Direct spectrofluorimetric methods as alternatives to compendial ones used for the quality control of biopharmaceuticals: development, validation and application

Abstract A simple, rapid, precise, accurate and sustainable spectrofluorimetric method (SFM) was developed, validated and applied for the determination of 4-aminobenzoic acid and aromatic amino acids (phenylalanine, tryptophan and tyrosine). These compounds are used in biopharmaceutical formulations and therefore must be analyzed by quality control laboratories to meet the criteria established in pharmacopoeias. In general, potentiometric titration (PT) is described in the compendia as the official analytical technique. However, this method showed low sensitivity and selectivity, and moreover was performed with a non-aqueous solvent (acetic acid), which led to higher consumption of reagents and consequently to the formation of residues. Therefore, the SFM was developed in aqueous medium at pH 7.2 using phosphate buffer. It was successfully validated according to the ICH guidelines and showed good linearity range (r>0.999), specificity, accuracy and precision (within and between days) and robustness. The test results were compared between the SFM and PT using raw material samples, while according to the F- and t-tests at 95% confidence level, no statistical difference was found between the methods.

Salivary Metabolites in Patients with Mucopolysaccharidosis

ABSTRACT Objective: To identify the salivary metabolites profile of Mucopolysaccharidosis (MPS) types I, II, IV, and VI patients. Material and Methods: The participants were asked to refrain from eating and drinking for one hour before sampling, performed between 7:30 and 9:00 a.m. Samples were centrifuged at 10.000 × g for 60 min at 4°C, and the supernatants (500µl) were stored at −80°C until NMR analysis. The salivary proton nuclear magnetic resonance (1H-NMR) spectra were acquired in a 500 MHz spectrometer, and TOCSY experiments were used to confirm and assign metabolites. Data were analyzed descriptively. Results: Differences in salivary metabolites were found among MPS types and the control, such as lactate, propionate, alanine, and N-acetyl sugar. Understanding these metabolite changes may contribute to precision medicine and early detection of mucopolysaccharidosis and its monitoring. Conclusion: The composition of low molecular weight salivary metabolites of mucopolysaccharidosis subjects may present specific features compared to healthy controls.

Synthesis, characterization and protection effect of black rice anthocyanins nano-composite against hepatotoxicity induced by methotrexate in rats

Abstract The present study aimed to investigate the beneficial of prepared black rice anthocyanins nano-composite (An-AgNps) against hepatotoxicity induced by methotrexate (MTX) in rats. Anthocyanins nano-composite was prepared by silver as the metallic ion reduction and were characterized by IR and SEM. The rats in our experiment were divided into five groups. Serum lipid profile, serum transaminases (ALT and AST), ALP, LDH, TBA, GSH and SOD were examined. The results show that SEM of An-AgNps has average particle size from 70 to 130nm. In the group treated with MTX; TC, TG, LDL-c, ALT, AST, ALP, LDH and TBA levels were significantly (P0.05) increased than NC, while, HDL-c, SOD and GSH levels were significantly (P0.05) decreased. On the other hand, An-AgNps + MTX treated groups were reversed the levels of all biomarkers similar to NC. In conclusion, the results show that An-AgNps has a protective effect on MTX-induced hepatotoxicity and oxidative stress.

Resumo O presente estudo teve como objetivo investigar o benefício de nanocompósito de antocianinas de arroz preto preparado (An-AgNps) contra a hepatotoxicidade induzida por metotrexato (MTX) em ratos. O nanocompósito de antocianinas foi preparado a partir da prata por meio da redução do íon metálico e caracterizado por IR e SEM. Os ratos em nosso experimento foram divididos em cinco grupos, e foram examinados o perfil lipídico sérico, as transaminases séricas (ALT e AST), ALP, LDH, TBA, GSH e SOD. Os resultados mostram que SEM de An-AgNps tem tamanho médio de partícula de 70 a 130 nm. No grupo tratado com MTX, os níveis de TC, TG, LDL-c, ALT, AST, ALP, LDH e TBA aumentaram significativamente (P 0,05) do que NC, enquanto os níveis de HDL-c, SOD e GSH diminuíram significativamente (P 0,05). Por outro lado, nos grupos tratados com An-AgNps + MTX, foram revertidos os níveis de todos os biomarcadores semelhantes ao NC. Em conclusão, os resultados mostram que o An-AgNps tem um efeito protetor contra a hepatotoxicidade induzida pelo MTX e o estresse oxidativo.

Analysis of pH, calcium ion release, and energy dispersive spectroscopy of a bioceramic root canal dressing

Abstract This study compared the pH and calcium ion release of calcium silicate- (Bio-C Temp) and calcium hydroxide-based (Ultracal XS) medications. Intracanal remnants of both medications were also evaluated using SEM-EDS after the removal protocol. Thirty-five bovine teeth were prepared. Fifteen were filled with Bio-C Temp and 15 with Ultracal XS. Five remained without intracanal medication (control group). Five samples from each experimental time (i.e.. 24, 72, and 168 hours) were used to measure pH and calcium ions release using a digital pH meter and microplate reader, respectively. Afterward, the peaks of the chemical elements composing both medications were analyzed in SEM-EDS. One-way ANOVA and Tukey's post hoc test analyzed the pH and calcium ion release data. Student's t-test compared the medications in each experimental time. SEM-EDS described the percentage of chemical elements in the samples. Bio-C Temp and Ultracal XS showed a significant pH increase from 24 to 168 hours (p<0.05). Ultracal XS showed a higher pH value at 24 hours than Bio-C Temp (p<0.05) but were similar at 72 and 168h (p > 0.05). Calcium ion release did not depend on the experimental period (p > 0.05). Bio-C Temp showed lower calcium ions release than Ultracal XS at 24 hours (p<0.05). SEM-EDS analyses showed the remains of both medications, but the concentration of Si, Al, and W ions was present only in the calcium silicate-based medication. Bio-C Temp presented alkaline pH and a satisfactory calcium ion release over the time. The remaining of both medications were present after the protocols for paste removal.

