System level design of the ITER bolometer port plug cameras.

The ITER bolometer diagnostic is planned to have 550 lines of sight (LOS) distributed all over the vessel. 240 channels are provided by cameras mounted in two upper ports and in one equatorial port. This paper describes the current status of the system level design of the port cameras and the solutions proposed on how to implement all required camera components while meeting a multitude of competing requirements. Sensor holders, support structures, and different apertures depending on the camera type (pinhole or collimator), cable connectors, ceramic track plates, and many mineral insulated cables have to be integrated within a restricted space envelope to guarantee functionality. The design of the internal electrical interfaces and the external mechanical mountings will be described as well. Using the example of an upper port camera with 60 LOS, the assembly of the camera components is explained and two currently discussed architecture options for the remote handling maintenance scheme in the hot cell are compared.

Bis[(mu-acetato[mu-bis(salicylidene-1,3-propanediaminoato]zinc(II)]zinc(II).

In the title linear trinuclear compound, [Zn[Zn(CH(3)COO)(C(17)H(16)N(2)O(2))](2)], the central Zn(2+) ion, which is located on an inversion centre, has a distorted octahedral coordination involving four bridging O atoms from two N,N'-bis(salicylidene)-1,3-propanediaminate ligands in the equatorial plane and one O atom from each bridging acetate group in the axial positions. The coordination around the terminal Zn(2+) ion is irregular square pyramidal, with two O and two N atoms of the ligand in the basal plane and one O atom from an acetate group in the apical position. The acetate bridges linking the central and terminal Zn(2+) ions are mutually trans. The Zn.Zn distance is 3.0520 (8) A. The relationship of this structure to that of [Zn[Cu(CH(3)COO)(C(17)H(16)N(2)O(2))](2)] is discussed.

Horse complement protein C9: primary structure and cytotoxic activity.

Lack of hemolytic activity of horse serum is an inherent property of horse C9. To understand the molecular reasons for this deficiency we have cloned C9 cDNA from a horse liver cDNA library and have sequenced the cDNA yielding the complete coding sequence for horse C9. Purification of C9 from horse plasma and microsequencing established the N-terminus of the mature protein and verified that the correct horse C9 cDNA clone had been isolated. The deduced amino acid sequence corresponds to a mature protein of 526 amino acids that is 77% identical to human C9. It has the same domain structure as human C9 and contains 22 cysteines and four invariant tryptophans. The few differences include the N-terminus, which is an unblocked glycine in horse C9 but pyroglutamine in human C9, and three potential N-glycosylation sites compared to two in human C9. The N-terminal difference is unimportant since microsequencing of bovine C9, which is strongly hemolytic, established that it also has an unblocked glycine identical to horse C9. There are no obvious structural differences apparent that could resolve the differences in hemolytic potency between the two molecules. Aside from a few conservative replacements, both C9 sequences are identical between positions 250 and 360. This region includes the membrane interaction domain in C9 and the postulated transmembrane segment that is thought to constitute the wall of a putative transmembrane pore and, therefore, should be required for cytotoxicity. In agreement with this prediction we have observed that, in contrast to the marked decrease in hemolytic activity, horse C9 is very efficient in killing a variety of Gram-negative bacteria. These results demonstrate that horse C9 is a structurally competent molecule with efficient cytotoxic activity. Its inability to lyse erythrocytes may be related to the action of control proteins on target cell membranes.