Influence of different opacities and layering technique of nanotechnology composite resins regarding the wavelength and fluorescence intensity: in vitro study / Influencia de diferentes opacidades y la técnica de estratificación de resinas compuestas de nanotecnología en la longitud de onda e intensidad de fluorescencia: estudio in vitro

Objective: To evaluate the influence of opacity and the layering technique on the fluorescence of different composite resins. Materials and Methods: Two opacities (enamel and dentin) and the layering technique (enamel + dentin) of the composite resins: Filtek® Z350 and Palfique LX5 were evaluated in vitro. Composite resin discs were fabricated using a preformed matrix of 10 mm diameter and 0.5 mm thick for the single opacity groups and 10 mm thick for the layering technique groups, using 2 layers of 0.5 mm thickness of each opacity (n = 5). Specimens were analyzed using the Raman spectroscopy method. Data were analyzed using the Kruskall-wallis and Mann-Whitney U tests. Results: When evaluating the intensity of fluorescence, no statistically significant difference was found when comparing the layering technique and enamel opacity (p2> 0.05) and an increase in the dentin opacity value for both brands of composite resin. Regarding wavelength, no statistically significant difference was found when comparing the layering technique with enamel opacity and dentin opacity for both Filtek® Z350 and Palfique LX5® composite resins (p2 > 0.05). Conclusions: The fluorescence intensity of the layering technique is similar to enamel opacity for both composite resins. Likewise, the wavelength of the layering technique is similar to the enamel opacity and dentin opacity for both brands.

Objetive: Evaluar la influencia de la opacidad y de la técnica de estratificación en la fluorescencia de diferentes resinas compuestas. Materiales y Métodos: Se evaluó in vitro 2 opacidades (Esmalte y Dentina) y la técnica de estratificación (Esmalte + Dentina) de las resinas compuestas: Filtek® Z350 y Palfique LX5. Se fabricaron discos de resina compuesta, utilizando una matriz preformada de 10 mm de diámetro y 0,5 mm de grosor para los grupos de opacidad única y 10 mm de grosor para los grupos de técnica estratificada, utilizando 2 capas de 0,5 mm de cada opacidad (n = 5). Los especímenes se analizaron mediante el método de Espectroscopía Raman. Los datos se analizaron utilizando la prueba de Kruskall-wallis y Prueba U de Mann Whitney. Resultado: Al evaluar la intensidad de fluorescencia no se encontró diferencia estadísticamente significativa entre los pares: Técnica estratificada versus Opacidad Esmalte para ambas marcas de resina compuesta Filtek® Z350 y para Palfique LX5® (p2 > 0,05). Para longitud de onda no se encontró diferencia estadísticamente significativa entre los pares: Técnica estratificada versus Opacidad Esmalte y Técnica estratificada VS Opacidad Dentina para ambas resinas compuesta Filtek® Z350 y Palfique LX5® (p2> 0,05). Conclusión: La intensidad de fluorescencia de la técnica estratificada es similar a la opacidad Esmalte para ambas resinas compuestas. De igual manera la longitud de onda de la técnica estratificada es similar a la opacidad Esmalte y opacidad Dentina para ambas marcas.

Comparison of biofilm models for producing artificial active white spot lesions

Abstract Creating artificial caries-like lesions that mimic the complex changes observed in natural caries is essential for properly evaluating new strategies, dental materials, and devices designed to arrest their progression and avoid more costly and invasive treatments. Objective This study compared three protocols for developing artificial white spot lesions (WSL) using biofilm models. Methodology In total, 45 human enamel specimens were sterilized and allocated into three groups based on the biofilm model: Streptococcus sobrinus and Lactobacillus casei (Ss+Lc), Streptococcus sobrinus (Ss), or Streptococcus mutans (Sm). Specimens were incubated in filter-sterilized human saliva to form the acquired pellicle and then subjected to the biofilm challenge consisting of three days of incubation with bacteria (for demineralization) and one day of remineralization, which was performed once for Ss+Lc (four days total), four times for Ss (16 days total), and three times for Sm (12 days total). After WSL creation, the lesion fluorescence, depth, and chemical composition were assessed using Quantitative Light-induced Fluorescence (QLF), Polarized Light Microscopy (PLM), and Raman Spectroscopy, respectively. Statistical analysis consisted of two-way ANOVA followed by Tukey's post hoc test (α=0.05). WSL created using the Ss+Lc protocol presented statistically significant higher fluorescence loss (ΔF) and integrated fluorescence (ΔQ) in comparison to the other two protocols (p<0.001). Results In addition, Ss+Lc resulted in significantly deeper WSL (137.5 µm), followed by Ss (84.1 µm) and Sm (54.9 µm) (p<0.001). While high mineral content was observed in sound enamel surrounding the WSL, lesions created with the Ss+Lc protocol showed the highest demineralization level and changes in the mineral content among the three protocols. Conclusion The biofilm model using S. sobrinus and L. casei for four days was the most appropriate and simplified protocol for developing artificial active WSL with lower fluorescence, higher demineralization, and greater depth.

