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41.
42.
JL Wright LM Lawson PD Pare BJ Wiggs S Kennedy JC Hogg 《Canadian Metallurgical Quarterly》1983,127(4):474-477
To investigate the effect of smoking status on pulmonary function and pathologic changes in the peripheral airways, we studied 97 patients who underwent thoracotomy for coin lesions. The patients were divided into 4 groups: nonsmokers (n = 9), current smokers (n = 51), and those who had ceased smoking for less than (n = 18) or more than (n = 19) 2 yr prior to surgery. We found that current smokers had evidence of air-flow obstruction with abnormal lung volumes when compared with nonsmokers. Ex-smokers had lung volumes similar to those of nonsmokers, but showed evidence of obstruction, with the FEV1/FVC between the values found for nonsmokers and current smokers. Examination of the small airways showed that the membranous bronchioles of current smokers and ex-smokers displayed only increased goblet cell metaplasia when compared with those in nonsmokers; the respiratory bronchioles of current and ex-smokers showed increases in intraluminal and airway wall inflammatory cells, wall fibrosis, and pigment deposition. We conclude that patients who currently smoke cigarettes have reduced lung function that is associated with abnormalities of airway structure. Although those who have stopped smoking have function that is closer to the nonsmoking group, there is no apparent difference in structural change between current and ex-smokers. 相似文献
43.
The eutectic alloys Al-Al2Cu and Al-Al3Ni have been unidirectionally solidified at rates from 1.05 to 6.80 in, per min by a semicontinuous casting technique, and
then tested in tension at room temperature. In both alloys the flow stress and ultimate tensile strength increased with increasing
solidification rate, except for the highest solidification rate. The increases in matrix work-hardening rate with solidification
rate were too great to be accounted for by dislocation pileup mechanisms, but were found to correlate with elastic constraint
effects of the matrix aluminum phase by the reinforcing phases. In the Al-Al2Cu eutectic the strength of the Al2Cu platelets increased as the platelet width decreased with increasing growth rate. Misalignment of the composite caused by
either a cellular or a macroscopically concave solid-liquid interface resulted in a decrease in the ultimate strength, especially
in the rod-like Al-Al3Ni alloy. This has been related to the fracture behavior of the composites. The very low fracture toughness of the lamellar
Al-Al2Cu eutectic is consistent with models of composite materials, and seriously limits the alloy’s usefulness for engineering
applications. 相似文献
44.
45.
Young Bethany; Boccaccini Marcus T.; Conroy Mary Alice; Lawson Kristy 《Canadian Metallurgical Quarterly》2007,38(2):169
What unique assessment issues do evaluators face when conducting mental retardation evaluations in capital cases? This article describes 4 assessment issues and reports how 20 evaluators in 1 state have approached them: (a) What methods are appropriate for evaluating adaptive functioning in this context? (b) Should information about criminal behavior be used as evidence of adaptive functioning? (c) Should correctional officers serve as informants regarding adaptive behavior? and (d) How should the Flynn effect influence the interpretation of intelligence test scores? Implications for practice are that practitioners should expect to be asked about the relation between criminal behavior and adaptive functioning, must think carefully about the validity of tests of adaptive functioning for inmates, and must be knowledgeable about the current state of Flynn effect research. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
46.
M. I. Baskes S. Y. Hu S. M. Valone G. F. Wang A. C. Lawson 《Scientific Modeling and Simulation》2007,14(3):379-388
We employ molecular dynamics and Monte Carlo (MC) methods to simulate the rearrangement of Ga atoms from a randomly distributed Pu-Ga alloy and study the resultant effect on thermodynamic properties. The results show that all of the first neighbor Ga-Ga bonds are removed at all temperatures considered (200, 400 and 600 K) while the number of 2NN and 3NN bonds increase, and the number of 4NN bonds decreases. These results imply that Ga atoms develop strong short range ordering in the solid solution. The ordering causes an enthalpy decrease about ~3–4 meV/atom for different temperatures in the 5 at. % Ga alloy. This energy change is clearly important in the calculation of the Pu-Ga phase diagram. In addition, MC calculations at 200 K show pronounced Ga segregation. 相似文献
47.
