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The duration that a single odor needs to be sniffed for identification was determined for 18 humans. A hot wire anemometer and an oscilloscope were used to monitor the duration, volume and inhalation rate of sniffs. In Experiment 1 subjects used 1, 3 or 5 natural sniffs, or an unlimited number of natural sniffs to sample seven dissimilar single odors of moderate perceived intensity, and demonstrated that each odor could be identified with a single sniff. In Experiment 2 subjects demonstrated that each of the odors could be identified with the shortest sniff (0.42 sec) they could physically achieve. In Experiment 3 tests with two of the odorants at several concentrations showed that sniff duration influences identification over a narrow range of concentrations that is just above the recognition threshold. These results together with earlier data that described the optimum conditions for the detection of an odor and the perception of odor intensity, provide information that is necessary for the development of a standard olfactometer and standard methods for human olfactory measurements.  相似文献   
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Pyomyositis: characteristics at CT and MR imaging   总被引:9,自引:0,他引:9  
Gordon  BA; Martinez  S; Collins  AJ 《Radiology》1995,197(1):279
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SUMMARY A case is reported of pseudohyperphosphataemia in association with a monoclonal gammopathy of undetermined significance.  相似文献   
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Abnormalities in glucose metabolism are thought to be among the main causes of cataract formation. The authors have made noninvasive biochemical measurements of the lens that provide information concerning glucose metabolism in the lens epithelium. The autofluorescence of reduced pyridine nucleotides (PN) and oxidized flavoproteins (Fp) within the rabbit lens were noninvasively measured as a function of depth using redox fluorometry. The peak of the autofluorescence at 440 nm (excited at 360 nm) and 540 nm (excited at 460 nm) were determined at the lens epithelium. When 8 mM sodium pentobarbital, a known inhibitor of mitochondrial respiration, was applied to the lens, the autofluorescence peak at 440 nm increased and that at 540 nm decreased. The 440 nm autofluorescence is thought to be from reduced pyridine nucleotides, whereas the 540 nm autofluorescence is from the oxidized flavoprotein. Blocking lens respiration with pentobarbital caused an increase in the PN/Fp ratio by a factor of 3 within 3.5 hr after pentobarbital application.  相似文献   
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BACKGROUND: Diagnosis of atopic dermatitis (AD) depends on clinical features because no definitive diagnostic test exists. Criteria proposed by Hanifin and Rajka (Acta Derm Venereol (Stockh) 1980; Suppl 92: 44-47) were acceptable for hospital-based studies but were found not to be suitable for field studies. A UK working party formulated clinical diagnostic criteria that could be used in both hospital and epidemiological settings. Validation studies of the criteria showed widely variable results, probably due to different clinical settings and ethnicity. AIM AND OBJECTIVE: This study was undertaken to validate Hanifin and Rajka's criteria and to assess the comparative efficacy of their criteria and the UK working party's diagnostic criteria in the diagnosis of AD in a hospital setting in North India. SUBJECTS AND METHODS: This study serially included 101 patients with AD and 48 controls of paediatric age group. The study period was from July 2003 to December 2004. RESULTS: Hanifin and Rajka's criteria (sensitivity 96%, specificity 93.75%, positive predictive value 97% (PPV) and negative predictive value (NPV) 91.84%) had a statistical advantage over the UK working party's diagnostic criteria (sensitivity 86%, specificity 95.83%, PPV 97.75% and NPV 76.67%), with a P-value < 0.005.  相似文献   
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SUMMARY Impotence is a common symptom which can cause considerable distress to both the sufferer and his partner. The use of pharmacotherapy to improve erectile function will continue to increase as safe and effective drugs are developed. However, restoring erectile function should not be the only treatment objective. It is also essential to address personal and emotional factors in the sufferer, conflicts in his relationship with his partner, and sexual problems in his partner, all of which may be instrumental in causing or maintaining the presenting impotence. We advocate a combined approach with appropriate medical treatment and sex and couple therapy  相似文献   
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