Upper storage-capacity limit and multiple occupancy phenomena in H2-hydroquinone clathrates using Monte Carlo and DFT simulations.

The upper hydrogen-storage capacity limit of the ß-hydroquinone clathrate has been investigated using hybrid Grand-Canonical Monte Carlo/Molecular Dynamics simulations, for temperatures ranging from 77 K to 300 K. The evolution with pressure of the cage occupancies has been monitored in detail, describing the progressive nature of the uptake process. It is found that the storage capacity of the pure ß-HQ + H2 clathrate could reach 0.6 wt% (weight percentage) only for pressures above 1400 bar, at ambient temperature. The enhancement of the storage capacities by the multiple occupancy phenomenom was accordingly shown to be very limited by the need for extreme conditions. Following this observation, an unmodified version of the van der Waals & Platteeuw theory was applied allowing for the prediction of experimentally accessible formation pressures. Density functional theory calculations were addittionnaly performed to comprehensively characterize the hydrogen diffusion process within the clathrate crystalline structure, considering different occupancy scenarios.

S100A12 protein as a porcine health status biomarker when quantified in saliva samples.

The S100A12 protein was validated as a biomarker of health status in porcine saliva samples using a semi-quantitative approach based on Western blotting in four healthy and sixteen diseased animals, and in four animals with severe respiratory disease during three days of antibiotic therapy. Afterwards, a non-competitive sandwich immunoassay was then developed, validated, and used to quantify S100A12 in clinical porcine samples, using 14 healthy and 25 diseased pigs. Finally, the S100A12 concentrations in the saliva of ten pigs with respiratory disease were monitored during antibiotic therapy. Diseased animals showed higher concentrations of S100A12 than healthy animals, and the high concentrations of S100A12 in pigs with respiratory distress were reduced after antimicrobial therapy. The assay developed showed good precision and accuracy, as well as a low limit of detection of 3.19 ng/mL. It was possible to store saliva samples at -20 °C, or even at 4 °C, for two weeks before analysis without losing the validity of the results. The concentrations of S100A12 observed in serum and saliva samples showed a moderately positive association with a correlation coefficient of 0.48. The concentrations of the new validated biomarker S100A12 are highly associated with the novel salivary biomarker of inflammation, adenosine deaminase, and moderately to highly associated with the total oxidant status. The results reported in this study provide a new way of evaluating inflammatory diseases in pigs using saliva samples, which should be further explored for disease prevention and monitoring in the field.

Influence of the circadian cycle, sex and production stage on the reference values of parameters related to stress and pathology in porcine saliva.

BACKGROUND: The concentration of biomarkers in saliva could be influenced by several factors not related to the specific condition under analyses, which should be considered for proper clinical interpretation. In the present study, the circadian rhythm of C-reactive protein (CRP), haptoglobin (Hp), Pig-MAP, S100A12, Cu, Zn, Adenosine deaminase (ADA), total protein (TP), total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), cortisol and α-amylase in saliva of 20 female and 20 male pigs was investigated. Moreover, the influence of sex and production phase (post-weaning, fattening and finishing) on the concentrations of biomarkers in a total of 414 healthy pigs was studied and the reference intervals for all salivary biomarkers were calculated accordingly. RESULTS: All parameters except Pig-MAP, OSI and α-amylase varied significantly along the daytime, and most of them peak around early afternoon (13-15 h). The cosinor analysis described the temporal dynamics of circadian rhythms for all parameters. The range values showed differences between male and female pigs in 8 out of the 13 biomarkers, with higher concentrations in females in comparison to male pigs. The influence of the production phase on the salivary concentrations was observed for all the biomarkers. The highest concentrations were observed for Pig-MAP, S100A12 and α-amylase in post-weaning animals, for TP in growing pigs and for OSI in finishing animals. Most of the sex-influenced biomarkers showed the highest concentrations at growing stages with some exceptions such as ADA or Hp that showed the peak at finishing and post-weaning stages respectively. CONCLUSIONS: It is necessary to establish the optimal daytime for routine saliva sampling to avoid circadian variations and for that end, the time interval between 10:00 a.m. to 12:00 a.m. is highly recommended. The factors sex and production phase influence the concentration of biomarkers and should be considered for proper biomarker interpretation. The reference intervals presented here for each salivary biomarker will help to correctly interpret the results of these analytes and contribute to the use of saliva as a non-invasive sample for the diagnosis and monitoring of the health status of swine farms.

