438 research outputs found

    Boundary critical behaviour of two-dimensional random Ising models

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    Using Monte Carlo techniques and a star-triangle transformation, Ising models with random, 'strong' and 'weak', nearest-neighbour ferromagnetic couplings on a square lattice with a (1,1) surface are studied near the phase transition. Both surface and bulk critical properties are investigated. In particular, the critical exponents of the surface magnetization, 'beta_1', of the correlation length, 'nu', and of the critical surface correlations, 'eta_{\parallel}', are analysed.Comment: 16 pages in ioplppt style, 7 ps figures, submitted to J. Phys.

    Fluorescence studies on new potential antitumoral benzothienopyran-1-ones in solution and in liposomes

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    Fluorescence properties of four new potential antitumoral compounds, 3-arylbenzothieno[2,3-c]pyran-1-ones, were studied in solution and in lipid membranes of dipalmitoyl phosphatidylcholine (DPPC), egg yolk phosphatidylcholine (Egg-PC) and dioctadecyldimethylammonium bromide (DODAB). The 3-(4-methoxyphenyl)benzothieno[2,3-c]pyran-1-one (1c) exhibits the higher fluorescence quantum yields in all solvents studied. All compounds present a solvent sensitive emission, with significant red shifts in polar solvents for the methoxylated compounds. The results point to an ICT character of the excited state, more pronounced for compound 1c. Fluorescence (steady-state) anisotropy measurements of the compounds incorporated in liposomes of DPPC, DODAB and Egg-PC indicate that all compounds have two different locations, one due to a deep penetration in the lipid membrane and another corresponding to a more hydrated environment. In general, the methoxylated compounds prefer hydrated environments inside the liposomes. The 3-(4- fluorophenyl)benzothieno[2,3-c]pyran-1-one (1a) clearly prefers a hydrated environment, with some molecules located at the outer part of the liposome interface. On the contrary, the preferential location of 3-(2-fluorophenyl)benzothieno[2,3-c]pyran-1-one (1b) is in the region of lipid hydrophobic tails. Compounds with a planar geometry (1a and 1c) have higher mobility in the lipid membranes when phase transition occurs.Portugal and FEDER (Fundo Europeu de Desenvolvimento Regional), for financial support through Centro de Física (CFUM) and Centro de Química (CQ-UM) of University of Minho and through the Project PTDC/QUI/81238/2006. M.S.D. Carvalho and R.C. Calhelha acknowledge FCT for their PhD grants SFRH/BD/47052/2008 and SFRH/BD/29274/2006, respectively.Fundação para a Ciência e a Tecnologia (FCT

    Whipple's disease with neurological manifestations - Case report

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    Whipple's disease (WD) is an uncommon multisystem condition caused by the bacillus Tropheryma whipplei. Central nervous system involvement is a classical feature of the disease observed in 20 to 40% of the patients. We report the case of a 62 yeards old man with WD that developed neurological manifestations during its course, and discuss the most usual signs and symptoms focusing on recent diagnostic criteria and novel treatment regimens.622A34234

    Antrum Approach Planning for Removal of Impacted Tooth Using Cone-Beam Computed Tomography

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    Due to the great number of structures in the maxillofacial region, cone-beam computed tomography (CBCT) is an important procedure in presurgical planning for removal of impacted teeth. Most of the information provided by this imaging technique cannot be visualized in conventional radiographs. In addition, CBCT reduces patient exposure to radiation in comparison with helical computed tomography and provides dental practitioners with easy access. We report the clinical case of a patient who underwent a surgical procedure for removal of an impacted maxillary premolar. CBCT-assisted presurgical treatment was used, enabling a more conservative surgical access, a less traumatic and less time consuming procedure than conventional surgical intervention

    Qualidade dos cuidados de enfermagem e satisfação do paciente atendido em um hospital de ensino

