We demonstrate a gas spectroscopy technique, using self-mixing in a 3.4 terahertz quantum-cascade laser (QCL). All previous QCL spectroscopy techniques have required additional terahertz instrumentation (detectors, mixers, or spectrometers) for system pre-calibration or spectral analysis. By contrast, our system self-calibrates the laser frequency (i.e., with no external instrumentation) to a precision of 630 MHz (0.02%) by analyzing QCL voltage perturbations in response to optical feedback within a 0-800 mm round-trip delay line. We demonstrate methanol spectroscopy by introducing a gas cell into the feedback path and show that a limiting absorption coefficient of ∼1×10 cm is resolvable.
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http://dx.doi.org/10.1364/OL.43.002225 | DOI Listing |
Phytomedicine
December 2024
Scabies Laboratory, Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; School of Biomedical Sciences, University of Queensland, St Lucia, Brisbane, QLD, Australia. Electronic address:
Background: Scabies is a debilitating and neglected infectious disease with limited effective treatment options and affecting millions of people worldwide, mainly in poor and overcrowded settings. Essential oils from Australasian Myrtaceae are known to have parasiticidal properties, often attributed to the presence of β-triketones, which are known inhibitors of the tyrosine catabolism pathway through inhibition of hydroxyphenylpyruvate dioxygenase (HPPD).
Purpose: In this study, essential oils from mānuka (Leptospermum scoparium) were evaluated in vitro for miticidal and ovicidal activities and their active β-triketone constituents (flavesone, leptospermone, and isoleptospermone) were identified.
Anal Chem
January 2025
Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China.
Detection of trace gases, such as radioactive carbon dioxide, clumped isotopes, and reactive radicals, is of great interest and poses significant challenges in various fields. Achieving both high selectivity and high sensitivity is essential in this context. We present a highly selective molecular spectroscopy method based on comb-locked, mid-infrared, cavity-enhanced, two-photon absorption.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China.
Vinylene-linked Covalent Organic Frameworks (V-2D-COFs) are a class of promising porous organic materials that feature fully π-conjugated structures, high crystallinity, ultrahigh chemical stability, and extraordinary optoelectronic properties. However, the types of reactions and the availability of monomers for synthesizing linked COFs are considerably limited by the irreversibility of the C═C bond, and the complete π-conjugated structure restricts their in-depth research in hydrophilicity, membrane materials, and proton conductivity. Postsynthetic modification (PSM), which can avoid these problems by incorporating functional moieties into the predetermined framework, provides an alternative way to construct diverse V-2D-COFs.
View Article and Find Full Text PDFCurr Microbiol
January 2025
Microbial Biotechnology Laboratory, Life Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam, 781035, India.
Medicinal plants often harbour various endophytic actinomycetia, which are well known for their potent antimicrobial properties and plant growth-promoting traits. In this study, we isolated an endophytic actinomycetia, A13, from the leaves of tea clone P312 from the MEG Tea Estate, Meghalaya, India. The isolate A13 was identified as Streptomyces sp.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Institute of Materials, China Academy of Engineering Physics, Jiangyou 621908, China.
Solar-driven dry reforming of methane (DRM) offers a milder, more cost-effective, and promising environmentally friendly pathway compared to traditional thermal catalytic DRM. Numerous studies have extensively investigated inexpensive Ni-based catalysts for application in solar-driven DRM. However, these catalysts often suffer from activity loss due to carbon accumulation.
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