Phycobiliproteins have gained increasing attention for their antidiabetic potential, yet the specific bioactive peptides and their targets and molecular mechanisms have remained unclear. In this study, four peptides with potential hypoglycemic activity were identified through virtual screening. Network pharmacology was employed to elucidate their hypoglycemic mechanism in the treatment of T2DM. A subsequent in vitro assay confirmed that the synthesized peptides, GR-5, SA-6, VF-6, and IR-7, exhibited significant inhibitory activity against α-glucosidase and DPP-IV. In insulin-resistant HepG2 models, all four peptides exhibited no cytotoxicity. Among them, GR-5 demonstrated the most promising therapeutic potential by remarkably enhancing cellular glucose consumption capacity. Furthermore, GR-5 administration substantially increased glycogen synthesis and enzymatic activities of hexokinase and pyruvate kinase with statistically significant improvements compared to the control groups. This study provides novel peptide candidates for T2DM treatment and validates an integrative strategy for targeted bioactive peptide discovery, advancing the development of algal protein-based therapeutics.

Objectives: To examine the joint association of hydration status and sleep quality with prevalent type 2 diabetes mellitus (T2DM) and to quantify their additive and multiplicative interactions. Methods: This cross-sectional study included 4762 participants from the baseline Hainan Prospective Cohort Study. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the four combinations of hydration status and sleep quality. Additive interaction was assessed with the relative excess risk due to interaction (RERI), the attributable proportion (AP), and the synergy index (S); multiplicative interaction was assessed with a product term. Predicted probabilities were estimated by g-computation. Results: The prevalence of T2DM was 8.13% (387/4762). Compared with non-dehydration and good sleep quality, the combination of dehydration and poor sleep quality was associated with substantially higher odds of prevalent T2DM (adjusted OR 9.92, 95% CI 7.14 to 14.00). All three additive interaction measures were statistically significant (RERI 7.74, 95% CI 4.99 to 10.50; AP 78.04%, 95% CI 69.28 to 86.80; S 7.57, 95% CI 3.49 to 16.42), as was the multiplicative interaction (OR 3.96, 95% CI 2.30–6.90). On the absolute risk scale, the interaction contrast was 14.53 percentage points (95% CI: 11.01 to 18.34), with an attributable proportion of 80.5% (95% CI: 66.3 to 94.6) and a synergy index of 5.14 (95% CI: 2.94 to 17.25). The predicted probability of prevalent T2DM was highest in the combined dehydration and poor sleep group. Conclusions: The combination of dehydration and poor sleep quality was associated with higher odds of prevalent T2DM than either condition alone, and a statistically significant additive interaction was observed. Because these additive interaction measures were derived from odds ratios for a non-rare outcome, their absolute magnitude may be overestimated on the odds-ratio scale; the risk-difference-scale measures confirmed the interaction. Given the cross-sectional design, reverse causation cannot be excluded, and longitudinal data are needed to clarify the temporal sequence of these associations.

Olivine-type LiFePO₄ is a promising cathode candidate for lithium-ion batteries. In this study, undoped and a series of Co-substituted Li_xCoᵧFePO₄ (x = 0.85–1.00, y = 0–0.15) nanocomposites were synthesised by sol–gel auto-combustion using organic–inorganic hybrid xerogel precursors. The effects of sol pH, calcination temperature, calcination holding time and Co²⁺-doping content on crystal structure, phase composition, crystallinity, particle morphology, magnetic-hysteresis performance and Fe valence-state distribution were systematically explored using TG-DTA, XRD, FT-IR, SEM, VSM and Mössbauer spectroscopy. XRD analyses reveal that intermediate-pH conditions (pH 6.5–7.5) readily produce crystalline impurities including LiFeO₂ and Fe₂O₃, whereas high-pH environments (pH 8.5–9.5) facilitate the formation of pure-phase olivine-structured products. Diffraction-peak sharpness increases with rising calcination temperature, indicating improved crystallinity, and the samples treated at 800 °C exhibit the sharpest diffraction signals. As the doping level increases, the (311) diffraction peak first shifts toward lower and then higher angles; correspondingly, the unit-cell volume first increases to a maximum and then declines, whereas the crystallite size varies non-monotonically, confirming that Co doping predominantly modifies the lattice geometry. For the heavily doped Li_0.85Co_0.15FePO₄, carbothermal reduction induced by excessive thermal treatment (T > 700 °C or extended holding) yields a secondary phosphide phase that is tentatively indexed as Co₂P from two weak reflections. Within the Co-substituted series, the 700 °C—10 h condition gives a single-phase product with the highest saturation magnetisation (Ms = 3.45 emu·g⁻¹), which decreases to 2.07 emu·g⁻¹ at 800 °C. VSM results demonstrate a decoupling between the saturation magnetisation (Ms) and the coercivity (Hc); the weak ferromagnetic hysteresis observed in all samples signals trace ferromagnetic secondary phases—most plausibly amorphous or nanoscale products of xerogel thermal decomposition that lie below the XRD detection limit—rather than indicating phase purity; this attribution is indirect and is critically assessed below. Mössbauer spectroscopy validates the coexistence of dominant high-spin Fe²⁺ and minor Fe³⁺ species within the samples. High-level Co substitution (y = 0.15) lowers the relative proportion of the Fe³⁺ impurity species to 7.2% and alters the local Fe coordination environments without generating magnetically ordered sextet components. This work demonstrates that the sol–gel-derived hybrid xerogel is a tunable platform for fabricating phosphate-based battery nanocomposites and provides insights for the gel-precursor-directed design of energy-storage functional materials.