Platelet aggregation and haemostasis parameters during stress echocardiography with dobutamine in the population of patients treated with percutaneous coronary intervention

Uvod: Agregabilnost trombocita i proces aktivacije hemostaze tokom ishemije miokarda u sklopu fizičkog ili mentalnog stresa, može biti jedan od brojnih faktora koji utiču na proces tromboze stenta nakon perkutane koronarne intervencije. Pacijenti i metode istraživanja: Studijsku populaciju čini 121 asimptomatskih pacijenata koji su imali uspešnu perkutanu koronarnu intervenciju četiri meseca pre visokodozne dobutamin stres ehokardiografije. Agregabilnost trombocita na epinefrin (EPI) i adenozin difosfat (ADP) je određena metodom light transmission aggregometry (LTA) zajedno sa aktivnošću proteina C i antitrombina u plazmi pre i u piku opterećenja tokom stres testa. Pacijenti su bili podeljeni u nekoliko grupa shodno tome da li su imali poremećaje kontraktilnosti određenih segmenata miokarda u miru ili u naporu. Svi pacijenti su u vreme dobutamin stres ehokardiografije bili na terapiji klopidogrelom i aspirinom. Rezultati: Nema statistički značajne razlike u agregabilnosti trombocita na ADP (47,50% prema 50,20%; p=0,970) kao ni na EPI (59,30% prema 60,30%; p=0,600) pre i u piku DSE. Statistički značajna razlika je utvrđena u aktivnosti antikoagulantnih proteina, antitrombina (84,85 IU/L prema 74,75 IU/L; p=0,001) i proteina C (77,75 IU/L prema 67,60 IU/L; p<0,001). Značajnost razlike u antitrombinu i proteinu C odnosi se na rezultat pre i u piku testa. Nije utvrđena značajna razlika u agregabilnosti trombocita i aktivnosti antikoagulantnih proteina u plazmi kod pacijenta sa ili bez indukovane ishemije u piku dobutamin stres ehokardiografije. Pacijenti koji su imali povišen wall motion score index (WMSI) u piku dobutamin stres ehokardiografije su imali veću agregabilnost trombocita na EPI (68,60% prema 54,70% p=0,017) nego pacijenti sa normalnom kontraktilnošću miokarda. Zaključak: Nema promena vrednosti u agregabilnosti trombocita pre i posle dobutamin stres ehokardiografije, međutim, dolazi do smanjenja aktivnosti antikoagulantnih proteina u plazmi u piku testa. Agregabilnost trombocita na EPI značajno raste u piku DSE kod pacijenata sa segmentnom hipokontraktilnošću miokarda.Introduction: Platelets aggregability and the activation of hemostasis, during myocardial ischemia within physical or mental stress, can be one of many factors that influence the process of stent thrombosis after percutaneous coronary intervention. Patients and methods: The study population included 121 asymptomatic patients who had successful percutaneous coronary intervention four months before high-dose dobutamine stress echocardiography. Platelets aggregability on epinephrine (EPI) and adenosine diphosphate (ADP) were determined by Light Transmission Aggregometry (LTA), together with plasma activity of protein C and antithrombin before dobutamine stress echocardiography and at the peak stage of the stress test. Patients were divided into several groups whether they have baseline or induced disturbance of segmental myocardial kinetics or not. All patients were on clopidogrel and aspirin therapy at the time of dobutamine stress echocardiography. Results: There were no statistically significant difference in platelets aggregability on ADP (47.50% vs. 50.20%; p=0.970) as well as on EPI (59.30% vs. 60.30%, p=0.600) before and at the peak dobutamine stress echocardiography. A statistically significant difference was found in the anticoagulant activity of the antithrombin (84.85 IU/L vs. 74.75 IU/L, p=0.001) and protein C (77.75 IU/L vs. 67.60 IU/L, p<0.001). Significance of differences in antithrombin and the protein C, refers to the result before and at the peak levels of the test. There was no significant difference in Platelets aggregability and plasma activity of anticoagulant proteins in patients with or without induced myocardial ischemia at the peak of dobutamine stress echocardiography. Patients who had increased wall motion score index (WMSI) at the peak of dobutamine stress echocardiography had higher EPI induced platelets aggregability (68.60% vs. 54.70% p=0.017) than patients with normal myocardial contractility. Conclusion: There are no changes in the platelets aggregability before and after dobutamine stress echocardiography, however, plasma activity of anticoagulant proteins decreased at the peak level of the test. Platelet aggregability on EPI significantly increases at the peak of dobutamine stress echocardiography in patients with segmental myocardium hypocontractility

