We present absolute line center frequencies for 24 fundamental ν3 ro-vibrational P-branch transitions near 4.5 μm in N2O with an absolute expanded (multiplied by 2) frequency uncertainty of 800 kHz. The spectra are acquired with a swept laser spectrometer consisting of an external-cavity quantum cascade laser whose instantaneous frequency is continuously tracked against a near-infrared frequency comb. The measured absorbance profiles have a well-calibrated frequency axis, and are fitted to determine absolute line center values. We discuss the main sources of uncertainty.
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http://dx.doi.org/10.1364/OE.21.001020 | DOI Listing |
J Struct Biol
December 2024
Advanced Research Institute, Institute of Science Tokyo, 1-5-45 Yushima Bunkyo-ku 113-8510, Tokyo, Japan. Electronic address:
Lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are bioactive lysophospholipids derived from cell membranes that activate the endothelial differentiation gene family of G protein-coupled receptors. Activation of these receptors triggers multiple downstream signaling cascades through G proteins such as Gi/o, Gq/11, and G12/13. Therefore, LPA and S1P mediate several physiological processes, including cytoskeletal dynamics, neurite retraction, cell migration, cell proliferation, and intracellular ion fluxes.
View Article and Find Full Text PDFMicrosyst Nanoeng
December 2024
College of Optical and Electronic Technology, China Jiliang University, Hangzhou, 310018, China.
Metasurface with natural static structure limits the development of dynamic metasurface holographic display with rapid response and broadband. Currently, liquid crystal (LC) was integrated onto the metasurface to convert the passive metasuface into an active one. But, majority of LC-assisted active metasurfaces often exhibit trade-offs among degree of freedom (DoF, typically less than 2), information capacity, response speed, and crosstalk.
View Article and Find Full Text PDFPhotoacoustics
February 2025
Dipartimento di Scienze di Base ed Applicate per l'Ingegneria, Sapienza Università di Roma, Rome 00161, Italy.
A compact and robust optical excitation photoacoustic sensor with a self-integrated laser module excitation and an optimized differential resonator was developed to achieve high sensitivity and full linear range detection of carbon dioxide (CO) based on dual modes of wavelength modulated photoacoustic spectroscopy (WMPAS) and resonant frequency tracking (RFT). The integrated laser module equipped with three lasers (a quantum cascade laser (QCL), a distributed feedback laser (DFB) and a He-Ne laser) working in a time-division multiplexing mode was used as an integrated set of spectroscopic sources for detection of the designated concentration levels of CO. With the absorption photoacoustic mode, the WMPAS detection with the QCL and DFB sources was capable of CO detection at concentrations below 20 %, yielding a noise equivalent concentration (NEC) as low as 240 ppt and a normalized noise equivalent absorption coefficient (NNEA) of 4.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China.
Cuproptosis that utilizes copper ionophore to induce programmed cell death holds promise for enhancing the effectiveness of conventional anticancer therapies and triggering efficient adaptive immune responses. However, the non-tumor-specific release of Cu ions can induce cuproptosis and cause irreversible damage to normal tissues. To maximize the therapeutic effects of tumor-specific cuproptosis, this work reports for the first time the regulation of degradation behaviors of Cu-based nanomaterials using graphene quantum dots (GQDs) as a protection layer.
View Article and Find Full Text PDFJ Phys Chem Lett
December 2024
Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 841051, Israel.
Triplet 1,4-spiro[2.4]heptadiyl () has been shown experimentally to undergo rapid ring-opening and subsequent 1,2-hydrogen shift upon generation via photolysis of a diazene precursor at cryogenic temperatures. Modern computational tools elucidate the potential energy surface and kinetics behind this cascade reaction, disproving the earlier hypothesized mechanism invoking hot molecule effects in the first ring-opening step and tunneling in the second hydrogen transfer step.
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