Influence of direction of the applied magnetic field on losses and magnetizations of superconductors

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3-D modeling of heterogeneous and anisotropic superconducting media

In this paper, we investigate the 3-D computation of the current distribution in the heterogeneous superconducting media with a discontinuous anisotropic E - J constitutive power law. The resulting 3-D vectorial non-linear diffusion problem satisfied by the electric field is solved in each region of the media with a discontinuous Galerkin method combined with a 3-D semi-implicit scheme recently proposed for the 3-D modeling of homogeneous bulk superconductors. Numerical applications on the media consisting of two embedded anisotropic superconducting regions with and without a conductive matrix are computed. Both critical current density J-{c} and power law exponent n are uniform in each region but discontinuous in the media. The results will show the continuity of the diffusion phenomena in the media and the differences between both isotropic and anisotropic cases under an applied axial sinusoidal magnetic field

Modeling of 3D Magnetoelectric Devices

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Cytotoxicity of the methanol extracts and compounds of Brucea antidysenterica (Simaroubaceae) towards multifactorial drug-resistant human cancer cell lines

Youmbi LM, Makong YSD, Mbaveng AT, et al. Cytotoxicity of the methanol extracts and compounds of Brucea antidysenterica (Simaroubaceae) towards multifactorial drug-resistant human cancer cell lines. BMC Complementary Medicine and Therapies. 2023;23(1): 48.BACKGROUND: Cancer remains a global health concern and constitutes an important barrier to increasing life expectancy. Malignant cells rapidly develop drug resistance leading to many clinical therapeutic failures. The importance of medicinal plants as an alternative to classical drug discovery to fight cancer is well known. Brucea antidysenterica is an African medicinal plant traditionally used to treat cancer, dysentery, malaria, diarrhea, stomach aches, helminthic infections, fever, and asthma. The present work was designed to identify the cytotoxic constituents of Brucea antidysenterica on a broad range of cancer cell lines and to demonstrate the mode of induction of apoptosis of the most active samples.; METHODS: Seven phytochemicals were isolated from the leaves (BAL) and stem (BAS) extract of Brucea antidysenterica by column chromatography and structurally elucidated using spectroscopic techniques. The antiproliferative effects of the crude extracts and compounds against 9 human cancer cell lines were evaluated by the resazurin reduction assay (RRA). The activity in cell lines was assessed by the Caspase-Glo assay. The cell cycle distribution, apoptosis via propidium iodide (PI) staining, mitochondrial membrane potential (MMP) through 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining, and the reactive oxygen species (ROS) via 2,7-dichlorodihydrofluoresceine diacetate (H2DCFH-DA) staining, were investigated by flow cytometry.; RESULTS: Phytochemical studies of the botanicals (BAL and BAS) led to the isolation of seven compounds. BAL and its constituents 3, (3-(3-Methyl-1-oxo-2-butenyl))1H indole (1) and hydnocarpin (2), as well as the reference compound, doxorubicin, had antiproliferative activity against 9 cancer cell lines. The IC50 values varied from 17.42g/mL (against CCRF-CEM leukemia cells) to 38.70g/mL (against HCT116 p53-/- colon adenocarcinoma cells) for BAL, from 19.11M (against CCRF-CEM cells) to 47.50M (against MDA-MB-231-BCRP adenocarcinoma cells) for compound 1, and from 4.07M (against MDA-MB-231-pcDNA cells) to 11.44M (against HCT116 p53+/+ cells) for compound 2. Interestingly, hypersensitivity of resistant cancer cells to compound 2 was also observed. BAL and hydnocarpin induced apoptosis in CCRF-CEM cells mediated by caspase activation, the alteration of MMP, and increased ROS levels.; CONCLUSION: BAL and its constituents, mostly compound 2, are potential antiproliferative products from Brucea antidysenterica. Other studies will be necessary in the perspective of the discovery of new antiproliferative agents to fight against resistance to anticancer drugs. © 2023. The Author(s)