Spectroscopic Analysis Methods Research Articles

Study on the Characteristics of Crystal Formation and Transformation of Alkali-Activated Slag Minerals Induced by Weak Alkali

Strong-alkali activation is a prerequisite needed to ensure the full polymerization activity of alkali slag binder and establish excellent mechanical properties; however, it substantially increases the preparation cost. In this study, the effects of both strong and weak alkaline activators on the activation performance of alkali slag were examined, using a combination of X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy analysis methods. The reaction mechanism was analyzed under different alkaline conditions, and the preparation cost could be significantly reduced without significantly degrading mechanical properties. The results indicate that Ca(OH)2 can stimulate the reactivity of slag, resulting in a 40% decrease in compressive strength (compared to NaOH) but a 25–50% reduction in preparation cost. With increasing Ca(OH)2 dosage, the compressive strength first increases and then decreases. The best excitation effect is achieved at a dosage of 40 g Ca(OH)2 per 450 g GBFS. The formation of aluminosilicate is the main driving force for the observed increase in compressive strength. Excessive dosage of Ca(OH)2 will lead to its deposition in the specimen, thus affecting the development of compressive strength.

Cotteslosin D, a new cyclopentapeptide from a sponge-derived fungus Aspergillus versicolour 2-18

A new cyclopentapeptide, cotteslosin D (1), was isolated from the cultures of a sponge-derived fungus Aspergillus versicolour 2-18. The structure of 1 was eluvidated as cyclo-(N-Me-L-Tyr-L-Val-L-Pro-L-Tyr-L-Phe) on the basis of extensive spectroscopic analysis and chemical methods. Compound 1 displayed weak antibacterial activities against Escherichia coli and Staphylococcus aureus.

INFRARED SPECTROSCOPIC ANALYSIS OF COMPLEX COPPER(II) CONTAINING CATALYTIC SYSTEM

The synthesized 2 individual orthophosphate catalysts AlPO4 and Cu3(PO4)2 and 7 new complex aluminum-copper (II) orthophosphate catalytic systems of the type xAlPO4·yCu3(PO4)2 was obtained based on them were investigated by the method of IR spectroscopic analysis. At the same time, the content of both orthophosphates in the catalyst structure varies in the range of 0.5 - 99.5 wt. %. In the entire series of air-dry samples and those baked at the optimal heat treatment temperature (600 °С), the frequencies and intensities of the absorption bands of the IR spectra of the obtained catalytic systems of the type type xAlPO4·yCu3(PO4)2 are characterized by intense absorption in the region of valence vibrations of OH groups of water molecules (3610‒3005 cm-1). Valence vibrations of OH groups of water molecules, which take a direct part in the formation of hydrogen bonds, are observed in the region of 2380‒1880 cm-1. Characteristic manifestations of the hydrogen bond in the vibrational spectrum of H2O, which is part of the structure of the synthesized aluminum-copper (II) orthophosphate catalysts, are a low-frequency shift, an increase in intensity, and a broadening of the bands of valence vibrations of its OH groups. At the same time, in the region 1114‒400 cm-1, valence and deformation vibrations of the orthophosphate ion PO43- are observed, which are clearly expressed in the form of clear absorption bands in the dehydration products for all synthesized binary catalytic systems. Additional coordination of the orthophosphate anion with metal cations Al3+ and Сu2+ is observed. Heating all synthesized orthophosphate samples above 700 °С contributes to their complete dehydration and the emergence of IR spectra characteristic of anhydrous orthophosphate salts.

Isolation and Biomimetic Semisynthesis of Hyperzrones A and B, Two Nor-Polycyclic Polyprenylated Acylphloroglucinols with a Characteristic Cyclobutane Moiety, from Hypericum beanii.

Hyperzrones A (1) and B (2), two unprecedented nor-polycyclic polyprenylated acylphloroglucinols with a characteristic cyclobutane moiety, were discovered from Hypericum beanii. Their structures were determined by extensive spectroscopic analysis, X-ray crystallography, and quantum chemical calculation methods. A bioinspired semisynthesis of 1 and 2 was achieved from the natural precursor hypercalin B (3), featuring a Favorskii-type rearrangement and a visible-light-mediated [2 + 2] photocycloaddition. Several diverse derivatives were also obtained, providing a compound library for biological studies.

