Search results for "modeling"
showing 10 items of 4489 documents
The Influence of PRP on Early Bone Formation in Membrane Protected Defects. A Histological and Histomorphometric Study in the Rabbit Calvaria
2011
Background: Platelet rich plasma (PRP) has been proposed to be a useful adjunct to bone grafting. Purpose: The aim of the present study was to assess new bone formation in bone regeneration procedures using platelet rich plasma (PRP) alone or in combination with autogenous bone. Materials and Methods: Four surgically created, monocortical defects 5 mm in diameter in the calvariae of 15 New Zealand rabbits were grafted with a coagulum-filled control, PRP, particulated autogenous bone alone (A), or combined with PRP (A-PRP). Results: Mean platelet concentration of 1,761,930 ± 680,200/µl was achieved (5.30 ± 2.63 × fold of baseline). Animals were sacrificed 1, 2, and 4 weeks later. Histomorpho…
Fibro-osseous lesion of maxilla. Report of two cases in a family with review of literature
2011
Fibrous dysplasia is a disturbance of bone metabolism that is classified as a benign fibro-osseous lesion. Fibrous connective tissue containing abnormal bone, replaces normal bone. The etiology of fibrous dysplasia is unknown. The radiographic appearance of the irregularly shaped trabeculae aids in the differential diagnosis. Occurring most commonly in the second decade of life, the lesions of fibrous dysplasia can be surgically recontoured for esthetic or functional purposes once they become dormant.
Bisphosphonate-related osteonecrosis. Application of adipose-derived stem cells in an experimental murine model
2019
Background Bisphosphonate-related osteonecrosis of the jaw is a pathological condition without effective established treatment and preventive strategies. The aim of this study was to analyse the effect of adipose-derived stem cells (ASC) in an experimental murine model of osteonecrosis. Material and Methods 38 Wistar rats were injected intraperitoneally with zoledronic acid. After treatment, upper jaw molars were extracted. The animals were randomly assigned to one of two groups. In the control group, saline solution was applied over the alveolar sockets after the tooth extractions. In the treatment group, ASCs were applied instead of saline solution. The control and treatment groups were s…
Acquired IFNγ resistance impairs anti-tumor immunity and gives rise to T-cell-resistant melanoma lesions
2016
Melanoma treatment has been revolutionized by antibody-based immunotherapies. IFNγ secretion by CD8+ T cells is critical for therapy efficacy having anti-proliferative and pro-apoptotic effects on tumour cells. Our study demonstrates a genetic evolution of IFNγ resistance in different melanoma patient models. Chromosomal alterations and subsequent inactivating mutations in genes of the IFNγ signalling cascade, most often JAK1 or JAK2, protect melanoma cells from anti-tumour IFNγ activity. JAK1/2 mutants further evolve into T-cell-resistant HLA class I-negative lesions with genes involved in antigen presentation silenced and no longer inducible by IFNγ. Allelic JAK1/2 losses predisposing to …
Patient-specific simulation of the intrastromal ring segment implantation in corneas with keratoconus
2015
Purpose The purpose of this study was the simulation of the implantation of intrastromal corneal-ring segments for patients with keratoconus. The aim of the study was the prediction of the corneal curvature recovery after this intervention. Methods Seven patients with keratoconus diagnosed and treated by implantation of intrastromal corneal-ring segments were enrolled in the study. The 3D geometry of the cornea of each patient was obtained from its specific topography and a hyperelastic model was assumed to characterize its mechanical behavior. To simulate the intervention, the intrastromal corneal-ring segments were modeled and placed at the same location at which they were placed in the s…
Paysage & [et] infrastructures de transport : modélisation des impacts des infrastructures sur les réseaux écologiques
2013
The development of linear infrastructures leads to the fragmentation and the artificialisation of the landscape across scales. Landscape fragmentation is a spatial process that is accompanied by a progressive decrease of the connectivity between the elements needed to conduct ecological processes. Thus, maintaining a good level of connectivity between natural habitats, compatible with human activities, has become a major issue for the preservation of biodiversity.By mobilizing methods from graph theory and landscape ecology, the thesis seeks to demonstrate the value of landscape graphs to model ecological networks and analyze impacts of transportation infrastructures at regional scale.The m…
Victimization at school: relationship of parenting and functional-dysfunctional developmental variables
2015
El presente estudio tiene como principal objetivo analizar elpapel diferencial de la crianza (apoyo y comunicación versus control), devariables funcionales del desarrollo (empatía y mecanismos de afrontamientofuncionales) y las variables disfuncionales (inestabilidad emocional yafrontamiento improductivo) en la victimización ocurrida en el entorno escolar,o por el contrario, con el apego entre pares. Participaron en el estudio418 alumnos, 224 chicas y 194 chicos adolescentes, entre 13 y 14 años,escolarizados en los niveles de 3º y 4º curso de Educación SecundariaObligatoria. Para analizar estas relaciones se llevó a cabo un modelo deecuaciones estructurales EQS. Los resultados obtenidos mue…
Adaptation and Psychometric Properties of the Scale of Positive and Negative Experience (SPANE) in the General Colombian Population
2021
(1) Background: Diener’s Scale of Positive and Negative Experiences (SPANE) assesses the presence and intensity of positive and negative affects, since these are considered basic aspects of the study of well-being. This article studies its psychometric properties in the general Colombian population. (2) We conducted a cross-sectional study of a sample of 1255 Colombians and we used structural equation modeling to confirm the bifactor structure. Additionally, we studied invariance by gender, and convergent and concurrent validity. (3) We found acceptable fit indicators for the bifactor model (CFI = 0.889, RMSEA = 0.046, SRMR = 0.059) as well as for the convergent (CFI = 0.909, RMSEA = 0.050,…
Assessment of University Students’ Critical Thinking: Next Generation Performance Assessment
2019
Following employers’ criticisms and recent societal developments, policymakers and educators have called for students to develop a range of generic skills such as critical thinking (“twenty-first c...
Performance status and depressive symptoms as predictors of quality of life in cancer patients. A structural equation modeling analysis
2015
Objective: This study aimed to examine whether depressive symptoms and performance status are independent predictors of both the physical and psychological domains of health-related quality of life (HRQoL) in cancer patients. Methods: A sample of 4020 cancer patients (mean age 58 years, 51% women) was evaluated. Depressive symptoms were measured with the patient health questionnaire and HRQoL with the European Organisation for Research and Treatment of Cancer quality of life questionnaire core 30. The impact of the illness on everyday activities was assessed with physician ratings of both the Karnofsky performance status and the Eastern Cooperative Oncology Group performance status. The sim…