Christian Albrechts University Research Articles

General Method for the Preparation of Substituted 2-Amino-4H,5H-pyrano[4,3-b]pyran-5-ones and 2-Amino-4H-pyrano[3,2-c]pyridine-5-ones

Reaction of 4-hydroxy-6-methyl-2-pyrone (1a) as well as 4-hydroxy-6-methyl-2(1H)-pyridones (1b-d) with arylmethylene malononitriles or arylmethylene methyl cyanoacetates (2a-h) leads to the formation of the very stable 5,6-fused bicyclic 2-amino-4Hpyran derivatives 3a-3af.

Universalist Assumptions and Implications of Comparative Law: Should They be Deconstructed?

The panel was convened at 2 p.m., Friday, March 26, by its Chair, Marie-Claire Belleau, Universite Laval, Quebec, Canada, who introduced the panelists: Larry C. Becker, University of Tulsa College of Law, Tulsa, Oklahoma; Jorge Esquirol, Northeastern University School of Law, Boston, MA; Anne Peters, WaltherSchiicking Institute of International Law, Christian Albrechts University, Kiel, Germany; and Mathias Reimann, University of Michigan Law School, Ann Arbor, MI. The comments of one panelist, Anne Peters, are presented here.

The Leibniz-Labor AMS facility at the Christian-Albrechts University, Kiel, Germany

The AMS facility of the Leibniz-Labor für Altersbestimmung und Isotopenforschung of the Christian-Albrechts Universität is based on a 3 MV Tandetron from High Voltage Engineering Europa (HVEE) with a single cesium sputter ion source and a separator/recombinator for simultaneous injecton of the three isotopic carbon beams. The AMS system is similar to those at the Woods Hole Oceanographic Institution, USA, and the University of Groningen, The Netherland, but it has some new features based on experience at these two facilities. These include improved vacuum seals, beam diagnostics, X-ray and background suppression as well as a more reliable system control through a PLC-unit with a serial line to the main system computer. The open system design of the beam optics allows significant horizontal and vertical movement of the ion beams without loss to the walls of the system. This leads to plateaus in the response of the isotope beams and ratios to changing values of various ion optical elements. Combined with highly stable power supplies, this gives reproducible measurements. The acceptance tests, e.g., showed that Poisson counting statistics at 0.15% and 0.22% respectively, determined the statistical uncertainty in the 14C12C ratios measured for the individual samples of two test series. Strong discrimination of unwanted ions results in low background count rates in the detector, equivalent to an apparent age of 75000 years at present, in spite of the open architecture. Routine measurements since late January 1996 (to late May 1996) have dated 127 unknown samples, mostly foraminifera. The prototype of the carbonate to CO2 conversion system and the graphite system used for the measurements are also described.

Gynecologic surgery and endoscopy

†Yale University School of Medicine, New Haven, Connecticut, USA ‡;Christian Albrechts University of Kiel and Michaelis Midwifery School, Kiel, Germany

Letter: A note on medical history.

To the Editor.— Since a considerable number of dermatologists are interested in medical history, I wish to call the attention of the readers of theArchivesto a very interesting and dermatologically significant inaugural dissertation from the Christian-Albrechts University of Kiel in West Germany (1969). A copy of it was obtained from the author, Dr. Walther Dann, through the efforts of Dr. Robert Rosenthal of St. Paul. The title describes the nature of the thesis: The Illustration of Cutaneous Diseases from the Beginning of Modern Dermatology Until the End of the Nineteenth Century . The author's stated goals were to provide as completely as possible a list of 19th century dermatologic atlases and of a few relevant monographs, to describe their techniques of illustration, and to relate them with the development of dermatology. The principal commentary of the dissertation is divided into three periods of technical development of illustrative techniques. Also