Determination of concentrations of spectrally overlapping compounds has special difficulties. Several methods are available to calculate the constituents' concentrations in moderately complex mixtures. A method which can provide information about spectrally hidden components in mixtures is very useful. Two methods powerful in resolving spectral components are compared in this paper. The first method tested is the Derivative Matrix Isopotential Synchronous Fluorimetry (DMISF). It is based on derivative analysis of MISF spectra, which are constructed using isopotential trajectories in the Excitation-Emission Matrix (EEM) of background solution. For DMISF method, a mathematical routine fitting the 3D data of EEMs was developed. The other method tested uses classical Least Squares Fitting (LSF) algorithm, wherein Rayleigh- and Raman-scattering bands may lead to complications. Both methods give excellent sensitivity and have advantages against each other. Detection limits of DMISF and LSF have been determined at very different concentration and noise levels.
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http://dx.doi.org/10.1007/s10895-009-0526-3 | DOI Listing |
Chaos
January 2025
Centre for Mathematical Science, Lund University, Märkesbacken 4, 223 62 Lund, Sweden.
We investigate the dynamics of the adaptive Kuramoto model with slow adaptation in the continuum limit, N→∞. This model is distinguished by dense multistability, where multiple states coexist for the same system parameters. The underlying cause of this multistability is that some oscillators can lock at different phases or switch between locking and drifting depending on their initial conditions.
View Article and Find Full Text PDFDrug Dev Ind Pharm
January 2025
Ramanbhai Patel College of Pharmacy, Charotar University of Science and Technology (CHARUSAT), Changa - 388421, Anand, Gujarat, India.
Background: Tavaborole (TAV), a benzoxaborole derivative, is an FDA-approved antifungal agent for treating onychomycosis, a common and persistent fungal infection of the toenails.
Objective: This study aimed to develop a robust stability-indicating HPTLC method to determine TAV in nanostructured lipid carriers (NLC) using a comprehensive approach that includes risk assessment, and Analytical Quality by Design.
Methods: The critical method parameters influencing the HPTLC results were screened using a Placket-Burman screening design followed by its optimization using a central composite optimization design.
Alzheimers Dement
December 2024
The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
Background: Mitochondria are organelles where energy production takes place via oxidative phosphorylation, thus mitochondrial function influences the organs with large energy consumption, such as the brain. Mitochondria contain their own circular genome (mtDNA), which encodes essential proteins/RNAs involved in oxidative phosphorylation. The maternal inheritance of mtDNA, combined with a higher risk of Alzheimer's disease (AD) observed in females, suggest mtDNA may have a role in AD.
View Article and Find Full Text PDFBackground: Tauopathies are a group of neurodegenerative disorders which are characterized by the accumulation of abnormal tau protein in the brain. However, the mechanistic understanding of pathogenic tau formation and spread within the brain remains elusive. Astrocytes are major immune reactive cells in the brain and have been implicated in exacerbating tau pathology by releasing extracellular vesicles (AEVs) containing pro-inflammatory cytokines and chemokines upon activation.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA.
Background: The Apoliproprotein E (APOE) e4 allele is the most significant genetic risk factor for late-onset Alzheimer disease (AD). However, the risk associated with the APOE e4 allele differs across populations with individuals of African ancestry having a reduced risk than individuals of European (EU) ancestry. Further, single-nuclei RNAseq analysis in autopsy samples from AD APOEε4 homozygotes with EU Local Ancestry (LA) had a significantly increased APOEε4 expression compared to those with African LA, particularly in astrocytes.
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