Generalizing the ENO-DB2<Emphasis Type="Italic">p</Emphasis> transform using the inverse wavelet transform

The essentially non-oscillatory (ENO)-wavelet transform developed by Chan and Zhou (SIAM J. Numer. Anal. 40(4), 1369–1404, 2002) is based on a combination of the Daubechies-2p wavelet transform and the ENO technique. It uses extrapolation methods to compute the scaling coefficients without differencing function values across jumps and obtains a multiresolution framework (essentially) free of edge artifacts. In this work, we present a different way to compute the ENO-DB2p wavelet transform of Chan and Zhou which allows us to simplify the process and easily generalize it to other families of orthonormal wavelets.     

Gelation Kinetics and Mechanical Properties of Thiol-Tetrazole Methylsulfone Hydrogels Designed for Cell Encapsulation

Hydrogel precursors that crosslink within minutes are essential for the development of cell encapsulation matrices and their implementation in automated systems. Such timescales allow sufficient mixing of cells and hydrogel precursors under low shear forces and the achievement of homogeneous networks and cell distributions in the 3D cell culture. The previous work showed that the thiol-tetrazole methylsulfone (TzMS) reaction crosslinks star-poly(ethylene glycol) (PEG) hydrogels within minutes at around physiological pH and can be accelerated or slowed down with small pH changes. The resulting hydrogels are cytocompatible and stable in cell culture conditions. Here, the gelation kinetics and mechanical properties of PEG-based hydrogels formed by thiol-TzMS crosslinking as a function of buffer, crosslinker structure and degree of TzMS functionality are reported. Crosslinkers of different architecture, length and chemical nature (PEG versus peptide) are tested, and degree of TzMS functionality is modified by inclusion of RGD cell-adhesive ligand, all at concentration ranges typically used in cell culture. These studies corroborate that thiol/PEG-4TzMS hydrogels show gelation times and stiffnesses that are suitable for 3D cell encapsulation and tunable through changes in hydrogel composition. The results of this study guide formulation of encapsulating hydrogels for manual and automated 3D cell culture.     

Correcting the microscopic coefficient of surface tension of associated liquids

A correction to the association of saturation vapor molecules is introduced into the theory of microscopic surface tension proposed by Sinanoglu. It is determined that the calculated solubility of benzene in water coincides with the one measured using this correction.     

Grating-lens dispersive delay line

For problems of control and compression of pulses in picoseconds time scale a dispersive delay line based on control of spectral phase of radiation in a device consisting of diffraction grating and lenses is proposed and tested.     

Synthesis of (22R, 25R)-3β,26-Dihydroxy-5α-furostan-6-one #

The synthesis of a plant growth promoter furostanol which bears the characteristic functionality of teasterone on rings A and B is described.

     

Adenosine,adenosine monophosphate,and adenosine triphosphate adsorption from aqueous solutions on the surface of multiwall carbon nanotubes

Adenosine, adenosine monophosphate, and adenosine triphosphate adsorption from aqueous solutions on the surface of carbon nanotubes is studied. Adsorption isotherms are plotted and adsorption free energies, as well as areas per molecules of the adsorbates, are calculated at their concentrations in solutions of 0–10⁻³ mol/dm³. It is shown that the monomolecular adsorption is characterized by rather loose packing of adsorbate molecules on the nanotube surface, with the packing density increasing in the presence and upon a rise in the concentration of phosphate groups in adsorbate molecules. In the range of the polymolecular adsorption, at high adsorbate concentrations in solutions (C > (5–6) × 10⁻⁴ mol/dm³), the adsorption decreases in a series adenosine > adenosine monophosphate > adenosine triphosphate, i.e., with an increase in the solubility of the examined compounds in water.     

Crystal structure and thermal behavior of a chromium-piperazinium phosphate

(C₄N₂H₁₂)CrO(H_1.5PO₄)₂·H₂O has been synthesized hydrothermally using piperazine as organic template. Its crystal structure was solved ab initio using synchrotron powder X-ray diffraction data [monoclinic, a = 16.9649(4) Å, b = 9.8609(2) Å, c = 7.14375(14) Å, and β = 94.896(3)°, space group P2₁/a, Z = 4]. 1D structure is composed by isolated infinite anionic chains [CrO(H_1.5PO₄)₂]_n (vertex-sharing {CrO₆} octahedra joined by phosphate moieties). Their 2D plate-like morphology is propitiated by a very strong inter-chain interaction (P–O···H···O–P symmetric hydrogen bonds). KAS isoconversional method was applied to determine the activation energy for both thermal and thermo-oxidative decomposition of (C₄N₂H₁₂)CrO(H_1.5PO₄)₂·H₂O.