An energy approach to the fatigue life of ship propulsion systems

The conducted research investigations aimed to carry out an identification of the constructional materials fatigue state of the ship propulsions’ rotational mechanical units for diagnostic purposes. The fatigue cracks of the elements transmitting mechanical energy streams from the propulsion engines to the ship propellers or to the generators of the ship’s electric power station stand for a primary reason for the secondary, usually very extensive, damages within the ship’s main or auxiliary propulsion system. It inevitably leads to immobilizing the ship along with further consequences for her stability and unsinkability. The shafts line’s misalignment or bend represent the most frequent reasons of this kind damages. They usually occur as a consequence of the foundations’ static settlement of the shafts line’s main components, alternatively, as a consequence of the ship’s slight but frequent collisions during her handling in harbors. A laboratory test bed of the simple rotational mechanical unit driven by the electric engine has been especially designed and built for a purpose of the research program realization. It stands for, in a smaller scale, a physical model of the real object what makes possible an actual introducing the external inputs which are characteristic to the propulsion shafts line’s misalignment. The test bed was equipped with a measuring set enabling a registration of the course of the multisymptomatic, continuous and irreversible alterations of the shaft section’s fatigue state while it is subject to cyclic torsional-bending loads during the standard fatigue test. The measuring system makes possible a simultaneous observation of the parameters characterizing accumulation and dissipation processes of different energy forms in the slow- changeable, dynamic process of the fatigue test. A patent application regarding the solution related to energy symptoms measurements of the constructional materials’ high-cycle (mechanical) fatigue presented in the paper has been protected by the Patent Office of the Republic of Poland, as a utility pattern, the registration number: 67362 - “Laboratory test bed for energy examinations of the multisymptomatic high- cycle fatigue of the simple mechanical units’ constructional materials”

Modern regularization techniques for inverse modelling: a comparative study

Regularization techniques are used for computing stable solutions to ill-posed problems. The well-known form of regularization is that of Tikhonov in which the regularized solution is searched as a minimiser of the weighted combination of the residual norm and a side constraint-controlled by the regularization parameter. For the practical choice of regularization parameter we can use the L-curve approach, U-curve criterion introduced by us [1] and empirical risk method [2]. We present a comparative study of different strategies for the regularization parameter choice on examples of function approximation by radial basis neural networks. Such networks are universal approximators and can learn any nonlinear mapping. e.g. representing an magnetic inverse problem. Some integral equations of the first kind are considered as well

Analiza wpływu wybranych czynników anestezjologicznych na stan neurobehawioralny noworodka

