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11.
The fucose-containing polysaccharides of the brown alga Dictyota dichotoma were extracted with either trichloroacetic acid or HCl to give both water-soluble and water-insoluble materials. The latter had a high proportion (16 to 11%) of protein, and although all the sugars found in the water-soluble extracts were present, the major sugar in these water-insoluble polysaccharides was glucose. The water-soluble material extracted with HCl was a protein-free sulphated heteropolysaccharide. Complete removal of a glucan from the water-soluble extract was achieved by fractional precipitation with ethanol. The recovered glucan-free sulphated polysaccharide, which was rich in glucuronic acid, galactose, fucose and sulphate, showed high anticoagulating activity. 相似文献
12.
Mohamed M. El-Sayed 《Carbohydrate research》1982,110(2):277-282
Polysaccharides of the brown seaweed Turbinaria murrayana were isolated. Laminaran (3.2%) was isolated from the hot-water extract of the algae by using ion-exchange chromatography. Fucans (2.1%) were isolated from the hot-water extract, as well (4.7%) as from the extract of the algae with dilute acid. Acid hydrolsysis of the isolated fucans revealed glucose, amnnose, fucose, glucuronic acid, xylose, and galactose. Alginic acid (22.6%) was separated, and reduced to a neutral polysaccharide. The polysaccharides isolated were analyzed by methylation and Smith degradation. 相似文献
13.
Subpicosecond resonance Raman spectra of the early intermediates in the photocycle of bacteriorhodopsin 总被引:2,自引:1,他引:1
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R. van den Berg Du-Jeon-Jang Herbert C. Bitting M. A. El-Sayed 《Biophysical journal》1990,58(1):135-141
The resonance Raman spectra are presented for the species formed during the photocycle of bacteriorhodopsin (bR) on a timescale of 800-900 fs. In the ethylenic stretch region two intermediates were found with frequencies of 1,510 and 1,518 cm-1, corresponding to species with optical absorption maxima at 660 and 625 nm, respectively. This leads to the assignment of the 1,518 cm-1 band to the J625 intermediate. In the fingerprint region, the appearance of a vibration at 1,195 cm-1 strongly suggests that the isomerization indeed has taken place in a time less than the pulsewidth of our laser. This supports the previous proposals made on the basis of the optical spectra. The spectra are compared with those observed in tens of picoseconds up to nanoseconds. 相似文献
14.
The cyclic, semicontinuous production of L-phenylacetyl carbinol (L-PAC) from a benzaldehyde substrate by Saccharomyces cerevisiae ATCC 834 immobilized in calcium alginate beads was substantially enhanced to about 4.5 g/L in a second cycle by reactivation in fresh medium for 24 h, following an earlier 24-h period of production from substrate. Intermittent feeding of benzaldehyde was employed (four doses in 3 h). In subsequent similar cycles, however, the production returned to that produced in the first cycle, viz. L-PAC concentration of 2-3 g/L in the medium. Production of L-PAC was also increased by adaptation of the cells over 200 h of exposure to the benzaldehyde substrate (compared to wild-type cells) and by continuous (as compared to intermittent) feeding of the substrate. A liter as great as 10 g/L was obtained with wild-type cells by continuous feeding of benzaldehyde over 6 h. Immobilization not only protected the cells from toxic effects of substrate but also permitted them to be used during 7 cycles of semicontinuous operation over more than 200 h. 相似文献
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El-Sofany Walaa I. Osman Dalia Ahmed A. Mahran Asma M. May El-Manawaty A. El-Sayed Wael A. 《Russian Journal of Bioorganic Chemistry》2020,46(5):873-873
Russian Journal of Bioorganic Chemistry - erratum 相似文献
18.
Baioumy Asmaa Ali Swelim Hamdy Hamed Ibrahim Ahmed Adly Mohamed Fatma El-Sayed Marzouk Aleya Soliman El-Alfy Sherif Helmy 《Experimental & applied acarology》2021,85(2-4):331-354
Experimental and Applied Acarology - This study examined the acaricidal, histopathological and genotoxic effects of the entomopathogenic fungus Beauveria bassiana on engorged females of the fowl... 相似文献
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Yasmine Asaad Mansour El-Sayed M.M. Mosallam Shaymaa Hussein Ebtihal M.M. Elleithy Ihab M. Moussa Ayman S. Mubarak Turki M. Dawoud Roua A. Alsubki Jwaher H. Alhaji Hassan A. Hemeg Gehad A.H. EL-Bargeesy 《Saudi Journal of Biological Sciences》2021,28(1):217-223
This study illustrated the immunohistochemical distribution of androgen and vitamin D receptors of epididymis in 20 sexually mature ram (Rahmani breed) with average age ranged from (2_4) years and average weight ranged from (50_65kg). Androgen receptor was localized in the cytoplasm of both ciliated and non ciliated cells of efferent ductules, besides the principal cells via the entire epididymal duct. The principal cells of both corpus and proximal cauda epididymis showed the highest immunoreactivity to androgen receptors. Furthermore, vitamin D receptor was localized in the cytoplasm of all epithelium of the efferent ductules besides principal cells of all epididymal regions, however the immunoreaction was significantly higher in the efferent ductules, distal caput and distal cauda epididymis. In conclusion, these results suggest that the function of ram epididymis is regulated by both androgen and Vitamin D. 相似文献