Transcranial direct current stimulation in psychiatric disorders

The interest in non-invasive brain stimulation techniques is increasing in recent years. Among these techniques, transcranial direct current stimulation (tDCS) has been the subject of great interest among researchers because of its easiness to use, low cost, benign profile of side effects and encouraging results of research in the field. This interest has generated several studies and randomized clinical trials, particularly in psychiatry. In this review, we provide a summary of the development of the technique and its mechanism of action as well as a review of the methodological aspects of randomized clinical trials in psychiatry, including studies in affective disorders, schizophrenia, obsessive compulsive disorder, child psychiatry and substance use disorder. Finally, we provide an overview of tDCS use in cognitive enhancement as well as a discussion regarding its clinical use and regulatory and ethical issues. Although many promising results regarding tDCS efficacy were described, the total number of studies is still low, highlighting the need of further studies aiming to replicate these findings in larger samples as to provide a definite picture regarding tDCS efficacy in psychiatry

DOSAGEM DE MISTURA BETUMINOSA A FRIO E SEU ESTUDO SOB EFEITOS DE CARGAS ESTÁTICAS E REPETIDAS1

RESUMO Este trabalho apresenta os resultados de uma pesquisa experimental que objetivou estudar o comportamento mecânico de uma mistura betuminosa a frio sob efeitos de cargas estáticas e repetidas. Após a caracterização dos agregados e do ligante empregados na pesquisa, efetuou-se a mistura, a partir da dosagem Marshall, obtendo o teor de projeto equivalente a 8,5% de emulsão. Nesse teor de emulsão, moldaram-se várias amostras, que foram submetidas aos ensaios de módulo de resiliência, resistência à tração por compressão diametral e fadiga. A caracterização dos agregados e do ligante mostrou-se concordante com vários estudos, exceto o resíduo da peneiração, que não atendeu à exigência do IBP (1999). Para os ensaios com as misturas asfálticas, empregaram-se três corpos de prova, pesando cada um deles cerca de 1.200 g, compactados com 75 golpes em cada uma de suas faces. Observou-se que a estabilidade e a fluência Marshall de 620 kgf e de 4,20 mm, respectivamente, superaram o limite mínimo recomendado na especificação de serviço do DNIT (2010a). Com relação aos ensaios de módulo de resiliência e de resistência à tração por compressão diametral, obtiveram-se os valores de 1.616 MPa e 0,44 MPa, respectivamente, quando se verificou que os resultados foram bem inferiores aos encontrados em misturas a quente. Esse mesmo comportamento foi observado no ensaio de fadiga que, na maioria dos níveis de tensão aplicados, foi inferior a 1.000 aplicações do carregamento

Association between duration of untreated bipolar disorder and clinical outcome: data from a Brazilian sample

Objective: Bipolar disorder (BD) is often left untreated for long periods, and this delay in treatment correlates with unfavorable prognosis. The present study sought to assess the magnitude of duration of untreated bipolar disorder (DUB) in Brazil. We hypothesized that DUB would be longer in Brazil than in developed countries, and would be associated with poor clinical outcomes. Methods: One hundred and fifty-two psychiatric outpatients were evaluated for BD diagnosis, demographics, DUB, and clinical outcomes. Results: The mean age and mean DUB were, respectively, 38.9±10.8 and 10.4±9.8 years. An extended DUB was associated with early onset of BD (p < 0.001), depression as first mood episode (p = 0.04), and presence of BD in a first-degree relative (p = 0.012). Additionally, a longer DUB was associated with poorer clinical outcomes, such as elevated rates of rapid cycling (p = 0.004) and anxiety disorders (p = 0.016), as well as lower levels of current full remission (p = 0.021). Conclusion: As DUB may be a modifiable variable, better medical education regarding mental health, more structured medical services, and population-wide psychoeducation might reduce the time between onset and proper management of BD, thus improving outcome

Myoinositol reduction in medial prefrontal cortex of obsessive compulsive disorder: a proton magnetic resonance spectroscopy study

