Ligações de hidrogénio do tipo C-H...O em estruturas supramoleculares

Doutoramento em QuímicaNa presente dissertação foram estudadas ligações de hidrogénio em fase condensada, com especial destaque para as ligações de hidrogénio C-H…O, em sistemas simples e supramoleculares. Para atingir os objectivos propostos neste trabalho de investigação, foram utilizadas, de forma complementar, duas técnicas: a espectroscopia vibracional (de carácter experimental) e os cálculos ab initio (de carácter computacional). A espectroscopia vibracional permite detectar a associação de moléculas em fase condensada, enquanto que do ponto de vista computacional, os cálculos ab initio permitem obter informação referente aos mecanismos de associação envolvidos, nomeadamente no que respeita à possível estrutura de dímeros e compostos de inclusão em ciclodextrinas, energia da interacção e energia de inclusão. Adicionalmente, é apresentada uma nova metodologia PiMM – Pares em Materiais Moleculares – que permite não só uma atribuição completa do espectro vibracional, mas também a elucidação estrutural de alguns sistemas em estudo.In the present dissertation, the hydrogen bonds in the condensed phase, with special emphasis to the C-H…O hydrogen bonds, were studied in simple and supramolecular systems. In order to accomplish the final goals in this investigation, two techniques were used, in a complementary way: the vibrational spectroscopy (of experimental nature) and ab initio calculations (of computational nature). Vibrational spectroscopy allows the detection of molecular association in condensed phase, while from the computational pointof- view, the ab initio calculations provide information related with the involved association mechanisms, mainly in what concerns the possible structure of dimmers and inclusion compounds, the interaction energy and the inclusion energy. In addition, a new methodology PiMM – Pairs in Molecular Materials is presented, which allows a complete assignment of the vibrational spectra and also the structural elucidation of some systems in study

Identification of microplastics using Raman spectroscopy: latest developments and future prospects

Widespread microplastic pollution is raising growing concerns as to its detrimental effects upon living organisms. A realistic risk assessment must stand on representative data on the abundance, size distribution and chemical composition of microplastics. Raman microscopy is an indispensable tool for the analysis of very small microplastics (<20 μm). Still, its use is far from widespread, in part due to drawbacks such as long measurement time and proneness to spectral distortion induced by fluorescence. This review discusses each drawback followed by a showcase of interesting and easily available solutions that contribute to faster and better identification of microplastics using Raman spectroscopy. Among discussed topics are: enhanced signal quality with better detectors and spectrum processing; automated particle selection for faster Raman mapping; comprehensive reference libraries for successful spectral matching. A last section introduces non-conventional Raman techniques (non-linear Raman, hyperspectral imaging, standoff Raman) which permit more advanced applications such as real-time Raman detection and imaging of microplastics.publishe

What a difference a methyl group makes-probing choline-urea molecular interactions through urea structure modification

There is a lack of fundamental knowledge on deep eutectic solvents, even for the most extensively studied mixtures, such as the mixture of cholinium chloride and urea, which prevents a judicious choice of components to prepare new solvents. The objective of this work is to study and understand the fundamental interactions between cholinium chloride and urea that lead to the experimentally observed melting temperature depression. To do so, the structure of urea was strategically and progressively modified, in order to block certain interaction centres, and the solid–liquid equilibrium data of each new binary system was experimentally measured. Using this approach, it was concluded that the most important interaction between cholinium chloride and urea occurs through hydrogen bonding between the chloride anion and the amine groups. Any blockage of these groups severely hampers the melting point depression effect. Raman spectroscopy and DFT calculations were utilized to study in more detail this hydrogen bonding and its nuances.This work was developed in the scope of the project CICECO – Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (Ref. FCT UID/CTM/50011/2019) and Associate Laboratory LSRELCM, POCI-01-0145-FEDER-006984 (Ref. FCT UID/EQU/50020/2019), and project MultiBiorefinery (POCI-01-0145-FEDER-016403), all financed by national funds through the FCT/ MCTES (PIDDAC) and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. M. A. R. M. acknowledges financial support from NORTE-01-0145-FEDER-000006 – funded by NORTE2020 through PT2020 and ERDF. L. P. S. acknowledges FCT for her PhD grant (SFRH/BD/135976/2018). C. F. A. acknowledges FCT for her PhD grant (SFRH/BD/129040/2017). M. M. N. and M. M. F. acknowledge FCT for their researcher contracts (IF/01468/2015 and IF/00894/2015 respectively) under the program IF 2015.info:eu-repo/semantics/publishedVersio

Water in Deep Eutectic Solvents: New Insights From Inelastic Neutron Scattering Spectroscopy

