Entanglement and quantum phase transitions in matrix product spin one chains

We consider a one-parameter family of matrix product states of spin one particles on a periodic chain and study in detail the entanglement properties of such a state. In particular we calculate exactly the entanglement of one site with the rest of the chain, and the entanglement of two distant sites with each other and show that the derivative of both these properties diverge when the parameter $g$ of the states passes through a critical point. Such a point can be called a point of quantum phase transition, since at this point, the character of the matrix product state which is the ground state of a Hamiltonian, changes discontinuously. We also study the finite size effects and show how the entanglement depends on the size of the chain. This later part is relevant to the field of quantum computation where the problem of initial state preparation in finite arrays of qubits or qutrits is important. It is also shown that entanglement of two sites have scaling behavior near the critical point

Exact ground states for two new spin-1 quantum chains, new features of matrix product states

We use the matrix product formalism to find exact ground states of two new spin-1 quantum chains with nearest neighbor interactions. One of the models, model I, describes a one-parameter family of quantum chains for which the ground state can be found exactly. In certain limit of the parameter, the Hamiltonian turns into the interesting case $H=\sum_i ({\bf S}_i\cdot {\bf S}_{i+1})^2$. The other model which we label as model II, corresponds to a family of solvable three-state vertex models on square two dimensional lattices. The ground state of this model is highly degenerate and the matrix product states is a generating state of such degenerate states. The simple structure of the matrix product state allows us to determine the properties of degenerate states which are otherwise difficult to determine. For both models we find exact expressions for correlation functions.Comment: 22 pages, references added, accepted for publication in European Physics Journal

Cost-effectiveness of single-photon emission computed tomography for diagnosis of coronary artery disease: A systematic review of the key drivers and quality of published literature

Background: Single-photon-emission computed tomography (SPECT) being one of the most commonly used methods that significantly improved the detection of coronary artery disease. The objective of this study was to perform a systematic review of the cost-effectiveness of SPECT in diagnosis of coronary artery disease. Methods: Electronic databases including PubMed, Scopus and Web of Science were searched from 1997 through 2017. The full economic evaluations of SPECT as the first and only test in diagnosis of coronary artery disease were included in this study. Non-English studies, conference abstracts and letters/editorials were excluded. The Consolidated Health Economic Evaluation Reporting Standards checklist was used to review the methodological quality of included studies. Results: Eight studies met the systematic review inclusion criteria. In general, the quality of the included studies was high. The abstract of studies had the least degree of compliance with the Consolidated Health Economic Evaluation Reporting Standards checklist. The majority of the papers used decision tree model and estimated cost from a payer's perspective. This study revealed wide heterogeneity in the methodology particularly in setting, comparators, time horizon, and perspective. Conclusion: By conducting this systematic review on 8 valid studies, it was found that the cost-effectiveness of an imaging test strongly depends on the pretest likelihood of disease. The included studies on cost-effectiveness provide conflicting evidence in support of the use of SPECT in diagnosis of coronary artery disease. This study showed that the cost-effectiveness of an imaging test varied between subgroups of patients. © 201

A new family of matrix product states with Dzyaloshinski-Moriya interactions

We define a new family of matrix product states which are exact ground states of spin 1/2 Hamiltonians on one dimensional lattices. This class of Hamiltonians contain both Heisenberg and Dzyaloshinskii-Moriya interactions but at specified and not arbitrary couplings. We also compute in closed forms the one and two-point functions and the explicit form of the ground state. The degeneracy structure of the ground state is also discussed.Comment: 15 pages, 1 figur

Effectiveness of revascularization interventions compared with medical therapy in patients with ischemic cardiomyopathy: A systematic review protocol

Background: Cardiomyopathies is a group of heart diseases that directly affects the heart muscle, and their causes is not just high blood pressure, congenital and pericardial diseases but ischemic cardiomyopathy disease are also caused by vascular disorders, and to confirm the diagnosis, angiography is required. There are several methods for treating and controlling ischemic cardiomyopathy in world health systems and especially in the Iran health system, which include medical treatment, percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG). Methods: This systematic review will includes observational and interventional studies in English and Persian languages and evaluates effectiveness of revascularization interventions and medical therapy in patients with ischemic cardiomyopathy. Animal studies will not be considered. In this systematic review, our sources of information will be electronic databases, trial registries, and different types of grey literature. An electronic search is performed through PubMed, Cochrane library, Scopus, Web of Science, EMBASE, Tufts Medical Center Cost-Effectiveness Analysis Registry, NHS Economic Evaluations Database. To integrate the results of studies with similar results, meta-analysis will be used, for which Comprehensive Meta-Analysis (CMA) software will be used. Results are provided using relative risk with a 95 confidence interval for information. Results: The results of this systematic review will be published in a peer-reviewed journal. Conclusion: To our knowledge, this systematic review will be the first to evaluate existing research on the effectiveness of revascularization interventions compared with medical therapy in patients with ischemic cardiomyopathy. The review will benefit patients, healthcare providers, and policymakers. © 2018 the Author(s). Published by Wolters Kluwer Health, Inc

