Polycystic ovary syndrome (PCOS) involves complex genetic, metabolic, endocrine, and environmental factors. This study explores the effects of nicotinamide mononucleotide (NMN) in a letrozole-induced PCOS mouse model, focusing on metabolic regulation. Letrozole-induced aromatase inhibition elevated androgen and reduced bile acid levels, linking liver dysfunction and gut imbalance to PCOS. Letrozole-treated mice exhibited disrupted estrous cycles, ovarian congestion, and elevated testosterone. NMN intervention alleviated hyperandrogenism, ovarian abnormalities, and bile acid decline but did not fully restore the estrous cycle or improve lipid profiles. Metabolomic analysis showed that NMN partially reversed bile acid and lipid metabolism disturbances. These findings highlight NMN’s protective role in reducing hyperandrogenism and ovarian cyst formation. However, effective PCOS treatment should target liver and gut metabolism, not just ovarian symptoms, to mitigate systemic effects. Bile acid dysregulation may play a key role in PCOS progression and warrants further investigation.

Overcoming high draft forces has long been a primary challenge in conventional subsoiling. To better utilize this agronomically advantageous technique, it is necessary to substantially reduce the draft. Inspired by the digging behaviors of fossorial animals, a low-draft up-cutting subsoiling method was proposed in this study. Discrete element method (DEM) simulations were employed to study the draft-reducing performance of up-cutting tools compared with regular tools. The results showed that the up-cutting motion reduced the draft by 63.07%, 63.84%, and 58.92%, respectively, at rake angles of 45°, 60°, and 75%, and by 79.73%, 63.84%, and 45.22%, respectively, at advancement velocities of 0.5 m·s⁻¹, 1 m·s⁻¹, and 1.5 m·s⁻¹. An increase in up-cutting velocity reduces the draft. Soil disturbance, particle velocity distribution, and soil deformation and movement patterns change in ways that contribute to this reduction. The draft-reducing performance of a chain subsoiler developed based on the principle of soil-breaking by animal digging was verified using field tests, exhibiting a draft-reduction amplitude approaching or greater than 30%. This study shows the great application potential of the up-cutting method in reducing subsoiling drafts and provides a theoretical basis for future research.