[Preventive activities in women. PAPPS update 2022]. / Actividades preventivas en la mujer. Actualización PAPPS 2022.

In the 2022 PAPPS update we present those specific preventive activities for women's health, except those related to cancer prevention (which are included in another document) and those aspects related to differential gender morbidity, a cross-cutting aspect for all working groups. Contraception is an essential preventive activity, considering basic the right to decide both the number of children and the time to have them. We must inform about the possible contraceptive methods, guaranteeing the monitoring of their safety, efficacy and effectiveness (tables are included on changing from one method to another to preserve contraceptive protection). We must inform about emergency contraception and propose it in the event of unprotected intercourse. All this will be done through opportunistic screening without requiring screening for thrombophilia or dyslipidemia, but for arterial hypertension. Pregnancy is an important life experience and the family doctor should not remain oblivious. We must be competent both in the preconception consultation (recommending the intake of folic acid, avoiding exposure to occupational and environmental risks, screening for certain pathologies and assessing the intake of drugs not indicated during pregnancy) and in the monitoring of pregnancy. Whether or not we monitor the pregnancy, we must not disregard its control, taking advantage of this period to promote healthy lifestyles and participating in the intercurrent processes that may occur. Menopause in general and osteoporosis in particular exemplify the strategy of medicalization of vital processes that has been followed from different instances and organizations. In our update we address the prevention and treatment of symptoms secondary to estrogen deprivation. We also propose the prevention of osteoporosis, including carrying out densitometry based on the risk of fracture in the next 10 years, and therefore densitometric screening is not recommended in women under 60 years of age. In risk assessment we recommend the use of the frax tool or better, the calibration of the risk of hip fracture with prevalence data from our setting. We linked the indication for treatment with the Z-Score (bone mineral density compared with women of the same age), as it is a condition associated with aging.

Engaging Isatins in Multicomponent Reactions (MCRs) - Easy Access to Structural Diversity.

Multicomponent reactions (MCRs) are a valuable tool in diversity-oriented synthesis. Its application to privileged structures is gaining relevance in the fields of organic and medicinal chemistry. Isatin, due to its unique reactivity, can undergo different MCRs, affording multiple interesting scaffolds, namely oxindole-derivatives (including spirooxindoles, bis-oxindoles and 3,3-disubstituted oxindoles) and even, under certain conditions, ring-opening reactions occur that leads to other heterocyclic compounds. Over the past few years, new methodologies have been described for the application of this important and easily available starting material in MCRs. In this review, we explore these novelties, displaying them according to the structure of the final products obtained.

[Preventive activities in women's care]. / Actividades preventivas en la mujer. Actualización PAPPS 2020.

A review is presented of the scientific evidence on preventive activities in women's care in relation to pregnancy follow-up, preventive activities in the planning and follow-up of contraceptive methods, preventive activities in menopause, and the prevention of osteoporotic fractures.

Graphene IoNanofluids, Thermal and Structural Characterization.

Graphene is considered a promising substance in applications related to the capture and reduction of the environmental impact of fluorinated gases. However, further research is still required to explore all related possibilities. In this work, the potential use in this context of nanofluids (NFs), obtained by dispersing graphene nanosheets in fluorinated ionic liquids (FILs) is investigated. As a starting step, a thermal and structural characterization for this type of IoNanofluids (IoNFs) is presented. The highly nanostructured nature of FILs has been recently demonstrated. The presence of fluorinated moieties is responsible for enhancing the accommodation of solutes such as small gases. The strong tendency to self-assemble forming continuous and supramolecular structures, and the versatility to rearrange in several conformational features allows the stabilization of nano colloidal systems. It is essential to perform a comprehensive study of their structural features to understand the behavior of this type of heterogeneous systems. Therefore, we present screening on the phase and structural behavior of these novel IoNFs to discover and develop optimized systems where FILs turn out to be advantageous. Thermogravimetric analysis (TGA) was employed to evaluate IoNFs mass losses with temperature, and their solid-fluid phase transitions were located using a differential scanning calorimeter (DSC). Their rheological properties were also determined through oscillatory experiments, obtaining the viscous and loss moduli. In addition, the structural percolation transition was also identified.

