Profile Optimisation of a Solid Modular Hob in the Machining of Gears Made of Classic and Unusual, Innovative Materials.

Modular hobs are tools with very complex geometry. Regardless of the material of the gear wheels, they determine the accuracy of the gears made in the hobbing machining process. Gears are made of various, often innovative materials depending on the requirements. Sometimes, the materials are characterised by very high hardness (over 65 HRC). The mathematical basis for describing the faces of a hob presented in the article allows for modifying the rack profile shaping the gear wheel's teeth. The model's universality makes it possible to perform numerical simulations of the influence of individual parameters of the hob creation process (geometry of the grinding wheels and their setting in the shaping process) on the profile of the rake and flank surfaces. The cutting edge (rack edge) is the locus of points belonging to both of these surfaces and thus directly impacts the accuracy of the gear wheel that is shaped in the hobbing process. The article summarises the authors' long-term cooperation with the industry, resulting in a series of articles devoted to hobs. The issues presented in the article are significant to the machinery industry and hob manufacturers.

A-trait and risk-taking behavior in predicting injury severity among martial arts athletes.

Introduction: Trait anxiety (A-trait) can be seen as a multiplicative function of the person-situation interaction. Considering risk-taking behavior (R-TB), literature highlights instrumental and stimulating risk. The aim of the research is to investigate the level of A-trait (in physically dangerous conditions and in new, unusual situations) and the level of R-TB (instrumental and stimulating risk) in athletes, and to verify to what extent A-trait and risk-taking behavior predict injury severity. Materials and methods: One hundred and fifty-four senior martial arts athletes from grappling combat sports, striking combat sports and mixed martial artists (MMA) participated in the study. For assessing trait anxiety and risk-taking behavior, the Romanian adaptation of the Endler Multidimensional Anxiety Scales (EMAS), respectively the Romanian adaptation of the Makarowski's Stimulating and Instrumental Risk Questionnaire were used. Results: Using multivariate analysis of variance, significant differences between athletes (according to the sports disciplines practiced), in terms of A-trait and R-TB, were examined. Next, we checked the existing correlations between injury severity, A-trait and R-TB scores in athletes practicing striking combat sports, grappling combat sports and MMA. To verify whether there are significant differences in terms of trait anxiety, stimulating and instrumental risk between athletes who have suffered mild, moderate and/or severe injuries and athletes who have suffered only minor/mild injuries, t-Test for Independent Samples was used. Binomial logistic regression procedures were, also, performed, predicting athletes' likelihood of injury, based on R-TB and A-trait. Conclusion: A moderate or slightly below average level of anxiety in new, unusual situations and a higher level of instrumental risk are linked with a decreased likelihood of severe injuries in athletes. Martial arts athletes (in entire sample) who have suffered more severe injuries are more adrenaline-seeking in competition and use less rational thinking, taking more pleasure in just performing technical executions, regardless of the outcome.

Prospective, randomised comparison of two intravenous sedation methods for magnetic resonance imaging in children.

BACKGROUND: Children usually need sedation or even anaesthesia for magnetic resonance imaging (MRI) studies. As there is no universally accepted method for this purpose we undertook a prospective, randomised comparison of propofol and dexmedetomidine in children aged 1 to 10 years. METHODS: After Institutional Board approval and parents' informed consent 64 ASA status I or II children scheduled for MRI scan were enrolled. Patients were premedicated with intravenous (IV) midazolam (0.1 mg kg -1 ) and ketamine (1 mg kg -1 ) and randomised to propofol (P) or dexmedetomidine (D) group. A propofol bolus of 1 mg kg -1 followed by infusion of 4 mg kg -1 h -1 , or dexmedetomidine 1 µg kg -1 followed by 2 µg kg -1 h-1 infusion were used. Heart rate, SpO 2 and non-invasive blood pressure were monitored and recorded at 5 min intervals. Results were compared by means of standard statistical methods. RESULTS: Both dexmedetomidine and propofol after premedication with ketamine and midazolam are suitable for MRI sedation, although propofol use results in shorter recovery time. Less interventions are needed when dexmedetomidine is used.

The Personality and Resilience of Competitive Athletes as BMW Drivers-Data from India, Latvia, Lithuania, Poland, Romania, Slovakia, and Spain.

