Records |
Author |
Wang, J.; Zhang, K.; Meynen, V.; Bogaerts, A. |
Title |
Dry reforming in a dielectric barrier discharge reactor with non-uniform discharge gap : effects of metal rings on the discharge behavior and performance |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
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Volume |
|
Issue |
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Pages |
142953-29 |
Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The application of dielectric barrier discharge (DBD) plasma reactors is promising in various environmental and energy processes, but is limited by their low energy yield. In this study, we put a number of stainless steel rings over the inner electrode rod of the DBD reactor to change the local discharge gap and electric field, and we studied the dry reforming performance. At 50 W supplied power, the metal rings mostly have a negative impact on the performance, which we attribute to the non-uniform spatial distribution of the discharges caused by the rings. However, at 30 W supplied power, the energy yield is higher than at 50 W and the placement of the rings improves the performance of the reactor. More rings and with a larger cross-sectional diameter can further improve the performance. The reactor with 20 rings with a 3.2 mm cross-sectional diameter exhibits the best performance in this study. Compared to the reactor without rings, it increases the CO2 conversion from 7% to 16 %, the CH4 conversion from 12% to 23%, and the energy yield from 0.05 mmol/kJ supplied power to 0.1 mmol/kJ (0.19 mmol/kJ if calculated from the plasma power), respectively. The presence of the rings increases the local electric field, the displaced charge and the discharge fraction, and also makes the discharge more stable and with more uniform intensity. It also slightly improves the selectivity to syngas. The performance improvement observed by placing stainless steel rings in this study may also be applicable to other plasma-based processes. |
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Wos |
000986051300001 |
Publication Date |
2023-04-17 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1385-8947; 1873-3212 |
ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
15.1 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 15.1; 2023 IF: 6.216 |
Call Number |
UA @ admin @ c:irua:195603 |
Serial |
7264 |
Permanent link to this record |
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Author |
Kovács, A.; Yusupov, M.; Cornet, I.; Billen, P.; Neyts, E.C. |
Title |
Effect of natural deep eutectic solvents of non-eutectic compositions on enzyme stability |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Journal Of Molecular Liquids |
Abbreviated Journal |
J Mol Liq |
Volume |
366 |
Issue |
|
Pages |
120180-17 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Biochemical Wastewater Valorization & Engineering (BioWaVE); Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS) |
Abstract |
Natural deep eutectic solvents (NADES) represent a green alternative to common organic solvents in the biochemical industry due to their benign behavior and tailorable properties, in particular as media for enzymatic reactions. However, to fully exploit their potential in enzymatic reactions, there is a need for a more fundamental understanding of how these neoteric solvents influence the course of these reac-tions. Thus, the aim of this study is to investigate the influence of NADES with various molar composi-tions on the stability and structure of enzymes, applying molecular dynamics simulations. This can help to better understand the effect of individual compounds of NADES, in addition to eutectic mixtures. More specifically, we simulate the behavior of Candida antarctica lipase B (CALB) enzyme in NADES com-posed of choline chloride with either urea, ethylene glycol or glycerol. Hereto, we monitor the NADES microstructure, the general stability of the enzyme and changes in the structure of its active sites and sur-face residues. Our simulations show that none of the studied NADES systems significantly disrupt the microstructure of the solvent or the stability of the CALB enzyme within the time scales of the simula-tions. The enzyme preserves its initial structure, size and intra-chain hydrogen bonds in all investigated compositions and, for the first time reported, also in NADES with increased hydrogen bond donating com-pound ratios. As the main novelty, our results indicate that, in addition to the composition, the molar ratio can be an additional variable to fine-tune the physicochemical properties of NADES without altering the enzyme characteristics. These findings could facilitate the development and application of task -tailored NADES media for biocatalytic processes. (c) 2022 Elsevier B.V. All rights reserved. |
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Wos |
000865431800010 |
Publication Date |
2022-08-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0167-7322 |
ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
6 |
Times cited |
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Open Access |
Not_Open_Access |
Notes |
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Approved |
Most recent IF: 6 |
Call Number |
UA @ admin @ c:irua:191538 |
Serial |
7265 |
Permanent link to this record |
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Author |
Bal, K.M.; Neyts, E.C. |
Title |
Extending and validating bubble nucleation rate predictions in a Lennard-Jones fluid with enhanced sampling methods and transition state theory |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Journal Of Chemical Physics |
Abbreviated Journal |
J Chem Phys |
Volume |
157 |
Issue |
18 |
Pages |
184113-10 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We calculate bubble nucleation rates in a Lennard-Jones fluid through explicit molecular dynamics simulations. Our approach-based on a recent free energy method (dubbed reweighted Jarzynski sampling), transition state theory, and a simple recrossing correction-allows us to probe a fairly wide range of rates in several superheated and cavitation regimes in a consistent manner. Rate predictions from this approach bridge disparate independent literature studies on the same model system. As such, we find that rate predictions based on classical nucleation theory, direct brute force molecular dynamics simulations, and seeding are consistent with our approach and one another. Published rates derived from forward flux sampling simulations are, however, found to be outliers. This study serves two purposes: First, we validate the reliability of common modeling techniques and extrapolation approaches on a paradigmatic problem in materials science and chemical physics. Second, we further test our highly generic recipe for rate calculations, and establish its applicability to nucleation processes. |
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Wos |
000885260600002 |
Publication Date |
2022-11-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-9606 |
ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.4 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 4.4 |
Call Number |
UA @ admin @ c:irua:192076 |
Serial |
7266 |
Permanent link to this record |
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Author |
Lu, X.P.; Bruggeman, P.J.; Reuter, S.; Naidis, G.; Bogaerts, A.; Laroussi, M.; Keidar, M.; Robert, E.; Pouvesle, J.-M.; Liu, D.W.; Ostrikov, K.(K.) |
Title |
Grand challenges in low temperature plasmas |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Frontiers in physics |
Abbreviated Journal |
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Volume |
10 |
Issue |
|
Pages |
1040658-12 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Low temperature plasmas (LTPs) enable to create a highly reactive environment at near ambient temperatures due to the energetic electrons with typical kinetic energies in the range of 1 to 10 eV (1 eV = 11600K), which are being used in applications ranging from plasma etching of electronic chips and additive manufacturing to plasma-assisted combustion. LTPs are at the core of many advanced technologies. Without LTPs, many of the conveniences of modern society would simply not exist. New applications of LTPs are continuously being proposed. Researchers are facing many grand challenges before these new applications can be translated to practice. In this paper, we will discuss the challenges being faced in the field of LTPs, in particular for atmospheric pressure plasmas, with a focus on health, energy and sustainability. |
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Place of Publication |
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Wos |
000878212000001 |
Publication Date |
2022-10-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2296-424x |
ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
3.1 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 3.1 |
Call Number |
UA @ admin @ c:irua:192173 |
Serial |
7267 |
Permanent link to this record |
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Author |
Nematollahi, P.; Neyts, E.C. |
Title |
Identification of a unique pyridinic FeN4Cx electrocatalyst for N₂ reduction : tailoring the coordination and carbon topologies |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
Volume |
126 |
Issue |
34 |
Pages |
