RESUMO
The resolution of fluorescence microscopy images is limited by the physical properties of light. In the last decade, numerous super-resolution microscopy (SRM) approaches have been proposed to deal with such hindrance. Here we present Mean-Shift Super Resolution (MSSR), a new SRM algorithm based on the Mean Shift theory, which extends spatial resolution of single fluorescence images beyond the diffraction limit of light. MSSR works on low and high fluorophore densities, is not limited by the architecture of the optical setup and is applicable to single images as well as temporal series. The theoretical limit of spatial resolution, based on optimized real-world imaging conditions and analysis of temporal image stacks, has been measured to be 40 nm. Furthermore, MSSR has denoising capabilities that outperform other SRM approaches. Along with its wide accessibility, MSSR is a powerful, flexible, and generic tool for multidimensional and live cell imaging applications.
Assuntos
Algoritmos , Medicamentos Genéricos , Fases de Leitura , Microscopia de Fluorescência , Corantes FluorescentesRESUMO
Due to the wave nature of light, optical microscopy has a lower-bound lateral resolution limit of approximately half of the wavelength of visible light, that is, within the range of 200 to 350 nm. Fluorescence fluctuation-based super-resolution microscopy (FF-SRM) is a term used to encompass a collection of image analysis techniques that rely on the statistical processing of temporal variations of the fluorescence signal. FF-SRM aims to reduce the uncertainty of the location of fluorophores within an image, often improving spatial resolution by several tens of nanometers. FF-SRM is suitable for live-cell imaging due to its compatibility with most fluorescent probes and relatively simple instrumental and experimental requirements, which are mostly camera-based epifluorescence instruments. Each FF-SRM approach has strengths and weaknesses, which depend directly on the underlying statistical principles through which enhanced spatial resolution is achieved. In this review, the basic concepts and principles behind a range of FF-SRM methods published to date are described. Their operational parameters are explained and guidance for their selection is provided.
Due to light's wave nature, an optical microscope's resolution range is 200 to 350 nanometers. Several techniques enhance resolution; this work encompasses several fluorescence fluctuation super-resolution (FF-SMR) methods capable of achieving nanoscopic scales. FF-SRM is known to be suitable for fixed or live-cell imaging and compatible with most conventional microscope setups found in a laboratory. However, each FF-SRM approach has its strengths and weaknesses, which depend directly on the underlying principles through which enhanced spatial resolution is achieved. Therefore, the basic concepts and principles behind diverse FF-SRM methods are revisited in this review. In addition, their operational parameters are explained, and guidance for their selection is provided for microscopists interested in FF-SRM.
Assuntos
Corantes Fluorescentes , Processamento de Imagem Assistida por Computador , Microscopia de Fluorescência/métodosRESUMO
BACKGROUND: The aim of this systematic review was to identify, evaluate, and provide a current literature about the influence of heritability on the determination of occlusal traits. MATERIALS AND METHODS: MEDLINE, SCOPUS, Web of Science, LILACS, and Google Scholar were searched without restrictions up to March 2020. Studies with twin method were considered and the risk of bias assessment was performed using quality of genetic association studies checklist (Q-Genie). The coefficient of heritability (h2), model-fitting approaches, and coefficient correlation were used to estimate the genetic/environmental influence on occlusal traits. The GRADE tool was used to assess the quality of the evidence. RESULTS: Ten studies met the eligibility criteria. Three studies presented good quality, five moderate quality, and two poor quality. Most studies have found that the intra-arch traits, mainly the maxillary arch morphology, such as width (h2 16-100%), length (h2 42-100%), and shape (h2 42-90%), and the crowding, mainly for mandibular arch (h2 35-81%), are under potential heritability influence. The traits concerning the inter-arch relationship, as overjet, overbite, posterior crossbite, and sagittal molar relation, seem not to be genetically determined. The certainty of the evidence was graded as low for all outcomes. CONCLUSIONS: Although weak, the available evidence show that the heritability factors are determinant for the intra-arch traits, namely, arch morphology and crowding. Possibly due they are functionally related, the occlusal traits concerning the maxillary and mandibular relationship seem to have environmental factors as determinants. In this scenario, early preventive approaches can offer a more effective and efficient orthodontic treatment.
Assuntos
Má Oclusão Classe II de Angle , Má Oclusão , Sobremordida , Humanos , Mandíbula , MaxilaRESUMO
OBJECTIVE: To evaluate the extent of the association between instant gratification behavior and childhood obesity. STUDY DESIGN: PubMed, Scopus, EMBASE, EBSCOhost, and Cochrane databases were searched for the terms delayed gratification, children, and obesity. Studies were eligible if they included a sample of at least 100 children who were made to choose between an immediate reward and a larger one later, with the authors comparing the response in different populations and observing some relationship with obesity. A specifically designed data extraction form was used, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The methodologic quality of the included studies was assessed with the methodologic index for nonrandomized studies. RESULTS: Nine articles were included after we applied the inclusion and exclusion criteria. Almost all studies conducted the test in populations of preschool children and offered food and/or nonfood rewards. The studies found a clear relationship between an inability to defer gratification and overweight and obesity. The quality assessment of the publications was ranked high in 5 studies and medium in 4. CONCLUSIONS: Children with the inability to delay gratification are more likely to be overweight or obese. Observation of such trends is useful in its implications for reeducation programs. Although the methodologic quality of the eligible studies was acceptable, additional experimental controlled studies are required to associate these behaviors with other aspects.