全文获取类型
收费全文 | 114篇 |
免费 | 8篇 |
专业分类
林业 | 15篇 |
农学 | 7篇 |
29篇 | |
综合类 | 7篇 |
农作物 | 2篇 |
水产渔业 | 3篇 |
畜牧兽医 | 32篇 |
园艺 | 1篇 |
植物保护 | 26篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 9篇 |
2017年 | 10篇 |
2016年 | 8篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 9篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1997年 | 2篇 |
1991年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1967年 | 1篇 |
1893年 | 1篇 |
排序方式: 共有122条查询结果,搜索用时 15 毫秒
91.
Rosa Karla Nogueira Pestanana Edson Perito Amorim Cláudia Fortes Ferreira Vanusia Batista de Oliveira Amorim Larissa Santos Oliveira Carlos Alberto da Silva Ledo Sebastião de Oliveira e Silva 《Euphytica》2011,178(2):151-158
Bananas are tropical fruits grown worldwide playing a key role in market trade and especially used as main food source for
low income populations. In Brazil, bananas are mainly consumed in natura, occupying the second largest internal market. Nevertheless, this crop presents low availability of productive commercial
varieties with good agronomic characteristics. A strategy undertaken to solve this problem is the development of new cultivars
through conventional genetic breeding methods. However, this strategy presents some obstacles such as female sterility and
low number of seeds. In order to overcome these shortcomings, use of mutation induction aiming the selection of mutants with
desirable agronomic characteristics seems to have great potential for developing new cultivars. The objective of the present
work was to evaluate the genetic variability in putative banana ‘Pacovan’ (AAB genome, subgroup Prata Type) mutants submitted
to gamma ray irradiation, using a set of agronomical and molecular data (ISSR markers). The distance between the putative
‘Pacovan’ mutants varied from 0.26 to 0.64 with cophenetic correlation coefficient of 0.7669. Four mutants were selected based
on best agronomical characteristics and height. This data also shows that there is variability that can be explored after
the irradiation of ‘Pacovan’ banana mutants, which can be used in the genetic breeding program of banana aiming to develop
short new varieties that also present good agronomic characteristics. This is the first attempt to use combined data in order
to evaluate the genetic variability in putative banana mutants. 相似文献
92.
93.
Antoniassi NA Boabaid FM Souza RL Nakazato L Pimentel MF Filho JO Pescador CA Driemeier D Colodel EM 《Journal of zoo and wildlife medicine》2011,42(1):118-120
This report describes toxoplasmosis infection in a black-headed night monkey (Aotus nigriceps) from the Zoological Park of the Federal University of Mato Grosso, Brazil. The animal was submitted alive to the Veterinary Hospital of the Federal University of Mato Grosso presenting neurologic clinical signs. There were no improvements on the animal's clinical condition after treatment, so it was euthanized. At necropsy, the most significant gross lesions observed were hemorrhages diffusely scattered throughout the cerebral hemispheres. Histologic findings were characterized by nonsuppurative encephalitis and mild multifocal necrotizing nonsuppurative myocarditis. Groups of tachyzoites and cysts were observed surrounding the inflamed areas of cerebral parenchyma. Sections of the brain were submitted for immunohistochemistry examination for Toxoplasma gondii and Neospora caninum and also for polymerase chain reaction (PCR) to determine the presence of Toxoplasma gondii. The samples were positive for Toxoplasma gondii by PCR; however, cross reactivity was observed between Toxoplasma gondii and Neospora caninum antibodies. These findings were consistent with a toxoplasmosis infection in this animal. 相似文献
94.
João Guilherme L. N. Gaeti Marconni V. C. Lana Gustavo S. Silva Letycia Lerner Camila G. de Campos Fernanda Haruni Edson M. Colodel Eduardo F. Costa Luis G. Corbellini Luciano Nakazato Caroline A. Pescador 《Tropical animal health and production》2014,46(6):1059-1063
Ureaplasma diversum has been associated with various reproductive problems in cattle that include granular vulvovaginitis, weak calves, and abortion. This study was conducted in a beef herd situated in the Middle-West region of Brazil, and the objectives were to verify the presence of U. diversum and to elucidate its possible relationships with independent variables in this bovine herd population. A total of 134 vaginal mucous swabs were taken for polymerase chain reaction (PCR). Of these, 51 (38 %) were PCR positive for U. diversum. Of the 58 heifers with vulvovaginal lesions characterized by hyperemia, granulated lesions, and edema distributed throughout the vulvar mucosa, 37 (64 %) were U. diversum positive; of the 76 heifers without reproductive lesions, 14 (18 %) were U. diversum positive. All tested samples were negative for bovine herpesvirus 1 (BoHV-1). Multivariate logistic regression revealed that the following two variables were significantly associated with the presence of U. diversum: the presence of vulvar lesions (p?=?0.001) and the presence of a progesterone (P4) device (p?=?0.001). These findings indicate that U. diversum should be considered a pathogen that is associated with pustular vulvovaginitis in heifers from the Mato Grosso state and that additional studies of the risk factors associated with intravaginal P4 device transmission should be performed. 相似文献
95.
