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In the past few years, technological advancements enabled the development of novel electronic nicotine delivery systems (ENDS). Several empirical measures such as “nicotine flux” are being proposed to evaluate the abuse liability potential of these products. We explored the applicability of nicotine flux for clinical nicotine pharmacokinetics (PK) and 52-week quit success from cigarettes for a wide range of existing nicotine delivery systems. We found that the differences in nicotine flux for various nicotine delivery systems are not related to changes in PK, as nicotine flux does not capture key physiological properties such as nicotine absorption rate. Further, the 52-week quit success and abuse liability potential of nicotine nasal sprays (high nicotine flux product), and nicotine inhalers (nicotine flux similar to ENDS) are low, suggesting that nicotine flux is a poor metric for the assessment of nicotine delivery systems. PK indices are more dependable for characterizing nicotine delivery systems, and a nicotine plasma CmaxTmax > 1 could improve 52-week quit success from cigarettes. However, a single metric may be inadequate to fully assess the abuse liability potential of nicotine delivery systems and needs to be further studied. A combination of in vitro and in silico approaches could potentially address the factors influencing the inhaled aerosol dosimetry and resulting PK of nicotine to provide early insights for ENDS assessments. Further research is required to understand nicotine dosimetry and PK for ad libitum product use, and abuse liability indicators of nicotine delivery systems. This commentary is intended to (1) highlight the need to think beyond a single empirical metric such as nicotine flux, (2) suggest potential PK-based metrics, (3) suggest the use of in vitro and in silico tools to obtain early insights into inhaled aerosol dosimetry for ENDS, and (4) emphasize the importance of considering comprehensive clinical pharmacology outcomes to evaluate nicotine delivery systems.

Fatty acid synthase (FASN) is a metabolic enzyme responsible for the synthesis of fatty acids in milk and meat. The SNPs g.841G/C and g.17924A/G of the FASN gene significantly influence the fat and fatty acid content of milk from cows of various breeds. Therefore, these SNPs were selected for this study. This study aimed to analyze the relationship of SNPs and their genotypes with the fat content and fatty acid profile of milk from Polish Red-and-White (ZR), Polish Red (RP), and Polish Holstein–Friesian Red-and-White (RW) cows. Milk samples were obtained during a milking trial. SNP genotyping was performed using the real-time PCR (HRM) method. It was shown that SNPs (with specific genotypes) were significantly associated with the presence of fatty acids such as C18:1n9t and C18:2n6c in milk. In addition, it was found that the milk fat from the ZR (genotypic variant A/G, AA) and RP (genotypic variant GG, A/G) breeds often exhibited a more attractive fatty acids profile than the milk fat from RW cows. This information can be used by both cattle breeders and people interested in consuming functional foods.

Fat is an important energy and nutritional component of milk and consists of fatty acids. FASN (fatty acid synthase) is an enzyme that regulates the synthesis of fatty acids in the milk and meat of cattle. It was hypothesized that knowing the relationships between the genotypes of the tested single nucleotide polymorphisms (SNPs) and the content of fat and specific fatty acids would make it possible to improve milk quality in the selection process during cattle breeding. This study aimed to analyze the relationships of SNPs (g.16024A/G, g.16039T/C) of the FASN gene and their genotypes with the fat and fatty acid content of the milk of the following breeds: Polish Red-White (ZR), Polish Red (RP), and Polish Holstein-Friesian Red-White (RW). The SNP g.16060A/C was included in the study, although its effect on the fat composition of cow’s milk has not yet been widely studied. Milk was obtained during test milkings. SNP genotyping was performed using the real-time PCR (HRM) method. The milk from ZR and RP cows was more often characterized by a more favorable fatty acid profile than the milk from RW cows. This information can be used by cattle breeders and consumers of so-called functional food.

