Our study showed that the evaluated implants have good BIC features. Furthermore, based on histomorthometry and histology, Porous tantalum Trabecular Metal (A) and Trabecular Titanium (B) implants exhibit higher BIC with bone tissue.
Background: To compare structural features of the femoral bone of ovariectomized and non-ovariectomized rats after implantation of porous materials (TANTALUM, CONCELOC, TTM, ATLANT). Methods: Experiments were carried out on 56 white laboratory female rats aged 6 months. Rats were randomly assigned into groups: sham-operated control group (SH) or ovariectomy group (OVX). Four different commercial implant materials (TTM, CONCELOC, TANTALUM, ATLANT) were placed into the defects (diameter 2.5 mm, depth 3.0 mm) in the distal metaphysis of femurs. Rats were sacrificed 45 days after surgery. Histological study was performed and the percentage of the bone area (BA%) around the implant at a distance of 500 μm in the cancellous area was measured. Results: Formation of mature bone tissue of varying degrees around all of the implants was detected. In OVX rats cancellous bone defect zone was characterized by a high density of osteocytes on the surface. In the SH group, no differences in BA% among implant materials were found. In OVX rats, the BA% around ATLANT implants was 1.5time less (p = 0.002) than around TANTALUM. The BA% around the rest of the materials was not statistically different. Conclusions: Bone formation around the studied porous titanium and tantalum materials in the osteoporosis model was lower than in normal bone. There were differences in bone formation around the different materials in the osteoporosis model, while in the normal bone model, these differences were absent.
The article deals with one of the most intensively developing threats for civilian and military spheres - hostile use of Low, Slow and Small Unmanned Aerial Vehicles (LSS UAVs). The classification of the LSS UAVs is given. The existing threats of using LSS UAVs are divided into three categories. Special attention is paid to the third category of threats, the main feature of which is a high level of training of the operator. Main advantages and drawbacks of LSS UAVs are considered. It is determined that the best strategy is to employ a hierarchy of countermeasures including regulatory countermeasures (prevention, deterrence, denial), passive countermeasures (detection and interruption) and active countermeasures (destruction). State of the art and current problems of possible countermeasures are analysed. The most promising LSS UAVs’ counteraction technologies are described. Most attention is paid to specialized sensors and modern active counteraction means, such as programmable air burst munition and high-energy laser systems.
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