全文获取类型
收费全文 | 362篇 |
免费 | 26篇 |
出版年
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 13篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 26篇 |
2014年 | 35篇 |
2013年 | 26篇 |
2012年 | 41篇 |
2011年 | 25篇 |
2010年 | 18篇 |
2009年 | 13篇 |
2008年 | 21篇 |
2007年 | 20篇 |
2006年 | 15篇 |
2005年 | 18篇 |
2004年 | 13篇 |
2003年 | 14篇 |
2002年 | 15篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有388条查询结果,搜索用时 15 毫秒
381.
Hans Thijs Julie Garde Theo Goosen Brian Tomsett Klaas Swart Christa Heyting Henk W. J. van den Broek 《Molecular genetics and genomics : MGG》1995,247(3):343-350
We have examined polarity of meiotic gene conversion in the niiA-niaD gene cluster of Aspergillus nidulans in two-point crosses. The type and position of the mutations represented by the niaD alleles and the correlation between the relative frequency of gene conversion and the physical position of these mutations were determined. We show that polarity of meiotic gene conversion is 5′ to 3′ (transcribed strand) within the niaD gene. Additional crosses involving a niiA allele and a niaD allele show little polarity of gene conversion, which suggests that the recombination events leading to restoration of the niaD gene are initiated upstream of the coding region of the niaD gene but within the niiA-niaD gene cluster, possibly within the intergenic promoter region. 相似文献
382.
383.
Bert Hidding Marcel Klaassen Thijs de Boer Peter P. de Vries Bart A. Nolet 《Basic and Applied Ecology》2012,13(1):50-58
Deeper burial of bulbs and tubers has been suggested as an escape against below-ground herbivory by vertebrates, but experimental evidence is lacking. As deep propagule burial can incur high costs of emergence after dormancy, burial depth may represent a trade-off between sprouting survival and herbivore avoidance. We tested whether burial depth of subterraneous tubers is a flexible trait in fennel pondweed (Potamogeton pectinatus), facing tuber predation by Bewick's swans (Cygnus columbianus bewickii) in shallow lakes in winter. In a four-year experiment involving eight exclosures, winter herbivory by swans and all vertebrate summer herbivory were excluded in a full-factorial design; we hence controlled for aboveground vertebrate herbivory in summer, possibly influencing tuber depth. Tuber depth was measured each September before swan arrival and each March before tuber sprouting. In accordance with our hypothesis, tuber depth in September decreased after excluding Bewick's swans in comparison to control plots. The summer exclosure showed an increase in tuber biomass and the number of shallow tubers, but not a significant effect on the mean burial depth of tuber mass. Our results suggest that a clonal plant like P. pectinatus can tune the tuber burial depth to predation pressure, either by phenotypic plasticity or genotype sorting, hence exhibiting flexible avoidance by escape. We suggest that a flexible propagule burial depth can be an effective herbivore avoidance strategy, which might be more widespread among tuber forming plant species than previously thought. 相似文献
384.
Thijs Bosch Albert J de Neeling Leo M Schouls Kim W van der Zwaluw Jan AJW Kluytmans Hajo Grundmann Xander W Huijsdens 《BMC microbiology》2010,10(1):40
Background
Livestock has recently been identified as a new reservoir of methicillin-resistant Staphylococcus aureus (MRSA). Most isolates belong to ST398 and are non-typeable with PFGE using SmaI, making it difficult to study transmission and outbreaks. Therefore, a new PFGE using Cfr9I, a neoschizomer of SmaI was optimized and evaluated to investigate ST398 isolates. 相似文献385.
Rogier Bodewes Siamak Zohari Jesper S. Krog Matthew D. Hall Timm C. Harder Theo M. Bestebroer Marco W. G. van de Bildt Monique I. Spronken Lars E. Larsen Ursula Siebert Peter Wohlsein Christina Puff Frauke Seehusen Wolfgang Baumg?rtner Tero H?rk?nen Saskia L. Smits Sander Herfst Albert D. M. E. Osterhaus Ron A. M. Fouchier Marion P. Koopmans Thijs Kuiken 《Journal of virology》2016,90(9):4269-4277
386.
Bart L. Haagmans Judith M. A. van den Brand Lisette B. Provacia V. Stalin Raj Koert J. Stittelaar Sarah Getu Leon de Waal Theo M. Bestebroer Geert van Amerongen Georges M. G. M. Verjans Ron A. M. Fouchier Saskia L. Smits Thijs Kuiken Albert D. M. E. Osterhaus 《Journal of virology》2015,89(11):6131-6135
The ability of Middle East respiratory syndrome coronavirus (MERS-CoV) to infect small animal species may be restricted given the fact that mice, ferrets, and hamsters were shown to resist MERS-CoV infection. We inoculated rabbits with MERS-CoV. Although virus was detected in the lungs, neither significant histopathological changes nor clinical symptoms were observed. Infectious virus, however, was excreted from the upper respiratory tract, indicating a potential route of MERS-CoV transmission in some animal species. 相似文献
387.
388.