Aluminum is poorly absorbed following either oral or inhalation exposure and is essentially not absorbed dermally. The bioavailability of aluminum is strongly influenced by the aluminum compound and the presence of dietary constituents which can complex with aluminum and enhance or inhibit its absorption. Aluminum binds to various ligands in the blood and distributes to every organ, with highest concentrations found in bone and lung tissues. In living organisms, aluminum is believed to exist in four different forms: as free ions, as low-molecular-weight complexes, as physically bound macromolecular complexes, and as covalently bound macromolecular complexes. Absorbed aluminum is excreted principally in the urine and, to a lesser extent, in the bile, while unabsorbed aluminum is excreted in the faeces. (L739)
The main target organs of aluminum are the central nervous system and bone. Aluminum binds with dietary phosphorus and impairs gastrointestinal absorption of phosphorus. The decreased phosphate body burden results in osteomalacia (softening of the bones due to defective bone mineralization) and rickets. Aluminum's neurotoxicity is believed to involve several mechanisms. Changes in cytoskeletal protein functions as a results of altered phosphorylation, proteolysis, transport, and synthesis are believed to be one cause. Aluminum may induce neurobehavioral effects by affecting permeability of the blood-brain barrier, cholinergic activity, signal transduction pathways, lipid peroxidation, and impair neuronal glutamate nitric oxide-cyclic GMP pathway, as well as interfere with metabolism of essential trace elements because of similar coordination chemistries and consequent competitive interactions. It has been suggested that aluminum's interaction with estrogen receptors increases the expression of estrogen-related genes and thereby contributes to the progression of breast cancer (A235), but studies have not been able to establish a clear link between aluminum and increased risk of breast cancer (A15468). Certain aluminum salts induce immune responses by activating inflammasomes. (L739, A235, A236)
Not listed by IARC. IARC classified aluminum production as carcinogenic to humans (Group 1), but did not implicate aluminum itself as a human carcinogen. (L135) A link between use of aluminum-containing antiperspirants and increased risk of breast cancer has been proposed (A235), but studies have not been able to establish a clear link (A15468).
Aluminum targets the nervous system and causes decreased nervous system performance and is associated with altered function of the blood-brain barrier. The accumulation of aluminum in the body may cause bone or brain diseases. High levels of aluminum have been linked to Alzheimer's disease. A small percentage of people are allergic to aluminium and experience contact dermatitis, digestive disorders, vomiting or other symptoms upon contact or ingestion of products containing aluminium. (L739, L740)
Inhalating aluminum dust causes coughing and abnormal chest X-rays. A small percentage of people are allergic to aluminium and experience contact dermatitis, digestive disorders, vomiting or other symptoms upon contact or ingestion of products containing aluminium. (L739, L740)
Organometallic compositions and polyisocyanate compositions containing them
申请人:Imperial Chemical Industries PLC
公开号:US20020188047A1
公开(公告)日:2002-12-12
An organometallic composition, suitable for use in curing polyisocyanate compositions, includes a complex of at least one metal selected from iron, cobalt and aluminum and at least one &bgr;-dicarbonyl compound wherein when the metal is iron (II) or cobalt (II) the molar ratio of &bgr;-dicarbonyl compound to metal is in the range from 2.1:1 to 10:1, and when the metal is aluminum (III), iron (III) or cobalt (III) the molar ratio of &bgr;-dicarbonyl compound to metal is in the range from 3.1:1 to 10:1. A polyisocyanate composition containing the organometallic composition and a process for binding lignocellulosic material is also described.
Organic electroluminescent devices and methods of making organic electroluminescent devices are described. The organic electroluminescent devices include an organic emissive element that is positioned between two electrodes. The organic emissive element contains a trans-1,2-bis(acenyl)ethylene compound where the acenyl group is selected from 2-naphthyl, 2-anthracenyl, or 2-tetracenyl.
Semiconductor devices are described that include a semiconductor layer that contains a trans-1,2-bis(acenyl)ethylene compound. The acenyl group is selected from 2-naphtyl, 2-anthracenyl, or 2-tetracenyl. Additionally, methods of making semiconductor devices are described that include depositing a semiconductor layer that contains a trans-1,2-bis(acenyl)ethylene compound.
A process for preparing substituted pentacene compounds comprises the step of cyclizing substituted bis(benzyl)phthalic acids using an acid composition comprising trifluoromethanesulfonic acid, the substituted bis(benzyl)phthalic acids being represented by the following general formulas:
wherein each R (that is, each of the groups R
1
through R
8
) is independently an electron-donating group, a halogen atom, a hydrogen atom, or a combination thereof.
2-Pyridone derivatives as neutrophil elastase inhibitors and their use
申请人:Hansen Peter
公开号:US20070043036A1
公开(公告)日:2007-02-22
There are provided novel compounds of formula (I), wherein R
1
, R
2
, R
4
, R
5
, G
1
, G
2
, L, Y and n are as defined in the Specification and optical isomers, racemates and tautomers thereof, and pharmaceutically acceptable salts thereof; together with processes for their preparation, compositions containing them and their use in therapy. The compounds are inhibitors of neutrophil elastase.