"O hoje afetando o amanhã": pesquisando gravidez na adolescência no cotidiano escolar / "Today affecting tomorrow": researching teenage pregnancy in everyday school life / "El hoy afecta al mañana": investigación del embarazo adolescente en la vida escolar diaria / «Le présent affecte le futur¼: recherche sur la grossesse des adolescentes dans la vie scolaire quotidienne

Resumo: Este artigo analisou o processo de construção e execução de uma pesquisa acerca da gravidez na adolescência com jovens do ensino médio no cotidiano de uma escola pública estadual de Fortaleza-CE, a partir de um estudo qualitativo com base na pesquisa-intervenção. Por meio de um curso de extensão para estudantes secundaristas, desenvolveu-se uma pesquisa na escola em que as próprias jovens da escola pública foram copesquisadoras do tema gravidez na adolescência no cotidiano escolar. Utilizou-se as ferramentas metodológicas de diários de campo, questionário on-line e restituição. Os resultados mostraram que há diferenças nos papéis de mãe e pai na adolescência, dificuldades para a conclusão da vida escolar e prejuízos na inserção no mercado de trabalho, principalmente para as meninas. Portanto, a pesquisa possibilitou problematizar o lugar de representatividade das pautas de maternidade e paternidade fomentando espaços de escuta e dialogicidade na promoção da equidade com estudantes que experienciam a maternidade e paternidade.

Abstract: This article aimed to analyze the process of constructing and conducting research on teenage pregnancy with high school students in the daily life of a public school in Fortaleza, Ceará, based on a qualitative study using the Intervention Research approach. By an extension course for high school students, a research project was developed in the school in which the public school students themselves were co-researchers on the topic of teenage pregnancy in the school environment. The methodological tools used were field journals, online questionnaires, and restitution. Results showed differences in the roles of the mother and father during adolescence, difficulties in completing education, and obstacles in entering the job market, especially for girls. Therefore, this research could question the representation of maternity and paternity issues, promoting spaces for listening and dialogue in the promotion of equity with students who experience parenthood.

Résumé : Cet article a analysé la construction et réalisation d'une recherche avec de lycéens sur la grossesse adolescente dans la vie quotidienne d'une école publique de Fortaleza-CE, dès une étude qualitative de recherche-intervention. Avec un cours d'extension pour des élèves du secondaire, une recherche a été menée où les élèves de l'école publique étaient co-chercheurs sur la grossesse adolescente dans l'école. Des journaux de terrain, des questionnaires en ligne et des restitutions ont été utilisés. Les résultats ont montré des différences dans les rôles de mère et de père pendant l'adolescence, des difficultés à mener à terme leur scolarité et des préjudices dans leur insertion sur le marché du travail, surtout pour les filles. Donc, la recherche a permis de questionner la représentativité des enjeux de maternité et de paternité, en favorisant des espaces d'écoute et de dialogue pour promouvoir l'équité avec les étudiants qui vivent la maternité et la paternité.

Resumen: Este artículo tuvo como objetivo analizar el proceso de construcción e implementación de una investigación con estudiantes de secundaria sobre el tema del embarazo adolescente en la vida cotidiana de una escuela pública de Fortaleza, Ceará (Brasil), basada en un estudio cualitativo de investigación-intervención. A partir de un curso de extensión, se desarrolló una investigación en la escuela donde las propias estudiantes de secundaria fueron coinvestigadoras sobre el tema del embarazo adolescente. Se utilizaron como herramientas metodológicas un cuestionario en línea, diario de campo y restitución. Los resultados mostraron diferencias en el papel de la madre y el padre durante la adolescencia, dificultades para completar la vida escolar y dificultades para entrar en el mercado laboral, especialmente para las chicas. Por lo tanto, esta investigación permitió problematizar el papel representacional de la maternidad y la paternidad, propiciando espacios de escucha y de diálogo para promover la equidad con los estudiantes que experimentan estos roles.

Yeast population dynamics in Brazilian bioethanol production.

