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Background The aim of this study was to present our experience in the treatment of post-myocardial infarction ventricular septal defect and examine the various risk factors. Methods This is a retrospective study. From January 2010 to December 2018, 20 patients underwent an urgent /emergency surgical repair of post-myocardial infarction ventricular septal defect. Results The mortality in our group of patients was 45 %. Non-survivors compared to the survivors were all in cardiogenic shock (p=0.0098), had an emergency/salvage operation (p=0.0055), preoperative mechanical ventilation (p=0.0081), shorter time between intraaortic balloon pressure insertion and surgery (p=0.0115), shorter median time between ventricular septal defect and surgery, postoperative renal replacement therapy (p=0.0498), and more patients had a residual effect (p=0.0022). In multivariate analysis, preoperative mechanical ventilation (p=0.0001), postoperative renal replacement therapy (p=0.0021) and residual defect (p=0.0000027) were shown to be strong predictors for hospital mortality. Conclusion This analysis showed that post-myocardial infarction ventricular septal defect repair is a devastating complication and preoperative mechanical ventilation, postoperative renal replacement therapy and residual defect were identified to be the predictors of mortality. Initial stabilization of the patients, when it is possible, and a delayed repair, may improve the outcome of these patients (Tab. 3, Ref. 17).

Introduction Implantation of a total artificial heart is an alternative to durable biventricular assist device support in selected patients. We present our initial experience with the implantation of the SynCardia total artificial heart (TAH) in three patients. The first patient, was the first SynCardia (TAH) implantation in the Visegrad Four (V4) countries METHOD: Three patients with severe refractory end stage biventricular heart failure listed for heart transplant were indicated for SynCardia TAH implantationRESULTS: We present in details the perioperative and postoperative outcomes of these patients. The first and the third patient, after 195 and 126 days of TAH support respectively, had a successful heart transplants, the second patient died on 11th postoperative day. The cause of death was brain bleeding due to ruptured undiagnosed brain aneurysm. Conclusion SynCardia TAH is an alternative therapy in patients with end-stage biventricular heart failure waiting for heart transplantation. The SynCardia TAH with pulsatility resembles the physiologic circulation, improves the condition of the patients and increases survival compared to the biventricular assist devices. It is an intermediate step until the development of genetically modified animal hearts, engineered bioartificial hearts or hearts from induced pluripotent stem cells that would replace the failing heart in the patients with end-stage heart disease (Tab. 2, Fig. 1, Ref. 27).

Our activities were focused on the preparation of WS2 films on sapphire substrates by sulfurization of different thick sputtered W films. The influence of very thin W films in the range from 4 nm to 12 nm on the structural, morphological and optical properties of WS2 was investigated. XRD measurements revealed a polycrystalline nature with hexagonal symmetry and randomly connected nanocrystals with grain size about 6 nm for all WS2 films. Using Raman spectroscopy with a 532 nm laser excitation, the presence of characteristic E12g and A1g vibration modes was recorded and the multilayered nature of the prepared WS2 films was confirmed. FESEM observations revealed randomly oriented lamellar and flake-shaped microstructures with the basal plane of the WS2 crystallites. Thinner WS2 films (20 and 24 nm) showed highly dense horizontally aligned flakes. On the other hand, thicker WS2 films (33 and 42 nm) indicated a granular surface and the WS2 crystallites grew perpendicularly to the substrate surface. All examined WS2 films were transparent from 30 to 78% in the spectral range of 500 to 900 nm and showed a direct bandgap of 2.3 eV.

