Precision Mass Measurements of

Masses adjacent to the classical waiting-point nuclide ^{130}Cd have been measured by using the Penning-trap spectrometer ISOLTRAP at ISOLDE/CERN. We find a significant deviation of over 400 keV from earlier values evaluated by using nuclear beta-decay data. The new measurements show the reduction of the N=82 shell gap below the doubly magic ^{132}Sn. The nucleosynthesis associated with the ejected wind from type-II supernovae as well as from compact object binary mergers is studied, by using state-of-the-art hydrodynamic simulations. We find a consistent and direct impact of the newly measured masses on the calculated abundances in the A=128-132 region and a reduction of the uncertainties from the precision mass input data.

Synthesis and single-crystal x-ray diffraction examination of a structurally homologous series of tetracoordinate heteroleptic anionic lanthanide complexes: Ln[N[Si(CH3)2CH2CH2Si(CH3)2]]3(mu-Cl)Li(L)3 (Ln = Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb; (L)3 =(THF)3, (Et2O)3, (THF)2(Et2O)].

Anhydrous lanthanide(III) chlorides (Ln = Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) react with 3 equiv of lithium 2,2,5,5-tetramethyl-2,5-disila-1-azacyclopentanide, Li[N[Si(CH3)2CH2Ch2Si(CH3)2]], in THF or Et(2)O to afford the monomeric four-coordinate heteroleptic ate complexes Ln[N[Si(CH3)2CH2CH2Si(CH3)2]]3(mu-Cl)Li(THF/Et2O)3 (Ln = Sm (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6), Er (7), Tm (8), Yb (9)), whose solid-state structures were determined by the single-crystal X-ray diffraction technique. All complexes additionally were characterized by melting point determination, elemental analyses, and mass spectrometry.

Synthesis and characterization of a series of zinc bis[(alkyl)(trimethylsilyl)amide] compounds.

A series of 21 secondary (alkyl)(trimethylsilyl)amines HNR(TMS) [R = n-propyl (1), i-propyl (2), n-butyl (3), i-butyl (4), s-butyl (5), tert-butyl (6), c-pentyl (7), n-pentyl (8), i-pentyl (9), l-methylbutyl (10), 2-methylbutyl (11), 1-ethylpropyl (12), 1,2-dimethylpropyl (13), tert-pentyl (14), phenyl (15), c-hexyl (16), n-hexyl (17), N,N-dimethyl-3-aminopropyl (18), benzyl (19), n-heptyl (20), 1,1,3,3-tert-butyl (21); TMS = Si(CH3)3] has been prepared and fully characterized by elemental analyses, multinuclear (1H, 13C, 29Si, 14N) NMR, IR, UV/vis, MS, and boiling point. A new method for determination of boiling points of milligram-size samples, based on DSC (differential scanning calorimetry), is described. Each amine has been converted to the corresponding zinc bis(amide) compound Zn[N(TMS)(R)]2 [R = n-propyl (22), i-propyl (23), n-butyl (24), i-butyl (25), s-butyl (26), tert-butyl (27), c-pentyl (28), n-pentyl (29), i-pentyl (30), 1-methylbutyl (31), 2-methylbutyl (32), 1-ethylpropyl (33), 1,2-dimethylpropyl (34), tert-pentyl (35), phenyl (36), c-hexyl (37), n-hexyl (38), N,N-dimethyl-3-aminopropyl (39), benzyl (40), n-heptyl (41), 1,1,3,3-tert-butyl (42); TMS = Si(CH3)3] and subsequently fully characterized by elemental analyses, multinuclear (1H, 13C, 29Si, 14N) NMR, IR, UV/vis, MS, and TGA. The experimental IR has been compared to the computationally calculated one for compound 27. Observed trends in volatility of the compounds are discussed in the context of the dominant intermolecular forces present in the condensed phase.

[Continuous intragastric pH measurement in intensive care patients treated with ranitidine and tube feeding]. / Kontinuierliche intragastrale pH-Wert-Messung bei Intensivepatienten unter Ranitidin- und Sondenkostgabe.