14460-14469 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Although the heterogeneity of pyrolyzed Fe???N???C materials is known and has been reported previously, the atomic structure of the active sites and their detailed reaction mechanisms are still unknown. Here, we identified two pyridinic Fe???N4-like centers with different local C coordinates, i.e., FeN4C8 and FeN4C10, and studied their electrocatalytic activity for the nitrogen reduction reaction (NRR) based on density functional theory (DFT) calculations. We also discovered the influence of the adsorption of NH2 as a functional ligand on catalyst performance on the NRR. We confirmed that the NRR selectivity of the studied catalysts is essentially governed either by the local C coordination or by the dynamic structure associated with the FeII/FeIII. Our investigations indicate that the proposed traditional pyridinic FeN4C10 has higher catalytic activity and selectivity for the NRR than the robust FeN4C8 catalyst, while it may have outstanding activity for promoting other (electro)catalytic reactions. <comment>Superscript/Subscript Available</comment |
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Wos |
000859545200001 |
Publication Date |
2022-08-17 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447; 1932-7455 |
ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
3.7 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 3.7 |
Call Number |
UA @ admin @ c:irua:191469 |
Serial |
7268 |
Permanent link to this record |
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Author |
Sahun, M.; Privat-Maldonado, A.; Lin, A.; De Roeck, N.; Van de Heyden, L.; Hillen, M.; Michiels, J.; Steenackers, G.; Smits, E.; Ariën, K.K.; Jorens, P.G.; Delputte, P.; Bogaerts, A. |
Title |
Inactivation of SARS-CoV-2 and other enveloped and non-enveloped viruses with non-thermal plasma for hospital disinfection |
Type |
A1 Journal article |
Year |
2023 |
Publication |
ACS Sustainable Chemistry and Engineering |
Abbreviated Journal |
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Volume |
|
Issue |
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Pages |
1-10 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Center for Oncological Research (CORE); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Laboratory Experimental Medicine and Pediatrics (LEMP) |
Abstract |
As recently highlighted by the SARS-CoV-2 pandemic, viruses have become an increasing burden for health, global economy, and environment. The control of transmission by contact with contaminated materials represents a major challenge, particularly in hospital environments. However, the current disinfection methods in hospital settings suffer from numerous drawbacks. As a result, several medical supplies that cannot be properly disinfected are not reused, leading to severe shortages and increasing amounts of waste, thus prompting the search for alternative solutions. In this work, we report that non-thermal plasma (NTP) can effectively inactivate SARS-CoV-2 from non-porous and porous materials commonly found in healthcare facilities. We demonstrated that 5 min treatment with a dielectric barrier discharge NTP can inactivate 100% of SARS-CoV-2 (Wuhan and Omicron strains) from plastic material. Using porcine respiratory coronavirus (surrogate for SARS-CoV-2) and coxsackievirus B3 (highly resistant non-enveloped virus), we tested the NTP virucidal activity on hospital materials and obtained complete inactivation after 5 and 10 min, respectively. We hypothesize that the produced reactive species and local acidification contribute to the overall virucidal effect of NTP. Our results demonstrate the potential of dielectric barrier discharge NTPs for the rapid, efficient, and low-cost disinfection of healthcare materials. |
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Wos |
000964269500001 |
Publication Date |
2023-03-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2168-0485 |
ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.4 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 8.4; 2023 IF: 5.951 |
Call Number |
UA @ admin @ c:irua:194897 |
Serial |
7269 |
Permanent link to this record |
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Author |
Van Alphen, S. |
Title |
Modelling plasma reactors for sustainable CO2 conversion and N2 fixation |
Type |
Doctoral thesis |
Year |
2023 |
Publication |
|
Abbreviated Journal |
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Volume |
|
Issue |
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Pages |
202 p. |
Keywords |
Doctoral thesis; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
200 years ago, humanity started the industrial revolution by discovering fossil fuels, which lead to unprecedented technological advancements. However it has become alarmingly clear that the major environmental concerns associated with fossil fuels require a short-term transition from a carbon-based energy economy to a sustainable one based on green electricity. A key step concerning this transition exists in developing electricity-driven alternatives for chemical processes that rely on fossil fuels as a raw material. A technology that is gaining increasing interest to achieve this, is plasma technology. Using plasmas to induce chemical reactions by selectively heating electrons in a gas has already delivered promising results for gas conversion applications like CO2 conversion and N2 fixation, but plasma reactors still require optimization to be considered industrially competitive to existing fossil fuel-based processes and emerging other electricity-based technologies. In this thesis I develop computational models to describe plasma reactors and identify key mechanisms in three different plasma reactors for three different gas conversion applications, i.e. N2 fixation, combined CO2-CH4 conversion and CO2 splitting. I first developed models to describe a new rotating gliding arc (GA) reactor operating in two arc modes, which, as revealed by my model, are characterized by distinct plasma chemistry pathways. Subsequently, my colleague and I study the quenching effect of an effusion nozzle to this rotating GA reactor, reaching the best results to date for N2 fixation into NOx at atmospheric pressure, i.e., NOx concentrations up to 5.9%, at an energy cost down to 2.1 MJ/mol. Afterwards, I investigate the possible improvement of N2 admixtures in plasma-based CO2 and CH4 conversion, as significant amounts of N2 are often found in industrial CO2 waste streams, and gas separations are financially costly. Through combining my models with the experiment from a fellow PhD student, we reveal that moderate amounts of N2 (i.e. around 20%) increase both the electron density and the gas temperature to yield an overall energy cost reduction of 21%. Finally, I model quenching nozzles for plasma-based CO2 conversion in a microwave reactor, to explain the enhancements in CO2 conversion that were demonstrated in experiments. Through computational modelling I reveal that the nozzle introduces fast gas quenching resulting in the suppression of recombination reactions, which have more impact at low flow rates, where recombination is the most limiting factor in the conversion process. |
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ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:194811 |
Serial |
7270 |
Permanent link to this record |
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Author |
Le Compte, M.; Cardenas De La Hoz, E.; Peeters, S.; Smits, E.; Lardon, F.; Roeyen, G.; Vanlanduit, S.; Prenen, H.; Peeters, M.; Lin, A.; Deben, C. |
Title |
Multiparametric tumor organoid drug screening using widefield live-cell imaging for bulk and single-organoid analysis |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Jove-Journal Of Visualized Experiments |
Abbreviated Journal |
Jove-J Vis Exp |
Volume |
|
Issue |
190 |
Pages |
1-18 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Center for Oncological Research (CORE) |
Abstract |
Patient-derived tumor organoids (PDTOs) hold great promise for preclinical and translational research and predicting the patient therapy response from ex vivo drug screenings. However, current adenosine triphosphate (ATP)-based drug screening assays do not capture the complexity of a drug response (cytostatic or cytotoxic) and intratumor heterogeneity that has been shown to be retained in PDTOs due to a bulk readout. Live-cell imaging is a powerful tool to overcome this issue and visualize drug responses more in-depth. However, image analysis software is often not adapted to the three-dimensionality of PDTOs, requires fluorescent viability dyes, or is not compatible with a 384-well microplate format. This paper describes a semi-automated methodology to seed, treat, and image PDTOs in a high-throughput, 384-well format using conventional, widefield, live-cell imaging systems. In addition, we developed viability marker-free image analysis software to quantify growth rate-based drug response metrics that improve reproducibility and correct growth rate variations between different PDTO lines. Using the normalized drug response metric, which scores drug response based on the growth rate normalized to a positive and negative control condition, and a fluorescent cell death dye, cytotoxic and cytostatic drug responses can be easily distinguished, profoundly improving the classification of responders and non-responders. In addition, drug-response heterogeneity can by quantified from single-organoid drug response analysis to identify potential, resistant clones. Ultimately, this method aims to improve the prediction of clinical therapy response by capturing a multiparametric drug response signature, which includes kinetic growth arrest and cell death quantification. , |
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Wos |
000928020400010 |
Publication Date |
2022-12-24 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1940-087x |
ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.2 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 1.2 |
Call Number |
UA @ admin @ c:irua:193168 |
Serial |
7271 |
Permanent link to this record |
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Author |
Deben, C.; Cardenas De La Hoz, E.; Le Compte, M.; Van Schil, P.; Hendriks, J.M.H.; Lauwers, P.; Yogeswaran, S.K.; Lardon, F.; Pauwels, P.; van Laere, S.; Bogaerts, A.; Smits, E.; Vanlanduit, S.; Lin, A. |
Title |
