The kinetics of the chemical leaching of copper from low grade ore in ferric sulfate media was investigated using the constrained least square optimization technique. The experiments were carried out for different par...The kinetics of the chemical leaching of copper from low grade ore in ferric sulfate media was investigated using the constrained least square optimization technique. The experiments were carried out for different particle sizes in both the reactor and column at constant oxidation-reduction potential （Eh）, pH values, and temperature. The main copper mineral was chalcopyrite. About 40% of Cu recovery is obtained after 7 d of reactor leaching at 85℃ using -0.5 mm size fraction, while the same recovery is obtained at 75℃ after 24 d. Also, about 23% of Cu recovery is obtained after 60 d of column leaching for ＋4--8 mm size fraction whereas the Cu recovery is as low as about 15% for ＋8--12.7 and ＋12.7--25 mm size fractions. A 4-stage model for chalcopyrite dissolution was used to explain the observed dissolution behaviors. The results show that thick over-layers of sulphur components cause the parabolic behavior of chalcopyrite dissolution and the precipitation of Fe3＋ plays the main role in chalcopyrite passivation. In the case of coarse particles, transformation from one stage to another takes a longer time, thus only two stages including the initial reaction on fresh surfaces and S0 deposition are observed.展开更多
Mixed mesophilic and extreme thermophilic bioleaching were evaluated to remove copper from the molybdenite concentrate.Bioleaching tests were carried out in shake flasks and in a 50-L bioreactor.The shake flask tests ...Mixed mesophilic and extreme thermophilic bioleaching were evaluated to remove copper from the molybdenite concentrate.Bioleaching tests were carried out in shake flasks and in a 50-L bioreactor.The shake flask tests were performed with different inoculum size,solids density,pH.and temperature in order to identify optimum conditions.The highest amount of copper elimination,75%was obtained with extreme thermophilic microorganisms(at 12%inoculation,10%solids,65℃and a pH of 1.5).The highest copper elimination by mesophilic microorganisms was 55%(at 12%inoculation,5%solids,30℃at pH 2).The optimum conditions in shake flask tests were applied to 7 days batch tests in a50-L bioreactor.Extreme thermophilic experiment gave the best copper elimination of 60%(at 12%inoculation,10%solids,65℃and pH 1.5).Mesophilic test removed 50%of the copper(at 12%inoculation,10%solids,35℃at pH 2).展开更多
The precipitation of jarosite adversely affects the bio-leaching of copper sulfides in the Sarcheshmeh heap bio-leaching process. The variables of the initial concentration of ferrous iron in the growth medium, pH, an...The precipitation of jarosite adversely affects the bio-leaching of copper sulfides in the Sarcheshmeh heap bio-leaching process. The variables of the initial concentration of ferrous iron in the growth medium, pH, and temperature were examined in the laboratory to determine how they affect the precipitation of jarosite in the presence of Acidithiobacillus ferrooxidans bacteria. It was found that the maximum ferric precipitate occurred at a ferrous sulfate concentration of 50 g/L, a temperature of 32 ℃, and an initial pH value of 2.2. The effects of the precipitation of ferric iron on the quantities of ions that are important for A. ferrooxidans bacteria in aqueous phase, i.e., ferric, sulfate, potassium, phosphate, and magnesium ions, also were assessed. The results showed relatively similar patterns for the ferric and potassium ions, and then reason might have been the co-precipitation of these ions as constituent elements of jarosite mineral. At pH values greater than 1.6, the solubility of phosphate ions decreased dramatically due to the co-precipitation of phosphate ions with the jarosite precipitate and due to the significant growth rate of A. ferrooxidans bacteria in this pH range. Due to the dissolution of a gangue constituent in the ore, the magnesium levels increased in the first few days of the bio-leaching process;thereafter, it decreased slightly.展开更多
