120 results match your criteria: "Technical University of Sofia[Affiliation]"
Nature
August 2022
Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Although p53 inactivation promotes genomic instability and presents a route to malignancy for more than half of all human cancers, the patterns through which heterogenous TP53 (encoding human p53) mutant genomes emerge and influence tumorigenesis remain poorly understood. Here, in a mouse model of pancreatic ductal adenocarcinoma that reports sporadic p53 loss of heterozygosity before cancer onset, we find that malignant properties enabled by p53 inactivation are acquired through a predictable pattern of genome evolution. Single-cell sequencing and in situ genotyping of cells from the point of p53 inactivation through progression to frank cancer reveal that this deterministic behaviour involves four sequential phases-Trp53 (encoding mouse p53) loss of heterozygosity, accumulation of deletions, genome doubling, and the emergence of gains and amplifications-each associated with specific histological stages across the premalignant and malignant spectrum.
View Article and Find Full Text PDFSensors (Basel)
August 2022
Faculty of Telecommunications, Technical University of Sofia, bul. Kl. Ohridski 8, 1000 Sofia, Bulgaria.
Resource allocation (RA) has always had a prominent place in wireless communications research due to its significance for network throughput maximization, and its inherent complexity. Concurrently, graph-based solutions for RA have also grown in importance, providing opportunities for higher throughput and efficiency due to their representational capabilities, as well as challenges for realizing scalable algorithms. This article presents a comprehensive review and analysis of graph-based RA methods in three major wireless network types: cellular homogeneous and heterogeneous, device-to-device, and cognitive radio networks.
View Article and Find Full Text PDFSensors (Basel)
June 2022
Department of Electronics, Technical University of Sofia, 1000 Sofia, Bulgaria.
In this paper, we present an overview of the latest achievements in surface acoustic wave (SAW) sensors for gas or liquid fluid, with a focus on the electrodes' topology and signal processing, as related to the application of the sensing device. Although the progress in this field is mainly due to advances in the materials science and the sensing coatings, the interdigital (IDT) electrodes' organization is also an important tool for setting the acoustic-wave-distribution mode, and, thus, for improvement of the SAW performance. The signal-conditioning system is of practical interest, as the implementation of the SAW, as a compact and mobile system is dependent on this electronic circuit.
View Article and Find Full Text PDFMaterials (Basel)
June 2022
Electrical Faculty, Technical University of Sofia, 1000 Sofia, Bulgaria.
No systematic study of antioxidant containing coatings and their anti-biofilm action has been reported so far. The utilization of antioxidants in protective coatings to inhibit marine biofilm formation is a current challenge. The aim of this preliminary study was to prepare, characterize and compare the efficiency of low adhesive siloxane composite coatings equally loaded with different antioxidants against mono-species biofilms formation.
View Article and Find Full Text PDFPLoS One
June 2022
Department of Medical Genetics, Medical Faculty, Medical University-Sofia, Sofia, Bulgaria.
Genetic disease burden in ancient communities has barely been evaluated despite an ever expanding body of ancient genomes becoming available. In this study, we inspect 2729 publicly available ancient genomes (100 BP-52000 BP) for the presence of pathogenic variants in 32643 disease-associated loci. We base our subsequent analyses on 19 variants in seven genes-PAH, EDAR, F11, HBB, LRRK2, SLC12A6 and MAOA, associated with monogenic diseases and with well-established pathogenic impact in contemporary populations.
View Article and Find Full Text PDFNanomaterials (Basel)
June 2022
Western-Caucasus Research Center, 352808 Tuapse, Russia.
Due to the unique combination of physicochemical and structural properties of carbyne-enriched nanocoatings, they can be used for the development of high-end electronic devices. We propose using it for the development of sensor platforms based on silicon bulk micromachined membranes that serve as a part of microcapacitors with flexible electrodes, with various sizes and topologies. The carbyne-enriched nanocoating was grown using the ion-assisted pulse-plasma deposition method in the form of 2D-ordered linear-chain carbon with interchain spacing in the range of approximately 4.
View Article and Find Full Text PDFSensors (Basel)
April 2022
Faculty of Telecommunications, Technical University of Sofia, 1756 Sofia, Bulgaria.
In recent years, the IoT has emerged as the most promising technology in the key evolution of industry 4.0/industry 5.0, smart home automation (SHA), smart cities, energy savings and many other areas of wireless communication.
View Article and Find Full Text PDFPlants (Basel)
March 2022
Faculty of Food Technology Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia.
Wheat-based short-dough cookies are considered low nutritional value foods because their recipes are high in fat and sugar. The aim of this study was to investigate the effects of replacing part of the wheat flour (WF) with different types of malted barley flour (MBF), while reducing sucrose in the recipe, in order to produce cookies with increased nutritional value, enhanced functional properties, and acceptable technological and sensory characteristics. Three types of brewer's MBF (, , and ) were used to replace WF in amounts of 20, 40, and 60%, while simultaneously reducing the addition of sucrose.