Background: Recent studies indicate that patients with obsessive-compulsive disorder (OCD) present abnormal levels of glutamate (GLU), glutamine (GLN) and g– aminobutyric acid (GABA) in frontal and striatal regions. These abnormalities could be related to deficits in corticostriatal circuits described in neuroimaging literature. But there is still no consensus about the role of the glutamatergic cycle in OCD, since other studies did not observe any differences in GLU (GLX) concentrations in OCD. GLU, GLN and GABA are metabolites of very difficult detection by conventional proton magnetic resonance spectroscopy (1H MRS), given its low signal and partial overlap with other metabolites. In this study we propose to use a twodimensional JPRESS 1H MRS sequence, that allows the discrimination of overlapping metabolites by observing the differences in J-coupling (second dimension of the spectrum), leading to a higher accuracy of all metabolites in the brain, including GABA, GLU and GLN. The objective of this study is to use 2D-JPRESS sequence to identify the alterations of neurometabolism present in OCD. Methods: Twenty one OCD patients (mean age 34.7y [range 19-58y]) and 14 healthy controls (HC, mean age 31.9y [range 18-47y]) were evaluated with a 3T Achieva Philips MRI scanner. Symptom severity of OCD was measured with the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). All participants also filled the Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI) to assess symptoms of depression and anxiety, respectively. We used ProFit 2.0 Matlab program to quantify creatine (Cr), N-acetyl-aspartate, glutathione, myo-inositol (MI), lactate, GABA, GLN, and GLU. The voxel was situated in medial prefrontal cortex (mPFC) and varied from 2x2x2cm3 to 2.5x2.5x2.5cm3. We used FSL routines to segment voxel content into percentages of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) and metabolite concentrations were corrected for different voxel composition. Statistics were performed with SPSS: each metabolite was entered as a dependent variable in an univariate linear model with group as the fixed factor and age, and sex as covariates. For correlation analysis, we used Pearson correlation and Pearson partial correlation, controlling for CSF (two-tailed). Comparisons of demographic data (age and sex) were performed with student t-test and chi-squared. Results: Groups did not differ for sex (patients: 12 male / 9 female; HC: 8 male / 6 female), age, GM, WM or CSF (all p-values 4 0.05), but significantly differ in terms of depression and anxiety symptoms (both BDI and BAI p-values o 0.002). All patients were free of medication at the time of the scan and the mean Y-BOCS score was 27.9 þ 6.1. There were no between-group differences regarding GLU, GLN or GABA, but OCD patients showed lower levels of MI (p ¼ 0.006, corrected for Bonferroni multiple comparisons correction). Moreover, we did not observe any correlation between levels of the metabolites evaluated and clinical data (Y-BOCS, BDI or BAI) in the OCD group. Conclusions: We did not find differences in absolute values of GLU, GLN or GABA between OCD patients and HC. On the other hand, MI was decreased in the mPFC of OCD patients. Our findings are in line with other negative studies in the literature on regards to GLU, GLN and GABA levels that have used different 1H MRS sequences to measure these metabolites. Even measuring isolated levels of GLU we could not find evidences that support the glutamatergic hypothesis for OCD. Regarding MI, our results also corroborate previous investigations of the involvement of MI in the physiopathology of OCD: one study presented MI decreases in childhood and adolescent OCD in a brain region similar to ours (anterior cingulate cortex) and the other showed a negative correlation between MI levels in the orbitofrontal cortex and symptom severity. Together, these findings highlight the importance of inositol in the neurobiology of OCD. An important limitation was the relative small sample size of groups, in particular the HC group. Future studies with larger sample sizes should investigate the role of inositol in OCD, whether it could be a good treatment predictor or if it could play a role in OCD symptoms improvement

Classificação tecnológica de solos e resíduos industriais, com e sem tratamento térmico, para fins rodoviários Technological classification of soils and industrial residues with and without thermal treatment for forest road pavement

