Recebido em 4/7/11; aceito em 27/2/11; publicado na web em 15/6/12 DIURON SORPTION ONTO CLAY MINERAL FRACTIONS. The objective of the present study was to evaluate the adsorption of the herbicide Diuron onto smectite and Fe oxides minerals. Ninety mg of each mineral, 1 mL of 0.15 mol L -1 CaCl 2 and 8 mL of Diuron (0.25-10.00 mg L -1 ) were used in triplicates. These materials were shaken, ultra centrifuged and the supernatant collected and analysed on a UV-Vis spectrophotometer. The Diuron presented low adsorption onto clay mineral fractions. Adsorption was greater onto Fe oxides at pH 7.0, possibly due to proximity to the point of zero charge of these minerals.Keywords: smectite; Fe oxides; herbicides. INTRODUÇÃOAo longo dos anos, o elevado crescimento das atividades agrícolas sempre foi acompanhado pelo intenso uso de pesticidas 1-3 principalmente no Brasil, que é considerado o maior consumidor do mundo. 4 Dentre os pesticidas, a classe dos herbicidas -que matam ou suprimem o crescimento de plantas invasoras específicas -é responsável pela maior parte das vendas e do consumo em nível mundial. 5,6 Embora sejam insumos agrícolas de reconhecida importância, a utilização inadequada e sem conhecimento da ação e dos efeitos secundários pode acarretar danos ambientais, o que reforça a necessidade de estudos sobre o seu destino final: o solo. O comportamento de herbicidas no solo é bastante complexo e resulta de vários fatores, dentre os quais, destaca-se o processo de sorção, que denota a interação entre o soluto e a fase sólida do solo.7 Esta depende das características químicas da molécula do herbicida 1,8,9 e das propriedades e dos constituintes do solo.

The aim of this work was to study ecotechnology for the management of degraded areas originally covered by the

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Background: Some studies indicated that body mass index (BMI) is inversely proportional to serum testosterone concentrations in men. Purposes: This study aimed to analyze the effects of aging and obesity on total testosterone (TT), free testosterone (FT), bioavailable testosterone (BT), luteinizing hormone (LH), and sex hormone-binding globulin (SHBG) levels. Methods: A cross-sectional study was performed to assess the clinical and laboratory profiles of 701 patients treated at a private urology clinic in Ponta Grossa, Brazil, from January 2016 to December 2018. Results: Patients’ age ranged from 16 to 88 years (mean, 56.9 ± 13.62 years). Age did not significantly influence serum TT concentrations, except compared to patients aged >70 years. However, changes were observed in FT and BT (p < 0.05). The mean SHBG increased with age (p < 0.05). A tendency toward LH elevation was observed in older patients, but it was not statistically significant. An inverse proportional relationship between TT, FT, and BT and the testosterone deficiency rate (TT < 300 ng/dL) was observed within BMI groups (p < 0.05). The testosterone deficiency rate was 21.5% in individuals with normal BMI, 29% in overweight individuals, and 37% in obese individuals. Conclusions: Aging affected the testosterone concentrations in men and became increasingly evident using FT and BT instead of TT. SHBG increased with age. Obesity was associated with a decrease in TT, FT, and BT but also increased the rate of hypogonadism.