Superficial characteristics of titanium after treatment of chorreated surface, passive acid, and decontamination with argon plasma

Background. Titanium is characterized by its biocompatibility, resistance to maximum stress, and fatigue and non-toxicity. The composition, surface structure, and roughness of titanium have a key and direct influence on the osseointegration processes when it is used in the form of dental implants. The objective of the present study is to characterize, at chemical, superficial, and biological levels, the result of the application of the sandblasted with large-grit and acid-etched (SLA) treatment consisting of coarse-grained and double-passivated acid blasting with subsequent decontamination with argon plasma on the surface of titanium implants type IV. (2) Methods. Four Oxtein® dental implants (Zaragoza, Spain) were investigated with the following coding: Code L63713T (titanium grade IV, 3.75 mm in diameter, and 13 mm in length). The surface of the implants was SLA type obtained from coarse-grained, double passivated acid, and decontaminated with argon plasma. The samples were in their sealed packages and were opened in our laboratory. The X-ray photoelectron spectroscopy (XPS) technique was used to characterize the chemical composition of the surface, and the scanning electronic microscope (SEM) technique was used to perform topographic surface evaluation. Cell cultures were also performed on both surfaces. (3) Results. The superficial chemical analysis of the studied samples presented the following components, approximately, expressed in atomic percentage: O: 39%; Ti: 18%; C: 39%; N: 2%; and Si: 1%. In the same way, the topographic analysis values were obtained in the evaluated roughness parameters: Ra: 1.5 μm ± 0.02%; Rq: 1.31 μm ± 0.33; Rz: 8.98 μm ± 0.73; Rp: 5.12 μm ± 0.48; Rv: 3.76 μm ± 0.51; and Rc: 4.92 μm ± 0.24. At a biological level, the expression of osteocalcin was higher (p < 0.05) on the micro-rough surface compared to that machined at 48 and 96 h of culture. (4) Conclusions. The data obtained in our study indicate that the total carbon content, the relative concentration of titanium, and the roughness of the treatment performed on the implants are in agreement with those found in the literature. Further, the roughness of the treatment performed on the implants throws a spongy, three-dimensional surface suitable for bone growth on it. The biological results found are compatible with the clinical use of the surface tested

Superficial characteristics of titanium after treatment of chorreated surface, passive acid, and decontamination with argon plasma

Background. Titanium is characterized by its biocompatibility, resistance to maximum stress, and fatigue and non-toxicity. The composition, surface structure, and roughness of titanium have a key and direct influence on the osseointegration processes when it is used in the form of dental implants. The objective of the present study is to characterize, at chemical, superficial, and biological levels, the result of the application of the sandblasted with large-grit and acid-etched (SLA) treatment consisting of coarse-grained and double-passivated acid blasting with subsequent decontamination with argon plasma on the surface of titanium implants type IV. (2) Methods. Four Oxtein® dental implants (Zaragoza, Spain) were investigated with the following coding: Code L63713T (titanium grade IV, 3.75 mm in diameter, and 13 mm in length). The surface of the implants was SLA type obtained from coarse-grained, double passivated acid, and decontaminated with argon plasma. The samples were in their sealed packages and were opened in our laboratory. The X-ray photoelectron spectroscopy (XPS) technique was used to characterize the chemical composition of the surface, and the scanning electronic microscope (SEM) technique was used to perform topographic surface evaluation. Cell cultures were also performed on both surfaces. (3) Results. The superficial chemical analysis of the studied samples presented the following components, approximately, expressed in atomic percentage: O: 39%; Ti: 18%; C: 39%; N: 2%; and Si: 1%. In the same way, the topographic analysis values were obtained in the evaluated roughness parameters: Ra: 1.5 μm ± 0.02%; Rq: 1.31 μm ± 0.33; Rz: 8.98 μm ± 0.73; Rp: 5.12 μm ± 0.48; Rv: 3.76 μm ± 0.51; and Rc: 4.92 μm ± 0.24. At a biological level, the expression of osteocalcin was higher (p < 0.05) on the micro-rough surface compared to that machined at 48 and 96 h of culture. (4) Conclusions. The data obtained in our study indicate that the total carbon content, the relative concentration of titanium, and the roughness of the treatment performed on the implants are in agreement with those found in the literature. Further, the roughness of the treatment performed on the implants throws a spongy, three-dimensional surface suitable for bone growth on it. The biological results found are compatible with the clinical use of the surface tested

