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.

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

Infrared spectral band screening based on partial least squares is used for the quantitative analysis of mannitol-calcium chloride cocrystal / 药学学报

Mannitol-calcium chloride metal organic framework (MOF) cocrystal significantly improved the tabletability of β-mannitol and could be developed as a new tablet filler. However, mannitol monomer was found in the product during the scale-up production of the excipient, which significantly affected the functional properties of the excipient. In this study, we intend to quantify the multi-component eutectic system of mannitol-calcium chloride. In this experiment, the MOF cocrystal excipient mannitol-calcium chloride cocrystal was used as the model compound, and infrared spectrum was collected. Based on partial least squares regression (PLSR) method, the abnormal bands were removed and the spectrum was preprocessed by normalization. The quantitative correction model of mannitol-calcium chloride MOF cocrystal content in cocrystal excipients was established and compared by two different variable screening methods, genetic algorithm (GA) and competitive adaptive reweighting algorithm (CARS). Two different variable screening methods, GA method and CARS method, were used to screen out 160 and 14 variables, respectively. The mannitol-calcium chloride cocrystal model established by CARS-PLSR method had the best performance, and the average relative error (MRE) and corrected root mean square error (RMSEC) of the model were 0.008 8 and 0.892 5, respectively, the determination coefficient (R2) of the model was increased from 0.978 3 to 0.994 4. The quantitative method of eutectic system established in this study has high prediction accuracy, fast detection speed and good stability, which is of great significance for optimizing the preparation process conditions and quality control methods of such eutectic excipients.

Suckermouth catfish bone extract as bone graft raw material for bone-healing promotes bone growth in bone loss / Extrato de osso de bagre como material de reparo promove o crescimento ósseo em perda óssea

Objective: This study aimed to evaluate the properties of suckermouth catfish bone extract, which allows it to be adopted as a raw material for bone graft following its graft in an artificial defect of a rat model. Material and Methods: Hydroxyapatite (HA) from suckermouth catfish bone extract was characterized using Fourier-transform infrared spectroscopy (FTIR), and its toxicity was evaluated by Brine Shrimp Lethality Test (BSLT). This material was grafted on artificial defects in rats' femoral bones, which were observed immunologically by Enzyme-linked immunosorbent assay (ELISA) after one week and four weeks, and radiographically in the second week, and histologically in the second and fourth weeks. Results: FTIR shows that this material consists of phosphate, hydroxyl, and carbonate groups, while the BSLT results show that this material is not toxic. Observations by ELISA showed an increase in the expression of Tumor necrosis factor alpha (TNF-α) in defects with HA in the fourth week. Radiographically the defect did not show closure in the second week. In contrast, histological analysis showed a better bone healing process in the defect, which was applied with the HA of the suckermouth catfish bone. Conclusion: The HA extracted from the suckermouth catfish bone has beneficial properties as an alternative to bone graft raw material and, more investigated needed to support this biomaterial to be used in the treatment of bone loss (AU)

Objetivo: Avaliar as propriedades do extrato de osso de bagre, que permitem sua adoção como material bruto para enxerto ósseo, em um defeito ósseo artificial em ratos. Material e Métodos: A hidroxiapatita (HA) do extrato de osso de bagre foi caracterizada usando espectroscopia infravermelha por transformada de Fourier (FTIR), e sua toxicidade foi avaliada pelo Teste de Letalidade do Camarão de Sal (BSLT). Esse material foi enxertado em defeitos artificiais nos ossos femorais de ratos. Análise imunológica por meio do ensaio imunoenzimático (ELISA) foi realizada uma e quatro semanas após a colocação dos enxertos. Análises radiográficas foram feitas na segunda semana e histológica na segunda e quarta semanas. Resultados: A FTIR mostrou que esse material é composto por grupos de fosfato, hidroxila e carbonato, enquanto os resultados do BSLT mostraram que esse material não é tóxico. As observações pelo ELISA mostraram um aumento na expressão do fator de necrose tumoral alfa (TNF-α) nos defeitos com HA na quarta semana. Radiograficamente, o defeito não apresentou fechamento na segunda semana. Em contraste, a análise histológica mostrou um melhor processo de cicatrização óssea no defeito que foi aplicado com a HA do osso de bagre. Conclusão: A HA extraída do osso de bagre possui propriedades benéficas como alternativa ao material bruto para enxerto ósseo, sendo necessárias mais investigações para apoiar esse biomaterial a ser usado no tratamento da perda óssea.(AU)

Evaluation of Physiochemical Properties, Thermal Behavior and Phytopharmaceutical Potential of Citrus aurantium’s Essential Oil

The study investigates the therapeutic potential of the Citrus aurantium var. amara essential oil extracted from the blossoms of the bitter orange plant by examining its chemical composition, thermal stability, and potency against infectious disease-causing pathogens. Initially, the volatile components of the essential oil were evaluated by obtaining a chromatographic fingerprint using HPTLC and FTIR spectrum identification. Furthermore, a thermal profile of the essential oil was obtained using the thermogravimetric-differential thermal analysis and differential scanning calorimetric analysis. A predetermined set of antibiotic-resistant microorganisms were used to examine the antibacterial activity of the essential oil. Lastly, its anti-inflammatory activity was assessed using the albumin denaturation assay. The research concluded that the Citrus aurantium var. Amara essential oil exhibits potential therapeutic characteristics which can be further explored through in vivo studies.

