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At least 505 records · Page 28Linked to original sources
PubMed1978

Autoclaving of lubricated dental instruments.

Test organisms forced mechanically into lubricated, rotating dental instruments (handpieces) were all killed during autoclaving at 134 degrees C for 8 min, even when protected by serum and oil. The test organisms were: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and spores of Bacillus stearothermophilus. Also when testing the sterility of autoclaved simulated instrument surfaces (brass cylinders and pieces of a cotton fabric) which had been inoculated with bacteria and dried before they were sprayed with oil, there was no growth of the test organisms. In addition to the other test organisms, spores of Bacillus subtilis and Gram-positive, anaerobic bacteria isolated from used handpieces that had been exposed to several autoclavings were used. Some of the handpieces that had been left to dry after use in the dentist's office before they were autoclaved, were shown not to be sterile. Therefore, the authors suggest that autoclaving of the instruments should take place shortly after use and prescribed cleaning.

Bacteria↗
PubMed2005

Molecular mechanisms for the functionality of lubricant additives.

Wear limits the life-span of many mechanical devices with moving parts. To reduce wear, lubricants are frequently enriched with additives, such as zinc phosphates, that form protective films on rubbing surfaces. Using first-principles molecular dynamics simulations of films derived from commercial additives, we unraveled the molecular origin of how antiwear films can form, function, and dissipate energy. These effects originate from pressure-induced changes in the coordination number of atoms acting as cross-linking agents to form chemically connected networks. The proposed mechanism explains a diverse body of experiments and promises to prove useful in the rational design of antiwear additives that operate on a wider range of surface materials, with reduced environmental side effects.

Journal Article↗
PubMed1993

Biodegradation of a synthetic lubricant by Micrococcus roseus.

A bacterium that was able to utilize Emkarate 1550 (E1550), a synthetic lubricant ester, as the sole source of carbon was isolated. The isolate was tentatively identified as Micrococcus roseus. The components of the E1550 ester, octanoate, decanoate, and 1,1,1-tris(hydroxymethyl)propane (TMP), were detected in the culture medium of cells growing on the ester. The TMP tertiary alcohol accumulated during growth and was not utilized by this isolate. The detection of the components of the ester in the supernatant of cultures indicated that one of the first steps in its degradation was cleavage of the ester bonds. Esterase activity was significantly enhanced in cells grown on E1550 compared with esterase activity measured in cells grown on acetate.

Biodegradation, Environmental↗
PubMed2006

Sarcoidal granuloma developing not only at the entry site of industrial lubricating oil, but also at a regional lymph node and entry points of venepuncture.

We describe a 40-year-old male who presented with sarcoidal granulomas not only at the entry site of an industrial lubricating oil containing silicone in the right thumb, but also in a regional lymph node and at the entry points of venepuncture in both forearms. Laboratory tests and chest X-ray showed no evidence of sarcoidosis.

Accidents, Occupational↗
PubMed2004

Quantitative determination of moisture in lubricants by Fourier transform infrared spectroscopy.

This paper describes the development of a practical Fourier transform infrared (FT-IR) method for the determination of moisture in lubricants through the combined use of signal transduction and differential spectroscopy to circumvent matrix effects. The acid-catalyzed stoichiometric reaction of 2,2-dimethoxypropane (DMP) with moisture to produce acetone was used to provide IR signals proportional to the amount of moisture present in oils. Calibration standards were prepared by spiking polyalphaolefin (PAO) gravimetrically with water using dioxane as a carrier. For FT-IR analysis, standards and samples were diluted with acidified isooctane and then split, with one aliquot treated with DMP and the other with a blank reagent. The spectra of the two aliquots were collected, and a differential spectrum was obtained so as to ratio out the invariant spectral contributions from the sample. Quantitation for moisture was based on measurement of the peak height of the nu(C=O) absorption of acetone at 1717 cm(-1), yielding a standard error of calibration of approximately 40 ppm H2O. The method was validated by standard addition of water in dioxane to PAO containing added base as well as to new and used oils. In all cases the method responded quantitatively to standard addition, the average standard error of prediction being approximately 80 ppm, with the results showing only a minor dependence on the oil formulation. From an analytical perspective, the FT-IR method is both more reproducible and more accurate than Karl Fischer methods and has advantages in terms of environmental considerations, sample size, and speed of analysis as well as the variety of oil types that can be handled. Signal transduction/differential spectroscopy may have broader utility as an alternative means for the determination of low levels of moisture in complex matrices.