The application of the response surface methodology and the central composite design（CCD） technique for modeling and optimization of the influence of some operating variables on copper,molybdenum and rhenium recover...The application of the response surface methodology and the central composite design（CCD） technique for modeling and optimization of the influence of some operating variables on copper,molybdenum and rhenium recoveries in a bioleaching process was investigated.Three main bioleaching parameters,namely pH,solid concentration and inoculum percent,were changed during the bioleaching tests based on CCD.The ranges of the bioleaching process variables used in the design were as follows：pH1.46-2.14,solid concentration 0.95%-11.05%,and inoculum percent 1.59%-18.41%.A total of 20 bioleaching tests were carried out by the CCD method according to software-based designed matrix.Empirical model equations were developed according to the copper,molybdenum and rhenium recoveries obtained with these three parameters.Model equations of responses at the base of parameters were achieved by using statistical software.The model equations were then individually optimized by using quadratic programming to maximize copper,molybdenum and rhenium recoveries individually within the experimental range.The optimum conditions for copper recovery were pH 1.68,solid concentration 0.95% and the inoculum 18.41%（v/v）,while molybdenum and rhenium recoveries were 2.18% and 24.41%,respectively.The predicted values for copper,molybdenum and rhenium recoveries were found to be in good agreement with the experimental values.Also jarosite formation during bioleaching tests was also investigated.展开更多
Caucasus region is located in the center of Alpine-Himalayan orogenic belt. It is made of two Great and Lesser Caucasus fold thrust belts and an intramountain area called Trans caucasus or Mid caucasus. This region co...Caucasus region is located in the center of Alpine-Himalayan orogenic belt. It is made of two Great and Lesser Caucasus fold thrust belts and an intramountain area called Trans caucasus or Mid caucasus. This region contains a system of oceanic crust subduction, island arcs, volcanic arcs, back arc basins and rifts. The earthquakes of 60 km in depth are the evidences of deep brittle zone under Great Caucasus. Without considering Prototethys, Paleotethys and Neotethys Oceans, the tectonic situation of this region is not possible to study. The oceanic lithosphere under oceanic lithosphere subduction made Trans caucasus containing a trans crust. The subduction of Prototethys under Baltic made Great Caucasus and the subduction of Paleotethys under Iran, made Lesser Caucasus. The earth sutures caused by the closure of Prototethys and Paleotethys Oceans are clear in the region. The direction of Paleotethys subduction in lesser Caucasus is a considerable issue. Most of the existing evidences prove the southward direction which is different from Paleotethys subduction in Alborz of Iran. The lithospheric type of Midcaucasus is different from Caspian. Midcaucasus plays the role of determining collision type in the region.展开更多
The objectives of present study were to evaluate the potential of Lactobacillus reuteri or Lactobacillus casei combined with black pepper extract(BPE)and ethylenediamine tetraacetic acid(EDTA)for controlling the growt...The objectives of present study were to evaluate the potential of Lactobacillus reuteri or Lactobacillus casei combined with black pepper extract(BPE)and ethylenediamine tetraacetic acid(EDTA)for controlling the growth of E.coli O157:H7 and improving the chemical,microbiological and sensory quality of ground beef stored at 10℃ for 12 days.The in vitro results indicated that the combination of L.casei with BPE and EDTA had the most potent antibacterial effect against E.coli and resulted in 2.7 log CFU/ml reduction.In ground beef,the combination of L.reuteri or L.casei with BPE and EDTA decreased E.coli and aerobic mesophilic bacteria counts up to 1 and 1.6 log CFU/g,respectively.Meanwhile,this combination significantly reduced the lipid oxidation rate(up to 60%)and improved odor and overall acceptability scores of ground beef.It was concluded that the combination of L.casei with BPE and EDTA could be used in ground beef to control microbial proliferation,retard lipid oxidation,and improve sensory quality.展开更多
The copper extraction in shaking bioreactors was modeled and optimized using response surface methodology（RSM）. Influential parameters in the mesophilic bioleaching process of a low-grade copper ore including p H va...The copper extraction in shaking bioreactors was modeled and optimized using response surface methodology（RSM）. Influential parameters in the mesophilic bioleaching process of a low-grade copper ore including p H value, pulp density, and initial concentration of ferrous ions were comprehensively studied. The effect of leaching time on the response（copper extraction） at the 1st, 4th, 9th, 14 th and 22 nd days of treatment was modeled and examined. The central composite design methodology（CCD） was used as the design matrix to predict the optimal level of these parameters. Then, the model equation at the 22 nd day was optimized using the quadratic programming（QP） to