RESUMO
We investigated the melt-spinning potential of a poly(3-hydroxybutyrate)/poly(3-hydroxybutyrate-co-4-hydroxybutyrate) blend using a piston spinning machine with two different spinneret diameters (0.2 and 0.5 mm). Results from the differential scanning calorimetry, dynamic mechanical thermal analysis, and tensile testing showed distinct filament properties depending on the monofilaments' cross-sectional area. Finer filaments possessed different melting behaviors compared to the coarser filaments and the neat polymer, indicating the formation of a different type of polymer crystal. Additionally, the mechanical properties of the finer filament (tensile strength: 21.5 MPa and elongation at break: 341%) differed markedly from the coarser filament (tensile strength: 11.7 MPa, elongation at break: 12.3%). The hydrolytic stability of the filaments was evaluated for 7 weeks in a phosphate-buffered saline solution and showed a considerably reduced elongation at break of the thinner filaments. Overall, the results indicate considerable potential for further filament improvements to facilitate textile processing.
RESUMO
Pregnancy after cardiac transplantation poses immense challenges. Maternal risks include hypertensive disorders of pregnancy, rejection, and failure of the cardiac allograft that may lead to death. Fetal risks include potential teratogenic effects of immunosuppression and prematurity. Because of the high-risk nature of pregnancy in a heart transplant patient, management of reproductive health after cardiac transplantation should include preconception counseling to all women in the reproductive age group before and after cardiac transplantation. Reliable contraception is vital as nearly half of the pregnancies in this population are unintended. Despite the associated risks, successful pregnancies after cardiac transplantation have been reported. A multidisciplinary approach proposed in this review is essential for successful outcomes. A checklist for providers to guide management is provided.