This paper reports a high efficiency uptake of captopril (CPT), employing magnetic graphene oxide (MGO) as the adsorbent. The graphene oxide (GO) was produced through an oxidation and exfoliation method, and the magnetization technique by the co-precipitation method. The nanomaterials were characterized by FTIR, XRD, SEM, Raman, and VSM analysis. The optimal condition was reached by employing GO·Fe₃O₄ at pH 3.0 (50 mg of adsorbent and 50 mg L⁻¹ of CPT), presenting values of removal percentage and maximum adsorption capacity of 99.43% and 100.41 mg g⁻¹, respectively. The CPT adsorption was dependent on adsorbent dosage, initial concentration of adsorbate, pH, and ionic strength. Sips and Elovich models showed the best adjustment for experimental data, suggesting that adsorption occurs in a heterogeneous surface. Thermodynamic parameters reveal a favorable, exothermic, involving a chemisorption process. The magnetic carbon nanomaterial exhibited a high efficiency after five adsorption/desorption cycles. Finally, the GO·Fe₃O₄ showed an excellent performance in CPT removal, allowing future application in waste management.

Among biotic and abiotic stresses, the most restrictive for plant distribution is salt stress, where different concentrations might exert harmful effects on seed germination. Recently, nanomaterials were used successfully to mitigate these stresses, indicating that plants may be able to develop normally in adverse conditions. The aim of this study was to examine the effects of graphene oxide (GO) on the germination of Persian clover seedlings under salt stress conditions. Following sown on substrate paper, seeds were tested after exposure to different concentrations of graphene oxide (0, 125, 250, or 500 mg L^-1 GO), sodium chloride (0; -0.1; -0.2; -0.3, or -0.4 MPa NaCl) and/or GO + salt concomitantly, and then stored for 7 days in a germination chamber at 20°C in the presence of light. Seed germination and growth parameters of seedlings were determined. Graphene oxide demonstrated protective effect against salt stress as evident by no marked adverse effects on seed germination where GO blocked the salt-induced reduction in germination. The results obtained provide references for the safe application of nanomaterials and emphasize the significance of GO as a promising material for reducing the toxicity of salts in agriculture.

We report a peculiar magnetization reversal observed in magnetron-sputtered Co, Fe, and Ni films. We found that some recoil (minor) magnetization curves lie entirely and way outside the major loop, a phenomenon referred to here as a recoil-curve overshoot. The greatly enhanced recoil curve's remanence and coercivity result in an up to 2.5-fold increase of loop's area. The model of pairs of exchange-coupled grains with misaligned anisotropy axes reproduces, in a very good agreement with the experiment, all key features of the recoil-curve overshoot as well as the kink that some major loops present before saturation. The disclosed features of the ferromagnetic hysteresis provide further insights into this important classical phenomenon.

Seed conditioning with ultraviolet light (UV-C) might (1) improve crop yield and quality, (2) reduce the use of agrochemicals during cultivation, and (3) increase plant survival in high salinity environments. The aim of this study was to examine the effects of UV-C conditioning of white oat seeds at two doses (0.85 and 3.42 kJ m^-2) under salinity stress (100 mM NaCl). Seeds were sown on germination paper and kept in a germination chamber at 20°C. Germination and seedling growth parameters were evaluated after 5 and 10 days. Data demonstrated that excess salt reduced germination and initial growth of white oat seedlings. In all the variables analyzed, exposure of seeds to UV-C under salt stress exerted a positive effect compared to non-irradiated control. The attenuating influence of UV-C in germination was greater at 0.85 than at 3.42 kJ m^-2. Thus, data indicate that conditioning white oat seeds in UV-C light produced greater tolerance to salt stress. These findings suggest that UV-C conditioning of white oat seeds may be considered as a simple and economical strategy to alleviate salt-induced stress.

Atualmente, a radiação ultravioleta tem recebido maior atenção devido à preocupação com os?? possíveis impactos positivos ou negativos nas respostas fisiológicas das plantas. Neste contexto, o objetivo deste estudo foi avaliar a influência da radiação ultravioleta (UV-B e UV-C) na germinação de sementes de soja. Inicialmente, as sementes foram submetidas a diferentes tempos de exposição à luz UV (0, 1, 2, 4 e 8 horas) com intensidade de radiação 2.5 W m^-2. Em seguida, foram semeadas em papel germitest e mantidas em câmara BOD, a 25 ºC e fotoperíodo de 12 horas. Foram realizados os testes de germinação (aos 8 dias), primeira contagem (aos 5 dias), comprimento e massa seca de plântulas. Os resultados indicaram que a exposição à luz UV-B e UV-C (a partir de 1 hora - 9000 J m^-2) reduziu a percentagem de germinação, o comprimento e a massa seca da parte aérea das plântulas de soja. O decréscimo do comprimento radicular foi observado a partir de 2 (UV-C) e 4 horas (UV-B) de exposição à luz. Conclui-se que, nas condições deste estudo, a exposição das sementes de soja à radiação UV-B e UV-C afetou a porcentagem de germinação e o crescimento inicial das plântulas.