In this article, the authors construct a special reproducing kernel Hilbert space of mixed Korobov–Sobolev type. To address the main problems, an appropriate hybrid function system is employed. The arithmetic associated with this function system is used to define the notion of the mean square worst-case error of the integration in the considered space. An explicit formula for this error expressed in terms of the functions of the employed system is obtained.
Perfluorinated alkyl substances (PFAS), such as perfluorooctanoic acid (PFOA) and perfluorooctanesulphonic acid (PFOS), are persistent water contaminants known to interact with biological membranes. In this study, the effects of PFOA and PFOS on membrane interfacial properties were investigated using 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) large unilamellar vesicles (LUVs) and Laurdan generalized polarization (GP) as a probe of membrane dipolar relaxation. Under control conditions, POPC vesicles exhibited a liquid-disordered phase (negative GP values). While PFOA did not induce significant changes in GP, PFOS caused a significant decrease, indicating enhanced interfacial hydration and dipolar relaxation. These differences are attributed to structural features of PFAS, with PFOS exhibiting stronger interfacial anchoring and membrane perturbation. Overall, the results demonstrate that PFOS more effectively disrupts membrane interfacial properties, suggesting a greater potential to affect membrane function and associated cellular processes.
In late summer 2019, Acidovorax citrulli the causative agent of bacterial seedling blight and fruit blotch (BFB) of cucurbit plants was first detected in a commercial watermelon production area in the village of Sopot, Kavadarci, North Macedonia. Later, in the summer of 2019 and also in 2020, A. citrulli was observed on watermelon fruits (Citrullus lanatus L., varieties “Bibo” and “Olakala”) in the Strumica region in the Eastern part of North Macedonia. Initial symptoms included water-soaked, irregular spots on the fruits that appeared greasy and dark olive green, eventually developing into brown lesions. Round, cream-coloured, Gram-negative bacterial isolates were obtained from symptomatic fruit tissue, which were slow-growing, nonfluorescent, aerobic, and oxidase-positive. In recent years, the disease has spread globally, primarily through the inadvertent distribution of contaminated commercial seeds, emerging as a significant pathogen of cucurbitaceous plant species worldwide. Due to costly lawsuits filed by growers against seed companies and the lack of effective management methods, BFB poses a serious threat to the cucurbit industry, particularly to watermelons and melons. Acidovorax citrulli is a seed-borne pathogen and is listed as an A1 quarantine pathogen by EPPO in 2021. Despite the economic importance of the disease, little is known about the basic aspects of A. citrulli pathogenesis in our country. Based on the fruit symptoms, pathogenicity tests, biochemical tests, serological and PCR analyses, the pathogen was identified as Acidovorax citrulli. To our knowledge, based on the current findings, including symptomatology, pathogenicity tests, biochemical characterization and PCR analyses, this is the first detailed study of A. citrulli causing bacterial fruit blotch on watermelon in North Macedonia.
The aim of this study is to trace and establish the correlations between the vegetative (average number, average height, and average thickness of shoots) and reproductive characteristics (average fruit weight and average yield) of the Bulgarski Rubin cultivar grown in the semi-mountainous conditions of the Central Balkan Mountains. Bulgarian raspberry varieties are adapted to our soil and climatic conditions and successfully realize their genetic potential in them. The study was conducted during the period 2018-2020 in a demonstration plantation of Research Institute of Mountain Stockbreeding and Agriculture, Troyan, which was established in 2016, with a planting scheme of 3.00/0.50 m. The study was carried out in two stages: the first stage was carried out in 2018, and the second stage was carried out in 2019. Statistical analyses show a high correlation between the average number of shoots and the average yield during the first two experimental years, and very high in the third year. During the three-year period, a very high correlation was found between the vegetative indicators of average height and average shoot thickness.
This study evaluates whether applying pre-processing to Sentinel-1 GRD (Ground Range Detected) SAR images alters the accuracy of glacier surface velocity estimates obtained with an offset-tracking algorithm. The pre-processing includes applying thermal noise removal and radiometric calibration deriving sigma0 type products. The research focuses on glaciers near the Bulgarian research base on Livingston Island (Antarctica), using available in-situ GNSS velocity measurements as ground truth. Three nearly identical processing chains were implemented in ESA's SNAP software: one including radiometric calibration (producing sigma0) and thermal noise removal, one with only thermal noise removal, and one with neither. All other processing steps and parameters were held constant to isolate the effect of calibration and thermal noise removal.
