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Anna Pajor-Świerzy, Katarzyna Kozak, Dorota Duraczyńska, Agata Wiertel-Pochopień, Jan Zawała, Krzysztof Szczepanowicz Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Kraków, PolandCorrespondence: Anna Pajor-Świerzy, Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Kraków, Poland, Email anna.pajor-swierzy@ikifp.edu.plIntroductions: Ink based on metallic nanoparticles has been widely used so far for the fabrication of electronic circuits and devices using printing technology. This study aimed at the analysis of the effect of the silver shell thickness of nickel@silver core@shell (Ni@Ag) nanoparticles (NPs) on the fabrication and conductive properties of deposited coatings.Methods: The process of the synthesis of Ni@Ag NPs with various silver shell thicknesses was developed. The physicochemical properties (size, stability against aggregation process) of synthesized Ni@Ag nanoparticles were analyzed. The films based on ink containing Ni@Ag NPs with different silver shell thicknesses were fabricated and sintered in a temperature range of 120– 300 °C and at times from 15 to 90 min. The dependence of their conductive properties on the applied temperature and time as well as silver shell thickness was evaluated.Results: Ni NPs were coated with 10, 20, 30, 35, 45, and 55 nm silver shell thickness. The resistivity of coatings based on obtained NPs depends on the thickness of the Ag shell and the sintering temperature. After sintering at 300 °C, the highest decrease in its value (at an optimal sintering time of 60 min) from about 100 μΩ·cm to 9 μΩ·cm was observed when the thickness of the shell increased from 10 to 55 nm. At the lowest sintering temperature (120 °C) the highest conductivity (about 50% of that for bulk nickel) was obtained for films based on Ni@Ag NPs with 45 and 55 nm of the silver shell thickness.Discussions: The analysis of the resistivity of the sintered films showed that higher conductivity was obtained for the coatings formed from Ni@Ag NPs with the thicker Ag shell; moreover, thicker shells allowed a lowering of sintering temperature due to higher conductivity and a lower melting point of silver in comparison to nickel NPs. Keywords: core@shell nanoparticles, the thickness of the silver shell, thermal sintering, conductive properties, metallic coatings

Під час одужання від COVID-19 важлива сильна імунна відповідь, на стан якої впливають різноманітні мікроелементи. Вітамін D важливий для регуляції імунної відповіді та захисту від респіраторних інфекцій. Вітамін А також має імуномодулю- ючу дію, пригнічуючи реплікацію вірусу та посилюючи імунну відповідь, тим самим знижуючи захворюваність і смертність від COVID-19. Метою дослідження було вивчити рівні вітамінів A, D і ретинолзв'язуючого білка 4 у дітей з COVID-19, а також їх зв'язок із тяжкістю захворювання. Матеріал і методи дослідження: обстежено 112 дітей віком від 1 місяця до 18 років із COVID-19, підтвердженим методом полімеразної ланцюгової реакції (ПЛР) у мазках з носа або позитивним серологічним тестом (IgM та IgG або IgM). У всіх дітей визначали рівень вітаміну D колориметричним методом імуноферментного аналізу (ІФА) з використанням тест-системи Monobind. Рівні вітаміну А та ретинолзв'язуючого білка 4 (RBP4) визначали колориметричним методом імуноферментного аналізу (ELISA) з використанням тест-системи Elabscience. Комісія з біоетики Тернопільського національного медичного університету імені І. Горбачевського МОЗ України (протокол № 73 від 03.04.2023) схвалила дослідження. Індивідуальна інформована згода на цей аналіз була отримана від усіх опікунів дітей. Статистичний аналіз здійснювався за допомогою програми «Stat Plus» (під час статистичної обробки отриманих даних для середніх значень розраховано їх 95 % довірчий інтервал (95 % ДІ), а критерієм достовірності для перевірки рівності медіан кількох вибірок є критерій Крускала- Уолліса (H-критерій). Рівень статистичної значущості прийнято Р<0,05). Дане дослідження є фрагментом науково- дослідної роботи «Оптимізація діагностики клініко- патогенетичних характери- стик коронавірусної інфекції COVID-19 у дітей з коморбідною патологією та особливості лікування « (державна реєстрація No 0123U100064, 2023-2025 рр). Результати дослідження. Середній вік дітей становив (7,04 ± 5,75) років (95 % ДІ 5,96-8,12). За ступенем тяжкості у 57 дітей (50,89 %) перебіг захворювання був легким, у 43 дітей (38,39 %) - середньої тяжкості, у 12 дітей (10,72 %) - тяжкий. Концентрація вітаміну D у дітей із легким перебігом COVID-19 становила 30,91 нг/мл; при середньотяжкому перебігу - 29,10 нг/мл; у дітей із тяжким перебігом - 22,42 нг/мл (Р < 0,05). Рівень вітаміну А також різнився у дітей з різним ступенем тяжкості захворювання: при легкому перебігу COVID-19 він становив 456,10 нг/мл; 347,30 нг/мл при середньому ступені тяжкості та 242,90 нг/мл при тяжкому перебігу (Р < 0,001). При цьому рівень ретинолзв'язуючого білка 4 становив 30,66 нг/мл при легкому перебігу; 33,07 нг/мл при середньому ступені тяжкості захворювання; і 23,28 нг/мл при тяжкому перебігу. Висновки: Діти із середньотяжким та важким перебігом COVID-19 мають значно нижчі рівні вітамінів A, D і RBP4 порівня- но з неінфікованими людьми. Рівні вітаміну A і RBP4 залежали від віку, а рівень вітаміну D не мав вікових закономірностей. Нижчий рівень вітамінів A і D пов'язаний з більш високим рівнем прозапальних маркерів - СРБ, лейкоцитів і ШОЕ. [ABSTRACT FROM AUTHOR]

