A two-step chemical approach to synthesize high quality Fe 3 O 4 nanodisc is reported. The magnetic hyperthermia properties of the nanodisc and isotropic nanoparticles are investigated systematically. The results suggest that the nanodisc shows much higher specifi c absorption rate (SAR) than isotropic nanoparticles. This is attributed to the parallel alignment of nanodisc with respect to the alternating current magnetic fi eld, which is confi rmed by good agreement between experimental results and micromagnetic simulation. It is found that such parallel alignment could enhance the SAR value by a factor of ≈2 with respect to the randomly oriented case. The above results indicate that the nanodisc provides an excellent thermal seed for magnetic hyperthermia. This study sheds the light on the magnetic hyperthermia mechanism of magnetic nanodisc and it also opens the window to explore high effi ciency thermal seeds by controlling the orientation of magnetic nanostructures.

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Octahedral Fe3O4 nanoparticles show a wide size range for high SAR values to be used as an excellent thermal seed for magnetic hyperthermia cancer treatment.

We discuss the design, realization and experimental characterization of a GaN-based hybrid Doherty power amplifier for wideband operation in the 3-3.6 GHz frequency range. The design adopts a novel, simple approach based on wideband compensator networks. Second-harmonic tuning is exploited for the main amplifier at the upper limit of the frequency band, thus improving gain equalization over the amplifier bandwidth. The realized amplifier is based on a packaged GaN HEMT, and shows, at 6 dB of output power back-off, a drain efficiency higher than 38 % in the 3-3.6 GHz band, gain around 10 dB, and maximum power between 43 dBm and 44 dBm, with saturated efficiency between 55 % and 66 %. With respect to the state of the art, we obtain, at a higher frequency, a wideband amplifier with similar performances in terms of bandwidth, output power, and efficiency, through a simpler approach. Moreover, the measured constant maximum output power of 20 W suggests that the power utilization factor of the 10 W (Class A) GaN HEMT is excellent over the amplifier band.

Uniform wüstite Fe0.6 Mn0.4 O nanoflowers have been successfully developed as an innovative theranostic agent with T1 -T2 dual-mode magnetic resonance imaging (MRI), for diagnostic applications and therapeutic interventions via magnetic hyperthermia. Unlike their antiferromagnetic bulk counterpart, the obtained Fe0.6 Mn0.4 O nanoflowers show unique room-temperature ferromagnetic behavior, probably due to the presence of an exchange coupling effect. Combined with the flower-like morphology, ferromagnetic Fe0.6 Mn0.4 O nanoflowers are demonstrated to possess dual-modal MRI sensitivity, with longitudinal relaxivity r1 and transverse relaxivity r2 as high as 4.9 and 61.2 mm(-1) s(-1) [Fe]+[Mn], respectively. Further in vivo MRI carried out on the mouse orthotopic glioma model revealed gliomas are clearly delineated in both T1 - and T2 -weighted MR images, after administration of the Fe0.6 Mn0.4 O nanoflowers. In addition, the Fe0.6 Mn0.4 O nanoflowers also exhibit excellent magnetic induction heating effects. Both in vitro and in vivo magnetic hyperthermia experimentation has demonstrated that magnetic hyperthermia by using the innovative Fe0.6 Mn0.4 O nanoflowers can induce MCF-7 breast cancer cell apoptosis and a complete tumor regression without appreciable side effects. The results have demonstrated that the innovative Fe0.6 Mn0.4 O nanoflowers can be a new magnetic theranostic platform for in vivo T1 -T2 dual-mode MRI and magnetic thermotherapy, thereby achieving a one-stop diagnosis cum effective therapeutic modality in cancer management.

Multifunctional films can have important applications. Transparent and flexible films with high conductivity and magnetic properties can be used in many areas, such as electromagnetic interference (EMI) shielding, magnetic switching, microwave absorption, and also biotechnology. Herein, novel highly conductive and superparamagnetic thin films with excellent transparency and flexibility have been demonstrated. The films were formed from a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS; Clevios PH1000) aqueous solution added with iron oxide (FeO) nanoparticles that have a size of ∼20 nm by spin-coating. The PEDOT:PSS/FeO films have a high conductivity of 1080 S/cm through treatment with methylammonium iodide in an organic solvent. The high-conductivity PEDOT:PSS/FeO films can also have a saturation magnetization of 25.5 emu/g and an EMI shielding effectiveness of more than 40 dB in the 8-12.5 GHz (X band) frequency range. The PEDOT:PSS/FeO films have additional advantages, like excellent transparency, good mechanical flexibility, low cost, and light weight. In addition, we fabricate flexible PEDOT:PSS/FeO silk threads with a high magnetism and conductivity.

An extremely low frequency alternating magnetic field of 20 Hz was proved to be able to remarkably accelerate the drug release from optimized ZIF-90 nanospheres with incorporated Fe3O4 nanoparticles acting as actuator.