Direct evidence for the magnetic ordering of Nd ions in NdFeAsO by high resolution inelastic neutron scattering

We investigated the low energy excitations in the parent compound NdFeAsO of the Fe-pnictide superconductor in the $\mu$eV range by a back scattering neutron spectrometer. The energy scans on a powder NdFeAsO sample revealed inelastic peaks at E = 1.600 $\pm 0.003 \mu$eV at T = 0.055 K on both energy gain and energy loss sides. The inelastic peaks move gradually towards lower energy with increasing temperature and finally merge with the elastic peak at about 6 K. We interpret the inelastic peaks to be due to the transition between hyperfine-split nuclear level of the $^{143}$Nd and $^{145}$Nd isotopes with spin $I = 7/2$. The hyperfine field is produced by the ordering of the electronic magnetic moment of Nd at low temperature and thus the present investigation gives direct evidence of the ordering of the Nd magnetic sublattice of NdFeAsO at low temperature

Production of a Fermi gas of atoms in an optical lattice

We prepare a degenerate Fermi gas of potassium atoms by sympathetic cooling with rubidium atoms in a one-dimensional optical lattice. In a tight lattice we observe a change of the density of states of the system, which is a signature of quasi two dimensional confinement. We also find that the dipolar oscillations of the Fermi gas along the tight lattice are almost completely suppressed.Comment: 4 pages, 4 figures, revised versio

Orbitally Driven Spin Pairing in the 3D Non-Magnetic Mott Insulator BaVS3: Evidence from Single Crystal Studies

Static electrical and magnetic properties of single crystal BaVS_3 were measured over the structural (T_S=240K), metal-insulator (T_MI=69K), and suspected orbital ordering (T_X=30K) transitions. The resistivity is almost isotropic both in the metallic and insulating states. An anomaly in the magnetic anisotropy at T_X signals a phase transition to an ordered low-T state. The results are interpreted in terms of orbital ordering and spin pairing within the lowest crystal field quasi-doublet. The disordered insulator at T_X<T<T_MI is described as a classical liquid of non-magnetic pairs.Comment: 4 pages, 5 figures, revtex, epsf, and multicol style. Problem with figures fixed. To appear in Phys. Rev. B Rap. Com

Cyclosporin A differentially inhibits multiple steps in VEGF induced angiogenesis in human microvascular endothelial cells through altered intracellular signaling

The immunosuppressive agent cyclosporin A (CsA), a calcineurin inhibitor which blocks T cell activation has provided the pharmacologic foundation for organ transplantation. CsA exerts additional effects on non-immune cell populations and may adversely effect microvascular endothelial cells, contributing to chronic rejection, a long-term clinical complication and significant cause of mortality in solid-organ transplants, including patients with small bowel allografts. Growth of new blood vessels, or angiogenesis, is a critical homeostatic mechanism in organs and tissues, and regulates vascular populations in response to physiologic requirements. We hypothesized that CsA would inhibit the angiogenic capacity of human gut microvessels. Primary cultures of human intestinal microvascular endothelial cells (HIMEC) were used to evaluate CsA's effect on four in vitro measures of angiogenesis, including endothelial stress fiber assembly, migration, proliferation and tube formation, in response to the endothelial growth factor VEGF. We characterized the effect of CsA on intracellular signaling mechanisms following VEGF stimulation. CsA affected all VEGF induced angiogenic events assessed in HIMEC. CsA differentially inhibited signaling pathways which mediated distinct steps of the angiogenic process. CsA blocked VEGF induced nuclear translocation of the transcription factor NFAT, activation of p44/42 MAPK, and partially inhibited JNK and p38 MAPK. CsA differentially affected signaling cascades in a dose dependent fashion and completely blocked expression of COX-2, which was integrally linked to HIMEC angiogenesis. These data suggest that CsA inhibits the ability of microvascular endothelial cells to undergo angiogenesis, impairing vascular homeostatic mechanisms and contributing to the vasculopathy associated with chronic rejection

Adiposity and the development of dyslipidemia in APOE epsilon 2 homozygous subjects:A longitudinal analysis in two population-based cohorts