The large-scale and nonaseptic fermentation of sugarcane feedstocks into fuel ethanol in biorefineries represents a unique ecological niche, in which the yeast Saccharomyces cerevisiae is the predominant organism. Several factors, such as sugarcane variety, process design, and operating and weather conditions, make each of the ∼400 industrial units currently operating in Brazil a unique ecosystem. Here, we track yeast population dynamics in 2 different biorefineries through 2 production seasons (April to November of 2018 and 2019), using a novel statistical framework on a combination of metagenomic and clonal sequencing data. We find that variation from season to season in 1 biorefinery is small compared to the differences between the 2 units. In 1 biorefinery, all lineages present during the entire production period derive from 1 of the starter strains, while in the other, invading lineages took over the population and displaced the starter strain. However, despite the presence of invading lineages and the nonaseptic nature of the process, all yeast clones we isolated are phylogenetically related to other previously sequenced bioethanol yeast strains, indicating a common origin from this industrial niche. Despite the substantial changes observed in yeast populations through time in each biorefinery, key process indicators remained quite stable through both production seasons, suggesting that the process is robust to the details of these population dynamics.

Why do some patients with acute ischemic stroke fail to improve after intravenous thrombolytic therapy? A case-control study / Por que alguns pacientes com acidente vascular cerebral isquêmico agudo após terapia trombolítica endovenosa não melhoram? Um estudo caso-controle

Introdução: a terapia trombolítica é a principal medida salvadora adotada em vítimas de acidente vascular cerebral isquêmico (AVCI), adequada para a maioria delas. Entretanto, alguns pacientes não apresentam evolução clínica, piorando o prognóstico, o que constitui uma lacuna científica essencial. Objetivo: analisar os determinantes da não melhora clínica em pacientes com AVC em uso de trombolíticos rt-PA.Método: estudo observacional retrospectivo caso-controle, realizado de 2014 a 2017 por meio de busca ativa de prontuários de pacientes com AVC submetidos à terapia trombolítica em um hospital de referência no Ceará. A falência clínica foi caracterizada como ausência de redução no National Institutes of Health Stroke Scale-Score (NIHSS).Resultados: um total de 139 pacientes incluídos no estudo em uma única unidade de AVC. A média de idade foi de 66,14 anos (variando de 34 a 95). O seguimento de 24 horas foi completado em 100% dos pacientes. Resultado favorável 24 horas pós-trombólise foi observado em 113 pacientes (81,29%), e não houve melhora clínica em 26 (18,7%). A transformação hemorrágica pós-trombólise foi um forte preditor de não melhora (p=0,004), e diabetes foi o principal fator de risco modificável encontrado (p=0,040).Conclusão: diabetes e transformação hemorrágica após trombólise foram identificados como fatores de risco para não melhora clínica em pacientes com AVC agudo submetidos à terapia trombolítica.

Introduction: thrombolytic therapy is the primary saving measure adopted in ischemic cerebrovascular accident (ICVA) victims, adequate for most of them. However, some patients do not show clinical progress, worsening the prognosis, which constitutes an essential scientific gap.Objective: to analyze the determinants of clinical non-improvement in stroke patients who used rt-PA thrombolytic agentes.Methods: retrospective observational case-control study, carried out from 2014 to 2017 through an active search of medical records of CVA patients undergoing thrombolytic therapy in a reference hospital in Ceará. Clinical failure was characterized as no reduction in the National Institutes of Health Stroke Scale-Score (NIHSS).Results: a total of 139 patients enrolled in the study in a single CVA unit. The mean age was 66.14 years (range 34 to 95). The 24-hour follow-up was completed in 100% of patients. A favorable result 24 hours post-thrombolysis was observed in 113 patients (81.29%), and there was no clinical improvement in 26 (18.7%). Post-thrombolysis hemorrhagic transformation was a strong predictor of no improvement (p=0.004), and diabetes was the main modifiable risk factor found (p=0.040).Conclusion: diabetes and hemorrhagic transformation after thrombolysis were identified as risk factors for clinical non-improvement in patients with acute stroke undergoing thrombolytic therapy.

Structural Analysis and Development of Notum Fragment Screening Hits.

The Wnt signaling suppressor Notum is a promising target for osteoporosis, Alzheimer's disease, and colorectal cancers. To develop novel Notum inhibitors, we used an X-ray crystallographic fragment screen with the Diamond-SGC Poised Library (DSPL) and identified 59 fragment hits from the analysis of 768 data sets. Fifty-eight of the hits were found bound at the enzyme catalytic pocket with potencies ranging from 0.5 to >1000 µM. Analysis of the fragments' diverse binding modes, enzymatic inhibitory activities, and chemical properties led to the selection of six hits for optimization, and five of these resulted in improved Notum inhibitory potencies. One hit, 1-phenyl-1,2,3-triazole 7, and its related cluster members, have shown promising lead-like properties. These became the focus of our fragment development activities, resulting in compound 7d with IC50 0.0067 µM. The large number of Notum fragment structures and their initial optimization provided an important basis for further Notum inhibitor development.

