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71.
CJ Cooksey 《Biotechnic & histochemistry》2014,89(5):384-387
The history, origin, identity, chemistry and uses of Congo red are described. Originally patented in 1884, Congo red soon found applications in dyeing cotton, as a pH indicator for chemists and as a biological stain. Unlike the majority of the 19th century synthetic dyes, it still is available commercially. 相似文献
72.
Response of a zooplankton community to the addition of unsaturated fatty acids: an enclosure study 总被引:1,自引:0,他引:1
1. The effect of the addition of emulsions with different fatty acid composition to a semi-natural zooplankton community was studied in enclosures.
2. The reactions of different taxa in the zooplankton community to the addition of the emulsions were different. The copepods showed almost no reaction, nor did the selective cladocerans ( Bosmina ) or rotifers ( Synchaeta or Polyarthra ). The non-selective filterfeeding cladocerans Daphnia and Ceriodaphnia , and the rotifer Keratella , showed responses to the addition of the emulsions.
3. Keratella showed the highest density in the enclosures with high amounts of highly unsaturated fatty acids added, whereas both Daphnia and Ceriodaphnia reached the highest numbers in the enclosures where we added emulsions of saturated fatty acids only.
4. Our results suggest that different taxa may be limited by different factors, even though they use similar food sources. Hence, we conclude that it is very difficult to generalize on the limiting factors in aquatic systems. 相似文献
2. The reactions of different taxa in the zooplankton community to the addition of the emulsions were different. The copepods showed almost no reaction, nor did the selective cladocerans ( Bosmina ) or rotifers ( Synchaeta or Polyarthra ). The non-selective filterfeeding cladocerans Daphnia and Ceriodaphnia , and the rotifer Keratella , showed responses to the addition of the emulsions.
3. Keratella showed the highest density in the enclosures with high amounts of highly unsaturated fatty acids added, whereas both Daphnia and Ceriodaphnia reached the highest numbers in the enclosures where we added emulsions of saturated fatty acids only.
4. Our results suggest that different taxa may be limited by different factors, even though they use similar food sources. Hence, we conclude that it is very difficult to generalize on the limiting factors in aquatic systems. 相似文献
73.
The results described in the accompanying article support the model in
which glucosylphosphoryldolichol (Glc-P-Dol) is synthesized on the
cytoplasmic face of the ER, and functions as a glucosyl donor for three
Glc-P-Dol:Glc0-2Man9-GlcNAc2-P-P-Dol glucosyltransferases (GlcTases) in the
lumenal compartment. In this study, the enzymatic synthesis and structural
characterization by NMR and electrospray-ionization tandem mass
spectrometry of a series of water-soluble beta-Glc-P-Dol analogs containing
2-4 isoprene units with either the cis - or trans - stereoconfiguration in
the beta-position are described. The water- soluble analogs were (1) used
to examine the stereospecificity of the Glc-P-Dol:Glc0-2Man9GlcNAc2-P-P-Dol
glucosyltransferases (GlcTases) and (2) tested as potential substrates for
a membrane protein(s) mediating the transbilayer movement of Glc-P-Dol in
sealed ER vesicles from rat liver and pig brain. The Glc-P-Dol-mediated
GlcTases in pig brain microsomes utilized [3H]Glc-labeled Glc-P-Dol10,
Glc-P-(omega, c )Dol15, Glc-P(omega, t,t )Dol20, and Glc-P-(omega, t,c
)Dol20as glucosyl donors with [3H]Glc3Man9GlcNAc2-P-P-Dol the major product
labeled in vitro. A preference was exhibited for C15-20 substrates
containing an internal cis -isoprene unit in the beta-position. In
addition, the water-soluble analog, Glc-P-Dol10, was shown to enter the
lumenal compartment of sealed microsomal vesicles from rat liver and pig
brain via a protein-mediated transport system enriched in the ER. The
properties of the ER transport system have been characterized. Glc-
P-Dol10was not transported into or adsorbed by synthetic PC-liposomes or
bovine erythrocytes. The results of these studies indicate that (1) the
internal cis -isoprene units are important for the utilization of Glc-P-Dol
as a glucosyl donor and (2) the transport of the water- soluble analog may
provide an experimental approach to assay the hypothetical "flippase"
proposed to mediate the transbilayer movement of Glc-P-Dol from the
cytoplasmic face of the ER to the lumenal monolayer.
相似文献
74.
