全文获取类型
收费全文 | 1395篇 |
免费 | 86篇 |
专业分类
林业 | 113篇 |
农学 | 50篇 |
基础科学 | 3篇 |
298篇 | |
综合类 | 93篇 |
农作物 | 85篇 |
水产渔业 | 132篇 |
畜牧兽医 | 582篇 |
园艺 | 27篇 |
植物保护 | 98篇 |
出版年
2024年 | 3篇 |
2023年 | 21篇 |
2022年 | 19篇 |
2021年 | 39篇 |
2020年 | 42篇 |
2019年 | 42篇 |
2018年 | 56篇 |
2017年 | 63篇 |
2016年 | 77篇 |
2015年 | 39篇 |
2014年 | 73篇 |
2013年 | 65篇 |
2012年 | 96篇 |
2011年 | 122篇 |
2010年 | 64篇 |
2009年 | 37篇 |
2008年 | 95篇 |
2007年 | 74篇 |
2006年 | 82篇 |
2005年 | 76篇 |
2004年 | 65篇 |
2003年 | 64篇 |
2002年 | 48篇 |
2001年 | 17篇 |
2000年 | 19篇 |
1999年 | 14篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1986年 | 3篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 3篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有1481条查询结果,搜索用时 15 毫秒
41.
Mogens T Christophersen Nana Dupont Kristina S Berg-S?rensen Christel Konnerup Tina H Pihl Pia H Andersen 《Acta veterinaria Scandinavica》2014,56(1):20
Background
Outcomes of colic treatment are of great interest to clinicians, horse owners and insurers. One commonly used criterion of success is the overall short-term survival rate. This is used as to compare treatments and to measure quality of veterinary care, but may be biased by demographic or social factors such as attitudes towards animal suffering and euthanasia. The aims of this study were to 1) describe and analyse characteristics in horses with signs of colic referred to the University Hospital for Large Animals (UHLA), University of Copenhagen, Denmark over a 10-year period and 2) to compare these rates with those published in other comparable studies.Results
The overall survival rate for colic horses over the 10-year study period was 68% (confidence intervals (CI): 66–71%; 1087/1588). In the medical group, 1093 horses, short-term survival was 87% (CI: 85–89%). Thirty one % of referred horses were given diagnoses requiring surgical intervention (CI: 29–33%). In this group 32% of the horses were euthanized before surgery (CI: 28–36%; 159/495). Of the surgical cases 27% (CI: 23-31%) were euthanized or died during surgery. Of the horses that recovered from surgery 25% died or were euthanized (CI: 19–32%; 48/189), while 75% survived to discharge (CI: 68–81%).Conclusions
The short term survival rates of Danish horses with colic were similar or lower to those reported from other countries. Apart from variability of veterinary care, attitudes towards euthanasia vary among the countries, which may bias the outcomes. This study indicates that qualitative interview studies on owners’ attitudes towards animal suffering and euthanasia need to be conducted. Our opinion is that survival rates are not valid as sole indicators of quality of care in colic treatment due to selection bias. If the survival rates are to be compared between hospitals, techniques or surgeons, prospective studies including mutually agreed-on disease severity scores and a predefined set of reasons for euthanasia are needed. 相似文献42.
Mohamed Faize Marie-Noëlle Brisset Jean-Stéphane Venisse Jean-Pierre Paulin Michel Tharaud 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(6):547-553
A virulent strain of Erwinia amylovora, the causal agent of fire blight of Maloideae, and two of its non-virulent hrp mutants (a secretory and a regulatory mutant) were inoculated into apple cell suspensions either alone or in mixed inoculations. In single inoculations, death of 4- to 5-day-old apple cells occurred only when the concentration of the virulent strain of E. amylovora reached a threshold inoculum concentration of 104CFUml–1, while high concentrations of the hrp mutants were unable to kill apple cells. When mixed inoculated with the virulent parental strain, both hrp mutants protected apple cells from death caused by the virulent strain. The protective effect was associated with a decrease in the population level of the virulent strain and it was dependent on the non-virulent to virulent inoculum concentration suggesting a competition between the non-virulent mutant and the virulent strain. However, no differential protective ability between the two types of mutants could be noticed, contrary to previous results obtained with apple seedlings or apple flowers in which the regulatory mutant was significantly more effective than the secretory mutant. In conclusion, inoculation of apple cell cultures with E. amylovora does not seem to be a model suitable for investigating mechanisms leading to protection. 相似文献
43.