Analysis of the distribution of microhardness, mineral, and organic content of human, bovine, and ovine teeth / Análisis de la distribución de microdureza, contenido mineral y orgánico de dientes humanos, bovinos y ovinos

Objetive. Human teeth have been commonly used for in vitro and in situ studies. Cu­rrently, other animals' teeth have been purposed for dental research to overcome human teeth' problematic availability. This study aimed to investigate the enamel and dentin from human, bovine, and ovine teeth concerning the microhardness, organic, and in­ organic contents via micro­Raman spectroscopy. Methods. Human, bovine, and ovine teeth were divided according to their type and age into seven groups: Ovine; Bovine­12 months; Bovine­24 months; Bovine­36 months; Bovine­48 months; Bovine­+60 months; Human (control). The enamel's microhardness (superficial and deep) and den­tin (superficial, middle, and deep) were analyzed. The calcium/phosphate ratio and am­ide contents were determined by micro­Raman spectroscopy. Results. Overall, the mi­crohardness of human enamel was superior to the other species. Dentin's microhardness was similar among groups. Ovine group showed lower values of calcium/phosphate ratio than human. Amide content was similar between bovine and human. The microhardness and calcium/phosphate ratio of enamel and dentin, respectively, decreased as the age of bovine teeth increased. Conclusions. Researchers must be aware and take into consider­ation the differences of ovine and bovine enamel compared to human enamel. Other al­ternatives that are more similar to the microhardness of human enamel should be sought. Bovine teeth of 12 and 24 months are suitable substitutes for dentin of human teeth. Researchers must also be aware of the age of the animals and specify it in the studies.

Objetivo. Los dientes humanos se han utilizado comúnmente para estudios in vitro e in situ. Actualmente, los dientes de otros animales se han destinado a la investiga­ción dental para superar la disponibilidad problemática de los dientes humanos. Este estudio tuvo como objetivo investigar el esmalte y la dentina de los dientes humanos, bovinos y ovinos en relación con la microdureza y los contenidos orgánicos e inor­gánicos a través de la espectroscopia micro­Raman. Métodos. Los dientes humanos, bovinos y ovinos se dividieron según su tipo y edad en siete grupos: Ovinos; Bovino­12 meses; Bovino­24 meses; Bovino­36 meses; Bovino­48 meses; Bovino­+60 meses; Hu­mano (control). Se analizó la microdureza del esmalte (superficial y profunda) y de la dentina (superficial, media y profunda). La relación calcio/fosfato y los contenidos de amida se determinaron mediante espectroscopía micro­Raman. Resultados. En general, la microdureza del esmalte humano fue superior a la de otras especies. La microdureza de la dentina fue similar entre los grupos. El grupo ovino mostró valores más bajos de la relación calcio/fosfato que el humano. El contenido de amida fue similar entre bovinos y humanos. La microdureza y la relación calcio/fosfato del esmalte y la dentina, respectiva­mente, disminuyeron a medida que aumentaba la edad de los dientes bovinos. Conclusiones. El esmalte de los dientes ovinos y bovinos no es un sustituto adecuado del de los dientes humanos. Se deben buscar otras alternativas que sean similares a la microdureza del esmalte humano. Sin embargo, los dientes bovinos de 12 y 24 meses son sustitutos adecuados de la dentina de los dientes humanos. Los investigadores deben conocer la edad de los animales y especificarla en los estudios.

Study of laser fluorescence spectroscopy in livers of rats with hypothermic ischemia

Purpose: After partial hepatectomy (PH), the remaining liver (RL) undergoes regenerative response proportional to the host. Limited literature exists on hepatic viability after tissue injury during hypothermic preservation. Spectroscopy measures cellular fluorescence and is explored for tissue characterization and parameter investigation. This study aimed to assess fluorescence analysis (spectroscopy) in evaluating liver viability and its relationship with hepatic tissue regeneration 24 hours after PH. Additionally, we analyzed liver regeneration in RL after 70% partial hepatectomy under hypothermic conditions with laser irradiation. Methods: Fifty-six Wistar rats were divided into four groups: total non-perfused liver (control), total perfused liver, partial hepatectomy "in situ", and partial hepatectomy "ex situ". Tissue analysis was performed at 0 and 24 hours using spectroscopy with laser devices emitting at 532 (green) and 405 nm (violet). Results: Spectroscopy identified tissue viability based on consistent results with Ki67 staining. The fluorescence spectra and Ki67 analysis displayed similar patterns, linking proliferative activity and absorption intensity. Conclusions: Fluorescence spectroscopy proves to be promising for real-time analysis of cellular activity and viability. Metabolic activity was observed in groups of live animals and hypothermically preserved samples, indicating cellular function even under blood deprivation and hypothermic conditions.

