Silver nanoparticles modified ZnO nanocatalysts for effective degradation of ceftiofur sodium under UV-vis light illumination.

Light-induced photocatalytic degradation of ceftiofur sodium (CFS) has been assessed in the presence of plasmonic zinc oxide nanostructures (ZnONSTs), like, ZnO nanoparticles, ZnO nanorods (ZnONRs) and ZnO nanoflowers (ZnONFs). Silver nanoparticles (Ag NPs) loaded ZnO nanostructures (Ag-ZnONSTs) are obtained through seed-assisted chemical reaction followed by chemical reduction of silver. The surface modification of ZnO nanostructures by Ag NPs effectually altered their optical properties. Further, the surface plasmonic effect of Ag NPs facilitates visible light absorption by ZnONSTs and improved the photogenerated electron and hole separation, which makes the ZnONSTs a more active photocatalyst than TiO2 (P25) nanoparticles. Especially, Ag-ZnONRs showed higher CFS oxidation rate constant (k' = 4.6 × 10-4 s-1) when compared to Ag-ZnONFs (k' = 2.8 × 10-4 s-1) and Ag-ZnONPs (k' = 2.5 × 10-4 s-1), owing to their high aspect ratio (60:1). The unidirectional transport of photogenerated charge carriers on the Ag-ZnONRs may be accountable for the observed high photocatalytic oxidation of CFS. The photocatalytic oxidation of CFS mainly proceeds through •OH radicals generated on the Ag-ZnONRs surface under light illumination. In addition, heterogeneous activation of peroxymonosulfate by Ag-ZnONRs accelerates the rate of photocatalytic mineralization of CFS. The quantification of oxidative radicals supports the proposed CFS oxidation mechanism. Stability studies of plasmonic Ag-ZnONSTs strongly suggests that it could be useful to clean large volume of pharmaceutical wastewater under direct solar light irradiation.

Natural and anthropogenic oil impacts on benthic foraminifera in the southern Gulf of Mexico.

The Campeche Sound is the major offshore oil producing area in the Southern Gulf of Mexico (SGoM). To evaluate the impact of oil related activities in the ocean floor sediments, we analyzed the geochemical (major and trace element, organic carbon and hydrocarbon concentrations) and biological (benthic foraminifera) composition of 62 superficial sediment samples, from 13 to 1336 m water depth. Cluster and Factor analysis of all the variables indicate that their distribution patterns are mainly controlled by differences between the terrigenous and carbonate platforms in the SGoM. Benthic foraminiferal assemblages were abundant and diverse, and their distribution patterns are mainly determined by water depth and sedimentary environment. However, most of the abundant species are opportunistic and/or low-oxygen tolerant, and many of their tests show oil stains and infillings, characteristic of oil polluted locations, suggesting the environment has been modified by natural seepage or oil-related activities. To determine if these conditions are natural or anthropogenic in origin, pre - industrial settings should be studied. Organic carbon (Corg) content (0.6-2.9%) and total hydrocarbon concentrations (PAHs 1.0-29.5 µg kg-1) were usually higher around the oil platforms area, the natural hydrocarbon seeps ("chapopoteras") area and offshore rivers, but there is no accumulation of oil related trace elements in these areas. However, the comparison with international sediment quality benchmarks indicates that Cd, Cr and Ni concentrations are above the threshold effect level, and also As, Ba and Cu are above the probable effect level benchmarks, which indicate that these element concentrations might be of potential ecological concern. Comprehensive studies involving different proxies, and assessing pre-industrial conditions, must be undertaken before assessing environmental health of marine benthic ecosystems.

Methylene blue removal from contaminated waters using heterogeneous catalytic ozonation promoted by natural zeolite: mechanism and kinetic approach.

This paper presents experimental results of a methylene blue removal system based on heterogeneous catalytic ozonation in the presence of natural zeolite. The effect of pH (2-10) and the presence of radical scavengers (acetate ions) on homogeneous and heterogeneous ozonation systems are assessed at laboratory scale. Results show that heterogeneous catalytic ozonation using natural zeolite increases methylene blue removal rate with respect to the single ozonation process at all pH values. The inhibitory effect of free-radical scavengers is impaired by zeolite, suggesting that methylene blue oxidation reactions take place mainly on the zeolite surface. The increase in methylene blue removal rate could be related to ozone interaction with hydroxyl groups present on the zeolite surface (S--OH2(+), S--OH, S--O(-)), which plays a key role in the reaction mechanism.

