714 research outputs found

    Quantum theory cannot consistently describe the use of itself

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    Quantum theory provides an extremely accurate description of fundamental processes in physics. It thus seems likely that the theory is applicable beyond the, mostly microscopic, domain in which it has been tested experimentally. Here we propose a Gedankenexperiment to investigate the question whether quantum theory can, in principle, have universal validity. The idea is that, if the answer was yes, it must be possible to employ quantum theory to model complex systems that include agents who are themselves using quantum theory. Analysing the experiment under this presumption, we find that one agent, upon observing a particular measurement outcome, must conclude that another agent has predicted the opposite outcome with certainty. The agents' conclusions, although all derived within quantum theory, are thus inconsistent. This indicates that quantum theory cannot be extrapolated to complex systems, at least not in a straightforward manner.Comment: 11 + 8 pages, 4 figures; substantially rewritten, including change of title; close to published versio

    Ein auf Petri-Netzen basierendes Geschäftsprozessmodell und dessen Anwendung im E-Commerce

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    Der Gedanke der prozessorientierten Sicht reicht viele Jahrzente zurück, hat sich aber erst in jüngerer Zeit unter dem Gesichtspunkt von Kunden- und Resultatausrichtung, Qualitätssicherung, Supply Chain Management, Effizienzsteigerung und damit Wettbewerbsfähigkeit durchgesetzt. Der Wechsel von einer Aufbau- hin zu einer Prozessorganisation erfolgt initial im Entwurf und in der Umsetzung des neuen Prozessmodells. Anschliessend ist es Aufgabe der Führung, diese Prozesse laufend zu überwachen und zu steuern. Dabei stellt sich zum einen die Frage nach dem geeigneten Modell und zum anderen die nach der geeigneten Modellsprache. Die vorliegende Arbeit unterzieht zwei in der Praxis häufig anzutreffende Prozessmodelle sowie die mathematisch begründeten, formalen Petri-Netze einer Beurteilung aus Sicht der Wirtschaftsinformatik. Danach folgt ein Vorschlag, welcher auf den Petri-Netzen beruht, aber im Gegensatz zu diesen besser an die Bedürfnisse der Geschäftsprozessmodellierung angepasst ist, was in der anschliessenden Beurteilung gezeigt wird. Die meisten Geschäftsprozesse erfahren heutzutage eine informationstechnische Unterstützung, deren Realisierung nicht zuletzt aufgrund unterschiedlicher Modelle auf seiten Betrieb und auf seiten Informatik mit hohem Aufwand verbunden ist. Am Beispiel eines in einem Webshop ablaufenden Bestellprozesses wird gezeigt, wie mit dem vorgestellten Modellansatz sowohl die fachliche Sicht wie die technische Sicht im selben Modell abgebildet werden kann und so Potential für kürzere Entwicklungswege geschaffen werden kann

    Lordoplasty: report on early results with a new technique for the treatment of vertebral compression fractures to restore the lordosis

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    Cement augmentation using PMMA cement is known as an efficient treatment for osteoporotic vertebral compression fractures with a rapid release of pain in most patients and prevention of an ongoing kyphotic deformity of the vertebrae treated. However, after a vertebroplasty there is no chance to restore vertebral height. Using the technique of kyphoplasty a certain restoration of vertebral body height can be achieved. But there is a limitation of recovery due to loss of correction when deflating the kyphoplastic ballon and before injecting the cement. In addition, the instruments used are quite expensive. Lordoplasty is another technique to restore kyphosis by indirect fracture reduction as it is used with an internal fixateur. The fractured and the adjacent vertebrae are instrumented with bone cannulas bipediculary and the adjacent vertebrae are augmentated with cement. After curing of the cement the fractured vertebra is reduced by applying a lordotic moment via the cannulas. While maintaining the pretension the fractured vertebra is reinforced. We performed a prospective trial of 26 patients with a lordoplastic procedure. There was a pain relief of about 87% and a significant decrease in VAS value from 7.3 to 1.9. Due to lordoplasty there was a significant and permanent correction in vertebral and segmental kyphotic angle about 15.2° and 10.0°, respectively and also a significant restoration in anterior and mid vertebral height. Lordoplasty is a minimal invasive technique to restore vertebral body height. An immediate relief of pain is achieved in most patients. The procedure is safe and cost effectiv

    Restructuring during pretreatment of platinum/alumina for enantioselective hydrogenation

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    The influence of reductive and oxidative heat treatment on the enantioselectivity of chirally modified Pt/alumina has been reinvestigated, using the hydrogenation of ketopantolactone as a test reaction. Enhancement in ee by 39-49% has been observed after treatment in hydrogen at 250-600°C, as compared to untreated or preoxidized catalysts. The changes in ee after reductive and oxidative treatments are reversible, and always the final treatment is decisive. A HRTEM study indicates that adsorbate‐induced restructuring of Pt crystallites during hydrogen treatment at elevated temperature can play a role in the selectivity improvement, but the changes are superimposed by the strong structure‐directing effect of the alumina support. The possible contribution of other effects (complete reduction of Pt n+ surface species, removal of impurities, or change of Pt particle size) could be exclude

    The value of different resistance parameters in distinguishing biopsy-proved dysfunction of renal allografts

