[en] All 16 cavities of the energy upgrading program for the HERA storage ring showed increased losses on the second or any successive cool down in contrast to superior values on the first cool down. The authors attribute this deterioration to Hydrogen which contaminates the Niobium during chemical polishing. The low oxygen content of the new Niobium material (RRR double-bond 300) allows the Hydrogen to diffuse to the surface and to produce NbH precipitation at low temperatures. The well known Hydrogen degassing process at 800 C cannot be applied to the authors cavities because of the complex construction. They investigated chemical polishing methods in respect to Hydrogen contamination and tried to find a Hydrogen cleaning procedure at room temperature

[en] Superconducting 500 MHz cavities have been developed at DESY for the purpose of increasing the electron beam energy of the HERA storage ring. The system consists of 16 cavities, 8 cryostats and a LHe distribution line. The authors report about the test of the components and give first results of operating experience. The individual components were tested at DESY and installed in HERA in January 1991

[en] After the successful prototype program 16 superconducting cavities including the necessary cryostats, RF- and cryogenic infrastructure are under industrial production. The whole system will be installed in HERA before summer 1990 to increase the e^- energy up to 33.5 GeV. We report about the status of these activities as well as about parallel research on superconductivity (pipe cooling, Nb- sputtered Cu-cavities and HTc-RF measurements). (author)

[en] Introduction. - Curative therapy for patients with small-cell lung cancer (SCLC) is based on multidrug chemotherapy combinations and radiotherapy. After a long time follow-up, the aim of the study was to evaluate the efficacy and toxicity of sequential chemo-radiotherapy and the effect of prophylactic cranial irradiation (PCI). Methods. - From 1995-2005, 96 patients with SCLC (64 limited-disease [LD], 32 extensive-disease [ED]; median age 61 years [range 39-79]) were treated at our department with varying chemotherapy regimens and sequential mediastinal radiotherapy (50 Gy + 10 Gy boost in case of residual disease after chemotherapy). Afterwards, 15 patients with LD, good general condition and at least partial response after local treatment received PCI (30 Gy). Results. - After a median follow-up of 78.6 months, 20 patients remained alive (20.8%, median survival time 18.2 months). The 2-/5-year overall survival rates were 33.8% and 12.6%, the 2-/5-year loco-regional control rates were 30.3% and 24.5%, respectively. Distant metastases occurred in 43 patients (24 cerebral). Cerebral metastasis occurred in 6.7% and 27.2% of the patients with PCI and without PCI respectively. Only tumor stage showed a statistically significant impact on overall survival and loco-regional control in multivariate analysis. Radiotherapy was well tolerated. Grade 3/4 toxicity occurred in seven patients. Prognosis of patients with SCLC remains poor. Administration of PCI in selected patients bears a decrease in the incidence of cerebral metastases. Alternative chemotherapy schemes as well as irradiation schemes and techniques should be the substance of future randomized trials. (authors)