Three-Dimensional Fermi Surface of Overdoped La-Based Cuprates.

We present a soft x-ray angle-resolved photoemission spectroscopy study of overdoped high-temperature superconductors. In-plane and out-of-plane components of the Fermi surface are mapped by varying the photoemission angle and the incident photon energy. No k_{z} dispersion is observed along the nodal direction, whereas a significant antinodal k_{z} dispersion is identified for La-based cuprates. Based on a tight-binding parametrization, we discuss the implications for the density of states near the van Hove singularity. Our results suggest that the large electronic specific heat found in overdoped La_{2-x}Sr_{x}CuO_{4} cannot be assigned to the van Hove singularity alone. We therefore propose quantum criticality induced by a collapsing pseudogap phase as a plausible explanation for observed enhancement of electronic specific heat.

Nuclear and magnetic spin structure of the antiferromagnetic triangular lattice compound LiCrTe2 investigated by [Formula: see text]SR, neutron and X-ray diffraction.

Two-dimensional (2D) triangular lattice antiferromagnets (2D-TLA) often manifest intriguing physical and technological properties, due to the strong interplay between lattice geometry and electronic properties. The recently synthesized 2-dimensional transition metal dichalcogenide LiCrTe[Formula: see text], being a 2D-TLA, enriched the range of materials which can present such properties. In this work, muon spin rotation ([Formula: see text]SR) and neutron powder diffraction (NPD) have been utilized to reveal the true magnetic nature and ground state of LiCrTe[Formula: see text]. From high-resolution NPD the magnetic spin order at base-temperature is not, as previously suggested, helical, but rather collinear antiferromagnetic (AFM) with ferromagnetic (FM) spin coupling within the ab-plane and AFM coupling along the c-axis. The value if the ordered magnetic Cr moment is established as [Formula: see text]. From detailed [Formula: see text]SR measurements we observe an AFM ordering temperature [Formula: see text] K. This value is remarkably higher than the one previously reported by magnetic bulk measurements. From [Formula: see text]SR we are able to extract the magnetic order parameter, whose critical exponent allows us to categorize LiCrTe[Formula: see text] in the 3D Heisenberg AFM universality class. Finally, by combining our magnetic studies with high-resolution synchrotron X-ray diffraction (XRD), we find a clear coupling between the nuclear and magnetic spin lattices. This suggests the possibility for a strong magnon-phonon coupling, similar to what has been previously observed in the closely related compound LiCrO[Formula: see text].

Revisiting Goodenough-Kanamori rules in a new series of double perovskites LaSr1-xCaxNiReO6.

The magnetic ground states in highly ordered double perovskites LaSr1-xCaxNiReO6 (x = 0.0, 0.5, 1.0) are studied in view of the Goodenough-Kanamori rules of superexchange interactions in this paper. In LaSrNiReO6, Ni and Re sublattices are found to exhibit curious magnetic states separately, but no long range magnetic ordering is achieved. The magnetic transition at ~255 K is identified with the independent Re sublattice magnetic ordering. Interestingly, the sublattice interactions are tuned by modifying the Ni-O-Re bond angles through Ca doping. Upon Ca doping, the Ni and Re sublattices start to display a ferrimagnetically ordered state at low temperature. The neutron powder diffraction data reveals long range ferrimagnetic ordering of the Ni and Re magnetic sublattices along the crystallographic b-axis. The transition temperature of the ferrimagnetic phase increases monotonically with increasing Ca concentration.

Odontogenic orbital cellulitis associated with cavernous sinus thrombosis and pulmonary embolism: a case report.

BACKGROUND: This case illustrates the importance of prompt assessment and treatment of orbital cellulitis. In fact the ocular signs and symptoms may be associated with systemic complications which should be investigated and identified as soon as possible to avoid a poor prognosis. CASE PRESENTATION: A 46-year-old white woman presented to our emergency room with proptosis, ophthalmoplegia, and conjunctival chemosis of her left eye. An ophthalmologist, having diagnosed orbital cellulitis in her left eye, suspected a cavernous sinus thrombosis. Hematochemical and radiological examinations confirmed the cavernous sinus thrombosis and also showed septic pulmonary embolism. A blood culture indicated Streptococcus constellatus, which is a member of the Peptostreptococcus family, a saprophyte of the oral mucosa that can be pathogenic in immunocompromised persons. The odontogenic origin was then confirmed by dental radiography which showed a maxillary abscess. Her eye signs regressed after antibiotic and anticoagulant therapy. CONCLUSIONS: This complex case shows the importance of a multidisciplinary approach for the management of orbital cellulitis, for the prompt diagnosis and treatment of eye injuries and possible complications, so as to avoid serious and permanent sequelae.

The aphrodisiac and adaptogenic properties of ginseng.

Ginseng is the root of the perennial herbs of Panax quinquefolium and Panax ginseng which contain a series of tetracyclic triterpenoid saponins (ginsenosides) as active ingredients. It is considered a tonic or adaptogenic that enhances physical performance (including sexual), promotes vitality and increases resistance to stress and ageing. The adaptogenic properties of ginseng are believed to be due to its effects on hypothalamic-pituitary-adrenal axis, resulting in elevated plasma corticotropin and corticosteroids levels. When used appropriately, ginseng appears to be safe. Nevertheless, documented side effects include hypertension, diarrhoea, restlessness, mastalgia and vaginal bleeding.

Cannabis and cannabinoid receptors.

Cannabis and cannabinoids exert many of their biological functions through receptor-mediated mechanisms. Two types of cannabinoid receptors have been identified, namely CB(1) and CB(2), both coupled to a G protein. CB(1) receptors have been detected in the central nervous system (where they are responsible for the characteristic effects of Cannabis, including catalepsy, depression of motor activity, analgesia and feelings of relaxation and well being) and in peripheral neurons (where their activation produces a suppression in neurotransmitter release in the heart, bladder, intestine and vas deferens). Cannabinoid CB(2) receptors have only been detected outside the central nervous system, mostly in cells of the immune system, presumably mediating cannabinoid-induced immunosuppression and antinflammatory effects. With the discovery of cannabinoid receptors for exogenous cannabinoids, also endogenous cannabinoids (anandamide, 2-arachidonylglycerol) have been described.