Effectiveness of revascularization interventions compared with medical therapy in patients with ischemic cardiomyopathy: A systematic review protocol

Background: Cardiomyopathies is a group of heart diseases that directly affects the heart muscle, and their causes is not just high blood pressure, congenital and pericardial diseases but ischemic cardiomyopathy disease are also caused by vascular disorders, and to confirm the diagnosis, angiography is required. There are several methods for treating and controlling ischemic cardiomyopathy in world health systems and especially in the Iran health system, which include medical treatment, percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG). Methods: This systematic review will includes observational and interventional studies in English and Persian languages and evaluates effectiveness of revascularization interventions and medical therapy in patients with ischemic cardiomyopathy. Animal studies will not be considered. In this systematic review, our sources of information will be electronic databases, trial registries, and different types of grey literature. An electronic search is performed through PubMed, Cochrane library, Scopus, Web of Science, EMBASE, Tufts Medical Center Cost-Effectiveness Analysis Registry, NHS Economic Evaluations Database. To integrate the results of studies with similar results, meta-analysis will be used, for which Comprehensive Meta-Analysis (CMA) software will be used. Results are provided using relative risk with a 95 confidence interval for information. Results: The results of this systematic review will be published in a peer-reviewed journal. Conclusion: To our knowledge, this systematic review will be the first to evaluate existing research on the effectiveness of revascularization interventions compared with medical therapy in patients with ischemic cardiomyopathy. The review will benefit patients, healthcare providers, and policymakers. © 2018 the Author(s). Published by Wolters Kluwer Health, Inc

Phantom Mimicry on the Normal Branch of a DGP-inspired Braneworld Scenario with Curvature Effect

It has been shown recently that phantom-like effect can be realized on the normal branch of the DGP setup without introduction of any phantom matter neither in the bulk nor on the brane and therefore without violation of the null energy condition. It has been shown also that inclusion of the Gauss-Bonnet term in the bulk action modifies this picture via curvature effects. Here, based on the Lue-Starkman conjecture on the dynamical screening of the brane cosmological constant in the DGP setup, we extend this proposal to a general DGP-inspired $f(R,\phi)$ model that stringy effects in the ultra-violet sector of the theory are taken into account by inclusion of the Gauss-Bonnet term in the bulk action. We study cosmological dynamics of this setup, especially its phantom-like behavior and possible crossing of the phantom divide line especially with a non-minimally coupled quintessence field on the brane. In this setup, scalar field and curvature quintessence are treated in a unified framework.Comment: 25 Figures, To appear in MPL

Exact symmetry breaking ground states for quantum spin chains

We introduce a family of spin-1/2 quantum chains, and show that their exact ground states break the rotational and translational symmetries of the original Hamiltonian. We also show how one can use projection to construct a spin-3/2 quantum chain with nearest neighbor interaction, whose exact ground states break the rotational symmetry of the Hamiltonian. Correlation functions of both models are determined in closed form. Although we confine ourselves to examples, the method can easily be adapted to encompass more general models.Comment: 4 pages, RevTex. 4 figures, minor changes, new reference

Global, Regional, and National Levels and Trends in Burden of Oral Conditions from 1990 to 2017: A Systematic Analysis for the Global Burden of Disease 2017 Study

Government and nongovernmental organizations need national and global estimates on the descriptive epidemiology of common oral conditions for policy planning and evaluation. The aim of this component of the Global Burden of Disease study was to produce estimates on prevalence, incidence, and years lived with disability for oral conditions from 1990 to 2017 by sex, age, and countries. In addition, this study reports the global socioeconomic pattern in burden of oral conditions by the standard World Bank classification of economies as well as the Global Burden of Disease Socio-demographic Index. The findings show that oral conditions remain a substantial population health challenge. Globally, there were 3.5 billion cases (95% uncertainty interval [95% UI], 3.2 to 3.7 billion) of oral conditions, of which 2.3 billion (95% UI, 2.1 to 2.5 billion) had untreated caries in permanent teeth, 796 million (95% UI, 671 to 930 million) had severe periodontitis, 532 million (95% UI, 443 to 622 million) had untreated caries in deciduous teeth, 267 million (95% UI, 235 to 300 million) had total tooth loss, and 139 million (95% UI, 133 to 146 million) had other oral conditions in 2017. Several patterns emerged when the World Bank's classification of economies and the Socio-demographic Index were used as indicators of economic development. In general, more economically developed countries have the lowest burden of untreated dental caries and severe periodontitis and the highest burden of total tooth loss. The findings offer an opportunity for policy makers to identify successful oral health strategies and strengthen them; introduce and monitor different approaches where oral diseases are increasing; plan integration of oral health in the agenda for prevention of noncommunicable diseases; and estimate the cost of providing universal coverage for dental care