Tuberculosis is a multisystemic infectious disease that can affect all tissues and organs. Extrapulmonary tuberculosis (EPTB) is defined as the localization of the disease outside the lungs. This study included extrapulmonary samples (EP) sent to the Tuberculosis diagnostic laboratory of Ondokuz May & imath;s University Faculty of Medicine between January 2010 and December 2022. In the laboratory, samples were subjected to Ehrlich-Ziehl-Neelsen (EZN) staining, culture on Lo & uml;wenstein-Jensen (LJ) medium, BACTEC MGIT 960 system (BD, USA), and PCR (2010-2019 GeneXpert MTB/RIF, 2020-2022 BD MAX MDR-TB) for diagnosis. A total of 10 547 extrapulmonary samples were examined in the study. Growth was detected in 185 (1.75%) of the EP samples. Mycobacterium tuberculosis complex was identified in 181 of these samples, while growth of nontuberculous mycobacteria was observed in four samples. Of the samples with growth, 167 (90.27%) were isolated from the adult patient group; 18 (9.73%) were from the pediatric patient group. Looking at the distribution of clinics that sent the samples, it was found that 100 (54%) samples were sent from internal medicine clinics, 67 (36%) from surgical clinics, and 18 (10%) from pediatric clinics. Abscesses accounted for 37 (20%),surgical material 35 (19%),urine 28 (15%),thoracentesis fluid 20 (11%),cerebrospinal fluid 16 (9%), paracentesis fluid 8 (4%), pleural fluid 8 (4%),and others (pericardial fluid, peritoneal fluid, joint fluid, aspiration, exudate, etc.) 33 (18%). EZN positivity in these samples was found to be 18% (33/185). Tuberculosis PCR was applied to 102 (102/185) of these EP samples, and PCR positivity was detected in 79 samples (78%). Of the 79 samples with detected PCR positivity, AFB positivity was also observed in 26 (33%). The detection rate of the M. tuberculosis complex in extrapulmonary specimens has been found to be quite low. Among extrapulmonary specimens, the highest positivity rate was observed in abscess specimens. The use of multiple diagnostic methods (culture + PCR) for detecting M. tuberculosis in extrapulmonary specimens may improve the detection rate.
Knee osteoarthritis is a major cause of disability worldwide. Although commonly used patient-reported outcome measures effectively assess pain and function, they often demonstrate ceiling effects in high-functioning patients, particularly after unicompartmental knee arthroplasty (UKA). The Forgotten Joint Score-12 (FJS-12) was developed to assess joint awareness during daily activities, reflecting a core goal of arthroplasty: a joint that is no longer consciously perceived. The aim of this study was to translate, culturally adapt, and validate the Bulgarian version of the FJS-12 and to evaluate its clinical utility in patients with knee osteoarthritis. A two-phase study design was used. Phase 1 involved forward-backward translation, expert committee review, and pilot testing to produce a culturally adapted Bulgarian version of the FJS-12 in accordance with established guidelines for the cross-cultural adaptation of patient-reported outcome measures (PROMs). Phase 2 consisted of psychometric validation in patients with knee osteoarthritis treated with UKA. Internal consistency was assessed using Cronbach's alpha, test-retest reliability using the intraclass correlation coefficient (ICC), and construct validity through correlations with established PROMs, including Western Ontario and McMaster Universities (WOMAC) and Knee Injury and Osteoarthritis Outcome Score (KOOS). The Bulgarian FJS-12 demonstrated good comprehensibility and high patient acceptance. The mean FJS-12 score was 79.5 +/- 17.0. Internal consistency was high (Cronbach's alpha = 0.958), and test-retest reliability was excellent (ICC(3, 1) = 0.973). No floor or ceiling effect was observed. The FJS-12 showed significant negative correlations with WOMAC pain, stiffness, function, total score. In the subgroup with available KOOS data, significant positive correlations were found with KOOS Symptoms, Quality of Life, and total score. The Bulgarian version of the FJS-12 is a reliable and valid PROM for assessing joint awareness in patients with knee osteoarthritis after UKA. It provides clinically relevant information that complements traditional outcome measures by capturing residual joint awareness not detected by pain-and function-based instruments.
