Publications

Abstract <jats:title>Abstract</jats:title> <jats:p>In Portugal, open consultations (OCs) in primary health care address urgent medical needs, constituting 40–50% of family doctor activity. Frequent attenders (FAs), often presenting nonacute issues, significantly contribute to health care overuse. This study aimed to identify factors associated with frequent OC use in a primary health care unit during 2022. A retrospective cross-sectional analysis was conducted on 4,269 adult patients, with frequent attendance defined as four or more consultations (≥90th percentile). Sociodemographic and clinical factors, including age, sex, employment, chronic conditions, and multimorbidity, were examined using binomial logistic regression. FAs (n = 570, 13.4%) accounted for 36.2% of all consultations. Significant associated variables included female sex (OR = 1.417), economic insufficiency (OR = 1.323), and multimorbidity (OR = 1.678). Conditions such as musculoskeletal (OR = 2.146), psychological (OR = 2.040), and neurological (OR = 1.550) disorders were strongly linked to frequent attendance. While FAs represent a minority of patients, their disproportionate use of OC services underscores the need for targeted interventions, such as individualized care plans and resource optimization, to balance demand and availability. These findings highlight critical areas for policy and practice to enhance health care efficiency.</jats:p>

Abstract The thermal behaviour of bathophenanthroline and bathocuproine has been studied using several techniques, namely, differential scanning calorimetry and thermogravimetry. To determine their respective enthalpies of sublimation, vapor pressure measurements were carried out using different methods, such as Knudsen effusion mass loss/mass spectrometry, isothermal thermogravimetry, and a quartz crystal microbalance technique. Furthermore, the enthalpies of sublimation were determined by measuring the heat change of the sublimation process using high-temperature Calvet microcalorimetry. The results obtained in this work allowed the determination of the standard molar enthalpies of sublimation at 298.15 K, for bathophenanthroline and bathocuproine. The values obtained were (183.8 +/- 2.2) kJ & sdot;mol- 1 and (206.2 +/- 2.8) kJ & sdot;mol- 1, respectively. Additionally, the standard molar enthalpies of fusion were determined to be (30.4 +/- 0.4) kJ & sdot;mol- 1 and (26.5 +/- 1.6) kJ & sdot;mol- 1 for bathophenanthroline and bathocuproine, respectively. The analysis of the results allows a deeper understanding of the phase transition behavior for these compounds from the condensed to the gaseous phases, elucidating molecular decomposition and the inherent intermolecular forces governing the species.

Abstract This study presents the first investigation of the sublimation behavior of tin tetraiodide, SnI4, 4 , using effusion- based techniques, within a low temperature range (313-340) K. The temperature range covered in the experiments was lower than in previously reported studies based on static methods. Knudsen Effusion Mass Loss (KEML) measurements were performed in the range of (317.1-339.6) K using effusion cells with different orifice sizes. The vapor pressures were measured in the range (0.13-1.13) Pa and were found to be independent of the orifice size. The standard molar enthalpy and Gibbs energy of sublimation at 298.15 K obtained by the Clarke and Glew fit of experimental data are (88.1 +/- 0.9) kJ & sdot;mol-1 & sdot; mol- 1 and (38.96 +/- 0.08) kJ & sdot;mol-1, & sdot; mol- 1 , respectively. Knudsen Effusion Mass Spectrometry (KEMS) experiments were also performed in the range (313.3-331.7) K, resulting in a sublimation enthalpy value in good agreement with the KEML values and not negligibly higher vapor pressure values. KEMS vapor pressure data were also analyzed by the third-law method. A comparison of our experimental results with the literature data available for both sublimation and evaporation properties of SnI4 4 is reported. Additionally, ancillary DFT and ab initio calculations were performed to estimate the molecular properties of SnI4(g) 4 (g) and the extent of the gas-phase dissociation to SnI2 2 and I2. 2 .

Abstract Combined experimental and computational studies were performed aiming the analysis of energetic properties vs structural characteristics of three methyl nitrobenzoate isomers (methyl 2-nitrobenzoate, M2NB, methyl 3-nitro benzoate, M3NB, methyl 4-nitrobenzoate, M4NB). The experimental studies include the determination of the enthalpy of formation in the condensed state (crystal and liquid) of the compounds by static combustion, and the determination of enthalpies of phase transition, using Differential Scanning Calorimetry, high temperature Calvet microcalorimetry and the Knudsen effusion method. These data were combined to derive the enthalpy of formation of the methyl nitrobenzoate isomers in the gaseous phase, at T = 298.15 K. At the computational level, the gas-phase enthalpy of formation of the methyl nitrobenzoate isomers were estimated using theoretical approaches, resorting to the G3(MP2)//B3LYP composite method and to appropriate hypothetical gas-phase reactions. The enthalpies of formation obtained experimental and computationally will be discussed and the energetic structural synergies for the three methyl nitrobenzoate, along with other analogous isomers, will be also analyzed.

Abstract The thermochemical study of the 1,3-bis(N-carbazolyl)benzene (NCB) and 1,4-bis(diphenylamino)benzene (DAB) involved the combination of combustion calorimetric (CC) and thermogravimetric techniques. The molar heat capacities over the temperature range of (274.15 to 332.15) K, as well as the melting temperatures and enthalpies of fusion were measured for both compounds by differential scanning calorimetry (DSC). The standard molar enthalpies of formation in the crystalline phase were calculated from the values of combustion energy, which in turn were measured using a semi-micro combustion calorimeter. From the thermogravimetric analysis (TGA), the rate of mass loss as a function of the temperature was measured, which was then correlated with Langmuir's equation to derive the vaporization enthalpies for both compounds. From the combination of experimental thermodynamic parameters, it was possible to derive the enthalpy of formation in the gaseous state of each of the title compounds. This parameter was also estimated from computational studies using the G3MP2B3 composite method. To prove the identity of the compounds, the H-1 and C-13 spectra were determined by nuclear magnetic resonance (NMR), and the Raman spectra of the study compounds of this work were obtained.

