261 research outputs found

    Functional Differential Equations for the Free Energy and the Effective Energy in the Broken-Symmetry Phase of phi^4-Theory and Their Recursive Graphical Solution

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    Extending recent work on QED and the symmetric phase of the euclidean multicomponent scalar \phi^4-theory, we construct the vacuum diagrams of the free energy and the effective energy in the ordered phase of \phi^4-theory. By regarding them as functionals of the free correlation function and the interaction vertices, we graphically solve nonlinear functional differential equations, obtaining loop by loop all connected and one-particle irreducible vacuum diagrams with their proper weights.Comment: Author Information under http://www.physik.fu-berlin.de/~kleinert/institution.html Latest update of paper also at http://www.physik.fu-berlin.de/~kleinert/31

    Effect of age on the prognostic value of left ventricular function in patients with acute coronary syndrome:a prospective registry study

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    Objective: This study aims to study the prognostic impact of LV function on mortality and examine the effect of age on the prognostic value of left ventricular function.  Methods: We examined the Myocardial Ischaemia National Audit Project (MINAP) registry (2006-2010) data with a mean follow up of 2.1 years. LV function was categorized into good (ejection fraction (EF) ≥50%), moderate (EF 30-49%) and poor (EF <30%) categories. Cox-proportional hazards models were constructed to examine the prognostic significance of LV function in different age groups (<65, 65-74, 75-84 and ≥85 years) on all-cause mortality adjusting for baseline variables.  Results: Of 424,848 patients, LV function data available for 123,609. Multiple imputations were used to impute missing values of LV function and the final sample for analyses were drawn from 414,305. After controlling for confounders, 339,887 participants were included in the regression models. For any age group, mortality was higher with worsening degree of LV impairment. Increased age reduced the adverse prognosis associated with reduced LV function (hazard ratios (HRs) of death comparing poor LV function to good LV function were 2.11 95%CI 1.88-2.37 for age <65 years and 1.28 95%CI 1.20-1.36 for age ≥85 years. Older patients had a high mortality risk even in those with good LV function. HRs of mortality for ≥85 compared to <65 years (HR=1.00) within good, moderate and poor ejection fractions groups were 5.89, 4.86 and 3.43, respectively.  Conclusions: In patients with ACS, clinicians should interpret the prognostic value of LV function taking into account patient’s age

    A Table of Third and Fourth Order Feynman Diagrams of the Interacting Fermion Green's Function

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    The Feynman diagrams of the Green's function expansion of fermions interacting with a non-relativistic 2-body interaction are displayed in first, second and third order of the interaction as 2, 10 and 74 diagrams, respectively. A name convention for the diagrams is proposed and then used to tabulate the 706 diagrams of fourth order. The Hartree-Fock approximation summons up 2, 8, 40 and 224 of them, respectively.Comment: 12 pages, 13 figures, 16 tables. Index typo in Sect III corrected. More lines in Table XV. Three more references. Expanded Summar

    Recursive Graphical Construction for Feynman Diagrams of Quantum Electrodynamics

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    We present a method for a recursive graphical construction of Feynman diagrams with their correct multiplicities in quantum electrodynamics. The method is first applied to find all diagrams contributing to the vacuum energy from which all n-point functions are derived by functional differentiation with respect to electron and photon propagators, and to the interaction. Basis for our construction is a functional differential equation obeyed by the vacuum energy when considered as a functional of the free propagators and the interaction. Our method does not employ external sources in contrast to traditional approaches.Comment: Author Information under http://www.physik.fu-berlin.de/~kleinert/institution.html Latest update of paper also at http://www.physik.fu-berlin.de/~kleinert/29

    Multivisceral resection of pancreatic neuroendocrine tumours: a report of two cases

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    Pancreatic neuroendocrine tumours (pNETs) are rare and surgical resection offers the only possibility of cure for localised disease. The role of surgery in the setting of locally advanced and metastatic disease is more controversial. Emerging data suggests that synchronous surgical resection of pancreas and liver may be associated with increased survival. We report two cases of synchronous, one stage multivisceral resections for pNET and associated reconstruction. We highlight the technical issues involved in such extensive resections and demonstrate that one stage multivisceral operations can be achieved safely

    Relationship between anemia and mortality outcomes in a national acute coronary syndrome cohort: Insights from the UK Myocardial Ischemia National Audit Project registry