A description of hydroquinone clathrates using molecular dynamics: Molecular model and crystalline structures for CH4 and CO2 guests.

The crystalline structure of hydroquinone clathrates has been studied using molecular dynamics. A flexible non-polarizable all-atom molecular model, based on the original Optimized Potentials for Liquid Simulations force field with recalculated point electric charges, has been used to describe the hydroquinone molecule, and the crystalline solid structure of the α native phase has been analyzed. Then, the ß clathrates have been studied, considering CO2 and CH4 as guest molecules, and also the empty clathrate structure. In all cases, the lattice parameters obtained through molecular simulation show excellent agreement with reported experimental values, showing that the molecular model selected is able to reproduce both the native crystalline phase and also the clathrate structures. In addition, the process of clathrate guest molecule release upon heating has been characterized, and the simulations show a good correspondence with the very recent experimental trends observed for both guest molecules analyzed.

Actividades preventivas en la mujer. Actualización PAPPS 2018 / No disponible

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Avaliação diagnóstica na síndrome disfunção cognitiva canina / Diagnostic Evaluation of Canine Cognitive Dysfunction Syndrome

O objetivo do presente estudo foi avaliar o questionário observacional e os testes de reatividade como forma de triagem e diagnóstico da disfunção cognitiva em cães idosos. Foram estudados 10 cães acima de sete anos, que apresentavam queixas comportamentais. Foi utilizado questionário que abordava questões comportamentais, como desorientação, atividade, interação socioambiental, alterações no padrão do sono e casa-sujidade. As respostas foram convertidas em pontuações, cujo somatório classificou o cão com disfunção cognitiva canina (DCC), ou borderline (BL), ou sem alterações comportamentais (SAC). Logo depois, foram realizados, em todos os cães, os seguintes testes cognitivos: open field, curiosidade, interação com humano e com espelho. Pela avaliação do questionário, foi determinado que dois cães tinham DCC, três eram BL, cinco eram SAC. Os cães classificados com DCC tinham idade superior aos demais e apresentaram alterações em todos os testes de reatividade, enquanto os cães BL apresentaram alterações em dois testes de reatividade e os SAC não apresentaram alterações. Conclui-se que, com o aumento da expectativa de vida canina, o questionário observacional foi um instrumento de triagem para a identificação dos cães classificados com DCC, BL e SAC, e os testes de reatividade como um método inovador para identificar o verdadeiro estado cognitivo dos pacientes idosos.(AU)

The objective was to evaluate the observational questionnaire and the reactivity tests as a way of screening and diagnosis of cognitive dysfunction in elderly dogs. Ten dogs over seven years of age, with behavioral complaints, were studied. A questionnaire was used that addressed behavioral issues such as disorientation, activity, socioenvironmental interaction, changes in sleep pattern, and house-dirtiness. Responses were converted into scores, which summed the dog with canine cognitive dysfunction (DCC), or Borderline (BL) or without behavioral changes (SAC). Soon after, the following cognitive tests were performed on all dogs: open field, curiosity, interaction with human and with mirror. Through questionnaire evaluation, two dogs had CHD, three were BL, and five were SAC. The dogs classified with DCC were older than the others and presented alterations in all reactivity tests, while the BL dogs presented changes in two reactivity tests and CAD showed no alterations. With the increase in canine life expectancy, the observational questionnaire was a screening instrument for the identification of dogs classified with DCC, BL and SAC and the reactivity tests as an innovative method to identify the true cognitive status of the dogs elderly patients.(AU)

Tuning the electrical conductivity of exfoliated graphite nanosheets nanofluids by surface functionalization.

