Stealth magnetoliposomes based on calcium-substituted magnesium ferrite nanoparticles for curcumin transport and release

Despite the promising pharmacological properties of curcumin, the transport and effective release of curcumin is still a challenge. The advances in functionalized nanocarriers for curcumin have also been motivated by the anticancer activity of this natural compound, aiming at targeted therapies. Here, stealth (aqueous and solid) magnetoliposomes containing calcium-substituted magnesium ferrite nanoparticles, CaxMg1−xFe2O4 (with x = 0.25, 0.50, 0.75) were developed as nanocarriers for curcumin. The magnetic nanoparticles exhibit superparamagnetic properties and crystalline structure, with sizes below 10 nm. The magnetoliposomes based on these nanoparticles have hydrodynamic diameters around or below 150 nm and a low polydispersity. The influence of an alternating magnetic field (AMF) on drug release over time was evaluated and compared with curcumin release by diffusion. The results suggest the potential of drug-loaded magnetoliposomes as nanocarriers that can be magnetically guided to the tumor sites and act as agents for a synergistic effect combining magnetic hyperthermia and controlled drug release.This research was funded by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CF-UM-UP (UID/FIS/04650/2019) and through the research project PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020), financed by European Fund of Regional Development (FEDER), COMPETE2020 and Portugal2020. The magnetic measurements were supported by projects UTAP-EXPL/NTec/0046/2017, NORTE-01-0145-FEDER-028538 and PTDC/FIS-MAC/29454/2017. The APC was also funded by FCT. B.D.C. acknowledges FCT for a PhD grant (SFRH/BD/141936/2018)

Novel magnetoliposomes based on shape-anisotropic nanoparticles for combined chemotherapy and magnetic hyperthermia

In this work, a new method for magnetoliposomes synthesis with improved and adequate structural, physicochemical and magnetic properties was developed. The overall results confirmed the development of a promising new method for the synthesis of cubic-shaped magnetic ferrite nanoparticles and a novel route for drug-loaded SMLs with improved features. The properties of these multifunctional nanosystems point to their future effective application in cancer therapy.Compete 2020, Portugal 2020, FEDER, PTDC/QUI-QFI/28020/2017, UIDB/04650/2020. SFRH/BD/141936/201

Magnetoliposomes based on shape anisotropic calcium/magnesium ferrite nanoparticles as nanocarriers for doxorubicin

Multifunctional lipid nanocarriers are a promising therapeutic approach for controlled drug release in cancer therapy. Combining the widely used liposome structure with magnetic nanoparticles in magnetoliposomes allies, the advantages of using liposomes include the possibility to magnetically guide, selectively accumulate, and magnetically control the release of drugs on target. The effectiveness of these nanosystems is intrinsically related to the individual characteristics of the two main components-lipid formulation and magnetic nanoparticles-and their physicochemical combination. Herein, shape-anisotropic calcium-substituted magnesium ferrite nanoparticles (Ca0.25Mg0.75Fe2O4) were prepared for the first time, improving the magnetic properties of spherical counterparts. The nanoparticles revealed a superparamagnetic behavior, high saturation magnetization (50.07 emu/g at 300 K), and a large heating capacity. Furthermore, a new method for the synthesis of solid magnetoliposomes (SMLs) was developed to enhance their magnetic response. The manufacturing technicalities were optimized with different lipid compositions (DPPC, DPPC/Ch, and DPPC/DSPE-PEG) originating nanosystems with optimal sizes for biomedical applications (around or below 150 nm) and low polydispersity index. The high encapsulation efficiency of doxorubicin in these magnetoliposomes was proven, as well as the ability of the drug-loaded nanosystems to interact with cell membrane models and release DOX by fusion. SMLs revealed to reduce doxorubicin interaction with human serum albumin, contributing to a prolonged bioavailability of the drug upon systemic administration. Finally, the drug release kinetic assays revealed a preferable DOX release at hyperthermia temperatures (42 °C) and acidic conditions (pH = 5.5), indicating them as promising controlled release nanocarriers by either internal (pH) and external (alternate magnetic field) stimuli in cancer therapy.This research was funded by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CF-UM-UP (UIDB/04650/2020) and through the research project PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020), co-financed by European Fund of Regional Development (FEDER), COMPETE2020 and Portugal2020. B.D.C. acknowledges FCT for a PhD grant (SFRH/BD/141936/2018)

Magnetoliposomes containing calcium ferrite nanoparticles for applications in breast cancer therapy

