Understanding the complex phase diagram of uranium: the role of electron-phonon coupling

We report an experimental determination of the dispersion of the soft phonon mode along [1,0,0] in uranium as a function of pressure. The energies of these phonons increase rapidly, with conventional behavior found by 20 GPa, as predicted by recent theory. New calculations demonstrate the strong pressure (and momentum) dependence of the electron-phonon coupling, whereas the Fermi-surface nesting is surprisingly independent of pressure. This allows a full understanding of the complex phase diagram of uranium, and the interplay between the charge-density wave and superconductivity

The eck fistula in animals and humans

In all species so far studied, including man, portacaval shunt causes the same changes in liver morphology, including hepatocyte atrophy, fatty infiltration, deglycogenation, depletion and disorganization of the rough endoplasmic reticulum (RER) and its lining polyribosomes and variable but less specific damage to other organelles. Many, perhaps all, biosynthetic processes are quickly depressed, largely secondary to the selective damage to the RER, which is the "factory" of the cell. These structural and metabolic changes in the liver after portal diversion are caused by the diversion around the liver of the hepatotrophic substances in portal venous blood, of which endogenous insulin is the most important. In experimental animals, the injury of Eck's fistula can be prevented by infusing insulin into the tied-off hilar portal vein. The subtle but far-reaching changes in hepatic function after portal diversion have made it possible to use this procedure in palliating three inborn errors of metabolism: glycogen storage disease, familial hypercholesterolemia, and α1-antitrypsin deficiency In these three diseases, the abnormalities caused by portal diversion have counteracted abnormalities in the patients that were caused by the inborn errors. In these diseases, amelioration of the inborn errors depends on the completeness of the portal diversion. In contrast, total portal diversion to treat complications of portal hypertension is undesirable and always will degrade hepatic function if a significant amount of hepatopetal portal venous blood is taken from the liver. When total portal diversion is achieved (and this is to be expected after all conventional shunts), the incidence of hepatic failure and hepatic encephalopathy is increased. If portal diversion must be done for the control of variceal hemorrhage, a selective procedure such as the Warren procedure is theoretically superior to the completely diverting shunt. In practice, better patient survival has not been achieved after selective shunts than after conventional shunts, but the incidence of hepatic encephalopathy has been less. © 1983 Year Book Medical Publishers, Inc

2015 update of the evidence base:World Allergy Organization anaphylaxis guidelines

The World Allergy Organization (WAO) Guidelines for the assessment and management of anaphylaxis provide a unique global perspective on this increasingly common, potentially life-threatening disease. Recommendations made in the original WAO Anaphylaxis Guidelines remain clinically valid and relevant, and are a widely accessed and frequently cited resource. In this 2015 update of the evidence supporting recommendations in the Guidelines, new information based on anaphylaxis publications from January 2014 through mid- 2015 is summarized. Advances in epidemiology, diagnosis, and management in healthcare and community settings are highlighted. Additionally, new information about patient factors that increase the risk of severe and/or fatal anaphylaxis and patient co-factors that amplify anaphylactic episodes is presented and new information about anaphylaxis triggers and confirmation of triggers to facilitate specific trigger avoidance and immunomodulation is reviewed. The update includes tables summarizing important advances in anaphylaxis research. Keywords: Anaphylaxis, Epinephrine, Auto-injector, Food allergy, Stinging insect venom allergy, Drug allergy, Latex allergy, Exercise-induced anaphylaxis, Systemic allergic reaction, Adrenalin

Copper–Fluorenephosphonate Cu­(PO3-C13H9)·H2O: A Layered Antiferromagnetic Hybrid

International audienceA Cu(PO3-C13H9)·H2O hybrid compound has been synthesized by a hydrothermal method from Cu(NO3)2·3H2O and 9H-fluorene-2-phosphonic acid [C13H9PO(OH)2]. Its structure was determined by X-ray diffraction performed on a single crystal. The compound crystallizes in the monoclinic centrosymmetric space group P21/a [a = 7.4977(5), b = 7.5476(5), c =22.3702(16) Å, β = 97.794(3)°, V = 1254.23(15) Å3, Z = 4]. Its lamellar structure consists of alternating organic and inorganic layers. Its organic sub-network is made up of a double layer of fluorene molecules, and its inorganic layer is composed of copper(II) dimers connected to phosphonate groups. In the structure, the neighbouring fluorenyl planes are almost orthogonal to each other, which indicates the absence of π stacking. A study of its magnetic properties, performed on a polycrystalline powder sample, showed antiferromagnetic interactions between the spin carriers without any ordering down to 1.8 K. The interactions between the two copper(II) species within the dimers were evaluated at J = –6.13(5) cm–1 with respect to the spin Hamiltonian H = –JSCu1SCu2. A fluorescence study under excitation at 266 nm showed the disappearance of fluorescence emission in the solid state. This has been attributed to fluorescence quenching by the metallic counterpart

Copper(II) n-Alkylphosphonates Used as Nanofillers: Single Crystal, Powder Structure Studies and Influence of the Alkyl Chain Length on the Magnetic Properties

International audienceThis article reports the synthesis, structures and the physical properties of a homologous series of copper alkylphosphonates. Cu(O3PCH2CH3)·H2O (CuPC2) and Cu(O3PCH2CH2CH3)·H2O (CuPC3) are both monoclinic with the same space group P21/a. Hydrothermal synthesis gave blue plate-like crystals allowing single crystal resolution. The synthesis in solution of the homologous series, from phosphonic acids possessing different alkyl chain lengths (chains with n = 2, 3, 6, 10, 14 or 18 carbon atoms), spontaneously produced either monohydrated Cu[O3P−(CH2)n–1−CH3]·H2O (n = 2, 3, 6) or dehydrated materials Cu[O3P−(CH2)n–1−CH3] for n = 10, 14 and 18. The differences between the hydrated and dehydrated forms occur mainly in the inorganic slabs. The loss of the water molecule leads to a modification of the bonding scheme and the isolated [Cu2O8] dimers present in the hydrated inorganic layer are, in the dehydrated form, connected together by means of one edge. This structural change accounts for the different magnetic behaviour. In the case of dehydrated compounds, these materials were dispersed into a polyamide matrix. It has been observed that the magnetic behaviour is transferred to the polyamide composite