BTX abatement using Chilean natural zeolite: the role of Brønsted acid sites.

In wastewater treatment facilities, air quality is not only affected by conventional unpleasant odour compounds; toxic volatile organic compounds (VOCs) are also found. In this study, the adsorptive capacity of Chilean natural zeolite toward VOC removal was evaluated. Moreover, the influence of zeolite chemical surface properties on VOC elimination was also investigated. Three modified zeolite samples were prepared from a natural Chilean zeolite (53% clinoptilolite, 40% mordenite and 7% quartz). Natural and modified zeolite samples were characterised by nitrogen adsorption at 77 K, elemental analyses and X-ray fluorescence (XRF). Chemical modifications of natural zeolite showed the important role of Brønsted acid sites on the abatement of VOCs. The presence of humidity has a negative effect on zeolite adsorption capacity. Natural zeolites could be an interesting option for benzene, toluene and xylene vapour emission abatement.

Gestión de garantía de calidad en un policlínico de terapia de anticoagulación oral, Hospital de Carabineros de Chile, Santiago, Chile: satisfacción del cliente como índice de calidad en un hospital público / Gestion of quality control in an outpatient anticoagulant clinic, Hospital de Carabineros de Chile: client satisfaction as an index of quality in a public hospital

El presente estudio prospectivo tiene como objetivo desarrollar instrumentos metodológicos que permitan evaluar y garantizar la calidad de los servicios médicos que se otorgan en la nueva policlínica de control de la anticoagulación oral (TACO) mediante la investigación de la satisfacción del paciente. Las perspectivas del estudio son: infraestructura, procesos, resultados de la atención integral y cuestionamiento del elemento de satisfacción del cliente. Sujetos, materiales y método: Una muestra de 82 de 127 (65 por ciento) pacientes atendidos durante el mes de Marzo de 2010, fueron estudiados utilizando una encuesta estándar, formulada en base a los resultados de un estudio piloto previo. Pacientes que por su enfermedad no tenían capacidad para completar la encuesta fueron excluidos, como aquellos quienes no quisieron participar y los que tuvieron su control por vía telefónica. Resultados: En general la Policlínica tuvo una evaluación de excelente en 48 por ciento de los pacientes, con un promedio sobre 17 puntos (rango 0 a 20). El equipo logró cumplir con las expectativas de 95 por ciento de los pacientes. Hubo diferencias en las evaluaciones entre el equipo profesional y no profesional, pero ambos obtuvieron un promedio sobre 4 (1 a 5). Hubo una diferencia significativa en la evaluación obtenida entre el estudio piloto y el definitivo, respecto al cumplimiento de las expectativas del paciente. Conclusiones: En la encuesta de control de calidad, la Unidad en general obtuvo una calificación buena, pero identificó áreas para mejorar el servicio y atención. Demostró que la calidad de gestión es dependiente del equipo total y el resultado final depende de la participación de todos. Es un proceso largo y no exento de dificultades, la encuesta es parte de la iniciación con la toma de consciencia del problema. Modificaciones a la encuesta son necesarios para el seguimiento y forma parte de la estrategia institucional.

The present prospective study had as its objective the development of instruments which permitted the evaluation of the quality of medical services provided by the outpatient anticoagulant clinic, using client satisfaction as an index of quality. The form of the study included the elements of infrastructure, processes, results of the clinical attention and addressing the element of patient satisfaction. Materials, Methods and Patients: A sample of 82 of the 127 patients attended during March 2010 was studied using a standard questionnaire, based on the results of an earlier pilot study. Patients, who for their illness, were not capable of completing the questionnaire, were excluded from the study, as well as those who did not wish to participate or had their anticoagulation controlled by phone. Results: In general, the outpatient clinic had an excellent evaluation in 48 percent of cases, with an average score of 17 points (range 0-20). The team achieved a 95 percent rate of fulfilling the patients expectations. Although there were differences between the evaluation of the professional and non-professional teams, both obtained an average score of over 4 (range 1-5). The evaluation of the patients improved in the definitive study in comparison with the original pilot study. Conclusions: The survey of quality control showed that the outpatients clinic obtained a qualification classed as good, but identified areas which needed to ve improved. It shows that the quality of care is dependent on the performance of the whole team and the results depend on the participation of all. Implementing quality control is a long process and not extent of problems. Modifications to the questionnaire are necessary for follow up work and form part of the Hospitals Quality Control.

