Volume 8 (2021): Edition 2 (July 2021)

In this study we developed well validated thermodynamic models for solution behavior and solid-liquid equilibrium for all fluoride binary systems, for which activity data are available. The subject of modeling study are 5 fluoride systems of the type 1-1 (HF-H₂O, NaF-H₂O, KF-H₂O, RbF-H₂O, and CsF-H₂O) and one of 1-2 type (H₂SiF₆-H₂O) from low to very high concentration at 298.15 K. Models are developed on the basis of Pitzer ion interactions approach. The recommendations on mean activity coefficients (γ_±) have been used to construct the model for HF-H₂O system. To parameterize models for all other 5 binary systems we used all available raw experimental osmotic coefficients data (φ) for whole concentration range of solutions, and up to saturation point. The predictions of new developed here models are in excellent agreement with experimental osmotic coefficients data, and with recommendations on activity coefficients in binary solutions from low to very high concentration: up to 20 mol. kg⁻¹ in HF-H₂O, and up to 35.6 mol.kg⁻¹ in CsF-H₂O. The Deliquescence Relative Humidity (DRH (%)) and thermodynamic solubility products (as ln K^o_sp) of 4 solid phases [NaF(s), KF.2H₂O(s), RbF(s), and CsF(s)] have been determined on the basis of evaluated model parameters and using experimental m(sat) solubility data.

The present work focuses on evaluation of the toxic effects of an exposure to lead (Pb) on the liver mitochondria function in Wistar rats and the protective role of the fennel essential oils (FEO).

The experiments were conducted on Wistar rats, which were treated daily through orally gavages during 21 days. 24 animals were divided into four groups of 6 rats each one: the control group received water, while group II received FEO (0.5 mg/kg); group III received Pb (25 mg/kg), and group IV received Pb + FEO in the doses of (0,5 + 25 mg/kg). The mitochondrial dysfunction induced by lead is expressed by reducing mitochondrial respiration (O₂ consumption) associated with an increase in mitochondrial swelling and permeability compared to the control group. A disturbance in the rates of oxidative stress biomarkers was also observed. This disturbance was expressed by an increase of the MDA rate and the Cytochromes C activity associated with depletion in the GSH rate and GPx activity compared to the control group. The rat’s co-treatment with FEO restored all these parameters to values similar to the Control.

The whole of these results shows well that the exposure to the lead causes disturbances on the level mitochondrion, which are attenuated by fennel essential oils.

The aim of the present study is to identify medicinal plants used for decorative purposes by the local population along the Northern Black Sea coast (Bulgaria). A survey was conducted in the period 2014-2020. The interviews with the local population were conducted “face to face” with the help of pre-prepared original questionnaires. The surveyed locals are 709 people from 32 settlements. Respondents were randomly selected. They are of different age groups, gender, ethnicity, education and employment. The folk names of the used medicinal plants are recorded. The results show that a significant proportion of respondents (52.89%) use medicinal plants for decorative purposes. The medicinal plants used for decorative purposes by the locals are 73 species, belonging to 61 genera from 30 families. The present study is part of a larger ethnobotanical study of medicinal plants in the region of the North Black Sea coast.

The current ethnobotanical study summarizes the use of medicinal plants by locals in the region of the Northern Black Sea Coast, Bulgaria. The survey was conducted in the period between 2014 and 2020. After prior informed consent, 709 local residents from 32 settlements were interviewed. The interviews with the local population were conducted using the “face to face” technique with the help of pre-prepared original questionnaires. The study presents quantitative ethnobotanical information on the use of medicinal plants in the study area. The results were analyzed using quantitative indices: Respondent Consensus Ratio (F_IC), Loyalty Level Index (FL) and Significance Value Index (IVs). A total of 332 species of medicinal plants belonging to 250 genera of 90 families have been identified for the region of the Northern Black Sea Coast. The largest number of citations are registered for the use of medicinal plants for culinary purposes and for use in human medicine. The use of medicinal plants in other household applications has been studied.

Ophrys sphegodes subsp. helenae (Renz) Soó & D.M.Moore is a Balkan endemic, for which so far there are data for distribution only on the territory of 2 countries: Greece and Albania. During a study of the flora of the Voyvodsko plateau, located in the northeastern part of the Republic of Bulgaria, in April 2019 a locality of this species was discovered. The development of the population in the period April 2019 - May 2021 was monitored. The population consists of 3 individuals located on an area of 0.5 m². Of these, 2 individuals are in a generative state and 1 individual is in a vegetative state. The abiotic and biotic conditions in the habitat are described. It is characterized by a rich floristic diversity: the associated species are 60 in number. Anthropogenic impact has been reported. The prospects for the existence of the population are indicated. It is proposed to declare the territory around the locality a protected area in order to preserve the habitat from negative anthropogenic impacts.