Vascular Spectrum of Imaging Findings in COVID-19: Ischemic, Hemorrhagic, and Thromboembolic Complications

Abstract Ischemic strokes secondary to occlusion of large vessels have been described in patients with COVID-19. Also, venous thrombosis and pulmonary thromboembolism have been related to the disease. Vascular occlusion may be associated with a prothrombotic state due to COVID-19-related coagulopathy and endotheliopathy. Intracranial hemorrhagic lesions can additionally be seen in these patients. The causative mechanism of hemorrhage could be associated with anticoagulant therapy or factors such as coagulopathy and endotheliopathy. We report on cases of ischemic, thrombotic, and hemorrhagic complications in six patients diagnosed with SARS-CoV-2 infection. Chest computed tomography (CT) showed typical SARS-CoV-2 pneumonia findings in all the cases, which were all confirmed by either serology or reverse transcription polymerase chain reaction (RT-PCR) tests.

Computational Approaches and Tools as Applied to the Study of Rhythms and Chaos in Biology.

The temporal dynamics in biological systems displays a wide range of behaviors, from periodic oscillations, as in rhythms, bursts, long-range (fractal) correlations, chaotic dynamics up to brown and white noise. Herein, we propose a comprehensive analytical strategy for identifying, representing, and analyzing biological time series, focusing on two strongly linked dynamics: periodic (oscillatory) rhythms and chaos. Understanding the underlying temporal dynamics of a system is of fundamental importance; however, it presents methodological challenges due to intrinsic characteristics, among them the presence of noise or trends, and distinct dynamics at different time scales given by molecular, dcellular, organ, and organism levels of organization. For example, in locomotion circadian and ultradian rhythms coexist with fractal dynamics at faster time scales. We propose and describe the use of a combined approach employing different analytical methodologies to synergize their strengths and mitigate their weaknesses. Specifically, we describe advantages and caveats to consider for applying probability distribution, autocorrelation analysis, phase space reconstruction, Lyapunov exponent estimation as well as different analyses such as harmonic, namely, power spectrum; continuous wavelet transforms; synchrosqueezing transform; and wavelet coherence. Computational harmonic analysis is proposed as an analytical framework for using different types of wavelet analyses. We show that when the correct wavelet analysis is applied, the complexity in the statistical properties, including temporal scales, present in time series of signals, can be unveiled and modeled. Our chapter showcase two specific examples where an in-depth analysis of rhythms and chaos is performed: (1) locomotor and food intake rhythms over a 42-day period of mice subjected to different feeding regimes; and (2) chaotic calcium dynamics in a computational model of mitochondrial function.

Non-invasive neuromonitoring in intensive care units in Colombia / [Neuromonitoreo no invasivo en unidades de cuidados intensivos en Colombia].

Continuous non-invasive electroencephalographic monitoring is an essential technique for critical care patients as it shows directly and indirectly the patient's brain activity and makes it possible to relate it with findings in the clinical status. It is highly sensitive, although its specificity is lower, so they can show alterations of the state of consciousness without clarifying the etiology. Continuous electroencephalographic recording in patients with altered levels of consciousness, seizures, and convulsive and non-convulsive status epilepticus has been increasing in recent years as real-time feedback of the cerebral function shows evolution changes and allows for the identification of electric and subclinical epileptic seizures that are highly important since they do not have clinical correlations. These findings in electroencephalographic monitoring also help to modify pharmacological and antiseizure treatments. For practitioners, they are advantageous when making timely decisions that impact the prognosis of the patient.

El monitoreo electroencefalográfico no invasivo continuo es una técnica indispensable en los pacientes neurológicos críticos, ya que muestra de forma directa e indirecta su actividad cerebral y permite relacionar los hallazgos con su estado clínico. Es muy sensible, aunque su especificidad es menor, por lo que puede demostrar la alteración del estado de conciencia sin aclarar su etiología. El uso del registro electroencefalográfico continuo en pacientes con alteraciones del estado de conciencia, convulsiones, o estado epiléptico convulsivo y no convulsivo, se ha incrementado en los últimos años porque permite obtener información en tiempo real de la función cerebral y de los cambios en el tiempo; además, facilita la detección de crisis epilépticas subclínicas y electrográficas, estas últimas de gran importancia, ya que no presentan correlación clínica. Los hallazgos del monitoreo permiten modificar el tratamiento farmacológico y anticonvulsivo, y constituyen una gran ventaja para el médico tratante en la toma de decisiones oportunas que redunden en la mejoría del pronóstico del paciente.

[Determination of glucose levels by means of spectroscopy as a non-invasive method]. / Determinación niveles de glucosa por medio de espectroscopía como método no invasivo.

Background: Diabetes mellitus is one of the most serious public health problems in Mexico. The most worrying factor is the lack of control of it, which has a direct impact, causing severe damage to the health and quality of life of the patient and its family, as well as an economic burden to the health system. The development of a non-invasive method for measuring blood glucose would provide to patients a simple and painless way of monitoring and consequently better control of diabetes. Objective: To investigate, develop and validate a non-invasive sensor by means of spectroscopy for the estimation of the blood glucose level. Material and methods: An analysis of a cross-sectional analytical correlation study was carried out in the facilities of the laboratory at the UMAE No. 1, Bajío. Voluntary adult patients who attended the laboratory of the UMAE to take serum glucose levels were included, and simultaneously the measurement was carried out through a non-invasive method by spectroscopy and, later, both results were compared to demonstrate the validity of the device. Results: By the Bland-Altman mean difference analysis, it was identified that only one patient had an extreme value, and that the method to measure glucose non-invasively overestimates up to 10.2% of the central glucose value. Conclusions: Comparing these results with the standards for digital glucometers, it is concluded that our device is capable of providing accurate glucose levels.

Introducción: la diabetes mellitus es uno de los problemas más graves de salud pública que enfrenta México. El factor más preocupante es la falta de control de la misma, lo que incide de manera directa, causando daños severos a la salud y la calidad de vida del paciente y familiares, así como una carga económica al país. El desarrollo de un método no invasivo para la medición de la glucemia proporcionaría a los pacientes una forma sencilla e indolora de monitoreo y, en consecuencia, un mejor control de la diabetes. Objetivo: investigar, desarrollar y validar un sensor no invasivo por medio de la espectroscopía para la estimación del nivel de glucosa en sangre. Material y métodos: se realizó un análisis de estudio transversal analítico de correlación realizado en las instalaciones del laboratorio de la UMAE No 1, Bajío. Se incluyeron pacientes adultos voluntarios que acudieron al laboratorio de dicha unidad para la toma de niveles de glucosa sérica y de manera simultánea se realizó la medición a través de método no invasivo por espectroscopía y, posteriormente, se compararon ambos resultados para demostrar la validez del dispositivo. Resultados: mediante el análisis de la diferencia de medias de Bland-Altman, se identificó que solamente un paciente tuvo un valor extremo, y que el método para medir la glucosa de manera no invasiva sobreestima hasta un 10.2% del valor de glucosa central. Conclusión: comparando dichos resultados con las normas para glucómetros digitales se concluye que nuestro dispositivo es capaz de proporcionar niveles de glucosa certeros.

Neuromonitoreo no invasivo en unidades de cuidados intensivos en Colombia / Non-invasive neuromonitoring in intensive care units in Colombia

Resumen | El monitoreo electroencefalográfico no invasivo continuo es una técnica indispensable en los pacientes neurológicos críticos, ya que muestra de forma directa e indirecta su actividad cerebral y permite relacionar los hallazgos con su estado clínico. Es muy sensible, aunque su especificidad es menor, por lo que puede demostrar la alteración del estado de conciencia sin aclarar su etiología. El uso del registro electroencefalográfico continuo en pacientes con alteraciones del estado de conciencia, convulsiones, o estado epiléptico convulsivo y no convulsivo, se ha incrementado en los últimos años porque permite obtener información en tiempo real de la función cerebral y de los cambios en el tiempo; además, facilita la detección de crisis epilépticas subclínicas y electrográficas, estas últimas de gran importancia, ya que no presentan correlación clínica. Los hallazgos del monitoreo permiten modificar el tratamiento farmacológico y anticonvulsivo, y constituyen una gran ventaja para el médico tratante en la toma de decisiones oportunas que redunden en la mejoría del pronóstico del paciente.

Abstract | Continuous non-invasive electroencephalographic monitoring is an essential technique for critical care patients as it shows directly and indirectly the patient's brain activity and makes it possible to relate it with findings in the clinical status. It is highly sensitive, although its specificity is lower, so they can show alterations of the state of consciousness without clarifying the etiology. Continuous electroencephalographic recording in patients with altered levels of consciousness, seizures, and convulsive and non-convulsive status epilepticus has been increasing in recent years as real-time feedback of the cerebral function shows evolution changes and allows for the identification of electric and subclinical epileptic seizures that are highly important since they do not have clinical correlations. These findings in electroencephalographic monitoring also help to modify pharmacological and antiseizure treatments. For practitioners, they are advantageous when making timely decisions that impact the prognosis of the patient.

Determinación niveles de glucosa por medio de espectroscopía como método no invasivo / Determination of glucose levels by means of spectroscopy as a non-invasive method

Introducción: la diabetes mellitus es uno de los problemas más graves de salud pública que enfrenta México. El factor más preocupante es la falta de control de la misma, lo que incide de manera directa, causando daños severos a la salud y la calidad de vida del paciente y familiares, así como una carga económica al país. Por lo tanto, el desarrollo de un método no invasivo para la medición de la glucemia proporcionaría a los pacientes una forma sencilla e indolora de monitoreo y, en consecuencia, un mejor control de la diabetes. Objetivo: investigar, desarrollar y validar un sensor no invasivo por medio de la espectroscopía para la estimación del nivel de glucosa en sangre. Material y métodos: se realizó un análisis de estudio transversal analítico de correlación realizado en las instalaciones del laboratorio de la UMAE No 1, Bajío. Se incluyeron pacientes adultos voluntarios que acudieron al laboratorio de dicha unidad para la toma de niveles de glucosa sérica y de manera simultánea se realizó la medición a través de método no invasivo por espectroscopía y, posteriormente, se compararon ambos resultados para demostrar la validez del dispositivo. Resultados: mediante el análisis de la diferencia de medias de Bland-Altman, se identificó que solamente un paciente tuvo un valor extremo, y que el método para medir la glucosa de manera no invasiva sobreestima hasta un 10.2% del valor de glucosa central. Conclusión: comparando dichos resultados con las normas para glucómetros digitales se concluye que nuestro dispositivo es capaz de proporcionar niveles de glucosa certeros.

