A computational fluid dynamics model of a healthy, a stenotic and a post-operatory stented human trachea was developed to study the respiration under physiological boundary conditions. For this, outflow pressure waveforms were computed from patient-specific spirometries by means of a method that allows to compute the peripheral impedance of the truncated bronchial generation, modelling the lungs as fractal networks. Intratracheal flow pattern was analysed under different scenarios. First, results obtained using different outflow conditions were compared for the healthy trachea in order to assess the importance of using impedance-based conditions. The resulted intratracheal pressures were affected by the different boundary conditions, while the resulted velocity field was unaffected. Impedance conditions were finally applied to the diseased and the stented trachea. The proposed impedance method represents an attractive tool to compute physiological pressure conditions that are not possible to extract in vivo. This method can be applied to healthy, pre- and post-operatory tracheas showing the possibility of predicting, through numerical simulation, the flow and the pressure field before and after surgery.
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http://dx.doi.org/10.1080/10255842.2011.615743 | DOI Listing |
Sci Rep
January 2025
Department of Orthopaedic Trauma, The Second Affiliated Hospital of Dalian Medical University, No. 467 Zhongshan Road, Shahekou District, Dalian, 116027, Liaoning, China.
Anterior cervical interbody fusion (ACDF) has become a classic surgical procedure for the treatment of cervical degenerative diseases, and various interbody cages are widely used in this procedure. We used 3D printing technology to produce a new type of plate-locking cage, anticipating to achieve high fusion rate with the high biomechanical stability. This study is to compare the biomechanical characteristics between a newly designed interbody cage and a conventional Zero-profile cage during ACDF using finite element analysis.
View Article and Find Full Text PDFJ R Soc Interface
January 2025
Department of Engineering Mechanics, KTH Royal Institute of Technology, Stockholm, Sweden.
Culturing living cells in three-dimensional environments increases the biological relevance of laboratory experiments, but requires solutes to overcome a diffusion barrier to reach the centre of cellular constructs. We present a theoretical and numerical investigation that brings a mechanistic understanding of how microfluidic culture conditions, including chamber size, inlet fluid velocity and spatial confinement, affect solute distribution within three-dimensional cellular constructs. Contact with the chamber substrate reduces the maximally achievable construct radius by 15%.
View Article and Find Full Text PDFJ Environ Manage
January 2025
School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, 100083, China; Qilaotu Mountain National Observation and Research Station of Chinese Forest Ecosystem, Chifeng, 024400, China.
Climate change has profound implications for the distribution of suitable habitats for woody species. In this study, we assessed the optimal distribution thresholds for twelve woody species on the Loess Plateau using the Maximum Entropy (MaxEnt) model, incorporating sample points of tree species alongside relevant environmental variables. We analyzed the sustainability of potentially suitable zones and proposed a framework for selecting a regulatory model to establish the most suitable creation zones in response to future climate change.
View Article and Find Full Text PDFPLoS One
January 2025
QUT Centre for Data Science, Queensland University of Technology, Brisbane, Queensland, Australia.
Background: Spatial data are often aggregated by area to protect the confidentiality of individuals and aid the calculation of pertinent risks and rates. However, the analysis of spatially aggregated data is susceptible to the modifiable areal unit problem (MAUP), which arises when inference varies with boundary or aggregation changes. While the impact of the MAUP has been examined previously, typically these studies have focused on well-populated areas.
View Article and Find Full Text PDFInt J Gen Med
January 2025
School of Biomedical Engineering & State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai, People's Republic of China.
Purpose: Conventional brain MRI protocols are time-consuming, which can lead to patient discomfort and inefficiency in clinical settings. This study aims to assess the feasibility of using artificial intelligence-assisted compressed sensing (ACS) to reduce brain MRI scan time while maintaining image quality and diagnostic accuracy compared to a conventional imaging protocol.
Patients And Methods: Seventy patients from the department of neurology underwent brain MRI scans using both conventional and ACS protocols, including axial and sagittal T2-weighted fast spin-echo sequences and T2-fluid attenuated inversion recovery (FLAIR) sequence.
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