University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 9 4 1998 12 01 DETERMINATION OF PHYLOGENlETIC ALLIES IN SOME SPECIES OF CROCUS IN IRAN THROUGH THE STUDY OF SOLUBLE PROTEINS, PEROXIDASES AND POLYPHENOL OXUDASES - 31476 EN Journal Article The taxonomic affinity of six species of Crocus (C, cancellatus subsp. Damascenus C. almehensis, C. gilanicus, C. sativus, C.pallassi subsp. haussknechtii,C. speciosus subsp. speciosus) from Iran were studied usingdifferent electrophoresis techniques. The similarity index of the species was computed by comparison of protein bands of - Corm and seed tissues, and the related dendrogms of affinity dies were drawn. The local populations of C. cancellatus constitute the first cluster of dendrogram and along with autumnal species form a common cluster. C. almehensis, which in contrast to other species is vernal, joined them at a farther distance https://jsciences.ut.ac.ir/article_31476_78147341bba904f5b3f3c6123055a974.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 9 4 1998 12 01 APPLICATION OF TWO-DIMENSIONAL ELECTROPHORESIS AND NIH 3T3 CELL TRANSFECTION ASSAY IN THE STUDY OF TUMOR-AS SOCIATED PROTEINS AND GENOMIC DNA TUMOROGENICITY IN MALIGNANT HUMAN ESOPHAGEAL SPECIMENS - 31477 EN Journal Article Total protein and DNA extracted from histologically diagnosed normal nonmalignant and esophageal tumor tissues were used for analysis of polypeptides pattern by two-dimensional gel electrophoresis and DNA transforming activity in NIH 3T3 cell transfection assay, respectively. In comparison to normal tissues, eight polypeptides underwent down-regulation or disappeared, while seven polypeptides were subjected to up-regulation or appeared for the first time in tumor tissues. We suggest that the first eight polypeptides are necessary for maintenance of normal phenotype and the other seven polypeptides are involved in the development of malignant phenotype. However, results obtained from NIH 3T3 cell transfection with esophageal tumorous DNA showed that such DNAs lack transforming efficiency. These data may agree with the published reports about the absence of activated transforming oncogenes such as the ras family in esophageal cancer specimens https://jsciences.ut.ac.ir/article_31477_9dfe9454b8b6c1b80bbb33fb12e890af.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 9 4 1998 12 01 KINETIC DETERMINATION OF ASCORBIC ACID a WITH SPECTROPHOTOMETRIC DETECTION - 31478 EN Journal Article A simple and rapid method has been developed for the determination of ascorbic acid in fruit and pharmaceutical products. The method is based on the measurement of the reaction rate between ammonium molybdate and ascorbic acid in acidic media. The reaction was monitored spectrophotometrically at 800 nm by fixed-time and variable-time methods. The calibration graph was linear in the range of 5 0 ×1 0 - 6.0 ×10 M ascorbic acid when using a fixed-time method. The relative standard deviation for ten replicate analyses is 2.7% for 5.0 × 10 a scorbic acid. The limit of detection is 2.0×10 M. T he effect ofvarious species was studied for this determination. https://jsciences.ut.ac.ir/article_31478_dee7539590036bbddca5ab8fc0b8357e.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 9 4 1998 12 01 SPECTROPHOTOMETRIC STUDY OF THE THERMODYNAMICS AND KINETICS OF CHARGE-TRANSFER COMPLEXATION OF DIBENZO- 18-CROWN-6 WITH IODINE IN CHLOROFORM SOLUTION - 31479 EN Journal Article The charge-transfer complexation reaction between iodine and dibenzo- 18-crown- 6 (DB18C6) has been studied spectrophotometrically in chloroform solution at different temperatures. The resulting donor-acceptor complex was formulated as (DB 18C6…I )I . The spectrophotometric results , as well as the conductivity measurements, indicated that the gradual release of tiiodide ion from its contact ion paired form, in the molecular complex, into the solution is the rate determining step of the reaction. The rate constants at various temperatures and the activation parameters E , ?H and AS were calculated. The enthalpy and entropy of the complex formation reaction were evaluated from the temperature dependence of the formation constant. It was found that the resulting charge-transfer complex is both enthalpy and entropy stabilized. https://jsciences.ut.ac.ir/article_31479_4467c5ebcc8206601625e713d31605f9.