Identification of the New Psychoactive Substance Eutylone / 法医学杂志

OBJECTIVES@#To establish a method to identify unknown sample based on the combined use of Fourier transform infrared spectroscopy (FTIR), gas chromatography-quadrupole time-of-flight mass spectrometry (GC-QTOF-MS), ultra-high performance liquid chromatography-linear ion trap quadrupole-orbitrap mass spectrometry (UPLC-LTQ-Orbitrap MS) and 1H-nuclear magnetic resonance spectroscopy (1H-NMR) technique.@*METHODS@#The unknown sample was directly analyzed by FTIR. The unknown sample was dissolved in methanol solution containing internal standard SKF525A and the supernatant was detected by GC-QTOF-MS and UPLC-LTQ-Orbitrap MS. The unknown sample was dissolved in methanol-d4 solution for structural analysis of 1H-NMR.@*RESULTS@#The characteristic absorption peaks of FTIR spectra obtained from unknown sample were 1 682 (C=O bond), 1 503, 1 488, 1 436, 1 363, 1 256, 1 092, 1 035, 935, 840 and 800 cm-1, the characteristic fragment ions (m/z) of GC-QTOF-MS were 86.096 4 (base peak), 58.065 1, 149.023 5, 121.028 6 and 65.038 6, the accurate mass [M+H]+ detected by UPLC-LTQ-Orbitrap MS was 236.127 7. The sample was identified as synthetic cathinone new psychoactive substance Eutylone by 1H-NMR.@*CONCLUSIONS@#The method established in this study can be used for structural confirmation of Eutylone.

Analysis of Olibanum and Myrrha by Differential Scanning Calorimetry and Fourier Transform InfraRed / 国际中医中药杂志

Objective:To distinguish the differences between Olibanum and Myrrha by using modern analytical methods such as Differential Scanning Calorimeter (DSC) and Fourier Transform InfraRed (FT-IR). Methods:By collecting Olibanum and Myrrha in different growing areas and different processed prosecures, this paper to analizes the influence of temperature increase and its speed , as well as the particle size on the DSC experiment. The DSC method was used to perform a differential thermal map of Olibanum and Myrrha scanning and analysis; FT-IR was used to scan and analyze 20 batches of Olibanum and Myrrha. Results:TThe results of DSC analysis showed that the DSC experimental condition ranged between 30-600 ℃; the speed of temperature increase was 30 ℃/min; the particle size was 100 mesh. The DSC spectra of of Olibanum and Myrrha were significantly different. Only the processed products of frankincense had endothermic peak near 297 ℃, and there was no characteristic peak in this temperature range. Their exothermic peaks are close at 326 ℃, but their enthalpy values are quite different. The position of endothermic peak near 100 ℃ is close to the size of peak shape. FT-IR test showed that the absorption peaks of Olibanum and Myrrha at wave numbers 2 925, 1 710, 1 454, 1 371, 1 242, 1 029 cm -1 appeared, and the positions of strong peaks were also similar. The intensity of the characteristic peak of Myrrha wave number 1 029 cm -1 is greater than that of Olibanum. Conclusion:The DSC spectra of Olibanum and Myrrha are significantly different, and the difference between the two FT-IR spectra is small. Differential scanning Calorimetry is an effective, fast, and simple way to identify resinous Chinese medicinal materials, and is worthy of further popularization.

Secondary protein in the muscle of exercised rats that received creatine supplementation / Proteína secundaria en el músculo de ratones ejercitados que recibieron suplemento de creatina / Proteína secundária no músculo de ratos exercitados que receberam suplemento de creatina

ABSTRACT Introduction: Currently there is a lack of clarity around the use of Fourier transform infrared (FT-IR) spectroscopy to analyze the effect of creatine (Cr) supplementation on the secondary structures of skeletal muscle tissue protein subjected to exercise. Objective: The objective of this study was to evaluate the spectral characteristics of the tibialis anterior muscle in rats subjected to exercise in a pool and to Cr supplementation. Methods: Experiment 1. First, an experiment was conducted to ensure that FT-IR would be able to detect change in the secondary structures of skeletal muscle tissue protein in the group of sedentary rats (SED) and in the group of rats that received creatine supplementation (CRE). Experiment 2. Next, the effect of physical exercise on the spectral characteristics of muscle tissue, especially when compared to the groups without exercise practice, was examined. Results: It was possible to verify that the peaks centered on 1658 cm-1 (amide I) and 1546 cm-1 (amide II) are characteristic spectra and indicated as markers of protein content. Conclusion: Thus, FT-IR spectroscopy proved to be able to monitor changes in secondary structures of skeletal muscle protein in both animals that received supplements and in those subjected to exercise and both cases reconciled. Furthermore, the FT-IR technique proved to be a viable method for the nondestructive evaluation of skeletal muscle protein structures. Level of evidence II, Investigation of treatment results.

