Rapid Quantification of Escherichia coli O157:H7 and Salmonella Typhimurium in Lettuce Using Immunomagnetic Separation and a Microfluidic System.

Escherichia coli O157:H7 and Salmonella spp. are common foodborne pathogens. Simple, rapid and accurate methods to detect and enumerate these pathogens are required to prevent outbreaks of foodborne illness.

Real-Space Observation of Ligand Hole State in Cubic Perovskite SrFeO.

An anomalously high valence state sometimes shows up in transition-metal oxide compounds. In such systems, holes tend to occupy mainly the ligand p orbitals, giving rise to interesting physical properties such as superconductivity in cuprates and rich magnetic phases in ferrates. However, no one has ever observed the distribution of ligand holes in real space.

Double dome structure of the Bose-Einstein condensation in diluted S = 3/2 quantum magnets.

Bose-Einstein condensation (BEC) in quantum magnets, where bosonic spin excitations condense into ordered ground states, is a realization of BEC in a thermodynamic limit. Although previous magnetic BEC studies have focused on magnets with small spins of S ≤ 1, larger spin systems potentially possess richer physics because of the multiple excitations on a single site level. Here, we show the evolution of the magnetic phase diagram of S = 3/2 quantum magnet BaCoGeO when the averaged interaction J is controlled by a dilution of magnetic sites.

Magnetoelectric transfer of a domain pattern.

The utility of ferroic materials is determined by the formation of domains and their poling behavior under externally applied fields. For multiferroics, which exhibit several types of ferroic order at once, it is also relevant how the domains of the coexisting ferroic states couple and what kind of functionality this might involve. In this work, we demonstrate the reversible transfer of a domain pattern between magnetization and electric-polarization space in the multiferroic DyTbFeO.

Magnetochiral Dichroism in a Collinear Antiferromagnet with No Magnetization.

We show the directional dichroism in a collinear antiferromagnet MnTiO_{3}. The dichroism between two distinctive antiferromagnetic states with opposite signs of staggered magnetic moments can be regarded as magnetochiral dichroism in the absence of external fields. Electric-field reversal of antiferromagnetic domain causes a change in the absorption intensity of unpolarized light around 2.

Disordered skyrmion phase stabilized by magnetic frustration in a chiral magnet.

Magnetic skyrmions are vortex-like topological spin textures often observed to form a triangular-lattice skyrmion crystal in structurally chiral magnets with the Dzyaloshinskii-Moriya interaction. Recently, β-Mn structure-type Co-Zn-Mn alloys were identified as a new class of chiral magnet to host such skyrmion crystal phases, while β-Mn itself is known as hosting an elemental geometrically frustrated spin liquid. We report the intermediate composition system CoZnMn to be a unique host of two disconnected, thermal-equilibrium topological skyrmion phases; one is a conventional skyrmion crystal phase stabilized by thermal fluctuations and restricted to exist just below the magnetic transition temperature , and the other is a novel three-dimensionally disordered skyrmion phase that is stable well below .

Identification of Antiferromagnetic Domains Via the Optical Magnetoelectric Effect.

The ultimate goal of multiferroic research is the development of a new-generation nonvolatile memory devices, where magnetic bits are controlled via electric fields with low energy consumption. Here, we demonstrate the optical identification of magnetoelectric (ME) antiferromagnetic (AFM) domains in the LiCoPO_{4} exploiting the strong absorption difference between the domains. This unusual contrast, also present in zero magnetic field, is attributed to the dynamic ME effect of the spin-wave excitations, as confirmed by our microscopic model, which also captures the characteristics of the observed static ME effect.

Rapid on-site monitoring of Legionella pneumophila in cooling tower water using a portable microfluidic system.

Legionnaires' disease, predominantly caused by the bacterium Legionella pneumophila, has increased in prevalence worldwide. The most common mode of transmission of Legionella is inhalation of contaminated aerosols, such as those generated by cooling towers. Simple, rapid and accurate methods to enumerate L.

Current-Induced Nucleation and Annihilation of Magnetic Skyrmions at Room Temperature in a Chiral Magnet.

A magnetic skyrmion is a nanometer-scale magnetic vortex carrying an integer topological charge. Skyrmions show a promise for potential application in low-power-consumption and high-density memory devices. To promote their use in applications, it is attempted to control the existence of skyrmions using low electric currents at room temperature (RT).

Deformation of Topologically-Protected Supercooled Skyrmions in a Thin Plate of Chiral Magnet CoZnMn.

Magnetic skyrmions in CoZnMn thin plates are observed to deform in a metastable state prepared in a magnetic-field-cooling process by way of the thermal-equilibrium skyrmion phase. In cooling, the disk-shape skyrmions change to bar- or L-shaped elongated form, whereas the skyrmion density is nearly conserved. The deformation of the skyrmions in the supercooled metastable phase is observed irrespective of the crystallographic orientation of the thin plate, whereas the elongation direction nearly aligns along the magnetic easy axis.

Variation of Topology in Magnetic Bubbles in a Colossal Magnetoresistive Manganite.

The emergence of zero-bias bubbles (≈100 nm in diameter) with various Bloch lines and their triangular lattice is revealed in a colossal magnetoresistive material, La Sr MnO , by means of Lorentz transmission electron microscopy (LTEM). The magnetization dynamics, and accompanying changes of the topological number of bubbles via the field-driven motion of the Bloch lines, are demonstrated by in situ LTEM observations.

