| anchorage dependence | <cell biology, cell culture> The necessity for attachment (and spreading) in order that a cell will grow and divide in culture. Loss of anchorage dependence seems to be associated with greater independence from external growth control and is probably one of the best correlates of tumourigenicity in vivo. Anchorage independence is usually detected by cloning cells in soft agarose, only anchorage independent cells will grow and divide (as they will in suspension). (18 Nov 1997) |
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| physical dependence | <pharmacology> Physiologic adaptation of the body to the presence of opioid is required to maintain the same level of analgesia. (31 Dec 1997) |
| morphine dependence | Strong dependence, both physiological and emotional, upon morphine. (12 Dec 1998) |
| heroin dependence | Strong dependence, both physiological and emotional, upon heroin. (12 Dec 1998) |
| psychological dependence | <psychiatry> Pattern of compulsive drug use characterised by a continued craving for an opioid and the need to use the opioid for effects other than pain relief. (16 Dec 1997) |
| substance dependence | A pattern of behavioural, physiologic, and cognitive symptoms that develop due to substance use or abuse; usually indicated by tolerance to the effects of the substance and withdrawal symptoms that develop when use of the substance is terminated. (05 Mar 2000) |
| dependence | The quality or condition of relying upon, being influenced by, or being subservient to a person or object reflecting a particular need. Origin: L. Dependeo, to hang from (05 Mar 2000) |
| drug dependence | Use of a drug for a reason other than which it was intended or in a manner or in quantities other than directed. Drug dependence is a compulsion to take a drug to produce a desired effect or prevent unpleasant effects when the drug is withheld. Risk factors for drug abuse include: low self esteem, inability to deal with stress and emotional instability. Juveniles use drugs due to peer pressure. Signs of drug use in children include: a change in friends or group, long absences from home, poor performance in school, seclusion, stealing, lying, criminal behaviour, deteriorating family relationships, signs of drug intoxication and changes in behaviour. Commonly abused drugs include narcotic analgesic agents, benzodiazepines, cocaine, amphetamines, barbiturates, marijuana, LSD and phencyclidine. Many labs now offer quick and inexpensive urine drug screening. Psychological counseling and parental support will be necessary in children with this problem. (27 Sep 1997) |
| inverse density dependence | <epidemiology> See density dependence. (05 Dec 1998) |
| field dependence-independence | The ability to respond to segments of the perceptual experience rather than to the whole. (12 Dec 1998) |
| activation energy | <chemistry> The amount of energy (expressed in joules) that is needed to convert all the molecules in one mole of a reacting substance from a ground state to the transition state. (06 May 1997) |
| binding energy | <chemistry, radiobiology> The binding energy of a nucleus is the minimum energy required to dissociate it into its component neutrons and protons. Neutron or proton binding energies are those required to remove a neutron or proton, respectively, from a nucleus. Electron binding energy is that required to remove an electron from an atom or a molecule. (16 Dec 1997) |
| bioelectric energy sources | Implantable devices which convert biological energy (chemical energy of the metabolism of continuously regenerating body fluids or mechanical energy of periodic movements) to electrical energy. The sources include biogalvanic cells, biofuel cells, and ionic concentration cells. (12 Dec 1998) |
| biomass energy | See Bioenergy. (05 Dec 1998) |
| bond dissociation energy | This is the energy needed to break the bonds between two linked atoms. (09 Oct 1997) |