Reclaimed soils formed on mine spoils may modify the local natural radiation background because of differences in parent material, texture, and sorption properties. The present study evaluates the activity concentrations and distribution patterns of natural and anthropogenic radionuclides in reclaimed soils from three mining-affected areas in Bulgaria: Maritsa Iztok, Chukurovo, and Asarel-Medet. Gamma-ray spectrometry (HPGe detector; BDS EN ISO 18589-3) and selected physico-chemical analyses (pH, cation exchange capacity, organic carbon, and particle-size composition) were conducted on horizon-wise samples from the main soil profiles (Profiles 1-5). Natural radionuclides (U-238 series, Th-232 series, and K-40) exhibited object-specific patterns consistent with geogenic and textural controls. Spearman correlation and principal component analysis identified a geogenic/texture component dominated by U-238, Ra-226, and Th-232, which were positively associated with fine fractions and cation exchange capacity, and an opposing K-40 trend linked to coarser material. Pb-210 was more closely associated with sorption-related soil properties, suggesting combined control by texture, pH, and the sorption complex. Cs-137 was predominantly below the detection limit, with measurable values mainly in Maritsa Iztok and Chukurovo (West), and no consistent depth-related pattern indicative of substantial downward migration. The external hazard index (Hex) remained below 1 in all studied sites, indicating no radiological concern regarding external exposure.
Nickel and Ni-TiO2 nanocomposite coatings were deposited on nickel-aluminium bronze by selective electrochemical deposition. TiO2 nanoparticles below 100 nm were added to a commercial nickel electrolyte to obtain a Ni-TiO2 composite coating, which was compared with a pure Ni coating. The morphology, phase composition, surface roughness, Vickers microhardness and corrosion behaviour of the coatings were investigated. The Ni-TiO2 coating showed a compact morphology without defects visible at the optical-microscopy scale. The incorporation of TiO2 reduced the surface roughness and increased the microhardness from 196 to 215 HV0.2. X-ray diffraction confirmed an fcc Ni matrix and low-intensity reflections attributed to TiO2. Potentiodynamic polarization in 3.5 wt.% NaCl solution showed a more noble corrosion potential, lower corrosion current density and lower corrosion rate for the Ni-TiO2 coating. The results indicate that selective plating can produce compact Ni-TiO2 nanocomposite coatings with improved surface, mechanical and corrosion properties for potential marine applications.
This study aimed to investigate whether metabolic acidosis modifies the association between carboxyhemoglobin (COHb) and serum potassium in acute carbon monoxide (CO) poisoning patients. A cross-sectional analysis was conducted on 124 patients. Serum potassium was the outcome, COHb saturation the exposure, and metabolic acidosis was defined as a standard base excess (SBE) < 3 mmol/L. The interaction was analyzed using multiple linear regression. The interaction between COHb and metabolic acidosis on serum potassium was significant (beta = 0.0184, 95% CI: 0.0362 to 0.0005, P = 0.044). Subgroup analysis showed a stronger effect in patients with SBE < 4 mmol/L (beta = 0.0269, P = 0.002). In conclusion, metabolic acidosis significantly enhances the negative association between COHb and serum potassium in acute CO poisoning, with the effect intensifying with acidosis severity. This highlights the need for integrated assessment of blood gas and electrolyte indicators, particularly in patients with moderate to severe acidosis, to mitigate the risk of a pronounced COHb-driven decrease in potassium.
The aim of the study was to investigate the effectiveness of using various restorative complexes based on surfactants, and the effectiveness of soil cleaning for bioremediation of oil-contaminated peat soils. Carrying out remediation of oil-contaminated soil with the proposed composition, observing the processing technology and duration of exposure, shows a fairly high efficiency in reducing the oil content in the range of 69.7-87.6%, depending on the initial concentration. Peat and sorbent showed good results when combined with soil pH adjustment using lime and the addition of nitrogen-phosphorus fertilizers. The optimal exposure period for the recommended remediation composition was determined to be one month. Due to the loss of many coastal soils, studying the problem of cleaning up soil pollution is considered very important for Absheron Peninsula.
