Xenogeneic, extracorporeal liver perfusion in primates improves the ratio of branched-chain amino acids to aromatic amino acids (Fischer's ratio)

In fulminant hepatic failure (FHF), the development of hepatic encephalopathy is associated with grossly abnormal concentrations of plasma amino acids (PAA). Normalization of the ratio of branched-chain amino acids to aromatic amino acids (Fischer's ratio) correlates with clinical improvement. This study evaluated changes in PAA metabolism during 4 h of isolated, normothermic extracorporeal liver perfusion using a newly designed system containing human blood and a rhesus monkey liver. Bile and urea production were within the physiological range. Release of the transaminases AST, ALT and LDH were minimal. The ratio of branched (valine, leucine, isoleucine) to aromatic (tyrosine, phenylalanine) amino acids increased significantly. These results indicate that a xenogeneic extracorporeal liver perfusion system is capable of significantly increasing Fischer's ratio and may play a role in treating and bridging patients in FHF in the future

Fractal Behaviour in the O(3) Model

We study domain formation in the two-dimensional O(3) model near criticality. The fractal dimension of these domains is determined with good statistical accuracy.Comment: 6 pages + 3 figures (concatenated PS files, uuencoded gz-compressed

Intraossäre Infusion: Eine wichtige Technik auch für die Kinderanästhesie

Zusammenfassung: Die zeitgerechte Etablierung eines venösen Zugangs kann insbesondere bei Säuglingen und Kleinkindern eine große Herausforderung sein. Hier hat sich die intraossäre Infusionstechnik seit den 1940er Jahren als schnelle, effiziente und sichere Alternativmethode zur Schaffung eines Gefäßzugangs bewährt, um einem vitalgefährdeten Kind dringend benötigte Medikamente und Flüssigkeiten zu applizieren. Während in den internationalen Leitlinien zur pädiatrischen Notfallmedizin der intraossären Infusion eine hohe Priorität eingeräumt wird, greifen die meisten Anästhesisten nur sehr zögerlich auf diese langjährig bewährte Punktionstechnik zurück. Die vorliegende Arbeit beschreibt die intraossäre Infusionstechnik, stellt zwei unterschiedliche Kanülierungssysteme vor und diskutiert, basierend auf den aktuellen notfallmedizinischen Leitlinien sowie anhand von eigenen Fallbeispielen, potenzielle Indikationen für die Kinderanästhesie. Demnach sollten insbesondere akut vital-gefährdete Kinder mit Kreislaufstillstand, Laryngospasmus, akuter Atemwegsblutung, hypovolämischem Schock oder Hypothermie bei ausgedehnten Verbrennungen ohne liegenden bzw. rasch anzulegenden venösen Zugang mit einer intraossären Kanüle versorgt werden. Inwieweit die intraossäre Infusion auch beim nichtakut vital-gefährdeten Kind mit schwierigem oder unmöglichem peripheren Venenzugang in der Anästhesie überbrückend und zeitlich begrenzt eingesetzt werden sollte, wird die zukünftige Diskussion zeigen. Die erfolgreiche Anwendung der intraossären Infusionstechnik in der Kinderanästhesie verlangt die unmittelbare Verfügbarkeit der entsprechenden Ausrüstung, die umfassende Schulung und das regelmäßige Training sowie eine klare Regelung für ihre Anwendung innerhalb der Anästhesieabteilun

Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: A review

Abstract Negative potassium (K) balances on farmlands globally are widespread because fertiliser K input is often less than losses (leaching) and removal of K in hay, straw and grain, which leads to a rundown of plant-available K. When soil K reserves are not large and the plant-available K pools are not well buffered, the risk of K rundown in soils is high. In the south-west of Western Australia, soil K rundown, particularly by continuous cropping or in systems where a large portion of crop biomass is removed, is increasing the prevalence of crop K deficiency even on soils where K was not previously a limiting factor for crop yields. While fertiliser K is required for adequate supply of plant-available K, maximising K use efficiency is also important for cropping profitability and sustainability in dryland agriculture. Plant K uptake and use efficiency can be affected by soil types, crop species and sequences, seasonal conditions, and K management. In water-limited environments, crop K nutrition, especially root access to subsoil K, plays a crucial role in promoting root growth, regulating plant water relations and alleviating biotic and abiotic stresses. Optimised use of both soil and fertiliser K is increasingly necessary to sustain crop yields under stressed conditions in the context of K rundown in soils

Commensurability effects in superconducting Nb films with quasiperiodic pinning arrays

We study experimentally the critical depinning current Ic versus applied magnetic field B in Nb thin films which contain 2D arrays of circular antidots placed on the nodes of quasiperiodic (QP) fivefold Penrose lattices. Close to the transition temperature Tc we observe matching of the vortex lattice with the QP pinning array, confirming essential features in the Ic(B) patterns as predicted by Misko et al. [Phys. Rev. Lett, vol.95, 177007 (2005)]. We find a significant enhancement in Ic(B) for QP pinning arrays in comparison to Ic in samples with randomly distributed antidots or no antidots.Comment: 4 pages, 3 figure

Estimation of wind storm impacts over Western Germany under future climate conditions using a statistical-dynamical downscaling approach

A statistical–dynamical regionalization approach is developed to assess possible changes in wind storm impacts. The method is applied to North Rhine-Westphalia (Western Germany) using the FOOT3DK mesoscale model for dynamical downscaling and ECHAM5/OM1 global circulation model climate projections. The method first classifies typical weather developments within the reanalysis period using K-means cluster algorithm. Most historical wind storms are associated with four weather developments (primary storm-clusters). Mesoscale simulations are performed for representative elements for all clusters to derive regional wind climatology. Additionally, 28 historical storms affecting Western Germany are simulated. Empirical functions are estimated to relate wind gust fields and insured losses. Transient ECHAM5/OM1 simulations show an enhanced frequency of primary storm-clusters and storms for 2060–2100 compared to 1960–2000. Accordingly, wind gusts increase over Western Germany, reaching locally +5% for 98th wind gust percentiles (A2-scenario). Consequently, storm losses are expected to increase substantially (+8% for A1B-scenario, +19% for A2-scenario). Regional patterns show larger changes over north-eastern parts of North Rhine-Westphalia than for western parts. For storms with return periods above 20 yr, loss expectations for Germany may increase by a factor of 2. These results document the method's functionality to assess future changes in loss potentials in regional terms

Laser-Accelerated proton beams as diagnostics for cultural heritage

This paper introduces the first use of laser-generated proton beams as diagnostic for materials of interest in the domain of Cultural Heritage. Using laser-accelerated protons, as generated by interaction of a high-power short-pulse laser with a solid target, we can produce proton-induced X-ray emission spectroscopies (PIXE). By correctly tuning the proton flux on the sample, we are able to perform the PIXE in a single shot without provoking more damage to the sample than conventional methodologies. We verify this by experimentally irradiating materials of interest in the Cultural Heritage with laser-accelerated protons and measuring the PIXE emission. The morphological and chemical analysis of the sample before and after irradiation are compared in order to assess the damage provoked to the artifact. Montecarlo simulations confirm that the temperature in the sample stays safely below the melting point. Compared to conventional diagnostic methodologies, laser-driven PIXE has the advantage of being potentially quicker and more efficien

The Hopper: A Wearable Robotic Device Testbed for Micro-Gravity Bone-Loading Proof-of-Concept

Wearable robotic systems are showing increased potential for addressing crew countermeasures needs. Wearable robots offer a compactness, programmability, and eccentric loading capability not present in more conventional exercise equipment. Correspondingly, advancements in the man to machine interface has progressed, allowing for higher loads to be applied directly to the person in new and novel ways. Recently, the X1 exoskeleton, a lower extremity wearable robot originally designed for mobility assistance and rehabilitation, underwent human subject testing to assess its potential as a knee dynamometer. This was of interest to NASA physiologists because currently strength is not assessed in flight due to hardware limitations, and thus there is a poor understanding of the time course of in-flight changes to muscle strength. The study concluded that the X1 compared well with the Biodex, the "gold standard" in terrestrial dynamometry, with coefficients of variation less than 6.0%. In a following study, the X1 powered ankle was evaluated for its efficacy in exercising calf muscles. Current on-orbit countermeasures equipment does not adequately protect the calf from atrophy. The results of this study were also positive (targeted muscle activity demonstrated via comparing pre- and post-exercise magnetic resonance imaging T2 measurements), again showing the efficacy of wearable robotic devices for addressing the countermeasure needs of our astronauts. Based on these successes and lessons learned, the Grasshopper was co-developed between IHMC (Florida Institute for Human and Machine Cognition) and NASA. The Grasshopper, or the Hopper for short, is a wearable robotic device designed to address muscle and bone density loss for astronauts spending extended periods of time in micro-gravity. The Grasshopper connects to the user's torso like a hiking backpack, over the shoulders and around the waist. At the feet are footplates that strap to the user. There are two actuators, one at each "knee" joint, which are capable of high fidelity torque control. Because the Hopper uses motors instead of gravity to create the load on the user, the device is suited for use on space missions. Exercise in zero-gravity conditions is critical to maintain muscle strength and bone mass. In operation, the actuators try to fold up, or collapse, the device, putting a compressive load between the user's feet and torso. This force is similar to carrying a heavy backpack. The user then bends and extends his or her knees, replicating a weightlifting squat exercise. The applied load is precisely controlled by a computer, and can be programmed to simulate gravitation loads or any desired load prescription, such as free-weight squat exercise. It is even possible to perform eccentric exercises, or negatives, without the need for a spotter. Because the hip joints, as well as the spine and long leg bones, are in the applied load path, there is the potential to stimulate bone growth, countering the typical bone loss when astronauts return from extended duration space travel

Kinderanästhesie zur Protonenbestrahlung: Medizin fernab der Klinik

Zusammenfassung: Die Betreuung von Kleinkindern für die Protonentherapie stellt fachlich und menschlich hohe Anforderungen an das Anästhesieteam. Das Anästhesiepersonal soll in Kinderanästhesie speziell ausgebildet und erfahren sein, insbesondere da die Kinder sich oft in einem reduzierten Allgemeinzustand befinden. Die Infrastruktur soll gemäß den aktuellen anästhesiologischen Standards eingerichtet sein. Die ständige visuelle Überwachung des sedierten Patienten und das lückenlose Monitoring der Vitaldaten müssen gewährleistet sein. Propofol eignet sich ideal für die Sedierung von Kleinkindern in Spontanatmung für die Protonentherapie. Auch bei repetitiver Gabe über mehrere Wochen wird Propofol sehr gut toleriert. Eine enge Zusammenarbeit zwischen Radioonkologe, Onkologe und Anästhesist ist notwendig, um interkurrent auftretende medizinische Probleme optimal zu behandeln. Die besonderen Belange onkologischer Patienten müssen bei der Therapieplanung berücksichtigt werde