Background and aims: Familial dysbetalipoproteinemia (FD), characterized by remnant lipoprotein accumulation and premature cardiovascular disease, occurs in homozygous carriers of the APOE epsilon 2 allele, but genetic predisposition alone does not suffice for the clinical phenotype. Cross-sectional studies suggest that a second metabolic hit-notably adiposity or insulin resistance-is required, but the association between these risk factors and development of FD has not been studied prospectively. Methods: For this study, we evaluated 18,987 subjects from two large prospective Dutch population-based cohorts (PREVEND and Rotterdam Study) of whom 118 were homozygous APOE epsilon 2 carriers. Of these, 69 subjects were available for prospective analyses. Dyslipidemia-likely to be FD-was defined as fasting triglyceride (TG) levels >3 mmol/L in untreated subjects or use of lipid lowering medication. The effect of weight, body mass index (BMI), waist circumference, type 2 diabetes mellitus and non-TG metabolic syndrome on development of dyslipidemia was investigated. Results: Eleven of the 69 epsilon 2 epsilon 2 subjects (16%) developed dyslipidemia-likely FD-during follow-up. Age-, sexand cohort-adjusted risk factors for the development of FD were BMI (OR 1.19; 95%CI 1.04-1.39), waist circumference (OR 1.26 95%CI 1.01-1.61) and presence of non-TG metabolic syndrome (OR 4.39; 95%CI 1.04-18.4) at baseline. Change in adiposity during follow-up was not associated with development of dyslipidemia. Conclusions: Adiposity increases the risk of developing an FD-like lipid phenotype in homozygous APOE epsilon 2 subjects. These results stress the importance of healthy body weight in subjects at risk of developing FD

Ion detection in the photoionization of a Rb Bose-Einstein condensate

Two-photon ionization of Rubidium atoms in a magneto-optical trap and a Bose-Einstein condensate (BEC) is experimentally investigated. Using 100 ns laser pulses, we detect single ions photoionized from the condenstate with a 35(10)% efficiency. The measurements are performed using a quartz cell with external electrodes, allowing large optical access for BECs and optical lattices.Comment: 14 pages, 7 figure

Lifetime determination of excited states in Cd-106

Two separate experiments using the Differential Decay Curve Method have been performed to extract mean lifetimes of excited states in 106 Cd. The inedium-spin states of interest were populated by the Mo-98(C-12, 4n) Cd-106 reaction performed at the Wright Nuclear Structure Lab., Yale University. From this experiment, two isomeric state mean lifetimes have been deduced. The low-lying states were populated by the Mo-96(C-13, 3n)Cd-106 reaction performed at the Institut fur Kernphysik, Universitat zu Koln. The mean lifetime of the I-pi = 2(1)(+) state was deduced, tentatively, as 16.4(9) ps. This value differs from the previously accepted literature value from Coulomb excitation of 10.43(9) ps

Geschlechterspezifische Unterschiede bei der endovaskulären Behandlung der peripheren arteriellen Verschlusskrankheit – Eine systematische Literaturübersicht

Zusammenfassung Hintergrund Es gibt Hinweise auf geschlechterspezifische Unterschiede bei der Entwicklung, Diagnostik und Behandlung der symptomatischen peripheren arteriellen Verschlusskrankheit (PAVK). Obwohl Frauen in der Literatur etwa 50 % der behandelten Kohorten ausmachen, ist deren Anteil in kontrollierten randomisierten Studien zur PAVK gering. Leitlinien enthalten bisher kaum geschlechtersensitive Empfehlungen, und die Ergebnisse retrospektiver Beobachtungsstudien widersprechen sich. Diese systematische Literaturrecherche soll verfügbare Beobachtungsstudien zu Geschlechterunterschieden bei der endovaskulären Behandlung der symptomatischen PAVK identifizieren. Material und Methoden Es wurde eine systematische Literaturanalyse auf der Basis einer PubMed-Recherche mit dem Schwerpunkt auf retrospektive Beobachtungsstudien zum Vergleich der Behandlungsergebnisse zwischen Männern und Frauen durchgeführt. Ergebnisse Insgesamt konnten 37 Publikationen identifiziert werden, die eine Kohorte von 5.489.558 Patientinnen und Patienten (40,3 % Frauen) beschreiben. Fünf Studien nutzten Propensity Score Matching zur Kontrolle von Störfaktoren. In 23 Studien wurden Behandlungsergebnisse nach der Dauer des Krankenhausaufenthalts bzw. nach 30 Tagen berichtet. Während 10 Studien einen Behandlungsnachteil bei Frauen identifizieren konnten, berichteten 6 Studien über einen Behandlungsnachteil bei Männern. Die weiteren 21 Studien konnten keine eindeutigen Unterschiede zeigen. Schlussfolgerungen Die verfügbare Real-World-Evidenz lässt aufgrund der methodischen Limitationen der eingeschlossenen Studien und deren unzureichender Vergleichbarkeit keine eindeutige Aussage zu geschlechterspezifischen Unterschieden bei der endovaskulären Behandlung der PAVK zu