The geometric characteristics include severity of stenosis, tortuosity of the lesion segment, curvature of the lesion segment, angle of the lesion and length of the lesion.

<p>A: Tortuosity (T) was taken as the ratio of the length from the ostium of the coronary segment to 1 cm distal to the stenosis (L) to the distance between the ends of the segment (C). B: The severity of the stenosis is the ratio of the cross-section area in the remain lumen at the stenosis and the healthy proximal segment. C: Curvature (unit: 1/m) of the stenotic artery segment was measured, of which the ends of the segment were 1cm proximal to the stenosis and 1cm distal to the stenosis. D: The angle of the lesion was measured at the immediate distal edge of the lesion (unit: degree). E: The length of the lesion was also measured (unit: mm).</p

The distribution of the flow and the corresponding WSS distribution in the stenotic coronary artery.

<p>A: The streamline of the flow distribution color-coded with velocity magnitude showed that blood flow is separated at the downstream of the stenosis, leading to the occurrence of the recirculation zone (red arrow) (unit: m/s). Severe stenosis (>80%) resulted in the increasing of the resistance of the vascular bed, leading to the flow reversal at the upstream bifurcation (yellow cross-star). B: The vessel wall shear stress distribution showed that the maximum wall shear stress is found at the distal stenosis (red cross-star), disturbance of the flow is found in downstream, leading to the altered distribution of the wall shear stress (red frame) (unit: Pa). C and D: The streamline of the flow distribution color-coded with velocity magnitude in the cross-section area showed a more significant secondary flow pattern at the upstream (as in C labeled with yellow cross-star corresponding to the location showed in A) compare to that at the downstream of distal stenosis (as in D labeled with red arrow corresponding to the location showed in A) (unit: m/s).</p

The effect of stenosis severity on the recirculation zone.

<p>Streamline of the flow distribution are illustrated (unit: m/s). The length the recirculation increase with the severity of the stenosis. Severity of the stenosis in A, B, C and D is 28.2%, 57%, 76.6% and 86.3% with the corresponding length of the recirculation zone is 0 mm, 5.02 mm, 6.48 mm to 16.77 mm, respectively. Recirculation zone is not only seen at the downstream of the stenosis, but also at the upstream bifurcation (labeled with red cross-star in C).</p

The FFRCT distribution in the coronary arterial geometries with stenosis.

<p>The FFRCT at the stenosis decreased as the severity of the stenosis increased. Degree of the stenosis in A, B and C was 57%, 76,6% and 86.4%, the corresponding FFRCT value was 0.687, 0.603 and 0.57, respectively.</p

Validation of the calculation is provided by comparing calculated FFRCT to the measurement FFR.

<p>A: Agreement between the FFRCTA and FFR is evaluated by Bland-Altman agreement test, the mean±SD bias of is 0.00269 ± 0.01899. B: Agreement between FFRCT and FFR is also evaluated by linear regression that R² = 0.974 with 95% confident interval.</p

Molecular Dynamics Simulation of Transport and Structural Properties of CO₂ Using Different Molecular Models

The diffusion coefficients (<i>D</i>_s), viscosities (η), and structural properties of carbon dioxide (CO₂) have been studied using molecular dynamics (MD) simulation. Three fully flexible models (MSM-flex, EPM2-flex, and TraPPE-flex) from the literature are used to model CO₂. Present simulations have extended the temperature range from 223 K to 450 K and pressures up to 200 MPa for the first time. Generally, the simulation results show a good agreement with the experimental ones. The overall satisfaction of the EPM2-flex model is found to be the best, with an average absolute relative deviation of 6.83 % for <i>D</i>_s and of 2.87 % for η, respectively. However, the TraPPE-flex model performs best at low temperatures below 273 K. Meanwhile, the lifetime of CO₂ molecules in the first solvation shell (τ^s) is calculated, and the qualitative correlation between τ^s and <i>D</i>_s as well as τ^s and η is discussed. Finally, the structures of CO₂ fluid in different thermodynamic states are investigated by calculating radial distribution functions and using a clustering algorithm

The streamline of the flow distribution color-coded with velocity magnitude.

<p>The pulsatile effect of the blood flow on the distribution of the recirculation. A, B, C and D illustrated 4 time points during one cardiac cycle. A: The recirculation disappeared at the low flow rate; B, C and D: The area of the recirculation zone varied along with the flow rate while the lengths of the recirculation zone were relatively consistence (5mm).</p

The streamlines of the flow distributions color-coded with velocity magnitude.

<p>Increasing of the resistance due to the distal stenosis leads to the flow reversal at the upstream bifurcation that blood flow is redistributed to the side branch as showed in A (unit: m/s). Examples of the disappearing of the recirculation zone at the downstream of the stenosis as showed in B (unit: m/s).</p

Relationship among stenosis severity, tortuosity, curvature, angle, lesion length with wall shear stress in the reconstructed patient-specific coronary arteries.

<p>A: effect of stenosis severity (percent diameter stenosis) on maximum wall shear stress; B: effect of tortuosity on maximum wall shear stress; C: effect of curvature on maximum wall shear stress; D: effect of lesion length on maximum wall shear stress; E: effect of angle of the lesion segment on maximum wall shear stress. Third-order nonlinear cur fit with 95% confident interval is shown in A with R² equals 0.521.</p

Measured and simulated data of cumulative emissions of CH₄ and N₂O from a winter wheat – single rice rotation system from November 13, 2009 to October 10, 2010.

a<p>CK, without both N fertilization and straw incorporation; N, with N fertilization; NS, with both N fertilization and straw incorporation;</p>b<p>Data in the parenthesis indicate the standard deviation of three replicated experiments.</p