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    The data concerning the value of duplex sonography in diagnosing parenchymatous renal allograft dysfunction are controversial. Most early studies did not take into consideration the many factors influencing resistance parameters. We therefore performed a prospective, biopsy-controlled study with exclusion of all known sources of error regarding resistance parameters. Furthermore we investigated the value of a new resistance parameter, the systolic deceleration percentage. Forty-seven duplex sonographic studies were performed on 43 patients (30 male, 13 female, median age 47 years, range 7-70). Fourteen studies were done on normally functioning grafts (control group) an average of 33 days after transplantation. Thirty-three studies were performed on dysfunctional grafts immediately prior to biopsy. Grafts which had been transplanted more than a year previously or with vascular findings or any other clinical or sonographic pathology probably explaining function deterioration were excluded. In all patients, the resistive index (RI), pulsatility index (PI) and systolic deceleration percentage (DP) were calculated in the main renal artery and in the interlobar artery. Of the 33 grafts with dysfunction, nine had vascular rejection (VR), 11 interstitial rejection (IR), 11 cyclosporin A toxicity (CAT) and two other histologies (OR). The mean RI in normal grafts (NO) was 0.71±0.06 in the main artery and 0.68±0.06 in the interlobar artery, in VR 0.86±0.12 and 0.80±0.18, in IR 0.72±0.05 and 0.70±0.07, in CAT 0.67±0.06 and 0.65±0.07 and in OR 0.64±0.07 and 0.60±0.01. For PI, the values were 1.45±0.23 and 1.41±0.28 (NO), 3.5±2.13 and 2.92±2.16 (VR), 1.55±0.26 and 1.46±0.33 (IR), 1.32±0.25 and 1.27±0.26 (CAT) and 1.30±0.34 and 1.13±0.04 (OR). For DP we calculated 28±5% and 29±6% (NO), 43±14% and 36±6% (VR), 29±9% and 27±9% (IR), 31±8% and 32±7% (CAT ) and 32±4% and 28±3% (OR). The sensitivity/specificity for VR with a cutoff mean+2 SD was 0.44/1 for RI, 0.55/0.97 for PI and 0.33/0.89 for DP. It was concluded that:(1) despite the high selection of our patient group, diagnostic accuracy of duplex sonography for diagnosing parenchymatous function disorder in renal allograft remains insufficient; (2) in vascular rejection only, the resistance parameters differ significantly from the values of normal allografts; (3) the higher the cutoff of resistance parameters, the better the specificity and the worse the sensitivity for diagnosing vascular rejection; (4) of all investigated resistance parameters, the RI is the most practical due to a simple measurement techniqu

    A practical guide to the handling and administration of talimogene laherparepvec in Europe.

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    Talimogene laherparepvec is a herpes simplex virus-1-based intralesional oncolytic immunotherapy and is the first oncolytic virus to be approved in Europe. It is indicated for the treatment of adults with unresectable melanoma that is regionally or distantly metastatic (stage IIIB, IIIC, and IVM1a) with no bone, brain, lung, or other visceral disease. Talimogene laherparepvec is a genetically modified viral therapy, and its handling needs special attention due to its deep freeze, cold-chain requirements, its potential for viral shedding, and its administration by direct intralesional injection. This review provides a practical overview of handling, storage, and administration procedures for this agent in Europe. Talimogene laherparepvec vials should be transported/stored frozen at a temperature of -90°C to -70°C, and once thawed, vials must not be refrozen. Universal precautions for preparation, administration, and handling should be followed to avoid accidental exposure. Health care providers should wear personal protective equipment, and materials that come into contact with talimogene laherparepvec should be disposed of in accordance with local institutional procedures. Individuals who are immunocompromised or pregnant should not prepare or administer this agent. Talimogene laherparepvec is administered by intralesional injection into cutaneous, subcutaneous, and/or nodal lesions that are visible, palpable, or detectable by ultrasound. Treatment should be continued for ≥6 months. As with other immunotherapies, patients may experience an increase in the size of existing lesion(s) or the appearance of new lesions (ie, progression) prior to achieving a response ("pseudo-progression"). As several health care professionals (eg, physicians [dermatologists, surgeons, oncologists, radiologists], pharmacists, nurses) are involved in different stages of the process, there is a need for good interdisciplinary collaboration when using talimogene laherparepvec. Although there are specific requirements for this agent's storage, handling, administration, and disposal, these can be effectively managed in a real-world clinical setting through the implementation of training programs and straightforward standard operating procedures

    Early renal transplant dysfunction due to arterial kinking stenosis

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    The main differential diagnoses of early renal trans-plant dysfunction include ischaemic damage, cyclospo-rin toxicity, and rejection [1]. Rarer causes include bleeding, ureteral obstruction, urinary leak, venou

    Fallstudie Amag Leasing AG: «Videobasierte Identifikation als Wegbereiter für das Online-Leasing»

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    Die fortschreitende Digitalisierung in der Automobilbranche macht auch vor dem Leasinggeschäft nicht Halt. Neue Technologien bieten Ansatzpunkte Produkte, Prozesse und Geschäftsmodelle zu innovieren. Die vorliegende Fallstudie beschreibt, wie die AMAG Leasing AG die Potenziale der videobasierten Online-Identifikation ausschöpfen will, um Kunden ein durchgängiges Online-Leasing ohne Medienbrüche anbieten zu können. Neben einem bereits durchgängig automatisierten Bewilligungsprozess wird dabei der frühzeitige Einbezug der Kundenperspektive zum Schlüsselfaktor
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