全文获取类型
收费全文 | 3652篇 |
免费 | 328篇 |
国内免费 | 1篇 |
出版年
2023年 | 23篇 |
2022年 | 15篇 |
2021年 | 111篇 |
2020年 | 62篇 |
2019年 | 96篇 |
2018年 | 76篇 |
2017年 | 70篇 |
2016年 | 131篇 |
2015年 | 198篇 |
2014年 | 208篇 |
2013年 | 245篇 |
2012年 | 310篇 |
2011年 | 264篇 |
2010年 | 164篇 |
2009年 | 140篇 |
2008年 | 164篇 |
2007年 | 156篇 |
2006年 | 163篇 |
2005年 | 156篇 |
2004年 | 140篇 |
2003年 | 137篇 |
2002年 | 121篇 |
2001年 | 24篇 |
2000年 | 34篇 |
1999年 | 27篇 |
1998年 | 23篇 |
1997年 | 19篇 |
1996年 | 25篇 |
1995年 | 24篇 |
1994年 | 15篇 |
1993年 | 19篇 |
1992年 | 27篇 |
1991年 | 23篇 |
1990年 | 31篇 |
1989年 | 28篇 |
1988年 | 18篇 |
1987年 | 25篇 |
1986年 | 16篇 |
1985年 | 37篇 |
1984年 | 32篇 |
1983年 | 21篇 |
1982年 | 23篇 |
1981年 | 24篇 |
1980年 | 17篇 |
1979年 | 21篇 |
1978年 | 19篇 |
1975年 | 15篇 |
1973年 | 16篇 |
1972年 | 15篇 |
1967年 | 13篇 |
排序方式: 共有3981条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The influence of a synthetic adjuvant active glycopeptide, N-acetylmuramyl-l-alanyl-d-isoglutamine (MDP), and of some of its analogs on the in vitro immune response to sheep red blood cells was studied using Mishell and Dutton in vitro stimulation system. When MDP and adjuvant active analogs were incubated with normal spleen cells, increased cell recovery was observed after 3 or 4 days of culture, showing a good correlation between the adjuvant activity in vivo and the enhancement of cell viability in vitro. The analogs which were found to have an adjuvant activity in vivo were equally effective in stimulating in vitro both the background hemolytic PFC and the immune response to sheep red blood cells. However, those which were inactive in vivo were effective in vitro but only at high concentration levels. 相似文献
5.
Maria Wilbe Martine Lund Ziener Anita Aronsson Charlotte Harlos Katarina Sundberg Elin Norberg Lisa Andersson Kerstin Lindblad-Toh ?ke Hedhammar G?ran Andersson Frode Lingaas 《PloS one》2010,5(8)
Symmetrical lupoid onychodystrophy (SLO) is an immune-mediated disease in dogs affecting the claws with a suggested autoimmune aethiology. Sequence-based genotyping of the polymorphic exon 2 from DLA-DRB1, -DQA1, and -DQB1 class II loci were performed in a total of 98 SLO Gordon setter cases and 98 healthy controls. A risk haplotype (DRB1*01801/DQA1*00101/DQB1*00802) was present in 53% of cases and 34% of controls and conferred an elevated risk of developing SLO with an odds ratio (OR) of 2.1. When dogs homozygous for the risk haplotype were compared to all dogs not carrying the haplotype the OR was 5.4. However, a stronger protective haplotype (DRB1*02001/DQA1*00401/DQB1*01303, OR = 0.03, 1/OR = 33) was present in 16.8% of controls, but only in a single case (0.5%). The effect of the protective haplotype was clearly stronger than the risk haplotype, since 11.2% of the controls were heterozygous for the risk and protective haplotypes, whereas this combination was absent from cases. When the dogs with the protective haplotype were excluded, an OR of 2.5 was obtained when dogs homozygous for the risk haplotype were compared to those heterozygous for the risk haplotype, suggesting a co-dominant effect of the risk haplotype. In smaller sample sizes of the bearded collie and giant schnauzer breeds we found the same or similar haplotypes, sharing the same DQA1 allele, over-represented among the cases suggesting that the risk is associated primarily with DLA-DQ. We obtained conclusive results that DLA class II is significantly associated with risk of developing SLO in Gordon setters, thus supporting that SLO is an immune-mediated disease. Further studies of SLO in dogs may provide important insight into immune privilege of the nail apparatus and also knowledge about a number of inflammatory disorders of the nail apparatus like lichen planus, psoriasis, alopecia areata and onycholysis. 相似文献
6.
Dane Bicanic Darko Dimitrovski Svjetlana Luterotti Ksenija Marković Charlotte van Twisk Josephus G. Buijnsters Otto Dóka 《Food biophysics》2010,5(1):24-33
The trans-lycopene content of fresh tomato homogenates was assessed by means of the laser photoacoustic spectroscopy, the laser optothermal
window, micro-Raman spectroscopy, and colorimetry; none of these methods require the extraction from the product matrix prior
to the analysis. The wet chemistry method (high-performance liquid chromatography) was used as the absolute quantitative method.
Analytical figures of merit for all methods were compared statistically; best linear correlation was achieved for the chromaticity
index a* and chroma C*. 相似文献
7.
8.
9.
10.