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.

Forensic Pathological Diagnosis of Acute and Old Myocardial Infarction Using Fourier Transform Infrared Spectroscopy / 法医学杂志

OBJECTIVES@#Fourier transform infrared spectroscopy (FTIR) was used to analyze myocardial infarction tissues at different stages of pathological change to achieve the forensic pathology diagnosis of acute and old myocardial infarction.@*METHODS@#FTIR spectra data of early ischemic myocardium, necrotic myocardium, and myocardial fibrous tissue in the left ventricular anterior wall of the sudden death group of atherosclerotic heart disease and the myocardium of the normal control group were collected using hematoxylin-eosin (HE) and immunohistochemistry (IHC) staining as a reference, and the data were analyzed using multivariate statistical analysis.@*RESULTS@#The mean normalized spectra of control myocardium, early ischemic myocardium and necrotic myocardium were relatively similar, but the mean second derivative spectra were significantly different. The peak intensity of secondary structure of proteins in early ischemic myocardium was significantly higher than in other types of myocardium, and the peak intensity of the α-helix in necrotic myocardium was the lowest. The peaks of amide Ⅰ and amide Ⅱ in the mean normalized spectra of myocardial fibrous tissue significantly shifted towards higher wave numbers, the peak intensities of amide Ⅱ and amide Ⅲ were higher than those of other types of myocardium, and the peak intensities at 1 338, 1 284, 1 238 and 1 204 cm-1 in the mean second derivative spectra were significantly enhanced. Principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) showed that FTIR could distinguish different types of myocardium.@*CONCLUSIONS@#FTIR technique has the potential to diagnose acute and old myocardial infarction, and provides a new basis for the analysis of the causes of sudden cardiac death.

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.

Rapid and sensitive analysis of trace β-blockers by magnetic solid-phase extraction coupled with Fourier transform ion cyclotron resonance mass spectrometry / 药物分析学报

A rapid and sensitive method for analyzing trace β-blockers in complex biological samples,which involved magnetic solid-phase extraction(MSPE)coupled with Fourier transform ion cyclotron reso-nance mass spectrometry(FTICR-MS),was developed.Novel nanosilver-functionalized magnetic nano-particles with an interlayer of poly(3,4-dihydroxyphenylalanine)(polyDOPA@Ag-MNPs)were synthesized and used as MSPE adsorbents to extract trace β-blockers from biological samples.After extraction,the analytes loaded on the polyDOPA@Ag-MNPs were desorbed using an organic solvent and analyzed by FTICR-MS.The method was rapid and sensitive,with a total detection procedure of less than 10 min as well as limits of detection and quantification in the ranges of 3.5-6.8 pg/mL and 11.7-22.8 pg/mL,respectively.The accuracy of the method was also desirable,with recoveries ranging from 80.9％to 91.0％following the detection of analytes in human blood samples.All the experimental results demonstrated that the developed MSPE-FTICR-MS method was suitable for the rapid and sensitive analysis of trace β-blockers in complex biological samples.

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.

Measurement of corneal epithelial thickness parameters by Fourier domain optical coherence tomography to identify early keratoconus / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To explore the value of corneal epithelial thickness parameters in the diagnosis of early keratoconus by Fourier domain optical coherence tomography(FD-OCT).<p>METHODS: Retrospective control study. Patients with early keratoconus who were admitted to the Department of Ophthalmology of the First Affiliated Hospital of Soochow University from January 2015 to October 2020 and patients who received laser refractive surgery for myopia during the same period were included in this study. Using FD-OCT to measure the cornea in circle centralized by the pupil and with diameter of 9mm in the early-keratoconus group and the control group. This was to obtain the thickness parameter of corneal epithelium with diameter of 7mm, the respective averaged thickness value of corneal epithelium and the respective averaged thickness value of the full corneal layer on each of the 25 divisions. The parameter value differences between the early-keratoconus group and the control group were compared, and the diagnosis value of parameters that hold difference was analyzed. <p>RESULTS: The Min-e value in early-keratoconus group was significantly lower than that of the control group. On contrary, the value of Std.Dev, Max-Min-e, and Max-e were significantly higher in early-keratoconus group than that in latter one(all <i>P</i><0.001). The value of Std.Dev and Max-Min-e hold a greater diagnostic efficiency on diagnosis of early keratoconus(AUC=0.937, 0.928), while Max -e value and Min-e value performed a medium diagnostic efficiency(AUC=0.871, 0.797). Analysis on thickness of corneal epithelium on the 25 divisions found that the thickness of corneal epithelium at infratemporal region of inner ring(EIT1)became thinner most obviously in early-keratoconus group, with greatest diagnostic efficiency(AUC=0.827). The average corneal thickness of the 25 zones of the early keratoconus group was significantly thinner than that in the normal control group. Averaged corneal thickness at infratemporal region of inner ring(CIT1)hold a relatively high diagnostic efficiency among the 25 divisions(AUC=0.903).<p>CONCLUSION: The parameter values of corneal epithelium thickness including Std.Dev, Max-Min-e, Max-e, Min-e, the averaged thickness value of corneal epithelium at infratemporal region of inner ring, and the thickness value of full corneal layer at infratemporal region of inner ring can all be used for diagnosis of early keratoconus.

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.

