Gold nanoparticles (AuNPs) are highlighted due to their low toxicity, compatibility with the human body, high surface area to volume ratio, and surfaces that can be easily modified with ligands. ...Biosynthesis of AuNPs using plant extract is considered a simple, low-cost, and eco-friendly approach. Brazilian Red Propolis (BRP), a product of bees, exhibits anti-inflammatory, anti-tumor, antioxidant, and antimicrobial activities. Here, we described the biosynthesis of AuNPs using BRP extract (AuNP
) and its fractions (AuNP
, AuNP
, AuNP
) and evaluated their structural properties and their potential against microorganisms and cancer cells. AuNPs showed a surface plasmon resonance (SPR) band at 535 nm. The sizes and morphologies were influenced by the BRP sample used in the reaction. FTIR and TGA revealed the involvement of bioactive compounds from BRP extract or its fractions in the synthesis and stabilization of AuNPs. AuNP
and AuNP
exhibited antimicrobial activities against all strains tested, showing their efficacy as antimicrobial agents to treat infectious diseases. AuNPs showed dose-dependent cytotoxic activity both in T24 and PC-3 cells. AuNP
and AuNP
exhibited the highest in vitro cytotoxic effect. Also, the cytotoxicity of biogenic nanoparticles was induced by mechanisms associated with apoptosis. The results highlight a potential low-cost green method using Brazilian red propolis to synthesize AuNPs, which demonstrated significant biological properties.
This article focuses on clinical applications of arterial spin labeling (ASL) and is part of a wider effort from the International Society for Magnetic Resonance in Medicine (ISMRM) Perfusion Study ...Group to update and expand on the recommendations provided in the 2015 ASL consensus paper. Although the 2015 consensus paper provided general guidelines for clinical applications of ASL MRI, there was a lack of guidance on disease-specific parameters. Since that time, the clinical availability and clinical demand for ASL MRI has increased. This position paper provides guidance on using ASL in specific clinical scenarios, including acute ischemic stroke and steno-occlusive disease, arteriovenous malformations and fistulas, brain tumors, neurodegenerative disease, seizures/epilepsy, and pediatric neuroradiology applications, focusing on disease-specific considerations for sequence optimization and interpretation. We present several neuroradiological applications in which ASL provides unique information essential for making the diagnosis. This guidance is intended for anyone interested in using ASL in a routine clinical setting (i.e., on a single-subject basis rather than in cohort studies) building on the previous ASL consensus review.
Racial Inequalities in Oral Health Bastos, J.L.; Celeste, R.K.; Paradies, Y.C.
Journal of dental research,
07/2018, Letnik:
97, Številka:
8
Journal Article
Recenzirano
Together with other social categories, race has been at the core of much scholarly work in the area of humanities and social sciences, as well as a host of applied disciplines. In dentistry, debates ...have ranged from the use of race as a criterion for the recommendation of specific dental procedures to a means of assessing inequalities in a variety of outcomes. What is missing in these previous discussions, though, is a broader understanding of race that transcends relations with genetic makeup and other individual-level characteristics. In this review, we provide readers with a critique of the existing knowledge on race and oral health by answering the following 3 guiding questions: (1) What concepts and ideas are connected with race in the field of dentistry? (2) What can be learned and what is absent from the existing literature on the topic? (3) How can we enhance research and policy on racial inequalities in oral health? Taken together, the reviewed studies rely either on biological distinctions between racial categories or on other individual characteristics that may underlie racial disparities in oral health. Amidst a range of individual-level factors, racial inequalities have often been attributed to lower socioeconomic status and “health-damaging” cultural traits, for instance, patterns of and reasons for dental visits, dietary habits, and oral hygiene behaviors. While this literature has been useful in documenting large and persistent racial gaps in oral health, wider sociohistorical processes, such as systemic racism, as well as their relationships with economic exploitation, social stigmatization, and political marginalization, have yet to be operationalized among studies on the topic. A nascent body of research has recently begun to address some of these factors, but limited attention to structural theories of racism means that many more studies are needed to effectively mitigate racial health differentials.
Liver enzyme activities can be employed as biomarkers, but liver can only be obtained with death of the specimen. On the other hand, blood withdrawal is a non-lethal procedure. Accordingly, the ...hypothesis of this study is to verify if glutathione peroxidase (GPX) and glutathione S-transferase (GST) activities in blood parallel those in the liver of the hypoxia-tolerant fish, Piaractus mesopotamicus (pacu), submitted to hypoxia conditions. GPX was assayed with H2O2 in cytosols from both liver and erythrocytes and exhibited no significant variation, either in erythrocytes or in liver, when comparing pacus under normoxia with those under hypoxia (42 h). GST activity with chloro-dinitrobenzene (CDNB), an artificial substrate suitable for almost all GST isoenzymes, was compared to activity with 4-hydroxy-nonenal (4-HNE), a physiological endogenous substrate. GST activity with CDNB did not change in liver or in erythrocyte cytosols in pacus under hypoxia compared to those under normoxia. On the other hand, a significant decrease in erythrocyte activity with 4-HNE was observed after 42 h of hypoxia in both erythrocytes and liver, which may be a response to increased lipid oxidation in erythrocytes. Erythrocyte GST activity was 3-fold higher with 4-HNE than with CDNB, indicating that 4-HNE is a more appropriate substrate to determine GST activity in pacu erythrocytes.
