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Search Results: 1 - 10 of 297973 matches for " Jürg Niederbacher "
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Correlation between the Childhood-Asthma Control Test and the Criterion for Clinical Asthma Control  [PDF]
Carlos José Ortiz-Lizcano, Jürg Niederbacher-Velásquez, Luis Alfonso Díaz-Martínez
Health (Health) , 2016, DOI: 10.4236/health.2016.87065
Abstract: Setting: Three pediatric pneumatologist offices in Bucaramanga, Colombia. Objective: To establish the concordance between medical criteria and the Childhood-Asthma Control Test (cACT). Design: Study of the assessment of diagnostic technology using transverse sampling. 127 asthma patients aged between 4 and 11 years and their parents filled before clinical evaluation made by a pediatric pneumologist. Patients were classified as controlled or not controlled. Criteria validity was established comparing this classification using Cohen’s kappa and performance indicators according to ROC analysis. Results: 78% of the patients were controlled; patients who are not controlled have a higher score in cACT (mean difference: 3.25 points). Concordance among cACT subscales is acceptable (ρ = 0.554). cACT’s sensitivity was 53.6%, specificity 78.8%, positive likelihood ratio (LR+) 2.53, and negative likelihood ratio (LR-) 0.59. The best cut-off point is 15, with 98% sensitivity, a specificity of 14.3%, LR+ in 1.14, and LR- in 0.14. Conclusions: cACT is a valid tool to determine asthma control in children without replacing medical criteria or other clinical tests. In populations with difficult access to high complexity services, it is useful to decide whether urgent referral to the specialist is necessary.
Contaminación biológica intradomiciliaria y su relación con síntomas respiratorios indicativos de asma bronquial en preescolares de Bucaramanga, Colombia
Herrera,Astrid B; Rodríguez,Laura A; Niederbacher,Jürg;
Biomédica , 2011,
Abstract: introduction. indoorair pollution may play an important role in development and exacerbation of asthma in children. objective. the association between the presence of indoor biological contaminants and respiratory symptoms related to asthma was assessed in preschool children. materials and methods. this cross-sectional study was undertaken in bucaramanga, colombia, and included children <7 years of age living in two urban areas of with different levels of outdoor air pollution. the 678 children were an average of 3.5 years of age. respiratory symptoms indicative of asthma and indoor air pollutants were assessed by previously validated questionnaires.. biological samples potentially containing mites and fungi were collected by standardized laboratory methods. the log binomial regression model was used for multivariate analysis, using adjusted prevalence ratios (pr). results. the prevalence of asthmatic respiratory symptoms was 8.0%; (95% c.i: 5.6-9.6), without significant differences between the two areas. binomial model analysis showed that asthma symptoms were associated with mites (pr 1.78; 95% c.i. 1.0-3.0), acremonium sp (pr 6.24; 95 c.i.: 3.8-10.0) and a history of child pneumonia (pr 4.0; 95% c.i. 2.5-6.4), allergic rhinitis (pr 1.9; 95% c.i.: 1.2-3.1), prematurity (pr 3.4; 95% c.i. 1.8-6.5), parents with asthma (pr 2.6; 95% c.i. 1.4-5.0) and pet ownership (pr 0.4; 95% c.i. 0.2-0.9). conclusions. the indoor exposure to biological contaminants (dust mites and fungi), history of prematurity, pneumonia, rhinitis and family history of asthma increased the occurence of symptoms suggestive of asthma in young children.
