全文获取类型
收费全文 | 101篇 |
免费 | 8篇 |
出版年
2021年 | 3篇 |
2020年 | 2篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 6篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1988年 | 5篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有109条查询结果,搜索用时 156 毫秒
1.
New enrichment method for isolation of pathogenic Yersinia enterocolitica serogroup O:3 from pork 总被引:3,自引:0,他引:3
G Wauters V Goossens M Janssens J Vandepitte 《Applied and environmental microbiology》1988,54(4):851-854
A new enrichment medium for the recovery of pathogenic Yersinia enterocolitica serogroup O:3 from naturally infected meat products based on three selective agents, Irgasan, ticarcillin, and potassium chlorate (ITC), was compared with several other one- or two-step enrichments. Y. enterocolitica serogroup O:3 was recovered from 96.5% of 29 pork tongues, 24% of 50 ground pork samples, 16% of 25 masseter muscle samples, and 61% of tonsils. ITC was by far the most sensitive method for the recovery of Y. enterocolitica O:3, especially from ground meat and masseter muscles, while cold and two-step enrichments yielded better results for nonpathogenic strains. Plating of ITC enrichments onto SS-deoxycholate-calcium agar gave overall better results than plating onto cefsulodin-Irgasan-novobiocin agar for serogroup O:3. 相似文献
2.
Isolation and partial characterization of an unusual human immunodeficiency retrovirus from two persons of west-central African origin. 总被引:12,自引:4,他引:8
下载免费PDF全文
![点击此处可从《Journal of virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
R De Leys B Vanderborght M Vanden Haesevelde L Heyndrickx A van Geel C Wauters R Bernaerts E Saman P Nijs B Willems et al. 《Journal of virology》1990,64(3):1207-1216
An unusual human retrovirus was isolated from two patients with persistent generalized lymphadenopathy who originate from West-Central Africa and are currently residing in Belgium. Although the virus shared a number of the same biological and morphological properties as human immunodeficiency retrovirus type 1 (HIV-1) and HIV-2, significant antigenic differences could be demonstrated. Several of the viral proteins also differed in molecular weight from the corresponding HIV-1 and HIV-2 proteins. Partial chemical cleavage of the most highly conserved viral proteins resulted in patterns which differed from those of HIV-1 and HIV-2. Furthermore, nucleic acid hybridization experiments were capable of discriminating between the virus types. Sequence analysis of the viral U3 region revealed a unique enhancer organization not found in other immunodeficiency viruses. The data indicated that the new isolate is more closely related to HIV-1 than to HIV-2 but clearly differs in a number of important respects. 相似文献
3.
The phylogeny of Greya Busck (Lepidoptera: Prodoxidae) was inferred from
nucleotide sequence variation across a 765-bp region in the cytochrome
oxidase I and II genes of the mitochondrial genome. Most parsimonious
relationships of 25 haplotypes from 16 Greya species and two outgroup
genera (Tetragma and Prodoxus) showed substantial congruence with the
species relationships indicated by morphological variation. Differences
between mitochondrial and morphological trees were found primarily in the
positions of two species, G. variabilis and G. pectinifera, and in the
branching order of the three major species groups in the genus. Conflicts
between the data sets were examined by comparing levels of homoplasy in
characters supporting alternative hypotheses. The phylogeny of Greya
species suggests that host-plant association at the family level and larval
feeding mode are conservative characters. Transition/transversion ratios
estimated by reconstruction of nucleotide substitutions on the phylogeny
had a range of 2.0-9.3, when different subsets of the phylogeny were used.
