Structural characterization of functionalized gold nanoparticles for drug delivery in cancer therapy: a NMR based approach

In the present paper, we report results from a study of the structure and physicochemical properties of gold nanoparticles modified with poly(ethylene glycol) (PEG) designed for the drug delivery of the proteasome inhibitor Bortezomib (BTZ) in cancer therapy. A number of advanced analytical techniques were used to define important physicochemical characteristics such as composition, structure, surface properties, particle size and morphology. A new approach based on detailed NMR studies was employed to define specific intermolecular interactions and mechanisms of drug immobilization and location into surface modified gold nanoparticles (AuNPs). Particularly important information was gained from analysis of NMR spectroscopic parameters such as the spectral line shape, translation diffusion, the nuclear Overhauser effect (NOE) and spin-lattice relaxation (T-1). The results confirmed the coexistence of two different types of BTZ inclusion into polyethylene glycol coated gold nanoparticles: (i) association with the polymer chains by weak H-bonds and/or dipole-charge interactions and (ii) adsorption on the surface of the gold nanoparticles. The results allowed for determination of the overall structure of Bortezomib loaded PEG coated AuNPs, which is related to the therapeutic drug efficacy and activity in the treatment of cancer

Factorial design as a tool for the optimization of plga nanoparticles for the co-delivery of temozolomide and o6-benzylguanine

Poly(D,L-lactic-co-glycolic) (PLGA) nanoparticles (NPs) have been widely studied for several applications due to their advantageous properties, such as biocompatibility and biodegradability. Therefore, these nanocarriers could be a suitable approach for glioblastoma multiforme (GBM) therapy. The treatment of this type of tumours remains a challenge due to intrinsic resistance mechanisms. Thus, new approaches must be envisaged to target GBM tumour cells potentially providing an efficient treatment. Co-delivery of temozolomide (TMZ) and O6-benzylguanine (O6BG), an inhibitor of DNA repair, could provide good therapeutic outcomes. In this work, a fractional factorial design (FFD) was employed to produce an optimal PLGA-based nanoformulation for the co-loading of both molecules, using a reduced number of observations. The developed NPs exhibited optimal physicochemical properties for brain delivery (dimensions below 200 nm and negative zeta potential), high encapsulation efficiencies (EE) for both drugs, and showed a sustained drug release for several days. Therefore, the use of an FFD allowed for the development of a nanoformulation with optimal properties for the co-delivery of TMZ and O6BG to the brain

Molecular interactions between Vitamin B12 and membrane models: A biophysical study for new insights into the bioavailability of Vitamin

Vitamin B12 (VB12) deficiency is one of the most common malnutrition problems worldwide and is related to its poor bioavailability. The lipid composition of cell membranes and molecule-cell membrane lipid interactions are major factors affecting the bioavailability of nutrients. So, the study of these interactions may allow predicting the behavior of VB12 at cellular membranes and the effects on its activity. Thus, lipid vesicles with lipid composition similar to the majority of eukaryotic cell membranes were used as biomembrane models, and their interactions with VB12 molecules were evaluated. For that, different parameters were assessed such as the lipophilicity of VB12, its preferential location in the membrane and its effect on the physical properties of the bilayer. VB12 showed high affinity for the biological membranes, not inducing any biophysical changes in their properties. The interactions of VB12 with the membrane was affected by the complexity of the bilayer, since its increase in order and rigidity hinders the diffusion of molecules. Thus, the low bioavailability of VB12 is not related with its interactions with the biological membranes. (c) 2020 Elsevier B.V

A atuação do assistente social em uma unidade pública de saúde (Policlínica) no município de Miracema do Tocantins

The present work aims to understand the performance of social service in a public health unit in the municipality of Miracema do Tocantins. It seeks to identify the actions developed by the social service professional in health; Verify the relationship of the social worker in the public health unit with the multidisciplinary team and know the demands for the social worker in the health unit studied here. The research problem was guided by the following questions: What has been the conception of work assumed by the social worker in the focus unit of the study? What is the role of the social worker in face of the reality of health in force in the mentioned unit? The research is qualitative-quantitative. Among the procedures adopted, a bibliographic survey was carried out to identify the existing studies and a better understanding of the subject. Finally, field research was carried out in the mentioned public health unit with the purpose of understanding the performance of the social service in the public health unit. A questionnaire containing questions related to the way the social worker worked in a public health unit was used. The questionnaire was sent to the social worker of the public health unit. The research revealed that, although there may be health problems, the work of the social service professional should be in the perspective of enabling the users to know their rights and to commit and become involved in the surveillance, Organize themselves, claim improvements, can propose and decide through the instruments of participation.O presente trabalho objetiva compreender, a atuação do serviço social em uma unidade pública de saúde no município de Miracema do Tocantins. Busca identificar as ações desenvolvidas pelo profissional de serviço social na saúde; verificar a relação do assistente social na unidade pública de saúde junto à equipe multidisciplinar e conhecer as demandas destinadas para o assistente social na unidade de saúde aqui estudada. A problemática da investigação norteou-se pelas seguintes questões: Qual tem sido a concepção de trabalho assumida pelo assistente social na unidade foco do estudo? Qual o papel do assistente social diante da realidade de saúde vigente na unidade citada? A pesquisa tem caráter quali-quantitativo. Dentre os procedimentos adotados foi realizado um levantamento bibliográfico para identificação dos estudos já existentes e melhor compreensão da temática. Por fim, foi feita a pesquisa de campo na referida unidade pública de saúde com o propósito de compreender a atuação do serviço social na unidade pública de saúde. Foi utilizado um questionário contendo questões relacionadas à forma de trabalho do assistente social em uma unidade pública de saúde. O questionário destinou-se à assistente social da unidade pública de saúde. A pesquisa revelou que, muito embora possa haver problemas voltados para a área da saúde, o trabalho do profissional de serviço social deve estar na perspectiva de possibilitar que os usúarios conheçam os seus direitos e se compromeam e se envolvam na fiscalização, acompanhamento do atendimento, se organizem, reivindique melhorias, possam propor e decidir através dos intrumentos de participação

