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Cadmium (Cd) contamination of farmland soils is a widespread problem around the globe, and rice (Oryza sativa L.) tends to accumulate more Cd and is considered as one of the major sources of Cd intake in humans, especially consuming rice-derived products. The current study investigated the effects of foliar applied aspartic acid (Asp) on growth parameters, biomass, chlorophyll concentration, gas exchange characteristics, Cd uptake, and antioxidative capacity in the shoots and roots of rice seedlings exposed to Cd stress. For this, 30-day-old rice nursery was transferred in the soil with aged Cd contamination (2.86 mg kg). After 2 weeks of growth, different concentrations (0, 10, 15, and 20 mg L) of Asp were foliar applied four times with a 7-day interval, and the crop was harvested after 10 weeks of transplanting. Foliar applied Asp increased the plant height, shoot and root dry weight, chlorophyll concentration, and gas exchange parameters, while it reduced the Cd concentrations in both shoots and roots as well as shoot to root Cd translocation factor compared to the control. Foliar application of Asp reduced the malondialdehyde content and electrolyte leakage in rice parts compared to the control in a dose-additive manner. The activities of key antioxidant enzymes increased while peroxidase activity decreased by exogenous Asp. The increase in plant weight and photosynthesis might be due to lower Cd concentrations in plants which may reduce the oxidative stress and also help the plants to minimize direct damage caused by Cd to the photosynthetic organs.

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There are varied spin states in dilute magnetic semiconductors, and carriers are not the only elementary excitations that carry the spin. This article reports a study of spin interactions in excitons of ZnSe:NiI(II) nanostructures. High-quality ZnSe:NiI(II) nanobelts (NBs) prepared by chemical vapor deposition show a zinc blende structure by x-ray diffraction and Raman spectroscopy. The temperature-dependent photoluminescence spectra of doped NBs show independent free exciton (FX) and exciton magnetic polaron (EMP) peaks at room temperature with ferromagnetically coupled Ni ions. A single-mode lasing profile was obtained with femtosecond laser excitation due to condensation of EMPs over a threshold. The luminescence lifetimes at different pump powers indicated different relaxation profiles, confirming the formation of coherent EMP aggregates. At a slightly higher dopant concentration, a weak peak at the high-energy side of the FX peak showed up separately at low temperature; this should be the magnetic polaron emission band from the antiferromagnetically coupled Ni(II) pair binding with a FX (antiferromagnetic magnetic polaron). These results illustrate the typical spectroscopic characteristics of spin-spin magnetic coupling, exciton-spin or phonon interactions in dilute magnetic semiconductor nanostructures, showing that their different coupled spin types could work as exciton binders for their collective excitons, with possible use in spin nanophotonic devices and quantum modulations.