Pub Date : 2026-03-01Epub Date: 2026-02-20DOI: 10.1016/j.vibspec.2026.103896
Baiyun Wang , Liang Zhang , Guohua Wu , Longfei Yin , Xuewen Long , Ting Mei , Yishu Tang
Cancer poses a serious threat to global public health, and early and accurate diagnosis is crucial for improving patient prognosis and reducing mortality rates. In this study, we used serum Raman spectroscopy combined with PCA-CNN model to diagnose three types of liver diseases, including hepatitis B, liver cirrhosis, and Hepatocellular Carcinoma. Established a serum Raman spectroscopy database containing three types of diseases and healthy controls. Compared with traditional methods such as SVM and PCA-LDA, PCA-CNN has higher efficiency and accuracy. Based on the collected 327 samples, PCA was used to extract features with a 95 % contribution rate and the 1D-CNN model was used for four classification. After five fold cross validation, the overall weighted average accuracy was 83.79 %. When the precision was 0.85,specificity was 0.95, F1 was 0.84, and AUC was 0.94, it improved by at least 4 % compared to traditional classification methods such as SVM. It provides a new method for rapid and non-invasive identification of multiple selected liver diseases, and contributes to clinical diagnosis.
{"title":"Serum Raman spectroscopy combined with PCA-CNN model for the diagnosis of hepatitis B, liver cirrhosis, and Hepatocellular Carcinoma","authors":"Baiyun Wang , Liang Zhang , Guohua Wu , Longfei Yin , Xuewen Long , Ting Mei , Yishu Tang","doi":"10.1016/j.vibspec.2026.103896","DOIUrl":"10.1016/j.vibspec.2026.103896","url":null,"abstract":"<div><div>Cancer poses a serious threat to global public health, and early and accurate diagnosis is crucial for improving patient prognosis and reducing mortality rates. In this study, we used serum Raman spectroscopy combined with PCA-CNN model to diagnose three types of liver diseases, including hepatitis B, liver cirrhosis, and Hepatocellular Carcinoma. Established a serum Raman spectroscopy database containing three types of diseases and healthy controls. Compared with traditional methods such as SVM and PCA-LDA, PCA-CNN has higher efficiency and accuracy. Based on the collected 327 samples, PCA was used to extract features with a 95 % contribution rate and the 1D-CNN model was used for four classification. After five fold cross validation, the overall weighted average accuracy was 83.79 %. When the precision was 0.85,specificity was 0.95, F1 was 0.84, and AUC was 0.94, it improved by at least 4 % compared to traditional classification methods such as SVM. It provides a new method for rapid and non-invasive identification of multiple selected liver diseases, and contributes to clinical diagnosis.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103896"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-01-28DOI: 10.1016/j.vibspec.2026.103893
Kursad Osman Ay , Bükay Yenice Gürsu , Betül Yılmaz Öztürk , İlknur Dağ
Acetamiprid is a widely used pesticide recommended for its relatively low toxicity; however, prolonged application may cause extensive environmental problems. Reports have highlighted its adverse effects on non-target organisms and its potential to alter soil microbial activity due to substantial environmental exposure. Moreover, pesticide residues may enter the human body through various routes, influencing the microbiota. Candida species, normally commensal on mucosal surfaces, can cause opportunistic infections under immunocompromised conditions. Among them, C. parapsilosis has emerged as one of the most frequently isolated yeast species in recent fungal infections, primarily due to its biofilm-forming capacity. In this study, the impact of acetamiprid on C. parapsilosis biofilm was assessed using Raman spectroscopy, a label-free technique with advantages such as high sensitivity, specificity, and the ability to quantitatively reveal biochemical changes in biofilm structures. Biofilms were developed on glass slides and subsequently treated with acetamiprid, while untreated biofilms served as controls. Raman spectral analysis demonstrated significant reductions in band intensities related to proteins, lipids, polysaccharides, and DNA in acetamiprid-treated samples compared to controls. These findings indicate that Raman spectroscopy can serve as a powerful approach to rapidly and effectively examine pesticide effects on biofilms and provide insights into potential antibiofilm strategies. Furthermore, the data raise the possibility of considering acetamiprid for novel antibacterial applications, combination therapies, and implications in food and agricultural safety. Nevertheless, in vitro findings should be supported with comprehensive toxicological studies to validate the broader impact of such applications.
