55 research outputs found

    THE IRON SPIN TEXTURE IN ANNEALED AMORPHOUS Fe/Tb MULTI-LAYERS

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    Fe/Tb multilayers have been obtained by vacuum evaporation with Tb-layer thickness fixed to 40Å and amorphous Fe-layer thickness fixed to 19Å. 57Fe-Mössbauer spectrometry was used to obtain information on the structure and the spin texture of the multilayers before and after annealing at 530K for different durations of the annealing. The Mössbauer results indicate that the Perpendicular Magnetic Anisotropy (PMA) was stabilised and reinforced after annealing.Fe/Tb multilayers have been obtained by vacuum evaporation with Tb-layer thickness fixed to 40Å and amorphous Fe-layer thickness fixed to 19Å. 57Fe-Mössbauer spectrometry was used to obtain information on the structure and the spin texture of the multilayers before and after annealing at 530K for different durations of the annealing. The Mössbauer results indicate that the Perpendicular Magnetic Anisotropy (PMA) was stabilised and reinforced after annealing

    The potential anticancer activities of platinum(II) complexes with tridentate N'N'N' pincer ligands

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    519-530Treatment of cis/trans-[PtCl2(N≡CR)2] 1 (R = CH3 (1a), C2H5 (1b), C6H5 (1c), CH2C6H4(p-CH3) (1d)) with 1,3-diiminoisoindoline 2 gives access to the corresponding symmetrical (1,3,5,7,9-pentaazanona-1,3,6,8-tetraenato) platinum(II) complexes [PtCl{NH=C(R)N=C(C6H4)NC=NC(R)=NH}] 3a-d, in good yields (65–77%). The compounds 3a-d have been characterized by IR, 1H, 13C and DEPT-135 NMR spectroscopies, ESI-MS and elemental analyses. GIAO/DFT studies have been performed to confirm the molecular structure of the platinum(II)-pincer 3d by comparing the experimental and theoretical 1H and 13C NMR chemical shifts, and it has shown good correlations between experimental and calculated chemical shifts for proton and carbon with correlation coefficients of 0.9947 and 0.9968, respectively. Molecular electrostatic potential is used to investigate the nucleophilic or electrophilic regions in the molecule 3d. The antimicrobial activities of compounds 3a-d are determined against different bacterial pathogens and yeasts. No toxicity is recorded against Artemia saline as a test organism for 3a-c, while moderate toxicity is found for 3d at 0.62 µM. Comparable antitumor activities are found for 3a-d against human colon HCT116 and human breast (MCF-7) cancer cell lines. The complexes 3a-d have shown good binding affinities to ct-DNA in the range of 6.00´105 to 8.33´105 and the conducted molecular docking studies suggest an intercalation mode of binding with DNA by the isoindole fragment of the ligands. Overall, this class of tridentate ligands have shown good potential in designing platinum(II) complexes with promising biological and anticancer activities. Moreover, the presence of the side chains on the ligands provides great design flexibility by introducing some chemical and/or physical characteristics

    The potential anticancer activities of platinum(II) complexes with tridentate N'N'N' pincer ligands

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    Treatment of cis/trans-[PtCl2(N≡CR)2] 1 (R = CH3 (1a), C2H5 (1b), C6H5 (1c), CH2C6H4(p-CH3) (1d)) with 1,3-diiminoisoindoline 2 gives access to the corresponding symmetrical (1,3,5,7,9-pentaazanona-1,3,6,8-tetraenato) platinum(II) complexes [PtCl{NH=C(R)N=C(C6H4)NC=NC(R)=NH}] 3a-d, in good yields (65–77%). The compounds 3a-d have been characterized by IR, 1H, 13C and DEPT-135 NMR spectroscopies, ESI-MS and elemental analyses. GIAO/DFT studies have been performed to confirm the molecular structure of the platinum(II)-pincer 3d by comparing the experimental and theoretical 1H and 13C NMR chemical shifts, and it has shown good correlations between experimental and calculated chemical shifts for proton and carbon with correlation coefficients of 0.9947 and 0.9968, respectively. Molecular electrostatic potential is used to investigate the nucleophilic or electrophilic regions in the molecule 3d. The antimicrobial activities of compounds 3a-d are determined against different bacterial pathogens and yeasts. No toxicity is recorded against Artemia saline as a test organism for 3a-c, while moderate toxicity is found for 3d at 0.62 µM. Comparable antitumor activities are found for 3a-d against human colon HCT116 and human breast (MCF-7) cancer cell lines. The complexes 3a-d have shown good binding affinities to ct-DNA in the range of 6.00´105 to 8.33´105 and the conducted molecular docking studies suggest an intercalation mode of binding with DNA by the isoindole fragment of the ligands. Overall, this class of tridentate ligands have shown good potential in designing platinum(II) complexes with promising biological and anticancer activities. Moreover, the presence of the side chains on the ligands provides great design flexibility by introducing some chemical and/or physical characteristics

