Showing 8 results for Karbassi
Volume 1, Issue 1 (4-2014)
Abstract
Background:Estrogens play a substantial role in the proliferation, progression and treatment of breast cancer by binding with two estrogen receptors, alpha and beta (ERα and ERβ). Resistance to endocrine therapy is a major problem in the treatment of breast cancers and, in some cases, may be related to loss of ER gene expression. We have already showed that ERα methylation occurs in high frequency and may be one of the important mechanisms for ERα gene silencing in a subset of Iranian primary sporadic breast cancers. In the other hand, the CpG Island methylation status of ERβ and the relationship between clinicopathological features and the pattern of ERβ methylation in sporadic breast cancer are still unknown, especially in Iranian women. Methods: In this study, we examined the exact role of DNA methylation in the estrogen receptors, alpha and beta genes using Combined Bisulfite Restriction enzyme Analysis (COBRA) and Methylation specific polymerase chain reaction (MSP) methods in 34 tissue and 40 peripheral white blood cells in the breast cancers. Results and Conclusions: ERα promoter methylation was identified in 29(72.5%) tissue samples and 35(87.5%) peripheral blood. Among these ERα-methylated cases, the co-occurrentmethylation of ER promoter in peripheral blood and tissue samples was evident in 25 (71.4%) patient (P=0.56). Furthermore, ERβ promoter methylation was detected in 13(32.5%) tissue samples and 4(10.0%) peripheral blood specimens. Of these ERα-methylated cases, the co-ocurrent methylation of ERβ promoter in the peripheral blood and tissue samples was evident in 1(7.7%) patient (P= 0.11). Based on COBRA analysis the percentage of DNA methylation at methylation-sensitive BstUI restriction site of the ERα promoter A ranged from 1% to 91%. The percentages at promoters A region showed a borderline associations with lymph node involvement (P=0.079, r=0.55) and a significant correlation with the grade of tumors (p= 0.27, r=0.65). No significant relation was found between ERα promoter and ERβ promoter methylation (Odds ratio =2.82, 95%, CI =0.28–28.5, P=0.36). The methylation of promoter ON was observed in only a subset of tumors without ER by IHC. In addition, we did not find any significant correlationbetween the prognostic factors such as grade, tumor size, lymph node involvement, and methylation status of this promoter. Our results indicate that methylation of ERβ promoter ON is not responsible for the loss of gene expression in of all breast tumors.
Volume 4, Issue 4 (Winter 2021)
Abstract
Research subject: In recent years, due to limited water resources and the extraordinary increase in nitrates in the environment, efforts to remove and control in order to benefit from the natural adsorbents have been made. Although according to the negatively charged surface of bentonite particles, absorbent needs improvement.
Research approach: In the current study, the adsorption of nitrate columns by the modified calcium montmorillonite adsorbent was investigated. Furthermore, In order to change the surface load and increase the adsorption efficiency, three-step acid leaching, oxidation layering, and loading of the cationic surfactant hexadecyltrimethylammonium bromide on the adsorbent were performed. Molecular interaction and crystallography of pure montmorillonite and synthetic nano-adsorbent (ACZ) were characterized by Fourier transform infrared spectroscopy and X-ray analysis. Moreover, the morphology of ACZ nano adsorbents was evaluated using Transmission electron microscopy and scanning electron microscopy.
Main results: Nanoparticle compaction and less access to pores and cavities in the fixed bed column reduced the adsorbent capacity inside the column compared to the discontinuous system.
The results showed that an increase in inlet concentration from 80 to 150 mg/L increased the adsorption capacity from 67.39 to 88.25 mg/g. Reducing the inlet flow rate increased the penetration time, interaction, and greater access to the binding sites for nitrate ions and finally improved the column performance and increased the inlet flow rate reduced the adsorption capacity and breakthrough time. Therefore, the adsorption of nitrate ions by the stage of internal mass transfer is controlled and depends on the duration of interaction and the possibility of penetration into the active sites. With increasing the bed height from 4.2 to 9 cm, there was a significant increase in adsorption capacity from 60.608 to 77.167 mg/g. The effect of detergents and recovery showed an absorption column; After 3 leaching steps, acid leaching played an important role in increasing column recovery. Experimental data with correlation coefficients of R2>0.95 corresponded to Thomas and Yoon-Nelson kinetic models.
