全文获取类型
收费全文 | 340篇 |
免费 | 46篇 |
专业分类
林业 | 8篇 |
农学 | 10篇 |
57篇 | |
综合类 | 14篇 |
农作物 | 15篇 |
水产渔业 | 24篇 |
畜牧兽医 | 232篇 |
园艺 | 4篇 |
植物保护 | 22篇 |
出版年
2023年 | 11篇 |
2022年 | 3篇 |
2021年 | 19篇 |
2020年 | 23篇 |
2019年 | 15篇 |
2018年 | 24篇 |
2017年 | 20篇 |
2016年 | 18篇 |
2015年 | 22篇 |
2014年 | 20篇 |
2013年 | 21篇 |
2012年 | 22篇 |
2011年 | 31篇 |
2010年 | 18篇 |
2009年 | 13篇 |
2008年 | 18篇 |
2007年 | 19篇 |
2006年 | 16篇 |
2005年 | 18篇 |
2004年 | 13篇 |
2003年 | 10篇 |
2002年 | 5篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
排序方式: 共有386条查询结果,搜索用时 15 毫秒
61.
Elaine C Fitches Howard A Bell Michelle E Powell Emma Back Chiara Sargiotti Robert J Weaver John A Gatehouse 《Pest management science》2010,66(1):74-83
BACKGROUND: The toxicity of a fusion protein, ButalT/GNA, comprising a venom toxin (ButaIT) derived from the red scorpion, Mesobuthus tamulus (F.), and Galanthus nivalis agglutinin (GNA), was evaluated under laboratory conditions against several pest insects. Insecticidal activity was compared with SFI1/GNA, a fusion comprising a venom toxin (SFI1) derived from the European spider Segestria florentina (Rossi) and GNA, which has been previously demonstrated to be effective against lepidopteran and hemipteran pests, and to GNA itself. RESULTS: Injection assays demonstrated that both fusion proteins were toxic to lepidopteran larvae, dipteran adults, coleopteran adults and larvae and dictyopteran nymphs. ButalT/GNA was more toxic than SFI1/GNA in all cases. GNA itself made a minor contribution to toxicity. Oral toxicity of ButalT/GNA towards lepidopteran pests was confirmed against neonate Spodoptera littoralis (Boisd.), where incorporation at 2% dietary protein resulted in 50% mortality and > 85% reduction in growth compared with controls. ButaIT/GNA was orally toxic to Musca domestica L. adults, causing 75% mortality at 1 mg mL?1 in aqueous diets and, at 2 mg g?1 it was orally toxic to Tribolium castaneum (Herbst.), causing 60% mortality and a 90% reduction in growth. CONCLUSIONS: Toxicity of the ButaIT/GNA recombinant fusion protein towards a range of insect pests from different orders was demonstrated by injection bioassays. Feeding bioassays demonstrated the potential use of the ButaIT/GNA fusion protein as an orally active insecticide against lepidopteran, dipteran and coleopteran pests. These experiments provide further evidence that the development of fusion protein technology for the generation of new, biorational, anti‐insect molecules holds significant promise. © Crown Copyright 2009. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd. 相似文献
62.
63.
Patrizia Casagrande Proietti Annalisa Bietta Chiara Brachelente Elvio Lepri Irit Davidson Maria Pia Franciosini 《Journal of veterinary science (Suw?n-si, Korea)》2010,11(3):221-225
The aim of this study was to evaluate the presence of Helicobacter (H.) spp. in swine affected by gastric ulceration. Stomachs from 400 regularly slaughtered swine were subjected to gross pathological examination to evaluate the presence of gastric ulcers. Sixty-five samples collected from ulcerated pars esophagea and 15 samples from non-ulcerated pyloric portions were submitted to histopathological and molecular analyses, to detect Helicobacter spp., H. suis and H. pylori by PCR. Feces and saliva swabs were also collected from 25 animals in order to detect in vivo the presence of Helicobacter spp.. Gastric ulcers were detected in 373 cases (93%). The presence of ulcers in association with inflammatory processes was further confirmed by histological examination. Forty-nine percent (32/65) of the ulcerated esophageal portions as well as 53% (8/15) of the non-ulcerated pyloric portions were positive for Helicobacter spp. by PCR. The Helicobacter spp. positive samples were also positive for H. suis, while H. pylori was not detected. These results were confirmed by restriction enzyme analysis. With regard to feces and saliva samples, 15/25 (60%) and 16/25 (64%) were positive for Helicobacter spp. PCR, respectively but all were negative in H. suis and H. pylori specific PCR. 相似文献
64.
A prerequisite in any conservation programme of Plant Genetic Resources is estimation of diversity. The inventory of wild and naturalized relatives of priority crops in Venezuela (CWR) is based on the main Catalogues of Flora in the country, selecting taxa closely related to crops, according to the concepts of “gene pool” and “taxonomic group”. We included 47 genera, 217 species and 228 taxa belonging to 28 plant families. Among them, those with higher richness are: Fabaceae, Solanaceae, Araceae, Lauraceae, Dioscoreaceae, Poaceae, Rosaceae and Myrtaceae. Genera with a higher number of species are Xanthosoma, Persea, Dioscorea, Prunus, Psidium, Phaseolus, Solanum, Vigna, Capsicum, Manihot, Theobroma, Ipomoea and Oryza. A total of 26 endemic species are found, which belong to genera Xanthosoma, Persea, Dioscorea, Prunus and Manihot. The primary gene pool of crops include native species from genera such as Manihot, Solanum (Section Petota), Lycopersicon, Ananas, Capsicum, Dioscorea, Xanthosoma, Phaseolus, Theobroma, Ipomoea, Gossypium, Arracacia and Psidium. Genera with native species weakly related to crops are Saccharum, Persea, Ipomoea, Prunus, Vigna, Solanum (Section Melongena) and Daucus. Crop genera without native species in Venezuela are Allium, Musa, Brassica, Spinacia, Helianthus, Pisum, Lactuca, Citrus, Elaeis, Beta, Glycine and Triticum. Only a few taxa have already been evaluated according to the IUCN criteria, and Venezuelan accessions of crop wild relatives in national and international genebanks are very scarce. 相似文献
65.
