University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 15 4 2004 12 01 Purification and Characterization of an Antibacterial, Antifungal and Non Hemolytic Peptide from Rana Ridibunda - 31609 EN Journal Article Amphibians have a large variety of antimicrobial peptides that serve as natural innate barriers limiting microbial infection or, in some instances, act as an integral component in response to inflammation or microbial infection. A novel peptide with antibacterial effects and without hemolytic activity was purified from skin secretions of Rana ridibunda by multisteps cation-exchange FPLC, reversed-phase HPLC and was called Ridibundin 1. Circular dichroism spectra revealed that this peptide strongly prefers to form an amphipathic ?-helical structure in the presence of 50% trifluoroethanol. Acting as wide-spectrum microbicides against a variety of bacteria, Ridibundin 1 also shows no hemolytic activity on erythrocyte. These properties reveal its unique characteristics and potential therapeutic application https://jsciences.ut.ac.ir/article_31609_c3ad4331d5fac2ce23e520b0cc0fcb5e.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 15 4 2004 12 01 In Vitro Flower Production in Some Species of Hyoscyamus (H. pusillus L., H. arachnoideus Pojark, and H. niger L.) - 31610 EN Journal Article Various plant organ segments including segments from roots (root tip, and root collar), stems, leaves, and also seeds of several Hyoscyamus species (i.e. H. pusillus, H. arachnoideus, annual and biennial H. niger from two distinct geographical regions) were cultured on MS media with various growth regulator combinations, to assess the ability of flower production. Statistical assessments showed significant differences between various explants cultured on different media. That is, the subculture of the leaves obtained from H. pusills leaf culture on MS medium containing BAP (1.5 mg/L), on MS medium containing IAA (0.2 mg/L) and Kin (1.5 mg/L), led to the highest flower production. In addition, when cultured on MS medium containing 2,4-D (0.32 mg/L), the seeds of annual H. niger showed high flower production. https://jsciences.ut.ac.ir/article_31610_729fbaf01455353285fd43871be6ebb7.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 15 4 2004 12 01 Inhibition of Human Erythrocyte Glucose 6-Phosphate Dehydrogenase by Cadmium, Nickel and Aluminium - 31611 EN Journal Article https://jsciences.ut.ac.ir/article_31611_30de3848a3d427de6774066e0b9b09bc.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 15 4 2004 12 01 Detection of abl/bcr Fusion Gene in Patients Affected by Chronic Myeloid Leukaemia by Dual-Colour Interphase Fluorescence in situ Hybridisation - 31612 EN Journal Article Conventional cytogenetic is the standard technique for detection of Philadelphia (Ph) chromosome in chronic myeloid leukemia (CML). Evaluation of abelson murine leukemia/breakpoint cluster region (abl/bcr) fusion using dual-colour fluorescence in situ hybridization (D-FISH) is an alternative approach allowing rapid and reliable detection of the disease. We employed the technique of interphase D-FISH to detect the abl/bcr fusion in 21 patients and the results were compared to those of conventional cytogenetic analysis. A significant agreement was observed between the results, indicating the accuracy of interphase D-FISH. The technique can overcome the disadvantage of conventional cytogenetic methods, which depends on cell culture and analysis of banded chromosomes, since the analysis is performed by signal counting on uncultured target cells. Furthermore D-FISH provides a more reliable method for evaluating the degree of clone remission to patients with CML after therapy compared to the conventional cytogenetic analysis. https://jsciences.ut.ac.ir/article_31612_413f2dc2067072c4339624db3d9fa537.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 15 4 2004 12 01 Modified Titanium Content in Titanosilicates Mesoporous Molecular Sieves MCM-41 as Selective Catalyst for Epoxidation of Alkenes - 31613 EN Journal Article Ti-MCM-41 was synthesized at pH 3, 7 and 11. The titanium content was determined by AAS and found to be 4%, 3.2% and 4.5%, respectively. In order to increase the titanium content in Ti-MCM-41, Ti(IV) ions were grafted onto Ti-MCM-41 using TiCl4 in toluene and Ti(OBu)4 in ethanol. The incorporation of Ti was determined to be 28% and 30%, respectively. The oxidation of olefins such as cyclopentene, cyclohexene, norbornene and trans-2-hexene-1-ol with TBHP in the presence of Ti-grafted Ti-MCM-41 were carried out in CHCl3. This system successfully catalized the oxidation of these olefins toward the corresponding epoxides with 60 to 90% reactivity and 95 to 100% selectivity https://jsciences.ut.ac.ir/article_31613_de26c8e50deca7dbd638148d8799ce74.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 15 4 2004 12 01 Microwave-Assisted Efficient and Chemoselective Acetalization of Aldehydes with Trimethyl Orthoformate - 31614 EN Journal Article Efficient and chemoselective protection of aldehydes to the corresponding dimethyl acetals have been carried out by mixture of trimethyl orthoformate and methanol in the presence of a catalytic amount of TMSCl or AlCl3 under microwave irradiation. Under these conditions, acetalization of ketones does not take place and they remain intact under reaction conditions. The results are compared with the reaction of an aldehyde with trimethyl orthoformate in the presence of a mild Lewis acid. https://jsciences.ut.ac.ir/article_31614_728c80d8a69ff8c92e3d9a046bece8f8.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 15 4 2004 12 01 Stabilizing Effect of Organic Stabilizer (EDTA, 1,2 Propane diol, Benzoic Acid and Phenol) on the Thermal Degradation of Polyvinyl Chloride (PVC) - 31615 EN Journal Article https://jsciences.ut.ac.ir/article_31615_3a68abc388606a36771c8c8b8bf64129.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 15 4 2004 12 01 On Commutative Reduced Baer Rings - 31616 EN Journal Article It is shown that a commutative reduced ring R is a Baer ring if and only if it is a CS-ring; if and only if every dense subset of Spec (R) containing Max (R) is an extremally disconnected space; if and only if every non-zero ideal of R is essential in a principal ideal generated by an idempotent. https://jsciences.ut.ac.ir/article_31616_fd982f3faf6faa7b8049fcb713afb2b7.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 15 4 2004 12 01 Scheduled Review Methods for Controllable State Variables - 31617 EN Journal Article In many real systems in which a state variable should be controlled for being in appropriate range, the length of control (review) intervals is taken to be constant. In such systems, when the cost of reviews and out-of-range values of the state variable are considerable, this method may not be optimal. In this paper we let the length of review intervals to be variable during each operating cycle and construct the related mathematical cost model. Then two scheduled review methods, called U2 and U3, are introduced and the relative annual system costs are analyzed. The model is developed for the case of negative exponential variate as the time between successive consumption points. It is shown that the new methods results a significant reduction in the expected annual cost of the system. https://jsciences.ut.ac.ir/article_31617_6597f708e3b4e2bfd2bbc97920d69e59.pdf

University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 15 4 2004 12 01 Controlling of Absorption and Dispersion Spectrum via Electromagnetically Induced Transparency - 31618 EN Journal Article In this paper we examine the absorption and dispersion properties of a weak probe field via Electromagnetically Induced Transparency (EIT) in a four-level system. It is shown that under certain condition, using this model, the absorption cancellation is appeared and the medium becomes transparent to the weak probe field. It will be shown that the controlling of absorption and dispersion spectrum depends on some atomic parameters. The effects of quantum interference on the absorption and dispersion spectrum are also investigated https://jsciences.ut.ac.ir/article_31618_ec04a75ca6302d347df2f803efe8c5bd.pdf