A study was conducted to investigate the body movements of participants waiting to be interviewed in one of two conditions: preparing to answer questions truthfully or preparing to lie. The effects of increased self-awareness were also investigated, with half of the participants facing a mirror; the other half facing a blank wall. Analysis of covertly obtained video footage showed a significant interaction for the duration of hand/arm movements between deception level and self-awareness. Without a mirror, participants expecting to lie spent less time moving their hands than those expecting to tell the truth; the opposite was seen in the presence of a mirror. Participants expecting to lie also had higher levels of anxiety and thought that they were left waiting for less time than those expecting to tell the truth. These findings led to the identification of further research areas with the potential to support deception detection in security applications. 相似文献
48.
M. E. Dodd P. C. Hendry N. S. Lawson P. V. E. McClintock C. D. H. Williams 《Journal of Low Temperature Physics》1999,115(1-2):89-105
Zurek suggestedNature 317
, 505; 1985) that the Kibble mechanism, through which topological defects such as cosmic strings are believed to have been created in the early Universe, can also result in the formation of topological defects in liquid
4
He, i.e. quantised vortices, during rapid quenches through the superfluid transition. Preliminary experiments (Hendry et al., Nature 368
, 315; 1994) seemed to support this idea in that the quenches produced the predicted high vortex-densities. The present paper describes a new experiment incorporating a redesigned expansion cell that minimises vortex creation arising from conventional hydrodynamic flow. The post-quench line-densities of vorticity produced by the new cell are no more than 10
10
m
–2
, a value that is at least two orders of magnitude less than the theoretical prediction. We conclude that most of the vortices detected in the original experiment must have been created through conventional flow processes. 相似文献
49.
D Praticò L Iuliano A Mauriello L Spagnoli JA Lawson J Rokach J Maclouf F Violi GA FitzGerald 《Canadian Metallurgical Quarterly》1997,100(8):2028-2034
F2-Isoprostanes are prostaglandin (PG) isomers formed in situ in cell membranes by peroxidation of arachidonic acid. 8-epi PGF2alpha and IPF2alpha-I are F2-isoprostanes produced in humans which circulate in plasma and are excreted in urine. Measurement of F2-isoprostanes may offer a sensitive, specific, and noninvasive method for measuring oxidant stress in clinical settings where reactive oxygen species are putatively involved. We determined whether isoprostanes were present in human atherosclerotic lesions, where lipid peroxidation is thought to occur in vivo. 8-epi PGF2alpha ranged from 1.310-3.450 pmol/micromol phospholipid in atherectomy specimens compared with 0.045-0.115 pmol/micromol phospholipid (P < 0.001) in vascular tissue devoid of atherosclerosis. Corresponding values of IPF2alpha-I were 5.6-13.8 vs. 0.16-0.44 pmol/micromol phospholipid (P < 0.001). Levels of the two isoprostanes in vascular tissue were highly correlated (r = 0.80, P < 0.0001). Immunohistochemical studies confirmed that foam cells adjacent to the lipid necrotic core of the plaque were markedly positive for 8-epi PGF2alpha. These cells were also reactive with anti-CD68, an epitope specific for human monocyte/macrophages. 8-epi PGF2alpha immunoreactivity was also detected in cells positive for anti-alpha-smooth muscle actin antibody, which specifically recognizes vascular smooth muscle cells. Our results indicate that 8-epi PGF2alpha and IPF2alpha-I, two distinct F2-isoprostanes and markers of oxidative stress in vivo, are present in human atherosclerotic plaque. Quantitation of these chemically stable products of lipid peroxidation in target tissues, as well as in biological fluids, may aid in the rational development of antioxidant drugs in humans. 相似文献
50.
Since its creation in 1970, the College of American Pathologists Quality Assurance Service Committee has provided important and highly respected interlaboratory programs for daily quality control. In 1988, this committee extended its domain by announcing Q-Probes, a unique benchmarking program for laboratory quality assurance. Because of the success and rapid growth of this program during the next 2 years, the Quality Assurance Service Committee expanded into two committees, namely, QAS-QC and QAS-QA, with expertise concentrated, respectively, in quality control and quality assurance. These committees have compiled a history of significant scientific and educational contributions to members, the international laboratory community, other physicians, and patients. New directions for both committees are now underway so that their contributions can continue in the rapidly changing field of pathology and laboratory medicine. 相似文献