Magnetic Structure Investigations at the Nuclear Center

The magnetic structure of the compounds UOS, ß-CoSO4, YCO5, and HoCO5 is briefly described. UOS is antiferromagnetic. The Néel temperature is Tn=55°K. The magnetic cell is doubled in the c direction with a ++ - - sequence of U moments along c. The apparent spin is S∼1. The negative interaction corresponds to U-O-U links. In ß-CoSO4 (high-temperature modification, space group Pbnm), Co atoms are in 000, 00½, ½½½, ½½0. Here three different antiferromagnetic spin modes, mutually perpendicular, Ax(+ - - +), Gy(+-+-), and Cz(++ - - ), in the Wollan-Koehler notation, are coupled. Direction cosines are 0.71, 0.50, and 0.50, respectively. The Co moment is about 3,84 µB at 4.2°K. A field-induced spin flip to the configuration Fx, Cy, Gz is predicted. YCO5 is ferromagnetic at room temperature with a moment value of Co practically equal to that of metallic Co and moment direction along c, which is conserved down to 4.2°K. In HoCO5 the moment of Ho is opposite to those of the Co atoms. When cooling from room to liquid helium temperature, the direction of easy magnetization changes from near c to a direction in the basal plane and the Ho moment increases from 4 to about 9 µB. The compensation temperature is 70°K

Source control in emergency general surgery: WSES, GAIS, SIS-E, SIS-A guidelines

Intra-abdominal infections (IAI) are among the most common global healthcare challenges and they are usually precipitated by disruption to the gastrointestinal (GI) tract. Their successful management typically requires intensive resource utilization, and despite the best therapies, morbidity and mortality remain high. One of the main issues required to appropriately treat IAI that differs from the other etiologies of sepsis is the frequent requirement to provide physical source control. Fortunately, dramatic advances have been made in this aspect of treatment. Historically, source control was left to surgeons only. With new technologies non-surgical less invasive interventional procedures have been introduced. Alternatively, in addition to formal surgery open abdomen techniques have long been proposed as aiding source control in severe intra-abdominal sepsis. It is ironic that while a lack or even delay regarding source control clearly associates with death, it is a concept that remains poorly described. For example, no conclusive definition of source control technique or even adequacy has been universally accepted. Practically, source control involves a complex definition encompassing several factors including the causative event, source of infection bacteria, local bacterial flora, patient condition, and his/her eventual comorbidities. With greater understanding of the systemic pathobiology of sepsis and the profound implications of the human microbiome, adequate source control is no longer only a surgical issue but one that requires a multidisciplinary, multimodality approach. Thus, while any breach in the GI tract must be controlled, source control should also attempt to control the generation and propagation of the systemic biomediators and dysbiotic influences on the microbiome that perpetuate multi-system organ failure and death. Given these increased complexities, the present paper represents the current opinions and recommendations for future research of the World Society of Emergency Surgery, of the Global Alliance for Infections in Surgery of Surgical Infection Society Europe and Surgical Infection Society America regarding the concepts and operational adequacy of source control in intra-abdominal infections

Étude par diffraction neutronique du spinelle FeCr2S4

Neutron diffraction study of the spinel FeCr2S4 shows the degree of inversion to be zero and the sulphur parameter to be u = 0,2608. Low temperature results agree with a simple ferrimagnetic model.L'étude par diffraction de neutrons du spinelle FeCrS4 montre que le degré d'inversion est nul et que le paramètre du soufre est de u = 0,2608. L'étude à basse température a confirmé l'existence d'un ferrimagnétisme simple

PROPRIÉTÉS MAGNÉTIQUES DE MONOCRISTAUX D'OXYSULFURE D'YTTERBIUM

Des mesures de susceptibilité magnétique, d'aimantation en champ fort, de chaleur spécifique, d'absorption optique réalisées sur des monocristaux d'Yb2O2S ont montré que le niveau fondamental de l'ion Yb3+ est un doublet (g∥ = 2,9, g⊥ = 3,8) très éloigné (240 cm-1) du premier niveau excité. Des expériences de diffraction neutronique sous champ magnétique ont permis d'étudier le processus d'aimantation et de mettre en évidence la très faible anisotropie dans le plan de base.We have performed magnetic susceptibility, high field magnetization, specific heat and optical absorption measurements on Yb2O2S single crystals. The ground state of the Yb3+ ion is a doublet (g∥ = 1.9, g⊥ = 3,8) well separated from the first excited level (240 cm-1). Magnetization process and very low anisotropy in the basal plane have been evidenced by Neutron Diffraction measurements in applied magnetic field