Carbonatites from the southern brazilian platform. A review. II. Isotopic evidences

Early and Late Cretaceous alkaline and alkaline– carbonatitic complexes from southern Brazil are located along the main tectonic lineaments of the South America Platform. Calcium-, magnesium-, and ferrocarbonatites are well represented and frequently associated even in the same complex. Primary carbonates present significant variations in C–O isotopic compositions, which are mainly due to isotope exchange with H2O–CO2-rich hydrothermal fluids, whereas fractional crystallization or liquid immiscibility probably affects the δ18O and δ13C values by no more than 2δ‰. Our isotope exchange model implies that the most significant isotopic variations took place in a hydrothermal environment, e.g., in the range 400–80°C, involving fluids with the CO2/H2O ratio ranging from 0.8 to 1. Sr–Nd–Pb isotope systematics highlight heterogeneous mixtures between HIMU and EMI mantle components, similar to the associated alkaline rocks and the flood tholeiites from southern Brazil. In spite of the strong variation shown by C–O isotopes, Sr-Nd–Pb–Os isotopic systematics could be related to an isotopically enriched source where the chemical heterogeneities reflect a depleted mantle “metasomatized” by small-volume melts and fluids rich in incompatible elements. These fluids are expected to have promoted crystallization of K-rich phases in the mantle, which produced a veined network variously enriched in LILE and LREE. The newly formed veins (enriched component) and peridotite matrix (depleted component) underwent a different isotopic evolution with time as reflected by the carbonatites. These conclusions may be extended to the whole Paraná–Etendeka system, where isotopically distinct parent magmas were generated following two main enrichment events of the subcontinental lithospheric mantle at 2.0–1.4 and 1.0–0.5 Ga, respectively, as also supported by Re–Os systematics. The mantle sources preserved the isotopic heterogeneities over a long time, suggesting a non convective lithospheric mantle beneath different cratons or intercratonic regions. Overall, the data indicate that the alkaline–carbonatitic magmatism originated from a locally heterogeneous subcontinental mantle

Carbonatites from the Southern Brazilian platform: I

We present a comprehensive overview of the geochemical characteristics and evolution of the carbo- natites from the southern Brazilian Platform (Paraná Basin). The carbonatites from dierent complexes dis- play large compositional variability in terms of abun- dances of incompatible and rare earth elements. This is in agreement with an origin from heterogeneous litho- spheric sources, as conrmed by isotopic data (see Speziale et al., this issue). The characteristic major and trace element abundances of these carbonatites present compelling evidence for invoking liquid unmixing as the main mechanism of their formation and evolution albeit few exceptions. We propose an evolutionary trend for the Brazilian carbonatites, which can be summarized as following: exsolution of the primary Ca- or Mg-carbona- titic liquids systematically takes place at the phonolite- peralkaline phonolite stage of magma dierentiation; this is followed by progressive Fe-enrichment and by nal emplacement of uorocarbonatites associated with hydrothermal uids

Differences in HPV infection and HPV-related lesions between the cervix and anus in hiv-positive women

Introduction: the prevalence of cervical and anal human papillomavirus (HPV) infection in women infected with human immunodeficiency virus (HIV) is high. However, little is known about the differences in the susceptibility of these infections and related lesions. The aim of this study was to describe the association between the prevalence of cervical and anal HPV infection and HPV-related lesions in HIV-positive women. Methods: this study included 88 HIV-positive women attending an outpatient clinic in a university hospital. Ectocervical, endocervical, and anal samples were collected for colpocytology and anal cytology. A polymerase chain reaction-based technique was used to detect HPV deoxyribonucleic acid in endocervical and anal swab samples. Results: the cervical and anal HPV positivity rates were 35.21% and 78.8%, respectively. The presence of HPV-related lesions on colpocytology was associated with anal HPV positivity (P = 0.027). The ratio between cervical HPV infection and cervical HPV-related lesions was 2.5. The ratio between anal HPV infection and anal HPV-related lesions was 4.3. Overall, 30% had concomitant HPV DNA in the cervix and anus. Conclusion: there are differences in the susceptibility of infections and related lesions between the cervix and anus. Despite a higher incidence of anal HPV, the progression to HPV-related lesion does not occur via the same manner in the cervix and anus. Moreover, cervical HPV-related lesions in HIV-positive women may serve as a cue for anal preventive strategies, and further investigations in these women may be useful.