The decline of this ratio with the increase in maximum sequence divergence
among taxa indicates that transitions are masked by transversions along
deeper internodes or long branches of the phylogeny. Among transitions,
substitutions of A-->G and T-->C outnumbered their reciprocal
substitutions by 2-6 times, presumably because of the approximately 4:1
(77%) A+T-bias in nucleotide base composition. Of all transversions,
73%-80% were A<-->T substitutions, 85% of which occurred at third
positions of codons; these estimates did not decrease with an increase in
maximum sequence divergence of taxa included in the analysis. The high
frequency of A<-->T substitutions is either a reflection or an
explanation of the 92% A+T bias at third codon positions.
相似文献
4.
Romeo Claudia Piscitelli Anna Pia Santicchia Francesca Martinoli Adriano Ferrari Nicola Wauters Lucas A. 《Biological invasions》2021,23(12):3847-3857
Biological Invasions - It is widely assumed that spillover of alien parasites to native host species severely impacts naïve populations, ultimately conferring a competitive advantage to... 相似文献
5.
Wauters AM Perré Y Bizeray D Leterrier C Richard-Yris MA 《Chronobiology international》2002,19(3):543-559
The aim of this study was to determine whether the presence of a maternal hen influences the quality, quantity, and distribution of activity in young chicks. Brooded and nonbrooded chicks were observed during the entire light phase when they were 4 d of age. Our results revealed that although both brooded and nonbrooded chicks expressed the same behavioral items and in quite the same quantity, activity bouts were much longer in brooded chicks. However, only brooded chicks presented a high level of ultradian rhythmicity. Moreover, the brooded chicks made greater use of the space. The presence and the behavior of maternal hens appeared to provide structuring factors for the expression of the chicks' behavior. 相似文献
6.
The aim of this study was to understand the relationship between production of food calls by maternal hens and food context. In a series of experiments with broody hens, we manipulated quality of items, quantity of food, food experience and dispersion of food items. We measured the frequency of food calling during standardized tests. Our results show that all the variables tested had significant effects on food calling. These results present some similarities and some discrepancies with previous reports on food calling by cockerels. 相似文献
7.
A wide-ranging examination of plastid (pt)DNA sequence homologies within
higher plant nuclear genomes (promiscuous DNA) was undertaken. Digestion
with methylation-sensitive restriction enzymes and Southern analysis was
used to distinguish plastid and nuclear DNA in order to assess the extent
of variability of promiscuous sequences within and between plant species.
Some species, such as Gossypium hirsutum (cotton), Nicotiana tabacum
(tobacco), and Chenopodium quinoa, showed homogenity of these sequences,
while intraspecific sequence variation was observed among different
cultivars of Pisum sativum (pea), Hordeum vulgare (barley), and Triticum
aestivum (wheat). Hypervariability of plastid sequence homologies was
identified in the nuclear genomes of Spinacea oleracea (spinach) and Beta
vulgaris (beet), in which individual plants were shown to possess a unique
spectrum of nuclear sequences with ptDNA homology. This hypervariability
apparently extended to somatic variation in B. vulgaris. No sequences with
ptDNA homology were identified by this method in the nuclear genome of
Arabidopsis thaliana.
相似文献
8.
