A laboratory incubation experiment was conducted to elucidate the effect of acetate on lead bioavailability and toxicity to microbial biomass in a red soil. Results indicated that the application of acetate along o...A laboratory incubation experiment was conducted to elucidate the effect of acetate on lead bioavailability and toxicity to microbial biomass in a red soil. Results indicated that the application of acetate along or at the lower lead levels of 100 and 200 μg/g soil stimulated the soil microbial biomass. The addition of acetate at the higher lead levels of 300, 450 and 600 μg/g soil caused significantly greater reductions in the biomass carbon(C mic ) and the biomass nitrogen (N mic ), compared with the control or the same lead levels applied individually. A greater increase in the biomass C:N ratio occurred by acetate addition at the same lead levels. The concentration of 0.01 mol/L CaCl 2 extractable lead was considerably higher in the lead plus acetate treatments than at the same lead levels with no acetate. Based on these results, it was concluded that the application of acetate might have suppressed the lead adsorption in the soil which in turn resulted in its more bioavailability and hence more toxicity to the soil microbial biomass.展开更多
Ex-situ electroremediation tests were conducted on the lead-contaminated red soils to find out the optimum condition for the most efficient removal of lead pollution from the red soil, and to examine the relation of t...Ex-situ electroremediation tests were conducted on the lead-contaminated red soils to find out the optimum condition for the most efficient removal of lead pollution from the red soil, and to examine the relation of the pH of the soil with the electroremediation efficiency. The results show that the electroremediation technology is efficient to remedy Pb contaminated red soils, and the removal efficiency can be enhanced by controlling pH value in the cathode reservoir with HNO3. The average removal efficiency of Pb is enhanced from 24.5% to 79.5%, and the energy consumption reaches 285 kW·h per m3 red soil.展开更多
Using the SAS software, the data of environmental factors vs. red tide biomass were analysed during the process of Skeletonema costatum red tide which broke out in the Changjiang Estuary on June 9～15, 1990. The resul...Using the SAS software, the data of environmental factors vs. red tide biomass were analysed during the process of Skeletonema costatum red tide which broke out in the Changjiang Estuary on June 9～15, 1990. The results of the multivariate statistical analysis show that the environmental factors are similar in their developing and maintenance periods and that the values of environmental factors begin to be restored to normal levels during the disappearing period.The results obtained from using the methods of correlation, variable cluster and main component analyses are basically identical. The important factors contributing to the occurrence of this red tide are atmospherical pressure, water temperature, salinity, pH, No3-, -N, Po43--P and Fe, among which,salinity, Fe and PO43--P are the leading factors which have triggered the occurrence of the red tide as determined by the step-by-step regression analysis. Meanwhile, the linear discrimination functions have been established for the red tide. The environmental factor data of another occurring process of Skeletonema costatum red tide in the Changjiang Estuary have been chosen for red tide discrimination with satisfactory results.展开更多
Results of investigation of X-ray diffraction, infrared and optical spectra of powders of the ruthenium dioxide, lead-silicate glass as well as their mixture before and after sintering are reported. Sintering conditio...Results of investigation of X-ray diffraction, infrared and optical spectra of powders of the ruthenium dioxide, lead-silicate glass as well as their mixture before and after sintering are reported. Sintering conditions typical for thick film resistors were used. Intensity of main lines of RuO2 in X-ray diffraction patterns of sintered mixtures decreases and they slightly shift towards small angles. No new reflexes appear in these patterns. Absorbance of RuO2 in the range of 2.5-100 μm is proportional to and featureless. Infrared spectrum of lead-silicate glass has absorption bands of [SiO4]4- tetrahedra and Pb-O bonds only. Optical spectrum of RuO2 has wide absorption bands at 950 and 370 nm. Spectra of the mixture of RuO2 and glass powders before and after sintering are different indicating that there is interaction between them during the sintering process. Concentration of free charge carriers estimated from the optical spectra is about 1021 cm-3.展开更多
Lipstick is the most widely used cosmetic product. Although lipstick gives a lot of social, psychological and therapeutic benefits, it may harm the consumers. Because most lipsticks contained high lead level and long ...Lipstick is the most widely used cosmetic product. Although lipstick gives a lot of social, psychological and therapeutic benefits, it may harm the consumers. Because most lipsticks contained high lead level and long term use of high lead level lipstick may harm the consumers. Research findings have suggested that administration of various antioxidants can prevent or subdue various toxic effects of lead and generation of oxidative stress. <strong><em>Hylocereus polyrhizus</em></strong> (Red dragon fruit) is widely available in Myanmar and it contains powerful antioxidant amaranth colorant called betacyanin pigment. It can prevent the oxidative stress caused by low level of lead, thus suitable as natural colorant for lipstick. As a role of pharmacist, this research was intended to minimize the adverse effects of lipsticks by formulating natural lipstick with betacyanin pigment obtained from <strong><em>H. polyrhizus</em></strong> and other natural ingredients. Formulation of lipstick was carried out by heating and blending method with homogenizer at a speed of 12000 rpm. Then, pH, melting point, surface abnormalities, aging stability, perfume stability and antioxidant activity were performed as quality evaluation. Skin irritation test, microbial analysis and lead content determination were carried out as safety evaluation. Formulated lipsticks with betacyanin pigment of <em><strong>H. polyrhizus</strong></em> have acceptable quality. The IC50 of standard ascorbic acid and formulated lipstick were 4.51 μg/ml and 22.23 μg/ml respectively. In quantitative analysis for microbiological control, formulated lipstick had no visible colony and in qualitative analysis, <strong><em>Staphylococcus aureus</em></strong>, <strong><em>E. coli</em></strong> and <strong><em>Pseudomonas aeruginosa</em></strong> were not detected in 0.5 g of formulated lipsticks. Moreover, lead content of formulated lipstick was only 2.9 ppm that is within allowable limit and it had negligible skin irritancy. Therefore, lipstick with betacyanin pigment of <em><strong>H. polyrhizus</strong></em> can utilize as Cosmeceutical.展开更多
文摘A laboratory incubation experiment was conducted to elucidate the effect of acetate on lead bioavailability and toxicity to microbial biomass in a red soil. Results indicated that the application of acetate along or at the lower lead levels of 100 and 200 μg/g soil stimulated the soil microbial biomass. The addition of acetate at the higher lead levels of 300, 450 and 600 μg/g soil caused significantly greater reductions in the biomass carbon(C mic ) and the biomass nitrogen (N mic ), compared with the control or the same lead levels applied individually. A greater increase in the biomass C:N ratio occurred by acetate addition at the same lead levels. The concentration of 0.01 mol/L CaCl 2 extractable lead was considerably higher in the lead plus acetate treatments than at the same lead levels with no acetate. Based on these results, it was concluded that the application of acetate might have suppressed the lead adsorption in the soil which in turn resulted in its more bioavailability and hence more toxicity to the soil microbial biomass.
