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π-π stacking interactions are versatile because they are involved in many processes, such as protein folding, DNA stacking, and drug recognition. However, from the point of view of crystal engineering, there is an incipient knowledge of its exploitation. A comparison of these interactions with hydrogen bonds shows a huge difference in their employment as a reliable non-covalent interaction. And different reasons can be listed to explain why hydrogen bonding can be considered a more robust interaction than π-π stacking. For instance, hydrogen bonds encompass a wide energy range (25-40 kJ mol-1). From this, these interactions can be classified as strong, moderate, and weak. Hence, the first two can be considered highly to moderately directional to be exploited in crystal engineering. This aspect is relevant for them to be used in a relatively reliably way in this area of supramolecular chemistry. On the other hand, in the case of π-π stacking, the energy range is 0-10 kJ mol-1, thus implying that hydrogen bonds or any other energetically more robust contact would predominate in the competition for establishing packing interactions in a given arrangement. In this sense, if stacking is pretended to be exploited from the point of view of crystal engineering, one of the points that must be ensured is that this interaction will be the one energetically predominant. However, although there are other factors to consider, it seems that energetics is the dominant one. In this line, our research group has obtained and studied many single-crystalline structures of coordination and organometallic compounds containing fluorinated thiolates. This being particularly true in the case of the thiolate 2,3,5,6-S(C6F4H-4) bound to different metals, where it has been observed that they preferentially tend to establish πF-πF stacking interactions, results that have been reported in several papers. Thus, from this perspective, we have explored, using ConQuest (CCDC) a number of structures to observe how feasible is to find stacking in coordination and organometallic compounds containing the thiolate 2,3,5,6-S(C6F4H-4).

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The evaluation of the oral health-related quality of life (OHRQoL) is important for clinical assessment and could be an indicator of the quality of the treatment received. Objective: To evaluate the OHRQoL in adults with removable prostheses in relation with patient characteristics such as age, sex, type and time of use of the prosthesis, previous experience and perception about the stability of the prosthesis. Materials and Methods: 217 patients from the Dental Clinic of the National University of San Marcos-Peru were evaluated after rehabilitation with a removable prosthesis. A structured questionnaire was applied by telephone interview. The evaluation of the OHRQoL was carried out using the General/Geriatric Oral Health Evaluation Index (GOHAI). For the statistical analysis, the Mann Whitney U test, the Kruskal-Wallis H test and the Spearman correlation were used. Results:The sample included 63 men (29%) and 154 women (71%) with an average age of 66.34. The average GOHAI score was 52.44+8.15. The GOHAI score was related to age (p=0.241), sex (p=0.110), type of prosthesis (p=0.069), previous experience (p=0.293), and perception of movement of the prosthesis (p<0.001). Conclusions: The GOHAI score indicates a moderate quality of life related to oral health after prosthetic rehabilitation. The GOHAI index can be considered effective for the evaluation of the OHRQoL.

La evaluación de la calidad de vida relacionada a la salud oral (CVRSO) resulta importante para la valoración clínica pudiendo ser un indicador de la calidad en el tratamiento recibido. Objetivo: Evaluar la CVRSO en adultos con rehabilitación protésica removible relacionándola con características de los participantes como edad, sexo, tipo y tiempo de uso de la prótesis, experiencia previa y percepción sobre la estabilidad de la misma. Materiales y Métodos: Se evaluaron 217 pacientes de la Clínica Odontológica de la Universidad Nacional Mayor de San Marcos-Perú, posterior a la rehabilitación con prótesis removible. Se aplicó un cuestionario estructurado mediante entrevista vía telefónica. La evaluación de la CVRSO se realizó mediante el índice de Evaluación de Salud Oral General/Geriátrica (GOHAI). Para el análisis estadístico se utilizaron las pruebas de U de Mann Whitney, H de Kruskal-Wallis y correlación de Spearman. Resultado: La muestra incluyó 63 hombres (29%) y 154 mujeres (71%) con una edad media de 66.34. La puntuación media del GOHAI fue de 52.44 + 8.15. Se relacionó la puntuación del GOHAI con la edad (p=0.241), sexo (p=0.110), tipo de prótesis (p=0.069), experiencia previa (p=0.293) y percepción de movimiento de la prótesis (p<0.001). Conclusion: La puntuación del GOHAI indica una moderada calidad de vida relacionada a la salud oral después de la rehabilitación protésica. El índice GOHAI puede considerarse efectivo para la evaluación de la CVRSO.

