Juliana Braga Gomes

Caracterização de substâncias húmicas extraídas de solos e de lodo orgânico

The extraction of humic substances (HS) from A-horizons of two soils from Rio Grande do Sul (Oxisol, LR, and Mollisol, BZ) and from an organic sludge (LO) was investigated, employing two methods: (1) the HS were extracted with 0.5 mol L-1 NaOH, after treating the sample with 0.5 mol L-1 HCl; (2) the extraction with 0.15 mol L-1 sodium pyrophosphate solution (pH 7) was introduced before the alkaline and after the acid treatments. In each step, the contents of HS, fulvic acids (FA) and humic acids (HA) were determined by spectroscopic and gravimetric methods, and the contents of co-extracted Fe, Al, Si and Ca in the extracts of method 2 were measured by atomic absorption. The elemental composition of HA was determined and their chemical structure and characteristics were evaluated from the C/N, H/C and O/C ratios and from UV/Vis spectroscopy data. In the Oxisol, method 1 extracted a greater amount of HS, and in method 2 the pyrophosphate step extracted only AF. On the other hand, method 2 was more efficient in the Mollisol, and the greatest yield was obtained in the pyrophosphate step. These results suggest that in the Oxisol, the HS interact mainly through ligand exchange reactions and hydrogen bonding, while in the Mollisol, cation bridges are also an important mechanism. The NaOH-extracted HA showed higher H/C and lower O/C ratios than the pyrophosphate-extracted ones, indicating that the neutral solution solubilized HS with higher aromatic character and oxygenation grade.

Métodos para avaliação das emissões de gases do efeito estufa no sistema solo-atmosfera

The sellection of the method for evaluating greenhouse gases (GHG) emissions is an important step in studies aiming at the development of agricultural practices with potential to mitigate the global warming. The objective of this review was to present advantages and disvantages of available methods to quantify fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in the soil-atmosphere system. Carbon sequestration or annual net influx rates of C-CO2 in conservation tillage systems can be evaluated through the soil carbon budget. In situ evaluations can be carried out with closed chambers, where alkaline traps are used to determination of daily influxes of CO2 while gas chromatography and automatic infrared gas analyzers permit to estimate horary fluxes. In addition to CO2, gas chromatography is able to measure N2O and CH4 emissions, gases that have a global warming potential 296 and 23 times higher than CO2, respectively. Measurement of the three GHG emissions permit to estimate the net effect of soil management systems on atmosphere rodiative forcing in equivalent C.

Sorção de atrazina em cambissolo húmico do Rio Grande do Sul sob vegetação nativa

A acumulacao de herbicidas no ambiente em virtude de sua larga utilizacao em sistemas agricolas, associada a alta persistencia, e extremamente preocupante, considerando os efeitos maleficos que alguns destes compostos causam a flora e a fauna. A atrazina (2-cloro-4-etilamino-6-isopropilamino-s-triazina) e um dos herbicidas mais utilizados na atualidade e tem sido detectada em teores consideraveis em mananciais e solos. O objetivo deste estudo foi avaliar o comportamento sortivo da atrazina comercial em Cambissolo Humico em condicoes naturais e em ausencia de materia orgânica. Foram determinadas isotermas de sorcao de atrazina comercial em amostras do horizonte A na sua forma natural e na forma oxidada. A quantidade maxima de herbicida sorvido variou de 8 % (amostra oxidada) a 49 % (amostra natural) da quantidade adicionada. A aplicacao do modelo de Freundlich na forma linear aos dados experimentais forneceu altos coeficientes de correlacao para a sorcao em amostra natural (r = 0,960, P < 0,01) e na amostra oxidada (r = 0,937, P < 0,01). O coeficiente nf (modelo de Freundlich) obtido na amostra natural (1,40) indica que a afinidade do sorbato pelo sorvente aumentou com o progresso da sorcao, enquanto, na amostra oxidada, o comportamento foi inverso (nf = 0,78). O valor do coeficiente Kf foi de 1,10 L kg-1 na amostra natural e de 0,84 L kg-1 na amostra oxidada, enquanto o coeficiente de distribuicao da atrazina (Kd) foi de 4,64 e 0,33 L kg-1, respectivamente. Estes resultados mostram que a materia orgânica foi o sorvente determinante na retencao de atrazina no Cambissolo humico. Adicionalmente, o valor de Koc de 103 L kg-1 obtido classifica a atrazina comercial como de alta mobilidade para o sistema atrazina-solo estudado.

