Abstract: Background: There are few studies comparing percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) for the treatment of bifurcation lesions of unprotected left main coronary artery (ULMCA). In the present study, we compared 1-year clinical outcomes of PCI with drug-eluting stent (DES) versus CABG in patients with ULMCA true bifurcation lesions. Methods: We evaluated a total of 276 consecutive patients with ULMCA true bifurcation lesions who underwent PCI with DES (n = 208) or CABG (n = 68). Propensity score (PS) adjustment and matching were applied to balance the baseline differences between groups. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE). Results: At 1 year, the incidence rate of MACCE was no significant difference between the PCI and CABG groups (12.5% vs. 19.1%, P = 0.163; PS-adjusted hazard ratio [HR]: 0.77, 95% confidence interval [CI]: 0.37-1.63; P = 0.498); the rates of death (2.4% vs. 8.8%, P = 0.018) and the composite of death, myocardial infarction or stroke (7.7% vs. 17.6%, P = 0.019) were observed less fre- quently in the PCI group, which were no longer significantly different after PS adjustment (for death, PS-adjusted HR: 0.41, 95% CI: 0.11-1.61, P = 0.203; for the composite of death, myocardial infarction or stroke, PS-adjusted HR: 0.59, 95% CI: 0.25-1.37, P = 0.219). Conclusions: For the treatment of ULMCA true bifurcation lesions, PCI with DES was associated with similar 1-year clinical outcomes when compared with CABG.
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From the IVUS database of our institute, we recruited 113 patients who had undergone drug-eluting stent implantation for coronary bifurcation lesions and had a SB diameter >2.5 mm and a diameter stenosis of SB <20%, as assessed by quantitative coronary angiography. Stent implantation was performed in the main vessel (MV), but not in the SB. We excluded patients for whom pre-intervention and post-inter- vention IVUS images of the MV were not available. Patients who underwent any intervention in the SB before or after stent implantation were also excluded. This study was ap- proved by the institutional review board of our institute, and written informed consent was obtained from each patient.
vs culotte two-stent technique in bifurcation lesions (SBs ≥ 2.50 mm and > 50% SB diameter stenosis) may provide further information on the role of two-stent techniques in this subset of bifurcations. Until then, a two-stent technique may be considered up-front for bifurcations with large SB (diam- eter ≥ 2.75 mm) and significant disease extending into the SB. In choosing the two-stent technique for LMCA bifurca- tion, several techniques such as T-stenting, T and Protrusion stenting (TAP), DK crush, and culotte (Figure 3) may be used according to the bifurcation angle. Therefore, intra- coronary imaging is recommended to ensure the adequate stent and vessel expansion in all LMCA bifurcation segments according to the reference size of the vessel: cutoff values for MLA after stenting ostial LCx 5.0 mm 2 , ostial LAD
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Abstract— Coronary artery disease (CAD) is associated with plaque formation in coronary arteries. Left main coronary bifurcation is one of the most affected regions in the human coronary system. Atherosclerotic plaque formation occurs at the sites of branching and bifurcations where low wall shear stress (WSS), oscillating WSS, flow division, particle residence time and stasis are found to occur. Study of blood flow through left main bifurcation in human subjects is difficult due to the lack of adequate techniques The purpose of this work is to simulate and analyse blood flow through left main coronary bifurcation under different stenosed conditions and to predict the possibility of further atherogenesis. Blood flow through left main coronary bifurcation is simulated and analysed using 3D computational fluid dynamics (CFD) model and the results are compared with that of 2D. The seven cases of bifurcation lesions described in literature are modeled and simulated. GAMBIT® and FLUENT® softwares were used for geometry creation and analysis respectively. Most of the 3D results are in agreement with that of 2D. Area weighted Average Wall Shear Stress (AAWSS) and vorticity are found minimum for normal bifurcation and the graphs follow similar but well defined trends with an offset compared to 2D. Average WSS (AWSS) for the regions with less than 1 Pa. is maximum for normal bifurcation and minimum for the lesion type 1.0.0 which infer that normal left main bifurcation is more resistant to atherogenesis compared to atherosclerotic LM bifurcations. The next inference is that among the types of lesions, the type 1.0.0 is severe in terms of greatest risk of plaque proliferation. The observation that the presence of lesions in either distal main branch or side branch or both together along with LM lesion ( Type 1.1.0, Type1.1.1 and Type 1.0.1) increases AWSS and hence resist further atherogenesis better, is in confirmation with 2D results. Area Weighted Average Vorticity is established as a feature for lesion type identifcation.
