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排序方式: 共有273条查询结果,搜索用时 109 毫秒
1.
Ya. O. Loginov G. G. Khudaigulov S. P. Chetverikov A. I. Melent’ev O. N. Loginov 《Applied Biochemistry and Microbiology》2011,47(3):311-314
Highly viscous polysaccharide (250–350 kDa) of an alginate nature with a predominance of α-L-guluronic acid (M/G = 0.22) was
obtained from Azotobacter vinelandi. The yield of polysaccharide was 20.5 ± 0.5 g/l when cultured in a medium containing molasses at a viscosity of the cultural
liquid of over 30000 cSt. The biopolymer is stable at pH 4.0–9.0 in a wide temperature range and well soluble in highly mineralized
water; it retains a high viscosity level and can be used in the petroleum industry for enhanced oil recovery. 相似文献
2.
I S Petropavlovskaia T I Osokina N S Akatova N E Smirnova L P Loginov 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1978,(8):55-60
The authors carried out serological typing of 98 Pseudomonas aeruginosa strains, isolated from patients of burn department of the Sklifosovsky First Aid Institute in January-July, 1974, and of 215 strains obtained from other sources; their sensitivity to 13 antibiotics was determined. Pseudomonas aeruginosa cultures isolated from the patients were typed with O-sera of 10 serological types. The presence of several hospital strains of Pseudomonas aeruginosa was found by means of serological typing; along with these there were revealed cultures of this causative agent sporadically appearing in the department. Sensitivity to some antibiotics could serve as an additional criterion for differentiation of Pseudomonas aeruginosa strains of the same serological type. 相似文献
3.
Effect of applied and internal hormones on vitrification and apical necrosis of different plants cultured in vitro 总被引:2,自引:0,他引:2
Natalia V. Kataeva Irena G. Alexandrova Raisa G. Butenko Elena V. Dragavtceva 《Plant Cell, Tissue and Organ Culture》1991,27(2):149-154
Development of vitrification and apical necrosis was followed in Camellia sinensis, Gerbera jamesonii, Malus domestica and hybrid Populus tremula x P. alba shoots cultured in vitro on Murashige & Skoog (MS) medium with different concentrations of growth regulators. High humidity in the culture vessels and excess of BA in the medium were found to be the major factors influencing vitrification. Lack of exogenous cytokinin in the medium during successive subcultures induced apical necrosis in poor-rooting species (Malus domestica, Camellia sinensis). The level of internal phytohormones (ABA, IAA, IPA, 2iP, Z, ZR) was determined in the apple shoots by means of ELISA. The content of internal cytokinins in the vitrified apple shoots was several times greater than in normal ones, which supports the hypothesis that excess of cytokinins, inducing rapid divisions of cells in meristems in the atmosphere with high humidity, is responsible for vitrification. Apical necrosis of the plantlets that appeared after cultivation on cytokinin-free medium is the result of deficiency in endogenous hormones in apple shoots and this being confirmed by analysis of endogenous hormones in apple shoots.Abbreviations BA
benzyladenine
- BHT
butylated hydroxy-toluene
- ABA
abscisic acid
- IAA
indole-3-acetic acid
- ELISA
enzyme-linked immunosorbent assay
- IPA
isopentenyladenosine
- 2iP
isopentenyladenine
- NAA
naphthyl-3-acetic acid
- TBS
trishydroxymethylaminomethane buffered saline
- TLC
thin layer chromatography
- Z
zeatin
- ZR
zeatin riboside 相似文献
4.
Changes in the charge of sarcoplasmic reticulum (SR) vesicles are studied using lipophilic ions, which are adsorbed by the membrane phase. Upon addition of MgATP, phenyldicarbaundecaborane (PCB-) and tetraphenylboron (TPB-) are taken up by the SR vesicles, while tetraphenylphosphonium (TPP+) is released into the water phase. The PCB- uptake occurs as well under conditions when SR membrane is shunted by high Cl- concentration. MgATP induces minor additional binding of PCB- in the presence of oxalate and it is followed by release of the lipophilic anion from the vesicles. EGTA partly reverses the ATP effect, and calcium ionophore A23187 plus EGTA reverses it completely. Vesicles that were preliminarily loaded by Ca2+ demonstrated higher passive and lower ATP-dependent PCB- binding. Activation of isolated Ca2+-ATPase in the presence of 0.1 mM EGTA results in PCB- release into the medium and additional TPP+ binding to the enzyme. We suggest that the redistribution of the lipophilic ions between the water phase and SR membrane reflects charge changes in Ca2+-binding sites inside both SR vesicles and Ca2+-ATPase molecules in the course of Ca2+ translocation. 相似文献
5.
