Localized Nanoindentation Paradigm for Revealing Sutured Tissue Interface Mechanics and Integrity.

This study investigates the nanoindentation technique to elucidate the quasi-static and dynamic stress response at the wounded and sutured tissue interface. In vitro modeling and wound healing analysis enable an understanding of sutured tissue interface integrity, modulus, and stability using an artificial abdominal wall model. Sutured tissues with simple interrupted suturing (SIS) demonstrated a 35-40% higher modulus than simple continuous suturing (SCS). High-density suturing with a suture space of 2.5 mm exhibited a 2-fold higher modulus than low-density suturing with a suture space of 5 mm. The elastic modulus of the sutured pad immersed in deionized water was ∼70-95% of the dry condition. The dynamic stress data indicate that long-term body motions-triggered stress instability at the wound interface was affected by suturing style and density. The pivotal factors determining wound healing are quasi-static and dynamic modulus at the sutured interface, which is intimately associated with patient pain, wound complications, healing speed, and blood flow. The proposed method and data are an original approach to addressing wound healing, contributing to patient well-being and identifying, interpreting, and breaking the drawn-out debates in the suturing field.

Room-Temperature Spray Deposition of Large-Area SnO2 Electron Transport Layer for High Performance, Stable FAPbI3 -Based Perovskite Solar Cells.

The performance and scalability of perovskite solar cells (PSCs) is highly dependent on the morphology and charge selectivity of the electron transport layer (ETL). This work demonstrates a high-speed (1800 mm min-1 ), room-temperature (25 °C-30 °C) deposition of large-area (62.5 cm2 ) tin oxide films using a multi-pass spray deposition technique. The spray-deposited SnO2 (spray-SnO2 ) films exhibit a controllable thickness, a unique granulate morphology and high transmittance (≈85% at 550 nm). The performance of the PSC based on spray-SnO2 ETL and formamidinium lead iodide (FAPbI3 )-based perovskite is highly consistent and reproducible, achieving a maximum efficiency of ≈20.1% at an active area (A) of 0.096 cm2 . Characterization results reveal that the efficiency improvement originates from the granular morphology of spray-SnO2 and high conversion rate of PbI2 in the perovskite. More importantly, spray-SnO2 films are highly scalable and able to reduce the efficiency roll-off that comes with the increase in contact-area between SnO2 and perovskite film. Based on the spray-SnO2 ETL, large-area PSC (A = 1.0 cm2 ) achieves an efficiency of ≈18.9%. Furthermore, spray-SnO2 ETL based PSCs also exhibit higher storage stability compared to the spin-SnO2 based PSCs.