ATR-FTIR spectroscopy imaging of bone repair in mandibular laser-osteotomy.

The aim of this study was to verify the effectiveness of attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy in the characterization of bone repair in mandibular osteotomy using erbium, chromium-doped yttrium, scandium, gallium and garnet (Er,Cr:YSGG) laser and multilaminate drill on each side. Two mandible bone fragments were removed from 30 rabbits, and the process of bone repair was studied immediately, 3, 7, 15, 21, and 28 days after the surgery. The histological analysis allowed detecting differences in the early stages of tissue repair after bone cutting performed with the Er,Cr:YSGG laser or multilaminate drill. The ATR-FTIR spectroscopy technique was sensitive to changes in the organic content of bone tissue repair process.

Rapid identification of breast cancer subtypes using micro-FTIR and machine learning methods.

Breast cancer (BC) molecular subtypes diagnosis involves improving clinical uptake by Fourier transform infrared (FTIR) spectroscopic imaging, which is a non-destructive and powerful technique, enabling label free extraction of biochemical information towards prognostic stratification and evaluation of cell functionality. However, methods of measurements of samples demand a long time to achieve high quality images, making its clinical use impractical because of the data acquisition speed, poor signal to noise ratio, and deficiency of optimized computational framework procedures. To address those challenges, machine learning (ML) tools can facilitate obtaining an accurate classification of BC subtypes with high actionability and accuracy. Here, we propose a ML-algorithm-based method to distinguish computationally BC cell lines. The method is developed by coupling the K-neighbors classifier (KNN) with neighborhood components analysis (NCA), and hence, the NCA-KNN method enables to identify BC subtypes without increasing model size as well as adding additional computational parameters. By incorporating FTIR imaging data, we show that classification accuracy, specificity, and sensitivity improve, respectively, 97.5%, 96.3%, and 98.2%, even at very low co-added scans and short acquisition times. Moreover, a clear distinctive accuracy (up to 9 %) difference of our proposed method (NCA-KNN) was obtained in comparison with the second best supervised support vector machine model. Our results suggest a key diagnostic NCA-KNN method for BC subtypes classification that may translate to advancement of its consolidation in subtype-associated therapeutics.

Classification of the social distance during the COVID-19 pandemic from electricity consumption using artificial intelligence.

Accurately quantifying the social distancing (SD) practice of a population is essential for governments and health agencies to better plan and adapt restrictions during a pandemic crisis. In such a scenario, the reduction of social mobility also has a significant impact on electricity consumption, since people are encouraged to stay at home and many commercial and industrial activities are reduced or even halted. This paper proposes a methodology to qualify the SD of a medium-sized city, located in the northwest of the state of Rio Grande do Sul (RS), Brazil, using data of electricity consumption measured by the municipality's energy utility. The methodology consists of combining a data set, and an average consumption profile of Sundays is obtained using data from 4-months, it is then defined as a high SD profile due to the typical lower social activities on Sundays. An supervised and an unsupervised artificial neural network (ANN) are trained with this profile and used to analyze electricity consumption of this city during the COVID-19 pandemic. Low, moderate, and high SD ranges are also created, and the daily population behavior is evaluated by the ANNs. The results are strongly correlated and discussed with government restrictions imposed during the analyzed period and indicate that the ANNs can correctly classify the intensity of SD practiced by people. The unsupervised ANN is used more easily and in different scenarios, so it can be indicated for use by public administration for purposes of assess the effectiveness of SD policies based on the guidelines established during the COVID-19 pandemic.

Antimicrobial resistance of Escherichia coli isolates from spray‑chilled sheep carcasses during cooling / Resistencia antimicrobiana en aislados de Escherichia coli de canales de ovejas asperjadas durante la refrigeración / Resistência antimicrobiana de isolados de Escherichia coli de carcaças ovinas aspergidas durante o resfriamento

Abstract Background: Multidrug-resistant bacteria present in food of animal origin raise human and animal health concerns. Objective: To assess antimicrobial resistance of Escherichia coli isolates from sheep carcasses subjected to spray-chilling with water (4 and 10 hours) during cooling. Methods: Thirty surface swabs were collected from carcasses before and after the last water spray in two slaughter periods. In a first assessment (1st sampling), three spray-chilled carcasses (4 hours), three non-sprayed and one control carcass were sampled. In a second assessment (2nd sampling), the same number of carcasses and treatments were maintained, but spray-chilling was extended to 10 hours. All samples collected were isolated and submitted to susceptibility test using 16 (1st sampling) and 17 (2nd sampling) antimicrobials, respectively. Results: Overall, E. coli isolates were resistant most antimicrobials. Spray-chilled and control carcasses (10 hours) showed resistance to meropenem. Conclusion: E. coli isolates from carcasses subjected to spray-chilling with water for 10 hours had higher antimicrobial resistance to one, two, and four antimicrobial classes, characterizing a multidrug resistance profile. These results highlight the need to monitor health status throughout the meat production processes.