Introduction. An increasing percentage of children are born through C-sections. Both mother and child are exposed to potential obstetric, anesthesia and neonatal complications. Hypoxia associated with obstetric or anesthetic complications can lead to fetal hypoxia, and induce adaptation difficulties in the postpartum period or permanent developmental disorders. Knowledge of issues related to the perioperative care of the mother and child will minimize complications and provide high-quality care.Aim. The aim of the study was to analyze the impact of opioids in analgesia and hypotension during C-section on neonatal neurobehavioral state.Material and Methods. The study involved 102 mothers and their babies born by C-section. The study was approved by the Bioethics Committee of PUM. The inclusion criterion was the lack of systemic diseases in the mother and the gestational age over 36 weeks. All mothers were subarachnoidally anesthetized for the labor. Newborns after two days of life were assessed by NBAS (Neonatal Behavioral Assessment Scale).Results. Neonatal reflexes in the study group were normal. Newborns of mothers who were added fentanyl to anesthesia, did not differ in behavior from the others (p>0.05). After adding Morphini Sulfas 0.1% Spinal to anesthesia there were observed statistically significant differences in the behavior of newborns, compared to infants whose mothers did not receive it, in terms of sound stimulus habituation (p=0.04) in favor of those whose mothers received MF Spinal intrathecally. Children of mothers anaesthetized without the addition of MF Spinal presented higher self-calming abilities than the others (p=0.03). The ability of calming down differed infants of mothers whose blood pressure declined during anesthesia (p=0.04).Conclusions. Subarachnoid anesthesia with opioid supplementation for C-section as well as an anesthesia-related decrease in blood pressure slightly affected neurobehavioral state of infants born by C-section comparing to those whose mothers had not received opioids intraspinally and had not experienced a blood pressure decrease. (JNNN 2016;5(3):92–98)Wstęp. Drogą cięcia cesarskiego rodzi się coraz większy odsetek dzieci. Niezależnie od przyczyn, z jakich zostało wykonane, zarówno matka, jak i dziecko narażeni są na potencjalne powikłania położnicze, anestezjologiczne, neonatologiczne. Niedotlenienie związane z powikłaniami położniczymi, czy anestezjologicznymi może prowadzić do niedotlenienia dziecka płodowego, a tym samym wpłynąć na trudności adaptacyjne w okresie poporodowym czy trwałe zaburzenia rozwojowe. Znajomość zagadnień związanych z opieką okołooperacyjną nad matką i dzieckiem pozwoli na minimalizację powikłań i zapewnienie wysokiej jakości opieki.Cel. Celem badań była analiza wpływu podaży opioidów w analgezji oraz obniżenia ciśnienia tętniczego podczas cięcia cesarskiego na stan neurobehawioralny noworodka.Materiał i metody. Badaniem objęto 102 pary noworodków i ich matek, które urodziły przez cięcie cesarskie. Na badanie uzyskano zgodę Komisji Bioetycznej PUM. Kryterium włączenia stanowił brak chorób układowych u matek oraz wiek ciążowy powyżej 36 tygodnia ciąży. Wszystkie matki znieczulane były do porodu podpajęczynówkowo. Szczegóły dotyczące znieczulenia uzyskano z karty znieczulenia. Noworodki po ukończeniu 2 doby życia zostały ocenione skalą NBAS (Neonatal Behavioural Assessment Scale) zgodnie z zasadami przeprowadzenia badania.Wyniki. Odruchy noworodkowe w badanej grupie były prawidłowe. Stan neurobehawioralny w większości badanych pozycji nie wykazywał różnic między badanymi. Noworodki matek, którym do leków znieczulenia dodano Fentanyl, nie różniły się zachowaniem od pozostałych (p>0,05). Po dodaniu Morphini Sulfas 0,1% Spinal do znieczulenia przewodowego zaobserwowano istotne statystycznie różnice w zachowaniu noworodków w porównaniu do dzieci, których matki jej nie otrzymały w zakresie habituacji bodźca dźwiękowego (p=0,04) na korzyść tych, których matki otrzymały dokanałowo MF Spinal. Dzieci matek znieczulanych bez dodatku MF Spinal prezentowały samouspokajanie się na wyższym poziomie od pozostałych (p=0,03). Umiejętność uspokajania się różniła noworodki matek, u których obniżyło się ciśnienie tętnicze podczas znieczulenia (p=0,04).Wnioski. Opieka nad matką i dzieckiem powinna być zindywidualizowana w oparciu o potrzeby matki i dziecka wynikające z samopoczucia matki i stanu neurobehawioralnego dziecka. (PNN 2016;5(3):92–98

Wpływ modułu porodowego na triadę: matka–ojciec–dziecko

Introduction. Enabling a mother to have early contact with her baby regardless of a delivery module, and giving a father the opportunity to take care of baby and partner are important aspects of obstetric care, having effects on bonding. Aim of the study. Assess the influence of the delivery module on the interactions within the mother-father-newborn triad. Material and methods. Subjects were women (n = 200) and their babies born naturally (n = 92) and via c-section (n = 108). A research instrument was a questionnaire evaluating interactions within a triad. The analysis of the results was conducted using the Mann-Whitney U test and the Fisher test. The difference was regarded as statistically insignificant for p ≤ 0.05. Results. There were statistically significant differences in breastfeeding (p = 0.0001) and the way of talking to children (p = 0.04) depending on the delivery module. There were no statistically significant differences in other parameters (p > 0.05). Conclusions. Women after c-section had direct contact with their babies after delivery considerably less frequently, which had an impact on their attitudes and hindered the formation of dyadic bonds.Wstęp. Umożliwienie matce wczesnego kontaktu z dzieckiem oraz ojcom możliwości włączania się w opiekę nad noworodkiem i partnerką należy do ważnych aspektów opieki położniczej rzutujących na tworzenie się więzi w triadzie. Cel pracy. Ocena wpływu modułu porodowego na zachowania w triadzie. Materiał i metody. W badaniu udział wzięły położnice wraz dziećmi (n = 200) urodzonymi naturalnie (n = 92) oraz przez cięcie cesarskie (n = 108). Zastosowano kwestionariusz oceniający zachowania w triadzie. Analizę wyników przeprowadzono testem U Manna-Whitneya i Fishera. Za istotne przyjęto prawdopodobieństwo p ≤ 0,05. Wyniki. Zaobserwowano znamienne różnice między karmieniem piersią (p = 0,0001), sposobem mówienia do dziecka (p = 0,04), a modułem porodowym. W pozostałych z ocenianych parametrów nie zaobserwowano różnic (p > 0,05). Wnioski. Kobiety rodzące cięciem cesarskim częściej nie miały z dzieckiem bezpośredniego kontaktu po porodzie, wpływając na jakość postawy i utrudniając tworzenie więzi w diadzie