José P. G. F. Silva Edson L. L. Baldin Efrain S. Souza Vinícius F. Canassa André L. Lourenção 《Journal of pest science》2013,86(4):649-657
Stink bugs are among the major pests of soybean [Glycine max (L.) Merrill] worldwide. Piezodorus guildinii [Westwood] (Hemiptera: Pentatomidae) is one of the predominant pest species, causing more severe damage in many regions than other stink bugs. Its attack reduces yield and quality of the beans. Plant resistance is a valuable strategy in integrated pest management that can reduce insect populations below economic injury level. Here, we report the resistance of 17 soybean entries to P. guildinii. PI 229358, PI 274454, L1-1-01, “IAC 19,” PI 171451, PI 227687, “IAC 100,” IAC 78-2318, PI 274453, and IAC 74-2832 caused high nymphal mortality (greater than 90 %), indicating the expression of antibiosis. “IAC 100,” IAC 74-2832, PI 274453, and “IAC 24” also increased the length of the nymphal stage of P. guildinii, showing the same mechanism of resistance. Our findings may be useful for breeding programs that focus on the resistance of soybeans to insects. 相似文献
96.
ABSTRACT A hydrophobic 19.7-kDa amylase inhibitor (AI) was purified from corn kernels by 95% ethanol extraction and anionic exchange chromatography. The AI has an isoelectric point of 3.6 and was very stable at different pH values and high temperatures, maintaining 47.6% activity after heating to 94 degrees C for 60 min. Amino acid analysis indicated high valine, leucine, glycine, alanine, and glutamic acid/glutamine content, and especially high valine content (41.2 mol%). This inhibitor is not a glycoprotein. It required 30-min preincubation to maximize complex enzyme-inhibitor formation when the amylase from Fusarium verticillioides was tested. The optimal pH of interaction was 6.5. It showed broad-spectrum activity including the following amylases: human saliva, porcine pancreas, F. verticillioides, as well as those from some insects of agricultural importance (Acanthoscelides obtectus, Zabrotes subfasciatus, Sitophilus zeamais, and Prostephanus truncatus). This novel hydrophobic protein not only inhibited the amylase from F. verticillioides but also decreased the conidia germination. Thus, this protein represents an approach to decrease the production of fumonisin in corn, either by using it as a molecular marker to detect fungal resistance or through genetic engineering. 相似文献
97.
Moreira ED Mendes de Souza VM Sreenivasan M Nascimento EG Pontes de Carvalho L 《Veterinary parasitology》2004,122(4):245-252
In Brazil, zoonotic visceral leishmaniasis (ZVL) control programs based on the mass elimination of seropositive dogs have failed to reduce the number of leishmaniasis cases. However, these programs have been done under sub-optimal conditions. We studied a cohort of dogs in an urban area in Brazil to determine, whether a dog-culling program optimized with: (i) replacement of a relatively low-sensitivity indirect immune-fluorescent test on blood eluate by a more sensitive enzyme-linked immunosorbent assay on serum blood samples; (ii) shortening of the time interval from serodiagnosis to removal of dogs; (iii) screening a high proportion of the dog population could reduce the incidence of canine Leishmania infection (CLI). The study ran from December 1997 to July 2000, with four follow-up assessments performed at approximately 8-month intervals. All dogs seropositive for anti-Leishmania antibodies were promptly eliminated. A large number of new dogs immigrated to the study area throughout the study period. They comprised 43.8-49.8% of the cohort at each follow-up assessment, and upto 15% of them already had Leishmania infection. Overall, 42 news cases of CLI were identified, for a crude incidence rate of 11.8 cases per 100 dog-years (95% CI 8.6-15.6). In the first, second, third and fourth follow-up assessments the incidence rates were 8.2 (95% CI 3.0-17.9), 12.2 (95% CI 6.3-21.2), 16.4 (95% CI 8.5-28.6) and 13.6 (95% CI 7.1-23.8), respectively. There was no statistically significant change in these rates throughout the study period. Our results suggest that dog-culling programs do not reduce the incidence of CLI, even with an optimized intervention. Possible reasons for this failure include: currently available serologic methods lack sufficient sensitivity and/or specificity to accurately identify all infected dogs warranting removal in order to prevent Leishmania transmission; destroyed dogs are immediately replaced by susceptible puppies, and quite often, by already infected dogs; and other reservoirs may be involved in maintaining canine infection. Further efforts on ZVL control should be directed to developing new strategies or to testing control methods already in place with properly designed trials. 相似文献
98.