OrBITS : label-free and time-lapse monitoring of patient derived organoids for advanced drug screening |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Cellular Oncology (2211-3428) |
Abbreviated Journal |
Cell Oncol |
Volume |
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Issue |
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Pages |
1-16 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Center for Oncological Research (CORE) |
Abstract |
Background Patient-derived organoids are invaluable for fundamental and translational cancer research and holds great promise for personalized medicine. However, the shortage of available analysis methods, which are often single-time point, severely impede the potential and routine use of organoids for basic research, clinical practise, and pharmaceutical and industrial applications. Methods Here, we developed a high-throughput compatible and automated live-cell image analysis software that allows for kinetic monitoring of organoids, named Organoid Brightfield Identification-based Therapy Screening (OrBITS), by combining computer vision with a convolutional network machine learning approach. The OrBITS deep learning analysis approach was validated against current standard assays for kinetic imaging and automated analysis of organoids. A drug screen of standard-of-care lung and pancreatic cancer treatments was also performed with the OrBITS platform and compared to the gold standard, CellTiter-Glo 3D assay. Finally, the optimal parameters and drug response metrics were identified to improve patient stratification. Results OrBITS allowed for the detection and tracking of organoids in routine extracellular matrix domes, advanced Gri3D (R)-96 well plates, and high-throughput 384-well microplates, solely based on brightfield imaging. The obtained organoid Count, Mean Area, and Total Area had a strong correlation with the nuclear staining, Hoechst, following pairwise comparison over a broad range of sizes. By incorporating a fluorescent cell death marker, infra-well normalization for organoid death could be achieved, which was tested with a 10-point titration of cisplatin and validated against the current gold standard ATP-assay, CellTiter-Glo 3D. Using this approach with OrBITS, screening of chemotherapeutics and targeted therapies revealed further insight into the mechanistic action of the drugs, a feature not achievable with the CellTiter-Glo 3D assay. Finally, we advise the use of the growth rate-based normalised drug response metric to improve accuracy and consistency of organoid drug response quantification. Conclusion Our findings validate that OrBITS, as a scalable, automated live-cell image analysis software, would facilitate the use of patient-derived organoids for drug development and therapy screening. The developed wet-lab workflow and software also has broad application potential, from providing a launching point for further brightfield-based assay development to be used for fundamental research, to guiding clinical decisions for personalized medicine. |
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Wos |
000898426100001 |
Publication Date |
2022-12-12 |
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Edition |
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ISSN |
2211-3428; 2211-3436 |
ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.6 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 6.6 |
Call Number |
UA @ admin @ c:irua:192698 |
Serial |
7272 |
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Author |
Wang, J. |
Title |
Plasma catalysis : study of CO2 reforming of CH4 in a DBD reactor |
Type |
Doctoral thesis |
Year |
2022 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
XVI, 232 p. |
Keywords |
Doctoral thesis; Engineering sciences. Technology; Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The plasma-based dry reforming in a dielectric barrier discharge (DBD) reactor is important to achieve sustainable goals, but many challenges remain. For example, the conversion and energy yield of DBD reactors are relatively low, and the catalysts or packing materials used in existing studies cannot improve them, possibly due to the unsuitable properties and structures of catalysts or packing materials for plasma processes. In order to study the effect of catalyst structure on plasma-based dry reforming, a controllable synthesis of the catalyst supports or templates was explored. In Chapter 2, an initially immiscible synthesis method was proposed to synthesize uniform silica spheres, which can replace the organic solvent-based Stöber method to successfully synthesize silica particles with the same size ranges as the original Stöber process without addition of organic solvents. Using the silica spheres as templates, 3D porous Cu and CuO catalysts with different pore sizes were synthesized in Chapter 3 to study the effect of catalyst pore size on the plasma-catalytic dry reforming. In most cases, the smaller the pore size, the higher the conversion of CH4 and CO2 due to the reaction of radicals and ions formed in the plasma. An exception are the samples synthesized from 1 μm silica, which show better performance due to the electric field enhancement for pore sizes close to the Debye length. Besides the pore size, the particle diameter of the catalyst or packing is also one of the important factors affecting the interaction between plasma and catalyst. In Chapter 4, SiO2 spheres (with or without supported metal) were used to study the effect of different support particle sizes on plasma-based dry reforming. We found that a uniform SiO2 packing improves the conversion of plasma-based dry reforming. The conversion of plasma-based dry reforming first increases and then decreases with increasing particle size, due to the balance between the promoting and hindering effect of the particle filling on the plasma discharge. Chapter 5 is to improve the design of the DBD reactor itself, in order to try to increase its low energy yield. Some stainless steel rings were put over the inner electrode rod of the DBD reactor. The presence of rings increases the local electric field, the displaced charges and the discharge fraction, and also makes the discharge more stable and with more uniform intensity. The placement of the rings improves the performance of the reactor at 30 W supplied power. |
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Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:194045 |
Serial |
7273 |
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Author |
Tchakoua, T.; Gerrits, N.; Smeets, E.W.F.; Kroes, G.-J. |
Title |
SBH17 : benchmark database of barrier heights for dissociative chemisorption on transition metal surfaces |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Journal of chemical theory and computation |
Abbreviated Journal |
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Volume |
19 |
Issue |
1 |
Pages |
245-270 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Accurate barriers for rate controlling elementary reactions on metal surfaces are key to understanding, controlling, and predicting the rate of heterogeneously catalyzed processes. While barrier heights for gas phase reactions have been extensively benchmarked, dissociative chemisorption barriers for the reactions of molecules on metal surfaces have received much less attention. The first database called SBH10 and containing 10 entries was recently constructed based on the specific reaction parameter approach to density functional theory (SRP-DFT) and experimental results. We have now constructed a new and improved database (SBH17) containing 17 entries based on SRP-DFT and experiments. For this new SBH17 benchmark study, we have tested three algorithms (high, medium, and light) for calculating barrier heights for dissociative chemisorption on metals, which we have named for the amount of computational effort involved in their use. We test the performance of 14 density functionals at the GGA, GGA+vdW-DF, and meta-GGA rungs. Our results show that, in contrast with the previous SBH10 study where the BEEF-vdW-DF2 functional seemed to be most accurate, the workhorse functional PBE and the MS2 density functional are the most accurate of the GGA and meta-GGA functionals tested. Of the GGA+vdW functionals tested, the SRP32-vdW-DF1 functional is the most accurate. Additionally, we found that the medium algorithm is accurate enough for assessing the performance of the density functionals tested, while it avoids geometry optimizations of minimum barrier geometries for each density functional tested. The medium algorithm does require metal lattice constants and interlayer distances that are optimized separately for each functional. While these are avoided in the light algorithm, this algorithm is found not to give a reliable description of functional performance. The combination of relative ease of use and demonstrated reliability of the medium algorithm will likely pave the way for incorporation of the SBH17 database in larger databases used for testing new density functionals and electronic structure methods. |
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Wos |
000903286100001 |
Publication Date |
2022-12-19 |
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Series Issue |
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Edition |
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ISSN |
1549-9618 |
ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.5 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 5.5; 2023 IF: 5.245 |
Call Number |
UA @ admin @ c:irua:193426 |
Serial |
7274 |
Permanent link to this record |
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Author |
Nematollahi, P. |
Title |
Selectivity of Mo-NC sites for electrocatalytic N₂ reduction : a function of the single atom position on the surface and local carbon topologies |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Applied surface science |
