Problems of operation of positive pressure ventilators on the basis of surveys of Polish officers of the State Fire Service.

Positive pressure ventilators (PPV) used by 97.7% of officers of the National Fire Service in Poland, are characterized by work that is not in line with the expectations of the firefighters. In order to improve the technical and operational features of these devices, a survey was conducted among 25,000 eligible firefighters, identifying the application of these devices, problems in use and expected development directions. A total of 682 officers voluntarily completed the survey. Based on their findings, it was determined that ventilators are most often used to smoke out buildings after or during a fire. Mentioned problems when using these devices were mainly noise (78.2%), exhaust emissions (68.5%), and impediments to mobility through the device's relatively heavy weight (40.2%). Other inconveniences were mentioned by less than 20% of firefighters. Polish firefighters expect the development of these devices mainly in terms of the above-mentioned features (noise reduction (81.7%) and reduction of the weight and size of the ventilators (about 50%)). Other expectations relate to the improvement of smoke removal in buildings: increasing the efficiency of smoke removal (46.4%) and efficiency regarding the rate of smoke removal in a building by increasing the size of the incoming airflow from the building's surroundings (33.2%). About 15% of firefighters expect changes in the operation of the ventilator itself, that is, an increase in the effective operating time (electric ventilators) and an increase in the device's uptime. The aim of the article is to identify the issues encountered during the operation and to indicate the expected direction of development for PPV by users. This information can be used by engineers to initiate new development work on these devices.

Analysis of the air stream flow parameters generated by the positive pressure ventilator-full scale experiment and CFD simulation.

Positioning the positive pressure ventilator in front of the door opening affects the effectiveness of the rescue operation carried out during a fire. An important factor determining the effectiveness of the positive pressure ventilator is also the layout of the rooms within the gas exchange path and the obstacles present there. The purpose of this article is to assess the feasibility of using analyses such as large eddy simulation (LES) to verify the efficiency of mobile fans under simulation conditions, without the need for time-consuming experimentation (also for complex room volumes of buildings). The article presents a comparative analysis to assess the degree of convergence of flow parameters obtained during an experiment (in a multi-story building) and computational fluid dynamics (CFD) simulations. For volumetric flow rate, convergence was achieved at levels ranging from 0.4% (for 5 m) to 11.5% (1 m), and for pressure values, the differences achieved ranged from 0.6% (5 m) to 30.1% (4 m). This paper demonstrates that the LES model can be used to perform CFD simulations in the area of assessing the performance of a positive pressure ventilator. The article also describes a test methodology for determining the flow parameters of an air stream, which can be used to perform numerical simulations.

Newly developed cardiovascular risk factors in rheumatoid arthritis patients initiating biologic treatment.

Introduction: Rheumatoid arthritis (RA) is a risk factor (RF) for cardiovascular (CV) disease, a leading cause of mortality in RA patients. Material and methods: Consecutive records of RA patients with high disease activity screened upon biologic therapy initiation were reviewed between January 2001 and 2018. Patients with at least 6-month follow-up and baseline disease activity scores were enrolled (n = 353) and stratified into manifest CV disorder ("overt CVD"), any traditional CV risk factor ("atCVrisk") and no CV risk factor ("vlCVrisk") groups. Results: Overall, mean (SD) patient age was 51.4 (±12.2) years, and 291 (82.4%) subjects were female. Median follow-up was 41.9 (IQR 18.6, 80) months. Overall, 89 (25.2%) individuals developed at least one new CV RF, of which 65 (18.4%) acquired one and 24 (6.8%) two or more. Incident lipid disorders (42, 11.9%), followed by hypertension (14, 4%), atrial fibrillation (17, 4.8%) and venous thromboembolism (VTE) (16, 4.5%), were common. Incident major adverse cardiac events (MACE) were not reported in the vlCVrisk group, in contrast to atCVrisk (n = 8, 4.2%) or overt CVD (n = 4, 18.2%). Age was a significant predictor of incident CV risk factor (HR 1.04, 95% CI: 1.02-1.07; p < 0.01). In age-adjusted analyses, only baseline body mass index (BMI) (HR 1.11, 95% CI: 1.04-1.18; p < 0.01), but not ever smoking (p = 0.93), male sex (p = 0.26), positive RF (p = 0.24), positive ACPA (p = 0.90), or baseline disease activity (p = 0.19), were independent predictor of incident CV risk factors. Conclusions: Patients with RA initiating biologics should be screened for cardiometabolic risk factors, especially at an older age. The presence of at least one risk factor may be linked to a worse long-term prognosis.