Abstract The gas-phase enthalpies of formation of two fragrance compounds, methyl anthranilate and butyl anthranilate, at T = 298.15 K, were determined from the combination of the corresponding enthalpies of vaporisation and energies of combustion, obtained from Calvet microcalorimetry and combustion calorimetry measurements, respectively. Additionally, theoretical calculations were performed, using the G3(MP2)//B3LYP composite method, to estimate the gas-phase enthalpies of formation of the two fragrance compounds. The good agreement between the experimental and computational gas-phase enthalpies of formation of the methyl anthranilate and butyl anthranilate, provided the confidence for extending the theoretical study to propyl anthranilate. Furthermore, the results were interpreted in terms of enthalpic increments, aiming to evaluate and understand the energetic effect inherent to the alkyl group (methyl, ethyl, propyl or butyl) present in the ester functional group of the anthranilate derivatives. (c) 2021 Elsevier Ltd.

Abstract Recent density-functional theory (DFT) calculations raised the possibility that diamond could be degenerate with graphite at very low temperatures. Through high-accuracy calorimetric experiments closing gaps in available data, we reinvestigate the relative thermodynamic stability of diamond and graphite. For T400 K, graphite is always more stable than diamond at ambient pressure. At low temperatures, the stability is enthalpically driven, and entropy terms add to the stability at higher temperatures. We also carried out DFT calculations: B86bPBE-25X-XDM//B86bPBE-XDM and PBE0-XDM//PBE-XDM results overlap with the experimental -T Delta S results and bracket the experimental values of Delta H and Delta G, displaced by only about 2x the experimental uncertainty. Revised values of the standard thermodynamic functions for diamond are Delta H-f(o)=-2150 +/- 150 J mol(-1), Delta S-f(o)=3.44 +/- 0.03 J K-1 mol(-1) and Delta(f)G(o)=-3170 +/- 150 J mol(-1).

Abstract In the present work, a detailed thermochemical, experimental and theoretical, study of benzocaine is presented. The enthalpy of formation in crystalline state at T = 298.15 K was obtained from combustion calorimetry experiments [Δ<inf>f</inf>H<inf>m</inf>^°cr=-415.2±1.7kJ∙mol^-1], within an oxygen atmosphere, using a static bomb calorimeter. The phase transition enthalpies (fusion, vaporization, and sublimation) were obtained by different techniques, namely differential scanning calorimetry, Calvet microcalorimetry, thermogravimetry, and the Knudsen effusion method. The results obtained by the different techniques are as follows: Δ<inf>cr</inf>^lH<inf>m</inf>^°298.15 K=21.4±0.1 kJ⋅mol⁻¹; Δ<inf>l</inf>^gH<inf>m</inf>^°298.15 K=84.9±1.0 kJ⋅mol⁻¹; Δ<inf>cr</inf>^gH<inf>m</inf>^°298.15 K=106.8±0.4 kJ⋅mol⁻¹. From the experimental results, the enthalpy of formation of the aforesaid compound, in the gas phase, was calculated at T = 298.15 K as: Δ<inf>f</inf>H<inf>m</inf>^°g=-308.4±1.8kJ∙mol^-1. Theoretical enthalpies were computed using the Gaussian G4 composite method, atomization reactions, and the weighted Boltzmann average method. For the latter, the conformational diversity of the molecular structure of the compound was considered. Using the above data and using a similar approach, the theoretical entropy of benzocaine was computed as well. The experimental and theoretical values obtained were compared and an excellent accordance was found. Using the experimental and theoretical results, Gibbs energy of formation in crystalline and gaseous states of benzocaine, at T = 298.15 K were calculated as: Δ<inf>f</inf>G<inf>m</inf>^°cr=-164.4kJ∙mol^-1 and Δ<inf>f</inf>G<inf>m</inf>^°g=-123.9kJ∙mol^-1, respectively. Finally, the results obtained from the enthalpies of phase change are compared with those previously reported in the literature, in order to propose an exact value for these properties.

Abstract The energy involved in the structural switching of acyl and hydroxyl substituents in the title compounds was evaluated combining experimental and computational studies. Combustion calorimetry and Knudsen effusion techniques were used to determine the enthalpies of formation, in the crystalline state, and of sublimation, respectively. The gas-phase enthalpy of formation of both isomers was derived combining these two experimental data. Concerning the computational study, the G3(MP2)//B3LYP composite method was used to optimize and determine the energy of the isomers in the gaseous state. From a set of hypothetical reactions it has been possible to estimate the gas-phase enthalpy of formation of the title compounds. The good agreement between the experimental and computational gas-phase enthalpies of formation of the 1-acetyl-2-naphthol and 2-acetyl-1-naphthol isomers, provided the confidence for extending the computational study to the 2-acetyl-3-naphthol isomer. The structural rearrangement of the substituents in position 1 and 2 in the naphthalene ring and the energy of the intramolecular hydrogen bond are the factors responsible for the energetic differences exhibited by the isomers. The gas phase tautomeric keto <-> enol equilibria of theo-acetylnaphthol isomers were analyzed using the Boltzmann's distribution.