全文获取类型
收费全文 | 340篇 |
免费 | 16篇 |
专业分类
林业 | 17篇 |
农学 | 3篇 |
24篇 | |
综合类 | 24篇 |
农作物 | 3篇 |
水产渔业 | 17篇 |
畜牧兽医 | 250篇 |
园艺 | 8篇 |
植物保护 | 10篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 15篇 |
2019年 | 11篇 |
2018年 | 5篇 |
2017年 | 12篇 |
2016年 | 15篇 |
2015年 | 3篇 |
2014年 | 15篇 |
2013年 | 13篇 |
2012年 | 15篇 |
2011年 | 16篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 12篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 8篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 10篇 |
2001年 | 11篇 |
2000年 | 14篇 |
1999年 | 11篇 |
1992年 | 12篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 12篇 |
1988年 | 11篇 |
1987年 | 13篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有356条查询结果,搜索用时 15 毫秒
161.
162.
H W Hannah 《Journal of the American Veterinary Medical Association》1989,194(9):1182-1183
163.
Suryaningrum Febyana Jarvis Rebecca M. Buckley Hannah L. Hall David Case Bradley S. 《New Forests》2022,53(4):589-602
New Forests - Planting trees is widely regarded as an important part of climate change mitigation and adaptation efforts. As a result, large-scale tree planting projects have been initiated around... 相似文献
164.
Journal of Pest Science - The efficacy and high specificity of the RNA interference pathway has prompted its exploration as a potential molecular management tool for many insect pests, including... 相似文献
165.
166.
167.
The aim of the study was to assess whether the hair of stray and domestic dogs in Egypt was contaminated with the eggs of the zoonotic parasite Toxocara canis, and also to identify risk factors for T. canis for contamination. Paired samples of hair and feces were collected from 53 stray and 47 domestic dogs, and hair samples were obtained from a further 11 stray and 9 domestic dogs. All samples were examined to identify T. canis eggs and, if eggs were found, their maturation stage. Eggs were identified in 26.6% of stray and 10.7% of domestic dog's hair samples. A significantly increased risk of embryonated T. canis eggs in hair samples was found in stray dogs (p=0.04), stray dogs had 3.18 (95% CI: 1.04-9.74) times the odds of having T. canis eggs present compared with domestic dogs. There was also a significant difference (p=0.02) between the mean quantity of eggs per gram in stray (77.6±6.54) and domestic (48.7±6.65) dog's hair. Fecal examination found a T. canis egg prevalence of 35.8% and 21.3% in stray and domestic dogs, respectively. As no domestic dogs which were positive from hair samples had negative fecal samples, this indicates that the presence of T. canis eggs in hair is probably due to self contamination. Two stray dogs had positive hair samples but negative fecal samples indicating that contamination may also be environmental. As both non-embryonated and embryonated T. canis eggs were found in the hair of domestic dogs, direct contact with dogs may be a potential risk factor for transmission of T. canis eggs to humans. 相似文献
168.
The prevalence of livestock ectoparasites is the result of a complex interaction of factors such as parasite and host abundance, host susceptibility, climate and, critically, farmer husbandry and intervention strategies, all of which change seasonally in space and time. Given the complexity of the interacting factors, the effects of any climate change on disease incidence are hard to predict, as accordingly are the optimal husbandry responses required to ameliorate any effects. Here cutaneous myiasis in sheep, by the blowfly Lucilia sericata in the United Kingdom, is used to highlight the impact of a range of such issues. Cutaneous myiasis would be expected to be highly sensitive to even small changes in climate and therefore provides a good model to illustrate the problems inherent in attempting to predict the effect of climate change on livestock disease incidence. Both simulation and spatial species distribution models, show that the range of elevated temperatures predicted by current climate change scenarios are likely to result in an elongated blowfly season with earlier spring emergence and a higher cumulative incidence of strike. Strike incidence would be expected to increase, particularly for ewes in early summer. However, under higher IPCC emissions senarios (+3 °C), parts of central and southern England may become too hot and dry for strike by L. sericata to persist in mid-summer. Under these conditions, it is possible that other, more pathogenic Mediterranean agents of myiasis, such as Wohlfahrtia magnifica could replace L. sericata. Nevertheless, the models suggest that simple changes in some husbandry practices, such as shearing or trap use, could have an important effect in reducing early season ewe strike incidences by L. sericata. The work reviewed here, suggests that climate warming is likely to increase the risk of fly strike incidence, with consequent animal welfare and economic problems. However, practical measures exist which, with modest changes in husbandry practices, should be able to manage expected increases in strike, under the range of climate changes currently predicted. The work demonstrates that attempts to predict the likely impact of climate change on disease incidence must take into account changes in farmer behaviour and animal management practices as well as parasite biology. 相似文献
169.
Jordi López-Alvarez LltVet MRCVS Sonja Fonfara Dr Med Vet MRCVS Brigite Pedro DVM MRCVS Hannah Stephenson BVMS MRCVS Peter J. Cripps BSc BVSc MSc PhD MRCVS Joanna Dukes-McEwan BV MS MVM PhD MRCVS 《Journal of Veterinary Cardiology》2011,13(3):183-195
Objectives
Loss of temporal synchrony of myocardial contraction has been shown to reduce systolic function and be responsible for disease progression in people. The objective of this study is the assessment of inter- and intra ventricular synchrony in healthy Doberman Pinschers and those with dilated cardiomyopathy (DCM) by use of conventional Doppler and tissue velocity imaging.Animals
A total of 60 scans from 35 client-owned Doberman Pinschers presented for cardiac evaluation were analysed.Methods
Retrospective analysis of data. Using the European Society of Veterinary Cardiology DCM taskforce scoring system, Doberman Pinschers were classified into 4 groups: Control (Group 1; n = 12), depressed systolic function other than DCM (Group 2; n = 9), preclinical DCM (Group 3; n = 8) and symptomatic DCM (Group 4; n = 6). The time intervals between the beginning of the QRS complex and the peak velocity of pulmonic flow (Q-P) and the peak aortic flow (Q-Ao) were used to assess global synchrony between both ventricles. The time intervals between the beginning of the QRS complex and the peak myocardial systolic velocity (Q-peak S) and the onset of myocardial systolic velocity (Q-start S) were measured at the base of the right and left ventricular free wall (RVFW and LVFW) and interventricular septum (IVS), and used to determine segmental longitudinal inter- and intra ventricular synchrony.Results
No significant loss of global or segmental longitudinal inter- or intra ventricular synchrony was identified between the groups.Conclusion
Impairment of longitudinal fibre synchrony does not appear to be significantly associated with clinical status of DCM in Doberman Pinschers, although it was identified in certain individuals. 相似文献170.
Buckley M Walker A Ho SY Yang Y Smith C Ashton P Oates JT Cappellini E Koon H Penkman K Elsworth B Ashford D Solazzo C Andrews P Strahler J Shapiro B Ostrom P Gandhi H Miller W Raney B Zylber MI Gilbert MT Prigodich RV Ryan M Rijsdijk KF Janoo A Collins MJ 《Science (New York, N.Y.)》2008,319(5859):33; author reply 33
We used authentication tests developed for ancient DNA to evaluate claims by Asara et al. (Reports, 13 April 2007, p. 280) of collagen peptide sequences recovered from mastodon and Tyrannosaurus rex fossils. Although the mastodon samples pass these tests, absence of amino acid composition data, lack of evidence for peptide deamidation, and association of alpha1(I) collagen sequences with amphibians rather than birds suggest that T. rex does not. 相似文献