A nondestructive method for quantitative parchment characterization and sensitive indication of its deterioration stage was developed. Synchronous fluorescence (SF) measurements were applied for the first time to parchment samples. The method provides detailed spectral features, which are useful for parchment characterization. The discrimination of parchment samples into groups (modern, historical, and artificially aged) was successfully performed. The SF spectra could be resolved into specific fluorophores, which were related to the parchment condition. The spectral data indicate a continuous change in the collagen-to-gelatin ratio during the aging process. Depth-resolved synchronous fluorescence spectra were also measured. The data indicate that parchments possess a layered structure, and the dominant fluorophore in the upper layer is different from those in the lower layers. Layer-resolved profiling allows for quantifying the contribution of each fluorophore in each given layer. This way, significant differences between modern, artificially aged, and historical samples can be observed.
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http://dx.doi.org/10.1007/s00216-009-3065-5 | DOI Listing |
Physiol Rep
February 2025
Berlin Institute of Health at Charité, Universitätsmedizin Berlin, Center of Functional Genomics, Berlin, Germany.
The zona glomerulosa (ZG) synthesizes the mineralocorticoid aldosterone. The primary role of aldosterone is the maintenance of volume and electrolyte homeostasis. Aldosterone synthesis is primarily regulated via tightly controlled oscillations in intracellular calcium levels in response to stimulation.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
Department of General Surgery, The Second Xiangya Hospital, Central South University, Changsha, China.
Sulfur-containing small molecules, mainly including cysteine (Cys), homocysteine (Hcy), glutathione (GSH), and hydrogen sulfide (HS), are crucial biomarkers, and their levels in different body locations (living cells, tissues, blood, urine, saliva, ) are inconsistent and constantly changing. Therefore, it is highly meaningful and challenging to synchronously and accurately detect them in complex multi-component samples without mutual interference. In this work, we propose a steric hindrance-regulated probe, NBD-2FDCI, with single excitation dual emissions to achieve self-adaptive detection of four analytes.
View Article and Find Full Text PDFNeurophotonics
January 2025
Northeastern University, Department of Bioengineering, Boston, Massachusetts, United States.
Significance: Functional brain imaging experiments in awake animals require meticulous monitoring of animal behavior to screen for spontaneous behavioral events. Although these events occur naturally, they can alter cell signaling and hemodynamic activity in the brain and confound functional brain imaging measurements.
Aim: We developed a centralized, user-friendly, and stand-alone platform that includes an animal fixation frame, compact peripheral sensors, and a portable data acquisition system.
Sci Rep
January 2025
Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
Observing quantum mechanical characteristics in biological processes is a surprising and important discovery. One example, which is gaining more experimental evidence and practical applications, is the effect of weak magnetic fields with extremely low frequencies on cells, especially cancerous ones. In this study, we use a mathematical model of ROS dynamics in cancer cells to show how ROS oscillatory patterns can act as a resonator to amplify the small effects of the magnetic fields on the radical pair dynamics in mitochondrial Complex III.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Biochemistry, Jawaharlal Nehru Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, Uttar Pradesh, India. Electronic address:
Persistence of long-term hyperglycemia results in the glyco-oxidation of plasma proteins, which is considered to be a significant factor in metabolic dysfunction, linking hyperglycemia to the emergence of vascular complications. Methylglyoxal (MGO), a dicarbonyl species formed excessively under diabetes, elevates the oxidative stress, enhancing the generation of superoxide anion, which ultimately reacts with nitric oxide (NO•) to form peroxynitrite (PON). PON, being a powerful nitro-oxidizing agent distorts protein structure, hampering its function.
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