Evaluación de control de calidad, gestión y costos del hemograma en un hospital complejo tipo 1 / Evaluation of hemogram quality control, management and cost in a complex hospital type 1

Determinar criterios de evaluación morfológica del hemograma, basados en parámetros clínicos y resultados del contador hematológico, en términos de gestión, costos y clínica en un hospital tipo 1. Pacientes, materiales y métodos: muestras de hemogramas de pacientes del hospital de carabineros de Chile durante el mes de agosto de 2009, analizadas en un equipo HMX Beckman-Coulter y evaluadas morfológicamente por Tecnólogo Médico(TM). Se registraron parámetros clínicos como hemoglobina, leucocitos y plaquetas; además se consideró el lugar de derivación, especialidad y edad del paciente. Se determinaron los costos e ingresos en función de los resultados obtenidos. Resultados: de los 2.222 pacientes evaluados, existió concordancia entre el Tecnólogo Médico y el analizador en 93,3 por ciento de los casos, con una sensibilidad de 97,3 por ciento y una especificidad de 88,9 por ciento con valores predictivos positivo y negativo de 95,9 por ciento y 92,7 por ciento respectivamente, para detectar una muestra anormal. Con los criterios de selección fue posible eliminar la evaluación morfológca en 79,5 por ciento de los casos, permitiendo un ahorro de $3655929 en el mes por concepto de hemogramas. Discusión: el estudio demostró que es posible disminuir el número de evaluaciones morfológicas realizadas al hemograma a valores similares obtenidos en estudios internacionales, con reducción significativa de los costos y tiempos de TM.

Objective: to determine criteria for the morphological analysis of the full blood count, based on the clinical parameters and the results of the full blood count using an automatic counter in terms of cost and clinicla implications in a distric hospital. Patients, Materials and Method: Full blood count samples from patients attended in the Hospital de Carabineros de Chile during the month of August 2009 were analyzed using HmX Beckman-Coulter and evaluated morpholigically by the Medical Science Officer(Medical Technologist). Clinical parameters, hemoglobin, white cell count platete count were registered, as well the origin of the specimen, medical speciality an patient age. The cost an income derived from the full blood count were determined by the Unit of Cost, Hospital of Carabineros and the changes in costs calculated in function of the results obtained. Results: Of the 2,222 patients evaluated, there was a concordance between the Clinical Science Officer(Medical Technologist) and the automatic counter in 93,9 percent of the samples, with a sensitivity of 97,3 percent and a specificy of 88,9 percent, a positive and negative predictive evalues of 95,9 percent and 92,7 percent respectively for detecting an abnormal sample. Using the criteria of selection it was possible to eliminate the evaluation morphological in 79,5 percent of the samples permitting a saving of $3655929 per month for the analysis of full morphological evaluations of the blood count without losing clinically important data in 80 percent of the samples, which is similar to that reported internationally, with a significant decrease in cost an Medical Scientific Officer time.

Heterogeneous catalytic ozonation of cationic dyes using volcanic sand.

This work aims to present experimental results on the treatment of methylene blue contaminated waters using heterogeneous catalytic ozonation promoted by volcanic sand. The effect of pH (2-8), and the presence of radical scavengers (acetate ions) in homogeneous and heterogeneous systems are evaluated at laboratory scale. Heterogeneous catalytic ozonation using volcanic sand increases methylene blue removal rate. In the presence of free radical scavengers, only a 37% reduction on methylene blue removal rate is observed in the heterogeneous system, as compared with 70% when homogeneous ozonation is used. The results obtained here indicate the importance of chemical surface properties on methylene blue oxidation reactions, suggesting that acid surface sites of volcanic sand play a key role on the reaction mechanism.

