Kaposi's sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8 (HHV-8), belongs to the gammaherpesvirus subfamily and encodes ϳ80 open reading frames (ORFs). Among them are a few candidates for immediate-early genes (e.g., K5). We developed a monoclonal antibody (MAb), 328C7, against the K5 antigen. This MAb reacted with the K5 gene product by immunoscreening of a cDNA library from BCBL-1 cells, and this result was confirmed by transfection of the K5 ORF into Cos-7 cells. After induction of lytic infection by treatment with 12-O-tetradecanoylphorbol-13-acetate, MAb 328C7 reacted with an antigen in the cytoplasm of BCBL-1 and BC-3 cells as early as after 4 h of induction. Immunoelectron microscopy showed that the K5 antigen was situated mainly in the endoplasmic reticulum but was not present on the virion or in the nucleus. Northern blotting with a K5-specific probe revealed a single transcript of 1.2 kb, while Western blotting showed the antigen to be a 36-kDa polypeptide. The 5 and 3 ends were then determined by rapid amplification of cDNA, followed by sequencing of RACE products, and a splice was revealed upstream of the K5 ORF. K5 expression was unaffected by the respective DNA and protein synthesis inhibitors phosphonoformic acid and cycloheximide plus actinomycin D, confirming its immediate-early nature. Transient-transfection assays showed that the K5 promoter was transactivated by ORF 50 (KSHV Rta), a homolog of Epstein-Barr virus Rta, but the K5 gene product exhibited no transregulation of its own promoter or those of DNA polymerase and the human immunodeficiency virus type 1 long terminal repeat. This is the first such analysis of an immediateearly gene product; determination of its specific biological function requires further investigation.

Eight titanium complex greases (i.e., benzoic acid/stearic acid and sebacic acid/stearic acid titanium complex greases, and greases containing PTFE, or nanotitanium dioxide, or nano-silicon dioxide) were synthesized using 3-L reaction vessel. Their physical characteristics were characterized and their tribological properties were evaluated by using a four-ball tester. Chemical compositions of the boundary films generated on worn surfaces were analyzed with the use of scanning electron microscope and X-ray photoelectron spectrometer. Results show titanium complex greases containing PTFE, or nano-titanium dioxide, or nano-silicon dioxide exhibited excellent tribological performance. The mechanism for the frictionreduction and antiwear effect of all titanium complex greases was also proposed and discussed from a tribochemistry point of view.

Four types of titanium complex grease were synthesized using a 3-l reaction vessel, and their friction and wear behavior were evaluated using a four-ball tester in the presence of two base oils: neopentyl polyol ester and a mixture oil of neopentyl polyol ester, 650SN, and epoxidized soy bean oil (4.5:2.5:1), with two compositions: benzoic acid/stearic acid and sebacic acid/stearic acid. The results indicate that mixed oil-based titanium complex grease has excellent tribological properties. Moreover, compositions affect the physical characteristics of titanium complex grease but have little effect on the frictionreduction, antiwear, and load-carrying capability of the same types of oil-based titanium complex grease. In addition, base oils also affect the tribological property of titanium complex grease. Based on scanning electron microscopy and x-ray photoelectron spectrometer of the worn surfaces of steel balls lubricated with the different types of grease, synergistic boundary lubrication was proposed to illustrate the friction-reduction and antiwear properties of titanium complex grease.Keywords Titanium complex grease Á Friction and wear Á Load-carrying capacity Á Scanning electron microscope (SEM) Á X-ray photoelectron spectroscope (XPS)

Purpose -The purpose of this paper is to study, analyze and present the lubricating mechanism and tribological properties of two types of oil-based titanium complex grease containing Polytetrafluoroethylene (PTFE). Design/methodology/approach -Two types of oil-based sebacic acid/stearic acid titanium complex greases containing PTFE additive were synthesized using 3 L reaction vessel, and the base oils including neopentyl polyol ester and mixed oil of 650SN and neopentyl polyol (1:1.8). Frictionreduction, antiwear, and load-carrying properties of greases were evaluated using a four-ball tester, and their dropping point and penetration were characterized using relevant ASTM standards. Morphologies of wear scar and chemical states of typical elements on worn surfaces were characterized by means of scanning electron microscope and X-ray photoelectron spectroscopy, respectively. Findings -Tribological results show that titanium complex grease containing PTFE had better friction-reduction and antiwear properties than base grease. However, PTFE could not improve the load-carrying capacity of base grease. Moreover, a synergistic effect between deposited film and adsorptive film contributes to good tribological properties of titanium complex grease. Practical implications -Such a very useful lubricating material could be used in industrial applications including steel plants, power plants, packaging, and fertilizer industries. Originality/value -The lubricating mechanism of titanium complex grease containing PTFE was proposed by tribochemical analysis of worn surfaces. The mechanism should become the direction of the theoretical and applied research of grease in the future.