There are three basic procedures used for an assessment of the electrical heart field from the body surface: standard electrocardiography, vectorcardiography, and body surface potential mapping (BSPM). BSPM has two major advantages over both other methods: 1) it allows exploring the entire chest surface, thus providing all the information on the cardiac electric field available at the body surface; 2) it is more sensitive in detecting local electrical events, such as local conduction disturbances or regional heterogeneities of ventricular recovery. Nevertheless the results obtained using BSPM procedure cannot answer all questions about real causality of detected changes of the electrical heart field. We tried therefore to use mathematical model of the electrical field in order to answer these questions. A simple and anatomical forward calculation model was used to test the hypothesis whether the altered position of the heart could explain heterogeneity of repolarization at late stages of pregnancy in humans. The hypothesis was declined. Further findings included: A. Repolarization duration (represented by QT interval) in healthy subjects are distributed regularly and predictably on the body surface carrying no information about local pathology. B. At any systemic analysis of ventricular repolarization, it is vital to consider the regions where any electrode systems record low amplitudes due to methodological, not pathological reasons. C. Anatomical (heterogeneous) model did not yield superior results over simple (homogenous) ones possibly since none reflected the specific torso geometry of individual patients., O. Kittnar, M. Mlček., and Obsahuje bibliografii a bibliografické odkazy
High temperature alters the internal microstructure of rocks and consequently changes the physical and mechanical properties of rocks. Many studies have been carried out to examine the transformations in the microstructures of rocks under high temperature through near infrared spectroscopy (NIR), Raman spectroscopy, or thermo gravimetric analysis (TGA). The current review synthesizes the data from a number of literatures and summarizes the major transformations of silica rocks under high temperature. The analysis shows that silica rocks starts to lose the water adsorbed in open pores upon heating at about 150 °C. At 200-300 °C, the reaction between SiOH (silanole) in the rocks generates new Si-O-Si bonds as well as H2O, and decreases the open pores. The rocks undergo volume expansion at >550 °C, and the volume contracts and forms new micro pores or cracks which play an important role in the evacuation of the water., Jishi Geng, Qiang Sun, Yuchun Zhang and Yuliang Zhang., and Obsahuje bibliografické odkazy
Persistent Scatterer Interferometry (PSI), a remote sensing technique, is used for detecting surface deformation in the cities of Prague and Ostrava. PSI is able to detect vertical movements with an accuracy of less than 1 mm for a long time series of the SAR data, but the maximum detectable rate of movement is only a few centimetres per year. This technique is quite suitable for detecting recent movements in most Prague localities. On the other hand, in Ostrava and its surroundings, affected by undermining, where subsidences (1992-2006) amount to decimetres per year, movements cannot be fully detected by the PSInSAR technique. The paper presents results of analysing PSI data for two localities in Prague and one locality in the Ostrava areas. The localities are strictly situated in built-up areas with many suitable reflectors. Data from the ERS-1/2 and ENVISAT satellites covering a 13-year period for the Prague (1992-2005) and a 14-year period for the Ostrava (1992-2006) area were used. Annual movement velocities and time-series of reflectors were determined. At these three localities, where different types of movements were identified, the application and possible limitations of PSI in urban areas are shown., Pavel Kadlečík, Vladimír Schenk, Zuzana Seidlová and Zdeňka Schenková., and Obsahuje bibliografii
The main objective of this paper is to explain how the application of various interpolation methods influence the determination of vertical crustal movements at any given point. The paper compares several methods of interpolation and verifies their suitability, including kriging, minimum curvature, nearest neighbor, natural neighbor, polynomial regression, inverse distance to a power, and triangulation with linear interpolation. The calculations show that the chosen interpolation method has significant influence on the final result of the study. Nearest neighbor method was chosen to be the best., Kamil Kowalczyk, Jacek Rapinski and Marek Mroz., and Obsahuje bibliografii
Úvod: Výsledky poskytované chirurgické péče v širším přesahu jsou obtížně dosažitelné. Práce testovala systém účtování zdravotní pojišťovně z hlediska využitelnosti dat. Metoda: Analyzováno bylo 6879 operací tříselné kýly v období 2008–2015. Využit byl systém účtování v DRG Vojenské zdravotní pojišťovny České republiky. Výsledky: Operace provedlo 156 pracovišť. V režimu jednodenní chirurgie bylo provedeno 3,8 % (248) výkonů, z toho 77 % (193) bylo operováno laparoskopicky. Za hospitalizace bylo provedeno 96,2 % (6631) výkonů, medián délky hospitalizace byl 4 dny. U hospitalizovaných pacientů byla otevřená plastika bez síťky provedena v 36,54 % (2423), otevřená plastika se síťkou v 19,84 % (1316), laparoskopická plastika v 43,61 % (2892). Reoperace pro recidivu v souboru byla v 1,85 % (127), po otevřené plastice bez síťky v 2,76 % (66), po otevřené plastice se síťkou v 1,66 % (22), po laparoskopické plastice v 1,19 % (37). Predikce recidiv do 5 let byla 2,42 % celkem. Hodnoceny byly i další parametry. Závěr: Studie potvrdila využitelnost systému pojištění k získání relevantních dat o léčbě vybrané diagnózy., Introduction: Information about actual results of provided surgical care is difficult to obtain. We tested the insurance company billing system in terms of data usability. Methods: 6,879 groin hernia surgeries carried out from 2008 to 2015 were analysed using registry data of one health insurance company. Results: Groin hernia surgeries were performed by 156 providers in the Czech Republic. Day surgeries were used in 3.8% cases (248), of which laparoscopic surgeries were used in 77% (193) of patients. The other 96.2% (6,631) surgeries were carried out on inpatients with the median hospital stay of 4 days. Of this number: open procedures without the use of a mesh were done in 36.54% (2,423), open procedures using a mesh in 19.84% (1,316), and laparoscopic procedures in 43.61% (2,892) cases. Reoperations for recurrence after hernia repair were done in 1.85% (127) of all cases, while 2.76% (66) reoperations were done after open procedures without the use of a mesh, 1.66% (22) after open procedures using a mesh, and 1.19% (37) after laparoscopic surgeries. The prediction rate for recurrent hernia incidence within 5 years was 2.42% in all cases. Others parameters were also evaluated. Conclusion: The study confirmed usefulness of the DRG data registry of health insurance companies for obtaining relevant information on the surgical procedures., and P. Chmátal, L. Tuka, D. Jandová