean climate conditions. 相似文献
38.
Guillermo Martínez Pastur Pablo L. Peri María V. Lencinas Marina García-Llorente Berta Martín-López 《Landscape Ecology》2016,31(2):383-399
Context
Although there is a need to develop a spatially explicit methodological approach that addresses the social importance of cultural ecosystem services for regional planning, few studies have analysed the spatial distribution on the cultural ecosystem services based on social perceptions.Objective
The main objective of this study was to identify cultural ecosystem service hot-spots, and factors that characterize such hot-spots and define the spatial associations between cultural ecosystem services in Southern Patagonia (Argentina).Methods
The study was carried out in Southern Patagonia (243.9 thousand km2) located between 46° and 55° SL with the Andes mountains on the western fringe and the Atlantic Ocean on the eastern fringe of the study area. The study region has a range of different vegetation types (grasslands, shrub-lands, peat-lands and forests) though the cold arid steppe is the main vegetation type. We used geo-tagged digital images that local people and visitors posted in the Panoramio web platform to identify hot-spots of four cultural ecosystem services (aesthetic value, existence value, recreation and local identity) and relate these hot-spots with social and biophysical landscape features.Results
Aesthetic value was the main cultural service tagged by people, followed by the existence value for biodiversity conservation, followed by local identity and then recreational activity. The spatial distribution of these cultural ecosystem services are associated with different social and biophysical characteristics, such as the presence of water bodies, vegetation types, marine and terrestrial fauna, protected areas, urbanization, accessibility and tourism offer. The most important factors are the presence of water in Santa Cruz and tourism offer in Tierra del Fuego.Conclusions
Our results demonstrate that this methodology is useful for assessing cultural ecosystem services at the regional scale, especially in areas with low data availability and field accessibility, such as Southern Patagonia. We also identify new research challenges that can be addressed in cultural ecosystem services research through the use of this method.39.
Fernando Jonas Sutili Luiz Carlos Kreutz Mirela Noro Leticia Trevisan Gressler Berta Maria Heinzmann Agueda Castagna de Vargas Bernardo Baldisserotto 《Veterinary immunology and immunopathology》2014,157(3-4):142-148
The aim of this study was to evaluate the activity of eugenol against the fish pathogen Aeromonas hydrophila and eugenol's effect on hematological and natural immune parameters in silver catfish (Rhamdia quelen). In vitro, eugenol showed weak activity against A. hydrophila, but in vivo, at a subinhibitory concentration (10 mg L?1), it promoted survival in infected silver catfish. Eugenol (50 μg mL?1) reduced the hemolytic activity of A. hydrophila supernatant in vitro in fish erythrocytes. Subjecting catfish to eugenol baths (5 and 10 mg L?1) for five days did not alter the hematological and immunological parameters studied in this work. Based on these results, eugenol can be used to treat or prevent bacterial diseases in fish. 相似文献
40.
Effect of inorganic and organic manganese supplementation on the performance and tissue manganese content of broiler chicks 总被引:2,自引:0,他引:2
Berta E Andrásofszky E Bersényi A Glávits R Gáspárdy A Fekete SG 《Acta veterinaria Hungarica》2004,52(2):199-209
The effects of dietary levels of manganese (Mn) in inorganic (MnO) and organic (Mn fumarate) forms were evaluated on cockerel chicks. A basal corn-soybean diet with 23 mg/kg Mn was supplemented with levels of 0, 30, 60 and 240 ppm Mn from both Mn sources. Each treatment was replicated in five pens of 10 chicks. The chicks were fed diets ad libitum from 14 to 49 days of age, after which five birds per treatment were sacrificed for pathomorphological examinations and analysis. The treatments did not exert significant effects on the body weight (BW), the feed/gain (F/G) ratio or the mortality rate. According to the necropsy findings, no growth retardation or emaciation occurred in either of the groups and the differences in the average absolute and relative organ weights were not significant (P > 0.05). Tissue analysis indicated that the tibia showed the greatest response to Mn, followed by the liver and kidney. Accumulation in the tibia was higher (P < 0.05) with supplements of 30, 60 and 240 mg/kg from both Mn sources (3.71, 3.78, 4.44, and 3.68, 4.00, 4.36 mg/kg DM, MnO and Mn fumarate, respectively) compared to the control group (3.21 mg/kg). Accumulation in the liver increased significantly (P < 0.05) only with supplements of 60 and 240 ppm independently of the Mn source (12.7, 14.2, and 14.0, 14.9 mg/kg, respectively) compared to the control (9.8 mg/kg). Similarly, kidney tissue Mn was higher (P < 0.05) only with supplements of 60 and 240 ppm (12.8, 12.8, and 13.1, 12.5 mg/kg, respectively) compared to the control (10.2 mg/kg). At the same level of supplementation of the two Mn sources there were no significant differences (P > 0.05) between the Mn concentrations of organs and tissues. Droppings sensitively reflected the intake, whereas blood plasma and feathers showed only the extreme Mn loading. 相似文献