Resumo Este estudo comparou o pH e a liberação de íons cálcio de medicações intracanais a à base de silicato de cálcio (Bio-C Temp) e à base de hidróxido de cálcio (Ultracal XS). Remanescentes de ambas as medicações também foram avaliados usando microscopia eletrônica de varredura e espectroscopia de dispersão de energia após o protocolo de remoção. Trinta e cinco dentes bovinos foram preparados. Quinze dentes foram preenchidos com Bio-C Temp e 15 com Ultracal XS. Cinco permaneceram sem medicação intracanal (grupo controle). Cinco amostras de cada tempo experimental (ou seja, 24, 72 e 168 horas) foram usadas para medir o pH e a liberação de íons de cálcio usando um medidor de pH digital e um leitor de microplacas, respectivamente. Em seguida, os picos dos elementos químicos que compõem os dois medicamentos foram analisados ​​em microscopia eletrônica de varredura e por espectroscopia de dispersão de energia. Os testes One-way ANOVA e post hoc de Tukey analisaram os dados de pH e liberação de íons cálcio. O teste t de Student comparou as medicações em cada tempo experimental. A microscopia eletrônica de varredura e a espectroscopia de dispersão de energia descreveu a porcentagem de elementos químicos nas amostras. O Bio-C Temp e o Ultracal XS mostraram um aumento significativo de pH de 24 a 168 horas (p<0,05). O Ultracal XS apresentou um valor de pH mais alto em 24 horas do que o Bio-C Temp (p<0,05), mas foi semelhante em 72 e 168h (p > 0,05). A liberação de íons cálcio não dependeu do período experimental (p> 0,05). O Bio-C Temp apresentou menor liberação de íons de cálcio do que Ultracal XS em 24 horas (p<0,05). As análises de microscopia eletrônica de varredura e espectroscopia de dispersão de energia mostraram remanescentes de ambas as medicações, mas a concentração de íons Si, Al e W estavam presentes apenas na medicação à base de silicato de cálcio. O Bio-C Temp apresentou pH alcalino e maior liberação de íons cálcio. Remanescentes de ambas as medicações estiveram presentes após os protocolos de remoção da pasta.

The luminous transmittance of the quartz-glass fiber posts is superior to glass fiber posts / Superioridade da transmitância luminosa dos pinos de fibra de quartzo

ABSTRACT Fiber-reinforced prefabricated intraarticular posts have gained popularity due to several favorable characteristics for clinical use compared to metallic intraradicular posts. Aim: To evaluate the light transmission capacity of two types of fiber posts, using two different methods. Materials and Method: The posts were divided into two groups: experimental group - quartz-glass fiber posts (n=10) and control group - glass fiber posts (n=10). The light transmittance of the samples was compared by means of light intensity test by photographs and ultraviolet-visible spectrophotometer. This test was analyzed by thirds: coronal, middle, and apical. The spectophotometer tested the luminous transmittance along the length of the post. The statistical analysis was conducted with a significance level of 0.05. Results: Light transmission was 97% on the coronal third, 68% in the middle third, and 27.66% in the apical third in the posts of the experimental group. In the posts of the control group, the light transmission was 95.33% in the coronal third, 80.66% in the middle third, and 41.33% in the apical third. Light transmission was significantly higher in the middle third of the posts of the experimental group when compared to the control group (p<0.05). The luminous transmittance of the posts of the experimental group was 97.4% with wavelengths of 400 nm, 97% at 450 and 500 nm, and 96.9% at 550 nm. In the posts of the control group, the luminous transmittance was 72.3% with wavelengths of 400 nm, 68.6% at 450 nm; 64.6% at 500 nm and 61.5% at 550 nm. The posts of the experimental group demonstrated significantly higher light transmittance than the control group (p<0.001). Conclusion: the luminous transmittance of quartz-glass fiber posts is higher than glass fiber posts.