Background: Diabetes mellitus is one of the most serious public health problems in Mexico. The most worrying factor is the lack of control of it, which has a direct impact, causing severe damage to the health and quality of life of the patient and its family, as well as an economic burden to the health system. Therefore, the development of a non-invasive method for measuring blood glucose would provide to patients a simple and painless way of monitoring and consequently better control of diabetes. Objective: Research, development and validation of a non-invasive sensor by means of spectroscopy for the estimation of the blood glucose level. Material and methods: An analysis of a cross-sectional analytical correlation study was carried out in the facilities of the laboratory at the UMAE No. 1, Bajío. Voluntary adult patients who attended the laboratory of the UMAE to take serum glucose levels were included, and simultaneously the measurement was carried out through a non-invasive method by spectroscopy and, later, both results were compared to demonstrate the validity of the device. Results: By the Bland-Altman mean difference analysis, it was identified that only one patient had an extreme value, and that the method to measure glucose non-invasively overestimates up to 10.2% of the central glucose value. Conclusion: Comparing these results with the standards for digital glucometers, it is concluded that our device is capable of providing accurate glucose levels.

Assessment of changes in the electrical activity of the brain during general anesthesia using portable electroencephalography / Evaluación de los cambios de la actividad eléctrica cerebral durante anestesia general usando electroencefalografía portable

Abstract Introduction The analysis of the electrical activity of the brain using scalp electrodes with electroencephalography (EEG) could reveal the depth of anesthesia of a patient during surgery. However, conventional EEG equipment, due to its price and size, are not a practical option for the operating room and the commercial units used in surgery do not provide access to the electrical activity. The availability of low-cost portable technologies could provide for further research on the brain activity under general anesthesia and facilitate our quest for new markers of depth of anesthesia. Objective To assess the capabilities of a portable EEG technology to capture brain rhythms associated with the state of consciousness and the general anesthesia status of surgical patients anesthetized with propofol. Methods Observational, cross-sectional study that reviewed 10 EEG recordings captured using OpenBCI portable low-cost technology, in female patients undergoing general anesthesia with propofol. The signal from the frontal electrodes was analyzed with spectral analysis and the results were compared against the reports in the literature. Results The signal captured with frontal electrodes, particularly α rhythm, enabled the distinction between resting with eyes closed and with eyes opened in a conscious state, and sustained anesthesia during surgery. Conclusions It is possible to differentiate a resting state from sustained anesthesia, replicating previous findings with conventional technologies. These results pave the way to the use of portable technologies such as the OpenBCI tool, to explore the brain dynamics during anesthesia.

Resumen Introducción El análisis de la actividad eléctrica cerebral mediante electrodos ubicados sobre el cuero cabelludo con electroencefalografía (EEG) podría permitir conocer la profundidad anestésica de un paciente durante cirugía. Sin embargo, los equipos de EEG convencionales, por su precio y tamaño, no son una alternativa práctica en quirófanos y los equipos comerciales usados en cirugía no permiten acceder a la actividad eléctrica. Disponer de tecnologías portables y de bajo costo aumentaría el número de investigaciones sobre la actividad cerebral bajo anestesia general y facilitaría la búsqueda de nuevos marcadores para la profundidad anestésica. Objetivo Evaluar la capacidad de una tecnología EEG portable de adquirir ritmos cerebrales relacionados con el estado consciente y el estado de anestesia general de pacientes en cirugía anestesiados con propofol. Métodos Estudio observacional de corte transversal en el que se analizaron datos de 10 registros EEG obtenidos mediante tecnología portable y de bajo costo OpenBCI, de pacientes de sexo femenino que fueron sometidas a anestesia general con propofol. La señal obtenida de los electrodos frontales se analizó mediante análisis espectral y se contrastaron los resultados con lo descrito en la literatura. Resultados La señal obtenida con electrodos frontales, especialmente el ritmo α, permitió diferenciar el reposo con ojos cerrados y ojos abiertos en estado consciente, del estado de mantenimiento de la anestesia durante cirugía. Conclusiones Se logra la diferenciación de estado de reposo y de mantenimiento de la anestesia replicando hallazgos previos de tecnologías convencionales. Estos resultados abren la posibilidad de utilizar las tecnologías portables como el OpenBCI para investigar la dinámica cerebral durante la anestesia.

Relationships Between Cardiovascular Autonomic Profile and Work Ability in Patients With Pure Autonomic Failure.

