Crystal Structure of catena-[(Tetrakis-μ2-acetato-μ2-4,4'-bipyridine) dicopper(Ⅱ)] Acetonitrile Solvate

The title compound,[Cu2(CH3COO)4(C8H10N2)]n·nCH3CN1 (C8H10N2,4,4'-bipy = 4,4'-bipyridine),has been solvothermally synthesized in CH3CN and characterized by X-ray diffraction.The crystal is of monoclinic,space group Cc with a = 22.626(6),b = 14.012(4),c =15.106(4) (A),β = 107.610(3)°,V = 4565(2) (A)3,C20H23Cu2N3O8,Mr = 560.49,Z = 8,Dc = 1.631 g/cm3,μ = 1.914 mm-1,Flack parameter = 0.48(1),F(000) = 2288,R = 0.042 and wR = 0.)98 for 8887 observed reflections (I ＞ 2σ(I)).It consists of nearly linear one-dimensional chains [Cu2(CH3COO)4(C8H10N2)]n derived from paddle-wheel [Cu2(CH3COO)4] unit linked by 4,4'-bipy,and CH3CN as guest molecule regularly decorates between the chains.     

An approach to analysis of single pier based on the variational principle in multi-layered soil

In this study, a variational approach to the settlement analysis of an axially loaded pier embedded in a multi-layered soil profile is presented. In this method, the soil profile and the embedded pier are divided into a number of sub-layers according to the actual number of soil layers observed in the field. The displacement shape function of each soil layer is given as a product of an exponential equation along the pier depth and the Bessel's solution in the radial direction. The displacement relationship among the layers can be derived through the transformation matrices. One of the major features of this method is that the total number of pier elements is the same as that of soil sub-layers. All the field components, such as the displacement, stress, and strain in the soil, can be calculated by closed-form solutions except that the only unknown variable is the value β which can be determined by iteration techniques. Comparisons were made with the results of finite element analysis and the field observation in pile-loaded tests.     

Diastereoselective synthesis of trans-trifluoromethyl-β-lactams and α-alkyl-β-trifluoromethyl-β-amino esters

The diastereoselective synthesis of β-lactams was examined from N-tosyl-1-chloro-2,2,2-trifluoroethylamine 3 and various nonactivated aliphatic acid chlorides in the presence of a Brønsted base. The mild reaction conditions allowed to get trifluoromethyl-β-lactams in good yields with high trans-diastereo selectivity. In addition, we also demonstrated that ring-opening of β-lactams easily provided α-alkyl-β-trifluoromethyl-β-amino esters.     

Study of As―Se―Te glasses by neutron-, X-ray diffraction and optical spectroscopic methods

The atomic structures of amorphous As₄₀Se_(60?x)Te_x (x = 10 and 15) and As₄₀Se₆₀ glasses have been investigated by neutron and high energy X-ray diffraction methods. The two datasets were modeled simultaneously by reverse Monte Carlo (RMC) simulation technique. The RMC simulations revealed a glassy network built-up from As(Se, Te)₃ pyramids in which Te atoms substitute Se atoms. The As―Se correlation function shows a strong and sharp first peak at 2.4 Å and two broad and much less intense peaks at 3.7 and 5.6 Å, related to 1st, 2nd and 3rd neighbor distances of the As―Se bonds, respectively. They are an evidence for existence of short and medium ordering in the studied glasses. The similarity of Θ_Te―As―Te and Θ_Se―As―Se bond distributions suggests that Te atoms have a similar role in the structure formation as Se atoms. The FTIR spectra analysis revealed impurity bonds of Se―H, As―O, Se―O, and Te―O in the glasses which contributed to enhanced absorption in visible spectral range. From the ellipsometric data analysis the optical constants and the energetic parameters of the studied glasses were established. The compositional variation of these parameters is explained in terms of chemical bonds formation and change in the density of charged defects.     

In situ ellipsometric study of surface immobilization of flagellar filaments

Protein filaments composed of thousands of subunits are promising candidates as sensing elements in biosensors. In this work in situ spectroscopic ellipsometry is applied to monitor the surface immobilization of flagellar filaments. This study is the first step towards the development of layers of filamentous receptors for sensor applications.Surface activation is performed using silanization and a subsequent glutaraldehyde crosslinking. Structure of the flagellar filament layers immobilized on activated and non-activated Si wafer substrates is determined using a two-layer effective medium model that accounted for the vertical density distribution of flagellar filaments with lengths of 300-1500 nm bound to the surface. The formation of the first interface layer can be explained by the multipoint covalent attachment of the filaments, while the second layer is mainly composed of tail pinned filaments floating upwards with the free parts. As confirmed by atomic force microscopy, covalent immobilization resulted in an increased surface density compared to absorption.     

Optical,structural, and photocatalytic properties of the nanosized titanium dioxide films deposited in magnetron discharge plasma

The conditions of the optimum and controlled deposition of titanium dioxide nanolayers in the cylindrical gas discharge plasma of a magnetron having a unique design are found and described. The examination of the grown films by Raman spectroscopy is used to determine the conditions of deposition of the amorphous and polycrystalline phases of titanium dioxide. The films deposited on a cold substrate are amorphous, and the films deposited on a heated substrate consist of polycrystalline anatase. The evolution of the spectral lines of argon, oxygen, and titanium and the discharge voltage drop are studied as a function of the magnitude and the direction of changing the discharge current. The results obtained are shown to be applied for contactless optical monitoring. The refractive index of the films n is shown to have a nonlinear dependence on the layer thickness, and the layers that have a high photocatalytic activity and can be used to remove inorganic pollutants from the environment are shown to be grown.     

Polymers for the Cell‐Specific Immobilisation of Megakaryocytic Cell Lines

Primary human megakaryocytes, the precursor cells of platelets, are difficult to collect and cultivate. Polymers that enrich these cells without affecting their regulation or function are of interest for basic research as well as for cord blood transplantation purposes since co‐transplantation of enriched megakaryocyte concentrates increase the success of stem cell therapy. Herein, polymer microarrays were used for the discovery of substrates for MEG‐01 cells, with five polymers identified which selectively bound cells of the megakaryocytic lineage. Flow cytometry and miRNA profiling revealed that immobilisation had only a minor effect on the cellular maturation status, making the identified substrates potential candidates for concentrating megakaryocytes from patients prior to transplantation.

     

Rheo-NMR in food science—Recent opportunities

For over 25 years, nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) techniques have been used to study materials under mechanical deformation. Collectively, these methods are referred to as Rheo-NMR. In many cases, it provides spatially and temporally resolved maps of NMR spectra, intrinsic NMR parameters (such as relaxation times), or motion (such as diffusion or flow). Therefore, Rheo-NMR is complementary to conventional rheological measurements. This review will briefly summarize current capabilities and limitations of Rheo-NMR in the context of material science and food science in particular. It will report on recent advances such as the incorporation of torque sensors or the implementation of large amplitude oscillatory shear and point out future opportunities for Rheo-NMR in food science.     

Recent Fourier and Laplace perspectives for multidimensional NMR in porous media

Multidimensional NMR techniques used in the measurement of molecular displacements, whether by diffusion or advection, and in the measurement of nuclear spin relaxation times are categorised. Fourier-Fourier, Fourier-Laplace and Laplace-Laplace methods are identified, and recent developments discussed in terms of the separation, correlation and exchange perspective of multidimensional NMR spectroscopy.