A Rough Set-Based Model of HIV-1 Reverse Transcriptase Resistome

Reverse transcriptase (RT) is a viral enzyme crucial for HIV-1 replication. Currently, 12 drugs are targeted against the RT. The low fidelity of the RT-mediated transcription leads to the quick accumulation of drug-resistance mutations. The sequence-resistance relationship remains only partially understood. Using publicly available data collected from over 15 years of HIV proteome research, we have created a general and predictive rule-based model of HIV-1 resistance to eight RT inhibitors. Our rough set-based model considers changes in the physicochemical properties of a mutated sequence as compared to the wild-type strain. Thanks to the application of the Monte Carlo feature selection method, the model takes into account only the properties that significantly contribute to the resistance phenomenon. The obtained results show that drug-resistance is determined in more complex way than believed. We confirmed the importance of many resistance-associated sites, found some sites to be less relevant than formerly postulated and—more importantly—identified several previously neglected sites as potentially relevant. By mapping some of the newly discovered sites on the 3D structure of the RT, we were able to suggest possible molecular-mechanisms of drug-resistance. Importantly, our model has the ability to generalize predictions to the previously unseen cases. The study is an example of how computational biology methods can increase our understanding of the HIV-1 resistome

The relevance of junctional rhythm during neurocardiogenic reaction provoked by tilt testing