The electrical conductivity of exfoliated graphite in water nanofluids has been experimentally determined, and compared with the same property when the dispersed nanosheets have been oxidized. The effect of oxidation on this property is different if compared with the case of sintered dry nanosheets. In any case, for the sintered raw material the conduction behaves as expected in a metal, while for the nanofluid it shows values and trends typical of a weak electrolyte solution. The effect of oxidation on the electrical conductivity of exfoliated graphite can be explained as being caused by the dissociation in the fluid phase of the moieties resulting from the chemical functionalization process. This opens the possibility of designing a functionalization process to tune the nanofluid electrical conductivity.

Computational study of the interplay between intermolecular interactions and CO2 orientations in type I hydrates.

Carbon dioxide (CO2) molecules show a rich orientation landscape when they are enclathrated in type I hydrates. Previous studies have described experimentally their preferential orientations, and some theoretical works have explained, but only partially, these experimental results. In the present paper, we use classical molecular dynamics and electronic density functional theory to advance in the theoretical description of CO2 orientations within type I hydrates. Our results are fully compatible with those previously reported, both theoretical and experimental, the geometric shape of the cavities in hydrate being, and therefore, the steric constraints, responsible for some (but not all) preferential angles. In addition, our calculations also show that guest-guest interactions in neighbouring cages are a key factor to explain the remaining experimental angles. Besides the implication concerning equation of state hydrate modeling approximations, the conclusion is that these guest-guest interactions should not be neglected, contrary to the usual practice.

Purification and determination of C-reactive protein and inter-α-trypsin inhibitor heavy chain 4 in dogs after major surgery through generation of specific antibodies.

Inter-α-trypsin inhibitor heavy chain 4 (ITIH4) and C-reactive protein (CRP) have been isolated from acute phase dog sera by affinity chromatography with insolubilized polyclonal antibodies anti pig Major Acute phase Protein (Pig-MAP) and with p-Aminophenyl Phosphoryl Choline, respectively. Isolated proteins were used to prepare specific polyclonal rabbit antisera that have allowed quantifying their concentration in serum samples by single radial immunodifussion. Both proteins were quantified in sera from female dogs that had undergone ovariohysterectomy (OVH, n=9) or mastectomy (n=10). The observed increases in CRP concentrations showed that surgical traumas induced an acute phase response of a great magnitude in the dogs. In both surgeries a four-fold increase of ITIH4 concentrations was detected. It can be concluded that ITIH4 is a new positive acute phase protein in dogs, as reported in other species.

Actividades preventivas en la mujer / No disponible

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On interfacial properties of tetrahydrofuran: Atomistic and coarse-grained models from molecular dynamics simulation.

We have determined the interfacial properties of tetrahydrofuran (THF) from direct simulation of the vapor-liquid interface. The molecules are modeled using six different molecular models, three of them based on the united-atom approach and the other three based on a coarse-grained (CG) approach. In the first case, THF is modeled using the transferable parameters potential functions approach proposed by Chandrasekhar and Jorgensen [J. Chem. Phys. 77, 5073 (1982)] and a new parametrization of the TraPPE force fields for cyclic alkanes and ethers [S. J. Keasler et al., J. Phys. Chem. B 115, 11234 (2012)]. In both cases, dispersive and coulombic intermolecular interactions are explicitly taken into account. In the second case, THF is modeled as a single sphere, a diatomic molecule, and a ring formed from three Mie monomers according to the SAFT-γ Mie top-down approach [V. Papaioannou et al., J. Chem. Phys. 140, 054107 (2014)]. Simulations were performed in the molecular dynamics canonical ensemble and the vapor-liquid surface tension is evaluated from the normal and tangential components of the pressure tensor along the simulation box. In addition to the surface tension, we have also obtained density profiles, coexistence densities, critical temperature, density, and pressure, and interfacial thickness as functions of temperature, paying special attention to the comparison between the estimations obtained from different models and literature experimental data. The simulation results obtained from the three CG models as described by the SAFT-γ Mie approach are able to predict accurately the vapor-liquid phase envelope of THF, in excellent agreement with estimations obtained from TraPPE model and experimental data in the whole range of coexistence. However, Chandrasekhar and Jorgensen model presents significant deviations from experimental results. We also compare the predictions for surface tension as obtained from simulation results for all the models with experimental data. The three CG models predict reasonably well (but only qualitatively) the surface tension of THF, as a function of temperature, from the triple point to the critical temperature. On the other hand, only the TraPPE united-atoms models are able to predict accurately the experimental surface tension of the system in the whole temperature range.

