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Contrast-enhanced magnetic resonance angiography (CE-MRA) plays a critical role in diagnosing and monitoring various vascular diseases. Achieving high-sensitivity detection of vascular abnormalities in CE-MRA depends on the properties of contrast agents. In contrast to clinically used gadolinium-based contrast agents (GBCAs), the new generation of ultrasmall ferrite nanoparticles-based contrast agents have high relaxivity, long blood circulation time, easy surface functionalization, and high biocompatibility, hence showing promising prospects in CE-MRA. This review aims to comprehensively summarize the advancements in ultrasmall ferrite nanoparticles-enhanced MRA for detecting vascular diseases. Additionally, this review also discusses the future clinical translational potential of ultrasmall ferrite nanoparticles-based contrast agents for vascular imaging. By investigating the current status of research and clinical applications, this review attempts to outline the progress, challenges, and future directions of using ultrasmall ferrite nanoparticles to drive the field of CE-MRA into a new frontier of accuracy and diagnostic efficacy. [ABSTRACT FROM AUTHOR]

The selective oxidation of alcohols has drawn significant attention in heterogeneous catalysis with the increasing use of Pickering interfacial catalysis (PIC) for green transformations of alcohols. However, it is still highly desirable to design and develop a solid catalyst with easy separation and recycling, made from abundant resources through a simple synthesis route, for the selective oxidation of alcohols. In this study, ferrite nanoparticles, synthesized via a hydrothermal process, were employed to act as a stabilizer and catalyst in PIC for the oxidation of benzyl alcohol using H2O2. The ferrite nanoparticles exhibited higher catalytic performance in PIC than in acetonitrile. The turnover number (TON) of the nanocatalyst in PIC was found to be 1.5–4 times higher than that in acetonitrile, and the reaction constant in PIC (kPIC = 0.712 h−1) was almost twice that in acetonitrile (kCH3CN = 0.310 h−1) for MnFe2O4 nanoparticles. Moreover, other alcohols could also be oxidized with moderately high conversion and selectivity in PIC. Significantly, the ferrite nanocatalyst could be easily separated from PIC using a magnet for reuse, achieving 88% BzOH conversion after five cycles. The use of hazardous organic solvents was avoided in PIC, making it a more advanced, green and sustainable reaction system. [ABSTRACT FROM AUTHOR]

Immunogenic cell death (ICD) can improve the therapeutic effects of cancer immunotherapy by initiating adaptive immune responses. Unlike the exogenous hyperthermia modality in clinics, magnetic hyperthermia (MH) is characterized by an iron oxide nano-agent acting as a heating source and the effects induced by heating acting at the intracellular region. However, the immunological effects of endogenous heating generated during MH and exogenous heating, and the difference in damage-associated molecular pattern (DAMP) emissions correlating with the ICD are unclear; whether MH elicits genuine ICD remains unknown. Herein, we have identified 10 distinct DAMP correlates of ICD induced by intracellular MH, and found that only heat shock proteins 70/90 were expressed after water bath heating (exogenous hyperthermia) in human triple-negative breast cancer (TNBC) MDA-MB-231 cells, murine TNBC 4T1 cells, and surgically resected specimens of ductal breast cancer from patients. In vivo vaccination assays were performed in immunocompetent BALB/c mice. The results demonstrated that MH with endogenous heating could stimulate the genuine ICD on 4T1 cells and achieved optimal therapeutic effects on 4T1 tumors, whereas exogenous heating under the same conditions failed to elicit these effects. These findings with regard to the MH induced genuine ICD with high efficiency are critical for the development of safe and effective therapeutics to amplify the therapeutic responses of cancer immunotherapy. [ABSTRACT FROM AUTHOR]

