Synthesis of (-)-Cannabimovone and Structural Reassignment of Anhydrocannabimovone through Gold(I)-Catalyzed Cycloisomerization

The first total synthesis of cannabimovone from Cannabis sativa and anhydrocannabimovone was achieved by means of a highly stereoselective gold(I)-catalyzed cycloisomerization. The results led to reassignment of the structure of anhydrocannabimovone

The effect of crystallization conditions on tantalum distribution in molybdenum and tungsten during electron beam zone melting

The distribution of tantalum in molybdenum and tungsten single crystals during electron beam floating zone melting under different crystallization conditions was investigated. The performed line chemical analysis of specimens proved creation of tantalum micro segregation, so-called growth striations, which showed themselves on concentration profiles as periodically alternating areas with increased and decreased concentrations of tantalum. The existence of these chemical inhomogeneities suggests that stationary conditions of the crystal growth were disturbed during the zone melting, i.e. fluctuations of microscopic rate of growth occurred due to convection in the melt. The determined effective distribution coefficients of tantalum in molybdenum and tungsten approach to calculated theoretical values of the equilibrium distribution coefficient

A theoretical study of the structural phases of Group 5B - 6B metals and their transport properties

In order to predict the stable and metastable phases of the bcc metals in the block of the Periodic Table defined by groups 5B to 6B and periods 4 to 6, as well as the structure dependence of their transport properties, we have performed full potential computations of the total energies per unit cell as a function of the c/a ratio at constant experimental volume. In all cases, a metastable body centered tetragonal (bct) phase was predicted from the calculations. The total energy differences between the calculated stable and metastable phases ranged from 0.09 eV/cell (vanadium) to 0.39 eV/cell (tungsten). The trends in resistivity as a function of structure and atomic number are discussed in terms of a model of electron transport in metals. Theoretical calculations of the electrical resistivity and other transport properties show that bct phases derived from group 5B elements are more conductive than the corresponding bcc phases, while bct phases formed from group 6B elements are less conductive than the corresponding bcc phases. Special attention is paid to the phases of tantalum where we show that the frequently observed beta phase is not a simple tetragonal distortion of bcc tantalum

The action of bacterial serine proteases on cultured animal cell lines

Our research is direct to determination of serine proteases (subtilisin and glutamyl endopeptidase) action at establish cell lines. We determined that the serine proteases of bacillus are capable cytotoxic action at establish cell lines of animals. The cell lines are differentiating by sensitivity to proteins. The cell lines LEK and NGUK were more sensitive to subtilisin, and line Vero - glutamyl endopeptidase

Structural and magnetic properties of the (001) and (111) surfaces of the half-metal NiMnSb

Using the full potential linearised augmented planewave method we study the electronic and magnetic properties of the (001) and (111) surfaces of the half-metallic Heusler alloy NiMnSb from first-principles. We take into account all possible surface terminations including relaxations of these surfaces. Special attention is paid to the spin-polarization at the Fermi level which governs the spin-injection from such a metal into a semiconductor. In general, these surfaces lose the half-metallic character of the bulk NiMnSb, but for the (111) surfaces this loss is more pronounced. Although structural optimization does not change these features qualitatively, specifically for the (111) surfaces relaxations can compensate much of the spin-polarization at the Fermi surface that has been lost upon formation of the surface.Comment: 18 pages, 8 figure

Optical and magneto-optical properties of ferromagnetic full-Heusler films: experiments and first-principles calculations

We report a joint theoretical and experimental study focused on understanding the optical and magneto-optical properties of Co-based full-Heusler compounds. We show that magneto-optical spectra calculated within ab-initio density functional theory are able to uniquely identify the features of the experimental spectra in terms of spin resolved electronic transitions. As expected for 3d-based magnets, we find that the largest Kerr rotation for these alloys is of the order of 0.3o in polar geometry. In addition, we demonstrate that (i) multilayered structures have to be carefully handled in the theoretical calculations in order to improve the agreement with experiments, and (ii) combined theoretical and experimental investigations constitute a powerful approach to designing new materials for magneto-optical and spin-related applicationsComment: 20 pages, including 6 figures and 1 table. 40 refs. To be published in Phys. Rev.

What does authenticity and neolocalism mean to craft brewery visitors? Insights from the Midwest and the Great Plains

The global rise in craft beer produced by small and independent brewers has precipitated the development of craft beer tourism. Two concepts, neolocalism and authenticity, have emerged as critical for understanding the craft beer experience. However, established research on these topics, particularly from the consumer perspective, are still quite limited. To fulfill this gap, this study conducted 46 semi-structured in-depth interviews and observations in breweries located in the Midwest and Great Plains regions to explore the meaning of authenticity and neolocalism to craft brewery visitors. Analysis resulted in nine major themes, including 1) beer itself, 2) beer production, 3) brewery accessibility, 4) brewery design, 5) vibes of brewery, 6) brewery services, 7) brewery place identity, 8) community engagement, and 9) local ownership. These findings enhance our conceptual understanding of neolocalism and authenticity from the craft beer visitors\u27 perspective. Potential implications and an agenda for future research are discussed

Quantum Equivalence of Massive Antisymmetric Tensor Field Models in Curved Space

We study the effective actions for massive rank-2 and rank-3 antisymmetric tensor field models in curved space-time. These models are classically equivalent to massive vector field and massive scalar field with minimal coupling to gravity respectively. We prove that effective action for massive rank-2 antisymmetric tensor field is exactly equal to one for massive vector field and effective action for massive rank-3 antisymmetric tensor field is exactly equal to one for massive scalar field. Prove is based on an identity for mass-dependent zeta-functions associated with Laplacians acting on $p$-forms.Comment: 8 pages, REVTeX fil

Surface Properties of the Half- and Full-Heusler Alloys

Using a full-potential \textit{ab-initio} technique I study the electronic and magnetic properties of the (001) surfaces of the half-Heusler alloys, NiMnSb, CoMnSb and PtMnSb and of the full-Heusler alloys Co$_2$MnGe, Co$_2$MnSi and Co$_2$CrAl. The MnSb terminated surfaces of the half-Heusler compounds present properties similar to the bulk compounds and, although the half-metallicity is lost, an important spin-polarisation at the Fermi level. In contrast to this the Ni terminated surface shows an almost zero net spin-polarisation. While the bulk Co$_2$MnGe and Co$_2$MnSi are almost half-ferromagnetic, their surfaces lose the half-metallic character and the net spin-polarisation at the Fermi level is close to zero. Contrary to these compounds the CrAl terminated (001) surface of Co$_2$CrAl shows a spin polarisation of about 84%.Comment: 14 pages, 6 figure

The soft and the hard pomerons in hadron elastic scattering at small t

We consider simple-pole descriptions of soft elastic scattering for pp, pbar p, pi+ p, pi- p, K+ p and K- p. We work at t and s small enough for rescatterings to be neglected, and allow for the presence of a hard pomeron. After building and discussing an exhaustive dataset, we show that simple poles provide an excellent description of the data in the region - 0.5 GeV^2 < t < -0.1 GeV^2, 6 GeV<sqrt(s)< 63 GeV. We show that new form factors have to be used, and get information on the trajectories of the soft and hard pomerons.Comment: 27 pages, 9 figures, LaTeX. A few typos fixed, and references correcte