Understanding the Phase Behavior of Tetrahydrofuran + Carbon Dioxide, + Methane, and + Water Binary Mixtures from the SAFT-VR Approach.

The high-pressure phase diagrams of the tetrahydrofuran(1) + carbon dioxide(2), + methane(2), and + water(2) mixtures are examined using the SAFT-VR approach. Carbon dioxide molecule is modeled as two spherical segments tangentially bonded, water is modeled as a spherical segment with four associating sites to represent the hydrogen bonding, methane is represented as an isolated sphere, and tetrahydrofuran is represented as a chain of m tangentially bonded spherical segments. Dispersive interactions are modeled using the square-well intermolecular potential. In addition, two different molecular model mixtures are developed to take into account the subtle balance between water-tetrahydrofuran hydrogen-bonding interactions. The polar and quadrupolar interactions present in water, tetrahydrofuran, and carbon dioxide are treated in an effective way via square-well potentials of variable range. The optimized intermolecular parameters are taken from the works of Giner et al. (Fluid Phase Equil. 2007, 255, 200), Galindo and Blas (J. Phys. Chem. B 2002, 106, 4503), Patel et al. (Ind. Eng. Chem. Res. 2003, 42, 3809), and Clark et al. (Mol. Phys. 2006, 104, 3561) for tetrahydrofuran, carbon dioxide, methane, and water, respectively. The phase diagrams of the binary mixtures exhibit different types of phase behavior according to the classification of van Konynenburg and Scott, ranging from types I, III, and VI phase behavior for the tetrahydrofuran(1) + carbon dioxide(2), + methane(2), and + water(2) binary mixtures, respectively. This last type is characterized by the presence of a Bancroft point, positive azeotropy, and the so-called closed-loop curves that represent regions of liquid-liquid immiscibility in the phase diagram. The system exhibits lower critical solution temperatures (LCSTs), which denote the lower limit of immiscibility together with upper critical solution temperatures (UCSTs). This behavior is explained in terms of competition between the incompatibility with the alkyl parts of the tetrahydrofuran ring chain and the hydrogen bonding between water and the ether group. A minimum number of unlike interaction parameters are fitted to give the optimal representation of the most representative features of the binary phase diagrams. In the particular case of tetrahydrofuran(1) + water(2), two sets of intermolecular potential model parameters are proposed to describe accurately either the hypercritical point associated with the closed-loop liquid-liquid immiscibility region or the location of the mixture lower- and upper-critical end-points. The theory is not only able to predict the type of phase behavior of each mixture, but also provides a reasonably good description of the global phase behavior whenever experimental data are available.

Molecular dynamics simulation of CO2 hydrates: Prediction of three phase coexistence line.

The three phase equilibrium line (hydrate-liquid water-liquid carbon dioxide) has been estimated for the water + carbon dioxide binary mixture using molecular dynamics simulation and the direct coexistence technique. Both molecules have been represented using rigid nonpolarizable models. TIP4P/2005 and TIP4P/Ice were used for the case of water, while carbon dioxide was considered as a three center linear molecule with the parameterizations of MSM, EPM2, TraPPE, and ZD. The influence of the initial guest occupancy fraction on the hydrate stability has been analyzed first in order to determine the optimal starting configuration for the simulations, paying attention to the influence of the two different cells existing in the sI hydrate structure. The three phase coexistence temperature was then determined for a pressure range from 2 to 500 MPa. The qualitative shape of the equilibrium curve estimated is correct, including the high pressure temperature maximum that determines the hydrate re-entrant behaviour. However, in order to obtain quantitative agreement with experimental results, a positive deviation from the classical Lorentz-Berthelot combining rules must be considered.

Marcadores de estrés oxidativo en el diagnóstico de artritis reumatoide / Oxidative stress markers in the diagnosis of rheumatoid arthritis

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