maximize the total copper extraction within the studied experimental range. Under the optimal condition（initial p H value of 2.0, pulp density of 1.59%, and initial concentration of ferrous ions of 0 g/L）, the total copper extraction predicted by the model is 85.98% which is significantly close to that obtained from the experiment（84.57%）. The results show that RSM could be useful to predict the maximum copper extraction from a low-grade ore and investigate the effects of variables on the final response. Besides, a couple of statistically significant interactions are derived between p H value and pulp density as well as p H value and initial ferrous ion concentration which are precisely interpreted. However, there is no statistically significant interaction between the initial ferrous ion concentration and the pulp density. Additionally, the response at optimal levels of p H value and pulp density is found to be independent on the level of initial ferrous concentration.展开更多
Particle-particle and particle-wall collisions in gas-solid fluidized beds lead to charge accumulation on particles.This work evaluated the effect of fluidization time on charge transfer and bipolar charging(charge se...Particle-particle and particle-wall collisions in gas-solid fluidized beds lead to charge accumulation on particles.This work evaluated the effect of fluidization time on charge transfer and bipolar charging(charge separation)and their influence on hydrodynamic structures in a fluidized bed.Experiments were performed with glass beads and polyethylene particles in a glass column.The pressure fluctuations and net electrostatic charge of particles were measured during fluidization.Wavelet and short-time Fourier transforms were used to analyze pressure fluctuations.The results revealed that bipolar charging is the dominant tribocharging mechanism in a bed of glass beads.Bipolar charging in a bed of particles with a narrow size distribution does not affect either hydrodynamic structures or the transition velocity to the turbulent regime.A large difference between the work functions of the wall and particle in the bed of polyethylene particles leads to high charge transfer.Formation of a stagnant particle layer on the wall eventually causes the energy of macro-structures to increase to its maximum.At longer fluidization times,the macro-structural energy decreases and bubbles shrink until the electrostatic charge reaches the equilibrium level.These results well describe the effect of fluidization time on hydrodynamic structures.展开更多
Total Quality Management is not just an admirable phenomenon but it is any client’s right and can be done through contribution of the staff and the managers as well as the client’s of an organization. The purpose of...Total Quality Management is not just an admirable phenomenon but it is any client’s right and can be done through contribution of the staff and the managers as well as the client’s of an organization. The purpose of the present study is to investigate the feasibility of TQM model and the attitude of the managers of health field of Yazd medical sciences university towards it. The present study was a descriptive and analytical one which was cross-section ally conducted from 2010 to 2011. The population under study consisted of the managers of the unit of staff vice-chancellor for health and treatment, the managers of health system and centers of cities and also the managers of Yazd’s public hospitals. 64 people were chosen using the formula for calculating the number of samples. A questionnaire with 48 questions was used. The questionnaire’s validity was approved by the faculty members whose major is management and its reliability by using α-cronbach 87%. To analyze the data, the software SPSS V.17 was used. Scoring method was based on likert. The findings of the study show that, considering feasibility of TQM, there is a significant relation between the awareness and attitude of the managers of health and treatment field on one side and the variables, age and University degree, on the other side p = 0.001. Considering binary logistic regression and the results obtained in the form of inter and backward stepwise, the most important factors affecting the feasibility of TQM among the managers of health and treatment field are the level of awareness and attitude with the predicted accuracy 79.3% and 87.9% respectively.展开更多
