全文获取类型
收费全文 | 9011篇 |
免费 | 594篇 |
国内免费 | 50篇 |
专业分类
林业 | 555篇 |
农学 | 456篇 |
基础科学 | 80篇 |
1612篇 | |
综合类 | 619篇 |
农作物 | 447篇 |
水产渔业 | 734篇 |
畜牧兽医 | 4190篇 |
园艺 | 136篇 |
植物保护 | 826篇 |
出版年
2023年 | 84篇 |
2022年 | 134篇 |
2021年 | 272篇 |
2020年 | 283篇 |
2019年 | 335篇 |
2018年 | 309篇 |
2017年 | 323篇 |
2016年 | 351篇 |
2015年 | 241篇 |
2014年 | 343篇 |
2013年 | 502篇 |
2012年 | 528篇 |
2011年 | 569篇 |
2010年 | 286篇 |
2009年 | 316篇 |
2008年 | 449篇 |
2007年 | 446篇 |
2006年 | 394篇 |
2005年 | 369篇 |
2004年 | 344篇 |
2003年 | 303篇 |
2002年 | 344篇 |
2001年 | 250篇 |
2000年 | 247篇 |
1999年 | 212篇 |
1998年 | 60篇 |
1997年 | 61篇 |
1996年 | 56篇 |
1995年 | 54篇 |
1994年 | 37篇 |
1993年 | 38篇 |
1992年 | 80篇 |
1991年 | 56篇 |
1990年 | 64篇 |
1989年 | 67篇 |
1988年 | 64篇 |
1987年 | 51篇 |
1986年 | 46篇 |
1985年 | 59篇 |
1984年 | 38篇 |
1983年 | 43篇 |
1982年 | 30篇 |
1980年 | 25篇 |
1979年 | 37篇 |
1978年 | 21篇 |
1977年 | 21篇 |
1974年 | 23篇 |
1973年 | 25篇 |
1972年 | 24篇 |
1970年 | 26篇 |
排序方式: 共有9655条查询结果,搜索用时 46 毫秒
91.
Plasma biomarkers profile of female dogs with mammary carcinoma and its association with clinical and pathological features
下载免费PDF全文
![点击此处可从《Veterinary and comparative oncology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
R. P. Soares L. G. R. Ribeiro K. A. Damasceno A. T. Costa A. Teixeira‐Carvalho O. A. Martins‐Filho G. D. Cassali 《Veterinary and comparative oncology》2016,14(1):88-100
The immunological biomarkers profiles were evaluated using Luminex as putative measures to monitor canine mammary carcinomas (MCs). Forty female dogs were categorized into benign mixed tumour (MC‐BMT = 28) and mammary carcinoma (MC=12). The ascendant biomarker signatures were used to compare the groups. For example, a higher frequency of MC‐BMT animals producing IL‐6, CXCL‐8 and CXCL‐10 was observed, whereas for the MC group IL‐2 and CXCL‐8 were detected. MC‐BMT animals without metastasis had an increase in the levels of IL‐2, CXCL‐8, CXCL‐10, IL‐6, TNF‐α, IL‐15 and a decrease in IL‐10 and CXCL‐8. MC‐BMT animals with metastasis showed only an increase in CXCL‐10 and a decrease in IL‐18. After comparing the ascendant signatures following the presence of metastasis in both groups, a higher frequency of dogs exhibiting IL‐10 production was observed. Pearson correlation (P = 0.0273) and receiver operating characteristic (ROC) curve analysis revealed that this pattern was associated with worse outcome and lower survival rates in MC animals. 相似文献
92.
Mammalian parental investment (i.e. care of descendant offspring) is largely biased towards maternal contributions due to the specific feeding needs of mammalian offspring; however, varying degrees of paternal investment have been reported in about 10% of all mammalian species. Within the order Carnivora, paternal contribution to rearing offspring is particularly high: an estimated 32% of all studied carnivore species exhibit direct paternal care. Despite the prominence of paternal investment in carnivores, the endocrine basis of this behaviour is not well understood. This review examines the current – highly constrained – state of knowledge about the endocrine basis of carnivore paternal investment. We attempt to link changes in androgen and glucocorticoid levels with variation in direct and indirect paternal care behaviour making specific predictions regarding the way forward. Well-studied species, such as bat-eared foxes (Otocyon megalotis), dwarf mongoose (Helogale parvula) and meerkats (Suricata suricatta), where social dynamics are relatively well understood, can act as ideal model systems through which we may further investigate the endocrine basis of paternal investment in carnivores. 相似文献
93.
Polymethylmethacrylate orbital implants with interconnecting channels. A retrospective study following enucleation in dogs and cats
下载免费PDF全文
![点击此处可从《Veterinary ophthalmology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
94.
95.
96.
97.
98.
99.