Sub-Nyquist field trial using time frequency packed DP-QPSK super-channel within fixed ITU-T grid.

Sub-Nyquist time frequency packing technique was demonstrated for the first time in a super-channel field trial transmission over long-haul distances. The technique allows a limited spectral occupancy even with low order modulation formats. The transmission was successfully performed on a deployed Australian link between Sydney and Melbourne which included 995 km of uncompensated SMF with coexistent traffic. 40 and 100 Gb/s co-propagating channels were transmitted together with the super-channel in a 50 GHz ITU-T grid without additional penalty. The super-channel consisted of eight sub-channels with low-level modulation format, i.e. DP-QPSK, guaranteeing better OSNR robustness and reduced complexity with respect to higher order formats. At the receiver side, coherent detection was used together with iterative maximum-a-posteriori (MAP) detection and decoding. A 975 Gb/s DP-QPSK super-channel was successfully transmitted between Sydney and Melbourne within four 50GHz WSS channels (200 GHz). A maximum potential SE of 5.58 bit/s/Hz was achieved with an OSNR = 15.8 dB, comparable to the OSNR of the installed 100 Gb/s channels. The system reliability was proven through long term measurements. In addition, by closing the link in a loop back configuration, a potential SE∙d product of 9254 bit/s/Hz·km was achieved.

[Controlled hypotension by sodium nitroprusside during neuroleptanalgesia, halothane-and enflurane anaesthesia at neurosurgical and maxillary-face-surgical operations (author's transl)]. / Kontrollierte Hypotension mit Natriumnitroprussid bei Neuroleptanalgesis, Halothan- und Enfluranenarkosen im intrakraniellen sowie kiefer-, mund-und gesichtschirurgischen Operationsgut

A new sodium-nitroprusside-preparation (Nipruss) was tested in 40 patients for a controlled hypotension in neurosurgical as well as maxillary- and face-surgical operations. Differences between the phases of hypotension by Nipruss were pointed out for NLA, halothane- and enflurane-narcosis. An initial hypotension of -48 per cent, caused by Nipruss, was accompanied by an increase of the cardiac frequency of +33 per cent. This was dependent on the different methods of anaesthesia. The doses necessary for an average permanent hypotension of -36 per cent varied between 1.3 and 22.3mug/kg/min. The results proved, that Nipruss guarantees a diminished blood field even be used without head-up-position and at moderate hypotension. In combination with halothane and enflurane, hypotension could be regulated easier than with NLA. However, this resulted often in a higher frequencyload of the heart, so that frequently beta-adrenergic blocking drugs had to be administered. The operation conditions were improved, incidents did not occur. The new preparation Nipruss has organizational and hygienic advantages.

[A further case of malignant hyperpyrexia and its treatment with lidocaine, methylprednisolone and verapamil (iproveratril) (author's transl)]. / Ein weiterer Fall maligner Hyperpyrexie und seine Behandlung mit Lidocain, Methylprednisolon und Verapamil

A dramatic case of anaesthetic-induced malignant hyperpyrexia is described. The treatment (ice packs, treatment of acidosis, glucose-insulin, methylprednisolone, lidocaine, verapamil, muscular relaxation and oxygen breathing) was effective. In the discussion, the pharmacological effects on the cardiac muscle are considered predominantly.