Reactive-oxygen-species-mediated mechanism for photoinduced antibacterial and antiviral activities of Ag3PO4.

Cubic-shaped Ag3PO4 crystals with a mean size of 1 µm were synthesized by a precipitation method from a mixed solution of AgNO3, Na2HPO4, and triethanolamine. The antibacterial activities against Escherichia coli, Listeria innocua, and Pseudomonas syringae DC3000 in both the absence and presence of Ag3PO4 under dark conditions and in the presence of Ag3PO4 under red-light (625 nm) and blue-light (460 nm) irradiation were examined. The concentrations of reactive oxygen species (ROS) were also measured in the antibacterial action of the Ag3PO4 against Escherichia coli. The photoinduced enhancement of the Ag3PO4 antibacterial activity under blue-light irradiation is explained by the formation of ROS during the antibacterial action of the Ag3PO4. Moreover, the antiviral activity of Ag3PO4 against amphotropic 10A1 murine leukemia virus enhanced under blue-light irradiation via ROS production. These results provide an insight into extended bio-applications of Ag3PO4.

Confined condensation synthesis and magnetic properties of layered copper hydroxide frameworks.

We present a confined condensation technique for the fabrication of layered copper hydroxide frameworks from lamellar copper-organic assemblies with long alkyl chains through the selective introduction of hydroxo bridging ligands. The complete transformations of two different lamellar copper-organic assemblies, Cu(C12H25SO4)2·4H2O (Cu-DS) and Cu2(C11H23CO2)4·2H2O (Cu-lau), into the corresponding layered copper hydroxide frameworks, Cu2(OH)3(C12H25SO4) (Cu-OH-DS) and Cu2(OH)1.8(C11H23CO2)2.2 (Cu-OH-lau), were achieved via confined condensation. The magnetic properties of both lamellar copper-organic assemblies, Cu-DS and Cu-lau, and both layered copper hydroxide frameworks, Cu-OH-DS and Cu-OH-lau, were investigated. It was found that drastic changes in the magnetic properties arise as a result of the confined condensation process.

Dual Effect of the Cubic Ag3PO4 Crystal on Pseudomonas syringae Growth and Plant Immunity.

We previously found that the antibacterial activity of silver phosphate crystals on Escherichia coli depends on their structure. We here show that the cubic form of silver phosphate crystal (SPC) can also be applied to inhibit the growth of a plant-pathogenic Pseudomonas syringae bacterium. SPC pretreatment resulted in reduced in planta multiplication of P. syringae. Induced expression of a plant defense marker gene PR1 by SPC alone is suggestive of its additional plant immunity-stimulating activity. Since SPC can simultaneously inhibit P. syringae growth and induce plant defense responses, it might be used as a more effective plant disease-controlling agent.

Copper Ion from Cu2O Crystal Induces AMPK-Mediated Autophagy via Superoxide in Endothelial Cells.

Copper is an essential element required for a variety of functions exerted by cuproproteins. An alteration of the copper level is associated with multiple pathological conditions including chronic ischemia, atherosclerosis and cancers. Therefore, copper homeostasis, maintained by a combination of two copper ions (Cu(+) and Cu(2+)), is critical for health. However, less is known about which of the two copper ions is more toxic or functional in endothelial cells. Cubic-shaped Cu2O and CuO crystals were prepared to test the role of the two different ions, Cu(+) and Cu(2+), respectively. The Cu2O crystal was found to have an effect on cell death in endothelial cells whereas CuO had no effect. The Cu2O crystals appeared to induce p62 degradation, LC3 processing and an elevation of LC3 puncta, important processes for autophagy, but had no effect on apoptosis and necrosis. Cu2O crystals promote endothelial cell death via autophagy, elevate the level of reactive oxygen species such as superoxide and nitric oxide, and subsequently activate AMP-activated protein kinase (AMPK) through superoxide rather than nitric oxide. Consistently, the AMPK inhibitor Compound C was found to inhibit Cu2O-induced AMPK activation, p62 degradation, and LC3 processing. This study provides insight on the pathophysiologic function of Cu(+) ions in the vascular system, where Cu(+) induces autophagy while Cu(2+) has no detected effect.