{"title":"Evaluation of pesticide acetamiprid on Candida parapsilosis biofilm using Raman spectroscopy","authors":"Kursad Osman Ay , Bükay Yenice Gürsu , Betül Yılmaz Öztürk , İlknur Dağ","doi":"10.1016/j.vibspec.2026.103893","DOIUrl":"10.1016/j.vibspec.2026.103893","url":null,"abstract":"<div><div>Acetamiprid is a widely used pesticide recommended for its relatively low toxicity; however, prolonged application may cause extensive environmental problems. Reports have highlighted its adverse effects on non-target organisms and its potential to alter soil microbial activity due to substantial environmental exposure. Moreover, pesticide residues may enter the human body through various routes, influencing the microbiota. <em>Candida</em> species, normally commensal on mucosal surfaces, can cause opportunistic infections under immunocompromised conditions. Among them, <em>C. parapsilosis</em> has emerged as one of the most frequently isolated yeast species in recent fungal infections, primarily due to its biofilm-forming capacity. In this study, the impact of acetamiprid on <em>C. parapsilosis</em> biofilm was assessed using Raman spectroscopy, a label-free technique with advantages such as high sensitivity, specificity, and the ability to quantitatively reveal biochemical changes in biofilm structures. Biofilms were developed on glass slides and subsequently treated with acetamiprid, while untreated biofilms served as controls. Raman spectral analysis demonstrated significant reductions in band intensities related to proteins, lipids, polysaccharides, and DNA in acetamiprid-treated samples compared to controls. These findings indicate that Raman spectroscopy can serve as a powerful approach to rapidly and effectively examine pesticide effects on biofilms and provide insights into potential antibiofilm strategies. Furthermore, the data raise the possibility of considering acetamiprid for novel antibacterial applications, combination therapies, and implications in food and agricultural safety. Nevertheless, <em>in vitro</em> findings should be supported with comprehensive toxicological studies to validate the broader impact of such applications.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103893"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-01-15DOI: 10.1016/j.vibspec.2026.103885
Ana L.F. de Barros , Enio Frota da Silveira
Nitrogenous bases such as adenine, guanine, cytosine, and thymine are central to molecular biology, yet their intermolecular interactions in the solid state remain incompletely characterized. In this work, we present a systematic FTIR study of all six binary mixtures of canonical nucleobases under ambient solid-state conditions, comparing the experimental spectra of the mixtures with the arithmetic mean of their pure components. Significant non-linear spectral deviations are observed, including the appearance of new bands, shifts in peak position, changes in intensity, and modifications of band shape; pronounced effects are particularly noted in both the 1700–1500 cm⁻¹ and fingerprint (∼1500–600 cm⁻¹) regions. Representative interaction-induced wavenumber shifts on the order of 5–20 cm⁻¹ are observed for key vibrational modes associated with CO, CN, and ring deformation bands, depending on the specific nucleobase pairing. They provide direct spectroscopic evidence that intermolecular interactions, rather than simple additive behavior, govern the vibrational response of binary nucleobase assemblies. These effects indicate that hydrogen bonding, π–π stacking, and local environment perturbations strongly influence vibrational behavior when different base molecules coexist. Our analysis builds upon established solid-state spectroscopic assignments of individual nucleobases and previous investigations of non-irradiated binary systems, extending them through a systematic, comparative experimental approach. By mapping and cross-comparing all six binary combinations, this study demonstrates that each pairing generates a distinct non-linear vibrational fingerprint, reflecting base-specific intermolecular organization and supramolecular packing. Such results serve as a chemical/ biochemical baseline for understanding intermolecular interactions in nucleobase mixtures. Importantly, this baseline provides a robust reference for disentangling purely interaction-driven vibrational effects from radiation-induced chemical modifications in future studies. In this context, the present data set establishes a reference framework for future comparisons with irradiated systems, supporting investigations relevant to supramolecular chemistry, molecular recognition, and prebiotic chemistry. Moreover, the identification of interaction-sensitive infrared markers contributes to the interpretation of spectroscopic observations of complex organic matter in astrochemical and cosmic environments.
