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排序方式: 共有862条查询结果,搜索用时 46 毫秒
51.
RB Cain P Fortnagel S Hebenbrock GW Kirby HJ McLenaghan GV Rao S Schmidt 《Canadian Metallurgical Quarterly》1997,238(1):197-201
Vitamin E is one of the most important lipid-soluble antioxidant nutrients. Severe vitamin E deficiency can have a profound effect on the central nervous system. Cystic fibrosis, chronic cholestatic liver disease, abetalipoproteinemia, short bowel syndrome, isolated vitamin E deficiency syndrome and other malabsorption syndromes all may cause varying degrees of neurologic deficits due to related vitamin deficiencies. The classic abnormalities in vitamin E deficiency progress from hyporeflexia, ataxia, limitations in upward gaze and strabismus to long-tract defects, profound muscle weakness and visual field constriction. Patients with severe, prolonged deficiency may develop complete blindness, dementia and cardiac arrhythmias. Treatment must be tailored to the underlying cause of vitamin E deficiency and may include oral or parenteral vitamin supplementation. The more advanced the deficits, the more limited the response to therapy. Therefore, a good neurologic examination and periodic serum vitamin E levels are essential in patients at risk of vitamin E deficiency. 相似文献
52.
OA Biloivan SV Dziadevich OP Soldatkin MF Starodub GV Iel''ska 《Canadian Metallurgical Quarterly》1997,69(2):14-18
ULTRA was established on the 1st April 1990, to consider applications made by registered medical practitioners seeking approval to transplant an organ between 2 living unrelated persons in the United Kingdom. 相似文献
53.
Kovacs Maria; Iyengar Satish; Goldston David; Obrosky D. Scott; Stewart James; Marsh Judith 《Canadian Metallurgical Quarterly》1990,58(2):189
Mothers of children with newly diagnosed insulin-dependent diabetes mellitus (IDDM) were assessed repeatedly over a period of 6 years in order to determine the psychological correlates of managing this chronic illness. Both maternal depression and overall emotional distress after the 1st year of the IDDM increased slightly with illness duration and were also influenced by other factors. Mothers' adjustment shortly after their children were diagnosed with IDDM was a strong predictor of their long-term emotional symptomatology. However, mothers' symptoms over time were not related to medical aspects of IDDM (i.e., the extent of the children's metabolic control, number of rehospitalizations, or their compliance with the medical regimen) and were also unrelated to the levels of depression or anxiety reported by their children. Mothers generally found it easier to cope with the IDDM the longer their children had the illness. However, the degree to which mothers perceived the IDDM to be bothersome or difficult to manage at any given point in time was associated with their overall levels of emotional distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
54.
Nutritional chemistry of chromium 总被引:1,自引:0,他引:1
G V Iyengar 《The Science of the total environment》1989,86(1-2):69-74
There has been considerable progress in understanding the role of chromium in human nutrition. However, the lack of data on the forms of chromium-absorption from foods by the gastro-intestinal tract, and our concomitant inability to obtain an accurate assessment of the daily mobile pool of metabolically active chromium in the human body continues to be an impediment in assessing the overall impact of chromium nutrition. Based on recent chromium data on human tissues and body fluids available in the literature, an assessment of chromium content in different body compartments as well as in the total body is presented. However, on the analytical side, a few problems still persist and, therefore, a reliable analysis for chromium is restricted to a few selected laboratories. 相似文献
55.
Systematic studies have been made of the grain growth and density of sintered ZnO-based systems containing one or more additive oxides of the type Nb2O5, Bi2O3, Sb2O3, CoO, Cr2O3, MnO2, NiO and Al2O3. These samples were characterized using such techniques as scanning electron microscopy, X-ray diffraction and electron probe microanalysis. The influence of the nature and amount of additive oxides and sintering temperature is discussed in relation to microstructure, density and the phases present. 相似文献
56.
57.
Experimental investigations have been carried out to study the dynamic damage growth in glass/polyester composites. Detonation of two PETN explosive charges on a modified single edge notch (MSEN) specimen provides the dynamic load in the form of a planar tensile wave. High speed photography is used to record the dynamic damage events. The results show that damage grows perpendicular to the loading direction, similar to the static growth; the damage zone splits analogous to the crack branching in unreinforced polyester. The damage propagation velocity in a composite is higher than the crack propagation velocity in polyester resin. The damage area grows at an average rate of 4.3 m2/sec. Static experiments show that about 4 percent of the total energy is spent on the fiber-matrix interface debonding. The damage zone under dynamic loads is much higher than under static loads. 相似文献
58.
59.
Current psychological theory and research affirm the positive affective and motivational consequences of having personal choice. These findings have led to the popular notion that the more choice, the better—that the human ability to manage, and the human desire for, choice is unlimited. Findings from 3 experimental studies starkly challenge this implicit assumption that having more choices is necessarily more intrinsically motivating than having fewer. These experiments, which were conducted in both field and laboratory settings, show that people are more likely to purchase gourmet jams or chocolates or to undertake optional class essay assignments when offered a limited array of 6 choices rather than a more extensive array of 24 or 30 choices. Moreover, participants actually reported greater subsequent satisfaction with their selections and wrote better essays when their original set of options had been limited. Implications for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
60.
Kalayil Manian Manesh Anantha Iyengar GopalanShanmugasundaram Komathi 《Catalysis communications》2010,11(10):913-918
A novel organic–inorganic hybrid nanocatalyst, Ag nanoparticles supported poly[N-(3-Trimethoxy silyl)propyl]aniline (Ag@PTMSPA), was prepared by a simple one-step method. X-ray diffraction analysis, field emission transmission electron microscopy and X-ray photo electron spectroscopy reveal the coexistence of Ag nanoparticles (average size ∼ 10 nm) and PTMSPA in Ag@PTMSPA. N2 adsorption–desorption experiments provide the textural properties of the catalyst, such as surface area (86.6 m2/g), pore volume (1.3 × 10− 1 cm3/g) and pore size (4.2 nm). UV–visible spectroscopy was used to follow the kinetics of reduction of 4-nitrophenol (4-NP) by sodium borohydride (NaBH4) in the presence of Ag@PTMSPA catalyst. 相似文献