BACKGROUND: Individual differences in personality and resilience are related to a variety of social behaviors. The current study sought to answer the question of whether BMW drivers exhibit different personality profiles and resilience levels compared with drivers of other car brands. PARTICIPANTS AND PROCEDURE: An international study was carried out in India, Latvia, Lithuania, Poland, Romania, Slovakia, and Spain on a sample of 448 athletes using the 20-item Mini-IPIP and the Resilience Scale. The results of BMW drivers (n = 91) were compared with the results of drivers of other German car brands (n = 357). RESULTS: BMW drivers were characterized by higher neuroticism compared with drivers of other German car brands. They also showed higher resiliency, both in terms of total score and scores on the subscales of: personal coping competences and tolerance of negative emotions, tolerance of failures and perceiving life as a challenge, and optimistic attitude towards life and capacity for self-mobilization in difficult situations. The greatest difference was observed for the factor of tolerance of failures and perceiving life as a challenge. Using the Dwass-Steel-Critchlow-Fligner (DSCF) pairwise comparison test, gender differences between athletes (as BMW drivers and drivers of other German car brands, respectively) were discussed. Additionally, the results of the main logistic regression analyses emphasized that neuroticism represents a better predictor of BMW preference in the case of athletes (as drivers) than the scores obtained for resilience. CONCLUSIONS: BMW drivers differed from drivers of other German car brands only with regard to neuroticism. A higher level of neuroticism can affect mental health and the overall quality of life in athletes; aggression and distress management are essential. Athletes (as BMW drivers) also showed differences in resiliency levels. Understanding the mechanisms of behavior among BMW drivers is possible through considering their personality and individual differences.

Thermal and Stress Properties of Briquettes from Virginia Mallow Energetic Crops.

The article discusses the influence of briquetting/compaction parameters. This includes the effects of pressure and temperature on material density and the thermal conductivity of biomass compacted into briquette samples. Plant biomass mainly consists of lignin and cellulose which breaks down into simple polymers at the elevated temperature of 200 °C. Hence, the compaction pressure, compaction temperature, density, and thermal conductivity of the tested material play crucial roles in the briquetting and the torrefaction process to transform it into charcoal with a high carbon content. The tests were realized for samples of raw biomass compacted under pressure in the range from 100 to 1000 bar and at two temperatures of 20 and 200 °C. The pressure of 200 bar was concluded as the most economically viable in briquetting technology in the tests conducted. The conducted research shows a relatively good log relationship between the density of the compacted briquette and the compaction pressure. Additionally, higher compaction pressure resulted in higher destructive force of the compacted material, which may affect the lower abrasion of the material. Regarding heat transfer throughout the sample, the average thermal conductivity for the compacted biomass was determined at a value of 0.048 ± 0.001 W/(K∙m). Finally, the described methodology for thermal conductivity determination has been found to be a reliable tool, therefore it can be proposed for other applications.

Evaluation of Work Mode and Its Importance for Home-Work and Work-Home Relationships: The Role of Resilience, Coping with Stress, and Passion for Work.

The COVID-19 pandemic necessitated and facilitated the introduction of telework in organizations. This has also impacted the workers' relationship between work and private life. The aim of the current study was to examine the links between resilience and mode of work (stationary vs. remote) and the work-home and home-work relationships, and whether they are mediated by passion for work and strategies of coping with stress. The study was carried out on a sample of 1251 participants from Great Britain, India, Latvia, Lithuania, Norway, Poland, Romania, Serbia, Slovakia, and Vietnam. The following measures were used: The Survey Work-Home Interaction, The Brief Resilience Coping Scale, The Passion Scale, and the Brief COPE. Results showed that the more stationary the mode of work, the lower the intensity of the negative influence of personal life on work. Resilience was revealed to have a positive effect on worker functioning. The study also showed a relationship between education and gender and passion for work. Finally, the importance of furthering the knowledge on the home-work and work-home relationships among teleworkers is discussed.

Coping Strategies and Perceiving Stress among Athletes during Different Waves of the COVID-19 Pandemic-Data from Poland, Romania, and Slovakia.

