Wave function analyses of scandium-doped aluminium clusters, AlnSc (n = 1-24), and their CO2 fixation abilities.

Nanoclusters represent a connection between (i) solid state systems and (ii) species in the atomic and molecular domains. Additionally, nanoclusters can also have very interesting electronic, optical and magnetic properties. For example, some aluminium clusters behave as superatoms and the doping of these clusters might strengthen their adsorption capabilities. Thus, we address herein the structural, energetic and electronic characterisation of scandium-doped aluminium clusters (AlnSc (n = 1-24)) by means of density functional theory calculations and quantum chemical topology wave function analyses. We studied the effect of Sc-doping on the structure and charge distribution by considering pure Al clusters as well. The quantum theory of atoms in molecules (QTAIM) reveals that interior Al atoms have large negative atomic charges (≈2a.u.) and hence the atoms surrounding them are considerably electron deficient. The Interacting Quantum Atoms (IQA) energy partition allowed us to establish the nature of the interaction between the Al13 superatom and the Al12Sc cluster with Al to form the complexes Al14 and Al13Sc, respectively. We also used the IQA approach to examine (i) the influence of Sc on the geometry of the AlnSc complexes along with (ii) the cooperative effects in the binding of AlnSc and Aln+1 clusters. We also exploited the QTAIM and IQA approaches to study the interaction of the electrophilic surface of the examined systems with CO2. Overall, we observe that the investigated Sc-doped Al complexes with a marked stability towards disproportionation reactions exhibit strong adsorption energies with CO2. Concomitantly, the carbon dioxide molecule is considerably distorted and destabilised, conditions which might prepare it for further chemical reactions. Altogether, this paper gives valuable insights on the tuning of the properties of metallic clusters for their design and exploitation in custom-made materials.

Multiconfiguration Pair-Density Functional Theory for Chromium(IV) Molecular Qubits.

Pseudotetrahedral organometallic complexes containing chromium(IV) and aryl ligands have been experimentally identified as promising molecular qubit candidates. Here we present a computational protocol based on multiconfiguration pair-density functional theory for computing singlet-triplet gaps and zero-field splitting (ZFS) parameters in Cr(IV) aryl complexes. We find that two multireference methods, multistate complete active space second-order perturbation theory (MS-CASPT2) and hybrid multistate pair-density functional theory (HMS-PDFT), perform better than Kohn-Sham density functional theory for singlet-triplet gaps. Despite the very small values of the ZFS parameters, both multireference methods performed qualitatively well. MS-CASPT2 and HMS-PDFT performed particularly well for predicting the trend in the ratio of the rhombic and axial ZFS parameters, |E/D|. We have also investigated the dependence and sensitivity of the calculated ZFS parameters on the active space and the molecular geometry. The methodologies outlined here can guide future prediction of ZFS parameters in molecular qubit candidates.

Towards an atomistic understanding of polymorphism in molecular solids.

Understanding and controlling polymorphism in molecular solids is a major unsolved problem in crystal engineering. While the ability to calculate accurate lattice energies with atomistic modelling provides valuable insight into the associated energy scales, existing methods cannot connect energy differences to the delicate balances of intra- and intermolecular forces that ultimately determine polymorph stability ordering. We report herein a protocol for applying Quantum Chemical Topology (QCT) to study the key intra- and intermolecular interactions in molecular solids, which we use to compare the three known polymorphs of succinic acid including the recently-discovered γ form. QCT provides a rigorous partitioning of the total energy into contributions associated with topological atoms, and a quantitative and chemically intuitive description of the intra- and intermolecular interactions. The newly-proposed Relative Energy Gradient (REG) method ranks atomistic energy terms (steric, electrostatic and exchange) by their importance in constructing the total energy profile for a chemical process. We find that the conformation of the succinic acid molecule is governed by a balance of large and opposing electrostatic interactions, while the H-bond dimerisation is governed by a combination of electrostatics and sterics. In the solids, an atomistic energy balance emerges that governs the contraction, towards the equilibrium geometry, of a molecular cluster representing the bulk crystal. The protocol we put forward is as general as the capabilities of the underlying quantum-mechanical model and it can provide novel perspectives on polymorphism in a wide range of chemical systems.

Longitudinal Evaluation of Cerebellar Signs of H-ABC Tubulinopathy in a Patient and in the taiep Model.

Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a central neurodegenerative disease due to mutations in the tubulin beta-4A (TUBB4A) gene, characterized by motor development delay, abnormal movements, ataxia, spasticity, dysarthria, and cognitive deficits. Diagnosis is made by integrating clinical data and radiological signs. Differences in MRIs have been reported in patients that carry the same mutation; however, a quantitative study has not been performed so far. Our study aimed to provide a longitudinal analysis of the changes in the cerebellum (Cb), corpus callosum (CC), ventricular system, and striatum in a patient suffering from H-ABC and in the taiep rat. We correlated the MRI signs of the patient with the results of immunofluorescence, gait analysis, segmentation of cerebellum, CC, and ventricular system, performed in the taiep rat. We found that cerebellar and callosal changes, suggesting a potential hypomyelination, worsened with age, in concomitance with the emergence of ataxic gait. We also observed a progressive lateral ventriculomegaly in both patient and taiep, possibly secondary to the atrophy of the white matter. These white matter changes are progressive and can be involved in the clinical deterioration. Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) gives rise to a spectrum of clinical signs whose pathophysiology still needs to be understood.

Water clusters as bifunctional catalysts in organic chemistry: the hydrolysis of oxirane and its methyl derivatives.

This contribution explores the bifunctional catalytic activity of water clusters ((H2O)n with n = 1-5) in organic chemistry similar to that observed in the formation of H2SO4 in acid rain (Chem. Commun., 53, 3516, (2017)). We considered for this purpose the Hydrolysis of Epoxides (HE), in particular, that of oxirane and its methyl derivatives. Surrounding water molecules with H-bond cooperative effects decrease the activation energy of the rate-limiting step of HE in condensed phase, especially when they lead to an anti-periplanar attack on the alkoxide leaving group. Furthermore, the water molecules have a bifunctional catalytic role in HE by (i) increasing the nucleophilic and electrophilic character of the attacking oxygen atom and the leaving group of the reaction, respectively, and (ii) placing the reactants in a suitable disposition for the substitution to occur. Overall, this investigation provides relevant insights into the collective action of water molecules on organic reactions in neutral, basic and acid media.

Cooperativity and Anticooperativity in Ion-Water Interactions: Implications for the Aqueous Solvation of Ions.

Non-additive effects in hydrogen bonds (HB) take place as a consequence of electronic charge transfers. Therefore, it is natural to expect cooperativity and anticooperativity in ion-water interactions. Nevertheless, investigations on this matter are scarce. This paper addresses the interactions of (i) the cations Li+ , Na+ , K+ , Be2+ , Mg2+ , and Ca2+ together with (ii) the anions F- , Cl- , Br- , NO3- and SO42- with water clusters (H2 O)n , n=1-8, and the effects of these ions on the HBs within the complete molecular adducts. We used quantum chemical topology tools, specifically the quantum theory of atoms in molecules and the interacting quantum atoms energy partition to investigate non-additive effects among the interactions studied herein. Our results show a decrease on the interaction energy between ions and the first neighbouring water molecules with an increment of the coordination number. We also found strong cooperative effects in the interplay between HBs and ion-dipole interactions within the studied systems. Such cooperativity affects considerably the interactions among ions with their first and second solvation shells in aqueous environments. Overall, we believe this article provides valuable information about how ion-dipole contacts interact with each other and how they relate to other interactions, such as HBs, in the framework of non-additive effects in aqueous media.

Auditory impairment in H-ABC tubulinopathy.

Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a neurodegenerative disease due to mutations in TUBB4A. Patients suffer from extrapyramidal movements, spasticity, ataxia, and cognitive deficits. Magnetic resonance imaging features are hypomyelination and atrophy of the striatum and cerebellum. A correlation between the mutations and their cellular, tissue and organic effects is largely missing. The effects of these mutations on sensory functions have not been described so far. We have previously reported a rat carrying a TUBB4A (A302T) mutation and sharing most of the clinical and radiological signs with H-ABC patients. Here, for the first time, we did a comparative study of the hearing function in an H-ABC patient and in this mutant model. By analyzing hearing function, we found that there are no significant differences in the auditory brainstem response (ABR) thresholds between mutant rats and WT controls. Nevertheless, ABRs show longer latencies in central waves (II-IV) that in some cases disappear when compared to WT. The patient also shows abnormal AEPs presenting only Waves I and II. Distortion product of otoacoustic emissions and immunohistochemistry in the rat show that the peripheral hearing function and morphology of the organ of Corti are normal. We conclude that the tubulin mutation severely impairs the central hearing pathway most probably by progressive central white matter degeneration. Hearing function might be affected in a significant fraction of patients with H-ABC; therefore, screening for auditory function should be done on patients with tubulinopathies to evaluate hearing support therapies.

