Margarita Kouzmanova

Dr. Margarita Kouzmanova

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Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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5 June 2021 in Cells
Verified
Journal Article
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LZLyuben Zagorchev
Lyuben Zagorchev
AAAlexandra Atanasova
Alexandra Atanasova
IAIvanela Albanova
Ivanela Albanova
ATAnelia Traianova
Anelia Traianova
VMVasil Academy of Bulgaria Mladenov
Vasil Academy of Bulgaria Mladenov
DTDenitsa Teofanova
Denitsa Teofanova
Members of the genus Cuscuta are generally considered to be non-photosynthetic, stem-holoparasitic flowering plants. Under certain circumstances, at least some members of the genus are capable of limited photosynthesis. The galls of the Smicronyx weevils formed on Cuscuta campestris are particularly rich in chlorophylls compared to the stem of the parasitic plant. In the present study, we aimed to characterize the photosynthetic activity in the inner and outer gall cortices in comparison to the non-photosynthetic stems and a reference plant (Arabidopsis thaliana). The recorded prompt chlorophyll fluorescence transients were analyzed using JIP test. Detailed analysis of the chlorophyll fluorescence confirmed the presence of actively functioning photosynthetic machinery, especially in the inner cortex of the galls. This photosynthesis, induced by the insect larvae, did not reach the levels of the photosynthetic activity in Arabidopsis thaliana plants. Thylakoid protein complexes were identified by separation with two-dimensional Blue Native/SDS PAGE. It appeared that some of the complexes presented in A. thaliana are missing in C. campestris. We hypothesize that the insect-triggered transition from non-photosynthetic to photosynthetic tissue in the gall is driven by the increased requirements for nutrients related to the larval nutrition.

8 July 2022 in Sensors
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Journal Article
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NANikolay Todorov Atanasov
Nikolay Todorov Atanasov
GAGabriela Atanasova
Gabriela Atanasova
BABoyana Dimitrova Angelova
Boyana Dimitrova Angelova
MPMomchil Paunov
Momchil Paunov
MGMaria Gurmanova
Maria Gurmanova
MKMargarita Kouzmanova
Margarita Kouzmanova
In recent years, there has been a rapid development in the wearable industry. The growing number of wearables has led to the demand for new lightweight, flexible wearable antennas. In order to be applicable in IoT wearable devices, the antennas must meet certain electrical, mechanical, manufacturing, and safety requirements (e.g., specific absorption rate (SAR) below worldwide limits). However, the assessment of SAR does not provide information on the mechanisms of interaction between low-intensity electromagnetic fields emitted by wearable antennas and the human body. In this paper, we presented a detailed investigation of the SAR induced in erythrocyte suspensions from a fully textile wearable antenna at realistic (net input power 6.3 mW) and conservative (net input power 450 mW) conditions at 2.41 GHz, as well as results from in vitro experiments on the stability of human erythrocyte membranes at both exposure conditions. The detailed investigation showed that the 1 g average SARs were 0.5758 W/kg and 41.13 W/kg, respectively. Results from the in vitro experiments demonstrated that the short-term (20 min) irradiation of erythrocyte membranes in the reactive near-field of the wearable antenna at 6.3 mW input power had a stabilizing effect. Long-term exposure (120 min) had a destabilizing effect on the erythrocyte membrane.

17 July 2025 in Proceedings of the Bulgarian Academy of Sciences
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MPMomchil Paunov
Momchil Paunov
BABoyana Dimitrova Angelova
Boyana Dimitrova Angelova
VGVasilij Nikolaevich Goltsev
Vasilij Nikolaevich Goltsev
GAGabriela Atanasova
Gabriela Atanasova
BABlagovest Atanasov
Blagovest Atanasov
MKMargarita Kouzmanova
Margarita Kouzmanova
With the increasing application of wireless technologies in crop production, the question whether radiofrequency (RF) electromagnetic fields (EMF) influence crops becomes significant. Effects of RF EMF on plants were studied at genetic, physiological, morphological, anatomical levels, and the obtained results were contradictory. EMF could affect plant growth, biomass accumulation and metabolite synthesis, and thus the quality and quantity of the crop yield. The aim of this study was to examine long-term effects of EMF emitted by wireless sensors used in precision agriculture on economically important wheat and maize varieties, during the sensitive early period of crop development. We investigated morphological (growth rate, biomass) and physiological characteristics (photosynthetic pigments, reducing sugars, anthocyanins and malondialdehyde) 10 days after 2-hour irradiation of sprouts with 900 MHz 370 V/m continuous electromagnetic wave. None of the examined parameters displayed statistically significant difference between control and exposed plants. We concluded that the 900 MHz EMF is safe for crops subjected to precision agriculture technologies even at strong electric field exposures for two hours.

