41 research outputs found

    The impact of light based technologies in the future of healthcare

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    There has been an increasing interest in light-based technologies offering cheap, fast and noninvasive disease detection and treatment. In 2016, the market of light-based technologies represented >64% of the total medical imaging market ($90.7 billion in total) and more than twice the radiological imaging market that included X-Ray, ultrasound, magnetic resonant imaging and others. Light-based technologies have steadily increased with the mobile and home healthcare, as well as wearable devices dominating the market to monitor quality of sleep, sports performance, and blood oxygenation in general (including COVID-19 cases). Given the importance of light in the future of healthcare, this paper covers how light-based technologies are used to find diseases early (screening) and accurately (diagnostics) in both whole body (systemically with screening tests) or localized parts of the body (during surgery)

    Characterization of teeth fluorescence properties due to coffee pigmentation: towards optimization of quantitative light-induced fluorescence for tooth color assessment

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    The assessment of tooth color is typically performed by subjective comparison with a visual shade guide or by using objective optical techniques such as quantitative light-induced fluorescence (QLF). QLF measurements rely on the precise wavelength calibration of fluorescence excitation and emission for enhancing the contrast between the white sound tooth and stained areas. These areas may change the fluorescence emission differently depending on the color that is most absorbed by the stain on the tooth surface. Although previous studies have monitored the staining contrast generated by the consumption of beverages on teeth, the information provided is based on total intensity. However, this intensity varies from each QLF device configuration and comparison across studies may not be possible. Few studies report the wavelength-dependent characterization of the staining process, which allow the comparison on the light attenuation on specific wavelengths and can be used to design fluorescence equipment with improved contrast for the tooth color assessment. In this study, we quantified the fluorescence spectral features (fluorescence intensity, wavelength shift of the maximum intensity, full width at half maximum, and wavelength-dependent intensity attenuation) of teeth in several degrees of coffee pigmentation by using 445 nm excitation. Most of the pigmentation effect was observed on the fluorescence intensity and a linear behavior was observed for the full width at half maximum (around 11.8% increase for each pigmentation level). We characterized the fluorescence properties of each degree of pigmentation level. Both spectral features and fluorescence properties can be used to design novel fluorescence equipment capable of increasing the contrast between white and stained teeth

    New insights of Raman spectroscopy for oral clinical applications

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    Oral injuries are currently diagnosed by histopathological analysis of biopsy, which is an invasive procedure and does not give immediate results. On the other hand, the Raman spectroscopy technique is a real-time and minimally invasive analytical tool with a notable diagnostic capability. At the current stage, researchers are widely aware of the diagnostic potential of the technique and how it is considered promising for providing biochemical information in real time and without damaging the tissue. The problem originates from a lack of relevant studies and clinical trials that could show the actual use of Raman spectroscopy to help patients. Our goal here is to narrow the relationship between physicists, chemists, engineers, computer scientists, and the medical community, and in fact discuss the potential of Raman spectroscopy as a novel clinical analysis method. In the present study, we focused on the use of Raman spectroscopy as a daily clinical practice. In this context, additional studies and in vivo tests should be performed with the same approach as a real application. We want to show the scientific and industrial community what is really necessary for this, starting from a clinical point of view. Using our previous experience publishing different oral pathologies and types of samples, we also aim to discuss the current state and potential of Raman spectroscopy and what is required to implement Raman spectroscopy for oral clinical applications

    Diffuse reflectance spectroscopy for determination of optical properties and chromophore concentrations of mice internal organs in the range of 350 nm to 1860 nm