Nickel tolerance and accumulation by bacteria from rhizosphere of nickel hyperaccumulators in serpentine soil ecosystem of Andaman, India 总被引:1,自引:0,他引:1
Rhizosphere microorganisms harboring nickel hyperaccumulators, Rinorea bengalensis (Wall.) O. K. and Dichapetalum gelonioides ssp. andamanicum (King) Leenh. endemic to serpentine outcrops of Andaman Islands, India, were screened for their tolerance and accumulation
of Ni. The rhizosphere soils from both the plants were rich in total and available Ni along with Co, Cr, Fe and Mg but poor
in microbial density and were dominated by bacteria. Out of total 123 rhizosphere microorganisms (99 bacteria and 24 fungi),
bacteria were more tolerant to Ni than fungi. Viable cells of selected Ni-tolerant bacterial isolates (MIC = 13.6–28.9 mM
Ni) belonging to Pseudomonas, Bacillus and Cupriavidus were capable of accumulating nickel (209.5–224.0 μM Ni g−1 protein) from aqueous solution. Cupriavidus pauculus KPS 201 (MTCC 6280), showing highest degree of nickel tolerance (MIC 28.9 mM Ni) and uptake (224.0 μM Ni g−1 protein, 60 min) was used for detailed study. Kinetics of nickel uptake in C. pauculus KPS 201 followed a linearized Lineweaver-Burk plot. The K
m and V
max for nickel uptake by minimal medium grown-cells approximated 1.5 mM Ni and 636.9 μM Ni g−1 protein, respectively. The uptake process was inhibited by Co, Cu, Cd, Mg, Mn and Zn, however, complete inhibition was not
achieved even in presence of 500 mM Mg. Metabolic inhibitors, sodium azide (1.0 mM) and carbonyl cyanide m-chlorophenylhydrazone (0.4 mM) strongly inhibited nickel uptake suggesting the process as an energy dependent one. The present
study clearly shows that bacteria in the rhizosphere of Ni-hyperaccumulators are capable of tolerating high concentration
of Ni and also possesses nickel uptake potential. The Ni-hyperaccumulators in combination with these Ni-resistant bacteria
could be an ideal tool for nickel bioremediation. 相似文献
9.
Di Pierro Erica Ghisla Anne Wauters Lucas A. Molinari Ambrogio Martinoli Adriano Gurnell John Tosi Guido 《European Journal of Wildlife Research》2011,57(3):585-595
Space-use patterns of seed predators are strongly affected by spatiotemporal variation in the abundance of different tree
seeds, their major food source. However, most studies have measured relationships between overall food availability and space
use, and there are few cases where effects of different food resources have been explored. We studied the effects of two food
resources, Norway spruce and silver fir seeds, on space and habitat use in red squirrel in a subalpine conifer forest from
2000 to 2006. Fir seeds disperse in the autumn of the year they are produced, spruce the following spring. We estimated spruce
and fir seed availability within individual home ranges and monitored home-range size using radiotelemetry. Males had larger
home ranges than females and the sexes responded differently to variation in food and density. Spruce seed availability negatively
affected home-range and core-area sizes of males in spring–summer. Space use was not affected by fir seed availability. Squirrels
positively selected spruce for foraging and spruce was always preferred over fir. Our results showed that spruce, but not
fir, affected space and habitat use of squirrels, suggesting they do not behaviourally respond to early seed dispersal in
fir. 相似文献
10.
Francesco Bisi Mosé Nodari Nuno Miguel Dos Santos Oliveira Elisa Masseroni Damiano G. Preatoni Lucas A. Wauters Guido Tosi Adriano Martinoli 《European Journal of Wildlife Research》2011,57(2):305-312
Populations on the limits of species’ distribution can show different behavioral adaptations to strong ecological pressure
than in the central part of the range. We investigated space use patterns of alpine mountain hare (Lepus timidus) at two areas on the southern edge of the species’ range. We monitored 34 hares between 2005 and 2008, estimating home range
size, overlap, and site fidelity, and compared our results with space use in Scottish and North-European populations. Home
ranges of mountain hares did not differ between two study areas with different habitat types. Subadult animals used larger
ranges than adults and both age groups reduced home range size in autumn, a period that might be critical for hares due to
changes in diet and/or high energy expenditure during the previous breeding season. Home ranges in these alpine populations
were smaller than in Scandinavian populations but within the range of populations in different habitat types in Scotland.
Seasonal home ranges overlapped considerably, but differed among the sexes: male–female overlap was higher than same sex (male–male
and female–female) spatial overlap. Seasonal shifts of home ranges were small, and site fidelity remained high over the seasons,
suggesting that resource distribution remained constant throughout the year and that the knowledge of an intensively frequented
area is an important element of habitat quality. We concluded that habitat structure and availability of mates interact in
affecting mountain hare space use in alpine habitats. 相似文献