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1.
Recently Gorbunov et al. reported that nitric oxide (.NO) can directly oxidize alpha-tocopherol to alpha-tocopheroxyl radical (Gorbunov et al., Biochem. Biophys. Res. Commun., 219, 835-841, 1996). We have reinvestigated this reaction and report that a direct reaction between .NO and alpha-tocopherol does not occur. However, the reaction between .NO and oxygen generates an oxidant which oxidizes alpha-tocopherol to alpha-tocopheryl quinone. Exposure of alpha-tocopherol to a low flux of .NO generated from spermine NONOate (100 microM) results in no consumption of alpha-tocopherol under either aerobic or anaerobic conditions. A higher flux of .NO, generated from 1 mM spermine NONOate, oxidizes alpha-tocopherol only under aerobic conditions. Artifactual oxidation of alpha-tocopherol can be observed when using commercial .NO that is contaminated with higher oxides of nitrogen, such as dinitrogen trioxide and dinitrogen tetraoxide.  相似文献   

2.
The main purpose of the present study was to examine the links between sports participation and self-esteem, with particular interest in the possible mediating role of physical self-esteem. The participants in this study were 382 students (167 boys; 215 girls) in Grades 5-8. Participants completed a series of paper and pencil measures, detailing their sports participation, as well as their self-perceptions concerning physical and general self-esteem. Sports participation was related to all indices of self-esteem and this was equally true for boys and girls. Two distinct but related factors were identified as components of physical self-esteem (Physical appearance and Physical competence), differentially associated with self-esteem for boys and girls. Results supported a mediational model, with physical self-esteem mediating the relationship between sports participation and general self-esteem. Significant sex differences were noted with regard to specific indices of physical self-esteem. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

3.
In this paper the relationship between microstructure and stress-strain behavior in tensile test of high strength pipeline steel was investigated.The steel with polygonal ferrite-bainite(PF + B) microstructure has a round-house type tensile stress-strain curve with low Y/T ratio,highly uniform elongation and high n-value,which means PF + B microstructure has the best deformability(i.e.Ideal stress-strain behavior) among the four microstructures.The steel with acicular ferrite-martensite&austenite(AF + MA) microstructure has a continuous-yielding type tensile stress-strain curve,whose deformability is worse than that of PF + B microstructure.Both the steels of polygonal ferrite-acicular ferrite(PF + AF) and polygonal ferrite-pearlite (PF+P) microstructure have luders elongation type tensile stress-strain curve with high Y/T ratio,low uniform elongation and low n-value,which means PF + AF and PF + P microstructures have the worst deformability among the four microstructures.  相似文献   

4.
Our objective was to assess the clinical significance of the sonographically derived head-to-abdomen circumference ratio in small-for-gestational-age (SGA) fetuses. The head-to-abdomen ratio was determined in 134 singleton SGA fetuses without ultrasound evidence of malformations at 26-40 weeks' gestation. Data were collected regarding antenatal surveillance, umbilical artery Doppler velocimetry and neonatal outcome. In SGA fetuses, the head-to-abdomen ratio, adjusted for gestational age, had a normal frequency distribution, positively skewed with regard to fetuses with normal birth weight. An elevated head-to-abdomen ratio was found in 56 SGA fetuses (42%), and was associated with increased perinatal mortality (odds ratio 3.27; 95% confidence internal 1.04-9.34), lower birth weight (1533 +/- 635 g vs. 2022 +/- 655 g, p < 0.0001) and lower gestational age at delivery (34 +/- 3.6 weeks vs. 36.3 +/- 3.6 weeks, p < 0.005). However, logistic regression revealed that the most powerful antenatal determinants of pregnancy outcome were Doppler velocimetry of the umbilical artery, followed by biophysical profile, while no independent correlation was found with the head-to-abdomen ratio. The existence of two distinct categories of SGA fetuses, 'symmetric' and 'asymmetric', remains uncertain. An elevated head-to-abdomen ratio is an adverse risk factor for pregnancy outcome. However, this parameter has no clearcut clinical value when umbilical artery Doppler velocimetry and biophysical antenatal testing are available.  相似文献   