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BACKGROUND: It is imperative to eliminate bacteria present in water in order to avoid problems in healthy. Escherichia coli and Salmonella typhi bacteria are two common pollutants and they are developing resistance to some of the most used bactericide. Therefore new biocide materials are being tested. Thus, gold nanoparticles are proposed to inhibit the growth of these two microorganisms. RESULTS: Gold nanoparticles were supported onto clinoptilolite, mordenite and faujasite zeolites. Content of gold in materials varied between 2.3 and 2.8 wt%. The size, dispersion and roughness of gold nanoparticles were highly dependent of the zeolite support. The faujasite support was the support where the 5 nm nanoparticles were highly dispersed. The efficiency of gold-zeolites as bactericides of Escherichia coli and Salmonella typhi was determined by the zeolite support. CONCLUSIONS: Gold nanoparticles dispersed on zeolites eliminate Escherichia coli and Salmonella typhi at short times. The biocidal properties of gold nanoparticles are influenced by the type of support which, indeed, drives key parameters as the size and roughness of nanoparticles. The more actives materials were pointed out Au-faujasite. These materials contained particles sized 5 nm at surface and eliminate 90-95% of Escherichia coli and Salmonella typhi colonies.

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En la mayoría de los países los programas de atención odontológica se centran en aspectos tecnológicos y curativos de la odontología, en lugar de fomentar la prevención y los programas comunitarios de salud oral, que se muestran como estartegias más eficaces para mejorar la salud oral comunitaria y tendrían un mayor efecto sobre el estado de salud bucodental de una comunidad. Precisamente, a partir de esta constatación, se propone la alternativa de la odontología social y se discute sus alcances.

In most countries the programs of dental attention centre on technological and curative aspects of dentistry, instead of promoting the prevention and the community programs of dental health, wich appear as more effective strategies to improve the oral community health. It would have a bigger effect on the oral health of a community. Based in this reality, the alternative of social dentistry and his scopes are discussed.

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Los hemangiomas infantiles son los tumores vasculares benignos más frecuentes en la infancia, que ocurren mayormente en los pacientes pretérmino y en un 80 por ciento afectan cabeza y cuello, con serias complicaciones hasta en un 20 por ciento de los pacientes. Su ritmo evolutivo se caracteriza por una fase proliferativa y otra involutiva que pueden durar años. En la actualidad han sido utilizados los betabloqueadores, como el propranolol oral, con muy buenos resultados. Presentamos una serie de 3 casos de pacientes con hemangioma infantil atendidos en consulta de dermatología del Hospital Pediátrico Docente Juan Manuel Marquez, tratados con propranolol de producción nacional por vía oral a 2 mg/kg/d en 2 subdosis con muy buenos resultados(AU)

The infantile hemangiomata are the benign vascular tumors more frequent in childhood occurring mainly in pre-term patients and in a 80 percent involve the head and the neck with serious complications up to a 20 percent of patients. Its evolution rhythm is characterized by a proliferative phase and another involutional that may be present for years. Nowadays, the beta-blockers have been used, e.g. the oral propranolol with very good results. This is the presentation of three cases with infantile hemangioma seen in the dermatology consultation from the Juan Manual Márquez Teaching Children Hospital and treated with 2 mg/dk/d at two subdose of propranolol of national production with very good results(AU)

