Search

Objective: To study the effects of dietary fibers with different structures on calcium balance and biomechanical properties. Methods: Rats were fed a basal diet supplemented with 50 g/kg wheat bran, cellulose, xylan, pectin, inulin, konjac gum or their mixture. The contents of calcium in diets, feces, urine and femur were detected by atomic absorption spectrometry (AAS). The levels of total calcium, free calcium and bound calcium in serum were measured by an electrolyte analyzer. The maximum load of femur was measured by a three-point bending method. The effects of different dietary fibers on calcium absorption, blood calcium level, urinary calcium loss, calcium retention, bone calcium content and bone biomechanical properties were compared. Results: The calcium absorption rates in the wheat bran and cellulose supplementation groups were higher than those in the xylan, pectin, inulin and konjac supplementation groups, and the difference between the xylan and konjac supplementation groups and the wheat bran supplementation group was significant (P 0.05), but the concentrations of bound calcium and total calcium in the wheat bran supplementation group were higher than those in the other groups. The bone calcium content and bone biomechanical properties in the pectin supplementation group were significantly lower than those in the other groups, and the maximum load of femur was the highest in the xylan supplementation group. Conclusion: The intestinal calcium absorption of low fermentable dietary fibers such as wheat bran and cellulose is higher than that of high fermentable dietary fibers such as xylan, pectin, inulin and konjac. Xylan can improve the biomechanical properties of rat bones. Different dietary fibers have different effects on calcium absorption, bone calcium content and calcium balance in rats.

Litchi pericarp is rich in polyphenols, and demonstrates significant biological activity. This study assessed the therapeutic effects of litchi pericarp extract (LPE) on type 2 diabetes mellitus in db/db mice. The results showed that LPE ameliorated symptoms of glucose metabolism disorder, oxidative stress, inflammatory response, and insulin resistance in db/db mice. The mechanistic studies indicated that LPE activates adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and suppresses the protein expression of phosphoenolpyruvate carboxykinase (PEPCK), thereby reducing hepatic gluconeogenesis. Additionally, LPE facilitates the translocation of nuclear factor erythroid2-related factor 2 (Nrf2) into the cell nucleus, initiating the transcription of antioxidant factors superoxide dismutase (SOD) and NAD(P)H: quinone oxidoreductase 1 (NQO1), which alleviate oxidative stress and reduce oxidative damage. Furthermore, LPE blocks nuclear factor kappa-B (NF-κB) nuclear translocation and subsequent inflammatory response initiation, thereby reducing inflammation. These findings indicate that LPE addresses type 2 diabetes mellitus by activating the AMPK energy metabolic pathway and regulating the Nrf2 oxidative stress and NF-κB inflammatory signaling pathways. [ABSTRACT FROM AUTHOR]

Quantum excitation is usually regarded as a transient process occurring instantaneously, leaving the underlying physics shrouded in mystery. Recent research shows that Rydberg-state excitation with ultrashort laser pulses can be investigated and manipulated with state-of-the-art few-cycle pulses. We theoretically find that the efficiency of Rydberg state excitation can be enhanced with a short laser pulse and modulated by varying the laser intensities. We also uncover new facets of the excitation dynamics, including the launching of an electron wave packet through strong-field ionization, the re-entry of the electron into the atomic potential and the crucial step where the electron makes a U-turn, resulting in twin captures into Rydberg orbitals. By tuning the laser intensity, we show that the excitation of the Rydberg state can be coherently controlled on a sub-optical-cycle timescale. Our work paves the way toward ultrafast control and coherent manipulation of Rydberg states, thus benefiting Rydberg-state-based quantum technology. [ABSTRACT FROM AUTHOR]