Is semantic verbal fluency impairment explained by executive function deficits in schizophrenia?

Objective: To investigate if verbal fluency impairment in schizophrenia reflects executive function deficits or results from degraded semantic store or inefficient search and retrieval strategies. Method: Two groups were compared: 141 individuals with schizophrenia and 119 healthy age and education-matched controls. Both groups performed semantic and phonetic verbal fluency tasks. Performance was evaluated using three scores, based on 1) number of words generated; 2) number of clustered/related words; and 3) switching score. A fourth performance score based on the number of clusters was also measured. Results: SZ individuals produced fewer words than controls. After controlling for the total number of words produced, a difference was observed between the groups in the number of cluster-related words generated in the semantic task. In both groups, the number of words generated in the semantic task was higher than that generated in the phonemic task, although a significant group vs. fluency type interaction showed that subjects with schizophrenia had disproportionate semantic fluency impairment. Working memory was positively associated with increased production of words within clusters and inversely correlated with switching. Conclusion: Semantic fluency impairment may be attributed to an inability (resulting from reduced cognitive control) to distinguish target signal from competing noise and to maintain cues for production of memory probes

Decrease in suicide rates in Brazil during the COVID-19 pandemic

Natural disasters such as public health epidemics may potentially affect suicide rates. The global COVID-19 pandemic poses an unprecedented challenge for healthcare systems and general populations worldwide. In this retrospective ecological study, we aimed to examine any changes in the suicide rates during the COVID-19 pandemic and to assess the relationship between COVID-19 death rates and deaths by suicide in Brazil. Data on suicide and COVID-19 case numbers were extracted from the Ministry of Health agencies and grouped weekly. We performed a time series analysis of suicide rates, a comparison of mean suicide rates between the pre-COVID-19 period and the COVID-19 period, and conducted a Poisson regression to examine the relationship between deaths due to COVID-19 and suicide rates. Our results showed decreased suicide rates during the COVID-19 pandemic. We also found that deaths owing to COVID-19 impact those owing to suicide after 10 weeks in the upward direction; however, we did not observe for enough time to see a change in the suicide rate curve. These findings are fundamental to understand suicidal behaviors in epidemic situations. However, the field needs more studies evaluating the impact of significant public health events on suicidality, incorporating extended follow-up periods

A 10-year ecological study of the methods of suicide used by Brazilian adolescents

Suicide among adolescents has become a major public health problem worldwide. Our study sought to describe the most commonly used methods of suicide among adolescents aged 10 to 19 years in Brazil between 2006 and 2015. Complete data were obtained from the Brazilian Health Informatics Department (DATASUS) and coded into seven categories of suicide methods. The following statistical analyzes were performed: chi-square (χ2) tests to examine the association between the frequency of each suicide method and the year; odds ratios (OR) and 95% confidence intervals (95%CI) compared the relative chances of each suicide method occurring between boys and girls. In total, 8,026 suicides among Brazilian adolescents were registered over the analyzed period. The most commonly used method of suicide by both sexes was hanging (2015 = 70.3%), and the most significant increase was observed in girls (2015 = 65.82%). The proportional use of arms (2006 = 14.2%; 2015 = 9.1%) and poisoning (2006 = 13.3%; 2015 = 9.2%) decreased over the period. The increase in hanging is worrisome, mostly due to difficulties to impose access barriers and to its high lethality. In such context, a comprehensive understanding of suicide behaviors among adolescents in Brazil should be drawn to inform general prevention measures and, more specifically, the reasons for the increase in hanging need to be further investigated

The cleaning of silver objects with a basic solution of sodium glycinate: a study on artificially and naturally tarnished silver

The appearance of silver objects deteriorates due to the formation of a brown-to-black tarnish layer. Several methods are available for removing these tarnished layers, ranging from polishing through chemical cleaning to electrochemical methods. This study presents a lowcost and low-toxicity method that uses sodium glycinate to clean silver. Cleaning tests were performed on both artificially tarnished prototypes and naturally tarnished objects after characterizing them; scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX) were used to characterize the artificially tarnished prototypes, and X-ray fluorescence (XRF) was used to characterize the naturally tarnished objects. The aggressiveness of the baths was analyzed by measuring the leached amount obtained through atomic absorption spectroscopy (AAS) and SEM. The procedures used for cleaning the artificially tarnished prototypes served as a guide for cleaning two naturally tarnished objects: a halo and a crown. Cleaning was guided by the presented method’s characteristics as well as the object’s unique characteristics and condition