chemical

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chemical

 [kem´ĭ-k'l]
1. pertaining to chemistry.
2. a substance composed of chemical elements, or obtained by chemical processes.

chem·i·cal

(kem'i-kăl),
Relating to chemistry.

chemical

/chem·i·cal/ (kem´ĭ-k'l)
1. pertaining to chemistry.
2. a substance composed of chemical elements, or obtained by chemical processes.

chemical

[kem′əkəl]
Etymology: Gk, chemeia, alchemy
1 n, a substance composed of chemical elements or a substance produced by or used in chemical processes.
2 adj, pertaining to chemistry.

Pearl Index

Obstetrics A formula that allows comparison of the efficacy of contraceptive methods, calculated as the pregnancy rate in population divided by 100 yrs of exposure. See Breast feeding, Coitus interruptus, Condoms, Morning-after pill, Contraception, Natural family planning, Norplant, Rhythm method, RU 486.
Pearl index–pregnancies/100 years of use
Physiologic 15-30/100 years: Coitus interruptus, natural family planning (rhythm or safe period), eg calendar method, evaluation of cervical mucosa or temperature, breast feeding
Chemical 15-20/100 years: Contraceptive sponges
Barrier 2-20/100 years: Intrauterine devices, condoms
Hormonal 1-3/100 years
Surgical << 1/100 years: Ligation of fallopian tubes, vas deferens  

chem·i·cal

(kem'i-kăl)
Relating to chemistry.

chemical

1. pertaining to chemistry.
2. a substance composed of chemical elements, or obtained by chemical processes. See also toxin.

chemical adjuvant
a chemical added to another to improve its activity. For example, mineral gels added to vaccines. May also be a chemical added to feed to improve digestion, e.g. monensin in ruminants. These are more commonly referred to as additives. See also adjuvant.
agricultural chemical
chemical used in agriculture. Includes pesticides, anthelmintics, fertilizers, algaecides, herbicides, soil fumigants and the like.
chemical environment
that part of the animals' environment that is composed of chemicals. For farm livestock this includes fertilizers, defoliants, worm drenches, insect sprays, adjuvants to feed. For companion animals see household chemical (below).
household chemical
the roster of chemicals that one can expect to find in the average household. Includes insect sprays and repellents, snail bait, rodenticide, garden sprays, human medicines and the like.
chemical pneumonitis
results from aspiration of gastric acids.
chemical senses
see olfaction (2), taste.
chemical shearing
causing the fleece of sheep to be shed by the administration of a chemical substance to the sheep. Cyclophosphamide and mimosine have been used experimentally but there is no commercially available system.
chemical spoilage
occurs in preserved foods, especially canned ones. Is usually the result of interaction between the contents and an imperfect container. There may be gas produced, e.g. hydrogen swells, or discoloration of the tin.
chemical warfare
agents used include: (1) systemic poisons, e.g. hydrocyanic acid; (2) lung irritants, e.g. chlorine, phosgene; (3) lacrimators (weeping stimulators), e.g. CN, CAP, CS; (4) sternutators (sneeze stimulators); (5) vesicants, e.g. mustards, nitrogen mustards, arsenic mustards and nettle gases; (6) nerve gases, e.g. organophosphorus compounds.

Patient discussion about chemical

Q. How do you know when depression is chemical or situational? I've been feeling frustrated lately and while I think I show some signs of depression I think it is more a feeling down because of recent changes in my life. Every time I have seen a professional they all want to start me on some drug and having really seen no improvement over the years I swore off them years ago. When is it depression or "My life sucks right now"?

A. Thank you Johanna for sharing this with us.

Q. ADHD medications work on these brain chemicals? Hope you all know about the different types of brain chemicals, so the ADHD medications work on these brain chemicals?

A. Yes Alexzander. The active ingredients in the common ADHD medications are amphetamines. The amphetamines artificially increase the amount of certain neurotransmitters in the brain, speeding up the brain (thus the term “speed” for amphetamines). This makes the frontal area more active, at least while the drug is acting.

Q. How do you tell the difference between chemical burns, and burns from fire? Please don't spare on gross words i would like to know everything there is to burns.

A. Here is a ton of info on both-
http://en.wikipedia.org/wiki/Chemical_burn
http://en.wikipedia.org/wiki/Burn_%28injury%29

More discussions about chemical
References in periodicals archive ?
Each of these changes - tighter emissions controls, alternative fuels and alternative heat-exchange materials - will push engine temperatures higher, introduce new chemical environments and make more demands on gaskets, seals, hose, diaphragms, fuel lines, injectors and exhaust system components.
To update our original life estimation study conducted on compound M1-20, we conducted a similar study on an experimental oilfield elastomer compound EXP utilizing the same chemical environment.
15 /PRNewswire/ -- Based on its recent analysis of the gaskets market, Frost & Sullivan recognizes the Flexitallic Group with the 2008 North American Frost & Sullivan Product Value Leadership of the Year Award for its comprehensive product line of gaskets that offer excellent sealing under intense temperature, pressure, and chemical environments.
Dr Sanjay Garg, a research investigator in the U-M Department of Biological Chemistry, said that the dendritic cells alter the chemical environment outside cells in a way that promotes activation of the T cells.
Green tea includes catechin, an anticancer material which is only sensitive to cancer cells, but it vanishes in the body's chemical environment quickly when it is used in normal doses," Sarah Shafiei, the researcher of the project, said.
We realised that in this aggressive chemical environment we would not be able to use normal point detectors," said Eukos Kurti, the Managing Director of Elektrovill.
That could prove a fatal drink in a chemical environment.
There is increasing evidence that the foetus never experiences a state of true wakefulness in utero and is kept, by the presence of its chemical environment, in a continuous sleep-like unconsciousness or sedation," it stated.
Now, by carefully controlling the chemical environment in their petri dishes, Osborne and her colleagues have added nerve cells to their cornea recipe.
Hodgson will look at potential changes in the chemical environment for the critical area of the wet end.
A second paradigm shift in environmental health has occurred in recent years: a broadening of focus from the chemical environment to the built environment.
Ms Tucker, who worked on reducing toxin levels in pregnant women in the US, advised prospective mothers to "try to rely on a less chemical environment in your own home".

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