Sándor Kéki

Prof. Sándor Kéki

Department of Applied Chemistry, University of Debrecen, Hungary
orcid

Research Focus & Metrics

Academic Career Length

35Years (1992-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
29 December 2017 in Polymers
Verified
Journal Article
Open access
PDF file
Jozsef Karger-KocsisJozsef Karger-Kocsis
Jozsef Karger-Kocsis
Sándor KékiSándor Kéki
Sándor Kéki
Shape memory polymer (SMP) is capable of memorizing one or more temporary shapes and recovering successively to the permanent shape upon various external stimuli. Beside of the above mentioned one-way variants, also two-way shape memory polymers (SMPs) and shape memory (SM) systems exist which feature a reversible shape change on the basis of “on-off switching” of the external stimulus. The preparation, properties and modelling of shape memory epoxy resins (SMEP), SMEP foams and composites have been surveyed in this exhaustive review article. The underlying mechanisms and characteristics of SM were introduced. Emphasis was put to show new strategies on how to tailor the network architecture and morphology of EPs to improve their SM performance. To produce SMEPs novel preparation techniques, such as electrospinning, ink printing, solid-state foaming, were tried. The potential of SMEPs and related systems as multifunctional materials has been underlined. Added functionality may include, among others, self-healing, sensing, actuation, porosity control, recycling. Recent developments in the modelling of SMEPs were also highlighted. Based on the recent developments some open topics were deduced which are merit of investigations in future works.

1 April 2021 in Polymer Testing
Verified
Journal Article
Open access
RKRéka Lilla Kovács
Réka Lilla Kovács
MCMáté Csontos
Máté Csontos
SGSzilvia Gyöngyösi
Szilvia Gyöngyösi
JEJános Elek
János Elek
BPBence Parditka
Bence Parditka
ZEZoltán Erdélyi
Zoltán Erdélyi

20 November 2011 in Chromatographia
Verified
Journal Article
Closed access
PDF file
ÁKÁkos Kuki
Ákos Kuki
LNLajos Nagy
Lajos Nagy
GDGyörgy Deák
György Deák
MNMiklós Nagy
Miklós Nagy
MZMiklós Zsuga
Miklós Zsuga
Sándor KékiSándor Kéki
Sándor Kéki

21 April 2021 in Applied Sciences
Verified
Journal Article
Open access
PDF file
B(Bianca Onita (Mladin)
Bianca Onita (Mladin)
PAPaul Albu
Paul Albu
HHHildegard Herman
Hildegard Herman
CBCornel Balta
Cornel Balta
VLVasile Lazar
Vasile Lazar
Anca DinischiotuAnca Dinischiotu
Anca Dinischiotu
This study assessed the distribution of heavy metals in the gills, kidney, and liver, correlated with the severity of histopathological changes, of three fish species with different feeding habitats (Barbus barbus, Squalius cephalus, and Chondrostoma nasus) from the Crișul Negru river, Romania. The levels of copper (Cu), chromium (Cr), cadmium (Cd), lead (Pb), and zinc (Zn) in fish tissues were measured by atomic absorption spectrophotometry. Histopathology and the expressions of TNF-α and proliferation cell nuclear antigen (PCNA) were investigated by immunohistochemistry and Western blot. Our data suggest a significant correlation between the bioconcentration level of metals and structural changes. The carnivorous species was the most affected compared to the omnivorous and herbivorous ones, and the most affected organ was the kidney. Moreover, the correlation of tissue damage with the PCNA and TNF-α expression levels revealed that the herbivorous species presented less extended lesions, likely due to higher activated repair mechanisms and lower levels of inflammation. In conclusion, our data and the subsequent statistical analysis suggest that feeding behavior could be correlated with the histopathological alterations and might be used for a more profound evaluation of aquatic environment safety and analysis of aquatic ecosystems.

Verified
Journal Article
Open access
PDF file
EBEdina Bakondi
Edina Bakondi
SSSalam Bhopen Singh
Salam Bhopen Singh
ZHZoltán Hajnády
Zoltán Hajnády
MNMáté Nagy-Pénzes
Máté Nagy-Pénzes
ZRZsolt Regdon
Zsolt Regdon
László VirágLászló Virág
László Virág
Activated macrophages upregulate inducible nitric oxide synthase (iNOS) leading to the profuse production of nitric oxide (NO) and, eventually, tissue damage. Using macrophage NO production as a biochemical marker of inflammation, we tested different parts (flower, leaf, and stem) of the medicinal plant, Spilanthes acmella. We found that extracts prepared from all three parts, especially the flowers, suppressed NO production in RAW macrophages in response to interferon-γ and lipopolysaccharide. Follow up experiments with selected bioactive molecules from the plant (α-amyrin, β-caryophylline, scopoletin, vanillic acid, trans-ferulic acid, and spilanthol) indicated that the N-alkamide, spilanthol, is responsible for the NO-suppressive effects and provides protection from NO-dependent cell death. Spilanthol reduced the expression of iNOS mRNA and protein and, as a possible underlying mechanism, inhibited the activation of several transcription factors (NFκB, ATF4, FOXO1, IRF1, ETS, and AP1) and sensitized cells to downregulation of Smad (TF array experiments). The iNOS inhibitory effect translated into an anti-inflammatory effect, as demonstrated in a phorbol 12-myristate 13-acetate-induced dermatitis and, to a smaller extent, in cerulein-induced pancreatitis. In summary, we demonstrate that spilanthol inhibits iNOS expression, NO production and suppresses inflammatory TFs. These events likely contribute to the observed anti-inflammatory actions of spilanthol in dermatitis and pancreatitis.

28 May 2016 in Analytical and Bioanalytical Chemistry
Verified
Journal Article
Closed access
PDF file
BABorbála Antal
Borbála Antal
ÁKÁkos Kuki
Ákos Kuki
LNLajos Nagy
Lajos Nagy
TNTibor Nagy
Tibor Nagy
MZMiklós Zsuga
Miklós Zsuga
Sándor KékiSándor Kéki
Sándor Kéki