Biological pollution and its relationship with respiratory symptoms indicative of asthma, Bucaramanga, Colombia Contaminación biológica intradomiciliaria y su relación con síntomas respiratorios indicativos de asma bronquial en preescolares de Bucaramanga, Colombia
Astrid Berena Herrera,Laura A. Rodríguez,Jürg Niederbacher
Biomédica , 2011,
Abstract: Introduction. Indoor air pollution may play an important role in development and exacerbation of asthma in children. Objective. The association between the presence of indoor biological contaminants and respiratory symptoms related to asthma was assessed in preschool children. Materials and methods. This cross-sectional study was undertaken in Bucaramanga, Colombia, and included children <7 years of age living in two urban areas of with different levels of outdoor air pollution. The 678 children were an average of 3.5 years of age. Respiratory symptoms indicative of asthma and indoor air pollutants were assessed by previously validated questionnaires.. Biological samples potentially containing mites and fungi were collected by standardized laboratory methods. The log binomial regression model was used for multivariate analysis, using adjusted prevalence ratios (PR). Results. The prevalence of asthmatic respiratory symptoms was 8.0%; (95% C.I: 5.6-9.6), without significant differences between the two areas. Binomial model analysis showed that asthma symptoms were associated with mites (PR 1.78; 95% C.I. 1.0-3.0), Acremonium sp (PR 6.24; 95 C.I.: 3.8-10.0) and a history of child pneumonia (PR 4.0; 95% C.I. 2.5-6.4), allergic rhinitis (PR 1.9; 95% C.I.: 1.2-3.1), prematurity (PR 3.4; 95% C.I. 1.8-6.5), parents with asthma (PR 2.6; 95% C.I. 1.4-5.0) and pet ownership (PR 0.4; 95% C.I. 0.2-0.9). Conclusions. The indoor exposure to biological contaminants (dust mites and fungi), history of prematurity, pneumonia, rhinitis and family history of asthma increased the occurence of symptoms suggestive of asthma in young children. Introducción. La contaminación en el hogar puede desempe ar un papel importante en el desarrollo y exacerbación del asma infantil, sobre todo entre ni os genéticamente predispuestos. Objetivos. Evaluar la asociación entre la presencia de contaminantes biológicos intradomiciliarios y síntomas indicativos de asma, en preescolares de Bucaramanga, Colombia Materiales y métodos. Se hizo un estudio de corte transversal analítico, en menores de 7 a os, en dos zonas de la ciudad con niveles diferentes de contaminación atmosférica por material particulado. Se evaluaron los síntomas respiratorios indicativos de asma y los contaminantes intradomiciliarios mediante cuestionarios previamente validados, las mediciones biológicas de ácaros y hongos por métodos de laboratorio estandarizados, y se usó el modelo log binomial para el análisis multivariado, que permitió evaluar asociaciones mediante la estimación de las razones de prevalencia. Resultados. Par
Incidencia y factores asociados al síndrome sibilante del lactante, área Metropolitana de Bucaramanga, Colombia Incidence and associated factors to wheezing in infants, Bucaramanga Metropolitan Area, Colombia
Sandra Janneth Moreno,Jürg Niederbacher,José Fidel Latorre,Diana Carolina Archila
Revista de la Universidad Industrial de Santander. Salud , 2011,
Abstract: Introducción: Los cuadros broncoobstructivos en lactantes son causa frecuente de consulta a servicios ambulatorios, acudir a urgencias u hospitalización. Se presentan en forma recurrente o recidivante, con secuelas a largo plazo. Objetivo: Establecer la incidencia y los factores asociados para desarrollar síndrome sibilante (SS) y su recurrencia durante los dos primeros a os de vida. Metodología: Estudio retrospectivo de cohorte. Se indagó sobre presencia de sibilancias, edad de la primera crisis, eventos en los primeros dos a os de vida, y aspectos reconocidos previamente como factores de riesgo. Se estimó tasa de incidencia y probabilidad de estar libre de SS a los dos a os, así como los factores asociados con la presencia de SS recurrente y no recurrente. Resultados: Se estudiaron 139 varones y 159 ni as residentes en el área Metropolitana de Bucaramanga, Colombia. La tasa de incidencia a dos a os es de 1,22 episodios/100 meses-persona (IC95% 0,97-1,47), con probabilidad de llegar al segundo cumplea os sin SS es 67,0% (IC95% 60,7 a 72,4%). Los factores asociados con SS no recurrente fueron historia familiar de rinitis (RR 2,56) o asma (RR 2,11), y convivir con fumadores (RR 2,00); SS recurrente fueron historia familiar de rinitis (RR 8,79) o asma (RR 3,43), consumo de alimentos alergénicos (RR 6,82), asfixia perinatal (RR 6,36), asistir al jardín infantil (RR 3,37) y convivir con menores de 10 a os (RR 1,63). Discusión: La incidencia de SS es similar a la encontrada en países desarrollados. Muchos factores asociados son prevenibles, que de intervenirse