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排序方式: 共有931条查询结果,搜索用时 23 毫秒
1.
M Centola K Lin C Sutton JR Berenson LA Kunkel L Rosen BH Hahn RR Robinson 《Canadian Metallurgical Quarterly》1996,20(5-6):465-469
We have assessed the specificity of antibodies from the leukemic B cells of five patients with both chronic lymphocytic leukemia and autoimmune hemolytic anemia (CLL-AHA). Leukemic cells from one patient displayed surface immunoglobulin with heavy and light chain isotypes identical to that of the patient's anti-red blood cell (RBC) antibodies, and the leukemic cells secreted antibodies in vitro with anti-RBC activity. However, in the remaining patients, the leukemic cells displayed surface immunoglobulin with light chain isotypes different from that of the patient's anti-RBC antibodies and secreted antibodies in vitro with no detectable anti-RBC activity. Thus, there are two distinct classes of CLL-AHA patients, differentiated by the presence or absence of an anti-RBC antibody-producing leukemic B cell clone. The apparent heterogeneity in the source of pathogenic anti-RBC antibodies may impact the treatment response of the two classes of CLL-AHA patients. 相似文献
2.
Electrochemical analyses on the biocompatible alloys Ti-50Zr and Ti-13Nb-13Zr, as-cast and heat-treated, in distinct electrolytes (simulating or not physiological media: pH 7, Ringer, PBS, phosphate buffer and Na2SO4 solutions; pH 1, H2SO4, HNO3, CH3SO3H, HClO4 and H3PO4 solutions) are reported. Analyses of the open-circuit potential values indicated that either as-cast or heat-treated samples of both alloys present the same tendency to spontaneously form an oxide film on their surfaces and that the oxide grown in the Na2SO4 solution presents better protection characteristics than those formed in the phosphate buffer, Ringer and PBS solutions, in this order. Cyclic voltammograms obtained in the Ringer and PBS solutions showed that the Ti-13Nb-13Zr alloy does not transpassivate up to potentials of 8 V (versus SCE), while the Ti-50Zr alloy presents corrosion at potentials lower than 2 V (versus SCE), indicating that this alloy is less resistant to corrosion in solutions simulating physiological conditions. The obtained pit potential values showed that the heat treatment has very little influence on the corrosion behavior of the alloys. Finally, both alloys did not present transpassivation at potentials up to 8 V (versus SCE) in the H2SO4, HNO3, CH3SO3H and H3PO4 solutions; however, when immersed in the HClO4 solution the Ti-50Zr alloy underwent pit corrosion while the Ti-13Nb-13Zr alloy remained corrosion resistant in this potential range. 相似文献
3.
The present work investigated the photodegradation of real textile effluents by advanced oxidative process (AOP) using TiO2/H2O2/sunlight system. The procedures were carried out at ambient conditions in March 2005. The results were evaluated by COD reduction concomitant to the increase in inorganic ion concentration (mineralization) and the analysis of the effluent characteristic spectral wavelengths: 228, 254, and 284 nm (simple aromatic compounds), 310 nm (conjugated aromatic compounds), and 390, 450, and 530 (color). As this study is not restricted to the decolorization process, it allows a more reliable evaluation of effluent mineralization. The results indicate that solar radiation is as efficient as or even more efficient than artificial radiation was in previous studies and that it also allows a reduction in effluent treatment operational costs. 相似文献
4.
PLUREL是一个探讨城市边缘区土地利用战略与可持续影响评估工具的综合项目,选取7个案例以探索城市土地之间利用的关系.自从二战以后,城市化是土地用途变化最为显著的过程.不同空间模式、文化、规划政策和迥异的城市化或城市衰退的驱动力等因素导致城乡之间出现土地利用联系和功能关联.研究阐述了城市扩张的后果及正面影响,并从7个方面提出了城市边缘区的土地利用战略及可持续影响评估工具:交通、土地利用和露天空间规划之间的更好协同作用,优良治理和政策集成方法,通过保护和密实化实现城市控制,发展拥有美丽内城区的紧凑型花园城市,确保生物多样性、创建促进健康的交通系统,保护和开发蓝色和绿色基础设施,促进本地生产和短循环和生态服务系统.以期通过已有的城市发展和城乡关系建设知识和经验,努力向发展中国家提供支持. 相似文献
5.
6.
Lamoussa J. Kere Sousso Kelouwani Kodjo Agbossou Yves Dubé Nilson Henao Raymond Courteau 《International Journal of Hydrogen Energy》2014
This paper investigates a hydrogen-based genset maximum efficiency tracking problem in the context of electric vehicle range extension. This genset is cheaper than fuel cells and has the desirable property of being greenhouse gas emission free in addition to being less pollutant than the conventional gasoline based gensets. Using Taylor's series, a parametric efficiency model is built iteratively. This model is used by a nonlinear optimization method which searches for the optimal operating conditions for a maximum achievable efficiency. The root-mean-square-error between experimental data and the model is less than 5 × 10−4. The hardware-in-the-loop simulation demonstrated that the proposed tracking approach is effective. In addition, it can improve the hydrogen-based genset efficiency up to 7.15% compared to the commonly used industrial method based on a constant speed drive approach. 相似文献
7.
