The ratchet effect of a sine-Gordon kink is investigated in the absence of any external force while the symmetry of the field potential at every time instant is maintained. The directed motion appears by a time shift of the sine-Gordon potential through a time-dependent additional phase. A symmetry analysis provides the necessary conditions for the existence of net motion. It is also shown analytically, by using a collective coordinate theory, that the novel physical mechanism responsible for the appearance of the ratchet effect is the coupled dynamics of the kink width with the background field. Biharmonic and dichotomic periodic variations of the additional phase of the sine-Gordon potential are considered. The predictions established by the symmetry analysis and the collective coordinate theory are verified by means of numerical simulations. Inversion and maximization of the resulting current as a function of the system parameters are investigated.
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http://dx.doi.org/10.1103/PhysRevE.94.012221 | DOI Listing |
J Agric Food Chem
January 2025
China-Kenya Joint Laboratory for Ecological Pest Control of Citrus, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Biopesticide and Chemical Biology, MOE, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
RNA pesticides have emerged as a promising alternative to conventional chemical pesticides due to their high specificity and minimal environmental impact. However, the instability of RNA molecules in the environment and the challenges associated with their effective delivery to target pests limit their broader application. This study addresses these challenges by developing a dual delivery system using chitosan (CS) and Metal-Organic Frameworks (MOFs) to enhance the delivery and efficacy of double-stranded RNA (dsRNA) and cycloxaprid against , a vector of citrus greening disease.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Department of Ophthalmology, Reina Sofia University Hospital and University of Cordoba, 14004 Cordoba, Spain.
Gold nanoparticles (AuNPs) play a key role in the field of nanomedicine due to their fascinating plasmonic properties as well as their great biocompatibility. An intriguing application is the use of plasmonic photothermal therapy (PPTT) mediated by anisotropic AuNPs irradiated with a near-infrared (NIR) laser for treating ocular diseases in ophthalmology. For this purpose, bipyramidal-shaped AuNPs (BipyAu), which were surface-functionalized with three different organic ligands (citrate, polystyrene sulphonate (PSS), and cetyltrimethylammonium bromide (CTAB)), were synthesized.
View Article and Find Full Text PDFPediatr Dev Pathol
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In recent years, infection has emerged as a main concern in the field of children's public health. This bacterium, known to be a pollutant, can be found in various settings such as hospital wards, equipment, breast milk, nutrient solution, and so on. With its high pathogenicity and toxicity, infection can lead to severe and life-threatening symptoms, particularly in premature infants.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Tianjin Key Laboratory of Advanced Functional Porous Materials, Institute for New Energy Materials and Low-Carbon Technologies, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China.
Electrochemical water splitting is a promising approach to convert renewable energy into hydrogen energy and is beneficial for alleviating environmental pollution and energy crises, and is considered a clean method to achieve dual-carbon goals. Electrocatalysts can effectively reduce the reaction energy barrier and improve reaction efficiency. However, designing electrocatalysts with high activity and stability still faces significant challenges, which are closely related to the structure and electronic configuration of catalysts.
View Article and Find Full Text PDFJ Mater Chem B
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MXenes are a class of 2D transition metal carbides and nitrides (MXT) that have attracted significant interest owing to their remarkable potential in various fields. The unique combination of their excellent electromagnetic, optical, mechanical, and physical properties have extended their applications to the biological realm as well. In particular, their ultra-thin layered structure holds specific promise for diverse biomedical applications.
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