47 research outputs found

    An algorithm and case study for the object oriented abstraction

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    Model checking of software systems becomes more effective each day. However it still can not handle huge state spaces of real software. Particularly, concurrent systems are hard to verify. Abstraction techniques are one of the solutions aimed at managing the complexity problem. This paper describes the object oriented abstraction algorithm. It allows semi-automatic abstraction of real (i.e. Java) programs. A novelty method for constructing class abstractions is shown. It uses additional program annotations expressed in a formal manner. Proposed techniques are shown in a context of algorithms used in the Bandera toolset. A short case study of this approach is also shown

    Ultra-diluted gas transmittance revisited

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    The paper analyzes a model of optical transmittance of ultra-diluted gas, considering gas particles' non-locality and the quantum effect of their wave function spreading derived from solving the Schr\"odinger equation for a free particle. The analysis does not depend on a particular form of the wave function, but it assumes the reality of wave function. Among others, we show conserved mass gas clouds may become significantly more transparent than predicted by classic transmittance laws. This unexpected phenomenon is possible because mass conservation is governed by the sum of probabilities, while the Markov chain's product of probabilities controls the transmittance. Furthermore, we analytically derive the upper limit the closed system transmittance may grow and demonstrate a boundless, open gas cloud transmittance may grow up to 100%. Finally, we show the impact on interpretations of quantum mechanics. The model is naturally applicable in deep space conditions, where the environment is sparse. Furthermore, the model responds to dark matter requirements.Comment: 10 pages, 5 figure

    On the falsification of the pilot-wave interpretation of quantum mechanics

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    Quantum mechanics has lacked a widely recognized interpretation since its birth. Many interpretations are under consideration because they are difficult to disprove experimentally. In this paper, we show that the results of a recent experiment go against one of them: the pilot-wave interpretation. This is because the key assumption of this interpretation, particle locality, contradicts the assumption of wave function nonlocality on which the experiment is founded. This is a rare example of a quantum model and an experiment not indifferent to the interpretation of quantum mechanics.Comment: 3 page

    Współczesne wykorzystanie tikagreloru w ośrodkach medycznych w Polsce jako odzwierciedlenie przestrzegania wytycznych dotyczących terapii przeciwpłytkowej