5.
Individuals differ in their adjustment to stressful life events, with some exhibiting impaired functioning, including depression, while others exhibit impressive resilience. The present study examined the hypothesis that the ability to deploy a particularly adaptive type of emotion regulation—cognitive reappraisal—may be a protective factor. It expands upon existing research in three ways. First, participants' ability to use reappraisal (cognitive reappraisal ability: CRA) was measured by using a behavioral challenge that assessed changes in experiential and physiological domains, rather than questionnaires. Second, all participants had been exposed to one or more recent stressful life events, a context in which emotion regulation may be particularly important. Third, a community sample of 78 women aged 20 to 60 was recruited, as opposed to undergraduates. Results indicate that, at low levels of stress, participants' CRA was not associated with depressive symptoms. However, at high levels of stress, women with high CRA exhibited less depressive symptoms than those with low CRA, suggesting that CRA may be an important moderator of the link between stress and depressive symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

6.
This is a case study of a 49 year old spinster, with a history of temporal lobe epilepsy for more than 20 years. She was admitted to a psychiatric ward twice in one month, with two distinct types of psychoses, peri-ictal and inter-ictal psychosis. During peri-ictal psychoses, EEG tracing showed seizure activity, while a relatively normal EEG tracing was present during inter-ictal psychosis. The importance of a good clinical assessment to differentiate these two conditions is discussed.  相似文献   

7.
The nature of the physiological stimulus inducing decidualization in the endometrium is unknown. In this study we attempted to verify a recent report that relaxin can induce decidualization in intact mice primed with a high dose of estradiol valerate (5 micrograms) and a low dose (10 micrograms) of medroxyprogesterone acetate. In our study, neither s.c. nor intrauterine relaxin, nor intraluminal arachis oil, (an established deciduogenic stimulus) were able to induce decidualization. In addition, while oil was able to induce decidualization (increased uterine weight, and positive Pontamine Sky Blue and stromal alkaline phosphatase reactions) in ovariectomized mice treated with a regimen of estradiol and medroxyprogesterone acetate designed to produce optimum uterine sensitivity, no decidualization occurred in response to either s.c. or intraluminal relaxin. This study fails to provide any support for a role for relaxin as a deciduogenic stimulus.  相似文献   

8.
Cognitive neuroscience has provided strong support for the idea that there are multiple memory systems. Recent evidence suggests that remembering and knowing may be two types of recognition with different neural substrates. The remember/know distinction is not equivalent to the explicit/implicit distinction because both remembering and knowing are impaired after damage to medial temporal lobe structures. A number of converging lines of evidence suggest that the relationship between remembering and knowing is one redundancy, with "knowing" processes also active during remembering. Remembering appears to depend additionally on frontal lobe functioning.  相似文献   

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In the literature, it is usual to find women and younger subjects reporting higher levels of dental anxiety than men and older subjects. Fear of pain was found to be the most important predictor of dental anxiety and issues of control were also related to such anxiety. Therefore, it was predicted that gender and age differences would be reflected in attitudes to pain and control. Subjects were randomly selected from the voters' list in metropolitan Toronto and mailed a questionnaire with a request for cooperation in a study of their thoughts, feelings, and behaviour regarding dental treatment. The questionnaire included demographic data, measures of dental anxiety and painful experiences as well as the Pain Anxiety Symptoms Scale and the Iowa Dental Control Index. The results supported the main predictions. In addition, attitudes to pain and control were found to be complex phenomena with characteristic gender differences.  相似文献   