RESUMO Os pinos intra-articulares pré-fabricados reforçados com fibras têm ganhado popularidade devido a várias características favoráveis ao uso clínico em comparação com os pinos intra-radiculares metálicos). Objetivo: Avaliar a capacidade de transmissão de luz de dois tipos de pinos de fibra, usando dois métodos diferentes. Materiais e Método: Os pinos foram divididos em dois grupos: grupo experimental - pinos de fibra de vidro de quartzo e grupo controle - pinos de fibra de vidro. A transmitância de luz das amostras foi comparada por meio de teste de intensidade de luz por fotografias e espectrofotômetro ultravioleta-visível. Este teste foi analisado por terços: coronal, médio e apical. O espectrofotômetro testou a transmitância luminosa ao longo do comprimento do pino. A análise estatística foi realizada com nível de significância de 0,05. Resultados: A transmissão luminosa foi de 97% no terço coronal, 68% no terço médio e 27,66% no terço apical nos pinos do grupo experimental. Nos pinos do grupo controle, a transmissão de luz foi de 95,33% no terço coronal, 80,66% no terço médio e 41,33% no terço apical. A transmissão luminosa foi significativamente maior no terço médio dos pinos do grupo experimental quando comparado ao grupo controle (p<0,05). A transmitância luminosa dos pinos do grupo experimental foi de 97,4% com comprimento de onda de 400 nm, 97% em 450 e 500 nm e 96,9% em 550 nm. Nos postes do grupo controle, a transmitância luminosa foi de 72,3% com comprimento de onda de 400 nm, 68,6% em 450 nm; 64,6% a 500 nm e 61,5% a 550 nm. Os pinos do grupo experimental demonstraram transmitância de luz significativamente maior do que o grupo controle (p<0,001). Conclusão: a transmitância luminosa dos pinos de fibra de vidro de quartzo é maior do que pinos de fibra de vidro.

Use of Extracorporeal Membrane Oxygenation and Cerebral Oximetry in a Stage 1 Norwood Repair for Hypoplastic Left Heart Syndrome

The role of extracorporeal membrane oxygenation (ECMO) and its indications in stage I Norwood palliation are controversial. The decision to initiate ECMO and its timing remains difficult with no definitive cut?off points or evidence?based guidelines. It varies on a case?to?case basis. We report a case where the use of ECMO was beneficial after stage I Norwood palliation with severe ventricular dysfunction. The systemic?to?pulmonary artery shunt was kept open to balance the systemic and pulmonary circulations. Cerebral oximetry can be useful as an additional monitoring modality to guide management, monitor cerebral perfusion, and help detect cerebral steal.

Validación de un modelo para la estimación del contenido de agua del suelo mediante espectroscopía en el infrarrojo cercano

El monitoreo del contenido de humedad en el suelo es especialmente importante, ya que proporciona información relevante para tomar decisiones acertadas, en cuanto a riego, fertirriego y manejo del estrés hídrico. Este trabajo tiene como objetivo validar un modelo de estimación del contenido de agua en el suelo, mediante espectroscopía de reflectancia difusa en el rango del infrarrojo cercano. Los suelos evaluados provienen de los municipios de Puerto Gaitán (Meta), Espinal (Tolima) y Mosquera (Cundinamarca). En los dos primeros se establecieron redes rígidas, para seleccionar los puntos de muestreo y empleando dos profundidades en cada caso (0-10 y 10-30; 0-10 y 10-25 cm, respectivamente). Para el tercero, se describieron 77 calicatas y se tomaron muestras a 0-10 y 10-35 cm de profundidad. Posteriormente, se evaluó el contenido de humedad considerando 0, 15 y 30 % de humedad. Los datos obtenidos se analizaron con estadística descriptiva. Se empleó la validación cruzada y externa para cada modelo y se obtuvo un modelo general, a partir de los datos de los tres sitios. Los modelos obtenidos para cada sitio de muestreo y el modelo general tienen buena capacidad predictiva. Según los resultados, se afirma que la espectroscopía de reflectancia difusa NIR es una excelente opción para determinar el contenido de agua en el suelo. De igual manera, a partir del análisis de componentes principales, se identificó una diferenciación entre contenidos de agua de los suelos estudiados.

Monitoring soil moisture content is especially important as it provides relevant information for making informed decisions regarding irrigation, fertigation, and water stress management. This study aims to validate a model for estimating soil water content using diffuse reflectance spectroscopy in the near-infrared range. The evaluated soils come from the municipalities of Puerto Gaitán (Meta), Espinal (Tolima), and Mosquera (Cundinamarca). In the first two municipalities, rigid networks were established to select sampling points, with two depths considered for each case (0-10 and 10-30 cm; 0-10 and 10-25 cm, respectively). For the third municipality, 77 soil pits were described, and samples were taken at depths of 0-10 and 10-35 cm. Subsequently, moisture content was evaluated at 0, 15, and 30 % moisture levels. The obtained data were analyzed using descriptive statistics. Cross-validation and external validation were applied to each model, and a general model was developed based on the data from all three sites. The obtained models for each sampling site and the general model demonstrated good predictive capacity. Based on the results, it is affirmed that near-infrared diffuse reflectance spectroscopy is an excellent option for determining soil water content. Similarly, principal component analysis identified differentiation between water contents of the studied soils.

Fabricación y caracterización de pozos cuánticos para el estudio de la interacción luz-materia / Fabrication and characterization of quantum wells for the study of light-matter interaction

