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排序方式: 共有1716条查询结果,搜索用时 15 毫秒
81.
82.
NE Avis KW Smith RK Hambleton HA Feldman A Selwyn A Jacobs 《Canadian Metallurgical Quarterly》1996,34(11):1102-1120
OBJECTIVES: The purpose of this study was to design a multidimensional measure of health-related quality of life appropriate for patients with cardiovascular disease that was psychometrically sound, brief, and easy to administer. METHODS: Qualitative interviews conducted with healthy subjects and patients with cardiovascular diseases identified nine major quality of life domains. Based on the responses of 129 cardiovascular disease patients recruited from hospitals and clinics, a criterion-based approach was used to select 35 questionnaire items that best tapped these domains. Psychometric properties of the Multidimensional Index of Life Quality (MILQ) were tested with a sample of 348 patients with various cardiovascular diseases. RESULTS: Cronbach's alpha was 0.76 or higher for eight of the nine MILQ domains. Test-retest reliability coefficients were 0.73 or greater in all but two domains. Individual domain scores as well as a weighted overall quality of life index were correlated highly with self-assessed health and the number of heart-related symptoms. CONCLUSIONS: The Multidimensional Index of Life Quality is a psychometrically reliable and valid instrument for measuring quality of life in patients with cardiovascular diseases. The MILQ also may be a suitable measure for other types of chronic diseases. 相似文献
83.
Coffee drinking may serve as a cue for cigarette smoking. The association of coffee drinking and cigarette smoking in the natural environment was studied in 6 participants who recorded every instance of ad lib cigarette smoking and coffee drinking for 4 consecutive days. The rate of cigarette smoking was higher during intervals associated with coffee drinking (2.4 cigarettes/hr) than at other times of the day (1.0 cigarettes/hr). However, diary records revealed that on average only 14% of cigarettes were smoked while drinking coffee, and only 55% of coffee-drinking events were accompanied by cigarettes. These results suggest that coffee drinking may exert some stimulus control over smoking in the natural environment. However, given the limited number of coffee-drinking episodes compared with cigarettes consumed in a day, the contributions of coffee drinking to maintaining smoking behavior are probably minimal. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
84.
D Karunagaran E Tzahar RR Beerli X Chen D Graus-Porta BJ Ratzkin R Seger NE Hynes Y Yarden 《Canadian Metallurgical Quarterly》1996,15(2):254-264
Overexpression of the erbB-2 gene contributes to aggressive behavior of various human adenocarcinomas, including breast cancer, through an unknown molecular mechanism. The erbB-2-encoded protein is a member of the ErbB family of growth factor receptors, but no direct ligand of ErbB-2 has been reported. We show that in various cells ErbB-2 can form heterodimers with both EGF receptor (ErbB-1) and NDF receptors (ErbB-3 and ErbB-4), suggesting that it may affect the action of heterologous ligands without the involvement of a direct ErbB-2 ligand. This possibility was addressed in breast cancer cells through either overexpression of ErbB-2 or by blocking its delivery to the cell surface by means of an endoplasmic reticulum-trapped antibody. We report that ErbB-2 overexpression enhanced binding affinities to both EGF and NDF, through deceleration of ligand dissociation rates. Likewise, removal of ErbB-2 from the cell surface almost completely abolished ligand binding by accelerating dissociation of both growth factors. The kinetic effects resulted in enhancement and prolongation of the stimulation of two major cytoplasmic signaling pathways, namely: MAP kinase (ERK) and c-Jun kinase (SAPK), by either ligand. Our results imply that ErbB-2 is a pan-ErbB subunit of the high affinity heterodimeric receptors for NDF and EGF. Therefore, the oncogenic action of ErbB-2 in human cancers may be due to its ability to potentiate in trans growth factor signaling. 相似文献
85.
