Wavevector-dependent optical properties from wavevector-independent proper conductivity tensor

We discuss the calculation of the refractive index by means of the ab initio scalar dielectric function and point out its inherent limitations. To overcome these, we start from the recently proposed fundamental, microscopic wave equation in materials in terms of the frequency- and wavevector-dependent dielectric tensor, and investigate under which conditions the standard treatment can be justified. Thereby, we address the question of neglecting the wavelength dependence of microscopic response functions. Furthermore, we analyze in how far the fundamental, microscopic wave equation is equivalent to the standard wave equation used in theoretical optics. In particular, we clarify the relation of the "effective" dielectric tensor used there to the microscopic dielectric tensor defined in ab initio physics.Comment: consistent with published version in Eur. Phys. J. B (2020

Quantum Field Theoretical Green Functions and Electronic Structure

Die vorliegende Arbeit stellt eine rein theoretische Untersuchung dar, deren Hauptziel darin besteht, die Theorie der elektronischen Struktur vom Standpunkt der Quantenfeld- und Vielteilchentheorie aus zu entwickeln. Dabei habe ich versucht, alle Konzepte und Definitionen im quantenfeldtheoretischen Rahmen einzuf\"{u}hren.Die Einteilchenn\"{a}herung hingegen wird nur als Spezialfall behandelt, spielt jedoch keine konzeptionelle Rolle. Ein weiteres Ziel dieser Arbeit besteht darin, Analogien zwischen der ``Electronic Structure Theory'' und anderen Gebieten der Physik zu erhellen. Das konkrete Thema dieser Dissertation ist die Anwendung von Greenschen Funktionen auf die Quantentheorie der Materialeigenschaften des Festk\"{o}rpers, insbesondere der elektronischen Struktur. Die Arbeit ist in zwei Teile gegliedert: (i) eine Zusammenfassung und Diskussion des allgemeinen vielteilchen- und quantenfeldtheoretischen Rahmens und (ii) die Theorie der elektronischen Green-Funktionen.he present thesis is a purely theoretical study, the main goal of which is the theoretical development of Electronic Structure Theory from the quantum field theoretical and many-body theory point of view. I have tried to introduce all concepts and definitions in the quantum field theoretical framework. The independent electron approximation is always treated as a special case of the general many-body theory, but does not play any conceptual role. Another goal of this thesis has been the elucidation of various analogies between Electronic Structure Theory and other branches of physics. The concrete topic of this thesis is the application of Green function methods to the quantum theory of materials properties in the solid state, in particular to Electronic Structure Theory. The thesis is divided into two parts, (i) a review and discussion of some aspects of the general Many-Body Theory and non-relativistic Quantum Field Theory background and (ii) electronic Green functions methods

Frequency-independent terahertz anomalous Hall effect in DyCo5, Co32Fe68 and Gd27Fe73 thin films from DC to 40 THz

The anomalous Hall effect (AHE) is a fundamental spintronic charge‐to‐charge‐current conversion phenomenon and closely related to spin‐to‐charge‐current conversion by the spin Hall effect. Future high‐speed spintronic devices will crucially rely on such conversion phenomena at terahertz (THz) frequencies. Here, it is revealed that the AHE remains operative from DC up to 40 THz with a flat frequency response in thin films of three technologically relevant magnetic materials: DyCo5, Co32Fe68, and Gd27Fe73. The frequency‐dependent conductivity‐tensor elements σxx and σyx are measured, and good agreement with DC measurements is found. The experimental findings are fully consistent with ab initio calculations of σyx for CoFe and highlight the role of the large Drude scattering rate (≈100 THz) of metal thin films, which smears out any sharp spectral features of the THz AHE. Finally, it is found that the intrinsic contribution to the THz AHE dominates over the extrinsic mechanisms for the Co32Fe68 sample. The results imply that the AHE and related effects such as the spin Hall effect are highly promising ingredients of future THz spintronic devices reliably operating from DC to 40 THz and beyond

AHA/ACC Guidelines for Preventing Heart Attack and Death in Patients With Atherosclerotic Cardiovascular Disease: 2001 Update: A Statement for Healthcare Professionals From the American Heart Association and the American College of Cardiology

