scholarly journals Stochastic bifurcation characteristics of SMA intravascular stent subjected to radial and axial excitations

2014 ◽  
Vol 24 (6) ◽  
pp. 2465-2473
Author(s):  
Zhiwen Zhu ◽  
Wendi Zhang ◽  
Jia Xu
Keyword(s):  
Stochastic Bifurcation ◽  
Intravascular Stent

scholarly journals Successful removal of a central venous catheter misplaced in the right subclavian artery using an intravascular stent: a case report

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Haruka Yoshida ◽  
Shinichiro Ikemoto ◽  
Yasuyuki Tokinaga ◽  
Kanako Ejiri ◽  
Tomoyuki Kawamata
Keyword(s):  
Central Venous Catheter ◽  
Subclavian Artery ◽  
Axillary Artery ◽  
Insertion Site ◽  
Venous Catheter ◽  
Central Venous ◽  
Thrombotic Complications ◽  
Successful Removal ◽  
Intravascular Stent ◽  
The Right

Abstract Background Cannulation of a central venous catheter is sometimes associated with serious complications. When arterial cannulation occurs, attention must be given to removal of a catheter. Case presentation A 62-year-old man was planned for emergency thoracic endovascular aortic repair. After the induction of anesthesia, a central venous catheter was unintentionally inserted into the right subclavian artery. We planned to remove the catheter. Since we considered that surgical repair would be highly invasive for the patient, we decided to remove it using a percutaneous intravascular stent. A stent was inserted through the right axillary artery. The stent was expanded immediately after the catheter was removed. Post-procedural angiography revealed no leakage from the catheter insertion site and no occlusion of the right subclavian and vertebral arteries. There were no obvious hematoma or thrombotic complications. Conclusions A catheter that has been misplaced into the right subclavian artery was safely removed using an intravascular stent.

scholarly journals Neurotrophin-3 accelerates reendothelialization through inducing EPC mobilization and homing

2020 ◽  
Vol 15 (1) ◽  
pp. 241-250
Author(s):  
Yan Chen ◽  
Jian Cao ◽  
Weixia Peng ◽  
Wen Chen
Keyword(s):  
Growth Factors ◽  
Carotid Artery ◽  
Animal Experiments ◽  
Flow Chamber ◽  
Control Group ◽  
Angiogenic Growth Factors ◽  
Neurotrophin 3 ◽  
Stromal Cell Derived Factor ◽  
Intravascular Stent ◽  
Endothelial Growth Factor

AbstractRapid endothelialization is an effective way to treat intimal hyperplasia after intravascular stent implantation. Blood vessels and nerves coordinate with each other in function, while neurotrophin-3 (NT-3) is an important class of nerve growth factors. Our study found that NT-3 promoted endothelial progenitor cell (EPC) mobilization, and the proportion of EPCs in peripheral blood was increased by 1.774 times compared with the control group. Besides, NT-3 promoted the expression of stromal cell-derived factor-1α (SDF-1α), matrix metalloproteinase-9 (MMP9), and chemokine (C-X-C motif) receptor 4 (CXCR4) in EPCs, which increased by 59.89%, 74.46%, and 107.7%, respectively, compared with the control group. Transwell experiments showed that NT-3 enhanced the migration of EPCs by 1.31 times. Flow chamber experiments demonstrated that NT-3 captured more circulating EPCs. As shown by ELISA results, NT-3 can promote the paracrine of vascular endothelial growth factor, interleukin-8, MMP-9, and SDF-1 from EPCs. Such increased angiogenic growth factors further accelerated the closure of endothelial cell scratches. Additionally, EPC-conditioned medium in the NT-3 group significantly inhibited the proliferation of vascular smooth muscle cells. Then animal experiments also illustrated that NT-3 prominently accelerated the endothelialization of injured carotid artery. In short, NT-3 accelerated rapid reendothelialization of injured carotid artery through promoting EPC mobilization and homing.

Feedback-Induced Variations of Distribution in a Representative Gene Model

2015 ◽  
Vol 25 (07) ◽  
pp. 1540008
Author(s):  
Peijiang Liu ◽  
Zhanjiang Yuan ◽  
Lifang Huang ◽  
Tianshou Zhou
Keyword(s):  
Gene Expression ◽  
Power Law ◽  
Positive Feedback ◽  
Bimodal Distribution ◽  
Stochastic Bifurcation ◽  
Protein Distribution ◽  
Identical Cell ◽  
Induced Changes ◽  
Gene Switching ◽  
Cell To Cell Variability

Gene expression is inherently noisy, implying that the number of mRNAs or proteins is not invariant rather than follows a distribution. This distribution can not only provide the exact information on the dynamics of gene expression but also describe cell-to-cell variability in a genetically identical cell population. Here, we systematically investigate a two-state model of gene expression, a model paradigm used to study expression dynamics, focusing on the effect of feedback on the type of mRNA or protein distribution. If there is no feedback, then the distribution may be bimodal, power-law tailed, or Poisson-like, depending on gene switching rates. However, we find that feedback can tune or change the type of the distribution in each case and tends to unimodalize the distribution as its strength increases. Specifically, positive feedback can change not only a power-law tailed distribution into a bimodal or Poisson-like distribution but also a bimodal distribution into a Poisson-like distribution (implying that stochastic bifurcation can take place). In addition, it can make a Poisson-like distribution become more peaked but does not change the type of this distribution. In contrast to positive feedback, negative feedback has less influence on the shape of the distributions except for the bimodal case. In all cases, the noise-feedback curve used extensively in previous studies cannot well reflect the feedback-induced changes in the shape of distributions. Feedback-induced variations in distribution would be important for cell survival in fluctuating environments.

Structural Modal Multifurcation With Internal Resonance: Part 2—Stochastic Approach

1993 ◽  
Vol 115 (2) ◽  
pp. 193-201 ◽  
Author(s):  
R. A. Ibrahim ◽  
B. H. Lee ◽  
A. A. Afaneh
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Axial Load ◽  
Random Excitation ◽  
Stochastic Bifurcation ◽  
Density Level ◽  
Analytical Treatment ◽  
Asymmetric Mode ◽  
Non Gaussian ◽  
Gaussian Closure

Stochastic bifurcation in moments of a clamped-clamped beam response to a wide band random excitation is investigated analytically, numerically, and experimentally. The nonlinear response is represented by the first three normal modes. The response statistics are examined in the neighborhood of a critical static axial load where the normal mode frequencies are commensurable. The analytical treatment includes Gaussian and non-Gaussian closures. The Gaussian closure fails to predict bifurcation of asymmetric modes. Both non-Gaussian closure and numerical simulation yield bifurcation boundaries in terms of the axial load, excitation spectral density level, and damping ratios. The results of both methods are in good agreement only for symmetric response characteristics. In the neighborhood of the critical bifurcation parameter the Monte Carlo simulation yields strong nonstationary mean square response for the asymmetric mode which is not directly excited. Experimental and Monte Carlo simulation exhibit nonlinear features including a shift of the resonance peak in the response spectra as the excitation level increases. The observed shift is associated with a widening effect in the response bandwidth.

Theory of stochastic bifurcation in BWRs and applications

2003 ◽  
Vol 43 (1-4) ◽  
pp. 201-207 ◽  
Author(s):  
H. Konno ◽  
S. Kanemoto ◽  
Y. Takeuchi
Keyword(s):  
Stochastic Bifurcation
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