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1.
Two lichen metabolites, rhizonaldehyde ( 1 ) and rhizonyl alcohol ( 2 ), were isolated from the acetone extract of Lobaria pulmonaria by chromatographic methods, and their chemical structures were determined by UV/VIS, IR, and 1D‐ and 2D‐NMR spectroscopic methods. The gastroprotective and in vivo antioxidant activities of extracts of L. pulmonaria and its metabolites, 1 and 2 , were investigated in indomethacin‐induced ulcer models in rats. The gastric lesions were significantly reduced by acetone, hexane, and CHCl3 extracts, with 75.3–41.5% inhibition. Rhizonyl alcohol ( 2 ) significantly reduced the gastric lesions with an inhibition rate of 84.6–42.8%, whereas rhizonaldehyde ( 1 ) significantly increased the gastric lesions. Antioxidant parameters and myeloperoxidase activities were also evaluated in the gastric tissues of the rats. Indomethacin caused oxidative stress, which resulted in lipid peroxidation in gastric tissues by decreasing the levels of the antioxidants as compared to healthy rat tissues. In contrast to indomethacin, all extracts and rhizonyl alcohol ( 2 ) caused a significant decrease in lipid peroxidation levels and an increase in antioxidant parameters, superoxide dismutase, glutathione peroxidase, and glutathione‐S‐transferase, and reduced glutathione in gastric tissues. The administration of rhizonyl alcohol ( 2 ) also resulted in a decrease in gastric myeloperoxidase activity increased by indomethacin. The gastroprotective effect of rhizonyl alcohol ( 2 ) can be attributed to its antioxidant properties and its suppressing effect on neutrophil infiltration into gastric tissues.  相似文献   
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We found no significant effect (p > 0.38) of clipping surrounding non‐native annuals on the performance or survival of plantings of the native Nassella pulchra. However, the preplanting productivity of the three sites had a significant effect (p < 0.001) on the demography and water relations of Nassella. Survival was 85% on the lowest productivity site and it decreased by 6% for each additional 100 kg in average aboveground productivity between 2,400 and 3,600 kg/ha. Plants experienced greater water stress in higher productivity sites. Together, these results suggest that the original habitat of N. pulchra may have been in more marginal ecological sites rather than the more fertile soils of the Central Valley.  相似文献   
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In this study, we aimed to investigate whether there is any relationship between gastric cancer and iodine concentrations in blood and urine in the northeast Anatolia region, where iodine deficiency is common. A total of 56 patients, diagnosed as gastric cancer and 25 healthy volunteers were included in the study. The methods used were based on the Sandell-Kolthoff reaction. The urine iodine concentration (UIC) and serum protein-bound iodine (PBI) levels were higher in patients with gastric cancer compared with healthy control subjects. The UIC in stage IV was higher than all other stages and the control group. The UIC was higher in stages III and IV compared with stages I and II. However, serum PBI levels in stage III were higher compared with stages I, and II and also control group. The serum PBI level in stage IV was higher than stage II and the control group. In the patient and control groups, there were no significant differences in serum PBI and UIC with regard to age or sex. Our results suggested that urinary and blood iodine concentration might be a useful marker for following the disease.  相似文献   
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There are numerous reports on the effects of electromagnetic radiation (EMR) in various cellular systems. Melatonin and caffeic acid phenethyl ester (CAPE), a component of honeybee propolis, were recently found to be potent free radical scavengers and antioxidants. Mechanisms of adverse effects of EMR indicate that reactive oxygen species may play a role in the biological effects of this radiation. The present study was carried out to compare the efficacy of the protective effects of melatonin and CAPE against retinal oxidative stress due to long-term exposure to 900 MHz EMR emitting mobile phones. Melatonin and CAPE were administered daily for 60 days to the rats prior to their EMR exposure during our study. Nitric oxide (NO, an oxidant product) levels and malondialdehyde (MDA, an index of lipid peroxidation), were used as markers of retinal oxidative stress in rats following to use of EMR. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were studied to evaluate the changes of antioxidant status in retinal tissue. Retinal levels of NO and MDA increased in EMR exposed rats while both melatonin and CAPE caused a significant reduction in the levels of NO and MDA. Likewise, retinal SOD, GSH-Px and CAT activities decreased in EMR exposed animals while melatonin and CAPE caused a significant increase in the activities of these antioxidant enzymes. Treatment of EMR exposed rats with melatonin or CAPE increased the activities of SOD, GSH-Px and CAT to higher levels than those of control rats. In conclusion, melatonin and CAPE reduce retinal oxidative stress after long-term exposure to 900 MHz emitting mobile phone. Nevertheless, there was no statistically significant difference between the efficacies of these two antioxidants against to EMR induced oxidative stress in rat retina. The difference was in only GSH-Px activity in rat retina. Melatonin stimulated the retinal GSH-Px activity more efficiently than CAPE did.  相似文献   
