optical activity


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activity

 [ak-tiv´ĭ-te]
1. the quality or process of exerting energy or of accomplishing an effect.
2. a thermodynamic quantity that represents the effective concentration of a solute in a non-ideal solution. Symbol a.
3. the number of disintegrations per unit of a radioactive material. Symbol A.
4. the presence of recordable electrical energy in a nerve or muscle.
a's of daily living (ADL) activities that are necessary for daily care of oneself and independent community living. It includes using the toilet and grooming, dressing, and feeding oneself; independent community living includes driving, shopping, homemaking, care of family, work activities, and so on. See also self care, self care deficit, and self care assistance.(See accompanying table.)
deficient diversional activity a nursing diagnosis approved by the North American Nursing Diagnosis Association, defined as the experiencing by an individual of decreased stimulation from, interest in, or engagement in recreational or leisure activities. Formerly called diversional activity deficit. Possible causes include prolonged hospitalization or immobility at home, frequent and lengthy treatments such as renal dialysis, and a monotonous, nonstimulating environment. The patient usually gives subjective evidence that this condition exists by verbalizing a feeling of boredom or stating a desire for something to do or gives objective evidence by acting depressed or restless.

Nursing interventions that could be appropriate for diversional activity deficit include interviewing the patient to assess the current situation and to assist in developing plans for activities that provide interest and stimulation. These activities could include music, games, reading, handwork, or any other pastimes enjoyed by the patient. Patients may need assistance in identifying available resources and motivation to take advantage of the activities they provide.
enzyme activity the catalytic effect exerted by an enzyme, expressed as units per milligram of enzyme (specific activity) or molecules of substrate transformed per minute per molecule of enzyme (molecular activity).
malignant ventricular ectopic activity ventricular fibrillation or ventricular tachycardia with syncope, heart failure, myocardial ischemia, or hypotension.
optical activity the ability of a chemical compound to rotate the plane of polarization of plane-polarized light.
physical activity bodily movements, such as those accompanying activities of daily living.
pulseless electrical activity (PEA) continued electrical rhythmicity of the heart in the absence of effective mechanical function; it may be due to uncoupling of ventricular muscle contraction from electrical activity or may be secondary to cardiac damage with respiratory failure and cessation of cardiac venous return. Called also electromechanical dissociation.
purposeful activity in occupational therapy, tasks or experiences in which the individual actively participates that require and elicit coordination between the sensory, motor, cognitive, and psychological systems. Each person has a unique set of purposeful activities, influenced by his or her life roles, and, when doing one of them, directs attention to the task itself rather than to the internal processes involved. Activities may yield immediate results or may require sustained effort and repetition, and they may either represent new responses or be part of complex, longstanding patterns of behavior.
sustained rhythmic activity the continuous generation of action potentials within the heart in the absence of artificial or external stimulation.
triggered activity activity in which nondriven action potentials arise from afterpotentials that were caused by the previous action potential.

optical activity

The property of some substances in solution of causing of a ribbon-like beam of polarized light projected through the solution to twist through a small angle. Some substances cause rotation of the beam to the left (levorotatory), some to the right (dextrorotatory). Some optically active drugs are more potent in one form than in the other; a few are almost inert in one rotatory form.

optical activity,

n the property of a substance that enables it to rotate plane-polarized light counterclockwise or clockwise.

activity

the quality or process of releasing energy or of accomplishing an effect.

displacement activity
an instinctive behavior pattern, exhibited out of context and believed to be a means of relieving tension in the animal. Usually performed when the animal is in a state of high arousal or when it is frustrated in the performance of some instinctive activity. Seen as sexual mounting, digging, tail chasing, or excessive grooming in cats.
economic activity
a method of producing a specific product, e.g. fine wool, white veal.
enzyme activity
the catalytic effect exerted by an enzyme, expressed as units per milligram of enzyme (specific activity) or molecules of substrate transformed per minute per molecule of enzyme (molecular activity).
activity gross income
the total value of production, rather than the income, for a particular activity.
activity gross margin
the gross income of an activity less its variable costs.
intermediate activity
production of a commodity which is not sold but is used as an input to some other enterprise, e.g. crop used on the farm as stock feed.
optical activity
the ability of a chemical compound to rotate the plane of polarization of plane-polarized light.
References in periodicals archive ?
The chemistry of the main group metal halides has been widely explored for several decades owing to the promising physical properties that such compounds often exhibit including semiconductivity, luminescence, and non-linear optical activity.
Targeted applications of the solids vary from highly selective separations agents, porous solids for gas storage, compounds with second order non-linear optical activity, and the formation of highly ordered proton conducting solids.
They are adept at testing volatile oils and analyzing the optical activity of amino acids, vitamins, hormones and steroids.
The promise of photonic BC systems underscores the importance of characterizing their local optical properties, since the optical activity of single microphase domains and defect structures may dictate device function.