Recognition of S1 and S2 heart sounds with two-stream convolutional neural networks / 生物医学工程学杂志

Auscultation of heart sounds is an important method for the diagnosis of heart conditions. For most people, the audible component of heart sound are the first heart sound (S1) and the second heart sound (S2). Different diseases usually generate murmurs at different stages in a cardiac cycle. Segmenting the heart sounds precisely is the prerequisite for diagnosis. S1 and S2 emerges at the beginning of systole and diastole, respectively. Locating S1 and S2 accurately is beneficial for the segmentation of heart sounds. This paper proposed a method to classify the S1 and S2 based on their properties, and did not take use of the duration of systole and diastole. S1 and S2 in the training dataset were transformed to spectra by short-time Fourier transform and be feed to the two-stream convolutional neural network. The classification accuracy of the test dataset was as high as 91.135%. The highest sensitivity and specificity were 91.156% and 92.074%, respectively. Extracting the features of the input signals artificially can be avoid with the method proposed in this article. The calculation is not complicated, which makes this method effective for distinguishing S1 and S2 in real time.

Effects of hyaluronic acid with different molecular weight on the transdermal absorption of reduced glutathione / 中国药科大学学报

@#This paper aimed at studying the effects of hyaluronic acid (HA) with different molecular weights on the transdermal absorption and retention of reduced glutathione (GSH) in the isolated skin of SD rats. Franz diffusion cell method was used to investigate the effects with different molecular weights HA on the in vitro transdermal penetration of GSH and the storage in different layers of the skin. AutoDock molecular docking was used to study the interaction between GSH and HA. Attenuated total reflection Fourier transformed infrared spectroscopy (ATR-FTIR) and H&E section staining were used to characterize the changes and effects of lipids and proteins in the rat stratum corneum after HA acts on the skin. The results of in vitro transdermal experiments showed that HA with different molecular weights had a significant impact on the amount of GSH passing through the skin, that as the molecular weight of HA increased, the effect of preventing GSH from passing through the skin became stronger, that in terms of skin storage, HA with different molecular weights could increase the storage of GSH in the stratum corneum, and that HA with a molecular weight below 7K could also significantly increase the storage of GSH in the dermis. The molecular docking results showed that HA and GSH had a relatively strong interaction, which could form intermolecular hydrogen bonds; and the results of ATR-FTIR and H&E staining showed that HA could interact with lipids and keratins in the stratum corneum of the skin. Such interaction can increase the permeability of the stratum corneum of the drug, however, as a water-soluble GSH, it may be involved in the formation of intermolecular hydrogen bonds with HA. In the structure of HA hydrogel, the amount of GSH drug passing through the intact skin is reduced; but at the same time, this interaction also provides a reservoir for the formation of GSH, thus increasing its storage in the skin. Through comparison of the storage capacity of GSH in the stratum corneum and dermis of the isolated skin due to the increase of HA with different molecular weights, it has been found that the storage capacity of HA with low relative molecular weight is the best.

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.

Discrimination of species and populations of the genus Cichla (Cichliformes: Cichlidae) in rivers of the Amazon basin using otolithic morphometry

ABSTRACT The genus Cichla is a highly diverse group, with 16 species already described. Externally, some species are very similar and discriminating between them may be very difficult. Nevertheless, discrimination of fish stocks is essential for management purposes. Morphometric analyses of otoliths have been successfully used to distinguish species and fish stocks, especially in marine environments. This study evaluated whether sagittal otolith shape can be used to discriminate among the species Cichla temensis, C. monoculus, and C. orinocensis, as well as within populations of C. temensis in rivers of the Amazon. Shape indices and Fourier coefficients were used to describe the shape of the otoliths. Among the groups of species, the morphology of the sagittal otolith of C. temensis was totally distinct from the species C. monoculus and C. orinocensis. While among populations of C. temensis, individuals from the Negro and Jatapú Rivers were different, regardless of the methods used. These results confirm the ability to differentiate species and populations by using the morphology of otoliths. However, more research is needed to verify the role of genetic versus environmental and biotic effects, and thus be able to explain the discrimination observed in otoliths.

RESUMO O gênero Cichla é bastante diverso, com 16 espécies descritas. Algumas espécies são externamente muito similares e sua discriminação pode ser bastante difícil. Ao mesmo tempo, a discriminação de estoques pesqueiros é essencial para propostas de manejo. Análises morfométricas em otólitos têm sido utilizadas com sucesso para a distinção de espécies e estoques pesqueiros, principalmente em ambientes marinhos. Este estudo avaliou se o formato do otólito sagittal pode ser utilizado para discriminar entre espécies Cichla temensis, C. monoculus e C. orinocensis, bem como dentro de populações de C. temensis em diferentes rios amazônicos. Índices de forma e coeficientes de Fourier foram utilizados para descrever a forma dos otólitos. Dentre as espécies, a morfologia do otólito sagittal do C. temensis mostrou ser totalmente distinta das espécies C. monoculus e C. orinocensis. Enquanto no grupo das populações de C. temensis, os indivíduos dos rios Negro e Jatapú mostraram-se diferentes independente dos métodos utilizados. Esses resultados confirmam a capacidade de diferenciação de espécies e populações através da morfologia dos otólitos. No entanto, são necessárias mais pesquisas para verificar o papel dos efeitos genéticos em comparação aos efeitos ambientais e bióticos para explicar a discriminação observada nos otólitos.

The Interaction between Aptamer and Beclomethasone Based on High Resolution Mass Spectrometry and Molecular Docking / 中国生物化学与分子生物学报

Beclomethasone is an effective glucocorticoid, and beclomethasone-aptamer is a short single-stranded DNA with affinity and specificity to beclomethasone. The interaction between them is still unclear. The study of the interaction between aptamers and beclomethasone has a certain significance for the application of aptamers. In this study, high-resolution Fourier transform ion cyclotron resonance mass spectrometer (FT-MS) and molecular docking simulation technology were used to study the interaction between aptamer and beclomethasone. Firstly, under the optimized conditions of high-resolution mass spectrometry parameters, the complex of aptamer and beclomethasone was detected by the negative ion scanning mode with the electrospray ion source. Based on the results of high-resolution mass spectrometry, most of the compounds were -8-valent ions, and their dissociation constant K

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.