Barcoded bulk QTL mapping reveals highly polygenic and epistatic architecture of complex traits in yeast.

Mapping the genetic basis of complex traits is critical to uncovering the biological mechanisms that underlie disease and other phenotypes. Genome-wide association studies (GWAS) in humans and quantitative trait locus (QTL) mapping in model organisms can now explain much of the observed heritability in many traits, allowing us to predict phenotype from genotype. However, constraints on power due to statistical confounders in large GWAS and smaller sample sizes in QTL studies still limit our ability to resolve numerous small-effect variants, map them to causal genes, identify pleiotropic effects across multiple traits, and infer non-additive interactions between loci (epistasis). Here, we introduce barcoded bulk quantitative trait locus (BB-QTL) mapping, which allows us to construct, genotype, and phenotype 100,000 offspring of a budding yeast cross, two orders of magnitude larger than the previous state of the art. We use this panel to map the genetic basis of eighteen complex traits, finding that the genetic architecture of these traits involves hundreds of small-effect loci densely spaced throughout the genome, many with widespread pleiotropic effects across multiple traits. Epistasis plays a central role, with thousands of interactions that provide insight into genetic networks. By dramatically increasing sample size, BB-QTL mapping demonstrates the potential of natural variants in high-powered QTL studies to reveal the highly polygenic, pleiotropic, and epistatic architecture of complex traits.

Phenotypic and molecular evolution across 10,000 generations in laboratory budding yeast populations.

Laboratory experimental evolution provides a window into the details of the evolutionary process. To investigate the consequences of long-term adaptation, we evolved 205 Saccharomyces cerevisiae populations (124 haploid and 81 diploid) for ~10,000,000 generations in three environments. We measured the dynamics of fitness changes over time, finding repeatable patterns of declining adaptability. Sequencing revealed that this phenotypic adaptation is coupled with a steady accumulation of mutations, widespread genetic parallelism, and historical contingency. In contrast to long-term evolution in E. coli, we do not observe long-term coexistence or populations with highly elevated mutation rates. We find that evolution in diploid populations involves both fixation of heterozygous mutations and frequent loss-of-heterozygosity events. Together, these results help distinguish aspects of evolutionary dynamics that are likely to be general features of adaptation across many systems from those that are specific to individual organisms and environmental conditions.

Eosinopenia as predictor of infection in patients admitted to an internal medicine ward: a cross-sectional study.

BACKGROUND: The identification of infection in an internal medicine ward is crucial but not always straightforward. Eosinopenia has been proposed as a marker of infection, but specific cutoffs for prediction are not established yet. We aim to assess whether there is difference in eosinophil count between infected and noninfected patients and, if so, the best cutoffs to differentiate them. METHODS: Cross-sectional, observational study with analysis of all patients admitted to an Internal Medicine Department during 2 consecutive months. Clinical, laboratory and imaging data were analyzed. Infection at hospital admission was defined in the presence of either a microbiological isolation or suggestive clinical, laboratory, and/or imaging findings. Use of antibiotics in the 8 days before hospital admission, presence of immunosuppression, hematologic neoplasms, parasite, or fungal infections were exclusion criteria. In case of multiple hospital admissions, only the first admission was considered.Sensitivity and specificity values for eosinophils, leukocytes, neutrophils, and C-reactive protein were determined by receiver operating characteristic curve. Statistical analysis was performed with IBM SPSS Statistics® v25 and MedCalc Statistical Software® v19.2.3. RESULTS: A total of 323 hospitalization episodes were evaluated, each corresponding to a different patient. One hundred fifteen patients were excluded. A total of 208 patients were included, 62.0% (n = 129) of them infected at admission. Ten patients had multiple infections.Infected patients had fewer eosinophils than uninfected patients (15.8 ±â€Š42 vs 71.1 ±â€Š159 cell/mm3; P < .001). An eosinophil count at admission ≤69 cell/mm3 had a sensitivity of 89.1% and specificity of 54.4% (area under the curve 0.752; 95% confidence interval 0.682-0.822) for the presence of infection. Eosinophil count of >77 cells/mm3 had a negative likelihood ratio of 0.16. CONCLUSIONS: Eosinophil count was significantly lower in infected than in uninfected patients. The cutoff 69 cells/mm3 was the most accurate in predicting infection. Eosinophil count >77 cells/mm3 was a good predictor of absence of infection.

