Magnetoelectric biodegradable uniform composite microactuators for biomedical applications.

Reversible addition‐fragmentation chain transfer (RAFT) polymerization has been used to synthesize a star‐shaped light‐harvesting polymer comprising six diblock copolymer arms of styryl coumarin (St‐Coumarin) and methyl acrylate (MA) surrounding a ruthenium (II) trisbipyridyl energy trap core. The efficiency of excitation energy transfer from the styryl coumarin units to the Ru(II) core is increased to 90% compared to 60% for the analogous star polymer without MA blocks. The enhanced excitation energy transfer efficiency arises from the role of the MA blocks in diminishing the competitive quenching of photoexcited St‐coumarin chromophores by dithiobenzoyl polymer end groups present from the RAFT polymerization procedure.

This paper addresses a novel single‐ended Zeta (SEZE) converter topology for bidirectional power flow in grids, enabling both vehicle‐to‐grid (V2G) and grid‐to‐vehicle (G2V) operations. The primary challenge tackled is the reduction of total harmonic distortion (THD) and improvement of power quality in grid‐connected charging systems. The SEZE topology distinguishes itself with a modular structure, fewer switching devices, and enhanced energy transfer efficiency, directly addressing conventional limitations related to size, complexity, and harmonic performance. The SEZE framework uses the fuzzy logic controller (FLC) for operating the converter in V2G and G2V modes. During the V2G operation, the FLC controller provides the lowest current THD of 3.51% whereas the PID and PI controllers provide a THD of 4.83% and 10.83%. Moreover, in the G2V mode, the FLC controller provides the lowest current THD of 3.02% whereas the PID and PI controllers provide a THD of 5.02% and 6.64%. From the results, it is identified that the FLC works better than the conventional PID and PI controllers. The proposed converter also shows an efficiency of 97.1% and grid compliance than existing charging architectures. The SEZE converter, with fuzzy control, greatly improves power quality and makes sure that power can be transferred efficiently from V2G and G2V.

The polymer aggregation morphology in thin films strongly depends on the state of the solution and the film processing conditions, which lead to important impacts on the optoelectronic properties. In this work, the aggregation behaviors of ladder-type poly(p-phenylene) (Me-LPF) in dilute toluene solutions and spin-coated films are investigated by concentration- and temperature-dependent fluorescence spectroscopy and atomic force microscopy (AFM) combined with X-ray diffraction. Spin coating is normally a typical method for amorphous and isotropic films. In Me-LPF, the preassembly in solution plays an important role in aggregation behaviors in spin-coated film. The driving force of aggregation would be weak side-chain entanglement in the absence of intermolecular π–π interactions, which are very sensitive to temperature. The polymer chain aggregation is observed in dilute toluene solutions (>8 μg/mL) and spin-coated films at room temperature, which induces fluorescence quenching of the 0–0 emission band. It comes from enhanced energy transfer efficiency in aggregates by shortened intermolecular distance and ordered molecular orientation. These results supply a facile spin-coating process to prepare high order films, which show potential application in optoelectronic devices.

Nanorods in nanotechnology called a specific type of morphology of nanoscale materials that their dimensions range is from 1 to 100 nm. Nanorods can be synthesized from metal or semi-conductive material with a surface to volume ratio of 3–5. One method of making nanorods is direct chemical method. Ligands compounds as a shape control agents cause growth the nanorods and create stretched and extended modes of them. In recent years, magnetic nanorods are one of the nanorods that have been raised in the field of nano medicine [Nath S, Kaittanis C, Ramachandran V, Dalal NS, Perez JM. Synthesis, magnetic characterization, and sensing applications of novel dextran-coated iron oxide nanorods. Chem Mater. 2009;21:1761–7.]. Superparamagnetic properties of magnetic nanorods causes to sensing be done with high accuracy. In addition, other applications of magnetic nanorods are in the field of separation and treatment [Hu B, Wang N, Han L, Chen ML, Wang JH. Magnetic nanohybrids loaded with bimetal core–shell–shell nanorods for bacteria capture, separation, and near-infrared photothermal treatment. Chemistry. 2015;21:6582–9.]. Therefore, in biomedical applications, the nanorods are used usually with biological molecules such as antibodies [Schrittwieser S, Pelaz B, Parak WJ, Lentijo-Mozo S, Soulantica K, Dieckhoff J, et al. Homogeneous protein analysis by magnetic core–shell nanorod probes. ACS Appl Mater Interfaces. 2016;8:8893–9.]. For this purpose, in the present work we will try to introduce magnetic nanorods and mention their different methods of synthesis and applications.

