2001
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MICROSOMEMEDIATED BENZO[A]PYRENEDNA BINDING AND INHIBITION BY CYTOSOLIC FRACTIONS FROM LIVER AND SKIN OF ADULT AND WEANLING RATS
https://jsciences.ut.ac.ir/article_31811.html
1
Biotransformation of benzo[a]pyrene (BaP) in the presence of microsomal fractions derived from liver and epiderm of adult and weanling rats was examined. The aim of this study was to evaluate the effect of age on the capacity of two organs in transformation of BaP. Subcellular fractions were prepared from skin and liver by ultracentrifugation and were used as the source of BaP metabolizing enzymes in a reconstitution assay system. Microsomal fractions are sources of cytochrome P450 and cytosols are the source of glutathione Stransferase (GST). In a metabolic activation assay system, cytochrome P450 catalyses the formation of reactive epoxide of BaP which can then interact with exogenous DNA. Adult rat liver microsomes with the highest cytochrome P450 and maximum capacity for BaPDNA adducts formation (~204 pmol BaP bound/mg DNA) are considered as positive control in this assay system. The adduct formation in the presence of adult and young rats was approximately 204 and 27 pmol/mg DNA, respectively. Microsomes prepared from skin samples of adult and young rats mediated approximately 49 and 16 pmol BaP binding to DNA respectively. With the addition of cytosol to the microsomemediated system an in vitro detoxification model has been established. The results obtained by the addition of different cytosolic samples showed that liver cytosol which contains highest GST activity caused about 28% inhibition in BaP binding to DNA. The inhibitory effects of cytosolic fraction from weanling liver, adult skin and weanling skin were 17, 19 and ~9% respectively. These data show that isolated subcellular fractions from young rats are less efficient in the biotansformation of BaP. However, the results obtained in vitro do not reflect the changes in vivo. Further, in vivo experiments should be carried out after BaP administration to animals to confirm the differences in the BaPDNA adduct formation and BaPglutathione conjunction in tissues of young and adult animals.
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EMBRYOGENESIS AND RHIZOGENESIS
IN MATURE ZYGOTIC EMBRYOS OF OLIVE (OLEA EUROPAEA L.) CULTIVARS MISSION AND KRONEIKI
https://jsciences.ut.ac.ir/article_31812.html
1
Organogenesis and neoformant plantlet production were studied by culturing the different parts of mature embryo including radicle and proximal and distal parts of cotyledon of Mission and Kroneiki cultivars. Different parts of embryos were cultures in OMc medium containing growth regulators, such as indole butyric acid (IBA) and 2isopentenyl adenine (2ip) or IBA and naphthalene acetic acid (NAA). 21 days old calli were subcultured in medium without growth regulators or with auxin (IBA and NAA). Cultures were maintained in dark or 16h light/8h dark. Differentiation in the explants of Mission and Kroneiki cultivars depended on culture conditions. In both cultivars, the potentiality of embryogenesis in calli from radicle was more than calli from proximal, and in the latter was more than calli from distal parts of cotyledons. In addition, somatic embryogenesis was higher in dark. Subcultures of different parts in medium with auxin inhibited the embryogenesis. Rhizogenesis occurred in subcultures medium with or without auxin and in different photoperiods. In both cultivars the potentiality of rhizogenesis in calli from radicle and calli from different parts of cotyledon were observed. Differences between rhizogenesis from different cultivars and different subculture media were significant.
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PECTIC ENZYME PATTERNS OF FUSARIUM OXYSPORUM VIRULENT ISOLATES
FROM CHICKPEA IN IRAN
https://jsciences.ut.ac.ir/article_31813.html
1
The pectic enzymes produced in vitro by 8 isolates (5 Highly virulent and 3 Weakly virulent) of Fusarium oxysporum , were detected by spectrophotometry, and characterized by polyacrylamide gel electrophoresis with substratecontaining gels (zymogram). Analysis of the polygalacturonase (PG) isozyme banding patterns (zymogram) identified two distinct phenotypes among the isolates from chickpea (Cicer arietinum), F. oxysporum zymogram group one (FOZG1) and FOZG2. Of the 8 isolates tested, 5 isolates had the FOZG1 phenotype, and 3 isolates had the FOZG2 phenotype. There were two virulent groups among these isolates: highly virulent (HV) and weakly virulent (WV). The HV isolates were all FOZG1 and WV isolates were FOZG2. Analysis of the pectic enzyme activity of different isolates on PZ medium demonstrated that PG and pectin lyase (PNL) were the predominant enzyme activities in FOZG1 (HV) compared with FOZG2 (WV) isolates, while the pectate lyase (PL) showed enzyme activity in both FOZG1 and FOZG2 groups. Therefore, from these results it can be hypothesized that PG and PNL enzymes may be important in pathogenicity of F. oxsporum isolates in Iran.