Screening of a Custom-Designed Acid Fragment Library Identifies 1-Phenylpyrroles and 1-Phenylpyrrolidines as Inhibitors of Notum Carboxylesterase Activity.

The Wnt family of proteins are secreted signaling proteins that play key roles in regulating cellular functions. Recently, carboxylesterase Notum was shown to act as a negative regulator of Wnt signaling by mediating the removal of an essential palmitoleate. Here we disclose two new chemical scaffolds that inhibit Notum enzymatic activity. Our approach was to create a fragment library of 250 acids for screening against Notum in a biochemical assay followed by structure determination by X-ray crystallography. Twenty fragments were identified as hits for Notum inhibition, and 14 of these fragments were shown to bind in the palmitoleate pocket of Notum. Optimization of 1-phenylpyrrole 20, guided by structure-based drug design, identified 20z as the most potent compound from this series. Similarly, the optimization of 1-phenylpyrrolidine 8 gave acid 26. This work demonstrates that inhibition of Notum activity can be achieved by small, drug-like molecules possessing favorable in vitro ADME profiles.

Phase Inversions Observed in Thermoresponsive Pickering Emulsions Stabilized by Surface Functionalized Colloidal Silica.

In this study, the emulsification performance of functionalized colloidal silica is explored with the aim to achieve phase inversion of particle-stabilized (Pickering) emulsion systems. An increased understanding of inversion conditions can facilitate surfactant-free emulsion fabrication and expand its use in industrial applications. Phase inversion was achieved by adjusting the temperature but without changing the composition of the emulsion formulation. Silica nanoparticles modified with hydrophobic propyl groups and hydrophilic methyl poly(ethylene)glycol (mPEG) groups are used as emulsifiers, enabling control of the wettability of the particles and exploration of phase inversion phenomena, the latter due to the thermoresponsiveness of the attached PEG chains. The phase inversion conditions as well as the reversibility of the emulsion systems were examined at varying electrolyte concentrations and pH values of the suspensions. Transitional phase inversions, from oil-in-water and water-in-oil and back, were observed in functionalized silica particle-stabilized butanol emulsions at distinct temperatures. The phase inversion temperature was affected by electrolyte concentration and pH conditions due to salting-out effects, PEG-silica interactions, and the effects of the particle surface charge. Investigations of phase inversion conditions, temperature, and hysteresis effects in Pickering emulsions can improve the theoretical understanding of these phenomena and facilitate the implementation of low-energy emulsion preparation.

High-resolution lineage tracking reveals travelling wave of adaptation in laboratory yeast.

In rapidly adapting asexual populations, including many microbial pathogens and viruses, numerous mutant lineages often compete for dominance within the population1-5. These complex evolutionary dynamics determine the outcomes of adaptation, but have been difficult to observe directly. Previous studies have used whole-genome sequencing to follow molecular adaptation6-10; however, these methods have limited resolution in microbial populations. Here we introduce a renewable barcoding system to observe evolutionary dynamics at high resolution in laboratory budding yeast. We find nested patterns of interference and hitchhiking even at low frequencies. These events are driven by the continuous appearance of new mutations that modify the fates of existing lineages before they reach substantial frequencies. We observe how the distribution of fitness within the population changes over time, and find a travelling wave of adaptation that has been predicted by theory11-17. We show that clonal competition creates a dynamical 'rich-get-richer' effect: fitness advantages that are acquired early in evolution drive clonal expansions, which increase the chances of acquiring future mutations. However, less-fit lineages also routinely leapfrog over strains of higher fitness. Our results demonstrate that this combination of factors, which is not accounted for in existing models of evolutionary dynamics, is critical in determining the rate, predictability and molecular basis of adaptation.

Impacts of acidification on brown trout Salmo trutta populations and the contribution of stocking to population recovery and genetic diversity.

