Thickness of the buccal bone wall and root angulation in the maxilla and mandible: an approach to cone beam computed tomography

Background: The objective of this paper is to anatomically describe the bone morphology in the maxillary and mandibular tooth areas, which might help in planning post-extraction implants. Methods: CBCT images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to December 2014. The thickness of the facial wall was measured at the crest, point A, 4mm below, point B, and at the apex, point C. The second parameter was the angle formed between the dental axis and the axis of the basal bone. Results: A total of 403 teeth were measured. In the maxilla, 89.4% of incisors, 93.94% of canines, 78% of premolars and 70.5% of molars had a buccal bone wall thickness less than the ideal 2mm. In the mandible, 73.5% of incisors, 49% of canines, 64% of premolars and 53% of molars had <1mm buccal bone thickness as measured at point B. The mean angulation in the maxilla was 11.67±6.37° for incisors, 16.88±7.93° for canines, 13.93±8.6° for premolars, and 9.89±4.8° for molars. In the mandible, the mean values were 10.63±8.76° for incisors, 10.98±7.36° for canines, 10.54±5.82° for premolars and 16.19±11.22° for molars. Conclusions: The high incidence of a buccal wall thickness of less than 2mm in over 80% of the assessed sites indicates the need for additional regeneration procedures, and several locations may also require custom abutments to solve the angulation problems for screw-retained crowns

Improved wear performance of ultra high molecular weight polyethylene coated with hydrogenated diamond like carbon

Hydrogenated diamond like carbon (DLCH) thin films were deposited on medical grade ultra high molecular weight polyethylene (UHMWPE) by radio frequency plasma enhanced chemical vapor deposition. The DLCH coating thicknesses ranged from 250 to 700. nm. The substrates were disks made of UHMWPEs typically used for soft components in artificial joints, namely virgin GUR 1050 and highly crosslinked (gamma irradiated in air to 100. kGy) UHMWPEs. Mechanical and tribological properties under bovine serum lubrication at body temperature were assessed on coated and uncoated polyethylenes by means of nano-hardness and ball-on-disk tests, respectively. Morphological features of the worn surfaces were obtained by confocal microscopy and scanning electron microscopy. This study confirms an increase in surface hardness and good wear resistance for coated materials after 24. h of sliding test compared to uncoated polyethylene. These results point out that to coat UHMWPE with DLCH films could be a potential method to reduce backside wear in total hip and knee arthroplasties.Ministerio de Ciencia y Educación MAT2006-12603- C02-01, CSD2008-0002

Estructura valorativa de la motivación del alumnado de Formación Profesional hacia sus prácticas curriculares

The study which is part of this work puts its objectives in a double dimension: meet the overall assessment of the motivation of students with regard to practices in the company, and establish those elements that reach a lower rating for each factor identified.Analysis statistical data we employ descriptive and multivariate techniques, specifically the principal component analysis for categorical data (CATPCA), in order to obtain the information of the original variables that configure each dimension and order them according to their estimation.The results show that students are highly motivated, as globally 77.5% of the scores are high, compared with the 9.1% are low. They are the aspects relating to processes directly related to ICTs and equity in the workplace, as well as others related to the performance of the work, reaching the lower valuations, which leads to conclude the need to intervene in these aspects.El estudio en el que se enmarca este trabajo sitúa sus objetivos en una doble dimensión: conocer la valoración global de la motivación del alumnado con respecto a la realización de prácticas en la empresa, y establecer aquellos elementos que alcanzan una menor valoración para cada factor identificado. En el análisis estadístico de los datos empleamos técnicas descriptivas y técnicas multivariantes, concretamente el análisis de componentes principales para datos categóricos (CATPCA), a fin de obtener la información de las variables originales que configuran cada dimensión y ordenarlas según su valoración. Los resultados obtenidos muestran que el alumnado está altamente motivado, ya que globalmente el 77,5% de las puntuaciones son altas, frente al 9,1% que son bajas. Son los aspectos referidos a procesos relacionados directamente con las TIC y los recursos propios del ámbito laboral, así como otros relacionados con el desempeño del trabajo, los que alcanzan las valoraciones más bajas, lo que lleva a concluir la necesidad de intervenir en estos aspectos