The identification of organic materials in cultural heritage objects is crucial for elucidating historical artistic practices and for designing appropriate conservation strategies. This study presents an integrated analytical protocol for the characterization of organic materials in wall paintings through the combined application of complementary analytical techniques. The performance of the proposed approach is demonstrated through several case studies of Bulgarian monuments. The findings indicate that a combination of Fourier transform infrared spectroscopy (FTIR) with enzyme-linked immunosorbent assay (ELISA), thermogravimetric analysis (TGA) and analytical pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC-MS) facilitates the reliable identification of organic materials, even in minimal samples.
Haustorium formation is the key developmental event enabling parasitism in the genus Cuscuta, yet comparative data on the enzymatic mechanisms underlying haustoriogenesis across taxonomically distinct species remain scarce. In this study, we investigated whether iso enzymatic profiles associated with early haustorium formation are taxonomically dependent within Cuscuta. Nine species representing three major subgenera-Grammica, Cuscuta, and Monogynella-were analyzed. Haustoria were induced using artificial hosts, and soluble protein extracts from the haustorial region were subjected to zymographic analysis of peroxidases, proteases, and cellulases. Peroxidases exhibited the highest diversity, with 16 distinct isoforms detected and clear interspecific and intersubgeneric differences. Protease activity was represented by a limited number of isoforms with species-specific electrophoretic mobility, whereas cellulase activity was detected only in two species. Cluster analysis based on combined peroxidase and protease iso enzyme profiles produced a dendrogram that largely reflected established taxonomic relationships, clearly separating the three subgenera. These findings demonstrate that iso enzymatic patterns during haustoriogenesis are not random but are evolutionarily linked to major lineages within Cuscuta. The results support the hypothesis that taxonomically related dodder species employ similar enzymatic strategies during host invasion, providing functional biochemical support for existing phylogenetic frameworks.
A new extension of the class of the ordinary Generalized Nets (GNs) is defined - GNs with Inhibitor Arcs (GNIA). In a GNIA, some of the arcs can inhibit the tokens that are transferred through them. Algorithm for transfer of tokens in GNIA and algorithm for GNIA functioning are described. It is proved that the class of all GNIAs is a conservative extension of the class of the ordinary GNs. The new extension can be used in the modelling of information service networks, such as overall telecommunication systems.
Preimplantation developmental arrest remains a major cause of embryo loss during in vitro culture, including in embryos for which morphology alone does not explain developmental failure. Because short-read RNA sequencing has limited ability to resolve transcript isoforms, intron retention, and repetitive-element-derived transcripts, we applied Oxford Nanopore long-read sequencing to 16 post-ICSI samples from seven patients, including four 0PN oocytes and 12 developmentally arrested embryos. The arrested samples showed marked heterogeneity in mitochondrial transcript fraction and mitochondrial variant profiles. In addition, arrested embryos displayed a recurrent long-read signature characterized by increased chimeric alignments, elevated intron retention, impaired developmental isoform switching, and enhanced LINE-1-associated signal. The most disorganized embryos also showed reduced expression of subcortical maternal complex components, particularly NLRP7, together with weaker BRCA1-related transcript output and a FAS-associated stress/apoptosis profile. These findings support a model in which a subset of arrested human embryos undergo coordinated failure of RNA processing, repeat control, and maternal genome-stability-associated programs. Long-read transcriptomics may provide a useful framework for studying embryo arrest at the level of transcript structure and repetitive-element activity, features that are not readily captured by gene-level short-read approaches.
