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Kirigami metamaterials have enabled a plethora of morphing patterns across art and engineering. However, the inverse design of kirigami for complex shapes remains a puzzle that so far cannot be solved without relying on complex numerical methods. Here, we present a purely geometric design method to overcome the reliance on sophisticated numerical algorithms and showcase how to leverage it for three distinct types of morphing targets, i.e., the contracted shape, the deployed shape, and the internal trajectories of the rotating units in kirigami specimens. Our results unveil the fundamental relations between the kirigami deformation and the shape of its rotating units and enable us to establish the underpinning physics through theoretical investigations validated via numerical simulations. This work brings ground-rule insights into morphing matter with rotating units and offers an intuitive, firsthand geometric route for the swift design of complex kirigami.
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http://dx.doi.org/10.1103/PhysRevLett.134.176103 | DOI Listing |
Phys Eng Sci Med
September 2025
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424, Indonesia.
This study introduces a novel optimization framework for cranial three-dimensional rotational angiography (3DRA), combining the development of a brain equivalent in-house phantom with Figure of Merit (FOM) a quantitative evaluation method. The technical contribution involves the development of an in-house phantom constructed using iodine-infused epoxy and lycal resins, validated against clinical Hounsfield Units (HU). A customized head phantom was developed to simulate brain tissue and cranial vasculature for 3DRA optimization.
View Article and Find Full Text PDFAdv Med Educ Pract
September 2025
Department of Neuroscience, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, 16132, Italy.
The reduction in clinical rotation hours, particularly in high-demand pediatric subspecialties such as Neonatal Intensive Care Units (NICU) and Pediatric Emergency Rooms (ER), has highlighted the need for innovative approaches to enhance pediatric residency education. A 2019 survey of Italian pediatric residency programs revealed that most residents receive fewer than five hours of simulation-based training annually, with 66% participating in no simulation activities. Additionally, pediatric ER rotation hours have seen significant reductions-daytime rotations decreased by 29%, while nighttime rotations were reduced by 60% over the past four years at the University of Genoa.
View Article and Find Full Text PDFSports Biomech
September 2025
Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata City, Japan.
Body roll during front crawl swimming refers to spinal rotation along the longitudinal axis. It is typically evaluated at the shoulders and pelvis; however, the middle and lower thoracic and lumbar spine are overlooked. Therefore, we aimed to investigate the differences in rotation angles and peak timing across the upper (shoulder roll), middle and lower thoracic spine, lumbar spine, and pelvis (hip roll) during front crawl swimming.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2025
Department of Artificial Intelligence, Donders Center for Cognition, Radboud University, Nijmegen, GD 6525, Netherlands.
We present a geometric design rule for size-controlled clustering of self-propelled particles. We show that active particles that tend to rotate under an external force have an intrinsic, signed parameter with units of curvature which we call curvity, that can be derived from first principles. Experiments with robots and numerical simulations show that properties of individual robots (radius and curvity) control pair cohesion in a binary system, and the stability of flocking and self-limiting clustering in a swarm, with applications in metamaterials and in embodied decentralized control.
View Article and Find Full Text PDFTransfusion
September 2025
Department of Clinical Immunology and Transfusion Medicine, Karolinska University Hospital, Stockholm, Sweden.
Background: The use of low-titer O whole blood (LTOWB) is requested in the treatment of major bleeding, initially used in military medicine but now increasingly utilized in civilian prehospital care. The advantage is the administration of a balanced transfusion, red blood cells, coagulation factors, and platelets, in one bag. The challenges are the availability of LTOWB and difficulties in predicting the need in major bleeding, leading to the risk of wastage.
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