HIV/AIDS risk among female sex workers who use crack in Southern Brazil

OBJECTIVE: To understand the social context of female sex workers who use crack and its impact on HIV/AIDS risk behaviors. METHODODOLOGICAL PROCEDURES: Qualitative study carried out in Foz do Iguaçu, Southern Brazil, in 2003. Twenty-six in-depth interviews and two focus groups were carried out with female commercial sex workers who frequently use crack. In-depth interviews with health providers, community leaders and public policy managers, as well as field observations were also conducted. Transcript data was entered into Atlas.ti software and grounded theory methodology was used to analyze the data and develop a conceptual model as a result of this study. ANALYSIS OF RESULTS: Female sex workers who use crack had low self-perceived HIV risk in spite of being engaged in risky behaviors (e.g. unprotected sex with multiple partners). Physical and sexual violence among clients, occasional and stable partners was widespread jeopardizing negotiation and consistent condom use. According to health providers, community leaders and public policy managers, several female sex workers who use crack are homeless or live in slums, and rarely have access to health services, voluntary counseling and testing, social support, pre-natal and reproductive care. CONCLUSIONS: Female sex workers who use crack experience a plethora of health and social problems, which apparently affect their risks for HIV infection. Low-threshold, user-friendly and gender-tailored interventions should be implemented, in order to increase the access to health and social-support services among this population. Those initiatives might also increase their access to reproductive health in general, and to preventive strategies focusing on HIV/AIDS and other sexually transmitted infections.

Futuros sobre a margem operacional da refinação do petróleo bruto: crack spreads

Mestrado em Contabilidade Internacional

Growth patterns in early childhood and the onset of menarche before age twelve

OBJECTIVE: To examine the relationship between growth patterns in early childhood and the onset of menarche before age 12. METHODS: The study included 2,083 women from a birth cohort study conducted in the city of Pelotas, Southern Brazil, starting in 1982. Anthropometric, behavioral, and pregnancy-related variables were collected through home interviews. Statistical analyses were performed using Pearson's chi-square and chi-square test for linear trends. A multivariable analysis was carried out using Poisson regression based on a hierarchical model. RESULTS: Mean age of menarche was 12.4 years old and the prevalence of menarche before age 12 was 24.3%. Higher weight-for-age, height-for-age, and weight-for-height z-scores at 19.4 and 43.1 months of age were associated with linear tendencies of increased prevalence and relative risks of the onset of menarche before age 12. Girls who experienced rapid growth in weight-for-age z-score from birth to 19.4 months of age and in weight-for-age or height-for-age z-scores from 19.4 to 43.1 months of age also showed higher risk of menarche before age 12. Higher risk was seen when rapid growth in weight-for-age z-score was seen during these age intervals and the highest risk was found among those in the first tertile of Williams' curve at birth. Rapid growth in weight-for-height z-score was not associated with menarche before age 12. CONCLUSIONS: Menarche is affected by nutritional status and growth patterns during early childhood. Preventing overweight and obesity during early childhood and keeping a "normal" growth pattern seem crucial for the prevention of health conditions during adulthood.

Symphysis-fundal height curve in the diagnosis of fetal growth deviations

OBJECTIVE: To validate a new symphysis-fundal curve for screening fetal growth deviations and to compare its performance with the standard curve adopted by the Brazilian Ministry of Health. METHODS: Observational study including a total of 753 low-risk pregnant women with gestational age above 27 weeks between March to October 2006 in the city of João Pessoa, Northeastern Brazil. Symphisys-fundal was measured using a standard technique recommended by the Brazilian Ministry of Health. Estimated fetal weight assessed through ultrasound using the Brazilian fetal weight chart for gestational age was the gold standard. A subsample of 122 women with neonatal weight measurements was taken up to seven days after estimated fetal weight measurements and symphisys-fundal classification was compared with Lubchenco growth reference curve as gold standard. Sensitivity, specificity, positive and negative predictive values were calculated. The McNemar χ2 test was used for comparing sensitivity of both symphisys-fundal curves studied. RESULTS: The sensitivity of the new curve for detecting small for gestational age fetuses was 51.6% while that of the Brazilian Ministry of Health reference curve was significantly lower (12.5%). In the subsample using neonatal weight as gold standard, the sensitivity of the new reference curve was 85.7% while that of the Brazilian Ministry of Health was 42.9% for detecting small for gestational age. CONCLUSIONS: The diagnostic performance of the new curve for detecting small for gestational age fetuses was significantly higher than that of the Brazilian Ministry of Health reference curve.

