Development and Characterization of PBSA-Based Green Composites in 3D-Printing by Fused Deposition Modelling

Fused deposition modelling is a rapidly growing additive manufacturing technology due to its ability to build functional parts with complex geometries. The mechanical properties of a built part depend on several process parameters. The effect of wood content on the properties of 3D printed parts has been studied. Four types of filaments using poly(butylene succinate-co-adipate) (PBSA) with different reinforcement levels of Typha stem powder 0%, 5%, 10%, and 15% by weight were used for 3D printing. The density of the filaments and parts printed in this study increased with the Typha stem powder content. The thermal stability, mechanical performance, and viscoelastic properties of the different biocomposite filaments and 3D printed objects were analysed. The results show an increase in the crystallisation kinetics and a slight decrease in the thermal stability of the biomaterials. Compared to virgin PBSA FDM filaments, the PBSA biocomposite filament filled with Typha stem powder showed an increase in the tensile strength of the parts and specimens from 2.5 MPa to 8 MPa and in the modulus of elasticity from 160 MPa to 375 MPa, respectively, with additions of 5%, 10%, and 15% by mass. The addition of Typha stem fibres generated an increase in the elastic behaviour and relaxation time of the biomaterial structure, visualised by increases in the values of the viscosity components. The surface morphology reveals a decrease in the porosity of the printed samples.

[Prevention of mother to child HIV transmission in an African hospital, Bamako-Mali]

AIM

Pregnant women HIV infection has main risk the contamination of newborn. MTCT actions permit to reduce that risk.

MATERIAL AND METHODS

Our survey has been realized in Gabriel Touré teaching hospital gynecology and obstetrics and pediatric departments. It is about an observational prospective and descriptive survey that spreads on a period from January 2005 to December 2008. Has been included in the study all the HIV positive pregnant women followed in our service and their babies that had received ARV prophylaxis and 18 months of life serology.

RESULTS

We recorded 211 HIV positive pregnant women on a total of 9291 childbirths (2.27%). We noted 90.52% of HIV-1 vs 7.11% of type 2. The mother treatment consisted in a tri therapy in 77.25 vs 0.47% of bi anti retroviral and 22.28% of mono anti retro viral therapy. Maternal viral load was undetectable at the moment of delivery in 78.20% of cases. We noted vaginal delivery in 84.36% vs 15.64% of caesarean section. Newborns respectively received 67.32%; 4.88% and 22.92% of bi, tri and mono therapy. They formula-fed in 98.98%. The mother to child HIV transmission rate was 1.98%.

CONCLUSION

HIV prevalence in pregnant patients is relatively height. HARRT in HIV positive mothers associated to bi therapy and formula feeding to their infants permit to obtain low vertical HIV transmission rate.

[Fractionation of the total extract of Khaya senegalensis Barks. Value of the formulation of an anti-inflammatory ointment]

The aim of this work was to compare the anti-inflammatory activity of the total extract of Khaya senegalensis Barks and its different fractions for optimizing the active ingredients which be used in the ointment formulation. For that, a fractionation was performed followed by anti-inflammatory tests based on the method of the croton oil induced oedema. Three fractions were obtained and the comparison of their activity with the one of the total extract has shown the following results: 37.10%, 45.65%, 22.30% and 22.36% respectively for the extract, fraction n1, fraction n2 and fraction n3. The statistical analysis ofthe results (Student Test; p = 0.05) have revealed that the fraction nl is significatively more active than the others. However, there was not a significant difference between the inhibition induced by the fraction n1 and the total extact one, even the mean value of this latter is lower. Therefore, it seems enough to use the total extract as active ingredient for developing an anti-inflammatory ointment.

[Preparation of a syrup with Bakis roots (Tinospora bakis) and evaluation of its choleretic activity in rats]

The aim of this work was to prepare a pharmaceutical using the aqueous extract of bakis roots and to check if the choleretic activity of this latter was maintained in cholestatic rats. So, a sirup was prepared and tested. The obtained results had shown that the aqueous extract maintained its choleretic activity. Indeed, when it was used at a dose of about 7.5 mg/100 g of weight, the sirup induced a significant increase of bilary secretion in healthy rats and cholestatic rats, confirming the results observed with the aqueous extract. Therefore, futher investigations in order to improve the quality of the sirup can be considered before performing clinical trials.

[Inflammatory ointment from shea butter and hydro-alcoholic extract of Khaya senegalensis barks (Cailcederat)]

In a former study, it was proved that the alcoholic solution of hydro-alcoholic extract of Khaya senegalensis barks had an anti-inflammatory activity on animals after a local application. In this work, ointments made from the same extract and three different excipients (vaseline, lanoline and shea butter (crude and refined)) have been prepared and tested by the method of the croton oil inhibited ear oedema. Results showed inhibition percentages of the ear oedema of 58.8%, 66.7% and 75.4% when the hydro-alcoholic extract was tested at respective doses of 1%, 2% and 3% in shea butter. The two other excipients, (vaceline and Lanoline) tested at the dose of 3% showed between 52% and 58% of inhibitions. The interest of this study was to demonstrate the possibility to maintain the anti-inflammatory activity of Khaya senegalensis barks by using them in a galenic form, easy to prepare and which is, in addition, more adapted than the extract to possible clinical trials.