(1) Background: Advanced heart failure often accompanies ventricular arrhythmias, necessitating antiarrhythmic therapies. Amiodarone, commonly used for this purpose, may induce thyroid dysfunction due to its high iodine content. However, the prevalence and correlation of thyroid dysfunction with amiodarone in end-stage heart failure patients remain unclear. Aim: This study aimed to evaluate the prevalence and types of thyroid dysfunction and their association with amiodarone among 200 patients diagnosed with advanced heart failure eligible for transplantation. (2) Methods: Consecutively enrolled patients received treatment following the European Society of Cardiology guidelines and were followed-up for two years. Ventricular arrhythmias affected 58.5% of the cohort, with 24.5% receiving amiodarone therapy. (3) Results: Thyroid metabolism dysfunction was evident in 61 patients, notably overrepresented in women (p = 0.0028). Hyperthyroidism (34 patients) and hypothyroidism (27 patients) were observed, with a significant amiodarone-related correlation. Despite this, thyroid dysfunction was not associated with increased mortality among the studied group. (4) Conclusions: Thyroid dysfunction is prevalent in advanced heart failure patients, with a notable proportion linked to amiodarone. However, its presence does not correspond to higher mortality rates. Understanding these associations is crucial for effective management in this patient population. Further exploration is warranted to refine approaches to thyroid dysfunction in refractory heart failure.

Torque Teno Virus (TTV), first discovered in 1997, is a non-pathogenic, highly prevalent virus with a notable presence in the human virome. TTV has garnered attention as a potential indicator of immunocompetence in recipients of solid organ transplants. In this review, we discuss the role of TTV as a potential marker for immunosuppression optimization, prediction of graft rejection, and as an indicator of opportunistic infections. We discuss TTV’s behavior over the course of time after transplantation, TTV’s implications in different immunosuppressive regimens, and potential utility in vaccinations. The review synthetizes findings from various studies depicting its potential clinical utility for future personalized patient care.

Abstract During the coronavirus disease (COVID-19) pandemic, wearing face masks in public spaces became mandatory in most countries. The risk of self-contamination when handling face masks, which was one of the earliest concerns, can be mitigated by adding antiviral coatings to the masks. In the present study, we evaluated the antiviral effectiveness of sodium chloride deposited on a fabric suitable for the manufacturing of reusable cloth masks using techniques adapted to the home environment. We tested eight coating conditions, involving both spraying and dipping methods and three salt dilutions. Influenza A H3N2 virus particles were incubated directly on the salt-coated materials, collected, and added to human 3D airway epithelial cultures. Live virus replication in the epithelia was quantified over time in collected apical washes. Relative to the non-coated material, salt deposits at or above 4.3 mg/cm2 markedly reduced viral replication. However, even for larger quantities of salt, the effectiveness of the coating remained dependent on the crystal size and distribution, which in turn depended on the coating technique. These findings confirm the suitability of salt coating as antiviral protection on cloth masks, but also emphasize that particular attention should be paid to the coating protocol when developing consumer solutions.

Understanding how habitat characteristics influence common bottlenose dolphin, Tursiops truncatus, distribution and behavior can be useful for conservation. The dolphin community in Roanoke Sound, North Carolina primarily exhibits seasonal residency and there is limited information on their habitat use. The objectives of this study were to increase habitat use knowledge and determine the relationship between habitat characteristics and dolphin distribution using standardized photographic-identification data (2009 – 2017). A hot spot (Getis-Ord Gi*) analysis showed dolphins frequently use the southern region containing the mouth of the estuary for feeding and traveling. Habitat characteristics were modeled with zero-altered gamma (ZAG), generalized linear (GLM), and generalized additive (GAM) models to predict dolphin group density. Models showed that groups were more likely to be present in areas with greater benthic slope variation and shallow areas closer to land, and that different habitat characteristics were associated with feed, social, and travel activities. This study suggests that Roanoke Sound provides a seasonal foraging area and travel corridor between the estuaries and coastal waters. This information contributes baseline knowledge of how habitat potentially influences dolphin distribution and behavior which can be useful for management and conservation, especially in areas where habitat changes and impacts need to be assessed.

