Veronika Mihaylova

Dr. Veronika Mihaylova


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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1 July 2013 in Applied Spectroscopy Reviews
Verified
Journal Article
Closed access
RDRumyana Djingova
Rumyana Djingova
VMVeronika Mihaylova
Veronika Mihaylova
VLValentina Lyubomirova
Valentina Lyubomirova
DTDimiter L. Tsalev
Dimiter L. Tsalev
The study of the ionome (ionomics) is defined as quantitative and simultaneous measurement of the element composition of living organisms and changes in this composition in response to physiological stimuli, development stage, and genetic modifications (Salt et al., Ann. Rev. Plant Biol., Vol. 59, 2008). The necessity of understanding the regulation processes of elements in the organisms demands determination of many elements in the organism, tissue, and cell (Baxter, Plant Biol., Vol. 12, 2009). A prospect for ionomics is environmental pollution where great variety of conditions and pollutants exist resulting in concentration and interelemental changes in the plant ionome. The capabilities of and problems with several multielement analytical techniques, including instrumental neutron activation analysis (INAA), X-ray fluorescence, inductively coupled plasma–atomic emission spectrometry (ICP-AES), inductively coupled plasma–mass spectrometry (ICP-MS), and atomic absorption spectrometry (AAS), which are adequate and most promising in ionomic and environmental studies of plants, are reviewed. References are confined mainly to the last 10–15 years. Information about concentrations, roles, binding forms, and pollution sources of the elements and comparison between methods with respect to limits of detection, determined elements, interferences, and economic considerations are tabulated. Some combinations of instrumental techniques supplementing each other are highly valued, namely, ICP-MS and ICP-AES and INAA and AAS or ICP-AES.

1 November 2013 in International Journal of Environmental Analytical Chemistry
Verified
Journal Article
Closed access
VMVeronika Mihaylova
Veronika Mihaylova
VLValentina Lyubomirova
Valentina Lyubomirova
RDRumyana Djingova
Rumyana Djingova
An ICP-MS method for determination of 60 elements in plant samples is proposed based on optimization of digestion, recommending use of HF besides HNO3 and H2O2 and calibration procedures, using CRMs for construction of calibration curves. Adequate choice of analytical isotopes and various measurement conditions (cold plasma for the determination of Al, Ba, Ca, Fe, K, Mg, Mn, Na, Si and Sr and DRC mode for determination of Ag, As, Ni, Pd, Pt, Se and V) as well as introduction of appropriate corrections lead to determination of as large number of elements with quadropole ICP-MS as with the more expensive SF-ICP-MS. Two measurements are performed: cold plasma and standard/DRC mode. The analytical characteristics of the method are demonstrated by analysis of five CRMs and the agreement of the experimental results with the certified/information/literature values is very good. Detection limits are low enough to permit the determination of all elements but platinum metals at background level. The applicability of the method is demonstrated by analysis of Taraxacum officinale (dandelion) samples collected from regions with different anthropogenic influence. The results indicate high degree of pollution round the Pb-Zn smelter with As, Cd, Cu, Ni, Pb and Zn and increased concentrations of B, Be, Bi, Hg, In, Mn, Sb, Se, Sn, Ti, Tl, V and Zr. The dandelion sample, collected along a highway has increased concentrations of traffic released elements: Pt, Pd, Rh, Ce, La, Pb as well as Cu, Zn, Ba and Rb.

24 February 2022 in Processes
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Journal Article
Open access
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Mihaela KirilovaMihaela Kirilova
Mihaela Kirilova
IYIvaylo Yotinov
Ivaylo Yotinov
Irina SchneiderIrina Schneider
Irina Schneider
NDNora Dinova
Nora Dinova
YTYovana Todorova
Yovana Todorova
YTYana Topalova
Yana Topalova
Biological treatment is a key technology in landfill leachate treatment However, often its efficiency is not high enough due to the pollutants in concentrations above the critical ones. The present study aimed to investigate the adaptive responses that occur in activated sludge (AS) during landfill leachate purification. A model process with AS from a municipal wastewater treatment plant and landfill leachate in increasing concentrations was constructed. The data showed that when dilutions 25 and 50 times had been applied the structure of the AS was preserved, but the COD cannot be reduced below 209 mg O2/L. The feed of undiluted leachate destroyed the AS structure as SVI was reduced to 1 mL/g, biotic index to 1, floc size was greatly reduced and COD remained high (2526 mg O2/L). The dominant group of protozoa was changed from attached to free-swimming ciliates. An increase of the bacterial groups responsible for the xenobiotics elimination (aerobic heterotrophs, genera Pseudomonas, Acinetobacter, Azoarcus, Thauera, Alcaligenes) was registered. This was accompanied by a significant increase in free bacteria. The obtained data showed that for optimal treatment of this type of water it is necessary to include a combination of biological treatment with another non-biological method (membrane filtration, reverse osmosis, etc.).

27 February 2015 in Journal of Soils and Sediments
Verified
Journal Article
Closed access
PDF file
VLValentina Lyubomirova
Valentina Lyubomirova
VMVeronika Mihaylova
Veronika Mihaylova
RDRumyana Djingova
Rumyana Djingova

13 September 2023 in Pharmaceutics
Verified
Journal Article
Open access
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Anife AhmedovaAnife Ahmedova
Anife Ahmedova
RMRositsa Asenova Mihaylova
Rositsa Asenova Mihaylova
SSSilviya Stoykova
Silviya Stoykova
VMVeronika Mihaylova
Veronika Mihaylova
NBNikola Burdzhiev
Nikola Burdzhiev
DMDenitsa Momekova
Denitsa Momekova
Research on platinum-based anticancer drugs continuously strives to develop new non-classical platinum complexes. Pt(IV) prodrugs are the most promising, and their activation-by-reduction mechanism of action is being explored as a prospect for higher selectivity and efficiency. Herein, we present the anticancer potency and chemical reactivity of Pt(IV) complexes formed by linking pyrene butyric acid with cisplatin. The results from cytotoxicity screening on 10 types of cancer cell lines and non-malignant cells (HEK-293) indicated IC50 values as low as 50–70 nM for the monosubstituted Pt(IV) complex against leukemia cell lines (HL-60 and SKW3) and a cisplatin-resistant derivative (HL-60/CDDP). Interestingly, the bis-substituted complex is virtually non-toxic to both healthy and cancerous cells of adherent types. Nevertheless, it shows high cytotoxicity against multidrug-resistant derivatives HL-60/CDDP and HL-60/Dox. The reactivity of the complexes with biological reductants was monitored by the NMR method. Furthermore, the platinum uptake by the treated cells was examined on two types of cellular cultures: adherent and suspension growing, and proteome profiling was conducted to track expression changes of key apoptosis-related proteins in HL-60 cells. The general conclusion points to a possible cytoskeletal entrapment of the bulkier bis-pyrene complex that could be limiting its cytotoxicity to adherent cells, both cancerous and healthy ones.

1 January 2013 in Proceedings of the Bulgarian Academy of Sciences
Verified
Journal Article
Closed access
VMVeronika Mihaylova
Veronika Mihaylova
BTBoyan Todorov
Boyan Todorov
RDRumyana Djingova
Rumyana Djingova