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11.
Pseudomonas sp. strain B-300, which is able to utilize 2-chlorobenzoic acid, was isolated from a soil sample by enrichment culture. This strain was shown to grow on 2-chlorobenzoic acid and to completely degrade the substrate with concomitant chlorine ion release. Concentrations of 2-chlorobenzoic acid higher than 0.5% (w/v) were toxic to the cells. Our study also suggested that in the presence of glucose, 2-chlorobenzoic acid is converted to catechol or chlorocatechol; these are in turn transformed to muconic and chloromuconic acid, respectively, suggesting a repression by glucose of some of the degradation pathway enzymes. A similar scheme was already described for 3-chlorobenzoate degradation by pAC25 plasmid.  相似文献   
12.
A series of novel hGRF(1-29)-NH2 analogs were synthesized and biotinylated. The immunological and biological activities of these analogs were then characterized. To distance the biotin moiety from the putative bioactive core, a C-terminal spacer arm consisting of -Gly-Gly-Cys-NH2 (-GGC) was added to hGRF(1-29)-NH2 (hGRF29) and analogs, with subsequent biotinylation performed at the cysteine residue. Neither addition of the C-terminal spacer arm nor biotinylation affected affinity of these analogs for GRF antibody. Relative to hGRF(1-44)-NH2 (hGRF44: potency = 1.0), the biotinylated analogs were equipotent in vitro to their nonbiotinylated, parent compounds: [desNH2Tyr1,D-Ala2,Ala15]hGRF29-GGC-(tpBiocyt in)-NH2 (4.7) = [Ala15]hGRF29-GGC-(tpBiocytin)-NH2 (3.9) greater than hGRF29-GGC-(tpBiocytin)-NH2 (0.8). Based upon cumulative GH release data in vivo (0-60 min postinjection), [desNH2Tyr1,D-Ala2,Ala15]hGRF29-GGC-(tpBiocyt in)-NH2, [Ala15]hGRF29-GGC-(tpBiocytin)-NH2, and hGRF29-GGC-(tpBiocytin)-NH2 displayed 8.6, 5.5, and 0.8 times, respectively, the potency of hGRF44. These in vivo potency values were not significantly different from the corresponding parent compounds (i.e., with or without the C-terminal spacer arm). In summary, biotinylated hGRF analogs have been developed that retain full immunoreactivity and potent bioactivity (in vitro and in vivo), thus permitting their use in GRF receptor isolation, ELISA, and histochemical procedures.  相似文献   
13.
A new flavone glucoside macrophylloside has been isolated from the whole plant of Primula macrophylla and its structure was determined by spectroscopic methods as 2′-hydroxy-7-O-β- -glucopyranosyloxyflavone. Sitosterol glucoside was also isolated for the first time from this plant.  相似文献   
14.
Summary A selective technique is described for the isolation of mutants of Escherichia coli lacking uridine phosphorylase and the location of the gene specifying this enzyme on the bacterial chromosome is determined. Using strains with appropriate lesions it is shown that there are three routes via which 5-fluorouracil can be converted to compounds which inhibit cell growth.  相似文献   
15.
Résumé Les auteurs décriventPseudoscymnus simmondsi, espèce nouvelle deCoccinellidae prédatrice dePinnaspis strachani (Cooley) surFicus palmata au Pakistan occidental. Les autres espèces du genre sont connues seulement de l'Extrême-Orient.

This research has been financed in part by a grant made by the United States Department of Agriculture, Agricultural Research Service.  相似文献   
16.
Body weight, testicle size and peripheral testosterone concentrations were measured in 35 water buffalo bulls at 5, 15, 17, 21, 25 and 38 months of age. These parameters were studied in all animals during the same month (October), so the changes due to age were independent of changes in photoperiod and temperature. Body weight increased linearly with age. The testicular size measured in terms of scrotal circumference as related to age, showed a curvilinear increase; the average rate of testicular growth was maximum between 15 and 25 months. Plasma testosterone levels were low between 5 and 21 months. A significant rise in plasma concentration of testosterone was observed at 25 months reaching peak levels at 38 months. The mean age of sexually mature bulls at the time of first ejaculation of semen with motile sperm, was 24.9±0.9 months (n=9). It has been concluded that in the Nili-Ravi buffalo bulls the sexually quiescent period (prepubertal) extends up to 15 months of age and sexual maturation as indicated by the presence of motile sperm in the ejaculate is attained at about 25 months.  相似文献   
17.
Effect of soil acidity and saturating cation on adsorption of urea in soil   总被引:1,自引:0,他引:1  
Summary Elevating the pH of two extremely acid tropical soils from an initial pH of 4 to 5 with Ca(OH)2 and NaOH solutions resulted in a sharp decrease in urea adsorption. Further increases in pH to 9 caused only slight further decrease in urea adsorption. Ca treatment resulted in slightly higher adsorption than Na treatment over the full range of pH values studied for a clay soil with high smectite content, and for a loam with kaolinite mineralogy below pH 7. Above pH 7 a kaolinitic loamy soil gave slightly higher adsorption with Na treatment than with Ca.  相似文献   
18.
Rafiq Ahmad 《BioControl》1978,23(2):161-162
Hyperodes bonariensis Kuschel underwent ovarial diapause from March to August in the Bariloche area in Argentina. Feeding on germinating seedlings ofTriticum aestivum L. andPoa annua L. in continuous dark induced the weevil for oviposition in 24 and 32 days, respectively. Breeding techniques are described forH. bonariensis and its parasitePatasson atomarius (Brethes).  相似文献   
19.
The presence of pigment cells in the leg muscle of Silver Campine fowl is ascertained. Transverse sections of legs of 16 and 21 day embryos gave similar results. Analysis of the states of differentiation indicates three types of pigment cells contained by the leg muscles. The relationship between the tissue environment and the melanoblast differentiation is discussed.  相似文献   
20.
Summary Rhodococcus equi cells immobilized onto porous celite beads were active in side-chain cleavage of cholesterol. The effect of bead size, adsorption time and washing cycles were examined. The degradation of cholesterol side-chain using adsorbed cells was studied in batch and semi-continuous systems. Compared to free cells (80 mol%), the end-product (1,4-androstadiene-3,17-dione and 4-androstene-3,17-dione) profile was lower (70 mol%) with the celite-adsorbed system. Correspondence to: B. N. Johri  相似文献   
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