We investigate the stabilization of perturbed nonlinear systems using output-based periodic event-triggered controllers. Thus, the communication between the plant and the controller is triggered by a mechanism, which evaluates an output- and input-dependent rule at given sampling instants. We address the problem by emulation. Hence, we assume the knowledge of a continuous-time output feedback controller, which robustly stabilizes the system in the absence of network. We then implement the controller over the network and model the overall system as a hybrid system. We design the event-triggered mechanism to ensure an input-to-state stability property. An explicit bound on the maximum allowable sampling period at which the triggering rule is evaluated is provided. The analysis relies on the construction of a novel hybrid Lyapunov function. The results are applied to a class of Lipschitz nonlinear systems, for which we formulate the required conditions as linear matrix inequalities. The effectiveness of the scheme is illustrated via simulations of a nonlinear example.

Discounted costs are considered in many fields, like reinforcement learning, for which various algorithms can be used to obtain optimal inputs for finite horizons. The related literature mostly concentrates on optimality and largely ignores stability. In this context, we study stability of general nonlinear discrete- time systems controlled by an optimal sequence of inputs that minimizes a finite-horizon discounted cost computed in a receding horizon fashion. Assumptions are made related to the stabilizability of the system and its detectability with respect to the stage cost. Then, a Lyapunov function for the closed-loop system with the receding horizon controller is constructed and a uniform semiglobal stability property is ensured, where the adjustable parameters are both the discount factor and the horizon length. Uniform global exponential stability is guaranteed by strengthening the initial assumptions, in which case explicit bounds on the discount factor and the horizon length are provided. We compare the obtained bounds in the particular cases where there is no discount or the horizon is infinite, respectively, with related results in the literature and we show our bounds improve existing ones on the examples considered.

UDK: 630*36:631.372]:65.015(497.6) This paper presents the research results of the skidding productivity for the Ecotrac 120V skidder in mountainous areas of MU „Igmanˮ in Bosnia and Herzegovina. Time and work study were performed. Multiple regression analysis was used for determination of work operations time consumption depending on influencing factors. The following influencing factors were recorded: the condition of the tractor road (surface), the skidding distance, the winching distance, number of pieces in the load, the volume of the load and the slope of the tractor road. The share of productive time in the total work time is 58.47%. The average value of the influencing factors was established: unloaded travel distance 585.26 m, loaded travel distance 490.49 m, winching distance 16.83 m, number of pieces in the load 5.95, the volume of the load 5.17 m3 and the volume of the piece in the load 1.02 m3. The half-tree length method was used. Standard time for skidding and daily skidding productivity were expressed depending on the skidding distance, while average values were used for other influencing factors. The standard time for skidding was 6.57 min/m3 at a skidding distance of 100 m, i.e. 17.60 min/m3 at a skidding distance of 1,500 m. The daily skidding productivity ranges from 73.07 m3/day at a skidding distance of 100 m to 27.28 m3/day at a skidding distance of 1,500 m. Comparison of the daily skidding productivity with the results of other researches showed that the Ecotrac 120V skidder in this particular case realizes approximately the same skidding productivity under similar working conditions.

Introduction: In patients with acute myocardial infarction (AMI) early risk assessment of development of complications is of great importance. It is proven that aldosterone level has a major role in progression of cardiovascular pathology. Aim: Determination of influence of aldosterone plasma level in the progression of heart disease in patients without signs of heart failure after AMI. Material and Methods: Research included 207 patients, hospitalized in the acute phase of myocardial infarction, and who were divided into two groups: 127 patients with no clinical signs of heart failure and 60 patients with heart failure. Results: The serum aldosterone concentration was 73.4% higher in the group of decompensated patients, 128 pg/mL (75.4-236 pg/mL) in decompensated and 73.7 pg/mL (42.7 -115.25 pg/mL) in compensated. In the group of compensated patients, changes in aldosterone levels showed a statistically significant effect on the incidence of post-infarction angina (p=0.0001) as well as reinfarction (p=0.009). There is a connection between changes in aldosterone plasma level and positive stress test (p=0.012). Conclusion: In patients with AMI, elevated serum aldosterone level can be prognostic factor of the progression of coronary heart disease, development of heart failure, as well of development of post-infarction angina, myocardial reinfarction and pathological finding on the stress test.

