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Ma&lstrok;gorzata &Lstrok;ysek-G&lstrok;adysi&nacute;ska,1 Magdalena Starz,2 Agnieszka Borowiec-S&eogon;k,2 Iwona Sufin,2 Anna Wieczorek,1 Magdalena Chrapek,3 Dorota Zar&eogon;bska-Michaluk,4 Patrycja Sufin,2 Stanis&lstrok;aw G&lstrok;uszek,4 Wioletta Adamus-Bia&lstrok;ek4 1Institute of Biology, Jan Kochanowski University, Kielce, Poland; 2Meduniv Sp. z o.o, Kielce, Poland; 3Department of Mathematics, Jan Kochanowski University, Kielce, Poland; 4Institute of Medical Sciences, Jan Kochanowski University, Kielce, PolandCorrespondence: Wioletta Adamus-Bia&lstrok;ek, Jan Kochanowski University, Institute of Medical Sciences, IX Wieków Kielc 19a, Kielce, 25-516, Poland, Tel +48 788 860 604, Email wioletta.adamus-bialek@ujk.edu.plPurpose: The COVID-19 pandemic has been going on for almost three years, and so far, many preventive and therapeutic strategies have been developed. The issue of subsequent booster vaccinations is currently being discussed. We aimed to analyze how the third dose of vaccination against COVID-19 correlates with the dynamics of IgG anti-SARS-CoV-2 spike protein antibody levels in a group of healthy people.Patients and Methods: The prospective study included 93 participants before and after a second booster of COVID-19 vaccination, from whom 4 blood samples were collected at intervals. The levels of IgG anti-SARS-CoV-2 in serum were identified using the chemiluminescent immunoassay specific for the receptor-binding domain (RBD) of the S1 protein. The analysis of the results was performed using appropriate statistical methods, considering p < 0.05 as a statistically significant value.Results: The IgG levels were significantly higher and less diverse after the same follow-up time from the second booster vaccination compared to the first booster. The antibody levels were positively correlated with female, healthcare workers, the elderly and participants with a negative COVID-19 history. Furthermore, the increase in IgG antibodies after the second booster vaccination correlated inversely with the baseline level of antibodies before the vaccination. The latest results showed that antibody levels dropped 1.5-fold after approx. 10 months from the second booster vaccination but still remained at a protective level.Conclusion: Booster vaccinations seem to better stimulate immune memory, and in the case of borderline IgG level induces the greatest increase in antibodies. It is worth considering the individual parameters of patients and measuring antibodies before vaccination.Keywords: pandemic, virus, infection, immune response

Izabela Gacon, Jolanta E Loster, Aneta WieczorekDepartment of Dental Prosthetics, Institute of Dentistry at Jagiellonian University, Kraków, PolandObjectives: To answer to the following questions: is there any relationship between oral hygiene and the growth of yeast in patients without mucosal inflammation; and is there a need for mycological examination patients without mucosal inflammation?Background: Patients with candidiasis may report varied symptoms, but such infections are most often asymptomatic. In addition to its high incidence in denture users (60%–100%), there is a concern that Candida species from the oral cavity may colonize the upper gastrointestinal tract and lead to septicemia, which has a 40%–79% mortality rate and can require a prolonged hospital stay. It is thus important for all physicians to be aware of the risk factors, diagnosis, and treatment of oral candidiasis in older patients.Methods: A retrospective study was carried out on a group of patients who had undergone mycological examination and assessment of the intensity of yeast growth, and oral hygiene.Results: Ninety-one denture wearers who lacked signs of clinical inflammation were included in the study. The growth of Candida albicans was as follows: 14 patients had up to 20 colonies; 19 patients had over 20 colonies. Ten percent of patients with good oral hygiene proved to have more than 20 yeast colonies. 5% of patients with bad oral hygiene had more than 20 colonies.Conclusions: There was no relationship found between hygiene and the growth rate of fungal microorganisms. In patients without clinical symptoms of stomatitis, mycological examination should be considered.Keywords: removable dentures, stomatitis, hygiene, Candida albicans