AIM:The most important side effect of methotrexate(MTX)is mucositis.The purpose of this study was to evaluate the effect of turmeric extract on intestinal damage and oxidative stress in rats receiving methotrexate.MET...AIM:The most important side effect of methotrexate(MTX)is mucositis.The purpose of this study was to evaluate the effect of turmeric extract on intestinal damage and oxidative stress in rats receiving methotrexate.METHODS:Experiments were performed on male Wistar albino rats divided into six groups.First group received normal saline orally,the second group received turmeric extract(100 mg·kg-1)orally for 30 days,the third group received turmeric extract(200 mg·kg)orally for 30 days,the fourth group received a single dose of methotrexate(20 mg·kg)i.p.at day 30,the fifth group received turmeric extract(100 mg·kg)orally for 30 days and a single dose of methotrexate(20 mg·kg)i.p.at day 30,and the sixth group received turmeric extract(200 mg·kg)orally for 30days and single dose of methotrexate(20 mg·kg)i.p.at day 30.Four days after methotrexate injection,animals were anesthetized,blood samples were taken to determine total antioxidant status(TAS)and jejunum samples were taken for glutathione peroxidase(GPx),superoxidase dismutase(SOD),catalase(CAT),aldehyde malondialdehyde(MDA),and histopathological assessment.RESULTS: Microscopic evaluation from intestinal tissues of the MTX treated group,showed severe villus shortening and blunting,inflammatory cell infiltration and hemorrhage in lamina propria,along with epithlial cell necrosis.Levels of SOD,GSH-Px and CAT decreased in the MTX received group,but increased significantly(P<0.05)in the turmeric+MTX groups.MTX increased lipid peroxidation,however,turmeric decreased peroxidation significantly(P<0.05).CONCLUSION:These results suggest that turmeric extract may protect the small intestine of rats from methotrexate-induced damage.Turmeric effects could result from its antioxidant properties.展开更多
Two-way concrete slabs are widely used around the world for the construction of many types of infrastructures and common buildings. The optimal sensor placement(OSP) in slabs with various opening positions is the most...Two-way concrete slabs are widely used around the world for the construction of many types of infrastructures and common buildings. The optimal sensor placement(OSP) in slabs with various opening positions is the most important issue in structural health monitoring(SHM) to increase reliability. In this study, a novel approach of OSP was evaluated to obtain the number and placement of sensors using examination of the closed loop performance. The nonlinear finite element(NFE) was used to discretize the mechanism behavior of slab. Multi-Objective Optimization based on the coordinate modal assurance criterion(COMAC) and cost considerations was considered in the optimization processes. All of the analysis, discretization and optimization process was designed and developed as a novel approach in Matlab by the author under the name ‘FEMS-COMAC’(FEM analysis of slab with COMAC). The points in the finite element method(FEM) mesh were classified as line by line information along the slab. The OSP in each line was optimized according to the objective function. The slabs with various width, thickness, aspect ratio and opening position were selected as case studies. The results of the OSP using the COMAC algorithm around the slab openings were compared with the novel ‘FEMS-COMAC’ method. The statistical analysis according Mann-Whitney criteria shows that there were significant differences between them in some of the case studies(mean P-value=0.54).展开更多
基金the support of Research & Development Division of Sarcheshmeh Copper Complex (Kerman/ Iran) and Tarbiat Modares University(Tehran/ Iran)
文摘The kinetics of the chemical leaching of copper from low grade ore in ferric sulfate media was investigated using the constrained least square optimization technique. The experiments were carried out for different particle sizes in both the reactor and column at constant oxidation-reduction potential （Eh）, pH values, and temperature. The main copper mineral was chalcopyrite. About 40% of Cu recovery is obtained after 7 d of reactor leaching at 85℃ using -0.5 mm size fraction, while the same recovery is obtained at 75℃ after 24 d. Also, about 23% of Cu recovery is obtained after 60 d of column leaching for ＋4--8 mm size fraction whereas the Cu recovery is as low as about 15% for ＋8--12.7 and ＋12.7--25 mm size fractions. A 4-stage model for chalcopyrite dissolution was used to explain the observed dissolution behaviors. The results show that thick over-layers of sulphur components cause the parabolic behavior of chalcopyrite dissolution and the precipitation of Fe3＋ plays the main role in chalcopyrite passivation. In the case of coarse particles, transformation from one stage to another takes a longer time, thus only two stages including the initial reaction on fresh surfaces and S0 deposition are observed.