Evaluation of 1064 nm Raman for meat and bone meal species discrimination: From raw form to chemical and physical components

The 1064 nm Raman spectroscopy technique was employed to characterize raw, bone fragments (BF), meat fragments (MF), lipid, and residue of meat and bone meal (MBM) samples. Employing three chemometric algorithms, species discrimination models were optimized for the aforementioned sample types, indicating that the presence of BF favored discriminant analysis for poultry samples, yielding a classification error of 0.000. The species discrimination model constructed using Raman spectra combined with PLS-DA algorithm for residue samples was found to be overall optimal, with classification error for four species samples all below 0.061. A detailed analysis of the BF related spectral variables contributing significantly to PLS-DA discriminant analysis was conducted. Finally, this study established the complementarity of Raman spectroscopy in species discrimination analysis from both a physical and chemical components perspective, laying the theoretical groundwork for the development of a high-precision 1064 nm Raman spectroscopic analysis method for MBM species discrimination.

Development and Characterization of PVA Membranes Modified with In(BTC) Metal–Organic Framework for Sustainable Pervaporation Separation of Isopropanol/Water

Development and Characterization of PVA Membranes Modified with In(BTC) Metal–Organic Framework for Sustainable Pervaporation Separation of Isopropanol/Water

Fast spectroscopic and multisensor methods for analysis of glucosamine and hyaluronic acid in dietary supplements

There is a lack of fast and inexpensive analytical methods for quantification of key ingredients in dietary supplements. Here we explore the potential of near infrared (NIR) spectrometry, attenuated total reflection infrared (ATR-IR) spectrometry and potentiometric multisensor system (MSS) in quantitative determination of glucosamine and hyaluronic acid in commercial samples of dietary supplements. All three methods have demonstrated their applicability for this task when combined with chemometric data processing. Principal Component Analysis (PCA) revealed similarities across the three techniques, indicating the presence of distinct sample composition. Partial least squares (PLS) models were constructed for glucosamine and hyaluronic acid quantification. The root mean square error of cross validation (RMSECV) for glucosamine quantification varied between 7.7 wt% and 8.9 wt%. NIR spectrometry has demonstrated the best accuracy for hyaluronic acid (RMSECV = 9.9 wt%), while ATR-IR and MSS yielded somewhat worse performance with RMSECV values of 12.1 and 11.3 wt%, respectively. The findings of this study indicated that NIR, ATR-IR and MSS exhibit reduced accuracy in comparison to complex and high-precision analytical techniques. However, they can be employed for the rapid, semi-quantitative evaluation of glucosamine and hyaluronic acid in dietary supplements, with the possibility of integration into routine quality control procedures.

Hydrogen evolution reaction activity of 3D-printed TiB2 and MgB2 matrix reinforced with graphene and carbon nanofiber in alkaline media

In the present study, the TiB2, MgB2/ Graphene (GRP)/PLA and TiB2, MgB2/Carbon Nanofiber (CNF)/PLA 3D-printed electrodes were fabricated via the Fused Deposition Modeling (FDM) technique. The hydrogen Evolution Reaction (HER) performance of 3D electrodes was studied using electrochemical impedance spectroscopy (EIS) and cathodic polarization analysis methods in 1 M KOH media. The EIS measurement results showed that the total resistance values were significantly reduced due to the addition of GRP and CNF to TiB2/PLA and MgB2/PLA 3D electrodes. In addition, the increase in current density with the addition of GRP and CNF to the 3D electrodes from the cathodic polarization curves supported the EIS measurement results. Moreover, a new activation method without using solvent was applied as different from the literature, to enhance the conductivity of 3D electrodes. The activation process was performed by implementing 50 cycles in 1 M KOH solution with the cyclic voltammetry method. As a result, with this study, both the synergistic effect of multiple composites and the application of the activation method have increased the HER efficiency of the 3D electrocatalyst. Thus, 3D electrocatalysts have been introduced to the energy application field.