This paper presents the results of wear tests of shot-peened and not shot-peened cast steels used in the mining machinery industry, in particular in the construction of chain drums for armoured face conveyors. Wear tests were carried out in the conditions corresponding to the real operating conditions of armoured face conveyors during drifting work in rocks such as sandstone. The operating factors subjected to the analyses included the presence of quartz abrasive and the impact of external dynamic forces. On the basis of the wear tests as well as the microhardness and microstructure examinations performed, it has been found that the action of an additional dynamic force has a synergistic impact on the process of abrasive wear in loose quartz abrasive. It has been further found that the value of abrasive wear of chain wheels operated in the conditions of a combined action of abrasive and a dynamic force depends on whether the area of mating of wheels with the chain was shot-peened or not before the wear tests – an increase in the abrasive wear was observed for the wheels made of cast steel subjected to shot peening in the area of mating with the chain. Lower resistance to abrasive wear of the cast steels subjected to shot peening before the wear tests could result from the formation of cracks in the surface layer caused by the action of shot.

The purpose of this study was to determine experimentally the wear properties of 5 groups of iron-based alloys used in the mining and transport machines exposed to the action of a hard abrasive material. The groups of materials to be examined included austempered ductile irons (ADI), steels and cast steel designed for quenching and tempering and for surface hardening, hard-wearing hardened steels and structural steels. The wear tests were carried out on a disc-on-disc test rig. The test samples were examined under conditions of sliding mating, while the leading destructive process was microcutting of the surface with loose corundum grain. The loss of mass of the examined samples was measured as a parameter characterizing the wear. Base on it, other wear coefficients were determined, for example the volume loss, the intensity of wear and the wear rate. The volume loss values determined were presented as a function of the strength and the initial hardness. Based on the results obtained, it was found that the hardened steel and ADI had comparable wear properties, while the ADI surface was strengthened probably as a result of the transition of austenite into martensite and the impact of the deformation of the graphite contained in ADI on the abrasive wear of the surface.

The paper presents the results of wear tests obtained for 4 groups of materials: surface-hardened alloy steels and alloy cast steels for structural applications, hard-wearing surface-hardened alloy cast steels, and austempered alloy cast irons. The wear tests have been performed on a specially designed test rig that allows reproducing the real operating conditions of chain wheels, including the rolling and sliding form of contact between elements. The chain wheels subjected to tests were operated with the use of loose quartz abrasive. This study presents results of measurements of material parameters, micro-structure of a surface subject to wear, as well as the linear wear determined for the materials considered. Based on the results, the following was found: the best wear properties were obtained for surface-hardened alloy steels and wear surface; strengthening of the ADI surface took place - most probably as a result of transformation of austenite into martensite; the uniformity of the structure of the materials affects the surface wear process. The study also indicated a significant degree of graphite deformation in ADI characterized by the upper ausferritic structure and its oblique orientation in relation to the surface, which resulted in a facilitated degradation of the surface caused by the quartz abrasive.

Abstract Background The association between fall risk-increasing drugs (FRIDs, medications known to be associated with falls) and the number of falls among generally healthy and active community-dwelling older adults is understudied. Prior studies have focused on individual medication classes or have predominantly relied on retrospective assessments of falls. The aim of this study was to investigate the association between FRID use at baseline and the prospective incidence rates of total, injurious and recurrent falls in community-dwelling older adults. Methods This is a 3-year observational analysis of DO-HEALTH, a randomized controlled trial, among community-dwelling adults aged ≥ 70 years without major diseases at baseline. The main exposures were use of at least one FRID and multiple FRIDs (≥ 2 FRIDs) at baseline. The number of total falls (including high- and low-trauma falls, as well as injurious falls) over 3 years of follow-up was defined as the primary outcome, and the number of injurious and the number of recurrent total falls (≥ 2 falls), as the two separate secondary outcomes. To examine these associations, separate negative binomial regression models controlled for the fixed effects of treatment allocation in the DO-HEALTH trial, study site, fall in the last year, age, sex, BMI, and walking aid were used. Additionally, an offset of the logarithm of each participant’s time in the study was included in the models. Results A total of 2157 participants were included, with a baseline median age of 74.0 years, 61.7% of whom were women, and 41.9% having experienced a prior fall in the year preceding enrolment. At baseline, 908 (42.1%) participants used at least one FRID, and 351 (16.3%) reported multiple FRIDs use. Prospectively, over 3 years of follow-up, 3333 falls were reported by 1311 (60.8%) out of the 2157 participants. Baseline use of at least one FRID was significantly associated with increased incidence rates of total falls (incidence rate ratio (IRR) [95% Confidence Interval (CI)] = 1.13 [1.01–1.27]), injurious falls (IRR = 1.15 [1.02–1.29]), and recurrent falls (IRR = 1.12 [1.01–1.23]) over 3 years. These associations were most pronounced among users of multiple FRIDs, with increased incidence rates of total falls (IRR = 1.22 [1.05–1.42]), injurious falls (IRR = 1.33 [1.14–1.54]) and recurrent falls (IRR = 1.14 [1.02–1.29]). Conclusion Our results suggest that FRID use is associated with increased prospective incidence rates of total, injurious, and recurrent falls even among generally healthy older adults. Trial registration DO-HEALTH is registered as NCT01745263 on clinicaltrials.gov, with a registration date of 2012-12-06.