The signature whistle of the Atlantic bottlenose dolphin (Tursiops truncatus) is a well-studied acoustic signal know for broadcasting identity and maintaining contact with conspecifics. Several studies have investigated the use of this signal surrounding the birth of calves to dolphin social groups, although there appears to be discrepancies between the findings of these studies. We aimed to add to the current literature in an attempt to reconcile some of these inconsistencies through investigation of signature whistle production by a bottlenose dolphin group two months prior to and two months following the birth of a calf to one of the social group members. We found that the production of signature whistles matching the contour belonging to our dolphin mother increased significantly in both the pre- and post-partum period. Heightened production of the mother’s signature whistle type in the first week of our focal calf’s life supports the establishment of a recognition system within this time period. Given that learning processes associated with the sound environment appear to begin shortly after calf birth, we also explored the signature whistle rates of the other social group members in an effort to determine whether any signature whistle production influenced the development of the dolphin calf’s own signature whistle type. We found that the signature whistles of the other social group members were significantly lower than production of the mother’s signature whistle until after the first week post-partum. None of the signature whistle types appeared to influence the signature whistle development of our focal calf within the scope of this study, however, as the calf did not develop a signature whistle in her first two months of life.

Simple Summary: The composition of milk fat is of interest to milk producers and consumers. Unsaturated fatty acids are important fats in the human diet, and their profile is influenced by the single-nucleotide polymorphisms (SNPs) of the FASN gene. This study aimed to determine the relationship of two selected SNPs and their genotypic variants with the fat content and fatty acid profile of milk from Polish Red-and-White (ZR), Polish Red (RP), and Polish Holstein–Friesian Red-and-White (RW) breeds. The frequencies of the genotypes of the SNPs were also determined for each breed included in this study. This study enabled the determination of cattle breeds (each with its specific genotype of a given SNP), which proved to be more conducive to the production of health-promoting milk, as evidenced by the fat and fatty acid content of the milk. It was found that, for one SNP, the RP breed (with a specific genotype) exhibited favorable characteristics, while in the case of the other SNP, the RP, ZR, and RW breeds (each with their specific genotypes) demonstrated favorable attributes. This information can be used in cattle-breeding efforts to improve the quality of milk produced. Fatty acid synthase (FASN) is a metabolic enzyme responsible for the synthesis of fatty acids in milk and meat. The SNPs g.841G/C and g.17924A/G of the FASN gene significantly influence the fat and fatty acid content of milk from cows of various breeds. Therefore, these SNPs were selected for this study. This study aimed to analyze the relationship of SNPs and their genotypes with the fat content and fatty acid profile of milk from Polish Red-and-White (ZR), Polish Red (RP), and Polish Holstein–Friesian Red-and-White (RW) cows. Milk samples were obtained during a milking trial. SNP genotyping was performed using the real-time PCR (HRM) method. It was shown that SNPs (with specific genotypes) were significantly associated with the presence of fatty acids such as C18:1n9t and C18:2n6c in milk. In addition, it was found that the milk fat from the ZR (genotypic variant A/G, AA) and RP (genotypic variant GG, A/G) breeds often exhibited a more attractive fatty acids profile than the milk fat from RW cows. This information can be used by both cattle breeders and people interested in consuming functional foods. [ABSTRACT FROM AUTHOR]

The paper provides and comments on the results of studies of the effect of sandstone-based abrasives and quartz sand alone on the wear of martensitic surfaces of wear-resistant steels. The wear process was examined on a ring-on-ring test rig seeking to determine the mass decrement parameter which characterised wear. In addition, SEM microscopy, optical profilometry and XRF analysis were used to analyse the abrasives used and damaged surfaces. The tests were conducted for three sandstone varieties, Carboniferous, Permian, and Cretaceous, and they made it possible to determine that the most intense process of deterioration of wear-resistant steels took place in the presence of quartz sand grain, while less intense wear was observed in the case of sandstone-based abrasives. The mass decrement values established in the presence of the sandstones in question did not differ significantly between individual sandstone varieties. Based on a surface damage analysis, the basic damage mechanism was found to be micro-scratching; however, with regard to the sandstones examined, it was also determined that individual grains could be pressed into surface irregularities and that films of soft hematite cement developed in the Permian sandstone and that inclusions of carbonaceous matter were formed in the Carboniferous sandstone. With reference to the wear process observations, a wear model was described for the surface of the steels examined in the presence of sandstone-based abrasives. This model presents the possibility of capturing wear products by unstable binder layers and changing the form of wear from three-body to two-body. [ABSTRACT FROM AUTHOR]