3,3'-thiodipropanol as a versatile refractive index-matching mounting medium for fluorescence microscopy.

High resolution fluorescence microscopy requires optimization of the protocols for biological sample preparation. The optical and chemical characteristics of mounting media are among the things that could be modified to achieve optimal image formation. In our search for chemical substances that could perform as mounting media, 3,3'-thiodipropanol (TDP) emerged as a sulfide with potentially interesting characteristics. In this work, several tests of its performance as a mounting medium for fluorescence microscopy of biological samples were performed, including the labeling of filamentous actin with fluorescent phalloidins. The refractive index dispersion curve of pH-adjusted TDP was experimentally obtained in the visible range and compared to the dispersion curves of commercial and lab-made mounting media. The effects on the fluorescence of commonly used dyes were tested by using TDP as a solvent and measuring the relative fluorescence quantum yield of the dyes. By being able to mix TDP in any concentration with water and 2,2'-thiodiethanol (TDE), it was possible not only to fine-tune the refractive index of the resulting solution, but also to preserve the compatibility of TDP with the most popular and efficient fluorescent actin staining used in biological microscopy.

Mortalidad por accidentes cerebrovasculares en el Hospital Clínico Quirúrgico Lucía Íñiguez Landín, Holguín, Cuba, 2012-2017 / Cerebrovascular Accidents Mortality at the Clinical Surgical Hospital "Lucía Íñiguez Landín", Holguín, Cuba, 2012-2017

RESUMEN Introducción: actualmente, el Accidente Cerebrovascular (ACV) produce importantes limitaciones, discapacidades y constituye una de las primeras causas de muerte a nivel mundial. La mortalidad hospitalaria es uno de los indicadores más utilizados para medir la calidad de la atención en los servicios de salud. Objetivo: determinar la tendencia de la mortalidad por ACV. Métodos: se realizó una investigación descriptiva de una serie de casos. El universo fueron 382 pacientes; el total de fallecidos con el diagnóstico clínico, tomográfico y/o necrológico de ACV, del 2012 hasta el 2017, en el Hospital Clínico-Quirúrgico Lucía Íñiguez Landín. Los datos recogidos fueron procesados estadísticamente. Resultados: en los años estudiados fallecieron por ACV, un promedio anual de 63 pacientes. El grupo etario de 71 a 80 años sobresalió con un promedio de 17,5 fallecidos. Llamó la atención la tendencia al aumento del grupo de 51 a 60 años. Predominó el sexo masculino con un promedio de 35,6 fallecidos; aunque la tendencia fue a igualarse. Prevalecieron las hemorragias intracerebrales con 34 fallecidos como promedio, y la hipertensión arterial acompañó a más del 50% de los fallecidos, en la mayoría de los años estudiados. Las causas directas de los fallecimientos fueron: el edema cerebral y la hipertensión endocraneana refractaria, principalmente durante las estadías hospitalarias cortas o intermedias. Conclusiones: la mortalidad por ACV tuvo un comportamiento similar en los diferentes años; pero con una tendencia a elevarse con el tiempo y aparecer en edades más tempranas.

ABSTRACT Introduction: nowadays, Cerebrovascular Accident (CVA) invalidantes patients and is one of the main mortality causes around the world. Hospital mortality is one of the most adequate indicators to measure the attention quality, in health services. Objective: to determine mortality tendency of CVA. Methods: a descriptive series of cases research, with the universe of the 382 deceased patients, diagnosed with tomographic and/or obituary of CVA, from 2012 to 2017, at the Clinical Surgical Hospital "Lucía Íñiguez Landín". Data were processed statistically. Results: during the years of study, an average of 62 patients perished for CVA. Age bracket from 71 to 80 stood out with 17.5 average. Tendency raised in the group from 51 to 60. Males prevailed with a mortality of 35.6 average; though it tend to become equal. Intracerebral Hemorrhages prevailed with a 34 average mortality, and arterial hypertension accompanied the 50% of dead patients, in most of the studied years. Mortality direct causes were the cerebral edema and intracraneal hypertension with refration, mainly when hospital stays were short or intermediates. Conclusions: CVA mortality behaved differently through the studied years; though it increased and appeared, more frequently, in premature ages.