{"title":"Infrared spectroscopy of binary nucleobase mixtures: Vibrational fingerprints of intermolecular interactions","authors":"Ana L.F. de Barros , Enio Frota da Silveira","doi":"10.1016/j.vibspec.2026.103885","DOIUrl":"10.1016/j.vibspec.2026.103885","url":null,"abstract":"<div><div>Nitrogenous bases such as adenine, guanine, cytosine, and thymine are central to molecular biology, yet their intermolecular interactions in the solid state remain incompletely characterized. In this work, we present a systematic FTIR study of all six binary mixtures of canonical nucleobases under ambient solid-state conditions, comparing the experimental spectra of the mixtures with the arithmetic mean of their pure components. Significant non-linear spectral deviations are observed, including the appearance of new bands, shifts in peak position, changes in intensity, and modifications of band shape; pronounced effects are particularly noted in both the 1700–1500 cm⁻¹ and fingerprint (∼1500–600 cm⁻¹) regions. Representative interaction-induced wavenumber shifts on the order of 5–20 cm⁻¹ are observed for key vibrational modes associated with C<img>O, C<img>N, and ring deformation bands, depending on the specific nucleobase pairing<em>.</em> They provide direct spectroscopic evidence that intermolecular interactions, rather than simple additive behavior, govern the vibrational response of binary nucleobase assemblies. These effects indicate that hydrogen bonding, π–π stacking, and local environment perturbations strongly influence vibrational behavior when different base molecules coexist. Our analysis builds upon established solid-state spectroscopic assignments of individual nucleobases and previous investigations of non-irradiated binary systems, extending them through a systematic, comparative experimental approach. By mapping and cross-comparing all six binary combinations, this study demonstrates that each pairing generates a distinct non-linear vibrational fingerprint, reflecting base-specific intermolecular organization and supramolecular packing. Such results serve as a chemical/ biochemical baseline for understanding intermolecular interactions in nucleobase mixtures. Importantly, this baseline provides a robust reference for disentangling purely interaction-driven vibrational effects from radiation-induced chemical modifications in future studies. In this context, the present data set establishes a reference framework for future comparisons with irradiated systems, supporting investigations relevant to supramolecular chemistry, molecular recognition, and prebiotic chemistry. Moreover, the identification of interaction-sensitive infrared markers contributes to the interpretation of spectroscopic observations of complex organic matter in astrochemical and cosmic environments.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103885"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-12DOI: 10.1016/j.vibspec.2026.103895
Adolf Krige , Ulrika Rova , Paul Christakopoulos , Lisbeth Olsson , Kerstin Ramser
Microbial electrosynthesis (MES) offers a sustainable alternative for the production of platform chemicals from CO2. Label-free Raman spectroscopy can provide direct insights into biomolecular changes in MES, reflecting metabolic activity and production. In this study defined co-cultures of electro-active bacteria, i.e. Sporomusa ovata and Clostridium carboxidivorans, were investigated by confocal resonance Raman micro-spectroscopy tuned to 532 nm to gain insights into the microbial processes of biomarkers involved in the Wood-Ljundahl pathway. The results were correlated to high-performance liquid chromatography (HPCL) and optical density measurements regarding the production rate of acetate, butyrate, ethanol and butanol. Pre-processed difference Raman spectra of co-cultures from S. ovata and C. carboxidivorans at ratios 1:10, 10:1, and 1:1 were compared to monocultures on day 1 and 2, revealing substantial variations in Raman intensity and thus the relative metabolic activity of NADH, NAD+, ferredoxin and cytochrome c. Such information may point to high metabolic activity at the start of acetate, butyrate, ethanol, and butanol production followed by a steady state at day four. This was verified by Raman difference spectra between fresh cultures and > 4 days old cultures, indicating a similar degree of metabolic activity after a certain time during ongoing production. Interestingly, the Raman spectra did not reveal any differences in metabolism depending on feedstocks, i.e. CO2 and H2 versus betaine or different ratios of co-cultures that were significantly more productive. This qualitative study demonstrates that resonance Raman spectroscopy is a viable tool for metabolic investigations of microbial electrosynthesis systems with potential for in situ investigations.