RESUMEN Introducción: Actualmente, no hay claridad en lo que se refiere al uso de la técnica de espectroscopia de Infrarrojo con transformada de Fourier (FT-IR) para análisis del efecto de la suplementación de creatina (Cr) sobre las estructuras secundarias de la proteína del tejido muscular esquelético sometido a ejercicio. Objetivo: El objetivo de este estudio fue evaluar las características espectrales del músculo tibial anterior de ratones sometidos a ejercicio en piscina y a la suplementación con Cr. Métodos: Experimento 1. En primer lugar, fue realizada una experiencia para asegurar que la FT-IR sería capaz de detectar la variación en las estructuras secundarias de la proteína del tejido muscular esquelético en el grupo de ratones sedentarios (SED) y el grupo de ratones que sólo recibieron suplemento de creatina (CRE). Experimento 2. A continuación, fue examinado el efecto del ejercicio físico sobre las características espectrales del tejido muscular, especialmente cuando comparado con los grupos sin práctica de ejercicio. Resultados: Fue posible verificar que los picos centrados en 1658 cm−1 (amida I) y 1546 cm−1 (amida II) son espectros característicos e indicados como marcadores del tenor proteico. Conclusión: Siendo así, la técnica de espectroscopia de FT-IR mostró ser capaz de monitorizar las variaciones en las estructuras secundarias de la proteína del tejido muscular esquelético, tanto en animales que recibieron suplementos, como en los que fueron sometidos a ejercicio y ambos casos conciliados. Además, la técnica FT-IR probó ser un método viable para la evaluación no destructiva de las estructuras proteicas en el músculo esquelético. Nivel de evidencia II, Investigación de los resultados del tratamiento.

RESUMO Introdução: Atualmente, não há clareza no que diz respeito ao uso da técnica de espectroscopia de infravermelho com transformada de Fourier (FT-IR) para análise do efeito da suplementação de creatina (Cr) sobre as estruturas secundárias da proteína do tecido muscular esquelético submetido a exercício. Objetivo: O objetivo deste estudo foi avaliar as características espectrais do músculo tibial anterior de ratos submetidos a exercício em piscina e à suplementação com Cr. Métodos: Experimento 1. Em primeiro lugar, foi realizada uma experiência para assegurar que a FT-IR seria capaz de detectar a variação nas estruturas secundárias da proteína do tecido muscular esquelético no grupo de ratos sedentários (SED) e no grupo de ratos que só receberam suplemento de creatina (CRE). Experimento 2. Em seguida, foi examinado o efeito do exercício físico sobre as características espectrais do tecido muscular, especialmente quando comparado com os grupos sem prática de exercício. Resultados: Foi possível verificar que os picos centrados em 1658 cm−1(amida I) e 1546 cm−1(amida II) são espectros característicos e indicados como marcadores do teor proteico. Conclusão: Assim sendo, a técnica de espectroscopia de FT-IR mostrou ser capaz de monitorar as variações nas estruturas secundárias da proteína do tecido muscular esquelético tanto em animais que receberam suplementos, quanto nos que foram submetidos a exercício e ambos os casos conciliados. Além disso, a técnica FT-IR provou ser um método viável para a avaliação não destrutiva de estruturas proteicas no músculo esquelético. Nível de evidência II, Investigação dos resultados do tratamento.

The influence of the particle's size on the setting reaction of sol-gel derived calcium silicate particles / A influência do tamanho de partícula na reação de presa de cimentos de silicate de cálcio produzidos por sol-gel

Introduction: This study aims to analyze the influence of particles size of sol-gel derived calcium silicate particles in the setting reaction of bioactive endodontic cements. Materials and Methods: Sol-gel derived calcium silicate particles were synthesized and sieved to separate the particles in different sizes: CS400, CS200, and CS100. A commercial MTA (Control) was used as control. The particle size and the specific surface area were assessed by laser diffraction and nitrogen adsorption. The cements were prepared with water as the liquid for the reaction. The setting time was conducted according to ISO 6876, and the setting kinetics was analyzed by Fourier trans-formed infrared spectroscopy (FTIR) at different time points between 120s to 72h. Results: The particle size varied from 9.45µm (CS400 ) to 31.01 (Control). The higher specific surface area valuer reached 15.14g/cm2 in the CS400. The smallest particle sizes, the higher specific surface area, and the lowest setting time were found for CS400 (p < 0.05). Control presented the highest setting time (p < 0.05). The FTIR analyses showed the differences in materials structure over time, with faster hydration and crystallization for CS400. The setting kinetics was slower for Control even when compared to a sol-gel derived group with similar particle size. Conclusion:The route of synthesis and the particle size influences the setting reaction of calcium silicate-based cements. The reduction of particle size for sol-gel derived calcium silicates lead to the acceleration of the setting reaction of the produced bioactive endodontic cement.

