The paper presents a theoretical model which can be used to simulate a vascular network which includes loops and bypass grafts, a feature not possible with previous models. Using the linearised Navier-Stokes equations, the linearised equation of a uniform thick-walled viscoelastic tube, and the equation of continuity, the model is applied to a vascular network which includes a bypass graft. This method represents each segment of an artery or graft by a four-terminal-network whose A, B, C, D parameters are functions of the frequency and physical characteristics of the segment. The model predicts the flow and pressure waveforms at any point in the human arterial network very accurately when compared with data obtained from normal patients, patients with arterial stenoses and for hypertensive patients. The model also gives results which are in close agreement with hydraulic experimental data for the input impedance of systems with bypass loops.
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http://dx.doi.org/10.1007/BF02441970 | DOI Listing |
ACS Sens
January 2025
Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
Solid-phase immunosorbent reactions, such as ELISA, are widely used for detecting, identifying, and quantifying protein markers. However, traditional centimeter scale well-based immunoreactors suffer from low surface-to-volume (S/V) ratios, leading to large sample consumption and a long assay time. Microfluidic technologies, particularly tubular microfluidic immunoreactors, have emerged as promising alternatives due to their high S/V ratios.
View Article and Find Full Text PDFJ Glob Health
January 2025
Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Background: Recreational screen time (RST) has been found to be associated with cognitive decline and neurodegenerative diseases. However, the association between RST and age-related macular degeneration (AMD), an ocular neurodegenerative disease, is still unclear. We aimed to elucidate the association between RST and AMD.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Republic of Korea.
The design of organic-peptide hybrids has the potential to combine our vast knowledge of protein design with small molecule engineering to create hybrid structures with complex functions. Here, we describe the computational design of a photoswitchable Ca-binding organic-peptide hybrid. The designed molecule, designated Ca-binding switch (CaBS), combines an EF-hand motif from classical Ca-binding proteins such as calmodulin with a photoswitchable group that can be reversibly isomerized between a spiropyran (SP) and merocyanine (MC) state in response to different wavelengths of light.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218.
The hippocampal dentate gyrus (DG) is thought to orthogonalize inputs from the entorhinal cortex (pattern separation) and relay this information to the CA3 region. In turn, attractor dynamics in CA3 perform a pattern completion or error correction operation before sending its output to CA1. In a mouse model of congenital hypoplasia of the DG, a deficiency in the (Wls) gene, specifically in cells expressing , which targets neuronal progenitors, led to an almost total absence of dentate granule cells and modestly impaired performance in spatial tasks.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
State Key Laboratory of Genetic Engineering, School of Life Sciences, Liver Cancer Institute of Zhongshan Hospital, Fudan University, Shanghai 200438, China.
Aging is a complex process that affects multiple organs, and the discovery of a pharmacological approach to ameliorate aging is considered the Holy Grail of medicine. Here, we performed an N-ethyl-N-nitrosourea forward genetic screening in zebrafish and identified an accelerated aging mutant named (), harboring a mutation in the - () gene. Loss of leads to a short lifespan and age-related characteristics in the intestine of zebrafish embryos, such as cellular senescence, genomic instability, and epigenetic alteration.
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