We studied 22 critically ill patients on long-term mechanical ventilation using continuous intragastric pH monitoring with an antimony electrode. Intragastric pH profiles were established for the duration of mechanical ventilation (mean: 7 days). The aim of our study was to achieve a gastric pH between 3.0 and 4.5 utilizing the H2-receptor antagonist ranitidine and nasogastric feeding with Nutricomp F. Patients were divided into three groups which were given (A) ranitidine boluses, (B) continuous ranitidine infusions, or (C) continuous ranitidine infusions together with enteral nutrition via the nasogastric tube. In group B we were able to obtain a pH value between 3.0 and 4.5 only in 11.6% of the observation period. With ranitidine boluses, there were even less measurements (9.3%) in the "optimal" pH range. The combination of continuous ranitidine application together with enteral alimentation made our attempts slightly more successful (20.0%). This failure to achieve the desired pH range encourages airway colonisation and nosocomial pneumonia at gastric pH greater than 4.5. At pH less than 3.0 there is a significantly higher incidence of acute stress ulcerations. Other therapeutic regimens e.g. the application of pirenzepine and sucralfate offer adequate protection of the gastric mucosa without raising the pH level.

[The history of anesthesia at the Heidelberg University]. / Zur Geschichte der Anästhesie an der Universität Heidelberg.

An account is given on the development of general anaesthesia at the university clinics of Heidelberg. During the last century mainly chloroform was employed for general anaesthesia. Important events were the first demonstration of Koller's local anaesthesia in the eye in 1884, the first intubation for anaesthesia in Heidelberg, performed by F. Kuhn of Kassel and the development by M. Neu of a rotameter apparatus for nitrous oxide/oxygen anaesthesia in 1910. From 1932 on the surgeon M. Kirschner advanced the methods of high pressure infiltration for regional anaesthesia and segmental hypobaric spinal anaesthesia. In 1951 K. H. Bauer requested R. Frey to set up an "anaesthesia squad" consisting of 2 physicians and 3 nurses to become the nucleus of today's Institute of Anaesthesiology, with O. H. Just as its first professor and chairman.

[Barbiturate infusion in severe brain trauma (preliminary report) (author's transl)]. / Barbituratinfusion bei schwerem Schädelhirntrauma (vorläufiger Bericht).

The pathophysiology of brain trauma regarding disturbances of energy and transmitter metabolism, development of intra- and extracellular cerebral oedema are briefly outlined. Possible mechanisms of action of barbiturates in amelioration of cerebral ischaemia, decrease of cerebral metabolism, preservation of membrane stability, reduction of cerebral oedema and intracranial pressure are reviewed. We report on 6 patients with severe brain trauma due to head injury whose intracranial pressure despite conventional treatment with hyperventilation, steroids and osmotic diuresis remained above 25 mm Hg. They were infused with thiopentone 6--12 mg/kg x h for 6 to 15 days, to reduce cerebral electrical activity to the point of "burst suppression" in the electroencephalogram. Three patients survived, two of them regaining their previous good health. The results in these patients are discussed as regards thiopentone dosage and severity of trauma. Marked cardiovascular instability in one case and cholostatic jaundice due to barbiturate administration in two cases were the most important side effects. Barbiturate infusion seems to be indicated in brain trauma with sustained elevation of intracranial pressure above 25 mm Hg despite vigorous conventional therapy. Monitoring most essential to this aggressive treatment scheme comprises measurement of intracranial pressure and continuous observation of the EEG.

[Clinical uses of electrostimulation anaesthesia (author's transl)]. / Die Elektrostimulationsanästhesie und ihre klinische Anwendung.

Since 1972 electrostimulation anaesthesia (ESA) has been employed in an attempt to reduce the amount of anaesthetic agents needed. In the beginning the Chinese combination of acupuncture points was used; at a later stage Benzer et al. inserted the needles paravertebrally and Abdulla replaced the needles by contact electrodes for ophthalmic operations. At the Department of Anaesthetics, Hamburg, the same course was followed, i.e. the classic acupuncture points were used originally, then the acupuncture points were used originally, then the technique was changed to paravertebral insertion of the needles and now only paravertebrally placed contact electrodes are being employed for inducing ESA for various surgical operations. All three techniques of ESA have proved satisfactory; but ESA with contact electrodes is considered the method of choice on account of both practical considerations and success rate.

[Electrostimulation anaesthesia for surgery of the limbs (author's transl)]. / Elektrostimulationsanästhesie bei Eingriffen an den Extremitäten.

In Germany electrostimulation anaesthesia (ESA) has, so far, not been considered suitable for surgical operations on the extremities. An attempt was made to develop a combination of acupuncture points that would allow the use of ESA for this type of surgery. Based on the experience gained with ESA in abdominal surgery the suitability of paravertebral contact electrodes for operations on the limb was studied. Because of its simplicity and efficacy this technique of ESA is highly recommended.