ayudaría a disminuir el riesgo de que los lactantes enfermen o que recurran. Salud UIS 2011; 43 (2): 131-140 Introduction: Bronchoobstructive disease in infants is frequent cause of assistance to primary and emergency services, and hospitalization, too. These are recurrent or non-recurrent, with long-term sequelae. Objective: To establish the incidence and associated factors for developing wheezing syndrome (WS) and its recurrence during the first two years of life. Methodology: A retrospective cohort. A survey was conducted to determine wheezing incidence, age at first crisis, event number in the first two years of life, and aspects previously recognized as risk factors. It was estimated incidence rate and likelihood of being free of WS at two years, as well as the associated factors with recurrent and non-recurrent WS. Results: We studied 139 boys and 159 girls dwelling in the Bucaramanga Metropolitan Area, Colombia. The incidence rate for two years is 1.22 events/100 person-months (95%CI 0,97-1,47),
Incidencia y factores asociados al síndrome sibilante del lactante, área Metropolitana de Bucaramanga, Colombia
Moreno,Sandra Janneth; Niederbacher,Jürg; Latorre,José Fidel; Archila,Diana Carolina; Ballesteros,Leonela Nataly; Cuadros,Carlos Augusto; Díaz,Luis Alfonso;
Revista de la Universidad Industrial de Santander. Salud , 2011,
Abstract: introduction: bronchoobstructive disease in infants is frequent cause of assistance to primary and emergency services, and hospitalization, too. these are recurrent or non-recurrent, with long-term sequelae. objective: to establish the incidence and associated factors for developing wheezing syndrome (ws) and its recurrence during the first two years of life. methodology: a retrospective cohort. a survey was conducted to determine wheezing incidence, age at first crisis, event number in the first two years of life, and aspects previously recognized as risk factors. it was estimated incidence rate and likelihood of being free of ws at two years, as well as the associated factors with recurrent and non-recurrent ws. results: we studied 139 boys and 159 girls dwelling in the bucaramanga metropolitan area, colombia. the incidence rate for two years is 1.22 events/100 person-months (95%ci 0,97-1,47), with a potential to reach the second birthday without ws of 67.0% (95%ci 60.7 to 72.4%). associated factors with non-recurrent ws were family history of recurrent rhinitis (rr 2.56) or asthma (rr 2.11), and live with smokers (rr 2.00); for recurrent ws were a family history of rhinitis (rr 8.79 ) or asthma (rr 3.43), consumption of allergenic food (rr 6.82), perinatal asphyxia (rr 6.36), to attend kindergarten (rr 3.37), and to be living with children under 10 years (rr 1,63). discussion: the incidence of ws is similar to others found in developed countries. many risk factors are preventable, and their intervention would help to reduce the risk to suffer ws. salud uis 2011; 43 (2): 131-140
Demand and Supply of Water for Agriculture: Influence of Topography and Climate in Pre-Alpine, Mesoscale Catchments  [PDF]
Jürg Fuhrer, Karsten Jasper
Natural Resources (NR) , 2012, DOI: 10.4236/nr.2012.33019
Abstract: With climate change, water may become limited for intensive agriculture even in regions presently considered “water-rich”. Information about the potential water requirement and its temporal and spatial variability can help to develop future water management plans. A case study was carried out for Switzerland with its highly complex pre-alpine topography and steep gradients in climate. The hydrological model WaSiM-ETH was used to simulate net irrigation requirement (NIR) for cropland, grassland and orchards using criteria to define irrigation periods based either on the water stress level (expressed by the ratio of actual (aET) to potential evapotranspiration ((pET) (Method 1) or on thresholds for soil water potential (Method 2). Simulations for selected catchments were carried out with a daily time step for the period 1981-2010 using a 500 × 500 m spatial resolution. Catchment-scale NIR ranged between 0 and 4.3 million m3 and 0 and 7.3 million m3 for the two methods, respectively, with no trend over the observation period in any catchment. During the heat wave in 2003, NIR increased by a factor of 1.5 to 2.3 relative to the mean, and in catchments where discharge is directly dependent on precipitation, NIR in the summer of 2003 reached the limits of river water availability. In contrast, in a region with water supply from glacier melt water, highest NIR in 2003 still remained far below total river discharge. The results show that NIR varies strongly between years and across the landscape, and even in a presently cool-temperate climate, irrigation may put pressure on regional water resources under extreme climatic conditions that may become more frequent by the end of the 21st century.