Coronavirus disease (COVID-19), an infectious disease caused by the SARS-CoV-2 virus, has affected numerous aspects of human functioning. Social contacts, work, education, travel, and sports have drastically changed during the lockdown periods. The pandemic restrictions have severely limited professional athletes' ability to train and participate in competitions. For many who rely on sports as their main source of income, this represents a source of intense stress. To assess the dynamics of perceived stress as well as coping strategies during different waves of the COVID-19 pandemic, we carried out a longitudinal study using the Perception of Stress Questionnaire and the Brief COPE on a sample of 2020 professional athletes in Poland, Romania, and Slovakia. The results revealed that in all three countries, the highest intrapsychic stress levels were reported during the fourth wave (all, p < 0.01) and the highest external stress levels were reported before the pandemic (p < 0.05). To analyze the data, analyses of variance were carried out using Tukey's post hoc test and η2 for effect size. Further, emotional tension was the highest among Polish and Slovak athletes in the fourth wave, while the highest among Romanian athletes was in the pre-pandemic period. The coping strategies used by the athletes in the fourth wave were more dysfunctional than during the first wave (independent t test and Cohen's d were used). The dynamics of the coping strategies­emotion focused and problem focused­were also discussed among Polish, Romanian, and Slovak athletes. Coaches and sports psychologists can modify the athletes' perceived stress while simultaneously promoting effective coping strategies.

Resilience, Occupational Stress, Job Satisfaction, and Intention to Leave the Organization among Nurses and Midwives during the COVID-19 Pandemic.

The current study on the intention to leave the organization among nurses and midwives aligns with the broader direction of research on the consequences of demanding jobs. This is particularly important in the context of the COVID-19 pandemic, which began in 2020 and is ongoing. The aim of the current study was to identify the levels of intention to leave the organization and job satisfaction in a sample of 390 Polish nurses and midwives. A multiple stepwise linear regression was carried out to establish which variables are predictors of job satisfaction and intention to leave the organization. The following measures were used in the study: Nurses' Occupational Stressor Scale, The Brief Resilience Coping Scale, The Turnover Intention Scale, The Job Satisfaction Scale, and an occupational questionnaire (number of workplaces, weekly number of evening and night shifts, working at a unit dedicated to treating COVID-19, working as a supervisor/executive). The current study showed that almost 25% of the sample reported high turnover intention, and a similar proportion reported low job satisfaction. Resilience was related to nurses' job satisfaction. In the predictive models for job satisfaction, the organizational factor of the number of workplaces was significant (positively related), while job experience was a negative predictor of intention to leave. The practical implications of the results and the need to continue research on this topic are also discussed.

Value of troponin T measurements for prediction of postoperative course and length of ICU stay of children after surgical correction of congenital heart disease.

BACKGROUND: The development of surgical and anaesthetic techniques improved the outcomes in children with congenital heart disease (CHD). After repair of defects using cardiopulmonary bypass (CPB) children often require prolonged respiratory or inotropic support in the intensive care unit (ICU). The aim of the study was to assess troponin T (TnT) values as a predictor of postoperative requirements and ICU length of stay (ICU-LOS) after cardiac surgery. METHODS: We included 41 patients who underwent corrective surgery for CHD between August and December 2017. TnT level was measured after induction of anaesthesia, 12 h after CPB (t2) and 24 h following CPB (t3). The Aristotle Basic Score for procedure complexity was calculated, total times of CPB and aortic cross-clamping were measured, and maximal Vasoactive-Inotropic Score and ICU-LOS were determined. Statistical relationships between TnT levels and the mentioned parameters were estimated. RESULTS: The median age of the patients was 37 months (14 days to 17 years). Three patients died. The median ICU-LOS was 42.7 hours. A positive correlation was found between ICU-LOS and TnT values at t2 ( Rs = 0.62, P = 0.008) and t3 ( Rs = 0.44, P = 0.018). TnT concentrations at t2 correlated significantly with: Aristotle score ( Rs = 0.50, P = 0.001), total time of CPB ( R s =0.58, P = 0.001), CC time ( Rs = 0.47, P = 0.002) and VIS ( Rs = 0.42, P = 0.001). TnT levels did not discriminate between survivors and non-survivors. CONCLUSIONS: Troponin T concentration is a useful tool to anticipate postoperative course and ICU-LOS in children after cardiac surgery.

