Kompakte Einspiegel-Laserstrahlablenkung für die Materialbearbeitung

Wir stellen einen kompakten Einspiegel 2D-Strahlablenker für Hochleistungs-Laser vor. Dieser Scanner ist für industrielle Anwendungen, wie zum Beispiel das hochpräzise Punktschweissen mit Lasern bis 5 kW Pulsleisung entwickelt worden. Er hat eine closed loop Bandbreite von typisch 700 Hz und über das ganze Scan-Feld eine maximale Stellzeit von weniger als 10 ms. Für eine nutzbare Spiegelfläche von (elliptisch) 30x40 mm2 ist das Totalvolumen des Scanners nur 30x40x50 mm3 und das Gewicht nur 90g. Die maximalen Ablenkwinkel sind ±3.5° was bei einer Brennweite von 100 mm ein Scan-Feld von ≈10x10 mm2 ergibt. Unter diesen Bedingungen kann mit einem Nd:YAG-Laser ein (beugungsbegrenzrer) Spot-Durchmesser von weniger als 10μm erreicht werden und eine Wiederholgenauigkeit von ungefähr 5μm

Comparing Results of Concurrent and Retrospective Designs in a Hospital Utilization Review

Hospital utilization reviews are performed on the basis of lists of explicit criteria, such as the Appropriateness Evaluation Protocol, both concurrently and retrospectively, in an increasing number of settings as part of efforts to improve the performance of hospitals and to reduce health care costs. Retrospective data collection has advantages in terms of expenses and ease of sampling, but relies on the quality of medical records. We report on a comparison between concurrent and retrospective data collection performed simultaneously and independently by two reviewers on the same hospital stays in the regional St-Loup Hospital. Results suggest that retrospective data collection produces higher rates of inappropriate hospital utilization, due to a limited number of criteria that are recorded concurrently, but are not found in the retrospective reading of medical records. These results should encourage a further investigation of the comparability between concurrent and retrospective designs in other settings. © 1997 Elsevier Science Ltd. All rights reserve

Radio and thermoluminescence studies in CsI doped with F centers

Radioluminescence, thermoluminescence, and u.v. excitation measurements in CsI additively colored crystals showed a new luminescent component at 2.5 eV. This is attributed to the radiative recombination of Vk centers with F centers. Another new component at 2.72 eV was observed only under uv excitation of 5.14 eV. This is related to the radiative recombination of localized excitons at F+ center sites (α band)

Study of Vk centers in CsI crystals

Vk centers were observed in CsI doped with Na+ and Tl+ after x-ray irradiation at liquid He temperature by using optical and EPR techniques. They are oriented along [100] directions. By studying thermoluminescence, 2 types of thermal migration were found, one due to linear displacement of the centers along the cubic axis and the other due to 90° rotations. They correspond to 2 glow peaks at 60 and 90°K, respectively

Kann die 18F-FDG-PET/CT-Untersuchung die Panendoskopie zur Detektion von synchronen Zweitkarzinomen ersetzen?

Ziel der Arbeit war es, die Wertigkeit der 18F-FDG-PET/ CT-Untersuchung bezüglich synchroner Zweitkarzinome im Vergleich mit der Panendoskopie beim initialen Staging zu untersuchen. 311 Patienten wurden mit beiden Untersuchungsmethoden abgeklärt. Als Referenz galt die zytologische, histologische und/oder klinische oder radiologische Untersuchung. Die Prävalenz für synchrone Zweitkarzinome betrug mit der Panendoskopie 4,5%, während die Prävalenz mittels PET/ CT-Untersuchung 6,1% betrug. Die Sensitivität für die Panendoskopie betrug 74%, die Spezifität 99,7%, der positiv prädiktive Wert 93% und der negativ prädiktive Wert 98%. Die Sensitivität für die PET/CT-Untersuchung betrug 100%, die Spezifität 95,7% der positiv prädiktive Wert 59% und der negativ prädiktive Wert 100%. Die PET/CT-Untersuchung scheint der Panendoskopie überlegen zu sein. Bei bezüglich synchroner Zweitkarzinome unauffälligem PET/CT kann die Panendoskopie auf die Endoskopie und Beurteilung des Primärtumors beschränkt werden kann. Aufgrund der hohen Kosten und der grossen Anzahl falsch positiver Resultate, welche durch das PET/CT generiert werden, empfehlen wir die Durchführung dieser Untersuchung nur bei fortgeschrittenen Tumoren mit der Frage nach Fernmetastasen. Die Panendoskopie bleibt weiterhin der Goldstandar

Intelligent Pinhole with Sub-Micrometer Resolution

An intelligent pinhole for confocal microscopy consisting of four position controlled blades forming a rectangular aperture from 3x3μm to 500 x 500 μm was built. This aperture can be positioned without drift under computer control in a positioning range with a sub-micrometer precision. Each blade is suspended by an elastic hinges and moved by a linear magnetic actuator. An integrated position transducer with a reproducibility of better than 40 nm allows a settling time of less than 75 ms. The whole pinhole system is small sized (40x40x20 mm) with an electrical consumption of less than 2W. A first application in a scanning confocal microscope demonstrated the usefulness of such a micro-opto-mechanical system