RESUMEN Los pozos cuánticos representan la base de una gran variedad de dispositivos electrónicos, entre ellos los ledes, láseres, fotodetectores y moduladores. Las propiedades optoelectrónicas de estos sistemas dependen de su composición química y del espesor de las capas crecidas. Por dicha razón, es necesario tener un control preciso durante su crecimiento. El presente trabajo tuvo como objetivo inducir el crecimiento epitaxial de pozos cuánticos intrínsecos (sin ningún dopaje) asimétricos acoplados y desacoplados de AlGaAs/ GaAs/AlGaAs, así como, establecer su caracterización mediante técnicas de espectroscopía óptica, como lo son la reflectancia diferencial, también conocida como espectroscopía de reflectancia anisotrópica (RAS) y la fotoluminiscencia (PL). Se realizó un estudio experimental de las interacciones entre niveles de energía en los pozos cuánticos asimétricos acoplados. Este tipo de estructuras son especialmente interesantes por permitir la formación y observación, no solo de excitones directos, dentro del mismo pozo, sino también, de excitones y triones indirectos, que se forman entre electrones de un pozo y huecos de otro pozo vecino (Transiciones intra-QW). Se hicieron crecer tres pozos intrínsecos, basados en arseniuro de galio (GaAs): un pozo individual (desacoplado) y un par de pozos asimétricos acoplados, a través de epitaxia por haces moleculares (MBE). Se observó el efecto del rompimiento de simetría (de D2d a C2v) en las propiedades espintrónicas de la estructura, a través de PL y RAS, a una temperatura de ~ 30 K. Se lograron establecer las técnicas y métodos necesarios para el crecimiento de pozos cuánticos intrínsecos, que constituyen la base para la creación de dispositivos y estructuras más complejas. El uso de técnicas espectroscópicas permitió demostrar la presencia de anisotropías ópticas, que repercuten en el comportamiento del espín de los excitones en pozos cuánticos.

ABSTRACT Quantum Wells are the basis for a great variety of electronic devices such as leds, lasers, photodetectors and modulators. Their optoelectronic properties depend on their chemical composition and the thickness of each layer. Therefore, a precise control during their growth is needed. This work has the objective of presenting the epitaxial growth of coupled and uncoupled asymmetric AlGaAs/GaAs/AlGaAs quantum wells and their characterization using optical techniques such as reflectance anisotropy spectroscopy (RAS) and photoluminescence (PL). An experimental study of the different interactions between the confined levels of energy in coupled quantum wells was carried on. This kind of structures is of special interest because they allow the formation and observation not only of direct excitons and trions inside a single quantum well, but of indirect excitons and trions, which are only formed by electrons of one quantum well and holes of the neighbor quantum well (IntraQW transitions). Three intrinsic quantum wells based on gallium arsenide (GaAs) were grown by molecular beam epitaxy (MBE), one single QW and a pair of coupled asymmetric QWs. The effect of breaking symmetry (from de D2d a C2v) on the spintronic properties of the structure was observed by RAS and PL measurements at ~ 30 K. The main techniques and methods for the growth of intrinsic quantum wells were established, which are the basis for the creation of devices with more complex structures. The use of spectroscopic techniques for the study of quantum wells allowed the demonstration of the presence of optical anisotropies that influence the behavior of exciton's spins at quantum wells.

Structural and Rheological Properties of Exopolysaccharides Produced by Some Lactic Acid Bacterial Strains Isolated from Palm Wine

Aims: This study evaluated the physical, chemical and rheological properties of exopolysaccharides (EPSs) produced by Lactic Acid Bacteria (LAB) isolated from palm wine. Materials and Methods: EPSs from palm wine LAB strains were produced on 6% sucrose broth, purified and freeze-dried prior to analyses. Molecular weights (MW), rheological and structural composition (functional groups) of the EPSs were determined using standard methods and Fourier transform infrared spectroscopy (FTIR). Results: The average MW of the EPSs ranged from 2.02×106 to 6.53×106 Da while the flow index (n) values ranged from 0.03-3.13 at 0.2%, 0.06-1.51 at 0.4%, 0.38 - 1.85 at 0.6%, 0.14 - 2.26 at 0.8% and 0.55 - 6.42 at 1% concentrations at elevated temperatures for EPS solutions from the ten LAB species. The FTIR spectrum revealed prominent peaks of various groups of OH (3420 cm-1) and CH3 bending (2090 cm-1) in all the EPSs corresponding to both hydroxyl and amine groups, and aliphatic C-H bonds, respectively. EPS synthesized by Leuconostoc lactis, Lactococcus lactis subsp lactis and Lactiplantibacillus plantarum showed weak absorption peaks (1148 – 1145 cm-1) indicating the C-O-C and C-O bonds, while absorption peaks of Lactobacillus lactis, Lactobacillus acidophilus and Lactiplantibacillus plantarum (1267 – 1253 cm-1) indicated O- acetyl ester and other non-sugar components. Conclusions: The FTIR spectra, rheological properties and molecular weight of EPSs synthesized by the ten LAB strains indicated potentials that could be exploited in different industrial applications, and as stabilizers in food industries

Depth of cure, mechanical properties and morphology of dual-cure bulk-Fill composites / Profundidad de curado, propiedades mecánicas y morfología de resinas compuestas duales

