Ferrocement has been increasingly used as a structural material which competes favorably with reinforced concrete and other building materials. The durability of ferrocement depends on several factors including the quality of ferrocement, mesh type, depth of cover over the mesh, the direction and magnitude of applied load(s) and its resistance to corrosion. Corrosion of mesh reinforcement in ferrocement is one of the important aspects which has not received sufficient attention from research workers. This paper presents the results of monitoring the corrosion performance of ferrocement specimens exposed to extremely aggressive conditions (6% NaCl solution at 60°C). Several parameters have been considered in this study, including type and arrangement of mesh reinforcement and depth of mortar cover over the meshes. Four methods were used for corrosion examination of the specimens; visual examination, corrosion potential, corrosion rate and microscopic examination.
Over the past decade, corrosion became a crucial problem on two counts: (a) it is expensive to repair and (b) it has widespread occurrence. The research evaluated the effects of corrosion on the properties and flexural behavior of ferrocement. Two series of specimens were tested. The first series were cast, placed in water and a suitable environment for 28 days, and then subjected to flexural test. The second series were placed in a weather simulator tank, with corrosive environmental conditions and after three months, were tested for flexure. From a careful examination of the results of the flexural tests it emerges that: 1. The presence of NaCl and temperature, as well as the prevalence of wet and dry conditions, have a considerable effect on the flexural behavior of ferrocement: it increases the brittleness of mortar, reduces the number of cracks and increases the crack width. 2. Slight increase in the first crack strength and maximum strength of specimens. 3. The effect of corrosion in reducing the strength of ferrocement specimens with ungalvanized wire meshes, is greater than its effect on specimens with galvanized wire meshes.
Ferrocement is a type of thin wall reinforced concrete construction where real composite action between the matrix phases and the reinforcement exists. This composite action results in excellent control of cracking, high tensile strength and durability [1]. This investigation is concerning with the experimental and theoretical behavior of ferrocement under tension. The effects of different arrangements of mesh reinforcement, with particular respect to the specimen thickness and mortar cover, on the cracking behavior and both first crack strength and ultimate strength were studied. The mechanical properties of the wire mesh and mortar which was used in this investigation were also studied. The results show that, under direct tension, the strength of ferrocement at first crack and ultimate load is not affected significantly by the arrangement of the reinforcement. However, specimens having reinforcement evenly distributed with minimum cover showed reduced crack widths and an increased number of small cracks at failure. The contribution of the tensile strength of the mortar and the specimen thickness on first crack strength is considered to be significant, while it can be considered negligible at ultimate strength.
The aim of this paper is to review and compare various analytical procedures which have been developed to predict the ultimate moment of ferrocement under flexure. One such procedure has been used as the basis of the computer program FAOFERRS, which has then been used to compare predictions with experimental results for specimens having various mesh arrangements. An attempt is made to predict the ultimate moment for specimens reported by other investigators and the results are compared and discussed.
Daru Journal Of Pharmaceutical Sciences (15608115)(3)pp. 82-87
Majority of the currently available anticancer drugs are designed to have selective toxicity to rapidly dividing cells. Among these agents the focus of many studies are compounds obtained from natural products with high therapeutic index. In this study the cytotoxicity of HESA-A, a marine compound, on cancer and normal cells was evaluated. HESA-A was prepared in normal saline as a stock solution (0.8 mg/ml, pH=7.4), sterilized and further diluted to final concentrations of 0.4, 0.2, 0.1 and 0.05 mg/ml. Cells (MDA-MB-468, Hep-2, Hela as cancer cells; L929 and McCoy as normal cells) were grown in completed RPMI 1640 and seeded in 96 well micro plates at a concentration of 1-5 × 104 cells/ml. After incubation for 24 h, different concentrations of HESA-A were added and cells were further incubated for 72 h. Using MTT assay, percent cell survival was determined by ELISA at 540 nm. Doxorubicin was used as a positive control (20 μg /ml). HESA-A (0.4 mg/ml) reduced the number of viable MDA-MB-468 and Hela cells to less than 50%. For Hep-2 cells the IC 50 was 0.8 mg/ml. In normal cells IC50 could not be obtained at any given concentrations. These results suggest that HESA-A in therapeutic doses and in a concentration dependent manner inhibits the growth of cancer cells more selectively than normal cells.