Aim: Aim of the article was to present a case of post transplantation invasive aspergillosis, successfully treated with conservative and surgical treatment. Case report: Patient, male, 44 years old, with second kidney transplant, required special preparation therapy, because he was sensitized, with concentration of Panel Reactive Antibody (PRA) class I 11% and PRA class II 76%. On the day of transplantation, induction was done with anti-thymocyte globulin (ATG) and glucocorticosteroids. After transplantation, plasmapheresis with ATG was performed. On the fourth day patient was anuric. Fine-needle biopsy of the graft was performed and showed positive CD4 antibodies for peritubular capillaries and humoral rejection. 14 plasmaphereses through 14 days, were negative and ATG treatment was suspended completely. Full therapeutic dosage of tacrolimus and mycophenolate mofetil were given during treatment. Four days after treatment patient was stable, but next day clinical status had worsened with dyspnea and fever. In sputum, spores of Aspergillus species were microscopically found, and radiologically by computerised tomography. Caspofungin was administered for seven days. Voriconazole therapy was given for first ten days by intravenous route and after then orally. Even with this treatment, there was no improvement in clinical picture, while CT scan of the lungs showed abscess collection in right lung. Lobectomy was performed and pus collection was found. After graft-nephroctomy, patient was treated with continous veno-venous hemodiafiltration (CV-VHDF) dialyses, with constant voriconazole therapy for the next three months (200mg two times per day). After one month of diagnosis, Galactomannan (GM) test was negative. Conclusion: Although highly sensitized patients, those who are on hemodialysis, in preparation for transplantation, receive intensive immunosuppressive therapy that suppress the immune system. Occurrence of secondary fungal infections especially infection by aspergillosis, is cause of high mortality of infected. Application GM test that detects existence of antibodies against Aspergillus antigens and usage of different type of immunosuppressive preparation can increase longevity of graft and patients in solid organ transplantation program. Aspergillosis is treated with voriconazole and surgery, and sometimes graft-nephrectomy if needed. Recommendation is that in all immunocompromised hosts and organ transplant recipient should have been tested with GM test.

Introduction: Cervical erosion and squamouse intraepithelial lesion of low grade are most common gynecological problems of women. These changes on cervix are cause of painful coitus and enhanced vaginal secretion. Cryotherapy is widely accepted method in treating these changes and sympthoms. Aim: The aim of this study is to examine the efficiency of cryotherapy in eliminating erosion of cervics and LSIL, as well as conditions following these states. Patients and methods: Cryotherapy was performed in 124 women with cervical erosion (N-74) and LSIL (N-50). Sympthoms that were followed are: vaginal secretion, abnormal vaginal bleeding and pain. Assessment of epithelisation of cervix and evaluation of sympthoms were done 4 and 6 weeks after cryotherapy and PAP test after 4 months in women with LSIL. Statistical method used in result processing was X2 test. Results: The average age of examined women is 37,75±8,2. Enhanced vaginal secretion had 87,09% (N-120), painful coitus 61,29% (N-76), pain in lesser pelvis 52,41% (N-65) and abnormal vaginal bleeding 28,22% (N-35). Erosion of cervix had 14% (N-7) of women with LSIL. After cryotherapy, enhanced vaginal secretion remained in 21,77% (N-27) of women, painful coitus remained in 8,06% (N-10), pain in lesser pelvis remained in 5,6% (N-7) and abnormal vaginal bleeding in 6,4% (N-8). Four weeks after cryotherapy, complete epithelisation of cervix was in 87,90% (N-109) and after six weeks in 93,54% (N-116) of examined women. LSIL was eliminated in 92% (N-46) of women after cryotherapy and in 8% (N-4) results remained the same. Conclusion: Cryotherapy is successful method of elimination of cervical erosion, LSIL and pains with enhanced vaginal secretion.

