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61.
We encountered a case of a girl where Human Parvovirus B19 infection was considered to have been concerned with the development of systemic type juvenile rheumatoid arthritis (JRA). While the affected child did not show any evident infectious erythema-like findings, changes in the serum antibody titer by the EIA method presented the pattern of first infection. During the clinical course the condition of the disease as JRA was serious and hemophagocytic syndrome developed concurrently. Furthermore, the resistance to the treatment was also noted. So the patient was treated with prednisolone combined with low dose weekly MTX therapy. The possibility of Human parvovirus B19 being concerned with the development of rheumatoid arthritis in one form or another has been suggested in recent years. In the disease type with systemic angititis as main pathophysiology, which is called systemic JRA we encountered this time, it is not clear how Human Parvovirus B19 was concerned with the development of this disease, but it appeared to hold a key position in studying pathophysiology of the development. 相似文献
62.
While continuous fiber, unidirectional composites are primarily evaluated for their longitudinal properties, the behavior
transverse to the fibers often limits their application. In this study, the tensile and creep behaviors of SCS-6/Ti-6Al-4V
composites in the transverse direction at 482 °C were evaluated. Creep tests were performed in air and argon environments
over the stress range of 103 to 276 MPa. The composite was less creep resistant than the matrix when tested at stress values
larger than 150 MPa. Below 150 MPa, the composite was more creep resistant than the unreinforced matrix. Failure of the composite
occurred by the ductile propagation of cracks emanating from separated fiber interfaces. The environment in which the test
was performed affected the creep behavior. At 103 MPa, the creep rate in argon was 4 times slower than the creep rate in air.
The SCS-6 silicon-carbide fiber’s graphite coating oxidized in the air environment and encouraged the separation of the fiber-matrix
interface. However, at higher stress levels, the difference in behavior between air- and argon-tested specimens was small.
At these stresses, separation of the interface occurred during the initial loading of the composite and the subsequent degradation
of the interface did not affect the creep behavior. Finally, the enrichment of the composite’s surface by molybdenum during
fabrication resulted in an alloyed surface layer that failed in a brittle fashion during specimen elongation. Although this
embrittled layer did not appear to degrade the properties of the composite, the existence of a similar layer on a composite
with a more brittle matrix might be very detrimental. 相似文献
63.
Phase Equilibria of the System SrO-CaO-CuO 总被引:2,自引:0,他引:2
65.
E Laubach MM Ritter C Giunta HC Geiss E Hiller A Superti-Furga P Schwandt B Steinmann 《Canadian Metallurgical Quarterly》1997,38(12):1225-1230
To establish the medium-term results of our transplant population, we retrospectively reviewed the charts of 51 consecutive patients who underwent orthotopic heart transplantation between July 1988 and April 1995. These patients comprised two groups: group A consists of 26 patients (age 6 days to 16.4 years, median 1.4 years) with no previous heart surgery, and group B consists of 25 patients (ages 0.1 to 14.3 years, median 8.3 years), all of whom had heart surgery before undergoing transplantation. There was no difference between these groups in early or late survival rates, and neither age at transplantation nor sex was an indicator of survival. There have been 14 deaths, six early (before hospital discharge) and eight late. Early deaths have predominantly been attributed to long-term ventilation and hemodynamic instability before transplantation, and late deaths to graft coronary artery disease (n = 4), acute coronary vasculitis (n = 3), and acute cellular rejection (n = 1). Although infection has resulted in significant morbidity (57 hospital admissions), there have been no late deaths resulting from infection. Sepsis accounts for four early deaths in chronically ill patients. Orthotopic heart transplantation in the pediatric patient with and without previous heart surgery is a viable option for those with end-stage heart disease and those in whom other surgical options carry a prohibitively high mortality rate. 相似文献
66.
How do people know whether they have an answer to a question before they actually find it in their memory? Two experiments explored this question. Ss were trained on relatively novel 2-digit?×?2-digit arithmetic problems (e.g., 23?×?27). Before answering each problem, Ss made a quick feeling of knowing judgment as to whether they could directly retrieve the answer from memory or had to compute it. Knowing the answer initially appeared to be linearly related to having a feeling of knowing the answer; however, when the frequency of exposure to complete problems and the frequency of exposure to parts of the problems were separately varied, feeling of knowing was better predicted by the frequency of presentation of the problem parts, not by knowledge of the answer. This suggests that the processes involved in knowing the answer are different from those involved in having a feeling of knowing. Specifically, an early feeling of knowing is not just based on an early read of the answer. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
67.
68.
We propose a new algorithm for vector quantization, the Activity Equalization Vector quantization (AEV). It is based on the winner takes all rule with an additional supervision of the average node activities over a training interval and a subsequent re-positioning of those nodes with low average activities. The re-positioning is aimed to both an exploration of the data space and a better approximation of already discovered data clusters by an equalization of the node activities. We introduce a learning scheme for AEV which requires as previous knowledge about the data only their bounding box. Using an example of Martinetz et al. [1], AEV is compared with the Neural Gas, Frequency Sensitive Competitive Learning (FSCL) and other standard algorithms. It turns out to converge much faster and requires less computational effort. 相似文献
69.
KarlRitter StefanWiebach 《材料热处理学报》2004,25(5):607-611
IN the past five years the process combination of vacuum hardening, respectively vacuum carburizing with high-pressure gas quenching was successfully introduced to the market, especially in the manufacture of gears. In the meantime furnace concepts for various applications are available to the industry. In the following report three plant varieties are introduced, which differ in process flexibility and throughput. This report also explains criteria for the selection of a furnace in view of the existing application requirements. Besides this a short introduction is given into the vacuum carburizing process and the high-pressure gas quenching technology. 相似文献
70.