Scavenger cells

When the ore contains a large amount of clay minerals, these form difficult to separate slimes, which hinder the recovery of the minerals (see Clays). The tailing from the scavenger cells can be cycloned to remove the slimes before the coarse material is floated in a tailings retreatment plant. The flotation product from the rougher cells of this plant can be reground and cleaned. This additional treatment of the tailings from the main copper flotation plant may improve the recovery of metal values by 1—3%. 

Brown, M.S., Basu, S.K., Falck, J.R., Ho, Y.K. and Goldstein, J.C. (1980). The scavenger cell pathway for lipoprotein degradation specificity of the binding site that mediates the uptake of negatively chaiged LDL by macrophages. J. Supramol. Struct. 13, 67-81. 

Macrophages Large scavenger cells present in connective tissue and many major organs that remove bacteria. 

On the other hand, large macromolecules are subjected to nonspecific phagocytic uptake. This can occur in liver and blood by means of scavenger cells (i.e., reticuloendothelial system [RES] cells). Large proteins such as adenosine deaminase (170 kDa) and somatotropin (192 kD a) accumulate in the liver and are cleared by RES cells (Table 13.4). 

Much research has focused on marijuana s effects on the immune system. Some research has shown that one type of immune system cell called the macrophage (scavenger cell) is particularly sensitive to THC exposure. Macrophages clear the body of viruses, bacteria, and particles that are inhaled or ingested. These studies found the presence of cannabinoid receptors on macrophages, suggesting that THC can disrupt normal immune system functions and may eventually inhibit the body s natural immune response. 

Festjens N, et al. Butylated hydroxyanisole is more than a reactive oxygen species scavenger. Cell Death Differ. 2006 13 166-169. 

The remaining third of the ammonia is trapped by the peripheral hepatocytes (= scavenger cells) due to their high affinity. By means of glutamine synthetase, glutamine is formed as a nontoxic transport form of ammonia. At the same time, it also serves to activate the urea cycle (= temporary ammonia detoxification), (s. fig. 3.13)... 

As a rule, 2 mol bicarbonate are required for the synthesis of 1 mol urea. The amount of urea eliminated in the urine is approximately 500 mmol/day (ca. 30 g). Normally, only about 25% of the capacity of the urea cycle are used. It is therefore virtually impossible for hyperammonaemia to be a sequela to isolated NH4+ hyperproduction alone. In patients with liver cirrhosis, the capacity for urea synthesis is reduced by approximately 80%, i. e. there is a considerable decrease in ammonia detoxification in the periportal field, predominantly due to a function loss on the part of the perivenous scavenger cells. 

Alkalosis and hypokalaemia (possibly caused by secondary hyperaldosteronism or use of diuretics) shift the dissociation constant towards free, toxic NH3. By contrast, ammonia is considered - in a process resembling a vicious circle - to be a secondary stimulus for aldosterone production. Thiazide diuretics in particular put an overload on the detoxification capacity of the scavenger cells. This is because of an insufficient supply of bicarbonate for carbamoyl phosphate synthetase reaction due to diuretic-induced inhibition of the mitochondrial carboanhydrase. 

One of the problem areas of the hot water process for tar sands extraction arises from the clay mineral fines, which comprises from less than 1% to over 15% of the mined material. These mineral fines interfere with efficient bitumen separation in the primary separation cell and require the operation of the backup scavenger cell to maintain bitumen recovery efficiencies. Selective mining could be used to avoid the problem by leaving high fines... 

A brain macrophage, simply put, is a macrophage in the brain. The normal brain parenchyma is devoid of macrophages they appear only when scavenger cells are needed. There are a number of potential sources of brain macrophages and these include CNS resident microglial cells, blood-borne monocytes, and perivascular and meningeal cells.2... 

The third step in the hot-water process is scavenging. Froth flotation with air is usually employed. The scavenger froth is combined with the separation-cell froth to be further treated and upgraded to synthetic crude oil. Tailings from the scavenger cell join the separation-cell tailings stream and go to waste. 

Lipid accumulation in smooth muscle cells and scavenger cells (resident macrophages and migrant plasma monocytes), and... 

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