Does nationality affect nurses' information security participation? A comparative study in Iran and Poland.

BACKGROUND: Confidential personal data breaches are a serious problem for medical service providers. They may result in high financial costs for medical care facilities and unnecessary stress for patients. Research on information security (IS) in healthcare has been insufficient thus far. International studies may add a new perspective on this issue. PARTICIPANTS AND PROCEDURE: A quantitative approach was assumed to analyse relationships between IS climate and IS indicators in countries with different cultures (Iran and Poland). The Information Security Climate Index was used in the study. The software PLS3 and SPSS 22 was used for data analysis. RESULTS: The results showed that the predicted factors of nurses' IS participation were different in Iran and Poland. In both countries, nurses' perception of the importance of IS had an effect on IS participation, but in Poland, IS compliance had an additional positive effect. In addition, IS compliance moderated the relationship between IS motivation and IS participation. CONCLUSIONS: Components of IS climate have a significant effect on nurses' IS participation in both Iran and Poland, though nationality can modify this relation. However, in both countries, by linking IS policies with human resource management activities such as performance appraisal and training, nurses' perception of IS importance can be increased and IS participation can be facilitated.

Usefulness of two types of pain monitors in newborns treated in NICU, in the opinion of experts: Results of the survey.

Pain experienced in the neonatal period has been shown to have serious short- and long-term consequences. It is also known that painkillers have side effects and should not be abused. The basis of proper pain management is assessment of pain, which in newborns is very difficult due to the lack of verbal communication. In these patients, behavioural scales are used to assess pain, but they have numerous shortcomings. For this reason, many newborns treated in the ICU are at risk of pain, so instrumental methods of detecting and assessing the severity of pain are being sought. During three months, seven Polish NICUs conducted research with the use of NIPE and SCA monitors. After this time, the heads of these departments filled in questionnaires regarding their individual opinions on the usefulness of these devices. All respondents found pain monitors useful in the NICU. The NIPE monitor was rated slightly higher, as its usefulness in assessing the effectiveness of analgosedation and in the management of patients in the postoperative period was better rated. The high acceptance of both devices by legal guardians of newborns is noteworthy. It should be stated that in newborns, any way to improve pain monitoring is valuable. In the opinion of Polish experts, pain monitors are useful in NICU. The NIPE monitor was assessed a little higher and was considered useful in the assessment of analgosedation and in postoperative treatment. Pain monitors can provide valuable support for pain assessment in newborns treated in the NICU.

Newborn infant parasympathetic evaluation for the assessment of analgosedation adequacy in infants treated by mechanical ventilation - a multicenter pilot study.

INTRODUCTION: Adequate analgosedation is important in infants treated in pediatric/neonatal intensive care units (P/NICUs), because both too deep and insufficient analgosedation is disadvantageous. To assess the severity of pain, several behavioral and behavioral-physiological scales are used, but their usefulness is limited. It is therefore justified to search for additional methods to assess the adequacy of analgosedation in these patients. The aim of the present study is to evaluate the usefulness of Newborn Infant Parasympathetic Evaluation (NIPE) in the assessment of analgosedation quality in infants requiring mechanical ventilation, who are treated in P/NICUs. MATERIAL AND METHODS: We performed simultaneously 180 COMFORT-B assessments and heart rate variability measurements using a NIPE monitor in 30 mechanically ventilated infants receiving analgosedation. A generalized linear mixed model with the logit link function was used in order to perform logistic regression analysis to assess the relationship between NIPEi/NIPEm and deep sedation. RESULTS: The multivariable logistic regression model showed that NIPEi and NIPEm values were higher when analgosedation was deep as compared to when it was moderate or insufficient (OR (95% CI): NIPEm - 1.065 (1.007-1.126), p = 0.03; NIPEi - 1.068 (1.016-1.123), p = 0.01). CONCLUSIONS: The NIPE indexes are significantly higher in patients whose assessment on the behavioral scale indicates deep analgosedation as compared to those in whom it indicates moderate or insufficient analgosedation. Allowing continuous monitoring, the NIPE device may be a valuable assisting tool in the assessment of analgosedation quality in mechanically ventilated newborns and infants.