基金supported by the National Iranian Copper Industry Co.
文摘Mixed mesophilic and extreme thermophilic bioleaching were evaluated to remove copper from the molybdenite concentrate.Bioleaching tests were carried out in shake flasks and in a 50-L bioreactor.The shake flask tests were performed with different inoculum size,solids density,pH.and temperature in order to identify optimum conditions.The highest amount of copper elimination,75%was obtained with extreme thermophilic microorganisms(at 12%inoculation,10%solids,65℃and a pH of 1.5).The highest copper elimination by mesophilic microorganisms was 55%(at 12%inoculation,5%solids,30℃at pH 2).The optimum conditions in shake flask tests were applied to 7 days batch tests in a50-L bioreactor.Extreme thermophilic experiment gave the best copper elimination of 60%(at 12%inoculation,10%solids,65℃and pH 1.5).Mesophilic test removed 50%of the copper(at 12%inoculation,10%solids,35℃at pH 2).
基金support provided by the R&D division of the Sarcheshmeh Copper Complex and Tehran Science and Research Branch at Islamic Azad University
文摘The precipitation of jarosite adversely affects the bio-leaching of copper sulfides in the Sarcheshmeh heap bio-leaching process. The variables of the initial concentration of ferrous iron in the growth medium, pH, and temperature were examined in the laboratory to determine how they affect the precipitation of jarosite in the presence of Acidithiobacillus ferrooxidans bacteria. It was found that the maximum ferric precipitate occurred at a ferrous sulfate concentration of 50 g/L, a temperature of 32 ℃, and an initial pH value of 2.2. The effects of the precipitation of ferric iron on the quantities of ions that are important for A. ferrooxidans bacteria in aqueous phase, i.e., ferric, sulfate, potassium, phosphate, and magnesium ions, also were assessed. The results showed relatively similar patterns for the ferric and potassium ions, and then reason might have been the co-precipitation of these ions as constituent elements of jarosite mineral. At pH values greater than 1.6, the solubility of phosphate ions decreased dramatically due to the co-precipitation of phosphate ions with the jarosite precipitate and due to the significant growth rate of A. ferrooxidans bacteria in this pH range. Due to the dissolution of a gangue constituent in the ore, the magnesium levels increased in the first few days of the bio-leaching process;thereafter, it decreased slightly.
基金supported by the National Iranian Copper Industry Co. and Geological Survey of Iran
文摘The application of the response surface methodology and the central composite design（CCD） technique for modeling and optimization of the influence of some operating variables on copper,molybdenum and rhenium recoveries in a bioleaching process was investigated.Three main bioleaching parameters,namely pH,solid concentration and inoculum percent,were changed during the bioleaching tests based on CCD.The ranges of the bioleaching process variables used in the design were as follows：pH1.46-2.14,solid concentration 0.95%-11.05%,and inoculum percent 1.59%-18.41%.A total of 20 bioleaching tests were carried out by the CCD method according to software-based designed matrix.Empirical model equations were developed according to the copper,molybdenum and rhenium recoveries obtained with these three parameters.Model equations of responses at the base of parameters were achieved by using statistical software.The model equations were then individually optimized by using quadratic programming to maximize copper,molybdenum and rhenium recoveries individually within the experimental range.The optimum conditions for copper recovery were pH 1.68,solid concentration 0.95% and the inoculum 18.41%（v/v）,while molybdenum and rhenium recoveries were 2.18% and 24.41%,respectively.The predicted values for copper,molybdenum and rhenium recoveries were found to be in good agreement with the experimental values.Also jarosite formation during bioleaching tests was also investigated.
