Capillary hemangioma of the testis.

Testicular hemangiomas are benign vascular neoplasms usually occurring in children. Pathologists must be aware of this entity when performing intraoperative frozen sections as, after diagnosis, testicle-sparing surgery is adequate. The authors present a typical case with immunohistochemical studies and a review of the literature.

Stiffness and passive peak force changes at the ankle joint: the effect of different joint angular velocities.

OBJECTIVE: To compare peak force and stiffness at the ankle joint in response to repetitive dorsiflexion at two joint angular velocities (5 and 25 deg s(-1)). DESIGN: Pre- post-repeated measures design. BACKGROUND: Stretching affects the biomechanical properties of tissues. In many instances, stretching is performed in a cyclic manner. An important factor that might influence the effects of stretching is the speed at which the tissues are lengthened. METHODS: Eighteen healthy subjects participated. A dynamometer repeatedly moved the ankle joint from 0 deg of dorsiflexion to 80% of maximum dorsiflexion over a 2 min period. Two joint angular velocities were examined: 5 and 25 deg s(-1). Force and angle data were recorded simultaneously. Electromyographic activity from plantar and dorsiflexor muscles was monitored. The variables of interest were peak passive force and average stiffness at the first and last repetition of motion. RESULTS: Peak force was significantly higher (P < 0.05) at 25 deg s(-1) for the first repetition. At both joint angular velocities, peak passive force decreased significantly over the 2 min of motion. The decreases were 13% and 21% at 5 and 25 deg s(-1) respectively. Peak passive force was not significantly different (P > 0.05) across velocities at 2 min. Stiffness was greater at 25 deg s(-1) initially (P < 0.05), however, it decreased significantly across time. The magnitude of the decrease was 20% and 31% at 5 and 25 deg s(-1) respectively. After 2 min of motion, there was no significant difference (P > 0.05) in stiffness across the joint angular velocities examined. CONCLUSION(S): The findings showed that while significant differences existed in stiffness and peak force across angular velocities at the start of the stretching motion, the differences decreased considerably with repeated motion, and were relatively similar within 2 min. RELEVANCE: It has long been thought that greater speeds of stretch are more likely to lead to muscle injury. Our findings suggest that it is most beneficial to stretch at a slow speed initially, thereafter, the speed of stretch may be increased.

Characteristics, quantity and thickening of sludge from a partial lime softening plant.

Water softening using the lime process leads to the production of large quantities of sludge. Determining the quantity of sludge produced and its dewatering properties is very important in the design, operation and cost of the subsequent sludge handling facilities. Presented are the results of a study on the partial softening process of a 200 MLD water treatment plant in Edmonton, Alberta, Canada. The plant currently softens surface water from a hardness of 180 mg l-1 as CaCO3 to 110 mg l-1 as CaCO3 in a solid contact clarifier. The sludge is gravity thickened prior to centrifugation after which the sludge is hauled off-site for disposal. Results from the study were used to assess the current operation as well as to provide required information for the facilities needs in view of a proposed expansion to double the current production. Results from measured data indicate that the sludge production can be established by a mass balance, chemical (Ca++, Mg++) balance or stoichiometric calculations. Bulk density of the lime sludge was correlated to the sludge solids content by a quadratic expression. Similarly, the settling velocities at various sludge densities were well correlated. The total organic carbon (TOC) content of the sludge was found to be unusually high. Analysis of operating records found that by maintaining a proper sludge blowdown interval and duration, the sludge withdrawal can be optimized for solid contact clarifiers with intermittent sludge withdrawal.