@article { author = {}, title = {STUDIES ON PHOSPHOLIPASE C FROM MELIA AZADIRACHTA SEEDS}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {The activity of phospholipase C in crude enzymatic preparation of Melia azadiracht seeds (Neem seeds) was studied by the use of lecithin as a substrate in aqueous medium. The enzyme activity was found optimum at pH 2.5 and temperature 35?C. The phospholipase C was found heat labile, being inactivated 88% within 10 minutes at 90°C}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31197.html}, eprint = {https://jsciences.ut.ac.ir/article_31197_4c131da55d7e8ccb024e6aa0d2ebd74a.pdf} } @article { author = {}, title = {PARTIAL PURIFICATION AND PROPERTIES OF L-GLUTAMINE: D-FRUCTOSE 6-P AMIDOTRANSFERASE FROM HUMAN PLACENTA}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {The first enzyme of the pathway for uridine diphosphate N-acetyl-D-glucosamine (UDPAG) biosynthesis i.e. L-glutamine: D-fructose 6-P amidotransferase (E.C. 2.6.1.16) was purified 52-fold from human placenta using methanol fractionation and column chromatography on DEAE-Sephadex A-50. The enzyme showed optimal activity in a broad range of pH from 5.8 to 7.8 in both phosphate and cacodylate buffers. Its K m value for D-fructose 6-P was found to be 2.14 mM. The enzyme was inhibited up to 76% in the presence of 0.12mM UDPAG. A K value of 6.6 ?M was obtained for the feedback inhibition of this enzyme by UDPAG}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31198.html}, eprint = {https://jsciences.ut.ac.ir/article_31198_379a5afcc4955d121319a38a7b95410b.pdf} } @article { author = {}, title = {THE EFFECT OF IONIC STRENGTH ON THE BINDING OF SODIUM N-DODECYL SULPHATE TO ASPERGILLUS NIGER CATALASE}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {The binding of sodium n-dodecyl sulphate (SDS) to Aspergillus niger catalase in various ionic strengths at pH 6.4 and a temperature of 27? and 37?C has been studied over a range of SDS concentrations using equilibrium dialysis and fluorescence spectroscopy techniques. The binding data were used and interpreted in terms of theoretical models (Scatchard Equation and Wyman Binding Potential). The cationic ionizable residues were estimated and have been compared with data from amino acid analysis}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31199.html}, eprint = {https://jsciences.ut.ac.ir/article_31199_13c31d71bebeaf5d294a35348664858f.pdf} } @article { author = {}, title = {FAST ATOM BOMBARDMENT MASS SPECTROMETRY (FABMS) ANALYSIS OF AN N- TERMINAL - BLOCKED PEPTIDE}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {FABMS analysis of T-lb peptide before and after one cycle of Edman degradation indicated an unblocked N-terminal Thr residue for this tryptic peptide. In contrast , our data showed a molecular protonated ion, MH + for T- la peptide at 655 mass units (mu) which is 42 mu higher than the MH ion of T- 1b peptide. In addition, T- la peptide was not amenable to one cycle of manual Edman degradation. These observations suggest that the N-terminal residue of T- 1 a peptide is blocked by a chemical group having a mass of 42 mu. This observation is consistent with the presence of an N-terminal acetyl group. This prediction was further investigated by complete characterization of the gas phased fragment ions, originated from the individual peptides, using link-scanning approach. The fragment ions again suggest an acetyl group attached to an N-terminal threonine. In addition, the fragment ions provide evidence that the two peptides (T-la and T-lb) have identical structures except for the N-acetyl group}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31200.html}, eprint = {https://jsciences.ut.ac.ir/article_31200_331f7b41e33370ddae16190f0f100677.pdf} } @article { author = {}, title = {STEREOSELECTIVE SYNTHESIS OF METHYL TETRA-0-METHYL a-AND P-D-GLUCO-AND MANNOPYRANOSIDES}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {Methyl tetra - 0-methyl- ?-D- glucopyranoside is stereoselectively prepared from tetramethyl-D- glucopyranose by using (MeI+NaH) in toluene (86%) or cyclohexane (85%), while its ?- isomer is best synthesized in hexamethyl phosphoramide (64%). Similarly, methyl tetra-o-methyl-?- D-mannopyranoside is synthesized in cyclohexane (80%), while its ?- isomer is predominantly prepared by (MeI+n-BuLi) in cyclohexane (98%). The ?-and ?- isomers of these glycosides were identified and quantified by G.C}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31201.html}, eprint = {https://jsciences.ut.ac.ir/article_31201_d9336c74c284aaa7a8e5b78a95096779.pdf} } @article { author = {}, title = {STUDIES ON PHOSPHOLIPASE C FROM MELIA AZADIRACHTA SEEDS}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {3,5- dinitrobenzoyl chloride-pyridine system has been used for dehydration of aldoximes and carboxamides at room temperature}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31202.html}, eprint = {https://jsciences.ut.ac.ir/article_31202_dc468d3f00aada954933c9e873c0552e.pdf} } @article { author = {}, title = {STUDIES ON SPIROHETEROCYCLES : SYNTHESIS OF NEW SPIRO 4- THIAZOLIDINONES AS POSSIBLE BIODYNAMICS}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {Spiro-4- thiazolidinones have been synthesized by the cyclocondensation of phthalazinyl hydrazones with cyclic ketones and substituted mercapto acetic acids. Compounds were screened for their antibacterial, antifungal