全文获取类型
收费全文 | 11068篇 |
免费 | 800篇 |
国内免费 | 34篇 |
专业分类
林业 | 905篇 |
农学 | 427篇 |
基础科学 | 98篇 |
2794篇 | |
综合类 | 497篇 |
农作物 | 605篇 |
水产渔业 | 1084篇 |
畜牧兽医 | 4411篇 |
园艺 | 252篇 |
植物保护 | 829篇 |
出版年
2023年 | 80篇 |
2022年 | 111篇 |
2021年 | 263篇 |
2020年 | 276篇 |
2019年 | 289篇 |
2018年 | 425篇 |
2017年 | 457篇 |
2016年 | 447篇 |
2015年 | 356篇 |
2014年 | 462篇 |
2013年 | 707篇 |
2012年 | 828篇 |
2011年 | 885篇 |
2010年 | 487篇 |
2009年 | 484篇 |
2008年 | 673篇 |
2007年 | 651篇 |
2006年 | 540篇 |
2005年 | 484篇 |
2004年 | 492篇 |
2003年 | 449篇 |
2002年 | 338篇 |
2001年 | 258篇 |
2000年 | 244篇 |
1999年 | 226篇 |
1998年 | 66篇 |
1997年 | 48篇 |
1996年 | 46篇 |
1995年 | 57篇 |
1994年 | 37篇 |
1993年 | 30篇 |
1992年 | 48篇 |
1991年 | 44篇 |
1990年 | 43篇 |
1989年 | 59篇 |
1988年 | 31篇 |
1987年 | 45篇 |
1986年 | 32篇 |
1985年 | 38篇 |
1984年 | 24篇 |
1983年 | 29篇 |
1980年 | 14篇 |
1979年 | 25篇 |
1978年 | 18篇 |
1976年 | 19篇 |
1973年 | 20篇 |
1972年 | 16篇 |
1968年 | 15篇 |
1967年 | 20篇 |
1966年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
Maria Caridad Montalvo Villalba Chantal J. Snoeck Licel de los Angeles Rodriguez Lay Aurélie Sausy Dayesi Hernández López Marite Bello Corredor Barbara Marrero Sanchéz Judith M. Hübschen 《Zoonoses and public health》2023,70(1):58-68
Surveillance of hepatitis E virus (HEV) in risk groups is an important strategy to monitor its circulation pattern and to timely detect changes thereof. The aims of this cross-sectional study were to estimate the prevalence of HEV infections in pigs and humans from different regions of the country, to identify risk factors for increasing anti-HEV IgG prevalence and to characterize HEV strains. The presence of anti-HEV antibodies was assessed by commercial ELISA in serum samples from the general population, farm and slaughterhouse employees, as well as pigs sampled in the three regions of Cuba from February to September 2016. Overall, individuals with occupational exposure to swine or swine products (70/248, 28.2%) were 4 times more likely to be seropositive compared to the general population (25/285, 8.7%; OR: 4.18; p < .001). Within the risk group, risk factors included age, number of years working in a professional activity with direct exposure to swine, geographic region and distance between residence and closest professional swine setting, while wearing gloves had a protective effect. Prevalence of total anti-HEV antibodies in swine was 88.2% (165/187) and HEV RNA was detected by real-time RT-PCR in 9.2% (16/173) swine stools. All HEV strains sequenced clustered within genotype 3. Some strains clearly belonged to subtype 3a, while another group of strains was related with subtypes 3b and 3 k but partial HEV sequences did not allow unequivocal subtype assignment. These findings suggest that the high HEV exposure in Cuban individuals with swine-related occupations could be due to enzootic HEV in certain regions, direct contact with infectious animals or their products as well as environmental contamination. 相似文献
72.
Andreas Palzer Kristina Haedke Karl Heinritzi Susanne Zoels Andrea Ladinig Mathias Ritzmann 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(3):285-287
The objective of this study was to determine the associations among Haemophilus parasuis, Mycoplasma hyorhinis, and porcine reproductive and respiratory syndrome (PRRS) virus (EU-field strain) infections in 95 pigs with polyserositis. A significant association between H. parasuis and M. hyorhinis was identified. H. parasuis and M. hyorhinis were significantly more often detected in PRRS virus positive pigs. 相似文献
73.
74.
Efficacy of Postoperative Antimicrobial Use for Clean Orthopedic Implant Surgery in Dogs: A Prospective Randomized Study in 100 Consecutive Cases 下载免费PDF全文
75.
76.
Hematologic and biochemical reference intervals for Wild Boar (Sus scrofa) captured by cage trap 下载免费PDF全文
77.
Doru Morar Gheorghe Dărăbuş Mirela Imre Marius Stelian Ilie Kálmán Imre 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2015,44(2):200-204
This case study describes the first genetically confirmed and clinically manifested autochthonous Ehrlichia canis infection in a 9‐year‐old female mixed‐breed dog from Romania. Health screening of the dog included clinical examination, evaluation of stained peripheral blood smear and hematologic variables, as well as serologic testing and molecular analysis. Clinical signs included fever, apathy, dehydration, pale mucous membranes, and weakness. The microscopic examination of the blood smear and immunologic assays for Borrelia burgdorferi, Anaplasma phagocytophilum, and E canis antibodies, and for Dirofilaria immitis antigen yielded negative results. Hematologic abnormalities included moderate nonregenerative anemia, leucopenia with neutropenia, and moderate thrombocytopenia. The biochemical abnormalities identified were hypoalbuminemia, and mildly increased serum enzyme activities of AST and ALT. In addition, increased urea and creatinine levels associated with low urine specific gravity and proteinuria were also present. Nested PCR amplification of the partial E canis 16S rRNA gene demonstrated the presence of this rickettsial pathogen in the dog's blood, which subsequently was confirmed through sequencing based on the 100% homology with GenBank deposited E canis isolates. After specific treatment with doxycycline (10 mg/kg, orally, SID) for one month, the proteinuria, and hematologic and serum biochemical abnormalities with the exception of mild azotemia resolved. This report supports the geographical expansion of canine ehrlichiosis caused by E canis in nonendemic regions of Europe. 相似文献
78.
Biochemical variables from Holstein‐Friesian calves older than one week are comparable to those obtained from adult animals of stable metabolic status on the same farm 下载免费PDF全文
79.
Plasma N‐terminal pro‐B‐type natriuretic peptide concentration in healthy retired racing Greyhounds 下载免费PDF全文
80.
Traditional veterinary anatomical models describe the branches of the caudal gluteal artery as the iliolumbar, cranial gluteal, lateral caudal, satellite of the ischiatic nerve and dorsal perineal arteries. However, some classical veterinary anatomy textbooks often indicate variations the general organization of the arterial tree, without giving any pattern of origin or illustrations of the different branching. The aim of this study was to investigate the presumptive variability of the caudal gluteal artery. Two hundred and thirty‐two pelvic halves from 116 adult dogs were examined. Twelve anatomical variations were found, nine occurring in more than 5% of the dogs, and three in <5%. A ‘long‐type’ internal iliac artery, which means short caudal gluteal and internal pudendal arteries, was identified, while a ‘perineal trunk’ was observed as an interesting arterial variation. If the caudal segment alone is taken into consideration, identical vascular patterns in both hemi‐pelvises are found in 17% of the dogs. Significant statistical correlation was found for four different types of anatomic variations and gender, two types of variations and body size, one type of variation for body side and one type of variation for head shape. 相似文献