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1.
Klin Monbl Augenheilkd ; 232(6): 773-8, 2015 Jun.
Article in German | MEDLINE | ID: mdl-25853946

ABSTRACT

BACKGROUND: An elevated intraocular pressure remains the main risk factor for the development and progression of glaucoma but other factors such as fluctuations of the intraocular pressure, the blood pressure, and the ocular perfusion pressure are gaining in importance. The influence of the anti-glaucomatous therapies on these parameters is barely investigated. This study investigates 1) a correlation between the fluctuations of the intraocular pressure, the blood pressure and the ocular perfusion pressure with the severity of the glaucoma damage and 2) if these parameters can be influenced by different anti-glaucomatous therapies. MATERIAL AND METHODS: Data from 121 glaucoma patients who had been hospitalised for 24-hour measurements of the intraocular pressure and blood pressure between 2003 and 2012 were analysed retrospectively. The patients were divided into groups by the severity of the glaucoma damage and by their anti-glaucomatous therapy. Mean values for the intraocular pressure, the blood pressure and the ocular perfusion pressure were calculated and correlated with the individual groups. The statistical analysis was performed with SPSS21.0 using Kruskal-Wallis and Mann-Whitney U tests for the comparison of the groups. RESULTS with p < 0.05 were considered statistically significant. RESULTS: The severity of the glaucoma damage correlated significantly with higher mean values of the intraocular pressure and its fluctuations, as well as with a nocturnal decrease of the blood pressure and low mean values of the ocular perfusion pressure (p < 0.0001). The anti-glaucomatous therapy decreased the intraocular pressure to normal values. A monotherapy with carboanhydrase inhibitors correlated with the lowest fluctuations of the ocular perfusion pressure while a quadri-therapy was associated with higher values of the intraocular pressure and its fluctuations. The anti-glaucomatous therapy did not show an association with the blood pressure or the ocular perfusion pressure. CONCLUSION: Glaucoma is negatively influenced by high intraocular pressure, nocturnal blood pressure decreases and ocular perfusion pressure fluctuations. A monotherapy with carboanhydrase inhibitors seems to be sufficient to decrease fluctuations of the intraocular pressure. Patients with a quadri-therapy should be monitored regularly as they present high values of intraocular pressure and its fluctuations. A hospitalisation of the patients with 24-hour measurements of the intraocular pressure and blood pressure provides information needed to improve the therapy or decide about surgical interventions.


Subject(s)
Blood Pressure , Circadian Rhythm , Glaucoma/physiopathology , Intraocular Pressure , Aged , Blood Flow Velocity , Female , Humans , Male , Reproducibility of Results , Sensitivity and Specificity
2.
J Environ Radioact ; 126: 1-7, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23917155

ABSTRACT

The verification of the Comprehensive Nuclear-Test Ban Treaty (CTBT) relies amongst other things on the continuous and worldwide monitoring of radioxenon. The characterization of the existing and legitimate background, which is produced mainly by nuclear power plants and isotope production facilities, is of high interest to improve the capabilities of the monitoring network. However, the emissions from legitimate sources can usually only be estimated. For this paper historic source terms of (133)Xe emissions from the isotope production facility at ANSTO, Sydney, Australia, have been made available in a daily resolution. Based on these high resolution data, different source term sets with weekly, monthly and yearly time resolution have been compiled. These different sets are then applied together with atmospheric transport modelling (ATM) to predict the concentration time series at two radioxenon monitoring stations. The results are compared with each other in order to examine the improvement of the prediction capability depending on the used time resolution of the most dominant source term in the region.


Subject(s)
Air Pollutants, Radioactive/analysis , Nuclear Power Plants , Radiation Monitoring , Xenon Radioisotopes/analysis , Models, Theoretical
3.
Rev Sci Instrum ; 82(1): 013303, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21280821

ABSTRACT

An electron-impact ion source based on photoelectron emission was developed for ionization of gases at pressures below 10(-4) mbar in an axial magnetic field in the order of 5 T. The ion source applies only dc fields, which makes it suitable for use in the presence of equipment sensitive to radio-frequency (RF) fields. The ion source was successfully tested under varying conditions regarding pressure, magnetic field, and magnetic-field gradient, and the results were studied with the help of simulations. The processes in the ion source are well understood, and possibilities for further optimization of generated ion currents are clarified.

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