Evolução do consumo de crack em coorte com histórico de tratamento

OBJETIVO: Analisar a evolução do consumo entre usuários de crack com histórico de tratamento. MÉTODOS: Uma coorte de, originalmente, 131 dependentes de crack admitidos em uma enfermaria de desintoxicação em São Paulo, SP, entre 1992 e 1994, foi re-entrevistada em três ocasiões: 1995-1996, 1998-1999 e 2005-2006. As variáveis averiguadas foram: dados demográficos, comportamento sexual de risco, padrões de consumo de crack e outras substâncias, prisões, desaparecimentos e óbitos. Na análise estatística empregou-se o teste de qui-quadrado, a regressão logística multinomial e regressão de Cox. RESULTADOS: Dos pacientes avaliados, 43 estavam abstinentes do crack (12 meses ou mais), 22 eram usuários, 13 estavam presos, dois desaparecidos e 27 estavam mortos. Foram identificados três grupos com trajetórias distintas de consumo pós-alta. Comportamento seguro com uso de preservativo foi identificado como fator relacionado ao grupo de abstinentes estáveis (p = 0,001). Teste HIV positivo na internação (p = 0,046); consumo de cocaína aspirada no último ano (p = 0,001) e tempo de uso de cocaína aspirada na vida (mais de 132 meses) (p = 0,000) foram fatores relacionados a uso de longo termo. Uso pregresso de cocaína endovenosa aumentou em 2,5 vezes as chances de óbito em 12 anos (p = 0,031) (IC95%: 1,08; 5,79). CONCLUSÕES: A recorrência e persistência do consumo nos anos pós-alta de tratamento refletem novas modalidades de uso do crack. Por outro lado, padrões de abstinência estável apontam a viabilidade dos processos de recuperação relativos ao uso de crack.

Fissura por crack: comportamentos e estratégias de controle de usuários e ex-usuários

OBJETIVO: Compreender a fissura do usuário de crack, bem como descrever os comportamentos desenvolvidos sob fissura e estratégias utilizadas para seu controle. PROCEDIMENTOS METODOLÓGICOS: Estudo qualitativo com amostra intencional por critérios de 40 usuários e ex-usuários de crack em São Paulo, SP, nos anos de 2007 e 2008. Os entrevistados foram recrutados pela técnica da bola de neve e submetidos à entrevista semi-estruturada em profundidade, até a saturação teórica. Após transcrição literal, seguiu-se a análise do conteúdo das entrevistas para elaboração de inferências e hipóteses alicerçadas nessas narrativas. ANÁLISE DOS RESULTADOS: Os entrevistados estavam igualmente distribuídos quanto ao sexo, possuíam idade entre 18 e 50 anos, abrangeram todos os níveis de escolaridade e a maior parte possuía poucos recursos financeiros. Além da fissura sentida na abstinência de crack e da fissura induzida por pistas ambientais e emocionais, constatou-se um tipo de fissura que faz parte do próprio efeito do crack. Esta última apareceu como forte fator mantenedor dos binges de consumo, que foram os maiores responsáveis pelo rebaixamento de valores do usuário, sujeitando-o a práticas arriscadas para a obtenção da droga. Os métodos mais citados para a obtenção de crack ou dinheiro para comprá-lo foram: prostituição, manipulação de pessoas, endividamento, troca de pertences por crack e roubo. Foram relatadas estratégias para o alívio da fissura e táticas farmacológicas e comportamentais para evitar o seu desenvolvimento, como: comer, ter relação sexual, jogar futebol, trabalhar, evitar o contexto social de uso de crack e usar drogas que causam sonolência. CONCLUSÕES: Os binges de consumo de crack são causados pela fissura induzida durante o uso da droga. As medidas criadas pelo próprio usuário para lidar com a sua fissura melhoram sua relação com o crack e podem ser ferramenta importante para o aprimoramento do tratamento.