Hydrothermal synthesis of LiFePO4

Poster presented at the 11th Conference of the Materials Research Society of Serbia - YUCOMAT 2009, Herceg Novi, Montenegro, August 31 – September 4, 2009

Hydrothermal Synthesis of LiFePO4 Powders as Cathode Material for Li-Ion Batteries

Poster presented at the 11th Conference of the Materials Research Society of Serbia - YUCOMAT 2009, Herceg Novi, Montenegro, August 31 – September 4, 2009

Infectivity of Trichinella spiralis larvae in pork buried in the ground

Time of survival and infectivity of Trichinella spiralis larvae in pig muscle tissue, buried at various depths in the ground were assessed. In the pork pieces the number of infective larvae was 250 ML/g. Meat originated from pig halves was divided in 39 equal pieces, 0.7 kg each, disposed in three groups of 13, and buried in depths of 30, 50, and 100 centimeters respectively. The pork was dug up at 13 intervals, approximately every week, until 91(st) day of the experiment. After each time interval, infectivity of larvae was assessed by bioassay on rats. The artificially infected rats were sacrificed on 42(nd) day after the infection and meat was examined by the following methods - artificial digestion and trichinoscopy. It was found that the larvae during all 90 days preserved infectivity in each depth

Influence of bucket wheel vertical vibration on bucket-wheel excavator (BWE) digging force

Ovaj rad daje postupak određivanja sile kopanja rotornog bagera uzimajući u obzir karakteristike kopanog materijala, reznu ivicu lopatice, brzinu rezanja i vertikalne vibracije radnog kotača (rotora). Sila kopanja ovisi o specifičnom otporu kopanju (SOK) i ukupnoj duljini reznih rubova lopatice koje su istovremeno u zahvatu s kopanim materijalom. SOK je uvjetovan karakteristikama kopanog materijala, brzine rezanja i slučajna je veličina, dok ukupna duljina reznih rubova lopatice ovisi o broju lopatica koje su istovremeno u zahvatu s kopanim materijalom i vertikalnim vibracijama radnog kotača. Funkcija promjene ukupne duljine reznih rubova lopatica u ovisnosti od vremena dobivena je na osnovu dinamičkog modela rotornog bagera u vertikalnoj ravni, uzimajući u obzir pomak središta radnog kotača.This paper provides a method of determining the BWE digging force considering the characteristics of soil which needs to be excavated, bucket cutting contour, cutting speed and vertical vibration of the bucket wheel. Digging force depends on the specific force resistance to excavation (SFRE) and the total length of buckets cutting contours that are simultaneously in mesh with the material. The SFRE is conditioned by the characteristics of material, cutting speed and it is random variable, while the total length of buckets cutting contours depends on the number of buckets that are simultaneously in mesh with the soil and vertical oscillations of the bucket wheel. Total length of buckets cutting contours time function is determined considering moving of bucket wheel center point, based on a dynamic model of BWE in the vertical plane

Bezbednosna provera - kontroverze u radu organa bezbednosti (komparativni pravni i bezbednosni pristup)

