Double-valence photoionization of SUVA134a molecule (CFH2 CF3 ).

RATIONALE: In this work we investigate the single-photon double ionization of the SUVA 134a (1,1,1,2-tetrafluoroethane) molecule in the energy range from 21.21 to 320 eV. Our experimental data are supported by Thomas' and Samson's models. It is shown that the double photoionization of the SUVA 134a can be expressed as a sum of the so-called shake-off (SO) and the knockout (KO) processes. METHODS: The experiments were executed at the TGM beamline at Laboratório Nacional de Luz Síncrotron in Campinas, Brazil. The source of EUV and X-ray radiation was a bending magnet that enabled us to work in the photon energy range of 21.21 to 320 eV. The spectrometer was devised to collect 100% of the ions with kinetic energies up to 30 eV. The photoelectron-photoion (PEPICO) and photoelectron-photoion-photoion (PE2PICO) coincidence techniques were used in the present work. RESULTS: The ratio of double-to-total photoionization as a function of the photon energy for the SUVA molecule exhibits remarkably similar behavior with other atomic and molecular systems. SO depends on large excess energy above the ionization threshold, enabling the photoelectron to leave the interaction region rather speedily to yield a sudden change in the Coulomb field that the shaken electron feels. The measured asymptotic SO probability is PSO (∞) = 0.09. CONCLUSIONS: The present analysis shows that the separation of SO and KO processes relies on the experimental evidence that there is no significant interference between SO and KO. The analysis also shows that the separate formulation of KO and SO presents a factual portrayal of double photoionization. Despite having 50 electrons, SUVA has lower double-to-total photoionization fraction (9%) in comparison, for instance, to argon atoms (~20%), which has 18 electrons. This lower e-e correlation could be attributed to its larger volume, that is, lower electron density.

Photoabsorption and Photoionization Cross Sections of Pyridine in the Vacuum-Ultraviolet Energy Range.

We have performed an experimental investigation into the interaction of vacuum-ultraviolet synchrotron radiation with pyridine molecules in the gas phase. Specifically, a double-ion chamber spectrometer was used to measure the absolute photoabsorption cross sections and the photoionization quantum yields from the ionization threshold to 21.5 eV. Moreover, photoionization and neutral-decay cross sections in absolute scale were derived from these data. In addition, the fragmentation pattern was investigated as a function of the photon energy by using a time-of-flight mass spectrometer and the photoelectron-photoion coincidence technique. Thus, the absolute partial ionization cross sections for each ionic fragment were obtained. Comparisons are made with experimental data available in the literature.

Ionization and Fragmentation of DCOOD Induced by Synchrotron Radiation at the Oxygen 1s Edge: The Role of Dimer Formation.

The ionization and photofragmentation of molecules in the core region has been widely investigated for monomers and dimers of organic molecules in the gas phase. In this study, we used synchrotron radiation to excite electrons of the oxygen K-edge in an effusive molecular beam of doubly deuterated formic acid. We used time-of-flight mass spectrometry and employed the spectroscopic techniques photoelectron-photoion coincidence and photoelectron photoion-photoion coincidence to obtain spectra of single and double coincidences at different pressures. Our results indicate the presence of ions and ion pairs that have charge-to-mass ratio higher than the monomer DCOOD, as the (DCOOD)·D(+), and pairs (DCO(+), DCO(+)) and (CO(+), DCO(+)). Comparing the spectra obtained for different pressures we can ascertain that these ions are formed by the fragmentation of DCOOD dimers.

Communication: Protonation process of formic acid from the ionization and fragmentation of dimers induced by synchrotron radiation in the valence region.