文摘Caucasus region is located in the center of Alpine-Himalayan orogenic belt. It is made of two Great and Lesser Caucasus fold thrust belts and an intramountain area called Trans caucasus or Mid caucasus. This region contains a system of oceanic crust subduction, island arcs, volcanic arcs, back arc basins and rifts. The earthquakes of 60 km in depth are the evidences of deep brittle zone under Great Caucasus. Without considering Prototethys, Paleotethys and Neotethys Oceans, the tectonic situation of this region is not possible to study. The oceanic lithosphere under oceanic lithosphere subduction made Trans caucasus containing a trans crust. The subduction of Prototethys under Baltic made Great Caucasus and the subduction of Paleotethys under Iran, made Lesser Caucasus. The earth sutures caused by the closure of Prototethys and Paleotethys Oceans are clear in the region. The direction of Paleotethys subduction in lesser Caucasus is a considerable issue. Most of the existing evidences prove the southward direction which is different from Paleotethys subduction in Alborz of Iran. The lithospheric type of Midcaucasus is different from Caspian. Midcaucasus plays the role of determining collision type in the region.
文摘The objectives of present study were to evaluate the potential of Lactobacillus reuteri or Lactobacillus casei combined with black pepper extract(BPE)and ethylenediamine tetraacetic acid(EDTA)for controlling the growth of E.coli O157:H7 and improving the chemical,microbiological and sensory quality of ground beef stored at 10℃ for 12 days.The in vitro results indicated that the combination of L.casei with BPE and EDTA had the most potent antibacterial effect against E.coli and resulted in 2.7 log CFU/ml reduction.In ground beef,the combination of L.reuteri or L.casei with BPE and EDTA decreased E.coli and aerobic mesophilic bacteria counts up to 1 and 1.6 log CFU/g,respectively.Meanwhile,this combination significantly reduced the lipid oxidation rate(up to 60%)and improved odor and overall acceptability scores of ground beef.It was concluded that the combination of L.casei with BPE and EDTA could be used in ground beef to control microbial proliferation,retard lipid oxidation,and improve sensory quality.
文摘The copper extraction in shaking bioreactors was modeled and optimized using response surface methodology（RSM）. Influential parameters in the mesophilic bioleaching process of a low-grade copper ore including p H value, pulp density, and initial concentration of ferrous ions were comprehensively studied. The effect of leaching time on the response（copper extraction） at the 1st, 4th, 9th, 14 th and 22 nd days of treatment was modeled and examined. The central composite design methodology（CCD） was used as the design matrix to predict the optimal level of these parameters. Then, the model equation at the 22 nd day was optimized using the quadratic programming（QP） to maximize the total copper extraction within the studied experimental range. Under the optimal condition（initial p H value of 2.0, pulp density of 1.59%, and initial concentration of ferrous ions of 0 g/L）, the total copper extraction predicted by the model is 85.98% which is significantly close to that obtained from the experiment（84.57%）. The results show that RSM could be useful to predict the maximum copper extraction from a low-grade ore and investigate the effects of variables on the final response. Besides, a couple of statistically significant interactions are derived between p H value and pulp density as well as p H value and initial ferrous ion concentration which are precisely interpreted. However, there is no statistically significant interaction between the initial ferrous ion concentration and the pulp density. Additionally, the response at optimal levels of p H value and pulp density is found to be independent on the level of initial ferrous concentration.
文摘Particle-particle and particle-wall collisions in gas-solid fluidized beds lead to charge accumulation on particles.This work evaluated the effect of fluidization time on charge transfer and bipolar charging(charge separation)and their influence on hydrodynamic structures in a fluidized bed.Experiments were performed with glass beads and polyethylene particles in a glass column.The pressure fluctuations and net electrostatic charge of particles were measured during fluidization.Wavelet and short-time Fourier transforms were used to analyze pressure fluctuations.The results revealed that bipolar charging is the dominant tribocharging mechanism in a bed of glass beads.Bipolar charging in a bed of particles with a narrow size distribution does not affect either hydrodynamic structures or the transition velocity to the turbulent regime.A large difference between the work functions of the wall and particle in the bed of polyethylene particles leads to high charge transfer.Formation of a stagnant particle layer on the wall eventually causes the energy of macro-structures to increase to its maximum.At longer fluidization times,the macro-structural energy decreases and bubbles shrink until the electrostatic charge reaches the equilibrium level.These results well describe the effect of fluidization time on hydrodynamic structures.
