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41.
42.
P. Sewes F. Alberts Marelize Daneel Adriaan A. S. Marais Denis A. Baranenko J. J. Marion Meyer 《Acta Physiologiae Plantarum》2018,40(2):24
The coca family (Erythroxylaceae) consists of trees and shrubs sub-divided into four genera: Aneulophus, Nectaropetalum, Pinacopodium, and Erythroxylum, which include species with highly valuable medicinal compounds. E. delagoense, E. emarginatum, and E. pictum are endemic to southern Africa and have great pharmaceutical potential based on their traditional uses. Previous studies have shown certain inconsistencies in terms of the presence or absence of tropane alkaloids in these species, resulting in a need for further research and clarification. Therefore, the aim of this study was to determine the seasonal variation of the immediate biosynthetic precursor of cocaine, the tropane alkaloid, ecgonine methyl ester in the three South African Erythroxylum species by means of gas chromatography–mass spectrometry, as well as to conduct a phytochemical screening for observing the presence of other potential compounds and tropane alkaloids. We found significant differences in tropane concentrations from the seasonal variation study, explaining the discrepancies in previous reports on its presence/absence in these species. Furthermore, we report for the first time on the occurrence of selected highly valuable tropane alkaloids in E. emarginatum currently used in ‘blockbuster medicine’. 相似文献
43.
The ultrastructure of the green dinoflagellate Lepididodinium viride M. M. Watanabe, S. Suda, I. Inouye Sawaguchi et Chihara was studied in detail. The nuclear envelope possessed numerous chambers each furnished with a nuclear pore, a similar arrangement to that found in other gymnodinioids. The flagellar apparatus was essentially identical to Gymnodinium chlorophorum Elbrächter et Schnepf, a species also containing chloroplasts of chlorophyte origin. Of particular interest was the connection of the flagellar apparatus to the nuclear envelope by means of both a fiber and a microtubular extension of the R3 flagellar root. This feature has not been found in other dinoflagellates and suggests a close relationship between these two species. This was confirmed by phylogenetic analysis based on partial sequences of the large subunit (LSU) rDNA gene of L. viride, G. chlorophorum and 16 other unarmoured dinoflagellates, including both the ‘type’ culture and a new Tasmanian isolate of G. chlorophorum. These two isolates had identical sequences and differed from L. viride by only 3.75% of their partial LSU sequences, considerably less than the difference between other Gymnodinium species. Therefore, based on ultrastructure, pigments and partial LSU rDNA sequences, the genus Lepidodinium was emended to encompass L. chlorophorum comb. nov. 相似文献
44.
Adhesion of Enterococcus mundtii ST4SA and Lactobacillus plantarum 423 to Caco-2 (human carcinoma epithelial) cells was visualized by fluorescent staining. Both strains showed good adhesion
compared to L. casei MB1, L. casei Shirota, L. johnsonii La1 and L. rhamnosus GG. No correlation was found between hydrophobicity, aggregation and adhesion to Caco-2 cells. Presence of antibiotics and
anti-inflammatory medicaments reduced adhesion of bacterial strains to Caco-2 cells. Proteins sensitive to pepsin, trypsin
and pronase are involved in the adhesion of E. mundtii ST4SA and L. plantarum 423 to Caco-2 cells. Adhesion of Listeria monocytogenes ScottA to Caco-2 cells was not prevented by E. mundtii ST4SA and L. plantarum 423. Cell-free culture supernatants of strains ST4SA and 423, containing the antimicrobial peptides plantaricin 423 and peptide
ST4SA, prevented the invasion of L. monocytogenes ScottA into Caco-2 cells. 相似文献
45.
J.L.F. Kock T. Strauss C.H. Pohl D.P. Smith P.J. Botes E.E. Pretorius T. Tepeny O. Sebolai A. Botha S. Nigam 《Antonie van Leeuwenhoek》2001,80(1):93-99
As previously found in various members of the Mucorales, 3-hydroxy oxylipins in Mucor genevensis are associated with the sporangia, i.e. mainly the columella structure and between aggregating sporangiospores. To determine if this phenomenon is also true in distantly related members, the mucoralean fungus Pilobolus was examined. This fungus is characterized by relatively large sub sporangial-columella structures which actively eject sporangia in a sticky liquid for attachment onto herbage surrounding its growth medium – in this case horse dung. Strikingly, this fungus produced a novel oxylipin i.e. a 3-hydroxy monounsaturated fatty acid, possibly a nonenoic acid, which is mainly associated with the sub sporangial-columella structure and aggregating sporangiospores. The specificity of the antibody against 3-hydroxy oxylipins used in immunofluorescence mapping of the mucoralean fungi, was further confirmed in the yeast, Saccharomycopsis malanga which produces 3-hydroxy palmitate in crystal form. These crystals occur between aggregating yeast cells. On the basis of the available data, we hypothesize that 3-hydroxy oxylipins probably function as adhesives, attaching fungal cells to each other or to other surfaces through entropic based hydrophobic forces and/or hydrogen bonds. 相似文献
46.