Abbreviated Journal |
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Volume |
612 |
Issue |
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Pages |
155908-155909 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Transition metal (TM) doped two-dimensional single-atom catalysts are known as a promising class of catalysts for electrocatalytic gas conversion. However, the detailed mechanisms that occur at the surface of these catalysts are still unknown. In the present work, we simulate three Mo-doped nitrogenated graphene structures. In each catalyst, the position of the Mo active site and the corresponding local carbon topologies are different, i.e. MoN4C10 with in-plane Mo atom, MoN4C8 in which Mo atom bridges two adjacent armchair-like graphitic edges, and MoN2C3 in which Mo is doped at the edge of the graphene sheet. Using Density Functional Theory (DFT) calculations we discuss the electrocatalytic activity of Mosingle bondNsingle bondC structures for nitrogen reduction reaction (NRR) with a focus on unraveling the corresponding mechanisms concerning different Mo site positions and C topologies. Our results indicate that the position of the active site centers has a great effect on its electrocatalytic behavior. The gas phase N2 efficiently reduces to ammonia on MoN4C8 via the distal mechanism with an onset potential of −0.51 V. We confirm that the proposed pyridinic structure, MoN4C8, can catalyze NRR effectively with a low overpotential of 0.35 V. |
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000901469900003 |
Publication Date |
2022-11-30 |
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Series Issue |
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Edition |
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ISSN |
0169-4332 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.7 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 6.7; 2023 IF: 3.387 |
Call Number |
UA @ admin @ c:irua:192430 |
Serial |
7275 |
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Author |
Kovács, A. |
Title |
A structured methodology for natural deep eutectic solvent selection and formulation for enzymatic reactions |
Type |
Doctoral thesis |
Year |
2023 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
viii, 216 p. |
Keywords |
Doctoral thesis; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Biochemical Wastewater Valorization & Engineering (BioWaVE); Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS) |
Abstract |
Natural deep eutectic solvents (NADES) show great promise as media for enzymatic reactions in areas where (bio)compatibility with natural or medicinal products is a must. While in theory they can be tailored to the intended reaction to ensure optimized yields, the knowledge to date is predominantly empirical, with some mechanistic reports providing a fragmented view at best. Therefore, it is not easy to explain experimental observations, let alone make predictions. The aim of this study was to develop a structured, holistic understanding of the effects of NADES media on enzymatic reactions, distinguishing between effects on solubility, solvation, viscosity, inhibition and denaturation. Experimental and computational chemistry methods were combined to separately study the interactions between enzyme, substrate, and NADES as reaction media. The initial enzyme activity and the final conversion of vinyl laurate transesterification by immobilized Candida antarctica lipase were studied experimentally. The direct effect of NADES on the same enzyme was modeled by molecular dynamics simulation. The effect of solubility was studied by both experimental and computational methods. To predict the solubility and viscosity of NADES, data-driven models were developed by combining group contribution and machine learning methods, based on the accumulated experimental knowledge on NADES found in the literature. Finally, the composed relationships and prediction models were applied to the practical example of deacetylation of mannosylerythritol lipids (MELs). The experimental findings show that the chosen NADES system has a significant effect on both the apparent initial activity and the final conversion. However, in the simulations, the enzyme retains its original structure; moreover, NADES has an additional stabilizing effect on the enzyme. In addition, changes in the molar ratio of the compounds in NADES do not show a significant effect on the stability of the enzyme. These results indicate that the main effect of NADES on the reaction is mainly related to the substrate-solvent interactions (solvation energy) and the viscosity of the system. On the other hand, the experimental results only confirmed the significance of solvation, viscosity did not show a clear correlation with the studied reaction parameters. The machine learning models built for solubility and viscosity gave quantitative predictions of these properties. The accumulated knowledge was used to optimize the yield in the deacetylation reaction of MELs. The combination of these methods provides fundamental knowledge about the effect of NADES on biocatalysis, but the results are also applicable to other uses of NADES. |
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Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:194886 |
Serial |
7276 |
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Author |
De Backer, J. |
Title |
The versatile nature of cytoglobin, the Swiss army knife among globins, with a preference for oxidative stress |
Type |
Doctoral thesis |
Year |
2023 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
XVIII, 232 p. |
Keywords |
Doctoral thesis; Pharmacology. Therapy; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Proteinscience, proteomics and epigenetic signaling (PPES) |
Abstract |
Since its discovery 20 years ago, many studies have been performed to gain insight into the functional role of cytoglobin (Cygb). However, Cygb has been proven to be a promiscuous protein. Yet, there is a consensus that Cygb is a cytoprotective protein involved in redox homeostasis. CYGB is a ubiquitously expressed hexacoordinated globin that is highly expressed in melanocytes and is often found to be downregulated during melanocyte-to-melanoma transition. In Chapter III, we investigated the molecular mechanism through which CYGB could be involved in redox regulation. Here, we showed that CYGB contains two redox-sensitive cysteine residues and that the formation of an intramolecular disulfide bridge resulted in the heme group becoming more accessible to external ligands. This supports the hypothesis that Cys38 and Cys83 serve as sensitive redox sensors. In Chapter IV we showed that CYGB mRNA and protein levels were elevated upon exposure to hypoxia. Interestingly, this upregulation was most likely HIF-2α-dependent. We propose that in melanoma, HIF-2α, rather than HIF-1α, positively regulates CYGB under hypoxic conditions in a cell type specific way. In Chapter V, the cytotoxic effect of indirect NTP treatment in two melanoma cell lines with divergent endogenous CYGB expression levels was investigated. We confirmed that NTP endows cytotoxicity that induces cell death through apoptosis and that this was mediated through the production of ROS. Moreover, we showed that CYGB protects melanoma cells from ROS-induced apoptosis by the scavenging of ROS. Interestingly, CYGB expression influenced the expression of NRF2 and HO-1. We identified the lncRNA MEG3 as a possible mechanism through which NRF2 expression and its downstream target HO-1 can be regulated by CYGB. In chapter VI, increased basal ROS levels and higher degree of lipid peroxidation upon RSL3 treatment contributed to the increased sensitivity of CYGB knockdown G361 cells to ferroptosis. Furthermore, transcriptome analysis demonstrates the enrichment of multiple cancer malignancy pathways upon CYGB knockdown, supporting a tumor-suppressive role for CYGB. Remarkably, CYGB expression regulation was identified as a critical determinant of the ferroptosis–pyroptosis therapy response. This suggests that CYGB is involved in the regulation of multiple modes of programmed cell death. FInally, we sought to delineate the RONS that are responsible for plasma-induced ICD. Our results highlight the importance of the short-lived species. Furthermore, we are first to demonstrate that NTP-created vaccine is safely prepared and offers complete protection. Moreover, we provide conclusive evidence that direct application of NTP induces ICD in melanoma. |
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Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:193568 |
Serial |
7277 |
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Author |
Surmenev, R.A.; Grubova, I.Y.; Neyts, E.; Teresov, A.D.; Koval, N.N.; Epple, M.; Tyurin, A.I.; Pichugin, V.F.; Chaikina, M.V.; Surmeneva, M.A. |
Title |
Ab initio calculations and a scratch test study of RF-magnetron sputter deposited hydroxyapatite and silicon-containing hydroxyapatite coatings |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Surfaces and interfaces |
Abbreviated Journal |
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Volume |
21 |
Issue |