Introdução: Este estudo tem como objetivo analisar a influência do tamanho de partículas de silicato de cálcio derivadas de sol-gel na reação de presa de cimentos endodônticos bioativos. Materiais e Métodos: Partículas de silicato de cálcio derivadas de sol-gel foram sintetizadas e peneiradas para separar as partículas em diferentes tamanhos: CS400, CS200 e CS100. Um MTA comercial (Controle) foi usado como controle. O tamanho das partículas e a área superficial específica foram avaliados por difração a laser e adsorção de nitrogênio. Os cimentos foram preparados com água como líquido para a reação. O tempo de presa foi conduzido de acordo com a ISO 6876, e a cinética de presa foi analisada por espectroscopia de infravermelho transformada de Fourier (FTIR) em diferentes pontos de tempo entre 120s a 72h. Resultados: O tamanho de partícula variou entre 9,45µm (CS400) e 31,01 (Controle). A maior área de superfície foi encontrada nas partículas do grupo CS400 (15.14g/cm2). Os menores tamanhos de partícula, a maior área de superfície específica e o menor tempo de presa foram encontrados para CS400 (p < 0,05). O Control apresentou o maior tempo de presa (p < 0,05). As análises de FTIR mostraram as diferenças na estrutura dos materiais ao longo do tempo, com hidratação e cristalização mais rápidas para CS400. A cinética de presa foi mais lenta para Control mesmo quando comparado a um grupo derivado de sol-gel com tamanho de partícula semelhante. Conclusão: A rota de síntese e o tamanho das partículas influenciam a reação de endurecimento dos cimentos à base de silicato de cálcio. A redução do tamanho de partícula para silicatos de cálcio derivados de sol-gel leva à aceleração da reação de pega do cimento endodôntico bioativo produzido.

Advances in characterization of pharmaceutical polymorphisms by vibrational spectroscopy / 药学学报

The determination and characterization of solid drug form polymorphisms plays an important role in drug quality control, selection of the production process and clinical efficacy evaluation. Vibrational spectroscopy is a powerful method for the characterization of drug polymorphisms. In this paper we review recent research and application advances in the polymorphic characterization of active pharmaceutical ingredients (APIs) and drug cocrystals/salts by using Fourier transform infrared (FTIR) and Raman spectroscopy to elucidate the characteristics of APIs and drug complexes. This may provide theoretical support for structural analysis during the development process for drugs.

Rapid identification of homology of carbapenem-resistant Escherichia coli by FTIR / 中华检验医学杂志

Objective:Evaluate the application of Fourier transform infrared spectroscopy in the identification of homology of carbapenem-resistant Escherichia coli(CREC). Methods:A total of 26 carbapenem-resistant Escherichia coli strains were isolated from 9 provinces in China in 2018. The 900-1 200 cm -1 was selected as a spectral region for the Euclidean distance calculating and average linkage clustering between all isolates.The single nucleotide polymorphism (SNP) was analyzed by whole genome sequencing (WGS). Results:Twenty-six CREC strains were divided into 14 infrared spectros copy(IR) types by FTIR. The same IR type belonged to the same sequence type type.Compared with cluster analysis based on WGS, the consistency of FTIR cluster analysis was 92.3% (24/26).Conclusions:FTIR presented excellent performance in identification of homology of CREC.Besides, with the advantages of simple operation and rapid acquisition of results, FTIR may be a useful tool in clinical labs.

Identification of Synthetic Cannabinoid New Psychoactive Substances 4F-MDMB-BUTINACA and MDMB-4en-PINACA / 法医学杂志

Objective To establish a method that combines a series of techniques including Fourier transform infrared spectrum （FTIR）, gas chromatography-mass spectrometry （GC-MS）, high resolution mass spectrometry and nuclear magnetic resonance spectroscopy （NMR） for identification of unknown substances. Methods The unknown samples （off-white powder and yellow crystal） seized in the actual cases were detected by FTIR, GC-MS （methanol as solvent）, high resolution mass spectrometry （methanol as solvent） and NMR （deuterated methanol as solvent）. Results The mass spectrum characteristic ions m/z of the main components in the samples measured by GC-MS were 219 （base peak）, 363, 307, 304, 275, 145, 131 and 213 （base peak）, 357, 301, 298, 269, 185, 171, 145 and 131, respectively. The accurate mass numbers [M+H]+ measured by high resolution mass spectrometry were 364.203 61 and 358.212 34, respectively. The unknown samples were identified as synthetic cannabinoid new psychoactive substances 4F-MDMB-BUTINACA and MDMB-4en-PINACA after data consultation and database retrieval and comparison, combined with infrared analysis and mass spectrometry data analysis, and their structures were confirmed by 1H-NMR. Conclusion The established multi-technology joint identification method can be used to identify 4F-MDMB-BUTINACA and MDMB-4en-PINACA in unknown samples. This method is fast, convenient, accurate, reliable and practical, and can provide reference for the identification of cases involving such substances in the future.