    X-ray crystal structure, NMR, DFT investigations, pharmaco-kinetic, and toxicity of sarcotrocheliol: A pyrane-based cemranoids of marine origin

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    69-80One of a recently discovered marine origin cembranoids has been studied experimentally and theoretically to obtain its thorough structural, electronic, spectroscopic, and biochemical activity. The exact molecular structure of sarcotrocheliol (C20H34O2) 1 has been determined for the first time using a single crystal X-ray diffraction analysis. Crystallography shows that the molecule is crystalline as an orthorhombic, space group of P212121, with a = 9.20(4) Å, b = 10.80(4) Å, c = 19.99(9) Å. 1H, 13C and DEPT-135 NMR measurements of sarcotrocheliol1have been measured in four different deuterated solvents: CDCl3, CD3CN, MeOH-d4 and DMSO-d6. Theoretical calculations have been performed to find the main structural and electronic properties of the compound and matched with the experimental properties. The density functional theory (DFT) method at B3LYP/6-311++G(d,p) level of theory has been used for all computed properties. Vibrational frequencies have been determined using DFT calculations and compared with the experimental values. Computed chemical shifts in the NMR have been determined by the GIAO method. The correlation coefficients between the calculated and experimental NMR chemical shifts have been found to be 0.92 and 0.998 for 1H and 13C NMR, respectively. Physicochemical parameters of the compound versus reference drugs have been done. The isolated compound meets the main criteria of the employed rules indicating a drug-like character. The molecular docking studies have been performed for the compound toward the breast and prostate cancers

    Carte des phénomènes d'inondation des bassins de Fès et Beni Mellal

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    Petrology and geodynamic significance of the post-collisional Pan-African magmatism in the Eastern Saghro area (Anti-Atlas, Morocco)

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    The Saghro Group consists of a thick volcanic-sedimentary sequence with intercalated basaltic lavas, the first magmatic event in eastern Saghro area. Nd isotopes of basaltic pillow lavas show T-DM model ages ranging from 640 to 580 Ma, which represent a maximum age for basalt eruption. Granitoids within the Saghro Group consist of a charnockitic suite, tonalites, granodiorites and monzogranites. They are high-K calc-alkaline (HKCA) with a post-collisional character, and were emplaced at high-levels in the crust. Their ages of emplacement are within the 580-560 Ma bracket, implying that the entire Saghro Group is slightly older than or partly coeval to granitoid emplacement and implying a common geodynamical setting. Sr-Nd isotopic compositions and Nd T-DM model ages point to a mixed origin, combining a juvenile mantle source and an Eburnean crustal component, which could be the West African Craton (WAC). The juvenile component in the Saghro granitoids could be the depleted upper mantle that has sourced the earlier basalts. Field observations, geochemical and geochronological data together support that, during the Pan-African orogeny, the Anti-Atlas was subjected to a regional transpressional to transtensional event. This event would have been responsible for the dissection of the northern margin of the WAC into several blocks, the development of deep sedimentary basins and the emplacement of HKCA magmas. (C) 2009 Elsevier Ltd. All rights reserved

    Crystal structure of trans-di­chloridobis­[N-(5,5-di­methyl-4,5-di­hydro-3H-pyrrol-2-yl-κN)acetamide]palladium(II) dihydrate

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    The title complex, [PdCl2(C8H14N2O)2]2H2O, was obtained by N–O bond cleavage of the oxadiazoline rings of the trans-[dichlorido-bis(2,5,5-trimethyl- 5,6,7,7a-tetrahydropyrrolo[1,2-b][1,2,4]oxadiazole-N1 )]palladium(II) complex. The palladium(II) atom exhibits an almost square-planar coordination provided by two trans-arranged chloride anions and a nitrogen atom from each of the two neutral organic ligands. In the crystal, N—HO, O—HO and O—HCl hydrogen bonds link complex molecules into double layers parallel to the bc plane.peerReviewe
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