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991.
992.
Jidong Kang David S. Wilkinson Mike Bruhis Mukesh Jain Pei Dong Wu J. David Embury Raja K. Mishra Anil K. Sachdev 《Journal of Materials Engineering and Performance》2008,17(3):395-401
In this article, we study the Portevin-Le Chatelier (PLC) bands and their influences on strain localization and fracture in
continuous cast (CC) AA5754 aluminum sheets. Three types of tensile tests are conducted: (1) tensile samples are pulled directly
to fracture at 223 K, (2) tensile samples are pulled at 223 K to initiate diffuse necking followed by unloading and reloading
to fracture at room temperature, and (3) tensile samples are pulled at 223 K to localized necking and unloaded followed by
reloading to fracture at room temperature. Furthermore, in situ V-bending test coupled with deformation mapping using digital
image correlation is used to study damage at large strains. The results show that PLC bands detect favorable geometrical sites
for shear band initiation. The formation of shear bands precedes damage and damage is a consequence of shear band formation.
This article was presented at Materials Science & Technology 2007, Automotive and Ground Vehicles symposium held September
16-20, 2007, in Detroit, MI. 相似文献
993.
myo-Inositol monophosphatase (IMP) is a soluble, Li(+)-sensitive protein that catalyzes the removal of a phosphate from myo-inositol phosphate substrates. IMP is required for de novo inositol synthesis from glucose 6-phosphate and for breakdown of inositol trisphosphate, a second messenger generated by the phosphatidylinositol signaling pathway. We cloned the IMP gene from tomato (LeIMP) and show that the plant enzyme is encoded by a small gene family. Three different LeIMP cDNAs encode distinct but highly conserved IMP enzymes that are catalytically active in vitro. Similar to the single IMP from animals, the activities of all three LeIMPs are inhibited by low concentrations of LiCl. LeIMP mRNA levels are developmentally regulated in seedlings and fruit and in response to light. Immunoblot analysis detected three proteins of distinct molecular masses (30, 29, and 28 kD) in tomato; these correspond to the predicted molecular masses of the LeIMPs encoded by the genes. Immunoreactive proteins in the same size range are also present in several other plants. Immunolocalization studies indicated that many cell types within seedlings accumulate LeIMP proteins. In particular, cells associated with the vasculature express high levels of LeIMP protein; this may indicate a coordinate regulation between phloem transport and synthesis of inositol. The presence of three distinct enzymes in tomato most likely reflects the complexity of inositol utilization in higher plants. 相似文献
994.
995.
996.
Corpora amylacea have been reported in around 60% of hippocampal sclerosis specimens. The aim was to determine whether there are clinical and quantitative hippocampal MRI differences between hippocampal sclerosis with and without corpora amylacea. Corpora amylacea density was determined in 46 resected hippocampi of patients with temporal lobe epilepsy, using a three dimensional microscopical counting technique. Forty one hippocampi had hippocampal sclerosis. Twenty six of the 41 (63%) hippocampal sclerosis specimens contained corpora amylacea, which were found in highest numbers in the CA1 subregion of the hippocampus. Corpora amylacea density in the CA1 correlated inversely with the neuronal density in CA1. Hippocampal sclerosis with corpora amylacea had the same clinical and quantitative hippocampal MRI characteristics as hippocampal sclerosis without corpora amylacea, and did not affect seizure outcome after surgery adversely. In conclusion, formation of corpora amylacea seems to be a pathological response to neuronal cell loss in most hippocampal sclerosis specimens, with no clear clinical and quantitative hippocampal MRI correlates. 相似文献
997.
JS Montaner R Hogg J Raboud R Harrigan M O'Shaughnessy 《Canadian Metallurgical Quarterly》1998,352(9144):1919-1922
998.
Bound-morphine skills of school-age, language-impaired (LI) children were explored with three tasks designed to assess multiple dimensions of this component of language. Ten English-speaking, school-age LI children (Mean age: 10:3) and ten children with normal language (Mean age: 9:9) served as subjects. A two-way analysis of variance revealed significant group differences. Fisher a priori testing documented significant group differences for a measure of English bound-morpheme skill levels, a measure of ability to generalize English bound-morphemes to novel words, and a measure of ability to learn novel bound-morphemes attached to novel words. The findings indicate that core features of developmental language impairment in preschool children--poor ability to learn, to use, and to generalize bound-morphemes--are also present in school-age, LI children. 相似文献
999.
1000.
RT Osteen DP Winchester DH Hussey RE Clive MA Friedman B Cady JS Chmiel WG Kraybill MM Urist RL Doggett 《Canadian Metallurgical Quarterly》1994,1(6):462-467
BACKGROUND: Trends in the care of patients with cancer are monitored annually by the Commission on Cancer of the American College of Surgeons. In 1991 a patient care evaluation study of breast cancer was conducted, which among other questions examined the correlation of health insurance with type or quality of care delivered for breast cancer on a national basis. METHODS: The tumor registry system of the American College of Surgeons was used to obtain data on patients with breast cancer diagnosed in 1983 and 1990. Trends in diagnosis and treatment were correlated with the type of insurance or lack of insurance. RESULTS: Data were obtained from hospitals in 50 states on a total of 41,651 patients. The largest number of patients were covered by Medicare. Fewer than 5% were considered medically indigent. Medically indigent patients presented with higher stage disease and did not participate in a trend toward downstaging, which occurred between the two study years. The treatment of medically indigent patients appeared to be appropriate and comparable with better insured patients. Insurance type (health maintenance organization vs. private) did not affect stage, treatment, or outcome. Decisions to use controversial therapies, such as chemotherapy for stage I disease, did not appear to be financially driven. CONCLUSION: A nationwide pattern of care study for breast cancer indicates that medically indigent patients present with more advanced disease compared with better insured patients, but once the diagnosis is made, treatment and outcome have little to do with insurance type. 相似文献