Abstract Patient satisfaction is a key indicator to assess the quality of gastrointestinal endoscopy. The aim of this study was to examine the Serbian translation and cross-cultural validation of the questionnaire for the assessment of satisfaction in patients who underwent gastrointestinal endoscopy. After obtaining the consent of the author of the original questionnaire, translation and cross-cultural validation of the GESQ (Gastrointestinal Endoscopy Satisfaction Questionnaire) were carried out in accordance with the conductors of the International Society for Pharmacoeconomics and Outcomes Research (ISPOR). The study was conducted in the Center for Gastroenterohepatology (GEH) of the Kragujevac Clinical Center and included 165 patients. The reliability of the Serbian translation of the GESQ was estimated by calculating Cronbach’s alpha for the whole questionnaire in order to implement the structural validation. The overall score of the questionnaire was compared and correlated with the total scores on the Short Subjective Well-being scale (KSB) and visual analogue scale (VAS), which were administered to the same patients. The Serbian translation of the GESQ showed high reliability with a Cronbach’s alpha coefficient of 0.763, good structure and homogeneity by randomly sharing the questionnaire into two parts. Exploratory factor analysis indicated the existence of four factors that explain 57.200% of the variability. The Serbian version of the GESQ showed similar psychometric characteristics to the original English questionnaire, with a similar factor structure, and represented a valid, reliable and acceptable tool for the assessment of patient satisfaction with the endoscopic examination of the digestive tract.

Introduction: Between 30 to 59% of patients with migraine without aura are undiagnosed and improperly treated, because primary care physicians are either too busy or unfamiliar with criteria for diagnosing migraine. Aim: The aim of our study was to translate the Migraine Screen Questionnaire (MS-Q) to BHS (Bosnian/Croatian /Serbian) language and to test reliability and validity of the translation on a sample of primary care patients. Material and Methods: The study was designed as cross-sectional, multi centric, diagnostic accuracy trial of an instrument for screening patients who visit general practitioners, with an aim to reveal migraine without aura. The instrument was the MS-Q, originally written in English and validated in Spanish population, and in this study being translated to BHS language. Results: Translation of the MS-Q to BHS language showed good diagnostic accuracy (sensitivity 80.0% and specificity 87.2%) and reliability (Cohen kappa 0.648) for migraine without aura, with significant screening yield among previously undiagnosed patients of 72.7%. The study also confirmed high percentage of patients with hidden MWA (52.9%) revealed by the MS-Q and ICH criteria that would otherwise remain undiagnosed. Conclusion: The MS-Q translation to BHS language could be considered as valid and reliable clinical instrument for revealing migraine without aura, similar by its performance to original questionnaire. It has considerable screening yield, discovering majority of patients with previously undiagnosed migraine without aura, whose definite diagnosis should later on be confirmed by the attending physicians using the ICH criteria.

Abstract Potentilla reptans is a little studied plant of the genus Potentilla, the family Rosaceae. The aim of this study is to determine antimicrobial effects of aqueous extracts of P. reptans aerial part and rhizome against standardized bacterial strains. The antimicrobial activity of aqueous extracts of P. reptans aerial part and rhizome was tested against one fungus, Candida albicans, and two standard bacterial strains, Staphylococcus aureus and Escherichia coli, using an agar diffusion method. Both examined extracts showed a significant antimicrobial activity against Escherichia coli and Staphylococcus aureus at the concentrations of 10 to 150 mg/ml. The rhizome extract showed stronger antimicrobial effect against the tested strains of bacteria than the aerial part extract. The obtained results represent preliminary results of antimicrobial activity of this plant and suggest that in future, the studies should examine antimicrobial activity against other bacterial strains and minimum inhibitory concentration.

Colorectal cancer (CRC) represents one of the most common cancers. It is frequently diagnosed at advanced stages, indicating on need for new diagnostic markers. The aim of this study was to determine systemic and fecal values of IL-17 and IL-33 in patients with CRC and the relationship with clinicopathological aspects of disease. The blood samples and feces liquid fraction of 50 patients with CRC were analyzed. Serum and fecal levels of IL-33 and IL-17 were measured using sensitive enzyme-linked immunosorbent assay (ELISA) kits. Fecal levels of Il-33 and IL-17 were increased in CRC patients with poor tumor tissue differentiation. Serum IL-33 and fecal IL-17 were increased in patients with presence of lung/liver metastasis or peritoneal carcinomatosis, respectively, while enhanced fecal IL-33 was detected only in patients with peritoneal carcinomatosis. Positive correlation between IL-33 and IL-17 values in sera and feces, respectively was also observed. We believe that increased local values of IL-33 and IL-17, reflected trough higher fecal concentration, in CRC patients with poor tumor tissue differentiation and with presence of lung/liver metastasis or peritoneal carcinomatosis may be considered as a sign of the tumor’s malignant progression and, consequently, of a poor prognosis for patients.