Acidity and basicity interplay in amide and imide self-association.

Amides dimerise more strongly than imides despite their lower acidity. Such an unexpected result has been rationalised in terms of the Jorgensen Secondary Interactions Hypothesis (JSIH) that involves the spectator (C[double bond, length as m-dash]OS) and H-bonded (C[double bond, length as m-dash]OHB) carbonyl groups in imides. Notwithstanding the considerable body of experimental and theoretical evidence supporting the JSIH, there are some computational studies which suggest that there might be other relevant intermolecular interactions than those considered in this model. We conjectured that the spectator carbonyl moieties could disrupt the resonance-assisted hydrogen bonds in imide dimers, but our results showed that this was not the case. Intrigued by this phenomenon, we studied the self-association of a set of amides and imides via 1H-NMR, 1H-DOSY experiments, DFT calculations, QTAIM topological analyses of the electron density and IQA partitions of the electronic energy. These analyses revealed that there are indeed repulsions of the type OS···OHB in accordance with the JSIH but our data also indicate that the C[double bond, length as m-dash]OS group has an overall attraction with the interacting molecule. Instead, we found correlations between self-association strength and simple Brønsted-Lowry acid/base properties, namely, N-H acidities and C[double bond, length as m-dash]O basicities. The results in CDCl3 and CCl4 indicate that imides dimerise less strongly than structurally related amides because of the lower basicity of their carbonyl fragments, a frequently overlooked aspect in the study of H-bonding. Overall, the model proposed herein could provide important insights in diverse areas of supramolecular chemistry such as the study of multiple hydrogen-bonded adducts which involve amide or imide functional groups.

Relationship of the drying process of a corn grain with the thermal emissivity and optical interference in the mid infrared range.

A study of the effect of the thin layer of free water in corn kernels on the emissivity and interference in the mid infrared range was performed. The emissivity was measured through thermal infrared images by direct method for 8 days, allowing observance that the thickness of free water modifies the quantity of emitted energy and emissivity; however, in the first days when the layer of free water is not optically thick the interference caused by the thin film of superficial water averts a correct measurement of the emissivity. This interference effect was studied and characterized, finding that the number of oscillations in the energy of the grain, observed and counted in a very small area, can be used to compute the thickness of the free water layer contained between the endosperm and the pericarp of the grain.

Procedure to diagnose onychomycosis through changes in emissivity on infrared images.

A noninvasive, quick, reliable, and relatively cheap procedure for the diagnosis of onychomycosis is put forward. It is known that a nail may show an abnormal appearance, although only 50% of all the nails having such an appearance may owe it to the presence of onychomycosis; hence, adequate diagnosis of nail disease is needed for appropriate prescription of medication and treatment of the nail. In order to contribute to the process of improvement in the diagnosis, a procedure based on the analysis of medium-range infrared images is presented in which it is possible to observe energy changes mostly due to the changes in emissivity of the nail. As a nail is more affected by onychomycosis, such changes become more intense. Also, it was found that a nail without onychomycosis has a lower temperature than toe skin, but has a higher emission of energy. Fifty percent of the ailments that may a cause a fingernail or toenail to have an abnormal appearance are not considered in the present work.

Cambios en la ingesta de sal y práctica de ejercicio físico en pacientes hipertensos por educación sanitaria en el primer nivel de atención de salud / Changes in salt ingestion and physical exercise in hypertensive patients by health education at the first level of health care attention

Aunque se asume que la educación sanitaria mejora los estilos de vida de los pacientes hipertensos, no existe suficiente bibliografía que apoye esta asociación. Objetivo: Evaluar el efecto de la educación sanitaria ofrecida a los pacientes hipertensos sobre sus prácticas de ingesta de sal y ejercicio físico. Material y métodos: Estudio descriptivo, transversal y basado en encuestas aplicadas a 179 pacientes hipertensos que acudieron entre junio y julio de 2009 a los servicios de medicina general, medicina interna y cardiología independientemente del motivo de atención. Se analizó con el programa SPSS versión 17.0 y aplicando el test de chi cuadrado. Resultados: El 67% fue del sexo femenino, 60,9% era mayor de 60 años y el 72,1% tenía educación secundaria o superior. El 25% había recibido charlas y 22% material educativo en salud en los últimos 6 meses. No se encontró asociación significativa entre haber recibido educación sanitaria con la práctica de actividad física regular ni de menor ingesta de sal. Conclusiones: En este estudio, la educación sanitaria no tuvo influencia sobre la práctica de ejercicio físico ni sobre la ingesta de sal.