Journal Article↗
PubMed1977

Human intoxication following inhalation exposure to synthetic jet lubricating oil.

A previously healthy member of an aircraft flight crew was acutely incapacitated during flight with neurologic impairment and gastrointestinal distress. His clinical status returned to normal within 24 hr. The etiology of his symptoms was related to an inhalation exposure to aerosolized or vaporized synthetic lubricating oil arising from a jet engine of his aircraft.

Adult↗
PubMed2000

[The method of time series modeling and its application in the spectral analysis of lubricating oil].

In this paper, we discuss the applications of time series modeling method in the analysis of lubricating oil of mechanical equipment. We obtained satisfactory results by applying AR model to perform time series modeling and forecasting analysis to the collected spectral analysis data of the air engine. So we have built a practical method for state monitoring and trouble forecasting of mechanical equipment.

English Abstract↗
PubMed1992

[Skin pathology from exposure to the lubricating coolant fluid MR-7].

The article narrates on pathologic developments in the skin caused by the lubricating cooling liquid MP-7. 63 workers, including machine operators and adjusters, were medically examined, as a result of which it was established that the MP-7 liquid manifested marked irritating properties and less expressed allergenic characteristics. Oil-induced folliculitis, allergic dermatitis and eczema cases constituted 85.4 +/- 4.6% rate, which confirmed the occupational origin of the lesions. Ample supply of hygienic clothes, other hygienic procedures, weekly change of overalls did not fully eliminate contact with the MP-7 liquid.

Adult↗
PubMed2004

TMJ lubrication system: its effect on the joint function, dysfunction, and treatment approach.

Normal temporomandibular joint (TMJ) movements primarily depend on free sliding of the disc down the slope of the eminence. Therefore, understanding the lubrication system and how aberrations in this system contribute to TMJ is important. Its effect on dysfunctions, such as disc displacement, anchored disc phenomenon, open lock, and osteoarthritis, are discussed in this article.

Arthralgia↗
PubMed2006

Inverse gas chromatography used to study lubricating oil oxidation mechanism via changes in Kovats and Flory-Huggins retention parameters.

Inverse gas chromatographic technique (IGC) was attempted as a new approach to follow the chemical changes that occur during lubricating base oil oxidation. Three groups of the oxidized base oils were prepared at different oxygen flow rates, periods and temperatures according to IP48 method. The corrected retention volumes (VR) were calculated for a series of selected test solutes possessing different functional groups on the oxidized base oils used as stationary phases. Kovats retention index (I), Flory-Huggins interaction parameter (Kinfinity1,2), and partial molar free energy of solution (deltaGinfinityL), were calculated for the given test solutes from their VR. The relationships between the I values and the oxidation variables were plotted and discussed. The obtained results were confirmed by potentiometric titration. The study reveals that the magnitudes of variation of I, Kinfinity1,2 or deltaGinfinityL retention parameters depend on the oxidation degree of the base oil. Large differences between the I values permit discrimination between the different oxidation steps.

Journal Article↗
PubMedDate not supplied

[Safety forms for industrial lubricating oils: a working proposal at the national level].

The health and safety data sheets for lubricating oils currently in use present considerable differences regarding the information they provide. Often, the information is either too generalized or incomplete--particularly on the chemical aspects of oils--and therefore the sheets are inadequate for the prevention and control of the occupational risks. For the purposes of harmonization, a data sheet has been prepared which takes into account the specific features of the products, and particularly the handling of confidential data. The most important oil manufacturers have been consulted, and they have agreed to use the data sheet in order to provide information on their products to the local health authorities. The widespread use of this data sheet should enable an easier comparison of the health and safety data of oils to be made, provide a better understanding of the information received and, consequently, evaluate the risks involved.

Confidentiality↗
PubMed1989

Ocular lubricants and corneal injury during anesthesia.

Seventy-six patients undergoing general endotracheal anesthesia were studied prospectively to determine whether simply taping the eyelids closed during the surgical procedure as opposed to taping the lids after instilling a bland lubricating ointment had any different effect on corneal or conjunctival epithelium. No significant difference was found.

Adult↗