BACKGROUND The purpose of this study is to report our experience in performing transapical (TA) TAVR with a balloon-expandable valve only by cardiac surgeons, with on site interventional cardiology support. METHODS A retrospective review of 97 consecutive patients that underwent TA TAVR due to severe symptomatic aortic stenosis was performed from 2012 to 2016. Median follow-up time was 20.5 months. Preoperative risk factors and postoperative outcomes were evaluated using Valve Academic Research Consortium-2 definitions. RESULTS All patients were high risk with a mean Euroscore of 7.28±7.77. Five year and 30-day mortality were 9.3 % and 1.1 %, respectively. Ninty six (98.9 %) of the patients had no or mild paravalvular leak seen by transesophageal echocardiography after implantation. Device success was 91.8%. Postoperatively there was a significant increase of the ejection fraction (50.8±7.1 % preoperatively vs 53.1±7.7 % postoperatively, p=0.009) and reverse remodeling of the left ventricle (left ventricular end-diastolic diameter preoperatively 50.8±7.1 mm vs 49.2±8.1 mm postoperatively, p=0.031). CONCLUSION Our experience demonstrates that TA TAVR can be performed only by cardiac surgeons, with on site interventional cardiology support safely and successfully with low and comparable postoperative mortality and rate of complications (Tab. 4, Fig. 1, Ref. 26).

We present structural, optical and electrical investigations of layered WS2 films prepared on tungsten. A two-step technique has been used to synthesize layered WS2 films using sulfurization of W films sputtered with thinner (1 and 2 nm) and thicker (14 and 28 nm) thicknesses at 800 °C. XRD analysis revealed that the examined films are polycrystalline with texture and have a 2H-WS2 hexagonal microstructure. Using Raman spectroscopy with the 532 nm laser excitation, the presence of E12g and A1g vibration modes was observed and the layered nature of WS2 was confirmed. FE SEM observations showed two different surface morphologies. The samples grown on thinner W films were not compact over the surface and agglomeration of nanosize grains in combination of triangles and flakes was visible. In another group the surface was lamellar and contained plenty of nanorods embedded vertically and/or inclined at different angles to the surface. Layered WS2 films exhibited a direct band gap in the range of 2.1–2.5 eV and they were n-type semiconductors with the sheet resistance in the order of several MΩ at room temperature.

INTRODUCTION The aim of this study is to summarize results and analyze risk factors for the development of wound infection in heart surgery patients after median sternotomy. METHOD In this retrospective analysis with assessment of multiple risk factors, we examined 143 patients with infection after median sternotomy treated with VAC therapy from total of 4,650 patients operated in our department from 2012 to 2015. RESULTS Total of 143 patients developed significant SSI treated by VAC therapy following cardiac surgery. Of these, only 14 patients developed DSWI and one patient was diagnosed with suspected osteomyelitis. BMI, female gender, and use of BIMA proved to be statistically significant risk factors in our study (p < 0.001). The acuteness of operations did not have a statistically significant effect. However, it had a significant effect on the severity of infection (p < 0.01). The severity of infection proved to be a significant prognostic factor for patients' outcome (p < 0.01). CONCLUSION In our study, BMI, female gender, and use of BIMA (bilateral internal mammary artery) in patients with DM were predictors for the development of SWI. The acuteness of operation did not have a statistically significant effect. However, it had a statistically significant effect on the severity of infection (Tab. 3, Ref. 30).

INTRODUCTION Minimal invasive aortic valve replacement has become a routine procedure. In this study, we compared the outcomes between conventional and minimal invasive aortic valve replacement via the partial upper sternotomy that were performed in our Institution. METHODS The 5 year survival and postoperative outcomes of 34 patients that underwent isolated MIAVR between the years 2010-2013 were compared with the outcomes of 34 randomly selected patients that underwent conventional AVR, after propensity match analysis. RESULTS There was no difference between the two groups concerning the early and late postoperative outcomes. MIAVR patients had a longer mean cross-clamp time (p = 0.002) and longer cardiopulmonary bypass time (p = 0.0005) compared to the AVR patients. 5 year mortality and survival were 4.17 % vs 16.67 % (p = 0.20) and 95.8 % vs 83.3 % (p = 0.37) in the MIAVR and AVR groups respectively. CONCLUSION This study showed a comparable 5 year survival and postoperative outcomes between the MIAVR and AVR groups. In our opinion, the minimal access aortic valve replacement can be performed safely with excellent long-term results in selected patients (Tab. 4, Fig. 1, Ref. 35).

