Interaction of lasers of various types with alloys based on Ni and Ti

Savremene legure na bazi nikla i titanijuma, sa većim brojem novih elemenata, imaju široku primenu. Tako dobijene nove legure titanijuma su od velikog praktičnog značaja u vazduhoplovstvu, a novodobijene legure nikla u energetici i nuklearnoj tehnici. U okviru ovog rada su prikazani rezultati tretiranja legura titanijuma i nikla snopovima lasera u vazduhu, na atmosferskom pritisku, kao i pojedinih uzoraka u vakumskim uslovima. Dobijene laserske modifikacije mikrostruktura uzoraka su analizirane različitim metodama ispitivanja, koje uključuju optičku i elektronsku mikroskopiju (SEM). Savremenim numeričkim metodama je, za izabrane režime rada lasera, simulirano grejanje do tačke topljenja odgovarajućeg materijala.Commonly implemented nickel and titanium alloys are nowadays alloyed with many new elements. Obtained in this way, new Ti-alloys are of great practical significance in aircraft industry, while Ni-alloys are important in energetic and nuclear technique. Selected alloys of titanium and nickel have been treated in vacuum by various thermo-mechanical regimes. Most of the samples have been exposed to laser beams in the air, at the atmospheric pressure, while some of the samples have been treated in vacuum conditions. Laser-induced modifications of the samples microstructures have been analyzed by various methods of investigation, which include optical- and electron microscopy (SEM). The heating up of the selected Ni- and Ti-alloys to the melting point, in selected regimes of laser operation, has been simulated by contemporary numerical methods

Interaction of lasers of various types with alloys based on Ni and Ti

Savremene legure na bazi nikla i titanijuma, sa većim brojem novih elemenata, imaju široku primenu. Tako dobijene nove legure titanijuma su od velikog praktičnog značaja u vazduhoplovstvu, a novodobijene legure nikla u energetici i nuklearnoj tehnici. U okviru ovog rada su prikazani rezultati tretiranja legura titanijuma i nikla snopovima lasera u vazduhu, na atmosferskom pritisku, kao i pojedinih uzoraka u vakumskim uslovima. Dobijene laserske modifikacije mikrostruktura uzoraka su analizirane različitim metodama ispitivanja, koje uključuju optičku i elektronsku mikroskopiju (SEM). Savremenim numeričkim metodama je, za izabrane režime rada lasera, simulirano grejanje do tačke topljenja odgovarajućeg materijala.Commonly implemented nickel and titanium alloys are nowadays alloyed with many new elements. Obtained in this way, new Ti-alloys are of great practical significance in aircraft industry, while Ni-alloys are important in energetic and nuclear technique. Selected alloys of titanium and nickel have been treated in vacuum by various thermo-mechanical regimes. Most of the samples have been exposed to laser beams in the air, at the atmospheric pressure, while some of the samples have been treated in vacuum conditions. Laser-induced modifications of the samples microstructures have been analyzed by various methods of investigation, which include optical- and electron microscopy (SEM). The heating up of the selected Ni- and Ti-alloys to the melting point, in selected regimes of laser operation, has been simulated by contemporary numerical methods

Primary percutaneous transluminal coronary angioplasty in the acute infarction of the right ventricle

Background. Predilection site for the acute myocardial infarction of the right ventricle, (AMI-RV) is the upper third of the right coronary artery and for this reason such an infarction is followed by numerous complications, primarily by conduction disorders and very often by sudden and rapid cardiogenic shock development. Methods. Primary percutaneous transluminal coronary angioplasty (PPTCA) was performed on three patients in whom the acute infarction of the right ventricular was diagnosed and who had been hospitalized six hours after the beginning of chest pain. In all three patients intracoronary stent was implanted. On the admission patients had been in the threatening cardiogenic shock, with the prominent chest pain and with the elevation of ST-segment in V4R>2 mV. In the course of intervention patients were administered low-molecular intracoronary heparin with direct platelet glycoprotein IIb/IIIa inhibitors (abciximab), according to the established procedure applied in such cases. Results. The complete dilatation of the infarcted artery was established with the signs of reperfusion and the further clinical course was completely normal, there was no heart failure and patients had no subjective difficulties. Conclusion. Invasive approach in the treatment of AMI-RV is justifiable, and possibly the therapy of choice of these patients, providing well trained and equipped team is available