文摘Total Quality Management is not just an admirable phenomenon but it is any client’s right and can be done through contribution of the staff and the managers as well as the client’s of an organization. The purpose of the present study is to investigate the feasibility of TQM model and the attitude of the managers of health field of Yazd medical sciences university towards it. The present study was a descriptive and analytical one which was cross-section ally conducted from 2010 to 2011. The population under study consisted of the managers of the unit of staff vice-chancellor for health and treatment, the managers of health system and centers of cities and also the managers of Yazd’s public hospitals. 64 people were chosen using the formula for calculating the number of samples. A questionnaire with 48 questions was used. The questionnaire’s validity was approved by the faculty members whose major is management and its reliability by using α-cronbach 87%. To analyze the data, the software SPSS V.17 was used. Scoring method was based on likert. The findings of the study show that, considering feasibility of TQM, there is a significant relation between the awareness and attitude of the managers of health and treatment field on one side and the variables, age and University degree, on the other side p = 0.001. Considering binary logistic regression and the results obtained in the form of inter and backward stepwise, the most important factors affecting the feasibility of TQM among the managers of health and treatment field are the level of awareness and attitude with the predicted accuracy 79.3% and 87.9% respectively.
基金supported by the Research Fund of Ardabil University of Medical Sciences
文摘AIM:The most important side effect of methotrexate(MTX)is mucositis.The purpose of this study was to evaluate the effect of turmeric extract on intestinal damage and oxidative stress in rats receiving methotrexate.METHODS:Experiments were performed on male Wistar albino rats divided into six groups.First group received normal saline orally,the second group received turmeric extract(100 mg·kg-1)orally for 30 days,the third group received turmeric extract(200 mg·kg)orally for 30 days,the fourth group received a single dose of methotrexate(20 mg·kg)i.p.at day 30,the fifth group received turmeric extract(100 mg·kg)orally for 30 days and a single dose of methotrexate(20 mg·kg)i.p.at day 30,and the sixth group received turmeric extract(200 mg·kg)orally for 30days and single dose of methotrexate(20 mg·kg)i.p.at day 30.Four days after methotrexate injection,animals were anesthetized,blood samples were taken to determine total antioxidant status(TAS)and jejunum samples were taken for glutathione peroxidase(GPx),superoxidase dismutase(SOD),catalase(CAT),aldehyde malondialdehyde(MDA),and histopathological assessment.RESULTS: Microscopic evaluation from intestinal tissues of the MTX treated group,showed severe villus shortening and blunting,inflammatory cell infiltration and hemorrhage in lamina propria,along with epithlial cell necrosis.Levels of SOD,GSH-Px and CAT decreased in the MTX received group,but increased significantly(P<0.05)in the turmeric+MTX groups.MTX increased lipid peroxidation,however,turmeric decreased peroxidation significantly(P<0.05).CONCLUSION:These results suggest that turmeric extract may protect the small intestine of rats from methotrexate-induced damage.Turmeric effects could result from its antioxidant properties.
文摘Two-way concrete slabs are widely used around the world for the construction of many types of infrastructures and common buildings. The optimal sensor placement(OSP) in slabs with various opening positions is the most important issue in structural health monitoring(SHM) to increase reliability. In this study, a novel approach of OSP was evaluated to obtain the number and placement of sensors using examination of the closed loop performance. The nonlinear finite element(NFE) was used to discretize the mechanism behavior of slab. Multi-Objective Optimization based on the coordinate modal assurance criterion(COMAC) and cost considerations was considered in the optimization processes. All of the analysis, discretization and optimization process was designed and developed as a novel approach in Matlab by the author under the name ‘FEMS-COMAC’(FEM analysis of slab with COMAC). The points in the finite element method(FEM) mesh were classified as line by line information along the slab. The OSP in each line was optimized according to the objective function. The slabs with various width, thickness, aspect ratio and opening position were selected as case studies. The results of the OSP using the COMAC algorithm around the slab openings were compared with the novel ‘FEMS-COMAC’ method. The statistical analysis according Mann-Whitney criteria shows that there were significant differences between them in some of the case studies(mean P-value=0.54).