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Pages |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A crucial property for implants is their biocompatibility. To ensure biocompatibility, thin coatings of hydroxyapatite (HA) are deposited on the actual implant. In this study, we investigate the effects of the addition of silicate anions to the structure of hydroxyapatite coatings on their adhesion strength via a scratch test and ab initio calculations. We find that both the grain size and adhesion strength decrease with the increase in the silicon content in the HA coating (SiHA). The increase in the silicon content to 1.2 % in the HA coating leads to a decrease in the average crystallite size from 28 to 21 nm, and in the case of 4.6 %, it leads to the formation of an amorphous or nanocrystalline film. The decreases in the grain and crystallite sizes lead to peeling and destruction of the coating from the titanium substrate at lower loads. Further, our ab initio simulations demonstrate an increased number of molecular bonds at the amorphous SiHA-TiO2 interface. However, the experimental results revealed that the structure and grain size have more pronounced effects on the adhesion strength of the coatings. In conclusion, based on the results of the ab initio simulations and the experimental results, we suggest that the presence of Si in the form of silicate ions in the HA coating has a significant impact on the structure, grain size, and number of molecular bonds at the interface and on the adhesion strength of the SiHA coating to the titanium substrate. |
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000697616300009 |
Publication Date |
2020-10-02 |
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Edition |
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ISSN |
2468-0230 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.2 |
Times cited |
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Approved |
Most recent IF: 6.2; 2020 IF: NA |
Call Number |
UA @ admin @ c:irua:181685 |
Serial |
7400 |
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Author |
Gerrits, N. |
Title |
Accurate simulations of the reaction of H₂ on a curved Pt crystal through machine learning |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Journal Of Physical Chemistry Letters |
Abbreviated Journal |
J Phys Chem Lett |
Volume |
12 |
Issue |
51 |
Pages |
12157-12164 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Theoretical studies on molecule-metal surface reactions have so far been limited to small surface unit cells due to computational costs. Here, for the first time molecular dynamics simulations on very large surface unit cells at the level of density functional theory are performed, allowing a direct comparison to experiments performed on a curved crystal. Specifically, the reaction of D-2 on a curved Pt crystal is investigated with a neural network potential (NNP). The developed NNP is also accurate for surface unit cells considerably larger than those that have been included in the training data, allowing dynamical simulations on very large surface unit cells that otherwise would have been intractable. Important and complex aspects of the reaction mechanism are discovered such as diffusion and a shadow effect of the step. Furthermore, conclusions from simulations on smaller surface unit cells cannot always be transfered to larger surface unit cells, limiting the applicability of theoretical studies of smaller surface unit cells to heterogeneous catalysts with small defect densities. |
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000734045900001 |
Publication Date |
2021-12-17 |
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Edition |
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ISSN |
1948-7185 |
ISBN ![sorted by ISBN field, ascending order (up)](img/sort_asc.gif) |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.353 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 9.353 |
Call Number |
UA @ admin @ c:irua:184717 |
Serial |
7413 |
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Author |
Adelmann, C.; Sankaran, K.; Dutta, S.; Gupta, A.; Kundu, S.; Jamieson, G.; Moors, K.; Pinna, N.; Ciofi, I.; Van Elshocht, S.; Bommels, J.; Boccardi, G.; Wilson, C.J.; Pourtois, G.; Tokei, Z. |
Title |
Alternative Metals: from ab initio Screening to Calibrated Narrow Line Models |
Type |
P1 Proceeding |
Year |
2018 |
Publication |
Proceedings of the IEEE ... International Interconnect Technology Conference
T2 – IEEE International Interconnect Technology Conference (IITC), JUN 04-07, 2018, Santa Clara, CA |
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154-156 |
Keywords |
P1 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We discuss the selection and assessment of alternative metals by a combination of ab initio computation of electronic properties, experimental resistivity assessments, and calibrated line resistance models. Pt-group metals as well as Nb are identified as the most promising elements, with Ru showing the best combination of material properties and process maturity. An experimental assessment of the resistivity of Ru, Ir, and Co lines down to similar to 30 nm(2) is then used to devise compact models for line and via resistance that can be compared to Cu predictions. The main advantage of alternative metals originates from the possibility for barrierless metallization. |
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000468672900051 |
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2018-09-06 |
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978-1-5386-4337-2; 978-1-5386-4337-2 |
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UA library record; WoS full record; WoS citing articles |
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no |
Call Number |
UA @ admin @ c:irua:160473 |
Serial |
7436 |
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Author |
Truong, B.; Siegert, K.; Lin, A.; Miller, V.; Krebs, F.C. |
Title |
Apical application of nanosecond-pulsed dielectric barrier discharge plasma causes the basolateral release of adenosine triphosphate as a damage-associated molecular pattern from polarized HaCaT cells |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Plasma medicine |
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Volume |
7 |
Issue |
2 |
Pages |
117-131 |
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A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Promising biomedical uses for nonthermal plasma (NTP) in the fields of regenerative medicine, cancer therapy, and vaccine delivery involve the noninvasive application of uniform nonequilibrium plasma (including dielectric barrier discharge plasma) to living skin. Whereas most investigations have focused on achieving desired therapeutic outcomes, fewer studies have examined the mechanisms and pathways by which epithelial cells respond to NTP exposure. Using a transwell apical-basolateral-chambered system to culture the human keratinocyte HaCaT cell line, in vitro experiments were performed to demonstrate the effects of nanosecond-pulsed dielectric barrier discharge (nsDBD) plasma on polarized epithelial cell viability, monolayer permeability, intracellular oxidative stress, and the release of adenosine triphosphate (ATP). Application of nsDBD plasma at 60 Hz or below had minimal or no effect on HaCaT monolayer viability or permeability. nsDBD plasma exposure did, however, result in frequency-dependent reductions in intracellular glutathione (indicating direct induction of oxidative stress by nsDBD plasma) and increased extracellular ATP concentrations in the ba-solateral (subepithelial) media, which are indicators of cellular stress and an NTP-induced inflammatory response. These studies provide new insights into nsDBD plasma-induced inflammation and local innate immune responses initiated by polarized epithelial tissues. |
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2017-02-24 |
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no |
Call Number |
UA @ admin @ c:irua:155656 |
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7465 |
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Author |
Faraji, F.; Neek-Amal, M.; Neyts, E.C.; Peeters, F.M. |
Title |
Cation-controlled permeation of charged polymers through nanocapillaries |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Physical review E |
Abbreviated Journal |
Phys Rev E |
Volume |
107 |
Issue |
3 |
Pages |
034501-34510 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Molecular dynamics simulations are used to study the effects of different cations on the permeation of charged polymers through flat capillaries with heights below 2 nm. Interestingly, we found that, despite being monovalent, Li+ , Na+ , and K+ cations have different effects on polymer permeation, which consequently affects their transmission speed throughout those capillaries. We attribute this phenomenon to the interplay of the cations' hydration free energies and the hydrodynamic drag in front of the polymer when it enters the capillary. Different alkali cations exhibit different surface versus bulk preferences in small clusters of water under the influence of an external electric field. This paper presents a tool to control the speed of charged polymers in confined spaces using cations. |
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000955986000006 |
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2023-03-17 |
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2470-0053 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.4 |
Times cited |
1 |
Open Access |
Not_Open_Access |
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Approved |
Most recent IF: 2.4; 2023 IF: 2.366 |
Call Number |
UA @ admin @ c:irua:196089 |
Serial |
7586 |
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Author |
Zhang, L. |
Title |
Characteristic diagnosis of atmospheric discharge plasma and kinetics study of reactive species |
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Doctoral thesis |
Year |
2021 |
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XVIII, 148 p. |
