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排序方式: 共有2465条查询结果,搜索用时 31 毫秒
61.
Yingjie Zhang Tao Wei Alan Xu Pranesh Dayal Daniel J. Gregg 《Journal of the American Ceramic Society》2021,104(11):5981-5989
As potential waste forms for immobilizing actinide-rich radioactive wastes, Eu2Ti2O7 (Eu as a surrogate for minor actinides) pyrochlore glass-ceramics were fabricated via hot isostatic pressing (HIPing) at 1200°C. The structure and microstructure at the reaction interface between the glass-ceramic waste form and the stainless steel (SS) canister under HIPing conditions were carefully investigated with scanning electron microscopy (SEM), transmission electron microscopy (TEM), and synchrotron single crystal X-ray diffraction (SC-XRD). The interactions at the reaction interface led to the formations of a ~10-µm-thick Cr2O3 layer as the oxidation front of the SS and a layer of a mixed oxide phase (Eu1.25SiCr0.8Ti1.2O7.5) on the glass-ceramic side of the reaction interface. The crystal structure of such a unique mixed oxide phase was revealed indubitably with a combination of synchrotron SC-XRD and TEM assisted with a focused ion beam (FIB) SEM system. The improved structural understanding of the reaction interface will help to support the utilization of HIPing as a versatile hot consolidation process for the treatment of radioactive wastes. 相似文献
62.
Gregg Keizer 《软件世界》2009,(9):12-12
面对IE竞争对手的抱怨和欧盟的反垄断诉讼,微软在IE8的进一步妥协确实出于无奈。微软已经不能为所欲为。 相似文献
63.
Single channel currents were activated by GABA (0.5 to 5 microM) in cell-attached and inside-out patches from cells in the dentate gyrus of rat hippocampal slices. The currents reversed at the chloride equilibrium potential and were blocked by bicuculline (100 microM). Several different kinds of channel were seen: high conductance and low conductance, rectifying and "nonrectifying." Channels had multiple conductance states. The open probability (Po) of channels was greater at depolarized than at hyperpolarized potentials and the relationship between Po and potential could be fitted with a Boltzmann equation with equivalent valency (z) of 1. The combination of outward rectification and potential-dependent open probability gave very little chloride current at hyperpolarized potentials but steeply increasing current with depolarization, useful properties for a tonic inhibitory mechanism. 相似文献
64.
DV Beard PL Molina KE Muller KM Denelsbeck BM Hemminger JR Perry MP Braeuning DH Glueck WD Bidgood M Mauro 《Canadian Metallurgical Quarterly》1995,197(3):753-758
PURPOSE: Interpretation time of serial staging chest CT cases, which each contained current and previous examinations, with a simple prototype workstation called filmstack was experimentally compared with interpretation time with a film alternator. MATERIALS AND METHODS: The filmstack displayed a "stack" of sections for each examination; user controls allowed rapid selection of preset attenuation windows and both synchronized and unsynchronized scrolling. Eight radiologists were timed as they used the filmstack and the film alternator to interpret four ergonomically complex serial CT cases. RESULTS: All reports dictated on the basis of findings with filmstack and film were of acceptable clinical accuracy. The time to examine a case with filmstack was significantly faster than the time with film, including the time to load and unload the alternator (99% confidence [P = .01]). There was no statistically significant difference in interpretation time between filmstack and prehung film. CONCLUSION: Use of a low-cost stacked CT workstation with a single 1,024 x 1,024 monitor is an effective means of interpreting cases that require comparison of multiple CT examinations. 相似文献
65.
66.
A detailed RFLP map was used to determine the chromosomal locations and subgenomic distributions of cotton (Gossypium) genes/QTLs that confer resistance to the bacterial blight pathogen, Xanthomonas campestris pv. malvacearum (Xcm). Genetic mapping generally corroborated classic predictions regarding the number and dosage effects of genes conferring Xcm resistance. One recessive allele (b6) was a noteworthy exception to the genetic dominance of most plant resistance alleles. This recessive allele appeared to uncover additional QTLs from both resistant and ostensibly susceptible genotypes, some of which corresponded in location to resistance (R)-genes effective against other Xcm races. One putatively "defeated" resistance allele (B3) reduced severity of Xcm damage by "virulent" races. Among the six resistance genes derived from tetraploid cottons, five (83%) mapped to D-subgenome chromosomes-if each subgenome were equally likely to evolve new R-gene alleles, this level of bias would occur in only about 1.6% of cases. Possible explanations of this bias include biogeographic factors, differences in evolutionary rates between subgenomes, gene conversion or other intergenomic exchanges that escaped detection by genetic mapping, or other factors. A significant D-subgenome bias of Xcm resistance genes may suggest that polyploid formation has offered novel avenues for phenotypic response to selection. 相似文献
67.