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The relationship between normal variation in IQ and common psychopathology was examined in a sample of 339 5- to 16-year-olds who were seen at a tertiary psychiatric clinic. The mean IQ was 9.6 points lower (95% CI 5.5 to 13.6 points lower) for conduct than for emotional disorders, with mixed disorders in between. For these common disorders, the mean IQ was 6.0 points lower (95% CI 1.6 to 10.3 points lower) for females than males. IQ variation in the normal range was inversely related to a dimensional measure of conduct problems - an association that was not attributable to social class or mediated by scholastic attainments. Other dimensional measures of psychopathology - covering emotional symptoms, developmental immaturity and relationship difficulties - were not significantly correlated with IQ. Limitations of the study are discussed in the paper.  相似文献   

14.
The relationship between microtubule dynamics and polyglutamylation of tubulin was investigated in young differentiating mouse brain neurons. Selective posttranslational labeling with [3H]glutamate and immunoblotting with a specific monoclonal antibody (GT335) enabled us to analyze polyglutamylation of both alpha and beta subunits. Nocodazole markedly inhibited incorporation of [3H]glutamate into alpha- and beta-tubulin, whereas taxol had no effect for alpha-tubulin and a stimulating effect for beta-tubulin. These results strongly suggest that microtubule polymers are the preferred substrate for polyglutamylation. Chase experiments revealed the existence of a reversal reaction that, in the case of alpha-tubulin, was not affected by microtubule drugs, suggesting that deglutamylation of this subunit can occur on both polymers and soluble tubulin. Evidence was obtained that deglutamylation of alpha-tubulin operates following two distinct rates depending on the length of the polyglutamyl chain, the distal units (4th-6th) being removed rapidly whereas the proximal ones (1st-3rd) appearing much more resistant to deglutamylation. Partition of glutamylated alpha-tubulin isoforms was also correlated with the length of the polyglutamyl chain. Forms bearing four to six units were recovered specifically in the polymeric fraction, whereas those bearing one to three units were distributed evenly between polymeric and soluble fractions. It thus appears that the slow rate component of the deglutamylation reaction offers to neurons the possibility to maintain a basal level of glutamylated alpha-tubulin in the soluble pool independently of microtubule dynamics. Finally, some differences observed in the glutamylation of alpha- and beta-tubulin suggest that distinct enzymes are involved.  相似文献   

15.
The effect of austenite yield strength on the transformation to martensite was investigated in Fe-10 pct Ni-0.6 pct C alloys. The strength of the austenite was varied by 1) additions of yttrium oxide particles to the base alloy and 2) changing the austenitizing temperature. The austenite strength was measured at three temperatures above theM s temperature and the data extrapolated to the experimentally determinedM s temperature. It is shown that the austenite yield strength is determined primarily by the austenite grain size and that the yttrium oxide additions influence the effect of austenitizing temperature on grain size. As the austenite yield strength increases, both theM s temperature and the amount of transformation product at room temperature decrease. The effect of austenitizing temperature on the transformation is to determine the austenite grain size. The results are consistent with the proposal1 that the energy required to overcome the resistance of the austenite to plastic deformation is a substantial portion of the non-chemical free energy or restraining force opposing the transformation to martensite.  相似文献   

16.
The current investigation explored the relation between (a) spouses' standards for their marriages and (b) attributions for relationship problems and reported emotional and behavioral responses. Three dimensions of relationship standards were assessed: boundaries, distribution of power between partners, and demonstrated investment in the relationship. Findings indicate it is not the levels of boundaries, power, and investment reflected in spouses' standards that were related to their attributions, emotions, and self-reported behavioral responses to relationship problems. Instead, negative causal attributions; attributions to boundary, power, and investment issues; negative emotional responses to relationship problems; and reported active-destructive behavioral responses to relationship problems were associated with (a) spouses' unmet standards and (b) how upset spouses became when their relationship standards were not met. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