Pure autonomic failure (PAF) is a rare disorder belonging to the group of synucleinopathies, characterized by autonomic nervous system degeneration. Severe orthostatic intolerance with recurrent syncope while standing are the two most disabling manifestations. Symptoms may start at middle age, thus affecting people at their working age. The aims of this study were to evaluate the autonomic and work ability impairment of a group of PAF patients and assess the relationships between cardiovascular autonomic control and work ability in these patients. Eleven PAF patients (age 57.3 ± 6.7 years), engaged in work activity, participated in the study. They completed the Composite Autonomic Symptom Score (COMPASS-31, range 0 no symptom-100 maximum symptom intensity) and Work Ability questionnaires (Work Ability Index, WAI, range 7-49; higher values indicate better work ability and lower values indicating unsatisfactory or jeopardized work ability). Electrocardiogram, blood pressure and respiratory activity were continuously recorded for 10 min while supine and during 75° head-up tilt (HUT). Autoregressive spectral analysis of cardiac cycle length approximated as the time distance between two consecutive R-wave peaks (RR) and systolic arterial pressure (SAP) variabilities provided the power in the high frequency (HF, 0.15-0.40 Hz) and low frequency (LF, 0.04-0.15 Hz) bands of RR and SAP variabilities. Cardiac sympatho-vagal interaction was assessed by LF to HF ratio (LF/HF), while the LF power of SAP (LFSAP) quantified the vascular sympathetic modulation. Changes in cardiovascular autonomic indexes induced by HUT were calculated as the delta (Δ) between HUT and supine resting positions. Spearman correlation analysis was applied. PAF patients were characterized by a moderate autonomic dysfunction (COMPASS-31 total score 47.08 ± 20.2) and by a reduction of work ability (WAI 26.88 ± 10.72). Direct significant correlations were found between WAI and ΔLFRR (r = 0.66, p = 0.03) and ΔLF/HFRR (r = 0.70, p = 0.02). Results indicate that patients who were better able to modulate heart rate, as revealed by a greater cardiac sympathetic increase and/or vagal withdrawal during the orthostatic stimulus, were those who reported higher values of WAI. This finding could be relevant to propose new strategies in the occupational environment to prevent early retirement or to extend the working life of these patients.

Synthesis, characterization, and incorporation of upconverting nanoparticles into a dental adhesive

Abstract: The purpose of this study was to describe the synthesis, characterization, and functionalization of b-NaYF4:30%Yb/0.5%Tm upconverting nanocrystals for use as nanofillers in a dental adhesive and microscopically evaluate the interface between the particles and a commercial adhesive. The upconverting nanoparticles were synthesized and purified by thermal decomposition, and their chemical composition determined by energy dispersive X-Ray spectroscopy. The crystalline structure was characterized using X-Ray diffraction and morphology and size were observed with scanning and transmission electron microscopy. Upconverting emission was evaluated by spectrophotometry irradiating the particles with a 975 nm diode laser. Particles were functionalized with polyacrylic acid and the success was confirmed by measurement of Zeta Potential and transmission electron microscopy. The results of X-ray diffraction found a pure hexagonal phase crystalline pattern. Scanning electron microscopy showed uniform dispersion of hexagonal-shaped particles of approximately 150 nm. Upconversion emission was observed in 344 nm, 361 nm, 450 nm, 474nm, 646 nm, 803 nm. Functionalization success was confirmed by formation of a stable aqueous colloid with a Zeta potential of −29.5mV and the absence of voids in the particle-adhesive interface on the transmission electron microscopy images. The reported synthesis and functionalization process produced upconverting nanoparticles emitting photons within the blue spectral region (450 nm and 474 nm).

The Decomposition and Forecasting of Mutual Investment Funds Using Singular Spectrum Analysis.

Singular spectrum analysis (SSA) is a non-parametric method that breaks down a time series into a set of components that can be interpreted and grouped as trend, periodicity, and noise, emphasizing the separability of the underlying components and separate periodicities that occur at different time scales. The original time series can be recovered by summing all components. However, only the components associated to the signal should be considered for the reconstruction of the noise-free time series and to conduct forecasts. When the time series data has the presence of outliers, SSA and other classic parametric and non-parametric methods might result in misleading conclusions and robust methodologies should be used. In this paper we consider the use of two robust SSA algorithms for model fit and one for model forecasting. The classic SSA model, the robust SSA alternatives, and the autoregressive integrated moving average (ARIMA) model are compared in terms of computational time and accuracy for model fit and model forecast, using a simulation example and time series data from the quotas and returns of six mutual investment funds. When outliers are present in the data, the simulation study shows that the robust SSA algorithms outperform the classical ARIMA and SSA models.

Influence of different phosphoric acids before application of universal adhesive on the dental enamel.