STUDY ON THE PATELLOFEMORAL JOINT USING MAGNETIC RESONANCE IMAGING: MORPHOLOGICAL VARIATION OF THE MEDIAL PATELLOFEMORAL LIGAMENT

ABSTRACTObjectives: To study the measurements and anatomical relationships of the patellofemoral joint using magnetic resonance imaging, and to evaluate the variation in the morphology of the medial patellofemoral ligament (MPFL) according to patients' heights and ages and the variation in measurements on other structures that are known to be involved in predisposition to patellar instability. Method: Twenty-three knees (18 patients) underwent magnetic resonance imaging and their interepicondylar distance, patellar height, trochlear depth, ventral trochlear prominence, trochlear groove angle, lateral facet tilt, lateral patellar tilt and size of the lateral and medial facets and their ratio were measured. These measurements were compared with the length and thickness of the MPFL. Results: The average length of the MPFL was 46.4 mm, while the average thicknesses of its patellar insertion, middle third and femoral insertion were, respectively, 1.7 mm, 1.4 mm and 1.2 mm. The thickness of the MPFL correlated positively with the lateral condyle and interepicondylar distance measurements, and negatively with the patients' ages. Conclusion: The morphology of the MPFL varies with the interepicondylar distance and the lateral condyle distance, and with patients' ages

Petrology and geochemical characterization of the mantle \ud sources in the northwest region of the Paraná continental \ud flood basalt province

The Paraná continental flood basalt (PCFB) province, one of the largest continental provinces preserved on Earth, has been the focus of many studies and is still a matter of debate. The PCFB covers more than 70% of the Paraná Basin as flows, sills, and dykes. The mineralogy of basalt is represented by plagioclase (An42-67; 40-55%), pyroxene (augite: W030-40En34-46Fs35-39;19-40%). magnetite (2 -10%), and olivine (F031-5O; <1.5%). Based on rheological calculations the lemperature of crystallization of the pyroxenes is estimated at 11OO°C. From a geochemical point of view, lhe origin \ud of the tholeiitic basalts with low-Ti02 (S 2%; Ribeira) in the northern PCFB province, characterized by the occurrence of basalts with higher concentrations of Ti02 (TiO2>2%) and incompatible trace elements, are here investigated through the deterrnination of Sr, Nd and Pb isotope ratios. The isotope data, along with trace element ratios are used to assess the possible role of the interaction with the continental crust and/or the Sub-Continental Lithospheric Mantle (SCLM). The Ribeira basalts investigated in this study have initial (134 Ma) 87Sr/86Sr, ratios of 0.705341 - 0.705931, 143Nd/144Nd, of \ud 0.512308 - 0.512097, 206Pb/204Pb, of 17.628 -17.810, 207Pb/204Pb, of 15.506 -15.541, and 208Pb/204Pb, of 37.859 - 38.154. These isotopic compositions do not display any correlation with Nb/Th, Nb/La or P2O5/K2O ratios, which also reflect thal these rocks were not significantly aftected by low-pressure crustal contamination. The geochemical composition of the northern PCFB may be explained through lhe involvement of fluids and/or small volume melts related to metasomatic processe

Lead isotope constraints on the mantle sources involved in the genesis of Mesozoic high-Ti tholeiite dykes (Urubici type) from the São Francisco Craton (Southern Espinhaço, Brazil)

