124 research outputs found
Low temperature dielectric relaxation in ordinary perovskite ferroelectrics: enlightenment from high-energy x-ray diffraction
Ordinary ferroelectrics exhibit a second order phase transition that is characterized by a sharp peak in the dielectric permittivity at a frequency-independent temperature. Furthermore, these materials show a low temperature dielectric relaxation that appears to be a common behavior of perovskite systems. Tetragonal lead zirconate titanate is used here as a model system in order to explore the origin of such an anomaly, since there is no consensus about the physical phenomenon involved in it. Crystallographic and domain structure studies are performed from temperature dependent synchrotron x-ray diffraction measurement. Results indicate that the dielectric relaxation cannot be associated with crystallographic or domain configuration changes. The relaxation process is then parameterized by using the Vogel–Fulcher–Tammann phenomenological equation. Results allow us to hypothesize that the observed phenomenon is due to changes in the dynamic behavior of the ferroelectric domains related to the fluctuation of the local polarization.Postprint (author's final draft
A protein profiling strategy for periodontal disease applications: the Perio-SalivaPRINT
Objectives: It is known that several clinical situations have characteristic molecular deregulations. Some molecular data underlying these deregulations can be found in saliva and have been annotated in databases (SalivaTecDB). Strategies are needed to identify the phenotypes characteristic of these deregulations. Our group has developed a strategy that allows the establishment of saliva protein profiles reflecting different conditions (health and disease). These profiles can be integrated to clinical data (SalivaPRINT Toolkit). The present work aims to identify the Periodontal Diseases (PD)-specific protein profiles. Methods: Unstimulated whole saliva was collected from a group of healthy subjects and a group of PD patients (with gingivitis, periodontitis or periimplantitis). Salivary proteins were separated by the Experion™ automated capillary electrophoresis. The protein profiles of each condition were integrated with the corresponding protein data retrieved from our in-house database (SalivaTecDB). Results: The strategy used enabled the determination of a total protein profile from saliva characteristic of each PDs -the Perio-SalivaPrint. The use of the SalivaPrint Toolkit allowed the identification of molecular weight ranges altered in PD. Using SalivaTecDB we were able to suggest proteins potentially involved in the underlying dysregulated mechanisms of the disease.
Conclusions: This approach enabled the determination of a Perio-SalivaPrint – protein profiles specific for gingivitis, periodontitis or periimplantitis - that could empower the use of saliva as a simple and less expensive diagnostic and monitoring fluid. The strategy presented could be an important tool for future applications in the early diagnostic/ screening of Periodontal Disease patients with applications in chairside monitoring.info:eu-repo/semantics/publishedVersio
Extrinsic response enhancement at the polymorphic phase boundary in piezoelectric materials
Polymorphic phase boundaries (PPBs) in piezoelectric materials have attracted significant interest in recent years, in particular because of the unique properties that can be found in their vicinity. However, to fully harness their potential as micro-nanoscale functional entities, it is essential to achieve reliable and precise control of their piezoelectric response, which is due to two contributions known as intrinsic and extrinsic. In this work we have used a (K,Na)NbO3-based lead-free piezoceramic as a model system to investigate the evolution of the extrinsic contribution around a PPB. X-ray diffraction measurements are performed over a wide range of temperatures in order to determine the structures and transitions. The relevance of the extrinsic contribution at the PPB region is evaluated by means of nonlinear dielectric response measurements. Though it is widely appreciated that certain intrinsic properties of ferroelectric materials increase as PPBs are approached, our results demonstrate that the extrinsic contribution also maximizes. An enhancement of the extrinsic contribution is therefore also responsible for improving the functional properties at the PPB region. Rayleigh’s law is used to quantitatively analyze the nonlinear response. As a result, an evolution of the domain wall motion dynamics through the PPB region is detected. This work demonstrates that the extrinsic contribution at a PPB may have a dynamic role in lead-free piezoelectric materials, thereby exerting a far greater influence on their functional properties than that considered to date.Postprint (author's final draft