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Doctoral thesis; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Low-temperature plasma has received extensive attention due to its promising application prospects in the field of air pollutants degradation and energy conversion. To fulfill the need for particular applications, constructing stable plasma sources and investigating the interaction mechanisms between plasma and substances have been hot research topics. This thesis reports the diagnosis and improvement of plasma sources, diagnosis of the active species in plasma and a modeling study of chemical kinetics processes. The main research contents are as follows: In Chapter 3, a diffuse sine AC dielectric barrier discharge (DBD) is successfully obtained by optimizing the electrode structure. It is found that using double-layer dielectric plates can limit the discharge current intensity and significantly improve the discharge uniformity. The electrical characteristics and gas temperature with different operating time show that the discharge stability is also improved by using double-layer dielectric plates. In Chapter 4, nanosecond pulses are employed to generate diffuse DBD plasmas. Three main discharge stages are distinguished by ICCD images, i.e., the streamer breakdown from the needle tip to the plate electrode, the regime transition from streamer to diffuse plasma, and the propagation of surface discharge on the plate electrode surface. The chapter reveales that in nanosecond pulsed discharges the vibrational temperature of N2 increases with the discharge duration, while the rotational temperature mainly stays constant, which means electron energy is transferred into the vibrational levels, but gas heating is not obvious during the discharge pulse. In Chapter 5, both sine AC DBD and nanosecond pulsed DBD, studied in Chapter 2 and 3, are used for formaldehyde degradation. It is found that nanosecond pulsed DBD has more homogenous characteristics, better stability, and lower plasma gas temperature. Moreover, the energy consumption of nanosecond pulsed DBD is much lower than that of AC DBD. In Chapter 6, a 0D chemical kinetics model is developed to investigate the underlying plasma chemistry of methane dry reforming in a nanosecond pulsed discharge. An overview of the dominant reaction pathways of CO2 and CH4 conversion into the major products is given. Furthermore, most of the CO2 molecules are populated into vibrational states during the pulse. Hence, the vibrational states of CO2 play an important role in its dissociation process. In general, this PhD thesis contributes to a better insight in the mechanisms of sinusoidal AC DBD and nanosecond pulsed DBD plasmas and their applications, i.e., decomposition of formaldehyde and dry reforming of methane. |
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Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:183166 |
Serial |
7605 |
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Author |
Heyne, M.H. |
Title |
Chemistry and plasma physics challenges for 2D materials technology |
Type |
Doctoral thesis |
Year |
2019 |
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Volume |
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Issue |
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Pages |
167 p. |
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Doctoral thesis; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Transition-metal dichalcogenides such as MoS2 or WS2 are semiconducting materials with a layered structure. One single layer consists of a plane of metal atoms terminated on the top and bottom by the chalcogen atoms sulfur, selenium, or tellurium. These layers show strong in-plane covalent bonding, whereas the Van-der-Waals bonds in between adjacent layers are weak. Those weak bonds allow the microcleavage and extraction of a monolayer. Transistors built on such monolayer nanosheets are promising due to high electrostatic controllability in comparison to a bulk semiconductor. This is important for fast switching speed and low-power consumption in the OFF-state. Nonetheless, prototypes of such nanosheet transistors show non-idealities due to the fabrication process. Closed films on a large area cannot be obtained by mechanical exfoliation from mm-sized crystals. For wafer-level processing, synthetic growth methods are needed. It is a challenge to obtain a few layer thick crystals with large lateral grains or even without grain boundaries with synthetic growth techniques. This requires pre-conditioned monocrystalline substrates, high-temperature deposition, and polymer-assisted transfer to other target substrates after the growth. Such transfer is a source of cracks in the film and degrades the layers' promising properties by residual polymer from the bond material. Apart from transfer, patterning of the stacked 2D layers is necessary to build devices. The patterning of a 2D material itself or another material on top of it is challenging. The integration of the nanosheets into miniaturized devices cannot be done by conventional continuous-wave dry etching techniques due to the absence of etch stop layers and the vulnerability of these thin layers. To eliminate these issues in growth and integration, we explored the deposition methods on wafer-level and low-damage integration schemes. To this end, we studied the growth of MoS2 by a hybrid physical-chemical vapor deposition for which metal layers were deposited and subsequently sulfurized in H2S to obtain large area 2D layers. The impact of sulfurization temperature, time, partial H2S pressure, and H2 addition on the stoichiometry, crystallinity, and roughness were explored. Furthermore, a selective low-temperature deposition and conversion process at 450 °C for WS2 by the precursors WF6, H2S, and Si was considered. Si was used as a reducing agent for WF6 to deposit thin W films and H2S sulfurized this film in situ. The impact of the reducing agent amount, its surface condition, the temperature window, and the necessary time for the conversion of Si into W and W into WS2 were studied. Further quality improvement strategies on the WS2 were implemented by using extra capping layers in combination with annealing. Capping layers such as Ni and Co for metal-induced crystallization were compared to dielectric capping layers. The impact of the metal capping layer and its thickness on the recrystallization was evaluated. The dielectric capping layer's property to suppress sulfur loss under high temperature was explored. The annealings, which were done by rapid thermal annealing and nanosecond laser annealing, were discussed. Eventually, the fabrication of a heterostack with a MoS2 base layer and selectively grown WS2 was studied. Atomic layer etching was identified as attractive technique to remove the solid precursor Si from MoS2 in a layer-by-layer fashion. The in-situ removal of native SiO2 and the impact towards MoS2 was determined. The created patterned Si on MoS2 was then converted into patterned WS2 on MoS2 by the selective WF6/H2S process developed earlier. This procedure offers an attractive, scalable way to enable the fabrication of 2D devices with CMOS-compatible processes and contributes essential progress in the field 2D materials technology. |
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UA @ admin @ c:irua:162027 |
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7662 |
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Van de Sompel, P.; Khalilov, U.; Neyts, E.C. |
Title |
Contrasting H-etching to OH-etching in plasma-assisted nucleation of carbon nanotubes |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
Volume |
125 |
Issue |
14 |
Pages |
7849-7855 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
To gain full control over the growth of carbon nanotubes (CNTs) using plasma-enhanced chemical vapor deposition (PECVD), a thorough understanding of the underlying plasma-catalyst mechanisms is required. Oxygen-containing species are often used as or added to the growth precursor gas, but these species also yield various radicals and ions, which may simultaneously etch the CNT during the growth. At present, the effect of these reactive species on the growth onset has not yet been thoroughly investigated. We here report on the etching mechanism of incipient CNT structures from OH and O radicals as derived from combined (reactive) molecular dynamics (MD) and force-bias Monte Carlo (tfMC) simulations. Our results indicate that the oxygen-containing radicals initiate a dissociation process. In particular, we show how the oxygen species weaken the interaction between the CNT and the nanocluster. As a result of this weakened interaction, the CNT closes off and dissociates from the cluster in the form of a fullerene. Beyond the specific systems studied in this work, these results are generically important in the context of PECVD-based growth of CNTs using oxygen-containing precursors. |
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000641307100032 |
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2021-04-06 |
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1932-7447; 1932-7455 |
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UA library record; WoS full record |
Impact Factor |
4.536 |
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OpenAccess |
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Most recent IF: 4.536 |
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UA @ admin @ c:irua:178393 |
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7729 |
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Grubova, I.Y. |
Title |
Density functional theory study of interface interactions in hydroxyapatite/rutile composites for biomedical applications |
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Doctoral thesis |
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2018 |
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251 p. |
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Doctoral thesis; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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UA @ admin @ c:irua:158087 |
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7760 |
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Nematollahi, P.; Ma, H.; Schneider, W.F.; Neyts, E.C. |
Title |