Necesidad de la evaluación morfológica del hemograma en un hospital complejo tipo 1: control de calidad y gestión / Necessity of the morphological evaluation of the haemogram in a complex hospital type 1: management and quality control

Objetivo: Determinar criterios de selección de muestras para la evaluación morfológica del hemograma, basados en parámetros clínicos y resultados del contador hematológico y en términos de gestión, costos y clínica, los resultados de un programa de selección de muestras para la evaluación morfológica del examen en un hospital tipo 1. Pacientes, Materiales y Método: Pacientes con una muestra tomada en el Hospital de Carabineros de Chile durante el mes de Agosto de 2009, las que fueron analizadas en un equipo Beckman Coulter HmX@ y evaluadas morfológicamente por el Tecnólogo Médico. Se registraron los parámetros clínicos tales como hemoglobina, leucocitos y plaquetas, además del lugar de derivación, especialidad y edad del paciente. Los resultados fueron analizados, tanto por alerta clínica como instrumental, incluyendo todos los parámetros considerados clínicamente importantes. Resultados: Participaron 2.222 pacientes, hubo concordancia entre el Tecnólogo Médico y el analizador en 93,9 por ciento de los casos, con una sensibilidad de 97,3 por ciento y una especificidad de 88,9 por ciento con valores predictivos positivo y negativo de 95,9 por ciento y 92,7 por ciento respectivamente, para detectar una muestra anormal. Por criterios de selección se eliminó la evaluación morfológica en 79,5 por ciento de los casos. Hubo 1,6 por ciento de casos falso-negativos en los criterios de morfología. Discusión: El estudio demostró que es posible disminuir el número de evaluaciones morfológicas hechas al hemograma en un 80 por ciento de los casos, lo cual es semejante a los estudios internacionales efectuados en un hospital tipo 1. El sistema de alerta clínica pone énfasis en la importancia de que el médico tratante ingrese la información clínica en la solicitud de hemograma. Hay una liberación importante de tiempo de Tecnólogo Médico para utilizar su capacidad en funciones de mayor complejidad.

Objectives: To determine selection criteria for the morphological evaluation of full blood count samples, based on clinical criterias and the results of an automatic hematological analyzer. To analyze the cost-benefits and gestion of such a selection procedure in samples obtained from a public general hospital. Patients, Materials and Methods: AII patients with a full blood count taken at the Hospital de Carabineros de Chile during August 2009 were included AII samples were analyzed using a Beckman-Coulter HmX@ automatic analyzer and analyzed morphologically by the Medical Science Officer. Patient details including age, sex, hematological parameters Hemoglobin, white cell and platelet count and place of reference were noted the results were analyzed using clinical and instrument alerts, including all clinical hematological parameters considered important. Results: 2,222 patients were included in the study. There were an agreement in analysis between the HmX and Medical Science Officer in 93.9 percent of cases, with a sensitivity of 93.9 percent specificity of 88.9 percent, a positive and negative predictive value of 95.9 percent and 927 percent respectively to detect and abnormal blood count. Owing to the selection criteria used it was possible to eliminate the need for morphological evaluation in 79.5 percent of cases, the possibility of a serious error of omission being minimal, only 1,6 percent of cases were false negative, on morphological and not clinical grounds. Discussion: The study showed that it is possible to decrease the number of morphological evaluations in 80 percent of cases, which is similar to the figures internationally reported for a general hospital. The clinical alert puts emphasis on the treating physician to complete clinical details on the order form. In total, there were 1.6 percent of false negative cases on morphological grounds y it is important to note that some morphological abnormalities will not be detected the...

Functional recovery of callosal axons following demyelination: a critical window.