"Since the original publication (in 1995) of the American Heart Association (AHA) consensus statement on secondary prevention, which was endorsed by the American College of Cardiology (ACC), important evidence from clinical trials has emerged that further supports the merits of aggressive risk reduction therapies for patients with atherosclerotic cardiovascular disease. As noted in that statement, aggressive risk factor management clearly improves patient survival, reduces recurrent events and the need for interventional procedures, and improves the quality of life for these patients. The compelling evidence from recent clinical trials was the impetus to revise the 1995 guidelines (Table). As examples, the many lipid reduction trials have generated significant changes in the National Heart, Lung, and Blood Institute’s Adult Treatment Panel III report. This report further defined target cholesterol levels, expanded indications for drug treatment, and initiated therapy earlier. Accumulating β-blocker data have resulted in broader indications for a larger patient group. The Heart Outcomes Prevention Evaluation (HOPE) trial has demonstrated the benefit of ACE inhibitor therapy in high-risk patients with cardiovascular disease without a history of an acute event. Further data from ongoing trials should provide insight into the potential benefits of treating lower risk patients with combined therapies. The Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial has provided evidence for clopidogrel benefit in certain patients. Diabetes management recommendations have been updated to include recent guidelines from the American Diabetes Association for risk factor management of diabetics and the growing body of evidence showing diabetics at high risk for cardiovascular events. The Heart and Estrogen/progestin Replacement Study (HERS) documented that hormone replacement therapy is ineffective for secondary prevention. The writing group revising this document also considered other important trials and reports, and they are included in the selected reading list.

Convergence Without Hard Criteria: Does EU Soft Law Affect Domestic Unemployment Protection Schemes?

(VLID)177126

Effect of Dietary Zinc Oxide on Morphological Characteristics, Mucin Composition and Gene Expression in the Colon of Weaned Piglets

The trace element zinc is often used in the diet of weaned piglets, as high doses have resulted in positive effects on intestinal health. However, the majority of previous studies evaluated zinc supplementations for a short period only and focused on the small intestine. The hypothesis of the present study was that low, medium and high levels of dietary zinc (57, 164 and 2,425 mg Zn/kg from zinc oxide) would affect colonic morphology and innate host defense mechanisms across 4 weeks post-weaning. Histological examinations were conducted regarding the colonic morphology and neutral, acidic, sialylated and sulphated mucins. The mRNA expression levels of mucin (MUC) 1, 2, 13, 20, toll-like receptor (TLR) 2, 4, interleukin (IL)-1β, 8, 10, interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) were also measured. The colonic crypt area increased in an age-depending manner, and the greatest area was found with medium concentration of dietary zinc. With the high concentration of dietary zinc, the number of goblet cells containing mixed neutral-acidic mucins and total mucins increased. Sialomucin containing goblet cells increased age-dependently. The expression of MUC2 increased with age and reached the highest level at 47 days of age. The expression levels of TLR2 and 4 decreased with age. The mRNA expression of TLR4 and the pro-inflammatory cytokine IL-8 were down-regulated with high dietary zinc treatment, while piglets fed with medium dietary zinc had the highest expression. It is concluded that dietary zinc level had a clear impact on colonic morphology, mucin profiles and immunological traits in piglets after weaning. Those changes might support local defense mechanisms and affect colonic physiology and contribute to the reported reduction of post-weaning diarrhea

Identification of mutations allowing Natural Resistance Associated Macrophage Proteins (NRAMP) to discriminate against cadmium.

Each essential transition metal plays a specific role in metabolic processes and has to be selectively transported. Living organisms need to discriminate between essential and non-essential metals such as cadmium (Cd(2+) ), which is highly toxic. However, transporters of the natural resistance-associated macrophage protein (NRAMP) family, which are involved in metal uptake and homeostasis, generally display poor selectivity towards divalent metal cations. In the present study we used a unique combination of yeast-based selection, electrophysiology on Xenopus oocytes and plant phenotyping to identify and characterize mutations that allow plant and mammalian NRAMP transporters to discriminate between their metal substrates. We took advantage of the increased Cd(2+) sensitivity of yeast expressing AtNRAMP4 to select mutations that decrease Cd(2+) sensitivity while maintaining the ability of AtNRAMP4 to transport Fe(2+) in a population of randomly mutagenized AtNRAMP4 cDNAs. The selection identified mutations in three residues. Among the selected mutations, several affect Zn(2+) transport, whereas only one, E401K, impairs Mn(2+) transport by AtNRAMP4. Introduction of the mutation F413I, located in a highly conserved domain, into the mammalian DMT1 transporter indicated that the importance of this residue in metal selectivity is conserved among NRAMP transporters from plant and animal kingdoms. Analyses of overexpressing plants showed that AtNRAMP4 affects the accumulation of metals in roots. Interestingly, the mutations selectively modify Cd(2+) and Zn(2+) accumulation without affecting Fe transport mediated by NRAMP4 in planta. This knowledge may be applicable for limiting Cd(2+) transport by other NRAMP transporters from animals or plants