This study evaluated selected structural and physical properties, such as degree of conversion (DC), Vickers hardness (VHN), and compression strength (CS), of three new dual-cure bulk-fill resin-based composites (RBCs; ACTIVA, HyperFIL, and Fill-Up) and compared them to those of a conventional RBC (Filtek Z250) at three clinically relevant depths. Samples (n=180) were prepared in three depths (2,4, and 6mm). Fourier-transform infrared spectroscopy (FTIR) analysis and VHN and CS tests were performed. The DC value was calculated by considering the relative change in the aliphatic C=C peaks. The fractured surfaces of representative samples were characterized using scanning electron microscopy (SEM). Data were statistically evaluated using two-way analysis of variance and post hoc Bonferroni tests (p<0.05). According to the VHN results, Filtek Z250 showed the highest bottom/top hardness ratio (97.94±1.01) at 2mm thickness and ACTIVA showed the lowest bottom/top hardness ratio (43.48±5.64) at 6mm thickness (p<0.001). According to the FTIR results, the DC decreased with increasing thickness in all materials (p<0.05). Filtek Z250 showed the highest (301±12.4 MPa) and ACTIVA exhibited the lowest (232±17.2 MPa) CS values at 2mm thickness (p<0.05). The lowest CS values were obtained for ACTIVA, and the highest values were obtained for Filtek Z250 for samples with thicknesses of 4 and 6mm, respectively (p<0.05). The structural features of restorative composites, such as the resin chemistry and filler type and content, and the operational parameters (i.e., material thickness and curing conditions) strongly affect crosslinking reactions and thus the DC, VHN, and CS values.

Este estudio evaluó propiedades físicas y estructurales, como el grado de conversión (DC), la dureza Vickers (VHN) y la resistencia a la compresión (CS), de tres nuevos compósitos a base de resina de curado dual tipo bulk (RBC; ACTIVA , HyperFIL y Fill-Up) y los comparó con los de una resina compuesta convencional (Filtek Z250) en tres profundidades clínicamente relevantes. Se prepararon muestras (n=180) en tres profundidades (2,4 y 6mm). Se realizaron análisis de espectroscopia infrarroja por transformada de Fourier (FTIR) y pruebas VHN y CS. El valor de DC se calculó considerando el cambio relativo en los picos alifáticos C=C. Las superficies fracturadas de muestras representativas se caracterizaron mediante microscopía electrónica de barrido (MEB). Los datos se evaluaron estadísticamente mediante análisis de varianza de dos vías y pruebas post hoc de Bonferroni (p<0,05). De acuerdo con los resultados de VHN, Filtek Z250 mostró la relación de dureza inferior/superior más alta (97,94±1,01) con un espesor de 2mm y ACTIVA mostró la relación de dureza inferior/superior más baja (43,48±5,64) con un espesor de 6mm (p<0,001). De acuerdo con los resultados de FTIR, la DC disminuyó al aumentar el espesor en todos los materiales (p<0,05). Filtek Z250 mostró los valores de CS más altos (301±12,4 MPa) y ACTIVA los más bajos (232±17,2 MPa) a 2mm de espesor (p<0,05). Los valores más bajos de CS se obtuvieron para ACTIVA y los valores más altos para Filtek Z250 para muestras con espesores de 4 y 6mm, respectivamente (p<0,05). Las características estructurales de las resinas compuestas de restauración, como la química; además del tipo y contenido del relleno, y los parámetros operativos (es decir, el espesor del material y las condiciones de curado) afectan en gran medida las reacciones de interacción química y, por lo tanto, los valores de DC, VHN y CS.

Effect of experimental bleaching gels with polymers Natrosol and Aristoflex on the enamel surface properties

Abstract Natrosol and Aristoflex® AVC polymers are widely applied in the cosmetic industry and have recently been applied as a thickener option in the composition of dental bleaching gels, with the purpose to reduce the adverse effects on enamel mineral components. The aim of this study was to evaluate the color variation (ΔE* ab, ΔE00, ∆WID), surface roughness (Ra), and mineral content quantification (Raman Spectroscopy) of dental enamel after bleaching treatment with experimental gel-based on 10% carbamide peroxide (CP), containing Carbopol, Natrosol, and Aristoflex® AVC. Sixty bovine teeth were randomly divided into 6 groups (n=10): Negative Control (NC) - no treatment; Positive Control (PC) - Whiteness Perfect 10% - FGM; CP with Carbopol (CPc); CP with Natrosol (CPn); CP with Aristoflex® AVC (CPa); NCP - no thickener. Data were analyzed, and generalized linear models (∆WID -T0 x T1) were used for repeated measurements in time for Ra and with a study factor for ΔE* ab and ΔE00. For the evaluation of the mineral content, data were submitted to one-way ANOVA and Tukey tests. For enamel topographic surface analysis the Scanning Electron Microscope (SEM) was performed. A significance level of 5% was considered. ΔE* ab and ΔE00 were significantly higher for CPc, CPn, CPa, and NCP groups. (∆WID) showed a significantly lower mean than the other groups for NC in T1. After bleaching (4-hour daily application for 14 days), Ra was higher in the CPc, CPn, and PC groups. For CPa, Ra was not altered. No significant difference was found in the quantification of mineral content. CPa preserved the surface smoothness more effectively. Aristoflex® AVC is a viable option for application as a thickener in dental bleaching gels, presenting satisfactory performance, and maintaining the whitening efficacy of the gel, with the advantage of preserving the surface roughness of tooth enamel without significant loss of mineral content.