Axonal dysfunction as a result of persistent demyelination has been increasingly appreciated as a cause of functional deficit in demyelinating diseases such as multiple sclerosis. Therefore, it is crucial to understand the ultimate causes of ongoing axonal dysfunction and find effective measures to prevent axon loss. Our findings related to functional deficit and functional recovery of axons from a demyelinating insult are important preliminary steps towards understanding this issue. Cuprizone diet for 3-6 wks triggered extensive corpus callosum (CC) demyelination, reduced axon conduction, and resulted in loss of axon structural integrity including nodes of Ranvier. Replacing cuprizone diet with normal diet led to regeneration of myelin, but did not fully reverse the conduction and structural deficits. A shorter 1.5 wk cuprizone diet also caused demyelination of the CC, with minimal loss of axon structure and nodal organization. Switching to normal diet led to remyelination and restored callosal axon conduction to normal levels. Our findings suggest the existence of a critical window of time for remyelination, beyond which demyelinated axons become damaged beyond the point of repair and permanent functional loss follows. Moreover, initiating remyelination early within the critical period, before prolonged demyelination-induced axon damage ensues, will improve functional axon recovery and inhibit disease progression.

Methylene blue removal from contaminated waters using O3, natural zeolite, and O3/zeolite.

This paper compares experimental results on methylene blue (MB) removal systems based on ozone oxidation, zeolite adsorption, and simultaneous adsorption-oxidation using ozone in the presence of natural zeolite. The effect of pH (2-8), and the presence of radical scavengers (sodium acetate) on process rates and removal efficiencies are assessed at laboratory scale. The experimental system consisted of a 1 L differential circular flow reactor and an ozone generator rated at 5 g O3/h. Results show that ozone oxidation combined with zeolite adsorption increases the overall MB oxidation rate with respect to ozonation process and zeolite adsorption. In presence of free radical scavenger, only a 25% of reduction on MB removal rate are observed in the simultaneous treatment, as compared with 70% when ozonation treatment is used, suggesting that MB oxidation reactions take mainly place on the zeolite surface.

Nitrate and phosphate leaching in a Phaeozem soil treated with biosolids, composted biosolids and inorganic fertilizers.

The use of organic wastes in agriculture may increase the production of crops by incorporating organic matter and nutrients into the soil, and by improving its physical characteristics; however, this use may cause environmental problems such as the leaching of certain ions. The objective of this study was to establish possible nitrogen and phosphorus leaching under real field conditions in Phaeozem soils. The experimental work was performed in a corn (Zea mays L.) field where three plots were conditioned with inorganic fertilizer, three plots with 4.5 Mgha(-1) of biosolids on dry basis, and three plots with the same amount of composted biosolids. The quality of biosolids and composted biosolids complied with the Mexican Official Standards. Soil water samples were collected with suction cups during two agricultural cycles and were analysed. Soil samples were also taken and analysed. The N-NO(3) concentrations in soil water fluctuated between 0.9 and 98mgL(-1) in the composted biosolid treatment, between 0.7 and 64 mgL(-1) in the biosolid treatment, and between 1 and 61 mgL(-1) in the inorganic fertilizer treatment. The maximum concentration of N-NO(2) and N-NH(3) in soil water was 1.02 and 2.65 mgL(-1), respectively. The greatest percentage of nitrogen leached is produced when inorganic fertilizer is used (37.4% and 24.0% N leached in the first and second years, respectively), followed by composted biosolids (17.1% and 13.5% N leached in the first and second years, respectively) and last by biosolids (11% for both years). This difference could be related to the form in which nitrogen is present in the fertilizers, while commercial fertilizer is as inorganic nitrogen, organic wastes are basically presented as organic nitrogen. The maximum PO(4)(3-) concentration in soil water was 1.9 mgL(-1) in the composted biosolid treatment, 1.7mgL(-1) in the biosolid treatment and 0.9 mgL(-1) in the inorganic fertilizer treatment. The estimated percentage of leached phosphorus was less than 1% for all treatments. The minimum leaching that occurred seemed to be due to a sorption-precipitation process.

Phenylalanyl-Glycyl-Phenylalanine Tripeptide: A Model System for Aromatic-Aromatic Side Chain Interactions in Proteins.

The performance of a wide range of quantum chemical calculations for the ab initio study of realistic model systems of aromatic-aromatic side chain interactions in proteins (in particular those π-π interactions occurring between adjacent residues along the protein sequence) is here assessed on the phenylalanyl-glycyl-phenylalanine (FGF) tripeptide. Energies and geometries obtained at different levels of theory are compared with CCSD(T)/CBS benchmark energies and RI-MP2/cc-pVTZ benchmark geometries, respectively. Consequently, a protocol of calculation alternative to the very expensive CCSD(T)/CBS is proposed. In addition to this, the preferred orientation of the Phe aromatic side chains is discussed and compared with previous results on the topic.