View Article and Find Full Text PDFAntioxidants (Basel)
February 2022
Department of Electrical Apparatus, Technical University of Sofia, 1756 Sofia, Bulgaria.
Background: The well-recognized but not fully explored antioxidant activity of marine-biota-derived, biologically active substances has led to interest in their study as substitutes of antibiotics, antiaging agents, anticancer and antiviral drugs, and others. The aim of this review is to present the current state of the art of marine-biota-derived antioxidants to give some ideas for potential industrial applications.
Methods: This review is an update for the last 5 years on the marine sources of natural antioxidants, different classes antioxidant compounds, and current derivation biotechnologies.
Sensors (Basel)
January 2022
Faculty of Electronic Engineering and Technologies, Technical University of Sofia, 1756 Sofia, Bulgaria.
In this work, we introduce and use an innovative approach for adaptive piecewise linear interval approximation of sensor characteristics, which are differentiable functions. The aim is to obtain a discreet type of inverse sensor characteristic, with a predefined maximum approximation error, with minimization of the number of points defining the characteristic, which in turn is related to the possibilities for using microcontrollers with limited energy and memory resources. In this context, the results from the study indicate that to overcome the problems arising from the resource constraints of smart devices, appropriate "lightweight" algorithms are needed that allow efficient connectivity and intelligent management of the measurement processes.
View Article and Find Full Text PDFBioorg Med Chem Lett
March 2022
Department of Chemistry, Faculty of Pharmacy, Medical University-Sofia, Bulgaria. Electronic address:
The paper reports on the facile and convenient synthesis of a series of novel 2,5-substituted 1,3,4-oxadiazoles 3a-f and that of aroylhydrazone-based molecular hybrids 5a-g from readily available starting materials. The structure of the compounds was confirmed by IR, H NMR, C NMR and HRESI-MS spectral data. The toxicological potential of the compounds was evaluated by monitoring the synaptosomal viability and the levels of reduced glutathione in rat brain synaptosomes, isolated by Percoll gradient.
View Article and Find Full Text PDFEntropy (Basel)
December 2021
Department of Mathematical Physics, Technical University of Sofia, 8800 Sliven, Bulgaria.
In this paper we study an impulsive delayed reaction-diffusion model applied in biology. The introduced model generalizes existing reaction-diffusion delayed epidemic models to the impulsive case. The integral manifolds notion has been introduced to the model under consideration.
View Article and Find Full Text PDFHeliyon
December 2021
Department of Aeronautics, Technical University of Sofia, 8 Kl. Ohridski Blvd, Sofia, Bulgaria.
Safety management systems (SMS) are widely accepted as a way of improving safety and are currently required by the aviation regulations. Safety training and education of all professionals in the aviation safety system is vital for the success of any safety management strategy. At the same time some of the terms in the field are not uniquely and consistently defined, e.
View Article and Find Full Text PDFNanomaterials (Basel)
September 2021
Institute of Optical Materials and Technologies "Acad. J. Malinowski", Bulgarian Academy of Sciences, Akad. G. Bonchev Str., bl. 109, 1113 Sofia, Bulgaria.
In this study, thin composite films of a sol-gel NbO matrix doped with coal fly ash Na-X zeolites were deposited by the spin-coating method. Fly ash of lignite coal collected from the electrostatic precipitators of one of the biggest TPPs in Bulgaria was used as a raw material for obtaining zeolites. Zeolite Na-X was synthesized by ultrasonic-assisted double stage fusion-hydrothermal alkaline conversion of coal fly ash.
View Article and Find Full Text PDFMaterials (Basel)
September 2021
Laboratory "CAD/CAM/CAE in Industry", Technical University of Sofia, 1000 Sofia, Bulgaria.
An e-textile mat with capacitive textile sensors was designed and manufactured to monitor body position and prevent decubitus ulcers in the case of bedridden people. The sensors were incorporated through a process of machine embroidery with electrically conductive threads. A new production method for the conductive threads is still expected to be developed, resulting in good conductive properties, high wear resistance and durability.
View Article and Find Full Text PDFMaterials (Basel)
August 2021
Photovoltaic Solar Energy Unit, Energy Department, CIEMAT, Avenida Complutense 40, 28040 Madrid, Spain.
Three means are investigated for further increasing the accuracy of the characterization of a thin film on a substrate, from the transmittance spectrum () of the specimen, based on the envelope method. Firstly, it is demonstrated that the accuracy of characterization, of the average film thickness d¯ and the thickness non-uniformity ∆d over the illuminated area, increases, employing a simple dual transformation utilizing the product ()(), where () is the smoothed spectrum of () and () is the substrate absorbance. Secondly, an approach is proposed for selecting an interval of wavelengths, so that using envelope points only from this interval provides the most accurate characterization of d¯ and ∆d, as this approach is applicable no matter whether the substrate is transparent or non-transparent.
View Article and Find Full Text PDFMembranes (Basel)
July 2021
Department of Microelectronics, Technical University of Sofia, 1000 Sofia, Bulgaria.
