Three-Dimensional Printing of Graphene Oxide/Poly-L-Lactic Acid Scaffolds Using Fischer-Koch Modeling

Accurately printing customizable scaffolds is a challenging task because of the complexity of bone tissue composition, organization, and mechanical behavior. Graphene oxide (GO) and poly-L-lactic acid (PLLA) have drawn attention in the field of bone regeneration. However, as far as we know, the Fischer-Koch model of the GO/PLLA association for three-dimensional (3D) printing was not previously reported. This study characterizes the properties of GO/PLLA-printed scaffolds in order to achieve reproducibility of the trabecula, from virtual planning to the printed piece, as well as its response to a cell viability assay. Fourier-transform infrared and Raman spectroscopy were performed to evaluate the physicochemical properties of the nanocomposites. Cellular adhesion, proliferation, and growth on the nanocomposites were evaluated using scanning electron microscopy. Cell viability tests revealed no significant differences among different trabeculae and cell types, indicating that these nanocomposites were not cytotoxic. The Fischer Koch modeling yielded satisfactory results and can thus be used in studies directed at diverse medical applications, including bone tissue engineering and implants.

Genotype × environment interaction for long-yearling weight in Canchim cattle quantified by reaction norm analysis

The objective of this study was to investigate the presence of genotype × environment interactions (G×E) for long-yearling weight in Canchim cattle (5/8 Charolais + 3/8 zebu) in Brazil using reaction norms (RN). The hierarchical RN model included the fixed effect of age of the animal (linear coefficient) and random effects of contemporary groups and additive animal genetic intercept and slope of the RN and contemporary group effects as random effects. Contemporary groups as the most elemental representation of management conditions in beef cattle were chosen to represent the environmental covariate of the RN. The deviance information criteria demonstrated that a homoskedastic residual RN model provided a better data fit compared with a heteroskedastic counterpart and with a traditional animal model, which had the worst fit. The environmental gradient for long-yearling weight based on contemporary group effects ranged from -105 to 150 kg. The additive direct variance and heritability estimates increased with increasing environmental gradient from 74.33 ± 22.32 to 1,922.59 ± 258.99 kg(2) and from 0.08 ± 0.02 to 0.68 ± 0.03, respectively. The high genetic correlation (0.90 ± 0.03) between the intercept and the slope of the RN shows that animals with the greatest breeding values best responded to environmental improvement, characterizing scale effect as the source of G×E for long-yearling weight. The phenotypic plasticity demonstrated by the slope of the RN of the animal indicates the possibility to change genotype expression along the environmental gradient through selection. The results demonstrate the importance of accounting for G×E in the genetic evaluation of this population.

Appearances of paranasal fungal sinusitis on computed tomography

The primary invasive granulomatous form of fungal sinusitis, due to inhalation of aspergillus spores, is commonest in the Sudan and the Gulf states. This condition often presents clinically as a chronic, severe sinusitis which has not responded to antibiotics. On CT scanning, the major feature is a soft tissue mass, which is either homogeneous or has lower attenuation components. There may be erosion or expansion of the bony margins of the sinuses. Intraorbital and/or intracranial extension sometimes occur.

Degenerative changes and detection of plasminogen in fetal membranes that rupture prematurely

Amniochorion obtained at caesarean section and vaginal delivery, at 34-36 weeks gestation and at term, have been studied by electron microscopy and immunofluorescence for evidence of amniotic epithelial degenerative changes and the presence of plasminogen. When delivery was by caesarean section between 34-36 weeks, electron microscopy revealed no degenerative changes in four cases, but in two cases they were widespread. All but one membrane obtained at term showed only minimal amniotic epithelial cell degenerative changes, but extensive change was seen when delivery was premature after premature membrane rupture. Plasminogen was seen in amniotic epithelium proportional to the degree of cell degeneration; it was absent from healthy membranes. These findings demonstrate that degenerative changes are extensively present in membranes that rupture prematurely, particularly before the onset of premature labour, and suggest a role for plasminogen in membrane rupture.