Heterogeneous catalytic ozonation of benzothiazole aqueous solution promoted by volcanic sand.

This paper presents experimental results on the catalytic effect of volcanic sand on benzothiazole ozonation. Experiments were assessed at laboratory scale, in a differential circular flow reactor composed of a volcanic sand fixed bed column of 19 cm3 and a 1 dm3 storage tank, operated in batch mode at 20 degrees C and pH 2-7. Experimental results show that ozone self-decomposition is enhanced by the presence of volcanic sand at all pH. At pH>pH(PZC), the increase in aqueous ozone decay could be related to ozone interaction with strong Lewis acid on metal oxide surface sites of the volcanic sand. Ozone self-decomposition reactions occurring on the volcanic sand are less affected by the presence of radical scavengers. Benzothiazole removal by ozonation is also enhanced by the presence of volcanic sand. Moreover, the inhibitory effect of free radical scavengers is also impaired by volcanic sand, suggesting that strong Lewis acid surface sites play a key role on the reaction mechanism.

[Unusual presentation of bilateral bullous Pneumocystis jiroveci pneumonia complicated with pneumothorax]. / Presentación inhabitual de un caso de neumonía bulosa aguda bilateral por Pneumocystis jiroveci complicada con neumotórax.

In patients with human immunodeficiency virus infection, pneumothorax overcomes in advanced stages of the illness, associated with infections by Mycobacterium tuberculosis or Pneumocystis jiroveci, in smokers and intravenous drug users. We present a case with this unusual complication: homosexual man, 30 years of age, with a history of one month of cough, progressive dyspnea, weight loss and diarrhea. He was hospitalized with the diagnosis of atypical pneumonia, respiratory failure and a presumptive HIV infection. His clinical course was complicated by the presence of bullae and pneumothorax by day 15 of hospitalization. The existence of Pneumocystis jiroveci in sputum was confirmed by a direct immunofluorescence test. The patient was treated with sulpha-trimethoprim, steroids, oxygen, but he died 21 days after admittance. The strategies recommended for treatment of pneumothorax appeared during P. jiroveci pneumonia in HIV positive patients are summarized.

Presentación inhabitual de un caso de neumonía bulosa aguda bilateral por Pneumocystis jiroveci complicada con neumotórax / Unusual presentation of bilateral bullous Pneumocystis jiroveci pneumonia complicated with pneumothorax

En los pacientes con infección por el virus de la inmunodeficiencia humana (VIH), el neumotórax se observa generalmente en etapas avanzadas de la enfermedad, asociado a patógenos como Mycobacterium tuberculosis o Pneumocystis jiroveci, en individuos tabáquicos y drogadictos endovenosos. Presentamos un caso de presentación inhabitual: varón homosexual, 30 años de edad, con tos durante un mes, dificultad respiratoria progresiva y baja de peso, agregándose posteriormente diarrea. Fue hospitalizado con los diagnósticos de insuficiencia respiratoria, neumopatía atípica y observación de infección por VIH. Evolucionó mal, complicándose a los 15 días con neumotórax y bulas pulmonares. El LDH elevado y después la inmunofluorescencia directa (+) confirmaron la etiología: P. jiroveci. El test de ELISA confirmó la pre-existencia de una infección por VIH. A pesar de una terapia enérgica con cotrimoxazol, corticoesteroides y oxígeno, el paciente falleció a los 21 días de su ingreso. Se describen las estrategias recomendadas para el manejo del neumotórax que acontece durante la neumonía por P. jiroveci en los pacientes portadores de infección por VIH.