Lipid-binding properties of TRIM72.

TRIM72 is known to play a critical role in skeletal muscle membrane repair. To better understand the molecular mechanisms of this protein, we carried out an in vitro binding study with TRIM72. Our study proved that TRIM72 binds various lipids with dissociation constants (K(d)) ranging from 88.2 ± 9.9 nM to 550.5 ± 134.5 nM. In addition, the intrinsic fluorescence of TRIM72 exponentially decreased when the protein was diluted with stirring. The time-resolved fluorescence decay occurred in a concentration- independent manner. The fluorescence-decayed TRIM72 remained in its secondary structure, but its binding properties were significantly reduced. The dissociation constants (K(d)) of fluorescence-decayed TRIM72 for palmitate and stearate were 159.1 ± 39.9 nM and 355.4 ± 106.0 nM, respectively. This study suggests that TRIM72 can be dynamically converted by various stimuli. The results of this study also provide insight into the role of TRIM72 in the repair of sarcolemma damage.

Canted antiferromagnetism and spin reorientation transition in layered inorganic-organic perovskite (C6H5CH2CH2NH3)2MnCl4.

This work presents the synthesis, structure determination and magnetic properties of a new complex, phenethylammonium tetrachloromanganate(II), (C(6)H(5)CH(2)CH(2)NH(3))(2)MnCl(4) (Mn-PEA). Single crystals of Mn-PEA were obtained from methanol solution using the solvent-evaporation method at room temperature. The crystal structure of Mn-PEA was determined by single-crystal X-ray diffraction (orthorhombic, space group Pbca, a = 7.2075(9), b = 7.3012(14), c = 39.413(6) Å and Z = 4). The structure consisted of an extended [MnCl(4)](2-) network and two phenethylammonium cations to form a two-dimensional halide perovskite structure. Temperature-dependent magnetization measurements indicated that Mn-PEA acted as a weak ferromagnet below T(C) = 44.3 K due to spin canting. Below T(C), the magnetic behavior differed significantly from the behavior commonly observed among weak ferromagnets. The susceptibility depended strongly on the crystal orientation, the external magnetic field strength, and the magnetic history. The isothermal magnetization for two orientations revealed a ferromagnetic moment with a spin-canting angle of 0.04° and a spin-flop transitions with H(sf) = 3.5 T. The weak ferromagnetism, which manifested as spontaneous magnetization and magnetic hysteresis near a field strength of zero, was driven by interplay between the easy axis and the antisymmetric Dzyaloshinsky-Moriya (DM) interaction, leading to directional dependent magnetic behavior.

Inorganic-organic chain assemblies as lamellar nanoreactors for growing one-dimensional Cu(OH)2 and CuO nanostructures.

One-dimensional Cu(OH)(2) or CuO nanostructures were fabricated using inorganic-organic chain assemblies, Cu(C(n)H(2n+1)X)(2)·nH(2)O (X = CO(2), SO(4)) as a lamellar nanoreactor, along with NaOH treatment. The shapes and aspect ratios of the Cu(OH)(2) or CuO nanostructures could be varied by adjusting the hydrophobicity of the lamellar nanoreactors.

Bis(2-phenyl-ethyl-ammonium) tetra-chloridocobaltate(II).

Crystals of the title compound, (C(6)H(5)CH(2)CH(2)NH(3))(2)[CoCl(4)], were grown by the solvent-evaporation method. This inorganic-organic hybrid compound exhibits a layered structure in which isolated CoCl(4) inorganic layers alternate with bilayers of phenylethylammonium cations. Although the inorganic anion is zero-dimensional, the layered structure is stabilized via N-H⋯Cl hydrogen bonds. The CoCl(4) tetra-hedra connect to the cations through N-H⋯Cl hydrogen bonds, building a two-dimensional network extending parallel to (010).