ABSTRACT: The first results of Pb isotope compositions of the high-Ti Mesozoic dykes of the Southern Espinhaço are presented. The results do not show large variations and are significantly more radiogenic than the Pb isotope compositions of the high-Ti tholeiites from the Paraná Continental Flood Basalts. The data combined with published geochemical and Sr-Nd isotope results rule out crustal contamination processes in the genesis of the dykes, requiring magma generation in metasomatized subcontinental lithospheric mantle with the involvement of HIMU-type and carbonatite components. The magmas may have been also derived from a mantle source containing ~4 - 5% of pyroxenite and ~1% of carbonatite melts, agreeing with published Os isotope compositions of high-Ti rocks from the Paraná Continental Flood Basalts. These metasomatizing agents could be responsible for mantle source refertilization, as was also proposed in the literature to explain the characteristics of xenoliths of the Goiás Alkaline Province, which also occurs in the border of the São Francisco Craton. Additionally, to evaluate the risks of Pb contamination during sample preparation for analysis, several experimental tests were accomplished, which indicate the need of sawed surface removal and a careful washing of small-sized rock fragments before powdering, especially for rocks with [Pb] < 7 µg/g

A qualidade de vida dos estudantes de medicina durante o ensino remoto no período da pandemia da COVID-19

Objective: to characterize the quality of life of medical students from a federal university in the interior of Minas Gerais, enrolled during remote education, during the COVID 19 pandemic period. Methods: cross-sectional study with application of online questionnaires adapted from V National Survey of the Socioeconomic and Cultural Profile of Undergraduates from Federal Institutions of Higher Education, the National Survey of Household Samples and the WHOQOLbref. Absolute and relative frequencies and means of sociodemographic and epidemiological variables were calculated, in addition to the scores of the questionnaire referring to quality of life. Results: 179 students participated, aged between 19 and 44 years (Me=23.6). Most were female (67.7%), 52.6% self-declared white race/color, 97.2% single, 98.8% from Brazilian states and two from other countries (1.2%). In relation to quality of life, the following domains were observed among the participants: physical – good (4.05), environment – good (4.04), social relationships – regular (3.85) and psychological – regular (3.68). The score related to general quality of life was 3.90, being considered regular. Final considerations: despite the fact that the physical and environmental domains obtained a good classification, the social and psychological relationships domains were considered regular, as well as general quality of life. It is suggested that this study serve as a subsidy to the coordination and direction of medical courses. Because, the planning and implementation of pedagogical and administrative interventions, related to the health problems of mental disorders and the impact of the COVID-19 pandemic, are essential to improve the quality of life of students.Objetivo: caracterizar a qualidade de vida dos estudantes do curso de medicina, de uma universidade federal do interior de Minas Gerais, matriculados durante o ensino remoto, no período da pandemia da COVID 19. Métodos: estudo transversal com aplicação de questionários online adaptados da V Pesquisa Nacional de Perfil Socioeconômico e Cultural dos Graduandos das Instituições Federais de Ensino Superior, da Pesquisa Nacional de Amostras de Domicílio e do WHOQOL-bref. Foram calculadas as frequências absolutas e relativas e as médias das variáveis sociodemográficas e epidemiológicas, além dos scores do questionário referente à qualidade de vida.Resultados: participaram 179 estudantes, com idades entre 19 e 44 anos (Me=23,6). A maioria do sexo feminino (67,7%), 52,6 % autodeclarados da raça/ cor branca, 97,2% solteiros, 98,8% naturais de estados brasileiros e dois naturais de outros países (1,2%). Observou-se entre os participantes, em relação à qualidade de vida, os seguintes domínios:  físico – boa (4,05), ambiente – boa (4,04), relações sociais – regular (3,85) e psicológico – regular (3,68). O escore relacionado à qualidade de vida geral, foi 3,90, sendo considerada regular. Considerações finais: apesar da constatação dos domínios físico e ambiental terem obtido boa classificação, os domínios relações sociais e psicológico foram considerados regulares, assim como qualidade de vida geral. Sugere-se que este estudo sirva de subsídio às coordenações e direções dos cursos de medicina. Pois, o planejamento e implementação de intervenções pedagógicas e administrativas, relacionadas aos agravos dos transtornos mentais e o impacto da pandemia da Covid -19, são fundamentais para melhorias da qualidade de vida dos estudantes