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TRANSFORMATION OF 2BENZOYLAMINO1(?NAPHTHYL)PROPAN1OL INTO 4METHYL1PHENYL BENZO[f] ISOQUINOLINE RATHER THAN ITS 3SUBSTITUTED ISOMER
https://jsciences.ut.ac.ir/article_31814.html
1
The necessary conditions to transform hydroxyamide (1) and 2oxazolines (2, 3) into 3 or 4methyl benzo[f] isoquinolines (4, 5) has been established. The mechanism of these reactions has been proposed claiming the existence of the protonated 2oxazoline (6) and the styrylamides (7) as intermediates.
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THE DEALKYLATION OF TERTIARY AMINES WITH THIOPHOSGENE AND
1CHLOROETHYL CHLOROTHIONOFORMATE
https://jsciences.ut.ac.ir/article_31815.html
1
Thiophosgene and 1chloroethyl chlorothionoformate react readily with tertiary amines, and give the dialkylamine hydrochloride after hydrolysis of the initial product with water. Benzyl and allyl groups are cleaved in preference to methyl and other alkyl groups. The rection with the isoquinoline alkaloid narcotine occurs particularly easily.
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SOLID STATE DESEMICARBAZONATION WITH HEXAMETHYLENETETRAMINEBROMINE: REGENERATION OF CARBONYL COMPOUNDS USING MICROWAVES
https://jsciences.ut.ac.ir/article_31816.html
1
Hexamethylenetetraminebromine on wet alumina rapidly regenerates carbonyl compounds from their corresponding semicarbazone using microwave under solventless system.
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HYDROGEOLOGICAL EVALUATION AND MANAGEMENT OF SARVESTAN BASIN,
BY UNGW MODEL
https://jsciences.ut.ac.ir/article_31817.html
1
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ON THE EXISTENCE OF PERIODIC SOLUTIONS FOR CERTAIN NONLINEAR DIFFERENTIAL EQUATIONS
https://jsciences.ut.ac.ir/article_31818.html
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Here we consider some nonautonomous ordinary differential equations of order n and present some results and theorems on the existence of periodic solutions for them, which are sufficient conditions, section 1. Also we include generalizations of these results to vector differential equations and examinations of some practical examples by numerical simulation, section 2. For some special cases that extendibility of the solutions can be verified and under other suitable conditions, we show that the frequency of the periodic solutions can be arbitrary small†.
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EXISTENCE OF A STEADY FLOW WITH
A BOUNDED VORTEX IN AN
UNBOUNDED DOMAIN
https://jsciences.ut.ac.ir/article_31819.html
1
We prove the existence of steady 2dimensional flows, containing a bounded vortex, and approaching a uniform flow at infinity. The data prescribed is the rearrangement class of the vorticity field. The corresponding stream function satisfies a semilinear elliptic partial differential equation. The result is proved by maximizing the kinetic energy over all flows whose vorticity fields are rearrangements of a prescribed function.
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TRANSFORMATION SEMIGROUPS AND TRANSFORMED DIMENSIONS
https://jsciences.ut.ac.ir/article_31820.html
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In the transformation semigroup (X, S) we introduce the height of a closed nonempty invariant subset of X, define the transformed dimension of nonempty subset S of X and obtain some results and relations.
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OPTIMAL NOZZLE SHAPES OF CO2N2H2O GASDYNAMIC LASERS
https://jsciences.ut.ac.ir/article_31821.html
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In an axisymmetric CO2N2H2O gas dynamic laser, let ? denote the intersection of the vertical plane of symmetry with the upper part of the (supersonic) nozzle. To obtain a maximal small signal gain, some authors have tested several families of curves for ?. To find the most general solution for ?, an application of Pontryagin’s principle led to the conjuncture that the optimal ? must consist of two straight lines of slopes m and 0 smoothly joined by a parabolic arc. (The parabolic section will vanish if nonsmooth ? is allowed.) The conjecture was settled in the affirmative for special cases. The present work extends these results in the following directions. (i) For the nonsmooth case, Pontryagin’s principle produces no singularity and ? consists of k straight lines of certain slopes m and 0. (ii) A “semiuncoupled” approximation is used to show, in (i), that k = 2. (“coupled” stands for the dynamic coupling between vibrational temperatures and translational temperature.) (iii) An uncoupled approximation is used in the smooth case to show that the general ? consists of a line segment of slope m, a parabolic arc and a horizontal line. (iv) The small signal gain increases whenever the slope m and/or the curvature of the parabolic section increase. However, the latter two quantities must be bounded to reduce gas detachment from the walls or oblique shock waves in the active media. (v) Finally, the optimal shapes and gains are numerically calculated for several values of the stagnation pressure and molar fractions of the gas mixture.
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HOW THE KONDO EFFECT CAN EXIST IN Gd INTERMETALLIC COMPOUNDS
https://jsciences.ut.ac.ir/article_31822.html
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Based on the crystal and magnetic structural properties of some Gd intermetallic compounds, it is shown that with increasing conduction electron concentration, Gd experiences electronic and magnetic instability, and that these behaviors point to the appearance of Kondo Lattice. We suggest that the conduction electrons have gained local character. It is shown that Kondo effect should be observed at around x=0.4. Resistivity studies confirm the calculations, and a Kondo temperature of around 70 K found for Gd2Au0.4Al0.6.
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