E. Rokita

Transport of traffic-related aerosols in urban areas.

This study was undertaken to assess the influence of traffic on particulate air pollution in an urban area, and to characterise the short-range transport of the aerosols generated by traffic. The study was conducted in Kraków, a city located in southern Poland with a population of approximately 800,000. Aerosol samples were collected using automatic sampling equipment at five sites located at different distances from the main road in Kraków, ranging from 5 to 1500 m. The sampling set-up allowed standardisation of the results due to continuous determination of the meteorological parameters (temperature, atmospheric pressure, wind speed and direction, rainfall and humidity). Aerosol particles were separated according to aerodynamic diameter into two size fractions: > 1.9 microm (coarse fraction); and 1.9-72 microm (fine fraction). The concentrations of 27 elements were measured in both size fractions (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Rb, Sr, Zr, Ba, Pb). The multielement analyses were performed by Particle-Induced X-ray Emission (PIXE) spectrometry. Traffic contribution to particulate air pollution was determined on the basis of 13 elements which were present above the detection limit in all samples (Mg, Al, Si, P, S, K, Ca, Ti, Mn, Fe, Cu, Zn, Pb). It was found that the traffic contribution in the coarse size fraction was approximately 80% up to 150 m from the road; it dropped abruptly by a factor of 2 over a distance of 150-200 m and declined further to 20% at 1500 m from the road. Traffic contribution for the fine particle concentrations of individual elements was 50-70% in the close vicinity of the road (5 m); then there was a decrease, followed by an increase at a greater distance from the road. Possible explanations for this behaviour of the fine particles are given.

The influence of target preparation and mode of irradiation on PIXE analysis of biological samples

Abstract The following methods of target preparation were examined and compared: dry ashing at high temperature, low temperature ashing in plasma asher, wet ashing, lyophilization at a temperature of 35°C, cryofixation with drying in vacuum and dehydration in alcohol with drying in vacuum. All these techniques were applied to prepare targets from five different rat organs: liver, kidney, brain, lung and muscle tissue. The dried and powdered sample material was pressed into pellets or was distributed on formvar film. The evaporation of the thin carbon layer on the investigated target and placing of the thin carbon film in front of a target were also tested. The targets were irradiated in vacuum using an external beam in the air chamber. The influence of the method of target preparation on the detection limits, time requirements and escape of elements from the sample material is discussed.

Comparison of trabecular bone architecture in young and old bones

In this study, different parameters currently applied for the description of trabecular bone architecture in young and old subjects are compared. Moreover, new parameters are proposed and assessed. For the investigations, the two-dimensional images of vertebral body sections are acquired with the use of a low-magnification digital camera. The parameters were calculated both for the skeleton and for the bone/marrow interface distinguished in the images of the trabecular network. The following methods of the descriptions of the trabecular bone architecture were considered: histomorphometric analysis (BV/TV, asymmetry, mean trabeculae length), fractal geometry technique, Euler characteristic, star volume of the marrow cavity, the mean distance between two points of the trabecular network, and the probability of disconnection (is straightforwardly connected with the number of separated parts of the network). Moreover, bone mineral density (BMD) was determined for comparative purposes. The quantities directly extracted form the images are also combined to produce new indexes, which better differentiate young and old bones. It was found that the BMD, the BV/TV, the star volume, the Euler number, and the probability of disconnection might be used as indicators of the age-related changes of trabecular bone. The parameters could be measured with the precision comparable to that of the BMD. The only exception is the probability of disconnection. Highly significant correlations were demonstrated between bone density (BMD, BV/TV) and trabecular architecture (SV/GV, probability of disconnection).

Application of thermography for the assessment of allergen-induced skin reactions

PURPOSE The allergic response is commonly identified and assessed by skin testing. The usual method to quantify skin reactions is to mark wheal and erythema regions and assess the surfaces affected by the reactions; however, subjective interpretation of the outcome may cause errors. Skin thermography supplemented by a mathematical model based on the pathophysiology of heat generation was evaluated as a novel, objective, and sensitive indicator of the skin prick test result. METHODS TH measurements were performed simultaneously with routine skin prick tests for 24 patients. Eight allergens and control (histamine) were examined. Thermographic images of both forearms were acquired every 70 s from 0 to 910 s after skin prick and analyzed with the use of dedicated software. The introduction of potential allergens and histamine at sites on the skin induces a complex sequence of events known as the local inflammatory response. The crucial steps of the process have been considered in the model. In the model, the authors assumed that the reaction takes place in the thin skin layer and that histamine is the principal mediator of the allergic reaction. Histamine penetrates the skin and binds to receptors of nearby capillaries and venules. The engorged vessels are, in turn, responsible for skin redness and an increase in skin temperature. RESULTS The model parameters were determined by fitting the analytical solutions to the spatiotemporal distributions of the differences between measured and baseline temperatures. The model reproduces experimental data very well. The coefficient of determination ranged from 0.805 to 0.995. Seven model parameters were tested to find the optimal marker of the intensity and kinetics of the allergic reaction. The parameter which quantifies a release of histamine after allergen injection has appeared to be the best indicator of the allergen-induced response. The parameter correlates with the routine assessment based on wheal and erythema areas (correlation coefficient = 0.98). CONCLUSIONS It was demonstrated that the thermographic measurements supplemented by the mathematical model offer a new approach to the quantification of allergen-induced skin reactions. Despite the applied simplifications, the proposed model reflected properly the mechanism of heat generation during skin prick test. Moreover, the continuous recording of the skin temperature represents an additional possibility to investigate the mechanism of the allergic reaction.

