Publications by authors named "Martin Orendac"

We have prepared silica matrix with hexagonal symmetry of pores (SBA-15) and loaded it with anticancer drug 5-Fluorouracil (5-FU) to promote it as a drug delivery system. GdO nanoparticles were incorporated into the matrix to enhance nanosystems applicability as contrast agent for MRI, thus enabled this nanocomposite to be used as multifunctional nano-based therapeutic agent. Drug release profile was obtained by UV-VIS spectroscopy, and it indicates the prolongated release of 5-FU during the first hours and the total release after 5 h.

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The title hydrated ionic complex, [Ni(CH3COO)(C12H12N2)2]ClO4·H2O or [Ni(ac)(5,5'-dmbpy)2]ClO4·H2O (where 5,5'-dmbpy is 5,5'-dimethyl-2,2'-bipyridine and ac is acetate), (1), was isolated as violet crystals from the aqueous ethanolic nickel acetate-5,5'-dmbpy-KClO4 system. Within the complex cation, the Ni(II) atom is hexacoordinated by two chelating 5,5'-dmbpy ligands and one chelating ac ligand. The mean Ni-N and Ni-O bond lengths are 2.

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The hydrolysis of Ln(ClO4)3 in the presence of acetate leads to the assembly of the three largest known lanthanide-exclusive cluster complexes, [Nd104(ClO4)6(CH3COO)60(μ3-OH)168(μ4-O)30(H2O)112]·(ClO4)18·(CH3CH2OH)8·xH2O (1, x ≈ 158) and [Ln104(ClO4)6(CH3COO)56(μ3-OH)168(μ4-O)30(H2O)112]·(ClO4)22·(CH3CH2OH)2·xH2O (2, Ln = Nd; 3, Ln = Gd; x ≈ 140). The structure of the common 104-lanthanide core, abbreviated as Ln8@Ln48@Ln24@Ln24, features a four-shell arrangement of the metal atoms contained in an innermost cube (a Platonic solid) and, moving outward, three Archimedean solids: a truncated cuboctahedron, a truncated octahedron, and a rhombicuboctahedron. The magnetic entropy change of ΔS(m) = 46.

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The transformation of Mn(II) glycolates (glc) between the three-dimensional coordination polymer [Mn(glc)2]n (1) and discrete mononuclear phase [Mn(glc)2 (H2O)2] (2) can be reversibly switched by water molecules, which dramatically change the magnetocaloric effect (MCE) of Mn(II) glycolates from the maximum of 6.9 J kg(-1)  K(-1) in 1 to 60.3 J kg(-1)  K(-1) in 2.

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The comprehensive study reported herein provides compelling evidence that anion templates are the main driving force in the formation of two novel nanoscale lanthanide hydroxide clusters, {Gd38(ClO4)6} (1) and {Gd48Cl2(NO3)} (2), characterized by single-crystal X-ray crystallography, infrared spectroscopy, and magnetic measurements. {Gd38(ClO4)6}, encapsulating six ClO4(-) ions, features a cage core composed of twelve vertex-sharing {Gd4} tetrahedrons and one Gd⋅⋅⋅Gd pillar. When Cl(-) and NO3(-) were incorporated in the reaction instead of ClO4(-), {Gd48Cl2(NO3)} is obtained with a barrel shape constituted by twelve vertex-sharing {Gd4} tetrahedrons and six {Gd5} pyramids.

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Two kinds of inorganic gadolinium(III)-hydroxy "ladders", [2×n] and [3×n], were successfully trapped in succinate (suc) coordination polymers, [Gd2(OH)2(suc)2(H2O)]n·2nH2O (1) and [Gd6(OH)8(suc)5(H2O)2 ]n·4n H2O (2), respectively. Such coordination polymers could be regarded as alternating inorganic-organic hybrid materials with relatively high density. Magnetic and heat capacity studies reveal a large cryogenic magnetocaloric effect (MCE) in both compounds, namely (ΔH=70 kG) 42.

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The large cryogenic magnetocaloric effect of a 3D oxydiacetate-bridged gadolinium-manganese MOF material, [Mn(H(2)O)(6)][MnGd(oda)(3)](2)·6H(2)O (1), was evaluated by magnetization and heat capacity measurements. A maximum -ΔS(m) of 50.1 J kg(-1) K(-1) for ΔH = 70 kG along with significant entropy change at lower field was found on account of the weak Mn···Gd ferromagnetic interactions and the small molecular mass.

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The immediate effects of whole body electromagnetic radiation (EMR) were used to study postnatal neurogenesis in the subventricular zone (SVZ) and rostral migratory stream (RMS) of Wistar rats of both sexes. Newborn postnatal day 7 (P7) and young adult rats (P28) were exposed to pulsed electromagnetic fields (EMF) at a frequency of 2.45 GHz and mean power density of 2.

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It is well established that strong electromagnetic fields (EMFs) can give rise to acute health effects, such as burns, which can be effectively prevented by respecting exposure guidelines and regulations. Current concerns are instead directed toward the possibility that long-term exposure to weak EMF might have detrimental health effects due to some biological mechanism, to date unknown. (1) The possible risk due to pulsed EMF at frequency 2.

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A novel polymeric one-dimensional compound Cu(tn)Cl2 (tn = 1,3-diaminopropane) was prepared and structurally characterized, and its spectral, magnetic, thermodynamic, and thermal properties were studied. The unique structure shows ladderlike chains composed of Cu(II) atoms and chloro bridging ligands [Cu(-mu(3)-Cl-)Cu2] running along the crystallographic c axis. The coordination geometry about copper (4 + 2) approximates that of a strongly elongated octahedron.

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