Skyrmion Lattice in a Chiral Magnet

Skyrmions represent topologically stable field configurations with particle-like properties. We used neutron scattering to observe the spontaneous formation of a two-dimensional lattice of skyrmion lines, a type of magnetic vortices, in the chiral itinerant-electron magnet MnSi. The skyrmion lattice stabilizes at the border between paramagnetism and long-range helimagnetic order perpendicular to a small applied magnetic field regardless of the direction of the magnetic field relative to the atomic lattice. Our study experimentally establishes magnetic materials lacking inversion symmetry as an arena for new forms of crystalline order composed of topologically stable spin states

Phosphate Adsorption from Aqueous Solutions onto Goethite, Bentonite, and Bentonite-Goethite System

The present paper examines the phosphate adsorption from aqueous solutions onto goethite, bentonite, and bentonite-goethite system. The properties of the materials were studied by X-ray diffraction (XRD), attenuated total reflectance (ATR), and NMR spectra and by the measurement of the specific surface area, the point of zero charge (p.z.c.) and the pore-specific volume. ATR and NMR spectra of bentonite and bentonite-goethite system show peaks which correspond to tetrahedrally and octahedrally coordinated Al. The specific surface area of the system differs according to the appropriate method used, while system's p.z.c. is higher than bentonite and lower than goethite. The pore-specific volume of bentonite-goethite system is higher than that of bentonite or goethite. According to XRD spectrum of bentonite-goethite system, goethite coats the (001) spacing of bentonite while the coating of (010) plane of bentonite is limited. The crystallinity of the system decreases and the negative permanent charge increases. Phosphate adsorption experiments took place at different pH (3.8-9.0) and concentrations (40.3-443.5 mu mol L-1) and constant capacitance model was applied to describe adsorption. A ligand exchange mechanism characterizes the model because the charge is divided among adsorbate and adsorbent. The constant capacitance model describes the adsorption mechanism in all examined pH. This model can be utilized in such systems using the surface protonation-dissociation constant of goethite and showing the exact shape of the adsorption isotherms for different pH values. The produced low-cost bentonite-goethite system presents the highest adsorption of P per kilogram of goethite

Extracellular matrix assembly: a multiscale deconstruction

The biochemical and biophysical properties of the extracellular matrix (ECM) dictate tissue-specific cell behaviour. The molecules that are associated with the ECM of each tissue, including collagens, proteoglycans, laminins and fibronectin, and the manner in which they are assembled determine the structure and the organization of the resultant ECM. The product is a specific ECM signature that is comprised of unique compositional and topographical features that both reflect and facilitate the functional requirements of the tissue

Prolegomena to Forum Bosnae (in lieu of an editorial)

A search for supersymmetry in final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of root s = 7 TeV. The data sample corresponds to an integrated luminosity of 4.98 fb(-1) collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, alpha(T), is used as the main discriminator between events with genuine and misreconstructed missing transverse energy. The search is performed in a signal region that is binned in the scalar sum of the transverse energy of jets and the number of jets identified as originating from a bottom quark. No excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of the constrained minimal supersymmetric extension of the standard model, and also in simplified models, with a special emphasis on compressed spectra and third-generation scenarios