In patients with human immunodeficiency virus infection, pneumothorax overcomes in advanced stages of the illness, associated with infections by Mycobacterium tuberculosis or Pneumocystis jiroveci, in smokers and intravenous drug users. We present a case with this unusual complication: homosexual man, 30 years of age, with a history of one month of cough, progressive dyspnea, weight loss and diarrhea. He was hospitalized with the diagnosis of atypical pneumonia, respiratory failure and a presumptive HIV infection. His clinical course was complicated by the presence of bullae and pneumothorax by day 15 of hospitalization. The existence of Pneumocystis jiroveci in sputum was confirmed by a direct immunofluorescence test. The patient was treated with sulpha-trimethoprim, steroids, oxygen, but he died 21 days after admittance. The strategies recommended for treatment of pneumothorax appeared during P. jiroveci pneumonia in HIV positive patients are summarized.

Ozonation of benzothiazole saturated-activated carbons: influence of carbon chemical surface properties.

The combined or sequential use of ozone and activated carbon to treat toxic effluents has increased in recent years. However, little is known about the influence of carbon surface active sites on ozonation of organic adsorbed pollutants. This paper presents experimental results on the effect of metal oxides and oxygenated surface groups on gaseous ozonation of spent activated carbons. Benzothiazole (BT) was selected as a target organic compound in this study due to its environmental concern. Activated carbons with different chemical surface composition were prepared from a Filtrasorb-400 activated carbon. Pre-treatment included: ozonation, demineralisation, and deoxygenation of activated carbon. Ozonation experiments of BT saturated-activated carbons were conducted in a fixed bed reactor loaded with 2 g of carbon samples. The reactor was fed with an O2/O3 gas mixture (2 dm3/min, 5 g O3/h), for a given exposure time, in the range 10-120 min, at 298 K and 1 atm. Results show that extended gaseous ozonation of activated carbon saturated with BT led to the effective destruction of the adsorbate by oxidation reactions. Oxidation of BT adsorbed on activated carbon seemed to occur via both direct reaction with ozone molecules, and by oxygen radical species generated by catalytic ozone decomposition on metallic surface sites.

[Cutaneous signs of endocrinopathies]. / Manifestations cutanées des pathologies endocriniennes.

Some cutaneous lesions accompany or reveal endocrine disorders. Identifying the endocrinopathy is very important because it sometimes allows corrective rather than symptomatic treatment. The most frequenly involved diseases include thyrotoxicosis, hypothyroidism, the auto-immune disorders of thyroid, Cushing syndrome, Addison disease, acromegaly, androgen-dependent disorders, hypopituitarism, hypoparathyroidism, pseudohypoparathyroidism and diabetes mellitus.

Structure and IR spectrum of phenylalanyl-glycyl-glycine tripetide in the gas-phase: IR/UV experiments, ab initio quantum chemical calculations, and molecular dynamic simulations.

We investigated the potential-energy surface (PES) of the phenylalanyl-glycyl-glycine tripeptide in the gas phase by means of IR/UV double-resonance spectroscopy, and quantum chemical and statistical thermodynamic calculations. Experimentally, we observed four conformational structures and we recorded their IR spectra in the spectral region of 3000-4000 cm(-1). Computationally, we investigated the PES by a combination of molecular dynamics/quenching procedures with high-level correlated ab initio calculations. We found that neither empirical potentials nor various DFT functionals provide satisfactory results. On the other hand, the approximative DFT method covering the dispersion energy yields a reliable set of the most stable structures, which we subsequently investigated with an accurate, correlated ab initio treatment. The global minimum contains three moderately strong intramolecular hydrogen bonds and is mainly stabilized by London dispersion forces between the phenyl ring, the carboxylic acid group, and various peptide bonds. A proper description of the last type of interaction requires accurate correlated ab initio calculations, including the complete basis set limit of the MP2 method and CCSD(T) correction terms. Since in our beam experiments the conformations are frozen by cooling from a higher temperature, it is necessary to localize the most stable structures on the free-energy surface rather than on the PES. We used two different procedures (rigid rotor/harmonic oscillator/ideal gas approximation based on ab initio characteristics and evaluation of relative populations from the molecular dynamic simulations using the AMBER potential) and both yield four structures, the global minimum and three local minima. These four structures were among the 15 most energetically stable structures obtained from accurate ab initio optimization. The calculated IR spectra for these four structures agree well with the experimental frequencies, which validates the localization procedure.