全文获取类型
收费全文 | 335篇 |
免费 | 33篇 |
出版年
2021年 | 5篇 |
2019年 | 6篇 |
2016年 | 10篇 |
2015年 | 12篇 |
2014年 | 11篇 |
2013年 | 8篇 |
2012年 | 10篇 |
2011年 | 9篇 |
2010年 | 9篇 |
2009年 | 6篇 |
2008年 | 15篇 |
2007年 | 13篇 |
2006年 | 8篇 |
2005年 | 11篇 |
2004年 | 7篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 13篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1982年 | 5篇 |
1979年 | 3篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1972年 | 6篇 |
1971年 | 5篇 |
1970年 | 5篇 |
1969年 | 3篇 |
1968年 | 6篇 |
1966年 | 4篇 |
1965年 | 3篇 |
1964年 | 3篇 |
1963年 | 4篇 |
1962年 | 7篇 |
1960年 | 4篇 |
1959年 | 3篇 |
1958年 | 2篇 |
排序方式: 共有368条查询结果,搜索用时 15 毫秒
41.
42.
43.
A reappraisal of the terverticillate penicillia using biochemical, physiological and morphological features. I. Numerical taxonomy 总被引:4,自引:0,他引:4
P D Bridge D L Hawksworth Z Kozakiewicz A H Onions R R Paterson M J Sackin P H Sneath 《Journal of general microbiology》1989,135(11):2941-2966
Three-hundred-and-forty-eight strains representing the major species of terverticillate penicillia, and including representatives of other closely and distantly related species, were included in a numerical taxonomic study. One-hundred characters were derived from morphological features, physiological and biochemical activities and SEM micrographs. Strains were compared by both Gower's coefficient and Pattern difference, and clustered using the average linkage algorithm. Thirty-seven species or species-complex clusters were recovered at approximately 70% similarity; they generally corresponded to existing taxonomic concepts. Several species were shown to contain variants or chemotypes which were often supported by differences in conidial shape and ornamentation. The use of different types of characters enabled a number of new and previously accepted species to be shown to be either variants or deteriorated examples of other species. Variation in properties both between and within species was considered, particularly in relation to strain stability. 相似文献
44.
45.
Wm. Bridge Cooke 《Mycopathologia》1965,25(1-2):195-200
Summary More than 2,300 strains of 70 species of yeasts have been tested on yeast autolysate agar at 37° C. Of these, all strains of 15 species grew at this elevated temperature while no strains of 13 species grew well. The remaining 42 species, represented by 2 or more strains each, included strains both capable and incapable of growth at 37° C. It is suggested that such species include two groups of strains, one capable of adaptation to growth conditions at elevated temperatures. In sewage-polluted waters such strains may be indicative of fecal pollution.U.S. Department of Health, Education, and Welfare, Bureau of State Services, Public Health Service. 相似文献
46.
The possible contribution of Na+-Ca2+ exchange to the triggering of Ca2+ release from the sarcoplasmic reticulum in ventricular cells remains unresolved. To gain insight into this issue, we measured the “trigger flux” of Ca2+ crossing the cell membrane in rabbit ventricular myocytes with Ca2+ release disabled pharmacologically. Under conditions that promote Ca2+ entry via Na+-Ca2+ exchange, internal [Na+] (10 mM), and positive membrane potential, the Ca2+ trigger flux (measured using a fluorescent Ca2+ indicator) was much greater than the Ca2+ flux through the L-type Ca2+ channel, indicating a significant contribution from Na+-Ca2+ exchange to the trigger flux. The difference between total trigger flux and flux through L-type Ca2+ channels was assessed by whole-cell patch-clamp recordings of Ca2+ current and complementary experiments in which internal [Na+] was reduced. However, Ca2+ entry via Na+-Ca2+ exchange measured in the absence of L-type Ca2+ current was considerably smaller than the amount inferred from the trigger flux measurements. From these results, we surmise that openings of L-type Ca2+ channels increase [Ca2+] near Na+-Ca2+ exchanger molecules and activate this protein. These results help to resolve seemingly contradictory results obtained previously and have implications for our understanding of the triggering of Ca2+ release in heart cells under various conditions. 相似文献
47.