TL Gregg 《Canadian Metallurgical Quarterly》1998,21(2):42-54; quiz 87-9
Many children every year will be treated in "adult" critical care units because of the limited pediatric trauma centers currently available. Assessment is an integral part of all pain management. Ideally, self-report is the gold standard for assessing pain; however, some children may not have the ability to use these tools. Nonverbal children may be assessed with behavioral tools such as the CHEOPS or FLACC. In children as young as 3 years old, the self-report tool called an OUCHER can be administered to assess their pain. Easy to apply nonpharmacological approaches are discussed with recommendations for nurses to incorporate into their daily care. 相似文献
68.
Superantigens stimulate T-lymphocyte proliferation and cytokine production, but the effects of superantigen exposure on cell function within a complex, highly regulated immune response remain to be determined. In this study, we demonstrate that superantigen exposure significantly alters the murine host response to bacterial antigens in an in vitro coculture system. Two days after exposure to the superantigen staphylococcal enterotoxin B, splenocytes cultured with Streptococcus mutans produced significantly greater amounts of gamma interferon (IFN-gamma) and interleukin-12 than did sham-injected controls. The majority of IFN-gamma production appeared to be CD8(+) T-cell derived since depletion of this cell type dramatically reduced the levels of IFN-gamma. To study host cell damage that may occur following superantigen exposure, we analyzed cytotoxicity to "bystander" fibroblast cells cultured with splenocytes in the presence of bacterial antigens. Prior host exposure to staphylococcal enterotoxin B significantly enhanced fibroblast cytotoxicity in the presence of bacteria. Neutralization of IFN-gamma decreased the amount of cytotoxicity observed. However, a greater reduction was evident when splenocyte-bacterium cocultures were separated from the bystander cell monolayer via a permeable membrane support. Increased cytotoxicity appears to be primarily dependent upon cell-cell contact. Collectively, these data indicate that overproduction of inflammatory cytokines may alter the activity of cytotoxic immune cells. Superantigen exposure exacerbates cytokine production and lytic cell activity when immune cells encounter bacteria in vitro and comparable activities could possibly occur in vivo. 相似文献
69.
S Verghese A Mullasari P Padmaja P Sudha MC Sapna KM Cherian 《Canadian Metallurgical Quarterly》1998,50(4):418-422
This study examines the long-term prognosis of patients with an abnormal exercise radionuclide angiogram in the absence of significant angiographic coronary artery disease (CAD). In general, patients without significant CAD have an excellent prognosis, but the long-term outcome for the subset of patients with an "ischemic" exercise test is not known. In this study, 161 patients with normal coronary arteries or insignificant CAD (< 50% left main and < 70% left anterior descending, left circumflex, or right), resting left ventricular (LV) ejection fraction > or = 0.50, and an abnormal exercise radionuclide angiogram (LV ejection fraction that decreased with exercise or peak exercise LV ejection fraction < 0.60) were followed for a median duration of 11.3 years. The mean delta LV ejection fraction was -0.07, 98 patients (61%) had a decrease in LV ejection fraction of > or = 5 units, and 40 patients (25%) had peak exercise LV ejection fraction < 0.50. During follow-up there were 19 deaths (only 1 of which was cardiac), 7 nonfatal myocardial infarctions, and 9 revascularization procedures. At 12 years, overall survival was 88%, better than the expected survival for the age- and sex-matched general population. Survival free of cardiac death or myocardial infarction was 94% and survival free of any cardiac event including revascularization was 88%. Thus, patients with an abnormal exercise radionuclide angiogram but without significant CAD have an excellent long-term prognosis. 相似文献
70.
Analysis of Bence Jones proteinuria by high resolution two-dimensional electrophoresis (2-DE) and immunoblotting reveals a complex pattern of light chain (LC) isoforms corresponding to the free monoclonal Bence Jones protein and its fragments. Replica blotting gives duplicate blots for LC typing (lambda, chi) and, under the conditions employed, leaves sufficient protein for Coomassie Blue staining of the urinary protein profile and pIIMr determination of the LC isoforms. Carrier ampholytes (CAs, in our "simplified" 2-DE system) and immobilised pH gradients (IPGs, in the Multiphor 2-DE system) give similar LC isoform patterns. Artifacts, including cone-like distortions and trailing "piggyback" spots, are visualised with both 2-DE systems. IPGs are advantageous as they allow reproducible detection of strongly basic LC isoforms by isoelectric focusing (under equilibrium conditions) without recourse to CA nonequilibrium pH gradient electrophoresis. 相似文献