Rapid Qualitative and Quantitative Analysis of Caffeine and Sodium Benzoate in Annaca by Infrared Spectroscopy / 法医学杂志

Objective To establish an infrared spectroscopic method for the rapid qualitative and quantitative analysis of caffeine and sodium benzoate in Annaka samples. Methods Qualitative and quantitative modeling samples were prepared by mixing high-purity caffeine and sodium benzoate. The characteristic absorption peaks of caffeine and sodium benzoate in Annaka samples were determined by analyzing the infrared spectra of the mixed samples. The quantitative model of infrared spectra was established by partial least squares （PLS）. Results By analyzing the infrared spectra of 17 mixed samples of caffeine and sodium benzoate （the purity of caffeine ranges from 10% to 80%）, the characteristic absorption peaks for caffeine were determined to be 1 698, 1 650, 1 237, 972, 743, and 609 cm-1. The characteristic absorption peaks for sodium benzoate were 1 596, 1 548, 1 406, 845, 708 and 679 cm-1. When the detection of all characteristic absorption peaks was the positive identification criteria, the positive detection rate of caffeine and sodium benzoate in 48 seized Annaka samples was 100%. The linear range of PLS quantitative model for caffeine was 10%-80%, the coefficient of determination （ R2） was 99.9%, the root mean square error of cross validation （RMSECV） was 0.68%, and the root mean square error of prediction （RMSEP） was 0.91%; the linear range of PLS quantitative model for sodium benzoate was 20%-90%, the R2 was 99.9%, the RMSECV was 0.91% and the RMSEP was 1.11%. The results of paired sample t test showed that the differences between the results of high performance liquid chromatography method and infrared spectroscopy method had no statistical significance. The established infrared quantitative method was used to analyze 48 seized Annaka samples, the purity of caffeine was 27.6%-63.1%, and that of sodium benzoate was 36.9%-72.3%. Conclusion The rapid qualitative and quantitative analysis of caffeine and sodium benzoate in Annaka samples by infrared spectroscopy method could improve identification efficiency and reduce determination cost.

Efeito de diferentes protocolos de colagem de bráquetes cerâmicos com LED de alta potência / Effect of different ceramic bracket bonding protocols with high power LED

OBJETIVO: Avaliar o efeito de diferentes protocolos de fotoativação na resistência de união ao cisalhamento (RUC) de bráquetes cerâmicos colados ao esmalte dentário, nas falhas de união através do índice remanescente adesivo (IRA) e no grau de conversão (GC) de uma resina utilizando o fotoativador de alta potência Valo™ Cordless® (Ultradent) no modo Xtra power (3.200 mW/cm2 ). METODOLOGIA: Os bráquetes foram colados (Transbond XT® , 3M Unitek) em 80 coroas de incisivos bovinos, distribuídas aleatoriamente em dois grupos (N=40): bráquetes monocristalinos (Grupo 1) e bráquetes policristalinos (Grupo 2). Cada grupo foi subdividido em 4 subgrupos (n=10) de acordo com o protocolo de fotoativação: 3 ou 6 segundos no centro; 3s na mesial/3s na distal; e 3s na cervical/3s na incisal. Após armazenamento por 4 meses (água destilada/37°C), realizou-se o ensaio de cisalhamento (100KgF, 1mm/min). Para análise do GC, foram confeccionados 80 discos de resina com os mesmos protocolos de fotoativação utilizados na colagem dos bráquetes. A RUC (MPa) foi avaliada descritivamente, pelo teste T de Student, ANOVA one- e two-way e pelo pós-teste de Tukey. O GC (%) foi avaliado descritivamente, pela ANOVA two-way e pelo pós-teste de Tukey. As falhas de união foram classificadas de acordo com o IRA, analisadas descritivamente e pelo teste de KruskalWallis. RESULTADOS: Em relação à RUC, todos os protocolos do Grupo 2 e apenas o de fotoativação no centro por 3 segundos do Grupo 1 apresentaram valores clinicamente aceitos; os valores foram significativamente afetados (p<0,01) pelo tipo de bráquete; e ao comparar as médias intergrupos correspondentes, observou-se p=0,003 entre os protocolos de 6s no centro e p=0,010 entre os protocolos de 3s na cervical/3s na incisal. Na avaliação do GC, os valores foram afetados de forma estatisticamente significativa pelo protocolo de fotoativação (p=0,002) e pela interação entre os fatores (tipo de bráquete*protocolo de fotoativação; p=0,033). Os escores 4 (39,4%; p>0,05) e 3 (72,5%; p=0,001) do IRA foram predominantes nos Grupos 1 e 2, respectivamente. CONCLUSÃO: Deve-se ter cautela ao realizar a colagem de bráquetes cerâmicos com o Valo™ Cordless® no modo Xtra power, pois observou-se RUCs altas. A RUC e o GC podem apresentar diferenças estatisticamente significativas a depender do tipo de bráquete e do protocolo de fotoativação aplicado. De modo geral, sugere-se utilizar o bráquete policristalino ao monocristalino e aplicar 3 segundos de fotoativação no centro do bráquete (AU).