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Los hemangiomas infantiles son los tumores vasculares benignos más frecuentes en la infancia, que ocurren mayormente en los pacientes pretérmino y en un 80 por ciento afectan cabeza y cuello, con serias complicaciones hasta en un 20 por ciento de los pacientes. Su ritmo evolutivo se caracteriza por una fase proliferativa y otra involutiva que pueden durar años. En la actualidad han sido utilizados los betabloqueadores, como el propranolol oral, con muy buenos resultados. Presentamos una serie de 3 casos de pacientes con hemangioma infantil atendidos en consulta de dermatología del Hospital Pediátrico Docente Juan Manuel Marquez, tratados con propranolol de producción nacional por vía oral a 2 mg/kg/d en 2 subdosis con muy buenos resultados

The infantile hemangiomata are the benign vascular tumors more frequent in childhood occurring mainly in pre-term patients and in a 80 percent involve the head and the neck with serious complications up to a 20 percent of patients. Its evolution rhythm is characterized by a proliferative phase and another involutional that may be present for years. Nowadays, the beta-blockers have been used, e.g. the oral propranolol with very good results. This is the presentation of three cases with infantile hemangioma seen in the dermatology consultation from the Juan Manual Márquez Teaching Children Hospital and treated with 2 mg/dk/d at two subdose of propranolol of national production with very good results

RESUMO

The rehydration process of a calcined MgAl-layered double hydroxide (LDH) with a Mg/Al molar ratio of 3 was systematically analyzed at different temperatures and relative humidity. Qualitative and quantitative experiments were done. In the first set of samples, the temperature or the relative humidity was varied, fixing the second variable. Both adsorption and absorption phenomena were present; absorption process was associated to the LDH regeneration. Of course, in all cases the LDH regeneration was confirmed by other techniques such as TGA, solid state NMR, and SAXS. In the second set of experiments, a kinetic analysis was performed, the results allowed to obtain different activation enthalpies for the LDH regeneration as a function of the relative humidity. The activation enthalpies varied from 137.6 to 83.3 kJ/mol as a function of the relative humidity (50 and 80%, respectively). All these experiments showed that LDH regeneration is highly dependent on the temperature and relative humidity.

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Layers of a layered double hydroxide, containing aluminum 4-fold coordinated, were partially folded in order to obtain a fibrous hydrotalcite-like compound. The hydrotalcite layers, in the presence of an anionic surfactant (sodium dodecyl sulfate) after hydrothermal treatment for 2 weeks, acquire a mesoporous-like arrangement. The transformation was monitored by techniques sensitive to structural and textural properties. Results suggest that brucite-like layers can be joined throughout unsaturated coordinated aluminum, that is, tetrahedral aluminum which links through hydrogen bonds to form aluminum octahedrally coordinated. The fractal dimension parameter was very sensitive to evolution from layered to fibrous hydrotalcites.

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The present study discusses the effect of gamma-irradiation on Cs+-exchanged X and A zeolites. The incorporation of Cs+ ions into A and X zeolites was performed using three different cesium salts (chloride, nitrate or acetate). Cs+ ions immobilized into the vitrified zeolites by thermal treatment are located in different sites of the zeolite networks. It is found that gamma-irradiation favors cesium retention depending on the cesium precursor salt used in the cationic exchange step.

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Small angle X-ray scattering (SAXS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) have been used to look at enamel from nine premolars, three each from individuals in low, medium and high risk caries groups. Only SAXS was able to detect consistent differences between any of the groups. In enamel from the high caries risk group, the micropores between the hydroxyapatite crystals were laminar. In enamel from the low caries risk group, the micropores were cylindrical. Other parameters varied between teeth but were not correlated with caries risk.

