118 research outputs found
Modelo de elementos finitos de la columna lumbar
En este trabajo se describe un modelo de Elementos Finitos de la columna lumbar
humana. El objetivo buscado es la utilización del mismo como herramienta de investigación
aplicada a la cirugÃa ortopédica de columna lumbar. Para conseguir este objetivo se ha
elaborado un modelo no lineal y paramétrico de la columna lumbar completa, el cual puede
modificarse con facilidad tanto en su geometrÃa como en sus caracterÃsticas mecánicas de
modo que puedan reflejarse tanto distintas alteraciones segmentarias como diversas técnicas
de fijación. También se expone la contrastación del modelo, realizada a partir de resultados
experimentales recogidos de la literatura sobre el tema.Peer Reviewe
Vulnerability assessment of buildings due to land subsidence using InSAR data in the ancient historical city of Pistoia (Italy)
A synthetic peptide from transforming growth factor beta type III receptor inhibits liver fibrogenesis in rats with carbon tetrachloride liver injury
Transforming growth factor beta1 (TGF-beta1) is a pleiotropic cytokine, which displays potent profibrogenic effects and is highly expressed in fibrotic livers. For this reason, development of TGF-B1 inhibitors might be of great importance to control liver fibrogenesis as well as other undesired side effects due to this cytokine. Potential peptide inhibitors of TGF-beta1 (derived from TGF-beta1 and from its type III receptor) were tested in vitro and in vivo using different assays. Peptides P11 and P12, derived from TGF-beta1, and P54 and P144, derived from its type III receptor, prevented TGF-beta1-dependent inhibition of MV1Lu proliferation in vitro and markedly reduced binding of TGF-beta1 to its receptors. P144 blocked TGF-beta1-dependent stimulation of a reporter gene under the control of human alpha2(I) collagen promoter. Intraperitoneal administration of P144 also showed potent antifibrogenic activity in vivo in the liver of rats receiving CCl4. These rats also showed a significant decrease in the number of activated hepatic stellate cells as compared with those treated with saline only. These results suggest that short synthetic peptides derived from TGF-beta1 type III receptor may be of value in reducing liver fibrosis in chronic liver injury
International phase II trial of dose escalation to dominant intraprostatic lesion (DIL) with real-time high dose rate (HDR) brachytherapy
European Space Agency experiments on thermodiffusion of fluid mixtures in space
Abstract.: This paper describes the European Space Agency (ESA) experiments devoted to study thermodiffusion of fluid mixtures in microgravity environment, where sedimentation and convection do not affect the mass flow induced by the Soret effect. First, the experiments performed on binary mixtures in the IVIDIL and GRADFLEX experiments are described. Then, further experiments on ternary mixtures and complex fluids performed in DCMIX and planned to be performed in the context of the NEUF-DIX project are presented. Finally, multi-component mixtures studied in the SCCO project are detailed
The RNA Polymerase PB2 Subunit of Influenza A/HongKong/156/1997 (H5N1) Restrict the Replication of Reassortant Ribonucleoprotein Complexes
BACKGROUND: Genetic reassortment plays a critical role in the generation of pandemic strains of influenza virus. The influenza virus RNA polymerase, composed of PB1, PB2 and PA subunits, has been suggested to influence the efficiency of genetic reassortment. However, the role of the RNA polymerase in the genetic reassortment is not well understood. METHODOLOGY/PRINCIPAL FINDINGS: Here, we reconstituted reassortant ribonucleoprotein (RNP) complexes, and demonstrated that the PB2 subunit of A/HongKong/156/1997 (H5N1) [HK PB2] dramatically reduced the synthesis of mRNA, cRNA and vRNA when introduced into the polymerase of other influenza strains of H1N1 or H3N2. The HK PB2 had no significant effect on the assembly of the polymerase trimeric complex, or on promoter binding activity or replication initiation activity in vitro. However, the HK PB2 was found to remarkably impair the accumulation of RNP. This impaired accumulation and activity of RNP was fully restored when four amino acids at position 108, 508, 524 and 627 of the HK PB2 were mutated. CONCLUSIONS/SIGNIFICANCE: Overall, we suggest that the PB2 subunit of influenza polymerase might play an important role for the replication of reassortant ribonucleoprotein complexes
Finite Element Analysis of Bone and Experimental Validation
This chapter describes the application of the finite element (FE) method to bone tissues. The aspects that differ the most between bone and other materials’ FE analysis are the type of elements used, constitutive models, and experimental validation. These aspects are looked at from a historical evolution stand point.
Several types of elements can be used to simulate similar bone structures and within the same analysis many types of elements may be needed to realistically simulate an anatomical part.
Special attention is made to constitutive models, including the use of density-elasticity relationships made possible through CT-scanned images. Other more complex models are also described that include viscoelasticity and anisotropy.
The importance of experimental validation is discussed, describing several methods used by different authors in this challenging field. The use of cadaveric human bones is not always possible or desirable and other options are described, as the use of animal or artificial bones. Strain and strain rate measuring methods are also discussed, such as rosette strain gauges and optical devices.publishe
Rubber Clay Nanocomposites
The use of nanofillers allows the development of nanocomposites with improved properties and novel applications. The technological goal is possible due to the new compounding method that allows a particle dispersion in the nanometer scale increasing the specific surface area.Fil: Cova Sánchez, Mariajose. Instituto Nacional de TecnologÃa Industrial. Instituto Nacional de TecnologÃa Industrial - Caucho; Argentina. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; ArgentinaFil: Bacigalupe, Alejandro. Universidad Nacional de San MartÃn. Instituto de Investigación e IngenierÃa Ambiental. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e IngenierÃa Ambiental; Argentina. Instituto Nacional de TecnologÃa Industrial. Instituto Nacional de TecnologÃa Industrial - Caucho; ArgentinaFil: Escobar, Mariano Martin. Instituto Nacional de TecnologÃa Industrial. Instituto Nacional de TecnologÃa Industrial - Caucho; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Mansilla, Marcela Angela. Instituto Nacional de TecnologÃa Industrial. Instituto Nacional de TecnologÃa Industrial - Caucho; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
- …