spectroscopic technique
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Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 546
Author(s):  
Klytaimnistra Katsara ◽  
Konstantina Psatha ◽  
George Kenanakis ◽  
Michalis Aivaliotis ◽  
Vassilis M. Papadakis

Raman spectroscopy is a well-defined spectroscopic technique sensitive to the molecular vibrations of materials, since it provides fingerprint-like information regarding the molecular structure of the analyzed samples. It has been extensively used for non-destructive and label-free cell characterization, particularly in the qualitative and quantitative estimation of amino acids, lipids, nucleic acids, and carbohydrates. Lymphoma cell classification is a crucial task for accurate and prompt lymphoma diagnosis, prognosis, and treatment. Currently, it is mostly based on limited information and requires costly and time-consuming approaches. In this work, we are proposing a fast characterization and differentiation methodology of lymphoma cell subtypes based on Raman spectroscopy. The study was performed in the temperature range of 15–37 °C to identify the best cell measurement conditions. The proposed methodology is fast, accurate, and requires minimal sample preparation, resulting in a potentially promising, non-invasive strategy for early and accurate cell lymphoma characterization.


2022 ◽  
Vol 34 (2) ◽  
pp. 272-278
Author(s):  
Thiyam Samrat Singh ◽  
Thiyam David Singh

Interaction of N-acetyl-L-cysteine (NAC) with Pr3+ (Pr(NO3)3·6H2O) and Nd3+ (Nd(NO3)3·6H2O) ions are studied in presence of Ca2+ (Ca(NO3)3·4H2O) ion in an aqueous and organic solvent by applying the spectroscopic technique for quantitative probe of 4f-4f transition. The complexation was determined by the variation in the intensities of 4f-4f absorption spectral bands and by applying the change of symmetric properties of electronic-dipole known as Judd-Ofelt parameters Tλ (λ = 2,4,6). On the addition of Ca2+ ion in the binary complexation of praseodymium and neodymium with N-acetyl-L-cysteine (NAC) there is an intensification of bands which shows the effect of Ca2+ toward the heterobimetallic complex formation. Other parameters like Slater-Condon (Fk), bonding (b1/2), the Nephelauxetic ratio (β), percentage covalency (δ) are also used to correlate the complexation of metals with N-acetyl-L-cysteine (NAC). With the minor change in coordination around Pr3+ and Nd3+ ions, the sensitivity of 4f-4f bands is detected and further used to explain the coordination of N-acetyl-L-cysteine (NAC) with Pr3+ and Nd3+ in presence of Ca2+. The variation in oscillator strength (Pobs), energy (Eobs) and dipole intensity parameter help in supporting the heterobimetallic complexation of N-acetyl-L-cysteine. In kinetics investigation, the rate of the complexation of both hypersensitive and pseudo-hypersensitive transition is evaluated at various temperature in DMF solvent. The value of the thermodynamic parameters such as ΔHo, ΔSo and ΔGo and activation energy (Ea) also evaluated.


2022 ◽  
Vol 29 (1) ◽  
Author(s):  
Yujin Kim ◽  
Daewoong Nam ◽  
Rory Ma ◽  
Sangsoo Kim ◽  
Myung-jin Kim ◽  
...  

Understanding the ultrafast dynamics of molecules is of fundamental importance. Time-resolved X-ray absorption spectroscopy (TR-XAS) is a powerful spectroscopic technique for unveiling the time-dependent structural and electronic information of molecules that has been widely applied in various fields. Herein, the design and technical achievement of a newly developed experimental apparatus for TR-XAS measurements in the tender X-ray range with X-ray free-electron lasers (XFELs) at the Pohang Accelerator Laboratory XFEL (PAL-XFEL) are described. Femtosecond TR-XAS measurements were conducted at the Ru L 3-edge of well known photosensitizer tris(bipyridine)ruthenium(II) chloride ([Ru(bpy)3]2+) in water. The results indicate ultrafast photoinduced electron transfer from the Ru center to the ligand, which demonstrates that the newly designed setup is applicable for monitoring ultrafast reactions in the femtosecond domain.


Author(s):  
Rafael Ribessi ◽  
Wilson Jardim ◽  
Jarbas Rohwedder ◽  
Thiago Neves

In this work we developed a promising analytical method combining Fourier transform nearinfrared (FT-NIR) spectroscopic technique and first-order multivariate calibration using partial least-squares (PLS) model to simultaneously quantify the main greenhouse gases (GHG’s): methane (CH4), carbon dioxide (CO2), nitrous oxide (N2O) and water vapor (H2O). The models were built using 70 mixtures with different concentration of these gases, 0.25-32.0 ppm to CH4 and N2O, and 50-1100 ppm to CO2 and different values of relative humidity (52-85%, 20 ºC) in synthetic air. After preparing each of the mixtures, they were analyzed by using FT-NIR and a reference analytical technique based on gas chromatography with mass spectrometric detection (GC-MS). The FT-NIR spectrometer was coupled with a long optical path cell, with 105.6 meters of optical path. In sequence, the spectra of all mixtures and its concentration values for each gas were used to build the multivariate calibration models, using PLS regressions. For this, the mixtures were grouped with Kennard Stone algorithm, 50 samples to calibration set and 20 samples to prediction set. The values of RMSEP (root mean square error of prediction) obtained for each model are 0.66, 28.7 and 0.66 ppm, respectively, for CH4, CO2, and N2O. The limits of quantification (LOQ) for each PLS models are 0.26, 3.6, and 0.99 ppm, respectively, for CH4, CO2, and N2O. The results show the potentiality of application of this system to monitoring emission sources in which the concentration of these gases are relatively high, as urban centers, industrial areas, and landfills.