Cine-teatro-cine: los vasos comunicantes en Edgar Neville

Edgar Neville desempeñó un importante papel en el cine y el teatro de su tiempo. Como dramaturgo escribió numerosas comedias de éxito, algunas tan famosas como La vida en un hilo y El baile. Tales títulos fueron también guiones de dos de sus mejores películas. Este artículo trata de examinar las relaciones entre cine y teatro a través de los dos ejemplos citados, que son auténticos experimentos de "vasos comunicantes" entre el teatro y el cine de Edgar Neville

Spanish society's perceptions about socially responsible investing

The debate surrounding the financial needs of investors and the impact on society of investment is considered to be an important research topic due to the growth of socially responsible financial markets. The objective of this research is to study the perception of the Spanish public about socially responsible investing (SRI) criteria and real-life investment needs. To examine the Spanish perception of SRI, we conducted a field survey. The results show that SRI is in an early stage and Spanish investors need more exact information regarding social, environmental, and governance criteria in order to invest in socially responsible companies and products

Changes in the influence of board characterisitcs on corporate results due to the recent global financial crisis

The main purpose of this study is to analyse the changes caused by the global financial crisis on the influence of board characteristics on corporate results, in terms of corporate performance, corporate risk-taking, and earnings management. Sample comprises S&P 500 listed firms during 2002-2008. This study reveals that the environmental conditions call for different behaviour from directors to fulfil their responsibilities and suggests changes in normative and voluntary guidelines for improving good practices in the boardroom

Estudio de sistemas monoaminérgicos en el oído interno

Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, leída el 30-20-1998En esta Memoria de Tesis Doctoral se han analizado los efectos de la estimulación acústica, la ganglionectomía cervical superior y la perfusión por vía aórtica de una disolución anticoagulante sobre las concentraciones cocleares de dopamina, noradrenalina, serotonina y sus metabolitos. Estos compuestos se han cuantificado mediante HPLC en cócleas de ratas expuestas a las situaciones experimentales anteriores. Asimismo se han cuantificado las concentraciones basales de estos compuestos en el vestíbulo de la rata. La estimulación acústica modificó el metabolismo de la dopamina y la noradrenalina cocleares y no afectó el de la serotonina, lo cual sugiere la liberación sináptica de dopamina y serotonina debido al ruido. El pretratamiento con un agonista dopaminérgico disminuyó las modificaciones inducidas por el ruido en el metabolismo de la dopamina, sugiriendo el bloqueo de su liberación sináptica. En esta Memoria se concluye además que la dopamina coclear procede fundamentalmente del sistema eferente olivococlear, la noradrenalina del ganglio cervical superior y la serotonina de la sangre, aunque una proporción importante de serotonina tiene otro origen, probablemente neural. En el vestíbulo se ha descrito por primera vez la presencia de dopamina y serotonina y se ha cuantificado además la concentración de noradrenalinaDepto. de Bioquímica y Biología MolecularFac. de Ciencias QuímicasTRUEpu

La interjección

Si la interjección no puede recibir un tratamiento gramatical (morfológico, sintáctico y semántico) similar al sustantivo, adjetivo, verbo o incluso preposición, ¿cuál debe ser la línea de investigación más adecuada para su análisis? Tal vez nuestro acercamiento en este trabajo habría de plantearse a priori la resolución de esta pregunta clave. Este es, en principio, nuestro objetivo, pero no como respuesta inicial, sino como conclusión a la que nos proponemos llegar después de haber realizado diversas reflexiones y consideraciones. Tal vez, con ella, se podría aportar nuevas perspectivas de análisis de tan controvertido fenómeno