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161.
A new series of 3-phenoxyazetidin-2-ones (β-lactams) were designed and synthesized for the evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In this study, the effects of a synthetic of β-lactam-structured COX-2 inhibitor with 4-(4-(methylsulfonyl)phenyl)-3-phenoxy-1-phenylazetidin-2-one on cell viability of cancerous lymphoblast isolated from patients diagnosed with acute lymphocytic leukemia (ALL) and normal lymphocytes collected from healthy donors were investigated. The viability % of cancer lymphoblast and normal lymphocyte treated 4-(4-(methylsulfonyl)phenyl)-3-phenoxy-1-phenylazetidin-2-one were tested with MTT assay. Apoptosis and necrosis were measured by double stains of annexin V and propidium iodide, and caspase-3 as a final mediator in apoptotic death measured by colorimetric assay. Mitochondria were isolated from both cancerous lymphoblast and normal lymphocytes to measure parameters of mitochondrial damage such as reactive oxygen species (ROS) formation, mitochondrial membrane potential decrease, swelling, and cytochrome c release following the administration of azithidine-2-one derivative, 4-(4-(methylsulfonyl)phenyl)-3-phenoxy-1-phenylazetidin-2-one. Our results showed that 4-(4-(methylsulfonyl)phenyl)-3-phenoxy-1-phenylazetidin-2-one inhibited proliferation of cancerous lymphoblast in a concentration-dependent manner by inducing apoptosis but not in normal lymphocytes. Treatment with azithidine-2-one derivative produced a rapid loss of mitochondrial transmembrane potential, stimulation of release of ROS and mitochondrial cytochrome c into cytosol, and subsequent induction of procaspase-9 processing. Data suggest that 4-(4-(methylsulfonyl)phenyl)-3-phenoxy-1-phenylazetidin-2-one-induced ROS production led to mitochondria-mediated death signaling that resulted in apoptosis in cancerous lymphoblast cells. The induction of apoptosis by azithidine-2-one compounds, such as 4-(4-(methylsulfonyl)phenyl)-3-phenoxy-1-phenylazetidin-2-one, may provide a mechanism for its cancer chemopreventive action in acute lymphocytic leukemia cells.  相似文献   
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163.
This study employs the Taguchi optimization methodology to optimize the effective parameters for the pesticide (Vapam) sorption onto soil modified with natural zeolite (clinoptilolite). The experimental factors and their ranges chosen for determination of the effective parameters were: initial Vapam concentration (0.4–1.6 mg/L), initial pH of the pesticide solution (2–12), the percentage of clinoptilolite in the modified soil (0–6 %), temperature (15–35°C) and shaking time (2–24 h). The orthogonal array (OA) L16 and the bigger the better response category of the Taguchi method were selected to determine the optimum conditions: initial Vapam concentration (1.2 mg/L), initial pH of the pesticide solution (2), the percentage of clinoptilolite in the modified soil (4 %), temperature (15°C) and shaking time (2 h). The results showed that in comparison with other parameters, the initial Vapam concentration was the most effective one for the sorption of this pesticide onto soil, modified with clinoptilolite. Moreover, after determining the optimum levels of the sorption process parameters, confirmation experiments were performed to prove the effectiveness of the Taguchi's experimental design methodology.  相似文献   
164.