In this study, the ACZ nano adsorbent column for rapid removal of nitrate ions from aqueous solutions was introduced and for use in reusable systems was proposed.
Volume 10, Issue 3 (Number 3 - 2008)
Abstract
The objective of this study was to examine the effects of the fluidized-bed drying me-thod on the final quality of two varieties of Iranian rice, medium- and long grain. The re-sults were compared to that of paddy drying using a traditional method. Rough rice was treated in the fluidized bed drier at 140ºC for 2 minutes. Similar samples were dried for 8-10 hrs by the traditional method. Dried samples were dehusked and polished. Quality factors, including trade quality (head rice yield percent and whiteness), cooking quality (amylose content, gelatinization temperature, gel consistency, aroma and flavor) and nu-tritional quality (thiamine and lysine contents), were then measured for each sample. Fi-nally, the data was analyzed. Results show that paddy drying in a fluidized bed dryer would reduce the quality factors except for rice whiteness for which conventional drying is more acceptable. Therefore modification of fluidized-bed drying technique is recom-mended.
Volume 11, Issue 3 (Number 3 - 2009)
Abstract
Proper conditions for producing crude beta-galactosidase from waste materials were de-termined. This enzyme is to be used in the production of lactose-hydrolyzed milk. Whey permeate was used as a basic medium. Twenty seven treatments were developed by 3 vary-ing factors of: yeast extract (1, 2, and 3 %), wheat steep liquor (1, 2, and 3 %), and whey powder (0.5, 1, and 1.5 %). Crude enzyme extract was obtained by sonication of the cells collected from cultivation of Lactobacillus delbrueckii ssp. bulgaricus in various media at 43oC. The beta-galactosidase activity was assessed using Ortho-Nitro-Phenyl-beta-D-galactopyranoside (ONPG). Yeast extract and whey powder had both significant effects (P< 0.01), while wheat steep liquor proved to be ineffective. Yeast extract had the most pro-nounced effect on the production of beta-galactosidase. The effect of the interactions of yeast extract-whey powder and wheat steep liquor-whey powder were significant at 5 % level (P< 0.05), while the effect of the interaction of yeast extract-wheat steep liquor was sig-nificant at 1% level (P< 0.01). Interaction effect of the 3 factors on the production of beta-galactosidae was significant (P< 0.01). The best combination for production of beta-galactosidase (4.924 U ml-1) was 3% yeast extract, 1.5% whey powder and 2% wheat steep liquor.
Volume 11, Issue 4 (1-2012)
Abstract
The aim of this study is analyzing the relationship between expenditure on research and productivity in agricultural sector for time series of 1980-2007. For this purpose actuarial causality between the cost of research and productivity vector auto regression (VAR) has been used. The results showed that there is one-way relationship between research and productivity. Also the diagrams of reaction functions showed that both research costs and productivity variables are sensitively related to change in the rate of other variables. Also for analyzing and determining a long-term equilibrium relationship between variables Johansen-Juselius cointegretion method was used that includes two tests of maximum eigenvalue test and trace test where there is a vector of cointegretion relationships that shows there is stability relationship between research and productivity as well.
Volume 13, Issue 4 (Number 4 - 2011)
Abstract
Crude Enzyme (beta-galactosidase) Extract (CEE) was produced by Lactobacillus ssp.
bulgaricus CHR Hansen Lb-12 and was applied in sterile milk which had been processed
through Ultra High Temperature method (UHT milk), for hydrolyzing lactose. Lactosehydrolyzed
milk was also produced by a pure and commercially available betagalactosidase
(Maxilact). Optimum quantities of CEE and Maxilact enzyme, for
producing lactose-hydrolyzed milk, during 6 hours of processing, were 0.418 and 0.512 U
ml-1, respectively. Using more than 0.418 U ml-1 CEE resulted in unacceptable acidity.