The role of the biomedical physicist in the education of the healthcare professions: An EFOMP project

The role of the biomedical physicist in the education of the healthcare professions has not yet been studied in a systematic manner. This article presents the first results of an EFOMP project aimed at researching and developing this important component of the role of the biomedical physicist. A background to the study expands on the reasons that led to the need for the project. This is followed by an extensive review of the published literature regarding the role. This focuses mainly on the teaching contributions within programmes for physicians, diagnostic radiographers, radiation therapists, and the postgraduate medical specializations of radiology, radiotherapy, interventional radiology and cardiology. Finally a summary list of the specific research objectives that need to be immediately addressed is presented. These are the carrying out of a Europe-wide position audit for the role, the construction of a strategic role development model and the design of a curriculum development model suitable for modern healthcare professional education.

A comprehensive SWOT audit of the role of the biomedical physicist in the education of healthcare professionals in Europe

Although biomedical physicists provide educational services to the healthcare professions in the majority of universities in Europe, their precise role with respect to the education of the healthcare professions has not been studied systematically. To address this issue we are conducting a research project to produce a strategic development model for the role using the well-established SWOT (Strengths, Weaknesses, Opportunities, Threats) methodology. SWOT based strategic planning is a two-step process: one first carries out a SWOT position audit and then uses the identified SWOT themes to construct the strategic development model. This paper reports the results of a SWOT audit for the role of the biomedical physicist in the education of the healthcare professions in Europe. Internal Strengths and Weaknesses of the role were identified through a qualitative survey of biomedical physics departments and biomedical physics curricula delivered to healthcare professionals across Europe. External environmental Opportunities and Threats were identified through a systematic survey of the healthcare, healthcare professional education and higher education literature and categorized under standard PEST (Political, Economic, Social-Psychological, Technological-Scientific) categories. The paper includes an appendix of terminology. Defined terms are marked with an asterisk in the text.

THE INFLUENCE OF METEOROLOGICAL PARAMETERS ON SHORT RANGE TRANSPORT OF AEROSOLS

Abstract The main goal of the present study was to evaluate the influence of meteorological conditions on short range transport of traffic-related aerosols. Samples were collected at five different distances from one of the main transit arteries in Krakow during the day (high traffic intensity) and night (low traffic intensity). The concentrations of 27 elements were determined using PIXE. The results showed that rainfall and wind direction and velocity are the most important factors influencing the elemental concentrations. If these parameters are not taken into account comparison of the data obtained at different locations during various meteorological conditions can lead to biased conclusions. Therefore, a simple standardisation of the results with respect to wind direction and velocity was applied which resulted in the determination of the range of transport of coarse traffic-related particles.

Proton microbeam study of calcium-phosphate complexes in human arteries

Abstract The proton microprobe was used for the determination of the elemental composition of Ca-P deposits in 3 types of human arteries (abdominal aorta, coronary artery, circle of Willis). The techniques used for the elemental analyses were PIXE and RBS. The distribution of concentrations of C, N, O, P, S, Cl, K, Ca, Fe, Cu, Zn, Br, Sr and Pb were measured. The chemical structure of the Ca-P deposits as well as the role of certain elements in the calcification process were considered. A comparison between different investigated arteries was also made.

Bone mineralization after strontium and fluoride treatment in osteoporosis

Abstract The proton microprobe in combination with proton induced X-ray emission (micro-PIXE) and with proton induced gamma-ray emission (micro-PIGE) are used to determine quantitatively the modulation of inorganic deposits formation by Sr and F ions in a cell culture model. The results indicate that the process may be investigated by the micro-PIXE determination of the amount of calcium deposited. It was found that F-treatment stimulate bone formation at doses much lower than Sr. At high doses an impaired mineralization is found for both elements. It was found that the mechanisms responsible for of F and Sr incorporations are different. The minimal F and Sr concentrations in the medium at which the incorporation may be investigated by micro-PIGE and micro-PIXE amount to ∼0.02 mg/l and

Application of Low Energy Proton Beam for Determination of Elemental Composition in Healthy and Pathological Tissues

In the aim of comparison of normal and pathological tissues two groups of samples were analysed. The first group consisted of gastric mucosa samples. Basing on the histological findings the samples were selected with different cancer cells count varying from very high value to the zero level (normal tissue). The second group of samples composed of blood serum, erythocytes, hairs and muscle tissue taken from patients with gall-blader or gastric cancer and those with noncancer gastro-intestinal tract disease. Using PIXE method the concentrations of the following elements were determined: P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr and Pb. The significant differences of the content of various elements in normal and pathological tissue were observed.