Available Instruments to Assess Pain in Infants.

Pain assessment in newborns and infants is challenging for clinicians. Although behavioral and behavioral-physiological scales are validated pain assessment instruments, their use in this age group has significant limitations. In this review, we summarize the methods currently available for assessing pain in neonates and infants. It is possible that these pain detection methods are also useful for assessing the quality of anesthesia and analgosedation in these populations. Further research should be aimed at confirming the usefulness of these tools in infants and identifying additional pain assessment options for clinical practice.

Implementation of Computed Tomography Angiography (CTA) and Computed Tomography Perfusion (CTP) in Polish Guidelines for Determination of Cerebral Circulatory Arrest (CCA) during Brain Death/Death by Neurological Criteria (BD/DNC) Diagnosis Procedure.

BACKGROUND: Brain death/death by neurologic criteria (BD/DNC) guidelines are routinely analyzed, compared and updated in the majority of countries and are later implemented as national criteria. At the same time, extensive works have been conducted in order to unify clinical procedures and to validate and implement new technologies into a panel of ancillary tests. Recently evaluated computed tomography angiography and computed tomography perfusion (CTA/CTP) seem to be superior to traditionally used digital subtraction angiography (DSA), transcranial Doppler (TCD) and cerebral perfusion scintigraphy for diagnosis of cerebral circulatory arrest (CCA). In this narrative review, we would like to demonstrate scientific evidence supporting the implementation of CTA/CTP in Polish guidelines for BD/DNC diagnosis. Research and implementation process: In the first of our base studies concerning the potential usefulness of CTA/CTP for the confirmation of CCA during BD/DNC diagnosis procedures, we showed a sensitivity of 96.3% of CTA in a group of 82 patients. CTA was validated against DSA in this report. In the second study, CTA showed a sensitivity of 86% and CTP showed a sensitivity of 100% in a group of 50 patients. In this study, CTA and CTP were validated against clinical diagnosis of BD/DNC supported by TCD. Additionally, we propose our CCA criteria for CTP test, which are based on ascertainment of cerebral blood flow (CBF) < 10 mL/100 g/min and cerebral blood volume < 1 mL/100 g in regions of interest (ROIs) localized in all brain regions. Based on our research results, CTA/CTP methods were implemented in Polish BD/DNC criteria. To our knowledge, CTP was implemented for the first time in national guidelines. CONCLUSIONS: CTA and CTP-derived CTA might be in future the tests of choice for CCA diagnosis, proper and/or Doppler pretest might significantly increase sensitivity of CTA in CCA diagnosis procedures. Whole brain CTP might be decisive in some cases of inconclusive CTA. Implementation of CTA/CTP in the Polish BD/DNC diagnosis guidelines does not show any major obstacles. We believe that in next edition of "The World Brain Death Project" CTA and CTP will be recommended as ancillary tests of choice for CCA confirmation during BD/DNC diagnosis procedures.

Estimation of Post-Cracking Dissipation Capabilities of Fiber Reinforced Concretes in Three Point Bending Test Monitored with Application of Digital Image Correlation System.

Concretes with dispersed reinforcement are increasingly used in structural engineering. The basic source of knowledge on their application and design are the Model-Code 2010 guidelines. These guidelines, however, apply mainly to steel rebar reinforcement and are not fully sufficient in the analysis of the load-bearing capacity of elements made of concrete with dispersed reinforcement. Therefore, scientific research in this field is carried out continuously. The main goal of our work is to provide experimental data for the calibration of constitutive models of the cracking mechanics of concrete with reinforcement in the form of steel and polypropylene fibers. This article shows the possibility of using the digital image correlation system (DIC) to achieve this goal. The method of sample preparation and the method of conducting the tests were modeled on the recommendations contained in the PN-EN 14651: 2007 standard. The tests were carried out on prismatic elements with a notch loaded in a three-point bending setup. The results of standard strength tests are presented in the form of column graphs and tables. As an extension, the results of calculations of energy dissipated in fracture process are given. Moreover, the experimentally obtained graphs of the relationship between the force, displacement and crack opening were presented, which were supplemented with the images of crack development obtained with the use of DIC. The development of the crack net is characterized not only qualitatively but also quantitatively as a function of deflection or crack mouth opening displacement. Conclusions concerning the adopted research methodology and the tested materials are presented at the end of the article.

