First Light Measurements of Capella with the Low-Energy Transmission Grating Spectrometer aboard the Chandra X-Ray Observatory.

We present the first X-ray spectrum obtained by the Low-Energy Transmission Grating Spectrometer (LETGS) aboard the Chandra X-Ray Observatory. The spectrum is of Capella and covers a wavelength range of 5-175 Å (2.5-0.07 keV). The measured wavelength resolution, which is in good agreement with ground calibration, is Deltalambda approximately 0.06 Å (FWHM). Although in-flight calibration of the LETGS is in progress, the high spectral resolution and unique wavelength coverage of the LETGS are well demonstrated by the results from Capella, a coronal source rich in spectral emission lines. While the primary purpose of this Letter is to demonstrate the spectroscopic potential of the LETGS, we also briefly present some preliminary astrophysical results. We discuss plasma parameters derived from line ratios in narrow spectral bands, such as the electron density diagnostics of the He-like triplets of carbon, nitrogen, and oxygen, as well as resonance scattering of the strong Fe xvii line at 15.014 Å.

[Cerebrovascular disorders and administration of oral contraceptives containing gestodene--causal relation or coincidence?]. / Zerebrovaskuläre Störungen unter Einnahme gestodenhaltiger oraler Kontrazeptiva--Kausalität oder Koinzidenz?

During the last two years oral contraceptives containing gestodene were suspected to cause cerebrovascular disorders. 52 cases with adverse neurological side effects were registered up to October 31, 1990. Anonymous protocols received from the Companies Schering AG and Wyeth Pharma were analyzed from a clinical point of view. There are different arterial and venous, thrombotic and embolic disorders caused by different pathogenetic principles. Only one third of the cases was documented by neuro-imaging to render possible actual diagnostic reliability. Suspected cases represent a great number of different cerebrovascular disorders usually observed in neurological and neurosurgical series, concerning both men and women, OC-users and non users.

[Perioperative preventive use of antibiotics in neurosurgery. Experience with a fixed antibiotic combination of mezlocillin and oxacillin (optocillin)]. / Perioperative Antibiotika-Prophylaxe in der Neurochirurgie. Erfahrungen mit einer fixen Antibiotika-Kombination von Mezlocillin und Oxacillin (Optocillin).

We report a retrospective account of 200 patients who have been surveyed after having undergone neurosurgical intervention. They received as perioperative antibiotic prophylaxis a combination of Mezlocillin and Oxacillin in a ratio of 2:1 (Optocillin) in their management. The clinical and bacteriological efficacy including the side effects was examined with standardisation of sterility measures in the operating theatre, careful standardised operative procedures and ward after care. No problems in wound healing were found. There was no certain evidence of side effects.

[Patients with craniocerebral injuries and their reintegration into vocational life. The effect of parameters independent of the accident on expert assessment]. / Schädel-Hirn-Verletzte und ihre Reintegration in das Erwerbsleben. Der Einfluss unfallunabhängiger Parameter auf die Begutachtung.

A prospective study of 60 patients with head injuries who received both primary care and an assessment at our Department, the influence of various parameters on the assessment was investigated. Catamnestically, the insurance-relevant results actually achieved are shown. It can be seen that at a 40 per cent incapacitation, reintegration into the work-a-day world is hardly possible.

[The effect of various surgical technics on neuroma development using the neodymium laser]. / Der Einfluss verschiedener Operationstechniken auf die Neurom-Entstehung unter Anwendung des Neodym-Yag-Lasers.

The development of neuroma after surgery of peripheral nerves is an unsolved problem. Conventional methods like suture after cutting by seizure or bipolar coagulation cannot control it until today. Contradict results are reported since different types of laser were introduced in surgery. In an animal experimental study on rats the Neodym Yag laser is superior to conventional methods described above. After severance and reanastomosis of the sciatic nerve by laser in none of these cases a development of neuroma could be observed until three months of surviving.

Degenerative and regenerative processes in the peripheral nerve after disconnection and reanastomosis using the Neodym Yag laser.

The development of neuroma after peripheral nerve surgery is still an unsolved problem. Such lesions are not yet controllable by conventional methods. Reports of results achieved using various types of laser surgery appear contradictory. In this experimental study on rats, the Neodym Yag laser was found to be superior the conventional methods. After severance and reanastomosis of the sciatic nerve using this type of laser, no development of neuroma was observed in any of the animals during the first three months of observation.

Calibration and efficiency of the Einstein objective grating spectrometer.

The Einstein Observatory, a large satellite dedicated to x-ray astronomy, carried the first large x-ray telescope to be placed in orbit and an objective grating spectrometer with two sets of gratings. This paper lists prelaunch calibration results and describes the derivation of spectrometer efficiency and resolution. Several calibration spectra are shown, and theoretical grating parameters are derived from the calibration results.