Drug Retention and Safety of Secukinumab in a Real-World Cohort of Ankylosing Spondylitis and Psoriatic Arthritis Patients.

Real-life data that support effectiveness of secukinumab (SEC), an interleukin 17A inhibitor, in Poland are few. We aimed to evaluate SEC effectiveness based on drug retention and safety measures reported in electronic medical records (EMRs) of patients with psoriatic arthritis (PsA) and ankylosing spondylitis (AS) from two tertiary-care centers in the region of Lesser Poland. A total one-hundred eighty seven (127 PsA and 60 AS) first (n = 112), second (n = 59) and third-line SEC users were enrolled. The mean (SD) age of the sample was 45.7 (12.9), and 48% were male. All patients were classified with active and severe disease prior to initiation. Administrative delays for SEC users last a median 2 weeks. Median delay from symptom onset to diagnosis was 4 years (IQR 8), and differed by predominant disease subtype. The inefficacy rate was 10.7% and 18.6% for first and second-line users with median (IQR) drug maintenance estimated at 1.22 years (1.46) and 1.51 (1.38), respectively. First-year drug loss defined as drug switch due to inefficacy or adverse event was rare, with median estimates of 0.91 (95% CI; 0.85, 0.97) and 0.86 (95% CI; 0.77, 0.95) for first and second-line, respectively.

Geometric Specification of Non-Circular Pulleys Made with Various Additive Manufacturing Techniques.

The paper presents the procedure of generating geometrical features on the contours of non-circular pulleys through the selection of materials and technological parameters for easy and efficient production of these parts. Based on the models designed in the computer aided design (CAD) system, several prototype non-standard pulleys were made, which were assessed for functional characteristics and correct operation of non-linear gears. The effect of additive technology on the geometric specification of non-circular pulleys was also assessed. The results showed that thanks to the use of additive methods, the need for costly manufacturing of such wheels with subtractive methods was eliminated. Additionally, it is not necessary to design specialized cutting tools or to use conventional or numerically controlled machine tools to manufacture these wheels. The test results showed that in case of selective laser sintering (SLS) the highest accuracy of mapping (0.01 mm) of geometrical features of the surface was obtained. This result is confirmed by the assessment of the morphology of the surface of the teeth of gears made with this technique, characterized by a uniform structure of the working surface of the wheel while maintaining a high tolerance of the outer profile of gear for selective laser sintering at the level of ±0.03 mm. Research has shown that most of the additive methods used to manufacture non-circular pulleys meet the required geometrical features and due to the short production time of these pulleys, these methods also facilitate quick verification of the designed pulley geometry.

Chemical compounds released by combustion of polymer composites flat belts.

Machines and devices for the production, transport and segregation of products are placed in production and storage rooms. Flat conveyor and drive belts are very often used for their construction. Due to heavy loads and difficult operating conditions, these belts can catch fire and, as a result, become the main source of air contaminants harmful to human health and life. This article examines the emission level of toxic chemical compounds most often produced during the thermal decomposition and combustion of flat drive and conveyor belts. Six types of flat belts, which were made of various polymer materials, i.e., polyamide, rubber, and polyurethane, and were pyrolyzed in a tube furnace at 950 °C, were tested for emission. Using an Fourier transform infrared spectroscopy gas analyser, five gaseous products of combustion were identified, i.e., carbon mono oxide, carbon dioxide, hydrogen cyanide, hydrogen bromide and sulfur dioxide (SO2). Chemical analysis showed that SO2 compounds and hydrogen bromide were present in only two samples. The test results indicate that gas emission concentration limits for all the tested belts were significantly exceeded. A comparative analysis of the concentration limits of V-belts described in the authors' earlier works shows that flat belts demonstrate lower emission levels of harmful compounds than V-belts. In addition, research has shown that compared to traditional rubber-based belts, belts made of modern materials exhibit no emission of hydrogen chloride compounds during thermal decomposition and combustion.

On Analyzing Routing Selection for Aerial Autonomous Vehicles Connected to Mobile Network.

This paper proposes a two-phase algorithm for multi-criteria selection of packet forwarding in unmanned aerial vehicles (UAV), which communicate with the control station through commercial mobile network. The selection of proper data forwarding in the two radio link: From UAV to the antenna and from the antenna to the control station, are independent but subject to constrains. The proposed approach is independent of the intra-domain forwarding, so it may be useful for a number of different scenarios of Unmanned Aerial Vehicles connectivity (e.g., a swarm of drones). In the implementation developed in this paper, the connection is served by three different mobile network operators in order to ensure reliable connectivity. The proposed algorithm makes use of Machine Learning tools that are properly trained for predicting the behavior of the link connectivity during the flight duration. The results presented in the last section validate the algorithm and the training process of the machines.