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    OBJECTIVES: assess the quality of nursing care, the patients' satisfaction and the correlation between both. METHOD: cross-sectional study, involving 275 patients hospitalized at a teaching hospital in the Central-West of Brazil. The data were collected through the simultaneous application of three instruments. Next, they were included in an electronic database and analyzed in function of the positivity, median value and Spearman's correlation coefficients. RESULTS: among the nursing care assessed, only two were considered safe - hygiene and physical comfort; nutrition and hydration - while the remainder were classified as poor. Nevertheless, the patients were satisfied with the care received in the domains assessed: technical-professional, confidence and educational. This can be justified by the weak to moderate correlation that was observed among these variables. CONCLUSION: Despite the quality deficit, the patients' satisfaction level with the nursing care received was high. These results indicate that the institution needs to center its objectives on a continuing evaluation system of the care quality, aiming to attend to the patients' expectations.OBJETIVOS: evaluar la calidad de los cuidados de enfermería, la satisfacción del paciente y la correlación entre ambos. MÉTODO: estudio trasversal con 275 pacientes internados en un hospital de enseñanza de la región Centro-Oeste de Brasil. Los datos fueron recolectados mediante la aplicación simultánea de tres instrumentos. A seguir, fueron digitalizados en un banco de datos electrónico y analizados en función de la positividad, valor de mediana y coeficientes de correlación de Spearman. RESULTADOS: entre los cuidados de enfermería evaluados, solamente dos fueron considerados seguros - higiene y conforto físico; nutrición e hidratación - y los demás clasificados como pobres. Sin embargo, los pacientes se mostraron satisfechos con los cuidados recibidos en los dominios evaluados: técnico-profesional, confianza y educacional. Eso puede ser justificado por la correlación débil a moderada observada entre esas variables. CONCLUSIÓN: A pesar del déficit de cualidad, fue encontrado alto nivel de satisfacción de los pacientes con los cuidados de enfermería recibidos. Tales resultados indican la necesidad de que la institución centre sus objetivos en un sistema de evaluación permanente de la cualidad del cuidado, visando atender a las expectativas de los pacientes.OBJETIVOS: avaliar a qualidade dos cuidados de enfermagem, a satisfação do paciente e a correlação entre ambos. MÉTODO: estudo transversal, realizado com 275 pacientes internados em um hospital de ensino da Região Centro-Oeste do Brasil. Os dados foram obtidos por meio da aplicação simultânea de três instrumentos. A seguir, foram digitados em banco de dados eletrônico e analisados em função da positividade, valor de mediana e coeficientes de correlação de Spearman. RESULTADOS: dentre os cuidados de enfermagem avaliados, apenas dois foram considerados seguros - higiene e conforto físico; nutrição e hidratação - e os demais foram classificados como pobres. Todavia, os pacientes mostraram-se satisfeitos com os cuidados recebidos nos domínios avaliados: técnico-profissional, confiança e educacional. Isso pode ser justificado pela correlação fraca a moderada observada entre essas variáveis. CONCLUSÃO: apesar do déficit de qualidade, houve alto nível de satisfação dos pacientes com os cuidados de enfermagem recebidos. Tais resultados apontam a necessidade de a instituição centrar seus objetivos num sistema de avaliação permanente da qualidade do cuidado, visando o atendimento das expectativas dos pacientes

    Relationships of Cetacea (Artiodactyla) Among Mammals: Increased Taxon Sampling Alters Interpretations of Key Fossils and Character Evolution

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    BACKGROUND: Integration of diverse data (molecules, fossils) provides the most robust test of the phylogeny of cetaceans. Positioning key fossils is critical for reconstructing the character change from life on land to life in the water. METHODOLOGY/PRINCIPAL FINDINGS: We reexamine relationships of critical extinct taxa that impact our understanding of the origin of Cetacea. We do this in the context of the largest total evidence analysis of morphological and molecular information for Artiodactyla (661 phenotypic characters and 46,587 molecular characters, coded for 33 extant and 48 extinct taxa). We score morphological data for Carnivoramorpha, Creodonta, Lipotyphla, and the raoellid artiodactylan Indohyus and concentrate on determining which fossils are positioned along stem lineages to major artiodactylan crown clades. Shortest trees place Cetacea within Artiodactyla and close to Indohyus, with Mesonychia outside of Artiodactyla. The relationships of Mesonychia and Indohyus are highly unstable, however--in trees only two steps longer than minimum length, Mesonychia falls inside Artiodactyla and displaces Indohyus from a position close to Cetacea. Trees based only on data that fossilize continue to show the classic arrangement of relationships within Artiodactyla with Cetacea grouping outside the clade, a signal incongruent with the molecular data that dominate the total evidence result. CONCLUSIONS/SIGNIFICANCE: Integration of new fossil material of Indohyus impacts placement of another extinct clade Mesonychia, pushing it much farther down the tree. The phylogenetic position of Indohyus suggests that the cetacean stem lineage included herbivorous and carnivorous aquatic species. We also conclude that extinct members of Cetancodonta (whales+hippopotamids) shared a derived ability to hear underwater sounds, even though several cetancodontans lack a pachyostotic auditory bulla. We revise the taxonomy of living and extinct artiodactylans and propose explicit node and stem-based definitions for the ingroup

    New potential antitumoral fluorescent tetracyclic thieno[3,2-b]pyridine derivatives: interaction with DNA and nanosized liposomes

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    Fluorescence properties of two new potential antitumoral tetracyclic thieno[3,2-b]pyridine derivatives were studied in solution and in liposomes of DPPC (dipalmitoyl phosphatidylcholine), egg lecithin (phosphatidylcholine from egg yolk; Egg-PC) and DODAB (dioctadecyldimethylammonium bromide). Compound 1, pyrido[2',3':3,2]thieno[4,5-d]pyrido[1,2-a]pyrimidin-6-one, exhibits reasonably high fluorescence quantum yields in all solvents studied (0.20 ≤ ΦF ≤ 0.30), while for compound 2, 3-[(p-methoxyphenyl)ethynyl]pyrido[2',3':3,2]thieno[4,5-d]pyrido[1,2-a]pyrimidin-6-one, the values are much lower (0.01 ≤ ΦF ≤ 0.05). The interaction of these compounds with salmon sperm DNA was studied using spectroscopic methods, allowing the determination of intrinsic binding constants, Ki = (8.7 ± 0.9) × 103 M-1 for compound 1 and Ki = (5.9 ± 0.6) × 103 M-1 for 2, and binding site sizes of n = 11 ± 3 and n = 7 ± 2 base pairs, respectively. Compound 2 is the most intercalative compound in salmon sperm DNA (35%), while for compound 1 only 11% of the molecules are intercalated. Studies of incorporation of both compounds in liposomes of DPPC, Egg-PC and DODAB revealed that compound 2 is mainly located in the hydrophobic region of the lipid bilayer, while compound 1 prefers a hydrated and fluid environment
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