The effect of water on the physicochemical properties of deep eutectic solvents (DES) is a trending research topic. In this work, inelastic neutron scattering (INS) spectroscopy, was used to probe intermolecular interactions in the water-deep eutectic solvent mixtures for the cases of choline chloride (the hydrogen bond acceptor) and three different hydrogen bond donors, with different degrees of acidity: urea, glycerol and lactic acid. It was found that quenching samples in liquid nitrogen is a procedure that may retain the liquid phase morphology of DES at the low temperatures required by INS spectroscopy. The three studied systems share the preference of water molecules to bind to chloride anion, as predicted by numerous molecular dynamics simulations. Despite this similarity, the three systems present several distinct INS features upon water addition that are related to their unique properties and structure at the molecular level. In the choline chloride:urea system, water molecules promote a strengthening of hydrogen bonds with the NH and OH donors, while for the choline chloride:lactic acid system INS probed the existence of solvated DES clusters instead of specifically interfering water molecules. This study takes advantage from the unique capabilities of INS and paves the way for future studies in these systems.publishe

Instrumentos de evaluación de necesidades en salud utilizados en la estrategia de Salud de la Familia

Este estudo, descritivo e exploratório, teve como objetivo geral conhecer os instrumentos utilizados para o reconhecimento das necessidades de saúde da população no âmbito da Estratégia de Saúde da Família. Abrangeu dois Distritos do Município de São Paulo. A base teórico-metodológica consistiu da Teoria de Intervenção Práxica de Enfermagem em Saúde Coletiva. Os dados foram coletados junto a unidades de saúde e equipes de saúde da família. Os resultados mostraram a inexistência de instrumentos específicos para o reconhecimento das necessidades em saúde da população. Discutem-se três contradições presentes no fenômeno estudado: a polaridade estrutural na conceituação de necessidade contida no SUS; o princípio da integralidade postulado pelo SUS e a possibilidade operacional das unidades de saúde e a antinomia teoria-prática no processo de trabalho das equipes da ESF. Conclui-se que é imperativo superar as contradições para redirecionar as políticas e as práticas rumo ao enfrentamento das necessidades em saúde.The main objective of this exploratory and descriptive study was to acknowledge the instruments used to assess health needs of the population in the Family Health Strategy. Two districts of Sao Paulo Municipality, Brazil, were taken as the scenario. The theoretical and methodological basis was the Theory of Praxical Intervention in Collective Health. Data were collected in Heath Care Units, with Family Health teams' members. The results showed the inexistence of specific instruments to assess health needs. The discussion addresses the three contractions identified: the structural polarity in the conceptualization of health needs in the Brazilian Unified Health Care System, the principle of integrality postulated by this System and the possibility of its implementation by the health care teams, and also the theory-practice antinomy in their labor process. The conclusion is that these contradictions must be overcome in order to redirect policies and practices towards health needs assessment.Estudio, descriptivo y exploratorio, cuyo objetivo general fue conocer los instrumentos utilizados para el reconocimiento de las necesidades de salud de la población en el ámbito de la ESF. Comprendió dos Distritos del Municipio de Sao Paulo. La base teórico-metodológica fue la Teoría de Intervención Práctica de Enfermería en Salud Colectiva. La recolección fue junto a las unidades y equipos de salud de la familia. Es evidente la inexistencia de instrumentos específicos para el reconocimiento de las necesidades en salud. Fueron discutidas tres contradicciones: la polaridad estructural al conceptuar las necesidades contenidas en el SUS; el principio de la integralidad postulado por el SUS, la posibilidad operacional de las unidades de salud y la antinomia teoría-práctica en el proceso de trabajo de los equipos de la ESF. Se concluye ser prioritario superar las contradicciones para redireccionar las políticas y las prácticas rumbo al enfrentamiento de las necesidades en salud.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

From PEF to PBF: what difference does the longer alkyl chain make a computational spectroscopy study of poly (butylene 2,5-furandicarboxylate)

This work explores the conformational preferences and the structureproperty correlations of poly(butylene 2,5-furandicarboxylate) (PBF), a longer chain analogue of the most well-known biobased polyester from the furan family, poly(ethylene 2,5-furandicarboxylate) (PEF). A thorough computational spectroscopic study–including infrared, Raman and inelastic neutron scattering spectroscopy, combined with discrete and periodic density functional theory calculations–allowed the identification of dominant structural motifs in the amorphous and crystalline regions. Discrete calculations and vibrational spectroscopy of semi-crystalline and amorphous samples strongly support the predominance of gauche, trans, gauche conformations of the butylene glycol fragment in both the crystalline and amorphous domains. In what concerns the furandicarboxylate fragment, amorphous domains are dominated by syn,syn conformations, while in the crystalline domains the anti,anti forms prevail. A possible crystalline structure–built from these conformational preferences and including a network of C-H···O hydrogen bond contacts—was optimized using periodic density functional theory. This proposed crystal structure avoids the unrealistic structural features of the previously proposed X-ray structure, provides an excellent description of the inelastic neutron scattering spectrum of the semi-crystalline form, and allows the correlation between microscopic structure and macroscopic properties of the polymer.publishe