The Toxicological Testing and Thermal Decomposition of Drive and Transport Belts Made of Thermoplastic Multilayer Polymer Materials.

The article presents the potential impact of flat drive and transport belts on people's safety during a fire. The analysis distinguished belts made of classically used fabric-rubber composite materials reinforced with cord and currently used multilayer polymer composites. Moreover, the products' multilayers during the thermal decomposition and combustion can be a source of emissions for unpredictable and toxic substances with different concentrations and compositions. In the evaluation of the compared belts, a testing methodology was used to determine the toxicometric indicators (WLC50SM) on the basis of which it was possible to determine the toxicity of thermal decomposition and combustion products in agreement with the standards in force in several countries of the EU and Russia. The analysis was carried out on the basis of the registration of emissions of chemical compounds during the thermal decomposition and combustion of polymer materials at three different temperatures. Moreover, the degradation kinetics of the polymeric belts by using the thermogravimetric (TGA) technique was evaluated. Test results have shown that products of thermal decomposition resulting from the neoprene (NE22), leder leder (LL2), thermoplastic connection (TC), and extra high top cower (XH) belts can be characterized as moderately toxic or toxic. Their toxicity significantly increases with the increasing temperature of thermal decomposition or combustion, especially above 450 °C. The results showed that the belts made of several layers of polyamide can be considered the least toxic in fire conditions. The TGA results showed that NBR/PA/PA/NBR belt made with two layers of polyamide and the acrylonitrile-butadiene rubber has the highest thermal stability in comparison to other belts.

Evaluation of the Thermal Stability and Surface Characteristics of Thermoplastic Polyurethane V-Belt.

This article proposes thermography as a non-contact diagnostic tool for assessing drive reliability. The application of this technique during the operation of the belt transmission with a heat-welded thermoplastic polyurethane V-belt was presented. The V-belt temperature changes depending on the braking torque load at different values of the rotational speed of the active pulley, which were adopted as diagnostic characteristics. In this paper, the surface morphology of the polyurethane (PU) belts was assessed on the basis of microscopic and hardness tests. A surface roughness tester was used to evaluate the surface wear. The surface morphology and topography of the materials was determined by scanning electron microscopy (SEM) and optical microscopy. It was found that the most favorable operating conditions occurred when the temperature values of active and passive connectors were similar and the temperature difference between them was small. The mechanical and structure results indicate that the wear of the PU belt was slight, which provided stability and operational reliability for V-belt transmission. The microscopic images lacked clear traces of cracks and scratches on the surface, which was confirmed by the SEM observations.

Legal regulations of restrictions of air pollution made by non-road mobile machinery-the case study for Europe: a review.

The high awareness of intensification and frequency of smog phenomenon all over the world in XXI age makes for detailed analyses of the reasons of its formation and prevention. The governments of the developed countries and conscious of real hazards, including many European countries, aim to restrict the emission of harmful gases. In literature, we can find the discussions on the influence of this phenomenon on the health and life of inhabitants of contaminated areas. Some elaborations of prognostic models, descriptions of pollution sources, the manner of their restriction, and the analysis of causal-consecutive correlation are also popular. The influence of pollutions resulting from the operation of vehicles, planes, and the industry are well described. However, every machine and device which is driven with a combustion engine has the effect on the general level of anthropogenic pollutions. These drives are subject of different regulations limiting their emission for service conditions and applications. One of the groups of such machines described in European and American regulations is non-road mobile machinery. The aim of this paper is the presentation of the problem of weak analysis and application of engineering and technological tools for machinery drive emission, despite of many publications on hazards and problems of emission. These machines have the influence on both the increase of global contamination and the machine users. The regulations of the European Union take into consideration the generated hazards and restrict the emission of machine exhaust gases by approval tests-these regulations are continually improved, and the effects of these works are new emission limits in 2019. However, these activities seem to be liberal as opposed to limits of the emission for passenger and goods vehicles where the technological development of the construction is greater and the regulations are the most rigorous. During the analysis of the development of non-road mobile machinery in the correlation with automotive vehicles, we can indicate engineering and technological solutions which are limiting the emission of non-road mobile machinery, but which are not applied. Due to liberal regulations for this group of machinery, the producers do not apply innovative solutions which can be found in road vehicles. The paper presents the synthetic review of existing EU regulations concerning limits of the emission of harmful exhaust gases which are generated by spark-ignition combustion engines of non-road mobile machinery. The authors show the divergences between the limits of the emission of harmful exhaust gases generated by road vehicles and non-road mobile machinery (boats and railway engines are not taken into account). The authors present the directions of the development of the combustion process control and systems limiting the emission of harmful exhaust gases. High innovative automotive industry was indicated as the direction of the development for limiting the influence of the emission on the environment by non-road mobile machinery.