OBJECTIVE: To evaluate the effect of different photoactivation protocols on shear bond strength (SBS) of ceramic brackets bonded to dental enamel, on bond failure through the adhesive remnant index (ARI) and on the degree of conversion (DC) of a resin using the highpower photo activator Valo™ Cordless® (Ultradent) in Xtra power mode (3.200 mW/cm2 ). METHODOLOGY: The brackets were bonded (Transbond XT® , 3M Unitek) on 80 crowns of bovine incisors, randomly distributed into two study groups (N=40): monocrystalline brackets (Group 1) and polycrystalline brackets (Group 2). Each group was subdivided into 4 subgroups (n=10) according to the photoactivation protocol used: 3 or 6 seconds in the center; 3s in the mesial/3s in the distal; and 3s in the cervical/3s in the incisal. After storage for 4 months (distilled water/37°C), the shear test (100KgF, 1mm/min) was performed. For DC analysis, 80 resin discs were made with the same photoactivation protocols used in bonding brackets. The SBS (MPa) was evaluated descriptively, using Student's T test, ANOVA one- and two-way and by Tukey's post-test. The DC (%) was assessed descriptively, by ANOVA two-way and by Tukey's post-test. Union failures were classified according to the ARI, analyzed descriptively and by Kruskal-Wallis' test. RESULTS: Regarding the SBS, all protocols in Group 2 and only the photoactivation on the center for 3 seconds of Group 1 presented clinically accepted values; the values were significantly affected (p<0.01) by the type of bracket; and when comparing the corresponding intergroup averages, p=0.003 was observed between the protocols of 6s in the center and p=0.010 between the protocols of 3s in the cervical/3s in the incisal. In the DC evaluation, the values were significantly affected by the photoactivation protocol (p=0.002) and by the interaction between the factors (type of bracket*photoactivation protocol; p=0.033). ARI scores 4 (39.4%; p>0.05) and 3 (72.5%; p=0.001) were predominant in Groups 1 and 2, respectively. CONCLUSION: Caution should be exercised when bonding ceramic brackets with Valo™ Cordless® in Xtra power mode, because high SBSs were observed. SBS and DC might present statistically significant differences depending on the type of bracket and the photoactivation protocol applied. In general, it is suggested to use the polycrystalline bracket to the monocrystalline and apply 3 seconds of photoactivation in the center of the bracket (AU).

Avaliação do ponto de congelamento do leite cru por espectroscopia de infravermelho com transformada de Fourier como método de triagem / [Fourier Transform Infrared spectroscopy (FTIR) as a screening method for freezing point in raw milk]

O objetivo deste estudo foi investigar a interferência do teor de gordura do leite no ponto de congelamento (PC) obtido pelo infravermelho com transformada de Fourier (FTIR). Uma fração de leite cru foi desnatada, obtendo-se creme e leite desnatado. O leite integral e o desnatado foram adicionados com água (0%, 2%, 5%, 10%, 15% e 20%). O leite desnatado remanescente foi adicionado com creme (5%, 10%, 15%, 20%) e água (0%, 2%, 5%, 10%, 15% e 20%). As amostras foram analisadas para PC (crioscópio eletrônico e FTIR) e composição (FTIR). O PC medido por FTIR foi altamente correlacionado com o método do crioscópio eletrônico (acima de 98,5%) e, como esperado, a adição de água foi significativa (P≤0,001) ao aumentar o PC do leite em ambos os métodos. No entanto, o alto teor de gordura no leite cru resultou na redução do PC ao se utilizar o FTIR, enquanto o baixo teor de gordura resultou em aumento do PC (P≤0,001). Uma vez que a adição de água causou o efeito inverso do alto teor de gordura no PC medido por FTIR, é importante considerar o teor de gordura do leite para evitar interpretações erradas do PC quando se utiliza o método FTIR.(AU)