Background: During neurocardiogenic reaction provoked by tilt testing (TT), different arrhythmias such as sinus bradycardia, sinus arrest, atrioventricular block or junctional rhythm or beats (JR) may occur. The characteristics of the JR during neurocardiogenic reaction have not yet been systematically assessed. It is not known whether the presence of JR during neurocardiogenic reaction is related to clinical characteristics of syncopal patients or the outcome of TT. Aim: To assess whether clinical outcome of TT and clinical data are related to the presence of JR during TT. Methods: The study group consisted of 532 patients aged 43.3 &#177; 18.2 years with positive TT, divided into four groups on the basis of the presence of JR and/or a ventricular pause (VP) during neurocardiogenic reaction: group VP(&#8211;)/JR(+) &#8212; JR present and VP absent, group VP(+)/JR(+) &#8212; both JR and VP present, group VP(+)/JR(&#8211;) &#8212; JR absent and VP present, and group VP(&#8211;)/JR(&#8211;) &#8212; both JR and VP absent. The control group consisted of 53 patients with no history of syncope or presyncope, including 46 patients with negative TT and seven patients with false positive TT. Results: Total loss of consciousness during TT occurred in group VP(&#8211;)/JR(+) less frequently than in groups VP(+)/JR(+) and VP(+)/JR(&#8211;), and more frequently than in group VP(&#8211;)/JR(&#8211;) (80% vs 96% vs 94% vs 62%; p < 0.05 for both comparisons). Group VP(&#8211;)/JR(+) was significantly younger than group VP(&#8211;)/JR(&#8211;) (37.3 &#177; 16.3 years vs 45.8 &#177; 18.9 years; p < 0.05) and had a lower number of syncopal events than group VP(+)/JR(+) and VP(+)/JR(&#8211;) (median [IQ]: 2.5 (1&#8211;6) vs 4 (2&#8211;12) and 4 (2&#8211;10), respectively; p < 0.05) and lower rate of traumatic injuries than group VP(+)/JR(+) and VP(+)/JR(&#8211;) (22% vs 45% and 39%, respectively; p < 0.05). Logistic regression analysis revealed that the presence of JR was associated with younger age, male gender, history of blood-instrumentation-injection phobia and higher number of syncopal spells in medical history. The ROC curve analysis revealed that a junctional rate of no more than 49 bpm was related to the total loss of consciousness during TT (p < 0.05). Conclusions: 1. JR frequently occurs during positive TT and in no subjects with negative TT. 2. Among patients with JR, two groups may be chosen on the basis of a VP occurrence, and these groups differ in respect to clinical characteristics and TT outcome. 3. Relatively rapid JR without VP is related to consciousness preservation during neurocardiogenic reaction at TT and fewer syncopal spells as well as syncope associated with injury in the past. 4. In patients with JR and VP, the JR is slower, of shorter duration, and more frequently single or pairs of junctional beats occur, which indicates high parasympathetic activity, whereas relatively rapid and stable JR may be the symptom of simultaneously increased sympathetic and parasympathetic activity.Background: During neurocardiogenic reaction provoked by tilt testing (TT), different arrhythmias such as sinus bradycardia, sinus arrest, atrioventricular block or junctional rhythm or beats (JR) may occur. The characteristics of the JR during neurocardiogenic reaction have not yet been systematically assessed. It is not known whether the presence of JR during neurocardiogenic reaction is related to clinical characteristics of syncopal patients or the outcome of TT. Aim: To assess whether clinical outcome of TT and clinical data are related to the presence of JR during TT. Methods: The study group consisted of 532 patients aged 43.3 +- 18.2 years with positive TT, divided into four groups on the basis of the presence of JR and/or a ventricular pause (VP) during neurocardiogenic reaction: group VP(&#8211;)/JR(+) &#8212; JR present and VP absent, group VP(+)/JR(+) &#8212; both JR and VP present, group VP(+)/JR(&#8211;) &#8212; JR absent and VP present, and group VP(&#8211;)/JR(&#8211;) &#8212; both JR and VP absent. The control group consisted of 53 patients with no history of syncope or presyncope, includin 46 patients with negative TT and seven patients with false positive TT. Results: Total loss of consciousness during TT occurred in group VP(&#8211;)/JR(+) less frequently than in groups VP(+)/JR(+) and VP(+)/JR(&#8211;), and more frequently than in group VP(&#8211;)/JR(&#8211;) (80% vs 96% vs 94% vs 62%; p < 0.05 for both comparisons). Group VP(&#8211;)/JR(+) was significantly younger than group VP(&#8211;)/JR(&#8211;) (37.3 +- 16.3 years vs 45.8 +- 18.9 years; p < 0.05) and had a lower number of syncopal events than group VP(+)/JR(+) and VP(+)/JR(&#8211;) (median [IQ]: 2.5 (1&#8211;6) vs 4 (2&#8211;12) and 4 (2&#8211;10), respectively; p < 0.05) and lower rate of traumatic injuries than group VP(+)/JR(+) and VP(+)/JR(&#8211;) (22% vs 45% and 39%, respectively; p < 0.05). Logistic regression analysis revealed that the presence of JR was associated with younger age, male gender, history of blood-instrumentation-injection phobia and higher number of syncopal spells in medical history. The ROC curve analysis revealed that a junctional rate of no more than 49 bpm was related to the total loss of consciousness during TT (p < 0.05). Conclusions: 1. JR frequently occurs during positive TT and in no subjects with negative TT. 2. Among patients with JR, two groups may be chosen on the basis of a VP occurrence, and these groups differ in respect to clinical characteristics and TT outcome. 3. Relatively rapid JR without VP is related to consciousness preservation during neurocardiogenic reaction at TT and fewer syncopal spells as well as syncope associated with injury in the past. 4. In patients with JR and VP, the JR is slower, of shorter duration, and more frequently single or pairs of junctional beats occur, which indicates high parasympathetic activity, whereas relatively rapid and stable JR may be the symptom of simultaneously increased sympathetic and parasympathetic activity

The discrete fragmentation equations : semigroups, compactness and asynchronous exponential growth

In this paper we present a class of fragmentation semigroups which are compact in a scale of spaces defined in terms of finite higher moments. We use this compactness result to analyse the long time behaviour of such semigroups and, in particular, to prove that they have the asynchronous growth property. We note that, despite compactness, this growth property is not automatic as the fragmentation semigroups are not irreducible

