113 research outputs found

    The longest functioning heart valve prosthesis?

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    Compatibility of Studies and Family: Approaches at the Medical Faculty Mannheim

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    The compatibility of studies or a career with children is becoming increasingly important. This is partly attributable to the fact that it is important for people of either gender to spend time with their families, their children. Not too long ago, raising children was almost exclusively the domain of the mother. On the other hand, more and more women study medicine. More than half of first year students are now female. Many of these young women, like their male counterparts, would like to start families. The possibility to both study and have children is particularly important during the “training” life phase

    Long-lived quantum memory enabling atom-photon entanglement over 101 km telecom fiber

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    Long-distance entanglement distribution is the key task for quantum networks, enabling applications such as secure communication and distributed quantum computing. Here we report on novel developments extending the reach for sharing entanglement between a single 87^{87}Rb atom and a single photon over long optical fibers. To maintain a high fidelity during the long flight times through such fibers, the coherence time of the single atom is prolonged to 7 ms by applying a long-lived qubit encoding. In addition, the attenuation in the fibers is minimized by converting the photon's wavelength to the telecom S-Band via polarization-preserving quantum frequency conversion. This enables to observe entanglement between the atomic quantum memory and the emitted photon after passing 101 km of optical fiber with a fidelity better than 70.8±\pm2.4%. The fidelity, however, is no longer reduced due to loss of coherence of the atom or photon but in the current setup rather due to detector dark counts, showing the suitability of our platform to realize city-to-city scale quantum network links.Comment: 11 pages, 8 figures, comments are welcom

    Naturschutzleistungen des Ökologischen Landbaus: Wiederansiedlung seltener und gefährdeter Ackerwildpflanzen naturräumlicher Herkünfte auf Ökobetrieben

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    Die Intensivierung der Landwirtschaft hat zum Rückgang vieler Ackerwildpflanzen geführt. Der Ökologische Landbau bietet günstige Voraussetzungen für ihren Schutz. Wie entsprechende Populationen etabliert werden können, untersuchte ein Verbundprojekt der Bayerischen Landesanstalt für Landwirtschaft, der Technischen Universität München und der Universität Kassel. Die AG Freising untersuchte drei seltene winterannuelle Arten (Consolida regalis, Legousia speculumveneris, Lithospermum arvense) in mehrfaktoriellen Feldversuchen, in Praxisaus-saaten auf Bio-Betrieben sowie in Gewächshausexperimenten. Messgrößen waren Individuendichte, Samenproduktion und Bodensamenvorrat der Zielarten, zudem wurde der Ertrag der Feldfrüchte bestimmt. Frühe Herbstsaaten und geringe Konkurrenz durch Kulturen brachten beste Erfolge. Zur erfolgreichen Ansiedlung der Ackerwildkräuter wird eine Aussaat in Blanksaat oder in reduziert gesäten Winterungen, wie Dinkel oder Roggen, bis spätestens Mitte Oktober empfohlen. Klee-Gras und Sommerungen wie Erbsen ermöglichten kaum bzw. kein Auflaufen der Zielarten, die jedoch teils im Bodensamenvorrat überdauern. Die AG Witzenhausen untersuchte die Wiederansiedlung von Ackerwildkräutern auf Praxis-betrieben. Dazu wurden artenreiche Spenderflächen identifiziert und autochthones Saatgut gefährdeter Arten entnommen. Samenmischungen wurden in Blühfenster und den benachbarten Getreidebestand ausgebracht. Zudem wurde die Übertragung von Oberboden arten-reicher Flächen getestet. Im Anlagejahr konnte sich bei beiden Verfahren ein Teil der eingebrachten Arten reproduzieren. Dies gelang bei Konkurrenz mit Getreide tendenziell schlechter. In den Folgejahren konnten bei Anbau von Getreide wiederum einige Arten nachgewiesen werden; die meisten Samen gelangten bei Bodenbearbeitung in tiefere Bodenschichten und reicherten die Samenbank an. Praxisempfehlungen zur Wiederansiedlung von Ackerwildkräutern auf ökologisch bewirtschafteten Äckern wurden als Broschüre veröffentlicht

    Extending Quantum Links: Modules for Fiber- and Memory-Based Quantum Repeaters

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    We analyze elementary building blocks for quantum repeaters based on fiber channels and memory stations. Implementations are considered for three different physical platforms, for which suitable components are available: quantum dots, trapped atoms and ions, and color centers in diamond. We evaluate and compare the performances of basic quantum repeater links for these platforms both for present-day, state-of-the-art experimental parameters as well as for parameters that could in principle be reached in the future. The ultimate goal is to experimentally explore regimes at intermediate distances, up to a few 100 km, in which the repeater-assisted secret key transmission rates exceed the maximal rate achievable via direct transmission. We consider two different protocols, one of which is better adapted to the higher source clock rate and lower memory coherence time of the quantum dot platform, while the other circumvents the need of writing photonic quantum states into the memories in a heralded, non-destructive fashion. The elementary building blocks and protocols can be connected in a modular form to construct a quantum repeater system that is potentially scalable to large distances.Comment: 48 pages in Word style, "White Paper" of Q.Link.X Consortiu