The potential of solution-processable reduced graphene oxide (rGO) films as wave impedance matching layers has been examined in a broad terahertz (THz) spectral bandwidth. The THz sheet conductivities of rGO films measured by THz time-domain spectroscopy were observed to be tunable and sensitive to the film thicknesses and reduction degrees, which can be efficiently controlled by our solution-processable fabrication method. Remarkable broadband impedance matching was achieved with a suitable rGO film, as shown by the suppression of the internal reflected THz pulses from the substrate in the spectra. The underlying mechanisms have been revealed both experimentally and theoretically. This work paves the way for developing rGO-based broadband and large-scale anti-reflection layers for THz components. [ABSTRACT FROM AUTHOR]

CoFe2O4/graphene oxide hybrids have been successfully fabricated via a facile one-pot polyol route, followed by chemical conversion into FeCo/graphene hybrids under H2/NH3 atmosphere. These magnetic nanocrystals were uniformly decorated on the entire graphene nanosheets without aggregation. The morphology, chemical composition and crystal structure have been characterized in detail. In particular, FeCo/graphene hybrids show significant improvement in both permeability and permittivity due to the combination of the high magnetocrystalline anisotropy of metallic FeCo and high conductivity of light-weight graphene. This leads to remarkable enhancement in microwave absorption properties. The maximum reflection loss of FeCo/graphene hybrids reaches −40.2 dB at 8.9 GHz with a matching thickness of only 2.5 mm, and the absorption bandwidth with reflection loss exceeding −10 dB is in the 3.4–18 GHz range for the absorber thickness of only 1.5–5 mm. Moreover, the experimental relationship between matching thickness and frequency is found to obey the quarter-wavelength matching model, facilitating the design of FeCo/graphene hybrid film for practical application. The results suggest that the FeCo/graphene hybrids developed here can serve as an ideal candidate for the manufacture of light-weight and high-efficiency microwave-absorbing devices. [ABSTRACT FROM AUTHOR]

Contrast-enhanced magnetic resonance angiography (CE-MRA) plays a critical role in diagnosing and monitoring various vascular diseases. Achieving high-sensitivity detection of vascular abnormalities in CE-MRA depends on the properties of contrast agents. In contrast to clinically used gadolinium-based contrast agents (GBCAs), the new generation of ultrasmall ferrite nanoparticles-based contrast agents have high relaxivity, long blood circulation time, easy surface functionalization, and high biocompatibility, hence showing promising prospects in CE-MRA. This review aims to comprehensively summarize the advancements in ultrasmall ferrite nanoparticles-enhanced MRA for detecting vascular diseases. Additionally, this review also discusses the future clinical translational potential of ultrasmall ferrite nanoparticles-based contrast agents for vascular imaging. By investigating the current status of research and clinical applications, this review attempts to outline the progress, challenges, and future directions of using ultrasmall ferrite nanoparticles to drive the field of CE-MRA into a new frontier of accuracy and diagnostic efficacy.

Terahertz (THz) technology has been a promising tool for sensing, spectroscopy, imaging, and communication. However, only few devices have shown efficient performance for future THz technology. Herein, we propose a device based on tunable magnetoplasmons in gated monolayer graphene for THz wave modulation and isolation. The relative transmission and the Faraday rotation angle of the device have been calculated by combining the Fresnel method with the voltage-dependent Drude model. Our results suggest that a superior modulation depth and giant Faraday rotation due to the cyclotron effect in the classical regime by intraband transitions in graphene offer an effective, uniform, and flexible tunability for THz wave. And the modulating and isolating manipulations by graphene can range from 0 to 2 THz, with electron-hole asymmetry originating from variable scattering rate of magnetoplasmons. Moreover, the thickness effect of the thin substrate is also studied for better performance of the device, taking advantage of the unavoidable Fabry-Perot (F-P) effect. This work demonstrates a pathway for efficient THz modulator and isolator based on the magneto-optical polarization effect in graphene.

By manipulating the interfacial interactions between the peptide templates and the silicate species derived from TEOS and APTES, a facile biomimetic method was developed for the fabrication of silica nanostructures exhibiting "string-of-beads" and fibrillar morphologies of varied sizes.