Cadmium (Cd) toxicity in plants leads to serious disturbances of physiological processes, such as inhibition of chlorophyll synthesis, oxidative injury to the plant cells and water and nutrient uptake. Response of Matricaria chamomilla L. to calcium chloride (CaCl2) enrichment in growth medium for reducing Cd toxicity were studied in this study. Hydroponically cultured seedlings were treated with 0, 0.1, 1, and 5 mM CaCl2, under 0, 120, and 180 μM CdCl2 conditions, respectively. The study included measurements pertaining to physiological attributes such as growth parameters, Cd concentration and translocation, oxidative stress, and accumulation of phenolics. Addition of CaCl2 to growth media decreased the Cd concentration, activity of antioxidant enzymes, and reactive oxygen species accumulation in the plants treated with different CdCl2, but increased the growth parameters. Malondialdehyde and total phenolics in shoots and roots were not much affected when plants were treated only with different CaCl2 levels, but it showed a rapid increase when the plants were exposed to 120 and 180 CdCl2 levels. CaCl2 amendment also ameliorated the CdCl2-induced stress by reducing oxidative injury. The beneficial effects of CaCl2 in ameliorating CdCl2 toxicity can be attributed to the Ca-induced reduction of Cd concentration, by reducing the cell-surface negativity and competing for Cd2+ ion influx, activity enhancement of antioxidant enzymes, and biomass accumulation.  相似文献   
165.
The ability of free and polysulphone immobilized biomass of Arthrobacter sp. to remove Cu2+ ions from aqueous solution was studied in batch and continuous systems. The Langmuir and Freundlich isotherm models were applied to the data. The Langmuir isotherm model was found to fit the sorption data indicating that sorption was monolayer and uptake capacity (Qo) was 175.87 and 158.7 mg/g for free and immobilized biomass respectively at pH 5.0 and 30 °C temperature, which was also confirmed by a high correlation coefficient, a low RMSE and a low Chi-square value. A kinetic study was carried out with pseudo-first-order reaction and pseudo-second-order reaction equations and it was found that the Cu2+ uptake process followed the pseudo-second-order rate expression. The diffusivity of Cu2+ on immobilized beads increased (0.402 × 10−4 to 0.435 × 10−4 cm2/s) with increasing concentration from 50 to 150 mg/L. The maximum percentage Cu2+ removal (89.56%) and uptake (32.64 mg/g) were found at 3.5 mL/min and 20 cm bed height. In addition to this the Bed Depth Service Time (BDST) model was in good agreement with the experimental data with a high correlation coefficient (>0.995). Furthermore, sorption and desorption studies were also carried out which showed that polysulphone immobilized biomass could be reused for up to six sorption–desorption cycles.  相似文献   
166.
This study employs the Taguchi optimization methodology to optimize the effective parameters for the pesticide (Vapam) sorption onto soil modified with natural zeolite (clinoptilolite). The experimental factors and their ranges chosen for determination of the effective parameters were: initial Vapam concentration (0.4-1.6 mg/L), initial pH of the pesticide solution (2-12), the percentage of clinoptilolite in the modified soil (0-6 %), temperature (15-35°C) and shaking time (2-24 h). The orthogonal array (OA) L(16) and the bigger the better response category of the Taguchi method were selected to determine the optimum conditions: initial Vapam concentration (1.2 mg/L), initial pH of the pesticide solution (2), the percentage of clinoptilolite in the modified soil (4 %), temperature (15°C) and shaking time (2 h). The results showed that in comparison with other parameters, the initial Vapam concentration was the most effective one for the sorption of this pesticide onto soil, modified with clinoptilolite. Moreover, after determining the optimum levels of the sorption process parameters, confirmation experiments were performed to prove the effectiveness of the Taguchi's experimental design methodology.  相似文献   
167.