•Pacu erythrocyte GPX activity is essential for hydrogen peroxide detoxification.•Activity from GPX and GST presented similar patterns in both tissues.•GST activity over 4-HNE is more sensitive to hypoxia than GST activity over CDNB.•Blood GST activity over 4-HNE is higher than over CDNB.
Algorithms for computer-aided diagnosis of dementia based on structural MRI have demonstrated high performance in the literature, but are difficult to compare as different data sets and methodology ...were used for evaluation. In addition, it is unclear how the algorithms would perform on previously unseen data, and thus, how they would perform in clinical practice when there is no real opportunity to adapt the algorithm to the data at hand. To address these comparability, generalizability and clinical applicability issues, we organized a grand challenge that aimed to objectively compare algorithms based on a clinically representative multi-center data set. Using clinical practice as the starting point, the goal was to reproduce the clinical diagnosis. Therefore, we evaluated algorithms for multi-class classification of three diagnostic groups: patients with probable Alzheimer's disease, patients with mild cognitive impairment and healthy controls. The diagnosis based on clinical criteria was used as reference standard, as it was the best available reference despite its known limitations. For evaluation, a previously unseen test set was used consisting of 354 T1-weighted MRI scans with the diagnoses blinded. Fifteen research teams participated with a total of 29 algorithms. The algorithms were trained on a small training set (n=30) and optionally on data from other sources (e.g., the Alzheimer's Disease Neuroimaging Initiative, the Australian Imaging Biomarkers and Lifestyle flagship study of aging). The best performing algorithm yielded an accuracy of 63.0% and an area under the receiver-operating-characteristic curve (AUC) of 78.8%. In general, the best performances were achieved using feature extraction based on voxel-based morphometry or a combination of features that included volume, cortical thickness, shape and intensity. The challenge is open for new submissions via the web-based framework: http://caddementia.grand-challenge.org.
We report the first stochastic dynamic causal modeling (sDCM) study of effective connectivity within the default mode network (DMN) in schizophrenia. Thirty-three patients (9 women, mean age = 25.0 ...years, SD = 5) with a first episode of psychosis and diagnosis of schizophrenia--according to the Diagnostic and Statistic Manual of Mental Disorders, 4th edition, revised criteria--were studied. Fifteen healthy control subjects (4 women, mean age = 24.6 years, SD = 4) were included for comparison. All subjects underwent resting state functional magnetic resonance imaging (fMRI) interspersed with 2 periods of continuous picture viewing. The anterior frontal (AF), posterior cingulate (PC), and the left and right parietal nodes of the DMN were localized in an unbiased fashion using data from 16 independent healthy volunteers (using an identical fMRI protocol). We used sDCM to estimate directed connections between and within nodes of the DMN, which were subsequently compared with t tests at the between subject level. The excitatory effect of the PC node on the AF node and the inhibitory self-connection of the AF node were significantly weaker in patients (mean values = 0.013 and -0.048 Hz, SD = 0.09 and 0.05, respectively) relative to healthy subjects (mean values = 0.084 and -0.088 Hz, SD = 0.15 and 0.77, respectively; P < .05). In summary, sDCM revealed reduced effective connectivity to the AF node of the DMN--reflecting a reduced postsynaptic efficacy of prefrontal afferents--in patients with first-episode schizophrenia.
Quantitative measurements of brain perfusion are influenced by perfusion-modifiers. Standardization of measurement conditions and correction for important modifiers is essential to improve accuracy ...and to facilitate the interpretation of perfusion-derived parameters. An extensive literature search was carried out for factors influencing quantitative measurements of perfusion in the human brain unrelated to medication use. A total of 58 perfusion modifiers were categorized into four groups. Several factors (e.g., caffeine, aging, and blood gases) were found to induce a considerable effect on brain perfusion that was consistent across different studies; for other factors, the modifying effect was found to be debatable, due to contradictory results or lack of evidence. Using the results of this review, we propose a standard operating procedure, based on practices already implemented in several research centers. Also, a theory of ‘deep MRI physiotyping’ is inferred from the combined knowledge of factors influencing brain perfusion as a strategy to reduce variance by taking both personal information and the presence or absence of perfusion modifiers into account. We hypothesize that this will allow to personalize the concept of normality, as well as to reach more rigorous and earlier diagnoses of brain disorders.