{"title":"Resonance Raman spectroscopy of NADH, NAD+ , ferredoxin and cytochrome c in Sporomusa ovata and Clostridium carboxidivorans for microbial electrosynthesis applications","authors":"Adolf Krige , Ulrika Rova , Paul Christakopoulos , Lisbeth Olsson , Kerstin Ramser","doi":"10.1016/j.vibspec.2026.103895","DOIUrl":"10.1016/j.vibspec.2026.103895","url":null,"abstract":"<div><div>Microbial electrosynthesis (MES) offers a sustainable alternative for the production of platform chemicals from CO<sub>2</sub>. Label-free Raman spectroscopy can provide direct insights into biomolecular changes in MES, reflecting metabolic activity and production. In this study defined co-cultures of electro-active bacteria, i.e. <em>Sporomusa ovata</em> and <em>Clostridium carboxidivorans,</em> were investigated by confocal resonance Raman micro-spectroscopy tuned to 532 nm to gain insights into the microbial processes of biomarkers involved in the Wood-Ljundahl pathway. The results were correlated to high-performance liquid chromatography (HPCL) and optical density measurements regarding the production rate of acetate, butyrate, ethanol and butanol. Pre-processed difference Raman spectra of co-cultures from <em>S. ovata</em> and <em>C. carboxidivorans</em> at ratios 1:10, 10:1, and 1:1 were compared to monocultures on day 1 and 2, revealing substantial variations in Raman intensity and thus the relative metabolic activity of NADH, NAD<sup>+</sup>, ferredoxin and cytochrome c. Such information may point to high metabolic activity at the start of acetate, butyrate, ethanol, and butanol production followed by a steady state at day four. This was verified by Raman difference spectra between fresh cultures and > 4 days old cultures, indicating a similar degree of metabolic activity after a certain time during ongoing production. Interestingly, the Raman spectra did not reveal any differences in metabolism depending on feedstocks, i.e. CO<sub>2</sub> and H<sub>2</sub> versus betaine or different ratios of co-cultures that were significantly more productive. This qualitative study demonstrates that resonance Raman spectroscopy is a viable tool for metabolic investigations of microbial electrosynthesis systems with potential for <em>in situ</em> investigations.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103895"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-17DOI: 10.1016/j.vibspec.2026.103899
Suzanne Reus , Lise Krebbers , Ana Radosavljević , Maarten R. van Bommel , Klaas Jan van den Berg
Degradation phenomena such as cracking and paint loss have been observed in dark blue paint strokes in Vincent van Gogh's paintings. Analysis of several samples taken from such paint strokes has confirmed that the paint contains Prussian blue pigment, linseed oil and a small amount of beeswax. Research into the chemical and mechanical processes taking place during the ageing of this paint is required to understand the cause behind the degradation phenomena. Therefore, attenuated total reflection Fourier transform infrared spectroscopy was used to study the chemical changes during the artificial ageing of oil paint reconstructions and correlate those changes with visual observations of the paints’ degradation. The influence of different pigments, as well as the pigment volume concentration and the presence of beeswax on the ageing of the reconstructions was investigated. The tested pigments include both soluble and insoluble Prussian blue prepared according to historical 19th-century recipes, modern Prussian blues, and a cobalt blue pigment. Ester hydrolysis was observed during artificial ageing for both cobalt blue and Prussian blue paints, but this effect was much larger for the latter. Additionally, NH3 adsorption and its subsequent conversion to NH4+ were observed in most Prussian blue reconstructions, which is expected to contribute to the increased ester hydrolysis rate in these paints and the formation of free fatty acid efflorescence. The type of Prussian blue pigment was found to influence the capability of NH3 adsorption and the formation of fatty acid efflorescence, as this was not found in all reconstructions.