BACKGROUND: There are different etching gels available, which have different composition, different pH, and different viscosity, and there is little information in the literature comparing all these products. OBJECTIVE: To evaluate the mean microshear bond strength and morphological characteristics of tooth enamel by evaluating different phosphoric acids combined with a universal adhesive system. MATERIALS AND METHODS: Eighty-four enamel samples were used, which were divided according to the acid conditioning: G1: Scotchbond Etchant (3M Oral Care), G2: Ultra-Etch (Ultradent), G3: Eco-Etch (IvoclarVivadent), G4: ETCH-37 with BAC (Bisco), G5: Etching gel (Densell), G6: Condac 37 (FGM), and G7: Scotchbond Universal Adhesive (3M Oral Care) in self-etch mode. For the adhesive procedure, Scotchbond Universal Adhesive was the one used as indicated the manufacturer's instructions, 0.9-mm-diameter resin cylinders were placed. The microshear bond strength test was performed after being stored for 24 hours in water. The morphological characteristics of tooth enamel were analyzed using the Raman confocal microscope alpha300RA. The analysis of variance (ANOVA) test and Tukey post-test were used to analyze the differences between the groups. RESULTS: The mean microshear bond strength values obtained for groups 1, 4, 5 were significantly greater than groups 2, 3, 6 and 7 (p < .05). All groups presented demineralization after the application of the etching acid, and few signs of demineralization were evident in group 7. CONCLUSIONS: Acid-etching with ETCH-37 with BAC, Etching gel, and Scotchbond Etchant improved the adhesive strength in the enamel using an universal adhesive, and acid-etching with Condac 37, Ultra-Etch, and Eco-Etch provides similar adhesive strength values to self-etch mode of universal adhesive. CLINICAL SIGNIFICANCE: All acid etchants should be considered as different. The test confirms that enamel etching prior to the application of a universal adhesive system depends on the selected acid etchand product.

Nuevo detector de enfermedades vestibulares basado en el análisis espectro temporal de nistagmogramas

Introducción: La exploración del sistema vestibular exige una evaluación precisa, sistemática y completa de la respuesta vestíbulo-ocular. Actualmente los sistemas solo analizan secciones definidas subjetivamente por especialistas clínicos en los registros del nistagmo, y se calculan parámetros en el dominio del tiempo, que a menudo se ven afectados por las interferencias y el ruido en el sistema de exploración durante las pruebas vestibulares. Objetivo: Presentar un nuevo sistema para la exploración y caracterización del nistagmo obtenido mediante electronistagmografía. Métodos: Los registros fueron adquiridos a partir de pruebas rotatorias en una muestra de 49 sujetos, se introdujo el análisis espectro temporal del nistagmo inducido, que permitió definir la zona de mayor interés clínico para el análisis durante las pruebas. Resultados: Se obtuvo un nuevo indicador espectro temporal, detector de enfermedades vestibulares, basado en la comparación del comportamiento del análisis espectral del nistagmo en la sección central de fases de velocidad constante y desaceleración de los registros clínicos. Se obtuvo una buena sensibilidad (90,32 %) y una buena especificidad (88,89 %) del nuevo indicador, relacionado con la determinación de personas enfermas en uno o ambos laberintos. Conclusiones: El método y el nuevo indicador definido, presentaron mayor capacidad diagnóstica, que el habitual análisis cuantitativo de las señales; mostraron una sensibilidad y especificidad superiores. Permiten llegar a conclusiones en la práctica clínica diaria, con mucha más rapidez que la valoración de los parámetros temporales habitualmente utilizados en los análisis, que presentan como debilidad, el amplio intervalo de valores normales.

Introduction: The exploration of the vestibular system requires an accurate, systematic and complete evaluation of the vestibule-ocular response. Currently, systems only analyze sections subjectively defined by clinical specialists in nystagmus records, and time domain parameters are calculated, which are often affected by interference and noise in the scanning system during vestibular tests. Objective: To present a new system for the exploration and characterization of nystagmus obtained by electronistagmography. Methods: The records were acquired from rotary tests in a sample of 49 subjects, the temporal spectrum analysis of the induced nystagmus was introduced, which allowed defining the area of ​​greatest clinical interest for the analysis during the tests. Results: A new temporal spectrum indicator was obtained, detector of vestibular diseases, based on the comparison of the behavior of the spectral analysis of nystagmus in the central section of constant velocity phases and deceleration of clinical records. A good sensitivity (90.32%) and a good specificity (88.89%) of the new indicator were obtained, related to the determination of sick people in one or both labyrinths. Conclusions: The method and the new defined indicator, presented greater diagnostic capacity, than the usual quantitative analysis of the signals; they showed superior sensitivity and specificity. They allow conclusions to be reached in daily clinical practice, much faster than the assessment of the temporal parameters usually used in the analyzes, which present as a weakness, the wide range of normal values.

Brazilian preschool children attending day care centers show an inadequate micronutrient intake through 24-h duplicate diet.