Dolphins are frequently described as curious animals; however, there have been few systematic investigations of how dolphins behave when they are curious and the extent to which individual differences in curiosity exist in dolphins. Previous research has described individual differences in dolphins’ frequency of interactions with environmental enrichment as well as quantifying curiosity-related traits of dolphins via personality assessments, though behavioral observation and trait rating components have not been part of the same study. The present study describes two different experiments designed to elicit curiosity in 15 bottlenose (Tursiops truncatus) and 6 rough-toothed (Steno bredanensis) dolphins. In Experiment 1, dolphins displayed more curiosity-related behavior toward a stimulus with spontaneous movement (jack-in-the box) compared to their reaction to a static control object; however, in Experiment 2, the subjects did not conform to hypotheses, and displayed few behavioral differences when shown expectation-violating stimuli compared to a control stimulus. The results of this study supported the hypothesis that there would be a wide range of individual differences in dolphins’ reactions to the stimuli, including differences between species and sex, as well as differences in trait ratings by trainers. These findings provide information that may be useful for future research aimed at assessing curiosity in dolphins, as well as for making environmental enrichment decisions for dolphins in human care.

The human gut microbiota include over 10 trillion microorganisms, such as bacteria, fungi, viruses, archaea, and protozoa. Many reports indicate the strong correlation between dysbiosis and the severity of cardiovascular diseases. Microbiota seem to interact with the host’s alloimmunity and may have an immunomodulatory role in graft rejection processes. In our study, we present the current state of the knowledge of microbiota in heart transplant recipients. We present up-to-date microbiota diagnostic methods, interactions between microbiota and immunosuppressive drugs, the immunomodulatory effects of dysbiosis, and the available strategies (experimental and clinical strategies) to modulate host microbiota.

This paper discusses the impact of coal abrasive materials of varied petrographic composition and claystones containing admixtures of coal matter on the surface wear of wear-resistant martensitic steels. Wear tests were conducted at a test stand for three petrographic varieties of hard coal: vitrinite, clarinite, and durinite, and five samples of claystone. These tests revealed no significant effect of the type of coal abrasive used on the value of mass loss from the surface of the wear-resistant steel samples. The reason behind the foregoing is the observed tendency of coal abrasives, irrespective of their petrographic variety, to penetrate surface irregularities, especially those attributable to previous surface treatment of the samples and the impact of wear products. The dominant forms of surface damage were surface fatigue chipping and scratches caused by the particles which detached themselves from the surface of the steel samples, as observed for all the analysed coal variants. On the surfaces of the samples seasoned in the presence of claystones, highly varied forms of damage were observed: microcutting, scaly surface cracks, delamination, and deep cracks. In these cases, it was possible that the abrasive grains had been pressed into the steel surface irregularities, but no layered forms of the pressed-in abrasive material were observed to have developed. The paper also presents a model for the formation of coal films and discusses their possible effect on wear minimisation.

Environmental enrichment is critical for maintaining cognitive welfare for animals in human care but is subject to individual preferences.  The interest in a video-based enrichment was assessed for a single killer whale (Orcinus orca) in human care.  The adult female was presented 20 video recordings featuring cetaceans, elephants, or humans with each video presented in two conditions: (1) with sound and (2) without sound.  Four additional presentations in which the television displayed a blank screen served as controls.  All sessions were videotaped and coded for time spent viewing the recordings, behavioral responses, and visual laterality.  The killer whale spent significantly more time at the television when programs were on screen compared to when the television was present but blank.  She was more likely to watch videos accompanied by sound than those presented without sound. Videos were more likely to be viewed monocularly rather than binocularly, with a right eye preference when viewing the videos the first time they were presented.  The highest rates of behavioral responses occurred during videos of cetaceans.  These results demonstrate that one killer whale responded to video recordings of different stimuli, suggesting that video recordings may be used as a form of enrichment for cetaceans and that not all video content and formats are equally interesting.

