eng
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
2345-6914
2004-09-01
15
3
31599
The Expression of Human Granulocyte Macrophage Colony Stimulating Factor by Heat-Induction in Escherichia coli
A self-regulated high-copy number plasmid containing chloramphenicol resistant gene, for the production of recombinant proteins under the regulation of bacteriophage ?pL promoter, was constructed. The designed 5024 base pair expression plasmid contained a heat sensitive repressor cI857 coding gene to regulate the function of ?pL promoter under heat shock induction. Using the constructed vector, for the first time, periplasmic production of human granulocyte macrophage colony stimulating factor (hGM-CSF) under heat induction was demonstrated. The developed hGM-CSF expressing system in this study has potential for the secretion of nearly 100% of expressed proteins into the Escherichia coli periplasmic space upon temperature up-shift.
https://jsciences.ut.ac.ir/article_31599_158f15b1380030261fedf7e2be861d1d.pdf
eng
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
2345-6914
2004-09-01
15
3
31600
Molecular Cloning and Expression of Nucleocapsid Gene of Chicken Infectious Bronchitis Virus Strain Massachusetts H120
Chicken infectious bronchitis virus (IBV) causes severe respiratory and renal dysfunction in chickens. In the present study, we used reverse transcription-polymerase chain reaction (RT-PCR) to amplify the nucleocapsid (N) protein gene of strain Massachusetts (Mass) H120 of IBV that is commonly used in the vaccine production in Iran. The PCR product with the expected size of 1.2 kb was cloned into a TA-vector and subsequently sub-cloned into expression vector pET-23a(+). The recombinant plasmids were transformed into competent BL21(DE3) strain of E. Coli. The recombinant N protein was expressed as a soluble fusion protein tagged at its C-terminal with 6 x His residues. In Western blot analysis, a convalescent serum from a chicken tested positive by a commercial IBV detection kit specifically reacted with the recombinant protein. The IBV negative chicken serum did not react with the recombinant protein. In a reciprocal experiment, antiserum raised against the purified fusion protein reacted with the corresponding proteins of strains H120 and 4/91. This is the first report of cloning and expression of the N protein gene cDNA of strain Mass H120 of IBV in a bacterial expression system. The potential uses of the cloned gene and the recombinant N protein have been discussed.
https://jsciences.ut.ac.ir/article_31600_493f2fee86c7b603d027221f3a5e365d.pdf
eng
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
2345-6914
2004-09-01
15
3
31601
The Role of Chromosomal Aberration in Childhood Leukemia
https://jsciences.ut.ac.ir/article_31601_afde9576e4ed6a34abcbe2ff489727e6.pdf
eng
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
2345-6914
2004-09-01
15
3
31602
PCR and RFLP Analysis for Identification and Typing of Helicobacter pylori Strains from Gastric Biopsy Specimens
https://jsciences.ut.ac.ir/article_31602_17a3bbd1e5679bc39598353c95075485.pdf
eng
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
2345-6914
2004-09-01
15
3
31603
Down Regulation of DHFR Promoter Activity by PML Transcription Repressor
https://jsciences.ut.ac.ir/article_31603_cd232dba822de405e7b258ef00f5a8df.pdf
eng
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
2345-6914
2004-09-01
15
3
31604
Denitration of Nitroesters with Tributyltin Hydride in the Presence of Azobisisobutyronitrile (AIBN)
Among the different reducing agents tributyltin hydride was found to be a powerful reducing agent for the denitration of a series of tertiary and secondary nitroesters. The organotin residues removed from the crude product using saturated potassium fluoride solution. The yield of the reactions was 62-98%.
https://jsciences.ut.ac.ir/article_31604_f71434531f348d7f89aefe098818e199.pdf
eng
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
2345-6914
2004-09-01
15
3
31605
Dominant Association Species in Binary Mixtures of Methanol, Ethanol and Propanol in Nonpolar Solvents
The molecular associations in the binary mixtures of (methanol/solvent), (ethanol/solvent) and (propanol/solvent) were studied using NMR, FTIR and VLE data at different temperatures. The activity coefficients as the most important quantities representing the mixture deviation form ideal behavior were evaluated by using various association models to express the physical and chemical contributions of the activity coefficients. The parameters of these models were calculated. The results indicated that for methanol and ethanol the dominant associated species are the tetramer whereas for propanol it is the trimer. The differences between the parameters of activity coefficient models were calculated by considering the physical and chemical contributions separately and were expressed in terms of residual parameters for the activity coefficient models. The parameters of van Laar model were corrected on the basis of the existing dominant species in the associated mixtures and a simple linear relation was obtained for the parameters of the model for the dominant species in terms of the parameters for monomer
https://jsciences.ut.ac.ir/article_31605_98a24037e243a6c05b6379bae7560ed4.pdf
eng
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
2345-6914
2004-09-01
15
3
31606
Diagenetic Evolution of Mudstones: Black Shales to Laminated Limestones, an Example from the Lower Jurassic of SW Britain
https://jsciences.ut.ac.ir/article_31606_89a5dcdb13c90184e8d982b863fef1b3.pdf
eng
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
2345-6914
2004-09-01
15
3
31607
Limiting Properties of Empirical Bayes Estimators in a Two-Factor Experiment under Inverse Gaussian Model
The empirical Bayes estimators of treatment effects in a factorial experiment were derived and their asymptotic properties were explored. It was shown that they were asymptotically optimal and the estimator of the scale parameter had a limiting gamma distribution while the estimators of the factor effects had a limiting multivariate normal distribution. A Bootstrap analysis was performed to illustrate the theoretical results empirically.
https://jsciences.ut.ac.ir/article_31607_27b6f250c57c7a16fad0ae6e16e16958.pdf
eng
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
2345-6914
2004-09-01
15
3
31608
Residual Stress in Cu Sputtered Films on Glass Substrates at Different Substrate Temperatures
Copper films of 300 nm thickness deposited by planar magnetron sputtering on glass substrates, for substrate temperatures between 300 and 500 K, and deposition rate of 10 ?s?1. Microstructure of these films was obtained by X-ray diffraction, while the texture mode of diffractometer was used for stress measurement by the sin2? technique. The components of the stress tensor are obtained using measurements at three different ? angles of 0, 45 and 90 degrees by proposed technique in this work. The relation between stress in these films and the processes in film growth through structure zone model (SZM) is explained.
https://jsciences.ut.ac.ir/article_31608_f0038ac507f1b32ea9f29138954f9ab7.pdf