Electrical, mechanical, and thermal analysis of natural rubber/polyaniline-Dbsa composite

A composite of natural rubber (NR) with polyaniline (PANI) was obtained by mixing an aqueous dispersion of dodecylbenzenesulfonic acid (DBSA)-doped PANI with NR latex in different concentrations. Films were obtained by the casting method and characterized by ultraviolet visible near-infrared (UV-Vis-NIR) spectroscopy, thermogravimetry/differential thermogravimetry (TG/DTG), stress-strain testing, differential scanning calorimetry (DSC), and DC electrical conductivity measurements. The UV-vis-NIR spectrum showed that PANI remained doped in the composite, and this improved the mechanical and electrical proprieties of NR films and afforded them good thermal stability up to similar to 200 degrees C. The percolation threshold did not follow the universal critical exponent, and in this case, conduction preferentially occurs by hopping and tunneling.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Estadual Paulista, Departamento de Física e Química, Faculdade de Engenharia de Ilha Solteir

The association of depression and all-cause and cause-specific mortality:an umbrella review of systematic reviews and meta-analyses

Background Depression is a prevalent and disabling mental disorder that frequently co-occurs with a wide range of chronic conditions. Evidence has suggested that depression could be associated with excess all-cause mortality across different settings and populations, although the causality of these associations remains unclear. Methods We conducted an umbrella review of systematic reviews and meta-analyses of observational studies. PubMed, PsycINFO, and Embase electronic databases were searched through January 20, 2018. Systematic reviews and meta-analyses that investigated associations of depression and all-cause and cause-specific mortality were selected for the review. The evidence was graded as convincing, highly suggestive, suggestive, or weak based on quantitative criteria that included an assessment of heterogeneity, 95% prediction intervals, small-study effects, and excess significance bias. Results A total of 26 references providing 2 systematic reviews and data for 17 meta-analytic estimates met inclusion criteria (19 of them on all-cause mortality); data from 246 unique studies (N = 3,825,380) were synthesized. All 17 associations had P < 0.05 per random effects summary effects, but none of them met criteria for convincing evidence. Associations of depression and all-cause mortality in patients after acute myocardial infarction, in individuals with heart failure, in cancer patients as well as in samples from mixed settings met criteria for highly suggestive evidence. However, none of the associations remained supported by highly suggestive evidence in sensitivity analyses that considered studies employing structured diagnostic interviews. In addition, associations of depression and all-cause mortality in cancer and post-acute myocardial infarction samples were supported only by suggestive evidence when studies that tried to adjust for potential confounders were considered. Conclusions Even though associations between depression and mortality have nominally significant results in all assessed settings and populations, the evidence becomes weaker when focusing on studies that used structured interviews and those that tried to adjust for potential confounders. A causal effect of depression on all-cause and cause-specific mortality remains unproven, and thus interventions targeting depression are not expected to result in lower mortality rates at least based on current evidence from observational studies

Whole organisms or pure compounds? entourage effect versus drug specificity

As the therapeutic use of sacred plants and fungi becomes increasingly accepted by Western medicine, a tug of war has been taking place between those who advocate the traditional consumption of whole organisms and those who defend exclusively the utilization of purified compounds. The attempt to reduce organisms to single active principles is challenged by the sheer complexity of traditional medicine. Ayahuasca, for example, is a concoction of at least two plant species containing multiple psychoactive substances with complex interactions. Similarly, cannabis contains dozens of psychoactive substances whose specific combinations in different strains correspond to different types of therapeutic and cognitive effects. The “entourage effect” refers to the synergistic effects of the multiple compounds present in whole organisms, which may potentiate clinical efficacy while attenuating side effects. In opposition to this view, mainstream pharmacology is adamant about the need to use purified substances, presumably more specific and safe. In this chapter, I will review the evidence on both sides to discuss the scientific, economic, and political implications of this controversy. The evidence indicates that it is time to embrace the therapeutic complexity of psychedelics.2019-07-3

Mycosis fungoides and Sézary syndrome: clinical, histopathological and immunohistochemical review and update

This paper reviews the diagnostic and classificatory concepts of mycosis fungoides and Sézary syndrome in light of the latest normative publications. It describes the great variability of the clinical expression of mycosis fungoides in its early stages as well as the histopathological and immunohistochemical aspects that help with diagnosis. The diagnostic criteria required for characterizing Sézary syndrome and the staging system used for both mycosis fungoides and Sézary syndrome are described