The disease prevalence survey is one research approach available to epidemiologists working in preventive veterinary medicine. This paper demonstrates an application of sampling theory in the design of disease prevalence surveys and suggests ways in which this use of sampling methodology may enable the veterinary epidemiologists to better achieve their research objectives. 相似文献
99.
Replacing corn with sorghum in the diet alters intestinal microbiota without altering chicken performance 下载免费PDF全文
N. S. Fagundes R. Pereira C. Bortoluzzi J. M. Rafael G. S. Napty J. G. M. Barbosa M. C. M. Sciencia J. F. M. Menten 《Journal of animal physiology and animal nutrition》2017,101(5):e371-e382
Sorghum grain can be used to replace corn in broiler diets. However, the effects related to an abrupt change between these grains are not yet clear. The aim of this study was to evaluate the performance and intestinal health of broilers fed diets containing corn and/or sorghum during different periods of rearing. To accomplish this aim, 2100 male chicks were fed the following experimental diets: C100% (corn‐based diet); S100% (sorghum‐based diet); C:S50% (diet based on corn and sorghum 1:1); PC‐S (corn‐based diet in the pre‐starter phase and sorghum‐based diet in subsequent phases); and PS‐C (sorghum‐based diet in the pre‐starter phase and corn‐based diet in subsequent phases). The study was conducted with two simultaneous trials in a randomized block design as follows: a performance trial up to 40 days occurred in floor pens (n = 8), and the metabolism trial occurred in cages (n = 10). Performance, jejunal morphometry, number of goblet cells, apparent metabolizable energy (AME), apparent metabolizable energy corrected for nitrogen (AMEn) and the coefficient of apparent metabolizability of dry matter (CMDM) of the diets, and the intestinal microbiota of small intestine and caeca at 10 and 21 days of age (16S gene sequencing) were evaluated. The different experimental diets did not affect performance, jejunal epithelium, AME, AMEn or CMDM. However, the experimental diets altered the percentages of the genera Clostridium, Weissella, Bacillus and Alkaliphilus in the small intestine. In addition, the genera Lactobacillus and Desulfotomaculum in the caeca were altered. The age also affected the microbiota of the intestinal segments. In conclusion, feeding sorghum in place of corn as well as the grain change after the pre‐starter phase does not alter broiler performance. However, sorghum alters the intestinal microbiota, resulting in a lower percentage of Clostridium and a higher percentage of Lactobacillus in the small intestine and caeca, respectively. 相似文献
100.
Fabiana Bogas Bertollo Gabriela Cantarelli Lopes Edson Luiz Silva 《Water, air, and soil pollution》2017,228(10):398
An airlift biofilm reactor was employed to study phenol biodegradation by Pseudomonas putida. Hydrodynamic tests were also conducted in a conventional column to facilitate the comparison of the dynamic behavior in different types of columns. The three-phase airlift column offered better aeration than the conventional column as liquid and solid circulation in the downcomer favored bubble breakup, increasing oxygen dissolved in the liquid phase and favoring the phenol biodegradation process. Kinetic parameters of phenol biodegradation by P. putida were obtained in an agitated batch reactor, with the initial phenol concentration varying from 10 to 750 mg/L. Experimental data were fitted using different microbial growth models found in literature. The Yano and Koga model, which considers the formation of multiple inactive enzyme–substrate complexes, fitted well with our experimental data, with a correlation coefficient, R 2 = 0.952. An internal loop airlift bioreactor was used for aerobic phenol biodegradation in which polystyrene particles were utilized to support biomass immobilization. Several tests were performed by varying the influent phenol concentration, hydraulic retention time, upstream flow, and superficial air velocity. It was concluded that until an influent phenol concentration of approximately 300 mg/L, phenol acted as the limiting substrate. For higher phenol concentrations, oxygen became the limiting substrate. An increase in the oxygen concentration resulted in the complete consumption of phenol under high phenol concentration of 500 mg/L. 相似文献