987 research outputs found

    Transorbital transnasal endoscopic combined approach to the anterior and middle skull base: a laboratory investigation

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    Orbital approaches provide significant trajectory to the skull base and are used with differently designed pathways. The aim of this study is to investigate the feasibility of a combined transorbital and transnasal approach to the anterior and middle cranial fossa. Cadaveric dissection of five silicon-injected heads was used. A total of 10 bilateral transorbital approaches and 5 extended endonasal approaches were performed. Identification of surgical landmarks, main anatomical structures, feasibility of a combined approach and reconstruction of the superior orbital defect were examined. Rod lens endoscope (with 0° and 45° lenses) and endoscopic instruments were used to complete the dissection. The transorbital approach showed good versatility and provides the surgeon with a direct route to the anterior and middle cranial fossa. The transorbital avascular plane showed no conflict with major nerves or vessels. Large exposure area from crista galli to the third ventricle was demonstrated with significant control of different neurovascular structures. A combined transorbital transnasal approach provides considerable value in terms of extent of exposure and free hand movement of the two surgeons, and allows better visualisation and control of the ventral skull base, thus overcoming the current surgical limits of a single approach. Combination of these two minimally invasive approaches should reduce overall morbidity. Clinical trials are needed to evaluate the virtual applications of this approach

    Developing and Assessing a Social Networking Framework for Universities in Saudi Arabia

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    The interactive capacities of social networking have unleashed the potential for enhancing teaching and learning in the higher education sector. This research focuses on Saudi Arabia in order to determine the factors that must be considered for developing a social networking framework for the use in universities. The main research outcome is a social networking framework for higher education in Saudi Arabia which can be used by a range of stakeholders within higher educatio

    Simulations of events for the LUX-ZEPLIN (LZ) dark matter experiment

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    The LUX-ZEPLIN dark matter search aims to achieve a sensitivity to the WIMP-nucleon spin-independent cross-section down to (1–2)×10−12 pb at a WIMP mass of 40 GeV/c2. This paper describes the simulations framework that, along with radioactivity measurements, was used to support this projection, and also to provide mock data for validating reconstruction and analysis software. Of particular note are the event generators, which allow us to model the background radiation, and the detector response physics used in the production of raw signals, which can be converted into digitized waveforms similar to data from the operational detector. Inclusion of the detector response allows us to process simulated data using the same analysis routines as developed to process the experimental data

    Forensic dentistry now and in the future

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    Forensic dentistry (odontology) deals with the examination, handling and presentation of dental evidence for the legal system. In the UK this work mainly involves criminal cases but in many other countries its remit also extends to civil litigation. There are four main aspects to forensic dentistry: single body identification, Disaster Victim Identification (DVI), age estimation and bite mark identification and analysis. This article provides a brief introduction to the topics and discusses potential future developments that aim to reduce the subjectivity in the analysis process and simplify presentation of evidence to non-dental parties. CPD/Clinical Relevance: This article highlights ways that dental practitioners can assist legal investigations and, in particular, forensic dentists

    eNOS plays essential roles in the developing heart and aorta linked to disruption of Notch signalling

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    \ua9 2024. Published by The Company of Biologists Ltd. eNOS (NOS3) is the enzyme that generates nitric oxide, a signalling molecule and regulator of vascular tone. Loss of eNOS function is associated with increased susceptibility to atherosclerosis, hypertension, thrombosis and stroke. Aortopathy and cardiac hypertrophy have also been found in eNOS null mice, but their aetiology is unclear. We evaluated eNOS nulls before and around birth for cardiac defects, revealing severe abnormalities in the ventricular myocardium and pharyngeal arch arteries. Moreover, in the aortic arch, there were fewer baroreceptors, which sense changes in blood pressure. Adult eNOS null survivors showed evidence of cardiac hypertrophy, aortopathy and cartilaginous metaplasia in the periductal region of the aortic arch. Notch1 and neuregulin were dysregulated in the forming pharyngeal arch arteries and ventricles, suggesting that these pathways may be relevant to the defects observed. Dysregulation of eNOS leads to embryonic and perinatal death, suggesting mutations in eNOS are candidates for causing congenital heart defects in humans. Surviving eNOS mutants have a deficiency of baroreceptors that likely contributes to high blood pressure and may have relevance to human patients who suffer from hypertension associated with aortic arch abnormalities

    Mudanças das práticas discursivas de professores aprendendo matemáticas dinâmicas em um ambiente colaborativo online

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    Usando dados de uma disciplina de desenvolvimento profissional para professores de matemática em serviço, investigamos as mudanças nas práticas discursivas dos professores de Fundamental II e Ensino Médio em uma última parte da disciplina, em comparação com o início da disciplina. Os professores interagiram em um ambiente colaborativo online, conhecido como Virtual Math Teams com GeoGebra (VMTcG), com foco em práticas discursivas, matemáticas e colaborativas. De uma perspectiva sociocultural, acreditamos que os professores desenvolvem gradualmente o seu conhecimento tecnológico, pedagógico e do conteúdo (TPACK), interagindo discursivamente em equipes pequenas. Usando a análise de conteúdo convencional da revisão dos professores sobre seu discurso gravado, investigamos as mudanças nas práticas da perspectiva dos professores. Nossos resultados mostram que os professores perceberam que suas práticas discursivas diferiam importantemente de suas práticas no início do curso