Resumo Os polímeros Natrosol e Aristoflex® AVC são amplamente utilizados na indústria cosmética e foram recentemente aplicados como uma opção de espessante na composição de géis de clareamento dental, com o objetivo de reduzir os efeitos adversos sobre os componentes minerais do esmalte. O objetivo deste estudo foi avaliar a variação de cor (ΔE*ab, ΔE00, ∆WID), rugosidade da superfície (Ra), e quantificação do conteúdo mineral (Raman Spectroscopy) do esmalte dentário após clareamento dental com gel experimental baseado em 10% de peróxido de carbamida (CP), contendo Carbopol, Natrosol e Aristoflex® AVC. Sessenta dentes bovinos foram divididos aleatoriamente em 6 grupos (n=10): Controle Negativo (CN) - sem tratamento; Controle Positivo (CP) - Brancura Perfeita 10% - FGM; CP com Carbopol (CPc); CP com Natrosol (CPn); CP com Aristoflex® AVC (CPa); NCP - sem espessante. Os dados foram analisados e modelos lineares generalizados (∆WID -T0 x T1) foram usados para medições repetidas no tempo para Ra e com um fator de estudo para ΔE*ab e ΔE00. Para a avaliação do conteúdo mineral, os dados foram submetidos a testes unidirecionais de ANOVA e Tukey. Para a análise da superfície topográfica do esmalte, o Microscópio Eletrônico de Varredura (SEM) foi realizado. Um nível de significância de 5% foi considerado. ΔE*ab e ΔE00 foram significativamente maiores para os grupos CPc, CPn, CPa e NCP. (∆WID) mostrou uma média significativamente menor do que os outros grupos para NC em T1. Após o clareamento (aplicação diária de 4 horas por 14 dias), Ra foi maior nos grupos CPc, CPn e PC. Para CPa, Ra não foi alterado. Nenhuma diferença significativa foi encontrada na quantificação do conteúdo mineral. O CPa preservou a suavidade da superfície de forma mais eficaz. Aristoflex® AVC é uma opção viável para aplicação como espessante em géis de clareamento dental, apresentando desempenho satisfatório e mantendo a eficácia clareadora do gel, com a vantagem de preservar a rugosidade da superfície do esmalte dentário sem perda significativa de conteúdo mineral.

Culture of rat mesenchymal stem cells on PHBV-PCL scaffolds: analysis of conditioned culture medium by FT-Raman spectroscopy / Cultivo de células-tronco mesenquimais de rato sobre arcabouços de PHBV-PCL: análise do meio de cultura condicionado por espectroscopia de FT-Raman

Abstract Mesenchymal stem cells (MSCs) have great potential for application in cell therapy and tissue engineering procedures because of their plasticity and capacity to differentiate into different cell types. Given the widespread use of MSCs, it is necessary to better understand some properties related to osteogenic differentiation, particularly those linked to biomaterials used in tissue engineering. The aim of this study was to develop an analysis method using FT-Raman spectroscopy for the identification and quantification of biochemical components present in conditioned culture media derived from MSCs with or without induction of osteogenic differentiation. All experiments were performed between passages 3 and 5. For this analysis, MSCs were cultured on scaffolds composed of bioresorbable poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL) polymers. MSCs (GIBCO®) were inoculated onto the pure polymers and 75:25 PHBV/PCL blend (dense and porous samples). The plate itself was used as control. The cells were maintained in DMEM (with low glucose) containing GlutaMAX® and 10% FBS at 37oC with 5% CO2 for 21 days. The conditioned culture media were collected and analyzed to probe for functional groups, as well as possible molecular variations associated with cell differentiation and metabolism. The method permitted to identify functional groups of specific molecules in the conditioned medium such as cholesterol, phosphatidylinositol, triglycerides, beta-subunit polypeptides, amide regions and hydrogen bonds of proteins, in addition to DNA expression. In the present study, FT-Raman spectroscopy exhibited limited resolution since different molecules can express similar or even the same stretching vibrations, a fact that makes analysis difficult. There were no variations in the readings between the samples studied. In conclusion, FT-Raman spectroscopy did not meet expectations under the conditions studied.

Resumo As células-tronco mesenquimais (MSCs) possuem grande potencial para aplicação em procedimentos terapêuticos ligados a terapia celular e engenharia de tecidos, considerando-se a plasticidade e capacidade de formação em diferentes tipos celulares por elas. Dada a abrangência no emprego das MSCs, há necessidade de se compreender melhor algumas propriedades relacionadas à diferenciação osteogênica, particularmente liga à biomateriais usados em engenharia de tecidos. Este projeto objetiva o desenvolvimento de uma metodologia de análise empregando-se a FT-Raman para identificação e quantificação de componentes bioquímicos presentes em meios de cultura condicionados por MSCs, com ou sem indução à diferenciação osteogênica. Todos os experimentos foram realizados entre as passagens 3 e 5. Para essas análises, as MSCs foram cultivadas sobre arcabouços de polímeros biorreabsorvíveis de poli (hidroxibutirato-co-hidroxivalerato) (PHBV) e o poli (ε-caprolactona) (PCL). As MSCs (GIBCO®) foram inoculadas nos polímeros puros e na mistura 75:25 de PHBV / PCL (amostras densas e porosas). As células foram mantidas em DMEM (com baixa glicose) contendo GlutaMAX® e 10% de SFB a 37oC com 5% de CO2 por 21 dias. A própria placa foi usada como controle. Os meios de cultura condicionados foram coletados e analisadas em FT-Raman para sondagem de grupos funcionais, bem como possíveis variações moleculares associadas com a diferenciação e metabolismo celular. Foi possível discernir grupos funcionais de moléculas específicas no meio condicionado, como colesterol, fosfatidilinositol, triglicerídeos, forma Beta de polipeptídeos, regiões de amida e ligações de hidrogênio de proteínas, além da expressão de DNA. Na presente avaliação, a FT-Raman apresentou como uma técnica de resolução limitada, uma vez que modos vibracionais de estiramento próximos ou mesmo iguais podem ser expressos por moléculas diferente, dificultando a análise. Não houve variações nas leituras entre as amostras estudadas, concluindo-se que a FT-Raman não atendeu às expectativas nas condições estudadas.