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    Introduction. Ticagrelor is the newest P2Y12 inhibitor recommended as the first treatment option for acute myocardial infarction both with and without ST-segment elevation. Recent studies have revealed unsatisfactory use of novel P2Y12 inhibitors. The aim of our study was to assess the contemporary use of ticagrelor in major medical centres located in Kuyavian-Pomeranian, Pomeranian, and Warmian-Masurian voivodships. Materials and methods. Retrospective analysis of hospital records regarding the number of ticagrelor tablets purchased monthly was performed covering a three-year period from January 2015 to December 2017. Data from 15 major medical centres was analysed. Results. A total of 78,871 tablets of ticagrelor were purchased over the study period, with a monthly median of 2,013.5 and an interquartile range (IQR) of 1,255–2,996. The amount of ticagrelor increased monthly by 7.9%. The lowest monthly value (294, 0.37%) was recorded in the first month, while the highest (4,550, 5.77%) was in October 2017. The median of tablets purchased in 2017 (3,934, IQR 3,010–4,270) was over four times greater than in 2015 (980, IQR 728–1,288, p < 0.001) and more than double that in 2016 (1,689, IQR 1,353–2,479, p = 0.012). The highest reported amount of the drug in one centre (16,296, 20.6%) was 291 times greater than the amount in the centre with the lowest ticagrelor use (56, 0.07%, p = 0.27). Conclusions. The use of ticagrelor has been significantly increasing in recent years, which reflects the implementation of current guidelines by medical centres. Substantial heterogeneity regarding the use of ticagrelor is observed within particular centres.Wstęp. Tikagrelor to najnowszy doustny inhibitor receptora P2Y12 zalecany w leczeniu pierwszego rzutu w zawale sercazarówno z uniesieniem, jak i bez uniesienia odcinka ST. Ostatnie doniesienia wskazują na niezadowalające wykorzystaniew terapii nowych inhibitorów receptora P2Y12. Celem niniejszego badania była ocena współczesnego wykorzystaniatikagreloru w głównych ośrodkach medycznych zlokalizowanych na terenie województw kujawsko-pomorskiego, pomorskiegooraz warmińsko-mazurskiego.Materiały i metody. Przeprowadzono retrospektywną analizę danych pochodzących ze szpitalnych rejestrów, któredotyczyły miesięcznej liczby zakupionych tabletek tikagreloru. Badanie obejmowało okres 3 lat — od stycznia 2015 dogrudnia 2017 roku. Przeanalizowano dane pochodzące z 15 ośrodków medycznych. Wyniki. W trakcie okresu obserwacji kupiono w sumie 78 871 tabletek tikagreloru, a miesięczna mediana wyniosła2013,5 z przedziałem międzykwartylowym (IQR) 1255–2996. Ilość wykorzystywanego tikagreloru wzrastała miesięcznieo 7,9%. Najmniejszą ilość leku zarejestrowano w pierwszym miesiącu obserwacji (294; 0,37%), natomiast najwięcej tabletek(4550; 5,77%) kupiono w październiku 2017 roku. Mediana ilości tikagreloru w roku 2017 (3934, IQR 3010–4270)była ponad 4-krotnie większa od mediany w roku 2015 (980; IQR 728–1288; p &lt; 0,001) i ponad 2-krotnie większa odzaobserwowanej w 2016 roku (1689; IQR 1353–2479; p = 0,012). Ośrodek, w którym odnotowano największą sumarycznąilość zastosowanego tikagreloru (16 296; 20,6%), kupił w całym okresie obserwacji 291 razy więcej tabletek niżośrodek z najmniejszą zarejestrowaną ilością leku (56; 0,07%; p = 0,27).Wnioski. Wykorzystanie tikagreloru istotnie się zwiększyło w ostatnich latach, co odzwierciedla wprowadzanie docodziennej praktyki klinicznej zaleceń obecnych w aktualnych wytycznych dotyczących leczenia przeciwpłytkowego.Obserwuje się znaczne zróżnicowanie pod względem użycia tikagreloru w poszczególnych ośrodkach

    Influence of QRS duration and axis on response to cardiac resynchronization therapy in chronic heart failure with reduced left ventricular ejection fraction: A single center study including patients with left bundle branch block

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    Background: The aim of the study was to evaluate QRS duration and axis as predictors of response to cardiac resynchronization therapy (CRT) in order to reduce the proportion of non-responders.Methods: Retrospective single-center study including 42 CRT recipients, with left bundle branch block (LBBB), left ventricular ejection fraction (LVEF) &lt; 40%, in New York Heart Association (NYHA) class ≥ II. Response to CRT was declared as NYHA class improvement ≥ 1 (symptomatic) and LVEF improvement by ≥ 10% (echocardiographic) &gt; 6 months post implantation.Results: Symptomatic responders had longer pre- (172.3 ± 17.9 vs. 159.0 ± 18.3 ms; p = 0.027) and postimplantation (157.2 ± 24.1 vs. 136.7 ± 23.2 ms; p = 0.009) QRS duration. Preimplantation QRS &lt; 150 ms predicted poor response (odds ratio [OR] for response vs. lack of response 0.04; 95% confidence interval [CI] 0.001–0.74). Predictors of symptomatic response included: postimplantation QRS &gt; 160 ms (OR 7.2; 95% CI 1.24–41.94), longer QRS duration before (OR for a 1 ms increase 1.04, 95% CI 1.00–1.08) and post implantation (OR for a 1 ms increase 1.04; 95% CI 1.01–1.07). Area under the curve (AUC) for pre- and postimplantation QRS duration was 0.672 (95% CI 0.51–0.84) and 0.727 (95% CI 0.57–0.89), respectively, with cut-off points of 178.5 ms and 157 ms. For post implantation QRS axis, AUC was 0.689 (95% CI 0.53–0.85), with cut-off points of –60.5° or –38.5°. Preimplantation QRS axis was the only predictor of echocardiographic response (OR 0.98; 95% CI 0.96–1.00), with AUC of 0.693 (95% CI 0.54–0.85) and a threshold of –36°.Conclusions: Marked pre- and postimplantation QRS prolongation and preimplantation negative QRS axis deviation are moderate predictors of response to CRT