Growth and Raman scattering characterization of Cu2ZnSnS4 thin films

In the present work we report the results of the growth, morphological and structural characterization of Cu2ZnSnS4 (CZTS) thin films prepared by sulfurization of DC magnetron sputtered Cu/Zn/Sn precursor layers. The adjustment of the thicknesses and the properties of the precursors were used to control the final composition of the films. Its properties were studied by SEM/EDS, XRD and Raman scattering. The influence of the sulfurization temperature on the morphology, composition and structure of the films has been studied. With the presented method we have been able to prepare CZTS thin films with the kesterite structure.

Growth pressure dependence of Cu2ZnSnSe4 properties

In this work, we show a set of growth conditions, for the two step process, with which the growth of CZTSe is successful and reproducible. The properties of the best CTZSe thin films grown by this method were examined by SEM/EDS, XRD, Raman scattering, AFM/EFM, transmittance and reflectance measurements, photoluminescence (PL) measurements and hot point probe. A broad emission band was observed in the photoluminescence spectrum of the CZTSe thin film. The band gap energy was estimated to be around 1.05 eV at room temperature, using the transmittance and reflectance data, and CZTSe samples show p-type conductivity with the hot point probe. The different characterization techniques show that we could grow single phase CZTSe thin films with our optimized process conditions.

Influence of selenization pressure on the growth of Cu2ZnSnSe4 films from stacked metallic layers

Cu2ZnSnSe4 (CZTSe) is a p-type semiconductor with a high absorption coefficient, 104 to 105 cm-1, and is being seen as a possible replacement for Cu(In,Ga)Se2 in thin film solar cells. Yet, there are some fundamental properties of CZTSe that are not well known, one of them is its band gap. In order to resolve its correct value it is necessary to improve the growth conditions to ensure that single phase crystalline thin films are obtained. One of the problems encountered when growing CZTSe is the loss of Sn through evaporation of SnSe. Stoichiometric films are then difficult to obtain and usually there are other phases present. One possible way to overcome this problem is to increase the pressure of growth of CZTSe. This can be done by introducing an atmosphere of an inert gas like Ar or N2. In this work we report the results of morphological, structural and optical studies of the properties of CZTSe thin films grown by selenization of DC magnetron sputtered metallic layers under different Ar pressures. The films are analysed by SEM/EDS, Raman scattering and XRD.

Growth and characterization of Cu2ZnSn(S,Se)4 thin films for solar cells

Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) with their band gap energies around 1.45 eV and 1.0 eV, respectively, can be used as the absorber layer in thin film solar cells. By using a mixture of both compounds, Cu2ZnSn(S,Se)4 (CZTSSe), a band gap tuning may be possible. The latter material has already shown promising results such as solar cell efficiencies up to 10.1%. In this work, CZTSSe thin films were grown in order to study its structure and to establish the best growth precursors. SEM micrographs reveal an open columnar structure for most samples and EDS composition profiling of the cross sections show different selenium gradients. X-ray diffractograms show different shifts of the kesterite/stannite (1 1 2) peak, which indicate the presence of CZTSSe. From Raman scattering analysis, it was concluded that all samples had traces of CZTS and CZTSSe. The composition of the CZTSSe layer was estimated using X-ray diffraction and Raman scattering and both results were compared. It was concluded that Se diffused more easily in precursors with ternary Cu–Sn–S phases and metallic Zn than in precursors with ZnS and/or CZTS already formed. It was also showed that a combination of X-ray diffraction and Raman scattering can be used to estimate the ratio of S per Se in CZTSSe samples.

