Neural Induction Potential and MRI of ADSCs Labeled Cationic Superparamagnetic Iron Oxide Nanoparticle In Vitro

Magnetic resonance imaging (MRI) combined with contrast agents is believed to be useful for stem cell tracking in vivo, and the aim of this research was to investigate the biosafety and neural induction of SD rat-originated adipose derived stem cells (ADSCs) using cationic superparamagnetic iron oxide (SPIO) nanoparticle which was synthesized by the improved polyol method, in order to allow visualization using in vitro MRI. The scan protocols were performed with T2-mapping sequence; meanwhile, the ultrastructure of labeled cells was observed by transmission electron microscopy (TEM) while the iron content was measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). After neural induction, nestin and NSE (neural markers) were obviously expressed. In vitro MRI showed that the cationic PEG/PEI-modified SPIO nanoparticles could achieve great relaxation performance and favourable longevity. And the ICP-AES quantified the lowest iron content that could be detected by MRI as 1.56~1.8 pg/cell. This study showed that the cationic SPIO could be directly used to label ADSCs, which could then inductively differentiate into nerve and be imaged by in vitro MRI, which would exhibit important guiding significance for the further in vivo MRI towards animal models with neurodegenerative disorders

Output Feedback Control for Active Suspension Electro-Hydraulic Actuator Systems With a Novel Sampled-Data Nonlinear Extended State Observer

In this paper, an output feedback controller based on a novel sampled-data nonlinear extended state observer (SDNLESO) is proposed for an active suspension electro-hydraulic actuator (ASEHA) system to address the heavy nonlinearities, model uncertainties and sampled-data behavior. The designed controller only requires little prior knowledge about the controlled system for the purpose of position tracking. The SDNLESO, integrating a novel nonlinear extended state observer and an output predictor, is developed to simultaneously and continuously estimate the unmeasurable states and total disturbance for an error dynamic system rather than the original ASEHA system, where the actual discrete displacement tracking error between measurement output and the reference signal serves as the observer input. Then, a compensated controller is synthesized based on the obtained estimates, which is robust against the matched and mismatched disturbances of the system while being able to ensure an expected transient tracking performance and final tracking accuracy. By constructing weighted error system and using the geometric homogeneity theory, the SDNLESO convergence is proven, while the maximum allowable sampling period is derived theoretically for guiding the selection of the actual sampling interval. Moreover, the closed-loop system stability and the tracking error exponential convergence are guaranteed within the Lyapunov framework. Finally, a number of practical experiments are carried out on the ASEHA system test platform. The results show that the proposed control method is applicable and valid for nonlinear and uncertain ASEHA system despite the existence of a large actuator area ratio

Creation of a New Type of Ion Exchange Material for Rapid, High-capacity, Reversible and Selective Ion Exchange without Swelling and Entrainment

Ion-exchange materials, currently dominated by resins, are widely used in a plethora of areas. However, the drawbacks of conventional resins necessitate the creation of a new model of ion exchange materials that feature controllable swelling, easily accessible ion exchange sites, high ion exchange capacity, fast ion exchange kinetics, and high chemical stability as illustrated herein in the context of functionalizing a porous organic polymer (POP) with ion exchange groups. The advantages of POP-based ion exchange materials in comparison with conventional resins and other types of ion exchange materials have been highlighted through an evaluation of their performances in scavenging precious metals at trace concentrations, removal of nuclear waste model ions, and size-selective ion capture. Our work thereby provides a new perspective to develop ion functionalized POPs as a versatile type of ion exchange materials for various applications

Metal-Cation-Directed <i>de Novo</i> Assembly of a Functionalized Guest Molecule in the Nanospace of a Metal–Organic Framework

In this work, a new strategy is developed to encapsulate a metal-functionalized guest molecule into a metal–organic framework (MOF) via metal-cation-directed <i>de novo</i> assembly from the component fragments of the guest molecule. This strategy, as illustrated in proof-of-principle studies on the <i>de novo</i> assembly of metal­(II) phthalocyanine molecules into bio‑MOF‑1, can circumvent some drawbacks of existing approaches for encapsulating guest molecules into MOFs, such as inaccessibility for larger guest molecules due to limitations of the MOF window size and disruption of the MOF framework structure by functionalized guest molecules. Overall, this work provides a general yet versatile approach for encapsulating a broader range of metal-functionalized guest molecules into MOFs for various applications

Tuning Surface Energy of Zn Anodes via Sn Heteroatom Doping Enabled by a Codeposition for Ultralong Life Span Dendrite-Free Aqueous Zn-Ion Batteries

Aqueous Zn-ion batteries (AZBs) have been considered as one of the most promising large-scale energy storage systems, owing to the advantages of raw material abundance, low cost, and eco-friendliness. However, the severe growth of Zn dendrites leads to poor stability and low Coulombic efficiency of AZBs. Herein, to effectively inhibit the growth of Zn dendrites, a new strategy has been proposed, i.e., tuning the surface energy of the Zn anode. This strategy can be achieved by in situ doping of Sn heteroatoms in the lattice of metallic Zn via codeposition of Sn and Zn with a small amount of the SnCl2 electrolyte additive. Density functional theory calculations have suggested that Sn heteroatom doping can sharply decrease the surface free energy of the Zn anode. As a consequence, driven by the locally strong electric field, metallic Sn tends to deposit at the tips of the Zn anode, thus decreases the surface energy and growth of Zn at the tips, resulting in a dendrite-free Zn anode. The positive effect of the SnCl2 additive has been demonstrated in both the Zn∥Zn symmetric battery and the Zn/LFP and Zn/HATN full cell. This novel strategy can light a new way to suppress Zn dendrites for long life span Zn-ion batteries

Dual Functionalized Cages in Metal–Organic Frameworks via Stepwise Postsynthetic Modification

The introduction of bi- or multifunctionality into different cages of metal–organic frameworks (MOFs) has been of great interest because such MOF materials can demonstrate unique properties for various applications. Herein, we report a general strategy for creating different types of functionalized cages in MOFs by exerting control of the size of cage windows. Selective cage decoration was thereby enabled in such a manner that dual functional MOFs with different types of cages and pores can be created. The resultant different pore function MOF, DPF-MOF, is illustrated as a “proof of concept” in MOF MIL-101-Cr. An intermediate of a cascade reaction was successfully trapped and controlled the desired reaction direction. This DPF-MOF represents a new type of platform that, by trapping intermediates during the reaction processes, enhances our fundamental understanding of reaction chemistry in porous materials