文摘Ex-situ electroremediation tests were conducted on the lead-contaminated red soils to find out the optimum condition for the most efficient removal of lead pollution from the red soil, and to examine the relation of the pH of the soil with the electroremediation efficiency. The results show that the electroremediation technology is efficient to remedy Pb contaminated red soils, and the removal efficiency can be enhanced by controlling pH value in the cathode reservoir with HNO3. The average removal efficiency of Pb is enhanced from 24.5% to 79.5%, and the energy consumption reaches 285 kW·h per m3 red soil.
文摘Using the SAS software, the data of environmental factors vs. red tide biomass were analysed during the process of Skeletonema costatum red tide which broke out in the Changjiang Estuary on June 9～15, 1990. The results of the multivariate statistical analysis show that the environmental factors are similar in their developing and maintenance periods and that the values of environmental factors begin to be restored to normal levels during the disappearing period.The results obtained from using the methods of correlation, variable cluster and main component analyses are basically identical. The important factors contributing to the occurrence of this red tide are atmospherical pressure, water temperature, salinity, pH, No3-, -N, Po43--P and Fe, among which,salinity, Fe and PO43--P are the leading factors which have triggered the occurrence of the red tide as determined by the step-by-step regression analysis. Meanwhile, the linear discrimination functions have been established for the red tide. The environmental factor data of another occurring process of Skeletonema costatum red tide in the Changjiang Estuary have been chosen for red tide discrimination with satisfactory results.
文摘Results of investigation of X-ray diffraction, infrared and optical spectra of powders of the ruthenium dioxide, lead-silicate glass as well as their mixture before and after sintering are reported. Sintering conditions typical for thick film resistors were used. Intensity of main lines of RuO2 in X-ray diffraction patterns of sintered mixtures decreases and they slightly shift towards small angles. No new reflexes appear in these patterns. Absorbance of RuO2 in the range of 2.5-100 μm is proportional to and featureless. Infrared spectrum of lead-silicate glass has absorption bands of [SiO4]4- tetrahedra and Pb-O bonds only. Optical spectrum of RuO2 has wide absorption bands at 950 and 370 nm. Spectra of the mixture of RuO2 and glass powders before and after sintering are different indicating that there is interaction between them during the sintering process. Concentration of free charge carriers estimated from the optical spectra is about 1021 cm-3.
文摘Lipstick is the most widely used cosmetic product. Although lipstick gives a lot of social, psychological and therapeutic benefits, it may harm the consumers. Because most lipsticks contained high lead level and long term use of high lead level lipstick may harm the consumers. Research findings have suggested that administration of various antioxidants can prevent or subdue various toxic effects of lead and generation of oxidative stress. <strong><em>Hylocereus polyrhizus</em></strong> (Red dragon fruit) is widely available in Myanmar and it contains powerful antioxidant amaranth colorant called betacyanin pigment. It can prevent the oxidative stress caused by low level of lead, thus suitable as natural colorant for lipstick. As a role of pharmacist, this research was intended to minimize the adverse effects of lipsticks by formulating natural lipstick with betacyanin pigment obtained from <strong><em>H. polyrhizus</em></strong> and other natural ingredients. Formulation of lipstick was carried out by heating and blending method with homogenizer at a speed of 12000 rpm. Then, pH, melting point, surface abnormalities, aging stability, perfume stability and antioxidant activity were performed as quality evaluation. Skin irritation test, microbial analysis and lead content determination were carried out as safety evaluation. Formulated lipsticks with betacyanin pigment of <em><strong>H. polyrhizus</strong></em> have acceptable quality. The IC50 of standard ascorbic acid and formulated lipstick were 4.51 μg/ml and 22.23 μg/ml respectively. In quantitative analysis for microbiological control, formulated lipstick had no visible colony and in qualitative analysis, <strong><em>Staphylococcus aureus</em></strong>, <strong><em>E. coli</em></strong> and <strong><em>Pseudomonas aeruginosa</em></strong> were not detected in 0.5 g of formulated lipsticks. Moreover, lead content of formulated lipstick was only 2.9 ppm that is within allowable limit and it had negligible skin irritancy. Therefore, lipstick with betacyanin pigment of <em><strong>H. polyrhizus</strong></em> can utilize as Cosmeceutical.