Dolphins exchange information with conspecifics using different types of vocalizations that are often associated with specific behaviors. The present study used simultaneous acoustic and video recordings of captive bottlenose dolphins (Tursiops truncatus) in Honduras to describe potential correlations between the type of mouthing behavior (open mouth, mouthing, bite) and associated vocalizations (whistle, whistle-squawk, chirp, moan, burst-pulse ‘A’, burst-pulse ‘B’, clicks). Literature on sound-behavior relationships among odontocetes with the noted infrequent systematic analyses of mouth actions highlights the need for this investigation. The influence of aggression on vocalization use was also addressed. From this observational study a series of general expectations on the interaction of sound, mouth action, and aggressive context are presented. Mouth actions are associated with vocalizations more often than not, and results suggest an overall flexible association of vocalizations during mouth actions, with the production of various sounds altered during aggressive contexts. There is an apparent distinction of frequency-modulated sounds with mouthing, suggesting that frequency parameters are an important characteristic of information exchange during mouth actions, and further that mouth actions are individually distinct behaviors. A dichotomy of burst pulse sounds in association with aggressive and non-aggressive contexts also introduces the need to analyze pulsed sounds according to inter-pulse interval. This paper proposes that there may be an interactive function to the use of vocalizations during mouth actions that is not yet understood.

McCowan and Reiss first reported the “thunk” sound of the Atlantic bottlenose dolphin (Tursiops truncatus) during separations and discipline behavior of mother-calf dyads. This sound has been previously described as a wide-band, low frequency contact call, however the harmonic structure of this sound is more variable than previously described. Based on preliminary observations of the graded structure of thunks within our data set, we investigated the directionality of thunks with energies at higher frequencies. We recorded a bottlenose dolphin mother with her calf during the first 30-days of life, and analyzed thunk production during separation and discipline contexts. Two classifications of the thunk sound were compared to determine calf response and whether location cues were embedded in the higher harmonics of one of the thunk types. The mother oriented towards the calf significantly more during production of both thunk types during separation and discipline contexts. This sound may have potential directional information within the harmonic structure; however, we could not draw that conclusion based on our findings. Therefore, we present data here that indicates a graded structure to the harmonics of thunk sounds.

Social structures are critical to the success of many species and have repercussions on health, well-being, and adaptation, yet little is known about the factors which shape these structures aside from ecology and life history strategies. Dyadic bonds are the basis of all social structures; however, mechanisms for formations of specific bonds or patterns in which individuals form which types of bonds have yet to be demonstrated. There is a variety of evidence indicating personality may be a factor in shaping bonds, but this relationship has not been explored with respect to bond components and is yet to be demonstrated in dolphins. This study utilizes a captive population in a naturalistic environment to test for correlation between similarity within the dyad along each personality factor and the strength of the dyad’s bond characteristics. Personality was assessed using a Five Factor Model questionnaire. Dyadic bond strength and characteristic qualities were determined through an exploratory factor analysis to group behaviors recorded via underwater opportunistic focal-follow video. Discovered bond components differed from previous studies and were termed affiliative support, sociosexual, and conflict play.  Individuals who differed in Extraversion and Neuroticism displayed greater levels of bonding. This study expands our understanding of the formation of bonds between individuals and the evolution of social structure. Furthermore, it better equips us for making informed environmental policy decisions and improving captive animal care.