Estudou-se o comportamento mecânico das misturas solo-alcatrão, solo-cal-alcatrão e solo-cimento-alcatrão, com base nos ensaios de limites de liquidez e plasticidade, CBR, compressão simples e permeabilidade, visando a aplicabilidade destas em rodovias. Trabalhou-se com três amostras de solos (ETA, NV e VS), representativos das ocorrências da microrregião de Viçosa-MG. Foram empregados alcatrão, nos quantitativos de 0,25, 0,5, 1, 2, 4 e 6%, cal hidratada e cimento Portland, em conjunto com o alcatrão, na dosagem de 2%, considerando-se a energia do ensaio de compactação AASHTO Normal. A adição de alcatrão reduziu significativamente os valores de LL dos solos, mas com pouca variação nos valores de IP. Conclui-se que o alcatrão contribuiu para melhorar as características mecânicas e hidráulicas dos solos, para alguns tratamentos, não atingindo, entretanto, os padrões de resistência mecânica exigida pelo DNER para camadas de sub-base de pavimentos flexíveis. Quanto às misturas solo-cal-alcatrão e solo-cimento-alcatrão, constatou-se melhoria substancial nos parâmetros de resistência mecânica em relação aos solos, principalmente devido à ação cimentante da cal e do cimento, e que para alguns tratamentos esta ação foi potencializada pelo alcatrão, incidindo em resistência mecânica superior à das misturas solo-cal e solo-cimento. O alcatrão, em alguns tratamentos, ocasionou decréscimos na permeabilidade das misturas, com relação ao solo, de até dez vezes. O alcatrão mostrou ser um estabilizante de interesse para fins rodoviários apenas para determinadas condições, envolvendo tipo de solo e tipo e teor de alcatrão, o que indica que estudos nesta direção devem apresentar uma característica regional.<br>The behavior of the mechanical mixtures soil-wood tar, soil-lime-wood tar and soil-cement-wood tar, based on the Atterberg limits California Bearing Ratio (CBR), Unconfined Compression Strength (UCS) and permeability, were studied for application in forest road pavement. Three soil samples of (ETA, NV and VS) representative of Viçosa-MG occurrences were used. Wood-tar was used 0.25, 0.5, 1, 2, 4 and 6% and lime and cement mixture.The addition of wood-tar reduced the Atterberg values significantly. It was concluded that wood-tar improved the mechanical and hydraulic characteristics of the soils, for some treatments without, however, reaching however, the patterns of mechanical resistance demanded by DNER sub-base layers of flexible pavements. Regarding the mixtures soil-lime-wood tar and soil-cement-wood tar, substantial improvement was verified in the mechanical resistance parameters in relation to the soils, mainly due to the action of lime and cement. This action was found to be stronger for the wood tar in some treatments, leading to a higher mechanical resistance than that of the mixtures soil-lime and soil-cement. Wood tar caused a decrease in mixture permeability in relation to the soil up to 10 times. Wood tar was found to be an important stabilizer only for some forest road pavement conditions, involving soil type, and wood tar type and level, suggesting that studies on this area should present a regional characteristic

Influência da imersão em água na resistência mecânica de misturas solo-grits compactadas e curadas com vistas a aplicações em estradas florestais Influence of water submersion on the mechanical strength of compacted and cured soil-grits mixtures for forest roads applications

Avaliou-se o efeito da imersão em água dos corpos-de-prova sobre a resistência mecânica de misturas solo-grits. Trabalhou-se com dois solos da cidade de Viçosa, localizada na Zona da Mata Norte de Minas Gerais, Brasil, respectivamente de texturas predominantemente argilosa e arenosa e com o resíduo sólido industrial grits, um subproduto da indústria de celulose. Determinaram-se os parâmetros de resistência mecânica California Bearing Ratio (CBR) e Resistência à Compressão Não-Confinada (RCNC) de corpos-de-prova compactados nas energias de compactação referentes aos ensaios Proctor intermediário e Proctor modificado, com teores de grits na faixa de 4 a 28% e períodos de cura de 0, 7 e 28 dias. Com relação ao parâmetro CBR, os ensaios foram realizados segundo a metodologia tradicional (imersão em água dos corpos-de-prova por 96 horas) e sem a imersão em água, visando determinar possíveis perdas na capacidade-suporte das misturas. No que tange ao parâmetro compressão não-confinada, os ensaios foram realizados em obediência à norma brasileira para misturas solo-cimento (imersão em água durante quatro horas antes da ruptura dos corpos-de-prova) e sem a fase de imersão em água. Os resultados indicaram que a imersão em água dos corpos-de-prova influenciou significativamente a resistência mecânica das misturas solo-grits, que foram dependentes do tipo de ensaio empregado, tipo de solo, teor de grits, energia de compactação e período de cura.<br>This paper address the influence of water submersion on mechanical strength parameters of soil-grits specimens. Two residual soils, predominantly clayey and sandy soils from the city of Viçosa, located in the State of Minas Gerais, "Zona da Mata Norte", Brazil, and waste from cellulose industry were used in the study. The laboratory testing program consisted of CBR (California Bearing Ratio) and UCS (Unconfined Compression Strength) of specimens prepared with waste contents ranging from 4 to 28 %, compacted at the intermediate and modified compaction efforts, and cured during 0, 7 and 28 days. Laboratory tests were performed as follow: (i) CBR: tests were performed following the standard procedure, i.e. after 4 days water submersion before specimen penetration, and without submersion; and (ii) UCS: tests were performed following the Brazilian standard procedure, i.e. after 4 hours specimen submersion before testing, and without water submersion. The laboratory testing program data support that water submersion significantly influenced the tested mechanical strength parameters, which were dependent of the type of assay and soil, percentage of grits waste, compaction effort and cure