Although it is assumed that health care education improves life style in hypertensive patients, there is no enough evidence to support its implementation. Objective: Evaluate the effect of health care education on salt ingestion and physical exercise in hypertensive patients. Methods: Descriptive, cross-sectional study based on surveys applied to 179 hypertensive patients who attended the internal medicine and cardiology outpatient clinics from June to July 2009. Chi square test was performed using the SPSS statistical package version 17.0. Results: 67% were females; 69% were older than 60 years of age; 72.1% had secondary school level or superior education level. Health care education was received by 25% of the participants, 22% had received printed material in the last 6 months. Having received health care education was not associated with less salt ingestion or with more physical exercise. Conclusions: Health care education did not influence salt ingestion and physical exercise in this study.

Niveles de intervención familiar / Levels of family intervention

En la atención primaria lidiamos con variados problemas de salud con diverso impacto en el individuo y su familia. Asimismo, circunstancias previsibles en la vida del individuo y su familia requieren atenuar el impacto de un evento crítico para su desarrollo. Existen 5 cinco niveles de intervención familiar basados en el grado de involucramiento familiar bajo la premisa de que ello posibilitaría una mejor comprensión del problema del individuo y por tanto, mayores posibilidades de resolverlo. Es importante, además, diferenciar cuando un problema familiar requiere derivación a otro nivel de intervención. En nuestro país requerimos adecuar los servicios, formar profesionales con habilidades específicas para trabajar con familias y reforzar las normas que posibiliten el avance en este campo.

We face different health problems in primary care, and they have variable impact in both individuals and their families. Also, some foreseeable circumstances in the lives of the individual and of his/her family are required in order to mitigate the impact of a critical event on family development. There are five levels for family interventions, which are based upon the degree of familial involvement, assuming this would lead to better understanding the individual's problems, and this may also lead to a greater likelihood for solving them. It is also important to know when a family problem may require referral to a next level for intervention. In our country, we need to have adequate services, we have to train professionals with specific abilities in working with families and we also have to reinforce regulations that may facilitate advances in this field.

Flicker minimization in an LCoS Spatial Light Modulator.

We present a method for reducing the phase flicker originated by the pulsed modulation of a Liquid Crystal on Silicon (LCoS) Spatial Light Modulator (SLM). It consists in reducing the temperature of the LCoS in a controlled way, in order to increase the viscosity of the liquid crystal. By doing this, we increase the time response of the liquid crystal, and thus reduce the amplitude of phase fluctuations. We evaluate the efficacy of this method quantifying the temporal evolution of phase shift using an experiment that is insensitive to optical polarization fluctuations. Additionally, we determine the effect of the temperature reduction on the effective phase modulation capability of the LCoS. We demonstrate that a reduction of up to 80% of the flicker initial value can be achieved when the LCoS is brought to -8 °C.

Anticoncepción femenina por cirugía voluntaria, en la Secretaría de Salud, 1981-1984 / Female contraception by voluntary surgery in the Secretary of health, 1981-1984

En este artículo se presentan las características de las usuarias y de los servicios de anticoncepción quirúrgica voluntaria, en la Secretaria de Salud, durante el periodo 1981-1984. Los resultados indican que las aceptantes de esta forma de anticoncepción, se caracterizan por una paridad y un promedio de edad elevados, y por un uso de anticonceptivos previo a la intervención relativamente bajo. En cuanto a los servicios, destaca la elevada proporción de cirugías realizadas por médicos y cirujanos generales, el uso poco frecuente de la anestesia local y sedación, la prevalencia de la minilaparotomía y la laparoscopia, como vía de acceso empleada, y el número de complicaciones transoperatorias informadas dentro o abajo de los niveles internacionalmente aceptados