969 research outputs found

    Die "Canadian Head Rule" für Patienten mit leichtem Schädelhirntrauma:Ist die Anwendung in Münster sinnvoll?

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    Hintergrund: Sensitivität, Spezifität und Anwendbarkeit der Canadian Head Rule (CHR) wurde für Münsteraner Patienten evaluiert. Methoden: Eingeschlossen wurden 122 SHT-Patienten (m=74; w=48; 40.0 +/- 19.0J) der Jahre 1999-2000. Die Indikation zur CCT wurde entsprechend der CHR ermittelt und mit den CCT-Resultaten verglichen. Ergebnisse: 4/122 Patienten (3%) zeigten interventionspflichtige Verletzungen. Alle wurden durch die CHR erkannt. Die Indikation zur CCT bestand bei 67/122 Patienten (55%). 13/122 Patienten (11%) wiesen schwere Hirnverletzungen auf. Alle wurden durch die erweiterten Kriterien der CHR erkannt. Die Indikation zur CCT unter Beachtung der erweiterten Kriterien bestand bei 85/122 Patienten (78%). Schlussfolgerung: Die CHR zeigt eine hohe Sensitivität für interventionspflichtige, nicht aber für primär nicht-interventionspflichtiger Verletzungen

    Probing the Neutron Star Interior with Glitches

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    With the aim of constraining the structural properties of neutron stars and the equation of state of dense matter, we study sudden spin-ups, glitches, occurring in the Vela pulsar and in six other pulsars. We present evidence that glitches represent a self-regulating instability for which the star prepares over a waiting time. The angular momentum requirements of glitches in Vela indicate that at least 1.4% of the star's moment of inertia drives these events. If glitches originate in the liquid of the inner crust, Vela's `radiation radius' RR_\infty must exceed ~12 km for a mass of 1.4 solar masses. The isolated neutron star RX J18563-3754 is a promising candidate for a definitive radius measurement, and offers to further our understanding of dense matter and the origin of glitches.Comment: Invited talk at the Pacific Rim Conference on Stellar Astrophysics, Hong Kong, Aug. 1999. 9 pages, 5 figure

    The Magnificent Seven: Magnetic fields and surface temperature distributions

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    Presently seven nearby radio-quiet isolated neutron stars discovered in ROSAT data and characterized by thermal X-ray spectra are known. They exhibit very similar properties and despite intensive searches their number remained constant since 2001 which led to their name ``The Magnificent Seven''. Five of the stars exhibit pulsations in their X-ray flux with periods in the range of 3.4 s to 11.4 s. XMM-Newton observations revealed broad absorption lines in the X-ray spectra which are interpreted as cyclotron resonance absorption lines by protons or heavy ions and / or atomic transitions shifted to X-ray energies by strong magnetic fields of the order of 10^13 G. New XMM-Newton observations indicate more complex X-ray spectra with multiple absorption lines. Pulse-phase spectroscopy of the best studied pulsars RX J0720.4-3125 and RBS 1223 reveals variations in derived emission temperature and absorption line depth with pulse phase. Moreover, RX J0720.4-3125 shows long-term spectral changes which are interpreted as due to free precession of the neutron star. Modeling of the pulse profiles of RX J0720.4-3125 and RBS 1223 provides information about the surface temperature distribution of the neutron stars indicating hot polar caps which have different temperatures, different sizes and are probably not located in antipodal positions.Comment: 10 pages, 8 figures, to appear in Astrophysics and Space Science, in the proceedings of "Isolated Neutron Stars: from the Interior to the Surface", edited by D. Page, R. Turolla and S. Zan

    The use of admissions simulation to stabilize ancillary workloads

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    As part of the planning of a new hospital, an analysis was per formed to determine the number of procedures that would be performed in each of nineteen ancillary departments on a day of the week basis. Because the planned occupancy was not the maximum possible, attempts were made using simulation to smooth the daily ancillary loads by varying the admission day of elective, urgent inpatient and outpatient loads. The methodology, sample outputs, and main conclusions are presented.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69095/2/10.1177_003754978404300203.pd

    Comparison of magnetic resonance with computed tomography angiography for preoperative localization of the Adamkiewicz artery in thoracoabdominal aortic aneurysm patients