Anyinvolvementof coronary artery segment is assigned as suffix 1, suffix 0 was givenfor not involved segment. Forexample, lesion 1,0,1 means that proximal segment and distal part of the main branch hasdisease but side branch ostia are free of disease. Medina classification also fails to include two important features of bifurcation lesions: angulation and the size of the proximal healthy segment.
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Background: Kissing Balloon Inflation (KBI) technique was the first technique for percutaneous intervention in bifurcation lesions. It's the standard strategy in the two-stent procedure. Its benefit in one-stent approach remains uncertain. Several trials comparing KBI strategy with the No-KBI strategy in one-stent technique did not show any advantages in the clinical outcome. Clinical outcome and the follow up of ischemic symptoms is a useful method to compare the effectiveness of both strategies.
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In the provisional SB stenting group, the strict cross- over criteria resulted in SB stenting in only 3.7% of cases. The numerically increased rate of target lesion revascular- isation suggests that some SBs might have been under- treated by relying solely on visual assessed diameter stenosis and reduction in TIMI flow for SB stenting. Large SBs may supply a larger territory and the increased rate of angiographic SB restenosis after simple stenting may indicate a clinical relevant difference between the two strategies. We were not able to demonstrate a significant difference for longer SB lesions >5 mm likely due to the small subsample. Still, the numerical difference (16.5% vs 9.6%) could indicate that longer lesions more often require SB stenting which would be in line with other reports. 23 24 Previous studies on simple versus complex
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The design and properties of self-expanding stents make them potentially suitable for interventions in various complex coro- nary lesions, including vein graft lesions, bifurcation lesions, tortuous vessels, left main disease, small vessels, and lesions causing STEMI. Self-expanding stents have already been approved in Europe 35 for use in specific situations, such as bifur-
range as in Figure 3. It is well known that the presence of chaos is signaled by positive Lyapunov exponent. A nega- tive Lyapunov exponent is characteristic of dissipative (non-conservative) systems, which exhibit point stability. A Lyapunov exponent of zero is characteristic of a cycle-stable system. In this case, the orbits maintain their separation. The tangent bifurcation will be happened when the Lyapunov exponent is changed from the started posi- tive value to zero then to negative value. At I ref 1 7059 A . , where the fixed point changes from attracting to repelling and an attracting periodic orbit is born, the Lyapunov ex- ponent is 0. Just above I ref 2 7 A . , the Lyapunov expo- nent is positive, which means that the system is chaotic. This is the same range in which the bifurcation diagram given in Figure 3 showed a whole interval. For larger values of I ref , above 4.791 A, there is another short para-
shows that (3) has rich dynamic behaviors. In this section, we use the bifurcation diagrams, Lyapunov exponents and phase portraits to illustrate the above analytic results and find new dynamic behaviors of the model (3) as the parameters varies. The bifurcation parameters are considered in the following three cases:
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configuration, but also extend single equation to system of equations. For the first question, we apply the Rabinowitz’s global bifurcation theory and the Dancer’s unilateral global bifurcation theory to determine the range of parame- ter such that the existence of positive solution and negative solution. Under some appropriate assumptions, we also get the decay of positive solution and negative solution by fixing the parameter value on a small interval. We believe that our work is a useful contribution to the existing literature on asymptotically linear systems.
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Based on the experiments, overall vein images were successfully extracted. The Hessian matrix of Gaussian employed in this research can describe the intensity of blood vessel variation around each point of fundus image correctly. The sizes of the vessel were obtained from all the eigenvalue of Hessian Matrix in order to extract the blood vessel properly. Determining the point of bifurcation of the extracted blood vessel can be performed correctly and successfully. The smaller the Euclidian distance d(x, y) are the more similar two compared pixels so that these two pixels were considered as bifurcation point. On the other hand, the greater the distance value of d(x, y), the pixels that going to compared are more dissimilar.
We develop a dynamical model to understand the underlying dynamics of TUBERCULOSIS infection at population level. The model, which integrates the treatment of individuals, the infections of latent and recovery individuals, is rigorously analyzed to acquire insight into its dynamical features. The phenomenon resulted due to the exogenous infection of TUBERCULOSIS disease. The mathematical analysis reveals that the model exhibits a backward bifurcation when TB treatment remains of infected class. It is shown that, in the absence of treatment, the model has a disease-free equilibrium (DEF) which is globally asymptotically stable (GAS) and the associated reproduction threshold is less than unity. Further, the model has a unique endemic equili- brium (EEP), for a special case, whenever the associated reproduction thre- shold quantity exceeds unity. For a special case, the EEP is GAS using the central manifold theorem of Castillo-Chavez.