29 December 2025 in Applied Sciences
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Journal Article
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MKMargarita Kouzmanova
Margarita Kouzmanova
MPMomchil Paunov
Momchil Paunov
BABoyana Dimitrova Angelova
Boyana Dimitrova Angelova
VGVasilij Nikolaevich Goltsev
Vasilij Nikolaevich Goltsev
Smart agriculture technology is rapidly spreading for its economic benefits and increase in farming efficiency. The management of agricultural activities is fulfilled by a network of connected devices and sensors, using wireless technologies and software to exchange data over the Internet. The electromagnetic fields (EMFs) these systems use increase the background level in farmlands, and the crop plants are exposed to unusual levels of unnatural, polarized, coherent, and variable EM radiation. This combination determines EMF influence on plants. Many studies found effects at different levels of organization—molecular, organismal, and even ecosystem levels—but the underlying mechanisms are still not well understood. In this review paper, we attempted to clarify possible mechanisms on the very basic molecular level involved in the realization of biological effects, discussing the interaction of EMFs with water molecules in living systems, from their effects on biologically significant molecules, membranes, ion channels, and ion transport, oxidative processes in cells, and photosynthesis to the effects on plant growth and development. In conclusion, we discuss the obstacles to defining the conditions for the manifestation of beneficial or adverse effects and setting exposure limits.

15 May 2023 in BioRisk
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Journal Article
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BABoyana Dimitrova Angelova
Boyana Dimitrova Angelova
GAGabriela Atanasova
Gabriela Atanasova
NANikolay Todorov Atanasov
Nikolay Todorov Atanasov
MPMomchil Paunov
Momchil Paunov
MGMaria Gurmanova
Maria Gurmanova
MKMargarita Kouzmanova
Margarita Kouzmanova
The growing use of wireless communication devices has been significantly increasing the level of high frequency electromagnetic fields (EMFs) in the environment, which raises a concern for possible deleterious effects on living organisms. Long lasting exposure to low-intensity EMFs can cause effects on the molecular and cellular level, and a number of morphological and physiological changes. The aim of this work was to investigate the effects of 2.41 GHz EMF emitted by wireless communication systems on human erythrocytes after in vitro irradiation. The amount of the hemoglobin released from the cells was measured as an indicator for membrane destabilization. Effects of different exposure times (20 min or 4 h) and time elapsed after exposure to 2.41 GHz pulsed or continuous EMFs with different intensities, emitted from a textile (0.213–0.238 V/m) or a dipole (5, 20, 40 and 180 V/m) antenna, were investigated. The obtained results showed that the low intensity EMF had no significant effect on the hemoglobin release from irradiated cells; even a slight tendency for membrane stabilization was noticed 3–4 hours after the end of 20-min exposure to 0.213–0.238 V/m, 2.41 GHz EMF. There was no difference in the effects of continuous and pulsed EMFs. Increased hemoglobin release was observed only during the 4-hour exposure to 180 V/m, 2.41 GHz continuous EMF. Under these conditions, the temperature of the cell suspension had been rising, so we compared the results obtained under EMF with the effects of conventional heating. Moreover, after 1-hour exposure to 180 V/m the released hemoglobin level was a bit higher than the control one but the difference disappears within an hour after terminating the irradiation. In conclusion, the in vitro exposure to 2.41 GHz EMF emitted by wireless communication devices with power density below the reference level for population exposure does not change the stability of the cell membrane of human erythrocytes.

14 June 2026 in Applied Sciences
Verified
Journal Article
Open access
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MPMomchil Paunov
Momchil Paunov
BABoyana Dimitrova Angelova
Boyana Dimitrova Angelova
BABlagovest Nikolaev Atanasov
Blagovest Nikolaev Atanasov
NANikolay Todorov Atanasov
Nikolay Todorov Atanasov
MKMargarita Kouzmanova
Margarita Kouzmanova
VGVasilij Nikolaevich Goltsev
Vasilij Nikolaevich Goltsev
Internet of things long range (IoT/LoRa) devices emit radiofrequency electromagnetic fields (RF-EMF), ensuring long-range, low-power communication, and their use in precision agriculture continuously expands. Thus, the interest in the impact of low-intensity but long-term EMF exposure on plants has increased. In this study, maize plants were exposed to 868 MHz, 10 mW EMF for the first 28 days of their development with soil-buried antennas. Plants were divided into three groups: Control, Sham-exposed, and EMF-exposed. Biological effects were followed on morphological, physiological, and biochemical levels every week. The plant height values were fitted to a Gompertz function modeling the growth. The results showed slightly faster early development of EMF-exposed plants in about 21 days. The relative dry-leaf biomass from EMF-affected plants was a bit higher than in the Control and Sham groups until day 21. Chlorophyll fluorescence analysis (JIP-test) indicated photosynthetic stability. Antioxidant enzyme activity, antioxidant capacity, content of malondialdehyde, hydrogen peroxide, and reducing sugars were measured, and principal component analysis was done for all parameters. Overall, the developmental stage accounts for most of the observed variations in the data rather than EMF exposure. The results suggest that under the tested conditions, IoT/LoRa-emitted EMF did not provoke adverse effects in maize and acted as a modest modulator of physiological functions.