A study of metalloproteinases in fifty joint fluid specimens

OBJECTIVES: To study the activity and concentrations in joint fluid of gelatinases (A or matrix metalloproteinase (MMP)-2 and B or MMP-9), tissue inhibitor of metalloproteinases 1 (TIMP-1), and stromelysin-1 (MMP-3). METHODS: Synovial fluid specimens obtained as part of a diagnostic or therapeutic procedure were studied. Protein levels were determined, cells counted, crystals looked for and microbiological studies done. Gelatinolytic activity was determined quantitatively using computerized zymography. Proteins were identified by electrotransfer and immunorevelation. TIMP-1 and stromelysin-1 were assayed using an ELISA. Results were confronted with laboratory test and clinical findings. RESULTS: Of the 50 specimens studied, 25 were from joints with mechanical disorders and 25 from joints with inflammatory disorders. Activated MMP-2 was found in all the specimens, with no differences between the two groups. MMP-9 was found only in its inactive form. MMP-9, TIMP-1 and MMP-3 were found more often in inflammatory than in mechanical fluids and the levels of MMP-9 and TIMP-1 were correlated with neutrophil counts. In the 16 fluids from rheumatoid arthritis patients, levels of MMP-9 and TIMP-1 were closely correlated with serum C-reactive protein levels. CONCLUSIONS: MMP-9, TIMP-1, and MMP-3 levels show striking differences between inflammatory and mechanical joint fluids.     

A reaction between CO-adsorbed sulfur and butadiene on the Pt(111) surface

The desorption of methylthiol and propylthiol has been observed, induced by the co-adsorption of hydrogen, butadiene and sulfur on Pt(111). This phenomenon goes with increase of the total amount of sulfur adsorbed on the surface by a factor of 20%.     

Quantum-Mechanical Calculations of Molecular Force Fields at the SCF Ab Initio Level Methyl Halides as Test Cases

The possibilities of the present quantum-chemistry methods for calculating the vibrational properties of polyatomic molecules have been investigated, taking the CH₃X series (X = F, Cl, Br, I) as bench tests. Finite-difference computations carried out with various basis sets at the SCF ab initio level on methyl fluoride bring out the performance of the LCAO-MO method as concerns the prediction of molecular force constants and integrated infrared intensities. Extension of these calculations to other halides is made possible using pseudo-potentials for the interaction between the atomic cores and the valence-shell electrons of the molecule. The atomic force field parameters defined in terms of Cartesian displacement coordinates suffer from a certain lack of transferability, apparently due to the variations of the chemical bonding effects when passing from fluorine to iodine.     

Optical properties of Ag -TiO 2 nanocermet films prepared by cosputtering and multilayer deposition techniques

Ag -TiO2 nanocermet thin films, deposited for optical filtering applications by two sputtering techniques, codeposition and multilayer deposition, exhibit surface plasmon absorption in the spectral range 450 -500 nm. The cosputtering technique induces a columnar growth, whereas multilayer deposition produces a more-random distribution of silver inclusions. Both films have large, flat silver grains at the air -cermet interface. An optical double-heterogeneous layer model based on the experimental morphological parameters of the films accounts well for their experimental transmittance, notably for extra absorption near 700 nm, which is attributed to a surface plasmon in the flat silver grains of the surface.     

Optical Properties of Ag-TiO(2) Nanocermet Films Prepared by Cosputtering and Multilayer Deposition Techniques

Ag-TiO(2) nanocermet thin films, deposited for optical filtering applications by two sputtering techniques, codeposition and multilayer deposition, exhibit surface plasmon absorption in the spectral range 450-500 nm. The cosputtering technique induces a columnar growth, whereas multilayer deposition produces a more-random distribution of silver inclusions. Both films have large, flat silver grains at the air-cermet interface. An optical double-heterogeneous layer model based on the experimental morphological parameters of the films accounts well for their experimental transmittance, notably for extra absorption near 700 nm, which is attributed to a surface plasmon in the flat silver grains of the surface.     

Contact of a Finger on Rigid Surfaces and Textiles: Friction Coefficient and Induced Vibrations

The tactile information about object surfaces is obtained through perceived contact stresses and friction-induced vibrations generated by the relative motion between the fingertip and the touched object. The friction forces affect the skin stress-state distribution during surface scanning, while the sliding contact generates vibrations that propagate in the finger skin activating the receptors (mechanoreceptors) and allowing the brain to identify objects and perceive information about their properties. In this article, the friction coefficient between a real human finger and both rigid surfaces and fabrics is retrieved as a function of the contact parameters (load and scanning speed). Then, the analysis of the vibration spectra is carried out to investigate the features of the induced vibrations, measured on the fingernail, as a function of surface textures and contact parameters. While the friction coefficient measurements on rigid surfaces agree with empirical laws found in literature, the behaviour of the friction coefficient when touching a fabric is more complex, and is mainly the function of the textile constructional properties. Results show that frequency spectrum distribution, when touching a rigid surface, is mainly determined by the relative geometry of the two contact surfaces and by the contact parameters. On the contrary, when scanning a fabric, the structure and the deformation of the textile itself largely affect the spectrum of the induced vibration. Finally, some major features of the measured vibrations (frequency distribution and amplitude) are found to be representative of tactile perception compared to psychophysical and neurophysiologic works in literature.