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Adipocytes derived from 3T3-L1 cells are a gold standard for analyses of adipogenesis processes and the metabolism of fat cells. A widely used histological and immunohistochemical staining and mass spectrometry lipidomics are mainly aimed for examining lipid droplets (LDs). Visualizing other cellular compartments contributing to the cellular machinery requires additional cell culturing for multiple labeling. Here, we present the localization of the intracellular structure of the 3T3-L1-derived adipocytes utilizing vibrational spectromicroscopy, which simultaneously illustrates the cellular compartments and provides chemical composition without extensive sample preparation and in the naïve state. Both vibrational spectra (FTIR-Fourier transform infrared and RS-Raman scattering spectroscopy) extended the gathered chemical information. We proved that both IR and RS spectra provide distinct chemical information about lipid content and their structure. Despite the expected presence of triacylglycerols and cholesteryl esters in lipid droplets, we also estimated the length and unsaturation degree of the fatty acid acyl chains that were congruent with known MS lipidomics of these cells. In addition, the clustering of spectral images revealed that the direct surroundings around LDs attributed to lipid-associated proteins and a high abundance of mitochondria. Finally, by using quantified markers of biomolecules, we showed that the fixative agents, paraformaldehyde and glutaraldehyde, affected the cellular compartment differently. We concluded that PFA preserves LDs better, while GA fixation is better for cytochromes and unsaturated lipid analysis. The proposed analysis of the spectral images constitutes a complementary tool for investigations into the structural and molecular features of fat cells.

This study presented an analysis of the TeO 2 /GeO 2 molar ratio in an oxide glass system. A family of melt-quenched glasses with the range of 0-35 mol% of GeO 2 has been characterized by using DSC, Raman, MIR, refractive index, PLE, PL spectra, and time-resolved spectral measurements. The increase in the content of germanium oxide caused an increase in the transition temperature but a decrease in the refractive index. The photoluminescence spectra of europium ions were examined under the excitation of 465 nm, corresponding to 7 F 0 → 5 D 2 transition. The PSB (phonon sidebands) analysis was carried out to determine the phonon energy of the glass hosts. It was reported that the red ( 5 D 0 → 7 F 2 ) to orange ( 5 D 0 → 7 F 1 ) fluorescence intensity ratio for Eu 3+ ions decreased from 4.49 (Te0Ge) to 3.33 (Te15Ge) and showed a constant increase from 4.58 (Te20Ge) to 4.88 (Te35Ge). These optical features were explained in structural studies, especially changes in the coordination of [4] Ge to [6] Ge. The most extended lifetime was reported for the Eu 3+ doped glass with the highest content of GeO 2 . This glass was successfully used for the drawing of optical fiber.

This work reports on the fabrication and analysis of near-infrared and mid-infrared luminescence spectra and their decays in fluoroindate glasses co-doped with Yb 3+ /Ho 3+ . The attention has been paid to the analysis of the Yb 3+ → Ho 3+ energy transfer processed ions in fluoroindate glasses pumped by 976 nm laser diode. The most effective sensitization for 2 μm luminescence has been obtained in glass co-doped with 0.8YbF 3 /1.6HoF 3 . Further study in the mid-infrared spectral range (2.85 μm) showed that the maximum emission intensity has been obtained in fluoroindate glass co-doped with 0.1YbF 3 /1.4HoF 3 . The obtained efficiency of Yb 3+ → Ho 3+ energy transfer was calculated to be up to 61% (0.8YbF 3 /1.6HoF 3 ), which confirms the possibility of obtaining an efficient glass or glass fiber infrared source for a MID-infrared (MID-IR) sensing application.

The ErF 3 -doped oxyfluoride phospho-tellurite glasses in the (40-x) TeO 2 -10P 2 O 5 -45 (BaF 2 -ZnF 2 ) -5Na 2 O-xErF 3 system (where x = 0.25, 0.50, 0.75, 1.00, and 1.25 mol%) have been prepared by the conventional melt-quenching method. The effect of erbium trifluoride addition on thermal, structure, and spectroscopic properties of oxyfluoride phospho-tellurite precursor glass was studied by differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR), and Raman spectroscopy as well as emission measurements, respectively. The DSC curves were used to investigate characteristic temperatures and thermal stability of the precursor glass doped with varying content of ErF 3 . FTIR and Raman spectra were introduced to characterize the evolution of structure and phonon energy of the glasses. It was found that the addition of ErF 3 up to 1.25 mol% into the chemical composition of phospho-tellurite precursor glass enhanced 2.7 µm emission and upconversion. By controlled heat-treatment process of the host glass doped with the highest content of erbium trifluoride (1.25 mol%), transparent erbium-doped phospho-tellurite glass-ceramic (GC) was obtained. X-ray diffraction analysis confirmed the presence of BaF 2 nanocrystals with the average 16 nm diameter in a glass matrix. Moreover, MIR, NIR, and UC emissions of the glass-ceramic were discussed in detail and compared to the spectroscopic properties of the glass doped with 1.25 mol% of ErF 3 (the base glass).