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Conrad et al performed a study about the etiological involvement of an infectious agent in type 1 diabetes mellitus. They described the isolation of an unknown endogenous HERV-K10-like retroviral genome, IDDMK(sub 1,2)22, associated with a murine mammary tumor virus whose envelope gene encoded a superantigen. They used the U3-R-poly(A) oligonucleotide primer to detect the retroviral genome. However, in other experiments simulating the experimental conditions employed by Conrad et al, the transcribed genome was not detected and were not RNA specific.

Single-crystal X-ray diffraction techniques are used to gauge the molecular frameworks of the eight-coordinate tungsten hydride complexes W[PMesub(3)]sub(4)Hsub(2)Xsub(2) (X= F, Cl, Br, I) and W[PMesub(3)]sub(4)Hsub(2)F(FHF). Single-crystal neutron diffraction was also used to derive the molecular structure of another set of complexes. The structures of both complexes are similar. The results of the investigation are discussed.

In response to Larry Silver (EC 231 774) concerning whether attention deficit-hyperactivity disorder is a learning disability via a related disorder, this article proposes an interactional perspective that stresses the educational needs of the child within his/her total environmental context. It also summarizes the current empirical and clinical knowledge concerning these children. (DB)

The suitability of bis(pyrazolyethyl) ether ligands of zinc and cobalt in providing an NNO donor system that may model the binding of zinc to the protein backbone in enzymes such as thermolysin is discussed. Results indicate that the ether ligands are not particularly suitable in modeling the bioinorganic aspects of zinc chemistry, with cobalt more suited to this purpose.

The biodegradation of 2,4-diamino-6-nitrotoluene (2,4-DANT) by a Pseudomonas fluorescens species forms the metabolite 4-N-acetylamino-2-amino-6-nitrotoluene under anoxic and aerobic conditions. P. fluorescens initially reduces 2,4,6-trinitrotoluene to aminodinitrotoluenes and then to diaminonitrotoluenes under nitrate-limited conditions. The 2,4-DANT converts to the metabolite but 2,6-diamino-4-nitrotoluene is not degraded. The biodegradation is faster under anoxic conditions as compared to aerobic conditions.

Reviews the history and revisions of core curriculums in higher institutions of learning. Each school may be characterized by the priority of values it observes in its curricular structure. To the academic advisor, the values the curriculum represents are the trail markers that define the guide's terrain. (Author/BEF)

X-ray diffraction studies on a series of cationic divalent metal domplexes supported by the tris(1-isopropyl-4-tert-butylimidazolyl)phosphine ligand, {[pim(super Pr(super i),Bu(super t))]M(NO3)}(super +) (M = Co, Cu, Zn, Cd, Hg), demonstrate that the nitrate ligand coordination mode is strongly dependent upon the metal. In view of the steric demands of two ligand systems, the fine-tuning that is necessary to create synthetic analogues that accurately mimic the chemistry of metalloenzymes is accentuated.

The bifluoride complex Mo(PMe3)4H2F(FHF) is prepared using dihydride Mo(PMe3)5H2 as a precursor. Hence, hydrido-fluoro derivatives are obtained upon reaction with aqueous HF to give, after a series of steps, Mo(PMe3)4H2F2. The relationship between HF and Mo(PMe3)4H2F2 fragments in Mo(PMe3)4H2F2.(HF)2 and Mo(PMe3)4H2F2.(HF) is determined from the X-ray diffraction of the latter. HF is proved to undergo hydrogen-bonding with an Mo-F ligand thereby resulting to the bifluoride derivate complex Mo(PMe3)4H2F(FHF).

The structure solutions with delusive false minima is observed for the molecular crystallizing in polar space groups. In W(PMe3)4H2X2 (X = F, Cl, Br), a structure of trigonal dodecahedron with a abnormal order of PMe3 ligands is present, but in W(PMe3)4H2Cl2 the four PMe3 ligands are placed in one hemisphere of the molecule. The misleading structure of the false minimum is because of the inversion of the transoid PMe3 ligands along the z axis, of the genuine structure. In W(PMe3)4H2F2(H2O), the PMe3 ligands are also situated in one hemisphere.