Interplay between symmetry and spin-orbit coupling on graphene nanoribbons

We study the electronic structure of chiral and achiral graphene nanoribbons with symmetric edges, including curvature and spin-orbit effects. Curved ribbons show spin-split bands, whereas flat ribbons present spin-degenerate bands. We show that this effect is due to the breaking of spatial inversion symmetry in curved graphene nanoribbons, while flat ribbons with symmetric edges possess an inversion center, regardless of their having chiral or achiral edges. We find an enhanced edge-edge coupling and a substantial gap in narrow chiral nanoribbons, which is not present in zigzag ribbons of similar width. We attribute these size effects to the mixing of the sublattices imposed by the edge geometry, yielding a behavior of chiral ribbons that is distinct from those with pure zigzag edges. © 2013 American Physical Society.This work has been partially supported by the Spanish Ministries of Science and Innovation (MICINN) and Economy and Competitivity (MINECO) DGES under Grants No. MAT2009-14578-C03-03, No. PIB2010BZ-00512, No. FIS2010-21282-C02-02, No. FIS2011-23713, No.MAT2012-38045-C04-04, and No. FIS2012-33521.Peer Reviewe

Overcoming reading comprehension difficulties through a prosodic reading intervention: A single-case study

Apart from speed and accuracy, prosody has recently been included as another component of skilled reading, as its role in reading comprehension is being increasingly recognized. Prosodic reading refers to the use of prosodic features of language during reading, including suitable pauses, stress and intonation and appropriate phrasing. The aim of this research was to examine the impact of a prosodic reading intervention on the reading comprehension of a fourth-grade primary child with specific reading comprehension difficulties. An AB single-case design was used with baseline (A) and treatment (B) phases. The intervention, in 17 sessions, was based on repeated reading with a focus on expressiveness. Results pointed to improved reading fluency and reading comprehension scores over baseline scores. Nevertheless, more studies are needed to show conclusive evidence for improved comprehension as a result of prosody intervention. The implications of prosodic reading interventions for literacy development are discussed

A survey-based assessment of seagrass status, management and legislation in Europe

Seagrass meadows are ranked amongst the most productive ecosystems on Earth, providing high-value ecosystem services in coastal areas. Yet, seagrass habitats are declining worldwide at an unprecedented rate as a consequence of both anthropogenic and natural pressures, which suggests an inefficient management. Seagrasses are widespread along European coasts and the knowledge on their conservation status and management has been increased in the last decade although an overall view for the whole Europe is lacking. The general aim of this survey-based study was to assess the present status of seagrass habitat conservation, management and legislation in Europe based on the expert judgement of 25 participants from 19 coastal European countries. We specifically assessed the seagrass ecological status and their major threats; the level of awareness; the effort in mapping, monitoring and restoration; and the state of management plans and policy in each country. We furthermore reviewed the legislation for seagrass habitats in order to assess the protection status of seagrasses in Europe. The survey-based assessment revealed great differences among seagrass species and countries regarding their awareness, ecological status, mapping, monitoring and management. Several good examples of seagrass management, in cooperation with scientists, were identified although many countries still lack the fundamental tools for a proper management. A consistent body of legislation was compiled for most European countries, yet their implementation was reported to be rather variable and weak. The results of this study will provide guidelines for a more effective seagrass management and policy in Europe.info:eu-repo/semantics/publishedVersio

Application of Chelating Agents to Enhance Fenton Process in Soil Remediation: A Review

