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Meenu Panwar Rupinder Tewari Arvind Gulati Harsh Nayyar 《Acta Physiologiae Plantarum》2016,38(12):278
Salt stress has multiple damaging effects on plants including physiological damage, reduced growth, and productivity. Plant growth-promoting rhizobacteria (PGPR) are one of the valuable options to mitigate the negative effects of this stress. In the present study, native bacteria from chickpea’s rhizosphere were isolated, and checked for their salt tolerance and plant growth-promoting attributes (phosphate (P) solubilization, siderophores, indole-3-acetic acid (IAA) production, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase production). One isolate, subsequently identified as Pantoea dispersa, showed appreciable production of IAA (218.3 µg/ml) and siderophores (60.33% SU), P-solubilization (3.64 µg/ml) and ACC deaminase activity (207.45 nmol/mg/h) in the presence of 150 mM NaCl, under laboratory conditions. Salt stress in uninoculated chickpea (GPF2 cultivar) plants induced high accumulation of Na+ ions (3.86 mg g?1 dw) in the leaves, along with significant reduction in K+ uptake, membrane integrity, chlorophyll concentration, and leaf water content, thus resulting in impaired growth of the plant and yield (pods and seeds) in a salt concentration-dependent manner. The damage due to salt stress was restored significantly in plants inoculated with P. dispersa. A significant improvement in biomass (32–34%), pods number (31–34.5%), seeds number (32–35.7%), pods weight (30–32.6%), and seeds weight (27–35%) per plant occurred in salt stress-affected plants, which was associated with significant reduction in Na+ uptake, reduced membrane damage, significantly improved leaf water content, chlorophyll content, and K+ uptake. This study suggests for the first time that native P. dispersa strain PSB3 can be used to alleviate the negative effects of salt stress on chickpea plants and holds the potential to be used as a biofertilizer. 相似文献
74.
A study of bacterial surface oligosaccharides were investigated among
different strains of Neisseria gonorrhoeae to correlate structural features
essential for binding to the MAb 2C7. This epitope is widely expressed and
conserved in gonococcal isolates, characteristics essential to an effective
candidate vaccine antigen. Sample lipooligosaccharides (LOS), was prepared
by a modification of the hot phenol-water method from which de-O-acetylated
LOS and oligosaccharide (OS) components were analyzed by ES-MS-CID-MS and
ES-MSnin a triple quadrupole and an ion trap mass spectrometer,
respectively. Previously documented natural heterogeneity was apparent from
both LOS and OS preparations which was admixed with fragments induced by
hydrazine and mild acid treatment. Natural heterogeneity was limited to
phosphorylation and antenni extensions to the alpha-chain. Mild acid
hydrolysis to release OS also hydrolyzed the beta(1-->6) glycosidic
linkage of lipid A. OS structures were determined by collisional and
resonance excitation combined with MS and multistep MSn which provided
sequence information from both neutral loss, and nonreducing terminal
fragments. A comparison of OS structures, with earlier knowledge of MAb
binding, enzyme treatment, and partial acid hydrolysis indicates a generic
overlapping domain for 2C7 binding. Reoccurring structural features include
a Hepalpha(1-->3)Hepbeta(1-->5)KDO trisaccharide core branched on the
nonreducing terminus (Hep-2) with an alpha(1-->2) linked GlcNAc
(gamma-chain), and an alpha-linked lactose (beta-chain) residue. From the
central heptose (Hep-1), a beta(1-->4) linked lactose (alpha-chain),
moiety is required although extensions to this residue appear unnecessary.
相似文献
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Nineteen efficient phosphate-solubilizing fluorescent Pseudomonas from the cold deserts of the trans-Himalayas were screened for stress tolerance against temperature, alkalinity, salinity,
calcium salts, and desiccation. Phylogenetic analysis based on 16S rRNA gene sequencing placed these bacteria under three
groups with fourteen strains in Group I including Pseudomonas trivialis and P. poae, two strains in Group II together with Pseudomonas kilonensis and P. corrugata, and three strains in Group III along with Pseudomonas jessenii and P. moraviensis. Genetic diversity assessed by ERIC and BOX-PCR revealed variability among strains belonging to the same phylogenetic groups.