Minimal and normal-flow general anesthesia in patients undergoing surgery in prone position: impact on hemodynamics and regional cerebral oxygenation

Purpose: In this study, the aim to assess the combined effects of prone-positioning (PP) and minimal-flow (MF) general anesthesia on regional cerebral oxygenation (RCO) and systemic hemodynamics. Methods: This is a randomized prospective study aiming to evaluate changes in cerebral oxygenation and hemodynamic parameters in MF systemic anesthesia in patients undergoing surgery in PP. Patients were randomized to MF or normal-flow (NF) anesthesia. In the operating room, pulse rate, mean arterial pressure (MAP), peripheral hemoglobin oxygen saturation (spO2), and right- and left-side RCO (assessed by nearinfrared spectroscopy, NIRS) were measured perioperatively. Results: Overall, 46 patients were included (24 in the MF group and 22 in the NF group). The amount of anesthetic gas consumption was significantly lower in the low-flow (LF) group. In both groups, the mean pulse rate showed a decrease after PP. Before induction, RCO was significantly higher both at the right- and left-sides in the LF group compared to the NF group. This difference continued throughout the operation on the left-side and disappeared 10 min after intubation on the right-side. On the left side, mean RCO decreased after PP in both groups. Conclusion: MF anesthesia in PP did not reduce cerebral oxygenation compared to NF and was safe in terms of systemic hemodynamics and cerebral oxygenation.

Dissolution behavior of aripiprazole tablets based on near infrared spectroscopy / 药学实践杂志

Objective To establish a near infrared (NIR) quantitative model for the dissolution behavior of aripiprazole tablets. Methods The NIR spectra of aripiprazole tablets were collected and the dissolution tests were performed to determine the dissolution of each tablet at 3, 6, 9, 12, 15 and 30 min. The near infrared spectra regions of 4 000.00-4 396.90, 5 326.43-12 000.00 cm−1 were pretreated by Savitzky-Golay smoothing filter, and the dissolution behavior model was established by partial least squares method. Results The root mean square error of calibration (RMSEC) and the root mean square error of prediction (RMSEP) at different time points were analyzed. RMSEP was lower than 8%. The calibration correlation coefficient (RC) and the prediction correlation coefficient (RP) at different time points were above 0.95 (except for the point of 6 min). There was a good correlation between the NIR spectrum and the dissolution at each time point. Conclusion NIR spectroscopy could predict the dissolution behavior of aripiprazole tablets, which lays a foundation for online quality monitoring of tablets by NIR spectroscopy.

Research status and prospect on the cerebral vision in myopic patients / 中华实验眼科杂志

The visual signal generated by the eye receiving external light stimulation reaches the visual center through the visual pathway and is processed and integrated by the visual center to form a subjective sensation called cerebral vision.Cerebral vision reflects the function of the whole visual nervous system from the retina to the visual cortex.Abnormal cerebral vision has been found in myopes using electrophysiology, magnetic resonance imaging (MRI) and functional near-infrared spectroscopy (fNIRS). The abnormal electrophysiological results are mainly found in patients with high myopia and pathological myopia.MRI shows abnormal changes in the structure and function of several vision-related brain regions in patients with high myopia.Recently, by applying near-infrared brain function imaging technology combined with self-developed equipment, our team conducted a series of studies on the brain function of myopic patients and found that adult patients with moderate myopia and patients with pathological myopia have the abnormal cerebral vision.The mechanism of neural regulation of eye accommodation in myopic children needs further investigation.In this article, we reviewed the current status and outlook of myopic brain vision research in terms of myopia classification, myopic brain vision research methods, and myopic visual electrophysiology, MRI, and fNIRS studies.

Integration of traditional tests and biomarkers for the early diagnosis of neonatal necrotizing enterocolitis / 中华实用儿科临床杂志

Necrotizing enterocolitis (NEC) is the most common and serious acute intestinal necrotizing disease in newborns, especially in preterm infants.Infants with smaller gestational age are more prone to NEC.NEC-related mortality reaches up to 20%-30%, and 25% of the survivors suffer from serious sequelae such as the short bowel syndrome, growth restriction and long-lasting neurological dysplasia.Due to the atypical symptoms, early diagnosis of NEC is difficult, and the patient′s condition has already been serious at the time of diagnosis in general.Ultrasound and abdominal X-ray are traditional tools for the diagnosis of NEC.Serum, urine and fecal biomarkers have been gradually applied to clinical practice in recent years.Through integrating traditional tests with biological markers and optimizing the clinical decision-making system for NEC, precise clinical diagnosis and individualized treatment can be achieved.

Near-infrared spectroscopy-based study of the effects of gaming addiction disorders on brain cognitive control functions / 国际生物医学工程杂志

Objective:To explore the effects of game addiction disorders on brain cognitive control functions based on near-infrared spectroscopy.Methods:Thirteen subjects were screened according to the Online Game Addiction (OGA) Scale. The experimental paradigm was the stop-signal task. The relative concentration levels of oxyhemoglobin (HbO 2) and deoxyhemoglobin (Hb) in the prefrontal region of the brain during cognitive activity were collected using near-infrared spectroscopy to assess the cognitive control function of the subjects. Results:The game-addicted patients had lower keystroke accuracy in the stop-signal task than healthy subjects, and the difference was statistically significant ( P<0.05). Compared to healthy subjects, game-addicted patients had less activation in prefrontal areas and showed uncontrolled behavior and brain activity. Conclusions:Game addiction disorders impair brain cognitive control, which in turn triggers a weakening of cognitive control. The results of this study provide a reference for the prevention and treatment of game addiction.

