Biphasic calcium phosphates (BCP) of hydroxyapatite (HA) and tricalcium phosphate (TCP) as bone substitutes: Importance of physicochemical characterizations in biomaterials studies

AbstractThe data presented in this article are related to the research article entitled “Biphasic calcium phosphates bioceramics (HA/TCP): Concept, physicochemical properties and the impact of standardization of study protocols in biomaterials research” [1]. This article provides in depth study of BCP bone substitutes as valuable option in the field of tissue engineering. However, there are discrepancies in the literature regarding the ideal physicochemical properties of BCP and the ideal balance between different phase compositions for enhanced bone tissue engineering (M. Ebrahimi, M.G. Botelho, S.V. Dorozhkin, 2016; M. Ebrahimi, P. Pripatnanont, S. Suttapreyasri, N. Monmaturapoj, 2014) [1,2]. This is found to be mainly because of improper characterization of BCP bioceramics in basic studies and lack of standard study protocols in in vitro and in vivo research. This data article along with original article provide the basic data required for ideal characterization of BCP and other bioceramics in an attempt to provide basic standardized protocols for future studies

Intertextualidade mitológica presente no episódio de Inês de Castro, transcrito na epopeia camoniana

Este artigo tem por objetivo empreender uma análise interpretativa do episódio de Inês de Castro, transcrito em Os Lusíadas (1572), de Luís de Camões, e, sob a perspectiva intertextual, cotejá-lo com as três referências mitológicas presentes no canto – Rainha Semíramis, juntamente com os irmãos Rômulo e Remo, Tiestes e Atreu e, por fim, Polixena e Aquiles. Tais referências aproximam esse episódio às tragédias clássicas, tanto em sua estrutura, quanto em sua temática e corroboram para a importância literária e histórica da tragédia de Inês de Castro, imortalizada por Camões.This article aims to undertake an interpretive analysis of the episode of Inês de Castro, transcribed in Os Lusíadas (1572), by Luís de Camões, and, from an intertextual perspective, compare it with the three mythological references present in the song – Queen Semiramis, along with the brothers Romulus and Remus, Polyxena and Achilles, and finally, the brothers Thyestes and Atreus. Such references bring this episode closer to classic tragedies, both in its structure and in its theme and corroborate the literary and historical importance of the tragedy of Inês de Castro, immortalized by Camões

Ecosystem models cannot predict the consequences of conservation decisions

Ecosystem models are often used to predict the consequences of management decisions in applied ecology, including fisheries management and threatened species conservation. These models are high-dimensional, parameter-rich, and nonlinear, yet limited data is available to calibrate them, and they are rarely tested or validated. Consequently, the accuracy of their forecasts, and their utility as decision-support tools is a matter of debate. In this paper, we calibrate ecosystem models to time-series data from 110 different experimental microcosm ecosystems, each containing between three and five interacting species. We then assess how often these calibrated models offer accurate and useful predictions about how the ecosystem will respond to a set of standard management interventions. Our results show that for each timeseries dataset, a large number of very different parameter sets offer equivalent, good fits. However, these calibrated ecosystem models have poor predictive accuracy when forecasting future dynamics and offer ambiguous predictions about how species in the ecosystem will respond to management interventions. Closer inspection reveals that the ecosystem models fail because calibration cannot determine the types of interactions that occur within the ecosystem. Our findings call into question claims that ecosystem modelling can support applied ecological decision-making when they are calibrated against real-world datasets.Comment: 23 pages (main text + supplementary material) 9 figures (main text + supplementary material

Student skill development with the real world: Analyzing tert-Butyl alcohol content in gasoline samples

In the activity described in this communication, the authors present a simple experiment that can be implemented with moderate operational costs and that allows students to acquire the manipulative skills necessary for chromatographic analysis of a familiar fuel that still plays a fundamental role in providing energy for transport of passengers and goods. The use of gasoline formulations in a laboratory activity presents students with a motivating subject of study and an opportunity to apply analytical procedures to the characterization of controlled substances used in vehicle fuel formulations.The authors acknowledge support from the Foundation for Science and Technology (CQ/UM PEST-C/QUI/UIO686/2013 FCT, Portugal) and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU through the Chemistry Research Centre of the University of Minh

Online Searching in PBL Tutorials

This study aims to explore how online searching plays a role during PBL tutorials in two undergraduate health sciences curricula, Medicine and Dentistry. Utilizing Interactional Ethnography (IE) as an organizing framework for data collection and analysis, and drawing on a critical theory of technology as an explanatory lens, enabled a textured understanding of student practices and beliefs regarding online searching during face-to-face PBL tutorials. Two event maps trace key transitions in learning regarding online searching in one cycle of problem-based learning in each program. From a critical perspective, analysis of students’ stimulated recall interviews indicated that the use of students’ personal mobile devices with online searching capacity is considered a dynamic pedagogically and socially constructed process. Online searching during the PBL process is also viewed as a “site-of-struggle” where there are challenges for first-year undergraduates when implementing such learning technologies in PBL tutorials

Curvature and Hydrophobic Forces Drive Oligomerization and Modulate Activity of Rhodopsin in Membranes

