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Povzetek: Background and aims: Early detection of insulin resistance (IR) and obesity-related complications is crucial for preventing type 2 diabetes. This study aimed to identify dynamic metabolic biomarkers for more precise early detection of IR and metabolic abnormalities. Methods: This cross-sectional cohort study evaluated IR and metabolic biomarkers in 403 children with obesity (median age 13.18 years, 51.3 % female, 98.5 % with obesity) using an enhanced oral glucose tolerance test (eOGTT). IR was assessed via four indices, with the Matsuda Insulin Sensitivity Index (ISI-M) used as the primary measure. Participants were stratified into quartiles based on ISI-M. Results: Participants with the highest IR (Q1) were older (p = 0.002), had a higher body mass index, were in a more advanced pubertal stage (p < 0.001), and had significantly elevated glucose and insulin levels (p < 0.001 for both) compared to the most insulin sensitive (Q4), with significant differences observed across all quartiles (p < 0.050 for all). Insulin at 120 min demonstrated excellent diagnostic accuracy for IR (AUC=0.958). Triglyceride levels in Q1 showed minimal decline during the eOGTT, while greater declines were observed with increasing insulin sensitivity (p = 0.002 across quartiles), suggesting that a lack of decline in triglycerides may help identify IR. High-sensitivity C-reactive protein levels increased with IR (p = 0.024). Baseline beta-hydroxybutyrate levels were highest in the Q4 and showed the greatest absolute decrease during the eOGTT, compared to Q1 (p < 0.001 for both). Conclusions: We validated established IR markers in children with obesity, while demonstrating that eOGTT may offer improved characterization and earlier identification of those at risk for metabolic complications.
Ključne besede: insulin resistance, oral glucose tolerance test, OGTT, metabolic complications, screening, children, adolescents, obesity
Objavljeno v DiRROS: 11.11.2025; Ogledov: 216; Prenosov: 95
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Povzetek: Stainless steel forms a native film of mixed metal oxides, and organic impurities are likely to adsorb on the surface upon exposure to ambient conditions. For many applications, oxides and impurities should be removed, and several techniques have been used for decades. An innovative method is presented in this paper. The organic impurities were oxidized using a water solution of 1 M peroxynitric acid (PNA). Stainless steel samples were immersed in the solution, and the oxidation of organic impurities was evaluated by the ultra-thin depth profiling using secondary ion mass spectrometry (SIMS). A minute of treatment with PNA caused oxidation of organic impurities and a decrease in the SIMS CN– signal over an order of magnitude. Prolonged treatment caused the selective removal of the native iron oxide film, leaving a protective film of chromium oxide. Removal of the iron oxide film was also observed when stainless steel was treated with 1 M HNO3. The PNA method is useful for routine cleaning of stainless steel to remove the organic contaminants from the surface and keep the passive chromium oxide film intact. It is ecologically friendly and enables rapid decomposition of the traces of organic impurities likely to be adsorbed on the metallic surfaces.
Ključne besede: peroxynitric acid, surface modifications, secondary ion mass spectrometry
Objavljeno v DiRROS: 11.11.2025; Ogledov: 173; Prenosov: 86
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Objavljeno v DiRROS: 11.11.2025; Ogledov: 135; Prenosov: 100
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Povzetek: Spatial encoding in MRI is usually performed using gradient coils that produce a linearly increasing magnetic field Bz in a desired spatial direction such that its gradient is constant. However, it has been shown that spatial encoding in MRI can also be performed with coils that produce nonlinear magnetic fields. In this study, the performance of different types of nonlinear encoding coils, which have a simple design based on the use of a straight wire segment as a building block and a source of a highly nonlinear magnetic field, was experimentally tested in 2D and by simulation in 3D on coils with a nonsymmetric and a symmetric arrangement of these wire segments. All images were reconstructed using our newly presented method, in which the signals are first transformed from the time- to the frequency-domain, yielding a distorted image (spectrum), which is then geometrically and intensity corrected. The quality of the reconstructed images was quantified by comparing them with corresponding reference images obtained with conventional gradient coils. The reconstruction method was accurate for all tested encoding coils and showed that the symmetric coil type produced results that required significantly less corrections compared to the nonsymmetric coil type. Quantitative image quality measurements showed that all encoding coils, despite large differences in the magnetic field of the encoding coils, produce images of similar quality. The results of the study may help advance the design of “gradient” coils towards freer geometries, higher magnetic field gradients or lower inductance and thus faster switching times.
Ključne besede: spatial signal encoding, gradient coils, k-space, nonlinear coils, image reconstruction
Objavljeno v DiRROS: 11.11.2025; Ogledov: 195; Prenosov: 86
Celotno besedilo (4,92 MB)
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Ključne besede: dietary survey, dietary intake, energy, macronutrients, 24-h recall, FPQ, adults, elderly, Slovenia
Objavljeno v DiRROS: 11.11.2025; Ogledov: 202; Prenosov: 86
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