17.
OBJECTIVE: To assess the relationship between ethnicity and Health Care wishes, including Advance Directives, in a group of frail older persons in PACE (Program For All Inclusive Care Of The Elderly). DESIGN: Retrospective chart review of 1193 participants in the PACE program. SETTING: Program of All Inclusive Care Of The Elderly (PACE), a comprehensive managed care demonstration program serving frail older participants at 10 sites across the nation. PARTICIPANTS: A total of 1193 older adults, all of whom met state criteria for nursing home level of care. There were 385 non-Hispanic whites, 364 blacks, 156 Hispanics, and 288 Asians. MEASUREMENTS: Presence or absence of advance directives, type of health care wishes selected including living will, durable power of attorney, and health care proxy. RESULTS: Frail older white, black, Hispanic and Asian Americans differ significantly in their health care wishes and how they choose to express them. Blacks were significantly more likely to select aggressive interventions and less likely than non-Hispanic whites and Hispanics to utilize a written instrument for expressing health care wishes. Whites were significantly more likely to utilize written documents for advance directives, whereas Asians were more likely to select less aggressive interventions but were unlikely to use written advance directives. CONCLUSIONS: In this population, we found significant ethnic variations in choice of health care wishes. Although health care wishes are an individual decision, an awareness of cross cultural patterns can assist practitioners in addressing the concerns of their patients, as well as assisting Health Care Policy Development.  相似文献   

18.
The relationship between upper gastrointestinal hemorrhage and drug use was studied in 251 Chinese patients (179 men, 72 women) admitted to the Prince of Wales Hospital, Hong Kong, and control subjects matched for age and sex. There was a highly significant difference between the cases and control subjects in the use of NSAIDs (odds ratio 14.0, p < 0.00001), ulcer healing drugs (odds ratio 12.5, p < 0.00001), and Chinese proprietary medicines (odds ratio 16.0, p < 0.00001). There was also a significant difference in the use of analgesics (odds ratio 14.0, p = 0.001), paracetamol (odds ratio 2.5, p = 0.01), antacids (odds ratio 2.7, p < 0.001) and unknown drugs (odds ratio 4.7, p < 0.001). Cases also differed from control subjects regarding the use of tobacco (odds ratio 2.3, p < 0.001) and alcohol (odds ratio 1.7, p = 0.02), and the presence of peptic ulcer symptoms (odds ratio 29.8, p < 0.00001). Significantly more control subjects than cases were receiving aspirin, cardiovascular drugs, bronchodilators, oral hypoglycemic drugs/lipid-lowering drugs, and anticonvulsants/hypnotics, due to the inevitable differences in disease pattern between the 2 groups. NSAID use was a major factor associated with upper gastrointestinal hemorrhage from primarily peptic ulcers. Differences in the use of other drugs may reflect variations in disease patterns between cases and controls, the common practice of self-medication in Hong Kong, and the concomitant use of NSAIDs and ulcer healing drugs/antacids.  相似文献   

19.
Took depression and marital maladjustment measures of all 154 couples attending a clinic. Average age for men was 38 yrs, for women 35 yrs; average length of marriage was 19 yrs. A significant correlation between depression and marital maladjustment was found for self-report data and was replicated by therapists' ratings. Women were significantly more depressed than men though similar in average ratings of marital adjustment. Women's depression ratings were minimally related to their own their husbands' marital ratings. Men's depression ratings were related to both their own and their wives' marital ratings. Convergent validity was demonstrated for the Locke and Wallace Marital-Adjustment Test and the Beck Depression Inventory. Clinical implications of findings concerning both depression and marital maladjustment are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
Critically examines the evidence dealing with the alleged relationship between cannabis and violence and considers some of the variables that enter into such an assessment. The consensus is that marihuana does not precipitate violence in the majority of those using it sporadically or chronically; however, there are certain individuals, such as those suffering from temporal lobe dysrhythmia, and certain situations of set (the user's immediate condition at the time of drug use) and setting, in which marihuana may result in violence. (135 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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