Enoxacin inhibits growth of prostate cancer cells and effectively restores microRNA processing

Prostate cancer (PCa) is one of the most incident malignancies worldwide. Although efficient therapy is available for early-stage PCa, treatment of advanced disease is mainly ineffective and remains a clinical challenge. microRNA (miRNA) dysregulation is associated with PCa development and progression. In fact, several studies have reported a widespread downregulation of miRNAs in PCa, which highlights the importance of studying compounds capable of restoring the global miRNA expression. The main aim of this study was to define the usefulness of enoxacin as an anti-tumoral agent in PCa, due to its ability to induce miRNA biogenesis in a TRBP-mediated manner. Using a panel of five PCa cell lines, we observed that all of them were wild type for the TARBP2 gene and expressed TRBP protein. Furthermore, primary prostate carcinomas displayed normal levels of TRBP protein. Remarkably, enoxacin was able to decrease cell viability, induce apoptosis, cause cell cycle arrest, and inhibit the invasiveness of cell lines. Enoxacin was also effective in restoring the global expression of miRNAs. This study is the first to show that PCa cells are highly responsive to the anti-tumoral effects of enoxacin. Therefore, enoxacin constitutes a promising therapeutic agent for PCa.

The use of information and interactive processes in growth management

Tese de doutoramento em Engenharia do Ambiente, especialidade em Sistemas Sociais

In-situ X-ray diffraction studies during growth of Ni-Ti shape memory alloy films and their complementary ex-situ characterization

Shape Memory Alloy (SMA) Ni-Ti films have attracted much interest as functional and smart materials due to their unique properties. However, there are still important issues unresolved like formation of film texture and its control as well as substrate effects. Thus, the main challenge is not only the control of the microstructure, including stoichiometry and precipitates, but also the identification and control of the preferential orientation since it is a crucial factor in determining the shape memory behaviour. The aim of this PhD thesis is to study the optimisation of the deposition conditions of films of Ni-Ti in order to obtain the material fully crystallized at the end of the deposition, and to establish a clear relationship between the substrates and texture development. In order to achieve this objective, a two-magnetron sputter deposition chamber has been used allowing to heat and to apply a bias voltage to the substrate. It can be mounted into the six-circle diffractometer of the Rossendorf Beamline (ROBL) at the European Synchrotron Radiation Facility (ESRF), Grenoble, France, enabling an in-situ characterization by X-ray diffraction(XRD) of the films during their growth and annealing. The in-situ studies enable us to identify the different steps of the structural evolution during deposition with a set of parameters as well as to evaluate the effect of changing parameters on the structural characteristics of the deposited film. Besides the in-situ studies, other complementary ex-situ characterization techniques such as XRD at a laboratory source, Rutherford backscattering spectroscopy(RBS), Auger electron spectroscopy (AES), cross-sectional transmission electron microscopy (X-TEM), scanning electron microscopy (SEM), and electrical resistivity (ER) measurements during temperature cycling have been used for a fine structural characterization. In this study, mainly naturally and thermally oxidized Si(100) substrates, TiN buffer layers with different thicknesses (i.e. the TiN topmost layer crystallographic orientation is thickness dependent) and MgO(100) single crystals were used as substrates. The chosen experimental procedure led to a controlled composition and preferential orientation of the films. The type of substrate plays an important role for the texture of the sputtered Ni-Ti films and according to the ER results, the distinct crystallographic orientations of the Ni-Ti films influence their phase transformation characteristics.

Integrated analysis of climate, soil, topography and vegetative growth in Iberian viticultural regions

The Iberian viticultural regions are convened according to the Denomination of Origin (DO) and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation) were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate.

Feasibility of the extended finite element method for the simulation of composite bonded joints

Adhesive-bonding for the unions in multi-component structures is gaining momentum over welding, riveting and fastening. It is vital for the design of bonded structures the availability of accurate damage models, to minimize design costs and time to market. Cohesive Zone Models (CZM’s) have been used for fracture prediction in structures. The eXtended Finite Element Method (XFEM) is a recent improvement of the Finite Element Method (FEM) that relies on traction-separation laws similar to those of CZM’s but it allows the growth of discontinuities within bulk solids along an arbitrary path, by enriching degrees of freedom. This work proposes and validates a damage law to model crack propagation in a thin layer of a structural epoxy adhesive using the XFEM. The fracture toughness in pure mode I (GIc) and tensile cohesive strength (sn0) were defined by Double-Cantilever Beam (DCB) and bulk tensile tests, respectively, which permitted to build the damage law. The XFEM simulations of the DCB tests accurately matched the experimental load-displacement (P-d) curves, which validated the analysis procedure.