The objective of this study was to investigate the interference of milk fat content upon the Freezing Point (FP) obtained by Fourier-transform infrared (FTIR). A fraction of raw milk was skimmed, obtaining cream and skim milk. Whole and skim milk were added with water (0, 2, 5, 10, 15, and 20%). The remaining skim milk was added with cream (5, 10, 15, 20%) and water (0, 2, 5, 10, 15, and 20%). Samples were analyzed for FP (thermistor cryoscope and FTIR) and composition (FTIR). FP measured by FTIR was highly correlated with the thermistor cryoscope method (above 98.5%) and, as expected, water addition was significant (P≤0.001) upon increasing milk FP in both methods. However, high fat content in raw milk resulted in decreasing FP when using FTIR, while low fat content resulted in increased FP (P≤0.001). Since water addition caused the inverse effect of high fat on FP measured by FTIR, it is important to regard the fat content of milk to avoid misinterpretation of FP when using the FTIR method.(AU)

A Study of Chemical Composition of Gall Stones in a Tertiary Care Hospital.

Gallstones are a major health problem & have been recognized since antiquity. Gallstones are generally classified into pure cholesterol, pigment and mixed type. Knowing the chemical composition of gallstones is essential for determining etiopathogenesis of gallstone disease. Fourier Transform Infrared Spectroscopy (FTIR) method is the most widely used technique in chemical analysis of gall stones. Reports on chemical analysis of gallstones are available from different endemic regions of India. However, no reports are available about the composition and etiopathogenesis of gallstones in Himachal Pradesh. METHODSGallstones from 400 patients of cholelithiasis were collected after cholecystectomy at Indira Gandhi Medical College Hospital (I.G.M.C.), Shimla, between June 2016 to June 2018, and were subjected to chemical analysis by FTIR method. The data was further correlated with regard to age, gender, socio-economic status, various life style factors like diet, obesity, physical activity, with stone number and colour. RESULTSChemical analysis of gall stones revealed that pure cholesterol, mixed and pigment variety were 94 %, 2 % and 4 % respectively. Majority of the patients were below the age of 50 years (66 %). Male to female ratio was 2.7:1. Both sexes had predominantly pure cholesterol stones. Most of the patients belonged to the lower middle class (56.5 %) & all socio-economic classes showed predominantly pure cholesterol stones. Similarly, there was no predilection of any type of stone to a particular physical work category. 53.5 % patients were non-vegetarians and 46.5 % were vegetarians. There was no correlation between diet and BMI with type of stones. In our study, 66 % of patients had multiple stones. Multiple stones were seen in all varieties of stones. Pure cholesterol stones showed a variety of colours contrary to traditional classification. CONCLUSIONSIn Himalayan population, the predominant type of gall stones were pure cholesterol stones. Mixed stones and pigment containing stones were found in much smaller frequencies. This result is in contrast to that of rest of the Indian subcontinent from where larger percentage of pigment and mixed stones has been reported. And pure cholesterol stones showed maximum variation in colours contrary to our expectation.

α-Helical protein absorption at post-traumatic epileptic foci monitored by Fourier transform infrared mapping

Tissue analysis by Fourier transform infrared (FTIR) imaging can determine the biodistribution of molecules,without pre-analytical modification. We aimed to study the infrared spectroscopic changes of a-helical proteinsat post-traumatic epileptic (PTE) foci by FTIR. FITR mapping was applied to detect a-helical proteins in ratbrain tissue samples with post-traumatic epilepsy. Histological examination of brain sections showed that therat model of PTE was successfully established. At the PTE foci, high a-helical absorption regions wereevident, where the color difference and absorption were significantly different from those in the low-absorptionregions. This provided a distinctive and characteristic pattern at the site of lesions. The use of FTIR imagingmeans that it is possible to measure the molecular structural changes resulting from PTE pathologies in tissues,providing a novel adjunct to conventional pathological diagnostic techniques.

A comparative study of extraction techniques for maximum recovery of bioactive compounds from Ganoderma lucidum spores / Estudio comparativo de técnicas de extracción para la máxima recuperación de compuestos bioactivos a partir esporas de Ganoderma lucidum

SUMMARY This study aimed at evaluating effective methods for breaking the hard and insoluble spores of Ganoderma lucidum to recover functional biomolecules. Rupture techniques were evaluated such as manual maceration (RM), maceration with spheres of various materials (BR), and microwave exposure plus maceration with steel/ chrome spheres (MBR1). Spore rupture was evaluated using UV-Vis spectroscopy, which showed vibrations of 2955, 1642, 1240, 1080 and 1746 cm-1 corresponding to changes in spore walls. The MBR1 extract contained the largest amounts of carbohydrates (19.80 mg.g-1 spores) and polyphenols (2.21 mg.g-1 spores), whereas the BR extract had higher antioxidant activity (57.22%Inb DPPH). The MBR1 and BR extracts contained 62.2 and 73.5% glucose, respectively. Both methods also involved significant extraction of carbohydrates and proteins. The best way to extract biomolecules from spore walls is to perform a microwave heat treatment and break the walls with steel/chrome spheres; this produces large quantities of carbohydrates with antioxidant properties.