JW Erdman AJ Thatcher NE Hofmann JD Lederman SS Block CM Lee S Mokady 《Canadian Metallurgical Quarterly》1998,128(11):2009-2013
The algae Dunaliella bardawil and Dunaliella salina naturally contain large concentrations of all-trans and 9-cis beta-carotene (betaC). The purpose of this study was to compare the relative serum and tissue accumulation of all-trans and 9-cis betaC in ferrets fed different ratios of all-trans/9-cis betaC derived from two commercial sources, D. bardawil or D. salina (Betatene). Male ferrets (7 wk old) were fed carotene-free, pelleted diets for 27 d. Beginning on d 18, groups of ferrets (n = 6 or 7) received daily, one of six oral supplements varying in ratios of 9-cis and all-trans betaC mixed with approximately 1.0mL of Ensure. Four supplements containing 5.2-8.3 micromol total betaC were prepared from a 20% Betatene preparation, D. bardawil, a high-cis Betatene preparation, and Betatene further enriched in 9-cis betaC with all-trans betaC/9-cis betaC ratios of 2.2, 1.5, 0.6 and 0.4, respectively. Two control supplements, high and low betaC, were prepared from commercial betaC beadlets. The high control supplement had an all-trans/9-cis ratio of 19.0, whereas 9-cis betaC was not detected in the low supplement. On d 27, serum and tissues were obtained for HPLC analysis of betaC and its isomers. Analysis of livers showed that all-trans betaC was the primary isomer present, but 9-cis and other isomers were also detected in all groups. The hepatic all-trans/9-cis ratios were 5.9, 4.9, 2.5, 1.4, 52.2 and47.5, respectively, for the groups listed above. Lower amounts of all-trans and 9-cis betaC were found in kidneys compared with the liver, but ratios of all-trans/9-cis were not different among groups. Only trace amounts of 9-cis betaC were found in serum. These results demonstrate that the algae D. bardawil and D. salina provide a bioavailable source of betaC isomers, but, as in humans, absorption of 9-cis betaC is poor and any 9-cis betaC absorbed is apparently cleared by the liver. 相似文献
86.
Size-selective predation on groundwater bacteria by nanoflagellates in an organic-contaminated aquifer 总被引:1,自引:0,他引:1
NE Kinner RW Harvey K Blakeslee G Novarino LD Meeker 《Canadian Metallurgical Quarterly》1998,64(2):618-625
Time series incubations were conducted to provide estimates for the size selectivities and rates of protistan grazing that may be occurring in a sandy, contaminated aquifer. The experiments involved four size classes of fluorescently labeled groundwater bacteria (FLB) and 2- to 3-microns-long nanoflagellates, primarily Spumella guttula (Ehrenberg) Kent, that were isolated from contaminated aquifer sediments (Cape Cod, Mass.). The greatest uptake and clearance rates (0.77 bacteria.flagellate-1.h-1 and 1.4 nl.flagellate-1.h-1, respectively) were observed for 0.8- to 1.5-microns-long FLB (0.21-microns3 average cell volume), which represent the fastest growing bacteria within the pore fluids of the contaminated aquifer sediments. The 19:1 to 67:1 volume ratios of nanoflagellate predators to preferred bacterial prey were in the lower end of the range commonly reported for other aquatic habitats. The grazing data suggest that the aquifer nanoflagellates can consume as much as 12 to 74% of the unattached bacterial community in 1 day and are likely to have a substantive effect upon bacterial degradation of organic groundwater contaminants. 相似文献
87.
88.
Four research paradigms explored links from secrecy to the suppression and intrusive recurrence of secret thoughts. In Study 1, keeping a word secret enhanced cognitive accessibility of the word on a Stroop color-naming task. Study 2 revealed that secret memory topics were recalled earlier than topics about which a lie or the truth was told. Study 3 showed that when participants were keeping secrets, their ratings of suppression and intrusive thinking of the secret became positively correlated. Study 4 participants rated 50 everyday topics for intrusiveness, suppression, and secrecy. Across topics, positive mean within-subject correlations were found among these variables. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
89.
DE McCloskey RA Casero PM Woster NE Davidson 《Canadian Metallurgical Quarterly》1995,55(15):3233-3236
The need for antineoplastic compounds with novel mechanisms of action is great. One such agent is the recently synthesized polyamine analogue N1-ethyl-N11-((cyclopropyl)methyl)-4,8-diazaundecane (CPENSpm). Exposure of hormone-dependent and -independent human breast cancer cells to 0.1-10 microM CPENSpm led to both growth inhibition and induction of programmed cell death. Fragmentation of DNA to high molecular weight fragments and oligonucleosomal-sized fragments, both characteristic of programmed cell death, was determined to be time and concentration dependent. Depletion of natural polyamine pools and accumulation of the analogue was also demonstrated. These data provide the first evidence that a polyamine analogue induces programmed cell death. 相似文献
90.
NE Zakharova NP Vaneeva NE Iastrebova NG Kalina MM Tokarskaia VV Sergeev NV Tsvetkova NN Ovechko TV Sokolova 《Canadian Metallurgical Quarterly》1998,(6):82-83
A study was made into the functional status of hypophysis, adrenal cortex, ovaries, and thyroid gland in patients with kraurosis and leukoplakia vulvae. The above patients demonstrated profound disturbances in the system hypophysis-ovaries, that attest to the need for applying corrective therapies to treat the disturbed hormonal homeostasis. 相似文献