Nitric oxide (NO),
a pro-neurogenic and antineuroinflammatory gasotransmitter,
features the potential to develop a translational medicine against
neuropathological conditions. Despite the extensive efforts made on
the controlled delivery of therapeutic NO, however, an orally active
NO prodrug for a treatment of chronic neuropathy was not reported
yet. Inspired by the natural dinitrosyl iron unit (DNIU) [Fe(NO)
2
], in this study, a reversible and dynamic interaction between
the biomimetic [(NO)
2
Fe(μ-SCH
2
CH
2
OH)
2
Fe(NO)
2
] (
DNIC-1
) and serum
albumin (or gastrointestinal mucin) was explored to discover endogenous
proteins as a vehicle for an oral delivery of NO to the brain after
an oral administration of
DNIC-1
. On the basis of the
in vitro and in vivo study, a rapid binding of
DNIC-1
toward gastrointestinal mucin yielding the mucin-bound dinitrosyl
iron complex (DNIC) discovers the mucoadhesive nature of
DNIC-1
. A reversible interconversion between mucin-bound DNIC and
DNIC-1
facilitates the mucus-penetrating migration of
DNIC-1
shielded in the gastrointestinal tract of the stomach
and small intestine. Moreover, the NO-release reactivity of
DNIC-1
induces the transient opening of the cellular tight
junction and enhances its paracellular permeability across the intestinal
epithelial barrier. During circulation in the bloodstream, a stoichiometric
binding of
DNIC-1
to the serum albumin, as another endogenous
protein vehicle, stabilizes the DNIU [Fe(NO)
2
] for a subsequent
transfer into the brain. With aging mice under a Western diet as a
disease model for metabolic syndrome and cognitive impairment, an
oral administration of
DNIC-1
in a daily manner for 16
weeks activates the hippocampal neurogenesis and ameliorates the impaired
cognitive ability. Taken together, these findings disclose the synergy
between biomimetic
DNIC-1
and endogenous protein vehicles
for an oral delivery of therapeutic NO to the brain against chronic
neuropathy.
We report the phonon and magnetic properties of various well-stabilized Co3O4 nanoparticles. The net valence in cobalt (II)/(III) cation can be obtained by subtracting the Co2+ ions in tetrahedral interstices and Co3+ ions in the octahedral interstices, respectively, which will possess spatial inhomogeneity of its magnetic moment via Co2+ in tetrahedra and Co3+ in octahedral configurations in the normal spinel structure. Furthermore, the distribution of Co2+/Co3+ governed by various external (magnetic field and temperature) and internal (particle size and slightly distorted CoO6 octahedra) sources, have led to phenomena such as a large redshift of phonon-phonon interaction and short-range magnetic correlation in the inverse spinel structure. The outcome of our study is important in terms of the future development of magnetic semiconductor spintronic devices of Co3O4.
The deficiency of Y3Al5O12:Ce (YAG:Ce) luminescence in red component can be compensated by doping Gd3+, thus lead to it being widely used for packaging warm white light-emitting diode devices. This article presents a systematic study on the photoluminescence properties, crystal structures and electronic band structures of (Y1−xGdx)3Al5O12: Ce3+ using powerful experimental techniques of thermally stimulated luminescence, X-ray diffraction, X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS) and ultraviolet photoelectron spectra (UPS) of the valence band, assisted with theoretical calculations on the band structure, density of states (DOS), and charge deformation density (CDD). A new interpretation from the viewpoint of compression deformation of electron cloud in a rigid structure by combining orbital hybridization with solid-state energy band theory together is put forward to illustrate the intrinsic mechanisms that cause the emission spectral shift, thermal quenching, and luminescence intensity decrease of YAG: Ce upon substitution of Y3+ by Gd3+, which are out of the explanation of the classic configuration coordinate model. The results indicate that in a rigid structure, the charge deformation provides an efficient way to tune chromaticity, but the band gaps and crystal defects must be controlled by comprehensively accounting for luminescence thermal stability and efficiency.
A binder-free self-reconstructed (oxy)hydroxide@nanoporous Ni3P hybrid electrode is fabricated for rechargeable Zn battery with high capacity, excellent rate performance and cycling stability.
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