Diagnosis and results of treatment of heart myxoma

Background/Aim. Myxoma is the most common benign primary cardiac neoplasm, and usually originates from the left atrial septum. Early diagnosis of cardiac myxomas depends on a high index of a clinical suspicion. Surgical management must be done as soon as possible after diagnosis. The aim of this retrospective study was to present diagnostics and treatment outcome data of 61 patients with cardiac myxoma treated in the Military Medical Academy, Belgrade during a 49-years period. Methods. Intrahospital diagnosis was established in all the patients by the cardiologist. Diagnostic methods were various, in dependence on the examination period and suspected diagnosis. Results. Within a 49-years period (1961-2009) heart myxoma was diagnozed and treated in 61 patients in the Military Medical Academy, Belgrade. Most of the operated patients were females (38 or 62.3%). The operated patients were 19-68 years old. Average age of all the patients was 47.9%. The great majority of them (98.4%) had atrial, and only one operated patient had ventricular myxoma. In 13 (21.3%) of the patients heart myxoma was found out accidentally due to no previous cardiologic symptomatology. In most patients (27.44%) symptomatology was presented as thromboembolic disease. Because of the suspected ventricular myxoma in one patient, the patient was operated on, but Hodgkin's lymphoma was found out which, according to the subsequent course of the disease, could be justifiably recognized as primary heart lymphoma. This study presented brief descriptions of the course of the disease in 4 patients with myxomas in each of the cardiac cavities. Conclusion. The only diagnostic difficulty in cardiac myxoma is due to its asymptomatic and oligosymptomatic presence within the longer period of time, namely, its growth period. Echocardiography should be the standard method of cardiologic examination of these patients, which could considerably contribute to early diagnosis and treatment of heart myxoma. Surgical extirpation of myxoma is the only and very successful therapeutic method

Effects of a short-term differently dosed aerobic exercise on maximum aerobic capacity in breast cancer survivors: A pilot study

Background/Aim. Regular physical activity and exercise improves quality of life and possibly reduces risk of disease relapse and prolongs survival in breast cancer survivors. The aim of this study was to evaluate the impact of a 3-week moderate intensity aerobic training, on aerobic capacity (VO2max) in breast cancer survivors. Methods. A prospective, randomized clinical study included 18 female breast cancer survivors in stage I-IIIA, in which the primary treatment was accomplished at least 3 months before the study inclusion. In all the patients VO2max was estimated using the Astrand’s protocol on a bicycle-ergometer (before and after 3 weeks of training), while subjective assessment of exertion during training were estimated by the Category-Ratio RPE Scale. Each workout lasted 21 minutes: 3 minutes for warmup and cool-down each and 15 min of full training, 2 times a week. The workload in the group E1 was predefined at the level of 45% to 65% of individual VO2max, and in the group E2 it was based on subjective evaluation of exertion, at the level marked 4-6. Data on the subjective feeling of exertion were collected after each training course in both groups. Results. We recorded a statistically significant improvement in VO2max in both groups (E1 - 11.86%; E2 - 17.72%), with no significant differences between the groups. The workload level, determined by the percent of VO2max, was different between the groups E1 and E2 (50.47 ± 7.02% vs 55.58 ± 9.58%), as well as subjective perception of exertion (in the groups E1 and E2, 11.6% and 41.6% of training, respectively, was graded in the mark 6). Conclusion. In our group of breast cancer survivors, a 3-week moderate intensity aerobic training significantly improved the level of VO2max

Interakcija različitih tipova lasera sa legurama baziranim na niklu i titanijumu

Commonly implemented nickel and titanium alloys are nowadays alloyed with many new elements. Obtained in this way, new Ti-alloys are of great practical significance in aircraft industry, while Ni-alloys are important in energetic and nuclear technique. Selected alloys of titanium and nickel have been treated in vacuum by various thermo-mechanical regimes. Most of the samples have been exposed to laser beams in the air, at the atmospheric pressure, while some of the samples have been treated in vacuum conditions. Laser-induced modifications of the samples microstructures have been analyzed by various methods of investigation, which include optical- and electron microscopy (SEM). The heating up of the selected Ni- and Ti-alloys to the melting point, in selected regimes of laser operation, has been simulated by contemporary numerical methods.Savremene legure na bazi nikla i titanijuma, sa većim brojem novih elemenata, imaju široku primenu. Tako dobijene nove legure titanijuma su od velikog praktičnog značaja u vazduhoplovstvu, a novodobijene legure nikla u energetici i nuklearnoj tehnici. U okviru ovog rada su prikazani rezultati tretiranja legura titanijuma i nikla snopovima lasera u vazduhu, na atmosferskom pritisku, kao i pojedinih uzoraka u vakumskim uslovima. Dobijene laserske modifikacije mikrostruktura uzoraka su analizirane različitim metodama ispitivanja, koje uključuju optičku i elektronsku mikroskopiju (SEM). Savremenim numeričkim metodama je, za izabrane režime rada lasera, simulirano grejanje do tačke topljenja odgovarajućeg materijala