    Mudanças das práticas discursivas de professores aprendendo matemáticas dinâmicas em um ambiente colaborativo online

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    Using data from an inservice professional development course, we inquire into changes in secondary teachers’ discursive practices in a latter part of the course compared to the beginning of the course. Participants interacted in a collaborative online environment, known as Virtual Math Teams with GeoGebra (VMTwG), focusing on discursive, mathematical, and collaborative practices. From a sociocultural perspective, we believe that teachers gradually develop their Technological Pedagogical Content Knowledge (TPACK) by interacting discursively in small teams. Using conventional content analysis of the teachers’ review of their recorded discourse, we investigate changes in practices from the teachers’ perspective. Our results show that teachers perceived that their discursive practices differed importantly from their practices at the beginning of the course.Usando dados de uma disciplina de desenvolvimento profissional para professores de matemática em serviço, investigamos as mudanças nas práticas discursivas dos professores de Fundamental II e Ensino Médio em uma última parte da disciplina, em comparação com o início da disciplina. Os professores interagiram em um ambiente colaborativo online, conhecido como Virtual Math Teams com GeoGebra (VMTcG), com foco em práticas discursivas, matemáticas e colaborativas. De uma perspectiva sociocultural, acreditamos que os professores desenvolvem gradualmente o seu conhecimento tecnológico, pedagógico e do conteúdo (TPACK), interagindo discursivamente em equipes pequenas. Usando a análise de conteúdo convencional da revisão dos professores sobre seu discurso gravado, investigamos as mudanças nas práticas da perspectiva dos professores. Nossos resultados mostram que os professores perceberam que suas práticas discursivas diferiam importantemente de suas práticas no início do curso

    Indentation Fracture Toughness of Aluminium-Graphite Composites: Influence of Nano-particles

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    In the field of composite materials, extensive research has been undertaken on aluminum-graphite composites. However, a research gap has been identified regarding the specific influence of nano-sized graphite particles on their fracture toughness. Previous studies have predominantly focused on larger graphite particles or different reinforcement materials, resulting in relatively unexplored effects of nano-graphite particles. This research is deemed critical as it has the potential to generate lightweight, high-strength materials, aligning with the demands of aerospace, automotive, and structural engineering. The primary objective of this study is to investigate how the inclusion of nano-sized graphite particles affects the fracture toughness of aluminum-graphite composites. To achieve this objective, systematic dispersion and incorporation of nano-sized graphite particles into an aluminum matrix will be carried out. Mechanical testing, including fracture toughness assessments, will be conducted to evaluate the performance of the composite materials. Factors such as particle size, distribution, volume fraction, and interfacial bonding will also be characterized within the study. It is anticipated that the presence of nano-sized graphite particles will lead to a significant enhancement of the fracture toughness of the aluminum-graphite nanocomposites. This enhancement is expected to be attributed to crack deflection, tortuosity, altered stress distribution, and increased plastic deformation around cracks

    Influence of post space disinfection protocols on the push-out bond strength of fiber posts luted with self-adhesive cement

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    Optimizing the radicular dentin surface for adhesion while maintaining a microbe-free environment is critical for the long-term success of post-restored teeth. Accidental reinfection during post cementation highlights the importance of effective root canal disinfection. This study evaluated the effect of post space disinfection protocols on push-out bond strength of fiber posts cemented with self-adhesive cement (SARC). Sixty endodontically treated single-rooted premolars were randomly assigned to six disinfection groups (n = 10): saline control (C), BioPure MTAD (BMT), Q-Mix (QM), Chlor-XTRA (CX), MD Cleanser (MDC), and ethanol (ETH). Following post space preparation and disinfection, fiber posts were cemented with SARC. After thermal cycling, specimens were sectioned into 2 mm slices (coronal, middle, and apical) and subjected to push-out testing. Failure modes were assessed by electron microscopy, and data were analyzed using two-way ANOVA and Tukey’s post hoc test (α = 0.05). The MD Cleanser group demonstrated the highest push-out bond strength, followed by Chlor-XTRA, with statistically significant differences observed among all groups (p < 0.001). Proprietary irrigants containing surfactants (BioPure MTAD and Q-Mix) yielded significantly superior bond strength compared to the saline control (p < 0.001). Conversely, ethanol irrigation resulted in significantly lower values (p < 0.001). Coronal and middle segments exhibited superior bond strength compared to apical segments, with adhesive failures predominating. The findings indicate that post space disinfection with surface-active agents enhances fiber post retention, with MD Cleanser providing optimal results
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