New multiplexing scheme for monitoring fiber optic Bragg grating sensors in the coherence domain

A new multiplexing scheme for monitoring fiber optic Bragg gratings in the coherence domain has been developed. Grating pairs with different grating distances are distributed along a fiber line, and interference between their reflections is monitored with a scanning Michelson interferometer. The Bragg wavelength of the individual sensor elements is determined from the interference signal frequency

Experimentally Feasible Security Check for n-qubit Quantum Secret Sharing

In this article we present a general security strategy for quantum secret sharing (QSS) protocols based on the HBB scheme presented by Hillery, Bu\v{z}ek and Berthiaume [Phys. Rev A \textbf{59}, 1829 (1999)]. We focus on a generalization of the HBB protocol to $n$ communication parties thus including $n$-partite GHZ states. We show that the multipartite version of the HBB scheme is insecure in certain settings and impractical when going to large $n$. To provide security for such QSS schemes in general we use the framework presented by some of the authors [M. Huber, F. Minert, A. Gabriel, B. C. Hiesmayr, Phys. Rev. Lett. \textbf{104}, 210501 (2010)] to detect certain genuine $n$ partite entanglement between the communication parties. In particular, we present a simple inequality which tests the security.Comment: 5 pages, submitted to Phys. Rev.

Glutathione treatment protects the rat liver against injury after warm ischemia and Kupffer cell activation

Background/Aim: The generation of reactive oxygen species by activated Kupffer cells (KC) may contribute to reperfusion injury of the liver during liver transplantation or resection. The aim of our present studies was to investigate (1) prevention of hepatic reperfusion injury after warm ischemia by administration of the antioxidant glutathione (GSH) and (2) whether GSH confers protection through influences on KC toxicity. Methods: Isolated perfused rat livers were subjected to 1 h of warm ischemia followed by 90 min of reperfusion without (n = 5) or with GSH or catalase (n = 4-5 each). Selective KC activation by zymosan (150 mug/ml) in continuously perfused rat livers was used to investigate KC-related liver injury. Results: Postischemic infusion of 0.1, 0.5, 1.0 and 2.0 mM GSH, but not 0.05 mM GSH prevented reperfusion injury after warm ischemia as indicated by a marked reduction of sinusoidal LDH efflux by up to 83 +/- 13% (mean +/- SD; p < 0.05) and a concomitant significant improvement of postischemic bile flow by 58 +/- 27% (p < 0.05). A similar protection was conveyed by KC blockade with gadolinium chloride indicating prevention of KC-related reperfusion injury by postischemic GSH treatment. Postischemic treatment with catalase (150 U/ml) resulted in a reduction of LDH efflux by 40 +/- 9% (p < 0.05). Accordingly, catalase as well as GSH (0.1-2.0 mM) nearly completely prevented the increase in LDH efflux following selective :KC activation by zymosan in continously perfused rat livers. Conclusion: Postischemic administration of GSH protects the liver against reperfusion injury after warm ischemia. Detoxification of KC-derived hydrogen peroxide seem to be an important feature of the protective mechanisms. Copyright (C) 2002 S. Karger AG, Basel

GSH Attenuates Organ Injury and Improves Function after Transplantation of Fatty Livers

Ischemia-reperfusion injury (IRI) is increased after transplantation of steatotic livers. Since those livers are increasingly used for transplantation, protective strategies must be developed. Reactive oxygen species (ROS) play a key role in hepatic IRI. In lean organs, glutathione (GSH) is an efficient scavenger of ROS, diminishing IRI. The aim of this study was to evaluate whether GSH also protects steatotic allografts from IRI following transplantation. Fatty or lean livers were explanted from 10-week-old obese or lean Zucker rats and preserved (obese 4 h, lean 24 h) in hypothermic University of Wisconsin solution. Arterialized liver transplantation was then performed in lean syngeneic Zucker rats. Recipients of fatty livers were treated with GSH (200 mu mol/h/kg) or saline during reperfusion (2 h, n = 5). Parameters of hepatocellular damage and bile flow were measured. Transplantation of steatotic livers enhanced early reperfusion injury compared to lean organs as measured by increased aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase plasma levels. Bile flow was also reduced in steatotic grafts. Intravenous administration of GSH effectively decreased liver damage in fatty allografts and resulted in improved bile flow. Intravenous application of GSH effectively reduces early IRI in steatotic allografts and improves recovery of these marginal donor organs following transplantation. Copyright (C) 2010 S. Karger AG, Base

The halt of deep convection in the Greenland Sea: A natural experiment for the study of their causes and effects

