全文获取类型
收费全文 | 118篇 |
免费 | 6篇 |
专业分类
124篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 4篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1984年 | 1篇 |
1980年 | 3篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1968年 | 4篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1964年 | 7篇 |
1957年 | 1篇 |
排序方式: 共有124条查询结果,搜索用时 15 毫秒
51.
Inês Crespo Hermínio T?o Ana Belen Nieto Olinda Rebelo Patrícia Domingues Ana Luísa Vital Maria del Carmen Patino Marcos Barbosa Maria Celeste Lopes Catarina Resende Oliveira Alberto Orfao María Dolores Tabernero 《PloS one》2012,7(9)
Background
Glioblastoma multiforme (GBM) displays multiple amplicons and homozygous deletions that involve relevant pathogenic genes and other genes whose role remains unknown.Methodology
Single-nucleotide polymorphism (SNP)-arrays were used to determine the frequency of recurrent amplicons and homozygous deletions in GBM (n = 46), and to evaluate the impact of copy number alterations (CNA) on mRNA levels of the genes involved.Principal Findings
Recurrent amplicons were detected for chromosomes 7 (50%), 12 (22%), 1 (11%), 4 (9%), 11 (4%), and 17 (4%), whereas homozygous deletions involved chromosomes 9p21 (52%) and 10q (22%). Most genes that displayed a high correlation between DNA CNA and mRNA levels were coded in the amplified chromosomes. For some amplicons the impact of DNA CNA on mRNA expression was restricted to a single gene (e.g., EGFR at 7p11.2), while for others it involved multiple genes (e.g., 11 and 5 genes at 12q14.1–q15 and 4q12, respectively). Despite homozygous del(9p21) and del(10q23.31) included multiple genes, association between these DNA CNA and RNA expression was restricted to the MTAP gene.Conclusions
Overall, our results showed a high frequency of amplicons and homozygous deletions in GBM with variable impact on the expression of the genes involved, and they contributed to the identification of other potentially relevant genes. 相似文献52.
Vialás V Perumal P Gutierrez D Ximénez-Embún P Nombela C Gil C Chaffin WL 《Proteomics》2012,12(14):2331-2339
We used a brief trypsin treatment followed by peptide separation and identification using nano-LC followed by off-line MS/MS to identify the surface proteins on live Candida albicans organisms growing in biofilms and planktonic yeast cells and hyphae. One hundred thirty-one proteins were present in at least two of the three replicates of one condition and distributed in various combinations of the three growth conditions. Both previously reported and new surface proteins were identified and these were distributed between covalently attached proteins and noncovalently attached proteins of the cell wall. 相似文献
53.
54.
Whereas much information on the die-off of Escherichia coli in the aquatic environment is available, only few data support its growth under such conditions. We therefore investigated batch growth in microcosms containing different types of sterile freshwater. The water samples were inoculated with low starting cell concentrations of E. coli O157 (3 × 103 cells ml−1 ) and growth was followed using nucleic acid staining combined with flow cytometry. We demonstrated that E. coli O157 is able to grow in sterile freshwater at low carbon concentrations, which is against the common view that cell numbers decline over time when added to freshwater samples. A correlation between apparent assimilable organic carbon (AOCapp ) concentration and the final cell concentration reached by E. coli O157 was established ( P < 0.01). A considerable fraction of the AOCapp (34 ± 13%) was used by E. coli O157 but the numerical cell yield was about five-times lower in comparison with the bacterial AOC-test community, which originated from natural freshwater. On average, the maximum specific growth rate ( μ max ) of E. coli O157 growing in sterile freshwater at 30°C was 0.19 ± 0.07 h−1 . Batch growth assays at five different temperatures revealed a positive influence of temperature on μ max of E. coli O157. The results give new information on the behaviour of this common pathogen in the aquatic environment and contribute to microbial risk assessment in order to prevent spreading of water-borne diseases. 相似文献
55.
