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A human factors engineering analysis of a chemical containment laboratory was performed to develop appropriate standards for future laboratory design. In order to perform this evaluation, a state-of-the-art facility was studied in depth. Measurements and observations were made of key operating areas. In addition, technicians were observed and interviewed as they performed various tasks. Compiled data were compared to existing ergonomic standards. The occupational implications of instituting ergonomically developed laboratory design standards are as follows: increased worker health, safety and productivity, improved work quality and reduced stress.  相似文献   
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Purpose: It was investigated whether alterations in neuronal structure and function occasioned by strabismic amblyopia also may be reflected in alterations in the expression on Y type neurons of a Cat-301 antibody sensitive antigen in the lateral geniculate nucleus (LGN) and cortex of our cat model of strabismic amblyopia. Methods/Results: The percentage of positively labelled cells was reduced in LGN laminae that received input from the deviated eye in strabismic amblyopic cats compared with normal cats. In the strabismic cortex, the density of immunopositive neurons was significantly reduced compared with normal, the effect being most pronounced in layer IV Conclusions: Despite previous physiological recordings indicating a decrease in X-cell associated acuity in strabismic amblyopia, the present findings imply that the changes in the early visual experience occasioned by strabismus also produce specific molecular changes in theY neuronal class.  相似文献   
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Four separate experiments were carried out by dosing dogs (Beagles and Border collies) and red foxes with protoscoleces obtained from hydatid cysts in sheep from mid-Wales. The dogs and foxes were killed at intervals over a period from 34-180 days after infection and the intestines were examined for Echinococcus granulosus. Border collie dogs were efficient hosts in that large numbers of worms developed, with gravid segments present by 55 days after infection; but Beagle dogs were poor hosts in that only small numbers of immature worms developed. Foxes were poor hosts in that few or no worms developed, but gravid segments were seen in three of 29 foxes. The worms showed morphological features similar to the 'sheep' rather than the 'horse' strain.  相似文献   
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The effects of the D-1 agonist SKF 38393 on tonic activity of rat substantia nigra pars compacta dopamine neurons were studied using extracellular, single-unit recording techniques. Unlike nonselective D-1/D-2 dopamine agonists or the D-2 agonist quinpirole, SKF 38393 did not inhibit dopamine neuronal activity when applied iontophoretically or when administered intravenously in doses up to 20 mg/kg to chloral hydrate-anesthetized rats. Moreover, pretreatment with SKF 38393 did not alter the inhibitory response of these neurons to apomorphine or the D-2 agonist quinpirole. However, in locally anesthetized, gallamine-treated, artificially respired rats, dopamine cell activity was significantly altered by i.v. administration of SKF 38393; firing rate increases and decreases were observed. Administration of the inactive enantiomer of SKF 38393, S-SKF 38393, did not induce similar changes in parallel experiments. These results support the idea that unlike D-2 autoreceptor stimulation, D-1 receptor stimulation does not exert a direct local effect on dopamine neurons in the substantia nigra pars compacta and suggest that D-1 receptor stimulation at sites postsynaptic to the dopamine cells may indirectly affect the activity of some dopamine neurons through long-loop feedback mechanisms.  相似文献   
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