Isolation and purification of polyphenols, hypoglycemic and hypolipidemic and active constituent analysis of walnut septum polyphenols

Walnut septum is rich in polyphenolic substances, but the hypoglycaemic and hypolipidemic effects of walnut septum polyphenols (WSP) and the main active compounds responsible for these effects are still unknown. In the present study, WSP was firstly extracted, and then purified using D101 macroporous resin, and the purity of WSP obtained was 87.36 %. WSP inhibited the activity of α-glucosidase and pancreatic lipase with IC50 values of 36.2 μg/mL and 155.9 μg/mL, respectively. Furthermore, WSP increased glucose consumption and decreased oxidative stress in insulin-resistant C2C12 cells, as well as inhibited lipid accumulation in 3 T3-L1 adipocytes. Eight naturally active ligands for α-glucosidase and pancreatic lipase were identified from WSP by affinity ultrafiltration combined with liquid chromatography-mass spectrometry analytical methods. Further molecular docking showed strong binding between these eight ligands and the enzyme. The results of the study lay a scientific foundation for the development of walnut septum as a functional food for hypoglycemic and hypolipidemic.

Unusual Composition of the Sarezzano Reliquary Busts

The interdisciplinary study of two reliquary busts from Sarezzano (Piedmont, Italy) is a perfect example of the necessity to provide for material characterisation as a recurring common practice in historical studies and a mandatory step in conservation assessment. Furthermore, the diagnostics of cultural heritage play a crucial role in art historical research, providing relevant information on artefacts’ genesis, production technology, and conservation history. The study of the materials of the reliquary busts was performed by non-invasive (portable X-ray fluorescence spectrometry) and micro-invasive (stereomicroscope, attenuated total reflection Fourier transform infrared spectroscopy and powder X-ray diffraction analysis) methods. According to the results, the busts were found to be made of a tin–lead alloy, a rather unusual material for mediaeval reliquary busts. Moreover, the outcome suggests that the busts were originally silvered, except for the hair and beard which are still gilded. The analysis reveals the use of colophony as an adhesive buffer layer on the busts’ alloy, as well as inside them, to favour the metal working process, since it is found as degraded residue. Finally, even the typology of alloy decay is defined. All this information has enabled us to determine the artistic technique and estimate the value and quality of the material employed. In addition, it has led to the correct choice of materials and methods to be adopted during the restoration, and therefore the usage of more suitable solvents and tools.

Studying of serum bile acids metabolomics as potential biomarkers for differentiation between hepatocellular carcinoma and cholangiocarcinoma

BackgroundMetabolomics is an emerging field that quantifies numerous metabolites systematically aiming to determine the metabolites corresponding to each biological phenotype and then provide an analysis of the mechanisms involved. Bile acids (as an organic metabolites) are synthesized in the liver from cholesterol and could be used as indicator of hepatobiliary impairment. However, the role of these bile acids in the pathogenesis of cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC) is still unclear. Therefore, the current study aimed to use serum bile acid profiles potential diagnostic biomarkers for early detection of cholangiocarcinoma and differentiating it from hepatocellular carcinoma.Subjects and methodsUltra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS/ MS) analytical method was used for the measurement of bile acids in the serum of patients with hepatocellular carcinoma (n = 35), cholangiocarcinoma (n = 35), and control group (n = 35) to determine role as markers for differentiation between hepatocellular carcinoma and cholangiocarcinoma.ResultsThis study revealed that there was a significant increase in all 14 bile acids in both HCC and CCA compared to control. Also, there was significant increase in LCA, TCA, GDCA, and GCA in cholangiocarcinoma (CCA) compared to HCC with AUC 0.775, 0.825, 0.797, and 0.831 respectively with highest sensitivity and specificity for GCA (82% and 74%, respectively) for differentiation between the two types of cancers.ConclusionDetermination of the serum bile acids pattern using UPLC/MS/MS may help to differentiate between hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) especially GCA which may be a good biomarker for differentiation between two types of liver cancers.