For realizing the control of the preparation process for α-Fe2O3/Fe3O4 magnetic heterogeneous nanorods (MHNRs), the influence rules of key factors on the preparations of β-FeOOH nanorods (NRs) and α-Fe2O3/Fe3O4 MHNRs were revealed. Firstly, β-FeOOH nanorods (NRs) were fabricated with polyethylene glycol 2000 (PEG2k) as the growth inhibitor in specific directions via the hydrolysis process, for smaller size, the fabrication conditions for β-FeOOH NRs including Fe3+ concentration, PEG2k volume, hydrolytic temperature, and hydrolytic duration were optimized, and the optimal conditions were selected as 0.02M of Fe3+, 0.20g/L of PEG2k, 80°C of hydrolytic temperature, and 2h of hydrolytic duration, the β-FeOOH NRs with average length and diameter of 199nm and 55nm were obtained. Secondly, α-Fe2O3/Fe3O4 magnetic heterogeneous nanorods (MHNRs) were prepared with PEG2k as the reductant via the calcination-reduction process. For larger saturation magnetization (Ms) of α-Fe2O3/Fe3O4 MHNRs, the mass ratio of PEG2k and β-FeOOH NRs, calcination temperature, and calcination time were investigated as were 3:1, 450°C, and 2h, respectively. And α-Fe2O3/Fe3O4 MHNRs with the average length of 229nm, average diameter of 55nm, and Ms of 81.3 emu/g were obtained. The novel and facile preparation process for α-Fe2O3/Fe3O4 MHNRs shortened the preparation period, omitted the reduction process using hydrogen enhancing the preparation security, and relized the controlled particle size and properties, there were not heavy metal elements in the nanosystem, laying the groundwork for the biomedical applications of α-Fe2O3/Fe3O4 MHNRs.

Magnetic nickel ferrite (NiFe2O4) nanorods were prepared via an innovative alcohol-solution combustion-calcination technique and evaluated for removing methyl blue (MB), which may greatly benefit for dye-polluted water treatment. The magnetic nanorods were characterized by TEM, EDS, XRD, VSM, SAED, FTIR, XPS and BET, the results showed that the NiFe2O4 sample has high magnetic saturation (Ms) and soft superparamagnetic behavior, and these properties accounted for their facile separation from the aqueous solution when an external magnetic field was applied. To understand the adsorption mechanism, adsorption experiments were performed using adsorption kinetics and adsorption isotherms. The Temkin model and the pseudo-second-order kinetic model best described the adsorption characteristics of MB onto NiFe2O4 nanorods. The effect of pH on the adsorption process was investigated, when pH was 3–7, the maximum adsorption capacity was reached, which was about 62 mg·g−1. The recycling efficiency was also estimated, after 10 runs of regeneration, it remained 70.1% initial adsorption capacity, indicating the adsorbent could be efficiently reused for the adsorption of MB.

ROS-responsive chlorin e6 and silk fibroin loaded ultrathin magnetic hydroxyapatite nanorods for T1-magnetic resonance imaging guided photodynamic therapy in vitro