Bareetseng AS Kock JL Pohl CH Pretorius EE Botes PJ Van Wyk PW Nigam S 《Canadian journal of microbiology》2005,51(1):99-103
Immunofluorescence microscopy exposed the presence of novel 3-hydroxy oxylipins on the surfaces of aggregated hat-shaped ascospores of Ascoidea africana. These compounds were confirmed by gas chromatography - mass spectrometry analysis. Only the complete structure of a novel 3-hydroxy 10:1 could be determined. 相似文献
47.
Leeuw NJ Kock JL Pohl CH Bareetseng AS Sebolai OM Joseph M Strauss CJ Botes PJ van Wyk PW Nigam S 《Antonie van Leeuwenhoek》2006,89(1):91-97
Eremothecium coryli is known to produce intriguing spindle-shaped ascospores with long and thin whip-like appendages. Here, ultra structural
studies using scanning electron microscopy, indicate that these appendages serve to coil around themselves and around ascospores
causing spore aggregation. Furthermore, using immunofluorescence confocal laser scanning microscopy it was found that hydrophobic
3-hydroxy oxylipins cover the surfaces of these ascospores. Using gas chromatography–mass spectrometry, only the oxylipin
3-hydroxy 9:1 (a monounsaturated fatty acid containing a hydroxyl group on carbon 3) could be identified. Sequential digital
imaging suggests that oxylipin-coated spindle-shaped ascospores are released from enclosed asci probably by protruding through
an already disintegrating ascus wall. 相似文献
48.
Leeuw NJ Swart CW Ncango DM Pohl CH Sebolai OM Strauss CJ Botes PJ van Wyk PW Nigam S Kock JL 《Antonie van Leeuwenhoek》2007,91(4):393-405
Interesting distribution patterns of acetylsalicylic acid (ASA, aspirin) sensitive 3-hydroxy (OH) oxylipins were previously
reported in some representatives of the yeast genus Eremothecium—an important group of plant pathogens. Using immunofluorescence microscopy and 3-OH oxylipin specific antibodies in this
study, we were able to map the presence of these compounds also in other Eremothecium species. In Eremothecium cymbalariae, these oxylipins were found to cover mostly the spiky tips of narrowly triangular ascospores while in Eremothecium gossypii, oxylipins covered the whole spindle-shaped ascospore with terminal appendages. The presence of these oxylipins was confirmed
by chemical analysis. When ASA, a 3-OH oxylipin inhibitor, was added to these yeasts in increasing concentrations, the sexual
stage was found to be the most sensitive. Our results suggest that 3-OH oxylipins, produced by mitochondria through incomplete
β-oxidation, are associated with the development of the sexual stages in both yeasts. Strikingly, preliminary studies on yeast
growth suggest that yeasts, characterized by mainly an aerobic respiration rather than a fermentative pathway, are more sensitive
to ASA than yeasts characterized by both pathways. These data further support the role of mitochondria in sexual as well as
asexual reproduction of yeasts and its role to serve as a target for ASA antifungal action. 相似文献
49.
Two pyridine nucleotide dehydrogenases have been isolated from castor bean seed extracts by a combination of ion exchange chromatography on DEAE-Sepharose and gel permeation chromatography on Sephadex G-200. The enzymes were designated D-I and D-II according to their elution position on DEAE-Sepharose. Both enzymes D-I and D-II are globular proteins which have MWs of 66 000 and 60 000, respectively. Dehydrogenation is observed with both NADH and NADPH as electron donors, while the electron acceptor specificity demonstrates that the enzymes are probably NAD(P)H: quinone oxidoreductases. Successful coupling of dehydrogenase activity with that of peroxidase indicates a possible role of the enzymes in seed germination. 相似文献
50.
Holly J. Prudden Tara S. Beattie Natalia Bobrova Jasmina Panovska-Griffiths Zindoga Mukandavire Marelize Gorgens David Wilson Charlotte H. Watts 《PloS one》2015,10(12)