Resumen Antecedentes: las bacterias multirresistentes presentes en alimentos de origen animal son motivo de alerta para la salud humana y animal. Objetivo: verificar la resistencia a antimicrobianos de aislados de Escherichia coli en canales ovinas sometidas a aspersión (4 y 10 h) durante la refrigeración. Métodos: Luego de dos faenas de sacrificio, treinta hisopos fueron colectados en la superficie de las canales antes y después de la última aspersión. En un primer sacrificio (1era colecta) se recolectaron muestras de tres canales sometidas a aspersión (4 horas), tres sin aspersión y una canal como control. En un segundo sacrificio (2da colecta), el mismo número de canales y tratamientos se mantuvo, y el período de aspersión se extendió a 10 horas. Las muestras recogidas fueron aisladas y sometidas a la prueba de susceptibilidad utilizándo 16 (1.ª colecta) y 17 (2.ª colecta) antimicrobianos, respectivamente. Resultados: los aislamientos de E. coli fueron, en general, resistentes a las principales clases de antimicrobianos. Las canales con aspersión y el control (10 h) presentaron resistencia al meropenem. Conclusión: cuando la asperción duró 10 h, los aislados de E. coli presentaron mayor resistencia para una, dos y cuatro clases de antimicrobianos, es decir, fueron multirresistentes a los fármacos utilizados. Esto resalta la necesidad de monitorear el estado de salud durante todos los procesos de producción de carne.

Resumo Antecedentes: bactérias multirresistentes presentes em alimentos de origem animal são motivo de preocupação e alerta na saúde humana e animal. Objetivo: verificar a resistência antimicrobiana em isolados de Escherichia coli de carcaças de ovinos pulverizadas ou não (4 e 10 horas) durante a refrigeração. Métodos: foram coletados trinta swabs de superfície em carcaças antes e após a última aspersão em dois abates. Em outubro do 2015, três carcaças aspergidas foram amostradas, três sem aspersão e uma carcaça para controle, por um período de 4 horas. Em julho de 2016 (2ª coleta), o mesmo número de carcaças e tratamentos foram mantidos e o período de aspersão foi prolongado em 10 horas. As amostras coletadas foram isoladas e submetidas ao teste de susceptibilidade em 16 (1ª coleta) e 17 (2ª coleta) antimicrobianos, respectivamente. Resultados: isolados de E. coli foram, em geral, resistentes às principais classes de antimicrobianos. As carcaças e o controle aspergidos (10 h) apresentaram resistência ao meropenem. Conclusão: quando a aspersão de água durou 10 horas, os isolados de E. coli apresentaram maior resistência antimicrobiana a uma, duas e quatro classes de antimicrobianos, o que é uma multirresistência aos fármacos testados. Isso alerta para a necessidade de monitorar os aspectos de saúde durante todos os processos de produção de carne.

Noninvasive monitoring of photodynamic therapy on skin neoplastic lesions using the optical attenuation coefficient measured by optical coherence tomography.

Photodynamic therapy (PDT) has become a promising alternative for treatment of skin lesions such as squamous cell carcinoma. We propose a method to monitor the effects of PDT in a noninvasive way by using the optical attenuation coefficient (OAC) calculated from optical coherence tomography (OCT) images. We conducted a study on mice with chemically induced neoplastic lesions and performed PDT on these lesions using homemade photosensitizers. The response of neoplastic lesions to therapy was monitored using, at the same time, macroscopic clinical visualization, histopathological analysis, OCT imaging, and OCT-based attenuation coefficient measurement. Results with all four modalities demonstrated a positive response to treatment. The attenuation coefficient was found to be 1.4 higher in skin lesions than in healthy tissue and it decreased after therapy. This study shows that the OAC is a potential tool to noninvasively assess the evolution of skin neoplastic lesions with time after treatment.