The ecotour industry continues to grow with a distinct focus on providing the public with up-close encounters with cetaceans. As a result, research focusing on both the effects of ecotourism on cetaceans and the efficacy of conservation-focused educational interventions for whale-watching operators is necessary to monitor and develop industry standards. Each year, whale-watching tours target humpback whales along their Colombian Pacific breeding grounds. There are many benefits to ecotourism in this area, including the use of whale-watching vessels as a platform for scientific research and environmental education. However, some whale-watching operators may lack species-specific knowledge and/or do not follow the suggested industry guidelines. Researchers held educational seminars for whale-watching staff at six hotels that border the Gulf of Tribugá. Seminars focused on whale anatomy, behavior, anthropogenic effects on the species, and sustainable whale-watching protocols. Participants were asked to complete a questionnaire aimed to assess constructs related to the conservation of this species. This self-report information was accompanied by implicit measures (e.g., sighting duration, distance from whales) recorded during tours in situ. Behavioral observations aimed at assessing whales’ response to ecotour vessels demonstrated that whales increased rates of surface-active behaviors (e.g., tail slashes) with increasing nearness and duration. Whale-watching operators’ conduct during sightings demonstrated that positive attitudes toward humpback whales did not translate into adherence to sustainable practices. This relationship between the whale-watching operators’ questionnaire results and their behavior in the field demonstrates the need for careful monitoring of this developing industry. This project represents a preliminary evaluation of this budding ecotour industry. Continued efforts to increase knowledge while promoting self-advocacy, positive perceived behavioral control, subjective norms, behavioral intentions, and attitudes towards these animals will enable the safeguarding of near-shore waters essential for breeding and nursing humpback whales.

Wild bottlenose dolphin (Tursiops truncatus) behavior is impacted by a number of factors including season, time of day, and age.  However, less is known about how these factors may influence animals under professional care in zoos, aquariums and marine parks. Management practices such as scheduled feeding times, human interactions, lack of predators and show performances may also impact the activity budgets of dolphins.  The current study examined the rest, swim and play behavior of seven dolphins (three adults, four calves) at one facility. Data were collected over the entire 24-hour day for a period of one year. Observed behaviors were recorded in mutually exclusive categories including rest, low intensity swim, high intensity swim, low intensity play, high intensity play and social play. Data were analyzed to determine how often dolphins engaged in particular behaviors and if activity budgets varied due to season, time of day and age.  These dolphins spent the majority of their time in low intensity swim and low intensity play.  The activity budget varied between observational periods.  First, seasonal differences were found in low intensity swim, low intensity play, social play and high intensity play behaviors.  In the comparison for time of day, differences were found in rest, low intensity swim, low intensity play and social play.  Finally, no significant differences were found in age comparisons. Information gained from this study can help to better understand how different factors influence the behavior of bottlenose dolphins under professional care within zoos, aquariums and marine parks.

The rearing and socialization of bottlenose dolphin calves has been largely described as a female role, whether via direct maternal care or allomaternal parenting. Nevertheless, male associations have been observed but are rarely systematically investigated. This case study focused on the opportunistic occurrence of a single bottlenose calf and her associations with the mother, father and two unrelated allomothers in a captive setting. Observations were made postpartum of an adult male and his female calf multiple times per day over the course of the first year of the calf’s life, including social (proximity and orientation), aggressive (tail slapping/swatting, threats, jaw popping, chasing) and tactile behaviors. For comparative analyses, data were simultaneously collected on mother-calf and allomother interactions. The results revealed that cohabitation of the paternal male and offspring was prosocial, with negligible levels of aggression (0.03%) even during maternal estrous. The male demonstrated minimal aggressive behaviors toward the calf (e.g., chasing), none of which resulted in injury. Rather, the male’s interactions with the calf were considerably affiliative. Although the frequency of interactions between the paternal male and the calf were less than the mother’s, father-calf interactions were significantly more frequent than were calf interactions with other dolphins. Over the course of the study, the number of interactions the calf had with mother, father, and allomothers decreased. Overall, these results confirm that care can involve the paternal male, although the relative size of the enclosed setting limits extrapolations to the wild. Nonetheless, these observations suggest that some dolphin fathers may play a role in their calves’ social development and rearing.  Although additional research on calf socialization is required, the dolphin father in this study established and maintained a social bond with his female calf that was clearly affiliative, and these associations occurred significantly more often than those between the calf and her allomothers.

