4,649 research outputs found
Binding Mode between Trp-Dy(III) Complex and Herring Sperm DNA
No full textBy means of UV and fluorescence spectra, the binding ratios between Dy(III)(Trp)(3) and DNA. in physiological pH environment(pH7.40) were determined as n(Dy(III)(Trp)),:n(DNA) = 2:1 and n(Dy(III)):n(Trp)=1:3. The binding constant of K-25 degrees C= 5.75 x 10(7) L.mol(-1) and K-37 degrees C=3.27 x 10(5) L.mol(-1) were obtained by double reciprocal method. Thermodynamic function computation demonstrates that Delta S-r(m)circle minus and Delta H-r(m)circle minus are the primary driving power of the interaction between Dy(III)(Trp)(3) and DNA. By combination analysis of the Scatchard and viscometry methods, we suggested that the interaction mode between Dy(III)(Trp)(3) complex and herring sperm DNA be electrostatic and intercalation bindings
Polymeric micelles and the Dy-166/Ho-166 generator: A study of the loading mechanism of Dy/Dy-166 and Ho-166 into PCL-b-PEO polymeric micelles for imaging and cancer treatment
No full textA radioisotope used in radionuclide therapy is Holmium-166 (Ho-166). The treatment effectiveness of Ho-166 could be improved by the use of a so called in vivo Dysprosium-166(Dy-166)/Ho-166 generator. The application of this generator is hindered by an effect called internal conversion (IC). This affect can arise after the decay of Dy-166 to Ho-166, which can cause separation of Ho-166 from its carrier.Polymeric micelles might form a solution in the application of the Dy-166/Ho-166 generator in radionuclide therapy. The main goal of this thesis was to investigate and understand the loading mechanism of metallic species and polymeric micelles with a focus on the loading of Dy/Dy-166 and Ho-166. It was found that it was not effective to load metallic species (Dy/Dy-166) as free ions or as solid precipitates. Loading metallic species as aqueous hydroxides showed to be crucial for achieving a good loading and high stability. The second goal was to study if polymeric micelles were able to retain Ho-166 inside their core under the effects of internal conversion. No additional losses of Ho-166 were found when Dy/Dy-166 and Ho-166 were loaded into the micelles. It was concluded that the PCL-PEO micelles prevented the loss of Ho-166 under internal conversion effects.Applied Science
Crystallographic and magnetic properties of nitride R3Fe29-xCrxN4 (R = Y, Ca, Nd, Sm, Gd, Tb, and Dy)
No full textA systematic investigation of crystallographic and magnetic properties of nitride R3Fe29-xCrxN4 (R=Y, Ce, Nd, Sm, Gd, Tb, and Dy) has been performed. The lattice constants and unit cell volume decrease with increasing rare earth atomic number from Nd to Dy, reflecting the lanthanide contraction. After nitrogenation the relative volume expansion of each nitride is around between 5% and 7%. The nitrogenation results in a good improvement in the Curie temperature, the saturation magnetization and anisotropy fields at 4.2 K, and room temperature for R3Fe29-xCrxN4. Magnetohistory effects of R3Fe29-xCrxN4 and R3Fe29-xCrx (R=Nd and Sm) are observed in a low field of 0.04 T. First order magnetization process occurs in Sm3Fe24.0Cr5.0N4 in magnetic fields of 2.8 T at 4.2 K. After nitrogenation, the easy magnetization direction of Sm3Fe24.0Cr5.0 is changed from the easy-cone structure to the uniaxial. The good intrinsic magnetic properties of Sm3Fe24.0Cr5.0N4 make this compound a hopeful candidate for new high-performance hard magnets. (C) 1998 American Institute of Physics
Study on interaction between Dy(III)(NR)(3) complex and herring sperm DNA by spectroscopy
No full textThe action mode between Dy(III)(NR)(3) and herring sperm DNA is studied by ultraviolet-visible (UV-vis) and fluorescence spectra as well as electrochemistry. Double-reciprocal method studies show that the binding stoichiometry between Dy(III)(NR)(3) and DNA is 1 : 1, the binding constants at different temperatures are 1.15 x 10(5) L/mol at 25 degrees C and 2.09 x 10(5) L/mol at 35 degrees C, and the corresponding thermodynamic parameters are Delta H-r(m)Theta = 2.48 x 10(4) J/mol, Delta(r)G(m)(Theta) = -2.34 x 10(4) J/mol, Delta S-r(m)Theta = 161.7 J/(mol . K), Delta S-r(m)Theta is the driving force in this reaction. Combined with Scatchard method and melting method, the results suggest that, the interaction mode between Dy(III)(NR)(3) and herring sperm DNA is intercalation fashion and groove fashion
Development of Dy-free sintered NdFeB magnet through grain boundary engineering by diffusion of PrCu alloys