Resilience and Subjectively Experienced Stress Among Paramedics Prior to and During the COVID-19 Pandemic.

INTRODUCTION: Paramedics play a vital role in the healthcare system by providing professional support in situations of direct threat to patient health and life. They experience numerous difficulties during their work, which result in occupational stress. During the COVID-19 pandemic, their work has become even more demanding. The aim of the current study was to examine the role of resilience in the subjective experience of stress among paramedics during the COVID-19 pandemic. MATERIALS AND METHODS: The study was carried out in two phases, in October-November 2019 (N = 75) and in May-June 2020 (N = 84), using the Sense of Stress Questionnaire (Skala Poczucia Stresu) and the Resilience Scale (Skala Pomiaru Preznosci). RESULTS: Paramedics exhibited higher intrapsychic stress before the COVID-19 pandemic. Tolerance of failure and treating life as a challenge were higher during the pandemic, in contrast to optimism and the ability to mobilize in difficult situations. Paramedics who were in contact with patients with COVID-19 experienced higher stress. Perseverance and determination, openness to new experiences and sense of humor, as well as competences and tolerance of negative emotions were revealed to play a key part in mitigating subjectively experienced stress. CONCLUSION: Paramedics' subjectively experienced stress was lower during the COVID-19 pandemic. Paramedics who were in direct contact with patients with COVID-19 experienced higher stress. They had sufficient psychological resources, in the form of resilience (perseverance and determination, openness to new experiences, sense of humor, and competences and tolerance of negative emotions), which allowed them to cope with the situation of the COVID-19 pandemic.

Effects of Organizational Support and Organizational Justice on Police Officers' Work Engagement.

The impact of organizational support and organizational justice on work engagement was investigated in a group of police officers. A review of the literature revealed that studies reporting differences between the influence of supervisors and coworker justice and support on work engagement among police officers are grossly insufficient. This study hypothesized that organizational support and organizational justice would positively predict work engagement among police officers. It was also hypothesized that, among police officers, supervisor support is more strongly related to work engagement than coworker support and that supervisor justice is more strongly linked to work engagement than coworker justice. Participants were 170 police officers who worked in police departments in northern Poland. A regression analysis showed that supervisor support and supervisor justice had a positive effect on police officers' work engagement, whereby organizational support coupled with organizational justice accounted for 26% of the variability of work engagement. Theoretical and practical implications are discussed, and directions for future research are suggested.

Stress among nurses from countries variously affected by the COVID-19 pandemic - results collected in Poland and Iran.

BACKGROUND: Nursing involves numerous stressful situations, such as overwork, night shifts, responsibility for the patients' health, rapid pace of work, emotional demands, contact with suffering individuals, and patients' aggressive behaviors. The SARS-CoV-2 pandemic is an additional demand on the already demanding profession. Thus, the aim of the current study was to assess the character of the relationship between overwork and subjectively experienced stress, taking into account the moderating role of contact with patients and work in facilities dedicated for COVID-19 patients, and the strategies of coping with stress, including resilience, in countries affected by the pandemic to various degrees. MATERIAL AND METHODS: The study was carried out on 151 Iranian and 158 Polish nurses at the beginning of June 2020. The following research tools were used: the Overwork Climate Scale, the Brief COPE, the Resilience Scale, and the Perception of Stress Questionnaire. The participants were also asked about their contacts with patients infected with COVID-19, and work in facilities dedicated for such patients. RESULTS: Polish and Iranian nurses reported similar levels of overwork, but they differed with respect to the level of subjectively experienced stress and they used different coping strategies to various degrees. Contact with patients infected with COVID-19 and work in facilities dedicated for such patients also moderated the relationship between overwork climate and resilience. CONCLUSIONS: Stress levels among Iranian and Polish nurses during the pandemic are different and are related to the intensity of contact with patients infected with COVID-19. Culture and context have an important impact on coping strategies which requires further studies with a multinational approach. Med Pr. 2021;72(5):457-65.