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Abstact Cadmium is one of the most toxic pollutants in environment. Cadmium accumulation in blood affects the renal cortex and causes renal failure. In this study, we aimed to evaluate the effects of cadmium on rat liver tissue. Eighteen male albino rats aged ten weeks old were used in the study. 15 ppm of cadmium was administered to rats via consumption water daily. At the end of the 30th study day, the animals were killed under ether anesthesia. After the liver tissue samples were taken, histopathological and biochemical examinations were performed. Histopathologic changes have included vacuolar and granular degenerations in hepatocytes, heterochromatic nucleuses and sinusoidal and portal widenings. Central vein diameters were normal in cadmium exposed group. Whereas, there was statistically significant difference between two groups by means of sinusoidal (p< 0.001) and portal triad diameters (p< 0.01). Malondialdehyde (MDA) is an indicator of lipid peroxidation. In this study, MDA was used as a marker of oxidative stress-induced liver impairment in cadmium exposed rats. Superoxide dismutase (SOD) and catalase (CAT) activities were also measured to evaluate the changes in antioxidative system in liver tissues. Current findings showed that MDA levels were increased and SOD and CAT activities were decreased in cadmium exposed group compared to control group. The difference between two groups was statistically significant (pvalues: MDA,p< 0.01; CAT,p< 0.01 and SOD,p< 0.05). In conclusion, these findings suggest the role of oxidative mechanisms in cadmium-induced liver tissue damage  相似文献   
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In the present study, turkey proventriculus (stomach) was mixed with 10% NaCl (1:2 w/v) and extracted by centrifugation to produce crude extract. The partial purification of the extract was carried out by using Sephadex G-75 resin in gel filtration column chromatography. Crude extract (CE) and fractions obtained by gel filtration were analysed for milk-clotting activity (MCA), protein content, proteolytic activity (PA), and SDS-PAGE electrophoresis. The first 7 fractions did not have any activities; the fraction of 9, 10 and 11 had the most milk-clotting and proteolytic activities. Electrophoretic patterns proved that further purification steps should be applied for better results.  相似文献   
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Effects of Burning and Grazing on a Coastal California Grassland   总被引:5,自引:2,他引:3  
We tested the effects of fall burning and protection from livestock grazing as management to enhance native grasses on a coastal grassland in central California. Plants from the Mediterranean, introduced beginning in the late 1700s, have invaded and now dominate most of California's grasslands. Coastal grasslands are generally less degraded than those inland and have higher potential for restoration and conservation. Productivity of the experimental plots varied annually and declined over the course of the study because of rainfall patterns. Foliar cover of the native Danthonia californica (California oatgrass) increased more under grazing than grazing exclusion and did not respond to burning. Two other natives, Nassella pulchra (purple needlegrass) and Nassella lepida (foothill needlegrass), responded variably to treatments. The response of N. pulchra differed from that reported on more inland sites in California. Restoring these grasslands is complicated by differing responses of target species to protection from grazing and burning. The current practice of managing to enhance single species of native plants (e.g., N. pulchra) may be detrimental to other equally important native species.  相似文献   
10.
In order to maintain a good environmental status of surface waters, an assessment of water quality carried out at specific intervals to monitor the changes of water quality in function of time. Human knowledge and experience are currently focused on using assessment methods, especially the integration of multiple constraining factors and considering them in conjugation with the correct decision-making process concerning the environment. When surface water is highly exposed to human activities, either from recreational or economic activity, the degree of vulnerability is high, and the quality of surface water is highly compromised. In case of Lake Balaton, there are many activities that can disrupt water dynamics. The first goal of this study is to determine the location of the least and most polluted sites around Lake Balaton. The processing of data was carried out by using multi-criteria decision techniques and environmental impact assessment method based on physical–chemical parameters in comparison with the limiting parameters. Based on the results of those methods water quality needs to be improved in western parts of the lake by using several geoengineering treatment techniques. This work covers a novel approach to comparing methods based on sum of ranking differences, whereas many method comparison studies suffer from ambiguity or from comparisons not being quite fair. This problem can be avoided if there are differences between ideal and actual rankings.  相似文献   
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