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101.
IB Masters MM Eastburn PW Francis R Wootton PV Zimmerman RS Ware AB Chang 《Respiratory research》2005,6(1):16
Background
Flexible video bronchoscopes, in particular the Olympus BF Type 3C160, are commonly used in pediatric respiratory medicine. There is no data on the magnification and distortion effects of these bronchoscopes yet important clinical decisions are made from the images. The aim of this study was to systematically describe the magnification and distortion of flexible bronchoscope images taken at various distances from the object.Methods
Using images of known objects and processing these by digital video and computer programs both magnification and distortion scales were derived.Results
Magnification changes as a linear function between 100 mm (×1) and 10 mm (×9.55) and then as an exponential function between 10 mm and 3 mm (×40) from the object. Magnification depends on the axis of orientation of the object to the optic axis or geometrical axis of the bronchoscope. Magnification also varies across the field of view with the central magnification being 39% greater than at the periphery of the field of view at 15 mm from the object. However, in the paediatric situation the diameter of the orifices is usually less than 10 mm and thus this limits the exposure to these peripheral limits of magnification reduction. Intraclass correlations for measurements and repeatability studies between instruments are very high, r = 0.96. Distortion occurs as both barrel and geometric types but both types are heterogeneous across the field of view. Distortion of geometric type ranges up to 30% at 3 mm from the object but may be as low as 5% depending on the position of the object in relation to the optic axis.Conclusion
We conclude that the optimal working distance range is between 40 and 10 mm from the object. However the clinician should be cognisant of both variations in magnification and distortion in clinical judgements. 相似文献102.
BACKGROUND: Re-infection with Helicobacter pylori is more common in children than adults, and it is generally accepted that the family unit plays a significant role in primary childhood infection. We investigated whether the family unit plays a significant role in pediatric re-infection and if eradication of H. pylori from the entire family reduces the risk of childhood re-infection. METHODS: Fifty families, each with an H. pylori-infected pediatric index case (mean age 9.48 years), were recruited. A 13carbon urea breath test was performed on all family members in the same house as the index case. Each family unit was randomized into a 'family unit treatment' group (all infected family members treated) or an 'index case treatment' group (index case only treated). RESULTS: At long-term follow-up (mean 62.2 months), there were three re-infected children in the 'index case treatment' group compared with one in the 'family unit treatment' group. The re-infection rate was 2.4% per patient per year in the 'index case treatment' group and 0.7% per patient per year in the 'family unit treatment' group (p = .31). CONCLUSIONS: This study is the first to evaluate the effect of total family unit H. pylori eradication on pediatric re-infection rates and reports the longest period of re-infection follow-up in children. In childhood, re-infection with H. pylori is not significantly reduced by family unit H. pylori eradication. 相似文献
103.
Re-investigation of the effects of L-glutamine and L-asparagine on the Neurospora crassa NADP-specific glutamate dehydrogenase. 下载免费PDF全文
L-Glutamine, when purified free of traces of NH4+ present in solution, does not act as an alternative substrate to NH4+ for the NADP-specific glutamate dehydrogenase of Neurospora. L-Glutamine interferes with detection of small quantities of NH4+ by Nessler's reagent. L-Asparagine is not an alternative substrate to NH4+ for this enzyme. 相似文献
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107.
Background
Obsessive-compulsive disorder (OCD) is a disabling anxiety disorder, but most individuals delay seeking treatment. Internet-based cognitive behavioural therapy (iCBT) is an innovative service delivery method that may help to improve access to care, but the acceptability to consumers of such programs has not yet been established.Methodology
People with symptoms of OCD were invited to complete an online survey enquiring about demographic characteristics, symptom severity, and acceptability of Internet-based treatment. Demographic and symptom severity data were compared with people with OCD identified in a national epidemiological survey and with a sample of patients with OCD from a specialist outpatient anxiety clinic.Participants
129 volunteers to an online Internet survey, 135 patients at a specialist anxiety disorders outpatient clinic, and 297 cases identified in a national epidemiological survey.Main Measures
Demographic characteristics, and severity of symptoms as measured by the Kessler 10-Item scale, the 12-item World Health Organisation Disability Assessment Schedule - Second Edition and the Yale Brown Obsessive Compulsive Scale - Self Report Version.Principal Findings
The Internet sample was similar demographically but reported more severe symptoms than the comparison groups, although had similar severity of symptoms of OCD compared with other clinical samples reported in the literature. Participants reported Internet-based treatment for OCD would be highly acceptable.Conclusions
Internet-based treatment may reduce barriers to accessing treatment to people with OCD. Individuals in this study were similar demographically to other samples and had similar severity of symptoms as those identified in other clinical samples, suggesting that Internet-based treatment using techniques employed in face-to-face treatment may be effective in this group. Internet-based treatments for OCD need to be developed and evaluated. 相似文献108.
109.
Wootton Henry F. Morrongiello John R. Audzijonyte Asta 《Reviews in Fish Biology and Fisheries》2020,30(4):681-697
Reviews in Fish Biology and Fisheries - The size and age at which individuals mature is rapidly changing due to plastic and evolved responses to fisheries harvest and global warming. Understanding... 相似文献
110.
Barner AK Pfister CA Wootton JT 《Proceedings. Biological sciences / The Royal Society》2011,278(1710):1347-1355
Naturally isolated populations have conflicting selection pressures for successful reproduction and inbreeding avoidance. These species with limited seasonal reproductive opportunities may use selfing as a means of reproductive assurance. We quantified the frequency of selfing and the fitness consequences for inbred versus outcrossed progeny of an annual kelp, the sea palm (Postelsia palmaeformis). Using experimentally established populations and microsatellite markers to assess the extent of selfing in progeny from six founding parents, we found the frequency of selfing was higher than expected in every population, and few fitness costs were detected in selfed offspring. Despite a decline in heterozygosity of 30 per cent in the first generation of selfing, self-fertilization did not affect individual size or reproduction, and correlated only with a marginally significant decline in survival. Our results suggest both that purging of deleterious recessive alleles may have already occurred and that selfing may be key to reproductive assurance in this species with limited dispersal. Postelsia has an alteration of a free-living diploid and haploid stage, where the haploid stage may provide increased efficiency for purging the genetic load. This life history is shared by many seaweeds and may thus be an important component of mating system evolution in the sea. 相似文献