Development and characterization of functional O/W emulsions with chia seed (<i>Salvia hispanica</i> L.) by-products

The present work investigated the physicochemical properties of O/W emulsions containing functional ingredients (oil with high x-3 fatty acid content, protein and/or soluble fiber) from chia seeds. The effect of different protein–carbohydrate combinations (sodium caseinate and lactose, sodium caseinate and maltodextrin, chia protein-rich fraction and maltodextrin) and the presence of chia mucilage (0 and 0.2 % wt/wt) in the aqueous phase of chia O/W emulsions was studied as a function of droplet size distribution, Sauter mean diameter, f-potential, rheological properties and backscattering profiles. The use of sodium caseinate in combination with lactose or maltodextrin produced chia O/W emulsions with small droplet size (0.22–0.27 lm), high degree of uniformity in droplet size distribution, negatively charged droplets (at pH 6.5), pseudoplastic behavior and high physical stability. Emulsions with chia protein-rich fraction presented wider droplet size distribution and higher D[3,2] values than the previous ones, recording a Newtonian behavior. The addition of chia mucilage affected the physicochemical properties studied, mainly the rheological characteristics of emulsions.Centro de Investigación y Desarrollo en Criotecnología de AlimentosCentro de Tecnología de Recursos Minerales y Cerámic

Reviewing health needs assessment approaches in the Family Health strategy

Este estudo, descritivo e exploratório, teve como objetivo geral conhecer os instrumentos utilizados para o reconhecimento das necessidades de saúde da população no âmbito da Estratégia de Saúde da Família. Abrangeu dois Distritos do Município de São Paulo. A base teórico-metodológica consistiu da Teoria de Intervenção Práxica de Enfermagem em Saúde Coletiva. Os dados foram coletados junto a unidades de saúde e equipes de saúde da família. Os resultados mostraram a inexistência de instrumentos específicos para o reconhecimento das necessidades em saúde da população. Discutem-se três contradições presentes no fenômeno estudado: a polaridade estrutural na conceituação de necessidade contida no SUS; o princípio da integralidade postulado pelo SUS e a possibilidade operacional das unidades de saúde e a antinomia teoria-prática no processo de trabalho das equipes da ESF. Conclui-se que é imperativo superar as contradições para redirecionar as políticas e as práticas rumo ao enfrentamento das necessidades em saúde.Estudio, descriptivo y exploratorio, cuyo objetivo general fue conocer los instrumentos utilizados para el reconocimiento de las necesidades de salud de la población en el ámbito de la ESF. Comprendió dos Distritos del Municipio de Sao Paulo. La base teórico-metodológica fue la Teoría de Intervención Práctica de Enfermería en Salud Colectiva. La recolección fue junto a las unidades y equipos de salud de la familia. Es evidente la inexistencia de instrumentos específicos para el reconocimiento de las necesidades en salud. Fueron discutidas tres contradicciones: la polaridad estructural al conceptuar las necesidades contenidas en el SUS; el principio de la integralidad postulado por el SUS, la posibilidad operacional de las unidades de salud y la antinomia teoría-práctica en el proceso de trabajo de los equipos de la ESF. Se concluye ser prioritario superar las contradicciones para redireccionar las políticas y las prácticas rumbo al enfrentamiento de las necesidades en salud.The main objective of this exploratory and descriptive study was to acknowledge the instruments used to assess health needs of the population in the Family Health Strategy. Two districts of Sao Paulo Municipality, Brazil, were taken as the scenario. The theoretical and methodological basis was the Theory of Praxical Intervention in Collective Health. Data were collected in Heath Care Units, with Family Health teams' members. The results showed the inexistence of specific instruments to assess health needs. The discussion addresses the three contractions identified: the structural polarity in the conceptualization of health needs in the Brazilian Unified Health Care System, the principle of integrality postulated by this System and the possibility of its implementation by the health care teams, and also the theory-practice antinomy in their labor process. The conclusion is that these contradictions must be overcome in order to redirect policies and practices towards health needs assessment

Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049