Breast cancer is the most prevalent type of cancer in pre- and postmenopausal women in most Western countries. In the treatment of metastatic breast cancer, doxorubicin has the broadest spectrum of antitumor activity of any drug currently available but produces a dose-dependent cardiomyopathy that limits its clinical usefulness. The aim of this research project was to target the affected tissues, which contain estrogen receptors (ERs). Initially, a series of estrogen derivatives with side chains linked at the 3- and 17-positions of estrone were synthesized, and then novel anticancer prodrugs were obtained from these by further linking these compounds to doxorubicin by means of various alkyl spacer groups. These estrogenic prodrugs were designed to target tumor cells containing ERs, found in human breast cancer cells, and to release the active anticancer moiety when internalized. The estrogenic prodrugs were then biologically evaluated using in vitro chemosensitivity assays against human ER-positive (MCF-7) and ER-negative (MCF-7ADR and MT-1) breast tumor cells and a leukemia (K562) cell line. The results showed that estrone derivatives with substituted aminoalcohol side chains of various lengths (2-6 carbons) linked to the 17-position of estrone were mostly inactive. Estronedoxorubicin prodrugs containing doxorubicin at the 3-position of estrone (CCRL 1042 and CCRL 1036) were relatively inactive and nonselective against all cell lines tested. However, when doxorubicin was linked to the 17-position of estrone, these prodrugs had at least an order greater activity than their 3-linked counterparts. Using a short aminoxyspacer group (2 carbons) at this position produced CCRL 1035, which had a lower activity against all cell lines tested compared to doxorubicin. In contrast, the prodrug incorporating doxorubicin at the 17-position of estrone via a long spacer group (12 carbons, CCRL 1033) was both potent and selective against ER-positive cells MCF-7. These studies have shown that linking doxorubicin to the 17-position of estrone via a long alkyl spacer group conferred selectivity of cytotoxic action against ER-positive breast cancer tumor cells.
Deserts exist on every continent of the globe and cover more than 30% of the Earth's land surface. Although they typically do not have a large number of inhabitants, they are often the loci of economic and cultural activity. For example, the oil-producing nations of the Middle East are all found within a single arid region. At the same time, deserts tend to be fragile ecosystems, requiring little in the way of perturbations in order to cause tremendous changes in the landscape. The size, remoteness, and harsh nature of many of the world's deserts make it difficult and expensive to map or monitor these landscapes or to determine the effect of land use on them. Remote sensing is potentially a time- and cost effective way to fulfill these goals. In this research, we will discuss the uses and limitations of remote sensing in the world's deserts. The discussion will center on using remote sensing to detect and monitor landscape change and degradation in arid regions. Because vegetation is often linked to both the causes and consequences of arid land degradation, our discussion will further focus on the retrieval of vegetation parameters. In this paper, examples of successful applications of remote sensing to arid regions are given. Also, limitations and important considerations of remote sensing in arid regions are discussed. Ultimately, atmospheric remote sensing as it relates to land degradation in arid regions is discussed. And, a case study is presented in which various methods for estimation of vegetation cover are presented and compared.
Sadeghi, H., Asghari, G., Mostafavi, A., Esmaeili a.,
Publication Date: 2009
Daru Journal Of Pharmaceutical Sciences (15608115)(3)pp. 192-198
Background and the purpose of the study: Taxol, a natural antitumor agent, was first isolated from the extract of the bark of Taxus brevifolia Nutt., which is potentially a limited source for Taxol. In the search of an alternative source, optimum and cost benefit extracting solvents, various solvents with different percentage were utilized to extract Taxol from needles of Taxus baccata. Methods: One g of the dried needles of Taxus baccata, collected from Torkaman and Noor cities of Iran, was extracted with pure ethanol or acetone and 50% and 20% of ethanol or acetone in water. Solvents were evaporated to dryness and the residues were dissolved in 5 ml of methanol and filtered. To one ml of the filtrate was added 50 μl of cinamyl acetate as the internal standard and 20 μl of the resulting solution was subjected to the HPLC to determine the extraction efficiencies of tested solvents. Five μl of filtrate was also subjected to the LC-MS using water/acetonitrile (10/90) as mobile phase and applying positive electrospray ionization (ESI) to identify the authenticity of Taxol. Results: Results of this study indicated that Taxol extraction efficiency was enhanced as the percentage of ethanol or acetone was increased. HPLC analysis showed that Taxol could be quantified by UV detection using standard curve. The standard curve covering the concentration ranges of 7.8 - 500 μg/ml was linear (r2= 0.9992) and CV% ranged from 0.52 to 15.36. LC-MS analysis using ESI in positive-ion mode confirmed the authenticity of Taxol (m/z 854; M+H), as well as some adduct ions such as M+Na (m/z 876), M+K (m/z 892) and M+CH3CN+H2O (m/z 913). Conclusions: The results suggest that 100% acetone is the best solvent for the extraction of Taxol from Taxus baccata needles.