PRACTICAL RELEVANCE: Nasopharyngeal disease is a common presenting problem in feline medicine. CLINICAL CHALLENGES: The management of feline nasopharyngeal disease can be challenging at a number of levels. In many cases, a specific diagnosis may remain elusive. Some conditions may not be curable so owners need to understand the requirement for long-term management. In addition, treatment may be compromised by poor patient compliance. AUDIENCE: This review, which is directed at any clinicians involved in the management of cats with nasopharyngeal disease, discusses acute rhinitis (cat 'flu) and a variety of conditions causing chronic rhinosinusitis/chronic nasopharyngeal disease. The intention is to assist treatment decision making by reviewing the most appropriate therapies from the options available for these patients. EVIDENCE BASE: The information presented in this article is based on peer-reviewed publications and the clinical experience of the authors. 相似文献
44.
Baliarsingh Snigdha Sahoo Sonalina Jo Yong Hun Han Yeon Soo Sarkar Arup Lee Yong Seok Mohanty Jyotirmaya Patnaik Bharat Bhusan 《Aquaculture International》2022,30(2):1011-1035
Aquaculture International - Lectin protein families are diverse and multi-functional in crustaceans. The carbohydrate-binding domains (CRDs) of lectins recognize the molecular patterns associated... 相似文献
45.
François‐Joël Gatesoupe Denis Covès Aurelio Ortega Nikos Papandroulakis Olav Vadstein Fernando de la Gándara 《Aquaculture Research》2013,44(10):1511-1523
During the first 2 years of larval rearing trials with Atlantic bluefin tuna, survival was a challenging issue. As bacterial colonization of the gut has been shown to play a key role for other species, we studied the profiles of the microbiota associated with individual larvae at different stages in three distant hatcheries. The Bacterial Community Profile (BCP) was quantified based on PCR‐DGGE analyses of partial amplicons from 16S rDNA. Considerable individual variability in BCP was observed before onset of feeding, and the BCP did not show regular fluctuation during ontogenesis. Microalgae were added to the rearing tanks in two of the three hatcheries, but it was not possible to distinguish the effect of location from the effect of algal addition on BCP. In one hatchery, the larvae were reared either with algal addition or in mesocosm, but due to high individual variability, no significant difference in BCP was detected between the two groups. It was hypothesized that this variability was caused by differences in health, physiological status and developmental stage of the larvae. A practical conclusion from the study is the need to analyse a considerable number of individuals to reflect statistically significant differences between the microbial communities associated with rearing groups. 相似文献
46.
47.
Angelia S. M. Vanderlaan Alex R. Hanke Joël Chassé John D. Neilson 《Fisheries Oceanography》2014,23(1):83-100
The Atlantic bluefin tuna (Thunnus thynnus) population in the western Atlantic supports substantial commercial and recreational fisheries. Despite quota establishment and management under the auspices of the International Commission for the Conservation of Atlantic Tunas, only small increases in population growth have been estimated. In contrast to other western bluefin tuna fisheries indices, contemporary estimates of catch per unit effort (CPUE) in the southern Gulf of St. Lawrence have increased rapidly and are at record highs. This area is characterized by the Cold Intermediate Layer (CIL) that is defined by waters <3°C and located at depths of 30–40 m in September. We investigated the influence of several in situ environmental variables on the bluefin tuna fishery CPUE using delta‐lognormal modelling and relatively extensive and consistent oceanographic survey data, as well as dockside monitoring and mandatory logbook data associated with the fishery. Although there is considerable spatial and temporal variation of water mass characteristics, the amount of available habitat in the southern Gulf of St. Lawrence (assuming a > 3°C thermal ambit) for bluefin tuna has been increasing. The percentage of the water column occupied by the CIL was a significant environmental variable in the standardization of CPUE estimates. There was also a negative relationship between the spatial extents of the CIL and the fishery. Properties of the CIL account for variation in the bluefin tuna CPUE and may be a factor in determining the amount of available feeding habitat for bluefin tuna in the southern Gulf of St. Lawrence. 相似文献
48.
