Nanoimprinting and backside ultraviolet lithography for fabricating metal nanostructures with higher aspect ratio.

This paper introduces an innovative approach to increasing the aspect ratio of metal nanostructures fabricated using nanoimprint lithography (NIL). Although conventional NIL and metal lift-off processes can fabricate metal nanostructures, the achievable aspect ratio is often limited by the inherent constraints of NIL. In this study, we demonstrate that for an ultraviolet (UV) transparent substrate, metal nanostructures patterned via NIL can serve as a photomask. A negative-tone photoresist (PR) layer was then deposited on top of the patterned metal nanostructures. By illuminating the substrate from the backside with UV light and subsequently developing the PR, PR structures complementary and self-aligned to the metal layer were obtained. This enabled a second round of metal deposition and lift-off, thereby increasing the height of the metal structures and enhancing the aspect ratio. Experimentally, we demonstrated that this method can improve the aspect ratio from less than 1.0 to as high as 2.1. This paper also addresses the further developments and potential applications of this technique.

Synthesis of 2-(pyridylvinyl)chromen-4-ones and their N-oxide analogs for assessment of their biological activities as anticancer agents.

2-Styrylchromones have been shown to possess a broad spectrum of biological activities. Replacing the carbon atom in 2-styrylchromones with a nitrogen atom in the benzene rings forms 2-(pyridylvinyl)chromen-4-ones (aza-2-styrylchromones). We have synthesized a series of novel 2-(pyridylvinyl)chromen-4-ones and their pyridine N-oxides to evaluate them as potential anticancer agents against human non-small-cell lung cancer cells (A549). Among the 18 synthesized molecules, compounds 18 and 8a exhibited comparable inhibitory effects to 5-fluorouracil and showed no toxicity against normal cells.

Synthesis of selenophene-containing flavonols and 2-styrylchromones: Evaluation of their activities compared with selenophene-containing chalcones as potential anticancer agents.

Previously, we documented the synthesis and assessed the biological effects of chalcones containing selenium against HT-29 human colorectal adenocarcinoma cells, demonstrating their significant potential. As research on selenium-containing flavonoids remains limited, this article outlines our design and synthesis of three selenium-based flavonols and three 2-styrylchromones. We conducted evaluations of these compounds to determine their impact on human lung cancer cells (A549, H1975, CL1-0, and CL1-5) and their influence on normal lung fibroblast MRC5 cells. Additionally, we included selenium-based chalcones in our testing for comparative purposes. Our findings highlight that the simplest compound, designated as compound 1, exhibited the most promising performance among the tested molecules.

[Preliminary Experimental Study of Establishing a Lung Development Model with Specific Pathogen Free Preterm Pigs].

OBJECTIVE: To determine the best time for conducting cesarean section for the establishment of an animal model of lung development with specific pathogen free (SPF) preterm Bama minipigs under the condition of not making medical interventions such as hyperoxia, mechanical ventilation, or medication. METHODS: SPF Bama sows at gestational day (GD) 113, GD107, GD104, GD101, and GD98 were selected and cesarean sections were performed. Then, the viability of the preterm piglets were observed. Based on their general data, viability, and paraffin sections stained with hematoxylin and eosin, the best time for performing cesarean section in order to build a SPF preterm pig model of lung development was determined. RESULTS: Cesarean sections were performed on a total of 7 sows and 55 piglets were delivered, among which 25 were still alive 3 hours after delivery. Seven piglets of GD104 and all piglets of GD107 and GD113 survived, while piglets of GD98 and GD101 all died. The survival rate of piglets of GD104 was 33.33% (7/21). Piglets of GD98 already possessed fully developed physical appearance and lung shape. Piglets from GD104 had better lung expansion and higher density of thin-walled alveoli. The lungs of GD107 piglets were basically fully expanded, and the density of thin-walled alveoli was almost the same as that of normal full-term piglets. CONCLUSIONS: Findings of this study suggest that SPF preterm piglets of GD104 with no specific pathogen exposure and no medical intervention can be used to establish a SPF preterm pig model of lung development.