Stopping power and collective flow of nuclear matter in the reaction Ar+Pb at 0.8 GeV/u

Charged-particle exclusive data for Ar+Pb collisions at 0.772 GeV/u are analyzed in terms of collective variables for the event shapes in momentum space. Semicentral collisions lead to sidewards flow whereas nearly head-on collisions have spherical shapes in the c.m. frame, resulting from complete stopping of projectile motion. The hydrodynamical model predictions agree qualitatively with the data whereas the standard cascade model disagrees, lacking in stopping power and collective flow

Collective motion in nucleus-nucleus collisions at 800 MeV/nucleon

Semicentral Ar+KCl, La+La, and Ar+Pb collisions at 800 MeV/nucleon were studied using a streamer chamber. The results are analyzed in the framework of the transverse momentum analysis and in terms of the average sphericity matrix. A critical examination of the analysis procedures, both experimental and theoretical, is given. New procedures are described to account for overall momentum conservation in the reaction, and to correct for azimuthal variations in the detection efficiency. Average transverse momenta per nucleon in the reaction plane are presented for deuterons emitted in the forward hemisphere, as these provide the most reliable information. A Vlasov-Uehling-Uhlenbeck calculation with a stiff equation of state gives a good fit to the momenta in the Ar+Pb reaction. Flow effects parametrized further using the sphericity tensor are found stronger than in the cascade model and consistently weaker than predicted by hydrodynamics. Parameters from the sphericity tensor exhibit a larger variation as a function of multiplicity than do the average momenta per nucleon

Charakteristika und Outcome von 70 beatmeten COVID-19-Patienten : Bilanz nach der ersten Welle an einem universitären Zentrum

BACKGROUND In a pandemic situation the overall mortality rate is of considerable interest; however, these data must always be seen in relation to the given healthcare system and the availability of local level of care. A recently published German data evaluation of more than 10,000 COVID-19 patients treated in 920 hospitals showed a high mortality rate of 22% in hospitalized patients and of more than 50% in patients requiring invasive ventilation. Because of the high infection rates in Bavaria, a large number of COVID-19 patients with considerable severity of disease were treated at the intensive care units of the LMU hospital. The LMU hospital is a university hospital and a specialized referral center for the treatment of patients with acute respiratory distress syndrome (ARDS). OBJECTIVE Data of LMU intensive care unit (ICU) patients were systematically evaluated and compared with the recently published German data. METHODS Data of all COVID-19 patients with invasive and noninvasive ventilation and with completed admission at the ICU of the LMU hospital until 31 July 2020 were collected. Data were processed using descriptive statistics. RESULTS In total 70 critically ill patients were included in the data evaluation. The median SAPS II on admission to the ICU was 62~points. The median age was 66 years and 81% of the patients were male. More than 90% were diagnosed with ARDS and received invasive ventilation. Treatment with extracorporeal membrane oxygenation (ECMO) was necessary in 10% of the patients. The median duration of ventilation was 16 days, whereby 34.3% of patients required a tracheostomy. Of the patients 27.1% were transferred to the LMU hospital from external hospitals with reference to our ARDS/ECMO program. Patients from external hospitals had ARDS of higher severity than the total study population. In total, nine different substances were used for virus-specific treatment of COVID-19. The most frequently used substances were hydroxychloroquine and azithromycin. Immunomodulatory treatment, such as Cytosorb® (18.6%) and methylprednisolone (25.7%) were also frequently used. The overall in-hospital mortality rate of ICU patients requiring ventilation was 28.6%. The mortality rates of patients from external hospitals, patients with renal replacement therapy and patients with ECMO therapy were 47.4%, 56.7% and 85.7%, respectively. CONCLUSION The mortality rate in the ventilated COVID-19 intensive care patients was considerably different from the general rate in Germany. The data showed that treatment in an ARDS referral center could result in a lower mortality rate. Low-dose administration of steroids may be another factor to improve patient outcome in a preselected patient population. In the authors' opinion, critically ill COVID-19 patients should be treated in an ARDS center provided that sufficient resources are available.ZUSAMMENFASSUNG HINTERGRUND: Eine aktuelle, deutschlandweite Datenerhebung zeigte bei beatmeten Patienten mit COVID-19 eine Letalität von über 50 %. Auch am LMU Klinikum wurde eine große Anzahl an Patienten mit COVID-19 mit teils erheblicher Erkrankungsschwere intensivmedizinisch behandelt. FRAGESTELLUNG Die Daten der am LMU-Klinikum behandelten COVID-19-Patienten wurden systematisch ausgewertet und mit den deutschlandweiten Daten verglichen. METHODIK Für die vorliegende Studie wurden die Daten aller Patienten, die bis zum 31.07.2020 am LMU-Klinikum aufgrund von COVID-19 invasiv und nichtinvasiv beatmet wurden und deren Krankenhausaufenthalt zum Zeitpunkt der Auswertung bereits abgeschlossen war, analysiert und mittels deskriptiver Statistik aufgearbeitet. ERGEBNISSE Insgesamt wurden 70 kritisch kranke, beatmete Patienten (SAPS-II-Median: 62 Punkte) analysiert (Altersmedian: 66 Jahre, 81 % männlich). Über 90 % wurden wegen eines akuten Lungenversagens (ARDS) unterschiedlicher Schweregrade behandelt. Eine Therapie mittels extrakorporaler Membranoxygenierung (ECMO) war bei 10 % erforderlich. Die Übernahme von externen Kliniken im Rahmen einer ARDS/ECMO-Anfrage erfolgte bei 27,1 % der Patienten. Häufig eingesetzte immunmodulatorische Therapien waren die Behandlung mit Cytosorb® (18,6 %) und die prolongierte Gabe von Methylprednisolon (25,7 %). Die krankenhausinterne Letalität betrug 28,6 %. FAZIT Trotz erheblicher Erkrankungsschwere lag die Letalität bei beatmeten COVID-19-Intensivpatienten im LMU-Kollektiv deutlich unter der deutschlandweit erhobenen Letalität. Ein möglicher Faktor ist die Behandlung in einem Zentrum für ARDS