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    Background: We aim to determine the prevalence of anemia in ACS patients and compared their clinical characteristics, management and clinical outcomes to those without anemia in an unselected national ACS cohort. Methods and Results: The Myocardial Ischemia National Audit Project (MINAP) registry collects data on all adults admitted to hospital trusts in England and Wales with diagnosis of an ACS. We conducted a retrospective cohort study by analyzing patients in this registry between January 2006 and December 2010 and followed them up until August 2011. Multiple logistic regressions were used to determine factors associated with anemia and the adjusted odds of 30-day mortality with 1 g/dl incremental hemoglobin increase and the 30-days and 1-year mortality for anemic compared to non-anemic groups. Analyses were adjusted for covariates. Our analysis of 422,855 patients with ACS showed that 27.7% of patients presenting with ACS are anemic, and that these patients are older, have a greater prevalence renal disease, peripheral vascular disease, diabetes mellitus and previous acute myocardial infarction and are less likely to receive evidence based therapies shown to improve clinical outcomes. Finally our analysis suggests that anemia is independently associated with 30-day (OR 1.28, 95%CI 1.22-1.35) and 1-year mortality (OR 1.31, 95%CI 1.27-1.35) and we observed a reverse J-shaped relationship between hemoglobin levels and mortality outcomes. Conclusion: The prevalence of anemia in a contemporary national ACS cohort is clinically significant. Patients with anemia are older and multi-morbid, and less likely to receive evidence-based therapies shown to improve clinical outcomes with the presence of anemia independently associated mortality outcomes

    Recursive Graphical Solution of Closed Schwinger-Dyson Equations in phi^4-Theory -- Part1: Generation of Connected and One-Particle Irreducible Feynman Diagrams

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    Using functional derivatives with respect to the free correlation function we derive a closed set of Schwinger-Dyson equations in phi^4-theory. Its conversion to graphical recursion relations allows us to systematically generate all connected and one-particle irreducible Feynman diagrams for the two- and four-point function together with their weights.Comment: Author Information under http://www.physik.fu-berlin.de/~pelster

    Relationship Between Anemia and Mortality Outcomes in a National Acute Coronary Syndrome Cohort: Insights from the UK Myocardial Ischemia National Audit Project Registry

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    BACKGROUND: We aim to determine the prevalence of anemia in acute coronary syndrome (ACS) patients and compare their clinical characteristics, management, and clinical outcomes to those without anemia in an unselected national ACS cohort. METHODS AND RESULTS: The Myocardial Ischemia National Audit Project (MINAP) registry collects data on all adults admitted to hospital trusts in England and Wales with diagnosis of an ACS. We conducted a retrospective cohort study by analyzing patients in this registry between January 2006 and December 2010 and followed them up until August 2011. Multiple logistic regressions were used to determine factors associated with anemia and the adjusted odds of 30-day mortality with 1 g/dL incremental hemoglobin increase and the 30-day and 1-year mortality for anemic compared to nonanemic groups. Analyses were adjusted for covariates. Our analysis of 422 855 patients with ACS showed that 27.7% of patients presenting with ACS are anemic and that these patients are older, have a greater prevalence of renal disease, peripheral vascular disease, diabetes mellitus, and previous acute myocardial infarction, and are less likely to receive evidence-based therapies shown to improve clinical outcomes. Finally, our analysis suggests that anemia is independently associated with 30-day (OR 1.28, 95% CI 1.22-1.35) and 1-year mortality (OR 1.31, 95% CI 1.27-1.35), and we observed a reverse J-shaped relationship between hemoglobin levels and mortality outcomes. CONCLUSIONS: The prevalence of anemia in a contemporary national ACS cohort is clinically significant. Patients with anemia are older and multimorbid and less likely to receive evidence-based therapies shown to improve clinical outcomes, with the presence of anemia independently associated with mortality outcomes

    Association of increasing age with receipt of specialist care and long-term mortality in patients with non-ST elevation myocardial infarction

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    Background: observational studies suggest that older patients are less likely to receive secondary prevention medicines following acute coronary syndrome (ACS). Objectives: to examine the association of increasing age with receipt of specialist care and influence of specialist care on long-term mortality in patients with non-ST elevation myocardial infarction (NSTEMI). Design: a cohort study. Setting: National ACS registry of England and Wales. Subjects: a total of 85,183 patients admitted with NSTEMI between 2006 and 2010. Methods: logistic regression analyses to assess receipt of secondary prevention medicines (ACE inhibitor, β-blocker, statin, aspirin) by age group; multivariate Cox regression models to examine longitudinal effect of cardiologist care on all-cause mortality by age group. Results: mean age 72.0 years (SD 13.0 years), mean follow-up was 2.13 years. Older patients received less cardiologist care (70.2% of NSTEMI patients ≥85 years compared with 94.7% of patients <65) years and had more co-morbidity. Cardiologists prescribed more secondary prevention in all age groups than generalists, but this was mostly explained away by co-morbidity (receipt of statin crude OR 1.51 (1.27,1.80), fully adjusted OR 1.11 (0.92,1.33) in patients ≥85 years). Receiving cardiologist care compared with generalist care was associated with a decreased risk of death in all even after adjustment for co-morbidity, disease severity and secondary prevention; this benefit reduced incrementally with older age group (adjusted hazard ratio (HR) 0.58 (0.49,0.68) aged <65; 0.87 (0.82,0.92) aged ≥85). Conclusion: older patients with NSTEMI were less likely to see a cardiologist, but reduced treatment by generalists was explained away by co-morbidity. Cardiologist care was associated with lower mortality in all age groups than a generalist, but this survival benefit was less pronounced in older patients
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