Effect of inorganic carbon source on lipid production with autotrophic Chlorella vulgaris / 生物工程学报

We studied the effects of three inorganic carbon sources, Na2CO3, NaHCO3 and CO2, and their initial concentrations on lipid production of Chlorella vulgaris. Chlorella vulgaris could utilize Na2CO3, NaHCO3 and CO2 to produce lipids. After 10-day cultivation with each of the three inorganic carbon sources, lipid yield of Chlorella vulgaris reached its peak with the concentration increase of the inorganic carbon source, but dropped again by further increase of the concentration. The pH value of the culture medium for Chlorella vulgaris increased after the cultivation on inorganic carbon source. The optimal concentration of both Na2CO3 and NaHCO3 was 40 mmol/L, and their corresponding biomass dry weight was 0.52 g/L and 0.67 g/L with their corresponding lipid yield 0.19 g/L and 0.22 g/L. When the concentration of CO2 was 6%, Chlorella vulgaris grew the fastest and its biomass dry weight was 2.42 g/L with the highest lipid yield of 0.72 g/L. When the concentration of CO2 was too low, the supply of inorganic carbon was insufficient and lipid yield was low. A too high concentration of CO2 caused a low pH and lipid accumulation was inhibited. Na2CO3 and NaHCO3 were more favorable for Chlorella vulgaris to accumulate unsaturated fatty acids than that of CO2.

Study on quality assurance system of grade 3 laminar operation room / 中国实用护理杂志

ObjectiveTo explore the features of the cleanliness change with time during the use of laminar operating rooms in order to establish reliable quality assurance system. MethodsTwo grade 3 lami-nar operation rooms were chosen to be tested after one and a half year and two and a half years, laser counter was used to detect the static particulates after cleaning for 30 minutes and 45 minutes. ResultsAfter the laminar operation room was used for one and a half years the amount of 0.5 μm particulates in indoor air was less than 350 per liter, and after two and a half years it's above 350 per liter after cleaning for 30 minutes, an obvious difference than the previous one. The anaount of 1 μm and 2 pan particulates also increase obviously, but ff cleaning for 45 minutes the amount of 0.5 μm particulates in indoor air will fulfill the qualification. Al-though the amount of 0.5 μm, 1 pan and 2 μm particulates after 2 years using was higher than the one and a half yesrs'using after cleaning for 45 minutes, but the difference had no statistic meaning. CondusionsThe elesnliness of laminar operation rooms will drop as time prolonged, Amount of particulates in indoor air will in-crease too but the cleanliness can be ensured by extending cleaning time. After the quality assurance sys-tem was established the amount of smile particulates is still within the standard level