Protective antiviral immune responses to pseudorabies virus induced by DNA vaccination using dimethyldioctadecylammonium bromide as an adjuvant 总被引:3,自引:0,他引:3
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van Rooij EM Glansbeek HL Hilgers LA te Lintelo EG de Visser YE Boersma WJ Haagmans BL Bianchi AT 《Journal of virology》2002,76(20):10540-10545
To enhance the efficacy of a DNA vaccine against pseudorabies virus (PRV), we evaluated the adjuvant properties of plasmids coding for gamma interferon or interleukin-12, of CpG immunostimulatory motifs, and of the conventional adjuvants dimethyldioctadecylammonium bromide in water (DDA) and sulfolipo-cyclodextrin in squalene in water. We demonstrate that a DNA vaccine combined with DDA, but not with the other adjuvants, induced significantly stronger immune responses than plasmid vaccination alone. Moreover, pigs vaccinated in the presence of DDA were protected against clinical disease and shed significantly less PRV after challenge infection. This is the first study to demonstrate that DDA, a conventional adjuvant, enhances DNA vaccine-induced antiviral immunity. 相似文献
75.
Becker Claes Feuchtmayr Heidrun Brepohl Daniela Santer Barbara Boersma Maarten 《Hydrobiologia》2004,526(1):197-207
In an enclosure study in Schöhsee, a small mesotrophic lake in Northern Germany, the impact of copepods and daphniids on the seston community was studied. In general, these two guilds differ in their feeding behaviour. Copepods actively select their food, with a preference for larger particles, whereas most cladocerans are unselective filter-feeders. In this study we investigate how the impact of the two different grazers affects zooplankton growth. We combine results obtained in the laboratory with results measured in situ in the enclosures. Copepods and cladocerans were cultured on seston from enclosures that were inhabited by density gradients of copepods or daphniids. We observed that Daphnia grew faster on seston that was pre-handled by copepods than on seston that was pre-handled by daphniids, and that somatic growth decreased with increasing densities of daphniids in the enclosures. In contrast, we observed no differences in development rates for copepods grown on the different media. The population growth rates of Daphnia in the Daphnia treatments were determined in the enclosures. Growth differences in both somatic- and population growth of Daphnia were correlated to food quality aspects of the seston. In the laboratory we found that Daphnia growth was correlated with several fatty acids. The strongest regression was with the concentration of 20:43 (r
2= 0.37). This particular fatty acid also showed the highest correlation with growth after normalisation of the fatty acids to the carbon content of the enclosures (r
2= 0.33). On the other hand, in the enclosure the population growth correlated most to the particulate nitrogen content (r
2= 0.78) and only to the N:C ratio, when normalised to carbon (r
2= 0.51). 相似文献
76.
Length growth, instar durations, fecundity and mortality rates of fivespecies of microcrustacean zooplankton from a tropical reservoir weremeasured in relation to food quantity and temperature in laboratorycultures. Three cladocerans (Ceriodaphnia cornuta, Moina micrura,Diaphanosoma excisum), one calanoid copepod (Heliodiaptomus viduus), and onecyclopoid copepod (Mesocyclops thermocyclopoides) were studied. Filteredseston (45 µm mesh) from a local pond was used for food. Two foodconcentrations were employed: (1) 10 µg chlorophyll l–1(ca 0.25 mg Cl–1), and (2) 50 µg chlorophylll–1 (ca 1.25 mg C l–1). Food levels and watertemperature (22.5, 27.5, and 32.5 °C) used, roughly covered the rangesfound in the reservoir. Although all the three growth parameters were oftenaffected to some degree by temperature and food, the quantitative responseof the species differed. Also, the species reacted differently to the threepossible interactions (i.e. food×temperature,food×instar, andtemperature×instar). This contributed to the overalldifferences in the species responses. For the cladocerans, instar durationswere always affected by temperature. The food did not affect the durationtime of the adults and that of the combined juvenile instars, the latterexcept in one case significantly. For the two copepods food level affectedthe duration times of naupliar and copepodite instars, but the effect oftemperature was only significant for H. viduus. The development timesobserved for H. viduus were extraordinary long compared with values reportedin the literature for other tropical calanoids. This suggests that foodconditions in our culture were adversely affecting its growth rates. 相似文献
77.
CJ Cooksey 《Biotechnic & histochemistry》2017,92(7):506-512
Adolf Baeyer announced the discovery of fluorescein in 1871 and named it after its most striking property, i.e., fluorescence. I describe here the synthesis of fluorescein. There are seven molecular species in both the solid state or in solution. I also summarize some of the diverse applications of the dye, both medical and nonmedical, which depend mostly on the facile detection of fluorescein at low concentration. Both animal and human toxicity are examined. 相似文献
78.
CJ Cooksey 《Biotechnic & histochemistry》2014,89(2):111-113
The history, origin, identity, chemistry and use of Evans blue dye are described along with the first application to staining by Herbert McLean Evans in 1914. In the 1930s, the dye was marketed under the name, Evans blue dye, which was profoundly more acceptable than the ponderous chemical name. 相似文献
79.
80.