There are only a few sites where the deep ocean is ventilated from the surface. The responsible process known as deep convection is recognized to be a key process on the Earth’s climate system, but still it is scarcely observed, and its good representation by global oceanographic and climate models remains unclear. In the Arctic Ocean, the halt of deep convection in the Greenland Sea during the last three decades serves as a natural experiment to study: (1) the conditions that drive the occurrence or not of deep convection and (2) the effects of the halt of deep convection on the thermohaline properties of the deep water masses and circulation both locally and in adjacent ocean basins. Combining oceanic and atmospheric in-situ data together with reanalysis data, we observe that not only on average the winter net heat losses from the ocean to the atmosphere (Qo) have decreased during the last three decades in the Greenland Sea ( Qo (before the 1980s- after the 1980s) = 25 Wm-2) but the intensity and number of strong cooling events (Qo 800Wm-2). This last value for convection reaching 2000 m in the Greenland Sea seems critical to make the mixed layer deepening from being a non-penetrative process to one arrested by baroclinic instabilities. Besides, changes in the wind stress curl and preconditioning for deep convection have occurred, hindering also the occurrence of deep convection. Concerning the effects of the halt of deep convection, hydrographic data reveal that the temperature between 2000 meters depth and the sea floor has risen by 0.3 C in the last 30 years, which is ten times higher than the temperature increase in the global ocean on average, and salinity rose by 0.02 because import of relatively warm and salty Arctic Ocean deep waters continued. The necessary transports to explain the observed changes suggest an increase of Arctic Ocean deep water transport that would have compensated the decrease in deep water formation rate after the 1980s. The effects of these changes in adjacent basins remain unstudied, but the bottom waters seem to be upwelled towards the slope and the Jan Mayen ridge, being an exit for the Greenland Sea deep waters.0,000

Ischemic preconditioning attenuates portal venous plasma concentrations of purines following warm liver ischemia in man

Background/Aims: Degradation of adenine nucleotides to adenosine has been suggested to play a critical role in ischemic preconditioning (IPC). Thus, we questioned in patients undergoing partial hepatectomy whether (i) IPC will increase plasma purine catabolites and whether (ii) formation of purines in response to vascular clamping (Pringle maneuver) can be attenuated by prior IPC. Methods: 75 patients were randomly assigned to three groups: group I underwent hepatectomy without vascular clamping; group II was subjected to the Pringle maneuver during resection, and group III was preconditioned (10 min ischemia and 10 min reperfusion) prior to the Pringle maneuver for resection. Central, portal venous and arterial plasma concentrations of adenosine, inosine, hypoxanthine and xanthine were determined by high-performance liquid chromatography. Results: Duration of the Pringle maneuver did not differ between patients with or without IPC. Surgery without vascular clamping had only a minor effect on plasma purine transiently increased. After the Pringle maneuver alone, purine plasma concentrations were most increased. This strong rise in plasma purines caused by the Pringle maneuver, however, was significantly attenuated by IPC. When portal venous minus arterial concentration difference was calculated for inosine or hypoxanthine, the respective differences became positive in patients subjected to the Pringle maneuver and were completely prevented by preconditioning. Conclusion: These data demonstrate that (i) IPC increases formation of adenosine, and that (ii) the unwanted degradation of adenine nucleotides to purines caused by the Pringle maneuver can be attenuated by IPC. Because IPC also induces a decrease of portal venous minus arterial purine plasma concentration differences, IPC might possibly decrease disturbances in the energy metabolism in the intestine as well. Copyright (C) 2005 S. Karger AG, Basel

Review of Metabolic Surgery for Type 2 Diabetes in Patients with a BMI < 35 kg/m2

Bariatric/metabolic surgery is considered an accepted treatment option for type 2 diabetes mellitus (T2DM) with body mass index (BMI)  ≧  35 kg/m2. Mounting evidence also shows that metabolic surgery is effective for T2DM with BMI  <  35 kg/m2. To evaluate current status of metabolic surgery, we reviewed the available clinical studies which described surgical treatment for T2DM with mean BMI  <  35 kg/m2. 18 studies with 477 patients were identified. 30% of the patients was insulin users. The follow-up period ranged from 6 to 216 months. The weight loss effect was reasonable, not excessive. Mean BMI decreased from 30.4 to 24.8 kg/m2. Remission of T2DM was achieved in 64.7% of the patients with fasting plasma glucose and glycated hemoglobin approaching slightly above normal range. Clinical T2DM status was an important factor when selecting the eligible candidates for metabolic surgery. Postoperative complication rate of 10.3% with mortality of 0% in the studies has been acceptable. Even though it would be premature at this point to state that metabolic surgery is an accepted treatment option for T2DM with BMI < 35 kg/m2, it is clear that a high proportion of T2DM patients will derive substantial benefit from metabolic surgery

Breathing synchronized electrical stimulation of the abdominal muscles in patients with acute tetraplegia

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively