Evaluation of several flocculants for flocculating microalgae

Flocculation of microalgae with chitosan, polyacrylamide, Al2(SO4)3, NaOH and HNO3 was evaluated. Their flocculation efficiencies and optimal dosages were discussed. The effects of the flocculants on cells viability were also investigated and the cells were found to be intact during the flocculation process. Moreover, the effects of flocculants on the extractions were evaluated. Lipid content after flocculants treatments showed no significant differences. Carbohydrate content was lower but protein content was higher after NaOH treatment than those after other treatments. Furthermore, the five flocculated media maintained approximate growth yields to that of the fresh medium in microalgal cultivation, indicating the five flocculated media could be recycled, thereby reducing the cost of biodiesel production from microalgae. Finally, economic comparison of the flocculants was made and the cost of using HNO3, including flocculating cells and recycling medium, was found to be the lowest.

Perioperative venous thromboembolism in patients with gynecological malignancies: a lesson from four years of recent clinical experience

AIM

To analyze clinical characteristics of venous thromboembolisms (VTE) in gynecological malignancies, and to find a cost-effective prophylaxis procedure for post-operative VTE.

PATIENTS AND METHODS

We analyzed clinical characteristics of 751 patients who underwent definitive surgery for gynecologic malignancies, and cost-effectiveness of VTE prophylaxis.

RESULTS

VTE was diagnosed preoperatively in 4.5% of ovarian cancer cases, more frequently than any other type (p<0.005). Older age and greater length of operation were independent risk factors for postoperative VTE. To prevent eight VTEs in 738 malignant cases, which occurred during day 2 to 10, $617,783, $726,185, or $994,222 were necessary for continuous VTE prophylaxis, using either unfractionated heparin (UFH), low-molecular weight heparin or fondaparinux, respectively.

CONCLUSION

A strategy which might be cost-effective for post-surgical management of gynecological malignances is use of UFH three times combined with graduated compression stockings and intermittent pneumatic compression, thorough SpO2 monitoring, and perioperative measurements of the circumference of both sides of thighs and calves.