First Experimental Characterization of Microwave Emission from Cosmic Ray Air Showers.

We report the first direct measurement of the overall characteristics of microwave radio emission from extensive air showers. Using a trigger provided by the KASCADE-Grande air shower array, the signals of the microwave antennas of the Cosmic-Ray Observation via Microwave Emission experiment have been read out and searched for signatures of radio emission by high-energy air showers in the GHz frequency range. Microwave signals have been detected for more than 30 showers with energies above 3×10^{16} eV. The observations presented in this Letter are consistent with a mainly forward-directed and polarized emission process in the GHz frequency range. The measurements show that microwave radiation offers a new means of studying air showers at E≥10^{17} eV.

Kneelike structure in the spectrum of the heavy component of cosmic rays observed with KASCADE-Grande.

We report the observation of a steepening in the cosmic ray energy spectrum of heavy primary particles at about 8×10(16) eV. This structure is also seen in the all-particle energy spectrum, but is less significant. Whereas the "knee" of the cosmic ray spectrum at 3-5×10(15) eV was assigned to light primary masses by the KASCADE experiment, the new structure found by the KASCADE-Grande experiment is caused by heavy primaries. The result is obtained by independent measurements of the charged particle and muon components of the secondary particles of extensive air showers in the primary energy range of 10(16) to 10(18) eV. The data are analyzed on a single-event basis taking into account also the correlation of the two observables.

Detection and imaging of atmospheric radio flashes from cosmic ray air showers.

The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.

Transdiaphragmatic pericardial window: a new approach.

A new transdiaphragmatic laparoscope technique is proposed which provides a large window for drainage that is rapid, safe and eliminates the need for one lung ventilation, drainage tubes, and painful incisions.

New developments in the treatment of gastric carcinoma.

The recent successes being achieved with combination chemotherapy regimens strongly indicate that gastric cancer is chemosensitive. With these regimens, objective remission rates of more than 50% were recorded, including approximately 10% complete remission (CRs). The finding that locally advanced disease (LAD) and technically unresectable disease could be rendered resectable by preoperative chemotherapy (EAP) was important. The median survival time was 18 months for all patients and 24 months for disease-free patients. At 30+ months, 21% of all patients are still living disease free. The expected survival of patients with unresectable LAD is approximately 4-6 months without any treatment and 6-9 months with standard chemotherapy. Compared with the latter results, the preoperative use of etoposide, adriamycin, and platinum (EAP) seems to improve the prognosis of patients with LAD. Moreover, such a multimodal approach may increase the number of long-term survivors among patients with resectable gastric cancer, especially those whose stage indicates a high risk of relapse (stage IIIa or IIIb). However, partly because of the severe toxicities (myelo-suppression, nausea/vomiting), a considerable number of patients cannot be treated with these new regimens. Considering the predominantly palliative treatment intentions in far-advanced (metastasized) gastric cancer, regimens with low toxicities and acceptable activity should be preferred. For these reasons, we developed and investigated the combination etoposide, leucovorin, and 5-FU (ELF) in a phase II trial in elderly patients (greater than 65 years) and in patients with cardiac risks who could not be treated with anthracyclines. The overall response rate in 51 evaluable patients was 53%, including six clinical CRs (12%). The median remission duration was 9.5 months and the median survival time was 11 months. Tolerability was excellent. The high remission rate and long medical survival time achieved with ELF, plus its good tolerability, make this combination a valuable alternative to anthracycline-containing regimens. In addition to developing new treatment plans and strategies, it is also desirable to predict treatment outcome with an acceptable degree of certainty. Combinations of variable defined patient subgroups with significantly different probabilities for achieving objective response and for survival. The results of this analysis may contribute to a more patient-oriented and risk-adapted chemotherapy and to better comparability of future studies.

[The place of radiology in tuberous sclerosis (author's transl)]. / Zum Stellenwert der Röntgendiagnostik bei der tuberösen Sklerose (Morbus Bourneville).

Tuberous sclerosis is a rare disease in which hamartomas may be found in the brain, the retina, the skin and in other internal organs. The classic form of the disease showing mental retardation, epilepsy and adenoma sebaceum is easily recognised. Incomplete forms, however, can provide considerable diagnostic difficulties. Angiographically, appearances are found which cannot be differentiated with certainty from those of malignant tumours. Malignant tumours are very rare in this condition. Nephrectomy can be avoided if the diagnosis is made at an early stage. Two female patients are reported, in one of whom the diagnosis was made by renal angiography. Despite the presence of large tumours in both kidneys, these organs could be preserved by surgery. In the second patient there were also bilateral renal hamartomas, but surgery was not carried out. Both cases showed typical changes in the fingers and toes as well as intracerebral calcification, and in one the lungs were affected.