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    The development of photomedical modalities for diagnostics and treatment has created a need for knowledge of the optical properties of the targeted biological tissues. These properties are essential to plan certain procedures, since they determine the light absorption, propagation and penetration in tissues. One way to measure these properties is based on diffuse reflectance spectroscopy (DRS). DRS can provide light absorption and scattering coefficients for each wavelength through a non-invasive, fast and in situ interrogation, and thereby tissue biochemical information. In this study, reflectance measurements of ex vivo mice organs were investigated in a wavelength range between 350 and 1860 nm. To the best of our knowledge, this range is broader than previous studies reported in the literature and is useful to study additional chromophores with absorption in the extended wavelength range. Also, it may provide a more accurate concentration of tissue chromophores when fitting the reflectance spectrum in this extended range. In order to extract these concentrations, optical properties were calculated in a wide spectral range through a fitting routine based on an inverse Monte-Carlo look-up table model. Measurements variability was assessed by calculating the Pearson correlation coefficients between each pair of measured spectra of the same type of organ

    Biophotonics computer app: fostering multidisciplinary distance self-paced learning with a user-friendly interface

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    The biophotonics app enables multidisciplinary and self-paced learning in both in-person or virtual environments. The app can work offline and has a user-friendly interface well accepted by students. App instructions are publicly available

    Broadband extraction of tissue optical properties using a portable hybrid time-resolved continuous wave instrumentation: characterization of ex vivo organs

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    Successful demonstration of a unique portable CW - TDDO S system for accurate and multiwavelength retrieval of tissue optical properties. Determining these properties has potential to improve the diagnosis and treatment outcomes in clinical and sports settings

    Biophotonics box: educational kit for multidisciplinary outreach activities in optics and photonics

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    The biophotonics box enables multidisciplinary/interdisciplinary and self-paced learning with at-home experiments using low-resource components. Experiments can increase the interest of students in STEM subjects by emphasizing the real-life applications in biology and medicine

    Report of a case of anaplastic large cell lymphoma associated with a breast implant in a Brazilian patient

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    Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a T-cell lymphoproliferative disorder that has recently been recognized as an independent entity in the World Health Organization (WHO) classification of lymphomas. Despite the small number of reports to date, the number of cases is rapidly increasing. Of the few hundred cases that have been reported so far, very few came from Brazil and none have been reported to the local authorities. We encountered a case of BIA-ALCL and believe that its report to the local plastic surgery community could raise awareness to this emerging pathology. The prognosis is very good in most of the diagnosed cases. However, little is known about how and why silicone implants could trigger a lymphoid response that results in ALCL

    Online learning combining virtual lectures, at-home experiments and computer simulations: a multidisciplinary teaching and learning approach

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    We developed a fully-remote biophotonics workshop integrating webinars, computer simulations and at-home experiments to meet the needs of undergraduate students with diverse backgrounds and learning styles. Similar strategies/resources could be used in multidisciplinary programs

    Mechanisms and role of microRNA deregulation in cancer onset and progression

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    MicroRNAs are key regulators of various fundamental biological processes and, although representing only a small portion of the genome, they regulate a much larger population of target genes. Mature microRNAs (miRNAs) are single-stranded RNA molecules of 20–23 nucleotide (nt) length that control gene expression in many cellular processes. These molecules typically reduce the stability of mRNAs, including those of genes that mediate processes in tumorigenesis, such as inflammation, cell cycle regulation, stress response, differentiation, apoptosis and invasion. MicroRNA targeting is mostly achieved through specific base-pairing interactions between the 5′ end (‘seed’ region) of the miRNA and sites within coding and untranslated regions (UTRs) of mRNAs; target sites in the 3′ UTR diminish mRNA stability. Since miRNAs frequently target hundreds of mRNAs, miRNA regulatory pathways are complex. Calin and Croce were the first to demonstrate a connection between microRNAs and increased risk of developing cancer, and meanwhile the role of microRNAs in carcinogenesis has definitively been evidenced. It needs to be considered that the complex mechanism of gene regulation by microRNAs is profoundly influenced by variation in gene sequence (polymorphisms) of the target sites. Thus, individual variability could cause patients to present differential risks regarding several diseases. Aiming to provide a critical overview of miRNA dysregulation in cancer, this article reviews the growing number of studies that have shown the importance of these small molecules and how these microRNAs can affect or be affected by genetic and epigenetic mechanisms
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