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    ObjectivePreoperative localization of the Adamkiewicz artery and its segmental supplier in advance of thoracic aortic aneurysm (TAA) and thoracoabdominal aortic aneurysm (TAAA) repair is proposed to be useful to prevent postoperative paraplegia. The diagnostic potential of magnetic resonance angiography (MRA) and computed tomography angiography (CTA) was evaluated for the preoperative localization of the Adamkiewicz artery in white TAAA patients.MethodsThirty-nine consecutive patients with a TAA(A) scheduled for elective open surgical aortic repair preoperatively underwent MRA and CTA. Objective image quality was assessed by measuring the signal-to-noise ratio and contrast-to-noise ratio of the Adamkiewicz artery and was related to patient thickness. Two independent observers scored the location of the Adamkiewicz artery and the subjective image quality of vessel-background contrast of the Adamkiewicz artery, image noise, spinal cord tissue enhancement, epidural venous enhancement, and overall image quality.ResultsAverage detection rate for Adamkiewicz artery localization was 71% (67% to 74%) for CTA and 97% (94% to 100%) for MRA. Interobserver agreement was 82% for CTA and 94% for MRA. Signal-to-noise ratio was significantly higher (P < .001) and contrast-to-noise ratio was significantly (P < .001) lower for CTA than for MRA. Contrast of the Adamkiewicz artery (P < .001) and overall image quality (P < .004) were judged to be significantly better for MRA. Spinal cord tissue enhancement was judged stronger at CTA (P < .03), with significantly less epidural venous enhancement (P < .001). No significant difference was found in image noise. Signal-to-noise and contrast-to-noise decreased significantly (P < .001) with increasing patient thickness for CTA but not for MRA.ConclusionsLocalization of the Adamkiewicz artery in white TAAA patients is possible with both CTA and MRA. Compared with CTA, MRA is more favorable because of the higher Adamkiewicz artery detection rate, the higher contrast-to-noise ratio, and its independence of patient thickness

    Einflussfaktoren auf Gründungsdispositionen und Entrepreneurship-Merkmalen von Studierenden – Ein Vergleich von Russland und Deutschland

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    Dieser Beitrag geht mit dem internationalen Forschungsprojekt „Gründungen und Entrepreneurship bei Studierenden“ (GESt-Studie) einher, das zum Ziel hat, Gründungsneigungen und Entrepreneurship-Merkmale von Studierenden aus verschiedenen Ländern zielgruppendifferenziert zu analysieren, um daraus bedarfsorientierte Handlungsempfehlungen für eine adäquate Konzeptionierung von Gründungsausbildung und Gründungsförderung abzuleiten. Die Ergebnisse dieses Ländervergleiches veranschaulichen, dass die befragten Studierenden in Russland ein höheres Gründungsinteresse repräsentieren und sich insgesamt deutlich stärker mit Entrepreneurship beschäftigen als die in Deutschland befragten Studierenden. Allerdings basiert diese in Russland positivere Ausgangsbasis für eine Gründungsrealisierung stärker auf der Gründungsmotivation aus ökonomischer Notwendigkeit, die oftmals nicht auf innovativen Geschäftsideen beruht, heraus. Insgesamt betrachtet sind sowohl den Studierenden in Deutschland, von denen sich etwa jeder Zweite noch gar nicht mit der Gründungsthematik auseinandergesetzt hat, als auch den Studierenden in Russland, die stärker durch fehlende unternehmerische Qualifikationen von der Gründung abgehalten werden, insbesondere gründungsspezifische Grundkenntnisse und unternehmerische Fähigkeiten zu vermitteln, was fächerübergreifend und während des gesamten Studiums zu erfolgen hat.

    Interference and interaction effects in multi-level quantum dots

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    Using renormalization group techniques, we study spectral and transport properties of a spinless interacting quantum dot consisting of two levels coupled to metallic reservoirs. For strong Coulomb repulsion UU and an applied Aharonov-Bohm phase ϕ\phi, we find a large direct tunnel splitting Δ(Γ/π)cos(ϕ/2)ln(U/ωc)|\Delta|\sim (\Gamma/\pi)|\cos(\phi/2)|\ln(U/\omega_c) between the levels of the order of the level broadening Γ\Gamma. As a consequence we discover a many-body resonance in the spectral density that can be measured via the absorption power. Furthermore, for ϕ=π\phi=\pi, we show that the system can be tuned into an effective Anderson model with spin-dependent tunneling.Comment: 5 pages, 4 figures included, typos correcte

    Recent results on multiplicative noise

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    Recent developments in the analysis of Langevin equations with multiplicative noise (MN) are reported. In particular, we: (i) present numerical simulations in three dimensions showing that the MN equation exhibits, like the Kardar-Parisi-Zhang (KPZ) equation both a weak coupling fixed point and a strong coupling phase, supporting the proposed relation between MN and KPZ; (ii) present dimensional, and mean field analysis of the MN equation to compute critical exponents; (iii) show that the phenomenon of the noise induced ordering transition associated with the MN equation appears only in the Stratonovich representation and not in the Ito one, and (iv) report the presence of a new first-order like phase transition at zero spatial coupling, supporting the fact that this is the minimum model for noise induced ordering transitions.Comment: Some improvements respect to the first versio

    The predictive value of the modified early warning score for admission to the intensive care unit in patients with a hematologic malignancy – A multicenter observational study

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    Objectives: The modified early warning score (MEWS) is used to detect clinical deterioration of hospitalized patients. We aimed to investigate the predictive value of MEWS and derived quick Sequential Organ Failure Assessment (qSOFA) scores for intensive care unit admission in patients with a hematologic malignancy admitted to the ward. Design: Retrospective, observational study in two Dutch university hospitals. Setting: Data from adult patients with a hematologic malignancy, admitted to the ward over a 2-year period, were extracted from electronic patient files. Main outcome measures: Intensive care admission. Results: We included 395 patients with 736 hospital admissions; 2% (n = 15) of admissions resulted in admission to the intensive care unit. A higher MEWS (OR 1.5; 95 %CI 1.3–1.80) and qSOFA (OR 4.4; 95 %CI 2.1–9.3) were associated with admission. Using restricted cubic splines, a rise in the probability of admission for a MEWS ≥ 6 was observed. The AUC of MEWS for predicting admission was 0.830, the AUC of qSOFA was 0.752. MEWS was indicative for intensive care unit admission two days before admission. Conclusions: MEWS was a sensitive predictor of ICU admission in patients with a hematologic malignancy, superior to qSOFA. Future studies should confirm cut-off values and identify potential additional characteristics, to further enhance identification of critically ill hemato-oncology patients. Implications for Clinical Practice: The Modified Early Warning Score (MEWS) can be used as a tool for healthcare providers to monitor clinical deterioration and predict the need for intensive care unit admission in patients with a hematologic malignancy. Yet, consistent application and potential reevaluation of current thresholds is crucial. This will enable bedside nurses to more effectively identify patients needing adjunctive care, facilitating timely interventions and improved outcome.</p

    CC chemokine CCL5 plays a central role impacting infarct size and post-infarction heart failure in mice

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    Aims The chemokine CCL5 plays a critical role as neutrophil and macrophage activator do in atherosclerosis and myocardial infarction. Thus, we investigated whether the treatment with a neutralizing monoclonal antibody (mAb) to mouse CCL5 would provide therapeutic benefit when provoking a coronary-associated ischaemic event. Methods and Results C57Bl/6 mice were submitted to left coronary artery permanent ligature. Then, various parameters were monitored for up to 21 days. At5 min and 3days after coronary occlusion, mice received one intravenous injection of the rat anti-mouse CCL5 mAb or isotype IgG control. Infarct size was assessed histologically and by measuring serum cardiac troponin I levels. Kinetics of CCL5 tissue expression, leucocyte infiltration, matrix metalloproteinase (MMP) levels, and collagen deposition were histologically assessed. Serum chemokine levels were measured by enzyme-linked immunosorbent assay. Cardiac function and dimensions were assessed by magnetic resonance imaging (MRI). Chronic ischaemia increased both circulating and intracardiac levels of CCL5. At 24 h, treatment with the anti-CCL5 mAb resulted in a smaller infarct size and reduced circulating levels of chemokines. This effect was associated with reduction of neutrophil and macrophage infiltration within the infarcted myocardium. After 3 days of chronic ischaemia, anti-CCL5 mAb treatment reduced cardiac MMP-9. At 7 days, collagen content was significantly lower. At 21 days, neutralizing CCL5 improved mouse survival, cardiac myocyte size, and cardiac function. Conclusion Treatment with anti-CCL5 mAb significantly reduced both infarct size and post-infarction heart failure in a mouse model of chronic cardiac ischaemia. Cardioprotective effects were associated with the reduction of leucocyte recruitment within infarcted heart
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