Ballabio C Uberti F Di Lorenzo C Brandolini A Penas E Restani P 《Journal of agricultural and food chemistry》2011,59(24):12969-12974
Celiac disease is a food intolerance triggered by the ingestion of gluten-containing cereals; the only therapy is a strict gluten-free diet for life. In recent years, amaranth flour has received considerable attention as an interesting source for the formulation of gluten-free products due to its high nutritional value and low content of prolamins, the toxic proteins for celiacs. The aim of this study was to characterize 40 amaranth varieties using both SDS-PAGE/immunoblotting and ELISA to assess their possible tolerance by celiac subjects. All of the amaranth samples studied showed similar binding affinities for both specific anti-gliadin antibodies and human IgAs. In most amaranth grains, the content of gluten-like proteins measured by ELISA was <20 ppm. The molecular characterization of amaranth proteins suggests that amaranth is safe for celiacs to consume. It is recommended that the most suitable amaranth varieties are those having the lowest content of proteins cross-reacting with anti-gliadin antibodies. 相似文献
66.
Berlanda M Zotti A Brandazza G Poser H Calò P Bernardini M 《The Canadian veterinary journal. La revue veterinaire canadienne》2011,52(12):1334-1338
Magnetic resonance and computed tomography features of 4 cases of canine congenital vertebral anomalies (CVAs) are discussed. Two of the cases represent unusual presentations for such anomalies that commonly affect screw-tail or toy breeds. Moreover, the combination of CVAs and a congenital peritoneo-pericardial diaphragmatic hernia has never before been imaged. 相似文献
67.
68.
Alessandro Marchetti Chiara Piccini Sergio Santucci Igino Chiuchiarelli Rosa Francaviglia 《CATENA》2011,85(3):267-273
Soil surveys are an essential source of information for land management although a limited budget often reduces the amount of data available. Even if the dataset is limited, geostatistics can provide a valid estimation tool through a weighted moving average interpolation (kriging). Often, however, the spatial variability of soil properties appears smoothed and short range variability is underestimated by this kind of interpolation technique. A more realistic distribution of a given variable on the territory can be obtained through models based on stochastic simulation. 相似文献
69.
Fulvio Bordin Chiara Dalvit Mauro Caldon Laura Zulian Rosa Colamonico Simone Trincanato Barbara Mock Stefano Reale Franco Mutinelli Anna Granato 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2020,137(4):395-406
Scrapie is an ovine transmissible spongiform encephalopathy, and its susceptibility is associated with polymorphisms in the prion protein gene (PRNP). Genetic selection is currently the most effective mean for eradication of the susceptible VRQ allele in favour of resistant ARR allele. Maintenance of genetic diversity should be one of the major objectives in breeding programmes, especially in endangered breeds, and genetic information are an excellent alternative to pedigree data where these information are missing. The aim of our study was to determine changes of genetic variability in six native sheep breeds from autonomous province of Bolzano, northern Italy, following simulation of scrapie selection scenarios. A total of 684 rams were investigated for PRNP polymorphisms and for 10 microsatellite loci to estimate genetic variability. Across all loci, a total of 163 alleles were detected with a mean of 10.4 alleles per locus. Average observed (Ho) and unbiased expected (uHe) heterozygosity overall loci were 0.74 and 0.78, respectively, showing a statistically significant deviation from Hardy–Weinberg equilibrium (HWE) in all breeds. This heterozygosity deficit was confirmed by a positive fixation index (Fis), determining a moderate inbreeding in each breed. Simulating a soft selection, where only rams having at least a VRQ allele should be excluded from reproduction, Ho, uHe and Fis values remained almost unchanged, indicating that genetic variability should not be affected by the removal of these individuals. With a mild selection scenario, considering only rams with at least one ARR allele, we observed a decrease in the mean alleles per breed (8.9) and the maintenance of heterozygosity deficiency, except for two breeds, where it was any longer significant. These results showed that selection strategies allowing use of heterozygous as well homozygous ARR rams might be the right compromise to improve resistance to scrapie and to do not dramatically affect genetic variability of these breeds. 相似文献
70.
Maria Chiara Fontanella Maria Martin Daniele Tenni Gian Maria Beone Marco Romani 《水稻科学》2021,28(4):402-408
This study identified the role of milling and parboiling on arsenic (As) content and its species in large numbers of rice samples. Total As contents were 108 ± 33 μg/kg in polished rice grains (PR), 159 ± 46 μg/kg in unpolished rice grains (UR), 145 ± 42 μg/kg in parboiled polished rice grains (PPR) and 145 ± 44 μg/kg in parboiled unpolished rice grains (PUR). The percentages of inorganic As (iAs) were 66% ± 8% in PR and from 72% to 77% in other grain categories. The polishing process reduced the As content in the rice grains, removing outer part of the UR with high amount of As, whereas the parboiling technique transferred the semimetal content within the grain. Total As and iAs contents were not significantly different in UR, PPR and PUR, homogenizing its distribution inside the grains. The results allowed to understand how different operations affect As fate and its chemical forms in grains. 相似文献