Cell wall disturbance is an important step in the downstream process of improving the efficiency of lipid extraction from microalgae. Surfactants have been proven to be efficient alternatives to organic solvents in the extraction process. In this study, an effective approach involving deep eutectic solvent (DES) (choline chloride and carboxylic acids) treatment supplemented with surfactants has been developed to disrupt the cell walls of microalgae and increase the extraction of lipids suitable for biodiesel production. A combination of polar and non-polar solvents (ethyl acetate and n-butanol) was used for the lipid extraction process. Microalgae biomass pretreated with choline chloride malonic acid supplemented with the surfactant hexadecyl trimethylammonium chloride (HTAC) showed the best results, improving lipid extraction by 12.365%. Further elucidation of the detailed mechanism behind the cell disruption of the microalga wall by DES was achieved using density functional theory (DFT) methods. The DFT calculations revealed that hydrogen bonds between the chloride ion of the DES and hydrogen bond donor (HBD) molecules are key factors dominating the destruction of the cell wall structure of Chlorella pyrenoidosa. The optimization of lipid extraction was performed through a single-factor experiment, which included the effects of different variables (time, temperature, dosage of surfactant, and ratio of n-butanol to ethyl acetate). An extraction period of 60 min at 80 °C with a surfactant concentration of 0.5% at a 1:2 ratio of n-butanol to ethyl acetate was found to produce the maximum lipid yield (16.97%). Transesterification reactions were used to obtain fatty acid methyl esters from the optimized extracted lipids. Thus, it was determined that C16:0 (20.04%), C18:2 (29.95%), and C18:3 (21.21%) were the most prevalent fatty acids. The potential for producing biodiesel from C. pyrenoidosa was validated by the high yields of C18 fatty acid methyl esters, and the properties of biodiesel are within the European and US standards.

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Background: The majority of pregnancies and births proceed without complications. However, all pregnancies present risks of complications that could endanger the maternal prognosis. One of the most serious of these complications is the bleeding during delivery. It’s often unpredictable nature, when it occurs, involves an urgent obstetric situation which requires early diagnosis and rapid and effective follow-up. The general objective of this study was to assess the impact of the introduction of the active follow-up care of the third phase of childbirth in the prevention of bleeding during delivery with our place of study, the obstetrical gynecology department of Kindia regional hospital (Konacri Guinea), with the aim of optimizing the follow-up care of pregnant women during their childbirth. Methodology: We carried out a case-control study with both retrospective and prospective data collection on the records of participants with cases of hemorrhage during delivery in the gynecology department of the Kindia regional hospital. Retrospective data collection covered a period of 25 months before the active follow-up care of the third stage of childbirth and concerned the control group of study participants, while the one of prospective data covered a period of 19 months after the introduction of the active follow-up care of the third stage of childbirth from the 1st January 2019 to 30th September 2020 and concerned the cases group. The criteria for matching these two groups of study participants were the diagnosis and the follow-up of the delivery hemorrhage. Results: During our study period in the gynecology department of the Kindia regional hospital, we identified 223 cases of delivery hemorrhage out of 2198 deliveries before the period of introduction of the active follow-up care of the third stage. This represents an incidence of 10.14%, compared to 73 cases of delivery hemorrhage out of 2714 deliveries during the period of the active follow-up care of the third stage. For an incidence of 2.68%. We found that the hemorrhages during delivery did not spare any age group and were observed for all parities. There were common reasons for admission before and after the integration of the active follow-up care of the third stage of childbirth namely vulvar hemorrhage and physical asthenia, which were reflected in the clinical picture of all cases bleeding from the issue. In addition, headaches, dizziness, and thirst were found, but in different proportions and significantly less frequent since the introduction of the active follow-up care of the third stage of childbirth. This sign were in this context the consequence of the state of shock with respective frequencies of 46.63% and 28.76% before and after the introduction of the active follow-up care of the third stage of childbirth and anemia was present in all cases of delivery hemorrhage. Conclusion: The introduction of active follow-up care of the third stage of childbirth has reduced the frequency of delivery hemorrhages and may therefore help to reduce maternal morbidity and mortality.

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