Efficiency Of Mn2 Research Articles

Aqueous proton battery stably operates in mild electrolyte and low-temperature conditions

The double effects of ClO4− anion in term of the improvement of deposition/dissolution efficiency of Mn2+/MnO2 and low-temperature performance for aqueous proton battery.

A manganese (II)-based coordinative dendrimer with robust efficiency in intracellular peptide delivery

Peptides have gained increasing interests as drug candidates in modern pharmaceutical industry, however, the development of peptide drugs acting on intracellular targets is limited due to their membrane impermeability. Here, we reported the use of metal-terpyridine based coordinative dendrimer for cytosolic peptide delivery. Among the investigated transition metal ions, Mn2+-coordinated polymer showed the highest delivery efficiency due to balanced peptide binding and release. It showed robust efficiency in the delivery of peptides with different charge property and hydrophobicity into various primary cells. The efficiency of Mn2+-terpyridine based polymer is superior to cell penetrating peptides such as oligoarginines. The material also delivered an autophagy-inducing peptide derived from Beclin-1 into cells and efficiently induced autophagy in the cells. This study provides a promising alternative to cell penetrating peptides for cytosolic peptide delivery.

A novel versatile yolk-shell nanosystem based on NIR-elevated drug release and GSH depletion-enhanced Fenton-like reaction for synergistic cancer therapy

In this study, a versatile doxorubicin (DOX)-loaded yolk-shell nano-particles (HMCMD) assembled with manganese dioxide (MnO2) as the core and copper sulfide (HMCuS) as the mesoporous (∼ 6.4 nm) shell, was designed and synthesized. The resulting HMCMD possess excellent photothermal conversion efficiency. The DOX release from the yolk-shell nanoparticles could be promoted by laser irradiation, which increased the chemotherapy of DOX. Meanwhile, Mn2+ could be released from the HMCMD through a redox reaction between MnO2 and abundant glutathione (GSH) in tumor cells. The released Mn2+ could promote the decomposition of the intracellular hydrogen peroxide (H2O2) by Fenton-like reaction to generate the highly toxic hydroxyl radicals (·OH), thus exhibiting the effective chemodynamic therapy (CDT). Additionally, the efficiency of Mn2+-mediated CDT could be effectively enhanced by NIR irradiation. Further modification of polyethylene glycol (PEG) would improve the water solubility of the HMCMD to promote the uptake by MCF-7 cells. Hence, the HMCMD with synergistic effects of chemotherapy and chemodynamic/photothermal therapy would provide an alternative strategy in antitumor research.

Realizing efficient Mn2+ red emission via synergistic sensitization of Eu2+ and Tb3+ for white light-emitting diodes

Mn2+-activated red-emitting phosphors have emerged as promising candidates for phosphor-converted white light-emitting diodes (WLED). Unfortunately, optical center Mn2+ suffers from weak emission and inefficient excitation due to its forbidden d-d transition. Often, a sensitizer (e.g., Eu2+/Ce3+ or Tb3+) is required to pair with Mn2+ (mono-sensitization strategy) to enhance emission/excitation efficiency of Mn2+ (e.g., Eu2+/Ce3+/Tb3+→Mn2+), with the energy transfer (ET) principle. However, at present, sufficiently sensitizing Mn2+ by using the above strategy to yield a nearly pure, efficient Mn2+ red emission still remains challenging. Herein, we demonstrate a sufficient sensitization of Mn2+ in Sr3La3(PO4)3 compounds by utilizing two sensitizer ions, Eu2+ and Tb3+, to synergistically sensitize one Mn2+, which brings out a new, high-efficient Eu2+→Tb3+→Mn2+ ET, achieving almost pure, bright Mn2+ red emission without seeing the emissions from Eu2+ and Tb3+ in a composition-optimized sample. The intensity of the resulting Mn2+ red emission is better than that of each mono-sensitization strategy. Moreover, a high-quality WLED with high color-rendering-indexing of 91 and low correlated color temperature of 4436 K is achieved by using as-prepared red-emitting phosphor. We believe that such a strategy can be easily expanded to other systems, initiating a new pathway in designing the Mn2+-activated red phosphors.

