Structured Deformations of Continua: Theory and Applications

The scope of this contribution is to present an overview of the theory of structured deformations of continua, together with some applications. Structured deformations aim at being a unified theory in which elastic and plastic behaviours, as well as fractures and defects can be described in a single setting. Since its introduction in the scientific community of rational mechanicists (Del Piero-Owen, ARMA 1993), the theory has been put in the framework of variational calculus (Choksi-Fonseca, ARMA 1997), thus allowing for solution of problems via energy minimization. Some background, three problems and a discussion on future directions are presented.Comment: 11 pages, 1 figure, 1 diagram. Submitted to the Proceedings volume of the conference CoMFoS1

On the commutability of homogenization and linearization in finite elasticity

We study non-convex elastic energy functionals associated to (spatially) periodic, frame indifferent energy densities with a single non-degenerate energy well at SO(n). Under the assumption that the energy density admits a quadratic Taylor expansion at identity, we prove that the Gamma-limits associated to homogenization and linearization commute. Moreover, we show that the homogenized energy density, which is determined by a multi-cell homogenization formula, has a quadratic Taylor expansion with a quadratic term that is given by the homogenization of the quadratic term associated to the linearization of the initial energy density

Humic acids induce the expression of nitrate transporters in passion-fruit seedlings.

The management of organic fertilization in passion fruit has been carried out empirically based on the responses of the crops and the experience of farmers. Knowledge of the physiological responses of plants to organic fertilizers is essential to optimize fertilization programs. The objective of this study was to evaluate the differential expression of genes coding for nitrate transporters as well as plasma membrane H+-ATPase in passion fruit seedlings treated with different organic fertilizers in the presence or not of humic acids. The equivalent of one gram of total nitrogen dissolved in water from cattle manure, castor oil cake and urea were added and the seedlings were treated or not with a suspension of humic acids (2 mmol/L). Differential expression of low and high affinity nitrate transporters (PeNRT2.2 and PeNRT1.1 PeNRT2.2e) and H+-ATPase (PeMha) was performed by qRT-PCR. The use of cattle manure increased the differential expression of the high affinity transporter regarding to the control. The application of humic acids amplified the increase observed in the differential transcription of the high-affinity transporter with manure and urea fertilization, with no effect observed with the use of castor oil cake. Humic acids induced transcription of the gene encoding H+-ATPases in all treatments compared to control. The application of biofertilizer based on humic acids in low concentrations directly on the plant can be used with the objective of optimizing the organic fertilization of passion fruit with cattle manure and urea.Título em Português: Ácidos húmicos induzem a expressão dos transportadores de nitrato em mudas de maracujazeir

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

Pregnancy and Breastfeeding During COVID-19 Pandemic: A Systematic Review of Published Pregnancy Cases

Background: The COVID-19 pandemic is an emerging concern regarding the potential adverse effects during pregnancy. This study reviews knowledge on the impact of COVID-19 on pregnancy and describes the outcome of published cases of pregnant women diagnosed with COVID-19. Methods: Searches were conducted in PubMed®, Scopus®, Web of Science®, and MedRxiv® up to 26th June 2020, using PRISMA standards, to identify original published studies describing pregnant women at any gestational age diagnosed COVID-19. There were no date or language restrictions on the search. All identified studies were included irrespective of assumptions on study quality. Results: We identified 161 original studies reporting 3,985 cases of pregnant women with COVID-19 (1,007 discharged while pregnant). The 2,059 published cases with pregnancy outcomes resulted in 42 abortions, 21 stillbirths, and 2,015 live births. Preterm birth occurred in 23% of cases. Around 6% of pregnant women required admission to an intensive care unit and 28 died. There were 10 neonatal deaths. From the 163 cases with amniotic fluid, placenta, and/or cord blood analyzed for the SARS-CoV-2 virus, 10 were positive. Sixty-one newborns were positive for SARS-CoV-2. Four breast milk samples from 92 cases showed evidence of SARS-CoV-2. Conclusion: Emerging evidence suggests that vertical transmission is possible, however, there is still a limited number of reported cases with intrapartum samples. Information, counseling and adequate monitoring are essential to prevent and manage adverse effects of SARS-CoV-2 infection during pregnancy.This study was funded by national funding from the Foundation for Science and Technology - FCT, under the Unidade de Investigação em Epidemiologia - Instituto de Saúde Pública da Universidade do Porto (EPIUnit) (UIDB/04750/2020); the PhD Grant SFRH/BD/111794/2015 (CR) was co-funded by the FCT and the POCH/FSE Program