Large Exchange Bias, High Dielectric Constant, and Outstanding Ionic Conductivity in a Single‐Phase Spin Glass

The multigram synthesis of K2[Fe3S4] starting from K2S and FeS is presented, and its electronic and magnetic properties are investigated. The title compound obtains a defect variant of the K[Fe2Se2] structure type. Dielectric and impedance measurements indicate a dielectric constant of 1120 at 1 kHz and an outstanding ionic conductivity of 24.37 mS cm–1 at 295 K, which is in the range of the highest reported value for potential solid‐state electrolytes for potassium‐ion batteries. The Seebeck coefficient of the n‐type conductor amounts to −60 µV K−1 at 973 K. The mismatch of the measured electrical resistivity and the predicted metal‐like band structure by periodic quantum chemical calculations indicates Mott insulating behavior. Magnetometry demonstrates temperature‐dependent, large exchange bias fields of 35 mT, as a consequence of the coexistence of spin glass and antiferromagnetic orderings due to the iron vacancies in the lattice. In addition, the decreasing training effects of 34% in the exchange bias are identified at temperatures lower than 20 K. These results demonstrate the critical role of iron vacancies in tuning the electronic and magnetic properties and a multifunctional material from abundant and accessible elements

Life and Liesegang: Outcrop-Scale Microbially Induced Diagenetic Structures and Geochemical Self-Organization Phenomena Produced by Oxidation of Reduced Iron

The Kanab Wonderstone is sandstone (Shinarump Member, Chinle Formation) that is cemented and stained with iron oxide. The iron-oxide cementation and staining in these rocks have been considered examples of the Liesegang phenomenon, but we will show that they comprise a microbially induced structure. The spacing of bands of iron-oxide stain follow the Jablczynski spacing law (wherein the spacing between bands of iron-oxide stain increases as one traverses a series of bands) characteristic of Liesegang. Bands of iron-oxide cement exhibit more variable spacing and exhibit a weak but significant correlation between band thickness and distance between bands of cement. The pore-filling cement contains morphotypes that are similar in size and habit to those exhibited by microaerophilic iron-oxidizing bacteria. Other disseminated iron-oxide mineralization occurs as rhombohedra interpreted to be pseudomorphs after siderite. We interpret the cement to be produced by microbially mediated oxidation of siderite (a typical early diagenetic mineral in fluvial sandstones). Iron-oxidizing bacteria colonized the redox interface between siderite-cemented sand and porous sandstone. Microbes oxidized aqueous Fe(II), generating acid that caused siderite dissolution. The iron-oxide cement is the microbial product of a geochemical drive for organization; whereas the iron-oxide stain is true Liesegang. Together, they comprise a distinctive microbially induced structure with high preservation potential. Key Words: Biosignatures—Iron oxides—Diagenesis—Iron-oxidizing bacteria—Shinarump

The impact of herpes zoster and post-herpetic neuralgia on quality-of-life

International audienceBACKGROUND: The potentially serious nature of herpes zoster (HZ) and the long-term complication post-herpetic neuralgia (PHN) are often underestimated. One in four people will contract herpes zoster in their lifetime, with this risk rising markedly after the age of 50 years, and affecting one in two in elderly individuals. Pain is the predominant symptom in all phases of HZ disease, being reported by up to 90% of patients. In the acute phase, pain is usually moderate or severe, with patients ranking HZ pain as more intense than post-surgical or labour pains. Up to 20% of patients with HZ develop PHN, which is moderate-to-severe chronic pain persisting for months or years after the acute phase. We review the available data on the effect of HZ and PHN on patients' quality-of-life. DISCUSSION: Findings show that HZ, and particularly PHN, have a major impact on patients' lives across all four health domains--physical, psychological, functional and social. There is a clear correlation between increasing severity of pain and greater interference with daily activities. Non-pain complications such as HZ ophthalmicus can increase the risk of permanent physical impairment. Some elderly individuals may experience a permanent loss of independence after an acute episode of HZ. Current challenges in the management of HZ and PHN are highlighted, including the difficulty in administering antiviral agents before pain becomes established and the limited efficacy of pain treatments in many patients. We discuss the clinical rationale for the HZ vaccine and evidence demonstrating that the vaccine reduces the burden of the disease. The Shingles Prevention Study, conducted among >38,000 people aged >or=60 years old, showed that the HZ vaccine significantly reduces the burden of illness and the incidence of both HZ and PHN. In the entire study population, zoster vaccination reduced the severity of interference of HZ and PHN with activities of daily living by two-thirds, as measured by two questionnaires specific to HZ. SUMMARY: A vaccination scheme may positively impact the incidence and course of HZ disease, thereby improving patients' quality-of-life

Alternatives to robenidine to control gastrointestinal disorders of weaner rabbits in the field

Gastrointestinal disorders due to Eimeria sp. and E. coli overgrowth cause high mortality in weaner rabbits and the interest in alternatives to coccidiostats is high. This study aimed to investigate the superiority of natural feed additives towards robenidine preserving gastrointestinal health in the field. Rabbits were divided into four groups, Control Group (CG) exclusively supplemented with robenidine, Sainfoin Group (SG) was supplemented with a combination of robenidine and sainfoin, and two additional groups were respectively supplemented with Herb-All COCC-X (garlic; conessi tree) (HG: Herbal Group) and by a combination of Herb-All COCC-X and Klinofeed (clinoptilolite) (MG: Mineral Group). Eimeria sp. (98,40%) and E. coli overgrowth (73.60%) could be confirmed as the main causes for losses. High mortality rates (SG: 30.00% - MG: 47.50%), also in the groups receiving robenidine (SG: 30.00%; CG: 45.00%), reinforced the importance of alternatives in the field. The natural additives of groups SG, HG and MG did not have a significant influence on the weight gains and the oocyst counts in the jejunum/ileum and caecum of slaughter rabbits at the end of the trial, compared to group CG. Significantly higher oocyst shedding in SG (p = 1.4E-03) and HG (p = 1.4E-05) during the trial may be explained by a higher surviving rate of diseased rabbits in those groups, fostered by beneficial effects of the additives, which should be investigated further