DFT and microkinetic comparison of ru-doped porphyrin-like graphene and nanotubes toward catalytic formic acid decomposition and formation |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
Volume |
125 |
Issue |
34 |
Pages |
18673-18683 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Immobilization of single metal atoms on a solid host opens numerous possibilities for catalyst designs. If that host is a two-dimensional sheet, sheet curvature becomes a design parameter potentially complementary to host and metal composition. Here, we use a combination of density functional theory calculations and microkinetic modeling to compare the mechanisms and kinetics of formic acid decomposition and formation, chosen for their relevance as a potential hydrogen storage medium, over single Ru atoms anchored to pyridinic nitrogen in a planar graphene flake (RuN4-G) and curved carbon nanotube (RuN4-CNT). Activation barriers are lowered and the predicted turnover frequencies are increased over RuN4-CNT relative to RuN4-CNT. The results highlight the potential of curvature control as a means to achieve high performance and robust catalysts. |
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000693413400013 |
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2021-08-22 |
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1932-7447; 1932-7455 |
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UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
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OpenAccess |
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Most recent IF: 4.536 |
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UA @ admin @ c:irua:181538 |
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7805 |
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Shaw, P. |
Title |
Dual action of reactive species as signal and stress agents in plasma medicine : combined computational and experimental research |
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Doctoral thesis |
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2021 |
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191 p. |
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Doctoral thesis; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE) |
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Reactive oxygen and nitrogen species (RONS) generated by cold atmospheric plasma (CAP) can activate discrete signaling transduction pathways or disrupt redox cellular homeostasis, depending on their concentration. This makes that CAP possesses therapeutic potential towards wound healing, cancer, and other diseases. In order to effectively use CAP in the clinic, a clear understanding of the interaction of RONS with biomolecules (lipids, proteins and nucleic acids) from the atomic to the macro scale, and their biological significance, is needed. In this work, I have therefore studied the dual role of CAP-derived RONS, i.e., (i) in the signaling pathways involved in wound healing, and (ii) in their reaction with biomolecules to cause oxidation-mediated damage. I performed computer simulations to provide fundamental insight about the occurring processes that are difficult or even impossible to obtain experimentally. Furthermore, next to computational studies, I used both 2D and 3D tissue cultures. 3D model allows proliferation in a more physiologically relevant geometry that stimulates the production of extracellular matrix proteins. I investigated the treatment of human gingival fibroblasts with low doses of CAP-generated RONS. This treatment demonstrated that it can inhibit colony formation but does not induce cell death, induce the expression of metalloprotease proteins, induce extracellular matrix degradation, and promote cell migration, which could result in enhanced wound healing. In contrast, at high concentrations, RONS can disrupt the cell membrane integrity and induce cancer cell death through oxidative stress-mediated pathways. I discovered how oxidation of the cell membrane (lipid-peroxidation) can facilitate the access of a drug (Melittin) into cancer cells, and in this way, reduce the required therapeutic dose of Melittin in melanoma and breast cancer cells (demonstrated using in vitro, in ovo and in silico approaches). Furthermore, I studied how excessive lipid-oxidation in chemoresistant pancreatic cancer cells promotes ferroptotic cell death. This was due to the stimulation of the iron-dependent Fenton reaction by targeting a redox specific signaling network. However, upon oxidative stress, cells protect themselves via a sophisticated intracellular antioxidant system that involves the regulation of glutathione/glutathione peroxidase 4 (lipid repair enzyme). Cancer cells exhibited increased levels of intracellular RONS due to their hyper metabolism, leading to high expression of anti-oxidant systems. I therefore focus on the effect of reactive species on the intracellular anti-oxidant system and corresponding DNA damages in both temozolomide-sensitive as well as temozolomide-resistant glioblastoma spheroids, in a 3-dimensional tumor model with a more complex tumor microenvironment than cell monolayers. |
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UA @ admin @ c:irua:183751 |
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7828 |
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Chernozem, R., V; Romanyuk, K.N.; Grubova, I.; Chernozem, P., V.; Surmeneva, M.A.; Mukhortova, Y.R.; Wilhelm, M.; Ludwig, T.; Mathur, S.; Kholkin, A.L.; Neyts, E.; Parakhonskiy, B.; Skirtach, A.G.; Surmenev, R.A. |
Title |
Enhanced piezoresponse and surface electric potential of hybrid biodegradable polyhydroxybutyrate scaffolds functionalized with reduced graphene oxide for tissue engineering |
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A1 Journal article |
Year |
2021 |
Publication |
Nano Energy |
Abbreviated Journal |
Nano Energy |
Volume |
89 |
Issue |
B |
Pages |
106473 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Piezoelectricity is considered to be one of the key functionalities in biomaterials to boost bone tissue regeneration, however, integrating biocompatibility, biodegradability and 3D structure with pronounced piezoresponse remains a material challenge. Herein, novel hybrid biocompatible 3D scaffolds based on biodegradable poly(3-hydroxybutyrate) (PHB) and reduced graphene oxide (rGO) flakes have been developed. Nanoscale insights revealed a more homogenous distribution and superior surface potential values of PHB fibers (33 +/- 29 mV) with increasing rGO content up to 1.0 wt% (314 +/- 31 mV). The maximum effective piezoresponse was detected at 0.7 wt% rGO content, demonstrating 2.5 and 1.7 times higher out-of-plane and in-plane values, respectively, than that for pure PHB fibers. The rGO addition led to enhanced zigzag chain formation between paired lamellae in PHB fibers. In contrast, a further increase in rGO content reduced the alpha-crystal size and prevented zigzag chain conformation. A corresponding model explaining structural and molecular changes caused by rGO addition in electrospun PHB fibers is proposed. In addition, finite element analysis revealed a negligible vertical piezoresponse compared to lateral piezoresponse in uniaxially oriented PHB fibers based on alpha-phase (P2(1)2(1)2(1) space group). Thus, the present study demonstrates promising results for the development of biodegradable hybrid 3D scaffolds with an enhanced piezoresponse for various tissue engineering applications. |
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000703592700002 |
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2021-08-31 |
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2211-2855 |
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UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.343 |
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Most recent IF: 12.343 |
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UA @ admin @ c:irua:182579 |
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7914 |
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Alexiades, V.; Autrique, D. |
Title |
Enthalpy model for heating, melting, and vaporization in laser ablation |
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A1 Journal article |
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2010 |
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Electronic journal of differential equations |
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1-13 |
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A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Laser ablation is used in a growing number of applications in various areas including medicine, archaeology, chemistry, environmental and materials sciences. In this work the heat transfer and phase change phenomena during nanosecond laser ablation of a copper (Cu) target in a helium (He) background gas at atmospheric pressure are presented. An enthalpy model is outlined, which accounts for heating, melting, and vaporization of the target. As far as we know, this is the first model that connects the thermodynamics and underlying kinetics of this challenging phase change problem in a selfconsistent way. |
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000455668500001 |
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1072-6691 |
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UA @ admin @ c:irua:190550 |
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7925 |
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Sankaran, K.; Swerts, J.; Carpenter, R.; Couet, S.; Garello, K.; Evans, R.F.L.; Rao, S.; Kim, W.; Kundu, S.; Crotti, D.; Kar, G.S.; Pourtois, G. |
Title |
Evidence of magnetostrictive effects on STT-MRAM performance by atomistic and spin modeling |
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P1 Proceeding |
Year |
2018 |
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2018 Ieee International Electron Devices Meeting (iedm) |