With a continuous improvement of the production techniques for carbon nanofibers and carbon nanotubes along with an improvement of the available qualities of the materials, these reinforcements have been introduced into polymers, ceramics and metals. While in the field of polymers first success stories have been published on carbon nanofiller reinforcements, up to now metals containing these types of nanofillers are still a topic of intensive research. Basically a similar situation were found in those days, when micron sized carbon fibers came on the market. Today many applications of carbon fiber reinforced composites are existing, while metals reinforced with conventional carbon fibers are still only found in niche applications. Several reasons can be identified, why the introduction of carbon based nanofillers (nanofibers/nanotubes) into metallic matrices is a difficult task. Nevertheless it is worthwhile to carry out systematic studies in this field due to the excellent and promising thermal, electrical, mechanical or tribological properties of the nanofillers. This paper gives an overview and summarises the activities related to carbon nanotubes and nanofibers used as a reinforcement in metallic matrix materials. The main challenges and the potential with respect to material properties will be discussed.

Low energy vibrational excitations in single bonded fullerene dimeres (C59N)2 and (C60-)2 and in single wall carbon nanotubes were investigated by Raman spectroscopy. The two isoelectronic and isostructural dimeres exhibited very similar spectra with strongly resonance enhanced lines for the radial modes if excitation was with a red laser. For the biazafullerene for the first time all three geometrically allowed intercage modes could be identified. For the single wall carbon nanotubes the response from the radial breathing mode was analyzed for excitation with 20 different laser lines. The results were found to be consistent with contributions from all geometrically allowed tubes and a strong contribution to the force constant from intercage interaction.

The mechanical and electrical properties of a bulk material made of single wall carbon nanotubes (SWNT) are, due to weak intermolecular interaction, several orders of magnitude lower than those of the individual molecules themselves. We studied the effect of gamma‐irradiation on SWNT paper in air and under vacuum. For samples irradiated in air, changes in Young modulus and electrical conductivity were observed with maximum value for a dose of 170 kGy. Under vacuum there was only a small effect of irradiation. Raman studies of irradiated samples showed defects formation. Same experiments done with graphite showed similar results. A likely explanation of the results is that cross‐links between nanotubes were induced by irradiation in air.

Thin bundles of single wall carbon nanotubes were suspended between metal blocks deposited on a silicon substrate. SEM images confirm that the parts of bundles between the blocks are free standing and those outside the contacts are lying on the silicon substrate. Since the tubes are usually a few micrometers long Raman spectra for nanotubes with and without the contact could be taken. Raman spectra show differences in the position and shape of the RBM and G lines depending on the site of the measurement. The RBM mode is usually very weak as compared to the G line. The results showed that the geometry of the experiment should be taken into account for interpretation of single tube or thin bundle Raman experiments.

The hydrogen storage capacity in mechanically treated single wall carbon nanotubes (SWNTs) is investigated in this paper. In order to open the nanotubes three mechanical methods were applied: ball milling, ultrasonication and rubbing. Changes induced by the treatment were analyzed by Raman spectroscopy. The amount of hydrogen stored by the SWNTs reaches fractions of weight percents only. In the case of sonicated specimens, the hydrogen storage can be ascribed to titanium particles incorporated during the treatment.

The hydrogen adsorption capacity of various carbon nanostructures including single-wall carbon nanotubes, graphitic nanofibers, activated carbon, and graphite has been measured as a function of pressure and temperature. Our results show that at room temperature and a pressure of 80 bar the hydrogen storage capacity is less than 1 wt.% for all samples. Upon cooling, the capacity of hydrogen adsorption increases with decreasing temperature and the highest value was observed to be 2.9 wt. % at 50 bar and 77 K. The correlation between hydrogen storage capacity and specific surface area is discussed.

