Value of pre-operative embolization in surgery for nasopharyngeal angiofibroma

The value of embolization in surgery for nasopharyngeal angiofibroma is a controversial matter. We analysed retrospectively the results of surgical treatment in ten patients with a nasopharyngeal angiofibroma, the last five of whom underwent pre-operative embolization with Gelfoam. Embolization reduced the intraoperative blood loss at primary surgery from an average of 1510 ml in the non-embolized patients to 510 ml in the embolized patients and transfusions from an average of 4.4 units to none. Seven reoperations were performed on four non-embolized patients on account of tumour recurrence, while no recurrences were diagnosed among the pre-operatively embolized patients. Blood loss in the reoperations averaged 4065 ml, and transfusions 7.1 units. The results indicate that embolization is effective in reducing intraoperative blood loss and contributes to improved surgical results. We recommend it as a routine pre-operative adjunct to surgery for nasopharyngeal angiofibroma.     

Etiology of childhood pneumonia: serologic results of a prospective, population-based study

BACKGROUND: To investigate the etiology of pediatric community-acquired pneumonia, we conducted a prospective, population-based study covering the total population <15 years of age (n = 8851) in 4 municipalities in eastern Finland. MATERIALS AND METHODS: The number of patients was 201; chest radiographs were available for all cases and paired sera for serologic assays were available for >90% of cases. The methods included assays for antibody response to 3 pneumococcal antigens, specific pneumococcal immune complex assays and conventional antibody tests for mycoplasmal, chlamydial and viral infections. RESULTS: Serologic evidence of specific microbial etiology was obtained in 133 (66%) of the pneumonia patients. Bacterial infection was diagnosed in 102 cases (51%) and viral infection in 51 cases (25%). Streptococcus pneumoniae was the most common agent (57 cases; 28%), followed by Mycoplasma pneumoniae (44; 22%), respiratory syncytial virus (43; 21%) and Chlamydia spp. (29; 14%). Haemophilus influenzae was identified in only 6% and Moraxella catarrhalis in only 3% of the children. More than one specific infection was found in 51 patients (25%). The proportion of pneumococcal cases varied from 24 to 36% by age. Mycoplasma infections were seen mostly in patients > or =5 years and Chlamydia infections in patients > or =10 years of age. CONCLUSIONS: The results of our prospective, strictly population-based study confirm the importance of S. pneumoniae in the etiology of community-acquired pneumonia in children of all ages. M. pneumoniae and Chlamydia pneumoniae are important from the age of 5 years onwards.     

Value of measurement information: A simple case study on grade change decisions

Measurement systems produce information to support decision making. The added value of measurements is determined by how much the provided information improves decision making as uncertainty about decision consequences is reduced. We discuss through an example the value generation by measurement information in the context statistical decision theory (SDT). This example, a grade change decision, outlines the principle for determining added value in decision making. We discuss separately two value generation mechanisms: the direct value generation by reduced uncertainty on consequences and the indirect value generation through accumulating knowledge about the consequence model parameters. The first mechanism is solvable in analytic form and this allows comparing formulations of SDT in the analysis. We outline the analysis of the indirect value generation and show that even with this simple decision task the analysis is rather complex. We propose that the added-value analysis is the key to optimal design of measurement information systems.     

Characterisation of bioactive glass coatings on titanium substrates produced using a CO2 laser

Titanium and its alloys are widely used in load-bearing bioinert implants. Bioactive glasses (BAGs) form a chemical bond with bone, but they are not suitable for load-bearing applications. Creating a BAG coating on a titanium implant could combine the best properties of both materials. The results tend to be poor when conventional firing methods are applied to coat titanium with BAG. A local application of heat to melt the glass can be achieved by a CO2 laser. A new method is introduced to create BAG coatings on titanium locally in a controlled manner, with a focused CO2 laser beam. The coatings produced by this method precipitate calcium phosphate in vitro. Processing parameters (number of coated layers, laser power, and processing atmosphere) providing a firm attachment of the glass and good in vitro bioactivity were identified. XRD analysis showed no crystallisation of the glass due to processing with the laser. EDXA indicated the formation of a calcium phosphate layer, which FTIR suggested to be a hydroxyapatite. The results show CO2 laser processing to be a promising technique for the manufacture of 30-40 microm BAG coatings on titanium.     

A language-independent prettyprinter

A general-purpose prettyprinting program is presented. The input to the prettyprinter is a linear stream composed of visible symbols and elementary formatting instructions. The user can specify a set of alternative formats and the precedence of the alternatives. The prettyprinter attempts to select automatically the ‘best’ layout that fits on the bounded horizontal space available on the output medium. The prettyprinter is implemented as a library module, which makes it more flexible than many traditional prettyprinters that are written as main programs. For instance, formatted expressions can be mixed with plain text or displayed interactively on the user's terminal, and the application program can use several prettyprinters simultaneously.     

Area-Based Matching for Simultaneous Registration of Multiple 3-D Profile Maps

We propose an area-based method for the simultaneous registration of multiple 3-D data sets without known correspondences when a rough initial registration is known. The method is applicable to data sets which can be represented as single valued parametric surfaces. We introduce such a representation called a 3-D profile map for the data acquired by light striping. During registration, the relative orientations of the profile maps measured from different viewpoints are iteratively refined by matching the parametric surfaces in the overlapping areas in the sense that the mean of the squares of weighted distances between the surfaces is minimized. Incompatible matches are rejected by an adaptive weighting function and the minimization task is solved simultaneously for all the maps. Hierarchical techniques are utilized in order to better localize a global minimum and to speed up the processing. The computational operations are formulated using the notation of an image algebra and realized in a parallel manner thus reducing further the computation time. Test results are shown with real data.     

Sharing engineering design knowledge and delivering proven practices in engineering organizations

This paper presents an approach for improving the sharing of engineering design knowledge and proven practices in engineering organizations. The scope of engineering in this paper is automation engineering in relation to investment projects in process industries. The role of engineering design knowledge is connected to the overall engineering design process and a practical distributed information system architecture is presented, where the heterogeneous nature of the stored information is taken into account. An information system built for improving the accumulation and sharing of engineering design knowledge is presented as an example.     

Emotional Dimensions of User Experience: A User Psychological Analysis

User psychology is a human–technology interaction research approach that uses psychological concepts, theories, and findings to structure problems of human–technology interaction. As the notion of user experience has become central in human–technology interaction research and in product development, it is necessary to investigate the user psychology of user experience. This analysis of emotional human–technology interaction is based on the psychological theory of basic emotions. Three studies, two laboratory experiments, and one field study are used to investigate the basic emotions and the emotional mind involved in user experience. The first and second experiments study the measurement of subjective emotional experiences during novel human–technology interaction scenarios in a laboratory setting. The third study explores these aspects in a real-world environment. As a result of these experiments, a bipolar competence–frustration model is proposed, which can be used to understand the emotional aspects of user experience.