Panjehpour m., , Movahedian a., A., Sadeghi, H., Eghbali b., , Yegdaneh, A.
Publication Date: 2010
(3)pp. 111-116
The metabolically active tumor cells may be characterized by a pronounced adenosine release that regulates the growth and development of the tumor. Consequently, the expression pattern of defined receptor subtypes will be an important determinant for specific effects of adenosine on the control of tumor cell growth. In recent studies, the expression profile, signal transduction, molecular function and cell growth modulation of adenosine receptors in the human breast cancer cell lines has been reported. To investigate the possible roles of adenosine receptors in other types of human cancers, in this study, we characterized the expression profile of adenosine receptors in two different human cancer cell lines: prostate carcinoma cell line (Du-145) and lung adenocarcinoma cell line (Calu-6). Our purpose is to test the hypothesis that diverse human cancer cell lines, according to their adenosine receptor subclass status, would show differential growth modulation. Methods: RNA was extracted and reverse transcribed to cDNA. PCR primers were synthesized from human adenosine receptor cDNA sequences. PCR was performed under optimized condition for each receptor subtype. The PCR products were separated on agarose gels. Results: All two human cancer cell lines studied contained detectable amounts of mRNA specific for adenosine receptor except A3 subtypes. Conclusion: In conclusion the differentially expressed genes identified in this study might provide new insights into the possible roles of adenosine receptors on cell growth and development.
Research In Pharmaceutical Sciences (17355362)(2)pp. 119-125
The anti-cancer activity of metal ions in the lanthanide group is being considered recently. It has been reported that cerium salts might stimulate the metabolism and therefore, produce anti-cancer effects. However, little is known about the effects of protein-cerium complex in controlling cancer cell growth. The aim of the present study was to elucidate the possible pathways for the cytotoxic effect of cerium in the presence of apo-transferrin on two cancer cell lines (Hela and MCF-7), that express transferrin receptors 3-4 fold higher than normal cells. The effect of different concentrations of cerium (0.1, 1, 10, 100 μM) in the presence and absence of transferrin for 48 h and 72 h incubation periods (37°C, 5% CO2 and 95 humidity) was studied using the MTT assay. The results showed that cerium has a cell-proliferation inhibitory activity which is significantly increased by transferrin protein. Compared with the direct treatment of cancer cells with cerium, the presence of transferrin assisted inhibition of cell proliferation by 20% and 40% in Hela and MCF-7 cells, respectively. Though apo-transferrin could lightly induce cell growth particularly in MCF-7 cells by itself, this phenomenon could not overcome the cerium-protein cell-proliferation inhibition activity. In conclusion, our results indicate that at a certain concentration, the cerium compounds could be possibly involved in the control of cell proliferation and inhibiting the growth of cancer cells.