Itamar Barash Alexander Faerman Tamar Ratovitsky Raisa Puzis Margaret Nathan David R. Hurwitz Moshe Shani 《Transgenic research》1994,3(3):141-151
We produced transgenic mice carrying the native sheep -lactoglobulin (BLG) or fusion genes composed of the BLG promoter and human serum albumin (HSA) minigenes. BLG was expressed exclusively in the mammary glands of the virgin and lactating transgenic mice evaluated. In contrast, transgenic females carrying the BLG/HSA fusion constructs also expressed the HSA RNA ectopically in skeletal muscle, kidney, brain, spleen, salivary gland and skin. Ectopic expression of HSA RNA was detected only in strains that express the transgene in the mammary gland. There was no obvious correlation between the level of the HSA RNA expressed in the mammary gland and that found ectopically. In three transgenic strains analysed, the expression of HSA RNA in kidney and skeletal muscle increased during pregnancy and lactation, whereas in the brain HSA expression decreased during lactation in one of the strains. HSA protein was synthesized in skeletal muscle and skin of strain #23 and its level was higher in lactating mice compared with virgin mice. Expression of HSA was also analysed in males and was found to be more stringently controlled than in females of the same strains.In situ hybridization analyses localized the expressed transgene in the skin, kidney, brain and salivary glands of various transgenic strains. Distinct strain-specific and cell-type specific HSA expression patterns were observed in the skin. This is in contrast to the exclusive expression of the HSA transgene in epithelial cells surrounding the alveoli of the mammary gland. Taken together, these results suggest that the absence of sufficient mammary-specific regulatory elements in the BLG promoter sequences and/or the juxtaposition of the BLG promoter with the HSA coding sequences leads to novel tissue- and cell-specific expression in ectopic tissues of transgenic mice. 相似文献
6.
Raisa P. Gorshkova Natalia I. Korchagina Tatianna A. Medonova Elena N. Kalmykova Natalia N. Besednova Yury S. Ovodov 《Carbohydrate research》1980,84(2):237-243
Lipopolysaccharides (LPS) from various strains of Yersinia pseudotuberculosis type V have been isolated and characterised. Differences in sugar composition and serological activity of LPS from various strains within the same subtype of Y. pseudotuberculosis have been revealed. 相似文献
7.
Change in charge of the erythrocyte membrane during exposure to a pulsed electromagnetic field] 总被引:4,自引:0,他引:4
V A Loginov 《Biofizika》1991,36(4):614-620
By means of hydrophobic anion phenyldicarbaundecaboron electrophoresis in PAA gels and filtration through "Millipore" filters an increase of the total membrane charge and decrease in the amount of membrane-bound proteins (actin, glyceraldehyde-3-phosphatedehydrogenase) after erythrocyte ghosts exposition in pulsed electromagnetic field (PEMF, 1-10 Hz pulse frequency, 24 mTesla) were demonstrated. The effects of PEMF are explained by the changes in the distribution of electrostatic charges near the membrane protein-protein binding sites. 相似文献
8.
9.
The mechanism of stimulation of the adrenal cortex function by tetracycline was studied on albino rats. It was shown that tetracycline administered orally in a dose of 200 mg/kg regularly induced an increase in the corticosterone levels in the peripheral blood of the animals by the 15th day of the antibiotic use. It was shown on the animals with an experimentally suppressed function of the hypophysis by prolonged administration of hydrocortisone acetate that tetracycline primarily stimulated the hypophysis function resulting in production and excretion of increased amounts of the adrenocorticotropic hormone into the blood. The hormone increased the production of corticosterone in the adrenal glands which resulted in its higher levels in the peripheral blood. 相似文献
10.
Yury S. Ovodov Raisa G. Ovodova Valenthina I. Shibaeva Lidia V. Mikheyskaya 《Carbohydrate research》1975,42(1):197-199
Traces of either ferrous or ferric salts greatly increase the rate of the stepwise degradation of reducing sugars by alkaline hydrogen peroxide, as measured by formation of formic acid; addition of larger proportions of iron salts causes relatively smaller effects. The results showed that, unless unusually strict precautions are taken to exclude traces of iron, the free-radical cleavage of the hydroperoxide adducts of reducing sugars is far more rapid than the ionic cleavage. The catalytic effect of iron salts is counteracted by addition of magnesium salts. With d-glucose, inhibition of the catalytic effect of iron by magnesium depends on both the magnesium-iron ratio and the concentration at a given ratio. Measurements with various molar proportions of the salts indicated that a magnesium-iron complex, containing six atoms of magnesium to one of iron, is formed. Presumably, removal of iron by formation of this complex inhibits the free-radical degradation of hydroperoxide adducts. In marked contrast to the results obtained with reducing sugars, the degradation of potassium glyoxylate and of glyoxal by alkaline hydrogen peroxide is extremely rapid, and not catalyzed by iron or inhibited by magnesium. The results are in accord with an ionic, rather than a free-radical, cleavage of the hydroperoxide adducts of these compounds. The rapidity of the ionic reaction may be attributed to the ready availability of an electron pair from the adjoining carbon atom. 相似文献