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Gali and Monacelli (2005) observed that closed economy models and open economy models differ in two primary aspects: (1) some coefficients, such as the degree of openness, terms of trade, and substitutability among domestic and foreign goods, depend on the parameters that are exclusive to the open economy framework; and (2), the natural levels of output and interest rate depend upon both domestic and foreign disturbances, in addition to openness and terms of trade. Barnett and Eryilmaz (2014) use the same methodology as in section 4 to detect bifurcation phenomenon. For two-dimensional dynamical systems, they apply Theorem 1.1. For three-dimensional dynamical systems, they apply Theorem 4.1. They employed CL MatCont within MatLab for numerical analysis. Regarding different policy rules, Barnett and Eryilmaz (2014) consider contemporaneous, forward, and backward looking policy rules, as well as hybrid combinations. The calibrated values of the parameters are given in Gali and Monacelli (2005), which are 𝛽 = 0.99, 𝛼 = 0.4, 𝜎 = 𝜔 = 1, 𝜑 = 3, and 𝜇 = 0.086 . For the 𝑁 = 3 policy parameters, 𝜙 𝑥 = 0.125, 𝜙 𝜋 = 1.5, and 𝜙 𝑟 = 0.5.
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ruptured MCA aneurysms. Morphologic measurements identi- fied a higher AR and a lower DA ratio among the ruptured com- pared with the unruptured groups (AR: 2.24 ⫾ 0.75 for ruptured and 1.56 ⫾ 0.8 for unruptured; DA: 1.53 ⫾ 0.54 for ruptured and 2.14 ⫾ 0.8 for unruptured). They concluded that even branch diameter and aneurysm neck located at the center of the bifurca- tion might be related to aneurysm rupture. The present results confirmed that the highest rate of inflow and EL occurs at a DA ratio of 1, when the diameters of both branches are similar and symmetric flow distribution is observed between these branches (model A-I: 0.128 mW and B-I: 0.126 mW). A similar pattern was found at a DA ratio of 1.3, with a 6.9% difference between the EL of A-I and A-II and 2.9% between B-I and B-II. The significance of the DA ratio decreases when the bifurcation angle is asymmetric. However, at a DA ratio of 2, the flow distribution between branches changes to 90:10, which affects the influx inside the an- eurysm and EL, accordingly. The reduction of the EL for a DA ratio of 2 suggested that with the more even branch diameter with a lower DA ratio, the risk of rupture was higher.
An automated retinal feature extraction algorithm for person authentication with template security has been implemented and this method involves blood vessel segmentation, feature extraction, generation of feature template consisting of the bifurcation points, non invertible transformations of the template, and then carried with anonymous matching of these feature points. The number of matched points is used to compute the degree of matching. We have made a performance analysis by using the publicly available databases, namely DRIVE, VARIA and STARE databases and found that the proposed retinal authentication method gives us 100%, 96.3% and 90.1% recognition rates for the above databases respectively. Experiments on the public domain datasets shows that this scheme provides better recognition accuracy and lower error rates along with the ability to protect the biometric template, thus becomes a promising solution for privacy trustworthy biometric applications. As a future work we will address the practical issues of the latency for recognition and the performance can also be verified for multimodal biometrics by using noninvertible transformations
is combined with the mechanism of sustain bifurcation of invariant patterns that is inherent to the economy. The stability of bifurcating branches is investigated theoretically to demonstrate that most of them are asymptotically unstable. Among a plethora of theoretically possible spatial patterns, those which actually become stable for spatial economic models are investigated numerically. The solution curves of the economy are shown to display a complicated mesh-like structure, which looks like threads of warp and weft.
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Abstract. This paper is concerned mainly with the study of fractional order prey-predator system with time delay analyzing stage structure system, the characteristic equation which deals with the local stability is calculated and the existence of Hopf bifurcation is derived using Routh Hurwitz strategies.
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Based on the fact that Chua’s system is a classic model system of electronic circuits, we ﬁrst present modiﬁed Chua’s system with a smooth nonlinearity, described by a cubic polynomial in this paper. Then, we explore the distribution of the equilibrium points of the modiﬁed Chua circuit system. By using the averaging theory, we consider zero-Hopf bifurcation of the modiﬁed Chua system. Moreover, the existence of periodic solutions in the modiﬁed Chua system is derived from the classical Hopf bifurcation theorem.
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the aneurysm, its parent artery, and adjacent branches (4). When aneurysms are large, have a complex shape, or are located at a bifurcation where vascular branching is complex, it is often difficult or even impossible to define these mor- phologic features by using currently available im- aging technology. Intravascular sonography has be- come an important tool both for analysis of vascular lesion characteristics and guidance of ther- apeutic interventions in the coronary arteries and peripheral vascular system. The primary purpose of our study was to evaluate the feasibility of using intravascular sonography to measure the size of the aneurysm’s ostium and to establish its relationship to the parent artery and adjacent arterial branches.