The use of a Mamdani-type fuzzy model for assessing the performance of a boom stabilization systems in a field sprayer.

Fuzzy logic models are increasingly used to control simple and complex devices, as well as entire operating systems. In this study, a fuzzy logic model was applied to assess the performance a boom stabilization system in a field sprayer. The model was tested on a field sprayer with a trapezoid system for stabilizing the sprayer boom with a length of 21 m. Measuring cables for registering the displacement of the boom's terminal segments (right and left) in the vertical and horizontal plane were installed on the sprayer. The field sprayer was connected to a tractor. The model was based on two linguistic variables: "absolute displacement of the boom's terminal segments" and "boom stability index". It was assumed that the sprayer boom was stable when the displacement of the boom's terminal segments did not exceed 0.25% of boom length. The study demonstrated that the proposed model can be reliably used to assess boom stability in real time (during field operations). The time required to achieve boom stability was more than 2.5 times shorter in the vertical than in the horizontal plane, which can be attributed mainly to the structure of the stabilization system. The proposed model is universal, and it can be applied to evaluate other boom stabilization systems in field sprayers.

Minimally Invasive Intradiscal Delivery of BM-MSCs via Fibrous Microscaffold Carriers.

Current treatments of degenerated intervertebral discs often provide only temporary relief or address specific causes, necessitating the exploration of alternative therapies. Cell-based regenerative approaches showed promise in many clinical trials, but limitations such as cell death during injection and a harsh disk environment hinder their effectiveness. Injectable microscaffolds offer a solution by providing a supportive microenvironment for cell delivery and enhancing bioactivity. This study evaluated the safety and feasibility of electrospun nanofibrous microscaffolds modified with chitosan (CH) and chondroitin sulfate (CS) for treating degenerated NP tissue in a large animal model. The microscaffolds facilitated cell attachment and acted as an effective delivery system, preventing cell leakage under a high disc pressure. Combining microscaffolds with bone marrow-derived mesenchymal stromal cells demonstrated no cytotoxic effects and proliferation over the entire microscaffolds. The administration of cells attached to microscaffolds into the NP positively influenced the regeneration process of the intervertebral disc. Injectable poly(l-lactide-co-glycolide) and poly(l-lactide) microscaffolds enriched with CH or CS, having a fibrous structure, showed the potential to promote intervertebral disc regeneration. These features collectively address critical challenges in the fields of tissue engineering and regenerative medicine, particularly in the context of intervertebral disc degeneration.

Evaluation of regenerative processes in the pig model of intervertebral disc degeneration after transplantation of bone marrow-derived mesenchymal stem cells.

INTRODUCTION: The pathophysiology of degenerative disc disease (DDD) is complex and not fully understood. While surgical treatment and appropriate rehabilitation offer relief of acute symptoms, there is a need to find tissue engineering strategies for intervertebral disc repair to restore healthy higher and histological structure. The purpose of this study was to estimate the survival rate of transplanted cells and their post-delivery integration level at the damage site. MATERIAL AND METHODS: We used an in vivo porcine model to investigate autogenic bone marrow-derived mesenchymal stem cell (BM-MSC) transplantation for intervertebral disc repair. In our experiment we used a large animal model of DDD induced by percutaneous laser light deliveries. The percutaneous approach has also been used for delivery of BM-MSCs into the intervertebral disc space. RESULTS: After MSC transplantation, we observed a deceleration of the degenerative process in the intervertebral disc, relative to degenerative discs without MSC transplantation. CONCLUSIONS: By using a large animal model that mimicked the development of intervertebral degenerative disc disease, the present results are indicative of the clinical feasibility of this procedure.

Migration of human mesenchymal stem cells stimulated with pulsed electric field and the dynamics of the cell surface glycosylation.

BACKGROUND: The analysis of the stem cells' glycome dynamics at different stages of differentiation and migration makes possible the exploration of the cell surface glycans as markers of the stem cell functional status, and, in the future, compatibility between transplanted cell and host environment. OBJECTIVES: The objective of our study was to develop novel techniques of investigating cell motility and to assess whether the electric field of the therapeutic spinal cord stimulation system used in vivo contributes to the migration of human mesenchymal stem cells (hMSCs) in vitro. MATERIAL AND METHODS: We have investigated the electrotaxis of bone marrow-derived MSCs using pulsed electric field (PEF) in the range of 16-80 mV/mm and the frequency of 130 Hz and 240 Hz. The PEF-related dynamics of the cell surface glycosylation was evaluated using 6 plant lectins recognizing individual glycans. RESULTS: Pulsed electric field at physiological levels (10 mV/mm; 130 Hz) did not influence cellular motility in vitro, which may correspond to the maintenance of the transplanted cells at the lesion site in vivo. An increase of the PEF intensity and the frequency exceeding physiological levels resulted in an increase in the cellular migration rate in vitro. Pulsed electric field elevated above physiological intensity and frequency (40-80 mV/mm; 240 Hz), but not at physiological levels, resulted in changes of the cell surface glycosylation. CONCLUSIONS: We found the described approach convenient for investigations and for the in vitro modeling of the cellular systems intended for the regenerative cell transplantations in vivo. Probing cell surface glycomes may provide valuable biomarkers to assess the competence of transplanted cells.

Novel method of lung area extraction in chest perfusion computed tomography.

Chest perfusion computed tomography (pCT) is a useful technique in the medical diagnosis of how organs function. Perfusion CT scans are used to calculate perfusion parameters. In the case of automated methods of lung perfusion parameters calculation, the prior extraction of the lung area is desired to avoid unnecessary calculation in an area outside the lung cross-section and to avoid wasting time on processing signals of no diagnostic importance. Our new method is designed to extract a lung cross-section from a whole series of chest pCT images. It uses a complete sequence of pCT scans to extract the rough lung contour. Next each scan is processed individually, within the rough contour, to obtain a detailed, individual outline of the lungs. The proposed method and obtained results are presented and compared with methods known in literature.