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Joseph L. Keddie Laura J. Norton Edward J. Kramer Emmanuel P. Giannelis 《Journal of the American Ceramic Society》1993,76(10):2534-2538
Neutron reflectometry (NR) was used to directly measure the interface width between a titanium dioxide and a silicon dioxide film deposited by sol-gel processing. In a bilayer heated to 450°C, NR measurements showed that the interface width is 0.8 nm. This width is the same as the roughness of a sol-gel silicon dioxide surface after the same heat treatment, suggesting no interdiffusion or mixing at the bilayer interface. 相似文献
63.
The lipids ofNeurospora crassa, isolated in pure form from freeze-dried mycelium, were found to contain squalene, sterol esters, triglycerides, free fatty
acids, geranylgeraniol, free sterols, carotenoids, cardiolipin, phosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl
serine, and phosphatidic acid. The above compounds were isolated in pure form by column and thin layer chromatography and
were characterized by infrared spectroscopy and chromatographic mobilities. Fatty acid moieties were characterized by gas
liquid chromatographic retention times of their methyl esters relative to those of authentic standards. The fatty acid composition
of the triglycerides was found to be similar to that of phosphatidic acid, cardiolipin, and lecithin. 相似文献
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Two case studies illustrate the positive effects of group psychotherapy for elderly outpatients of a municipal hospital in an industrial community of Baltimore. Most of the outpatients were depressed about physical, mental, or social losses. A total of five brief therapy groups were established. Each group had a maximum of 12 members and met in the hospital for an hour and a half once a week for 12 consecutive weeks. Members could continue in subsequent 12-week sessions if they desired. As a result of their participation in groups, many members became involved in volunteer or part-time work, renewed contact with family and friends, and were better able to deal with life's stresses. 相似文献
66.
BACKGROUND: The clinical significance of the 14 and 6 positive spikes (PS) electroencephalographic (EEG) phenomenon is not well established. This study was performed to provide further data regarding the clinical correlates of the PS, particularly attention-deficit/hyperactivity and somatic symptoms. METHODS: Diagnostic information gathered through structured interviews was compared among four groups of psychiatric inpatients aged 4-17 years who underwent an EEG examination over a 2-year period. Groups consisted of patients with: 1) 14 and 6 PS (n = 25); 2) epileptic discharges (n = 29); 3) slow-wave abnormalities (n = 23); and 4) a normal EEG group age and sex matched to the 14 and 6 PS group (n = 25). RESULTS: Attention-deficit hyperactivity disorder (ADHD) symptoms were significantly more frequent in the PS group (chi 2 = 2.96, p < .05) compared to the other three groups combined. Although somatic symptoms were not increased in the 14 and 6 PS group, anxiety symptoms tended to occur more in this group (chi 2 = 3.50, p < .06). CONCLUSIONS: The PS profile appears associated with ADHD symptoms. Possible treatment implications of this finding (e.g., use of anticonvulsants in ADHD patients with PS) need to be explored. 相似文献
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Emission, fate and effects of soluble silicates (waterglass) in the aquatic environment 总被引:2,自引:0,他引:2
van Dokkum HP Hulskotte IH Kramer KJ Wilmot J 《Environmental science & technology》2004,38(2):515-521
Soluble silicates, commercially known as waterglass, are among the largest volume synthetic chemicals in the world. Silicon from waterglass is rapidly transformed to the biologically active orthosilicic acid (referred to as dissolved silicate). This paper aims to assess the impact of waterglass on the aquatic environment in Western Europe. The emission to surface waters from the four most relevant application areas, household detergents, pulp and paper production, water and wastewater treatment, and soil stabilization, is estimated to be ca. 88-121 kton of SiO2 per year. This is a small fraction (<2%) of the estimated total amount of dissolved silicate transported by rivers to the oceans. Locally, increases in dissolved silicate concentration will decrease the ratios of N:Si and P:Si, which could influence phytoplankton species composition and favor the growth of diatoms over other groups of algae. Significant adverse effects in aquatic ecosystems are not expected. 相似文献
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During the course of an intercomparison exercise it was possible to compare two JAERI phantoms with each other by using a multi-energy photon emitting lung set (241Am/152Eu). One belonged to the IAEA (Vienna), the other belonged to the Human Monitoring Laboratory (Ottawa). The intercomparison of the phantoms showed that they were statistically distinct from each other, although the differences were small. The counting efficiencies varied from each other by about 4% at 17 keV and 2% at photon energies above 17 keV. It was concluded that these difference were either due to small variations of chest wall thickness during the manufacturing process or positioning errors. The intercomparison also revealed a serious problem with one of the overlay plates of the HML's phantom. The adipose mass fraction of the overlay plate was found to be much greater (approximately 40%) than the manufacturer's stated value (10%). 相似文献
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Three cheetahs (Acinonyx jubatus) had a clinical history of chronic spiral bacteria-associated gastritis and three cheetahs had no clinical history of gastritis. Gastric biopsies were obtained from all six cheetahs prior to treatment for gastritis and 3 wk and 1 yr posttreatment. The cheetahs were treated with tetracycline hydrochloride 500 mg p.o. q.i.d., metronidazole 250 mg p.o. q.i.d., and bismuth subsalicylate 300 mg p.o. q.i.d. Each drug was administered concurrently for 7 days. Following this treatment, each cheetah was maintained on 300 mg bismuth subsalicylate p.o. s.i.d. for 1 yr. The three cheetahs with a history of gastritis were culture positive for Helicobacter acinonyx and remained positive during the entire study. The three cheetahs with no clinical history of gastritis were culture negative for H. acinonyx, but gastric biopsies revealed Gastrospirillum-like bacteria (tentatively named Helicobacter heilmannii) pretreatment. Gastric biopsies were negative for H. heilmannii on subsequent examinations. Although the treatment did not eradicate H. acinonyx, it did provide symptomatic relief from the vomiting, anorexia, and weight loss associated with clinical gastritis. The use of endoscopically guided gastric mucosal biopsies for urease testing and histopathologic examination of Warthin-Starry-stained sections is a sensitive and specific method of diagnosing spiral bacteria-associated gastritis. Treatment of spiral bacteria-associated gastritis in cheetahs should include the rational use of antibiotics (tetracycline or amoxicillin and metronidazole), bismuth compounds, and omeprazole and evaluation of husbandry methods to reduce stress. 相似文献
70.