| transition state | The activated state of a molecule that has partly undergone a chemicalreaction. (09 Oct 1997) |
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| transition state intermediate | In a chemical reaction, an unstable and high-energy configuration assumed by reactants on the way to making products. Enzymes are thought to bindand stabilise the transition state, thus lowering the energy of activation needed to drive the reaction to completion. (09 Oct 1997) |
| triplet state | A second excited state of a molecule (e.g., chlorophyll) produced by absorption of light to produce the singlet state, then loss of some energy (fluorescence) to arrive at the longer-lived triplet state The molecule may remain sufficiently long in the triplet state for a second activating light quantum to be effective in producing a "second triplet" state, obviously at still a higher level of excitation, hence reactivity. Alternatively, it may lose the triplet state energy directly and return to the ground state. (05 Mar 2000) |
| eunuchoid state | An imprecisely delineated condition of a male manifesting signs of inadequate androgen secretion during adolescent growth, regardless of the cause; usually referring to long legs, short trunk, and boyish beardless faces. (05 Mar 2000) |
| twilight state | A condition of disordered consciousness during which actions may be performed without the conscious volition of the individual and with no memory of such actions. Compare: somnambulic epilepsy. (05 Mar 2000) |
| excited state | <chemistry, radiobiology> An atom or nucleus which possesses more energy than its ground state energy. (16 Dec 1997) |
| lacunar state | The presence of lacunes in the brain. One of the major factors underlying cerebrovascular disease; high correlation with hypertension and atherosclerosis. Symptomatic forms include pure motor hemiplegia and pure hemisensory syndrome; multiple lacunar infarcts are the most common cause of pseudobulbar palsy. (05 Mar 2000) |
| local excitatory state | Increased irritability of a nerve fibre or muscle fibre which is produced by an ineffective electrical stimulus; summation of the stimuli may occur, resulting in a propagated impulse if two or more subliminal stimuli are applied in rapid succession. (05 Mar 2000) |