Publications by authors named "Hambach R"

Background: Recent lead (Pb) exposure reduction strategies enabled to lower children's blood lead levels (B-Pb) worldwide. This study reports the estimated intelligence gain and social cost savings attributable to recent exposure reduction based on reported B-Pb levels observed in adolescents sampled within the framework of the Flemish Environment and Health Studies (FLEHS, Belgium), i.e.

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Decomposition of a general arbitrary field into a set of Gaussian beams has been one of the challenges in the Gaussian beam decomposition method for field propagation through optical systems. The most commonly used method in this regard is the Gabor expansion, which decomposes initial fields into shifted and rotated Gaussian beams in a plane. Since the Gaussian beams used have zero initial curvatures, the Gabor expansion method does not utilize the ability of the Gaussian beams to represent the quadratic behavior of the local wavefront.

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The increasing use of freeform optical surfaces raises the demand for optical design tools developed for generalized systems. In the design process, surface-by-surface aberration contributions are of special interest. The expansion of the wave aberration function into field- and pupil-dependent coefficients is an analytical method used for that purpose.

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Electron scattering is always applied as one of the routines to investigate nanostructures. Nowadays the development of hardware offers more and more prospect for this technique. For example imaging nanostructures with inelastic scattered electrons may allow to produce component-sensitive images with atomic resolution.

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The optical design and analysis of modern micro-optical elements with high index contrasts and large numerical apertures is still challenging, as fast and accurate wave-optical simulations beyond the thin-element-approximation are required. We introduce a modified formulation of the wave-propagation-method and assess its performance in comparison to different beam-propagation-methods with respect to accuracy, required sampling densities, and computational performance. For typical micro-optical components, the wave-propagation-method is found to be considerably faster and more accurate at even lower sampling densities compared to the different beam-propagation-methods.

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Transmission electron microscopy has been a promising candidate for mapping atomic orbitals for a long time. Here, we explore its capabilities by a first-principles approach. For the example of defected graphene, exhibiting either an isolated vacancy or a substitutional nitrogen atom, we show that three different kinds of images are to be expected, depending on the orbital character.

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Background: Hepatitis E virus (HEV) infection is endemic in many developing countries, causing substantial morbidity. Transmission is primarily faeco-oral and is associated with both sporadic infections and epidemics in areas where poor sanitation and weak public health infrastructures exist. Recently, it has become clear that HEV is also an endemic disease in industrialized countries.

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Student healthcare workers represent a particular risk group for hepatitis B virus (HBV) transmission and should be vaccinated as early as possible after the start of their career. An overview of specific HBV policies in European Union countries was conducted through a cross-sectional survey. Answers were received from 17 countries.

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Healthcare personnel (HCP) are at risk from occupational exposure to airborne and bloodborne pathogens, and the risk of infection among HCP is greater than among the general population. The aim of the study was to characterize attitudes toward occupational recommended vaccines as well as the perception of risks of occupationally acquired infections. We surveyed 650 medical students to assess their perception of influenza and hepatitis B and their opinions and beliefs about influenza and hepatitis B vaccines.

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We present model-based image simulations for zero-loss and plasmon-loss filtered images at 20 kV for graphene and silicon based on the mutual coherence approach. In addition, a new approximation for the mixed dynamic form factor is introduced. In our calculation multiple elastic scattering and one inelastic scattering are taken into account.

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Purpose: Research on the effect of co-exposure to Cd and Pb on the kidney is scarce. The objective of the present study was to assess the effect of co-exposure to these metals on biomarkers of early renal effect.

Methods: Cd in blood (Cd-B), Cd in urine (Cd-U), Pb in blood (Pb-B) and urinary renal biomarkers, i.

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Objectives: Recent studies suggest adverse health effects after low exposure to cadmium (Cd). Brazing with Cd-containing solder exposes workers to Cd. The purpose of this study was to assess: (1) indicators of Cd exposure in blood (Cd-B)/ urine (Cd-U); (2) the association between Cd-B, Cd-U and renal and oxidative stress biomarkers.

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Background: Industrial composting is a relatively new and expanding activity. Several studies indicate that compost workers are at risk to develop health symptoms. The aim of this study was to assess the prevalence of work-related health symptoms among compost workers compared with control subjects.

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The aim of this research project was to learn more about work-related health risks among dental assistants in Flanders, Belgium. Forty-seven dental assistants completed an extensive questionnaire concerning ionized radiation, protection against infection and exposure to chemicals such as mercury, disinfectants and acrylates. Collective and personal means of protection, musculoskeletal disorders and work-related stress were also evaluated.

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Workers' perceptions with respect to health and safety at work are rarely taken into account when considering the development of prevention programs. The aim of this study was to explore workers' perceptions of chemical risks at the workplace, in order to investigate the prerequisites for a workplace health program. A qualitative study was conducted involving seven focus groups of 5-10 participants (blue-collar workers) each.

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The electron energy-loss function of graphite is studied for momentum transfers q beyond the first Brillouin zone. We find that near Bragg reflections the spectra can change drastically for very small variations in q. The effect is investigated by means of first principle calculations in the random phase approximation and confirmed by inelastic x-ray scattering measurements of the dynamic structure factor S(q, omega).

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We have measured a strictly linear pi plasmon dispersion along the axis of individualized single-wall carbon nanotubes, which is completely different from plasmon dispersions of graphite or bundled single-wall carbon nanotubes. Comparative ab initio studies on graphene-based systems allow us to reproduce the different dispersions. This suggests that individualized nanotubes provide viable experimental access to collective electronic excitations of graphene, and it validates the use of graphene to understand electronic excitations of carbon nanotubes.

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