Inadequate micronutrient intake in childhood harms growth and development, and it is related to increased rates of morbidity and mortality. The aim of this study is to evaluate the dietary intake and prevalence of inadequate micronutrient intake in preschool children (1-4 years old) attending two-day care centers. To assess children's dietary micronutrient intake, 24-h duplicate diets (n = 64) were collected for one week-day, including everything the children ate and drank both at home and in kindergarten. Anthropometric measurements were carried out to evaluate the children's nutritional status. The micronutrients copper, iron, calcium, magnesium, selenium, zinc, potassium, sodium, and manganese were determined by inductively coupled plasma mass spectrometry or graphite furnace atomic absorption spectrometry. Calcium and selenium were found with high inadequate intake rates: 50% and 42%, respectively, for children aged 1-3 years old, and 93% and 90% for children aged 4 years. Potassium was consumed in very low amounts, 13% and 5% of children aged 1-3 and 4 years old, respectively, achieved the adequate intake for the nutrient. Sodium intakes were excessive: 23% of the 1-3-year old and 42% of the 4-year-old children, respectively, had an intake higher than the tolerable upper levels. Regarding the nutritional status, overweight and obesity prevalence was 17%. Therefore, considering the damaging health effects for children of micronutrient deficiency and overweight and obesity status, it is necessary that government authorities be aware and update public policies and educational programs in order to promote healthy eating habits in early childhood.

Very High Frequency Oscillations of Heart Rate Variability in Healthy Humans and in Patients with Cardiovascular Autonomic Neuropathy.

Literature reports on the very high frequency (VHF) range of 0.4-0.9 Hz in heart rate variability (HRV) are scanty. The VHF presence in cardiac transplant patients and other conditions associated with reduced vagal influence on the heart encouraged us to explore this spectral band in healthy subjects and in patients diagnosed with cardiac autonomic neuropathy (CAN), and to assess the potential clinical value of some VHF indices. The study included 80 healthy controls and 48 patients with spinocerebellar ataxia type 2 (SCA2) with CAN. The electrocardiographic recordings of short 5-min duration were submitted to three different spectral analysis methods, including the most generally accepted procedure, and the two novel methods using the Hilbert-Huang transform. We demonstrated the presence of VHF activity in both groups of subjects. However, VHF power spectral density, expressed in relative normalized units, was significantly greater in the SCA2 patients than that in healthy subjects, amounting to 36.1 ± 17.4% vs. 22.9 ± 14.1%, respectively, as also was the instantaneous VHF spectral frequency, 0.58 ± 0.05 vs. 0.64 ± 0.07 Hz, respectively. These findings were related to the severity of CAN. We conclude that VHF activity of HRV is integral to the cardiovascular autonomic control.

Effect of non-thermal atmospheric plasma on the dentin-surface topography and composition and on the bond strength of a universal adhesive.

This study investigated the effect of application of non-thermal atmospheric plasma (NTAP) on the topography and composition of the dentin surface, as well as the microtensile bond strength (µTBS) of a universal adhesive to NTAP-treated dentin. Exposed flat dentin surfaces from human third molars were either treated with NTAP for 10 and 30 s or untreated (control). The dentin-surface topography and chemical composition were characterized by atomic force microscopy (n = 3) and Raman confocal spectroscopy (n = 5), respectively. The µTBS (n = 8) of Scotchbond Universal to dentin was determined after storage for 24 h and 1 yr, either by direct water exposure or under simulated pulpal pressure. In-situ zymography was used to evaluate the influence of NTAP on the dentin-enzymatic activity. Non-thermal atmospheric plasma produced no remarkable topographical or chemical alterations at the dentin surface; only the amount of phosphate decreased following 10 s of treatment with NTAP. After 1 yr of direct water exposure, the µTBS of NTAP-treated specimens did not differ statistically significantly from that of untreated controls, whereas simulated pulpal pressure-aging resulted in a significantly higher µTBS for NTAP-treated dentin. The dentin-enzymatic activity appeared to be treatment-dependent, but the untreated controls showed more intense fluorescence within the hybrid layer. Scotchbond Universal maintained its µTBS strength after 1 yr of direct water exposure and simulated pulpal pressure, although remarkable statistical differences between treatments were observed depending on the aging condition.

Study of the chemical interaction between a high-viscosity glass ionomer cement and dentin

Abstract Objective To investigate the chemical interactions between a high-viscosity glass ionomer cement (GIC) (KetacTM Molar Easymix, 3M ESPE, Seefeld, Bavaria, Germany) and human dentin. It was also analyzed the dynamics of GIC setting mechanism based on the time intervals required for the GIC and the GIC mixed with dentin to achieve stability. Material and Methods Each constituent of GIC - powder (P) and liquid (L) - and powdered dentin (D), as well as the associations P+L, D+L, and P+L+D in the concentrations of 29%, 50%, 65%, 78%, 82%, and 92% of GIC were analyzed with Fourier transform infrared (FTIR) and Raman spectroscopy. Results New optical absorption bands and/or Raman bands, which were not present in P, L, or D, were observed in the associations. The concentrations of 29% and 50% of GIC showed higher interaction, revealing that the amount of dentin influences the formation of new optical absorption or scattering bands. FTIR bands showed that the setting time to achieve bond stability was longer for the high-viscosity GIC (38±7 min) than for the sample with 29% of GIC (28±4 min). Conclusions The analysis revealed the formation of new compounds or molecular rearrangements resulting from the chemical interactions between GIC and dentin. Moreover, this study provides an effective method to evaluate the dynamics of the setting mechanism of GICs.