Summary form only given. Forster resonance energy transfer (FRET) is the dominant nonradiative energy transfer mechanism between a donor and acceptor fluorophore in nanometer proximity. FRET plays a pivotal role in the photosynthetic apparatus of plants and bacteria and many applications, ranging from photovoltaics and lighting, to probing molecular distances and interactions.It is an intriguing open question whether the FRET rate γFRET and the energy transfer efficiency ηFRET can also be controlled by the nanoscale optical environment, characterized by the local density of optical states (LDOS) [1]. Pioneering work suggested that the transfer rate depends linearly on the LDOS at the donor emission frequency [2], while later work suggested a dependence on the LDOS squared [3], or even a transfer rate independent of the LDOS [4]. We study the influence of the LDOS on Forster transfer, using precisely-defined, isolated, and efficient donor-acceptor pairs. The FRET pairs are dye molecules that covalently bound to the opposite ends of a 15 basepair long double-stranded with a precisely defined distance of 6.8 nm. Control over the LDOS is realized by positioning the FRET systems at well-defined distances (ranging from 60 nm to 270 nm) from a metallic mirror. The energy transfer rate γFRET and efficiency ηFRET are obtained by measuring the donor emission rate γDA in presence and the rate γD in absence of the acceptor using time-correlated single-photon counting based lifetime imaging. Our data unequivocally show that the FRET rate is independent of the LDOS at donor emission frequencies, consistent with quantum-optical theory. The FRET efficiency clearly changes with LDOS [5], since the LDOS alters the competition between the different decay processes. By controlling the radiative decay rate of the energy donor by the LDOS, the energy transfer efficiency can be enhanced or reduced. If a donor with unit quantum efficiency is placed in a 3D photonic bandgap, the energy transfer efficiency will approach 100 %, independent of the acceptor, and of the distances and orientations between the FRET partners.

In this study, novel di‐ and tetra‐pyrenylated BODIPY (boron‐dipyrromethene) dyes (Bdpy2 and Bdpy4) were synthesized via the Suzuki‐Miyaura cross‐coupling reaction, incorporating pyrene units at specific positions on the BODIPY core. Comprehensive structural characterization was achieved through FT‐IR, UV‐Vis, MALDI‐mass spectrometry, and NMR techniques. The optical properties were extensively analyzed in different solvents, revealing Q‐band absorption maxima at 531 nm for Bdpy2 and 533 nm for Bdpy4 in THF, along with red‐shifted emission peaks due to increased π–π stacking interactions. Bdpy4 displayed a fluorescence quantum yield of 0.68 and a fluorescence lifetime of 3.88 ns, surpassing Bdpy2′s values of 0.61 and 3.44 ns, respectively. These improved values in Bdpy4 highlight the enhanced energy transfer efficiency provided by the additional pyrene groups. Theoretical TD‐DFT calculations supported the experimental findings, indicating effective energy transfer from pyrene to the BODIPY core. These findings suggest that the high fluorescence efficiency and extended lifetimes of pyrenylated BODIPY derivatives make them promising candidates for optoelectronic applications, including bioimaging and energy harvesting.

Energy transfer pathways in the collisional activation of peptides

This paper presents a numerical study of transferring characteristics of momentum/energy during oxygen jetting into the slag–metal molten bath in basic oxygen furnaces by a multi-fluid volume of fluid model. The evolution of the momentum/energy and turbulence of jets along their axial travel were studied. The results were quantitatively compared within a wide range of oxygen supply pressures, at which the jets may be at under- or over-expanding state. The efficiency of the momentum/energy transfer from the jets to the molten bath was also assessed with respect to lance height and operation pressure. The numerical results show that the momentum and kinetic energy for the jets suffering from shock waves likely cause more intensive damping compared to the jets with expansion waves. The turbulence kinetic energy and turbulence dissipation rate are observed to firstly increase and then decrease. This effect is more pronounced at a lower operation pressure. Based on these results, the optimum lance height was identified for a rapid slagging operation. It is also shown that the efficiency of the energy transfer from the jets to the molten bath is very low. Decreasing lance height or increasing operation pressure promotes the efficiency of the momentum transfer from the jets to the molten bath but lowers the efficiency of the kinetic energy transfer.

We report tailed skyrmions—a new class of stable soliton solutions of the 2D chiral magnet model. Tailed skyrmions have elongated shapes and emerge in a narrow range of fields near the transition between the spin spirals and the saturated state. We analyze the stability range of these solutions in terms of external magnetic field and magnetocrystalline anisotropy. We calculate minimum energy paths and homotopies (continuous transitions) between tailed skyrmions of the same topological charge. The discovery of tailed skyrmions extends the diversity of already known solutions. This is illustrated by solitons with complex morphology, such as tailed skyrmion bags with and without chiral kinks.

Synthesis and Biomedical Applications of Magnetic Nanocomposites with Complex Morphologies

Interhead fluorescence energy transfer between probes attached to translationally equivalent sites on the regulatory light chains of scallop myosin

Aggregation structure of poly(γ-benzyl- l-glutamate) in benzene-DMF mixed solution probed by fluorescence depolarization and non-radiative energy transfer