A modified Colpitts oscillator (MCO) associated with a nonlinear transmission line (NLTL) with intersite nonlinearity is introduced as a self-sustained generator of a train of modulated dark signals with compact shape. Equations of state describing the dynamics of the MCO part are derived and the stationary state is obtained. Using the Routh-Hurwitz criterion, the result of a stability analysis indicates the existence of a limit cycle in certain parameter regimes and there the oscillation of the circuit delivers pulselike electrical signals. The train of generated signals is then transformed into a train of compact modulated dark voltage solitons by the NLTL. The exactness of this analytical analysis is confirmed by numerical simulations performed on the circuit equations. Finally, simulations show the capacity of this circuit to work as a generator of compactlike dark voltage solitons. The performance of the generator, namely, the pulse width and the repetition rate, is controlled by the magnitude of the characteristic parameters of the electronic components of the device.
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http://dx.doi.org/10.1103/PhysRevE.85.056606 | DOI Listing |
Nat Rev Mol Cell Biol
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Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
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January 2025
Photonics Research Centre, Universiti Malaya, Kuala Lumpur, 50603, Malaysia.
Two-dimensional (2D) hexagonal boron nitride (hBN) has garnered significant attention due to its exceptional thermal and chemical stability, excellent dielectric properties, and unique optical characteristics, making it widely used in deep ultraviolet (DUV) applications. However, the integration of hBN with plasmonic materials in the visible region (532 nm) has not been fully explored, particularly in terms of morphology regulation and size control of mono- and bimetallic nanoparticles (BMNPs) namely gold (Au), silver (Ag) and Au-Ag. A Schottky junction-based metal-semiconductor contact configuration is employed to achieve hot-carrier reflections on the metal side, enhancing the quantum efficiency of the photodetector.
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December 2024
Department of Biochemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, VA 20461; Department of Chemistry, Missouri University of Science and Technology, Rolla, MO, 65409. Electronic address:
We report a novel light-dependent activation mechanism for 2-haloacrylate hydratase (2HAH), a flavin-depu change endent dehalogenase. Initial assays revealed inconsistent enzyme activity, stabilized only after chemical reduction or exposure to bright light. Spectroscopic analysis showed that light accelerates flavin reduction by NAD(P)H, completing in 30 seconds under bright light versus slow reduction in the dark.
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January 2025
Department of Clinical Pharmacokinetics, Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka 812-8582, Japan.
Macrophage phagocytosis plays a role in cancer immunotherapy. The phagocytic activity of macrophages, regulated by circadian clock genes, shows time-dependent variation. Intervening in the circadian clock machinery of macrophages is a potentially novel approach to cancer immunotherapy; however, data on this approach are scarce.
View Article and Find Full Text PDFChemistry
December 2024
Indian Institute of Technology Kanpur, Chemistry, Department of Chemistry, Indian Institute of Technology Kanpur, 208016, Kanpur, INDIA.
Herein, the photophysical, photochemical properties and photogenerated excited state dynamics of two new Ru(II) complexes, viz. [Ru(p-ttp)(bpy)(PTA)]2+ [1]2+, [Ru(p-ttp)(phen)(PTA)]2+ [2]2+ having a phosphorus-based ligand PTA [p-ttp = p-tolyl terpyridine; bpy = 2,2'-bipyridyl; phen = 1,10-phenthroline and PTA = 1,3,5-triaza-7-phosphaadamantane] are reported. Upon excitation with 470 nm LED, [1]2+ and [2]2+ neither undergo ligand release nor exhibit room temperature luminescence/1O2 generation.
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