    Entangling single atoms over 33 km telecom fibre

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    Quantum networks promise to provide the infrastructure for many disruptive applications, such as efcient long-distance quantum communication and distributed quantum computing1,2 . Central to these networks is the ability to distribute entanglement between distant nodes using photonic channels. Initially developed for quantum teleportation3,4 and loophole-free tests of Bell’s inequality5,6 , recently, entanglement distribution has also been achieved over telecom fbres and analysed retrospectively7,8 . Yet, to fully use entanglement over long-distance quantum network links it is mandatory to know it is available at the nodes before the entangled state decays. Here we demonstrate heralded entanglement between two independently trapped single rubidium atoms generated over fbre links with a length up to 33 km. For this, we generate atom–photon entanglement in two nodes located in buildings 400 m line-of-sight apart and to overcome high-attenuation losses in the fbres convert the photons to telecom wavelength using polarization-preserving quantum frequency conversion9 . The long fbres guide the photons to a Bell-state measurement setup in which a successful photonic projection measurement heralds the entanglement of the atoms10. Our results show the feasibility of entanglement distribution over telecom fbre links useful, for example, for device-independent quantum key distribution11–13 and quantum repeater protocols. The presented work represents an important step towards the realization of large-scale quantum network links

    Does cardiac imaging surveillance strategy influence outcomes in patients with early breast cancer?

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    BackgroundMany patients with breast cancer receive therapies with the potential to cause cardiotoxicity. Echocardiography and multiple-gated acquisition (MUGA) scans are the most used modalities to assess cardiac function during treatment in high-risk patients; however, the optimal imaging strategy and the impact on outcome are unknown.MethodsConsecutive patients with stage 0-3 breast cancer undergoing pre-treatment echocardiography or MUGA were identified from a tertiary care cancer center from 2010-2019. Demographics, medical history, imaging data and clinical events were collected from hospital charts and administrative databases. The primary outcome is a composite of all-cause death or heart failure event. Clinical and imaging predictors of outcome were evaluated on univariable and multivariable analyses.Results1028 patients underwent pre-treatment MUGA and 1032 underwent echocardiography. The groups were well matched for most clinical characteristics except patients undergoing MUGA were younger, had more stage 3 breast cancer and more HER2 over-expressing and triple negative cases. Routine follow-up cardiac imaging scan was obtained in 39.3% of patients with MUGA and 38.0% with echocardiography. During a median follow-up of 2448 (1489, 3160) days, there were 194 deaths, including 7 cardiovascular deaths, and 28 heart failure events with no difference in events between the MUGA and echocardiography groups. There were no imaging predictors of the primary composite outcome or cardiac events. Patients without follow-up imaging had similar adjusted risk for the composite outcome compared to those with imaging follow-up, hazard ratio 0.8 (95% confidence interval 0.5,1.3), p=0.457.ConclusionThe selection of pretreatment echocardiography or MUGA did not influence the risk of death or heart failure in patients with early breast cancer. Many patients did not have any follow-up cardiac imaging and did not suffer worse outcomes. Cardiovascular deaths and heart failure event rates were low and the value of long-term cardiac imaging surveillance should be further evaluated

    The Alberta Heart Failure Etiology and Analysis Research Team (HEART) study

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    Background Nationally, symptomatic heart failure affects 1.5-2% of Canadians, incurs $3 billion in hospital costs annually and the global burden is expected to double in the next 1–2 decades. The current one-year mortality rate after diagnosis of heart failure remains high at >25%. Consequently, new therapeutic strategies need to be developed for this debilitating condition. Methods/Design The objective of the Alberta HEART program (http://albertaheartresearch.ca) is to develop novel diagnostic, therapeutic and prognostic approaches to patients with heart failure with preserved ejection fraction. We hypothesize that novel imaging techniques and biomarkers will aid in describing heart failure with preserved ejection fraction. Furthermore, the development of new diagnostic criteria will allow us to: 1) better define risk factors associated with heart failure with preserved ejection fraction; 2) elucidate clinical, cellular and molecular mechanisms involved with the development and progression of heart failure with preserved ejection fraction; 3) design and test new therapeutic strategies for patients with heart failure with preserved ejection fraction. Additionally, Alberta HEART provides training and education for enhancing translational medicine, knowledge translation and clinical practice in heart failure. This is a prospective observational cohort study of patients with, or at risk for, heart failure. Patients will have sequential testing including quality of life and clinical outcomes over 12 months. After that time, study participants will be passively followed via linkage to external administrative databases. Clinical outcomes of interest include death, hospitalization, emergency department visits, physician resource use and/or heart transplant. Patients will be followed for a total of 5 years. Discussion Alberta HEART has the primary objective to define new diagnostic criteria for patients with heart failure with preserved ejection fraction. New criteria will allow for targeted therapies, diagnostic tests and further understanding of the patients, both at-risk for and with heart failure
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