Growth of Fungal Cells and the Production of Mycotoxins

Some filamentous fungi are able to grow in food and produce toxic metabolites. It occurs mainly in grains, cereals, oilseeds and some by-products. The growth of fungi in a particular food is governed largely by a series of physical and chemical parameters. The production of toxic metabolites is not confined to a single group of molds irrespective of whether they are grouped according to structure, ecology, or phylogenetic relationships. Mycotoxins can be carcinogenic and cause several harmful effects to both human and animal organisms, in addition to generating large economic losses. The major mycotoxins found in food are the aflatoxins, fumonisins, ochratoxins, patulin, zearalenone, and trichothecenes, generally stable at high temperatures and long storage periods. Considering the difficult prevention and control, international organizations for food safety establish safe levels of these toxins in food destined for both human and animal consumption. Good agricultural practices and control of temperature and moisture during storage are factors which contribute significantly to inhibit the production of mycotoxins. The use of some fungistatic products, such as essential oils and antioxidants, as well as physical, mechanical, chemical, or thermal processing, represents important methods to have the concentration of mycotoxins reduced in food

Highlights of the Brazilian Thoracic Association guidelines for interstitial lung diseases

Interstitial lung diseases (ILDs) are heterogeneous disorders, involving a large number of conditions, the approach to which continues to pose an enormous challenge for pulmonologists. The 2012 Brazilian Thoracic Association ILD Guidelines were established in order to provide Brazilian pulmonologists with an instrument that can facilitate the management of patients with ILDs, standardizing the criteria used for the diagnosis of different conditions and offering guidance on the best treatment in various situations. The objective of this article was to briefly describe the highlights of those guidelines.As doenças pulmonares intersticiais (DPIs) são afecções heterogêneas, envolvendo um elevado número de condições, cuja abordagem ainda é um grande desafio para o pneumologista. As Diretrizes de DPIs da Sociedade Brasileira de Pneumologia e Tisiologia, publicadas em 2012, foram estabelecidas com o intuito de fornecer aos pneumologistas brasileiros um instrumento que possa facilitar a abordagem dos pacientes com DPIs, padronizando-se os critérios utilizados para a definição diagnóstica das diferentes condições, além de orientar sobre o melhor tratamento nas diferentes situações. Esse artigo teve como objetivo descrever resumidamente os principais destaques dessas diretrizes.Universidade de São Paulo Faculdade de Medicina Hospital das ClínicasUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Curso de Pós-Graduação de Doenças Pulmonares IntersticiaisUniversidade Federal de Ciências da Saúde de Porto AlegreSanta Casa de Porto Alegre Ambulatório de Doenças IntersticiaisSES Hospital Regional da Asa Norte Serviço de Doenças TorácicasFundação Jorge Duprat Figueiredo de Segurança e Medicina do Trabalho Serviço de MedicinaUniversidade Estadual de Campinas Faculdade de Ciências Médicas Departamento de Clínica MédicaUniversidade Federal do Estado do Rio de JaneiroUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PatologiaHospital do Servidor Público Estadual de São Paulo Serviço de Anatomia PatológicaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade de São Paulo Faculdade de Medicina de Ribeirão Preto Divisão de PneumologiaUniversidade Federal de Santa Catarina Departamento de Clínica MédicaUniversidade Federal de Santa Catarina Hospital UniversitárioHospital de Messejana Ambulatório de Doenças IntersticiaisHospital do Servidor Público Estadual de São Paulo Ambulatório de Doenças IntersticiaisUniversidade de São Paulo Faculdade de Medicina Instituto do CoraçãoUniversidade Federal FluminenseUniversidade de São Paulo Faculdade de MedicinaHospital Sírio Libanês Núcleo Avançado de TóraxUniversidade Federal da BahiaHospital do Servidor Público Estadual de São PauloHospital do Câncer Antônio Cândido CamargoUNIFESP, EPM, Curso de Pós-Graduação de Doenças Pulmonares IntersticiaisUNIFESP, EPM, Depto. de PatologiaUNIFESP, EPMSciEL