Vascular stents are expanded in blood vessels with lumens larger than their cardiac counterparts. Extreme radial expansion significantly reduces the expanded length of some designs, resulting in insufficient lesion coverage and inaccurate placement. It is hypothesized that expansion mechanisms of a balloon-expandable stent, driven by plastic hinges, are controlled by the cell topology. This hypothesis is first tested for stent expansion using kinematic and kinetic analyses, followed by more detailed finite element (FE) calculations. Three balloon-expandable stent designs are laser micro-machined for experimental verification of the length-diameter relations predicted by the analytical and FE models. It is found that stent designs with positive, negative, or zero foreshortening over expansion phase can be designed by tailoring unit cell geometries and hence obtain desired length-diameter and pressure-diameter characteristics.
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http://dx.doi.org/10.1016/j.jbiomech.2014.01.039 | DOI Listing |
Sci Rep
January 2025
China Academy of Railway Sciences Co. Ltd, Beijing, 100081, China.
The construction of tunnels can easily trigger the reactivation of old landslide bodies, posing a threat to the transportation safety. In this study, using methods such as engineering geological investigation, slope deformation monitoring, deep displacement monitoring, and numerical simulation, the interaction between landslides and tunnels was investigated from the perspective of landslide deformation and failure characteristics. The Walibie Tunnel (WLBT) of Shangri-La to Lijiang (XL) expressway was taken as an example.
View Article and Find Full Text PDFRecent research suggests that serotonergic psychedelics may simultaneously enhance connectedness to both social and natural worlds. This article synthesizes current evidence regarding psychedelics' effects on nature relatedness and social connectedness, examining underlying mechanisms through the framework of self-other overlap. Psychedelics appear to facilitate self-expansion through two complementary mechanisms: ego dissolution, which temporarily alters self-boundaries, and enhanced emotional processing, which increases empathic concern.
View Article and Find Full Text PDFViruses
January 2025
Department of Microbiology and Immunology, Miller School of Medicine, University of Miami/UHealth, Miami, FL 33136, USA.
Flaviviruses are a diverse group of viruses primarily transmitted through hematophagous insects like mosquitoes and ticks. Significant expansion in the geographic range, prevalence, and vectors of flavivirus over the last 50 years has led to a dramatic increase in infections that can manifest as hemorrhagic fever or encephalitis, leading to prolonged morbidity and mortality. Millions of infections every year pose a serious threat to worldwide public health, encouraging scientists to develop a better understanding of the pathophysiology and immune evasion mechanisms of these viruses for vaccine development and antiviral therapy.
View Article and Find Full Text PDFPlants (Basel)
January 2025
State Key Laboratory of Tree Genetics and Breeding, Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, Key Laboratory of National Forestry and Grassland Administration on Subtropical Forest Biodiversity Conservation, School of Life Sciences, Nanjing Forestry University, Nanjing 210037, China.
Chalcone synthase (CHS), the first key structural enzyme in the flavonoid biosynthesis pathway, plays a crucial role in regulating plant responses to abiotic stresses and hormone signaling. However, its molecular functions remain largely unknown in , which is one of the most economically and ecologically important bamboo species and the most widely distributed one in China. This study identified 17 genes in and classified them into seven subgroups, showing a closer evolutionary relationship to genes from rice.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Department of Physics, Washington State University, Pullman, WA 99163, USA.
This work aims to determine the mechanism of the photomechanical response of poly(Methyl methacrylate) polymer doped with the photo-isomerizable dye Disperse Red 1 using the non-isomerizable dye Disperse Orange 11 as a control to isolate photoisomerization. Samples are free-standing thin films with thickness that is small compared with the optical skin depth to assure uniform illumination and photomechanical response throughout their volume, which differentiates these studies from most others. Polarization-dependent measurements of the photomechanical stress response are used to deconvolute the contributions of angular hole burning, molecular reorientation and photothermal heating.
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