1,810 research outputs found
Drug Distribution and Stent Retention of Drug Eluting Stents
In this paper the examinations of drug eluting coronary stents are shown, such as the morphology of the coatings before expansion, drug distribution, the methodology and the value of stent retention. Surface qualities of drug coatings were examined with stereo-microscope, metallographic microscope and scanning electron microscope. Examinations with confocal microscope show drug distribution in the coatings. Stent retention is a very important property of the stent system. Stent retention is a force, needed to the stent slip down from the balloon. Three drug eluting coronary stents were tested with our method
Mechanical Properties of Coronary Veins
There are several publications available and experiments were done regarding to the vessel biomechanical properties. In the range we could find in vitro and in vivo assessments data for elasticity properties. Even though we have many results in this topic we still don’t have enough data for special veins. Three coronary veins were investigated from pig’s heart. The aim of these experiments was to define and measure the longitudinal tensile stress and tensile strength of coronary veins. The tensile tests were done successfully and the tensile stress was defined in the range of 1.66-2.57 MPa
Az empátia, tolerancia és segítőkészség vizsgálatára kidolgozott eljárás első alkalmazásának tapasztalatai
A sajátos nevelési igényű gyermekek integrált nevelése az 1993-as Közoktatási törvény óta a speciális oktatás választható alternatívája hazánkban. Maga a „sajátos nevelési igény” fogalma a korábban használatos „fogyatékos” terminust váltotta fel mind a szaknyelvben, mind a jogszabályok szóhasználatában. Ez azonban korántsem csak játék a szavakkal
Simulated extraction of stent stabilized coronary sinus leads
Cardiac resynchronization therapy (CRT) is an effective nonpharmacological therapeutic method for the treatment of selected patients with chronic heart failure with a wide QRS complex and mechanical dyssynchrony of cardiac ventricles. A new technique is used to stabilize the implanted coronary sinus lead in an appropriate position with an expanded coronary stent to maintain synchronous pacing of the left ventricle. The extraction of the previously stented lead might be indicated for any medical or technical reason. Neither the capability to stabilize the lead, nor the lead removal procedure and the necessary physical activity of extraction have been evaluated yet. The aim of our study is to simulate the extraction of a stent stabilized coronary sinus lead in in-vitro experiments. We evaluated the additional stabilization capability of the technique, as well as the extraction force needed to pull out the CS lead using stabilizing stents with different diameters and lengths
Calculation of Presumed Bearing Capacity of Shallow Foundations According to the Principles of Eurocode 7
Various simplified design procedures can be found in the literature, intended for the design of shallow foundations of lower importance buildings and pre-dimensioning. In most cases, these design procedures are based on vaguely defined soil types and parameters, and are not compatible with Eurocode. The aim of this paper is to establish a „design procedure by prescriptive measures”, according to the guidelines of Eurocode 7. Within this framework, previous design procedures are reviewed and a new procedure is developed for the simplified calculation of the bearing capacity of shallow foundations, conforming to the principles and rules of Eurocode 7
A statistical model for estimating mean maximum urban heat island
Investigations concentrated on the urban heat island (UHI) in its strongest development during the diurnal cycle.
Task includes development of statistical models in the heating and non-heating seasons using urban surface
parameters (built-up and water surface ratios, sky view factor, building height) and their areal extensions. Model
equations were determined by means of stepwise multiple linear regression analysis. As the results show, there is
a clear connection between the spatial distribution of the UHI and the examined parameters, so these parameters
play an important role in the evolution of the UHI intensity field. Among them the sky view factor and the building
height are the most determining factors, which are in line with the urban surface energy balance
Processing Stabilisation of PE with a Natural Antioxidant, Curcumin
The potential use of natural antioxidants for polyolefin stabilisation came into the centre of attention because of some doubts about the effects of the reaction products of synthetic phenolic antioxidants on human health. The effect of curcumin on the melt stability of polyethylene was investigated in this paper with and without a phosphonite stabiliser by using multiple extrusions. Irganox 1010 was applied as reference phenolic antioxidant. Curcumin was characterised by FT-IR and UV-VIS spectroscopy, as well as by thermal analysis. Its stabilisation efficiency was determined by measuring the chemical structure, the rheological properties, the residual thermo-oxidative stability, and the colour of the polymer. The results reveal that the melt stabilising efficiency of curcumin is superior to that of the synthetic antioxidant investigated and is further enhanced by the addition of the phosphonite secondary antioxidant. The changes in the characteristics of the polymer indicate that besides the phenolic OH groups also the linear linkage between the two methoxyphenyl rings of curcumin participates in the stabilisation reactions
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