Background and Objectives: The available research shows conflicting data on the heart rate variability (HRV) in metabolic syndrome (MetS) subjects. The discrepancy suggests a methodical shortcoming: due to the influence of physical activity, the standard measuring of HRV at rest is not comparable with HRV assessment based on 24h Holter monitoring, which is preferred because of its comprehensiveness. To obtain a more reliable measure and to clarify to what extent HRV is altered in MetS, we assessed a 24h HRV before and after the elimination of the influence of physical activity. Materials and Methods: We investigated 69 metabolic syndrome (MetS) and 37 control subjects, aged 50-55. In all subjects, 24h monitoring of electrocardiogram, blood pressure, and actigraphy profiles were conducted. To eliminate the influence of day-time physical activity on RR intervals (RRI), a linear polynomial autoregressive model with exogenous terms (ARX) was used. Standard spectral RRI analysis was performed. Results: Subjects with MetS had blunted HRV; the diurnal SDNN index was reliably lower in the MetS group than in control subjects. The elimination of the influence of physical activity did not reveal a significant HRV change in long-term indices (SDNN, SDANN, and SD2), whilst adjacent RRI values (RMSSD, pNN50, and SD1) and SDNN index significantly increased (p < 0.001). An increase in the latter indices highlighted the HRV difference between the MetS and control groups; a significant (p < 0.001) decrease of all short-term HRV variables was found in the MetS group (p < 0.01), and low-frequency spectral components were less pronounced in the MetS group. Conclusion: The application of a polynomial autoregressive model in 24h HRV assessment allowed for the exclusion of the influence of physical activity and revealed that MetS is associated with blunted HRV, which reflects mitigated parasympathetic tone.
Problem-based learning (PBL) is an educational method which involves learning by solving real problems. However, applying a PBL approach to engineering subjects in some cases became a challenging issue. Thus, it is important to determine the best ways in which engineering students can learn physics more effectively and solve problems relevant to their daily lives. The main aim of this study was to compare the final assessment grades in a physics course for students in the engineering program using PBL and traditional learning (TL) methods. The advantages and disadvantages of PBL and TL methods from the practical experience of lecturers are also presented. The study presented data of 460 first-year engineering students taking the physics course at Kaunas University of Technology. The information presented in this study is based on the insights, observations, and individual experiences of the authors as teaching staff. The results indicated that the application of the PBL method allows for enhancement in the teamwork, presentation, and critical thinking skills in physics. However, the TL method promotes the individual learning skills and wider theoretical knowledge in physics of students and is more suitable when the exam only includes closed-ended questions.
PbTiO3 is one of the most important ferroelectric materials with perovskite structure, which has piezoelectric, pyroelectric and ferroelectric properties. The synthesis of complex PbTiO3 thin films was researched in this work. It is a synthesis of PbTiO3 thin films by reactive magnetron layer by layer deposition of Ti and Pb layers in a plasma of oxygen and oxygen-argon mixture and using a solid state reactions between them during annealing at different temperatures (200-700oC, 1 h) in atmosphere. For getting a stoichiometry of thin films the dependence of deposition rate on partial oxygen pressure, magnetron power and geometry were researched. XRD diffraction and optical properties analysis were investigated in order to research the structural and the phase changes which depends on annealed temperature. The crystallization of pyrochlore Pb2Ti2O6 phase layers was observed at 200-4000C interval of temperatures. The perovskite PbTiO3phase appeared at 5000C.
The formation of deposited ferroelectric perovskite PbTiO3 thin films using layer-by-layer reactive magnetron sputtering was investigated in this work. Deposition rates of each layer (PbO and TiO2) for 7.2 and 9.2 nm/min, respectively, were chosen there. Silicon (110) substrate with the heater was moved periodically and parallel to the magnetron cathodes during deposition. The heater temperature (380 °C–700 °C) has influence on the stoichiometry of thin films. Perovskite phase of lead titanate was not obtained without post annealing. The reasons for this are discussed in the work. The results of the structure of thin layers deposited on silicon substrates at 380 °C and annealed for one hour at 700 °C in air have shown that a pure perovskite phase of PbTiO3 is formed there.
In the present research, hexagonal boron nitride (h-BN) films were deposited by reactive high-power impulse magnetron sputtering (HiPIMS) of the pure boron target. Nitrogen was used as both a sputtering gas and a reactive gas. It was shown that, using only nitrogen gas, hexagonal-boron-phase thin films were synthesized successfully. The deposition temperature, time, and nitrogen gas flow effects were studied. It was found that an increase in deposition temperature resulted in hydrogen desorption, less intensive hydrogen-bond-related luminescence features in the Raman spectra of the films, and increased h-BN crystallite size. Increases in deposition time affect crystallites, which form larger conglomerates, with size decreases. The conglomerates' size and surface roughness increase with increases in both time and temperature. An increase in the nitrogen flow was beneficial for a significant reduction in the carbon amount in the h-BN films and the appearance of the h-BN-related features in the lateral force microscopy images.
Ureteral ectopy is a congenital anomaly, affecting young dogs, predominantly bitches. The main complication of the disease is urinary incontinence, which leads to low life quality for both animals and their owners. However, only two less invasive surgical management options are reported. Laser ablation is quite popular, while monopolar electrocautery use is very rare.A 3-month and 1-week-old, 1.7 kg female Poodle was admitted to the Vetamicus clinic with severe urinary incontinence and moisture-associated dermatitis. After diagnosing intramural ectopy type during computed tomography scan and video cystoscopy, a search for surgical management options began. We proceeded with the monopolar cauterization technique, where a semirigid Karl Storz monopolar coagulating ball electrode is used to cut a mucous membrane partition between the ureter and urinary bladder. No complications occurred during or after the surgery. Ureter successfully healed and full continence was achieved together with sporadically using phenylpropanolamine syrup.The present case indicates that monopolar electrocautery use in intramural ectopy type management and possibly other urinary tract pathologies might be strongly beneficial.