The ionization and fragmentation of monomers of organic molecules have been extensively studied in the gas phase using mass spectroscopy. In the spectra of these molecules it is possible to identify the presence of protonated cations, which have a mass-to-charge ratio one unit larger than the parent ion. In this work, we investigate this protonation process as a result of dimers photofragmentation. Experimental photoionization and photofragmentation results of doubly deuterated formic acid (DCOOD) in the gas phase by photons in the vacuum ultraviolet region are presented. The experiment was performed by using a time-of-flight mass spectrometer installed at the Brazilian Synchrotron Light Laboratory and spectra for different pressure values in the experimental chamber were obtained. The coupled cluster approach with single and double substitutions was employed to assist the experimental analysis. Results indicate that protonated formic acid ions are originated from dimer dissociation, and the threshold photoionization of (DCOOD)⋅D(+) is also determined.

Ionization and Fragmentation of Formamide Induced by Synchrotron Radiation in the Valence Region via Photoelectron Photoion Coincidence Measurements and Density Functional Theory Calculations.

We have performed a theoretical and experimental study of the formamide (HCONH2) photofragmentation and photoionization processes in the gas phase. The experiment was perfomed by using a time-of-flight mass spectrometer using the photoelectron photoion coincidence (PEPICO) technique in the valence region, from photons with energy between 10 and 20 eV. We have obtained both mass and partial ion yield spectra, identified by the mass-to-charge ratio as a function of the photon energy. With this setup, we could ascertain the threshold energy for the production of formamide cation and its cationic fragments. The theoretical analysis of the formamide photofragmentation channels are fulfilled by the density functional theory (DFT) and the time-dependent density functional theory (TDDFT). The theoretical analysis allowed us to estimate, for example, which atoms are lost during the photofragmentation. We have also developed a theoretical-experimental analysis of the main fragments produced in the dissociation: m/q = 45 (HCONH2+), m/q = 44 (CONH2+), m/q = 29 (HCO+), m/q = 17 (NH3+), and m/q = 16 (NH2+).

Experimental evidence of twin fast metastable H(2(2)S) atoms from dissociation of cold H2 induced by electrons.

We report the direct detection of two metastable H(2^{2}S) atoms coming from the dissociation of a single cold H(2) molecule, in coincidence measurements. The molecular dissociation was induced by electron impact in order to avoid limitations by the selection rules governing radiative transitions. Two detectors, placed close to the collision center, measure the neutral metastable H(2(2)S) through a localized quenching process, which mixes the H(2^{2}S) state with the H(2^{2}P), leading to a Lyman-α detection. Our data show the accomplishment of a coincidence measurement which proves for the first time the existence of the H(2(2)S)-H(2(2)S) dissociation channel.

Surface-Altered Protonation Studied by Photoelectron Spectroscopy and Reactive Dynamics Simulations.

The extent to which functional groups are protonated at aqueous interfaces as compared to bulk is deemed essential to several areas in chemistry and biology. The origin of such changes has been the source of intense debate. We use X-ray photoelectron spectroscopy and all-atom reactive molecular dynamics simulations as two independent methods to probe, at the molecular scale, both bulk and surface distributions of protonated species of cysteine in an aqueous solution. We show that the distribution of the cysteine species at the surface is quite different from that in the bulk. We argue that this finding, however, cannot be simply related to a change in the extent of proton sharing between the two conjugate acid/base pairs that may occur between these two regions. The present theoretical simulations identify species at the surface that are not present in the bulk.

Terapia ocupacional e a educação para a interprofissionalidade em residências multiprofissionais em saúde / Occupational therapy and education for the inter-professionality in multi-professional health residencies

