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981.
Somatic embryogenesis of Panax ginseng in liquid cultures: a role for polyamines and their metabolic pathways 总被引:1,自引:0,他引:1
Claire Kevers Nathalie Le Gal Marta Monteiro Jacques Dommes Thomas Gaspar 《Plant Growth Regulation》2000,30(3):209-214
A callus with embryogenic capacity was generated fromroot sections of Panax ginseng and used as aninoculum source for embryogenic liquid cultures in athree-step process: – a suspension culture of cellaggregates in the presence of an auxin/cytokininmixture, – an induction medium containing auxin only(for 5 to 30 days), – a regeneration medium containingcytokinin only (for one month). Up to 25 embryos wererecovered per 2.5 g of aggregates in these conditions.Incorporation of polyamines or their precursorsarginine and ornithine into either the induction orregeneration media increased the number of embryosproduced by up to 4 times. Inhibitors of bothbiosynthesis and biodegradation of polyamines reducedthe number of embryos. These results support earlierfindings of the role of polyamines in the process ofsomatic embryogenesis. The success of these liquidcultures opens up the possibility of producing somaticembryos of Panax ginseng in bioreactors. 相似文献
982.
Núria Jiménez Maria Luisa Garcia Javier Galán Alberto Vallet Geoffrey Owen G. Michael Wall 《AAPS PharmSciTech》2009,10(4):1313-1320
The shelf-life of a previously developed two-part liquid–liquid enzyme ceruminolytic product was improved maintaining the
same final reconstituted composition and re-formulating the liquid enzyme portion as a drug granulate by a double wet granulation
process. The critical steps for the preparation of the granulate were studied (mixing/granulating times and drying) determining
the proteolytic activity, the residual ethanol, and the moisture content of the granulates. The original liquid–liquid formulation
had been proven effective as a ceruminolytic agent, but only had stability of greater than 75% enzyme activity for up to 18 months
and up to 1 day at room temperature after combining the two parts. The resulting improved product was proven to be stable
for up to 24 months at 30°C, and up to 3 days at room temperature after combining the two parts. Therefore, maintaining the
enzyme in a granulated form until reconstitution afforded an improvement in stability compared with the original two-part
liquid–liquid formulation. 相似文献
983.
Mood disorders affect the lives and functioning of millions each year. Epidemiological studies indicate that childhood trauma is predominantly associated with higher rates of both mood and anxiety disorders. Exposure of rats to stress during juvenility (JS) (27–29 days of age) has comparable effects and was suggested as a model of induced predisposition for these disorders. The importance of the environment in the regulation of brain, behavior and physiology has long been recognized in biological, social and medical sciences. Here, we studied the effects of JS on emotional and cognitive aspects of depressive-like behavior in adulthood, on Hypothalamic-Pituitary-Adrenal (HPA) axis reactivity and on the expression of cell adhesion molecule L1 (L1-CAM). Furthermore, we combined it with the examination of potential reversibility by enriched environment (EE) of JS – induced disturbances of emotional and cognitive aspects of behavior in adulthood. Three groups were tested: Juvenile Stress –subjected to Juvenile stress; Enriched Environment – subjected to Juvenile stress and then, from day 30 on to EE; and Naïves. In adulthood, coping and stress responses were examined using the elevated plus-maze, open field, novel setting exploration and two way shuttle avoidance learning. We found that, JS rats showed anxiety- and depressive-like behaviors in adulthood, altered HPA axis activity and altered L1-CAM expression. Increased expression of L1-CAM was evident among JS rats in the basolateral amygdala (BLA) and Thalamus (TL). Furthermore, we found that EE could reverse most of the effects of Juvenile stress, both at the behavioral, endocrine and at the biochemical levels. The interaction between JS and EE resulted in an increased expression of L1-CAM in dorsal cornu ammonis (CA) area 1 (dCA1). 相似文献
984.