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 9 4 1998 12 01 AROMATIZATION OF 1 , CDIHYDROPYRIDINES WITH OXYGEN OR AIR USING MANGANESE AND COBALT SALTS OF p-AMINOBENZOIC ACID SUPPORTED ON SILICA GEL AS OXIDIZING CATALYSTS - 31480 EN Journal Article Hantzsch 1,4-dihydropyridines are oxidized to the corresponding pyridine derivatives using oxygen or air and a mixture of the manganese and cobalt salts of parninobenzoic acid supported on silica gel as the catalysts. Reactions are clean and the catalysts can be recovered easily and reused repeatedly. https://jsciences.ut.ac.ir/article_31480_87688e644bd630526fedd4f22613cef9.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 9 4 1998 12 01 REACTIONS OF DIHYDROPYRIDINES WITH BENZYNE - 31481 EN Journal Article Reactions of 1 ,Zdihydropyridines (la-c) and 1,4-dihydropyridines (2a-c) in the presence of benzyne (3) under thermal conditions, and in the case of (2c) under photochemical conditions, have been investigated. Benzyne acts as an oxidizing agent to convert dihydropyridine (la) and (2a) to the corresponding pyridine (4) or adds as a dienophile to (lb-c). https://jsciences.ut.ac.ir/article_31481_5a897c4ac62db0e169de0b47ae9c2842.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 9 4 1998 12 01 PHY SICO-CHEMICAL CHARACTERISTICS OF MINERALIZING FLUIDS AT THE KAMARMEHDI MINE, TABAS REGION, IRAN - 31482 EN Journal Article The data obtained from field and geothermometric studies and also the REE composition of fluorites associated with lead mineralization at the Kamar-Mehdi mine are compatible with a structurally controlled, fissure filling, epigenetic, hydrothermal origin. Homogenization and last ice melting temperatures for primary fluid inclusions trapped in fluorite crystals indicate that the mineralization of fluorite and the associated (cogenetic ?) lead has taken place over a temperature range of 1 15- 125OC. The mineralizing fluids were dilute and do not show any apparent change in temperature and salinity with depth. Salinities of inclusion fluids range from 0.7 to 3.7 equivalent wt.% NaCl, and Na/Ca atomic ratio of inclusion leachates is low with all leachates containing appreciable amounts of K and Mg. The daughter minerals are mostly Ca, K, Al, Si, C1 phases https://jsciences.ut.ac.ir/article_31482_a65f1a3b683798dfd16d5850525c7b8e.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 9 4 1998 12 01 CHEBYSHEV SUBALGEBRAS OF JB-ALGEBRAS - 31483 EN Journal Article In this note, we characterize Chebyshev subalgebras of unital JB-algebras. We exhibit that if B is Chebyshev subalgebra of a unital JB-algebra A, then either B is a trivial subalgebra of A or A= H R .l, where H is a Hilbert space https://jsciences.ut.ac.ir/article_31483_d04853731ce0790af8fbd9de5c37c8c1.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 9 4 1998 12 01 SOME POINTS ON CASIMIR FORCES - 31484 EN Journal Article Casimir forces of massive ferrnionic Dirac fields are calculated for parallel plates geometry in spatial space with dimension d and imposing bag model boundary conditions. It is shown that in the range of ma>>l where m is mass of fields quanta and a is the separation distance of the plates, it is equal to massive bosonic fields Casimir force for each degree of freedom. We argue this equality exists for any massive anyonic field in two-dimensional spatial space. Also the ratio of massless ferrnionic field Casimir force to its bosonic correspondent in d-dimensional spatial spaceis (1- ) https://jsciences.ut.ac.ir/article_31484_bbd230052c26e38339105b7d1af05990.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 9 4 1998 12 01 EEDF MEASUREMENTS AND EXCITATION PROCESSES IN THE VICINITY OF A HELIUM DISCHARGE CONSTRICTION - 31485 EN Journal Article Axial distributions of plasma and floating potentials, electron number density and the electron energy distribution function (EEDF) have been measured in the double layer (DL) region of an He discharge constriction. Excitation processes in the constriction region are studied. Using a linearization method for the nonstationary balance equations and choosing appropriate discharge conditions, the step excitation rate by electron impact for the 2 S 3 D transition in He is determined https://jsciences.ut.ac.ir/article_31485_3ff5ad8918b875387908967a23b9a8d4.pdf