Алгоритмическое и программное обеспечение выделения значимых предикторов из медицинской документации осмотра пациента
В рамках данной работы произведен отбор значимых текстовых признаков и построение модели машинного обучения для классификации фрагментов медицинской документации. Исследование проводилось на основе данных документов "Осмотр в стационаре при поступлении" из историй болезни пациентов, страдающих рожистыми воспалениями. Произведен выбор наилучшей модели классификатора, подбор оптимальных гиперпараметров, а также оценка качества классификации.In the present study selection of significant text features and the machine learning model for the classification of medical records were made. The study was conducted on the basis of "Inspection in the hospital at admission" documents from the records of patients suffering from erysipelas. The selection of the best classifier model, selection of optimal hyperparameters, as well as assessment of the quality of classification were made
an international survey before and during the COVID-19 pandemic
Funding Information: The Société Française d’Anesthésie et de Réanimation (SFAR), Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias (SEMICYUC), Sociedad Argentina de Terapia Intensiva (SATI), Sociedad Chilena de Medicina Intensiva (SOCHIMI), Associação de Medicina Intensiva Brasileira (AMIB-Net) and the Brazilian Research in Intensive Care Network (BricNet) supported this survey. We would also like to thank our friend Tiago Rocha for making the amazing logo for this study. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brazil (CAPES)—Finance Code 001. Publisher Copyright: © 2022, The Author(s).Background: Since the publication of the 2018 Clinical Guidelines about sedation, analgesia, delirium, mobilization, and sleep deprivation in critically ill patients, no evaluation and adequacy assessment of these recommendations were studied in an international context. This survey aimed to investigate these current practices and if the COVID-19 pandemic has changed them. Methods: This study was an open multinational electronic survey directed to physicians working in adult intensive care units (ICUs), which was performed in two steps: before and during the COVID-19 pandemic. Results: We analyzed 1768 questionnaires and 1539 (87%) were complete. Before the COVID-19 pandemic, we received 1476 questionnaires and 292 were submitted later. The following practices were observed before the pandemic: the Visual Analog Scale (VAS) (61.5%), the Behavioral Pain Scale (BPS) (48.2%), the Richmond Agitation Sedation Scale (RASS) (76.6%), and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) (66.6%) were the most frequently tools used to assess pain, sedation level, and delirium, respectively; midazolam and fentanyl were the most frequently used drugs for inducing sedation and analgesia (84.8% and 78.3%, respectively), whereas haloperidol (68.8%) and atypical antipsychotics (69.4%) were the most prescribed drugs for delirium treatment; some physicians regularly prescribed drugs to induce sleep (19.1%) or ordered mechanical restraints as part of their routine (6.2%) for patients on mechanical ventilation; non-pharmacological strategies were frequently applied for pain, delirium, and sleep deprivation management. During the COVID-19 pandemic, the intensive care specialty was independently associated with best practices. Moreover, the mechanical ventilation rate was higher, patients received sedation more often (94% versus 86.1%, p < 0.001) and sedation goals were discussed more frequently in daily rounds. Morphine was the main drug used for analgesia (77.2%), and some sedative drugs, such as midazolam, propofol, ketamine and quetiapine, were used more frequently. Conclusions: Most sedation, analgesia and delirium practices were comparable before and during the COVID-19 pandemic. During the pandemic, the intensive care specialty was a variable that was independently associated with the best practices. Although many findings are in accordance with evidence-based recommendations, some practices still need improvement.publishersversionpublishe
New percutaneous techniques for perforating the pulmonary valve in pulmonary atresia with intact ventricular septum
A proposal for the evaluation of the bioeconomic efficiency of beef cattle production systems
Ciclo de vida de Aedes (Stegomyia) aegypti (Diptera, Culicidae) em águas com diferentes características
Dissolved Nitrogen and Phosphorus Dynamics in the Lower Portion of the Paraiba do Sul River, Campos dos Goytacazes, RJ, Brazil
Standards in semen examination:publishing reproducible and reliable data based on high-quality methodology
Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.Peer reviewe
- …