Social competence of physicians and medical students – a preliminary report

Background . Efficient functioning at work and in the environment depends on social and emotional competence, understood as complex skills that determine the effectiveness of behaviors in various professional and social situations. Objectives. The aim of this study was to determine the social competence of physicians and medical students with regard to the sociodemographic contributors which shape social competence. Material and methods . The study was conducted in 2015 and 2016 and it involved 90 physicians, including 25 GPs (27.8%) and 53 medical students of PMU in Szczecin. The median age of the physicians and the students was 32 and 25, respectively. The Social Competencies Questionnaire (SC Q) by Anna Matczak and a self-developed survey questionnaire were employed. Results. The ability of physicians to achieve medium and high levels of social competence increases by 8.5% with every year of seniority. Membership in scientific societies increases the odds of a high level of social competence fivefold in the ES scale and fourfold in the A scale. Physicians involved in the education of medical students were less likely to obtain medium and high scores (5 stens) in the A scale. An increase in seniority in the last workplace is accompanied by a 0.93 times lower probability of obtaining a high competence score in the A scale. Similarly, third cycle degree studies increase the odds of achieving high competence level by 7.48 times in the A scale. Conclusions . Low levels of competence can be expected from physicians with less seniority, not belonging to scientific societies, not involved in students’ education, working in only one place, and not participating in third cycle degree studies. This group should be provided with social competence training

Changes in disease burden in Poland between 1990-2017 in comparison with other Central European countries : a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND:Systematic collection of mortality/morbidity data over time is crucial for monitoring trends in population health, developing health policies, assessing the impact of health programs. In Poland, a comprehensive analysis describing trends in disease burden for major conditions has never been published. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides data on the burden of over 300 diseases in 195 countries since 1990. We used the GBD database to undertake an assessment of disease burden in Poland, evaluate changes in population health between 1990-2017, and compare Poland with other Central European (CE) countries. METHODS:The results of GBD 2017 for 1990 and 2017 for Poland and CE were used to assess rates and trends in years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life years (DALYs). Data came from cause-of-death registration systems, population health surveys, disease registries, hospitalization databases, and the scientific literature. Analytical approaches have been used to adjust for missing data, errors in cause-of-death certification, and differences in data collection methodology. Main estimation strategies were ensemble modelling for mortality and Bayesian meta-regression for disability. RESULTS:Between 1990-2017, age-standardized YLL rates for all causes declined in Poland by 46.0% (95% UI: 43.7-48.2), YLD rates declined by 4.0% (4.2-4.9), DALY rates by 31.7% (29.2-34.4). For both YLLs and YLDs, greater relative declines were observed for females. There was a large decrease in communicable, maternal, neonatal, and nutritional disease DALYs (48.2%; 46.3-50.4). DALYs due to non-communicable diseases (NCDs) decreased slightly (2.0%; 0.1-4.6). In 2017, Poland performed better than CE as a whole (ranked fourth for YLLs, sixth for YLDs, and fifth for DALYs) and achieved greater reductions in YLLs and DALYs than most CE countries. In 2017 and 1990, the leading cause of YLLs and DALYs in Poland and CE was ischaemic heart disease (IHD), and the leading cause of YLDs was low back pain. In 2017, the top 20 causes of YLLs and YLDs in Poland and CE were the same, although in different order. In Poland, age-standardized DALYs from neonatal causes, other cardiovascular and circulatory diseases, and road injuries declined substantially between 1990-2017, while alcohol use disorders and chronic liver diseases increased. The highest observed-to-expected ratios were seen for alcohol use disorders for YLLs, neonatal sepsis for YLDs, and falls for DALYs (3.21, 2.65, and 2.03, respectively). CONCLUSIONS:There was relatively little geographical variation in premature death and disability in CE in 2017, although some between-country differences existed. Health in Poland has been improving since 1990; in 2017 Poland outperformed CE as a whole for YLLs, YLDs, and DALYs. While the health gap between Poland and Western Europe has diminished, it remains substantial. The shift to NCDs and chronic disability, together with marked between-gender health inequalities, poses a challenge for the Polish health-care system. IHD is still the leading cause of disease burden in Poland, but DALYs from IHD are declining. To further reduce disease burden, an integrated response focused on NCDs and population groups with disproportionally high burden is needed