RESUMEN El objetivo de este estudio fue evaluar varios métodos de ruptura de las esporas de Ganoderma lucidum y extraer sus propiedades bioactivas. Para este propósito se evaluaron diferentes técnicas de rompimiento como: la maceración manual (RM), la maceración con esferas de diversos materiales (BR) y la exposición a microondas junto la maceración de las esporas con esferas de acero/cromo (MBR1). La ruptura de las esporas fue evaluada por espectroscopia UV-Vis, la cual mostró que las vibraciones 2955, 1642, 1240, 1080 y 1746 cm-1 correspondieron a cambios estructurales en las paredes de las esporas. El extracto MBR1 presento el mayor contenido de carbohidratos (19,80 mg.g-1) y polifenoles (2,21 mg.g-1), mientras que el extracto BR tuvo una mayor actividad antioxidante (57,22% Inb DPPH). Los extractos MBR1 y BR también presentaron en el análisis de monosacáridos un 62,2 y 73,5% de contenido glucosa. Como conclusión la mejor metodología para extraer biomoléculas de las paredes de las esporas de G. lucidum fueron el tratamiento térmico con microondas y la ruptura de las paredes con esferas de acero/cromo, porque este proceso permitió la extracción de una mayor cantidad de carbohidratos con posibles propiedades antioxidantes.

Discrimination of Periplaneta americana and other insectivorous herbs by FTIR spectroscopy combined with chemometrics / 中草药

Objective: To establish a method for the identification of the Periplaneta americana and other insectivorous herbs (Scorpio and Hirudo) based on infrared spectroscopy combined with chemometrics, and to provide a basis for the identification of the P. americana. Methods: Fourier transform infrared spectroscopy was used to collect the infrared spectrum data of three kinds of insect medicine powders. After the second order derivation of the obtained spectral data, the ordinate verticalization method and standardization method were used to optimize the spectrum. The spectral data was further analyzed by chemometrics, such as hierar chicalcluster analysis (HCA), principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). Results: There were differences in the infrared fingerprints of the P. americanas, Scorpios, Leeches. The absorption peaks of the P. americanas at 1 711, 1 410, and 712 cm-1 were obvious. The absorption peaks of the Scorpios at 1 753, 1 400, 1 168, and 717 cm-1 were obvious. The absorption peaks of the Leeches at 1 558, 1 457, 1 400, and 669 cm-1 were obvious, And the leeches have no absorption peak at 1 753-1 711 cm-1. The peak shape of the three insectivorous herbs was significantly different at 1 800-1 700 cm-1. In the second derivative spectrum, the positions of the main peaks are the same, but the intensity of the common peaks is different. Using the HCA analysis method, it was found that the three insectivorous herbs could be quickly distinguished. The PCA and PLS-DA analysis methods were used to find that the three insectivorous herbs were distributed in different regions. Conclusion: Infrared spectroscopy combined with chemometrics can easily and quickly identify the P. americanas and other insectivorous herbs (Scorpios and Leeches), and provide reference for the quality control and evaluation of P. americanas.

Chemical pattern recognition of YuanZhi San capsule based on FTIR and HPLC analysis / 国际药学研究杂志

Objective: To provide a scientific basis for the quality control of YuanZhi San capsule(YZSC). Methods: Fourier transform infrared spectroscopy(FTIR)combined with second derivative spectra was used to analyze the chemical components of YZSC;high performance liquid chromatography(HPLC)was used to establish the fingerprints of different batches of YZSC, the quality assessment of YZSC was carried out by similarity evaluation, cluster analysis(CA), principal component analysis(PCA)and orthogonal partial least squares discriminant analysis(OPLS-DA). Results: The main components of YZSC were carbohydrate, flavonoids, alkaloids, organic acids and saponins. There were 41 common peaks in the fingerprint, seven peaks were identified using reference substance, they were 3, 6'-disinapoylsucrose, ferulic acid, jatrorrhizine hydrochloride, palmatine chloride, berberine, quercetin and β-asarone. The similarity of 10 batches of samples was higher than 0.99. The CA and PCA analysis indicated that there were differences in different batches of YZSC, and they were mainly divided into two categories. By the OPLS-DA, 10 main chemical constituents were found to be the cause of the quality differences in the batches, and the peaks of berberine, 3, 6'-disinapoylsucrose, palmatine chloride, β-asarone, and jatrorrhizine hydrochloride were recognized by comparison with the reference substances. Conclusion: The chemical pattern recognition technology based on the FTIR and HPLC analysis might be used for the quality evaluation of YZSC.