A short synthesis of protected 3-deoxy-d-arabino-2-heptulosonates (DAH) from shikimic acid based on silyl group migration

The reaction of (2S,3S,4R)-2,3,4,7-tetrahydroxy-6-oxoheptanals with lower alcohols produced protected 3-deoxy-d-arabino-2-heptulosonates. The key transformation is based on an 1,4-O–O silyl group migration, followed by 6-exo-trig cyclisation to give the final pyranose.     

Dynamic acoustothermography

Two- and three-dimensional dynamic acoustothermography is carried out in model experiments. The temperature of the model plasticine objects was determined from the measurements of their thermal acoustic radiation in the course of their heating and cooling. The measurements were performed with the use of a planar array of 14 acoustothermometers and two planar arrays perpendicular to each other with 7 acoustothermometers in each of them. The results of measurements were used to plot a dynamic map of the temperature of acoustic brightness and to reconstruct the dynamics of variations in the parameters of the temperature distribution: the spatial coordinates of the heated region, its characteristic size and, maximal temperature. The duration of one measurement cycle was 10 s, the error in determining the position of the center and the size of the heated region did not exceed 1 mm, and the accuracy of the temperature’s calculation was about 1 degree. The results of the study may be used for controlling the temperature in the course of medical procedures that include heating of internal tissues in human patients.     

Acousto-thermometric recovery of the deep temperature profile using heat conduction equations

In a model experiment using the acousto-thermographic method, deep temperature profiles varying in time are recovered. In the recovery algorithm, we used a priori information in the form of a requirement that the calculated temperature must satisfy the heat conduction equation. The problem is reduced to determining two parameters: the initial temperature and the temperature conductivity coefficient of the object under consideration (the plasticine band). During the experiment, there was independent inspection using electronic thermometers mounted inside the plasticine. The error in the temperature conductivity coefficient was about 17% and the error in initial temperature determination was less than one degree. Such recovery results allow application of this approach to solving a number of medical problems. It is experimentally proved that acoustic irregularities influence the acousto-thermometric results as well. It is shown that in the chosen scheme of experiment (which corresponds to measurements of human muscle tissue), this influence can be neglected.     

Using size exclusion chromatography-RPLC and RPLC-CIEF as two-dimensional separation strategies for protein profiling

Bottom-up proteomics (analyzing peptides that result from protein digestion) has demonstrated capability for broad proteome coverage and good throughput. However, due to incomplete sequence coverage, this approach is not ideally suited to the study of modified proteins. The modification complement of a protein can best be elucidated by analyzing the intact protein. 2-DE, typically coupled with the analysis of peptides that result from in-gel digestion, is the most frequently applied protein separation technique in MS-based proteomics. As an alternative, numerous column-based liquid phase techniques, which are generally more amenable to automation, are being investigated. In this work, the combination of size-exclusion chromatography (SEC) fractionation with RPLC-Fourier-transform ion cyclotron resonance (FTICR)-MS is compared with the combination of RPLC fractionation with CIEF-FTICR-MS for the analysis of the Shewanella oneidensis proteome. SEC-RPLC-FTICR-MS allowed the detection of 297 proteins, as opposed to 166 using RPLC-CIEF-FTICR-MS, indicating that approaches based on LC-MS provide better coverage. However, there were significant differences in the sets of proteins detected and both approaches provide a basis for accurately quantifying changes in protein and modified protein abundances.     

Electroacoustic waves confined by a moving domain wall superlattice of a ferroelectric crystal

The dispersion properties of electroacoustic wave modes confined by a superlattice of uniformly moving 180° domain walls in a tetragonal ferroelectric crystal are considered. It is shown that the manifold of partial electroacoustic interfacial waves in the lattice is restricted to the first allowed band, the configuration of which in the plane of spectral variables can significantly vary under the action of the moving domain walls.     

Interaction of a shear wave with a moving domain wall in a ferromagnetic crystal with allowance for the external magnetic field

The boundary-value problem of the magnetoelastic wave interaction with a moving domain wall in a ferromagnetic crystal is solved in the nonexchange magnetostatic approximation with allowance for the external magnetic field. It is shown that the difference introduced by magnetic field between the ferromagnetic resonance frequencies of the domains does not cause any noticeably departure of the refraction characteristics of reflected and transmitted waves from those observed at zero frequency mismatch. By contrast, the magnitudes of the transmission and reflection coefficients strongly depend on the external magnetic field and on the mobility of the domain wall. The dependence of the magnitude of the reflection coefficient on the external magnetic field at a fixed angle of shear wave incidence is found to possess two ferromagnetic resonance peaks. The positions and heights of the peaks may vary depending on the mobility of the domain wall.