RESUMEN
In this study, we introduce an innovative photoacoustic frequency shift (PAFS) technique for hydrogen (H2) detection, complemented by both theoretical models and practical experiments. To mitigate cross-sensitivity, we analyzed the sound speeds of six different gases, confirming minimal interference with H2 due to significant velocity disparities. Central to our approach is the design of a miniaturized step-added T-type Photoacoustic Cell (PAC), with parameters meticulously optimized for enhanced performance. Using COMSOL Multiphysics' Thermal Viscous Acoustics module, we conducted simulations to evaluate the quality factor and acoustic pressure, both crucial for the sensor's efficiency. Additionally, we assessed the system's stability, influenced by gas flow, through gas velocity distribution analyses using the Computational Fluid Dynamics module. Experimental investigations focused on the system's sensing performance, revealing a distinct frequency shift of â¼45 Hz for every 1 % change in H2 concentration, with a high linear correlation (R2 = 0.99825). The system's response and recovery times were measured at 1.09 s and 1.25 s, respectively. Long-term stability, evaluated over 3000 s using Allan deviation, indicated a minimum detection limit (MDL) of 102.47 ppm at an integration time of 375 s. These findings validate the efficacy of the step-added T-type PAC in H2 detection.
RESUMEN
Circular RNAs (circRNAs) are implicated in the tumorigenesis of human cancers. However, the effects of circRNAs on laryngeal squamous cell carcinoma (LSCC) are largely unknown. Here, we aimed to explore the roles of circ_0023028 in LSCC development. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to measure circ_0023028, miR-486-3p, and Lin-Isl-Mec (LIM) and SH3 domain protein 1 (LASP1) mRNA. The characteristics of circ_0023028 were determined by RNase R digestion assay and Actinomycin D assay. Cell Counting Kit-8 (CCK-8) assay and colony formation assay were utilized for cell proliferation. Transwell assay was adopted for cell invasion and migration. Flow cytometry analysis was carried out to analyze cell cycle and apoptosis. RNA pull-down assay and dual-luciferase reporter assay were used to explore the association between miR-486-3p and circ_0023028 or LASP1. Western blot assay was adopted to measure LASP1 protein level. Murine xenograft model was executed to investigate the function of circ_0023028 in vivo. High expression of circ_0023028 was observed in LSCC tissues and cells. Circ_0023028 was stable and possessed a loop structure. Circ_0023028 silencing suppressed LSCC cell proliferation, metastasis and cell cycle process and induced apoptosis in vitro and hampered tumor growth in vivo. Further mechanism analysis demonstrated that circ_0023028 could sponge miR-486-3p to regulate LASP1 expression in LSCC cells. The malignant behaviors of LSCC cells mediated by circ_0023028 knockdown were rescued by the inhibition of miR-486-3p. Moreover, miR-486-3p suppressed LSCC cell progression via binding to LASP1. Circ_0023028 knockdown might impede the progression of LSCC by regulating miR-486-3p/LASP1 axis, which could provide a novel insight on the mechanism of LSCC progression.