全文获取类型
收费全文 | 256篇 |
免费 | 39篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 10篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 6篇 |
2012年 | 19篇 |
2011年 | 22篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 17篇 |
2006年 | 13篇 |
2005年 | 9篇 |
2004年 | 22篇 |
2003年 | 24篇 |
2002年 | 13篇 |
2001年 | 9篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1977年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有295条查询结果,搜索用时 31 毫秒
51.
Ping Gong Steven D. Siciliano Sonali Srivastava Charles W. Greer Geoffrey I. Sunahara 《人类与生态风险评估》2002,8(5):1067-1081
This study attempted to investigate if the tolerance of soil bacterial communities in general, and autotrophic ammonia-oxidizing bacteria (AOB) in particular, evolved as a result of prolonged exposure to metals, and could be used as an indigenous bioindicator for soil metal pollution. A soil contaminated with copper, chromium, and arsenic (CCA) was mixed with an uncontaminated garden soil (GS3) to make five test soils with different metal concentrations. A modified potential ammonium oxidation assay was used to determine the metal tolerance of the AOB community. Tolerance to Cr, Cu, and As was tested at the beginning and after up to 13 months of incubation. Compared with the reference GS3 soil, the five CCA soils showed significantly higher tolerance to Cr no matter which form of Cr (Cr3+, CrO4 2?, or Cr2O7 2?) was tested, and the Cr tolerance correlated with the total soil Cr concentration. However, the tolerance to Cu2+, As3+, and As5+ did not differ significantly between the GS3 soil and the five CCA soils. Community level physiological profiles using Biolog microtiter plates were also used to examine the chromate tolerance of the bacterial communities extracted after six months of exposure. Our results showed that the bacterial community tolerance was altered and increased as the soil Cr concentration was increased, indicating that the culturable microbial community and the AOB community responded in a similar manner. 相似文献
52.
Similarity of G-band patterns between the long arm of Chinese hamster chromosome 6 and mouse chromosome 2, combined with the assignments of AK1, ADA, and ITPA to hamster chromosome 6 and AK1 to mouse chromosome 2, suggested mouse chromosome 2 also might contain ADA and ITPA. Here, concordant segregation analysis of enzyme loci and chromosomes in mouse spleen X CHO as well as mouse microcell X CHO somatic cell hybrids established the assignments of ADA and ITPA onto mouse chromosome 2 in the region between the first G-band and the terminus (C1----ter). This assignment presents a demonstration of the conservation and evolution of enzyme and proto-oncogene loci linkage since two cellular homologs of viral oncogenes--c-src and c-abl--also map to mouse chromosome 2. In humans c-src, ADA, and ITPA remain conserved on chromosome 20, whereas AK1 and c-abl are together on chromosome 9. These observations and concepts are discussed with respect to the role of proto-oncogenes in chromosomal evolution and suggest the long arm of chromosome 6 as a fruitful place to look for c-src and c-abl in the Chinese hamster. 相似文献
53.
54.
55.
Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for the Discrimination of Food-Borne Microorganisms
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)
Maria Fiorella Mazzeo Alida Sorrentino Marcello Gaita Giuseppina Cacace Michele Di Stasio Angelo Facchiano Giuseppe Comi Antonio Malorni Rosa Anna Siciliano 《Applied microbiology》2006,72(2):1180-1189
A methodology based on matrix-assisted laser desorption ionization-time of flight mass spectrometry of intact bacterial cells was used for rapid discrimination of 24 bacterial species, and detailed analyses to identify Escherichia coli O157:H7 were carried out. Highly specific mass spectrometric profiles of pathogenic and nonpathogenic bacteria that are well-known major food contaminants were obtained, uploaded in a specific database, and made available on the Web. In order to standardize the analytical protocol, several experimental, sample preparation, and mass spectrometry parameters that can affect the reproducibility and accuracy of data were evaluated. Our results confirm the conclusion that this strategy is a powerful tool for rapid and accurate identification of bacterial species and that mass spectrometric methodologies could play an essential role in polyphasic approaches to the identification of pathogenic bacteria. 相似文献
56.
57.
E Colacino A Converso A De Nino A Leggio A Liguori L Maiuolo A Napoli A Procopio C Siciliano G Sindona 《Nucleosides & nucleotides》1999,18(4-5):581-583
The complete set of the 4'-aza analogues of 2',3'-dideoxynucleosides was synthesized by cycloaddition of N-tetrahydropiranyl or N-trityl methylene nitrones on suitably protected vinyl nucleobases. The convertible nucleoside approach was used in the preparation of cytosine and 5-methyl cytosine analogues. 相似文献
58.
Juliana Machado Ferreira Larissa Rosa de Oliveira Louise Wynen Marthán N. Bester Christophe Guinet Nadia Moraes-Barros Felipe Mello Martins Mônica M. C. Muelbert Ignacio B. Moreno Salvatore Siciliano Paulo Henrique Ott João Stenghel Morgante 《Polar Biology》2008,31(3):303-308
In this study, we present the first data about putative source populations of the vagrant Subantarctic fur seal, Arctocephalus tropicalis, found on the Brazilian coast, through the comparison of their mitochondrial DNA control sequences to exclusive haplotypes
from the main breeding colonies of the species. The results indicated that, despite the majority of the vagrant individuals
are from Gough Island (the closest breeding site to the Brazilian coast), they also come from other reproductive colonies,
such as Crozet Island, a distance around 16,500 km from the Brazilian coast. Furthermore, the molecular data identified three
possible management units: (1) Gough, (2) Amsterdam, and (3) Marion, Macquarie and Crozet. This significant genetic subdivision
must be taken into account in any future management plan for the species conservation, including rehabilitation and even reintroduction
of vagrant fur seals.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
59.
Michelangelo Mancuso Valeria Calsolaro Daniele Orsucci Gabriele Siciliano Luigi Murri 《Journal of bioenergetics and biomembranes》2009,41(5):411-416
The “mitochondrial cascade hypothesis” could explain many of the biochemical, genetic and pathological features of sporadic
Alzheimer’s disease (AD). Somatic mutations in mitochondrial DNA (mtDNA) could cause energy failure, increased oxidative stress
and accumulation of amyloid β, which in a vicious cycle reinforces mtDNA damage and oxidative stress. Despite the evidence
of mitochondrial dysfunction in AD, and despite the cognitive impairment frequently reported in patients with mtDNA mutation,
no causative mutation in the mtDNA have been linked to AD. Indeed, results of studies on the role of mtDNA polymorphisms or
haplogroups in AD are controversial. In this minireview, we summarize the actual knowledge about the involvement of mtDNA
in AD pathology. 相似文献
60.
Pittalà V Romeo G Salerno L Siracusa MA Modica M Materia L Mereghetti I Cagnotto A Mennini T Marucci G Angeli P Russo F 《Bioorganic & medicinal chemistry letters》2006,16(1):150-153
The discovery of a new series of selective and high-affinity alpha(1)-adrenoceptor (alpha(1)-AR) ligands, characterized by a 1H-pyrrolo[2,3-d]-pyrimidine-2,4(3H,7H)-dione system, is described in this paper. Some synthesized compounds, including 20, 22, and 30, displayed affinity in the nanomolar range for alpha(1)-ARs and substantial selectivity with respect to 5-HT(1A) and dopaminergic D(1) and D(2) receptors. Functional assays, performed on selected derivatives, showed antagonistic properties. 相似文献