261 research outputs found
Quantum impurity solvers using a slave rotor representation
We introduce a representation of electron operators as a product of a
spin-carry ing fermion and of a phase variable dual to the total charge (slave
quantum rotor). Based on this representation, a new method is proposed for
solving multi-orbital Anderson quantum impurity models at finite interaction
strength U. It consists in a set of coupled integral equations for the
auxiliary field Green's functions, which can be derived from a controlled
saddle-point in the limit of a large number of field components. In contrast to
some finite-U extensions of the non-crossing approximation, the new method
provides a smooth interpolation between the atomic limit and the weak-coupling
limit, and does not display violation of causality at low-frequency. We
demonstrate that this impurity solver can be applied in the context of
Dynamical Mean-Field Theory, at or close to half-filling. Good agreement with
established results on the Mott transition is found, and large values of the
orbital degeneracy can be investigated at low computational cost.Comment: 18 pages, 15 figure
Care after premenopausal risk-reducing salpingo-oophorectomy in high-risk women: Scoping review and international consensus recommendations
Women at high inherited risk of ovarian cancer are offered risk-reducing salpingo-oophorectomy (RRSO) from age 35 to 45 years. Although potentially life-saving, RRSO may induce symptoms that negatively affect quality of life and impair long-term health. Clinical care following RRSO is often suboptimal. This scoping review describes how RRSO affects short- and long-term health and provides evidence-based international consensus recommendations for care from preoperative counselling to long-term disease prevention. This includes the efficacy and safety of hormonal and non-hormonal treatments for vasomotor symptoms, sleep disturbance and sexual dysfunction and effective approaches to prevent bone and cardiovascular disease
Human IRF1 governs macrophagic IFN-Îł immunity to mycobacteria
Inborn errors of human IFN-γ-dependent macrophagic immunity underlie mycobacterial diseases, whereas inborn errors of IFN-α/β-dependent intrinsic immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria and related intramacrophagic pathogens. These children have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2, which is life-threatening in individuals with impaired IFN-α/β immunity. In leukocytes or fibroblasts stimulated in vitro, IRF1-dependent responses to IFN-γ are, both quantitatively and qualitatively, much stronger than those to IFN-α/β. Moreover, IRF1-deficient mononuclear phagocytes do not control mycobacteria and related pathogens normally when stimulated with IFN-γ. By contrast, IFN-α/β-dependent intrinsic immunity to nine viruses, including SARS-CoV-2, is almost normal in IRF1-deficient fibroblasts. Human IRF1 is essential for IFN-γ-dependent macrophagic immunity to mycobacteria, but largely redundant for IFN-α/β-dependent antiviral immunity
Prevention of osteoporosis with low dose oestrogens
SCOPUS: cp.jinfo:eu-repo/semantics/publishe
Clinical evidence supporting the rationale for constant oestrogen, intermittent progestogen hormone replacement therapy
Hormone replacement therapy (HRT) effectively relieves vasomotor and other symptoms associated with menopause, yet is underutilised by the majority of menopausal women. Current HRT regimens combine continuous oestrogen with continuous or sequential progestogen in order to achieve the beneficial effects of oestrogen while avoiding the potential for increased risk of endometrial cancer. Uterine bleeding and other adverse progestogenic effects are major reasons for patient noncompliance and early discontinuation of combination HRT, which can ultimately limit the achievement of long-term oestrogenic benefits. A novel constant 17β-oestradiol, intermittent norgestimate regimen has been developed based on theoretical hormone receptor dynamics in an attempt to minimise the hormonal doses needed, thereby potentially reducing the occurrence of adverse effects associated with higher oestrogen and progestogen doses. Clinical trial data with this novel low-dose HRT regimen demonstrate effective relief of vasomotor symptoms in postmenopausal women, acceptable bleeding rates, no endometrial hyperplasia, beneficial effects on lipids, and excellent tolerability. This regimen has the potential to increase long-term use resulting in important clinical benefits. © 2001 Elsevier Science Ireland Ltd.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
New therapeutic targets and agents for osteoporosis.
CommentEditorialSCOPUS: ed.jinfo:eu-repo/semantics/publishe
State of contraception in 2016
Introduction: The Pill and and other forms of hormonal contraception, if taken correctly, are very effective and safe for millions of women, but since a few years, due to debates and controversies about third- and fourth-generation pills, other options have gained in popularity. Objectives: to provide a review of oestroprogestative contraception (OP), progestative contraception, IUDs with a focus on their advantages and side-effects according to the specific needs of women.Methods: Literature review and lessons learned from clinical practice.Results: the importance of family and individual history, the life-style and socio-economic conditions are critical factors for advising women of the 15 contraceptive choices available to them. The risk/benefit ratio of OP contraception needs a yearly follow-up. The progestative contraception is the preferred option for women who have contraindication for estrogen, are older than forty, and/or have risk factors such as a history of venous thromboembolism, overweight and smoking. The IUD is well tolerated and causes few side effects. Among the other contraceptive methods, sterilization and diaphragms are briefly discussed. Conclusions: Among the many safe and effective contraceptive methods, it is important for general practitioners to know the advantages and the side effects of each method, as well as the specific conditions of the woman, to propose the best options available. In case of difficulties of follow up or adherence to daily uptake, in particular among adolescents, long-acting methods such as IUD or implants are preferable.Introduction: Longtemps préférée des femmes, les pilules sont en recul en Belgique depuis les polémiques sur les pilules de 3° et 4° génération. Si le recours à la contraception orale a diminué, d'autres pratiques contraceptives se sont renforcées. Objectifs: Fournir une description détaillée des contraceptifs oestroprogestatifs (OP), des contraceptifs à base de progestatifs seuls et des dispositifs intra-utérins, en soulignant leur intérêt mais aussi les risques de leur utilisation. Méthode: Revue de la littérature et expérience clinique. Résultats: L'importance des antécédents personnels, familiaux, et du style de vie est déterminante pour évaluer les indications des différentes méthodes. En ce qui concerne les contraceptifs OP, le rapport risque/bénéfice nécessite un suivi annuel. La contraception progestative est une option choisie par de nombreuses femmes, particulièrement celles qui ont plus de 40 ans, et/ou des facteurs de risque comme le tabac, le surpoids ou des antécédents de TEV. Le dispositif intra-utérin est généralement bien toléré comme méthode contraceptive car il présente peu d'effets secondaires ou de complications. Parmi les autres méthodes contraceptives, la stérilisation féminine et le diaphragme sont brièvement discutés. Conclusion: Parmi les nombreuses possibilités de choix contraceptifs, il est important de faire connaître les indications et contre-indications en tenant compte de la situation de la personne. En cas de difficulté de suivi et d'observance, en particulier chez les adolescentes, la prescription des méthodes à longue durée d'action est préférable
A qualitative systematic review of coasting, a procedure to avoid ovarian hyperstimulation syndrome in IVF patients
SCOPUS: re.jinfo:eu-repo/semantics/publishe
Information on nuclear medicine tests on the Internet.
LetterSCOPUS: le.jinfo:eu-repo/semantics/publishe
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