Persistent organic contaminants affecting soil and groundwater pose a significant threat to ecosystems and human health. Fenton oxidation is an efficient treatment for removing these pollutants in the aqueous phase at acidic pH. However, the in-situ application of this technology for soil remediation (where pHs around neutrality are required) presents important limitations, such as catalyst (iron) availability and oxidant (H2O2) stability. The addition of chelating agents (CAs), forming complexes with Fe and enabling Fenton reactions under these conditions, so-called chelate-modified Fenton process (MF), tries to overcome the challenges identified in conventional Fenton. Despite the growing interest in this technology, there is not yet a critical review compiling the information needed for its real application. The advantages and drawbacks of MF must be clarified, and the recent achievements should be shared with the scientific community. This review provides a general overview of the application of CAs to enhance the Fenton process for the remediation of soils polluted with the most common organic contaminants, especially for a deep understanding of the activation mechanisms and influential factors. The existing shortcomings and research needs have been highlighted. Finally, future research perspectives on the use of CAs in MF and recommendations have been provided.Depto. de Ingeniería Química y de MaterialesFac. de Ciencias QuímicasTRUEComunidad de MadridMinisterio de Cienciapu

Vis LED Photo-Fenton Degradation of 124-Trichlorobenzene at a Neutral pH Using Ferrioxalate as Catalyst

Chlorinated organic compounds (COCs) are among the more toxic organic compounds frequently found in soil and groundwater. Among these, toxic and low-degradable chlorobenzenes are commonly found in the environment. In this work, an innovative process using hydrogen peroxide as the oxidant, ferrioxalate as the catalyst and a visible light-emitting diode lamp (Vis LED) were applied to successfully oxidize 124-trichlorobenzene (124-TCB) in a saturated aqueous solution of 124-TCB (28 mg L−1) at a neutral pH. The influence of a hydrogen peroxide (HP) concentration (61.5–612 mg L−1), Fe3+ (Fe) dosage (3–10 mg L−1), and irradiation level (Rad) (I = 0.12 W cm−2 and I = 0.18 W cm−2) on 124-TCB conversion and dechlorination was studied. A D–Optimal experimental design combined with response surface methodology (RSM) was implemented to maximize the quality of the information obtained. The ANOVA test was used to assess the significance of the model and its coefficients. The maximum pollutant conversion at 180 min (98.50%98.50%) was obtained with Fe = 7 mg L−1, HP = 305 mg L−1, and I = 0.12 W cm−2. The effect of two inorganic anions usually presents in real groundwater (bicarbonate and chloride, 600 mg L−1 each) was investigated under those optimized operating conditions. A slight reduction in the 124-TCB conversion after 180 min of reaction was noticed in the presence of bicarbonate (8.31%) and chloride (7.85%). Toxicity was studied with Microtox® (Azur Environmental, Carlsbad, CA, USA) bioassay, and a remarkable toxicity decrease was found in the treated samples, with the inhibition proportional to the remaining 124-TCB concentration. That means that nontoxic byproducts are produced in agreement with the high dechlorination degrees noticed.Depto. de Ingeniería Química y de MaterialesFac. de Ciencias QuímicasTRUEUnión EuropeaComunidad de MadridMinisterio de Ciencia, Innovaciónpu

Is the plant Bolboschoenus maritimus an adequate biomonitor for trace metal contamination in saltmarshes? A field study from the Óbidos lagoon (Portugal)

Monitoring the negative impacts of trace metals is crucial to assess the health and stability of ecosystems. In salt marshes, halophyte plants were reported as possible bioaccumulators of these elements. The aim of this work was to explore the bioaccumulation potential of Bolboschoenus maritimus as a tool for monitoring the presence of metals in coastal environments. Bolboschoenus maritimus were collected from a brackish water lagoon, and the presence of the trace metals lead, cadmium, and nickel were seasonally evaluated in distinct parts of the plants, and in water and sediment samples. Lead was the trace metal with the highest concentration detected in water and sediments of the sampling site. The highest lead concentrations in B. maritimus were recorded in the spring season. The transport index indicated an accumulation of lead in the leaves of around 70% in the spring of 2009. Cadmium in leaves in spring and summer of 2009 reached values above 5 mg Cd. kg−1. Nickel was not detected in most samples collected. Bolboschoenus maritimus was considered an adequate biomonitor for lead and cadmium, since it bioaccumulates both metals with seasonally distinct results, as the bioaccumulation factor results indicated.info:eu-repo/semantics/publishedVersio