AbstractG protein-coupled receptors (GPCRs) are essential components of cellular signaling pathways. They are the targets of many current pharmaceuticals and are postulated to dimerize or oligomerize in cellular membranes in conjunction with their functional mechanisms. We demonstrate using fluorescence resonance energy transfer how association of rhodopsin occurs by long-range lipid-protein interactions due to geometrical forces, yielding greater receptor crowding. Constitutive association of rhodopsin is promoted by a reduction in membrane thickness (hydrophobic mismatch), but also by an increase in protein/lipid molar ratio, showing the importance of interactions extending well beyond a single annulus of boundary lipids. The fluorescence data correlate with the pKa for the MI-to-MII transition of rhodopsin, where deprotonation of the retinylidene Schiff base occurs in conjunction with helical movements leading to activation of the photoreceptor. A more dispersed membrane environment optimizes formation of the MII conformation that results in visual function. A flexible surface model explains both the dispersal and activation of rhodopsin in terms of bilayer curvature deformation (strain) and hydrophobic solvation energy. The bilayer stress is related to the lateral pressure profile in terms of the spontaneous curvature and associated bending rigidity. Transduction of the strain energy (frustration) of the bilayer drives protein oligomerization and conformational changes in a coupled manner. Our findings illuminate the physical principles of membrane protein association due to chemically nonspecific interactions in fluid lipid bilayers. Moreover, they yield a conceptual framework for understanding how the tightly regulated lipid compositions of cellular membranes influence their protein-mediated functions

Unveiling clones and integrons dynamics associated with carbapenemase-producing P. aeruginosa clinical isolates in a portuguese hospital

[Excerpt] Particular epidemic lineages (e.g. 235, 111, ST175 and 244) are associated with carbapenemase-producing P. aeruginosa (CPPA) isolates causing infections. Due to limited therapeutic options and possible carbapenemase spread, CPPA infections are of great concern. Nevertheless, the occurrence, genetic background and clonal dynamics over a long period of time of CPPA strains in Portuguese hospitals are unknown. The study aimed to assess the occurrence and the genetic background of CPPA isolates obtained from a Portuguese University Hospital. Carbapenem-resistant P. aeruginosa isolates obtained from different biological samples from inpatients attending the Hospital Geral de Santo António, Porto during 2006 (n=27) and 2011-3 (n=135) were included. Carbapenemase production was searched by Blue-Carba. Carbapenemase and associated integrons were characterized by PCRs and sequencing. Antimicrobial susceptibility was performed by disc diffusion, E-test and agar dilution methods. Clonality was assessed by MLST. The bla genes location was assessed by I-CeuI/ S1 PFGE and hybridization with specific probes. Plasmid analysis included identification of incompatibility groups by PCR and electrotransformation of P. aeruginosa PAO1. [...

Long-term evaluation of cantilevered versus fixed–fixed resin-bonded fixed partial dentures for missing maxillary incisors

© 2016 Elsevier LtdObjectives To evaluate the long-term longevity and patient-reported outcomes of two-unit cantilevered (CL2) and three-unit fixed–fixed (FF3) resin-bonded fixed partial dentures (RBFPDs) for the replacement of a maxillary permanent incisor. Materials and methods Twenty-eight subjects were randomly assigned to receive either a CL2 or FF3 RBFPD placed by one operator. Prosthesis longevity was determined by clinical examination and history. Success was defined as absence of complications requiring intervention and survival as retention of the original prosthesis in mouth. Subjects’ satisfaction was assessed using visual analogue scale (VAS) and oral health-related quality of life (OHRQoL) using Oral Health Impact Profile (OHIP-49). Outcomes were analysed with t-test/Mann–Whitney U test, chi-square and log-rank test at significance level α = 0.05. Results Twenty-two subjects were reviewed. Thirteen of fifteen CL2 and ten of fourteen FF3 RBFPDs were examined (79.3 percent response rate) with a mean service life of 216.5 ± 20.8 months. All CL2 RBFPDs survived with no complications while only 10 percent of FF3 experienced no complications and only 50 percent of them survived (both P = 0.000). CL2 had a significantly better success and survival rate than FF3 (P = 0.000 and P = 0.009, respectively). There was no significant difference in subjects’ satisfaction and OHRQoL apart from CL2 group subjects had a higher satisfaction in cleaning of the prosthesis (84.1 ± 13.6) than FF3 group (72.6 ± 11.7) (P = 0.05). Conclusions Two-unit cantilevered RBFPDs were observed to have a significantly better success and survival than the FF3 design for the replacement of a maxillary incisor. Good patient-reported outcomes have been found for RBFPDs in single-tooth replacement in aesthetic zone.postprin

Massive Schwinger model and its confining aspects on curved space-time

Using a covariant method to regularize the composite operators, we obtain the bosonized action of the massive Schwinger model on a classical curved background. Using the solution of the bosonic effective action, the energy of two static external charges with finite and large distance separation on a static curved space-time is obtained. The confining behavior of this model is also explicitly discussed.Comment: A disscussion about the infrared regularization and also two references are added. Accepted for publication in Phys. Rev. D (2001