Patient and family factors associated with family accommodation in obsessive–compulsive disorder

Obsessive–compulsive disorder (OCD) impacts family functioning as family members modify their personal and family routines, participate in rituals, and provide reassurance. These behaviors have been identified as family accommodation (FA), a phenomenon that, if ignored, may facilitate OCD symptoms and lead to poorer prognosis. Because FA has been recognized as a predictor of treatment outcome, we examined the prevalence of FA and identified patient and family sociodemographic and clinical variables associated with FA in an outpatient sample.

Effect of cognitive-behavioral group therapy for panic disorder in changing coping strategies.

BACKGROUND Cognitive-behavioral group therapy (CBGT) is an efficient treatment for panic disorder (PD). However, the role of CBGT in enhancing strategies to cope with stressful events has not been established. AIM To evaluate the effect of CBGT on the choice of coping strategy by PD patients compared to a group of individuals without mental disorders. METHODS Forty-eight PD patients who completed a 12-session CBGT protocol were compared to 75 individuals without mental disorders regarding coping strategies as evaluated by the Coping Strategies Inventory (CSI). The severity of PD was assessed at baseline and after CBGT through the Clinical Global Impression (CGI) scale, the Hamilton Anxiety Scale (HAM-A), and the Panic Inventory (PI). RESULTS Treatment was effective in reducing PD severity in all outcome measures. Patients used significantly fewer confrontation, escape and avoidance strategies after CBGT. The use of more adaptive coping strategies was related to a decrease in panic attacks and anticipatory anxiety. Application of the CSI showed that the use of strategies was also significantly different in patients as compared to the control group, except for escape and avoidance, which became similar after the CBGT protocol. CONCLUSIONS Despite the changes observed after the CBGT protocol, the choice of coping strategy was still different in patients vs. controls. The current CBGT protocol was used specifically to assess PD symptoms. Other cognitive tools should be included to address maladaptive coping strategies.

Translation and adaptation into Brazilian Portuguese of the Family Accommodation Scale for Obsessive-Compulsive Disorder - interviewer-Rated (FAS-IR)

OBJETIVO: Descrever o processo de traducao e adaptacao para o portugues do Brasil da Family Accommodation Scale for Obsessive-Compulsive Disorder - Interviewer-Rated (FAS-IR). METODO: O processo de traducao e adaptacao da escala envolveu quatro profissionais de saude bilingues. A escala foi inicialmente traduzida de forma independente para o portugues do Brasil por dois profissionais. A seguir, as duas versoes foram comparadas, resultando em uma versao inicial em portugues que foi aplicada a 15 familiares de pacientes com transtorno obsessivo-compulsivo (TOC), com diferentes niveis de instrucao, deliberadamente escolhidos para coletar as sugestoes de ajuste linguistico. Subsequentemente, a escala foi retrotraduzida independentemente por outros dois profissionais da saude. Depois de comparar as duas retrotraducoes, uma nova versao da escala foi gerada em ingles. Essa versao foi revisada e aprovada pelos autores da escala original. RESULTADOS: A versao em portugues do Brasil da escala FAS-IR mostrou ser facilmente compreendida e pode ser usada em familiares de pacientes com TOC de diferentes niveis socioeconomicos. CONCLUSAO: A FAS-IR adaptada ao portugues do Brasil fara com que profissionais de saude possam avaliar o nivel de acomodacao em familiares de pacientes com TOC e permitira a realizacao de futuros estudos com os objetivos de 1) estudar a influencia da acomodacao familiar na manutencao e, possivelmente, na facilitacao dos sintomas do TOC e 2) examinar o efeito da acomodacao familiar sobre os resultados do tratamento em populacoes de paises de lingua portuguesa.

Patient Rating of Therapeutic Factors and Response to Cognitive-Behavioral Group Therapy in Patients with Obsessive-Compulsive Disorder

Group therapy involves complex mechanisms that rely on certain therapeutic factors to promote improvement. The objective of this study was to assess patient rating of therapeutic factors during cognitive-behavioral group therapy (CBGT) and to investigate the correlation between patient rating and outcome of CBGT for the treatment of obsessive-compulsive disorder (OCD). In the present clinical trial, 15 patients participated in a 12-session CBGT protocol. Severity of symptoms was assessed before and after CBGT with the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Clinical Global Impression (CGI), Hamilton Anxiety Scale (HAM-A), and Beck Depression Inventory (BDI). Yaloms Curative Factors Questionnaire was administered at the end of each session for patient rating of the usefulness of 12 therapeutic factors to treat OCD. There was a significant interaction between improvement in obsessive-compulsive symptoms and patient rating of altruism, universality, interpersonal learning input and output, family re-enactment, self-understanding, and existential factors over time. The results show that group therapeutic factors positively influence the response to CBGT in OCD patients.