During the period 2019 - 2020, a study was conducted on soil type calcic chernozem with Venka 1 common winter wheat variety. The experiment is based on the block method, in four replications with a size of the experimental plot of 10 m2. Sowing was carried out in October with a sowing rate of 500 sprouts/m2 after the predecessor sugar beet. In the appropriate periods, treatments were made in 4 variants: 1) Control - untreated variant, 2) Treatment with biodynamic preparations: 500 + Fladen preparation + preparation 501, 3) Treatment with biological preparations: Heliosulfur + Free N. 4) Combined treatment with the same biodynamic and biological preparations.

Preparation 500 was applied in the phase of autumn and spring wheat tillering - 5% solution. Preparation 501 was applied in the phase ear formation - 1.5 g for 30 l of water/da. Fladen preparation is applied in the phase of autumn and spring tillering - 1.5% solution. Heliosulfur was applied in the ear formation phase - flowering at a dose of 50 ml/da, at an appropriate date on the biodynamic calendar. Free N was applied to the soil in the phase of autumn and spring tillering at a dose of 50 ml/da, at an appropriate date on the biodynamic calendar.

The analysis of the technological qualities is made according to the respective ISO methodology. The statistical data processing was performed with the STATGRAPH program.

The application of biodynamic and biological preparations and their joint use leads to an increase in the yield of wet gluten, as well as an increase in the content of N, P, K and protein in wheat grain. It has been proven that the combined use of biodynamic and biological preparations increases the content of dry matter, organic matter and the content of nitrogen-free extracts in wheat grain. The content of crude proteins has been shown to increase only in the varieties treated with biodynamic and biological preparations.

During the period 2019 - 2020, a study was conducted on soil type calcic chernozem with Kolorit triticale variety. The experiment is based on the block method, in four replications with a size of the experimental plot of 10 m². Sowing was carried out in October with a sowing rate of 500 sprouts/m² after the predecessor sugar beet. In the appropriate periods, treatments were made in 4 variants: 1) Control - untreated variant, 2) Treatment with biodynamic preparations: 500 + Fladen preparation + preparation 501, 3) Treatment with biological preparations: Heliosulfur + Free N, 4) Combined treatment with the same biodynamic and biological preparations.

Preparation 500 was applied in the phase of autumn and spring triticale tillering - 5% solution. Preparation 501 was applied in the phase of ear formation - 1.5 g for 30 l of water/da. Fladen preparation was applied in the phase of autumn and spring tillering - 1.5% solution. Heliosulfur was applied in the ear formation phase - flowering at a dose of 50 ml/da, on an appropriate date on the biodynamic calendar. Free N was applied to the soil in the phase of autumn and spring tillering at a dose of 50 ml/da, on an appropriate date on the biodynamic calendar.

The analysis of the technological qualities is made according to the respective ISO methodology. The statistical data processing was performed with the STATGRAPH program.

The application of biodynamic and biological preparations and their joint use leads to an increase in the content of Nitrogen-free Extracts, an increase in the content of Minerals and Ca in the variant treated with a combination of biodynamic and biological preparations. Treatment with biodynamic preparations has been shown to increase the dry matter and organic matter content of the grain, while when compared to the control one, a difference in the same indicators has been observed only in the second year of the experiment with biological preparations. Treatment with biodynamic and biological preparations and their joint use did not affect the content of N, P and K.

The study was conducted in the laboratory of the Agricultural Institute of Shumen. The germination energy and germination of winter wheat variety Venka 1 are reported following the adopted methodology. The germination energy was recorded on the fourth day of the experiment, and the germination and measurement of the coleoptile – on the eighth day. 10 granules of the following homeopathic preparations are pre-dissolved in distilled water: Calcium sulfuricum 6 D, Thallium sulfuricum 6 D, Sulfur, Graphites 6 D, Selenium, Ferrum metallicum 10 D, Magneziun fluoratum 10 D, Arsenicum album 12 D, Causticum Hanenmanni 30 D, Zincum metalicum 30 D.

The tested homeopathic preparations have no proven effect on the germination energy and germination of seeds in wheat variety Venka 1. The variants treated with the homeopathic preparations Thallium sulfuricum and Sulfur have been proven to exceed the standard one in terms of coleoptile length. Тhis work will serve as a basis the study of other homeopathic preparations to determine their impact on uniform germination and their aftereffect on plant growth.