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An evaluation of the quality of light sources and guides was carried out in response to a demand that sufficient light intensity should always be available for transurethral procedures when bleeding occurs. A light monitor was developed for the rapid assessment of the source intensity and light guide transmission. A simple test protocol was also developed for routine assessment of the sources and guides and for evaluation of new sources and guides before purchase. The sources and guides were classified in order of merit and coded to permit the selection of those of the highest quality; this guarantees a satisfactory level of illumination during surgery. 相似文献
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Radiofrequency coils are used as sensors in various applications such as nuclear magnetic resonance (NMR) imaging and displacement cardiograms (DCGs). In most cases the impedance and the resonant frequency of the coil are monitored to provide the required information. The paper describes the changes in reflected impedance and in resonant frequency of a coil when it is placed near a medium with properties ranging from a lossy dielectric to a pure conductor. The theory of interaction between the coil and the medium is investigated and a model based on the use of vector potentials is developed. One prediction of the theory is that placing the coil over body equivalent saline (lossy dielectric) at 15 MHz results in an increase in the inductance of the coil and a resultant decrease in resonant frequency. This prediction was supported experimentally. 相似文献
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Absence of an association between HLA-DRB1*04 and rheumatoid arthritis in newly diagnosed cases from the community. 总被引:2,自引:2,他引:0
W Thomson L Pepper A Payton D Carthy D Scott W Ollier A Silman D Symmons 《Annals of the rheumatic diseases》1993,52(7):539-541
OBJECTIVES--To determine HLA-DR4 and DR1 allele frequencies in a series of patients with newly diagnosed early inflammatory arthritis. METHODS--HLA-DR1 and DR4 frequencies were determined by oligonucleotide typing of 208 patients classified as having either rheumatoid arthritis (RA) or undifferentiated inflammatory polyarthritis. RESULTS--The frequency of occurrence of DR4 in these patients with RA did not differ significantly from that in controls in the United Kingdom (42 v 37%). HLA-DR1 was increased in the group with inflammatory polyarthritis (25 v 18%). CONCLUSIONS--The frequency of DR4 is not increased in newly diagnosed community based patients with RA. This supports the hypothesis that DR4 is less important as a marker for susceptibility to RA than it is for disease persistence or severity. 相似文献
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Studies of proteins that inhibit tissue factor activity have generally been conducted using either an extracted tissue homogenate ("thromboplastin") or tissue factor protein reconstituted into phospholipid vesicles rather than with tissue factor expressed in cell membranes (its physiological environment). In the present study, a human fibroblast cell strain was used to evaluate the effects of lipoprotein associated coagulation inhibitor (LACI), placental anticoagulant protein (PAP), and apolipoprotein A-II (apo A-II) on human tissue factor in cell membranes. LACI was tested from 7.8 to 500 pmol/L on fibroblasts cultured at cell densities ranging from 3,500 to 9,925 cells/well, and caused a progressive inhibition of tissue factor activity. PAP was tested from 3.9 nmol/L to 1 mumol/L at cell densities ranging from 4,500 to 15,400 cells/well and caused up to 83% inhibition of tissue factor activity. Inhibition by these proteins appeared to be influenced by cell density as well as whether the cells were intact or disrupted. Apo A-II, up to 1 mumol/L, did not inhibit the tissue factor activity of intact or disrupted fibroblasts at any cell density examined even though it did inhibit the activity of tissue factor in phospholipid vesicles. Of these inhibitors of tissue factor-dependent activation of factor X, LACI was the most effective in suppressing the generation of factor Xa activity. The effects obtained with apo A-II are clearly dependent on the nature of the tissue factor preparation with which it is tested. The disparity between the inhibitory effect of apo A-II on the activity of tissue factor reconstituted into lipid vesicles and the absence of effect on the activity of tissue factor remaining in cell membranes serves to reemphasize the necessity of reexamining results obtained with model systems using as nearly physiological reagents as possible. 相似文献
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HLA/Bf haplotypes were examined in a large three-generation Newfoundland family with a high incidence of Graves' disease. In that family Graves' disease was inherited in association with the haplotype HLA Aw24, Bw39 in some instances and with HLA B8-containing haplotypes in other instances. As all seven members of the family who suffered from Graves' disease were homozygous for the Bf S allele, the study for Bf was uninformative. However, the examination of other HLA/Bf haplotypes disclosed some interesting associations. One-hundred-and-five out of 168 HLA-A, -B, -Bf haplotypes were Bf S. Although numerically deviant, no unusual HLA B/Bf associations were observed. Bf F entered the family only once. A new finding is the association between HLA B27 and Bf S1; the haplotype entered the family once and was passed on to eight family members over three generations. Bf S1 was previously reported in association with HLA B12 or W21. None of these family members had ankylosing spondylitis. The Bf allele F1 entered the family three times, always in association with HLA B18. 相似文献
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Comparison of Real-Time, Quantitative PCR with Molecular Beacons to Nested PCR and Culture Methods for Detection of Mycobacterium avium subsp. paratuberculosis in Bovine Fecal Samples
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Ying Fang Wai-Hong Wu Jessica L. Pepper Jill L. Larsen Salvatore A. E. Marras Eric. A. Nelson William B. Epperson Jane Christopher-Hennings 《Journal of clinical microbiology》2002,40(1):287-291
An automated PCR with fluorescent probes (molecular beacons) detected Mycobacterium avium subsp. paratuberculosis in bovine feces. When the PCR was compared with culture in testing 41 fecal samples, kappa scores of 0.94 to 0.96, a sensitivity of 93 to 96%, and a specificity of 92% were obtained. Results were quantitated by using a standard curve derived from a plasmid containing IS900. A minimum quantity of 1.7 x 10(-4) pg of DNA, correlating to 1 to 8 CFU, was detected. 相似文献