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91.
In situ mapping of nitrifiers and anammox bacteria in microbial aggregates by means of confocal resonance Raman microscopy 总被引:1,自引:0,他引:1
Pätzold R Keuntje M Theophile K Müller J Mielcarek E Ngezahayo A Anders-von Ahlften A 《Journal of microbiological methods》2008,72(3):241-248
In the present work the exploration of microbial communities by confocal resonance Raman microscopy (CRRM) is reported. Using the resonance Raman effect of cytochrome c (Cyt c) we were able to record the microbial distribution of nitrifiers and anammox bacteria directly in their natural environment without the need of sample preparation. For this new non-invasive investigation a reference database of bacteria assumed to be found in microbial aggregates obtained from biological wastewater treatment was created. Reference spectra of enriched cultures of the interesting bacteria were taken by means of optical tweezers. Significant spectra were achieved in less than 1 s (excitation wavelength 532 nm, laser power 9 mW) due to the resonance Raman effect. In addition, the impact of different parameters on the reference spectra, such as integration time and culture conditions, was analysed. We successfully demonstrate the grouping of bacteria down to strain level based on the heterogeneity of the resonance Raman spectra of the heme protein Cyt c. 相似文献
92.
Pathways of bacterial contamination during egg incubation and larval rearing of turbot, Scophthalmus maximus 总被引:1,自引:0,他引:1
Overall microbial levels in the water system of a turbot farm were similar to those found in regular sea-water. At the end of an incubation period, however, the numbers of colony-forming units (CFU) in Artemiu cultures and turbot eg incubation jars were up to four orders of magnitude higher than sea-water level. Rinsing of the foot organisms (rotifers) prior to feeding them to turbot larvae, however, significantly reduced bacterial numbers, thus reducing the number of cross-contaminations. Several species of Aeromonas, Pseudomonas and Vibrio among others, were identified in the eggs and larvae, or in the water in which these were incubated. Scanning electron microscop shows that the surface of unfertilized turbot eggs is a breeding ground for bacteria; the removal of these eggs from incubation jars is therefore recommended. The epidermis of turbot larvae was virtually free ofmicroorganisms. 相似文献
93.
94.
Nicholas G. Brown Dar-Chone Chow Kevin E. Ruprecht Timothy Palzkill 《The Journal of biological chemistry》2013,288(24):17156-17166
The interactions between β-lactamase inhibitory proteins (BLIPs) and β-lactamases have been used as model systems to understand the principles of affinity and specificity in protein-protein interactions. The most extensively studied tight binding inhibitor, BLIP, has been characterized with respect to amino acid determinants of affinity and specificity for binding β-lactamases. BLIP-II, however, shares no sequence or structural homology to BLIP and is a femtomolar to picomolar potency inhibitor, and the amino acid determinants of binding affinity and specificity are unknown. In this study, alanine scanning mutagenesis was used in combination with determinations of on and off rates for each mutant to define the contribution of residues on the BLIP-II binding surface to both affinity and specificity toward four β-lactamases of diverse sequence. The residues making the largest contribution to binding energy are heavily biased toward aromatic amino acids near the center of the binding surface. In addition, substitutions that reduce binding energy do so by increasing off rates without impacting on rates. Also, residues with large contributions to binding energy generally exhibit low temperature factors in the structures of complexes. Finally, with the exception of D206A, BLIP-II alanine substitutions exhibit a similar trend of effect for all β-lactamases, i.e., a substitution that reduces affinity for one β-lactamase usually reduces affinity for all β-lactamases tested. 相似文献
95.
Corrado Marcenò Riccardo Guarino Javier Loidi Mercedes Herrera Maike Isermann Ilona Knollová Lubomír Tichý Rossen T. Tzonev Alicia Teresa Rosario Acosta Úna FitzPatrick Dmytro Iakushenko John A. M. Janssen Borja Jiménez‐Alfaro Zygmunt Kącki Iva Keizer‐Sedláková Vitaliy Kolomiychuk John S. Rodwell Joop H. J. Schaminée Urban Šilc Milan Chytrý 《应用植被学》2018,21(3):533-559
96.
97.
Ulrich Nowitzki Gabriel Gelius-Dietrich Maike Schwieger Katrin Henze William Martin 《European journal of biochemistry》2004,271(20):4123-4131
Two chloroplast phosphoglycerate kinase isoforms from the photosynthetic flagellate Euglena gracilis were purified to homogeneity, partially sequenced, and subsequently cDNAs encoding phosphoglycerate kinase isoenzymes from both the chloroplast and cytosol of E. gracilis were cloned and sequenced. Chloroplast phosphoglycerate kinase, a monomeric enzyme, was encoded as a polyprotein precursor of at least four mature subunits that were separated by conserved tetrapeptides. In a Neighbor-Net analysis of sequence similarity with homologues from numerous prokaryotes and eukaryotes, cytosolic phosphoglycerate kinase of E. gracilis showed the highest similarity to cytosolic and glycosomal homologues from the Kinetoplastida. The chloroplast isoenzyme of E. gracilis did not show a close relationship to sequences from other photosynthetic organisms but was most closely related to cytosolic homologues from animals and fungi. 相似文献
98.
99.
The Nox1/4 Dual Inhibitor GKT137831 or Nox4 Knockdown Inhibits Angiotensin‐II‐Induced Adult Mouse Cardiac Fibroblast Proliferation and Migration. AT1 Physically Associates With Nox4 下载免费PDF全文
100.
Markus Weiss Jürgen Schmidt Dieter Neumann Victor Wray Ruprecht Christ Dieter Strack 《Planta》1999,208(4):491-502
Tissue-specific accumulation of phenylpropanoids was studied in mycorrhizas of the conifers, silver fir (Abies alba Mill.), Norway spruce [Picea abies (L.) Karst.], white pine (Pinus strobus L.), Scots pine (Pinus silvestris L.), and Douglas fir [Pseudotsuga menziesii (Mirbel) Franco], using high-performance liquid chromatography and histochemical methods. The compounds identified were soluble
flavanols (catechin and epicatechin), proanthocyanidins (mainly dimeric catechins and/or epicatechins), stilbene glucosides
(astringin and isorhapontin), one dihydroflavonol glucoside (taxifolin 3′-O-glucopyranoside), and a hydroxycinnamate derivative (unknown ferulate conjugate). In addition, a cell wall-bound hydroxycinnamate
(ferulate) and a hydroxybenzaldehyde (vanillin) were analysed. Colonisation of the root by the fungal symbiont correlated
with the distribution pattern of the above phenylpropanoids in mycorrhizas suggesting that these compounds play an essential
role in restricting fungal growth. The levels of flavanols and cell wall-bound ferulate within the cortex were high in the
apical part and decreased to the proximal side of the mycorrhizas. In both Douglas fir and silver fir, which allowed separation
of inner and outer parts of the cortical tissues, a characteristic transversal distribution of these compounds was found:
high levels in the inner non-colonised part of the cortex and low levels in the outer part where the Hartig net is formed.
Restriction of fungal growth to the outer cortex may also be achieved by characteristic cell wall thickening of the inner
cortex which exhibited flavanolic wall infusions in Douglas fir mycorrhizas. Long and short roots of conifers from natural
stands showed similar distribution patterns of phenylpropanoids and cell wall thickening compared to the respective mycorrhizas.
These results are discussed with respect to co-evolutionary adaptation of both symbiotic partners regarding root structure
(anatomy) and root chemistry.
Received: 25 May 1998 / Accepted: 6 November 1998 相似文献