Collective motion in Ar+Pb collision at beam energies between 400 and 1800 MeV/nucleon

The energy dependence of rapidity distributions and flow effects was studied in central Ar+Pb collisions at 400, 800, and 1800 MeV/nucleon using a streamer chamber. Rapidity distributions for proton and pions are found to have a Gaussian shape whereas those for deuterons exhibit a two-peak structure at the two higher energies. The average in-plane transverse momentum per/nucleon and per/event shows saturation of flow around 800 MeV/nucleon for this asymmetric system. The aspect ratio of the sphericity tensor is closely correlated with the flow angle. This correlation appears to be independent of beam energy. The number of participating nucleons in central collisions varies from 213 at 400 to 135 at 1800 MeV/nucleon indicating that at the lowest energy almost the entire target nucleus participates in the collision.weitere Autoren

Multi-dimensional modeling and simulation of semiconductor nanophotonic devices

Self-consistent modeling and multi-dimensional simulation of semiconductor nanophotonic devices is an important tool in the development of future integrated light sources and quantum devices. Simulations can guide important technological decisions by revealing performance bottlenecks in new device concepts, contribute to their understanding and help to theoretically explore their optimization potential. The efficient implementation of multi-dimensional numerical simulations for computer-aided design tasks requires sophisticated numerical methods and modeling techniques. We review recent advances in device-scale modeling of quantum dot based single-photon sources and laser diodes by self-consistently coupling the optical Maxwell equations with semiclassical carrier transport models using semi-classical and fully quantum mechanical descriptions of the optically active region, respectively. For the simulation of realistic devices with complex, multi-dimensional geometries, we have developed a novel hp-adaptive finite element approach for the optical Maxwell equations, using mixed meshes adapted to the multi-scale properties of the photonic structures. For electrically driven devices, we introduced novel discretization and parameter-embedding techniques to solve the drift-diffusion system for strongly degenerate semiconductors at cryogenic temperature. Our methodical advances are demonstrated on various applications, including vertical-cavity surface-emitting lasers, grating couplers and single-photon sources

From Colonial Research Spirit to Global Commitment: Bayer and African Sleeping Sickness in the Mirror of History

In the early 20th century, a series of epidemics across equatorial Africa brought African sleeping sickness (human African trypanosomiasis, HAT) to the attention of the European colonial administrations. This disease presented an exciting challenge for microbiologists across Europe to study the disease, discover the pathogen and search for an effective treatment. In 1923, the first “remedy for tropical diseases”—Suramin—manufactured by Bayer AG came onto the market under the brand name “Germanin.” The development and life cycle of this product—which today is still the medicine of choice for Trypanosoma brucei (T.b), hodesiense infections—reflect medical progress as well as the successes and failures in fighting the disease in the context of historic political changes over the last 100 years

Werkstattunterricht und Stationenlernen

Miller S, Schroeder R. Werkstattunterricht und Stationenlernen. In: von Reeken D, ed. Handbuch Methoden im Sachunterricht. Kinder. Sachen. Welten. Dimensionen des Sachunterrichts. Vol Band 3. Baltmannsweiler: Schneider Verlag Hohengehren; 2017: 283-294