OBTAINING AN ACTIVE INGREDIENT FOR COTTON SEED TREATMENT BASED ON METHYLENDIUREA AND PARAAMINOBENZOIC ACID AND STUDYING ITS PHYSICOCHEMICAL CHARACTERISTICS

Seed treatment is the main method of protecting plants from infectious diseases. The article presents data on the production of a double compound based on methylene diurea and paraaminobenzoic acid and the study of its physicochemical characteristics. The chemical interaction in the three-component water-salt system methylenediurea (MDU) – para-aminobenzoic acid (PABA) – water was studied using the isothermal method of physicochemical analysis. The crystallization region of the new binary compound, the active substance, was established at a molar ratio MDU: PABA = 1:2. The formation of the double compound is confirmed by X-ray phase and IR spectroscopic methods of analysis. From the obtained X-ray phase analysis data, it follows that the reference lines of the double compound and their intensity differ from the X-ray patterns of the initial components. The IR spectra of MDM and PABA are characterized by intense absorption in the region of 3500-3390 cm-1 , 2000-500 cm-1 and 3500-3345 cm-1 , 1800-500 cm-1 , respectively. In the IR spectra of the new double compound MDM•2PABA, the absorption intensity in the region of 1800-500 cm-1 increases. A decrease in the absorption region of the stretching vibration of CO groups from 1626, 1626.3 cm-1 to 1612 cm-1 is observed in the case of the double compound MDM•2PABA. The results of the studies indicate the formation of a new compound. It is shown that the double compound has low hygroscopicity under summer, autumn, spring and winter storage conditions, high swelling and moisture capacity, and low solubility.

Catalytic Ozonation Treatment of Coal Chemical Reverse Osmosis Concentrate: Water Quality Analysis, Parameter Optimization, and Catalyst Deactivation Investigation.

Catalytic ozone oxidation, which is characterized by strong oxidizing properties and environmental friendliness, has been widely used in organic wastewater treatments. However, problems such as a low organic pollutant removal efficiency and unstable operation during the catalytic ozone treatment process for wastewater remain. To address these disadvantages, in this study, the treatment efficacy of catalytic ozone oxidation on a coal chemical reverse osmosis concentrate was investigated. The basic water quality indicators of the chemical reverse osmosis concentrate were analyzed. The effects of initial pollutant concentration, pH, ozone concentration, and catalyst concentration on the COD removal rate from the coal chemical reverse osmosis concentrate were explored. Water quality indicators of the chemical reverse osmosis concentrate before and after the catalytic ozone treatment were studied using spectroscopic analysis methods. The RO concentrate demonstrated large water quality fluctuations, and the catalytic ozonation process removed most of the pollutants from the treated wastewater. A possible deactivation mechanism of the ozone catalyst was also proposed. This study provides a theoretical reference and technical support for the long-term, efficient, and stable removal of organic pollutants from coal chemical reverse osmosis concentrate using a catalytic ozone oxidation process in practical engineering applications.

Terpenoids and steroids from aerial parts of Achillea alpina L. as PTP1B inhibitors: Kinetic analysis and molecular docking studies

Achillea alpina L. (Alpine yarrow) is a noteworthy herb in the genus Achillea with many uses in vegetables and traditionally used to treat stomach disorders. In our continuous research on the chemical constituents and biological activities of medicinal plants, ten previously undescribed terpenoids including eight eudesmane-type sesquiterpenes (1–8), one nor-eudesmane-type sesquiterpene (9), one cyclo-geraniol derivative (10), and twenty-one known compounds were isolated and structurally elucidated from the aerial parts of A. alpina. Structures and absolute configurations of the undescribed terpenoids were identified using comprehensive spectroscopic analysis (NMR, HRESI-MS, and CD data) and computational methods (ECD and NMR calculation). Enzyme inhibitory assays showed that the isolated sesquiterpene (19), triterpene (22), and sterol (26) were protein tyrosine phosphatase 1B (PTP1B) inhibitors with IC50 values ranging from 14.87 to 23.09 μM in comparison with positive control - ursolic acid, showing IC50 value of 5.93 ± 0.16 μM. Further enzyme kinetics and molecular docking studies were performed to provide valuable insights into their mechanism of action.