The preference for utilizing certain appendages (handedness) has been explored in human and nonhuman primates. Similarly to primates, dolphins possess hemispheres that allow an individual to present behaviorally dominant features as well as appendages (i.e., pectoral fins) that are utilized both as social facilitators as well as means to interact with objects. Thus, the possibility of handedness in a captive population of 27 bottlenose dolphins (Tursiops truncatus) was explored. Dolphins in a mother-offspring relationship made significantly more pectoral fin contacts than in the absence of this relationship (p < 0.001). No significant difference was observed between maternal siblings and non-maternal siblings in overall pectoral fin contact. Handedness indexes were calculated for 26 individuals that initiated pectoral fin contact with both conspecifics and flora (i.e., seagrass) in their habitat. No significant differences were observed between the sexes in handedness indexes, however calves displayed a significant right-fin handedness compared to both sub-adults and adults (p < 0.05). Both sub-adults and adults showed a left-fin handedness indexes, but no significant difference in the strength of this relationship among these two age classes was observed. Individual variation in handedness indexes was noted. These results suggest that handedness may be present in Atlantic bottlenose dolphins with regards to social contact, and a larger and more diverse sample size may provide a better understanding in why handedness may change across development.

The paper addresses the driving dynamics of emergency fire trucks. It focuses on the issues of braking, measuring real braking distances and calculating adhesion coefficients. It presents the results of measuring the real braking distances for firefighting vehicles - type water tenders. Measurements were taken on dry asphalt and depending on the vehicle's speed of travel. Experiments were conducted on five types of firefighting vehicles. The results of measurements are mainly used by fire protection units to the drivers' self-education to improve safety when driving to intervene.

Patients with pulmonary arterial hypertension (PAH) become candidates for lung or lung and heart transplantation when the maximum specific therapy is no longer effective. The most difficult challenge is choosing one of the above options in the event of symptoms of right ventricular failure. Here, we present two female patients with PAH: (1) a 21-year-old patient with Eisenmenger syndrome, caused by a congenital defect—patent ductus arteriosus (PDA); and (2) a 39-year-old patient with idiopathic PAH and coexistent PDA. Their common denominator is PDA and the hybrid surgery performed: double lung transplantation with simultaneous PDA closure. The operation was performed after pharmacological bridging (conditioning) to transplantation that lasted for 33 and 70 days, respectively. In both cases, PDA closure effectiveness was 100%. Both patients survived the operation (100%); however, patient no. 1 died on the 2nd postoperative day due to multi-organ failure; while patient no. 2 was discharged home in full health. The authors did not find a similar description of the operation in the available literature and PubMed database. Hence, we propose this new treatment method for its effectiveness and applicability proven in our practice.

The article provides a discussion on a methodology intended for testing of power transmission systems featuring an innovative highly torsionally flexible metal clutch patented by the co-authors of this paper. What this methodology takes into account is the amplitude and frequency analyses discussed in the article, as well as a sensing system based on diverse piezoelectric and magnetic phenomena, the Doppler effect, etc. Both contact and non-contact (laser measurement) methods were used during the tests. The purpose of the tests conducted at the stand, originally designed by the authors in accordance with the methodology proposed, was to evidence that using the innovative and patented, highly torsionally flexible metal clutch makes it possible to reduce the vibrations of multi-stage toothed gears, consequently reducing the forces affecting the gear bearings and those acting at the tooth space, which is to enable the service life of individual components of the power transmission systems intended for mining scraper conveyors to be significantly extended. Based on the studies and analyses performed by the authors, one can observe and conclude that the methodology proposed in the paper makes it possible to use an example of a relatively complex power transmission system in order to examine the relationships between the processes at work, i.e., the decline of the linear vibrations of the gear housing (which is undoubtedly positive in power transmission systems) at the expense of increasing torsional vibrations of the innovative clutch, the latter not to be considered unfavourable to users in the case analysed.

This paper deals with the issue of operating damage of combustion engine valves. It presents an innovative way and construction of a tool for strengtheningpiston engine valves by way of surface working. It presents the concept of machines for comprehensive surface working and for profiling the faces of combustion engine valves. It also includes the discussion of the methodology of working.