886 resultados para Concept glosses
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PURPOSE External beam radiation therapy is currently considered the most common treatment modality for intraocular tumors. Localization of the tumor and efficient compensation of tumor misalignment with respect to the radiation beam are crucial. According to the state of the art procedure, localization of the target volume is indirectly performed by the invasive surgical implantation of radiopaque clips or is limited to positioning the head using stereoscopic radiographies. This work represents a proof-of-concept for direct and noninvasive tumor referencing based on anterior eye topography acquired using optical coherence tomography (OCT). METHODS A prototype of a head-mounted device has been developed for automatic monitoring of tumor position and orientation in the isocentric reference frame for LINAC based treatment of intraocular tumors. Noninvasive tumor referencing is performed with six degrees of freedom based on anterior eye topography acquired using OCT and registration of a statistical eye model. The proposed prototype was tested based on enucleated pig eyes and registration accuracy was measured by comparison of the resulting transformation with tilt and torsion angles manually induced using a custom-made test bench. RESULTS Validation based on 12 enucleated pig eyes revealed an overall average registration error of 0.26 ± 0.08° in 87 ± 0.7 ms for tilting and 0.52 ± 0.03° in 94 ± 1.4 ms for torsion. Furthermore, dependency of sampling density on mean registration error was quantitatively assessed. CONCLUSIONS The tumor referencing method presented in combination with the statistical eye model introduced in the past has the potential to enable noninvasive treatment and may improve quality, efficacy, and flexibility of external beam radiotherapy of intraocular tumors.
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Aims: To evaluate the implications of an Absorb bioresorbable vascular scaffold (Absorb BVS) on the morphology of the superficial plaques. Methods and results: Forty-six patients who underwent Absorb BVS implantation and 20 patients implanted with bare metal stents (BMS) who had serial optical coherence tomographic examination at baseline and follow-up were included in this analysis. The thin-capped fibroatheromas (TCFA) were identified in the device implantation regions and in the adjacent native coronary segments. Within all regions, circumferential locations of TCFA and calcific tissues were identified, and the neointimal thickness was measured at follow-up. At six to 12-month follow-up, only 8% of the TCFA detected at baseline were still present in the Absorb BVS and 27% in the BMS implantation segment (p=0.231). Sixty percent of the TCFA in native segments did not change their phenotype at follow-up. At short-term follow-up, significant reduction in the lumen area of the BMS was noted, which was higher compared to that reported in the Absorb BVS group (-2.11±1.97 mm2 vs. -1.34±0.99 mm2, p=0.026). In Absorb BVS, neointima tissue continued to develop at midterm follow-up (2.17±0.48 mm2 vs. 1.38±0.52 mm2, p<0.0001) and covered the underlying tissues without compromising the luminal dimensions (5.93±1.49 mm2 vs. 6.14±1.49 mm2, p=0.571) as it was accommodated by the expanded scaffold (8.28±1.74 mm2 vs. 7.67±1.28 mm2, p<0.0001). Conclusions: Neointimal tissue develops following either Absorb BVS or BMS implantation and shields lipid tissues. The neointimal response in the BMS causes a higher reduction of luminal dimensions compared to the Absorb BVS. Thus, Absorb BVS may have a value in the invasive re-capping of high-risk plaques.
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Objectives: One important issue in sport and exercise psychology is to determine to what extent sports and exercise can help to increase self-esteem, and what the underlying mechanism might be. Based on the exercise and self-esteem model (EXSEM) and on findings from the sociometer theory, the mediating effect of physical self-concept and perceived social acceptance on the longitudinal relationship between motor ability and self-esteem was investigated. Design: Longitudinal study with three waves of data collection at intervals of ten weeks each. Method: 428 adolescents (46.3 % girls, mean age = 11.9, SD = .55) participated in the study, in which they performed three motor ability tests and completed paper-and-pencil questionnaires for physical self-concept and perceived social acceptance, as well as for self-esteem, at all three measuring points. Results: Using structural equation modelling procedures, the multiple mediation model revealed both physical self-concept and perceived social acceptance to be mediators between motor ability and self-esteem in the case of boys. In girls, on the other hand, the mediation between motor ability and self-esteem only takes place via physical self-concept. Conclusions: Gender differences in the relationship between motor ability and self-esteem suggest gender-specific interventions aimed at promoting self-concept.
