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The Kováts retention index is one of the most popular descriptors of the performance of organic compounds in gas chromatography (GC). The mathematical modeling of this index is an interesting and open problem in analytical chemistry. In this paper, two models for the prediction of the Kováts retention index are presented. Topologic, topographic and quantum-chemical descriptors were used as structural descriptors. Multiple linear regression (MLR) analysis provides the first model using the forward stepwise procedure for the variable selection. For the second one, an ensemble of artificial neural network (ANN) was constructed using the pruning algorithm. Both methods were validated by an external set of compounds, by the Golbraikh and Tropsha method and by the leave-one-out (LOO) and the leave many out (LMO) procedures. The R2, RMScv and Q2, values for the training sets were 0.884, 0.589 and 0.830 for NN and 0.974, 0.417 and 0.970 for MLR models, respectively. The robustness of both models was demonstrated. Both portrait the chromatographic performance of the sample but in this case, the results of MLR equation are better than the NN ones. The MLR model is recommended because of its simplicity.
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http://dx.doi.org/10.1016/j.chroma.2005.10.019 | DOI Listing |
J Phys Chem Lett
September 2025
Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074, China.
Ether-based electrolytes are widely acknowledged for their potential to form stable solid electrolyte interfaces (SEIs) for stable anode performance. However, conventional ether-based electrolytes have shown a tendency for cation-solvent co-intercalation phenomena on graphite electrodes, resulting in lower capacity and higher voltage platforms compared to those of neat cation insertion in ester-based electrolytes. In response, we propose the development of weakly solvating ether solvents to weaken the interaction between cations and solvents, thereby suppressing co-intercalation behavior.
View Article and Find Full Text PDFJ Aging Phys Act
September 2025
Department of Physical Education and Sports Science, University of Thessaly, Trikala, Greece.
Background/objective: Manual dexterity is critical for maintaining functional independence and quality of life in older adults, yet limited research has explored training interventions to enhance this skill. This study examined the effect of rhythmic gymnastics (RG) exercise programs, with and without apparatus, on the manual dexterity of older women.
Methods: Seventy-six women, aged over 65 (68.
Nucl Med Biol
August 2025
Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
Background: Glutamine is an important metabolic substrate in many aggressive tumors, with comparable importance to glucose metabolism. Utilizing human breast cancer mouse xenograft models, we studied the kinetics of the PET imaging agent, L-5-[C]-glutamine ([C]glutamine or [C]GLN) a biochemical authentic substrate for glutamine metabolism, to further characterize the metabolism of glutamine and downstream labeled metabolites. Studies were performed with and without inhibition of the enzyme, glutaminase (GLS), the first step in glutamine catabolism that generates glutamate, and key target for therapy directed to glutamine-metabolizing cancers.
View Article and Find Full Text PDFEpilepsy Behav
September 2025
Danone Research & Innovation, Uppsalalaan 12, 3584 CT Utrecht, the Netherlands. Electronic address:
Purpose: Ketogenic diet therapy (KDT) has been successfully used as an effective management option for drug resistant epilepsy (DRE) since the 1920 s. The ketogenic formulation studied here (KetoCal) is nutritionally complete, very high in fat, and low in carbohydrates and has played a crucial role in supporting the implementation of KDT for over twenty-five years. This scoping review aims to synthesise the existing literature regarding the safety, acceptability, and efficacy of the ketogenic formulation in supporting the management of DRE.
View Article and Find Full Text PDFJ Colloid Interface Sci
August 2025
School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China. Electronic address:
Prussian blue analogues (PBAs) have emerged as promising cathode materials for sodium-ion batteries (SIBs) due to their low cost, simple preparation, and high theoretical specific capacity. The integration of high-entropy concepts with framework-structured PBAs has pioneered a new pathway for performance optimization in SIBs cathodes. However, most scholars have only studied the five elements constituting high entropy as a whole, while challenges such as the role of each element and optimization of the proportions among constituent elements remain unresolved.
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