| 281. |
|
|
| 282. |
|
|
| 283. |
|
|
| 284. |
|
|
| 285. |
- Yoon, William J., 1984-, et al.
(författare)
-
Near-wall hemodynamic changes in subclavian artery perfusion induced by retrograde inner branched thoracic endograft implantation
- 2023
-
Ingår i: JVS-Vascular Science. - : Elsevier. - 2666-3503. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Left subclavian artery (LSA)-branched endografts with retrograde inner branch configuration (thoracic branch endoprosthesis, TBE) offer a complete endovascular solution when LSA preservation is required during zone 2 thoracic endovascular aortic repair (TEVAR). However, the hemodynamic consequences of the TBE have not been well-investigated. We compared near-wall hemodynamic parameters before and after the TBE implantation using computational fluid dynamic (CFD) simulations.Methods: Eleven patients who had undergone TBE implantation were included. Three-dimensional (3D) aortic arch geometries were constructed from the pre- and post-TBE implantation computed tomography images. The resulting twenty-two 3D aortic arch geometries were then discretized into finite element meshes for CFD simulations. Inflow boundary conditions were prescribed using normal physiologic pulsatile circulation. Outlet boundary conditions consisted of Windkessel models with previously published values. Blood flow, modeled as Newtonian fluid, simulations were performed with rigid wall assumptions utilizing SimVascular’s incompressible Navier-Stokes solver. We compared well-established hemodynamic descriptors: pressure, flow rate, time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and percent area with OSI >0.2 (%A OSI>0.2). Data were presented on the stented portion of the LSA.Results: TBE implantation was associated with a small decrease in peak LSA pressure (153 [IQR = 151 – 154] mmHg vs 159 [IQR = 158 – 160] mmHg, p = 0.005). No difference was observed in peak LSA flow rates between pre- and post-implantation: 40.4 [IQR = 39.5 – 41.6] cm3/sec vs 41.3 [IQR = 37.2 – 44.8] cm3/sec, p = 0.59. There was a significant post-implantation increase in TAWSS (15.2 [IQR = 12.2 - 17.7] dynes/cm2 vs 6.2 [IQR = 5.7 - 10.3] dynes/cm2, p = 0.003), leading to decreases in both OSI (0.088 [IQR = 0.063 -0.099] vs 0.1 [IQR = 0.096 - 0.16]; p = 0.03) and percentage of area (%A) with OSI >0.2 (10.4 [IQR = 5.8 - 15.8] vs 15.7 [IQR = 10.7 - 31.9], p = 0.13). Neither LSA side branch angulation (median, 81°, IQR = 77° - 109°) nor moderate compression (16% - 58%) appeared to have an impact on the pressure, flow rate, TAWSS, or %A with OSI >0.2 in the stented LSA.Conclusions: The implantation of TBE produces modest hemodynamic disturbances which are unlikely to result in clinically relevant changes.
|
|
| 286. |
- Yoon, Y., et al.
(författare)
-
Coupling Quantum States through a Continuum : A Mesoscopic Multistate Fano Resonance
- 2012
-
Ingår i: Physical Review X. - 2160-3308. ; 2:2, s. 021003-
-
Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a fully tunable realization of a multistate Fano resonance, in which a pair of remote quantum states experience an effective coupling due to their mutual overlap with a continuum. Our mesoscopic implementation of this system exploits the ability of the semiconductor nanostructures known as quantum point contacts (QPCs) to serve, in the low-density limit close to pinch-off, as an on-demand localized state. By coupling the states formed on two separate QPCs, through a two-dimensional electron gas that serves as a continuum, we observe a robust effective interaction between the QPCs. To explain this result, we develop a theoretical formulation, based on the ideas of the Schrieffer-Wolff transformation, which is able to reproduce our key experimental findings. According to this model, the robust character of the interaction between the two remote states arises from the fact that the interaction is essentially mediated by a large number of degenerate continuum states. While the continuum is often viewed as a source of decoherence, our experiment therefore instead suggests the possibility of using this medium to support the interaction of quantum states, a result that may allow new approaches to coherently couple nanostructures in extended geometries.
|
|
| 287. |
- Zaslavsky, A, et al.
(författare)
-
Regional control of tumor growth
- 2010
-
Ingår i: Molecular cancer research : MCR. - 1557-3125. ; 8:9, s. 1198-1206
-
Tidskriftsartikel (refereegranskat)
|
|
| 288. |
- Abou Ghayda, Ramy, et al.
(författare)
-
The global case fatality rate of coronavirus disease 2019 by continents and national income: A meta-analysis
- 2022
-
Ingår i: Journal of Medical Virology. - : WILEY. - 0146-6615 .- 1096-9071. ; 94:6, s. 2402-2413
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to provide a more accurate representation of COVID-19s case fatality rate (CFR) by performing meta-analyses by continents and income, and by comparing the result with pooled estimates. We used multiple worldwide data sources on COVID-19 for every country reporting COVID-19 cases. On the basis of data, we performed random and fixed meta-analyses for CFR of COVID-19 by continents and income according to each individual calendar date. CFR was estimated based on the different geographical regions and levels of income using three models: pooled estimates, fixed- and random-model. In Asia, all three types of CFR initially remained approximately between 2.0% and 3.0%. In the case of pooled estimates and the fixed model results, CFR increased to 4.0%, by then gradually decreasing, while in the case of random-model, CFR remained under 2.0%. Similarly, in Europe, initially, the two types of CFR peaked at 9.0% and 10.0%, respectively. The random-model results showed an increase near 5.0%. In high-income countries, pooled estimates and fixed-model showed gradually increasing trends with a final pooled estimates and random-model reached about 8.0% and 4.0%, respectively. In middle-income, the pooled estimates and fixed-model have gradually increased reaching up to 4.5%. in low-income countries, CFRs remained similar between 1.5% and 3.0%. Our study emphasizes that COVID-19 CFR is not a fixed or static value. Rather, it is a dynamic estimate that changes with time, population, socioeconomic factors, and the mitigatory efforts of individual countries.
|
|
| 289. |
|
|
| 290. |
- Beal, Jacob, et al.
(författare)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
|
|