The paper presents results of the wear tests of chain wheels made of austempered ductile iron with various content of residual austenite. The aim of this study was to demonstrate the impact of the dynamic surface treatment (shot peening) on wear properties of surface layers of the chain wheels tested that were subjected to the action of quartz abrasive. Apart from determining the value of the abrasive wear, examinations of the magnetic phase content in the microstructure were carried out and plots of hardness of the surface layer as a function of the distance from the surface and microstructure of the materials were prepared. Based on the results, the following was found: an increase in the abrasive wear and a reduction in the hardness of the surface layer of chain wheels subjected to shot peening, as well as reduction of susceptibility to negative action of the shot for cast irons with the structure of upper ausferrite.

Jolanta E Loster,1 Aneta Wieczorek,1 Bartłomiej W Loster2 1Department of Dental Prosthetics, 2Department of Orthodontics, Institute of Dentistry, Jagiellonian University Medical College, Kraków, Poland Aim: Denture-related stomatitis is a disorder that often affects denture wearers. The purpose of this study was to evaluate the intensity, genera, and frequency of yeasts in the oral cavity of complete denture wearers in terms of subject gender and age.Materials and methods: Nine hundred twenty patients (307 males and 613 females) with complete upper dentures were selected for the study and divided into four age groups: ≤50 years, 51–60, 61–70, and >70 years. Yeast samples were taken as a smear from the palate. The data were collected from January 15, 2007 to January 15, 2012.Results: The distribution of the number of yeast colonies by gender was statistically significant (P=0.02). Across all subjects, there was a statistically significant relationship between the intensity of yeast growth and the gender (P=0.01). In every age group, the number of infection-free individuals was greater among males than females. Intermediate, intense, and abundant growth of yeast occurred most frequently in the youngest group of females.Conclusion: The genera of Candida species and the frequency of yeast infection in denture wearers appear to be influenced by both age and gender. The complete denture wearers ≤50 years of age appeared to have the greatest proclivity to oral Candida infections. Keywords: Candida albicans, Candida species, yeasts, denture-related stomatitis

Nowadays, in positron emission tomography (PET) systems, a time of flight (TOF) information is used to improve the image reconstruction process. In TOF-PET, fast detectors are able to measure the difference in the arrival time of the two gamma rays, with the precision enabling to shorten significantly a range along the line-of-response (LOR) where the annihilation occurred. In the new concept, called J-PET scanner, gamma rays are detected in plastic scintillators. In a single strip of J-PET system, time values are obtained by probing signals in the amplitude domain. Owing to compressive sensing (CS) theory, information about the shape and amplitude of the signals is recovered. In this paper, we demonstrate that based on the acquired signals parameters, a better signal normalization may be provided in order to improve the TOF resolution. The procedure was tested using large sample of data registered by a dedicated detection setup enabling sampling of signals with 50-ps intervals. Experimental setup provided irradiation of a chosen position in the plastic scintillator strip with annihilation gamma quanta.

In correctly functioning maintenance systems it is most important to prevent possible failures. A reduction of the vibroacoustic effects accompanying the operation of machines and equipment, including transmissions, is among the factors that lower the probability of a failure. The paper presents the results of the research on the impact of operational factors on vibroacoustic conditions of transmissions. The factors covered by the analysis included a change in the mating conditions of gear wheels associated with the wear of tooth surfaces, operation of transmissions in subharmonic conditions of the main resonance and the temperature of the lubricating oil. The study demonstrated that it was possible to reduce the vibroacoustic effects generated by gear transmissions by changing the conditions of their operation. Based on the results obtained, it has been found that the operation of gear transmissions in accordance with the sustainable development principles requires technical services to take active measures consisting in the search for optimal operating conditions in terms of the vibroacoustic conditions.