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par Arsène Darmesteter
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Drugs may stimulate the immune system by forming stable new antigenic complexes consisting of the drug or drug metabolite which is covalently bound to a protein or peptide (hapten-carrier complex). Both, B- and T-cell immunity may arise, the latter directed to hapten modified peptides presented by HLA molecules. Beside this immunological stimulation, drugs can also stimulate the immune system through binding by non-covalent bonds to proteins like immune receptors. This so-called “pharmacological interaction with immune receptors” concept (“p-i concept”) may occur with HLA or TCR molecules themselves (p-i HLA or p-i TCR), and not the immunogenic peptide. It is a type of “off-target” activity of the drug on immune receptors, but more complex as various cell types, cell interactions and functionally different T cells are involved. In this review the conditions which lead to activation of T cells by p-i are discussed: important factors for a functional consequence of drug binding is the location of binding (p-i HLA or p-i TCR); the exact site within these immune receptors; the affinity of binding and the finding that p-i HLA can stimulate the immune system like an allo-allele. The p-i concept is able to solve some puzzles of drug hypersensitivity reactions and are a basis to better treat and potentially avoid drug hypersensitivity reactions. Moreover, the p-i concept shows that in contrast to previous beliefs small molecules do interact with immune receptors with functional consequence. But these interactions are not based on “immune recognition”, are at odds with some immunological concepts, but may nevertheless open new possibilities to understand and even treat immune reactions
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BACKGROUND Traumatic knee dislocation represents a rare but devastating injury. Several controversies persist regarding type of treatment, surgical timing, graft selection, repair versus reconstruction of the medial and lateral structures, surgical techniques and postoperative rehabilitation. A new technique for primary ACL stabilization, dynamic intaligamentary stabilization (DIS) was developed at the authors' institution. The purpose of this study was to analyze the clinical and radiological outcomes of surgically treated traumatic knee dislocations by means of the DIS technique for the ACL, primary suturing for PCL, MCL and LCL. METHODS Between 2009 and 2012, 35 patients treated surgically for traumatic knee dislocation with primary anterior cruciate ligament (ACL) reconstruction with DIS, suturing of the posterior cruciate ligament (PCL) and primary complete repair of collaterals, were evaluated clinically (IKDC score, SF12 health survey, Lysholm score, Tegner score) and radiologically with a mean follow up of 2.2 years (range 1.00-3.50 years) years. Instrumented anterior-posterior translation was measured (KT-2000). RESULTS Anterior/posterior translation (KT-2000) for the healthy and injured limb was 4.8mm (range 3-8mm) and 7.3mm (range 5-10) (89N) respectively. Valgus and varus stress testing in 30° flexion was normal in 26 (75%) and 29 (83%) patients, respectively. The IKDC score was B in 29 (83%) and C in 6 (17%) patients, while the mean Tegner score was 6 (range 4-8). The mean Lysholm score was 90.83 (range 81-95) and mean SF-12 physical and mental scores were 54.1 (range 45-60) and 51.0 (range 39-62) respectively. In 2 patients, a secondary operation was performed. CONCLUSIONS Early, one stage reconstruction with DIS can achieve good functional results and patient satisfaction with overall restoration of sports and working capacity without graft requirements.
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The present dissertation focuses on trust and comprises three empirical essays on the concept itself and its foundations. All three essays investigate trust as an expectation and rely on selfreport measures of trust. Whereas the first two chapters investigate social trust, the third chapter investigates political trust. Essentially, there are three related important debates to which the following chapters contribute. A first debate discusses problems with current selfreport measures. Scholars recently started to question whether standard trust questions really measure the same across countries and languages. Chapter 1 engages in this debate. Using data from Switzerland it studies whether different trust questions measure the same latent trust constructs across individuals belonging to three different culturallinguistic regions. The second debate concerns the socalled forms or dimensions of trust. Recently, scholars started investigating whether trust is a onedimensional construct, i.e. whether an individual's trust judgment differs for categories of trustees such as strangers, neighbors, family members and friends or not. Relying on confirmatory factor analysis Chapter 2 investigates whether individuals really do make a difference between different trustee categories and to what extent these judgments can be summarized into higherorder latent trust constructs. The third debate is concerned with causes of differences in trust across humans. Chapter 3 focuses on the role of laterlife experiences, more precisely victimization experiences and investigates their causal relationship with generalized social trust. Chapter 4 focuses on the impact of direct democratic institutions on the trust relationship between citizens and political authorities.
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Over the last 20 years, health literacy (German: Gesundheitskompetenz/health competency) has become a popular concept in research and health policy. Initially defined as an individual's ability to understand medical information, the definition has quickly expanded to describe individual-based resources for actions or conduct relevant to health, in different socio-cultural or clinical contexts. Today, researchers and practice experts can draw on a wide variety of definitions and measurements. This article provides an overview of the definitions, briefly introduces the "structure and agency" approach as an example of theorizing health literacy, and shows different types of operationalization. The article presents the strengths and shortcomings of the available concepts and measures and provides starting points for future research in public health and health promotion.
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Concept de travail du projet de développement de l'écotourisme dans la région de Mananara-Nord et du Triangle Bleu, Littoral Nord-Est, Madagascar: objectifs de l'étude, résultats attendus, approche choisie, étapes du travail.
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Rapport sur l'étude préliminaire du projet de développement de l'écotourisme dans la région de Mananara-Nord et du triangle bleu.