Objectives: The medicinal plant of Avicennia marina has been used widely in traditional medicine for treatment of skin disease and rheumatoid in Iran. The present investigation was carried out to study the anticancer effects of different crude extracts of A. marina's leaves against breast cancer cell line (MDA-MB 231). Methods: MDA-MB 231 and L929 healthy cells were separately cultured in RPMI-1640 medium completed with 10% fetal calf serum and penicillin / streptomycin (50 IU/ml and 50 μg/ ml respectively). Collected leaves were dried and powdered, then were soaked in five solvents with different lipophilicity. The cytotoxic effects of different concentration of crude extracts on cultured cells were measured using the MTT assay. Chromosomal DNA was extracted, isolated and resolved using agarose gel electrophoresis. Result: Methanolic extract exerted higher anti-cancer activity on human breast cancer cells compared with other extracts. IC50 of the methanolic extract was measured at 480 μg/ml. Furthermore, the methanol extract induced a significant growth inhibition and apoptosis in a dose-dependent manner on MDA-MB 231 as human cancer cells but there was no significant effect against L929 as normal cells. Methanolic extract showed time dependent growth inhibition effect so that, after 24, 48, and 72 h treatment cell growth was inhibited by 40%, 44%, and 59%, respectively. Conclusion: The present results suggest that valuable cytotoxic components could be isolated from this plant by partitioning methanol crude extract. Further investigations are underway in this regard.
Journal of Isfahan Medical School (10277595)29(125)
Background: Cardiovascular disease is one of the most prevalent diseases in the world and it is expected to be the main cause of death by 2020. The aim of this study was providing geographical distribution map of the rate of death caused by cardiovascular diseases in the cities of Isfahan province, Iran, during 2005 to 2009. Methods: The rate of all the deaths in Isfahan province within 2005 to 2009 was provided. The collected data was used to find out the rate of deaths due to cardiovascular diseases and preparing geographical distribution maps. Then, by putting down the death rates for different sexes (men and women), the geographical distribution map for deaths with regards to cardiovascular diseases was drawn. Finding: Death rates due to cardiovascular problems were higher in main and central cities of the province. Death rate was higher in men than women. Conclusion: The observed model main and central cities is probably due to unsuitable diet, lack of motion, using new technologies and environmental pollutions including existence of some elements due to environmental pollutants such as industries, transportations of vehicles and air pollution, which are more prevalent in the main cities of the province. Also, due to existence of medical university centers and more health facilities in the main cities of the province, such as Isfahan, Najafabad, Borkhar and Maymeh, the registration system for deaths and diagnosing the causes of deaths are more accurate than other cities and towns of the province. The difference between two sexes could be due to in heritage, male hormones, some social factors, increasing fat around abdomen in men, exciting or even offensive behaviors in men, ignoring weight increase in men as compared to women and smoking.
A series of 3-hydroxypyridin-4-one derivatives (HPOs) were synthesized and their partition coefficient values (Kpart) were determined. The cytotoxic effects of these iron chelators against Hela cancer cells were also evaluated. The IC50 of HPOs was determined using MTT assay. Among these ligands, compound 4e (Kpart=5.02) with an IC50 of 30 μM and 4f (Kpart=0.1) with an IC50 of 700 μM showed the lowest and highest IC50s, respectively. In conclusion, the introduction of a more hydrophobic functional group (such as butyl in compound 4e) on the nitrogen of pyridinone ring resulted in higher cytotoxic activity of ligands.
The aim of this study was to prepare stealth solid lipid nanoparticles (SLN S) of risperidone, for controlled delivery through the intravenous (i.v.) route to reduce the frequency of administration, dose and adverse effects during the short-term management of manifestation of psychotic disorders. Stealth SLNs were prepared by emulsification-solvent diffusion and sonication method by adding acetone/ethanol containing drug, lipid and stabilizer to aqueous phase, containing surfactant, under homogenization. The effect of lipid type, lipid percentage, stabilizer type and stabilizer percentage were evaluated on the particle size, zeta potential, drug loading efficiency and drug release for optimization of SLNs. Dialysis bag membrane was used to determine drug release, the Rose Bengal binding constant for surface hydrophobicity and serum protein adsorption. The cytotoxicity of SLNs on macrophages and red blood cells were also assessed in order to evaluate the impact of surface modifications on toxicity of the different formulations. The optimized formulation was composed of 0.05% stearyl alcohol (relative to the total volume of dispersion) and 25% PEG 40 stearate (relative to the weight of lipid) using a homogenization speed of 1000 rpm and 4 minutes sonication. The results showed that the in vitro specifications of stealth SLN S of risperidone are suitable for i.v. administration.
