Academic Center for Education, Culture and Research

About: Academic Center for Education, Culture and Research is a nonprofit organization based out in Tehran, Iran. It is known for research contribution in the topics: Population & Mesenchymal stem cell. The organization has 1100 authors who have published 1244 publications receiving 19093 citations.

ANALYSIS OF ARTEMISININ ISOLATED FROM Artemisia Annua L. BY TLC AND HPLC

Abstract: Artemisia annua L. (Quinghao) is a promising and potent source of antimalarial herbal drug. Its activity has been ascribed to the content of artemisinin; it has been analyzed by different chromatographic techniques. In this research, we have developed a TLC/UV, a simply available, rapid, and cost-efficient method, for the simultaneous determination of artemisinin. The crude extracts from plant samples were used together with a standard in our HPLC/UV and TLC/UV techniques. Artemisinin (standard and in the extract) was converted into a UV-absorbing compound, Q258 by being treated with 0.25% (by weight) NaOH solution and then 0.2 M acetic acid. The resulting TLC method utilizes separation on silica gel RP-18 with methanol, acetonitrile, ethyl acetate, acetic acid (30:20:2:1) as mobile phase, highly specific densitometric evaluation at 254 nm. This precise and accurate assay could be performed in the linear working range of 10–100 µg/mL and 1–40 µg/mL for TLC and HPLC methods, respectively. The new technique...

Application of canonical correlation analysis for detecting risk factors leading to recurrence of breast cancer

Abstract: Background: Advances in treatment options of breast cancer and development of cancer research centers have necessitated the collection of many variables about breast cancer patients. Detection of important variables as predictors and outcomes among them, without applying an appropriate statistical method is a very challenging task. Because of recurrent nature of breast cancer occurring in different time intervals, there are usually more than one variable in the outcome set. For the prevention of this problem that causes multicollinearity, a statistical method named canonical correlation analysis (CCA) is a good solution. Objectives: The purpose of this study was to analyze the data related to breast cancer recurrence of Iranian females using the CCA method to determine important risk factors. Patients and Methods: In this cross-sectional study, data of 584 female patients (mean age of 45.9 years) referred to Breast Cancer Research Center (Tehran, Iran) were analyzed anonymously. SPSS and NORM softwares (2.03) were used for data transformation, running and interpretation of CCA and replacing missing values, respectively. Data were obtained from Breast Cancer Research Center, Tehran, Iran. Results: Analysis showed seven important predictors resulting in breast cancer recurrence in different time periods. Family history and loco-regional recurrence more than 5 years after diagnosis were the most important variables among predictors and outcomes sets, respectively. Conclusions: Canonical correlation analysis can be used as a useful tool for management and preparing of medical data for discovering of knowledge hidden in them.

A Systematic Review for Estimation of HTLV-I Infection in the Blood Donors of Iran.

Abstract: HTLV-I infection is a worldwide health problem and approximately 15–20 million persons are estimated to be infected with this infection (1). High HTLV-I seroprevalence rates in the general population or specific groups such as blood donors, have been reported from southwest of Japan, Caribbean basin, South America, Sub-Saharan Africa, and northeastern Iran (1,2). Although most infected people remain asymptomatic, the virus is associated with exceptionally severe diseases, such as adult T-cell leukemia/lymphoma (ATL), and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) (3). HTLV-I infection could transmit from mother to child, predominantly through breastfeeding, via sexual intercourse, and parenteral transmission by transfusion of infected cellular blood products or sharing of needles and syringes (1,4). Presence of HTLV-I infection was reported in 1990 among the Jews emigrated from Mashhad, northeast of Iran (5), and then some patients with ATL were indentified in Mashhad who were seropositive for HTLV-I (6). In later studies, the rate of HTLV-I infection in Mashhad was reported 3% in general population (7) and about 2% in blood donors (8) in 1996. There were some small to large scale epidemiological studies that have reported the prevalence of HTLV-I infection in blood donors from various regions of the country. The widest survey has been conducted by Rezvan et al. in 21 regional blood centres in 1996. This study reported a 0.29% rate for HTLV-I infection in total serum samples; 1.97% among Mashhadi blood donors, and zero to 0.5 percent in other centres (8). Moreover, later surveys in several regions of Iran reported different rates of the infection in blood donors. Nevertheless, there is no overall estimation of the infection in the country. This study conducted to accurately estimate the prevalence of HTLV-I infection in the Iranian blood donors through a comprehensive systematic review of literature and evidences.

Effect of Solvents, Their Mixture and Thermal Annealing on the Performance of Solution Processed Polymer Light-Emitting Diodes.

Abstract: In this study, we first investigated changes seen in electrical and optical properties of a polymer light-emitting diode due to using different kinds of solvents and their mixture. Two-layer light emitting diodes with organic small molecules doped in a PVK polymer host were fabricated using (i) non-aromatic solvent chloroform with a high evaporation rate; (ii) aromatic solvent chlorobenzene with a low evaporation rate, and (iii) their mixture with different relative ratios. The effect of nano-scale layer thickness, surface roughness and internal nano-morphology on threshold voltage and the amount of electric current, the luminance and efficiency of a device were assessed. Results indicated the importance of majority charge carriers' type in the selection of solvent and tuning its properties. Then, the effect of thermal annealing on electrical and optical properties of polymer light emitting diodes was investigated. During the device fabrication, pre-annealing in 80 and/or 120 °C and post-annealing in 120 °C were performed. The nano-scale effect of annealing on polymer-metal interface and electric current injection was described thoroughly. A comparison between threshold voltage, luminance and electric current efficiency of luminescence for different annealing processes was undertaken, so that the best electric current efficiency of luminescence achieved at 120 °C pre-annealing accompanied with 120 °C post-annealing.

Pyrenochaetopsis tabarestanensis ( Cucurbitariaceae , Pleosporales), a new species isolated from rice farms in north Iran

Abstract: A pyrenochaeta-like species was isolated from soil in rice farms in Mazandaran Province (formerly Tabarestan), Iran. Phylogenetic analyses of SSU, LSU, ITS, β-tubulin and actin sequence data showed that the new collection clustered with species in Pyrenochaetopsis sensu stricto. In morphology, phylogeny and physiological characters, the new strains are distinct from other species, thus, they are introduced as a new species viz . P. tabarestanensis . Illustrations, descriptions and taxonomic notes are provided for P. tabarestanensis . Additionally, the phylogenetic relationships of Pyrenochaeta and Pyrenochaetopsis species in Cucurbitariaceae is discussed.