External foreign bodies

Tophi Chalky deposits of sodium urate occurring in gout. Tophi form most often around joints in cartilage, bone, bursae, and subcutaneous tissue and in the external ear, producing a chronic, foreign-body inflammatory response. If untreated, tophi can lead to joint deformity or destruction. 

The normal external auditory canal has several mechanisms that protect if from infections. The S-shaped anatomy of the external auditory canal provides protection from foreign bodies under normal circumstances. The tragus provides protection anteriorly, and hair from follicles found just inside the meatus prevent airborne debris from entering. 

For this reason, attempts are made to control crystallization through the use of solid nuclei. In theory, nuclei of the same polymer can be added to externally produce homogeneous nucleation. As an example of this droplet technique, the sample is ground so small that there are many small particles and the probability that a foreign body resides in a given particle decreases to near zero. 

The most important parameters to characterize blood compatibility are thrombocyte adhesion and thrombocyte number. In contact with a foreign body platelets tend to adhere similarly as in the case of an external injury. For this reason materials which show strong platelet adhesion as a consequence of their contact with a foreign body or provoke a decrease in the munber of blood platelets are considered as thrombogenic [94]. The decrease in the quantity of blood leucocytes after contact with a foreign body is a sign of a cellular immunore-sponse of the biological system toward the biomaterial. 

Escalation as rapid as this cannot be caused by the corrosion-erosion or overheating mechanisms described above. An external mechanical cause either from a seismic event, impact of a foreign body, or sudden catastrophic failure of a tubeplate, would be needed. To predict the consequences of such an event in which the sodium side of an SGU is suddenly raised to the steam-side pressure, the flow and pressure in the secondary circuit and the protective systems have to be calculated taking account of the compressibility of the sodium. 

The main quality concern in the food industry is undoubtedly safety. Safety entails keeping food free from contamination and preventing food-borne diseases. Food-borne diseases must be prevented by ensuring that processing is correctly carried out to avoid further microbial development (e.g., time-temperature profiles must be maintained during thermal treatment and cans or jars must be hermetically sealed). Food contamination includes macroscopic physical contamination (foreign bodies) and microscopic contamination by foreign bodies, microbes, or hazardous chemicals (e.g., pesticide residues). External contamination excludes all contaminants embedded in the product, and only concerns those that adhere... 

Like all of us, cells cannot survive without an external environment that operates successfully. The external environment brings oxygen and the nutrients needed to satisfy the cell s metabolic requirements. (Of course, they also bring foreign and potentially injurious chemicals to the cell.) These extracellular environments also allow for cells to maintain appropriate levels of fluids and electrolytes, and serve to remove cellular products that need to be excreted from the body. It is not hard to imagine how toxicant impairments of extracellular environments can be injurious. 

Suppose that a system d scribes a dosed cyde during which there is set free a quantity of heat Q while the kinetic energy passes from the valae to the value let denote the external work, that is, the work done by the forces that bodies foreign to the system exert on this system we shall then have the equation... 

The external application of white phosphorus to the skin gives rise to severe bums. Since the body temperature is about 37°C the handling of white phosphorus may ignite it. If this occurs the phosphorus adheres to the flesh being difficult to remove, causing an extremely painful and intractable burn. Indeed, an abstract from a French source reported in the "Foreign Department" section of the weekly London medical journal, the Lancet, advocated the use of burning phosphorus in medical practice (moxibustion). 

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