Acid extracts of nuclei of the unicellular algae Chlamydomonas reinhardtii were analysed by polyacrylamide gel electrophoresis and revealed a series of bands, the mobility of which indicates that histones are present. The H1-histone was further identified according to its solubility in 0.74 M perchloric acid and in 0.4 M NaCl as well as its response to a H1 specific antibody. These results are discussed in relation with the general organization of the chromatin in the lower eukaryotes. 相似文献
985.
Galán C. Smith M. Damialis A. Frenguelli G. Gehrig R. Grinn-Gofroń A. Kasprzyk I. Magyar D. Oteros J. Šaulienė I. Thibaudon M. Sikoparija B. 《Aerobiologia》2021,37(2):351-361
Aerobiologia - This study presents the results of a Europe-wide training and Quality Control (QC) exercise carried out within the framework of the European Aerobiology Society’s QC Working... 相似文献
986.
V Gal D Trajkovi? 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1984,46(4):435-442
Microtubular protein was exposed to gamma-radiation from 500 to 1000 Gy, Within that dose range its polymerization ability was decreased by 20-60 per cent when samples were irradiated in assembled state, and by 40-75 per cent when irradiated in unassembled state. Microtubules assembled from irradiated subunits were shorter and of more uniform lengths than control microtubules. For the dose of 1000 Gy the mean length and its standard deviation were reduced to about one-half of the values of the control. 相似文献
987.
Shewanella oneidensis MR-1 is an electroactive bacterium, capable of reducing extracellular insoluble electron acceptors, making it important for both nutrient cycling in nature and microbial electrochemical technologies, such as microbial fuel cells and microbial electrosynthesis. When allowed to anaerobically colonize an Ag/AgCl solid interface, S. oneidensis has precipitated silver nanoparticles (AgNp), thus providing the means for a surface enhanced confocal Raman microscopy (SECRaM) investigation of its biofilm. The result is the in-situ chemical mapping of the biofilm as it developed over time, where the distribution of cytochromes, reduced and oxidized flavins, polysaccharides and phosphate in the undisturbed biofilm is monitored. Utilizing AgNp bio-produced by the bacteria colonizing the Ag/AgCl interface, we could perform SECRaM while avoiding the use of a patterned or roughened support or the introduction of noble metal salts and reducing agents. This new method will allow a spatially and temporally resolved chemical investigation not only of Shewanella biofilms at an insoluble electron acceptor, but also of other noble metal nanoparticle-precipitating bacteria in laboratory cultures or in complex microbial communities in their natural habitats. 相似文献
988.
989.
990.
N. A. Kryazhevskikh E. V. Demkina N. A. Manucharova V. S. Soina V. F. Gal’chenko G. I. El’-Registan 《Microbiology》2012,81(4):435-445
Methods of reactivating the dormant forms (DFs) and nonculturable cells (NCs) of the bacterial communities of buried paleosoils and subsoil permafrost stored for long periods of time (thousands to millions of years), including completely sterile samples (CFU = 0), were developed. They were based on washing the DFs and NCs to remove anabiosis autoinducers (spore germination autoinhibitors) and introducing low molecular weight extracellular growth regulators of microbial or plant origin, such as alkylhydroxybenzenes of the alkylresorcinol subtype, indoleacetic acid, and wheat germ agglutinin. It was revealed that the dormant communities of permafrost and buried soils differed in their sensitivity to reactivating factors, probably due to different natural storage conditions of the tested soil substrates and the heterogeneity of dormant populations. The latter was confirmed by FISH (fluorescent in situ hybridization): applying the reactivation methods to the cells of the dormant permafrost community resulted in an increase in the number of metabolically active cells from 5 to 77% of their total number. In contrast, the addition of microbial anabiosis autoinducers (C12-AHB) to background surface soil and permafrost samples caused the transition of bacterial cells to the dormant or the nonculturable state, depending on the C12-AHB concentration and the sensitivity of the cells from the control soil or permafrost’ to it. The data obtained contribute to our knowledge concerning the role of intercellular communication factors and the survival of microorganisms under extreme environmental conditions. 相似文献