{"title":"Ageing of Prussian blue oil paints: The effect of the pigment studied using attenuated total reflection Fourier transform infrared spectroscopy","authors":"Suzanne Reus , Lise Krebbers , Ana Radosavljević , Maarten R. van Bommel , Klaas Jan van den Berg","doi":"10.1016/j.vibspec.2026.103899","DOIUrl":"10.1016/j.vibspec.2026.103899","url":null,"abstract":"<div><div>Degradation phenomena such as cracking and paint loss have been observed in dark blue paint strokes in Vincent van Gogh's paintings. Analysis of several samples taken from such paint strokes has confirmed that the paint contains Prussian blue pigment, linseed oil and a small amount of beeswax. Research into the chemical and mechanical processes taking place during the ageing of this paint is required to understand the cause behind the degradation phenomena. Therefore, attenuated total reflection Fourier transform infrared spectroscopy was used to study the chemical changes during the artificial ageing of oil paint reconstructions and correlate those changes with visual observations of the paints’ degradation. The influence of different pigments, as well as the pigment volume concentration and the presence of beeswax on the ageing of the reconstructions was investigated. The tested pigments include both soluble and insoluble Prussian blue prepared according to historical 19th-century recipes, modern Prussian blues, and a cobalt blue pigment. Ester hydrolysis was observed during artificial ageing for both cobalt blue and Prussian blue paints, but this effect was much larger for the latter. Additionally, NH<sub>3</sub> adsorption and its subsequent conversion to NH<sub>4</sub><sup>+</sup> were observed in most Prussian blue reconstructions, which is expected to contribute to the increased ester hydrolysis rate in these paints and the formation of free fatty acid efflorescence. The type of Prussian blue pigment was found to influence the capability of NH<sub>3</sub> adsorption and the formation of fatty acid efflorescence, as this was not found in all reconstructions.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103899"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-11DOI: 10.1016/j.vibspec.2026.103894
Jéssica Pires Farias , Paulo Henrique Gonçalves Dias Diniz , David Douglas de Sousa Fernandes , Luís Carlos de Souza Ferreira , Jaime Henrique Amorim
Rapid, non-invasive, and scalable diagnostic tools are essential for managing respiratory viral infections and enhancing pandemic preparedness. While vibrational spectroscopy coupled with chemometrics has emerged as a powerful biosensing tool, many SARS-CoV-2 studies remain constrained by limited sample sizes and narrow clinical characterization. This study evaluates the performance of attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy for detecting SARS-CoV-2 in saliva samples from a heterogeneous cohort of 207 symptomatic individuals with varying clinical severities. Using RT-qPCR as the gold standard, saliva spectra were processed using multivariate classification and variable selection algorithms. The optimized model, based on second-derivative Savitzky-Golay preprocessing and interval Successive Projections Algorithm-Partial Least Squares Discriminant Analysis (2d-SG/iSPA-PLS-DA), achieved an overall accuracy of 91.3 %, with 93 % sensitivity and 87 % specificity. These findings underscore that ATR-FTIR spectroscopy of saliva, supported by robust variable selection strategies, provides a high-performance, reagent-free screening platform suitable for clinical triage and large-scale surveillance of respiratory pathogens.
{"title":"ATR-FTIR spectroscopy and chemometric analysis as highly sensitive detection tool for SARS-CoV-2 infection in saliva from different types of COVID-19 severity","authors":"Jéssica Pires Farias , Paulo Henrique Gonçalves Dias Diniz , David Douglas de Sousa Fernandes , Luís Carlos de Souza Ferreira , Jaime Henrique Amorim","doi":"10.1016/j.vibspec.2026.103894","DOIUrl":"10.1016/j.vibspec.2026.103894","url":null,"abstract":"<div><div>Rapid, non-invasive, and scalable diagnostic tools are essential for managing respiratory viral infections and enhancing pandemic preparedness. While vibrational spectroscopy coupled with chemometrics has emerged as a powerful biosensing tool, many SARS-CoV-2 studies remain constrained by limited sample sizes and narrow clinical characterization. This study evaluates the performance of attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy for detecting SARS-CoV-2 in saliva samples from a heterogeneous cohort of 207 symptomatic individuals with varying clinical severities. Using RT-qPCR as the gold standard, saliva spectra were processed using multivariate classification and variable selection algorithms. The optimized model, based on second-derivative Savitzky-Golay preprocessing and interval Successive Projections Algorithm-Partial Least Squares Discriminant Analysis (2d-SG/iSPA-PLS-DA), achieved an overall accuracy of 91.3 %, with 93 % sensitivity and 87 % specificity. These findings underscore that ATR-FTIR spectroscopy of saliva, supported by robust variable selection strategies, provides a high-performance, reagent-free screening platform suitable for clinical triage and large-scale surveillance of respiratory pathogens.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103894"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-13DOI: 10.1016/j.vibspec.2026.103898
Sonia B. Diaz , Davide Romani , Silvia Antonia Brandán
Complete assignments of phosphatidylcholine (PC) have been performed combining the FTIR and FT-Raman spectra with density functional theory (DFT) calculations and the scaled quantum mechanical force field (SQMFF) methodology. Here, the effects of water and of alkyl R and R’ chains on the main vibration modes of two anhydrous (C1 and C1-R) and two mono-hydrated (C2 and C2-R) species of PC have been analysed considering the phosphate groups with local C2 V and C3 V symmetries. Then, the main scaled force constants have been reported. Stabilities, reactivities and descriptors of species have been evaluated by using atomic charges, molecular electrostatic potentials (MEP), natural bond orbital (NBO), atoms in molecules (AIM) and frontier orbital studies. Thus, substitution of H atoms by R and R′ groups in both C1-R and C2-R species leads to increased molecular volume (V) and polarizability (α), while the dipole moment decreases. Different intra-molecular interactions predicted by NBO and AIM calculations could justify such changes. Besides, the presence of water molecules in C2-R species increases its α value. Mulliken charges and the MEP energy increase when the alkyl R and R’ chains increase while C2 shows lower MEP energy. AIM studies show multiple interactions in both hydrophilic and hydrophobic moieties that eventually increase the stabilities of species being C2 and C2-R more stable than C1 and C1-R, suggesting that the water molecules stabilize both mono-hydrated species. The MEP, NBO, and the ω, χ, and μ descriptors account for the higher reactivity of C1-R compared with C1, C2, and C2-R.
{"title":"Complete vibrational assignments of phosphatidylcholine combining FTIR and FT-Raman spectra with DFT and SQMFF calculations","authors":"Sonia B. Diaz , Davide Romani , Silvia Antonia Brandán","doi":"10.1016/j.vibspec.2026.103898","DOIUrl":"10.1016/j.vibspec.2026.103898","url":null,"abstract":"<div><div>Complete assignments of phosphatidylcholine (PC) have been performed combining the FTIR and FT-Raman spectra with density functional theory (DFT) calculations and the scaled quantum mechanical force field (SQMFF) methodology. Here, the effects of water and of alkyl R and R’ chains on the main vibration modes of two anhydrous (C1 and C1-R) and two mono-hydrated (C2 and C2-R) species of PC have been analysed considering the phosphate groups with local <em>C</em><sub><em>2 V</em></sub> and <em>C</em><sub><em>3 V</em></sub> symmetries. Then, the main scaled force constants have been reported. Stabilities, reactivities and descriptors of species have been evaluated by using atomic charges, molecular electrostatic potentials (MEP), natural bond orbital (NBO), atoms in molecules (AIM) and frontier orbital studies. Thus, substitution of H atoms by R and R′ groups in both C1-R and C2-R species leads to increased molecular volume (V) and polarizability (α), while the dipole moment decreases. Different intra-molecular interactions predicted by NBO and AIM calculations could justify such changes. Besides, the presence of water molecules in C2-R species increases its α value. Mulliken charges and the MEP energy increase when the alkyl R and R’ chains increase while C2 shows lower MEP energy. AIM studies show multiple interactions in both hydrophilic and hydrophobic moieties that eventually increase the stabilities of species being C2 and C2-R more stable than C1 and C1-R, suggesting that the water molecules stabilize both mono-hydrated species. The MEP, NBO, and the ω, χ, and μ descriptors account for the higher reactivity of C1-R compared with C1, C2, and C2-R.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103898"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-16DOI: 10.1016/j.vibspec.2026.103897
Olivia-Stella Salm, Marina Kudrjashova, Maria Kulp
The accurate and efficient characterization of lignin hydroxyl groups is essential for understanding lignin reactivity and valorization potential in biorefinery applications. This study investigates the use of attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy combined with chemometric modeling as a sustainable alternative to traditional phosphorus nuclear magnetic resonance (31P NMR) spectroscopy for the quantitative analysis of lignin hydroxyl functionality. A dataset of organosolv lignins was analyzed using ATR-FTIR, and multivariate models—including partial least squares (PLS), interval PLS (iPLS), support vector machines (SVMs), and iPLS-SVMs—were developed to predict the content of aliphatic, syringyl, guaiacyl, and p-hydroxyphenyl hydroxyl groups. With the exception of guaiacyl, the models showed high predictive performance for all hydroxyl types, with R2P values above 0.95 and residual predictive deviation (RPD) values exceeding 4 for the aliphatic, syringyl, and p-hydroxyphenyl groups. The best performance for total aromatic hydroxyl prediction was achieved with the iPLS-SVM model. Compared to 31P NMR, the proposed method significantly reduced analysis time, eliminated hazardous solvents, and improved environmental sustainability, as evidenced by an AGREE greenness score of 0.88 versus 0.39 for 31P NMR. These results demonstrate that FTIR-based machine learning models offer a robust, rapid, and eco-friendly approach for routine lignin analysis and quality control in lignin-based product development.
{"title":"Green non-destructive approach for quantifying hydroxyl groups in lignin using ATR-FTIR spectroscopy and chemometric methods","authors":"Olivia-Stella Salm, Marina Kudrjashova, Maria Kulp","doi":"10.1016/j.vibspec.2026.103897","DOIUrl":"10.1016/j.vibspec.2026.103897","url":null,"abstract":"<div><div>The accurate and efficient characterization of lignin hydroxyl groups is essential for understanding lignin reactivity and valorization potential in biorefinery applications. This study investigates the use of attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy combined with chemometric modeling as a sustainable alternative to traditional phosphorus nuclear magnetic resonance (<sup>31</sup>P NMR) spectroscopy for the quantitative analysis of lignin hydroxyl functionality. A dataset of organosolv lignins was analyzed using ATR-FTIR, and multivariate models—including partial least squares (PLS), interval PLS (iPLS), support vector machines (SVMs), and iPLS-SVMs—were developed to predict the content of aliphatic, syringyl, guaiacyl, and <em>p</em>-hydroxyphenyl hydroxyl groups. With the exception of guaiacyl, the models showed high predictive performance for all hydroxyl types, with R<sup>2</sup><sub>P</sub> values above 0.95 and residual predictive deviation (RPD) values exceeding 4 for the aliphatic, syringyl, and <em>p</em>-hydroxyphenyl groups. The best performance for total aromatic hydroxyl prediction was achieved with the iPLS-SVM model. Compared to <sup>31</sup>P NMR, the proposed method significantly reduced analysis time, eliminated hazardous solvents, and improved environmental sustainability, as evidenced by an AGREE greenness score of 0.88 versus 0.39 for <sup>31</sup>P NMR. These results demonstrate that FTIR-based machine learning models offer a robust, rapid, and eco-friendly approach for routine lignin analysis and quality control in lignin-based product development.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103897"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-11-29DOI: 10.1016/j.vibspec.2025.103876
Hongda Chen
Direct absorption spectroscopy is extensively utilized in combustion diagnostics, offering valuable assistance in industrial production and aerospace applications. However, current approaches for processing substantial volumes of overlapped spectra encounter challenges related to slow processing speeds and inadequate precision. This research introduces a time series prediction model that integrates a Transformer self-attention mechanism with Long Short-Term Memory networks for spectroscopy and thermodynamic diagnostics, as well as spectral prediction in absorption spectroscopy. The proposed model proficiently adeptly captures spectral characteristics, including concentration, temperature, and pressure, from intricate unknown spectra. The model was verified in TDLAS. The prediction standard deviation for simulated spectra is less than 0.1, while the relative error for actual spectra is less than 1 %. Future advancements may involve the integration of spectral denoising and analysis techniques, along with few-shot learning methods, validation and optimization of the use of broadband spectrometers, to further optimize combustion gas detection solutions in industrial and aerospace domains.
