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排序方式: 共有596条查询结果,搜索用时 15 毫秒
81.
82.
MA Aboulghar RT Mansour GI Serour YM Amin A Kamal 《Canadian Metallurgical Quarterly》1996,66(5):753-756
We report a case of aortitis syndrome, in which carotid ultrasonography was a useful approach for the diagnosis. A 21-year-old woman was admitted to our hospital for persistent fever. No specific physical findings or laboratory abnormalities were observed except high fever and marked increase of erythrocyte sedimentation rate and c reactive protein. Since clinical trial of antibiotics and antituberculosis agents resulted in no effectiveness, prednisolone was started, but the effect was limited. After that, she complained of the neck pain, and vascular murmur became apparently audible at the pain site. Ultrasonography of the carotid artery revealed the smooth lumen and homogeneous, non-hyperechoic intimal thickening. Then aortography confirmed the diagnosis of aortitis syndrome. Cyclophosphamide combined with steroid therapy diminished the disease activity. In this case, carotid ultrasonography gave us the important information to enforce the aortography. If ultrasonography of the carotid artery has been popularized for aortitis syndrome, and its findings have been standardized, non-invasive diagnosis of this disease will be taken a step forward. 相似文献
83.
We suggest that toroidal structures in the state of psi-condensation of DNA may be caused by anisotropy on a meso-scale of several thousand A, the conformation of a DNA-molecule being determined by its elasticity and neutralization of phosphate charge. We model a molecule of B-DNA on an anisotropic elastic rod subject to a torque, and make the numerical simulation of the model that reveals that under appropriate conditions, which may be effected in experimental setting by changing the concentration of polymeric solutions, there are toroidal structures having the size of a few persistence lengths, in agreement with the experimental data. On changing the elastic modulii or characteristics of the counterion layer, we see the toroidal structures turn into the spherical ones. To understand the function of anisotropy it would be interesting to investigate the Z-DNA as regards psi-condensation. 相似文献
84.
85.
A rectangular channel electrophoresis system and a cylindrical sampling capillary combination allows chemical changes in nanoliter-volume samples to be monitored as a function of time. The electrophoretic microseparation is carried out in a rectangular channel with a 7 -cm-long, 40-microm x 2.5-cm geometry and is coupled to a 50-microm-i.d. cylindrical sample introduction capillary. The channel width dimension is used as a time axis by moving the outlet of the sampling capillary across the entrance of the separation channel. Detection of the separated analyte bands is achieved with laser-induced fluorescence and spatially resolved detection based on a charge-coupled device. The system is characterized with a series of fluorescein thiocarbamyl amino acid derivatives; limits of detection are < 10(-8) M for amino acids and 10(-9)M (425 zmol) for fluorescein. The ability to achieve a time-based dynamic microseparation is demonstrated by monitoring fluorescent product formation during the enzyme-catalyzed hydrolysis of fluorescein di-beta-D-galactopyranoside (FDG), a commonly used fluorescent substrate for enzymological studies. 相似文献
86.
Leukocyte transfusion-associated granulocyte responses in a patient with X-linked hyper-IgM syndrome
TP Atkinson CA Smith YM Hsu E Garber L Su TH Howard JT Prchal MP Everson MD Cooper 《Canadian Metallurgical Quarterly》1998,18(6):430-439
X-linked hyper-IgM syndrome (XHIM) is a severe congenital immunodeficiency caused by mutations in CD154 (CD40 ligand, gp39), the T cell ligand for CD40 on B cells. Chronic or cyclic neutropenia is a frequent complicating feature that heightens susceptibility to severe infections. We describe a patient with a variant of XHIM who produced elevated levels of serum IgA as well as IgM and suffered from chronic severe neutropenia. Eight of ten leukocyte transfusions with cells from a maternal aunt, performed because of mucosal infections, resulted in similar episodes of endogenous granulocyte production. Transfection studies with the mutant CD154 protein indicate that the protein is expressed at the cell surface and forms an aberrant trimer that does not interact with CD40. The data suggest that allogeneic cells from the patient's aunt, probably activated T cells bearing functional CD154, may interact with CD40+ recipient cells to produce maturation of myeloid precursors in the bone marrow. 相似文献
87.
YM Ivanchenko 《Canadian Metallurgical Quarterly》1995,52(1):79-81
Trisomy 8 is a frequently acquired cytogenetic abnormality in myeloid malignancies, but may also represent a constitutional chromosome abnormality with a wide phenotypic variation. We report a case of myelodysplastic syndrome (MDS) that developed in a child with trisomy 8 mosaicism and normal phenotype. Bone marrow (BM) cells all showed trisomy 8 with additional clonal abnormalities in most cells. Based on the present case and a review of previously published cases of myeloid malignancies in patients with trisomy 8 mosaicism, it appears likely that the malignant cells developed from the trisomic cell population, suggesting that constitutional trisomy 8 may be a predisposing condition to myeloid malignancies. Trisomy 8 in malignant cells is usually considered an acquired abnormality, but this implies a risk of ignoring a constitutional trisomy 8 mosaicism. Examination for constitutional trisomy 8, despite a normal phenotype, may therefore be warranted in hematologic malignancies with trisomy 8 of BM cells to evaluate further the possible association and to preclude erroneous use of trisomy 8 as a tumor marker. 相似文献
88.
Three reported charateristics of sudden death in the wild rat, (1) bradycardia, (2) decreased survival without whiskers, and (3) increased suvival with preexposure to the stressor, are demonstrated in the domestic rat. Differences in sudden death between wild and domestic rats are discussed as well as possible interpretations of the phenomenon. 相似文献
89.
The aim of this study was to determine the impact of the broadening of fuel specifications on the performance of a gas turbine combustor, particularly on soot formation and oxidation, and flame tube durability. Tests were conducted with a fully-developed combustor system, the main measurements comprising total radiation, exhaust smoke and temperatures at different locations. Five fuels were used: kerosine, as aviation fuel; gas oil, as the current industrial gas turbine fuel and possible future aviation fuel; R25 (where 25 is the volume percentage of residual fuel oil in the blend with gas oil), as equivalent to crude oil now in use in many utility gas turbines; and also R50 and R70 to represent future heavier fuels. Combustor pressures were 0.3, 0.7 and 1.0 MPa. Inlet air temperatures were 313, 390 and 460 K. Primary zone air/fuel mass ratios were 12, 15 and 25. Total air/fuel ratios were 60 and 120. Attempts were made to develop a mathematical model of the soot formation-oxidation processes that occur in the system, and to include in the model some parameters to represent the change in fuel properties. In this paper, comparison of the soot formation predictions of the model with the experimental data is seen to be favourable, particularly at full power conditions. 相似文献
90.
To estimate energy expenditure (EE) in elderly subjects, more age-specific data are required on energy costs of standardized activities. EE was assessed by using indirect calorimetry in 28 women aged 72 +/- 4 y (mean +/- SD) and in 29 middle-aged women (42 +/- 1 y) at rest (resting metabolic rate; RMR) and during sitting, sitting with standardized arm activity, and walking on a treadmill at 3 km/h. RMR and EE during sitting, and sitting with standardized arm activity did not differ significantly between the groups, although EE expressed as a ratio of arm activity to RMR (physical activity ratio, PAR) tended to be higher in the elderly subjects. Walking EE was significantly higher in the elderly women (16.4 +/- 4.0 kJ/min) than in the middle-aged women (12.7 +/- 2.3 kJ/min), also when expressed as PAR. It is suggested that elderly women walk less efficiently. Because PARs are frequently used to estimate daily EE, it is important to note that additional age-specific data might be required. 相似文献