The room temperature Raman spectra of the C84 isomers 22: D2 and 23: D2d are shown to resemble a downshifted and split C60 spectrum in the range of the radial cage modes below 450 cm−1. Additional Raman lines with a basically similar structure were found for three isomers of Sc2@C84 (Cs, C2v and D2d) below 200 and at 260 cm−1 and attributed to (Sc−C84)-vibrations. These modes are further specified with respect to their normal coordinates. Factor group splitting in the solid state of the Sc2@C84 D2d isomer explains for the larger number of (Sc−C84)-vibrations as found for the other isomers.

We report the isolation of nine isomers of [84]fullerene (C84). Of these minor isomers, six were sufficiently abundant to allow characterization by 13C NMR spectroscopy. These have, in order of decreasing abundance, D2(IV), D2d(II), Cs(V), D2d(I), D2(II), and C2(IV) molecular point group symmetry.

We present IR and Raman measurements of endohedral compounds Sc2@C84 with D2d symmetry and its empty counterpart C84. Our main task was to determine mutual carbon cage—Sc vibrations. The attention was therefore concentrated in the region below 300 cm−1 in which one expects this type of motions. Comparing spectra for empty and filled isomers with D2d symmetry we identified several candidates for the cage—Sc vibrations. The unexpected high number of such modes can be explained by site and correlation field splittings. Other modes observed in the region we attributed either to fundamental or combination modes of the cage. The temperature dependence of the spectra gave a better insight into the dynamics of the metallofullerene compounds. We observed a broadening of some modes in the mid-IR region with increasing temperature. From a model describing the interaction between cage modes and reorientational motion we obtained an activation energy for the reorientations.

We present IR transmission measurements for two isomers of the endohedral compound Sc2@C84 with D2d (No. 23) and D2 (No. 10) symmetry. The measurements were performed in the far- and mid-infrared region between 80 cm−1 and 4000 cm−1 and at temperatures from 80 K to 300 K. We identified several modes and investigated their dependence on the symmetry of the cage and on the temperature. The latter turned out to be rather strong and can be used to distinguish between modes of the metals in the cage and cage modes.

This paper presents the case report of a 50-year-old woman with a triple valve lesion of rheumatic origin and ischemic coronary disease. The patient underwent successful simultaneous triple valve surgery; the aortic and mitral valves were replaced by mechanical prostheses, and the tricuspid valve was repaired by annuloplasty, together with three aorto-coronary bypasses and endarterectomy of the right coronary artery. The peri- and postoperative courses were uneventful and the patient was discharged from hospital in good clinical condition 12 days after surgery.

The authors analyze 50 patients with endarterectomy of the coronary arteries during the periods of 1972-1974 and 1988-1990. The results of endarterectomy of the right and left coronary artery provide evidence of its justification in indicated cases whereby contrary to some departments the results of endarterectomy of the left coronary artery are comparable with endarterectomy of the right coronary artery.

The hydrogen storage in purified single-wall carbon nanotubes (SWNTs), graphite and diamond powder was investigated at room temperature and ambient pressure. The samples were sonicated in 5 M HNO3 for various periods of time using an ultrasonic probe of the alloy Ti-6Al-4V. The goal of this treatment was to open the carbon nanotubes. The maximum value of overall hydrogen storage was found to be 1.5 wt %, as determined by thermal desorption spectroscopy. The storage capacity increases with sonication time. The sonication treatment introduces particles of the Ti alloy into the samples, as shown by X-ray diffraction, transmission electron microscopy, and chemical analysis. All of the hydrogen uptake can be explained by the assumption that the hydrogen is only stored in the Ti-alloy particles. The presence of Ti-alloy particles does not allow the determination of whether a small amount of hydrogen possibly is stored in the SWNTs themselves, and the fraction of nanotubes opened by the sonication treatment is unknown.

Terahertz time-domain spectroscopy is applied to measure the absorption and dispersion by single-wall carbon nanotubes in the frequency range of 0.2-5 THz. In addition, we performed experiments to access the carrier and phonon relaxation rates in the nanotubes ensemble excited by a near infrared subpicosecond pulse.