Author(s):  
Min Xiao ◽  
Zhaochuan Chen ◽  
Yuan Zhang ◽  
Yanan Wen ◽  
Lihai Shang ◽  
...  

The constituents and content of dissolved organic matter (DOM) in the Qilian Mountain watershed were characterized with a spectroscopic technique, especially 3-DEEM fluorescence assisted by parallel factor (PARAFAC) analysis. The level of DOM in the surrounding area of Qinghai lake (thereafter the lake in this article specifically refers to Qinghai Lake)was highest at 9.45 mg C·L−1 and about 3 times less (3.09 mg C·L−1) in a cropland aquatic regime (the lowest value). In general, DOM was freshly autochthonously generated by plankton and plant debris, microorganisms and diagenetic effects in the aquatic environment (FI > 1.8). Component 1 (humic acid-like) and 3 (fulvic acid-like) determined the humification degree of chromophoric dissolved organic matter (CDOM). The spatial variation of sulfate and nitrate in the surrounding water regime of the lake revealed that organic molecules were mainly influenced by bacterial mediation. Mineral disintegration was an important and necessary process for fluorescent fraction formation in the cropland water regime. Exceptionally, organic moiety in the unused land area was affected by anespecially aridclimate in addition to microbial metabolic experience. Salinity became the critical factor determining the distribution of DOM, and the total normalized fluorescent intensity and CDOM level were lower in low-salinity circumstances (0.2–0.5 g·L−1) with 32.06 QSU and 1.38 m−1 in the grassland area, and higher salinity (0.6~0.8 g·L−1) resulted in abnormally high fluorescence of 150.62 QSU and absorption of 7.83 m−1 in the cropland water regime. Climatic conditions and microbial reactivity controlled by salinity were found to induce the above results. Our findings demonstrated that autochthonous inputs regulated DOM dynamics in the Qilian Mountains watershed of high altitude.


2021 ◽  
Vol 2015 (1) ◽  
pp. 012055
Author(s):  
Y Haddad ◽  
J Chrétien ◽  
S Margueron ◽  
J C Beugnot ◽  
G Fanjoux

Abstract We present in this work a non-destructive and non-invasive imaging spectroscopic technique with a high spatial and spectral resolution to characterize the light propagation behaviour along a centimetric length and nanometric size tapered optical fiber in operation.


2021 ◽  
Author(s):  
Eibar Flores ◽  
Nataliia Mozhzhukhina ◽  
Xinyu Li ◽  
Poul Norby ◽  
Aleksandar Matic ◽  
...  

The popularization of high-throughput spectroscopies to characterize functional materials requires the simultaneous development of new analysis tools to efficiently process large numbers of measurements into scientifically meaningful observables. Here we introduce PRISMA, an open-source tool to rapidly analyze hundreds of spectra in a semi-automated way. PRISMA follows a human-in-the-loop workflow, where the user interacts with an intuitive graphical user interface (GUI) to control multiple steps in the spectrum analysis process: trimming, baseline correction, and peak fitting. The user tunes the analysis in real-time and applies the optimal parameters to all spectra, outputting processed results in an easy-to-read csv format within seconds. Crucially, the tuned parameters are stored to guarantee the full reproducibility of the analysis. We describe the functionalities implemented in PRISMA and test its capabilities with three experimental cases relevant to the study of electrochemical energy storage and conversion devices: temperature-dependent Raman measurement of phase transitions, a linear Raman mapping of a graphite composite electrode, and an operando X-ray diffraction experiment of LiNiO2 Li-ion electrode. Even if X-ray diffraction is not a spectroscopic technique, diffraction patterns are represented as one-dimensional arrays of counts equally suitable for analysis with PRISMA. The case studies demonstrate the robustness of the app and its ability to unearth insightful trends in peak parameters, which are easier to represent, interpret and further analyze with more advanced techniques.


2021 ◽  
Author(s):  
Eibar Flores ◽  
Nataliia Mozhzhukhina ◽  
Xinyu Li ◽  
Poul Norby ◽  
Aleksandar Matic ◽  
...  

The popularization of high-throughput spectroscopies to characterize functional materials requires the simultaneous development of new analysis tools to efficiently process large numbers of measurements into scientifically meaningful observables. Here we introduce PRISMA, an open-source tool to rapidly analyze hundreds of spectra in a semi-automated way. PRISMA follows a human-in-the-loop workflow, where the user interacts with an intuitive graphical user interface (GUI) to control multiple steps in the spectrum analysis process: trimming, baseline correction, and peak fitting. The user tunes the analysis in real-time and applies the optimal parameters to all spectra, outputting processed results in an easy-to-read csv format within seconds. Crucially, the tuned parameters are stored to guarantee the full reproducibility of the analysis. We describe the functionalities implemented in PRISMA and test its capabilities with three experimental cases relevant to the study of electrochemical energy storage and conversion devices: temperature-dependent Raman measurement of phase transitions, a linear Raman mapping of a graphite composite electrode, and an operando X-ray diffraction experiment of LiNiO2 Li-ion electrode. Even if X-ray diffraction is not a spectroscopic technique, diffraction patterns are represented as one-dimensional arrays of counts equally suitable for analysis with PRISMA. The case studies demonstrate the robustness of the app and its ability to unearth insightful trends in peak parameters, which are easier to represent, interpret and further analyze with more advanced techniques.


2021 ◽  
pp. 100210
Author(s):  
Jijo Lukose ◽  
Ajayakumar Barik ◽  
V.K. Unnikrishnan ◽  
Sajan D. George ◽  
V.B. Kartha ◽  
...  

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