Reversal of pretreatment hypotension and control of hemorrhage in trauma patients by a simple device
JM Civetta ST Nussenfeld EL Nagel BH Kaplan TR Rowe F Pettijohn 《Canadian Metallurgical Quarterly》1977,43(1):20-29
The injection of a suspension of Walker 256 carcinoma cells into the carotid artery of rats produced a model of hematogenously spread cerebral metastases. Most animals died from massive extracerebral tumors of the head and jaw; brain tumors were present in only one-quarter. External carotid artery ligation prior to tumor inoculation did not increase the incidence of fatal brain tumor. When cyclophosphamide, 15 mg/kg, was injected as a single dose on the fourteenth day after tumor inoculation, most of the extracerebral tumor disappeared. Fifty percent of the animals so treated were cured of tumor, but 90% of the remainder died of large intracerebral tumors. Severe cytopathic changes resulting from cyclophosphamide were present in extracerebral or choroid plexus tumors but were mild or nonexistent in intracerebral tumors. These selective effects of cyclophosphamide suggest that water-soluble agents are less effective against tumor in the brain than against extracerebral tumors despite the fact that metastatic tumor breaks down the blood-brain barrier. 相似文献
8.
LS Wafelman BH Pollock J Kreutzer DS Richards AA Hutchison 《Canadian Metallurgical Quarterly》1999,75(2):73-81
Prognostic factors for survival of 62 fetuses and neonates with nonimmune hydrops fetalis (NIHF) were studied retrospectively. Twenty-eight infants survived >/=28 days which is 45% for all fetuses and newborns diagnosed with NIHF and 61% for liveborns with unresolved NIHF. Univariate analysis identified that mortality was associated with the presence of >/=2 serous cavity effusions and a need for chest compressions at birth. Multivariate logistic regression analysis confirmed that the presence of >/=2 serous cavity effusions was significantly associated with mortality from NIHF <28 days after birth [OR = 48.2 (CI 3.6, 662.9) (p < 0.004)]. We conclude that, compared to published cases from the 1970s and early 1980s, survival of liveborns with NIHF seems improved. The decrease in stillbirths is more notable. The severity of hydrops at birth is the key determinant for survival. 相似文献
9.
10.
JW Ely KS Berbaum GR Bergus BH Thompson BT Levy MA Graber ER Evans DA Bedell DS Fick 《Canadian Metallurgical Quarterly》1996,43(3):242-248
Percutaneous cardiopulmonary assist devices (PCPS) have become available in interventional cardiology within recent years. These tools offer the opportunity of performing percutaneous transluminal coronary angioplasty (PTCA) in high-risk patients characterized by significant stenoses of several coronary arteries and a poor left ventricular function. It is unclear for which patients PCPS are necessary and which patients will profit by PTCA as compared to coronary artery bypass grafting (CABG). Therefore, the anticipated risk of CABG and of PTCA without assist devices was calculated according to risk scores and compared with our results of assisted PTCA. In addition the long-term survival rate was investigated. In 35 patients (mean 65.5 years of age, 12 females, 23 males), we performed PTCA concomitant with the use of cardiac assist devices. The indications for the use of a cardiac assist device were severely impaired LV function (EF 30% +/- 8.9%) in combination with significant coronary artery disease (2.7 +/- 0.3 vessels) and a significant supply area of the vessel to be dilated. In 6 patients, PCPS was started before coronary angioplasty because of hemodynamic instability. In 21 cases, PCPS was on a standby basis without being connected to the patient's circulation. In 8 patients, a left heart assist device, the 14F-Hemopump, was inserted percutaneously. The patients were analyzed using risk scores of angioplasty and of coronary bypass graft surgery. The calculated risk of hemodynamic compromise during PTCA according to the risk scores was more than 50%. The anticipated risk of a fatal outcome following CABG would have been 19.8%. PTCA was performed on an average of 2.0 coronary arteries per patient and was successful in 85%. We observed a decline in angina pectoris classification (CCS) from 3.5 to 1.6. An average reduction of 1.1 NYHA class was achieved. The in-hospital mortality was 8.6% (3 patients: 1 x sepsis, 1 x early reocclusion, 1 x cerebral embolism). At 24 months follow-up, a re-PTCA was necessary in four cases because of restenosis. In the remainder, NYHA and CCS class were stable during the follow-up period. An additional five patients died during the first year and two patients in the second year. We conclude that PTCA with the use of a cardiac assist device shows favorable short-term results in a subset of patients with extended coronary artery disease and severely impaired LV function who are not suitable for nonsupported PTCA or CABG due to their risk profile. However, the long term results are not satisfying and stress the need for complete revascularisation with CABG once the patient's condition is stabilized by means of supported PTCA. 相似文献