Matrix metalloproteinase activity in equine synovial fluid: influence of age, osteoarthritis, and osteochondrosis

OBJECTIVE: To investigate the influence of age, osteoarthritis (OA), and osteochondrosis (OC) on the matrix metalloproteinase (MMP) activity in the synovial fluid (SF) of equine joints. METHODS: SF was collected from normal and osteoarthritic metacarpophalangeal joints (normal: 14 adult, 28 juvenile; OA: 22 adult). And from normal and osteochondrotic tarsocrural joints (5 months: 11 normal, 8 OC; 11 months: 7 normal, 6 OC). Subsequently, overall MMP activity was measured. RESULTS: The level of active MMPs was almost twofold higher in SF from juvenile horses (age up to 11 months) than in SF from mature animals (4-30 years; p < 0.001). In juvenile horses MMP activity was higher in 5 month old foals than in 11 month old foals (p < 0.01). In adult horses MMP activity was independent of age. In OA joints the activity was nearly twice as high as in normal joints (p < 0.001). In OC joints MMP activity was not significantly different from normal, age matched, control joints. CONCLUSIONS: MMP activity in SF from normal adult joints is not related to age. In juvenile joints MMP activity is significantly higher than activity in joints from adult animals. It is hypothesised that the gradual decrease in MMP activity with increasing age reflects the declining metabolic activity resulting from ceasing growth and the accompanying decrease in cartilage remodelling. The increased MMP activity in osteoarthritis joints most likely reflects matrix destruction. In osteochondrosis MMP mediated matrix degradation appears not to be different from normal joints.     

Thick rutile layer on titanium for tribological applications

In the present work, efforts have been made to oxidise the titanium surface, followed by very slow cooling to produce a thick and adherent oxide layer. The response of titanium to oxidation at various temperatures and timings has been investigated, in terms of layer thickness, phase evolution, surface morphology, oxide layer–substrate adhesion, hardness and tribological characteristics. A variety of experimental and analytical techniques, including X-ray diffraction, field-emission scanning electron microscopy, scanning electron microscopy, micro-hardness and tribological testing, have been used to characterise the resultant thermal oxidised surfaces. The results showed that a thick oxide layer with rutile TiO₂ and oxygen diffused Ti structure can be produced, which exhibited excellent adhesion with the titanium substrate, low friction and superior wear resistance during pin-on-disc sliding tests and thus good potential for tribological applications.     

Laryngeal foreign bodies in children

Laryngeal foreign bodies (F.B.) in children are relative rare, especially in infants under one year of age, and the diagnosis and removal are difficult. The history, the clinical and radiologic findings can be misleading. Seventeen patients with laryngeal F.B. (10 of them under one year of age) are presented, and the diagnostic problems and treatment are discussed. Foreign bodies were either objects of a sharp and thin quality, e.g. an eggshell fragment, or large, e.g. a piece of meat, causing apnea and death.     

Measurement of Nasal Mucosal Blood Flow by a Thermal Clearance Method

A new method for nasal mucosal blood flow measurement is described. The orifice of the nasal cavity is closed by a probe which includes a thermocouple. The temperature of the mucosa is increased, since cooling by airflow is now impossible. The temperature increase is due to blood flow. The rate of temperature increase depends both on blood flow and the heat capacity of the probe. A method to obtain mucosal blood flow from a temperature versus time curve is presented. Experimental results are compared to those obtained by other methods.     

Evaluation of neural networks defenses and attacks using NDCG and reciprocal rank metrics

International Journal of Information Security - The problem of attacks on neural networks through input modification (i.e., adversarial examples) has attracted much attention recently. Being...     

Analysis of reliability and power efficiency in cascode class-E PAs

Power efficiency in switched common source class-E amplifiers is usually obtained at the expense of device stress. Device stacking is a viable way to reduce voltage drops across a single device, improving long-term reliability. In this paper, we focus on cascode-based topologies, analyzing the loss mechanisms and giving direction to optimize the design. In particular, a new dissipative mechanism, peculiar of the cascode implementation, is identified and a circuit solution to minimize its effect is proposed. Prototypes, realized in a 0.13-/spl mu/m CMOS technology demonstrate 67% PAE while delivering 23 dBm peak power at 1.7 GHz. Good bandwidth was also realized with greater than 60% PAE over the frequency range of 1.4-2 GHz.