Free fatty acids (FFAs) participate in a variety of physiological functions. FFAs are associated with the development of type 2 diabetes mellitus (T2DM). Uyghurs and Kazaks have a different prevalence of T2DM, which cannot be explained by traditional risk factors. This study aimed to examine FFAs as potential biomarkers to distinguish between healthy and T2DM Uyghurs and Kazaks. This was a prospective study conducted at the Xianjiang Medical University from 01/2007 to 06/2010 in Uyghurs and Kazaks. The subjects were grouped as T2DM patients (Uyghurs: n=39; Kazaks, n=21) and controls (Uyghurs: n=35; Kazaks, n=40). Gas chromatography-mass spectrometry (GC-MS) and partial least squares discriminant analysis (PLS-DA) models were used to study the FFA profiles between Uyghurs and Kazaks with T2DM. PLS-DA analysis showed that among Kazaks, T2DM patients had lower C22:6, C18:3 n-6, and C20:3 n-6, but higher C22:0 levels compared with controls. Among Uyghurs, the most important variables to discriminate T2DM patients from controls were higher C22:6 and C20:4 n-6, and lower C22:0, C14:1, C18:3 n6, and C20:3 n6. Kazaks and Uyghurs displayed different FFA profiles between patients with T2DM and controls. These results suggest different risk factors and pathogenesis of T2DM between Kazaks and Uyghurs.

The transport and retention behavior of microplastics (MPs) in saturated porous media is a hot issue in the fields of ecological security and public health in contemporary society. In this study, the transport and retention behaviors of polystyrene microplastics (PS-MPs) in saturated porous media were systematically investigated under various environmental conditions, including humic acid (HA) concentration, ionic strength (IS), mass fraction of iron oxyhydroxide coated quartz sand (ω), and pH in the presence of HA. A series of column experiments were conducted, and all breakthrough curves and retention profiles were successfully simulated using a two kinetic sites attachment-detachment model (TKSADM) that distinguishes between chemical adsorption (Site 1) and physical retention (Site 2). Results demonstrated that increasing HA concentration from 1 to 10 mg L⁻¹ enhanced PS-MP transport, which was attributed to HA adsorption creating steric hindrance and enhancing electrostatic repulsion. In contrast, HA conditions, increasing IS from 0.1 to 100 mM progressively suppressed MP transport, with model parameters revealing a dramatic 30-fold increase in physical retention rate (k_att2) and a 2.8-fold increase in chemical adsorption capacity (S_max1/C₀), reflecting the dual role of IS in compressing the electrical double layer and inducing HA conformational collapse. Increasing the mass fraction of iron oxyhydroxide coated quartz sand (ω from 0.15 to 0.75) substantially inhibited PS-MP transferability, with both chemical adsorption rate (k_att1) and physical retention rate (k_att2) increasing by 57% and 83%, respectively, accompanied by a 79% increase in S_max1/C₀. This balanced enhancement reflects the dual role of iron oxyhydroxide coatings: increased surface roughness creating physical straining sites and Fe–OH groups providing abundant reactive sites for specific adsorption. Increasing pH from 6.0 to 10.0 substantially enhanced MP mobility, with all retention – related parameters decreasing monotonically: k_att1 decreased by 34%, k_att2 decreased by 52%, and S_max1/C₀ exhibited the most dramatic decline (71%), revealing a “pH-switching effect” on physical retention sites – activated at low pH and deactivated at high pH due to enhanced electrostatic repulsion and HA conformational extension. This study provides quantitative mechanistic insights into MP fate in subsurface environments and underscores the need to consider coupled effects of multiple environmental factors when predicting MP transport behavior.