R Bremner D C Du M J Connolly-Wilson P Bridge K F Ahmad H Mostachfi D Rushlow J M Dunn B L Gallie 《American journal of human genetics》1997,61(3):556-570
A deletion in the tumor-suppressor gene, RB, discovered by quantitative multiplex PCR, shows low penetrance (LP), since only 39% of eyes at risk in this family develop retinoblastoma. The 4-kb deletion spanning exons 24 and 25 (delta24-25) is the largest ever observed in an LP retinoblastoma family. Unlike the usual RB mutations, which cause retinoblastoma in 95% of at-risk eyes and yield no detectable protein, the delta24-25 allele transcribed a message splicing exon 23 to exon 26, resulting in a detectable protein (pRBdelta24-25) that lacks 58 amino acids from the C-terminal domain, proving that this domain is essential for suppression of retinoblastoma. Two functions were partially impaired by delta24-25-nuclear localization and repression of E2F-consistent with the idea that LP mutations generate "weak alleles" by reducing but not eliminating essential activities. However, delta24-25 ablated interaction of pRB with MDM2. Since a homozygous LP allele is considered nontumorigenic, the pRB/MDM2 interaction may be semi- or nonessential for suppressing retinoblastoma. Alternatively, some homozygous LP alleles may not cause tumorigenesis because an additional event is required (the "three-hit hypothesis"), or the resulting imbalance in pRB function may cause apoptosis (the "death allele hypothesis"). pRBdelta24-25 was also completely defective in suppressing growth of Saos-2 osteosarcoma cells. Targeting pRBdelta24-25 to the nucleus did not improve Saos-2 growth suppression, suggesting that C-terminal domain functions other than nuclear localization are essential for blocking proliferation in these cells. Since delta24-25 behaves like a null allele in these cells but like an LP allele in the retina, pRB may use different mechanisms to control growth in different cell types. 相似文献
48.
Physiological and biochemical characterization of Trichoderma harzianum, a biological control agent against soilborne fungal plant pathogens. 总被引:5,自引:0,他引:5
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
I Grondona R Hermosa M Tejada M D Gomis P F Mateos P D Bridge E Monte I Garcia-Acha 《Applied microbiology》1997,63(8):3189-3198
Monoconidial cultures of 15 isolates of Trichoderma harzianum were characterized on the basis of 82 morphological, physiological, and biochemical features and 99 isoenzyme bands from seven enzyme systems. The results were subjected to numerical analysis which revealed four distinct groups. Representative sequences of the internal transcribed spacer 1 (ITS 1)-ITS 2 region in the ribosomal DNA gene cluster were compared between groups confirming this distribution. The utility of the groupings generated from the morphological, physiological, and biochemical data was assessed by including an additional environmental isolate in the electrophoretic analysis. The in vitro antibiotic activity of the T. harzianum isolates was assayed against 10 isolates of five different soilborne fungal plant pathogens: Aphanomyces cochlioides, Rhizoctonia solani, Phoma betae, Acremonium cucurbitacearum, and Fusarium oxysporum f. sp. radicis lycopersici. Similarities between levels and specificities of biological activity and the numerical characterization groupings are both discussed in relation to antagonist-specific populations in known and potential biocontrol species. 相似文献
49.
50.
Molecular differences distinguish clonal lineages within East African populations of Fusarium oxysporum f.sp. cubense 总被引:1,自引:0,他引:1
E. M. Lodwig P. D. Bridge M. A. Rutherford J. Kung'u P. Jeffries 《Journal of applied microbiology》1999,86(1):71-77
Molecular approaches for the assessment of intraspecific diversity within an economically important plant pathogen were compared with traditional physiological methods (vegetative compatibility testing). The vegetative compatibility groups (VCGs) of 14 isolates of Fusarium oxysporum f.sp. cubense (FOC) from Kenya were first assessed using nitrate non-utilizing mutants. Nine of these isolates, from different areas of the country, were compatible with one or more of VCGs 0124, 0125, 0128 and 01220, i.e. they formed a single clonal lineage. Three isolates, all originating from the banana growing district of Kisii, were compatible with the VCG 01212 and formed a second distinct clonal lineage. Mutants could not be recovered from one isolate (62) and two isolates (27 and 30) were not vegetatively compatible with any of the VCG testers and may represent two novel VCGs. Polymerase chain reaction (PCR) fingerprinting, especially when using the M13 derived primer, was found to produce banding patterns that correlated with clonal lineage and also distinguished isolates 27 and 30 when analysed by unweighted pair group method analysis and principle co-ordinate analysis. This approach also distinguished FOC from F. oxysporum IMI350438 isolated from Triticum sp. and from isolates of Colletotrichum gloeosporioides . Total protein profiles were analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and although clonal lineages were not separated, isolates 27 and 30 were again distinguishable and FOC produced a different profile to F. oxysporum (IMI 350438) and C. gloeosporioides. 相似文献