Quenched Narrow-Line Laser Cooling of 40Ca to Near the Photon Recoil Limit

We present a cooling method that should be generally applicable to atoms with narrow optical transitions. This technique uses velocity-selective pulses to drive atoms towards a zero-velocity dark state and then quenches the excited state to increase the cooling rate. We demonstrate this technique of quenched narrow-line cooling by reducing the 1-D temperature of a sample of neutral 40Ca atoms. We velocity select and cool with the 1S0(4s2) to 3P1(4s4p) 657 nm intercombination line and quench with the 3P1(4s4p) to 1S0(4s5s) intercombination line at 553 nm, which increases the cooling rate eight-fold. Limited only by available quenching laser power, we have transferred 18 % of the atoms from our initial 2 mK velocity distribution and achieved temperatures as low as 4 microK, corresponding to a vrms of 2.8 cm/s or 2 recoils at 657 nm. This cooling technique, which is closely related to Raman cooling, can be extended to three dimensions.Comment: 5 pages, 4 figures; Submitted to PRA Rapid Communication

Shock-Driven Endotheliopathy in Trauma Patients Is Associated with Leucocyte Derived Extracellular Vesicles

Endotheliopathy following trauma is associated with poor outcome, but the underlying mechanisms are unknown. This study hypothesized that an increased extracellular vesicle (EV) concentration is associated with endotheliopathy after trauma and that red blood cell (RBC) transfusion could further enhance endotheliopathy. In this post hoc sub study of a multicentre observational trial, 75 trauma patients were stratified into three groups based on injury severity score or shock. In patient plasma obtained at hospital admission and after transfusion of four RBC transfusions, markers for endotheliopathy were measured and EVs were labelled with anti CD41 (platelet EVs), anti CD235a (red blood cell EVs), anti CD45 (leucocyte EVs), anti CD144 (endothelial EVs) or anti CD62e (activated endothelial EVs) and EV concentrations were measured with flow cytometry. Statistical analysis was performed by a Kruskall Wallis test with Bonferroni correction or Wilcoxon rank test for paired data. In patients with shock, syndecan-1 and von Willebrand Factor (vWF) were increased compared to patients without shock. Additionally, patients with shock had increased red blood cell EV and leucocyte EV concentrations compared to patients without shock. Endotheliopathy markers correlated with leucocyte EVs (ρ = 0.263, p = 0.023), but not with EVs derived from other cells. Injury severity score had no relation with EV release. RBC transfusion increased circulating red blood cell EVs but did not impact endotheliopathy. In conclusion, shock is (weakly) associated with EVs from leucocytes, suggesting an immune driven pathway mediated (at least in part) by shock

Plötzlicher Hörverlust und Magnesiumstatus

Einleitung: Magnesiuminfusionen werden als Therapieoption zur Behandlung des akuten Hörsturzes seit etwa 10 Jahren wiederholt beschrieben. Daten zum Magnesiumhaushalt der Hörsturzpatienten sind jedoch nicht bekannt.Methoden: Zwischen Juni 2015 und Oktober 2015 maßen wir bei allen stationär aufgenommenen Hörsturzpatienten der HNO-Klinik Nordhausen (n=33, 17 Frauen, 16 Männer, medianes Alter 64 Jahre, range 27-88 a) den Mg-Spiegel des Serums und korrelierten diesen mit dem Ausmaß des akuten Hörverlustes in Prozent (Röser 1973) sowie dem frequenzspezifischen Ausmaß in dB bei 500, 1000, 2000 und 4000 Hz im Vergleich zum gesunden Ohr. Ergebnisse: Bei einer Normalverteilung des Serum-Mg (0,87±0,05 mmol/l) unter den Patienten ließ sich zunächst keine Korrelation mit dem akuten Hörverlust nach Röser bzw. in den einzelnen Frequenzen feststellen. Jedoch fiel auf, dass es eine statistisch signifikante Häufung (p=100dB Differenz zum gesunden Ohr) auf einer Frequenz gibt, wenn der Serum-Mg mit Werten >0,90 mmol/l im oberen Anteil des Referenzbereiches liegt: In der Gruppe >=0,90 mmol/l Serum Mg fanden wir 10 Messungen mit totalem Verlust des Hörvermögens und 30 Messungen mit partiellem Verlust. In der Gruppe <0,90 mmol/l Serum-Mg fanden wir 4 Messungen mit totalem Verlust und 88 Messungen mit partiellem Verlust des Hörvermögens.Schlussfolgerungen: Erhöhtes Serum-Mg könnte ein Risikofaktor für eine plötzliche Ertaubung darstellen, so dass man die therapeutische Gabe von Magnesium beim akuten Hörsturz unbedingt nochmals überprüfen sollte.Der Erstautor gibt keinen Interessenkonflikt an

Thrust-related dome structures in the Karibib district and the origin of orthogonal fabric domains in the south Central Zone of the Pan-African Damara belt, Namibia

NatuurwetenskappeAardwetenskappePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Thrust-related dome structures in the Karibib district and the origin of orthogonal fabric domains in the south Central Zone of the Pan-African Damara belt, Namibia

The high-grade metamorphic south Central Zone (sCZ) exposes an oblique crustal section through the internal parts of the Pan-African Damara belt in Namibia. The structural pattern of the south Central Zone is characterized by kilometer-scale, northeast-trending dome structures for which a number of different origins have been proposed. Detailed structural mapping of the Karibib and Usakos domes in the Karibib district indicates an origin of the two domes as large tip-line folds located above blind thrusts. The two domes are overridden from the southeast by a crystalline thrust sheet along the Mon Repos thrust zone and the thrusts and associated folds form part of a deeply-eroded, foreland- (northwest-) vergent fold-and-thrust belt. Intrusive relationships of syn- and post-tectonic granitoids constrain the timing of thrusting to between 550 and 540 Ma, corresponding to the main phase of collisional tectonics in the Damara belt. On a regional scale, the south Central Zone is underlain by two orthogonal fabric domains. Northwest-vergent tectonic transport, documented in this study, dominates the lower amphibolite-facies northeastern parts of the south Central Zone. In contrast, a southwest-directed orogen-parallel extrusion is widely documented for the lower structural levels of the upper-amphibolite- to granulite-facies southwestern parts of the south Central Zone that contain voluminous synkinematic granites and widespread migmatization. Fabric development in the two orthogonal domains can be shown to be contemporaneous and related to the main collision between the Congo and Kalahari cratons at ca. 540-550 Ma. We suggest that the formation of the two orthogonal fabric domains represents the different crustal response of the rheologically layered crust to the late-Proterozoic crustal shortening. At shallower crustal levels, shortening of sufficiently strong crust in the Karibib district resulted in vertical thickening and orogen-normal folding and thrust transport. Shortening of the deeper levels of the sCZ resulted in pure shear deformation of the rheologically weakened and partially molten crust and the lateral, orogen-parallel displacement of rocks. © 2004 Elsevier B.V. All rights reserved.Articl