Efficient Strategies to Use ß-Cationic Porphyrin-Imidazolium Derivatives in the Photoinactivation of Methicillin-Resistant Staphylococcus aureus.

Bacterial resistance to antibiotics is a critical global health issue and the development of alternatives to conventional antibiotics is of the upmost relevance. Antimicrobial photodynamic therapy (aPDT) is considered a promising and innovative approach for the photoinactivation of microorganisms, particularly in cases where traditional antibiotics may be less effective due to resistance or other limitations. In this study, two ß-modified monocharged porphyrin-imidazolium derivatives were efficiently incorporated into polyvinylpyrrolidone (PVP) formulations and supported into graphitic carbon nitride materials. Both porphyrin-imidazolium derivatives displayed remarkable photostability and the ability to generate cytotoxic singlet oxygen. These properties, which have an important impact on achieving an efficient photodynamic effect, were not compromised after incorporation/immobilization. The prepared PVP-porphyrin formulations and the graphitic carbon nitride-based materials displayed excellent performance as photosensitizers to photoinactivate methicillin-resistant Staphylococcus aureus (MRSA) (99.9999% of bacteria) throughout the antimicrobial photodynamic therapy. In each matrix, the most rapid action against S. aureus was observed when using PS 2. The PVP-2 formulation needed 10 min of exposure to white light at 5.0 µm, while the graphitic carbon nitride hybrid GCNM-2 required 20 min at 25.0 µm to achieve a similar level of response. These findings suggest the potential of graphitic carbon nitride-porphyrinic hybrids to be used in the environmental or clinical fields, avoiding the use of organic solvents, and might allow for their recovery after treatment, improving their applicability for bacteria photoinactivation.

How does urban violence impact choices of cultural participation? The case of the Maré favela complex in Rio de Janeiro.

The impact of urban violence on society has been the subject of several studies, but the consequences of fear for habits of cultural consumption are missing in cultural economics research. This article investigates whether the fear of urban violence explains individuals' choice between different options of cultural participation with a particular focus on the activities of watching movies and listening to music. Based on individual data from a survey conducted in 2019 with 1211 residents from a conglomeration of sixteen favelas (slums) located in the Maré neighbourhood in Rio de Janeiro (Brazil), this study employs Simultaneous Bivariate Ordered Probit Models to verify the association between individuals' fear of violence and their choice of consuming culture in private or public spaces. Controlling for socioeconomic, demographic, and territorial variables, the findings indicate that consuming culture in private spaces is a substitute for public spaces when individuals are more afraid of violence. The results presented in this work provide evidence for the design and implementation of policies targeting territories impacted by high levels of violence.

Experience of neighbourhood violence and mental distress in Brazilian favelas: a cross-sectional household survey.

Background: Living in informal settlements with extensive neighbourhood violence has been shown to be linked with poorer mental health. However, there is little evidence as to whether different levels of personal experiences and fears of neighbourhood violence within such settlements affect mental health. This study assessed such personal experiences and fears of residents in favelas in Brazil. We tested whether variations predict mental health symptoms and quality of life, and whether this is independent of the influence of sociodemographic characteristics and poverty. Methods: In a population-based survey of adults living in a group of favelas in Rio de Janeiro, Brazil, we assessed: sociodemographic characteristics; extent of personal experiences and fear of neighbourhood violence; mental health symptoms on the Brief Symptom Inventory; and quality of life on the Manchester Short Assessment of Quality of Life. Univariate and multivariate regressions were fit to predict mental health symptoms and quality of life. Findings: We interviewed 1,211 residents. Both more experiences of neighbourhood violence and more fear of violence predicted higher levels of mental health symptoms and poorer quality of life. In multivariate regression analyses, the associations remained significant after adjusting for the influence of other factors, in particular female gender, younger age, and marked poverty. Interpretation: Even within a context in which the whole population can be exposed to violence and economic disadvantage, individual variations in the experiences of violence still make a significant difference for mental distress and quality of life. Policies to improve mental health and quality of life of residents in informal settlements need to address risk factors separately, most importantly the personal experiences of violence and poverty. Funding: Economic and Social Research Council and Arts and Humanities Research Council in the United Kingdom. Antecedentes: Viver em assentamentos informais, com ampla violência na vizinhança, parece estar associado a piores condições de saúde mental. No entanto, há poucas evidências de que, nestes locais, os diferentes níveis de experiências pessoais e o medo da violência na vizinhança afetem a saúde mental. Este estudo avaliou experiências pessoais e medos de moradores de favelas no Brasil. Testamos se tais variações predizem sintomas de saúde mental e qualidade de vida, e se isso é independente da influência das características sociodemográficas e da pobreza. Métodos: Com base em um inquérito domiciliar de base populacional, realizado com adultos residentes em um grupo de favelas do Complexo da Maré, Rio de Janeiro, Brasil, foram observadas: características sociodemográficas; a extensão das experiências pessoais de exposição à violência e o medo da violência na vizinhança; sintomas de saúde mental, a partir do Inventário de Sintomas Psicopatológicos (BSI); e qualidade de vida, a partir da escala Manchester Short Assessment of Quality of Life (MANSA). Regressões univariadas e multivariadas foram ajustadas para explicar variações nos sintomas de saúde mental e qualidade de vida. Resultados: Entrevistamos 1.211 pessoa adultas residentes na Maré. Tanto maiores níveis de exposição a experiências de violência na vizinhança quanto mais medo dessa violência estiveram relacionados a piores níveis de saúde mental (maior número e intensidade de sintomas no BSI) e pior qualidade de vida. Nas análises de regressão multivariada, tais associações permaneceram significativas mesmo após controlarmos pela influência de outros fatores, em particular sexo (feminino), idade (mais jovem) e pobreza acentuada. Interpretação: Mesmo em um contexto no qual toda a população pode estar exposta à violência e a desvantagens materiais e econômicas, as variações individuais nas experiências de violência ainda assim fazem diferença significativa nas condições de sofrimento mental e qualidade de vida. Políticas para melhorar a saúde mental e a qualidade de vida dos residentes de assentamentos informais, como as favelas, precisam abordar fatores de risco separadamente focando, principalmente, na redução da exposição a experiências pessoais de violência e da pobreza. Financiamento: Economic and Social Research Council (ESRC) e Arts and Humanities Research Council (AHRC), ambos do Reino Unido.

Photochemical degradation of the plant growth regulator 2-(1-naphthyl) acetamide in aqueous solution upon UV irradiation.

The photochemical degradation of 2-(1-naphthyl) acetamide (NAD) in aqueous solution using simulated sunlight excitation as well as UV light within the 254-300 nm range was investigated to obtain an insight into the transformation mechanism that could occur under environmental conditions. Several photoproducts were identified using HPLC/MS/MS techniques. The degradation quantum yield was found to be independent of the excitation wavelength, but showed a dependence of oxygen concentration. This increased by a factor of approximately 3 from aerated to oxygen-free solutions. There is a clear involvement of both triplet and singlet excited states in NAD photoreactivity. The participation of singlet oxygen as a significant route in NAD degradation was ruled out by comparison with the behavior using Rose Bengal as a photosensitizer. A mechanistic pathway implying hydroxylation process through NAD radical cation species as well as an oxidation reaction by molecular oxygen is proposed. The photochemical behavior of NAD appears to mainly involve the aromatic moieties without any participation of the amide side chain. Toxicity tests clearly show that the generated primary photoproducts are responsible for a significant increase in the toxicity. However, upon prolonged irradiation this toxicity tends to decrease.