Booster Sessions after Cognitive-Behavioural Group Therapy for Panic Disorder: Impact on Resilience, Coping, and Quality Of Life

BACKGROUND Panic disorder (PD) has a chronic nature, especially as a result of maladaptive coping strategies to deal with stressful events. AIMS To evaluate the impact of booster sessions with cognitive techniques on coping strategies, resilience, and quality of life (QoL) in patients previously submitted to standard cognitive-behavioural group therapy (CBGT) for PD. METHOD A controlled clinical trial with 44 patients with PD (intervention = 20; control = 24) who had previously completed a 12-week CBGT protocol. PD, anxiety, and depression severity symptoms were assessed at baseline and 1, 6, and 12 months after the booster sessions. Coping strategies, resilience, and QoL were assessed by Coping Strategies Inventory (CSI), Resilience Scale, and WHOQOL-BREF respectively. RESULTS Over time, a significant improvement in PD and depression symptoms was observed in both groups. A significant increase in the QoL social relations domain was found in the booster group, considering a time/group interaction. Coping and other QoL domains did not change after the booster sessions. Changes in resilience were dependent on the intensity of symptoms, with negative but non-significant correlations. CONCLUSIONS The improvement in PD and depression symptoms for both groups may be a result of the group format of the intervention. Group booster sessions after CBGT are useful to maintain the benefits obtained with CBGT.

Adsorção de ácidos húmicos em latossolo roxo natural e tratado com oxalato de amônio

The adsorption of two humic acids (HA) was carried out on a natural Oxisol (natural LR) and on an ammonium-oxalate treated sample (treated LR), in order to investigate the adsorption mechanisms and the main functional groups involved and relate the adsorptive capacity with the chemical and molecular characteristics of the adsorbates. The HA extracted with 0.5 N NaOH solution from a coal sample (HAc) and from a Mollisol sample (HAs) were characterized by elemental analysis and 13C-NMR spectroscopy. The experimental data were fitted according to the equation y = A tanh Bx and the model of Langmuir was also applied. The adsorbed samples were analyzed by Diffuse Reflectance Fourier Transformed Infrared Spectroscopy (DRIFT). The HA adsorption on the natural LR was of a chemical nature, with the ligand exchange reaction between the carboxyl groups and the mineral surfaces being an important mechanism, as shown by DRIFT. The AHc had a higher aromatic character and a higher carboxyl content in its molecule and was adsorbed in greater quantity than the AHs in both adsorbents. This result also suggests a possible participation of aromatic moieties in the organo-mineral interaction. The treated LR, which had a higher specific surface area (SSA = 140.9 m2 g-1), showed a greater adsorptive capacity than the natural LR (SSA = 66.1 m2 g-1). The higher SSA in the treated sample was related to the breakup of microaggregates by the oxalate treatment, caused by the extraction of the cementing portion of iron oxides that bonded the particles together. The interaction in this adsorbent, as estimated by the parametrization y = A tanh Bx, showed higher chemical affinity than in the natural sample. This can be related to the adsorbed oxalate that created hydrophobic adsorption sites, the exposure of more reactive sites after the treatment and the lower pH value. The Langmuir model was adequate to explain the adsorption in the natural sample, while in the treated sample, the results obtained were not satisfactory. Generally, the proposed parametrization y = A tanh Bx yielded the better fit (i.e. higher R2) in comparison to the Langmuir equation.

Impact of cognitive-behavioral group therapy for obsessive-compulsive disorder on family accommodation: A randomized clinical trial

The aim of this study was to assess the impact of cognitive-behavioral group therapy (CBGT) with the brief involvement of family members on family accommodation and to identify predictors of family accommodation reduction (patient and family member characteristics). This randomized clinical trial assessed 98 pairs of patients with obsessive-compulsive disorder (OCD) and their family members: 52 (53.1%) were allocated to the intervention group (12 CBGT sessions - two with the family member), and 46 (46.9%) to a waiting list (control group). Symptom severity and family accommodation were assessed before and after CBGT. There was significant improvement of OCD symptoms and family accommodation scores after CBGT in the intervention group vs. the control group. The following variables were significant predictors of family accommodation reduction after multivariate analysis: patient characteristics - absence of comorbid unipolar disorder, lower obsession score, and higher education level; family member characteristics - higher hoarding score. The model explained 47.2% of the variance in family accommodation scores after treatment. CBGT for patients with OCD and the brief involvement of family members contributed to reduce family accommodation. Both patient and family member characteristics were predictors of family accommodation reduction. This finding can help qualify CBGT protocols.