•Verification of numerical methods and validation of mathematical model for swirling flow in cyclones.•Experimental and numerical data for velocity profiles and pressure drop showed ...agreement.•Non-conventional profile observed for axial and tangential velocity associated with outlet geometry.•Improvement in small particles collection efficiency due to effect of gas outlet.
The collection efficiency of gas-solid flows in cyclones applied to fine particles is of fundamental importance. In this context, the effects of a reduction in the cross section of the vortex finder outlet duct together with a stretched cylindrical body on the flow pattern and performance of a conventional cyclone was investigated. A test facility and CFD-based modeling using an Eulerian-Lagrangian approach with the Reynolds stress turbulence model (RSM) were employed in experimental and numerical studies, respectively. Based on the results, an alternative design for a cyclone aimed at capturing fine particles (<5μm) is proposed, specifically, a reduced area at the end of the vortex finder acting as a post vortex finder device. Experimental results obtained by stereoscopy particle image velocimetry (stereo PIV) for the velocity fields of particles with small Stokes numbers were used for the model validation. Simulations were performed by computational fluid dynamics (CFD) for different inlet velocities (10.5 and 12.25m/s) and flow configurations, and a comparison between experimental data for the pressure drop and velocity profiles indicated good agreement, validating the CFD modeling. The application of Eulerian-Lagrangian modeling to particles of less than 5μm in diameter showed that the collection efficiency increases with a secondary swirling flow promoted by a reduction in the cross section of the vortex finder. Thus, this design represents a promising alternative for new cyclone applications.
The psychopathic traits boldness, meanness, and disinhibition are theorized to be underlined by trait fearlessness and externalizing vulnerability as etiologic neurobiological processes. However, ...little is known about the neurophysiological correlates of these traits. In this work, we explored how the three traits are associated with event‐related potential (ERP) components targeted at the etiological processes in a partial delayed threat conditioning task and in a go/no‐go task. Fifty community‐dwelling volunteers (25 women), without history of neurological or psychiatric conditions, were recruited and assessed for psychopathic traits using the triarchic psychopathy measure. Participants performed a threat conditioning task, and a go/no‐go task while undergoing an electroencephalography recording. Results from the threat conditioning task showed that boldness was significantly associated with reduced late positive potential. Concerning the go/no‐go task, disinhibition was significantly associated with reduced error‐related negativity ERP component. Overall, distinct psychopathic traits were found to be associated with distinct neurophysiological correlates of threat conditioning and response inhibition. This is consistent with models of psychopathy entailing trait fearlessness and externalizing proneness, and related brain mechanisms, as distinct processes underlying the expression of psychopathic traits.
This study focuses on the neurophysiological basis of the Triarchic Model of Psychopathy. More specifically, on the neural correlates of the etiological pathways (trait fearlessness and externalizing vulnerability) underlying the expression of distinct psychopathic traits of the Triarchic Model of Psychopathy. The main results suggest that while boldness was associated with reduced brain activity to threat conditioning and a better estimation of the probability of occurrence of a threatening event, disinhibition was associated with reduced brain activity to the occurrence of errors. Thus, we provided evidence for trait fearlessness and externalizing vulnerability as putative etiological mechanisms underlying the expression of boldness and disinhibition psychopathic traits.
Nowadays, debates addressing climate change, fossil fuels depletion and energy security highlight the need for a more sustainable built environment in order to reduce energy consumption and emission ...trends in the buildings sector. Meeting these targets is a challenge that calls for innovative research to improve the use of renewable energy sources, new technologies, and holistic tools and methodologies. Such research should integrate the dynamics and main drivers of energy supply and demand in buildings to support new policies, plans and actions towards lowering the built environment burdens. This paper brings together ten research topics concerning the energy and environmental performance of buildings, which can support a shift towards a more sustainable built environment. Background information and state of the art literature on the covered research topics is briefly summarized, gaps are identified and guidelines for future research are provided. The selected topics cover different stages along the lifetime of buildings (from design and operation, to retrofitting and end-of-life), different scale approaches (from building elements/components, to the building, district and urban scales), and different methods to assess the energy and environmental performance of buildings (life-cycle assessment, generative design methods and retrofitting tools). Other topics are discussed such as: nearly zero-energy buildings, the control of domestic energy resources in smart grid scenarios, the need to include end-users' behaviors in the dynamics of energy demand, the advantages of improving thermal storage by using phase change materials, the importance of reducing heating and cooling energy demand (maintaining indoor thermal comfort), and the optimization of heating and cooling fluids, and their system control.
PDF
