Universidade Federal de Santa Maria

Quantification of inorganic chlorides in crude oil is crucial for the petroleum industry because chlorides can cause corrosion, catalyst poisoning, and pipeline clogging. This work presents an innovative approach using nanoemulsion preparation for the direct potentiometric determination of inorganic chlorides in crude oil samples. The method, termed direct determination of chloride (CDD), uses an oil-in-water (O/W) nanoemulsion to transfer and solubilize inorganic chlorides from crude oil into an aqueous medium. Chloride quantification was performed by direct potentiometric titration of the O/W nanoemulsion. Applied to 15 crude oil samples (API gravity: 13.1-38.2), the proposed CDD method was compared with standard potentiometric titration, as per ASTM D6470, and quantification of chlorides by determining main metals (Na, Ca, and Mg) using flame atomic absorption spectrometry. The proposed method achieved a relative standard deviation below 5 % and a limit of quantification of 0.015 mg g^-1. Recovery ranged from 99.0 to 109.2 % for NaCl-added samples and from 97.1 to 99.0 % for those with mixed salts (70 wt % NaCl, 25 wt % CaCl₂, and 5 wt % MgCl₂). The CDD method showed no statistical differences from ASTM D6470 or flame atomic absorption spectrometry (p < 0.05), confirming that it successfully transfers and solubilizes inorganic chlorides from crude oil samples into the aqueous medium. By integrating nanoemulsion-based solubilization with potentiometric titration, the CDD method provides an accurate and precise technique for the determination of inorganic chlorides in crude oil, with the advantages of simple operation, reduced solvent consumption, and improved sustainability.

Physical activity (PA) alleviates depressive symptoms, but evidence on long-term effects and moderators remains inconclusive. We examined long-lasting effects on depressive symptoms after six months of a PA intervention and potential moderators (sex, age, and marital status) among adults with depressive symptoms.

This randomized controlled trial involved adults with depressive symptoms, assigned to a waitlist control or intervention group (IG). The 16-week intervention comprised two 90-minute sessions per week. The sessions included both theoretical components and various PA modalities. Depressive symptoms were assessed at baseline, post-intervention, and after six months, using the Patient Health Questionnaire-9. Generalized estimating equations were used to compare changes over time and between groups. Moderation effects were tested using three-way interaction terms (group-by-time-by-moderator).

A total of 78 participants (76.9 % women, mean age = ≈37.5 years for both groups) were randomized. In both groups depressive symptoms decreased over time, with significantly greater improvements in the IG (p = 0.017). Specific symptoms such as "feeling bad about yourself", "trouble concentrating", and "sluggishness or restlessness" showed particularly marked improvements among IG participants. Age moderated the intervention effect (p = 0.043), with stronger benefits observed in middle-aged adults (37-59 years) compared to younger adults (20-36 years). No moderating effects were found for sex or marital status. Remission rates were higher in the IG at post-intervention (51.3 % vs. 23.1 %) and follow-up (35.9 % vs. 5.2 %), with fewer cases of symptom worsening (18.0 % vs. 33.3 %).

A multicomponent PA intervention led to sustained a reduction in depressive symptoms, particularly among middle-aged adults.

Brazilian Registry of Clinical Trials (ReBEC): RBR-7466htj, April, 17 2023.

Cadmium (Cd) is a highly toxic heavy metal commonly introduced into agricultural soils through phosphate fertilizers. Cadmium accumulation poses serious risks to human health, crop productivity, and environmental sustainability. Although the toxic effects of Cd on plant development are well documented, effective and sustainable strategies to mitigate its impact on seed germination and early plant growth remain limited. Nanomaterials such as graphene oxide (GO) demonstrated potential in alleviating abiotic stress, but application in Cd-contaminated agricultural systems requires further investigation. Therefore, the aim of this study was to examine the potential of GO as a possible mitigator of adverse Cd-initiated effects on seed germination and initial growth of rice (Oryza sativa L.) seedlings. Rice seeds were treated with varying concentrations of GO (0 to 500 mg/L), Cd chloride (0 to 0.4 mM), and combination of GO + Cd chloride simultaneously. The experiment was conducted on a germitest paper, where the rolls were kept for 7 days in a germination chamber (25 ± 2 °C and 12 hr light). The germination and seedling growth were subsequently assessed. Cadmium exposure inhibited seed germination and early seedling development, particularly at concentrations from 0.1 mM. Graphene oxide, on the other hand, proved to be a suitable alternative to mitigate Cd-induced stress, showing a significant enhanced germination at concentrations of up to 250 mg/L. Graphene oxide demonstrated potential as a protective agent against Cd-induced toxicity in rice seeds, suggesting its promising application in improving crop resilience in metal-contaminated environments.