Simultaneous stabilization/solidification of Mn2+ and NH4+-N from electrolytic manganese residue using MgO and different phosphate resource

This study examined simultaneous stabilization and solidification (S/S) of Mn2+ and NH4+-N from electrolytic manganese residue (EMR) using MgO and different phosphate resource. The characteristics of EMR NH4+-N and Mn2+ S/S behavior, S/S mechanisms, leaching test and economic analysis, were investigated. The results show that the S/S efficiency of Mn2+ and NH4+-N could reach 91.58% and 99.98%, respectively, and the pH value is 8.75 when the molar ratio of Mg:P is 3:1 and the dose of PM (MgO and Na3PO4·12H2O) is 8wt%. In this process, Mn2+ could mainly be stabilized in the forms of Mn(H2PO4)2·2H2O, Mn3(PO4)2·3H2O, Mn(OH)2, and MnOOH, and NH4+-N in the form of NH4MgPO4·6H2O. Economic evaluation indicates that using PM process has a lower cost than HPM and HOM process for the S/S of Mn2+ and NH4+-N from EMR at the same stabilization agent dose. Leaching test values of all the measured metals are within the permitted level for the GB8978-1996 test suggested when the dose of PM, HPM and HOM is 8wt%.

Synthesis and Photoluminescence Properties of Sr<sub>3</sub>SiO<sub>5</sub>:Eu<sup>2+</sup>, Mn<sup>2+</sup>

The Mn2+ co-doped Sr3SiO5:Eu2+ phosphorsynthesized by conventional solid-state reaction had been investigated. Two controlling factors, firing temperature and Eu2+ concentrations, regarding to the synthesis and photoluminescence properties of Sr3SiO5:Eu2+ samples have been elucidated through photoluminescence (PL) analyses. The best firing temperature and Eu2+ concentrations of Sr3-xSiO5:Eu2+x phosphor was shown to be 1600oC and 0.03mol, respectively. In addition, the Mn2+ co-doped into Sr3SiO5:Eu2+, i. e. Sr3-x-ySiO5:Mnx2+,Euy2+, were also studied by PL analysis. It showed that the luminescent efficiency of Mn2+ co-doped into Sr3SiO5:Eu could be enhanced by 7%, as compared to the Sr3SiO5:Eu2+ phosphor. This study provides the fundamentals of synthesis and photoluminescence properties of (Sr3-x-ySiO5):Eux2+,Mn2+y phosphor for future research and application.

Neuronal dysfunction of a long projecting multisynaptic pathway in response to methamphetamine using manganese-enhanced MRI.

Manganese (Mn2+)-enhanced magnetic resonance imaging (MEMRI) is an emerging in vivo MR approach for pharmacological research. One new application of MEMRI in this area is to characterize functional changes of a specific neural circuit that is essential to the central effects of a drug challenge. To develop and validate such use of MEMRI in neuropharmacology, the current study applied MEMRI to visualize functional changes within a multisynaptic pathway originating from fasciculus retroflexus (FR) that is central to a commonly abused psychostimulant, methamphetamine (MA). Twelve rats were injected intraperitoneally with MA (10 mg/kg) or saline every 2 h for a total of four injections. After 6 days, Mn2+ was injected into the habenular nucleus (FR origin) of all animals, and MEMRI was repeatedly performed at certain points in time over 48 h. The evolution of Mn2+-induced signal enhancement was assessed across the FR tract, the ventral tegmental area (VTA), the striatum, the nucleus accumbens, and the prefrontal cortex (PFC), in both MA-injected animals and controls. MA treatment was found to affect the complexity and efficiency of Mn2+ uptake in the VTA, via the FR tract, with significantly increased Mn2+ accumulation in the VTA, the dorsomedial part of the striatum, and the PFC. MEMRI successfully visualizes disruptions in the multisynaptic pathway as the consequences of repeated MA exposure. MEMRI is potentially an important method in the future to investigate functional changes within a specific pathway under the influences of pharmacological agents, given its excellent functional, in vivo, spatial, and temporal properties.