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Topological structures reveal the hidden secrets and beauty in nature, such as the double helix in DNA, whilst, the manipulation of which in physical fields, especially in ultrafast structured light, draw booming attention. Here we introduce a new family of spatiotemporal light fields, i.e. helical pulses, carrying sophisticated double-helix singularities in its electromagnetic topological structures. The helical pulses were solved from Maxwell's equation as chiral extensions of toroidal light pulses but with controlled angular momentum dependence. We unveil that the double helix singularities can maintain their topological invariance during propagation and the field exhibits paired generation and annihilation of vortices and antivortices in ultrafast space-time, so as to be potential information carriers beating previous conventional vortex structured light.
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http://dx.doi.org/10.1515/nanoph-2024-0480 | DOI Listing |
Lab Chip
September 2025
Department of Engineering Design, Indian Institute of Technology Madras, India.
Microfluidic devices offer more accurate fluid flow control and lower reagent use for uniform nanoparticle synthesis than batch synthesis. Here, we propose a microfluidic device that synthesizes uniform iron oxide nanoparticles (IONPs) for highly efficient intracellular delivery. The 3D-printed device was fabricated, comprising two inlets in the T-shaped channel with an inner diameter of 2 mm, followed by a helical mixing channel with a single outlet.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
Departament de Química Inorgànica i Orgànica, Universitat de Barcelona, Diagonal 645, Barcelona, 08028, Spain.
Spins within molecules benefit from the atomistic control of synthetic chemistry for the realization of qubits. One advantage is that the quantum superpositions of the spin states encoding the qubit can be coherently manipulated using electromagnetic radiation. The main challenge is the fragility of these superpositions when qubits are to partake of solid-state devices.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
August 2025
Structural and Molecular Microbiology, Vlaams Instituut voor Biotechnology (VIB) Center for Structural Biology, Brussels 1050, Belgium.
The polar-growing have a complex cell envelope architecture characterized by the presence of a specialized outer membrane composed of mycolic acids. In some , this mycomembrane is further supported by a proteinaceous surface layer or "S-layer," whose function, structure, and mode of assembly remain largely enigmatic. Here, we isolated ex vivo PS2 S-layers from the industrially important and determined its atomic structure by 3D cryo-EM reconstruction.
View Article and Find Full Text PDFZhong Nan Da Xue Xue Bao Yi Xue Ban
March 2025
Department of Cardiovascular Surgery, Second Xiangya Hospital, Central South University; Hunan Engineering Research Center for Digital Heart, Changsha 410010.
Objectives: A ventricular assist device (VAD) is an electromechanical device used to assist cardiac blood circulation, which can be employed for the treatment of end-stage heart failure and is most commonly placed in the left ventricle. Despite enhancing perfusion performance, the implantation of left ventricular assist device (LVAD) transforms the local intraventricular flow and thus may increase the risk of thrombogenesis. This study aims to investigate fluid-particle interactions and thromboembolic risk under different LVAD configurations using three-dimensional (3D) reconstruction models, focusing on the effects of outflow tract orientation and blood flow rates.
View Article and Find Full Text PDFJ Comput Chem
July 2025
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research and Key Laboratory of Resource National and Local Joint Engineering Laboratory for New Petro-Chemical Materials and Fine Utilization of Resources, College of Chemistry and Chemical Engineering, Hunan Normal University, Chan
We investigated crystalline Im-3m HS at 200 GPa, a pressure regime where HS is generally considered to be an exotic superconductor. Simulated circularly polarized 10 femtosecond (fs) laser pulses were applied and we quantified the effects on the electron dynamics during the application of "pump" and candidate "probe" laser pulses to discover optimal "probe" laser pulses. This is undertaken for the first application of Next Generation Quantum Theory of Atoms in Molecules (NG-QTAIM) using the Hessian of the "spin-up" and "spin-down" contributions to the total electronic charge density ρ(r).
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