Six catalytic activities and cytotoxicity of immunoglobulin G and secretory immunoglobulin A from human milk

In the milk of healthy women, antibodies were found with different catalytic activities (abzymes), which are absent in the sera of other healthy people. Moreover, it was previously shown that DNase antibodies-abzymes of patients with autoimmune diseases are cytotoxic to cancer cells. In this work, it was first shown that IgG and secretory IgA (sIgA) do not possess embryotoxicity; they practically do not affect the development of fertilized eggs of sea urchins but demonstrate sperm toxicity. After addition to the eggs of sperm preincubated with IgG and sIgA, the number of unfertilized eggs was increased, in the case of sIgA 1.6-fold higher than that for IgG. The suppression of the growth of MCF-7 breast cancer cells by sIgA was 2.2 times more effective than with IgG antibodies. The relative enzymatic activity of milk sIgA was higher than IgG (-fold): 1.9 (DNase), 4.6 (amylase), 1.7 (peroxidase), 1.3 (protease), 3.7 [hydrolysis of poly(C)], 3.3 [hydrolysis of poly(U)], and 1.7 (oxidation of 3,3′-diaminobenzidine). One of the possible reasons for the observed difference between sIgA and IgG could be that all 6 catalytic activities of sIgA were, on average, 2.6 times higher than that for IgG. Correlation coefficients between all the relative 6 enzymatic activities of IgG and sIgA and their toxicity to sea urchin sperm and to cancer cells were calculated. Maximum correlation coefficients were observed for DNase (+0.71), protease (+0.64) activities for sIgA, as well as protease (+0.59) and RNase (+0.77) of IgG with their toxicity toward sperm. The correlation coefficients were also high between peroxidase activity (+0.85) of sIgA and poly(U) hydrolysis by IgG (+0.58) with their suppression of tumor cell growth. It has been suggested that the catalytic activities of abzymes may be important in the manifestation of their sperm toxicity and inhibition of cancer cell growth.     

ᶫ-Leucine Loading and Release in MIL-100 Nanoparticles

Synthesis of the MIL-100 metal-organic framework particles was carried out by hydrothermal (HT) and microwave (MW)-assisted methods. Transmission electron microscopy showed formation of microparticles in the course of hydrothermal synthesis and nanoparticles for microwave-assisted synthesis. Powder X-ray diffraction confirmed formation of larger crystallites for hydrothermal synthesis. Particle aggregation in aqueous solution was observed by dynamic light scattering. However, the stability of both samples could be improved in acetic acid solution. Nitrogen sorption isotherms showed high porosity of the particles. ᶫ-leucine molecule was used as a model molecule for loading in the porous micro- and nanoparticles. Loading was estimated by FTIR spectroscopy and thermogravimetric analysis. UV-VIS spectroscopy quantified ᶫ-leucine release from the particles in aqueous solution. Cytotoxicity studies using the HeLa cell model showed that the original particles were somewhat toxic, but ᶫ-leucine loading ameliorated the toxic effects, likely due to signaling properties of the amino acid.     

Constructive Analysis of Eigenvalue Problems in Control under Numerical Uncertainty

International Journal of Control, Automation and Systems - The eigenvalue problem plays a central role in linear algebra and its applications in control and optimization methods. In particular,...     

Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy analysis of electrochemically etched graphite tips created from pencil lead

Modern day pencil lead is a material of many possibilities. Manufacture process is fast, easy, and well established, yet the full potential of its use still remains to be uncovered. Graphite content ratio to binding clays determines basic properties of the lead like its toughness and color, but more interesting qualities like conductivity and reactivity as well. Properly employed electrochemical etching with a bubble membrane creates sharp and smooth graphite tips, which can be, given enough graphite content, used as probes in several measurement techniques. Observing and adjusting the tip creation process and the results for use in further research are the objectives of this paper.     

Deep Sea Exploration Recovery and Transport [DESERT] Vehicle and its Modes of Communication

Wireless Personal Communications - Man has explored less than 5% of three-fourths of the water on Earth. This is mostly due to lack of cheap and effective under-water transportation. Submarines and...     

Enabling connectivity for tactical networks in mountainous areas by aerial relays

A general modeling framework for realistic performance evaluations of tactical mobile ad-hoc networks deployed in mountainous areas is presented. The framework is easily extensible, and can be eventually automated. It can be also used to generate data for other network simulators. The framework utilizes the freely downloadable high resolution 3D terrain data to define time dependent trajectories of network nodes. The node speeds and directions are linked to the terrain profile which extends the previously proposed mobility models. The path-loss analysis along the node trajectories revealed the need for aerial relays to enable full network connectivity at all times. The network consisting of 5 cluster heads and a single stationary relay is considered as a case study. The relay location and its antenna height are optimized to achieve the line-of-sight connectivity over the whole mission duration. The antenna radiation pattern at the relay is incorporated in the analysis. The resulting star network topology is used by the cluster heads to broadcast their packets to all other cluster heads. Several relaying schemes including the amplify-and-forward and the decode-and-forward relaying are studied together with the go-back-N retransmissions to achieve the reliable data transfer.

     

The effect of layer thickness on adsorption and catalytic activity of sandwich-like ceramics

Scalable and easily implementable sol-gel approach for creating self-supported sandwich-like Al₂O₃/Fe₂O₃/Al₂O₃ films was proposed. A comprehensive study of the composition, microstructure, thermal, textural, catalytic, and adsorption properties were carried out. The possibility of varying the relative thickness of the layers allows to diversify functional properties of the materials. On the one hand, films with thick mesoporous alumina layers and a thin internal iron oxide layer behave as effective magnetically separable Cr(VI) adsorbents. On the other hand, thin thermally and chemically resistant mesoporous alumina layers, bounding the iron oxide layer, prevent degradation and deactivation of the catalytically active iron oxide sites in the catalysis process and provide full access of the reagents. The Al₂O₃/Fe₂O₃/Al₂O₃ films can be easily separated from a liquid medium due to rapid settling of large fragments and the possibility of magnetic separation. Thus, these films are convenient objects for various environmental applications.