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OBJECTIVE: The authors studied the sensitivity and specificity, as well the positive and negative predictive values, of a prognostic index conformed by diastolic blood pressure, total number of cigarettes smoked during the lifetime, severity of angina pectoris, positive family history of ischemic heart diseases, age (years), current cigarette smoking, and total to HDL-cholesterol ratio in order to anticipate the presence of significant coronary artery disease in patients with rheumatic cardiac valvulopathy. MATERIAL AND METHODS: A prospective, observational, non-randomized, cross-sectional and comparative study was performed in men and women > or = 30 and < or = 78 years of age, with rheumatic valve cardiopathy and who were submitted to catheterization and coronary angiography. RESULTS: We studied 102 patients (61 women and 41 men) 55.63 +/- 9.88 years of age, range: 30-78 years (women 56.09 +/- 11.48, and men 54.6 +/- 11.35 years of age, respectively). The patients had mitral valve disease 30 (29.41%), 49 (48.03%) had mitral valve disease associated with aortic valve disease and 23 (22.55%) had aortic valvular disease. Significant coronary artery atherosclerosis was present in eight patients (7.84%). Sensitivity and specificity analysis resulted as follows: sensitivity, 50% and specificity, 80.85%. Positive predictive value was 0.18 and negative predictive value 0.95. CONCLUSIONS: The index analyzed here is useful to predict cases without significant coronary artery disease in patients with rheumatic heart valvulopathy, but this index is not useful to identify significant coronary artery disease in such patients.

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We explored the affinity of calcite to adsorbed organic molecules as an approach to the conservation of cultural heritage built of marble and limestone. The utilization of phenylmalonic and benzylmalonic acids provided a hydrophobic adsorptive interface, adequate to prevent processes of aqueous weathering. Samples of marble powder (polycrystalline calcite) were impregnated with solutions of phenylmalonic and benzylmalonic acid at three concentrations (5 x 10(-2), 5 x 10(-3), and 5 x 10(-4) M) and different pH values (6.00, 7.00, and 8.00). The surface charge of the calcite suspensions was determined by potentiometric measurements under equilibrium conditions at room temperature in aqueous solution of the dicarboxylic acids, in order to understand the influence of the electrokinetic potential in the surface association. The adsorbed amounts were determined by calculation of the thermodynamic equilibria of solutions. The presence of the organic interface on the mineral surface was corroborated by Raman spectroscopy and small-angle X-ray scattering (SAXS). The results indicate effective adsorption of both dicarboxylic acids as a function of the concentration and pH, and several other conditions that favors coulombic interaction, an absence of electrophoretic mobility or surface electroneutrality related to the solid surface potentials. The coverage of pores by dicarboxylic adsorbate modified the geometrical pore shape and the pore size distribution, filling all the pores of larger than 80 A diameter, giving as a result a mesoporous structure. This change in the surface morphology by organic adsorbates constitutes a modification in the diffusional processes of the environment on the mineral surface.

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Phosphated alumina gels were prepared by the sol-gel method. Gels were aged from 1 to 8 days in air. Gel structure evolution, as time went on, was followed by 27Al magic angle spinning nuclear magnetic resonance, X-ray diffraction, and small-angle X-ray scattering. It is concluded that the aging time is a crucial parameter in the formation of coordinately unsaturated sites of aluminum (AlIV and AlV). The gel network is shown to have a fractal structure.

RESUMO

Samples of polycrystalline calcite were impregnated with solutions of malonic acid of three concentrations (5 x 10(-2), 5 x 10(-3) , and 5 x 10(-4) M) and different pH values (6.00, 7.00, and 8.00). The impregnation was carried out at room temperature to evaluate the adsorption of malonate ion in the calcite surface to optimize the conditions for possible application on limestone and marble in cultural heritage materials. The affinity of the malonate ion was determined through the potentiometric measurement of the surface charge and the corresponding adsorbed amounts by titration, Raman spectroscopy, and small-angle X-ray scattering (SAXS). The results indicate effective adsorption of the malonate ion on the surface at a pH value close to the point of zero charge (pHpzc approximately 8.20) and changes in some surface morphological properties such as the pore shape and the pore size distribution. The presence of a malonate adsorptive layer on calcite generates an interface interaction potential that may influence the reaction and transport mechanisms within the medium.