Aluminum body content

The gas pressure may produce a volume expansion, and the heating rate must be carefully controlled in bodies containing a high clay content. Other dehydration reactions producing gas are the dehydration of aluminum hydrates in the range 320-560°C and... 

The metering valve in an MDI is the critical component in the design of an effective delivery system. The main function of the metering valve is to reproducibly deliver a portion of the liquid phase of the formulation in which the medication is either dissolved or dispersed. The valve also forms the seal atop the canister to prevent loss of the pressurized contents. The valves generally comprise at least seven components that are constructed from a variety of inert materials. Typical materials of construction are acetal or polyester for the valve body, stainless steel or acetal for the valve stem, generally anodized aluminum for the ferrule, and butyl, nitrile, or neoprene for the elastomers used in the seals and gaskets [43],... 

We cut an AIN/W FGM sample (W content from 0 wt% to 30wt%) and performed X-ray diffraction on the cut surface using the Ka waves of Cu at 1 mm intervals. The results are shown in Fig. 3. As a result of identifying the compound phases formed in the AIN/W FGM sintered body from the positions of the peaks shown in the X-ray diffraction patterns, we confirmed the existence of aluminum nitride and metallic tungsten. Fig. 3 shows the results of X-ray diffraction at all measurement points. The measurement points indicate the presence of... 

Although trace element abnormalities occur in chronic renal failure, few symptoms have been attributed to them in nondialyzed patients. In dialysis patients these disturbances appear to be qualitatively similar but more severe (T7). They have been extensively reviewed by Alfrey (A5). Total body zinc (except in erythrocytes), strontium, aluminum, and tin are generally increased, whereas total body rubidium is decreased. Iron stores tend to be increased in the spleen and liver in dialyzed patients, especially after ferrous sulfate therapy. Copper is increased in lung tissue and decreased in heart tissue and erythrocytes. Molybdenum and cadmium are decreased in renal tissue but increased in liver tissue of dialyzed and nondialyzed patients. Total body zinc content is significantly increased (A5), but hypozincemia, frequently observed in dialysis patients, has been blamed for taste impairment and impotence and there is conflicting evidence on whether zinc repletion corrects these abnormalities (K4, Ml2). Nickel is also increased in the serum of uremic patients, but this does not appear to be associated with a corresponding increase in tissues (S5). It cannot be concluded that trace element retention in renal failure is of no clinical importance, as shown by the problem of aluminum intoxication, to be discussed later. In addition, trace elements such as rubidium and bromine, which are rapidly depleted in uremic patients on maintenance dialysis (A5), may prove to be essential in normal metabolism. Thus the clinical importance of these element alterations remains unclear. 

The typical daily dietary AE intake is 10 to 100 mg (Campbell et al., 1957), although absorption is normally minimal. This quantity of dietary AE is more than enough to account for the entire increase of brain AE observed in patients with dialysis dementia. Among 22 such patients, the mean brain AE content was 22 mg/kg dry weight. The normal human brain weighs about 1500 gm and is about 80% water, or 300 gm dry weight. Thus, the total increase in AE content for the whole brain is less than 7 mg in patients with dialysis dementia. Therefore, the entire increase of brain AE in such patients can theoretically be accounted for by dietary aluminum. The increase in body aluminum stores may also be, in part, the result of AE contamination from other sources, such as Al" in dialysate water, dialysis system aluminum pipes, or aluminum leaked from anodes. 

Many types of biological specimens can be analyzed for aluminum. Tissue and bone have been suggested as the specimens of choice to evaluate the true body burden [23-2S]. Since these specimens are not obtainable on a regular basis, blood aluminum levels have been analyzed to reflect a subject s aluminum burden [26-28], Most of these methods use serum or plasma as intUcator specimen. The monitoring of aluminum levels in these specimens is considered to be the most appropriate approach to ensure that aluminum toxicity problems do not develop in individual uremic or renal dialysis patients [27]. Urine samples have been analyzed for aluminum content for the biological monitoring of occupationally exposed persons. 

Elevated aluminum levels can be found in several body areas following increased aluminum exposure. For example, raised edumi-num levels have been found in the plasma, bone, liver, heart, striated muscle, and brain. - Liver emd bone are the tissues most frequently involved, and have the highest aluminum content. ... 

Alumina is used in ceramic products in varying amounts. However, discussion is usually limited to high alumina, which refers to those bodies containing 80 percent or more aluminum oxide. Ceramics with less than 80 percent alumina but still predominantly alumina are classified as porcelain. The most common aluminas are those containing 85,90, 94, 96, 99, 99.8, and 99.9%. Strength and other properties improve as the alumina percentage increases, bnt so do cost and complexity of processing. The properties are dependent not only on the alnmina content, but also on microstructure and porosity. 

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