Duckweeds are floating plants of the family Lemnaceae, comprising 5 genera and 36 species. They typically live in ponds or lakes and are found worldwide, except the polar regions. There are two duckweed subfamilies—namely Lemnoidea and Wolffioideae, with 15 and 21 species, respectively. Additionally, they have characteristic reproduction methods. Several metabolites have also been reported in various duckweeds. Duckweeds have a wide range of adaptive capabilities and are particularly suitable for experiments requiring high productivity because of their speedy growth and reproduction rates. Duckweeds have been studied for their use as food/feed resources and pharmaceuticals, as well as for phytoremediation and industrial applications. Because there are numerous duckweed species, culture conditions should be optimized for industrial applications. Here, we review and summarize studies on duckweed species and their utilization, metabolites, and cultivation methods to support the extended application of duckweeds in future.

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IntroductionElectroconvulsive therapy (ECT) is a functional treatment for a significant mental illness that involves a momentary application of electrical stimulation to induce generalized seizures. The use of right unilateral (RUL) and bilateral (BL) ECT has been controversial. Thus, the study aimed at comparing the effectiveness of RUL ECT and BL ECT in treating depression. MethodologyA longitudinal study was conducted between September 2016 and January 2021 at a tertiary care hospital in Sindh, Pakistan. All patients over the age of 18 with clinically diagnosed depression in the last month were included in the study. Baseline depression scores and post-treatment scores were determined using Hamilton Depression Rating Scale (HDRS). All patients were assigned to each treatment group. Group A was administered right unilateral electroconvulsive therapy, while group B was administered bilateral electroconvulsive therapy. Adverse effects were documented right after treatment, at four hours, and then one day after therapy. Depression severity was determined after each ECT session using the HDRS scale. Electroconvulsive therapy was discontinued when an HDRS score of 10 was achieved. ResultsThe mean HDRS score at baseline in the bilateral ECT group was 24.99 ± 3.938, which lowered to 17.56 ± 2.65 by the 3rd session, 12.45 ± 3.76 by the 6th session, and to 11.86 ± 2.3 by the end of treatment (p<0.0001). Similarly, the right unilateral ECT was equally effective in improving the depressive symptoms (p<0.0001). There was no significant difference between the efficacy of bilateral and unilateral placements of electrodes in electroconvulsive therapy (p=0.116).

Rice (Oryza sativa L.) is a widely consumed food source, and its geographical origin has long been a subject of discussion. In our study, we collected 44 and 20 rice samples from different regions of the Republic of Korea and China, respectively, of which 35 and 29 samples were of white and brown rice, respectively. These samples were analyzed using nuclear magnetic resonance (NMR) spectroscopy, followed by analyses with various data normalization and scaling methods. Then, leave-one-out cross-validation (LOOCV) and external validation were employed to evaluate various machine learning algorithms. Total area normalization, with unit variance and Pareto scaling for white and brown rice samples, respectively, was determined as the best pre-processing method in orthogonal partial least squares–discriminant analysis. Among the various tested algorithms, support vector machine (SVM) was the best algorithm for predicting the geographical origin of white and brown rice, with an accuracy of 0.99 and 0.96, respectively. In external validation, the SVM-based prediction model for white and brown rice showed good performance, with an accuracy of 1.0. The results of this study suggest the potential application of machine learning techniques based on NMR data for the differentiation and prediction of diverse geographical origins of white and brown rice.

A new ytterbium(III) complex, (DMAH2)3[Yb(Pydc)3].4H2O (1) {Pydc = Pyridine-2,6-dicarboxylate anion, DMAH = Dimethylamine} has been prepared under mild solvothermal conditions and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. The DMAH molecules in 1, generated in situ from hydrolysis of N,N-dimethylformamide are responsible to assemble 2D coordination polymers through N-H∙∙∙O and O-H∙∙∙O hydrogen bonding. Magnetic susceptibility measurements indicate that the complex (1) obeys the Curie Weiss law and the overall magnetic behavior is typical for the presence of weak antiferromagnetic exchange coupling interactions. Theoretical data for geometrical parameters of complex 1 agree well with the experimental data. Large HOMO-LUMO energy gap of 4.33 eV has provided kinetic stability to the complex 1. NBO analysis reflects that intramolecular charge transfer occurred between ligand and metal orbitals with the highest stabilization energy of 1024.04 kcal/mol. The negative electrostatic potential at the nitrogen and dianionic pyridine-2,6-dicarboxylate regions confirms that these are dynamic locations for Yb(III) binding.