The Expanded Cognitive Task Load Index (NASA-TLX) applied to Team Decision-Making in Emergency Preparedness Simulation

The study demonstrates the use of the expanded TLX instrument (Helton, Funke & Knott, 2014) for cognitive and team-related workload self-assessment of 38 participants, solving the UNISDR – ONU stop disasters game simulation. Subjectsin one group (GF; n=30) performed group decision-making without prior individual practice on the simulation. A subset of GF participants (n=6) subsequently reiterated the simulation alone, reassessing their cognitive workload. Another group (IF; n=8) individually performed the simulation and reiterated it in groups. Most GFparticipants, moving from group to singly conditions, reported decreasing physicaland temporal demands, unchanged self-assessed performance, and increased mentaldemands, effort and frustration. IF participants incurred increasing mental, physical and temporal demands, as well as increased effort, with decreasing frustration and better performance, from singly to group conditions. Team workload results differed across groups; GF had higher levels of reported team dissatisfaction, equivalent assessments of team support and lower assessments of coordination and communication demands coupled with decreased time sharing as well as lower team effectiveness, compared to IF. Results bear implications on training of decision-making teams; singly training team members preceding group training supportsteam-decision making effectiveness and individual performance within teams goingthrough first stages of a system learning curve.info:eu-repo/semantics/publishedVersio

BSA-PEG Hydrogel: A Novel Protein-Ligand Binding 3D Matrix

Hydrogel materials have good biomimetic properties and high potential for biomedical and bioanalytical applications. In this work, a hydrogel of serum albumin crosslinked with poly-(ethylene glycol) was prepared and characterized for its water content, protein structure and stability. The ability of the hydrogel to bind small molecule ligands with different hydrophobicity was evaluated using a homologous series of amphiphiles (NBD-Cn, n = 4, 6 and 8) and the calculated binding affinities were similar to that of free protein in solution. Overall, the results indicate this type of hydrogel system as a convenient tool for studying the binding of xenobiotics to tissue proteins.info:eu-repo/semantics/publishedVersio

Water use, transpiration and crop coefficients for irrigated hedgerow olives grown in Southern Portugal

Olive trees are well adapted to the Mediterranean-type agro-ecosystems of southern Portugal and have traditionally been cultivated in areas with no irrigation. According to the 2009 agricultural census, the olive tree cultivation area was around 336,000 ha, of which 164,000 ha are in the southern province of Alentejo. In this southern region of semi arid Mediterranean climate where the erratic annual precipitation of around 300 to 550 mm is not enough to fulfil crop water requirements when needed, summer irrigation is a necessity to prevent crop water stress and ensure profitable yields. Hundreds of high and also very high tree-density hedgerow orchards of the Spanish cultivar Arbequina have recently been established in the region to take advantage of the European Commission decision 2000/406/CE (Official Journal L 154, 27/06/2000 P. 0033-0033) that allowed the expansion of Portuguese olive tree planting quota to 30,000 ha of new orchards. With enhanced olive production and yield depending on irrigation water supply and management, estimating hedgerow olive orchard water uptake in southern Portugal and appropriately scheduling irrigation have since been the primary concern of researchers, farmers and water resources managers. The objective of this study was to establish relationships between olive transpiration and crop transpiration coefficients of very high tree-density hedgerow orchard grown in Alentejo under well-irrigated treatment A (3.05 mm d-1) and sustained deficit irrigation treatment B (2.12 mm d-1) regimes, to understand and improve their irrigation management. On both treatments, daily transpiration at the stand scale (mm day-1) was obtained by sap flow and by dividing the tree transpiration by the area of the planting pattern. The results were compared to the daily outputs obtained with the Penman-Monteith “big leaf” equation coupled with the Orgaz et al. (2007) specific model of bulk daily canopy conductance (Gc) for unstressed olive canopies. With the Willmott index of agreement IA and the root-mean-square error RMSE above 0.8 and below 0.4 mm d-1, respectively (Willmott, 1982), the synthetic model proved sufficiently precise to be used as an appropriate simulation tool for predicting olive stand transpiration for the region. Crop and stress transpiration coefficients were proposed for both treatments