{"title":"Multivariable prediction of concentration and temperature pressure from absorption spectra using B-LSTM-transformer model","authors":"Hongda Chen","doi":"10.1016/j.vibspec.2025.103876","DOIUrl":"10.1016/j.vibspec.2025.103876","url":null,"abstract":"<div><div>Direct absorption spectroscopy is extensively utilized in combustion diagnostics, offering valuable assistance in industrial production and aerospace applications. However, current approaches for processing substantial volumes of overlapped spectra encounter challenges related to slow processing speeds and inadequate precision. This research introduces a time series prediction model that integrates a Transformer self-attention mechanism with Long Short-Term Memory networks for spectroscopy and thermodynamic diagnostics, as well as spectral prediction in absorption spectroscopy. The proposed model proficiently adeptly captures spectral characteristics, including concentration, temperature, and pressure, from intricate unknown spectra. The model was verified in TDLAS. The prediction standard deviation for simulated spectra is less than 0.1, while the relative error for actual spectra is less than 1 %. Future advancements may involve the integration of spectral denoising and analysis techniques, along with few-shot learning methods, validation and optimization of the use of broadband spectrometers, to further optimize combustion gas detection solutions in industrial and aerospace domains.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"142 ","pages":"Article 103876"},"PeriodicalIF":3.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In near-infrared spectroscopy (NIRS) analysis, variations in component contents across different batches of samples cause changes in spectral characteristics, limiting the effectiveness of NIRS-based analysis models. Model Upgrade (MU) can address this by sharing the original model's knowledge with new batches, thereby reducing the time and material costs associated with remodelling. This study developed quantitative analysis models for mango dry matter content (DMC) and peach soluble solids content (SSC) using near-infrared (NIR) spectra collected at different seasons or maturation stages. A domain-adversarial training of neural networks (DANN) method was proposed to upgrade NIRS models for these fruits across various periods, overcoming limitations of traditional methods that require extensive calibration samples or linear corrections. Spectral preprocessing methods and the number of upgrade samples were optimized, and two recognized model upgrade methods including piecewise direct standardization (PDS) and slope/bias correction (SBC) were used for comparison with DANN. Results showed that preprocessing improved the NIR spectral quality for both fruits; DANN, using only 256 mango and 96 peach upgrade samples, simultaneously raised Rp to 0.983 (mango) and 0.916 (peach) while cutting RMSEP by 36.5 % (0.936–0.594) and 40.7 % (1.121–0.665), respectively, achieving the best cross-batch accuracy with < 50 % of the reference samples previously required. The proposed DANN method aligns feature distributions between domains through adversarial training, demonstrates high accuracy with fewer upgrade samples, and can further simplify the model construction issues related to numerous batches, large quantities, and long-time spans.
{"title":"Model upgrading method based on domain-adversarial neural networks (DANN) for near-infrared spectroscopy analysis","authors":"Yong Hao , Jingjing Peng , Xinyu Chen , Chuangfeng Huai","doi":"10.1016/j.vibspec.2025.103881","DOIUrl":"10.1016/j.vibspec.2025.103881","url":null,"abstract":"<div><div>In near-infrared spectroscopy (NIRS) analysis, variations in component contents across different batches of samples cause changes in spectral characteristics, limiting the effectiveness of NIRS-based analysis models. Model Upgrade (MU) can address this by sharing the original model's knowledge with new batches, thereby reducing the time and material costs associated with remodelling. This study developed quantitative analysis models for mango dry matter content (DMC) and peach soluble solids content (SSC) using near-infrared (NIR) spectra collected at different seasons or maturation stages. A domain-adversarial training of neural networks (DANN) method was proposed to upgrade NIRS models for these fruits across various periods, overcoming limitations of traditional methods that require extensive calibration samples or linear corrections. Spectral preprocessing methods and the number of upgrade samples were optimized, and two recognized model upgrade methods including piecewise direct standardization (PDS) and slope/bias correction (SBC) were used for comparison with DANN. Results showed that preprocessing improved the NIR spectral quality for both fruits; DANN, using only 256 mango and 96 peach upgrade samples, simultaneously raised R<sub>p</sub> to 0.983 (mango) and 0.916 (peach) while cutting RMSEP by 36.5 % (0.936–0.594) and 40.7 % (1.121–0.665), respectively, achieving the best cross-batch accuracy with < 50 % of the reference samples previously required. The proposed DANN method aligns feature distributions between domains through adversarial training, demonstrates high accuracy with fewer upgrade samples, and can further simplify the model construction issues related to numerous batches, large quantities, and long-time spans.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"142 ","pages":"Article 103881"},"PeriodicalIF":3.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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