Self-consistent solutions of Hedin's equations (HE) for the two-site Hubbard model (HM) have been studied. They have been found for three-point vertices of increasing complexity (Γ = 1 (GW approximation), Γ1 from the first-order perturbation theory, and the exact vertex Γ(E)). Comparison is made between the cases when an additional quasiparticle (QP) approximation for Green's functions is applied during the self-consistent iterative solving of HE and when QP approximation is not applied. The results obtained with the exact vertex are directly related to the present open question-which approximation is more advantageous for future implementations, GW + DMFT or QPGW + DMFT. It is shown that in a regime of strong correlations only the originally proposed GW + DMFT scheme is able to provide reliable results. Vertex corrections based on perturbation theory (PT) systematically improve the GW results when full self-consistency is applied. The application of QP self-consistency combined with PT vertex corrections shows similar problems to the case when the exact vertex is applied combined with QP sc. An analysis of Ward Identity violation is performed for all studied in this work's approximations and its relation to the general accuracy of the schemes used is provided.
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http://dx.doi.org/10.1088/0953-8984/27/31/315603 | DOI Listing |
Trends Cell Biol
December 2024
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
Technical advances over the past two decades have enabled robust detection of cell-free DNA (cfDNA) in biological samples. Yet, higher clinical sensitivity is required to realize the full potential of liquid biopsies. This opinion article argues that to overcome current limitations, the abundance of informative cfDNA molecules - such as circulating tumor DNA (ctDNA) - collected in a sample needs to increase.
View Article and Find Full Text PDFPharmacoecon Open
December 2024
Comparative Health Outcomes, Policy, and Economics (CHOICE) Institute in the School of Pharmacy at the University of Washington, Washington, USA.
It is well known that healthcare resource constraints influence the capacity to deliver care, affecting both the costs and outcomes of medical interventions. If these constraints are not adequately accounted for in economic evaluations, there may be a lack of understanding regarding the full impact of implementing health technologies, leading to decisions being made with suboptimal information. This paper offers an overview of the types of healthcare resource constraints and their potential effects, and introduces a framework grounded in operations research and health economics principles, outlining the methodological considerations for incorporating resource constraints into economic evaluations.
View Article and Find Full Text PDFNat Commun
November 2024
Breast Cancer Translational Research Laboratory, Institut Jules Bordet, Hôpital Universitaire de Bruxelles (H.U.B), Université Libre de Bruxelles (ULB), Brussels, Belgium.
In HER2-positive breast cancer, clinical outcome and sensitivity to HER2-targeted therapies are influenced by both tumor and microenvironment features. However, we are currently unable to depict the molecular heterogeneity of this disease with sufficient granularity. Here, by performing gene expression profiling in HER2-positive breast cancers from patients receiving adjuvant trastuzumab in the ALTTO clinical trial (NCT00490139), we identify and characterize five molecular subtypes associated with the risk of distant recurrence: immune-enriched, proliferative/metabolic-enriched, mesenchymal/stroma-enriched, luminal, and ERBB2-dependent.
View Article and Find Full Text PDFBiophys J
January 2025
Jožef Stefan Institute, Ljubljana, Slovenia. Electronic address:
The ability of biological systems to withstand and recover from various disruptions, such as spontaneous genetic mutations and environmental damage, largely relies on intricate feedback mechanisms. We theoretically study the mechanical response of an epithelial tissue facing damage in the form of a circular wound. Our model describes a feedback loop between the generation of active forces in the actomyosin and tissue mechanics, described by the vertex model.
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