全文获取类型
收费全文 | 496篇 |
免费 | 20篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 10篇 |
2016年 | 17篇 |
2015年 | 16篇 |
2014年 | 22篇 |
2013年 | 20篇 |
2012年 | 32篇 |
2011年 | 27篇 |
2010年 | 20篇 |
2009年 | 17篇 |
2008年 | 24篇 |
2007年 | 31篇 |
2006年 | 37篇 |
2005年 | 28篇 |
2004年 | 43篇 |
2003年 | 34篇 |
2002年 | 31篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有516条查询结果,搜索用时 125 毫秒
511.
Diarrheal and Environmental Isolates of Aeromonas spp. Produce a Toxin Similar to Shiga-Like Toxin 1
Quazi Manjurul Haque Akira Sugiyama Yoshito Iwade Yutaka Midorikawa Toru Yamauchi 《Current microbiology》1996,32(5):239-245
Diarrheal and environmental isolates of 39 strains of Aeromonas spp. were studied for detection of virulence factors. Although these 39 strains did not produce either heat-labile or heat-stable
enterotoxins, culture filtrates of 31 strains produced cytopathic effects on Vero cells. Among these, culture filtrates of
three strains of Aeromonas hydrophila and one strain of Aeromonas caviae could be neutralized by Escherichia coli O157:H7 Shiga-like toxin 1 antiserum. A single band of plasmid DNA of 2.14 kbp was isolated from these strains of Aeromonas spp. and E. coli O157:H7, which could be amplified by the polymerase chain reaction (PCR), employing oligonucleotide primers from the Shiga-like
toxin 1 (SLT1) gene of E. coli O157:H7. E. coli HB 101 cells when transformed with the same plasmid showed cytopathic effects on Vero cells, which indicates that the SLT
1 homolog gene(s) of Aeromonas spp. is plasmid encoded. These results suggest that Aeromonas spp. may also produce Shiga-like toxin 1, or at least a cytotoxin with some homology with the Shiga-like toxin 1 of E. coli O157:H7. 相似文献
512.
513.
514.
Kasahara Yasuhiro; Nakai Sumiko; Ogasawara Naotake; Yata Katsunori; Sadaie Yoshito 《DNA research》1997,4(5):335-339
We have determined a 35-kb sequence of the groESL-gutR-cotA(45°52°) region of the Bacillus subtilis genome.In addition to the groESL, gutRB and cotA genes reported previously,we have newly identified 24 ORFs including gutA and fruC genes,encoding glucitol permease and fructokinase, respectively. Theinherent restriction/modification system genes, hsdMR and hsdMM,were mapped between groESL and gutRB, and we have identifiedtwo open reading frames (ORFs) encoding 5-methylcytosine formingDNA methyl transferase and an operon probably encoding a restrictionenzyme complex. The unusual genome structure of few ORFs andlower GC content around the restriction/modification genes stronglysuggests that the region originated from a bacteriophage integratedduring evolution. 相似文献
515.
Lactuca sativa L. cv. Grand Rapids) seedlings under acidic conditions by a phytochrome-mediated response. Microbeam irradiation of 1 mm
root segments with the first (100 Jm−2) and second (1,000 Jm−2) maxima of the fluence response curve for red light induction of root hair initiation indicated that the ca. 5 mm apical portion of 12 mm long roots was the site of photoperception. The root hair-forming portion of the root was situated
at a distance of 1.7 mm from the root tip at the time of red light irradiation and extended (at most 1.5 mm) towards the basal
end at a later stage of development, irrespective of which portion of the root was irradiated with red light.
Received 13 August 1999/ Accepted in revised form 22 December 1999 相似文献
516.