Neutrophil extracellular traps formation in patients with eosinophilic granulomatosis with polyangiitis: association with eosinophilic inflammation.

OBJECTIVES: Eosinophilic granulomatosis with polyangiitis (EGPA) is associated with an inflammation and the presence of antineutrophil cytoplasmic antibodies (ANCA). Thus, we investigated the impact of ANCAs and eosinophilic inflammation on neutrophil activation and extracellular traps (NETs) formation. METHODS: We recruited 29 patients in the remission of EGPA (17 ANCA-negative and 12 ANCA-positive, including 7 p-ANCA-positive and 5 c-ANCA-positive patients). Healthy donors' neutrophils were stimulated with EGPA patients' serum. NETs formation was assessed by immunofluorescence and scanning electron microscopy. RESULTS: EGPA patients presented enhanced ability to generate NETs compared to healthy subjects (20.3±8.2% vs. 2.7±1.5%, p=0.0036). However, there were no differences in NETs formation between ANCA-positive and ANCA-negative patients (23±11.2% vs. 17±6.1%, p=0.15). There was also no correlation between NETs generation and the amount of circulating DNA in EGPA patients. Among ANCA-positive patients, p-ANCA-positives showed the highest percentage of NETs as compared to cANCA-positive and ANCA-negative patients (27.3±10.3% vs. 17.8±10.5% and vs. 17±6.1%, both p<0.01, respectively). Eosinophils number correlated with the percentage of NETs in the whole EGPA group (r=0.53, p=0.039), but we failed to observe the correlation with an eosinophil cationic protein (r=0.49, p=0.058). CONCLUSIONS: EGPA patients' serum has the ability to induce NETosis with no regard to the ANCA status in contrast to other vasculitides, where p-ANCA were considered as the main factor. Interestingly, NETs formation in EGPA patients connected with the number of eosinophils might be of major relevance. Further studies are required to assess which eosinophil-derived factors might be responsible for the neutrophils activation in EGPA patients.

Unfavorably Altered Fibrin Clot Properties in Patients with Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome): Association with Thrombin Generation and Eosinophilia.

OBJECTIVES: Given reports on the increased prevalence of thromboembolic incidents in patients with eosinophilic granulomatosis with polyangiitis (EGPA; Churg-Strauss syndrome), we investigated whether fibrin clot properties are unfavorably altered in EGPA. METHODS: Ex vivo plasma fibrin clot characteristics, including clot permeability, turbidimetry and efficiency of fibrinolysis using two assays, were investigated in 34 consecutive patients with remission in EGPA according to the Birmingham Vasculitis Activity Score version 3 (23 female, 11 male), aged 48 (range, 21-80) years. The control group comprised 34 age- and sex- matched volunteers. RESULTS: Compared with controls, patients with EGPA were characterized by denser fiber clots (estimated pore size, Ks, 7.30±0.93 vs 10.14±1.07 10-9 cm2), faster fibrin polymerization (lag phase in a turbidimetric curve, 41.8±3.6 vs 47.4±2.9 s), thicker fibrin fibers (maximum absorbance, ΔAbs, 0.87±0.09 vs 0.72±0.07), higher maximum levels of D-dimer released from clots (DDmax 4.10±0.46 vs 3.54±0.35 mg/L), and prolonged clot lysis time (t50%; 9.50±1.45 vs 7.56±0.87 min); all p<0.0001. Scanning electron microscopy images confirmed denser plasma fibrin networks composed of thinner fibers formed in EGPA. Antineutrophil cytoplasmic antibody status and C-reactive protein did not affect clot variables. Multivariate analysis adjusted for fibrinogen showed that Ks was predicted by eosinophil count, peak thrombin generation, factor VIII, and soluble CD40 ligand, whereas eosinophil count, peak thrombin generation and antiplasmin predicted t50%. CONCLUSION: This study is the first to show that EGPA is associated with prothrombotic plasma fibrin clot phenotype, which may contribute to thromboembolic manifestations reported in this disease.

[Mycophenolate mofetil in the treatment of selected connective tissue diseases]. / Mykofenolan mofetylu w leczeniu wybranych ukladowych chorób tkanki lacznej.

