Investigation of the Nonlinear Optical Properties of Silk Fibroin (SF) Using the Z-Scan Method.

Silk fibroin (SF), the primary protein in silkworm silk, has emerged as a promising organic nonlinear optical material due to its unique combination of optical transparency, biocompatibility, and environmental sustainability. In this study, we investigate the nonlinear optical properties of SF thin films using the -scan technique with femtosecond laser pulses (35 fs, 800 nm, 1 kHz). Our results reveal a strong self-defocusing effect (negative nonlinear refractive index) and significant multiphoton absorption, demonstrating SF's tunable nonlinear response.

Micro-CT Assessment of Heat and Vibration Effect on Sealant Penetration in Different Fissure Types.

Purpose: To make micro-CT comparison and evaluation of sealant penetration depth in different types of fissures after heating of the material or application of vibrations.

Materials And Methods: One hundred sound third molars have been sealed as follows: group 1 (n = 20), light-cured resin sealant at room temperature, group 2 (n = 20), light-cured resin sealant, preheated to 41.0°C, group 3 (n = 20), light-cured resin sealant, preheated to 51.

Unravelling hidden text and figures in paper-based archival documents with micro-spatially offset Raman spectroscopy imaging.

The preservation of paper-based archival documents is crucial for safeguarding historical and cultural heritage. Some records possess visually inaccessible text or images because of previous conservation measures, their method of construction, or historic damage. Micro-spatially Offset Raman Spectroscopy (micro-SORS) has emerged as a promising method for probing below or through opaque material substrates non-invasively.

Dual-Function Femtosecond Laser: β-TCP Structuring and AgNP Synthesis via Photoreduction with Azorean Green Tea for Enhanced Osteointegration and Antibacterial Properties.

β-Tricalcium phosphate (β-TCP) is a well-established biomaterial for bone regeneration, highly regarded for its biocompatibility and osteoconductivity. However, its clinical efficacy is often compromised by susceptibility to bacterial infections. In this study, we address this limitation by integrating femtosecond (fs)-laser processing with the concurrent synthesis of silver nanoparticles (AgNPs) mediated by Azorean green tea leaf extract (GTLE), which is known for its rich antioxidant and anti-inflammatory properties.

The effect of citric acid on mineralisation and vascular endothelial growth factor secretion from apical papilla stem cells.

Objective: To investigate the influence of citric acid on the osteogenic and angiogenic potential of stem cells from apical papillae (SCAPs).

Materials And Methods: Stem cells from apical papillae were isolated from freshly extracted third permanent molars. These cells were treated with 20 and 100 μM citric acid.