Autori su u radu sproveli komparativno istraživanje o procesu personalne bezbednosne provere nad građaninom koji se prijavio na konkurs za rad u državnim organima u svetu i Srbiji. Istraživanje je usmereno na definisanje bezbednosne provere i utvrđivanje bezbednosne smetnje u pravnoj i bezbednosnoj teoriji u svetu i u Srbiji - po prvi put. Kroz studije slučaja u pravnoj i bezbednosnoj literaturi u svetu, komparativnom, analizom postojeće literature, pravnom, istorijskom i metodom ankete, istraženo je nekoliko primera kojima se ukazuje na odnose demokratskog i nedemoktaskog društva i država prema primeni prava u bezbednosnoj proveri. Rezultati istraživanja upućuju da bi u Srbiji trebalo da dođe do promena u pravnim aktima i bezbednosnoj metodici procesa vršenja bezbednosne provere, kao i odnosa bezbednosnih organa prema pravima građana koji apliciraju na konkurse gde je bezbednosna provera sastavni deo procesa. Iz navedenog verujemo da rad može da nas uvede u ovaj teorijski izuzetno interesantan i istovremeno za praksu veoma značajan problem

Influence of air pollution on hospital admissions for cardiovascular and respiratory diseases in Niš, Serbia

Background/Aim. In studies that investigate the health effects of short-term air pollution exposure, population-wide changes in acute outcomes such as mortality, hospital admissions and healthcare visits are linked to short-term variations in ambient pollutant concentrations. The aim of this study was to estimate the association between daily outdoor black smoke and sulphur dioxide levels and hospital admissions for cardiovascular and respiratory diseases in Niš, within a period 2001-2005. Methods. A time series analysis was performed using separated regression models for each pollutant and disease group, by age groups and population as a whole. The effects of copollutant, meteorological factors and cyclic oscillations in hospitalization numbers were controlled. Results. A significant increase in hospital admissions was associated with a 10 μg/m3 increase in the concentration of black smoke, for cardiovascular diseases: 3.14% (&lt; 0.01) in children and youth under 19 years of age, 1.85% (&lt; 0.001) in 19-64 age group, and 0.84% (&lt; 0.05) in all ages, and for respiratory diseases: 1.77% (&lt; 0.05) in 19-64 age group, and 0.91% (&lt; 0.05) in all ages. The effects on hospitalizations for respiratory diseases in children and youth under 19 years of age, and for cardiovascular and respiratory diseases in the elderly were not statistically significant. The increase of sulphur dioxide level was associated with the increased number of hospitalizations, for both cardiovascular and respiratory diseases in all age groups, but the influence was not statistically significant. Conclusion. Outdoor pollutants concentrations in urban area of Niš were below regulated limit values during most of the investigated period days but it is shown that even such a level of pollution has a significant effect on hospital admissions for cardiovascular and respiratory diseases

Hydrothermal synthesis of LiFePO4 in presence of different organic additives

In this work we have investigated possibility to obtain pure LiFePO4 powder using different organic additives during hydrothermal synthesis at 180°C. Phase pure phospho olivine was obtained in presence of polyvinylpyrrolidone, while addition of polyvinyl alcohol leads to formation of LiFePO4 with impurities. Impurity phase was successfully avoided by introducing citric acid into reaction vessel. Phase composition was determined by XRPD. Morphology was revealed by particle size analyzer and FESEM

Reconstruction of the mandible with an autogenous corticocancellous bone graft and fibrin glue: An animal experiment

This paper reports on an experimental animal study evaluating a method of mandibular reconstruction in dogs using autogenous corticocaneclous bone graft and fibrin glue. Eight animals underwent a resection at the mandibular body and primary reconstruction was carried out using osteosynthesis plates and screws. The defect was bridged with an autogenous particulate bone graft from the anterior iliac crest. To accelerate bone healing, fibrin glue (FG) was mixed with particulate bone graft. The hypothesis of this study was based on the presumption that bone healing, in segmental reconstruction of the dog mandible with a particulate cancellous bone graft mixed with FG, would be successful. All dogs had eventful healing. The histological results were less favorable with regard to bone remodeling than the results obtained in similar experiments with a particulate corticocancellous bone graft

Laser Diffraction Particle Size Analysis of Non Spherical Particles Synthesized by Hydrothermal Method

Poster presented at the conference JUNIOR EUROMAT, Lausanne, Switzerland, 26–30. jul 2010