Bilayer coatings of barium strontium titanate (BaSrTiO)/poly [(vinylidenefluoride-co-trifluoroethylene] (PVDF-TrFE) were integrated on silicon Si (100) for pyroelectric devices. Pyroelectric properties of the composite were determined for different electrode materials (silver and aluminum) and different electrodes configurations creating an electric field in parallel and in-plane direction in the ferroelectric coating. For this purpose, parallel-plate and planar interdigital capacitors were fabricated.
View Article and Find Full Text PDFMicromachines (Basel)
April 2021
Faculty of German Engineering Education and Industrial Management (FDIBA), Technical University of Sofia, 1756 Sofia, Bulgaria.
Cell lysis is a process in which the outer cell membrane is broken to release intracellular constituents in a way that important information about the DNA or RNA of an organism can be obtained. This article is a thorough review of reported methods for the achievement of effective cellular boundaries disintegration, together with their technological peculiarities and instrumental requirements. The different approaches are summarized in six categories: chemical, mechanical, electrical methods, thermal, laser, and other lysis methods.
View Article and Find Full Text PDFInflammopharmacology
August 2021
Technical University of Sofia, Klement Ohridksi 8, 1000, Sofia, Bulgaria.
Coronavirus disease 2019 (COVID-19) is caused by the novel SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) first discovered in Wuhan, Hubei province, China in December 2019. SARS-CoV-2 has infected several millions of people, resulting in a huge socioeconomic cost and over 2.5 million deaths worldwide.
View Article and Find Full Text PDFPharmacol Res
May 2021
Technical University of Sofia, Klement Ohridksi 8, Sofia 1000, Bulgaria.
Evidence indicates a critical role of neuroinflammatory response as an underlying pathophysiological process in several central nervous system disorders, including neurodegenerative diseases. However, the molecular mechanisms that trigger neuroinflammatory processes are not fully known. The discovery of bitter taste receptors in regions other than the oral cavity substantially increased research interests on their functional roles in extra-oral tissues.
View Article and Find Full Text PDFPhys Rev E
February 2021
Department of Applied Physics, Faculty of Applied Mathematics and Informatics, Technical University of Sofia, 8 Kl. Ohridski Blvd., Sofia 1000, Bulgaria.
In this paper we have investigated through the numerical solution of the basic equation as well as through the dynamic model the influence of higher-order correction terms to the nonlinear amplification (absorption) and to the nonlinear refractive index on the self-frequency shift of Raman dissipative solitons. We have found a nonlinear dependence of the self-frequency shift of Raman dissipative solitons on the parameter describing intrapulse Raman scattering in the presence of the saturation of the nonlinear gain. With the increase of the absolute value of the saturation of the nonlinear gain, the maximum absolute value of the frequency shift decreases and its position moves to larger values of the parameter describing intrapulse Raman scattering.
View Article and Find Full Text PDFSensors (Basel)
January 2021
Faculty of Telecommunications, Technical University of Sofia, 1756 Sofia, Bulgaria.
To support upcoming novel applications, fifth generation (5G) and beyond 5G (B5G) wireless networks are being propelled to deploy an ultra-dense network with an ultra-high spectral efficiency using the combination of heterogeneous network (HetNet) solutions and massive Multiple Input Multiple Output (MIMO). As the deployment of massive MIMO HetNet systems involves a high capital expenditure, network service providers need a precise performance analysis before investment. The performance of such networks is limited because of presence of inter-cell and inter-tier interferences.
View Article and Find Full Text PDFMicromachines (Basel)
January 2021
Shenzhen Key Laboratory for Low-cost Healthcare, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen University Town, Shenzhen 518055, China.
The trends of wearable health monitoring systems have led to growing demands for gait-capturing devices. However, comfortability and durability under repeated stress are still challenging to achieve in existing sensor-enabled footwear. Herein, a flexible textile piezoresistive sensor (TPRS) consisting of a reduced graphene oxide (rGO)-cotton) fabric electrode and an Ag fabric circuit electrode is proposed.
View Article and Find Full Text PDFChemosphere
May 2021
Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev str. Bl. 9, 1113, Sofia, Bulgaria.
The combustion of coal in Thermal Power Plants generates fine dust particles (coal fly ash, CFA), which are collected from the flue gas streams and deposited as solid wastes. One of the technologically reliable solutions for utilization of CFA is its alkaline conversion into zeolites. The present study focuses on the influence of calcium content in CFA on the chemical and phase composition, morphology and surface properties of coal fly ash zeolites.
View Article and Find Full Text PDFEntropy (Basel)
March 2020
Department of Machine Elements and Non-metallic Constructions, Technical University of Sofia, Sofia 1000, Bulgaria.
In this paper, a new class of impulsive neural networks with fractional-like derivatives is defined, and the practical stability properties of the solutions are investigated. The stability analysis exploits a new type of Lyapunov-like functions and their derivatives. Furthermore, the obtained results are applied to a bidirectional associative memory (BAM) neural network model with fractional-like derivatives.
View Article and Find Full Text PDF