In order to assess the quality and suitability of waters in the Kor-Sivand river basin, 60 water samples from the Kor river and 90 water samples from wells in the basin were studied. Assessments were based on Piper's and Gibbs' diagrams for water quality, Food and Agricultural Organization's (FAO) guidelines, and US Salinity Laboratory diagram for water suitability. The results showed that the river water is of Ca-HCO(3) type, while well water is of Ca-Cl and Na-Cl type. Based on Gibbs' diagram, the source of soluble ions in the river water samples is the weathering of stones over which water flows, while evaporation was found to be the dominant process in the ion concentration of the well samples. According to the FAO Guidelines, the salinity of surface water for irrigation did not cause great restrictions; however, many of these waters could create potential permeability problems. In the groundwater samples, a high salt concentration is more important than the infiltration problem. Mg hazard values at some sites limit its use for agricultural purposes. One third of the river water samples and two thirds of well waters had more than 50% magnesium. Saturation indices showed that 94% of the analyzed water samples are supersaturated with calcite, aragonite, and dolomite. Based on the US Salinity Laboratory diagram, river water samples were classified as C(2)S(1) and C(3)S(1), while C(4)S(3), C(4)S(4), C(2)S(1), and C(3)S(1) were the most dominant classes in well samples. Some management practices necessary for sustainable development of water resources in the study area were discussed briefly, including appropriate selection of crops, adequate drainage, leaching, blending and cyclic use of saline water, proper irrigation method, and addition of soil amendment.  相似文献   
168.
This study attempts to develop a non-path-dependent model for environmental risk management and polycentric urban land-use planning in Gorgan Township area, Iran. Applying three suitability layers of environmental risk (soil erosion, flood risk, fire risk, and land susceptibility), urbanization potential, and integrated surface (environmental risk plus urbanization potential layers), a non-path-dependent Cellular Automata-Markov Chain (CA-MC) model was configured to execute three scenarios of polycentric urban growth allocation. Specifically, the modeling approach improved the traditional functionality of the CA-MC model from a prediction algorithm into an innovative land allocation tool. Besides, due to its flexibility, the non-path-dependent model was able to explicitly include different characteristics of the landscape structure ranging from physical land attributes to landscape functions and processes (natural hazards). Accordingly, three polycentric urban growth allocation efforts were undertaken and compared in terms of connectivity and compactness of the resultant patterns and consumption of other land resources. Based on results, the polycentric allocation procedure based on integrated suitability layer produced a more manageable pattern of urban landscape, while the growth option based on environmental risk layer was more successful for protecting farmlands against excessive urbanization. This study suggests that polycentric urban land-use planning under the strategy of rural land development programs is an available option for designing an urban landscape with lower exposure to natural hazards and more economic benefits to rural residents. Finally, the non-path-dependent modeling is a recommended approach, when highly flexible and interactive decision-support systems as well as trend-breaking scenarios are desired.  相似文献   
169.
The levels of mercury in tissues of Penaeus merguiensis from Musa estuary, northwest of the Persian Gulf, were investigated. This study assessed the relationship between mercury levels in hepatopancrea, gill, and muscle with sex, size, and season. The order of mercury concentrations in tissues of the shrimp P. merguiensis was as follows: hepatopancreas > gill > muscle. There was a positive correlation between mercury concentrations in shrimp species with sex and size of its food items. We expected to see higher mercury levels in tissues of female species because they are larger and can eat larger food items. Also, there was a positive correlation between mercury concentrations in shrimp species with its food source. Therefore, female species feed more on shrimp and plant and are contaminated with high levels of mercury. There was significant difference (p?<?0.05) in mercury levels between different seasons; higher mercury levels were found in July (summer season).  相似文献   
170.
Because of over-exploitation of sturgeon for caviar production, they have been listed worldwide in annex II of the Convention on International Trade in Endangered Species regulations; so caviar production using aquaculture is increasingly seen as a feasible way to reduce overfishing. The accumulation of the nonessential metals As, Ba, Cd, Hg, Pb, and Sn was determined in the caviar of farmed and wild Beluga sturgeon (Huso huso). The levels of As in both and Cd in wild samples were less than 0.01 mg kg?1 wet weight, and the comparison for all of the metals studied did not show large fluctuations in metal concentrations between farmed and wild caviar samples. The average for each toxic metal was below the permissible limits proposed by the UK’s Ministry of Agriculture, Fisheries and Foods (2000). The maximum allowable daily consumption rate of caviar was calculated; however, the health risks from caviar consumption are uncertain because the amount of caviar consumed by heavy users is not known.  相似文献   
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