Study of prefrontal cortex activation characteristics of patients with psychiatric disorders in verbal fluency task using functional near-infrared spectroscopy / 四川精神卫生

BackgroundFunctional near-infrared spectroscopy （fNIRS） is a new generation of imaging tool that can be used to assist the diagnosis of psychiatric disorders. However， whether the patterns of prefrontal cortex activation observed by fNIRS are specific for different psychiatric disorders remains to be explored. ObjectiveTo investigate the characteristics of prefrontal cortex activation in patients with depression， anxiety disorder， bipolar disorder and schizophrenia in verbal fluency task （VFT） using fNIRS. MethodsFrom September to December 2021， 39 patients with schizophrenia， 205 patients with depressive disorder， 212 patients with anxiety disorder and 77 patients with bipolar disorder meeting the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders， fifth edition （DSM-5） were recruited in the outpatient and inpatient department of West China Hospital， Sichuan University. fNIRS was used to monitor the prefrontal cortex hemodynamic changes of patients under VFT， and the clinical symptoms of patients were assessed by Symptom Checklist 90 （SCL-90） and Hypomania Checklist-32 items（HCL-32）. Differences in mean oxyhemoglobin （HbO2） concentration and the initial slope from 2 to 7 second during VFT were compared among patients with different diseases， and the correlation between mean HbO2 concentration/initial slope and clinical symptoms was analyzed by partial correlation analysis. ResultsThe concentration of HbO2 in channel 4 （Z=2.828， P=0.028） and channel 6 （Z=2.912， P=0.022） in patients with depression were significantly higher than those in patients with schizophrenia. Patients with anxiety had significantly higher changes in mean HbO2 concentration in channel 4 （Z=3.154， P=0.010）， channel 5 （Z=3.021， P=0.015）， channel 6 （Z=2.980， P=0.017） and of all channels （Z=2.881， P=0.024） than those of schizophrenia patients. There was a statistically significant difference in the initial slope of channel 3 between patients with depressive disorder and those with bipolar disorder （Z=2.691， P=0.039）. Among patients with bipolar disorder， the anger-hostility scores of SCL-90 were negatively correlated with the mean HbO2 concentration changes in channel 4 （r=-0.505， P=0.004）， channel 6 （r=-0.390， P=0.004）， channel 15 （r=-0.546， P=0.002）， channel 16 （r=-0.550， P=0.002） and the mean HbO2 concentration changes of all channels （r=-0.491， P=0.006）. ConclusionPatients with schizophrenia had lower activation in frontopolar and orbitofrontal region than patients with depression and anxiety disorder， and the initial slope of the right frontopolar， inferior frontal and orbitofrontal region in patients with depression is higher than patients with bipolar disorder. In addition， patients with bipolar disorder had less activation in the frontopolar and orbitofrontal lobe， the insular cover of Broca's area and the upper outer frontal cortex， and were more irritable and hostile. ［Funded by 1·3·5 Project for Disciplines of Excellence-Clinical Research Incubation Project， West China Hospital， Sichuan University （number， ZYJC21083）］

Effect of Catechol-O-Methyltransferase Genotype on Self-Reported Efficacy and Activity Changes in the Brain Prefrontal Area in Response to a Caffeine Placebo / 医薬品情報学

Objective: The placebo effect can enhance the response to treatment, even in the absence of pharmacological ingredients. One possible factor explaining the likelihood of the placebo effect in individuals is genetic polymorphisms in neurotransmitters. This study focused on gene polymorphisms in the catechol-O-methyltransferase (COMT) as an interindividual variable of the placebo effect.Design・Methods: All 120 participants were explained the effects of caffeine, including its ability to ameliorate drowsiness and increase concentration, and then given a placebo (lactose). The onset of the placebo effect was measured in terms of the degree of caffeine-reduced sleepiness using subjective indices of the Stanford Sleepiness Scale (SSS) and a feeling of drowsiness-Visual Analogue Scale (VAS). The mechanism of the placebo effect was objectively examined in terms of changes in cerebral blood flow in the prefrontal cortex of the brain. In addition, we investigated participants’ susceptibility to the placebo effect by examining genetic polymorphisms in COMT.Results: After taking the drug, sleepiness on the SSS and VAS was significantly improved (p＜0.001), although there was no change in prefrontal cortex activity. Among the 120 participants, 63 had a Val/Val-type polymorphism in COMT (52.5%), 45 had a Val/Met-type (37.5%), and 12 had a Met/Met-type (10.0%). There were no significant differences among COMT gene polymorphisms in the subjective measures of SSS and VAS. However, there was a tendency for the cerebral blood flow changes to be larger in the left hemisphere of the brain in individuals with the Met/Met type.Conclusion: There seems to be a relationship between prefrontal cortex activity and genetic polymorphisms. In particular, there may be a correlation between the expression of a placebo effect and COMT gene polymorphisms.