Marta Lizandra do Reo Leal Emmanuel Veiga de Camargo Daniel Henrique Ross Marcelo Beltrão Molento Sonia Terezinha dos Anjos Lopes João Batista Teixeira da Rocha 《Veterinary research communications》2010,34(6):549-555
The objective of this study was to evaluate oxidative stress in lambs experimentally infected with Haemonchus contortus and supplemented with selenium and vitamin E. Twenty male Corriedale lambs were divided into four experimental groups with
five animals each: G1 consisted of animals infected and supplemented with 0.2 mg/kg of live weight (LW) sodium selenite by
intramuscular injection (IM); G2 consisted of animals infected with larvae and supplemented with 0.2 mg/kg LW sodium selenite
IM and 2000 IU per animal of Vitamin E IM; G3 consisted of animals infected with larvae and supplemented with 2000 IU per
animal of Vitamin E IM; and G4 consisted of animals infected with larvae. The animals were infected orally with 500 H. contortus larvae (L3) every 48 hours for 20 days. For biochemical analyses and eggs per grams of feces (EPG) evaluation, blood and
feces were both collected at zero (T0), 20 (T1), 40 (T2) and 60 (T3) days. The weight of the animals was also measured at
these times. Lower TBARS values were observed in the supplemented animals compared to the control group. The groups supplemented
with Selenium exhibited blood GSH-Px activity higher than that of non-supplemented animals. Supplementation with selenium
provided greater antioxidant protection against oxidative stress generated from experimental infection of lambs with H. contortus. 相似文献
49.
Comparative evaluation of MCP gene in worldwide strains of Megalocytivirus (Iridoviridae family) for early diagnostic marker 下载免费PDF全文
A Mishra G‐H Nam J‐A Gim H‐E Lee A Jo D Yoon S Oh S Kim A Kim D‐H Kim Y C Kim H D Jeong H‐J Cha Y H Choi H‐S Kim 《Journal of fish diseases》2018,41(1):105-116
Members of the Iridoviridae family have been considered as aetiological agents of iridovirus diseases, causing fish mortalities and economic losses all over the world. Virus identification based on candidate gene sequencing is faster, more accurate and more reliable than other traditional phenotype methodologies. Iridoviridae viruses are covered by a protein shell (capsid) encoded by the important candidate gene, major capsid protein (MCP). In this study, we investigated the potential of the MCP gene for use in the diagnosis and identification of infections caused Megalocytivirus of the Iridoviridae family. We selected data of 66 Iridoviridae family isolates (53 strains of Megalocytivirus, eight strains of iridoviruses and five strains of Ranavirus) infecting various species of fish distributed all over the world. A total of 53 strains of Megalocytivirus were used for designing the complete primer sets for identifying the most hypervariable region of the MCP gene. Further, our in silico analysis of 102 sequences of related and unrelated viruses reconfirms that primer sets could identify strains more specifically and offers a useful and fast alternative for routine clinical laboratory testing. Our findings suggest that phenotype observation along with diagnosis using universal primer sets can help detect infection or carriers at an early stage. 相似文献
50.
Smits E Burvenich C Guidry AJ Massart-Leën A 《Veterinary immunology and immunopathology》2000,73(3-4):255-265
epithelium. Neutrophil migration across mammary arterial endothelial cells was almost completely dependent on CD18, the beta-chain of the beta(2) integrins, and to a lesser extent on CD11b, one of the alpha-chains of the beta(2) integrins. Neutrophil migration across collagen was partially blocked by monoclonal antibodies to CD18. No inhibition was observed by monoclonal antibodies to CD11b. Conversely, neutrophil diapedesis across mammary epithelial cells was dependent to a greater extent on CD11b. These results provide evidence for different CD11b/CD18-dependent mechanisms for neutrophil diapedesis across the various cell layers of the blood-milk barrier. 相似文献