Intracranial vessels develop early in embryonic life through mutual interaction and integration of aortic arches giving the carotid arteries and intrinsic longitudinal neural system forming the posterior circulation. Due to the relatively short time and faster pace of completion of development, minor absent/persistent segments may give rise to either asymptomatic anatomical variants or hemodynamically significant changes. Intracranial vessels - both anterior carotid and posterior vertebrobasilar systems - are known to have many common anatomical variations like hypoplastic segments (A1 or P1 segments of anterior or posterior cerebral arteries) and persistent carotid-vertebrobasilar anastomotic channels. These variants may be displayed using MRI and MRA which represent useful non-invasive investigative modality of the neck and Willis's circle. We report an interesting hitherto rarely reported anatomical variation in the form of spiral twisting of distal vertebral (V4 segments) and vertebrobasilar junction in a 36-year-old female and discuss the underlying embryological possibilities based on the embryological development of the vertebrobasilar system.
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http://dx.doi.org/10.1007/s00276-025-03593-0 | DOI Listing |
Surg Radiol Anat
March 2025
Department of Radio-Diagnosis, Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Pondicherry, 605006, India.
Intracranial vessels develop early in embryonic life through mutual interaction and integration of aortic arches giving the carotid arteries and intrinsic longitudinal neural system forming the posterior circulation. Due to the relatively short time and faster pace of completion of development, minor absent/persistent segments may give rise to either asymptomatic anatomical variants or hemodynamically significant changes. Intracranial vessels - both anterior carotid and posterior vertebrobasilar systems - are known to have many common anatomical variations like hypoplastic segments (A1 or P1 segments of anterior or posterior cerebral arteries) and persistent carotid-vertebrobasilar anastomotic channels.
View Article and Find Full Text PDFRSC Adv
March 2025
Department of Applied Chemistry and Biochemical Engineering, Graduate School of Engineering, Shizuoka University 3-5-1 Johoku, Chuo-ku Hamamatsu Shizuoka 432-8561 Japan
This study explores the development of a Joule-heated reaction field utilizing an electrically driven spiral-shaped catalyst for efficient CO methanation. Infrared thermal imaging in an uninsulated reactor reveals a rapid and uniform temperature rise along the spiral structure. With a 10 W input, CO conversion reached 80%, while 75% conversion was maintained even at 5 W.
View Article and Find Full Text PDFJ Am Chem Soc
March 2025
Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, P. R. China.
Helical assembly has been demonstrated to efficiently facilitate the circularly polarized luminescence (CPL) performances, but the synthesis of micro- and nanohelices from rigid achiral π-conjugated compounds remains challenging due to the absence of bilayer structures or complementary hydrogen-bonding interactions. Here, we develop an alloying strategy for the realization of helical microstructures from achiral anthracene/anthracene derivatives with -/-axis modification or anthracene/tetracene derivatives with -/-axis modification via solution coassembly. Interestingly, two anthracene derivatives bearing asymmetric phenyl/phenylethynyl groups and symmetric phenylethynyl groups can assemble into spiral microribbons with a fractal branching pattern.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2025
Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai Frontier Science Center of Mechanoinformatics, School of Mechanics and Engineering Science, Shanghai University, Shanghai 200072, China.
We present a nanoscale torsion-triggered actuation mechanism that utilizes torsion as a precise actuation signal to drive controlled nanoscale motion. Twisting an annular graphene film induces spiral wrinkles with shear deformations, forming smooth gradients in the atomic contact and curvature. These gradients create dual van der Waals (vdW) and elastic energy landscapes, which guide the robust outward migration of solid adsorbates along wrinkle troughs.
View Article and Find Full Text PDFSmall
March 2025
State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001, China.
Lightweight, hierarchical thin-walled tubes are essential in aerospace and transportation for their exceptional impact resistance and energy absorption capabilities. This study applies bionic design principles to revolutionize traditional thin-walled tube structures, enhancing their energy absorption performance. Inspired by natural models-spider webs, beetle elytra, cuttlebone, and spiral wood fibers-integrated bionic hierarchical thin-walled tubes (IBHTTs) with diverse bionic structural and material combinations are developed using additive manufacturing.
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