Synthesis of N-Substituted 3-Aminothiazolidin-4-ones Containing Hetaryl Fragments

Condensation of the N-(3,5-dichloropyridyl-2)- and N-(benzothiazolyl-2-thioacetyl)hydrazones of carbonyl compounds with thioglycolic acid gave the 3-(3,5-dichloropyridyl-2)amino- and 3-[N-(benzothiazolyl-2-thioacetyl)amino]-2-R¹-2-R²-thiazolidin-4-ones. Reaction of 1-(benzothiazolyl-2-thioacetyl)-4-R-thiosemicarbazides with chloroacetic acid in the presence of sodium acetate gave the 2-[N-(benzothiazolyl-2-thioacetyl)hydrazono]-3-R-thiazolidin-4-ones. It was found that the N-(benzothiazolyl-2-thioacetyl)hydrazones, both in the solid state and in solution, exist in the form of an equilibrium mixture of the EZ'- and EE'-isomers as a result of hindered rotation around the amide N-CO bond.     

Nonlinear image self-filtering with liquid crystal spatial light modulator

Nonlinear spatial filtering is realized due to the electro-optical effect in spatial light modulators (SLMs). Optical methods with nonlinear filtering are suggested for various optical applications such as optical inspection of photolithography masks, wavefront sensor, etc. A fast optical response of the SLM allows optical inspection with a video (or faster) rate. The optical system proposed is tolerant to the vibrations and temperature variations because of the dynamic properties of the SLM.     

Effect of Acetylacetone on the Residual Content of Formaldehyde in Urea-Formaldehyde Resin

The effect of small additions of acetylacetone and ammonia to urea-formaldehyde resin is considered. The occurring processes, involving the formation of 2,6-dimethyl-3,5-diacetyl-1,4-dihydropyridine and condensation of this compound and acetylacetone with terminal methylol groups of the resin, are discussed.     

On the mechanism of muon spin depolarization in the Spur model for Mu formation

The Mu formation mechanism due to Coulomb interaction of a muon with track electrons is considered. It is shown that taking into account the external electric field must essentially change the spin polarization behavior in liquid helium. The theory developed is consistent with experiments.     

Molecular structure of N,N′-o-phenylene-bis(salicylideneaminato)copper(II) studied by gas-phase electron diffraction and quantum-chemical calculations

The molecular structure of N,N′-o-phenylene-bis(salicylideneaminato)copper(II) (Cu(saloph)) was determined using the combination of gas-phase electron diffraction (GED), mass spectrometry, and quantum-chemical calculations. According to both experimental and theoretical approaches the molecule of Cu(saloph) is planar and possesses C _2v symmetry. Main structural parameters determined by GED experiment are the following (total error is given in a brackets): r _h1(Cu–N) = 1.960(20) Å, r _h1(Cu–O) = 1.913(17) Å, ∠NCuN = 82.7(18)°, ∠OCuO = 91.6(21)°, ∠NCuO = 92.9(9)°. The experimental structural parameters of Cu(saloph) molecules determined by X-ray single crystal analysis and GED experiments were discussed and compared to the theoretical ones.

     

Mass spectrometric study of the vaporization of N,N′-<Emphasis Type="Italic">o</Emphasis>-phenylene-bis(salicylideniminate) nickel(II), copper(II), and zinc(II) and N,N′-ethylene-bis(salicylaldiminate) zinc(II) complexes

The thermodynamics of vaporization of Ni(saloph), Cu(saloph), Zn(saloph), and Zn(salen) complexes are studied by Knudsen effusion method with mass spectrometric control of the vapor composition. It is noted that in the mass spectra of Zn(saloph) and Zn(salen), there are low-intensity peaks corresponding to ions of dimer. The effect of the nature of a metal and a ligand on the behavior of fragmentation of the complexes during their ionization with electrons is discussed. The enthalpies of sublimation, ΔH _s ^○ (T), are calculated by second law of thermodynamics: Ni(saloph) (502–578 K), 163 ± 1 kJ/mol; Cu(saloph) (475–550 K), 162 ± 1 kJ/mol; Zn(saloph) (571–637 K), 176 ± 4 kJ/mol; Zn(salen) (568–634 K), 169 ± 2 kJ/mol.     

AFM study of the extracellular connective tissue matrix in patients with pelvic organ prolapse

The method of atomic force microscopy (AFM) is used for the first time for morphological investigation of pathological changes in the extracellular matrix of skin connective tissue upon the prolapse of pelvic organs (common disorder among women). Skin samples of patients with clinically proven pelvic-organ prolapse and of patients that do not have any connective tissue related disease (control group) are investigated via AFM. The AFM study reveals that the extracellular matrix of the skin connective tissues from patients with pelvic-organ prolapse diverges from the normal in various organization levels including both micro- and nanotexture (packing of collagen fibers and fibrils, respectively). The results of AFM study of the normal and pathologically changed skin connective tissues are in good agreement with the data of clinical morphological analysis, which indicates the potential of AFM as an independent diagnostic tool.     

Suppression of Chaotic Generation Caused by the External Optical Feedback in a Laser Diode

It is shown by computer simulation and in experiments that chaotic generation caused by the external optical feedback in a laser diode can be suppressed by means of a delayed optoelectronic feedback controlled by the injection current. The suppression of chaotic generation is realized for an AlGaAs/GaAs laser of the quantum wall structure. In the presence of the external optical feedback provided by the mirror placed at a distance of 1~mm the noise of optical intensity is of the oder of 10 W, the single mode dominates in the spectrum, and its spectral width exceeds 600 MHz. The optoelectronic feedback controlled by the injection current reduces the noise by several times and narrows the generation line width down to 80 MHz.