Mycophenolate mofetil (MMF) is an inhibitor of inosine monophosphate dehydrogenase, which affects de novo purine synthesis and T- and B-cell proliferation. So far its efficacy and safety as an immunosuppressive treatment have been proven in organ transplantations and also in various autoimmune diseases. A literature search was conducted by using PubMed and the Cochrane library. This review focuses primarily on current treatment with MMF for systemic lupus erythematosus, systemic sclerosis, vasculitis and idiopathic inflammatory myopathies.

[Relapsing polychondritis--a challenge for modern diagnostics and treatment]. / Nawracajace zapalenie chrzastek--wyzwanie wspólczesnej diagnostyki i terapii.

Relapsing polychondritis is a rare autoimmune disease, which is due to sporadic occurrence, unexplained etiology and wide range of symptoms resulting in the difficulties in diagnosis. Recurrent inflammation leads to destruction of cartilaginous tissues, such as ear, nasal septum, larynx, trachea and bronchi, peripheral joints and vertebral structures. Blood vessels, the central nervous system, eyes, and the urinary tract can be involved as well. Clinical course of relapsing polychondritis is often modified by co-existing systemic diseases and remains misdiagnosed. In case of inappropriate or delayed treatment, serious and life-thretening complications may develop. In this article we present the most characteristic clinical features of the disease, differential diagnosis, focusing on current approaches to treatment.

Different reactivity of the proximal and distal segments of the radial artery to vasoconstrictors in patients undergoing coronary artery bypass grafting.

BACKGROUND: Complete arterial revascularisation using the radial artery (RA) is an attractive alternative to venous graft implantation for the coronary artery bypass grafting (CABG). In spite of the favourable long-term results of this approach, the sensitivity of RA to vasoconstriction and spasm is still limiting its use. It has been suggested that vasospastic properties of the artery may differ depending on the location (proximal or distal). AIM: To compare the vasoreactive properties of proximal and distal sections of RA grafts. METHODS: Proximal and distal segments of RA were obtained from 27 patients undergoing CABG and isometric recordings of changes in smooth muscle force were performed mounted in the organ bath. Responses to cumulatively increasing concentrations of phenylephrine (PE), angiotensin II (AT-II), prostaglandin F2 (PGF2) and endothelin-3 (ET-3) were evaluated. RESULTS: Both proximal and distal segments of RA constricted in response to KCl, PE, AT-II, PGF2 and ET-3. Proximal segments demonstrate significantly greater spastic response to KCl, as well as to receptor-mediated agonists PE and more importantly vasoactive peptide AT-II. These differences remained statistically significant after correcting for vessel size and weight. In contrast, reactivity of both segments of RA to increasing cumulative doses of PGF2 and ET-3 was similar. CONCLUSION: Proximal segments of the radial artery are more susceptible to vasoconstriction induced by PE and AT-II, which should be taken into consideration in the clinical setting of CABG surgery. Increased muscle content in this segment does not fully explain this difference, which may result from varying receptor density and properties.

[Lyme arthritis]. / Boreliozowe zapalenie stawów.

Lyme disease is a multi-system inflammatory disease caused by spirochetes of the Borrelia burgdorferi. Among multiplicity manifestations of Lyme disease, musculoskeletal symptoms also occur. In the following article authors present epidemiology of Lyme disease, pathogenesis of antibiotic-refractory Lyme arthritis, symptoms, diagnosis and management of Lyme arthritis based on recent guidelines prepared by an expert panel of the infectious Diseases Society of America.

[Difficulties in differential diagnosis of Sjögren's syndrome and systemic lupus erythematosus]. / Trudnosci w diagnostyce róznicowej zespolu Sjögrena i tocznia rumieniowatego ukladowego.

Sjögren's Syndrome (SS) is the second most common autoimmune disorder after rheumatoid arthritis (RA). It can be found as a lone condition (primary Sjögren's Syndrome) or may accompany other autoimmune rheumatic diseases (secondary Sjögren's Syndrome). Despite such frequent occurrence, accurate diagnosis of Sjögren Syndrome is difficult. These difficulties result from highly variable symptoms of SS as well as from common presence of other autoimmune disorders. In the following article authors present current knowledge concerning clinical symptoms, diagnostic methods and latest clinical guidelines on the diagnosis of SS. Differential diagnosis of SS and systemic lupus erythematosus (SLE) is also discussed.

Ordered mesoporous silicon carbide (OM-SiC) via polymer precursor nanocasting.

Ordered mesoporous SiC with high specific surface area (650-800 m(2) g(-1)) and well ordered pore structure was obtained via nanocasting of polycarbosilanes into SBA-15 and subsequent conversion of the polymer at 1300 degrees C.