Energy-Minimizing Curve Fitting for High-Order Surface Mesh Generation  [PDF]
Karsten Bock, Jrg Stiller
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.521309
Abstract: We investigate different techniques for fitting Bézier curves to surfaces in context of high-order curvilinear mesh generation. Starting from distance-based least-squares fitting we develop an incremental algorithm, which incorporates approximations of stretch and bending energy. In the process, the algorithm reduces the energy weight in favor of accuracy, leading to an optimized set of sampling points. This energy-minimizing fitting strategy is applied to analytically defined as well as triangulated surfaces. The results confirm that the proposed method straightens and shortens the curves efficiently. Moreover the method preserves the accuracy and convergence behavior of distance-based fitting. Preliminary application to surface mesh generation shows a remarkable improvement of patch quality in high curvature regions.
LDA Study of Particulate Flow in a Channel with Deformed Surface Locations and with Flow Conditioner  [PDF]
Mehdi Azimian, Hans-Jrg Bart
Open Journal of Fluid Dynamics (OJFD) , 2015, DOI: 10.4236/ojfd.2015.54035
Abstract: Hydroabrasion in particulate flows plays an important role in various industrial and natural processes. To predict the effects of particulate flow and the resulting phenomena such as erosion/abrasion in a pipeline, channel or a fitting, it is essential to characterize the effects in a simple standardized geometry. For this purpose, it is vital to initially understand the particulate flow behavior and motion in such geometries. In the present work, two series of experimental works by application of the LDA measurement technique were successfully conducted. First, the particulate flow behavior at downstream of a flow conditioner inside a channel with square cross-section was investigated. Shorter lengths for fully development of velocity profile by using the self-constructed flow conditioner were observed. Moreover, the flow at downstream of the conditioner was modeled with the CFD tool (ANSYS-CFX V. 14.57) and the simulation results were compared and validated by the LDA experimental data. Better agreement between the simulation results and experimental data was observed in the fully developed region. However, there are some deviations due to the actual pressure loss through the experimental loop and the calculated pressure loss value, which includes some assumptions for the loss coefficients. Furthermore, the particulate flow behavior and vortex generation inside the deformed locations of a channel surface were studied in detail. With the help of the Matlab program, it was possible to calculate and visualize the velocity vectors for each measured point inside the channel accurately.
Numerical Investigation of Particle Rebound Characteristics with Finite Element Method  [PDF]
Mehdi Azimian, Hans-Jrg Bart
Open Journal of Fluid Dynamics (OJFD) , 2017, DOI: 10.4236/ojfd.2017.73020
Abstract: In this work, investigation of particle rebound characteristics due to impact with surface of a target material is presented. The rebound of a spherical particle after impact on a planar surface was analyzed in detail. Specifically, the coefficient of restitution of the particle under various impact conditions was investigated numerically. This study has been conducted by carrying out a series of FEM-based (finite element method) simulations using ANSYS Autodyn software. First, a summary about the state of the art and the theoretical models for the elastic collisions were reviewed. Afterwards, the impact of an aluminum oxide particle on an aluminum alloy target surface was modeled. Using the Autodyn tool, the results were compared and validated by the experimental results of Gorham and Kharaz [1]. Selection of an appropriate equation of state (EOS) and a strength model for each material had a strong effect on the results. For both materials, the Shock EOS was applied for the final simulations. As the strength model, the Johnson-Cook and the elastic model were used, respectively. The agreement of the obtained numerical results with the experimental data confirmed that the proposed model can precisely predict the real behavior of the particle after the impact, when the material models are properly chosen. Furthermore, the effects of impact velocity and impact angle on the rebound characteristics of the particle were analyzed in detail. It was found that the selection of the exact value of friction coefficient has a drastic effect on the prediction of restitution coefficient values, especially the tangential restitution coefficient.
T Cell Homeostasis and Repertoire Contraction in Rheumatoid Arthritis
Jrg J Goronzy
Arthritis Research & Therapy , 1999, DOI: 10.1186/ar19
Abstract:
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