By controlling the 800 nm fs laser energy and applying an isopropyl alcohol environment, controlled sub-diffraction limited lithography with a characteristic structure of approximately 30 nm was achieved on the surface of diamond films, and diamond gratings with a period of 200 nm were fabricated. The fabrication of single grooves with a feature size of 30 nm demonstrates the potential for patterning periodic or nonperiodic structures, and the fabrication of 200 nm periodic grating structures demonstrates the ability of the technique to withstand laser proximity effects. This enhances the technology of diamond film nanofabrication and broadens its potential applications in areas such as optoelectronics and biology.
View Article and Find Full Text PDFIn this study, the time-spatial evolution of single-pulse femtosecond laser-induced plasma in sapphire is studied by using femtosecond time-resolved pump-probe shadowgraphy. Laser-induced sapphire damage occurred when the pump light energy was increased to 20 µJ. Based on its shadowgraphy image, the threshold electron density can be estimated to be about 2.
View Article and Find Full Text PDFPurpose: Chemotherapy treatments for cancer are always accompanied by a low concentration of drug delivered in the tumor area and severe side effects including systemic toxicity. Improving the concentration, biocompatibility, and biodegradability of regional chemotherapy drugs is a pressing challenge in the field of materials.
Methods: -Phenyloxycarbonyl-amino acids (NPCs) which exhibit significant tolerance to nucleophiles, such as water and hydroxyl-containing compounds, are promising monomers for the synthesis of polypeptides and polypeptoids.
Despite the great promise initially demonstrated by photothermal ablation (PTA) therapy, its inability to completely ablate large tumors is problematic, because this has been found to result in residual tumors at ablation margins and bring a relative high rate of subsequent recurrences and metastases. To address this issue, we herein report a smart photothermal nanosystem (PBM) based on FDA-approved Prussian blue (PB) nanoparticles, doped with Mn (III) to suppress the tumor debris left by incomplete ablation. Notably, our study demonstrated that PTA-induced hyperthermia plays a crucial role in initiating the cGAS-STING pathway by generating damaged cytosolic DNA.
View Article and Find Full Text PDFA simple method of fabricating (- (PMN-PT) deep grooves with high aspect ratios using an 800-nm femtosecond laser with chemical-selective etching is demonstrated. The 567-µm-deep grooves with aspect ratios of approximately 35 were obtained with no cracks or thermal affected zone. The morphologies and chemical compositions of grooves were analyzed by a scanning electron microscope with an energy dispersive x-ray spectrometer.
View Article and Find Full Text PDFIt is significant and challenging to use CO to produce polymeric materials, especially with olefins. Here, a novel strategy named "scrambling polymerizations" is designed and performed for the copolymerization of a CO -and-1,3-butadiene-derived valerolactone, 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one (EVL), with ϵ-caprolactone (CL) to prepare polyesters. Anionic ring-opening polymerization of CL and conjugated addition oligomerization of EVL take place individually to form PCL and EVL oligomers, respectively.
View Article and Find Full Text PDFPolysarcosine (PSar), a water-soluble polypeptoid, is gifted with biodegradability via the random ring-opening copolymerization of sarcosine- and alanine--thiocarboxyanhydrides catalyzed by acetic acid in controlled manners. Kinetic investigation reveals the copolymerization behavior of the two monomers. The random copolymers, named PaS, with high molecular weights between 5.
View Article and Find Full Text PDFInt J Nanomedicine
March 2022
Purpose: To develop an iron-based solid lipid nanoparticle (SLN) absorbable by the intestinal wall and assess the differential diagnostic value of intestinal lesions in magnetic resonance imaging (MRI).
Methods: SLNs were prepared with the simultaneous loading of trivalent Fe ions (Fe), levodopa methyl ester (DM), and fluorescein isothiocyanate (FITC). We evaluated the particle size, loading rate, encapsulation efficiency, and cytotoxicity of SLNs.
In this study, transient temporal-spatial evolutions of femtosecond (fs) laser pulse-induced filaments and electronic plasma when laser induced damage occurred in fused silica were investigated using fs time-resolved pump-probe shadowgraphy. The transient peak electron density increased and then decreased as delay time of probe beam increased. Its corresponding spatial positions moved from the sample surface to the inside of the sample, but remained at the nonlinear focus for a relatively long time.
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