Magnetoliposomes containing calcium ferrite (CaFe2O4) nanoparticles were developed and characterized for the first time. CaFe2O4 nanoparticles were covered by a lipid bilayer or entrapped in liposomes forming, respectively, solid or aqueous magnetoliposomes as nanocarriers for new antitumor drugs. The magnetic nanoparticles were characterized by UV/Visible absorption, XRD, HR-TEM, and SQUID, exhibiting sizes of 5.2 ± 1.2 nm (from TEM) and a superparamagnetic behavior. The magnetoliposomes were characterized by DLS and TEM. The incorporation of two new potential antitumor drugs (thienopyridine derivatives) specifically active against breast cancer in these nanosystems was investigated by fluorescence emission and anisotropy. Aqueous magnetoliposomes, with hydrodynamic diameters around 130 nm, and solid magnetoliposomes with sizes of ca. 170 nm, interact with biomembranes by fusion and are able to transport the antitumor drugs with generally high encapsulation efficiencies (70%). These fully biocompatible drug-loaded magnetoliposomes can be promising as therapeutic agents in future applications of combined breast cancer therapy.This research was funded by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CF-UM-UP (UID/FIS/04650/2013; UID/FIS/04650/2019), CQUM (UID/QUI/00686/2016; UID/QUI/00686/2019) and LA-26 (PEst-C/SAU/LA0026/2013), and through the research project PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020), financed by FCT, European Fund of Regional Development (FEDER), COMPETE2020 and Portugal2020. The magnetic measurements were supported by projects UTAP-EXPL/NTec/0046/2017, NORTE-01-0145-FEDER-028538 e PTDC/FIS-MAC/29454/2017. The APC was also funded by FCT. B.D.C. acknowledges FCT for a PhD grant (SFRH/BD/141936/2018)

Estimating adjusted prevalence ratio in clustered cross-sectional epidemiological data

BACKGROUND: Many epidemiologic studies report the odds ratio as a measure of association for cross-sectional studies with common outcomes. In such cases, the prevalence ratios may not be inferred from the estimated odds ratios. This paper overviews the most commonly used procedures to obtain adjusted prevalence ratios and extends the discussion to the analysis of clustered cross-sectional studies. METHODS: Prevalence ratios(PR) were estimated using logistic models with random effects. Their 95% confidence intervals were obtained using delta method and clustered bootstrap. The performance of these approaches was evaluated through simulation studies. Using data from two studies with health-related outcomes in children, we discuss the interpretation of the measures of association and their implications. RESULTS: The results from data analysis highlighted major differences between estimated OR and PR. Results from simulation studies indicate an improved performance of delta method compared to bootstrap when there are small number of clusters. CONCLUSION: We recommend the use of logistic model with random effects for analysis of clustered data. The choice of method to estimate confidence intervals for PR (delta or bootstrap method) should be based on study design

Tradução de artigos científicos no domínio da medicina: especificidades

Relatório de Estágio apresentado ao Instituto Superior de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Tradução e Interpretação Especializada, sob orientação de Doutor Manuel Fernando Moreira da SilvaNeste relatório descreve-se o trabalho realizado no estágio realizado no Centro de Estudos Matex para conclusão do Mestrado em Tradução e Interpretação Especializada no Instituto Superior de Contabilidade e Administração do Porto. De forma a melhor sustentar este relatório de estágio é apresentada uma análise sobre algumas teorias de tradução e, na sequência dessa mesma análise, foi escolhido o modelo proposto por Daniel Gouadec como metodologia de trabalho. Posteriormente é feita uma breve análise sobre o texto científico, a tradução na área da medicina e, também sobre as características de um artigo científico. Foram ainda descritas as dificuldades mais comuns na tradução de textos médicos juntamente com uma breve análise sobre terminologia científica e médica. Após esta revisão teórica, seguiu-se a fase relativa ao processo tradutivo, onde foram seguidas as fases propostas pelo modelo de Gouadec, na elaboração da tradução dos artigos científicos. Os artigos inserem-se na área da tradução técnica, nomeadamente da medicina. O presente trabalho revelou-se importante quer na aquisição de conhecimentos quer na prática do que é a tradução freelance em ambiente empresarial. Através do mesmo foi possível ficar a conhecer de perto muitas das especificidades e dificuldades que se podem encontrar na tradução técnica.In this report it is described the work developed during the traineeship in Centro de Estudos Matex for the conclusion of the Masters degree in Translations and Specialized Interpretations in the Institute of Accounting and Administration of Porto (ISCAP). In order to sustain better the traineeship report it is presented an analysis of some translations theories and in the sequence of this analysis it was chosen Daniel Gouadecs work methodology. Then a brief analysis was made on scientific text, translation in the medical area and also on the characteristics of a scientific article. . It was also described the most common difficulties in translating medical texts and together with a brief analysis on scientific terminology and medical terminology. After this theorical revision it followed the phase related to the translation process and all the phases proposed by Gouadec were followed in the translation of the scientific articles. The articles translated are from the technical translation area, namely medicine. This work has revealed to be important in the acquisition of practice knowledge of freelance translation in the corporate world. It was also possible to know closely all the specificities and difficulties you can find in technical translation

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

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio