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Thematological is a class of hereditary hematologic illnesses resulting from abnormalities in the production of one or more hemoglobin chains. Patients with β-Thematological may have a reduction in heavy metal levels as a result of iron chelate medication. The aim is to study the levels of heavy metals (toxic) in the blood of beta-Thematological patients and compare them to healthy people for the purpose of arriving at indicators through which it is possible to assist in early diagnosis of this disease or reduce symptoms. The study included 80 patients in comparison with age- and gender-matched 40 healthy individuals as controls. Samples were gathered between July 1, 2023, and September 1, 2023. The patients were interviewed for socio-demographic variables, and their medical histories were obtained from the hospital files. Cadmium and lead concentrations were determined using flame atomic absorption spectrometry (FAAS). All samples from Thematological patients were taken after the chelating therapy. Cadmium levels in Thematological patients were found to be lower in both genders in the control group. Lead levels were found to be greater in male Thematological patients and lower in female Thematological patients than those in the control group of female Thematological patients. Additionally, it was observed that patients from areas outside of Najaf's city center had greater levels of lead and cadmium than patients from the city center. Cadmium and lead levels in the serum were often low in Thematological patients. Heavy metals are eliminated when deferasirox chelate is taken. [ABSTRACT FROM AUTHOR]

The effective use of polymer carbon dots (PCD) in various fields of science and technology requires a more detailed understanding of the mechanisms of their photoluminescence formation and change as a result of their interaction with the environment. In this study, PCD synthesized via a hydrothermal method from citric acid and ethylenediamine are studied in various solvents using FTIR spectroscopy, optical absorption spectroscopy, and photoluminescence spectroscopy. As a result of the analysis of the obtained dependencies of such PCD spectral characteristics as the photoluminescence FWHM, the photoluminescence quantum yield, the photoluminescence lifetime on the acidity and basicity of the solvent, a hypothesis was formulated on the formation mechanism of hydrogen bonds between the PCD surface groups and the molecules of the environment, and conclusions were made about the donor–acceptor nature of the synthesized PCD. [ABSTRACT FROM AUTHOR]

The dual-comb spectrometer has emerged as a preferred instrument in multiheterodyne spectroscopy due to its high-resolution and fast-scanning capabilities. Conventional dual-comb spectroscopy (DCS) requires locking or reference systems, increasing both system complexity and cost, and limiting its commercial feasibility. Self-correction offers a promising alternative, though it demands a high refresh rate for interferograms (IGMs), corresponding to the repetition frequency difference, to counter system noise. This study examined the practical effects of self-correction at various refresh rates by measuring $\rm H^{13}C^{14}N$ absorption. The results indicate that higher repetition frequency differences improve self-correction performance, while lower repetition frequencies cause deviations in absorption line width and intensity. Practical applications must balance measurement bandwidth, which is constrained by the repetition frequency difference.

The differentially pumped rare-gas filter at the end of the VUV beamline of the Swiss Light Source has been adapted to house a windowless absorption cell for gases. Absorption spectra can be recorded from 7 eV to up to 21 eV photon energies routinely, as shown by a new water and nitrous oxide absorption spectrum. By and large, the spectra agree with previously published ones both in terms of resonance energies and absorption cross sections, but that of N2O exhibits a small shift in the {\tilde{\bf D}} band and tentative fine structures that have not yet been fully described. This setup will facilitate the measurement of absorption spectra in the VUV above the absorption edge of LiF and MgF2 windows. It will also allow us to carry out condensed-phase measurements on thin liquid sheets and solid films. Further development options are discussed, including the recording of temperature-dependent absorption spectra, a stationary gas cell for calibration measurements, and the improvement of the photon energy resolution.

Color is essential for the fashion and art of fabrics, with its retention being a quality measure of great significance for the brand and user. The colorfastness of some metallic fabrics has been established using absorption spectroscopy, by determining the quality and quantity of dye that bled after undergoing wash laundry processes. Two metallic fabrics (X and Y) and washing detergents (liquid and powdered) were used. The fabrics were washed using GyroWash machine set for normal (40°C) and hot (60°C) wash for durations of 60 min and 90 min. There was a repeat for a second wash. The wastewater after each wash (sample) was collected, and the absorption spectra were recorded using a double‐beam spectrophotometer. The quality of dyes drained was determined using Peakfit analysis to deconvolute the absorption spectrum to reveal the presence of multiple individual wavelengths, and quantified using their relative intensity values. The identified peaks were between 200 nm and 370 nm, which lie within the UV–Vis absorption band of synthetic dyes referred to as azo dyes. The liquid soap bled more dye under the same washing conditions, with fabric Y demonstrating an inferior ability to retain its dye compared to fabric X. A higher amount of dye was drained during the hot wash, with the amount of dye that bled from both fabrics reducing after the first wash. Euclidean similarity was performed using principal component analysis to identify the spectra close to the detergent solution (reference spectrum) in Euclidean distance sense. Points from the wastewater spectra similar to the reference had shorter absolute distances, indicating less bleeding, while more dissimilar points registered longer distance, indicating more bleeding. This absorption spectroscopy technique is scientific and objective compared to the conventional subjective gray scale method. It will help textile manufacturers develop standardized testing protocols to assess the colorfastness of metallic printed fabrics, ensuring that products meet quality standards before they reach the market. [ABSTRACT FROM AUTHOR]

Monodeuterated methane (CH3D) contributes greatly to absorption in the 1.58 μm methane transparency window. The spectrum is dominated by the 3ν2 band near 6430 cm−1, which is observed in natural methane and used for a number of planetary applications, such as the determination of the D/H ratio. In this work, we analyze the CH3D spectrum recorded by high-sensitivity differential absorption spectroscopy in the 6099–6530 cm−1 region, both at room temperature and at 81 K. Following a first contribution to this topic by Lu et al., the room-temperature line list is elaborated (11,189 lines) and combined with the previous 81 K list (8962 lines) in order to derive about 4800 empirical lower-state energy values from the ratio of the line intensities measured at 81 K and 294 K (2T-method). Relying on the position and intensity agreements with the TheoReTS variational line list, about 2890 transitions are rovibrationally assigned to twenty bands, with fifteen of them being newly reported. Variational positions deviate from measurements by up to 2 cm−1, and the band intensities are found to be in good agreement with measurements. All the reported assignments are confirmed by Ground-State Combination Difference (GSCD) relations; i.e., all the upper-state energies (about 1370 in total) have coinciding determinations through several transitions (up to 8). The energy values, determined with a typical uncertainty of 10−3 cm−1, are compared to their empirical and variational counterparts. The intensity sum of the transitions assigned between 6190 and 6530 cm−1 represents 76.9 and 90.0% of the total experimental intensities at 294 K and 81 K, respectively. [ABSTRACT FROM AUTHOR]

The natural polyphenol resveratrol is a biologically active compound that interacts with DNA and affects the activity of some nuclear enzymes. Its effect on the interaction between nucleosomes and poly(ADP-ribose) polymerase-1 (PARP1) and on the catalytic activity of PARP1 was studied using Western blotting, spectrophotometry, electrophoretic mobility shift assay, and single particle Förster resonance energy transfer microscopy. Resveratrol inhibited PARP1 activity at micro- and sub-micromolar concentrations, but the inhibitory effect decreased at higher concentrations due to the aggregation of the polyphenol. The inhibition of PARP1 by resveratrol was accompanied by its binding to the enzyme catalytic center and a subsequent decrease in PARP1 affinity to nucleosomal DNA. Concurrent binding of talazoparib to the substrate binding pocket of PARP1, which occurs in the presence of resveratrol, restores the interaction of PARP1 with nucleosomes, suggesting that the binding sites of resveratrol and talazoparib overlap. The data suggest that resveratrol can be classified as a natural inhibitor of PARP1. [ABSTRACT FROM AUTHOR]

A benzene ring and a lactone ring combine to form the chemical coumarin. Dye lasers have made significant advances in laser technology. The coumarin molecule itself is a non-fluorescent but it displays high fluorescence when electron-denoting substituents such as sulfonamide, benzopyrone, amine, benzothiazole, hydroxyl, methoxy are substituted at various positions. Substituted coumarin possesses the highest energy properties, photostability, and alteration in electron mobility, and therefore could be effectively used as dye lasers. These are considered some of the best fluorophores due to their outstanding photophysical and photochemical properties, which include high fluorescence quantum yields, great photostability, good functionality, and a wide spectrum range. Various inorganic materials are used in classic laser technology to generate the necessary emission. Inorganic lasers come in various types and can emit light in the electromagnetic spectrum's ultraviolet, visible, or infrared parts. Inorganic lasers have certain limitations, which is why coumarin lasers are becoming increasingly popular due to their many advantages. Compared to inorganic lasers, dye lasers offer far better tunability and cover the entire visible and near-infrared range. They only emit at very few specific wavelengths and in extremely narrow bands. The property is therefore presented in this review. [ABSTRACT FROM AUTHOR]

AbstractThe visible light absorption capabilities, along with its electrical characteristics, of a low-cost, plant-based, biopolymer, gum acacia, have been chemically modified by tailoring its defect concentrations via pH modification, where the acid solvent of fruit (peel) extracts of jamun was used to influence the chemical structure by reactive modification. Ultraviolet-visible and photoluminescence spectroscopy of the gum acacia biopolymer treated with the extracted anthocyanin from jamun peel showed a prominent, characteristic red shift in the visible spectrum range. Impedance spectroscopy analysis showed the occurrence of localized ionic conduction. The bulk conductivity of the modified specimens increased due to the profound release of conducting ions in the water-swollen network. The reactively modified biopolymer could be used in multiple fields of material science, specifically in energy device applications, viz., photovoltaics (PV), by utilizing its cost effectiveness and photolytic effectiveness. 2nd, as a polymer electrolyte and dye-sensitised solar cells (DSSCs) material by utilizing its capacity of gel formation. In our research described in this article, the underlying charge transfer mechanism for such responses was examined after crosslinking in the organic dyes extracted from the peel of jamun fruit with gum acacia. [ABSTRACT FROM AUTHOR]

Absorption spectra and cross-sections of Diisopropyl Methylphosphonate (DIMP) are measured in argon at temperatures of 600–1250 K in a shock tube using rapid scanning, broadband absorption spectroscopy. Measurements are obtained at approximately 2.3 kHz with each complete scan of the 925–1350 wavenumber band taking 90 microseconds. This technique enables spectra behind incident and reflected shocks to be obtained in a single test. In addition, multiple spectra are obtained behind the reflected shock during the test time. A significant reduction in absorption cross section with temperature is observed, and the spectra taken during the test time show no decomposition or significant changes, suggesting that vibrational equilibrium is achieved. [ABSTRACT FROM AUTHOR]

This paper presents a novel technique for extracting the alveolar part of human breath. Gas exchange occurs between blood and inhaled air in the alveoli, which is helpful in medical diagnostics based on breath analysis. Consequently, the alveolar portion of the exhaled air contains specific concentrations of endogenous EVOC (exogenous volatile organic compound), which, among other factors, depend on the person's health condition. As this part of the breath enables the screening for diseases, accurate sample collection for testing is crucial. Inaccurate sampling can significantly alter the composition of the specimen, alter the concentration of EVOC (biomarkers) and adversely affect the diagnosis. Furthermore, the volume of alveolar air is minimal (usually <350 mL), especially in the case of people affected by respiratory system problems. For these reasons, precise sampling is a key factor in the effectiveness of medical diagnostic systems. A new technique ensuring high accuracy and repeatability is presented in the article. It is based on analyzing the changes in carbon dioxide concentration in human breath using a fast and compensated non-dispersive infrared (NDIR) sensor and the simple moving adjacent average (SMAA) algorithm. Research has shown that this method accurately identifies exhalation phases with an uncertainty as low as 20 ms. This provides around 350 ms of breath duration for carrying out additional stages of the diagnostic process using various types of analyzers. [ABSTRACT FROM AUTHOR]

The interaction of Thorium(IV) with a group of non‐symmetric CF3‐diketones has been studied by means of electronic absorption spectroscopy in HCl aqueous solutions at I=0.5 M (NaCl) and T=298 K. Six heterocyclic dicarbonyl ligands (2‐thenoyl‐trifluoroacetone, 2‐furoyl‐trifluoroacetone, 2‐selenophen‐trifluoroacetone, 2‐tellurophen‐trifluoroacetone, phenyl‐trifluoroacetone, and 2‐naphthyl‐trifluoroacetone) demonstrate the chelation activity toward ThIV in the acidic pH range. Obtained values of the "true" stability constants lie in the range 6.2–6.8 logarithmic units, respectively. A significant (10–15 nm) bathochromic shift between the maximum absorption wavelength of lanthanide and actinide monocomplexes has been detected. Observed spectral shift increases with the atomic number of substituted chalcogen atoms in the heterocyclic ring of the corresponding ligand: 10 nm for furan, 11 nm for thiophen, 14 nm for selenophen, and 15 nm for tellurophene rings. The complexation with Thorium occurs in an acidic media, where studied ligands do not interact with transition and rare earth metals. Spectral and pH shifts make studied ligands useful reagents for the detection and analytical determination of Thorium in the mixture with other metals without prior separation. Quantum‐chemical simulations (DFT and TD‐DFT) demonstrate that the nine‐ and deco‐coordinated structures of ThoriumIV complexes reproduce experimental values within reasonable errors. [ABSTRACT FROM AUTHOR]

Photodynamic diagnosis and therapy (PDD and PDT) are emerging techniques for diagnosing and treating tumors and malignant diseases. Photoproducts of protoporphyrin IX (PpIX) used in PDD and PDT may be used in the diagnosis and treatment, making a detailed analysis of the photoproduct formation under various treatment and diagnosis conditions important. Spectroscopic and mass spectrometric analysis of photoproduct formation from PpIX dissolved in dimethyl sulfoxide were performed under commonly used irradiation conditions for PDD and PDT, i.e., wavelengths of 405 and 635 nm and fluence rates of 10 and 100 mW/cm2. Irradiation resulted in the formation of hydroxyaldehyde photoproduct (photoprotoporphyrin; Ppp) and formyl photoproduct (product II; Pp II) existing in different quantities with the irradiation wavelength and fluence rate. Ppp was dominant under 635 nm irradiation of PpIX, with a fluorescence peak at 673 nm and a protonated monoisotopic peak at m/z 595.3. PpIX irradiation with 405 nm yielded more Pp II, with a fluorescence peak at 654 nm. A higher photoproduct formation was observed at a low fluence rate for irradiation with 635 nm, while irradiation with 405 nm indicated a higher photoproduct formation at a higher fluence rate. The photoproduct formation with the irradiation conditions can be exploited for dosimetry estimation and may be used as an additional photosensitizer to improve the diagnostics and treatment efficacies of PDD and PDT. Differences in environmental conditions of the present study from that of a biological environment may result in a variation in the photoproduct formation rate and may limit their clinical utilization in PDD and PDT. Thus, further investigation of photoproduct formation rates in more complex biological environments, including in vivo, is necessary. However, the results obtained in this study will serve as a basis for understanding reaction processes in such biological environments. [ABSTRACT FROM AUTHOR]

The differentially pumped rare‐gas filter at the end of the VUV beamline of the Swiss Light Source has been adapted to house a windowless absorption cell for gases. Absorption spectra can be recorded from 7 eV to up to 21 eV photon energies routinely, as shown by a new water and nitrous oxide absorption spectrum. By and large, the spectra agree with previously published ones both in terms of resonance energies and absorption cross sections, but that of N2O exhibits a small shift in the band and tentative fine structures that have not yet been fully described. This setup will facilitate the measurement of absorption spectra in the VUV above the absorption edge of LiF and MgF2 windows. It will also allow us to carry out condensed‐phase measurements on thin liquid sheets and solid films. Further development options are discussed, including the recording of temperature‐dependent absorption spectra, a stationary gas cell for calibration measurements, and the improvement of the photon energy resolution. [ABSTRACT FROM AUTHOR]

Linear tomographic absorption spectroscopy (LTAS) is a non-destructive diagnostic technique widely employed for gas sensing. The inverse problem of LTAS represents a classic example of an ill-posed problem. Linear iterative algorithms are commonly employed to address such problems, yielding generally poor reconstruction results due to the incapability to incorporate suitable prior conditions within the reconstruction process. Data-driven deep neural networks (DNN) have shown the potential to yield superior reconstruction results; however, they demand a substantial amount of measurement data that is challenging to acquire. To surmount this limitation, we proposed an untrained neural network (UNN) to tackle the inverse problem of LTAS. In conjunction with an early-stopping method based on running variance, UNN achieves improved reconstruction accuracy without supplementary training data. Numerical studies are conducted to explore the optimal network architecture of UNN and to assess the reliability of the early-stopping method. A comparison between UNN and superiorized ART (SUP-ART) substantiates the exceptional performance of UNN. [ABSTRACT FROM AUTHOR]

The present manuscript reports the synthesis of undoped CeO2 and Ce1−xAgxO2 (x = 0.03, 0.05, and 0.07) nanoparticles using a microwave-assisted co-precipitation route to understand the Ag doping effect in CeO2 nanoparticles. The structural and optical properties of these nanoparticles were investigated using x-ray diffraction, UV–Vis–NIR, and PL spectroscopy. The XRD result confirmed the formation of cubic fluorite structures with undoped and Ag-doped CeO2 nanoparticles. The crystallite size of Ag-doped CeO2 nanoparticles was observed within the range of 26–47 nm. The absorption peak was observed using UV–Vis–NIR spectroscopy and obtained at below 400 nm, indicating a blue shift with the incorporation of Ag+ ions in the CeO2 nanolattice, and the causes are explained in terms of the BM effect and electronic transitions. The PL measurements were taken to determine the defects and excitation wavelength. The prepared samples depicted good luminescence properties with a high value color rendering index (CRI). The results demonstrated that Ag-doped CeO2 nanoparticles can be used for white light emission, since the structural and optical properties of semiconductors were enhanced upon doping with elements such as Ag. Therefore, these nanoparticles may act as promising candidates for various applications such as UV-absorption, photocatalysis, light-emitting diodes, luminescence, and optoelectronics. [ABSTRACT FROM AUTHOR]

Magic sized ZnSe nanoclusters have applications in a wide range of areas, such as bioimaging, bio-detection techniques, LEDs and solar cells etc. Despite extensive studies done on ZnSe quantum dots (QDs), the technological potential of photonic behaviour of their lower size range clusters is still largely unexplored. We herein present rapid mustered oil mediated synthesis of magic sized ZnSe with their identification as single-family entities by trapping a fixed position doublet in their absorption spectra. Consistent absorption peaks at 304/305 and 318/19 ​nm irrespective of methods employed are presented. The PL spectra show broad emissions between 350 and 550 ​nm dominating blue region of energy offering scope of further tunability. The mustard oil mediated synthesis was performed using thermal, microwave and ultrasound energy. Despite their size domain of about 2 ​nm, their broad XRD pattern have signature of crystalline nature. Mass spectrometry, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are in good support of ZnSe magic size clusters. Typically, blue region CIE coordinates are estimated from PL emission spectra.

Abstract Background Medicinal plant-mediated combinational therapies have gained importance globally due to minimal side effects and enhanced treatment outcomes compared to single-drug modalities. We aimed to analyze the cytotoxic potential of each conventional treatment i.e., photodynamic therapy (PDT), chemotherapy (doxorubicin hydrochloride; Dox-HCl) with or without various concentrations of medicinal plant extracts (PE) on soft tissue cancer Rhabdomyosarcoma (RD) cell line. Methods The Rhabdomyosarcoma (RD) cell line was cultured and treated with Photosensitizer (Photosense (AlPc4)), Chemo (Dox-HCl), and their combinations with different concentrations of each plant extract i.e., Thuja occidentalis, Moringa oleifera, Solanum surattense. For the source of illumination, a Diode laser (λ = 630 nm ± 1 nm, Pmax = 1.5 mW) was used. Photosensitizer uptake time (∼ 45 min) was optimized through spectrophotometric measurements (absorption spectroscopy). Drug response of each treatment arm was assessed post 24 h of administration using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5- 5-diphenyl-2 H- tetrazolium bromide (MTT) assay. Results PE-mediated Chemo-Photodynamic therapy (PDT) exhibited synergistic effects (CI

The photodecomposition behavior of cationic porphyrin ZnTMAP4+ (zinc tetrakis-(N,N,N-trimethylanilinium-4-yl) porphyrin) in water and complexed with clay nanosheets was investigated by light irradiation to the Soret band of ZnTMAP4+. The decomposition of ZnTMAP4+ was observed by UV–visible absorption spectroscopy. While the decomposition quantum yield (ϕdec) was 3.4 × 10−4 in water, that was 9.4 × 10−7 on the exfoliated clay nanosheets. It was revealed that the photostability of ZnTMAP4+ was stabilized by the complex formation with clay. When ZnTMAP4+ was intercalated between the stacked clay nanosheets, ϕdec was further decreased to 4.9 × 10−7. The photostability increased by 361 times and 693 times for the exfoliated and stacked state, respectively. These results indicate that the flat clay surface has the potential to control intra- and intermolecular photochemical reactions. [ABSTRACT FROM AUTHOR]

Here, the optical properties of the Nafion polymer membrane containing colloidal CdSe/CdS/ZnS nanocrystals embedded by diffusion have been studied. The CdSe/CdS/ZnS nanocrystals have a core/shell/shell appearance. All experiments were carried out at room temperature (22 ± 2) °C. A toluene solution was used to provide mobility to the active sulfone groups of the Nafion membrane and to embed the nanocrystals inside the membrane. The diffusion process of colloidal CdSe/CdS/ZnS nanocrystals into Nafion proton exchange membrane has resulted in a new molecular complex "Nafion–colloidal CdSe/CdS/ZnS nanocrystals". The kinetics of the nanocrystals embedding into the membrane matrix was investigated using luminescence analysis and absorption spectroscopy techniques. The embedding rate of CdSe/CdS/ZnS nanocrystals into the Nafion polymer membrane was approximately 4·10−3 min−1. The presence of new luminescence centers in the membrane was proved independently by laser emission spectroscopy. The luminescence spectrum of the resulting molecular complex contains intensity maxima at wavelengths of 538, 588, 643 and 700 nm. The additional luminescence maximum observed at the 643 nm wavelength was not recorded in the original membrane, solvent or in the spectrum of the semiconductor nanoparticles. The luminescence maximum of the colloidal CdSe/CdS/ZnS nanocrystals was registered at a wavelength of 634 nm. The intensity of the luminescence spectrum of the membrane with embedded nanocrystals was found to be higher than the intensity of the secondary emission peak of the initial nanocrystals, which is important for the practical use of the "Nafion–colloidal nanocrystals" complex in optical systems. The lines contained in the luminescence spectrum of the membrane, which has been in solution with colloidal nanocrystals for a long time, registered upon its drying, show the kinetics of the formation of the molecular complex "Nafion membrane–nanocrystals". Colloidal nanocrystals located in the Nafion matrix represent an analog of a luminescent transducer. [ABSTRACT FROM AUTHOR]

Background: Medicinal plant-mediated combinational therapies have gained importance globally due to minimal side effects and enhanced treatment outcomes compared to single-drug modalities. We aimed to analyze the cytotoxic potential of each conventional treatment i.e., photodynamic therapy (PDT), chemotherapy (doxorubicin hydrochloride; Dox-HCl) with or without various concentrations of medicinal plant extracts (PE) on soft tissue cancer Rhabdomyosarcoma (RD) cell line. Methods: The Rhabdomyosarcoma (RD) cell line was cultured and treated with Photosensitizer (Photosense (AlPc4)), Chemo (Dox-HCl), and their combinations with different concentrations of each plant extract i.e., Thuja occidentalis, Moringa oleifera, Solanum surattense. For the source of illumination, a Diode laser (λ = 630 nm ± 1 nm, Pmax = 1.5 mW) was used. Photosensitizer uptake time (∼ 45 min) was optimized through spectrophotometric measurements (absorption spectroscopy). Drug response of each treatment arm was assessed post 24 h of administration using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5- 5-diphenyl-2 H- tetrazolium bromide (MTT) assay. Results: PE-mediated Chemo-Photodynamic therapy (PDT) exhibited synergistic effects (CI < 1). Moreover, Rhabdomyosarcoma culture pretreated with various plant extracts for 24 h exhibited significant inhibition of cell viability however most effective outcomes were shown by low and high doses of Moringa oleifera compared to other plant extracts. Post low doses treated culture with all plant extracts followed by PDT came up with more effectiveness when compared to all di-therapy treatments. Conclusion: The general outcome of this work shows that the ethanolic plant extracts (higher doses) promote the death of cancerous cells in a dose-dependent way and combining Dox-HCl and photo-mediated photodynamic therapy can yield better therapeutic outcomes. [ABSTRACT FROM AUTHOR]

Anthraquinones constitute an important class of compounds with wide applications. The solubility of derivatives at 298.15 K was discussed in ethanol–water solution and at atmospheric pressure, the solubility of 1-amino-4-hydroxy-9,10-anthraquinone (AHAQ) in binary solvents (ethanol–water combinations) was determined. Colour strength and fastening properties depend upon the kind and position of a hydrophobic group connected to the phenoxy ring of Anthraquinone moiety. There is a continuing interest in the creation of novel anthraquinone derivatives with biological activities since they have demonstrated potential for treating multiple sclerosis. For this purpose, by utilizing voltammetric and absorption studies, interactions of various derivatives with calf thymus DNA (ct-DNA) and the cationic surfactant cetyltrimethylammoniumbromide (CTAB) were examined. Here prominent Hydrophobic interaction and electron transfer resulting in binding to CTAB micelles were observed. The polarity index of the media was assessed and associated with the electrochemical parameters. The medicinal behaviour of Anthraquinone derivatives was a result of electron transfer reactions with DNA. UV–Visible and fluorescence properties were due to the transitions between n* and π* orbitals. Large absorption band with low dichroic ratio was characteristic of various derivatives of Anthraquinone. Presence of –NH group proves various derivatives remarkable calorimetric and anionic sensors. [ABSTRACT FROM AUTHOR]

It was shown earlier that the use of fast protein and metabolites liquid chromatography (FPMLC) and low-cost deep UV–LED-based optical chromatographic sensors with PD-10 desalting columns as a separation element can facilitate the monitoring of patients on chronic peritoneal dialysis (PD). Previously, we established that the first peak in the FPMLC chromatograms of effluent dialysate is mainly responsible for proteins and could be used for the assessment of peritoneal protein loss in patients on PD, while the origin and clinical significance of the other two peaks still remain unclear. Optical absorption and fluorescence spectroscopy in the UV and visible regions of 240...720 nm were used for the analysis of PD effluent chromatographic fractions collected from a drainpipe of the sensor with photometric detection at 280 nm; chromatograms of twenty dialysate samples were processed. The absorption and fluorescence spectra of the first fraction demonstrated peaks at 270 nm and 330 nm, respectively, which is typical for proteins. The absorption spectra of the third fraction revealed the characteristic maxima of creatinine and uric acid, while the fluorescence spectra showed the characteristic peak of indoxyl sulfate 375 nm at 270 nm excitation. The second fraction had a single, extremely wide absorption band, strong fluorescence was observed at 440–450 nm while excited at 370 nm. Such spectral characteristics are typical for advanced glycation end products (AGE). Thus, it was demonstrated that deep UV–LED-based affordable chromatographic sensors could provide significantly more information about the composition of PD effluent dialysate than just the total protein concentration, including the contents of clinically significant metabolites, e.g., indoxyl sulfate and AGE. Moreover, the introduction of optical fluorescence detection could significantly improve the capabilities of such devices. [ABSTRACT FROM AUTHOR]

The epidermal growth factor receptor (EGFR) is a pivotal target in cancer therapy due to its significance within the tyrosine kinase family. EGFR inhibitors like AG-1478 and PD153035, featuring a 4-anilinoquinazoline moiety, have garnered global attention for their potent therapeutic activities. While pre-clinical studies have highlighted the significant impact of halogen substitution at the C3'-anilino position on drug potency, the underlying mechanism remains unclear. This study investigates the influence of halogen substitution (X = H, F, Cl, Br, I) on the structure, properties, and spectroscopy of halogen-substituted 4-anilinoquinazoline tyrosine kinase inhibitors (TKIs) using time-dependent density functional methods (TD-DFT) with the B3LYP functional. Our calculations revealed that halogen substitution did not induce significant changes in the three-dimensional conformation of the TKIs but led to noticeable alterations in electronic properties, such as dipole moment and spatial extent, impacting interactions at the EGFR binding site. The UV–visible spectra show that more potent TKI-X compounds typically have shorter wavelengths, with bromine's peak wavelength at 326.71 nm and hydrogen, with the lowest IC50 nM, shifting its lambda max to 333.17 nm, indicating a correlation between potency and spectral characteristics. Further analysis of the four lowest-lying conformers of each TKI-X, along with their crystal structures from the EGFR database, confirms that the most potent conformer is often not the global minimum structure but one of the low-lying conformers. The more potent TKI-Cl and TKI-Br exhibit larger deviations (RMSD > 0.65 Å) from their global minimum structures compared to other TKI-X (RMSD < 0.15 Å), indicating that potency is associated with greater flexibility. Dipole moments of TKI-X correlate with drug potency (ln(IC50 nM)), with TKI-Cl and TKI-Br showing significantly higher dipole moments (>8.0 Debye) in both their global minimum and crystal structures. Additionally, optical spectral shifts correlate with potency, as TKI-Cl and TKI-Br exhibit blue shifts from their global minimum structures, in contrast to other TKI-X. This suggests that optical reporting can effectively probe drug potency and conformation changes. [ABSTRACT FROM AUTHOR]

Synchrotron x-ray diffraction (SR-XRD) and X-ray absorption fine structure spectroscopy (XAFS) were used to investigate the crystal and electronic properties of boron-substituted CuFeO2 material at room temperature. Without boron substitution, the polycrystalline structures of the trigonal (rhombohedral) ' $R\bar{3}m$ R 3 ¯ m ' CuFeO2 (87.7%) and hexagonal 'P63/mmc' (12.3%), which were also present in each sample but in different proportions, were utilised to identify the base material. XRD patterns revealed that, beyond 10% boron substitution, the metal–oxygen bonds (Fe-O and Cu-O) weakened, resulting in the formation of new tetragonal 'I41/amd' CuFe2O4 crystals. Although the CuFeO2 structure was preserved, it is conceivable that the presence of other crystal structures could lead to the formation of new features. This state arose as a result of CuFe2O4 crystallization and the impact of boron activity on the surrounding oxygen structures. By measuring magnetisation at both swept temperatures (10–300 K) and applied magnetic fields (±30 kOe), the magnetic properties of the samples were investigated. In the 10–300 K temperature range, the polycrystalline samples exhibit a ferromagnetic property without a magnetic phase transition. This suggests that replacing B with Fe in CuFe1−xBxO2 does not influence the primary magnetic property of CuFeO2. The samples' saturation magnetisation (Ms) values gradually fall as the B substitution content increases with Fe. This is because there's a chance that the non-transition metal B in CuFe1−xBxO2 will boost antiferromagnetic superexchange Cu-O interactions while lowering the p-d exchange interaction. [ABSTRACT FROM AUTHOR]

Fabry–Perot interferometers (FPIs), comprising foundry-compatible dielectric thin films on sapphire wafer substrates, were investigated for possible use in chemical sensing. Specifically, structures comprising two vertically stacked distributed Bragg reflectors (DBRs), with the lower DBR between a sapphire substrate and a silicon-oxide (SiO2) resonator layer and the other DBR on top of this resonator layer, were investigated for operation in the near-ultraviolet (near-UV) range. The DBRs are composed of a stack of nitride-rich silicon-nitride (SiNx) layers for the higher index and SiO2 layers for the lower index. An exemplary application would be formaldehyde detection at sub-ppm concentrations in air, using UV absorption spectroscopy in the 300–360 nm band, while providing spectral selectivity against the main interfering gases, notably NO2 and O3. Although SiNx thin films are conventionally used only for visible and near-infrared optical wavelengths (above 450 nm) because of high absorbance at lower wavelengths, this work shows that nitride-rich SiNx is suitable for near-UV wavelengths. The interplay between spectral absorbance, transmittance and reflectance in a FPI is presented in a comparative study between one FPI design using stoichiometric material (Si3N4) and two designs based on N-rich compositions, SiN1.39 and SiN1.49. Spectral measurements confirm that if the design accounts for phase penetration depth, sufficient performance can be achieved with the SiN1.49-based FPI design for gas absorption spectroscopy in near-UV, with peak transmission at 330 nm of 64%, a free spectral range (FSR) of 20 nm and a full-width half-magnitude spectral resolution (FWHM) of 2 nm. [ABSTRACT FROM AUTHOR]

Whispering gallery mode resonator sensors are nondisruptive optical sensors that can detect and monitor perturbations in a gaseous environment. Through its resonant properties of peak wavelength, amplitude, and quality factor (Q factor), changes in concentration can be quantified within seconds and monitored over days with great stability. In addition, the small footprint, low cost, and high sensitivity are ideal properties for a disposable sensor that can be utilized in extreme environments. The large Q factor of the resonant cavity enables long interaction lengths and amplifies the effect of small changes in the background refractive index, which is detectable in picometer shifts of the resonance wavelength. However, this measurement is susceptible to changes in other environmental factors such as temperature, pressure, and humidity, which manifest on the picometer wavelength scale, reinforcing the need to decouple the variables. In this work, we compare the spectral response of different diameter resonators to carbon dioxide, nitrogen, and its mixtures, observing the spectral shifting and broadening of the cavity resonance near 1550 nm. In addition, the effect of environmental temperature on spectral shifting due to the thermo-optic effect is characterized and quantified. Lastly, the gas concentrations are changed in real time to showcase the tracking and recovery capabilities of the resonator sensor. [ABSTRACT FROM AUTHOR]

In absorption spectroscopy, it is challenging to detect absorption peaks with significant differences in their intensity in a single measurement. We enable high-dynamic-range measurements by dispersing scatterers within a sample to create a broad distribution of path lengths (PLs). The sample is placed within an integrating sphere (IS) to capture all scattered light of various PLs. To address the complexities of PLs inside the IS and the sample, we performed a ray-tracing simulation using the Monte Carlo (MC) method, which estimates the measured absorbance A and PL distribution from the sample's absorption coefficient µa and scattering properties at each wavelength λ. This method was validated using dye solutions with two absorption peaks whose intensity ratio is 95:1, employing polystyrene microspheres (PSs) as scatterers. The results confirmed that both peak shapes were delineated in a single measurement without flattening the high absorption peak. Although the measured peak shapes A(λ) did not align with the actual peak shapes µa(λ), MC enabled the reproduction of µa(λ) from A(λ). Furthermore, the analysis of the PL distribution by MC shows that adding scatterers broadens the distribution and shifts it toward shorter PLs as absorption increases, effectively adjusting it to µa. [ABSTRACT FROM AUTHOR]

Oxidative coupling of methane (OCM) is a promising process of direct transformation of CH4 to ethylene instead of a complicated two-step process in terms of first forming syngas through reforming or partial oxidation and then producing ethylene with Fischer–Tropsch synthesis (FTS). Na2WO4 has been one of the most studied catalysts of OCM. Here we investigated how the introduced transition metal elements Co, Mn, or Mo to Na2WO4 could influence the catalytic performance of OCM on the supported Na2WO4. It is found that Co, Mn and Mo can obviously promote catalytic activity of transforming CH4 and selectivity for producing ethylene and ethane in OCM performed on Na2WO4 supported on microporous silicate-1 (S-1). A similar promotion of Co, Mn and Mo to the catalytic activity and selectivity in OCM performed on Na2WO4 was found when the Na2WO4 was supported on Matériaux de l′Institut Lavoisier-53(Al) [MIL-53(Al)]. X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy studies of these catalysts with added transition metal Co, Mn or Mo show that these metals diffused into the lattice of Na2WO4, further suggesting that the promotional effect likely arises from modification of the active phase of the supported Na2WO4 during OCM. [ABSTRACT FROM AUTHOR]

The homoleptic cationic complex formed by reacting suitable manganese(II) salts with 2,2′-bipyridine-1,1′-dioxide (bipyO2) has been subjected to several studies in the past because of its peculiar absorption and electrochemical features. Here, the first single-crystal X-ray structure determination of a [Mn(bipyO2)3]2+ salt is reported, where the charge of the cation is balanced by perchlorate anions. The hydrated salt [Mn(bipyO2)3](ClO4)2 crystallizes in the monoclinic system (P21/n space group) and the asymmetric unit contains three cationic complexes and six perchlorate anions. The environment of the manganese(II) ions is best described as octahedral, with scarce variations among the three cations in the asymmetric unit. The bipyO2 ligands exhibit κ2 coordination mode, forming seven-membered metallacycles. The X-ray outcomes have been used as the starting point for DFT and TDDFT calculations, aimed to elucidate the charge transfer origin of the noticeable absorption in the visible range. The MLCT nature is confirmed by the hole and electron distributions associated with the spin-allowed transitions. DFT calculations on the related manganese(III) complex indicate that the geometry of [Mn(bipyO2)3]2+ changes only slightly upon oxidation, in agreement with the reversible electrochemical behaviour experimentally observed. [ABSTRACT FROM AUTHOR]

The intrinsic and extrinsic defects in LiNbO3 (LN) bulk crystals have been investigated with experimental and theoretical methods for many years. However, nowadays, scientific attention has turned to nanocrystals (e.g., for quantum nanophotonic applications). Herein, the results of spectroscopic measurements and theoretical calculations on Yb3+‐ or Er3+‐doped LN nanocrystals are presented. A series of congruent LN nanocrystals doped with Er3+ or Yb3+ have been produced by grinding process under wet conditions in a high‐energy ball mill. The effect of size reduction on the rare‐earth (RE) ions has been followed by absorption measurement of the characteristic electronic transitions using a Fourier‐transform infrared spectrometer. Out‐diffusion of the RE ions from the nano‐LN particle and the appearance of an unordered phase have been concluded from the experimental results. GULP software has been used to make force‐field calculations on a Li245Nb245O735 unit to model the nano‐LN structure containing Er3+ or Yb3+ dopants. From the calculations taking into account, one Er3+ or Yb3+ ion, their out‐diffusion, and the appearance of the ions in the unordered phase have been demonstrated, while in the double‐doped case, independent RE incorporation has been found. [ABSTRACT FROM AUTHOR]

The ammonia spectrum is revisited in the important 1.6 µm atmospheric transparency window between 5650 and 6350 cm $ ^{-1} $ − 1 on the basis of recently recorded high-resolution Fourier transform spectra. These spectra offer an improved frequency sampling and better traceability of the measurement conditions compared to previously studied Kitt Peak spectra (Cacciani et al. J. Quant Spectrosc Radiat Transf 2021; 258:107334. https://doi.org/10.1016/j.jqsrt.2020.107334). Overall, 4812 $ ^{14} $ 14 NH $ _3 $ 3 lines were measured in the 5650–6350 cm $ ^{-1} $ − 1 region corresponding to 4866 transitions including 2066 new ones compared with our previous study, included in the HITRAN2020 database. The energy of 1023 upper state levels (including 107 new ones) was derived from 2608 assigned transitions. Independently, ammonia spectra recorded in a supersonic jet expansion using a tunable extended cavity diode laser allow us to check the absolute transition energies in the 5980–6080 cm $ ^{-1} $ − 1 range. Accurate jet spectra calibration was achieved using CH $ _4 $ 4 reference line positions known with kHz accuracy. The position agreement with the FTS data is within the $ 4\times 10^{-4} $ 4 × 10 − 4 cm $ ^{-1} $ − 1 uncertainty of the positions measured in the jet expansion. A recommended line list of 5620 transitions is provided for $ ^{14} $ 14 NH $ _3 $ 3 in the considered 5650–6350 cm $ ^{-1} $ − 1 region. [ABSTRACT FROM AUTHOR]

The ammonia spectrum is revisited in the important 1.6 µm atmospheric transparency window between 5650 and 6350 cm $ ^{-1} $ − 1 on the basis of recently recorded high-resolution Fourier transform spectra. These spectra offer an improved frequency sampling and better traceability of the measurement conditions compared to previously studied Kitt Peak spectra (Cacciani et al. J. Quant Spectrosc Radiat Transf 2021; 258:107334. https://doi.org/10.1016/j.jqsrt.2020.107334). Overall, 4812 $ ^{14} $ 14 NH $ _3 $ 3 lines were measured in the 5650–6350 cm $ ^{-1} $ − 1 region corresponding to 4866 transitions including 2066 new ones compared with our previous study, included in the HITRAN2020 database. The energy of 1023 upper state levels (including 107 new ones) was derived from 2608 assigned transitions. Independently, ammonia spectra recorded in a supersonic jet expansion using a tunable extended cavity diode laser allow us to check the absolute transition energies in the 5980–6080 cm $ ^{-1} $ − 1 range. Accurate jet spectra calibration was achieved using CH $ _4 $ 4 reference line positions known with kHz accuracy. The position agreement with the FTS data is within the $ 4\times 10^{-4} $ 4 × 10 − 4 cm $ ^{-1} $ − 1 uncertainty of the positions measured in the jet expansion. A recommended line list of 5620 transitions is provided for $ ^{14} $ 14 NH $ _3 $ 3 in the considered 5650–6350 cm $ ^{-1} $ − 1 region. [ABSTRACT FROM AUTHOR]

Optical spectroscopy is a powerful tool for characterizing the properties of two-dimensional (2D) heterostructures. However, extracting the permittivity information of each 2D layer in optically thick heterostructures is challenging because of interference. To accurately measure the optical permittivity of each 2D layer in a heterostructure or on a substrate with a thick insulating spacer, such as oxides, we propose deterministic reflection contrast ellipsometry (DRCE). Our DRCE method has two advantages over conventional techniques. It deterministically measures the optical permittivity of 2D materials using only the measured reflection spectra of the heterostructure, rather than dispersion fitting as in spectroscopic ellipsometry. Additionally, the DRCE is free of excitonic energy errors in reflection-contrast spectroscopy. We believe that DRCE will enable accurate and rapid characterization of 2D materials. [ABSTRACT FROM AUTHOR]