Acidity of lactose-hydrolyzed milk produced through 0.418 U ml-1 of CEE was
significantly increased from 15 to 17 ºD, while enhancement of acidity in lactosehydrolyzed
milk produced through Maxilact enzyme was not significant. Total count of
lactose-hydrolyzed milk by 0.418 U ml-1 CEE, after 6 hours of processing was significantly
increased from 5 to 30 CFU (Colony Forming Unit). Sensory evaluation of lactosehydrolyzed
milk and ordinary UHT milk (as control) did not show any significant
differences with respect to acceptability of sweetness, taste, aftertaste and color.
Volume 14, Issue 3 (9-2011)
Abstract
Objective: Estrogen receptor alpha protein status is determined by routine immunohistochemistry analysis in all malignant breast tumors. This assay has its limitations. RNA based techniques are potential complements for immunohistochemistry but it must be noticed that gene silencing may occur at different levels from RNA to protein. The aim of this study was the comparison of the results from these two assays and characterizing the tumors subgroup in which gene expression occurs at RNA level but the target protein is absent.
Materials and Methods: 92 primary breast tumors including their clinical and IHC results were collected before treatment. Estrogen receptor gene expression of tumors was studied by Reverse Transcription Polymerase Chain Reaction (RT PCR). In this assay, GAPDH was used as a reference gene.
Results: 36.6 % of tumors with negative estrogen receptor protein showed gene expression at mRNA level. In this subgroup most of the patient were older than 50 years and in stages 3 or 4 of breast cancer and had poor prognosis according to Nottingham prognostic index. Most cases of the perineural invasion have been seen in this subgroup.
Conclusion: It seems that RT-PCR assay would enable us to recognize a subgroup of breast tumors with poor prognosis which expresses RNA but not protein.
Volume 19, Issue 5 (12-2019)
Abstract
Drought is an integral part of natural hazards. It usually occurs gradually and without any warning. Moreover, this phenomenon is usually created over time and does not disappear quickly Recently, some factors such as climate variability and the impact of climate change have influenced drought frequency and intensity in many parts of the world. Various definitions have been provided for drought but in general the lack of water resources in a specific period in a geographical area is considered as drought which implies this phenomenon as a regional hazard. IRAN is located in an arid and semi-arid region in which it experiences drought frequently. There are different types of drought such as meteorological, hydrological, agricultural and social-economic. These types are differentiated based on the factor which is rainfall, river flows, soil moisture, and social-economic consequences. There are many indices proposed for measuring drought severity; among them Standardized Precipitation Index (SPI), Palmer Drought Severity Index (PDSI) and Surface Water Supply Index (SWSI) could be mentioned. Each of these indices has its own pros and cons and is suitable for a particular type of drought. Therefore knowing the types of drought can provide a better understanding of shortages and their characteristics. Various factors are utilized for measuring these indices including precipitation, reservoir storage, discharge, temperature and potential evapotranspiration. In this study the three main aforementioned indices were first calculated for Aharchay watershed, located in East Azerbaijan province. Next based on combining these three indices with another two important parameters, groundwater level and solar radiation, a combined drought index is developed and calculated for the studied region. Considering the fact that the aforementioned parameters and indices have different level of importance in combined index, different weights based on expert opinions are assigned to the parameters considering how critical each parameter is in the overall drought analysis. This combined index demonstrated various climatic, hydrological and agricultural aspect of the region. In the next step, bivariate analysis of the two variables, intensity and duration, is carried out using copula. This is done by first checking the dependency between intensity and duration using Pearson, Spearman, and Kendall correlation coefficients. Second, various copula functions were fitted such as Gaussian, T, Clayton and Gumbel functions. Third, based on the Ordinary Least Square (OLS) and Kolmogorov–Smirnov (K-S) tests, the best copula functions were used. Lastly, based on the chosen copula the joint probability distributions were obtained. Two cases named “OR” and “AND” were defined for joint probability of the two variables and different return period curves is drawn. The results showed that the most severe drought in this watershed occurred in June 2004. Moreover, by assessing correlation coefficient between the considered indices it is shown that analysis of the drought in a region based solely on one index would neglect other imperative aspects in drought determination which necessitates a more integrated indicator. Furthermore, in bivariate analysis, return periods of “AND” cases were more than “OR” case. The results of this study could be utilized in preparedness and monitoring drought.