A formação em serviço realizada pelo programa de Residência Multiprofissional em Saúde (RMS) é uma estratégia educativa que visa a mudança do perfil dos profissionais da saúde para atuação no Sistema Único de Saúde (SUS). Dentre as profissões que compõem as residências, a terapia ocupacional foi eleita como foco deste estudo com o objetivo de conhecer e refletir sobre os desafios e tendências do processo de educação profissional e interprofissional na perspectiva de tutores, preceptores e residentes terapeutas ocupacionais. A metodologia eleita foi a abordagem qualitativa com realização de entrevistas e análise de conteúdo para a elaboração dos resultados e discussão. Foram realizadas 17 entrevistas em três programas de RMS de diferentes municípios do estado de São Paulo com cenários educativos realizados na atenção hospitalar e na atenção básica. Duas categorias empíricas foram identificadas nos resultados: (i) "Residência multiprofissional de saúde como dispositivo de mudança" dividida em duas subcategorias: "Trabalho em equipe" e "Trabalho na perspectiva do SUS" e (ii) "Singularidades na formação do terapeuta ocupacional em RMS" agrupada nas subcategorias: "Particularidades da inserção profissional do terapeuta ocupacional nos cenários educativos", "Produção de identidades e a fragmentação da atuação do terapeuta ocupacional nas RMS" e "Terapia ocupacional e as práticas colaborativas e interprofissionais no SUS". A pesquisa permitiu conhecer o potencial de mudanças dos programas de RMS em relação à formação dos residentes e à disseminação de práticas em saúde, colaborativas em equipe e sob a perspectiva do SUS. Os resultados apontaram a singularidade do processo formativo de terapeutas ocupacionais nas RMS que sofrem impactos pela insuficiente contratação de profissionais nos serviços, pelo desconhecimento do papel profissional do terapeuta ocupacional e pela fragmentação da atuação profissional nos cenários de prática; experiências...

The in-service education carried out by the multi-professional residency in health (MPRH) is a strategy that aims at a profile change of health professionals in order to prepare them to work in the Brazilian Unified Health System (SUS). Among the professions included in MPRH, the occupational therapy was selected as the focus of this study in order to explore and reflect on the challenges and tendencies of the professional and inter-professional education process from the perspective of occupational therapy tutors, preceptors, and residents. The selected methodology was the qualitative approach, carried out by means of interviews and content analyses that led to the elaboration of results and discussions. Seventeen interviews were carried out in three MPRH programs of different municipalities in the State of São Paulo, and had their educational scenarios centered in hospital care and basic health care. Two empiric categories were identified in the results: (i) "MPRH as a means of change," divided into two subcategories: "Team Work" and "Work from the perspective of SUS ," and (ii) "Singularities in the education of the occupational therapist in MPRH", which was grouped in the following subcategories: "Particularities of the inclusion of occupational therapists into the educational scenarios," "Production of identities and the fragmentation of the occupational therapists' work in MPRH" and "Occupational Therapy and the collaborative and inter-professional practices in SUS." The research allowed for the identification of possibilities of changes brought about the MPRH regarding the professional education of residents and the dissemination of collaborative practices among health service professionals from the perspective of SUS. Results pointed out the singularity of the educative process of occupational therapists in the MPRH, which are impacted by the insufficient professional staffing, the unawareness of the occupational therapist's...

Avaliação da qualidade de manteigas de fabricação caseira / Quality evaluation of home-made butters

Na cidade de Pelotas (RS) é comum a comercialização em feiras livres, de manteiga de fabricação caseira, a qual não possui parâmetros de identidade e qualidade estabelecidos pela legislação. O objetivo deste trabalho foi verificar a qualidade físico-química, sensorial e microbiológica de manteigas de fabricação caseira, comercializadas em feiras livres da cidade de Pelotas (RS), comparando-as com a qualidade de manteiga industrializada de marca tradicional. Foram realizadas determinações do teor de gordura, umidade, índice de peróxido e acidez, avaliações das características sensoriais e testes microbiológicos quanto à contagem de coliformes totais e fecais. Entre as amostras de manteigas analisadas apenas uma apresentou teor de umidade acima do permitido pela legislação. (...) Os testes microbiológicos mostraram que apesar da manipulação inadequada dos produtos, as amostras apresentaram padrão microbiológico dentro do permitido. Observou-se que de um total de 4 amostras coletadas, nenhuma se encontrava em condições de ser comercializada seguindo os parâmetros exigidos pela legislação.