Cluster analysis based on the growth characteristics under regimes of different stress levels placed the strains into three
distinct clusters displaying no correlation to their phylogenetic groups. Stress-tolerant strains differed in the level of
decline in phosphate solubilization under increasing intensity of various stress parameters. The highest decrease occurred
with 5% CaCO3, followed by 2.5% CaCO3, pH 11, 5% NaCl, temperature of 37°C, 40% PEG, 5% CaSO4, 2.5% NaCl, 2.5% CaSO4, pH 9 and temperature of 15°C. Two strains belonging to Phylogenetic Group I exhibited higher phosphate solubilization at
lower temperature. The results revealed that stress-tolerance ability was not limited to any particular phylogenetic group.
Knowledge about the genetic variants of phosphate-solubilizing fluorescent Pseudomonas with potential for tolerance to desiccation, alkalinity, temperature, and salinity could be useful in understanding their
ecological role under stressful environments of low phosphate availability. 相似文献
78.
Aims: To identify variable number tandem repeat (VNTR)-containing loci, and to use multilocus VNTR (MLVA) to discern genetic relationships among strains of Yersinia enterocolitica biovar 1A isolated from diverse sources.
Methods and Results: The whole genome sequence of Y. enterocolitica 8081 was analysed and eight VNTR loci with repeat sizes between 4 and 9 bp, and each containing more than four repeat copies were selected for MLVA typing of 88 strains of Y. enterocolitica . Of these, four loci were polymorphic and generated 26 MLVA genotypes among 81 strains of Y. enterocolitica biovar 1A. MLVA was found to be quite discriminatory (DI = 0·87). Cluster analysis and population modelling using minimum spanning tree (MST) clearly clustered Y. enterocolitica biovar 1A into two major groups.
Conclusions: The MLVA is easy to perform and can be used to discern clonal relationship among strains of Y. enterocolitica . Also the phylogenetic relationships obtained with MLVA genotypes were in good agreement with those established by other typing methods.
Significance and Impact of the Study: The MLVA method reported is relatively more discriminatory than the other genotyping methods and has the potential to be used as an epidemiological tool for the study of strains of Y. enterocolitica biovar 1A. 相似文献
Methods and Results: The whole genome sequence of Y. enterocolitica 8081 was analysed and eight VNTR loci with repeat sizes between 4 and 9 bp, and each containing more than four repeat copies were selected for MLVA typing of 88 strains of Y. enterocolitica . Of these, four loci were polymorphic and generated 26 MLVA genotypes among 81 strains of Y. enterocolitica biovar 1A. MLVA was found to be quite discriminatory (DI = 0·87). Cluster analysis and population modelling using minimum spanning tree (MST) clearly clustered Y. enterocolitica biovar 1A into two major groups.
Conclusions: The MLVA is easy to perform and can be used to discern clonal relationship among strains of Y. enterocolitica . Also the phylogenetic relationships obtained with MLVA genotypes were in good agreement with those established by other typing methods.
Significance and Impact of the Study: The MLVA method reported is relatively more discriminatory than the other genotyping methods and has the potential to be used as an epidemiological tool for the study of strains of Y. enterocolitica biovar 1A. 相似文献
79.
D. Y. Rogozin V. V. Zykov M. Y. Chernetsky A. G. Degermendzhy R. D. Gulati 《Aquatic Ecology》2009,43(3):661-672
The year-to-year variations of vertical distribution and biomass of anoxic phototrophic bacteria were studied during ice periods
2003–2005 and 2007–2008 in meromictic lakes Shira and Shunet (Southern Siberia, Russian Federation). The bacterial layers
in chemocline of both lakes were sampled with a thin-layer hydraulic multi-syringe sampler. In winter, biomass of purple sulphur
bacteria varied considerably depending on the amount of light penetrating into the chemocline through the ice and snow cover.
In relatively weakly stratified, brackish Shira Lake, the depth of chemocline varied between winters, so that light intensity
for purple sulphur bacteria inhabiting this zone differed. In Shira Lake, increased transparency of mixolimnion in winter,
high chemocline position and absence of snow resulted in light intensity and biomass of purple sulphur bacteria exceeding
the summer values in the chemocline of the lake. We could monitor snow cover at the lake surface using remote sensing and
therefore estimate dynamics and amount of light under ice and its availability for phototrophic organisms. In Shunet Lake,
the light intensities in the chemocline and biomasses of purple sulphur bacteria were always lower in winter than in summer,
but the biomasses of green sulphur bacteria were similar. 相似文献
80.