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Honey adulteration is a common practice that affects food quality and sale prices, and certifying the origin of the honey using non-destructive methods is critical. Guindo Santo and Quillay are fundamental for the honey production of Biobío and the Ñuble region in Chile. Furthermore, Guindo Santo only exists in this area of the world. Therefore, certifying honey of this species is crucial for beekeeper communities-mostly natives-to give them advantages and competitiveness in the global market. To solve this necessity, we present a system for detecting adulterated endemic honey that combines different artificial intelligence networks with a confocal optical microscope and a tunable optical filter for hyperspectral data acquisition. Honey samples artificially adulterated with syrups at concentrations undetectable to the naked eye were used for validating different artificial intelligence models. Comparing Linear discriminant analysis (LDA), Support vector machine (SVM), and Neural Network (NN), we reach the best average accuracy value with SVM of 93% for all classes in both kinds of honey. We hope these results will be the starting point of a method for honey certification in Chile in an automated way and with high precision.

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Composite veneers stand out in modern dentistry for their practicality, time-saving and excellent optical properties. This work describes the operative steps for the realization of veneers in composite resin in an academic clinical environment using a semi-direct technique. A 21-yearold female patient attended the clinic-school complaining of aesthetic dissatisfaction with her smile. In the clinical dental evaluation, multiple diastemas were observed in the upper anterior teeth, and resin cement residues from orthodontic bracket bonding. In addition, the patient expressed an interest in having bigger and whiter teeth. In view of the complaints reported by the patient, the following treatment sequence was proposed: 1. Removal of residual resin cement from all teeth; 2. Tooth whitening; 3. Confection of composite resin veneers using the semi-direct technique on the upper teeth (canine to canine). The die stone that had already been made for the home bleaching procedure was used for esthetic rehabilitation. The 6 veneers were made using a nanoparticulate resin. The veneers were cemented and adjusted. The 12-month follow-up showed an excellent marginal adaptation and an excellent aesthetic and function quality. The semi-direct technique may be considered a therapeutic option based on the conservation of sound tooth structure, minimal emotional stress during clinical work and excellent final optical and mechanical properties. Simplicity and practicality of the technique allow reproducibility and excellent results at a lower cost when compared to dental ceramics. (AU)

As facetas em resina composta destacam-se na odontologia moderna por sua praticidade, economia de tempo e excelentes propriedades ópticas. Este trabalho descreve as etapas operatórias para a realização de facetas em resina composta em ambiente clínico acadêmico utilizando a técnica semi-direta. Paciente do sexo feminino, 21 anos, compareceu à clínica-escola com queixa de insatisfação estética com seu sorriso. Na avaliação clínica odontológica, foram observados múltiplos diastemas nos dentes anteriores superiores e resíduos de cimento resinoso proveniente da colagem de braquetes ortodônticos. Além disso, a paciente manifestou interesse em ter dentes maiores e mais brancos. Diante das queixas relatadas pela paciente, foi proposta a seguinte sequência de tratamento: 1. Remoção do cimento resinoso residual detodos os dentes; 2. Clareamento dental; 3. Confecção de facetas de resina composta pela técnica semi-direta nos dentes superiores (canino a canino). O modelo de gesso já confeccionado para o clareamento caseiro foi utilizado para a reabilitação estética. As 6 facetas foram confeccionadas utilizando resina nanoparticulada. As facetas foram cimentadas e ajustadas. O seguimento de 12 meses mostrou uma excelente adaptação marginal e uma excelente qualidade estética e funcional. A técnica semi-direta pode ser considerada uma opção terapêutica baseada na conservação da estrutura dentária sadia, mínimo estresse emocional durante o trabalho clínico e excelentes propriedades ópticas e mecânicas finais. A simplicidade e praticidade da técnica permitem reprodutibilidade e excelentes resultados a um custo menor quando comparado às cerâmicas odontológicas. (AU)

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The misuse of antibiotics in the cattle sector can lead to milk contamination, with concomitant effects on the dairy industry and human health. Biosensors can be applied in this field; however, the influence of the milk matrix on their activity has been poorly studied in light of the preanalytical process. Herein, aptamer-conjugated gold nanoparticles (nanoaptasensors) were investigated for the colorimetric detection in raw milk of four antibiotics used in cattle. The effect of milk components on the colorimetric response of the nanoaptasensors was analyzed by following the selective aggregation of the nanoparticles, using the absorption ratio A520/A720. A preanalytical strategy was developed to apply the nanoaptasensors to antibiotic-contaminated raw milk samples, which involves a clarification step with Carrez reagents followed by the removal of cations through dilution, chelation (EDTA) or precipitation (NaHCO3). The colorimetric signals were detected in spiked samples at concentrations of antibiotics as low as 0.25-fold the maximum residue limits (MRLs) for kanamycin (37.5 µg/L), oxytetracycline (25 µg/L), sulfadimethoxine (6.25 µg/L) and ampicillin (1 µg/L), according to European and Chilean legislation. Overall, we conclude that this methodology holds potential for the semiquantitative analysis of antibiotic residues in raw milk obtained directly from dairy farms.