Anthropogenic acidification in SW-Scotland, from the early 19th Century onwards, led to the extinction of several loch (lake) brown trout (Salmo trutta) populations and substantial reductions in numbers in many others. Higher altitude populations with no stocking influence, which are isolated above natural and artificial barriers and subjected to the greatest effect of acidification, exhibited the least intrapopulation genetic diversity (34% of the allelic richness of the populations accessible to anadromous S. trutta). These, however, were characterised by the greatest interpopulation divergence (highest pairwise DEST 0.61 and FST 0.53 in contemporary samples) based on 16 microsatellite loci and are among the most differentiated S. trutta populations in NW-Europe. Five lochs above impassable waterfalls, where S. trutta were thought to be extinct, are documented as having been stocked in the late 1980s or 1990s. All five lochs now support self-sustaining S. trutta populations; three as a direct result of restoration stocking and two adjoining lochs largely arising from a small remnant wild population in one, but with some stocking input. The genetically unique Loch Grannoch S. trutta, which has been shown to have a heritable increased tolerance to acid conditions, was successfully used as a donor stock to restore populations in two acidic lochs. Loch Fleet S. trutta, which were re-established from four separate donor sources in the late 1980s, showed differential contribution from these ancestors and a higher genetic diversity than all 17 natural loch populations examined in the area. Genetically distinct inlet and outlet spawning S. trutta populations were found in this loch. Three genetically distinct sympatric populations of S. trutta were identified in Loch Grannoch, most likely representing recruitment from the three main spawning rivers. A distinct genetic signature of Loch Leven S. trutta, the progenitor of many Scottish farm strains, facilitated detection of stocking with these strains. One artificially created loch was shown to have a population genetically very similar to Loch Leven S. trutta. In spite of recorded historical supplemental stocking with Loch Leven derived farm strains, much of the indigenous S. trutta genetic diversity in the area remains intact, aside from the effects of acidification induced bottlenecks. Overall genetic diversity and extant populations have been increased by allochthonous stocking.

Biochemical profile in dairy cows with artificial induction of lactation / Perfil bioquímico de vacas leiteiras submetidas a indução artificial de lactação

The objective of this study was to determine the biochemical profile of dairy cows with induced lactation. For comparison, another group of normally calved cows was used as control. Lactation was induced in multiparous Holstein cows (n=10) with two norgestomet implants (3mg each implant) on day 1. The testing continued with intramuscular norgestomet (3mg/animal) on days 1, 3, 5, 7, 9, 11, 13 and 15. On days 1, 9, 16 to 18 and then every 14 days, bSTr (500mg/animal) was added. On day 16, the intravaginal implant was removed and intramuscular prostaglandin F2α (0.530mg/animal) and intramuscular estradiol benzoate (5mg/animal) were added. On days 16 to 18 dexamethasone (10mg/animal) was added, and from days 18 to 20 intramuscular metoclopramide (100mg/animal) was added. Milking began on day 19 of the induction. Blood was collected for a biochemical profile after 21 days in milk. It was found that urea and triglyceride concentrations were significantly higher in the induced cows (P<0.05). Therefore, it was concluded that the animals that had lactation induced did not present disorders related to the biochemical profile indicating that the hepatic function, renal function and lipidogram of the animals were not affected by the use of the drugs to induce lactation.(AU)

O objetivo deste estudo foi determinar o perfil bioquímico de vacas leiteiras com submetidas a indução de lactação. Para comparação, outro grupo de vacas que apresentaram parto normal foi usado como controle. A lactação foi induzida em vacas Holandesas (n=10) utilizando dois implantes de norgestomet (3mg cada implante) no dia 1. O protocolo continuou com a aplicação de norgestomet intramuscular (3mg / animal) nos dias 1, 3, 5, 7, 9, 11, 13 e 15. Nos dias 1, 9, 16 a 18 e depois a cada 14 dias, foi adicionado bSTr (500mg / animal). No dia 16, o implante intravaginal foi removido e adicionou-se prostaglandina F2a intramuscular (0,530 mg / animal) e benzoato de estradiol intramuscular (5mg / animal). Nos dias 16 a 18 foi adicionada dexametasona (10mg / animal) e dos dias 18 a 20 foi adicionada metoclopramida intramuscular (100 mg / animal). A ordenha começou no dia 19 da indução. O sangue foi coletado para mensuração do perfil bioquímico após 21 em leite. Verificou-se que as concentrações de ureia e triglicérides foram significativamente maiores nas vacas induzidas (P<0,05). Portanto, concluiu-se que os animais que tiveram a lactação induzida não apresentaram distúrbios relacionados ao perfil bioquímico, indicando que a função hepática, a função renal e o lipidograma dos animais não foram afetados pelo uso das drogas para induzir a lactação.(AU)

Chaos and the (un)predictability of evolution in a changing environment.

