Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy最新文献

{"title":"Aggressiveness evaluation of borderline serous ovarian tumors by analysis of Psammoma bodies present in cancer tissues using micro-FTIR spectroscopy","authors":"","doi":"10.1016/j.saa.2024.125301","DOIUrl":"10.1016/j.saa.2024.125301","url":null,"abstract":"<div><div>Borderline ovarian tumor is a type of tumor with generally low malignant potential. However, these tumors pose diagnostic challenges with benign and malignant epithelial ovarian tumors because the clinical symptoms are similar and investigation procedures for specific diagnosis are still debated. In addition, a small number of borderlines transform into high-grade serous ovarian carcinoma with a poor prognosis. Therefore, tools improving a better characterization of high-risk subtypes of borderline tumors to enable understanding of possible unfavorable evolution are essential for patients’ management. Psammoma bodies (PBs) are microcalcifications found both in serous epithelial ovarian cancer and serous borderline tumors with possible correlation with disease progression.</div><div>In this work, the chemical composition of PBs found in the tissues of borderline, high-grade and low-grade ovarian tumors was evaluated using micro-FTIR spectroscopy. Applying principal component analysis to spectral data, it was observed that among the borderline tumors analyzed (<strong>1-bl</strong>,<!--> <strong>2-bl</strong> <!-->and<!--> <strong>3-bl</strong>), the PBs of<!--> <strong>3-bl</strong> <!-->showed a different chemical content from that of the PBs of the high-grade and low-grade tumors, while the PBs of<!--> <strong>1-bl</strong> <!-->and<!--> <strong>2-bl</strong> <!-->appeared to have similar chemical content to the PBs of high- and low-grade tumors. The discriminating wavenumbers were found to be those related to carbonate CO₃²⁻ (1454, 1413 cm⁻¹ <!-->and 872 cm⁻¹) and phosphate PO₄³⁻ <!-->(1018 cm⁻¹ <!-->and 960 cm⁻¹) present in microcalcifications. A higher ratio between peak intensities at 1413 cm⁻¹ <!-->and 1018 cm⁻¹ <!-->(I₁₄₁₃/I₁₀₁₈) was observed in the PBs of<!--> <strong>3-bl</strong> <!-->compared with those of high- and low-grade ovarian carcinoma patients, which correlates with higher CO₃²⁻ content. On the other hand, the PBs of<!--> <strong>1-bl</strong> <!-->and<!--> <strong>2-bl</strong> <!-->showed a CO₃²⁻ <!-->level close to that of the PBs of high- and low-grade patients. Several studies on microcalcifications in breast carcinoma have reported that increased carbonate content is related to decreased tumor aggressiveness. Therefore, case <strong>bl-3</strong> appeared to be the less aggressive. The results obtained from FTIR analysis were in agreement with histopathological tumor classification and molecular analysis for BRAFV600E. The FTIR technique could become a reliable tool for identifying borderline low- and high-risk tumors.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the performance of machine learning and variable selection methods to identify document paper using infrared spectral data","authors":"","doi":"10.1016/j.saa.2024.125299","DOIUrl":"10.1016/j.saa.2024.125299","url":null,"abstract":"<div><div>Infrared spectroscopy is a valuable tool for forensic examinations because it realizes nondestructive and rapid analysis. Recent advancements in machine learning have facilitated the development of chemometrics, extending to applications in questioned document examination. In this study, support vector machine (SVM), feedforward neural network (FNN), and random forest (RF) models were constructed using the infrared spectral data of document paper samples to identify the manufacturer of document paper products. For model training, the infrared (IR) spectral regions were selected based on their variable importance as determined by the RF models. Narrowing the IR spectral data within the range of 1500–800 cm⁻¹ (selected according to variable importance measures) proved effective in terms of enhancing model performance while minimizing computational costs. The FNN and RF models trained on the second-derivative IR spectra in this range obtained F1-scores of 0.978 and 1.000, respectively. The findings of this study confirm the potential of machine learning methods for extracting and examining forensic features in document paper, resulting in robust models with low computational overhead.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase-transition of hydrophobic dipeptide l-phenylalanyl-l-alanine under high pressure via Raman spectroscopy","authors":"","doi":"10.1016/j.saa.2024.125290","DOIUrl":"10.1016/j.saa.2024.125290","url":null,"abstract":"<div><div>The study conducted on <span>l</span>-Phenylalanyl-<span>l</span>-Alanine (C₁₂H₁₆N₂O₃) dehydrated crystals under high-pressure conditions up to 7.0 GPa using Raman spectroscopy revealed significant modifications in both lattice and internal modes. Particularly, alterations were observed in modes associated with carbonyl and NH₂ functionalities around 1600 cm⁻¹. The Raman spectra exhibited distinct changes in modes related to torsions and stretching of the ring, suggesting a potential conformational change in specific pressure intervals: 2.6–3.0 GPa, and 5.0–5.1 GPa. Furthermore, notable changes between 0.4 and 1.0 GPa hinted at a structural transformation in the crystal. Additionally, Scanning Electron Microscopy-Field Emission Gun (SEM-FEG) was employed to elucidate the crystal pattern of Phe-Ala·2H₂O. The ambient study, incorporating calculations, infrared, and Raman spectroscopy, contributed to a comprehensive understanding of vibrational mode assignments. This research sheds light on the behavior of <span>l</span>-Phenylalanyl-<span>l</span>-Alanine dehydrated crystals under varying pressure conditions, offering valuable insights for medicinal and pharmacological applications.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142484692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of photobleaching of fluorescent proteins on FRET measurements under two-photon excitation","authors":"","doi":"10.1016/j.saa.2024.125294","DOIUrl":"10.1016/j.saa.2024.125294","url":null,"abstract":"<div><div>Förster resonance energy transfer (FRET) is a widely used technique for nanoscale molecular distance measurements, which makes FRET ideal for studying protein interactions and quaternary structure of protein complexes. In this work, we were interested in how photobleaching of donor and acceptor molecules affects the FRET results under various excitation conditions. We conducted a systematic study, under two-photon excitation, of the effects of the excitation power and the choice of excitation wavelengths upon the measured FRET efficiencies of multiplex protein constructs, consisting of one donor (D) and two acceptors (A) or one acceptor and a non-fluorescent tag (N), using both the kinetic theory of FRET and numerical simulations under given excitation conditions. We found that under low excitation power and properly chosen excitation wavelengths the relationship between the FRET efficiency of a trimeric construct ADA agrees within 2% with the FRET efficiency computed (via the kinetic theory of FRET in the absence of photobleaching) from two dimeric constructs ADN and NDA. By contrast, at higher excitation powers the FRET efficiencies changed significantly due to the photobleaching of both the donor (through direct excitation) and the acceptor (mostly through FRET-induced excitation). Based on these results and numerical simulations using a simple but competent algorithm, we developed guidelines for choosing appropriate experimental conditions for reliable FRET measurements, as well as for interpreting the results of existing experiments using different excitation schemes.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142515642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The optimization of sample preparation on zebrafish larvae in vibrational spectroscopy imaging","authors":"","doi":"10.1016/j.saa.2024.125288","DOIUrl":"10.1016/j.saa.2024.125288","url":null,"abstract":"<div><div>The zebrafish (Danio rerio) larvae are widely used in biomedical, pharmaceutical, and ecotoxicological studies. Their transparency and translational potential make them particularly valuable for fluorescence imaging. In addition to fluorescence imaging, microspectroscopy, which combines vibrational spectroscopy: Raman or Fourier transform infrared (FT-IR) with microscopy, allows the collection of spatially resolved, label-free information. According to available literature, it was the first application of FT-IR imaging in zebrafish larvae.</div><div>This study aims to compare different fixation methods for 10-day post-fertilization (dpf) zebrafish larvae using vibrational spectroscopy imaging. Paraformaldehyde (PFA), glutaraldehyde (GA), low temperature, and embedding in gelatin and agarose were investigated. Amides, lipids, and phosphates distribution were more informative in embedded samples but with challenging handling of the sample due to stiffness at −20 °C. FT-IR and Raman mapping revealed that frozen samples had better-preserved tissue structure than chemical fixation. PFA showed uniform amide distribution, while GA treatment exhibited tissue disruptions and denser protein networks in both. Handling of embedded samples is challenging for an operator, but provides more reliable results in developmental biology or disease modeling, compared to chemical treatment.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142515646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydroxyl group dynamics in defernite: Raman spectroscopy studies","authors":"","doi":"10.1016/j.saa.2024.125289","DOIUrl":"10.1016/j.saa.2024.125289","url":null,"abstract":"<div><div>A detailed examination of the altered silicate-carbonate xenolith embedded within the ignimbrite of the Upper Chegem Caldera revealed a new occurrence of a rare carbonate mineral known as defernite, with chemical formula Ca₆[(CO₃)_2-x(Si₂O₇)_x/2](OH)₇[Cl_1-x(H₂O)_x], where x ≈ 0.4. Defernite crystallizes as colorless to white fibrous aggregates, reaching 100–150 μm diameters. Subsequently, Raman investigations of defernite from the Upper Chegem Caldera were conducted to perform a comprehensive structural analysis and compare it with minerals found in other locations. During this examination, band assignments focused on the carbonate ion vibration (CO₃²⁻) with a band at 1085 cm⁻¹ and the hydroxyl group, characterized by a series of strong bands around 3590–3600 cm⁻¹, particularly evident in oriented crystals along the (0<!--> <!-->1<!--> <!-->0) plane. Experimentation involving the alteration of incident laser light polarization highlighted a reduction in the intensity of carbonate and hydroxyl-related bands and the activation of a band around 3390 cm⁻¹. This phenomenon is explained by the formation of hydrogen bonding between hydroxyl groups and chlorine or molecular water, potentially occupying chlorine positions. Lastly, a temperature-dependent experiment demonstrated the instability of the 3390 cm⁻¹ band, which dissipated with increasing temperature. This insight explains the band’s origin around 3590 cm⁻¹, ascribed to non-degenerate hydroxyl groups as a key marker within the defernite structure.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142484688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luminescence, temperature sensing and Judd-Ofelt analysis of Bi2Mo3O12:Eu3+ phosphors and the application in latent fingerprint visualization","authors":"","doi":"10.1016/j.saa.2024.125285","DOIUrl":"10.1016/j.saa.2024.125285","url":null,"abstract":"<div><div>Eu³⁺-activated materials have garnered significant attention due to their outstanding optical characteristics. In this work, the sol–gel method was successfully used to prepare Bi₂Mo₃O₁₂ phosphors doped with different amounts of Eu³⁺. The generated samples were identified as orthorhombic Bi₂Mo₃O₁₂ with a scheelite-like structure by X-ray diffraction analysis of the crystal structure. The sample’s morphology and size were examined using scanning electron microscopy and transmmission electron microscopy, which revealed irregular block morphology and tens to hundreds nanometers scale dimension. From the analysis of the concentration-dependent luminescence intensity of Eu³⁺, it was confirmed that the exchange interaction was responsible for the quenching of ⁵D₀ fluorescence of Eu³⁺. When excited at 374 nm, the phosphor emitted brilliant red light, with the highest emission occurring at 616 nm (⁵D₀→⁷F₂ transition), and the calculated color coordinates of the sample were (0.663, 0.336). By examining the temperature dependence of the emission spectra, the temperature sensing performance of the sample and the thermal quenching behavior of Eu³⁺ luminescence was explored. Furthermore, the optical transition property of Eu³⁺ was investigated by using the emission spectra and fluorescence lifetime within the context of Judd-Ofelt theory. Ultimately, latent fingerprint visualization of the sample on various object surfaces was studied, thanks to the intense luminescence and small particle size of the Bi₂Mo₃O₁₂:Eu³⁺ phosphor. The results indicated that the sample can clearly display the different hierarchical features of fingerprint on different object surfaces.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142515650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning assisted rapid approach for quantitative prediction of biochemical parameters of blood serum with FTIR spectroscopy","authors":"","doi":"10.1016/j.saa.2024.125283","DOIUrl":"10.1016/j.saa.2024.125283","url":null,"abstract":"<div><div>This study develops regression models for predicting blood biochemical data using Fourier-transform infrared spectroscopy (FTIR) analysis. Absorption at specific wavelengths of blood serum is revealed to have strong correlations with biochemical parameters, such as ALT, amylase, AST, protein, bilirubin, Gamma-GT, iron, calcium, uric acid, triglycerides, phosphatase and cholesterol, were shown. The results consistently demonstrate that Random Forest Regression outperforms other models, delivering impressive outcomes for the majority of the analyzed parameters. For some parameters we obtained a coefficient of determination of 0.95 and more (amylase, AST, iron, calcium, protein, uric acid and cholesterol), which makes this approach to be applicable in clinical diagnostics. These findings highlight the potential of FTIR analysis combined with regression models for precise assessment of blood biochemistry.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifunctional N-fused fluorescent probes for detection of iron ions and nitro explosives","authors":"","doi":"10.1016/j.saa.2024.125281","DOIUrl":"10.1016/j.saa.2024.125281","url":null,"abstract":"<div><div>In this work, two novel probes <strong>4a</strong> and <strong>4b</strong> were synthesized through Suzuki-Miyaura coupling reaction, whose structures were further confirmed by ¹H NMR, ¹³C NMR, high-resolution mass spectrometry (HRMS) and X-ray single crystal diffraction. The optical properties of the obtained molecules were investigated accordingly. Owing to different bridging fluorophores, there are certain differences in optical performance and detection ability between the two synthesized compounds. Especially, due to the subtle difference in orbitals energy and electron distribution displayed by the DFT calculations, <strong>4a</strong> possesses the characteristics of dual-state emission (DSE) molecule, while <strong>4b</strong> is an aggregation-induced emission (AIE) molecule. Interestingly, these two molecules can be developed into multifunctional detection probes, successfully applied for the fluorescence recognition of iron ions and common nitroaromatic compounds (NACs). At the same time, the probe molecules can also be applied to the detection of NACs in aqueous environment. What’s more, they can also be loaded on test strips and thin-films for fluorescence identification of NACs, thus being expected to be developed into portable detection tools for NACs.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phenylalanine-embedded carbazole-based fluorescent ‘turn-off’ chemosensor for the detection of metal ions","authors":"","doi":"10.1016/j.saa.2024.125277","DOIUrl":"10.1016/j.saa.2024.125277","url":null,"abstract":"<div><div>Fluorescent chemosensors are highly important for various applications including medical diagnostics, environmental monitoring, and industrial processing. Significant advancements have been made to produce sensors capable of detecting biologically and environmentally relevant ions. Specifically, carbazole-derived fluorophores are chemically stable agents with the ability to detect anions, cations, and small bioorganic molecules. However, most carbazole-based fluorescent probes for the detection of metal ions are Schiff bases and require stringent pH control to prevent hydrolysis. On the other hand, amide-based sensors that utilize stable amino acid scaffolds provide a robust sensing platform as well as a soft-chemical environment for detecting both soft and heavy metal ions. Herein, we explored an aromatic amino acid Phe-containing carbazole-based “turn-off” fluorescent chemosensor to improve the sensor specificity using π-conjugation and additional binding sites. The structure of the novel chemosensor was characterized by electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) spectroscopy. In addition, the sensing properties towards metal ions were studied using UV–vis and fluorescence spectroscopy. Among the various metal ions tested, the chemosensor showed high selectivity and sensitivity towards Co²⁺, Ni²⁺, and Cu²⁺ ions. The detection limits for Co²⁺, Ni²⁺, and Cu²⁺ ions were found to be 4.78 µM, 3.50 µM, and 5.17 µM respectively. Furthermore, the interaction of Phe-amino-carbazole with the various tested metal ions resulted in a flakes-like supramolecular structure, similar to the native Phe-amino-carbazole, whereas the interaction of the designed chemosensor with the Pb²⁺ metal ion resulted in a uniform 3D-circular disc-like supramolecular structure, as confirmed by electron microscopy experiment. This highlights the potential of the Phe-containing carbazole-derived chemosensor for the detection of multiple cations with a decrease in the fluorescence response with a lower detection limit.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}