Multiferroic heterostructures of Fe3O4/PZT (lead zirconium titanate), Fe3O4/PMN‐PT (lead magnesium niobate‐lead titanate) and Fe3O4/PZN‐PT (lead zinc niobate‐lead titanate) are prepared by spin‐spray depositing Fe3O4 ferrite film on ferroelectric PZT, PMN‐PT and PZN‐PT substrates at a low temperature of 90 °C. Strong magnetoelectric coupling (ME) and giant microwave tunability are demonstrated by a electrostatic field induced magnetic anisotropic field change in these heterostructures. A high electrostatically tunable ferromagnetic resonance (FMR) field shift up to 600 Oe, corresponding to a large microwave ME coefficient of 67 Oe cm kV−1, is observed in Fe3O4/PMN‐PT heterostructures. A record‐high electrostatically tunable FMR field range of 860 Oe with a linewidth of 330–380 Oe is demonstrated in Fe3O4/PZN‐PT heterostructure, corresponding to a ME coefficient of 108 Oe cm kV−1. Static ME interaction is also investigated and a maximum electric field induced squareness ratio change of 40% is observed in Fe3O4/PZN‐PT. In addition, a new concept that the external magnetic orientation and the electric field cooperate to determine microwave magnetic tunability is brought forth to significantly enhance the microwave tunable range up to 1000 Oe. These low temperature synthesized multiferroic heterostructures exhibiting giant electrostatically induced tunable magnetic resonance field at microwave frequencies provide great opportunities for electrostatically tunable microwave multiferroic devices.

We demonstrate a semiconducting material, TiO 2−δ , with ferromagnetism up to 880 K, without the introduction of magnetic ions. The magnetism in these films stems from the controlled introduction of anion defects from both the filmsubstrate interface as well as processing under an oxygen-deficient atmosphere. The room-temperature carriers are n-type with n ∼ 3 × 10 17 cm −3 . The density of spins is ∼10 21 cm −3 . Magnetism scales with conductivity, suggesting that a double exchange interaction is active. This represents a new approach in the design and refinement of magnetic semiconductor materials for spintronics device applications.(Some figures in this article are in colour only in the electronic version)Recent research efforts on the growth of magnetically ordered semiconductor materials [1,2] have received great attention because of potential new applications in spintronics devices [3]. The rationale for this optimism is the plausibility of integrating properties of both magnetic and semiconductor materials in new devices [1] (e.g. spin diodes [3-6] and spin-FETs [7]). Recent research has focused on dilute magnetic semiconductors (DMS) which were synthesized by introducing magnetic ions (e.g. Mn, Co, Fe, and etc) into conventional III-V [1, 2] and II-VI type semiconductors [8,9] or wide bandgap semiconductors including ZnO and TiO 2 [8][9][10][11][12][13]. Also, ferromagnetism was induced in films of hafnium dioxide, HfO 2 , deposited by pulsed laser deposition (PLD) on sapphire substrates and attributed to defect doping [10][11][12]. Bulk HfO 2 is intrinsically non-magnetic and electrically insulating. This report has created intense

Aim: This study aimed to develop a novel influenza A vaccine by conjugating the highly conserved extracellular region of the matrix 2 protein (M2e) of influenza A virus to gold nanoparticles (AuNPs) and to test the vaccine in a mouse influenza challenge model. Materials & methods: Citrate-reduced AuNPs (diameter: 12 nm) were synthesized, and characterized by transmission electron microscopy and dynamic light scattering. M2e was conjugated to AuNPs through thiol–gold interactions to form M2e–AuNP conjugates. Particle stability was confirmed by UV–visible spectra, and M2e conjugation was further characterized by x-ray photoelectron spectroscopy. Mice were immunized with M2e–AuNPs with or without CpG (cytosine-guanine rich oligonucleotide) as an adjuvant with appropriate control groups. Sera was collected and M2e-specific immunoglobulin (IgG) was measured, and immunized mice were challenged with PR8-H1N1 influenza virus. Results: M2e-capped AuNPs could be lyophilized and stably resuspended in water. Intranasal vaccination of mice with M2e–AuNP conjugates induced M2e-specific IgG serum antibodies, which significantly increased upon addition of soluble CpG as adjuvant. Upon challenge with lethal PR8, mice vaccinated with M2e-AuNP conjugates were only partially protected, while mice that received soluble CpG as adjuvant in addition to M2e–AuNP were fully protected. Conclusion: Overall, this study demonstrates the potential of using the M2e–AuNP conjugates with CpG as an adjuvant as a platform for developing an influenza A vaccine.

Polydimethylsiloxane (PDMS) silicone elastomer is extensively used in soft lithography processes to fabricate microscale or nano scale systems for microfluidic or cell culture applications. Though PDMS is biocompatible, it is not an ideal material for cell culture due to its poor cell adhesion properties. In this study, PDMS surfaces were modified to promote intestinal cell adhesion, in the interest of testing feasibility of using microfabricated PDMS systems for high throughput drug screening. Modification techniques included changing chemical composition of PDMS (i.e., varying curing to mixing agent ratio, and oxidization of PDMS surface by oxygen plasma), surface treatment of PDMS by coating with charged molecules (i.e., poly-D-lysine, L-alpha-phosphatidylcholine, and a layer bylayer coating), and deposition of extracellular matrix (ECM) proteins (i.e., laminin, fibronectin, and collagen). The influence of these modifications on PDMS properties, including elastic modulus and surface properties (wettability, chemical composition, topography, and protein adsorption) were characterized. Modification techniques were all found to change PDMS properties and influence the attachment and proliferation of Caco-2 cells over three days of culture to varying degrees. Generally, Caco-2 cells preferred to attach on collagen-coated, fibronectin-coated, and fibronectin-coated oxygen-plasma treated PDMS. The results highlight the importance of considering multiple physical and chemical factors that may be influenced by biomaterial modification and result in altered cell attachment to microfabricated systems, including surface hydrophobicity, chemical composition, stiffness, and topography. This study provides a foundation for further miniaturization, utilizing soft lithography techniques, of Caco-2 cell-based system for high-throughput screening of drug intestinal absorption during lead optimization in drug discovery. The understanding of different surface modifications on adjusting cell adhesion on PDMS allows systemic design of Biomicroelectromechanical Systems (BioMEMS) with tunable cell adhesion properties.

Strong magnetoelectric ͑ME͒ coupling was demonstrated in Fe 3 O 4 /PZN-PT ͑lead zinc niobate-lead titanate͒ multiferroic heterostructures obtained through a sputter deposition process. The dependence of the magnetic anisotropy on the electric field ͑E-field͒ is theoretically predicted and experimentally observed by ferromagnetic resonance spectroscopy. A large tunable in-plane magnetic anisotropy of up to 600 Oe, and tunable out-of-plane anisotropy of up to 400 Oe were observed in the Fe 3 O 4 /PZN-PT multiferroic heterostructures, corresponding to a large ME coefficient of 100 Oe cm/ kV in plane and 68 Oe cm/ kV out of plane, which match well with predicted results. In addition, the electric field manipulation of magnetic anisotropy is also demonstrated by the electric fields dependence of magnetic hysteresis loops, showing a large squareness ratio change of 44%. These Fe 3 O 4 /PZN-PT multiferroic heterostructures exhibiting large E-field tunable magnetic properties provide great opportunities for novel electrostatically tunable multiferroic devices.