    Successful reduction of severe mitral regurgitation after implantation of four MitraClip devices

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    Mitral regurgitation (MR) is one of the most common valvular heart diseases. According to the current guidelines, surgical treatment may be considered in symptomatic patients with severe functional MR. A therapy using the MitralClip (MC) system may be an alternative approach for patients who are at high surgical risk. The presented case report illustrates, as the first one in Poland, a very rare need for the implantation of 4 MC devices in a symptomatic patient with severe functional MR and indicates feasibility and safety of such management

    Epidemiology and chronobiology of out-of-hospital cardiac arrest in a subpopulation of southern Poland: A two-year observation

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    Background: Although recent studies indicate temporal variations in the incidence of out-of-hospital cardiac arrest (OHCA), the Polish experience in this research is scarce to date. We evaluated the epidemiology of OHCA and circadian, weekly and seasonal variations of OHCA frequency among the adult population of the Opole district, Poland. Methods: The retrospective analysis of 815 OHCA cases with presumed cardiac etiology was made based on dispatch cards from the Emergency Medical Center in Opole registered during a 2 year period (2006–2007). Results: The incidence of OHCA in the studied population was 1.56/1000 inhabitants per year. Mean age of the group was 69.2 ± 14.2 years, with the majority of men (63%), younger than women (66.1 vs. 74 years, p = 0.0001). The OHCA occurrence increased with age reaching a peak between 71 and 75 years. The incidence of OHCA stayed at stable low levels between 22:00 and 4:59 and started to increase at 5:00, with trimodal peaks: 8:00–10:59, 14:00–15:59 and 18.00–21.59. The lowest number of OHCA occurred from 00:00 to 5:59, the highest from 6:00 to 11:59 (13% vs. 32.4%, p &lt; 0.001). The day with the lowest occurrence of OHCA was Friday, the highest Saturday (10.9% vs. 16%, p = 0.01). Summer was the season of the lowest incidence of OHCA, while winter — the highest (22.6% vs. 26%, p = 0.04). These seasons were the warmest and the coldest one, respectively (average temperature 18.5°C vs. 0°C, p &lt; 0.001). Conclusions: Circadian and less marked, weekly variability in OHCA occurrence were confirmed. Existing seasonal differences may be affected by temperature. This is the first Polish analysis of a large subpopulation, which also includes seasonal temperature data

    Observational analysiS of out-of-hospital Cardiac Arrest occurRence and temporal variability patterns in subpopulation of southern POLand from 2006 to 2018: OSCAR-POL registry

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    Background: Temporal variability of out-of-hospital cardiac arrest (OHCA) occurrence was presented in previous studies, however, the data regarding long-term observation is scarce. The aim of this study was to investigate the temporal variability of OHCA occurrence during the long-time period and analyze the circadian pattern within particular timeframes. Methods: The retrospective analysis of 5058 OHCA cases was made covering the period from January 1st, 2006 to December 31st, 2018. Circadian, weekly, monthly and seasonal variabilities were investigated. The circadian variability of OHCA occurrence was assessed within particular years, seasons of the years, and days of the week. Results: The highest OHCA incidence was observed between 08:00 and 08:59 and the lowest between 01:00 and 01:59 (7.1% vs. 1.6%, p &lt; 0.001). After division into 6-h intervals, a significantly lower number of OHCA cases occurred between 00:00 and 05:59 (12.3%) in comparison to the highest number observed in between 06:00 and 11:59 (12.3 vs. 33.5%, p &lt; 0.001). The highest OHCA occurrence was observed on Monday (14.9%), however, no weekly variability was found (p = 0.557). The highest OHCA occurrence was observed in the winter and lowest in the summer (27.4% vs. 22.8%, p &lt; 0.001). Significant circadian variability was observed for every day of the week, season and year during the observation period (p &lt; 0.001). Conclusions: Circadian, monthly and seasonal variability of OHCA occurrence was confirmed in the long-term observation with no differences between particular days of the week. Significant circadian variability was observed within days of the week, seasons of the year, and particular years
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