Among the factors that may reduce the predictability of evolution, chaos, characterized by a strong dependence on initial conditions, has received much less attention than randomness due to genetic drift or environmental stochasticity. It was recently shown that chaos in phenotypic evolution arises commonly under frequency-dependent selection caused by competitive interactions mediated by many traits. This result has been used to argue that chaos should often make evolutionary dynamics unpredictable. However, populations also evolve largely in response to external changing environments, and such environmental forcing is likely to influence the outcome of evolution in systems prone to chaos. We investigate how a changing environment causing oscillations of an optimal phenotype interacts with the internal dynamics of an eco-evolutionary system that would be chaotic in a constant environment. We show that strong environmental forcing can improve the predictability of evolution by reducing the probability of chaos arising, and by dampening the magnitude of chaotic oscillations. In contrast, weak forcing can increase the probability of chaos, but it also causes evolutionary trajectories to track the environment more closely. Overall, our results indicate that, although chaos may occur in evolution, it does not necessarily undermine its predictability.

Delivery of Splice Switching Oligonucleotides by Amphiphilic Chitosan-Based Nanoparticles.

Splice switching oligonucleotides (SSOs) are a class of single-stranded antisense oligonucleotides (ssONs) being used as gene therapeutics and demonstrating great therapeutic potential. The availability of biodegradable and biocompatible delivery vectors that could improve delivery efficiencies, reduce dosage, and, in parallel, reduce toxicity concerns could be advantageous for clinical translation. In this work we explored the use of quaternized amphiphilic chitosan-based vectors in nanocomplex formation and delivery of splice switching oligonucleotides (SSO) into cells, while providing insights regarding cellular uptake of such complexes. Results show that the chitosan amphiphilic character is important when dealing with SSOs, greatly improving colloidal stability under serum conditions, as analyzed by dynamic light scattering, and enhancing cellular association. Nanocomplexes were found to follow an endolysosomal route with a long lysosome residence time. Conjugation of a hydrophobic moiety, stearic acid, to quaternized chitosan was a necessary condition to achieve transfection, as an unmodified quaternary chitosan was completely ineffective. We thus demonstrate that amphiphilic quaternized chitosan is a biomaterial that holds promise and warrants further development as a platform for SSO delivery strategies.

Proposta de melhorias na abordagem dos pacientes com hipertensão arterial no município de Inconfidentes - MG

A Hipertensão Arterial Sistêmica (HAS) é uma doença crônica de elevada prevalência na população brasileira, sendo considerada um sério problema de saúde pública e o principal fator de risco para o desenvolvimento de doenças cardiovasculares, renais e cerebrovasculares. Para o tratamento correto da HAS, independente da utilização de agentes farmacológicos, exige-se a mudança nos hábitos de vida, com ênfase na alimentação e prática de atividade física, algo que tem sido negligenciado. Quando diagnosticada precocemente e tratada de forma adequada pode evitar agravos aos portadores, proporcionando uma vida com qualidade, diminuindo internações hospitalares por complicações cardiovasculares e óbitos precoces. A carência de estudos avaliativos acerca da qualidade do processo do cuidado ao portador de hipertensão na atenção básica pode refletir a falta de avaliação em outros serviços e programas oferecidos à população. A abordagem correta deve visar o cuidado do paciente e não da doença, ou seja: uma abordagem que busque a parceria com a pessoa adoecida no seu cuidado de saúde e valorize o seu saber, promovendo a autonomia do indivíduo. O objetivo de tal abordagem será o de transmitir aos pacientes um mínimo de conhecimento sobre a doença e as suas comorbidades. Conscientizá-los da sua responsabilidade perante a sua doença (autonomia), do comprometimento familiar em ajudar no tratamento e da necessidade de se ter hábitos de vida saudáveis