An algorithm and case study for the object oriented abstraction

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

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

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

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

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

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

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

Percutaneous closure of the iatrogenic atrial septal defect following the transcatheter edge-to-edge mitral valve repair with MitraClip system led to instant improvement of hypoxemia — case report

Transcatheter edge-to-edge mitral valve repair (TEER) is an established alternative for patients with severe, symptomatic mitral regurgitation (MR) at high surgical risk. The TEER procedure requires transseptal access, therefore might lead to the development of persistent iatrogenic atrial septal defect (iASD). The clinical significance of iASD and optimal management particularly from a long-term perspective is not clear. Herein, we described a case report of a 76-year-old female with prior left atrial appendage occlusion and severe MR that underwent a TEER procedure using MitraClip® (MC) system. After the MC implantation, she developed acute hypoxemia due to interatrial right-to-left shunt and required immediate iASD closure

Treatment of severe mitral regurgitation with MitraClip system — a single-centre study

Introduction. MitraClip (MC) is a catheter-based device to treat mitral regurgitation (MR). This method uses a transseptal approach and is based on the creation of a double orifice mitral valve by suturing of the middle scallops of the mitral valve’s leaflets. Aim. The aim of the study was to assess the effectiveness of MC method in treating patients with severe MR. We analysed MR severity, patient’s clinical condition evaluated by New York Heart Association (NYHA) functional class, and the function of the left ventricle evaluated by Left Ventricle Ejection Fraction (LVEF). Methods. A retrospective single-centre study with patients hospitalised at the Department of Cardiology and Internal Medicine in Bydgoszcz. All diagnosed with severe MR and treated by performing MC procedure in the time period from August 2010 to December 2014. The following data from medical history (NYHA class) and echocardiography examinations (MR severity and LVEF) were analysed in three time points: before, right after the procedure, and after the follow-up period (four weeks since discharge). Results. The studied group consisted of 11 patients — 8 male, 3 female, aged 64.4 ( ± 10.2) years, treated with MC. All of the three analysed parameters improved relevantly as a result of the evaluated procedure. The percentage of patients classified as NYHA class III/IV presents as follows: 90% before the procedure, 55% after MC implantation (ns), and 44% after the follow-up period (p = 0.01). All patients suffered from severe-to-moderate (3+) and severe (4+) MR before the procedure. After implantation only 9% (ns) were still classified with 3+/4+ MR, and after the follow-up this percentage reached 18% (p = 0.0005). We observed relevant changes of LVEF. The average LVEF at baseline was 27.9 ± 2%, which increased to 29.6 ± 2% (ns) after the MC implantation and 34 ± 7% (p = 0.02) after the follow-up. Conclusion. MC therapy is effective in patients with severe symptomatic MR with congestive heart failure and decreased LVEF. It reduces MR severity both acutely and after the follow-up period and improves NYHA class and LVEF.