and antihypertensive activity. The combined elemental analyses and spectroscopic data prove the authenticity of the synthesized compounds}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31203.html}, eprint = {https://jsciences.ut.ac.ir/article_31203_17d2a7bd6895c4a10b4a849643cbaddd.pdf} } @article { author = {}, title = {LINEAR ALIPHATIC UNSATURATED POLYESTERS BASED ON CIS -2- BUTENE -1,4-DIOL: SYNTHESIS AND CHARACTERIZATION}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {A new homologous series of linear aliphatic polyesters, such as poly (cis-2- butenylene carboxylate)S, PBms (m is the number of methylene groups in the acid component, m=2-8 have been synthesized by direct polyesterification reactions in anisole, as solvent. FT-IR, 400 MHz H- NMR, C-NMR and elemental analysis were used to establish the structure of polyesters. Molecular weight distributions were studied by GPC. The most narrow distributions were found to be for PB2 and PB8, whereas, the average molecular weight for all polyesters, except PB6, was about 3000-400}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31204.html}, eprint = {https://jsciences.ut.ac.ir/article_31204_21db458be308faa7ac7777f856b35723.pdf} } @article { author = {}, title = {6P- TIGLOYLOXYGLECHOMAFURAN A NEW FURANOSESQUITERPENE FROM SALVIA GLUTINOSA}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {The aerial parts of Salvia glutinosa afforded in addition to lupeol, a - and ? - amyrin a furanosesquiterpene, its structure being established by high field NMR techniques. The relative configuration at C-1, C-10, C-4, C-5 and C-6 of 6?tigloyloxyglechomafuran 1 was determined by the observed NOE'S}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31205.html}, eprint = {https://jsciences.ut.ac.ir/article_31205_58debdab22d8cc89eba3fb892628a0d0.pdf} } @article { author = {}, title = {PETROLOGICAL AND GEOCHEMICAL STUDY OF CRUSTAL XENOLITHS FROM 1961 ERUPTION OF CALBUCO VOLCANO, CHILE (LATITUDE 41 20 S )}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {Twenty four samples of xenoliths and country rocks from the 1961 lava flow of Calbuco volcano have been studied. Fourteen samples have been analyzed for major elements and P, Ni, Ba, Cr, V, Zr, Sc, Y, and Sr. Five of these samples were further analyzed for Sm, Nd, Sr, and Pb isotope ratios. Seventeen samples were analyzed under the microscope and three samples were analyzed by microprobe for their pyroxene composition. Based on petrograghic studies xenoliths were divided into three groups. Fine grained xenoliths (groups I and II) probably formed from metamorphosed MORB-like basalts , whereas coarse grained xenoliths (group III) were apparently derived from cumulate minerals that crystallized from the Calbuco magma. The fine grained xenoliths were probably entrained in magma at intermediate levels of the crust, near the stability limit of amphibole to form pyroxene and plagioclase. In the coarse grained xenoliths amphibole that form at depth dehydrated as the xenoliths were brought to the surface. The country rocks are apparently unrelated to the xenoliths.}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31206.html}, eprint = {https://jsciences.ut.ac.ir/article_31206_821a9beb1406b08df96330dd206bbdea.pdf} } @article { author = {}, title = {AN EFFICIENT PRESENTATION FOR THE GROUP SL (2,121)}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {In this paper we give a 2-generator 2-relation presentation for the group SL(2,121). This proves that SL(2,121), the covering group of PSL(2,121), is efficient}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31207.html}, eprint = {https://jsciences.ut.ac.ir/article_31207_351b7ee8c8eaa0952dea236adfecf806.pdf} } @article { author = {}, title = {AXIAL FLOW IN A ROTATIONAL COAXIAL RHEOMETER SYSTEM 11: HERSCHEL BULKLEY MODEL}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {Following recent works of several authors like Huilgol, Bhattacharya etd. and Javadpour et al., this paper is to contribute further to the literature of axial flow in a rotational coaxial rheometer. We consider axial flow of Herschel Bulkley mode1 between two concentric cylinders with the inner one rotating, while the outer cylinder is held stationary. An attempt has been made to direct the analysis toward an examination of the relationship between moment (M) and angular velocity ( ) at the inner cylinder. The radial dependence of the shear stress and viscosity follows directly by our mathematical analysis with a simple numerical procedure. We describe the relationship between shear stress and shear rate and the dependence of these on axial flow rate in the annular region, for power law and Herschel Bulkley fluids}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31208.html}, eprint = {https://jsciences.ut.ac.ir/article_31208_71f308e87be0074149af365e1a0ceff7.pdf} } @article { author = {}, title = {SUBSTRATUM RADIATION AND CASIMIR EFFECT}, journal = {Journal of Sciences, Islamic Republic of Iran}, volume = {3}, number = {1}, pages = {-}, year = {1992}, publisher = {University of Tehran}, issn = {1016-1104}, eissn = {2345-6914}, doi = {}, abstract = {A heuristic way to calculate the approximate value of the Casimir force is introduced}, keywords = {}, url = {https://jsciences.ut.ac.ir/article_31209.html}, eprint = {https://jsciences.ut.ac.ir/article_31209_0ac7170baac98705020c8c5195a32946.pdf} }