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P1 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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For the first time, we demonstrate, using an atomistic description of a 30nm diameter spin-transfer-torque magnetic random access memories (STT-MRAM), that the difference in mechanical properties of its sub-nanometer layers induces a high compressive strain in the magnetic tunnel junction (MTJ) and leads to a detrimental magnetostrictive effect. Our model explains the issues met in engineering the electrical and magnetic performances in scaled STT-MRAM devices. The resulting high compressive strain built in the stack, particularly in the MgO tunnel barrier (t-MgO), and its associated non-uniform atomic displacements, impacts on the quality of the MTJ interface and leads to strain relieve mechanisms such as surface roughness and adhesion issues. We illustrate that the strain gradient induced by the different materials and their thicknesses in the stacks has a negative impact on the tunnel magneto-resistance (TMR), on the magnetic nucleation process and on the STT-MRAM performance. |
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000459882300147 |
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978-1-72811-987-8; 978-1-72811-987-8 |
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UA @ admin @ c:irua:158694 |
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7942 |
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Cui, Z. |
Title |
Experimental and theoretical study on SF6 degradation by packed-bed DBD plasma |
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Doctoral thesis |
Year |
2021 |
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Doctoral thesis; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Sulfur hexafluoride (SF6), as a man-made gas, is widely used in power industry, semiconductor industry and metal-processing industry. However, SF6 is a greenhouse gas and its global warming potential is 23500 times that of CO2. Besides, SF6 is very stable, with a lifetime in the atmosphere for more than one thousand years. Under natural conditions, only the ultraviolet light can make it slowly decomposed. Thus, the emission of SF6 has a great threat to the environment. In recent years, with the development of our national economy, the use of SF6 increased dramatically. And 90% of the SF6 emissions come from the power industry. In the meantime, the emission of SF6 exists a ‘hysteresis effect’, as many of the SF6-gas insulation equipment will retire in next decades, the emission of SF6 may increase sharply, and this may put great pressure on the environment. Therefore, it’s necessary to make efforts in controlling and treating the SF6 emission. Among the SF6 abatement technologies, the non-thermal plasma(NTP) represented by the dielectric barrier discharge(DBD) can effectively degrade SF6 and is suitable for large-scale industry applications. However, its energy efficiency still gets room for improvement and this kind of method has a defect that it’s hard to regulate the degradation by-products. Therefore, this paper proposed the combination of the packed bed reactor and the DBD technology to form a packed DBD discharge system for SF6 degradation, so that to further improve the energy efficiency and regulate the selectivity of by-products. By experiment and simulation research, the following innovations have been achieved: (1) Based on the packed bed DBD platform, the power parameter and gas-phase parameters of SF6 degradation were studied. It was found that the discharge process was significantly enhanced with the addition of packing particles, and the discharge energy efficiency was improved. The increase of input voltage can obviously increase the degradation rate, but reduces the energy efficiency. The increase of SF6 initial concentration and gas flow rate can improve the energy efficiency, but reduce the degradation rate. Therefore, both degradation rate and energy efficiency should be considered in deciding basic experimental conditions. (2) Active gases, such as O2, H2O and NH3, could effectively promote the degradation rate of SF6, and changed the product selectivity. In our packed bed DBD system, O2 and H2O have the optimal concentration conditions, which are 2% and 1%, respectively. The addition of O2 can promote the generation of S-O-F products, and inhibit the selectivity of SO2, while the addition of H2O had the opposite effects. In addition, the synergistic degradation of NH3 and SF6 will produce solid products, such as NH3HF, NH4HF2 and elemental S. For gaseous products, the increase of NH3 will lead to the generation of SO2 in the final degradation products and inhibit the generation of S-O-F products. (3) Different kinds of packing materials have great impacts on the degradation system in the discharge parameters, degradation rate and energy efficiency, as well as the products distribution. In the experiment, we compared the degradation results in three systems: glass beads packing, γ-Al2O3 packing and no-packing system. The packing of glass beads effectively improved the discharge voltage amplitude and discharge power, while had a limited effect on the equivalent capacitance of the dielectric. Besides, γ-Al2O3 packing had little effect on voltage amplitude, but obviously increased the equivalent capacitance of the dielectric. Furthermore, the degradation rate and energy efficiency in γ-Al2O3 system was higher than that of glass bead system. For products selectivity, γ-Al2O3 system was more desirable, where S-O-F type of product selectivity was suppressed and the SO2 selectivity increased significantly. By contrast, the glass beads system hardly affected the product selectivity. This results are presumably due to the relatively high dielectric constant of γ-Al2O3 particles and γ-Al2O3 itself may act as a reactant or a catalyst participating in the degradation reactions. (4) The size and status of the packing particles also have significant effects on the degradation process. The systems packed with 1, 2 and 4mm γ-Al2O3 particles for SF6 degradation were compared, and the 2mm system had the best performance, which may because the 2mm system had a good balance between the active contact area and the gas residence time. In addition, the packing pellets suffered from a hydration process slightly reduced the discharge parameters in the γ-Al2O3 packing system and significantly reduced the degradation rate was, which may because the H2O molecules pre-occupied the active sites on the γ-Al2O3 surface and reduced the discharge process. (5) Based on density functional theory (DFT), the degradation process of SF6 in the packed bed DBD system was studied at atomic scale. It was found that the SF6 can occur a physical adsorption at AlⅢ active sites on γ-Al2O3 surface. The activation barrier for the first degradation step of SF6 on γ-Al2O3 surface is much lower than in gas phase, which proved that the SF6 molecule is activated on the γ-Al2O3 surface. In addition, the plasma may affect the γ-Al2O3 surface to generate excess electrons or external electric fields. This two effects can change the adsorbed SF6 molecules from physical adsorption to chemisorption, together with an obvious stretching of S-F bonds, indicating that the plasma surface effects prmote the activation and decomposition of SF6 molecules. Furthermore, the stepwise degradation process of SF6 on γ-Al2O3 surface were investigated. The influence of radicals produced by plasma on the degradation process was analyzed. It was found that via Eley–Rideal (ER) reactions, high-energy radicals could effectively reduce the activation barriers and promote the surface reactions. Finally, the degradation mechanism of SF6 molecules in the packed bed plasma system was summarized, which may provide a theoretical basis for the study of harmless degradation of SF6. Keywords: SF6; Packed Bed DBD; Discharge Parameters; Products Analysis; Degradation Mechanism |
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UA @ admin @ c:irua:180819 |
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7946 |
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Clima, S.; O'Sullivan, B.J.; Ronchi, N.; Bardon, M.G.; Banerjee, K.; Van den Bosch, G.; Pourtois, G.; van Houdt, J. |
Title |
Ferroelectric switching in FEFET : physics of the atomic mechanism and switching dynamics in HfZrOx, HfO2 with oxygen vacancies and Si dopants |
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P1 Proceeding |
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2020 |
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P1 Proceeding; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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The fine balance between dipole-field energy and anion drift force defines the switching mechanism during polarization reversal: for the first time we show that only Pbcm mechanism obeys the ferroelectric switching physics, whereas P4(2)/nmc (or any other) mechanism does not. However, with lower energy barrier, it represents an important antiferroelectric mechanism. Constraints relaxation can lead to 90 degrees polarization rotation (domain deactivation). Intrinsically, the Si/VO-doping can switch faster than undoped HfO2 or HfZrOx. Theoretical Arrhenius model / intrinsic material switching (DFT) overestimates the switching speed extracted from experiments. |
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000717011600218 |
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2021-03-11 |
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978-1-7281-8888-1 |
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UA library record; WoS full record; WoS citing articles |
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Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:184730 |
Serial |
7963 |
Permanent link to this record |