全文获取类型
收费全文 | 67224篇 |
免费 | 3792篇 |
国内免费 | 94篇 |
专业分类
林业 | 4396篇 |
农学 | 2486篇 |
基础科学 | 418篇 |
8884篇 | |
综合类 | 7522篇 |
农作物 | 2333篇 |
水产渔业 | 3649篇 |
畜牧兽医 | 36559篇 |
园艺 | 964篇 |
植物保护 | 3899篇 |
出版年
2020年 | 597篇 |
2019年 | 581篇 |
2018年 | 1230篇 |
2017年 | 1288篇 |
2016年 | 1276篇 |
2015年 | 1076篇 |
2014年 | 1212篇 |
2013年 | 2783篇 |
2012年 | 2251篇 |
2011年 | 2627篇 |
2010年 | 1708篇 |
2009年 | 1574篇 |
2008年 | 2397篇 |
2007年 | 2469篇 |
2006年 | 2311篇 |
2005年 | 2080篇 |
2004年 | 1942篇 |
2003年 | 1934篇 |
2002年 | 1760篇 |
2001年 | 2470篇 |
2000年 | 2318篇 |
1999年 | 1835篇 |
1998年 | 721篇 |
1997年 | 645篇 |
1996年 | 636篇 |
1995年 | 712篇 |
1994年 | 595篇 |
1993年 | 589篇 |
1992年 | 1355篇 |
1991年 | 1492篇 |
1990年 | 1560篇 |
1989年 | 1444篇 |
1988年 | 1350篇 |
1987年 | 1329篇 |
1986年 | 1266篇 |
1985年 | 1192篇 |
1984年 | 998篇 |
1983年 | 793篇 |
1982年 | 566篇 |
1979年 | 885篇 |
1978年 | 686篇 |
1976年 | 576篇 |
1975年 | 568篇 |
1974年 | 716篇 |
1973年 | 703篇 |
1972年 | 704篇 |
1971年 | 693篇 |
1970年 | 653篇 |
1969年 | 608篇 |
1967年 | 553篇 |
排序方式: 共有10000条查询结果,搜索用时 304 毫秒
991.
Bozkurt İ. Adem Soylu Soner Kara Merve Doksöz Senem Filiz Altan Bülent Çarpar Hakan 《植物病害和植物保护杂志》2023,130(1):13-21
Journal of Plant Diseases and Protection - Citrus (Citrus spp. L.), which has high nutritional and economic value, is one of the most commonly grown fruits in Turkey. In spring 2020, large aerial... 相似文献
992.
993.
Journal of Plant Diseases and Protection - The root-knot nematodes (Meloidogyne spp.) are significant pathogens that affect the yield and fruit quality in pepper cultivars (Capsicum spp.).... 相似文献
994.
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
995.
996.
K. J. Nytko M. S. Weyland S. Dressel-Böhm S. Scheidegger L. Salvermoser C. Werner S. Stangl A. C. Carpinteiro B. Alkotub G. Multhoff S. Bodis C. Rohrer Bley 《Veterinary and comparative oncology》2023,21(4):605-615
Hyperthermia is a form of a cancer treatment which is frequently applied in combination with radiotherapy (RT) to improve therapy responses and radiosensitivity. The mode of action of hyperthermia is multifactorial; the one hand by altering the amount of the blood circulation in the treated tissue, on the other hand by modulating molecular pathways involved in cell survival processes and immunogenic interactions. One of the most dominant proteins induced by hyperthermia is the major stress-inducible heat shock protein 70 (Hsp70). Hsp70 can be found in the blood either as a free-protein (free HSP70) derived from necrotic cells, or lipid-bound (liposomal Hsp70) when it is actively released in extracellular vesicles (EVs) by living cells. The aim of the study was to evaluate the levels of free and liposomal Hsp70 before and after treatment with RT alone or hyperthermia combined with radiotherapy (HTRT) in dogs and cats to evaluate therapy responses. Peripheral blood was collected from feline and canine patients before and at 2, 4, 6 and 24 h after treatment with RT or HTRT. Hsp70 enzyme-linked immunosorbent assays (ELISAs) were performed to determine the free and liposomal Hsp70 concentrations in the serum. The levels were analysed after the first fraction of radiation to study immediate effects and after all applied fractions to study cumulative effects. The levels of free and liposomal Hsp70 levels in the circulation were not affected by the first singular treatment and cumulative effects of RT in cats however, after finalizing all treatment cycles with HTRT free and liposomal Hsp70 levels significantly increased. In dogs, HTRT, but not treatment with RT alone, significantly affected liposomal Hsp70 levels during the first fraction. Free Hsp70 levels were significantly increased after RT, but not HTRT, during the first fraction in dogs. In dogs, on the other hand, RT alone resulted in a significant increase in liposomal Hsp70, but HTRT did not significantly affect the liposomal Hsp70 when cumulative effects were analysed. Free Hsp70 was significantly induced in dogs after both, RT and HTRT when cumulative effects were analysed. RT and HTRT treatments differentially affect the levels of free and liposomal Hsp70 in dogs and cats. Both forms of Hsp70 could potentially be further investigated as potential liquid biopsy markers to study responses to RT and HTRT treatment in companion animals. 相似文献
997.
Santiago Peralta Suzin M. Webb William P. Katt Jennifer K. Grenier Gerald E. Duhamel 《Veterinary and comparative oncology》2023,21(1):138-144
Oral squamous cell carcinoma (OSCC) is the most common oral epithelial malignancy in dogs. It exhibits locally aggressive biological behaviour with the potential to metastasize, and a reported 1-year survival rate of 0% when left untreated. Expression studies suggest that aberrant MAPK signalling plays a key role in canine OSCC tumorigenesis, which is consistent with BRAF and HRAS MAPK-activating mutations reported in some tumours. Several morphological subtypes of canine OSCC have been described, with papillary, conventional, and basaloid as the most common patterns. We hypothesized that mutational differences may underlie these phenotypic variations. In this study, targeted Sanger sequencing and restriction fragment length polymorphism assays demonstrate that up to 85.7% of canine papillary OSCC (n = 14) harbour a BRAF p.V595E mutation. Assessment of neoplastic epithelial cell proliferation using Ki67 immunolabelling (n = 10) confirmed a relatively high proliferation activity, consistent with their known aggressive clinical behaviour. These findings underscore a consistent genetic feature of canine papillary OSCC and provide a basis for the development of novel diagnostic and targeted therapeutic approaches that can improve the quality of veterinary care. 相似文献
998.
999.