Motion picture study of the temporal and geometric parameters of ethanol fixation of an isolated neuron

The work has employed a combination of microscopic observation, filming and computer processing of the data obtained. The proper time, rate and latent period of fixation with ethanol of different concentration were analyzed in the isolated surviving neuron. The temporal parameters of fixation were shown to depend on the size of the neuron and the concentration of the fixator. The authors describe the regularities and distinctions in changes of large and small diameters as well as the volumes in vegetative neurons of different size in frog. An attempt has been made to consider the fixation not only as a momentary action but also as a prolonged-in-time complex morphological process.     

Stereotaxic surgery in the hyperkinetic form of infantile cerebral palsy

The results of 67 stereotaxic operations performed in 60 patients for the hyperkinetic form of infantile cerebral paralysis are presented. The efficacy of dentatotomy is compared with that of thalamotomy. Thalamotomy is most effective in patients with hemiatetosis and choreoatetoid hyperkinesis. Dentatotomy resulted not only in a reduction of hyperkinesis, but also in a considerable alleviation of muscle spasticity. The destruction of the lateral part of nuclels dentatus caused predominantly a reduction of the muscle tone and of involuntary movements of the lower extremities, and--to a lesser degree--of the upper as well. The destruction of the medial part of the nucleus dentatus resulted in a clear reduction of muscle dystony in the trunk.     

Influence of multiwalled carbon nanotubes on the processing behavior of epoxy powder compositions and on the mechanical properties of their fiber reinforced composites

This study reports the preparation of advanced carbon fiber composites with a nanocomposite matrix prepared by dispersing multiwall carbon nanotubes (CNTs) in a powder type epoxy oligomer with two different processing techniques (1) master batch dilution technique and (2) direct mixing (with the help of twin‐screw extruder in both cases). The master batch technique shows a better efficiency for the dispersion of the CNTs aggregates. The rheological results demonstrate that the incorporation of the CNTs into the epoxy oligomer leads, as expected, to a marked increase in the viscosity and of the presence of a yield stress point that also depends on the processing technique adopted. Carbon fiber (CFRP) and glass fiber (GFRP) composite materials were produced by electrostatic spraying of the epoxy matrix formulations on the carbon and glass fabric, respectively, followed by calendering and mold pressing. The mechanical properties of the obtained epoxy/CNT‐matrix composite materials, such as interlaminar fracture toughness, flexural strength, shear storage and loss moduli are discussed in terms of the processing techniques and fabric material. The incorporation of 1 wt% CNTs in the epoxy matrix results in a relevant increase of the fracture toughness, flexural strength and modulus of both CFRP and GFRP. POLYM. COMPOS., 37:2377–2383, 2016. © 2015 Society of Plastics Engineers     

Cationic Surfactants as Disinfectants against SARS-CoV-2

The virucidal activity of a series of cationic surfactants differing in the length and number of hydrophobic tails (at the same hydrophilic head) and the structure of the hydrophilic head (at the same length of the hydrophobic n-alkyl tail) was compared. It was shown that an increase in the length and number of hydrophobic tails, as well as the presence of a benzene ring in the surfactant molecule, enhance the virucidal activity of the surfactant against SARS-CoV-2. This may be due to the more pronounced ability of such surfactants to penetrate and destroy the phospholipid membrane of the virus. Among the cationic surfactants studied, didodecyldimethylammonium bromide was shown to be the most efficient as a disinfectant, its 50% effective concentration (EC50) being equal to 0.016 mM. Two surfactants (didodecyldimethylammonium bromide and benzalkonium chloride) can deactivate SARS-CoV-2 in as little as 5 s.