The aim of this study was to investigate the effects of optimized protein intake strategies on metabolic inflammatory markers in elderly patients with sarcopenic obesity. This prospective study enrolled 384 older adults with sarcopenic obesity, randomized into a control group (standard dietary intervention) and an observation group (standard diet plus optimized protein intake). Outcomes were assessed at baseline, 6, and 12 months, measuring metabolic-inflammatory markers (IL-6, TNF-alpha, CRP, irisin), muscle-related indices (SMI, HGS), obesity-related indices (BMI), nutritional parameters, and Sarcopenia Quality of Life (SarQoL) scores. At 6 and 12 months, inflammatory markers decreased significantly in both groups, with lower levels in the observation group (P < 0.05). Muscle mass and function improved significantly, while fat accumulation decreased, with superior results in the observation group. Nutritional indices and SarQoL scores also increased significantly, showing greater improvements in the observation group compared to controls (P < 0.05). Optimized protein intake strategies significantly ameliorate metabolic inflammatory status, reduce inflammatory markers, enhance muscle mass and function, decrease fat accumulation, and improve nutritional status and quality of life, warranting clinical promotion.
A surgical intervention such as total hip arthroplasty, triggers a complex stress response in the body, involving metabolic, neuroendocrine and inflammatory reactions that influence postoperative recovery. This study aimed to compare the perioperative cortisol response and early postoperative pain in patients undergoing THA under general anaesthesia (GA) versus spinal anaesthesia (SA). This study was conducted from October 2020 to June 2024 at the Clinic of Orthopedics and Traumatology in "Tsaritsa Yoanna" - ISUL University Hospital, and included two groups of patients: Group 1 (n = 30, GA) receiving general anaesthesia and Group 2 (n = 30, SA) receiving spinal anaesthesia. The examined parameters were: serum cortisol levels (reference values 4.3-22.4 ug/dl) at four time points preoperatively, 30 min after the surgical incision, 1 h after the end of surgery, and 24 h postoperatively. Pain intensity was assessed on days 1, 2, and 3 at rest using the VAS (Visual Analogue Scale). The results show that the patients in Group 1 (GA) had higher cortisol levels 30 min after the surgical incision, 1 h postoperatively, and 24 h after surgery, compared to the SA group, with the difference being statistically significant (p < 0.001). At 24 h postoperatively, cortisol levels in Group 1 showed a trend toward normalization but remained higher than in Group 2. Pain scores on the day of surgery were significantly higher in the general anaesthesia (GA) group. However, on the second and third postoperative day, pain levels in both groups normalized and the differences became statistically insignificant. The results of our study indicate that the choice of anaesthesia significantly affects the stress response and pain in patients undergoing hip joint surgery. Cortisol measurement analysis suggests a pronounced attenuation of stress response in patients with spinal anaesthesia undergoing this kind of surgery.
This paper discusses an inbuilt miniature inline voltage standing wave ratio (VSWR) meter and antenna analyser for handheld radio transceivers. Most high-end and special purpose handheld radios include a VSWR meter inside that measures the antenna parameters all the time while transmitting. Such a feature helps mitigate inadequate antennas, loss of power and sensitivity, overload of the final stage of the transmitter, excessive heat dissipation and battery energy wasting. Most such meters measure VSWR only and knowledge of this parameter is sufficient in most scenarios. The current article presents a simple to build, high efficiency and compact, yet sophisticated computer controlled VSWR meter that also measures other parameters of the antenna besides the VSWR. The meter capabilities are equal to or better than professional or specialized antenna analysers while being extremely small in size and low in complexity. The proposed device is capable of measuring complex antenna impedance and additionally revealing the value and sign of the antenna reactance, i.e. whether it is capacitive or inductive.
This paper explores the interesting relationship between Bernoulli numbers and the Schwarz lemma, two seemingly disparate concepts from number theory and complex analysis. Bernoulli numbers, a sequence of rational numbers, play a crucial role in various mathematical contexts, including power series expansions, the Riemann zeta function, and the Euler-Maclaurin formula. The Schwarz lemma, a fundamental result in complex analysis, provides constraints on analytic functions mapping the unit disc to itself. We investigate how these two areas intersect in the study of analytic functions and power series, highlighting how the properties of Bernoulli numbers influence the coefficients and behaviour of functions subject to the Schwarz lemma. By examining specific examples and deriving relevant identities, we uncover the subtle yet significant connections between these mathematical constructs, offering new insights into their combined in modern mathematical research.
