Measurement of ultrasound velocity in yolk and blastula of fish embryo in vivo.

An acoustic microscopy method for measuring the velocity of ultrasound in the yolk and blastula of bony fish embryos at early stages of development was proposed. The yolk and blastula were approximated as a sphere and a spherical dome, respectively, consisting of a homogeneous liquid. A theoretical model of ultrasonic wave propagation through a spherical liquid drop located on a solid substrate was developed in the ray approximation.

Natural Phaeosphaeride A Derivatives Overcome Drug Resistance of Tumor Cells and Modulate Signaling Pathways.

In the present study, natural phaeosphaeride A (PPA) derivatives are synthesized. Anti-tumor studies are carried out on the PC3, K562, HCT-116, THP-1, MCF-7, A549, NCI-H929, Jurkat, and RPMI8226 tumor cell lines, and on the human embryonic kidney (HEK293) cell line. All the compounds synthesized turned out to have better efficacy than PPA towards the tumor cell lines listed.

Acetylene in Organic Synthesis: Recent Progress and New Uses.

Recent progress in the leading synthetic applications of acetylene is discussed from the prospect of rapid development and novel opportunities. A diversity of reactions involving the acetylene molecule to carry out vinylation processes, cross-coupling reactions, synthesis of substituted alkynes, preparation of heterocycles and the construction of a number of functionalized molecules with different levels of molecular complexity were recently studied. Of particular importance is the utilization of acetylene in the synthesis of pharmaceutical substances and drugs.

Vinylation of a Secondary Amine Core with Calcium Carbide for Efficient Post-Modification and Access to Polymeric Materials.

We developed a simple and efficient strategy to access -vinyl secondary amines of various naturally occurring materials using readily available solid acetylene reagents (calcium carbide, KF, and KOH). Pyrrole, pyrazole, indoles, carbazoles, and diarylamines were successfully vinylated in good yields. Cross-linked and linear polymers were synthesized from -vinyl carbazoles through free radical and cationic polymerization.

Synthesis of 1,4-dihydrophosphinoline 1-oxides by acid-promoted cyclization of 1-(diphenylphosphoryl)allenes.

1-(Diphenylphosphoryl)alka-1,2-dienes (phosphonoallenes) in Brønsted (super)acids (TfOH, FSO3H, H2SO4) gave the corresponding 1,2-oxaphosphol-3-enium ions, that were studied by means of NMR and DFT calculations. Upon hydrolysis of reaction solution, these cations afforded 3-hydroxyalk-2-en-1-yl-diphenylphosphine oxides (phosphonoallyl alcohols). But in (super)acids the cations were slowly transformed into O-protonated forms of 1-phenyl-1,4-dihydrophosphinoline 1-oxides, which were monitored by NMR.

Synthesis of natural phaeosphaeride A derivatives and an in vitro evaluation of their anti-cancer potential.

Derivatives of phaeosphaeride A (PPA) were synthesised and characterised; then anti-cancer studies were carried out on the A549 cancer cell line. It was found that the acetyl derivative (compound 3) displayed comparable in vitro cytotoxicity to that of PPA (EC50=49±7 μM and EC50=46±5 μM, respectively), while chloroacetyl derivative 6 (EC50=33±7 μM) was found to have better efficacy towards the A549 cancer cell line.

Crystal structure of natural phaeosphaeride A.

The asymmetric unit of the title compound, C15H23NO5, contains two independent mol-ecules. Phaeosphaeride A contains two primary sections, an alkyl chain consisting of five C atoms and a cyclic system consisting of fused five- and six-membered rings with attached substituents. In the crystal, the mol-ecules form layered structures.

Acid-promoted transformations of 1-(diphenylphosphoryl)allenes: synthesis of novel 1,4-dihydrophosphinoline 1-oxides.

1-(Diphenylphosphoryl)alka-1,2-dienes (phosphonoallenes) in Brønsted (super)acids (TfOH, FSO3H, and H2SO4) at -70 to 120 °C for 30 min to 4 h gave, at first, (3-hydroxyalk-1-en-1-yl)diphenylphosphine oxides, as kinetically favorable reaction products, that are further converted into 1-phenyl-1,4-dihydrophosphinoline 1-oxides as thermodynamically stable compounds. The latter compounds are formed from phosphonoallenes under the action of a strong Lewis acid AlCl3 at room temperature for 10-120 min. This is a novel, simple and efficient (short reaction time, high yields) method for synthesis of such 1,4-dihydrophosphinoline 1-oxides.

Pulse-echo NDT of adhesively bonded joints in automotive assemblies.

A new method for the detection of void-disbonds at the interfaces of adhesively bonded joins is considered. Based on a simple plane wave model, the output waveform is presented as a sum of two responses associated with the reflection of the ultrasonic wave at the first metal-adhesive interface and the second metal-adhesive interface, respectively. The strong response produced by the wave reverberating in the first metal sheet is eliminated through comparison between the pulse-echo signal measured at the area under the test and reference waveform recorded for the bare first metal sheet outside of the joint.

Measurements of velocity and attenuation of leaky waves using an ultrasonic array.

A new method of measuring velocity and attenuation of leaky surface waves is presented. A single focused transmitting transducer and linear receiving array in a pitch-catch arrangement are used in the proposed system. The spatial distribution of the acoustic field in the leaky wave is recorded by the array, and the parameters of the leaky wave can be obtained by processing the output waveforms.

[Application of the method of acoustic microscopy for the study of eye tissues].

The paper describes the results of evaluation of potentialities of the application of scanning acoustic microscopy, which is still relatively new and as yet uncommon method of biological research, for the supravital study of animal eye structure in species with different eyeball size. Using the eyes of a goat, quail embryo (in situ) and frog tadpole (in vivo) as the examples, it was shown that non-destructive nature of the method used allows for the study of peculiarities of major morphologic structures in the state that is close to the natural one. Some acoustic images are presented showing eye structural elements along with the results of quantitative characteristic of the cornea, sclera and iris.