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131.
Perspective of plant growth promoting rhizobacteria (PGPR) containing ACC deaminase in stress agriculture 总被引:2,自引:0,他引:2
Saleem M Arshad M Hussain S Bhatti AS 《Journal of industrial microbiology & biotechnology》2007,34(10):635-648
Ethylene is a gaseous plant growth hormone produced endogenously by almost all plants. It is also produced in soil through
a variety of biotic and abiotic mechanisms, and plays a key role in inducing multifarious physiological changes in plants
at molecular level. Apart from being a plant growth regulator, ethylene has also been established as a stress hormone. Under
stress conditions like those generated by salinity, drought, waterlogging, heavy metals and pathogenicity, the endogenous
production of ethylene is accelerated substantially which adversely affects the root growth and consequently the growth of
the plant as a whole. Certain plant growth promoting rhizobacteria (PGPR) contain a vital enzyme, 1-aminocyclopropane-1-carboxylate
(ACC) deaminase, which regulates ethylene production by metabolizing ACC (an immediate precursor of ethylene biosynthesis
in higher plants) into α-ketobutyrate and ammonia. Inoculation with PGPR containing ACC deaminase activity could be helpful
in sustaining plant growth and development under stress conditions by reducing stress-induced ethylene production. Lately,
efforts have been made to introduce ACC deaminase genes into plants to regulate ethylene level in the plants for optimum growth,
particularly under stressed conditions. In this review, the primary focus is on giving account of all aspects of PGPR containing
ACC deaminase regarding alleviation of impact of both biotic and abiotic stresses onto plants and of recent trends in terms
of introduction of ACC deaminase genes into plant and microbial species. 相似文献
132.
Naila Abbas Sabir Hussain Farrukh Azeem Tanvir Shahzad Sajjad Haider Bhatti Muhammad Imran Zulfiqar Ahmad Zahid Maqbool Muhammad Abid 《World journal of microbiology & biotechnology》2016,32(11):181
Microbial biotechnologies for the decolorization of textile wastewaters have attracted worldwide attention because of their economic suitability and easiness in handling. However, the presence of high amounts of salts and metal ions in textile wastewaters adversely affects the decolorization efficiency of the microbial bioresources. In this regard, the present study was conducted to isolate salt tolerant bacterial strains which might have the potential to decolorize azo dyes even in the presence of multi-metal ion mixtures. Out of the tested 48 bacteria that were isolated from an effluent drain, the strain NA6 was found relatively more efficient in decolorizing the reactive yellow-2 (RY2) dye in the presence of 50 g L?1 NaCl. Based on the similarity of its 16S rRNA gene sequence and its position in a phylogenetic tree, this strain was designated as Proteus sp. NA6. The strain NA6 showed efficient decolorization (>90 %) of RY2 at pH 7.5 in the presence of 50 g L?1 NaCl under static incubation at 30 °C. This strain also had the potential to efficiently decolorize other structurally related azo dyes in the presence of 50 g L?1 NaCl. Moreover, Proteus sp. NA6 was found to resist the presence of different metal ions (Co+2, Cr+6, Zn+2, Pb+2, Cu+2, Cd+2) and was capable of decolorizing reactive dyes in the presence of different levels of the mixtures of these metal ions along with 50 g L?1 NaCl. Based on the findings of this study, it can be suggested that Proteus sp. NA6 might serve as a potential bioresource for the biotechnologies involving bioremediation of textile wastewaters containing the metal ions and salts. 相似文献
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A collection of clinical and environmental isolates of the opportunistic human pathogen, Aspergillus fumigatus, were screened for the presence of mycoviruses and 6.6?% of 366 isolates contained dsRNA segments ranging in size from ~1.0 to 4.0?kbp. The dsRNAs were categorised into three different groups comprising bipartite dsRNAs, quadripartite dsRNAs, representative isolates of which have both been sequenced, and an uncharacterised mycovirus, whose genome apparently consists of four dsRNAs 1-2.5?kbp in size. Here, we describe dsRNA incidence in the A. fumigatus isolates examined, their provenance and also note that on occasion individual isolates were infected with two groups of different dsRNAs. 相似文献
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The fluxes of CO(2) and oxygen during photosynthesis by cell suspensions of Tessellaria volvocina and Mallomonas papillosa were monitored mass spectrometrically. There was no rapid uptake of CO(2,) only a slow drawdown to compensation concentrations of 26 μM for T. volvocina and 18 μM for M. papillosa, when O(2) evolution ceased, indicating a lack of active bicarbonate uptake by the cells. Darkening of the cells after a period of photosynthesis did not cause rapid release of CO(2), indicating the absence of an intracellular inorganic carbon pool. However, upon darkening a brief burst of CO(2) was observed similar to the post-illumination burst characteristic of C(3) higher plants. Treatment of the cells of both species with the membrane-permeable carbonic anhydrase inhibitor ethoxyzolamide had no adverse effect on photosynthetic rate, but stimulated the dark CO(2) burst indicating the dark oxidation of a compound formed in the light. In the absence of any active accumulation of inorganic carbon photosynthesis in these species should be inhibited by O(2). This was investigated in four synurophyte species T. volvocina, M. papillosa, Synura petersenii, and Synura uvella: photosynthetic O(2) evolution rates in all four algae, measured by O(2) electrode, were significantly higher (40-50%) in media at low O(2) (4%) than in air-equilibrated (21% O(2)) media, indicating an O(2) inhibition of photosynthesis (Warburg effect) and thus the occurrence of photorespiration in these species. 相似文献
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Iqbal Ahmad Raheela Bano Syed Ghulam Musharraf Sofia Ahmed Muhammad Ali Sheraz Qamar ul Arfeen Muhammad Salman Bhatti Zufi Shad 《AAPS PharmSciTech》2014,15(6):1588-1597
The kinetics of photodegradation of moxifloxacin (MF) in aqueous solution (pH 2.0–12.0), and organic solvents has been studied. MF photodegradation is a specific acid-base catalyzed reaction and follows first-order kinetics. The apparent first-order rate constants (kobs) for the photodegradation of MF range from 0.69 × 10−4 (pH 7.5) to 19.50 × 10−4 min−1 (pH 12.0), and in organic solvents from 1.24 × 10−4 (1-butanol) to 2.04 × 10−4 min−1 (acetonitrile). The second-order rate constant (k2) for the [H+]-catalyzed and [OH−]-catalyzed reactions are 6.61 × 10−2 and 19.20 × 10−2 M−1 min−1, respectively. This indicates that the specific base-catalyzed reaction is about three-fold faster than that of the specific acid-catalyzed reaction probably as a result of the rapid cleavage of diazabicyclononane side chain in the molecule. The kobs-pH profile for the degradation reactions is a V-shaped curve indicating specific acid-base catalysis. The minimum rate of photodegradation at pH 7–8 is due to the presence of zwitterionic species. There is a linear relation between kobs and the dielectric constant and an inverse relation between kobs and the viscosity of the solvent. Some photodegraded products of MF have been identified and pathways proposed for their formation in acid and alkaline solutions.KEY WORDS: acid-base catalysis, kinetics, moxifloxacin, photodegradation, rate–pH profile, solvent effect 相似文献