Full text linkDy-free sintered magnets were fabricated by blending Neo powder with different amount of PrCu powder. With increasing PrCu from 0-10 wt.%, Hcj of the magnets gradually increases from the original 14.5 kOe to 18.6 kOe. The highest (BH)max achieved was 35.0 MGOe with 7.5 wt.% PrCu. It was found that PrCu was mainly distributed at grain boundary and triple junctions, leading to a reduced coupling among grains, thus an enhanced Hcj. The grain boundary engineering by the diffusion of PrCu alloy is an effective method to improve Hcj of Dy-free magnets.This is a manuscript of a conference proceeding published as Tang, Wei, Gaoyuan Ouyang, Jing Wang, Harika Dasari, Matthew J. Kramer, Jun Cui, and Iver E. Anderson. "Development of Dy-free sintered NdFeB magnet through grain boundary engineering by diffusion of PrCu alloys." Intermag 2023. Sendai, Japan, May 15-19, 2023. Copyright 2023 IEEE. Posted with permission
The importance of an accurate CH4 vibrational partition function in full dimensionality calculations of the H+CH4 -> H2+CH3 reaction
No full textBowman JM, Wang DY, Huang XC, Huarte-Larranaga F, Manthe U. The importance of an accurate CH4 vibrational partition function in full dimensionality calculations of the H+CH4 -> H2+CH3 reaction. JOURNAL OF CHEMICAL PHYSICS. 2001;114(21):9683-9684
beta-delayed proton decays and spin assignments for Tb-140, Dy-141 and Dy-143
No full textThe proton-rich isotopes Tb-140 and Dy-141 were produced via the fusion evaporation reaction Ca-40+ Cd-106. Their beta-delayed proton decays were studied by p-gamma coincidence in combination with a He-jet tape transport system, and half-lives, proton energy spectra, gamma-transitions following the proton emission, as well as beta-delayed proton branching ratios to the low-lying states in the grand-daughter nuclei were determined. Comparing the experimental data with statistical model calculations, the ground-state spins of Tb-140 and Dy-141 were found to be consistent with 7 and 9/2, respectively. The configuration-constrained nuclear potential energy surfaces (NPES) of Tb-140 and Dy-141 were calculated using the Woods-Saxon-Strutinsky method, which suggest the ground-state spins and parities of Tb-140 and Dy-141 to be 7(+) and 9/2(-), respectively. In addition, the configuration-constrained NPES of Dy-143 were calculated, which predict a 1/2(+) ground state and a 11/2(-) isomer with excitation energy of 198 keV. These findings are consistent with our previous experimental data on Dy-143 reported in Eur. Phys. J. A 16, 347 (2003).Physics, NuclearPhysics, Particles & FieldsSCI(E)3ARTICLE137-402
A half-sandwich organometallic single-ion magnet with hexamethylbenzene coordinated to the Dy(III) ion
No full textA half-sandwich organolanthanide complex, [(C6Me6)Dy(AlCl4)(3)], in which Dy((III)) is coordinated with a pi-bonded arene was synthesized and magnetically characterized. This complex displays slow magnetic relaxation and a hysteresis loop associated with single-ion magnet behavior. The orientation of the magnetic anisotropy axis is analyzed using ab initio calculations.Chemistry, MultidisciplinarySCI(E)[email protected]; [email protected]; [email protected]
Structural and magnetic properties of hydrides R3Fe29-xVxHy (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy)
No full textA systematic investigation of crystallographic and intrinsic magnetic properties of the hydrides R3Fe29 - xVxHy (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy) has been performed in this work. The lattice constants a, b, and c and the unit cell volume of R3Fe29 - xVxHy decrease with increasing rare-earth atomic number from Nd to Dy, except for Ce, reflecting the lanthanide contraction. Hydrogenation results in regular anisotropic expansions along the a-, b-, and c-axes in this series of hydrides. Abnormal crystallographic and magnetic properties of Ce3Fe27.5V1.5H6.5, like Ce3Fe27.5V1.5, suggest that the Ce ion is non-triply ionized. Hydrogenation leads to the increase in both Curie temperature for all the compounds and in the saturation magnetization at 4.2 K and RT for R3Fe29 - xVx with R = Y, Ce, Nd, Sm, Gd, and Dy, except for Tb. Hydrogenation also leads to a decrease in the anisotropy field at 4.2 K and RT for R3Fe29 - xVx with R = Y, Ce, Nd, Gd, Tb, and Dy, except for Sm. The Ce3Fe27.5V1.5 and Gd3Fe28.4V0.6 show the larger storage of hydrogen with y = 6.5 and 6.9 in these hydrides. (C) 1998 Elsevier Science B.V. All rights reserved
- …