SOLUBILITY POLYTEREME OF THE SYSTEM AMMONIUM SULPHATE - MAGNESIUM CHLORATE DEFOLIANT - WATER

The mutual influence of components in an aqueous system consisting of ammonium sulfate and magnesium chlorate defoliant was studied in a wide concentration range at a temperature of -27.0 to 4.5°C. On the state diagram of the system, the fields of crystallization of ice, magnesium chlorate hexahydrate, ammonium sulfate, and the compound (NH4)2SO4 ∙ 2NH4CIO3 ∙ 2MgSO4 ∙ H2O are delimited, which was identified and characterized by chemical, X-ray phase, thermal, and IR spectroscopic methods of analysis.

Investigation of the Process of Agglomeration of Phosphorites Using Phosphate-Siliceous Shales and Oil Sludge

Introduction This article aims to discuss the physico-chemical features of the agglomeration process of phosphorus fines using phosphate-siliceous shales and oil sludge. Methods The composition and structure of the starting materials and physico-chemical transformations under thermal influence are studied using IR spectrometry and differential thermal analysis methods. Results The results of IR spectrometric analysis of the phosphate siliceous shales are characterized by intense peaks at 493.78, 547.78, and 678.94 cm-1, corresponding to Ca-O-P compounds. Moreover, the wave oscillations in the region of 837.11-995.27 cm-1 indicate the characteristics of Si-O valence bonds, and in the region of 1114.86-1431 cm-1 depict the characteristics of Si-O-Al compounds. The IR spectrum of oil sludge is characterized by the presence of wave oscillations in the region of 1411.89-2904.80 cm-1 corresponding to petroleum components. Conclusion The differential thermal analysis of the investigated sample of phosphate-siliceous shale does not have intense endo- and exo-effects, and it is characterized by a significant predominance of hydrate compounds of aluminosilicate and carbonate components.

Heavy metal levels of outdoor dust from the Eastern Mediterranean Sea region and assessment of the ecological and health risk.

As a result of some chemical element (heavy metals) pollution of dust, environmental pollution of dust has become an increasing concern, necessitating an assessment of risks to both ecology and human health, particularly in urban areas. Most of these pollutants settle on the outdoors and eventually become part of the outdoor dust. These will have negative long-term repercussions on ecosystems and human health. In this research, energy dispersive X-ray fluorescence (EDXRF) spectrometry analytical method was used to assess the pollution characteristics of the eight heavy metals (HMs): Mn, Cu, As, Hg, Ni, Cr, Zn, and Pb in the East Mediterranean Sea area. The concentration of As, Mn, Cr, Cu, Hg, Ni, Pb, and Zn analyzed in outdoor dust samples varied from 0.94 to 19.52 mg kg-1, 190.08 to 1019.7 mg kg-1, 20.46 to 45.9 mg kg-1, 19.5 to 62.56 mg kg-1, 0.01 to 0.93 mg kg-1, 10.48 to 40.64 mg kg-1, 12. 6 to 36.1 mg kg-1, and 48.96 to 112.41mg kg-1, respectively. HMs have been detected in the outdoor dust samples analyzed in the study, and, as a result, mean concentrations followed the order Mn > Zn > Cu > Cr > Ni > Pb > As > Hg, respectively. The ecological risk was observed at various contamination levels, with As and Hg pollution being the most severe. The highest hazard quotient (HQ) for adults and children was determined as a result of As and Cr, respectively. According to the US-EPA health risk threshold, the cancer risk in the study area is negligible.

A spectroscopic analysis code for spatially resolved x-ray absorption data from the COAX platform.