Highly efficient gene transfer using a retroviral vector into murine T cells for preclinical chimeric antigen receptor-expressing T cell therapy.

Adoptive immunotherapy using chimeric antigen receptor-expressing T (CAR-T) cells has attracted attention as an efficacious strategy for cancer treatment. To prove the efficacy and safety of CAR-T cell therapy, the elucidation of immunological mechanisms underlying it in mice is required. Although a retroviral vector (Rv) is mainly used for the introduction of CAR to murine T cells, gene transduction efficiency is generally less than 50%.

Piezomagnetoelectric Effect of Spin Origin in Dysprosium Orthoferrite.

The piezomagnetoelectric effect, namely, the simultaneous induction of both the ferromagnetic moment and electric polarization by an application of uniaxial stress, was demonstrated in the nonferroelectric antiferromagnetic ground state of DyFeO(3). The induced electric polarization and ferromagnetic moment are coupled with each other, and monotonically increase with increasing uniaxial stress. The present work provides a new guiding principle for designing multiferroics where its magnetic symmetry is broken by external uniaxial stress.

Charge-order domain walls with enhanced conductivity in a layered manganite.

Interfaces and boundaries in condensed-matter systems often have electronic properties distinct from the bulk material and thus have become a topic of both fundamental scientific interest and technological importance. Here we identify, using microwave impedance microscopy, enhanced conductivity of charge-order domain walls in the layered manganite Pr(Sr0.1Ca0.

Uniaxial-stress control of spin-driven ferroelectricity in multiferroic Ba(2)CoGe(2)O(7).

We have demonstrated that spin-driven ferroelectricity in a tetragonal multiferroic Ba(2)CoGe(2)O(7) is controlled by applying uniaxial stress. We found that the application of compressive stress along the [110] direction leads to a 45° or 135° rotation of the sublattice magnetization of the staggered antiferromagnetic order in this system. This allows the spontaneous electric polarization to appear along the c axis.

Magnetic stripes and skyrmions with helicity reversals.

It was recently realized that topological spin textures do not merely have mathematical beauty but can also give rise to unique functionalities of magnetic materials. An example is the skyrmion--a nano-sized bundle of noncoplanar spins--that by virtue of its nontrivial topology acts as a flux of magnetic field on spin-polarized electrons. Lorentz transmission electron microscopy recently emerged as a powerful tool for direct visualization of skyrmions in noncentrosymmetric helimagnets.

High-pressure hydrothermal crystal growth and multiferroic properties of a perovskite YMnO3.

Orthorhombic perovskites RMnO(3) are representative of spin-driven ferroelectrics. When the radius of the rare-earth ion R is smaller than that of Dy, for instance in YMnO(3), the orthorhombic phase becomes metastable at ambient pressure, which impedes the crystal growth; thus, the detailed magnetic and multiferroic properties of the metastable phase have not been characterized. In this work, we successfully obtained single crystals of orthorhombic YMnO(3) using quasi-hydrothermal conditions under a high pressure of 5.

Above-room-temperature ferroelectricity in a single-component molecular crystal.

Ferroelectrics are electro-active materials that can store and switch their polarity (ferroelectricity), sense temperature changes (pyroelectricity), interchange electric and mechanical functions (piezoelectricity), and manipulate light (through optical nonlinearities and the electro-optic effect): all of these functions have practical applications. Topological switching of pi-conjugation in organic molecules, such as the keto-enol transformation, has long been anticipated as a means of realizing these phenomena in molecular assemblies and crystals. Croconic acid, an ingredient of black dyes, was recently found to have a hydrogen-bonded polar structure in a crystalline state.

Composite domain walls in a multiferroic perovskite ferrite.

Controlling ferromagnetism by an external electric field has been a great challenge in materials physics, for example towards the development of low-power-consumption spintronics devices. To achieve an efficient mutual control of electricity and magnetism, the use of multiferroics--materials that show both ferroelectric and ferromagnetic/antiferromagnetic order--is one of the most promising approaches. Here, we show that GdFeO(3), one of the most orthodox perovskite oxides, is not only a weak ferromagnet but also possesses a ferroelectric ground state, in which the ferroelectric polarization is generated by the striction through the exchange interaction between the Gd and Fe spins.

Proton dynamics and room-temperature ferroelectricity in anilate salts with a proton sponge.

Ferroelectricity as well as characteristic proton-transfer dynamics are achieved by combining a 2,3,5,6-tetra(2'-pyridyl)pyrazine (TPPZ) molecule with anilic acids (H2xa). Dielectric measurements revealed phase transitions at T(c) = 334 and 172 K for bromanilate (Hba(-)) and chloranilate (Hca(-)) salts, respectively. The room-temperature ferroelectricity of the (H2-TPPZ)(Hba)2 crystal is evidenced by the slow polarization reversal with modest pyroelectricity.

Rotation of orbital stripes and the consequent charge-polarized state in bilayer manganites.

Nanoscale self-organization of electrons is ubiquitously observed in correlated electron systems such as complex oxides of transition metals. The phenomenon of charge ordering (CO) or the formation of charge stripes, as observed for layered-structure cuprates and nickelates, is one such example. Among them, CO in manganites is closely tied to the orbital degree of freedom of 3d electrons, leading to staggered orbital ordering or the formation of orbital stripes in the layered structure.