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In this article we present the development of a biosensor system that integrates nanotechnology, optomechanics and a spectral detection algorithm for sensitive quantification of antibiotic residues in raw milk of cow. Firstly, nanobiosensors were designed and synthesized by chemically bonding gold nanoparticles (AuNPs) with aptamer bioreceptors highly selective for four widely used antibiotics in the field of veterinary medicine, namely, Kanamycin, Ampicillin, Oxytetracycline and Sulfadimethoxine. When molecules of the antibiotics are present in the milk sample, the interaction with the aptamers induces random AuNP aggregation. This phenomenon modifies the initial absorption spectrum of the milk sample without antibiotics, producing spectral features that indicate both the presence of antibiotics and, to some extent, its concentration. Secondly, we designed and constructed an electro-opto-mechanic device that performs automatic high-resolution spectral data acquisition in a wavelength range of 400 to 800 nm. Thirdly, the acquired spectra were processed by a machine-learning algorithm that is embedded into the acquisition hardware to determine the presence and concentration ranges of the antibiotics. Our approach outperformed state-of-the-art standardized techniques (based on the 520/620 nm ratio) for antibiotic detection, both in speed and in sensitivity.

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BACKGROUND: In Chile, in the next 20 years there will be an average number of 537,100 women of childbearing age with type 2 diabetes (T2DM). Half of these women, not knowing their diagnosis of diabetes will become pregnant with elevated glycosylated hemoglobin levels, increasing to 25% the risk of having offspring with congenital malformations. AIM: To calculate the cost-effectiveness of a diabetes detection strategy in women of childbearing age for the prevention of congenital malformations in the period 2020-2039. MATERIAL AND METHODS: The Markov stochastic model was used in two scenarios, namely A: No intervention and B: Intervention, detecting T2DM in Chilean women aged 15-49 years. We calculated the years of life lost due to premature death (YLL), years of life lost adjusted for disability (DALY) and total costs using American dollars (US$) of 2017, with a discount rate of 5%. RESULTS: In scenario A: 63,330 children with malformations would be born, YLLs and DALYs would be 800,750 and 1,544,775 respectively, and US$ 10,194,298,011 would be expended. In scenario B, these figures would be reduced in approximately 70% to 19,025 children born with malformations, YLLS and DALYs would be 40,539 and 464,033 respectively and US$ 3,354,321,968 would be expended. The costs of prevention would be US$ 6,590.94/malformation avoided, US$ 521.33/YLL avoided, and US$ 270.24/DALY avoided. CONCLUSIONS: In the context of an increasing prevalence of diabetes in women of childbearing age, our results suggest that the early detection of diabetes in Chilean women between 15 and 49 years of age, should be cost-effective to avoid an increase in congenital malformations for the next 20 years.

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BACKGROUND: In Chile, in the next 20 years there will be an average number of 537,100 women of childbearing age with type 2 diabetes (T2DM). Half of these women, not knowing their diagnosis of diabetes will become pregnant with elevated glycosylated hemoglobin levels, increasing to 25% the risk of having offspring with congenital malformations. AIM: To calculate the cost-effectiveness of a diabetes detection strategy in women of childbearing age for the prevention of congenital malformations in the period 2020-2039. MATERIAL AND METHODS: The Markov stochastic model was used in two scenarios, namely A: No intervention and B: Intervention, detecting T2DM in Chilean women aged 15-49 years. We calculated the years of life lost due to premature death (YLL), years of life lost adjusted for disability (DALY) and total costs using American dollars (US$) of 2017, with a discount rate of 5%. RESULTS: In scenario A: 63,330 children with malformations would be born, YLLs and DALYs would be 800,750 and 1,544,775 respectively, and US$ 10,194,298,011 would be expended. In scenario B, these figures would be reduced in approximately 70% to 19,025 children born with malformations, YLLS and DALYs would be 40,539 and 464,033 respectively and US$ 3,354,321,968 would be expended. The costs of prevention would be US$ 6,590.94/malformation avoided, US$ 521.33/YLL avoided, and US$ 270.24/DALY avoided. CONCLUSIONS: In the context of an increasing prevalence of diabetes in women of childbearing age, our results suggest that the early detection of diabetes in Chilean women between 15 and 49 years of age, should be cost-effective to avoid an increase in congenital malformations for the next 20 years.