Sophisticated tools such as computer vision techniques in combination with 1D lineout type analyses have been used in automating the analysis of spectral data for high energy density (HED) plasmas. Standardized automation can solve the problems posed by the complexity of HED spectra and the quantity of data. We present a spectroscopic code written for automated and streamlined analysis of spatially resolved x-ray absorption data from the COAX platform on Omega-60. COAX uses radiographs and spectroscopic diagnostics to provide shock position and density information. We also obtain the more novel spectral-derived spatial profile of the supersonic radiation flow into a low-density foam. Considerable effort has been spent modernizing our previous spectroscopic analysis method, including the development of new tools characterized by a faster runtime and minimal user input to reduce bias and a testing suite for verifying the accuracy of the various functions within the code. The new code analyzes our spectroscopic images in 1-2min, with added uncertainty and confidence.

Identification of Alzheimer’s disease and vascular dementia based on a Deep Forest and near-infrared spectroscopy analysis method

Alzheimer’s disease (AD) and vascular dementia (VaD) typically do not exhibit distinct differences in clinical manifestations and auxiliary examination results, which leads to a high misdiagnosis rate. However, significant differences in treatment approaches and prognosis between these two diseases underscore the critical need for an accurate diagnosis of AD and VaD. In this study, serum samples from 33 patients with AD patients, 37 patients with VaD, and 130 healthy individuals were collected, employing near-infrared aquaphotomics technology in combination with deep learning for differential diagnoses. Through an analysis of water absorption patterns among different diseases via aquaphotomics, the efficacies of traditional machine learning methods (Support Vector Machine and Decision Trees) and deep learning approaches (Deep Forest) in modeling were compared. Ultimately, by leveraging feature extraction techniques in conjunction with deep learning, a differential diagnostic model for AD and VaD was successfully developed. The results revealed that aquaphotomics could identify a certain correlation between the number of hydrogen bonds in water molecules and the development of AD and VaD; the deep learning model was found to be superior to traditional machine learning models, achieving an accuracy of 98.67 %, sensitivity of 97.33 %, and specificity of 100.00 %. The bands identified using the Competitive Adaptive Reweighting Algorithm method, primarily located at approximately 1300–1500 nm, showed a significant correlation with water molecules containing four hydrogen bonds. These results highlighted the potential role of the water molecule hydrogen-bond network in disease development and were consistent with the aquaphotomics analysis results. Therefore, the differential diagnostic model developed by integrating near-infrared spectroscopy and deep learning was proven to be effective and feasible, providing accurate and rapid diagnostic methods for AD and VaD diagnoses.

Diterpenoids with Potent Anti-Psoriasis Activity from Euphorbia helioscopia L.

Psoriasis, an immune-mediated inflammatory skin disorder, seriously affects the quality of life of nearly four percent of the world population. Euphorbia helioscopia L. is the monarch constituent of Chinese ZeQi powder preparation for psoriasis, so it is necessary to illustrate its active ingredients. Thus, twenty-three diterpenoids, including seven new ones, were isolated from the whole herb of E. helioscopia L. Compounds 1 and 2, each featuring a 2,3-dicarboxylic functionality, are the first examples in the ent-2,3-sceo-atisane or the ent-2,3-sceo-abietane family. Extensive spectroscopic analysis (1D, 2D NMR, and HRMS data) and computational methods were used to confirm their structures and absolute configurations. According to the previous study and NMR data from the jatropha diterpenes obtained in this study, some efficient 1H NMR spectroscopic rules for assigning the relative configurations of 3α-benzyloxy-jatroph-11E-ene and 7,8-seco-3α-benzyloxy-jatropha-11E-ene were summarized. Moreover, the hyperproliferation of T cells and keratinocytes is considered a key pathophysiology of psoriasis. Anti-proliferative activities against induced T/B lymphocytes and HaCaT cells were tested, and IC50 values of some compounds ranged from 6.7 to 31.5 μM. Compounds 7 and 11 reduced the secretions of IFN-γ and IL-2 significantly. Further immunofluorescence experiments and a docking study with NF-κB P65 showed that compound 13 interfered with the proliferation of HaCaT cells by inhibiting the NF-κB P65 phosphorylation at the protein level.