The paper describes a new powder composition specially developed for selective laser sintering (SLS). The aim is to obtain a ferro powder that can be sintered without need for a (sacrificial) polymer binder and that results in quasi dense parts that do not need any post-processing like furnace sintering, infiltration or HIP. The powder is a mixture of different types of particles (Fe, Cu, Ni and Fe3P). The composition and mixture ratio are justified by using phase diagrams. The powder has been tested using an own developed Nd: YAG SLS machine. The influence of process parameters (laser power, scan velocity, scan spacing and scan strategy) and the microstructural characteristics have been investigated. Attention is devoted to the binding mechanism (liquid phase sintering, through melting) and to the quality of resulting parts (density, balling effect,…).
No abstract is provided for this article.
Suramin and various other selected compounds were evaluated for their in vitro inhibitory effects on the infectivity and replication of human T-cell lymphotropic virus (HTLV/III)/lymphadenopathy-associated virus (LAV). As parameters for infectivity and replication, respectively, we followed the cytopathic effect of HTLV-III/LAV on ATH 8 cells, a T-cell clone with high susceptibility to HTLV-III/LAV, and the expression of HTLV-III/LAV p24 gag protein in H9 cells infected with HTLV-III/LAV. As the most effective inhibitors of HTLV-III/LAV the following substances emerged (in order of decreasing activity): Evans Blue approximately equal to suramin greater than phosphonoformic acid greater than Direct Yellow 50. Several purine nucleoside analogues including vidarabine, tubercidin, neplanocin A, dihydroxypropyladenine, pyrazofurin and ribavirin were not inhibitory to HTLV-III/LAV. In our test systems, involving a high multiplicity of infection, HPA-23, previously reported to be effective against LAV reverse transcriptase, showed no inhibitory effect on HTLV-III/LAV infectivity for ATH 8 cells and proved only weakly inhibitory to HTLV-III/LAV replication in H9 cells. Thus, among the anionic dyes that are structurally related to suramin, compounds were found which were as active as suramin itself, if not more so.
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This review article, while autobiographical to some extent, describes the discovery of ten (classes of) antiviral compounds that have made (or just did not make) it to the market for the therapy of viral infections, but each in its own way influenced the landscape of our dealing with virus infections: (i) valaciclovir, (ii) BVDU, (iii) DHPA, (iv) cidofovir, (v) adefovir, (vi) tenofovir, (vii) stavudine, (viii) HEPT, (ix) TIBO, and (x) AMD3100. Successful drug development, as is certainly true for antiviral drugs and exemplified for the acyclic nucleoside phosphonates cidofovir, adefovir and tenofovir, requires patience and perseverance, and a close continuous and dedicated interaction between Chemistry, Biology/Medicine and Industry.
An overview on the use of a viral pathogen as a bioterrorism agent: why smallpox? (B. Mahy). Smallpox: a potential agent of bioterrorism (R.J. Whitley). Potential antiviral therapeutics for smallpox, monkeypox and other orthopoxvirus infections (R.O. Baker, M. Bray, J.W. Huggins). Smallpox: a potential agent of bioterrorism (R.J. Whitley). Therapy and short-term prophylaxis of poxvirus infections: historical background and perspectives (J. Neyts, E. de Clercq). In vitro activity of potential anti-poxvirus agents (E.R. Kern). A review of compounds exhibiting anti-orthopoxvirus activity in animal models (D.F. Smee, R.W. Sidwell). Defense against filoviruses as biological weapons (M. Bray). Molecular diagnostics of viral hemorrhagic fevers (including Lassa fever, Yellow fever and Crimean-Congo hemorrhagic fever) (C. Drosten, B.M. Kummerer et al.). Arenaviruses other than Lassa virus (R.N. Charrel, X. de Lamballerie). Viruses of the bunya- and togaviridae families: potential as bioterrorism agents and means of control (R.W. Sidwell, D.F. Smee). Nipah virus - a potential agent of bioterrorism? (Sai-Kit Lam). Hantavirus - a potential agent of bioterrorism? (J.P. Clement). Tick-borne encephalitis (T.S. Gritsun, V.A. Lashkevich, E.A. Gould). The potential use of influenza virus as an agent for bioterrorism (R.M. Krug).