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Gold nanoparticles (AuNPs) are currently under intense investigation for biomedical and biotechnology applications, thanks to their ease in preparation, stability, biocompatibility, multiple surface functionalities, and size-dependent optical properties. The most commonly used method for AuNP synthesis in aqueous solution is the reduction of tetrachloroauric acid (HAuCl4) with trisodium citrate. We have observed variations in the pH and in the concentration of the gold colloidal suspension synthesized under standard conditions, verifying a reduction in the reaction yield by around 46% from pH 5.3 (2.4 nM) to pH 4.7 (1.29 nM). Citrate-capped AuNPs were characterized by UV-visible spectroscopy, TEM, EDS, and zeta-potential measurements, revealing a linear correlation between pH and the concentration of the generated AuNPs. This result can be attributed to the adverse effect of protons both on citrate oxidation and on citrate adsorption onto the gold surface, which is required to form the stabilization layer. Overall, this study provides insight into the effect of the pH over the synthesis performance of the method, which would be of particular interest from the point of view of large-scale manufacturing processes.

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In this paper, we report on spectral features emitted by a reaction shaft occurring in flash smelting of copper concentrates containing sulfide copper minerals such as chalcopyrite (CuFeS2), bornite (Cu5FeS4) and pyrite (FeS2). Different combustion conditions are addressed, such as sulfur-copper ratio and oxygen excess. Temperature and spectral emissivity features are estimated for each case by using the two wavelength method and radiometric models. The most relevant results have shown an increasing intensity behavior for higher sulfur-copper ratios and oxygen contents, where emissivity is almost constant along the visible spectrum range for all cases, which validates the gray body assumption. CuO and FeO emission line features along the visible spectrum appear to be a sensing alternative for describing the combustion reactions.

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Digital photonic sensors have greatly evolved to maximize sensitivity and spatial, spectral, and temporal imaging resolution. For low-energy photons, new designs have generated new types of noise that degrade the formed-image signal-to-noise ratio to values lower than 1. Fixed-pattern noise (FPN), which is produced by the non-uniform focal-plane-array optoelectronics response, is an ill-posed problem in infrared and hyperspectral imaging science. Here, we experimentally show that the FPN behaves as an object at a depth of infinity when a light field is captured by an imaging system. The proposed method is based on the capture of the light field of a scene and digital refocusing to any nearby objects in the scene. Unlike standard techniques for FPN reduction, our method does not require knowledge of the physical parameters of the optoelectronic transducer, the motion scene, or the presence of off-line blackbody sources. The ability of the proposed method to reduce FPN is measured by evaluating the structural similarity (SSIM) index employing a blackbody-based FPN reduction technique as a reference. This new interpretation of the FPN opens avenues to create new cameras for low-energy photons with the ability to perform denoising by digital refocusing.

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Achatina (Lissachatina) fulica was introduced in Brazil in the 1980s for commercial purposes ("escargot" farming) and nowadays, mainly by human activity, it is widespread in at least 23 out of 26 Brazilian states and Brasília, including the Amazonian region and natural reserves, where besides a general nuisance for people it is a pest and also a public health concern, since it is one of the natural intermediate host of Angiostrongylus cantonensis, ethiological agent of the meningoencephalitis in Asia. As Brazil is experiencing the explosive phase of the invasion, the Laboratório de Malacologia do Instituto Oswaldo Cruz/Fiocruz has been receiving samples of these molluscs for identification and search for Angiostrongylus cantonensis and Angiostrongylus costaricensis larvae. While examining samples of A. fulica different nematode larvae were obtained, including Aelurostrongylus, whose different species are parasites of felids, dogs, primates, and badger. Morphological and morphometric analyses presented herein indicated the species Aelurostrongylus abstrusus, as well as the occurrence of other nematode larvae (Strongyluris-like) found in the interior of the pallial cavity of A. fulica. This is the first report in Brazil of the development of A. abstrusus infective larvae in A. fulica evidencing the veterinary importance of this mollusc in the transmission of A. abstrusus to domestic cats. Since the spread of A. fulica is pointed out in the literature as one of the main causative spread of the meningoencephalitis caused by A. cantonensis the authors emphasize the need of sanitary vigilance of snails and rats from vulnerable areas for A. cantonensis introduction as the port side areas.

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