Coronavirus disease remains one of the most serious diseases in the world. The percentage of severe and fatal cases in children is lower than in adults. The search for biomarkers of disease severity continues. There is evidence of heterologous immunity between the causative agent of coronavirus infection and some other infectious agents. Both Bordetella pertussis and SARS-CoV-2 cause damage to the respiratory system. It should be noted that the incubation period and transmission mechanism are similar for these two microorganisms. Pertussis vaccinations are given in childhood. The purpose of the study is to find the charcteristics of the course of COVID-19 in school-aged children depending on the state of humoral immunity against pertussis toxin, assessing their level of immunoglobulin G against pertussis. Material and methods. 92 pediatric patients aged 6 to 17 years were studied, including 30 children without signs of the disease in the control group and 62 children with manifestations of laboratory-confirmed COVID-19. The clinical features of the disease and laboratory indicators (C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cells, D-dimer) were evaluated, as well as the levels of free salivary cortisol and vitamin D. According to the severity of the disease, 3 groups were formed: the first - 20 children with a mild course of COVID-19, the second - 33 patients with a moderate course of the disease, the third - 9 with a severe course of the disease. All children were tested for immunoglobulin G (Ig G) to pertussis toxin by enzyme-linked immunosorbent assay (VIROTECH B. pertussis PT Ig G ELISA, Rüsselsheim, Germany). The result was considered negative (no increase in the titer of specific class G antibodies to pertussis toxin), borderline, and positive (there is an increase in the titer of immunoglobulin G to pertussis toxin). Statistical analysis was performed using the program «Stat Plus» (Shapiro-Wilk test, mean  SD (standard deviation) with correct distribution of characteristics; median, upper and lower quartiles with incorrect distribution, Chi-square test, Man-Whitney test, Fisher's test). The study was conducted in accordance with the rules of patient safety and ethical principles of scientific medical research involving human subjects (2000). The permission to conduct this study was given by the Bioethics Commission (Protocol No. 61 of 13.11.2020). The parents (legal representatives) of the patients gave their written consent to the conduct of this study. This study is a fragment of research work «An Integrated Approach to Symptom Control, Long-Term Prognosis in the Context of Comorbid Pathology in the Clinic of Internal Diseases and Family Doctor Practice» (state registration No. 0118U000361). Results. The mean age of the patients was 11.573.82 years. The study groups did not differ in sex (x2=4.97, p=0.174) and age (p=0.490) composition. The level of humoral immunity against pertussis toxin differed significantly between the study groups. A positive and borderline result for the presence of specific immunoglobulin G to tetanus toxin was found in 75.86 % of children without signs of disease. At the same time, only 41.51 % of children with COVID-19 manifestations had a positive and borderline result (p=0.005). A positive and borderline result for the presence of specific immunoglobulin G to tetanus toxin was seen in 66.67 % of children with mild infection, 33.33 % of patients with moderate disease, and only 12.50 % of patients with severe disease (X2=16.91, P=<0.001). Children with a negative result for immunoglobulin G to pertussis toxin have significantly higher WBC count (1.3-fold), ESR (2.4-fold), D-dimer (3.4-fold), and CRP (1.5-fold) compared to patients with positive and borderline levels of these antibodies. In children with a negative result, there was a 6.25-fold increase in salivary free cortisol (p<0.001) and a 2.0-fold decrease in vitamin D levels (p<0.001). Conclusions. In children with COVID-19 manifestations, there was a significantly higher percentage of negative test results for the presence of IgG to pertussis toxin compared to the control group, indicating a lower level of humoral immunity to tetanus in this group of patients. In children with mild disease, there was a significantly higher percentage of positive and borderline test results for the presence of IgG to pertussis toxin (indicating a higher level of humoral immunity against this pathogen) compared to the groups of children with moderate and severe disease. The absence of specific immunoglobulins G to pertussis toxin is associated with an increase in the level of pro-inflammatory markers (leukocyte count, ESR, CRP) and D-dimer, which also indicates a more severe course of COVID-19. Patients who are negative for pertussis toxin antibodies have elevated cortisol levels as a marker of stress and decreased vitamin D levels. Both biologically active substances are involved in the immune response to infectious agents and may serve as additional non-specific markers of COVID-19 severity. Therefore, low humoral immunity to pertussis contributes to the increase in COVID-19 severity in childhood. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Radon (Rn-222) is a noble gas formed in the uranium path (U-238) as a decay product of radium (Ra-226). It is estimated to cause between 3% to 14% of all lung cancers, depending on the national average radon level and smoking prevalence. Radon molecules emit alpha radiation, which is characterized by low permeability through tissues, but due to its remarkably high energy, it has a high potential for DNA damage. The aim of our research was to assess the radon concentration inside the houses of patients with advanced lung cancer and to analyze their socio-economics status. PATIENTS AND METHODS: The measurements of radon concentration were performed in 102 patients with stage 3B or higher lung cancer in the region of Lublin, Poland. One month of radon exposure measurement was performed with alpha-track detectors. In addition, patients filled in a detailed survey about factors that might influence the concentration of radon inside their houses. RESULTS: The average concentration of radon during the exposure of the detector in the residential premises of the respondents was at the level of 69.0 Bq/m3 [37.0-117.0]. A few significant correlations were discovered, e.g., higher levels of radon in countryside houses or in houses equipped with air conditioning. CONCLUSIONS: As radon exposure is a modifiable risk factor for lung cancer, it is extremely important to find factors that may reduce its concentration in dwelling places. Since our research was performed in houses of people with lung cancer, taking corrective actions based on our findings could prevent new lung cancer incidence in patients' flatmates. [ABSTRACT FROM AUTHOR]