全文获取类型
收费全文 | 232篇 |
免费 | 23篇 |
专业分类
255篇 |
出版年
2022年 | 2篇 |
2020年 | 1篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 2篇 |
2008年 | 8篇 |
2007年 | 11篇 |
2006年 | 8篇 |
2005年 | 10篇 |
2004年 | 14篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2001年 | 13篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 9篇 |
1993年 | 9篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 2篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1973年 | 2篇 |
排序方式: 共有255条查询结果,搜索用时 0 毫秒
131.
Bacterial and archaeal populations at two shallow hydrothermal vents off Panarea Island (Eolian Islands, Italy) 总被引:1,自引:0,他引:1
Teresa Luciana Maugeri Valeria Lentini Concetta Gugliandolo Francesco Italiano Sylvie Cousin Erko Stackebrandt 《Extremophiles : life under extreme conditions》2009,13(1):199-212
The aim of this study was to investigate the microbial community thriving at two shallow hydrothermal vents off Panarea Island
(Italy). Physico-chemical characteristics of thermal waters were examined in order to establish the effect of the vents on
biodiversity of both Bacteria and Archaea. Water and adjacent sediment samples were collected at different times from two
vents, characterised by different depth and temperature, and analysed to evaluate total microbial abundances, sulphur-oxidising
and thermophilic aerobic bacteria. Total microbial abundances were on average of the order of 105 cells ml−1, expressed as picoplanktonic size fraction. Picophytoplanktonic cells accounted for 0.77–3.83% of the total picoplanktonic
cells. The contribution of bacterial and archaeal taxa to prokaryotic community diversity was investigated by PCR–DGGE fingerprinting
method. The number of bands derived from bacterial DNA was highest in the DGGE profiles of water sample from the warmest and
deepest site (site 2). In contrast, archaeal richness was highest in the water of the coldest and shallowest site (site 1).
Sulphur-oxidising bacteria were detected by both culture-dependent and -independent methods. The primary production at the
shallow hydrothermal system of Panarea is supported by a complex microbial community composed by phototrophs and chemolithotrophs. 相似文献
132.
Following substantial decline in malaria burden in Ethiopia, the country is planning to eliminate malaria in certain low transmission settings by 2020. To evaluate the attainability of this goal in-depth examination of malaria parasite carriage at community level is necessary. This study was, therefore, aimed at assessing the current situation of malaria in relation to ongoing control interventions in Jiga area, Jabi Tehnan District in northwest Ethiopia. A cross-sectional household (HH) survey was conducted in November-December 2013. Out of 2,574 HHs (11,815 people) in the entire Jabi Tehnan District, 392 (accommodating 1911 people) were randomly selected from three purposely selected villages. One randomly selected member from each selected HH was tested for malaria using rapid diagnostic test (mRDT). All participants tested for malaria (n = 392) were afebrile (axillary temperature <37.5°C). Eleven individuals (2.8%, 95% confidence interval (CI):1.2–4.4%) were found to be mRDT positive. Most HHs (95.9%, 95% CI: 93.5–97.5%) had at least 1 long-lasting insecticidal net (LLIN). Insecticide residual spraying (IRS) coverage the last six months was 85.5% (95% CI: 82.0–88.9%). Malaria prevalence remains unexpectedly high despite high HH coverage of control interventions. 相似文献
133.
Morphological,physiological, and molecular characterization of actinomycetes isolated from dry soil,rocks, and monument surfaces 总被引:1,自引:0,他引:1
Martin Eppard W. E. Krumbein Cathrin Koch Erhard Rhiel James T. Staley Erko Stackebrandt 《Archives of microbiology》1996,166(1):12-22
In an extended study on the biodiversity of rock-dwelling bacteria, the colony and cell morphology, physiology, protein patterns,
and 16S rDNA sequences of 17 bacterial strains isolated from different surfaces of rocks, stones, and monuments and from various
geographical locations were characterized. All except one strain, which was found to be a Bacillus, were members of the order Actinomycetales. The majority of the strains either were closely related to Geodermatophilus obscurus, which was also analyzed in this study, or formed a closely related sister taxon. All of these strains were isolated from
the surface of marble in Namibia and Greece and from limestone from the Negev desert, Israel. One strain, G10, of Namibia
origin was equidistantly related to Geodermatophilus obscurus, Frankia alni, Sporichthya polymorpha, and Acidothermus cellulolyticus. Three strains from rock varnish in the Mojave desert, California, were found to be highly related to Arthrobacter (formerly Micrococcus) agilis. All clusters could be confirmed from results of studies on morphological and physiological properties and from banding patterns
of whole cell proteins. Based on the results of tests, four additional strains were assigned to the lineage defined by strain
G10.
Received: 16 October 1995 / Accepted: 4 April 1996 相似文献
134.
135.
A 21-mer DNA oligonucleotide probe targeting the 23S rRNA of Mycobacterium leprae was developed and its high specificity demonstrated by dot-blot hybridization. Even under relaxed hybridization and washing conditions (20 degrees C below Tm) the probe was highly selective in that positive signals were only detected with M. leprae, about half of the slow-growing and one of the fast-growing reference mycobacteria and Gordona bronchialis. At more stringent washing temperatures (6 degrees C below Tm) only the rRNA of Mycobacterium leprae was detectable. 相似文献
136.
137.
138.
139.
Abstract The phylogenetic position of Dictyoglomus thermophilum has been determined by comparative sequence analysis of in vitro amplified 16S rRNA genes from the type strain as well as from a Dictyoglomus isolate. Results indicate that it forms a deep branch within the phylum of Thermotogales or may even represent its own phylum. It does not contain signature sequences within the 16S rRNA which could relate it to the Thermotogales group. 相似文献
140.
Sarikaya R Sepici-Dinçel A Caǧlan Karasu Benli A Selvi M Erkoç F 《Journal of biochemical and molecular toxicology》2011,25(3):169-174
The aim of this research was to evaluate the acute toxicity of fenitrothion to the crayfish (Astacus leptodactylus Eschscholtz, 1823), which is chosen as an alternative aquatic organism to fish by using the static test system and evaluate the basic lipid peroxidation parameters for the first 24 h. Crayfish of 27.3 ± 0.56 g mean weight and 10.0 ± 0.72 cm mean length were selected for the bioassay experiments. The experiments were repeated three times in 20 liters of tap water. The temperature of water was 21 ± 1°C. The data obtained were statistically evaluated by using a computer program developed by the United States Environmental Protection Agency, based on Finney's probit analysis method and the 96-h LC(50) value for crayfish was calculated to be 15.75 μg/L. The 95% lower and upper confidence limits for the LC(50) were 9.45 to 25.01 μg/L. In addition to the acute toxicity bioassay experiments, 24-h oxidative stress parameters such as malondialdehyde (MDA) levels and ferrous oxidation assay (FOX HP [hydrogen peroxide] equivalents) were also determined. Only MDA levels of hepatopancreas decreased at 5, 10, and 20 μg/L of fenitrothion doses. We can conclude that fenitrothion is highly toxic to crayfish, a nontarget organism in the ecosystem, and the lipid peroxidation indicators can be easily used for monitoring environmental effects. 相似文献