Letícia M. F. Sena Camila G. Morais Mariana R. Lopes Renata O. Santos Ana P. T. Uetanabaro Paula B. Morais Marcos J. S. Vital Marcos A. de MoraisJr. Marc-André Lachance Carlos A. Rosa 《Antonie van Leeuwenhoek》2017,110(1):53-67
Sixteen yeast isolates identified as belonging to the genus Sugiyamaella were studied in relation to D-xylose fermentation, xylitol production, and xylanase activities. The yeasts were recovered from rotting wood and sugarcane bagasse samples in different Brazilian regions. Sequence analyses of the internal transcribed spacer (ITS) region and the D1/D2 domains of large subunit rRNA gene showed that these isolates belong to seven new species. The species are described here as Sugiyamaella ayubii f.a., sp. nov. (UFMG-CM-Y607T = CBS 14108T), Sugiyamaella bahiana f.a., sp. nov. (UFMG-CM-Y304T = CBS 13474T), Sugiyamaella bonitensis f.a., sp. nov. (UFMG-CM-Y608T = CBS 14270T), Sugiyamaella carassensis f.a., sp. nov. (UFMG-CM-Y606T = CBS 14107T), Sugiyamaella ligni f.a., sp. nov. (UFMG-CM-Y295T = CBS 13482T), Sugiyamaella valenteae f.a., sp. nov. (UFMG-CM-Y609T = CBS 14109T) and Sugiyamaella xylolytica f.a., sp. nov. (UFMG-CM-Y348T = CBS 13493T). Strains of the described species S. boreocaroliniensis, S. lignohabitans, S. novakii and S. xylanicola, isolated from rotting wood of Brazilian ecosystems, were also compared for traits relevant to xylose metabolism. S. valenteae sp. nov., S. xylolytica sp. nov., S. bahiana sp. nov., S. bonitensis sp. nov., S. boreocarolinensis, S. lignohabitans and S. xylanicola were able to ferment d-xylose to ethanol. Xylitol production was observed for all Sugiyamaella species studied, except for S. ayubii sp. nov. All species studied showed xylanolytic activity, with S. xylanicola, S. lignohabitans and S. valenteae sp. nov. having the highest values. Our results suggest these Sugiyamaella species have good potential for biotechnological applications. 相似文献
56.
57.
Gabriel Lorencini Fiorin Andrea Sanchéz-Vallet Daniela Paula de Toledo Thomazella Paula Favoretti Vital do Prado Leandro Costa do Nascimento Antonio Vargas de Oliveira Figueira Bart P.H.J. Thomma Gonçalo Amarante Guimarães Pereira Paulo José Pereira Lima Teixeira 《Current biology : CB》2018,28(18):3023-3030.e5
58.
Mariana R. Lopes Carla A. Lara Marina E.F. Moura Ana Paula T. Uetanabaro Paula B. Morais Marcos J.S. Vital Carlos A. Rosa 《Fungal biology》2018,122(7):668-676
We investigated the yeast species associated with rotting wood samples obtained from Brazilian ecosystems, with a special focus on cellobiose-fermenting species. About 647 yeast strains were isolated from rotting wood samples collected from the areas of Atlantic rainforest, Cerrado, and Amazonian forest. Eighty-six known species and 47 novel species of yeasts were isolated. Candida boidinii, Cyberlindnera subsufficiens, Meyerozyma guilliermondii, Schwanniomyces polymorphus, Candida natalensis, and Debaryomyces hansenii were the most frequently isolated species. Among the cellobiose-fermenting yeasts, 14 known and three novel yeast species were identified. Scheffersomyces queiroziae, Sc. amazonensis, Yamadazyma sp.1, Hanseniaspora opuntiae, C. jaroonii, and Candida tammaniensis were the main ethanol-producing yeasts. These species also produced an intracellular β-glucosidase responsible for cellobiose hydrolysis. In fermentation assays using a culture medium containing 50 g L?1 cellobiose, ethanol production was observed in all cases; Sc. queiroziae and Sc. amazonensis showed the highest yield, efficiency, and productivity. Candida jaroonii and Yamadazyma sp.1 strains also showed high efficiency in cellobiose fermentation, while C. tammaniensis and H. opuntiae strains produced low amounts of ethanol. This study shows the potential of rotting wood samples from Brazilian ecosystems as a source of yeasts, including new species as well as those with promising biotechnological properties. 相似文献
59.
A central nervous system isolate from an acquired immunodeficiency syndrome (AIDS) patient of 103
Cryptococcus neoformans cells was instilled intranasally into guinea pigs. These were killed to evaluate the fate of the organisms and the response of the olfactory mucosa. Olfactory epithelium prevented the penetration ofCryptococcus neoformans and showed focal hyperplastic responses. The organisms, which manifested an affinity for the olfactory portion of the nasal cavities, were cleared from the olfactory space with no intervention from the immune system cells. By the end of the fifth week almost no organisms could be found and there was no histological evidence of dissemination. In contrast, destruction of the olfactory epithelium with zinc sulfate allowed the invasion of the subepithelial tissues, demonstrating the role of the olfactory mucosa in preventing infection withCryptococcus neoformans through the nasal route. The results and the model described in this report may be useful in clarifying the pathogenic mechanisms of cryptococcosis and the non immune mediated host responses toCryptococcus neoformans. 相似文献