Project PathoPig—A practical approach to strengthen post mortem analyses and early detection of pig diseases and zoonoses

Post mortem examinations are important for early detection and diagnosis of animal diseases and zoonoses. Over the last ten years, the number of necropsies in livestock has decreased considerably in Switzerland. To counteract this decline, the Federal Food Safety and Veterinary Office (FSVO) launched a project in 2014 called PathoPig. The aim is to evaluate the significance of pathologic-anatomical examinations for early detection of pig diseases and to investigate the impact of the findings on the improvement of pig health. Pig producers can participate if at least one of the following criteria is fulfilled: high morbidity and/or high mortality, unusual clinical signs, recurrent problems of unknown aetiology resistant to therapy or increased use of antimicrobials. Accordingly, the veterinarian examines the herd, fills in a standardised anamnesis protocol and submits one to three pigs representing the health problem to a designated pathology laboratory. After post mortem examination, the veterinarian offers specific recommendations to the farmer. Three to six months later, the Swiss Pig Health Service (SPHS) follows up the success of the veterinary recommendations. In 2014, 371 farms submitted pigs for PathoPig. In 84% of these cases, a conclusive diagnosis was obtained. In 56% of the cases, gastrointestinal problems were determined, most often (44%) caused by pathogenic Escherichia coli. In more than 80% of the cases, the animal health status could be improved considerably after the veterinary consultation. Increased post mortem examinations allowed more specific therapeutic treatments and management recommendations. Additionally, an improvement of collaboration between diagnostic laboratories, veterinarians and producers was achieved, thereby strengthening disease awareness and early detection of pig diseases and zoonoses in Switzerland

Efficacy of simultaneous vaccination with Enterisol® Ileitis and Ingelvac® CircoFLEXTM in a Swiss breeding farm

This study explores administration of two piglet vaccines as compared to the mono- and adjuvant-application. A vaccine against the Porcine Circovirus Type 2 (PCV2) cap protein subunit and a vaccine with attenuated live culture against Lawsonia (L.) intracellularis were applied to piglets aged 23.5 days on average. 1'405 animals were divided randomly into four groups. One piglet group was immunized with both vaccines while two other groups were immunized with a combination of one vaccine and adjuvants of alternate vaccination protocol and vice versa. These piglet groups were also compared to a control group supplemented with both adjuvants only. During fattening, pigs, which were simultaneously immunized with Enterisol(®) Ileitis and Ingelvac(®) CircoFLEX(TM) vaccine, gained significantly more weight (792 g/day) when compared to piglet groups mono-vaccinated with Ingelvac® CircoFLEXTM (772 g/day) or either with Enterisol® Ileitis (774 g/day). Moreover, immunized piglet groups showed significantly higher daily weight gain when compared to adjuvants only inoculated control group (751 g/day). Additionally, during fattening the control group displayed higher mortality (6,3 %) than the three vaccinated groups (Ingelvac(®) CircoFLEX(TM) 2,5 %, Enterisol(®) Ileitis 2,3 % and the combination of both vaccines 1,1 %). These data imply that simultaneous immunization with PCV2- and L. intracellularis specific vaccines positively benefit piglet growth observed by an additive effect on growth parameters in farms harboring both pathogens. Return of investment was calculated of 2.10 on the additional Enterisol(®) Ileitis vaccination

A compact, multi-sensor laser scanning head for processing and monitoring micro-spot welding

In order to improve the reliability of micro-spot welding of metal parts in production such as e.g. in electron guns for TV picture tubes, real-time information about the evolution of the welding process should be available to allow on-line modification of the laser parameters. Such information can be derived from a set of sensors that are mounted on a laser-scanning head. Different sensors are used to monitor the optical fiber output power to determine the evolution of temperature during the spot welding process, to measure plasma emission and back-reflected laser light. A vision channel and a CCD camera are used to control the position of the laser spot on the parts to be processed. The compact scanning head is composed of a tip/tilt laser scanner, a collimating lens and a focusing lens. The scanner is fast steering, with a bandwidth of 700Hz, and can tilt by +/-3.5 degrees with a repeatability better than 50 mu rad. The settling time for maximum deflection is less than 10ms. The scanning lens is a newly developed focusing lens designed to replace commercial cumbersome scanning lenses such as F-theta lenses, which have large volume, weight and price. This lens is based on the well-known Cooke triplet design and guarantees a constant shape of the spot all over the scan surface and is specially well suited for high power beam delivery. The scan field achieved by the system is limited to 25mm x 25mm. The laser used for this application is a pulsed Nd:YAG laser delivered by an optical fiber to the optical head. However, the system can be adapted to different types of lasers. Laser micro-spot welding on copper substrate has been performed in the frame of the Brite-Euram project MAIL. Smaller tolerances (a factor of 2 less) on the spot diameters were obtained in the case of a sensor controlled operation compared to the case where sensor control is not used