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Transmission line pulses (TLP) with 0–60V amplitude and 100ns pulse width have been applied for accelerated lifetime tests of GaAs devices. 1fnoise, RF noise and I/V measurements are applicable for the characterisation of the reliability of these devices. Different failure mechanisms can be identified by applying square pulses of varying amplitude and different polarity on a variety of samples. Correlation between anomalies in 1fnoise, RF noise and I/V characteristics has been determined. Using this novel method, the determination of failure threshold levels for current density, electric field and charge carrier temperature is possible and critical spots in device design can be ascertained.

The discharges of single phrenic units were examined in anesthetized, paralyzed, vagotomized and artificially ventilated dogs during hypothermia and during local cooling of the cervical spinal cord. The following results were obtained for individual phrenic motoneurons during hypothermia. The average frequency of impulses during discharge decreased with decreasing blood temperature. This effect was in principle independent of the arterial CO2 pressure (PaCO2). In some animals recruitment of additional units occurred with falling blood temperature. The response of phrenic units to CO2 stimulation was qualitatively identical at normal and at decreased blood temperatures, but was less pronounced during hypothermia. However, the thresholds of activation by PaCO2 of single phrenic motoneurons were lowered by hypothermia. The results suggest that the observed changes of phrenic motoneuron responses induced by hypothermia are caused by temperature effects on the respiratory output at both the central and the spinal level. An inhibitory influence of lowered blood temperature on the respiratory center is indicated by the reduced response to CO2 stimulation. On the other hand, the recruitment of motor units during hypothermia suggests a stimulating effect of cold on the phrenic motoneurons. The reduced discharge frequency of the single units during hypothermia may be ascribed to effects at the central and spinal levels.

Summary.: Chest trauma cases benefit to a great degree from adequate, timely initiated and consistent prehospital treatment. However, prehospital determination and evaluation of blunt chest trauma is associated with a high degree of uncertainety. The purpose of our study was to examine and determine, in a collective of 255 trauma patients, the value of additional prehospital pulse oximetric monitoring regarding the optimization of the emergency physician's diagnosis and treatment of blunt chest trauma. We conclude from our findings that, in addition to the physical examination, with the application of pulse oximetry the prehospital diagnosis of lung contusion as well as the early detection of tension pneumothorax are more accurate. Therefore, the combination of physical examination and pulse oximetric monitoring is a requirement for the optimization of prehospital diagnosis and therapy in blunt chest trauma.

Zusammenfassung: Die zeitgerechte Schaffung eines sicheren ven�sen Zugangs zum Gef��system ist im Rahmen der pr�klinischen Notfallversorgung von S�uglingen und Kleinkindern h�ufig schwierig oder gar unm�glich. Als Alternative zu der peripher-, insbesondere aber der zentralven�sen Punktion wird die intraoss�re (IO) Punktion empfohlen. Nach intensiver theoretischer und praktischer Schulung der Not�rzte wurde an der Rettungshubschrauberstation „Christoph 22“ die IO-Punktion f�r die Patientengruppe von bis zu 6 Lebensjahren als Alternative zur peripher- bzw. zentralven�sen Punktion eingef�hrt. Ziel der vorliegenden Studie war es, nach �ber zweij�hriger Anwendung dieser Methode die gesammelten Erfahrungen zusammenzufassen und einer kritischen Bewertung zu unterziehen. Bei insgesamt n PE =1455 Prim�reins�tzen betrug der Anteil von Patienten mit ≤6 Lebensjahren 6,2%. Bei 10 Patienten (11,1% vom Teilkollektiv mit ≤6 Lebensjahren) wurde eine IO-Punktion durchgef�hrt und zur Applikation von Medikamenten bzw. Infusionsl�sungen genutzt. In allen F�llen (10/10) war der erste intraoss�re Punktionsversuch erfolgreich (Punktionsort: proximale Tibia). Der Zeitbedarf f�r die Kan�lenlage betrug ≤60 s. Komplikationen, insbesondere Kan�lenfehllagen traten nicht auf. Eine medikament�se Narkoseinduktion war bei 2/10 Patienten notwendig; die erforderliche Medikamentendosierung sowie die Dauer bis zum Wirkungseintritt wurde von den Not�rzten als vergleichbar zu einem Vorgehen bei liegendem peripherven�sen Zugang beschrieben. Die IO-Punktion hat sich unserer Erfahrung nach als einfache sowie sichere und schnelle Alternative bei schwierigen peripherven�sen Venenverh�ltnissen bew�hrt.

Every tenth person in Central Europe is a pollinosis patient. The time of ripening and release of pollen, as well as pollen flight, all depend on the weather. Because each year is different from every other, mean values from pollen calendars do not provide any practical help for allergy-sufferers. For this reason, in many European countries, measuring networks have been established during the last 10 years as a basis for forecasting the prevalence of airborne pollen for the following 2–3 days, in connection with the weather forecast. Cooperation and communication also exist on a European level, and a European Pollen Database has been established.

From the results of the present experiments the following conclusion may be drawn: since phrenic motoneurones are activated by muscle stretching, it is possible that the involved muscle receptor afferents may influence the ventilatory control in muscular excercise.