Generalization of powder analyses of interest in biomedicine and ecology

Mikročestice, u prvom redu prahovi, koji su od interesa u mnogo oblasti, predstavljaju složeno područje istraživanja sa teorijske i metrološke tačke gledišta. Tačnost razmatranja i kontrole je od izuzetnog interesa za područja ekoloških i medicinskih normi i primena. U radu je razmatran matematički aparat, problematike korišćenja i distribucije prahova uz praktična rešenja, koja nudi savremena tehnika merenja.Microparticles, firstly, powders of interest in many area, represent complex research field ,from the theoretical and metrologic point of view. The exact consideration as well as control is of extremly importance for ecological and biomedical normative and application. The numerical and analytical point of view for powder distribution as well as practical modern solution are considered in this paper

Generalization of powder analyses of interest in biomedicine and ecology

Mikročestice, u prvom redu prahovi, koji su od interesa u mnogo oblasti, predstavljaju složeno područje istraživanja sa teorijske i metrološke tačke gledišta. Tačnost razmatranja i kontrole je od izuzetnog interesa za područja ekoloških i medicinskih normi i primena. U radu je razmatran matematički aparat, problematike korišćenja i distribucije prahova uz praktična rešenja, koja nudi savremena tehnika merenja.Microparticles, firstly, powders of interest in many area, represent complex research field ,from the theoretical and metrologic point of view. The exact consideration as well as control is of extremly importance for ecological and biomedical normative and application. The numerical and analytical point of view for powder distribution as well as practical modern solution are considered in this paper

Ischemic preconditioning

Background. Ischemic preconditioning is a phenomenon during which myocardium, subjected to brief episodes of ischemia followed by reperfusion, tolerates better the subsequent, more prolonged episode of this ischemia, thus reducing the infarction size substantially. Case report. Two patients with acute left anterior descendent artery occlusion received fibrinolytic therapy (alteplase) within 6 hours of the onset of chest pain, but developed myocardial infarctions of different sizes. The first patient, without the history of preinfarction angina, developed large anterior infarct, because there was no time either for ischemic preconditioning or for the coronary collateral vessels development. In the second patient, with 4-day history of preinfarction angina, the more favorable outcome was seen he developed smaller apical necrosis, with the great degree of myocardial viability in the infarct-related area. Conclusion. Ischemic preconditioning in patients with acute myocardal infarction results in the reduction of mortality, infarction size, as well as in the frequency of malignant arrhythmias

The results of the treatment of right ventricle myocardial infarction

Aim. To present the results and experience in diagnosing and treating of patients with acute right ventricle infarction, during the period of hospitalization of one month, with adjuvant analyses of the obtained results in the period of fifteen years. Methods. Acute right ventricle infarction porved clinicaly, enzymologicaly, by ECG, echochardiographically or scintigraphically we treated with thrombolitic therapy within first six hours after admittion, with salvaged PTA in case of the cardiogenic shock or AV block IIº−IIIº despite of thrommbolitic therapy, or with postponed PTA within first month of intrahospital treatment. Results. In the period from 1990 to 2004, 3 225 patients of both sexes were treated for acute myocardial infarction at the different localization in patients' at the mean age of 53.7 ± 5.8. One-hundredthirty - nine (43.9%) patients were treated with thrombolitic therapy according to the speed up protocole. Heparin was administered to 160 (50.7%) patients with water load, and 17 (5.4%) patients had the primary percutaneous transluminal coronary angioplasty (PPTCA), so that the mechanical blood flow could be established, by the implantation of a stent when necessary. In 316 patients with right ventricle infarction, 58 (18.3%) had postponed and salvaged percutaneous transluminal coronary angioplasty (PTCA). Twenty-two (15.8%) patients had thrombolitic therapy, whereas 36 (22.5%) patients were treated with heparin. We had a successful balloon dilatation in 21 (36.2%), whereas 32 (55.2%) patients had 1−3 intracoronary stents inplanted, depending upon the necessity, and 5 (8.6%) patients from this group were sent to surgical intervention. In the group of 214 (67.7%) patients treated with heparin or thrombolitic therapy combined therapy, with PTCA, 12 (5.7%) patients died, whereas in the group of 124 (39.3%) patients treated only with heparin 26 (16.2%) patients died, statistically significant difference (p < 0.001, χ2 = 18.423). Was noticed n the group of 1 204 patients with inferoposterior infarction, 122 (10.1% ) patients died. In the group of 316 patients with right ventricle infarction, 38 (12%) died. In the group of 888 control patients with inferoposterior infarction, but without right ventricle infarction, 84 (9.4%) patients died. In the group of 2 021 patients (62.2%) with anterior infarction, 248 (12.3%) died. Conclusion. The obtained results showed that the patients with right ventricle infarction, due to the great expansion of necrosis and the involvement of the inferoposterior wall of the left ventricle, as well as the ischemia of sinus and AV nodes, were the patients of a high risk. That was why it was essential to do urgent widening of the artery to reestablish blood flow either by using drugs or by means of mechanical methods