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1.
Within a few seconds after a sudden reduction of coronary blood flow regional contractile dysfunction ensues. The mechanisms responsible for the rapid reduction in contractile function during acute myocardial ischemia remain unclear, but may involve a rise in inorganic phosphate. When severe ischemia, such as resulting from a sudden and complete coronary artery occlusion, is prolonged for more than 20-40 min, myocardial infarction develops, and there is irreversible loss of contractile function. When myocardial ischemia is less severe but nevertheless prolonged, the myocardium is dysfunctional but can remain viable. In such ischemic and dysfunctional myocardium, contractile function is reduced in proportion to the reduction in regional myocardial blood flow; i.e. a state of "perfusion-contraction matching" exists. The metabolic status of such myocardium improves over the first few hours, as myocardial lactate production is attenuated and creatine phosphate, after an initial reduction, returns towards control values. Ischemic myocardium, characterized by perfusion-contraction matching, metabolic recovery and lack of necrosis, has been termed "short-term hibernating myocardium". Short-term hibernating myocardium can respond to an inotropic stimulation with increased contractile function, however, at the expense of a renewed worsening of the metabolic status. This situation of an increased regional contractile function at the expense of metabolic recovery during inotropic stimulation can be used to identify short-term hibernating myocardium. When inotropic stimulation is prolonged, the development of short-term hibernation is impaired and myocardial infarction develops. The mechanisms responsible for the development of short-term myocardial hibernation remain unclear at present; a significant involvement of adenosine and of activation of ATP-dependent potassium channels has been excluded. Whereas short-term hibernation is well characterized in animal experiments, the existence of hibernation over weeks or months (long-term hibernation) can only be inferred from clinical studies. Hibernation, as defined by Rahimtoola, is a state of chronic contractile dysfunction which is fully reversible upon reperfusion. Clinical syndromes consistent with the existence of myocardial hibernation include unstable and stable angina, acute myocardial infarction and left ventricular dysfunction and/or congestive heart failure. In long-term hibernating myocardium morphological alterations occur; the myofibrils are reduced in number and disorganized and myocardial glycogen content as well as the extracellular collagen network are increased. Thus, despite the fact that the myocardium remains viable during persistent ischemia and contractile dysfunction is reversible upon reperfusion, there are severe morphological alterations. Understandably, full functional recovery following reperfusion might therefore require weeks or even months.  相似文献   

2.
Are there sex differences in criteria for sexual relationships? The answer depends on what question a researcher asks. Data suggest that, whereas the sexes differ in whether they will enter short-term sexual relationships, they are more similar in what they prioritize in partners for such relationships. However, additional data and context of other findings and theory suggest different underlying reasons. In Studies 1 and 2, men and women were given varying "mate budgets" to design short-term mates and were asked whether they would actually mate with constructed partners. Study 3 used a mate-screening paradigm. Whereas women have been found to prioritize status in long-term mates, they instead (like men) prioritize physical attractiveness much like an economic necessity in short-term mates. Both sexes also show evidence of favoring well-rounded long- and short-term mates when given the chance. In Studies 4 and 5, participants report reasons for having casual sex and what they find physically attractive. For women, results generally support a good genes account of short-term mating, as per strategic pluralism theory (S. W. Gangestad & J. A. Simpson, 2000). Discussion addresses broader theoretical implications for mate preference, and the link between method and theory in examining social decision processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

3.
Meaningful and measurable aspects of short-term intraindividual variability have been established in what are conceptualized to be relatively stable interindividual differences dimensions. Illustrative are anxiety and other temperament traits as well as certain kinds of cognitive abilities. Reclamation of "signal" from the "noise" of intraindividual variability has rested heavily on research designs that involve frequently repeated observations. We extended this line of research to other trait-like domains by examining biweekly self-reports of world views and religious beliefs of a sample of elderly participants. The results indicated that not only is there occasion-to-occasion variability in the self-reports but the structure of these fluctuations is consistent over time and bears considerable resemblance to structures reported from cross-sectional data.  相似文献   

4.
Eight experiments with 98 college students tested the assertion that the capacity limit of short-term memory span (seven plus/minus two "chunks") is related to a fundamental limit in "working memory" of information processing. Each of 2 converging approaches led to findings that deny this hypothesis. The 1st approach examined performance when Ss determined which digit was missing when 8 different digits appeared sequentially in random order. Although this task requires memory for digits, it does not exhibit the properties of short-term memory span (sensitivity to rhythmic patterning and acoustic/articulatory interference). Thus, there must be a working memory that is distinct from the span memory of an ordered-recall task. The 2nd approach required that Ss perform information-processing tasks during the retention interval of memory span. According to the hypothesis that working memory and memory span are equivalent, interference should occur in this paradigm. There was no such interference provided that an initial rehearsal period for the memory span was allowed prior to the intervening task. (77 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

5.
KD Jordan  TG Mayer  RJ Gatchel 《Canadian Metallurgical Quarterly》1998,23(19):2110-6; discussion 2117
STUDY DESIGN: A prospective cohort design with two groups of patients representing short-term or long-term disability (n = 497) who were selected from a larger cohort (n = 938) of consecutively treated spinal disorder patients with chronic compensation injuries. OBJECTIVES: To prospectively evaluate the impact of length of spinal disability on socioeconomic outcomes of medically directed rehabilitation. SUMMARY OF BACKGROUND DATA: Despite an increasing tendency of managed care organizations to limit rehabilitation services for disabled workers with chronic spinal disorders, there has been a surprising lack of prospective research evaluating the impact of length of disability on objective socioeconomic treatment outcomes. Although only approximately 10% of all patients with spinal disorders are disabled beyond 4 months, they account for nearly 80% of all workers' compensation expenditures. Little is known about whether relatively early intervention improves outcomes after chronicity has been established or whether any predictors distinguish between these groups. METHODS: Two comparison groups of functional restoration tertiary treatment graduates were identified from the same community referral pool. The "long-term disabled" group involved a minimum of 18 months of disability (n = 252). This group was compared with a "short-term disabled" group (n = 245), no more than 8 months since injury, but chronic based on a minimum of 4 months after injury. The long-term disabled group showed significantly higher rates of pretreatment surgery than the short-term disabled group (P < 0.001). All patients were evaluated prospectively with specific physical, psychological, and occupational measurements. They also underwent a structured interview 1 year after treatment evaluating work status, health care use, and recurrent injury. RESULTS: The short-term disabled group showed statistically higher return to work (P < 0.001) and work retention (P < 0.05) relative to the long-term disabled group. However, health care use and recurrent lost time injury claims were low in both groups and did not differ significantly. No predictors of outcome were found among the prospectively collected physical performance or psychosocial variables. CONCLUSIONS: This study suggests that early tertiary nonoperative care, once patients with chronic spinal disorders are identified as having potentially high-cost chronic pain and disability, is efficacious in achieving goals of better work return and work retention. Such early rehabilitation may also prevent significant indemnity expense, as well as some late surgical interventions sought by progressively more desperate patients. However, individuals with long-term disability achieve respectable work return and retention rates, while faring no worse on other socioeconomic outcomes that represent major "cost drivers" to the workers' compensation system. Early intervention is not a panacea or a necessary condition for the successful rehabilitation of workers with disabling chronic spinal disorders.  相似文献   

6.
The performance of 26 children (3;0-4;0 years) who were born before 32 weeks gestation was compared with the performance of 26 full-term children on a range of short-term memory and language measures. The measures tested vocabulary, expressive language, phonological short-term memory, and general nonverbal ability. Preterm children scored more poorly across the full range of measures. The mildly depressed performance of the preterm group on the short-term memory and language measures was attributable to the large deficits on these tests shown by a subgroup of approximately one third of preterm children identified as being "at risk" for persisting language difficulties using the Bus Story Test (Bishop & Edmundson, 1987). The findings indicate that preterm birth and associated hazards may constitute a significant risk factor for specific language impairment in a sizable minority of children.  相似文献   

7.
Preweanling 17-day-old rats were tested for retention of the conditioned emotional response after a 5-min or 24-hr retention interval. For a variety of conditioning parameters (i.e., variation in conditioned stimulus modality, unconditioned stimulus intensity, number of training trials), conditioned responding was consistently weaker after 5 min than after 24 hr. This apparent "incubation," or "hypermnesic," effect was not found in adult rats, even when comparable conditioning levels were indicated on the 24-hr test. The transient short-term retention deficit observed in 17-day-old preweanlings was alleviated by placing the pup in its home cage during the 5-min retention interval or by extending the conditioning session. Fifteen-day-old rat pups did not benefit from home cage exposure or extended training and displayed the transient short-term retention deficit regardless. The results are discussed in terms of age-related effects on time-dependent memory consolidation.  相似文献   

8.
In patients with heart failure, therapy with "maximally tolerated" oral doses of diuretics, vasodilators, and digitalis results in a significant increase in the distance walked during the 6-minute walking test, compared with conventional therapy at "standard" doses, indicating an improvement in exercise tolerance. The 6-minute walk test is a simple, inexpensive, and well-tolerated test to measure changes in exercise tolerance induced by pharmacologic interventions, even on a short-term basis.  相似文献   

9.
The authors investigated spatial, temporal, and attentional manipulations in a short-term repetition priming paradigm. Brief primes produced a strong preference to choose the primed alternative, whereas long primes had the opposite effect. However, a 2nd brief presentation of a long prime produced a preference for the primed word despite the long total prime duration. These surprising results are explained by a computational model that posits the offsetting components of source confusion (prime features are confused with target features) and discounting (evidence from primed features is discounted). The authors obtained compelling evidence for these components by showing how they can cooperate or compete through different manipulations of prime salience. The model allows for dissociations between prime salience and the magnitude of priming, thereby providing a unified account of "subliminal" and "supraliminal" priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

10.
11.
Four experiments investigated the mechanisms responsible for the advantage enjoyed by high-frequency words in short-term memory tasks. Experiment 1 demonstrated effects of word frequency on memory span that were independent of differences in speech rate. Experiments 2 and 3 showed that word frequency has an increasing effect on serial recall across serial positions, but Experiment 4 showed that this effect was abolished for backward recall. A model that includes a redintegration process that operates to "clean up" decayed short-term memory traces is proposed, and the multinomial processing tree model described by R. Schweickert (1993) is used to provide a quantitative fit to data from Experiments 2, 3, and 4.  相似文献   

12.
The study described here is part of an evaluation of a pilot project concerning the implementation of three psychiatric crisis units in general hospitals in Belgium. The purpose was to evaluate the short-term outcome of a multidisciplinary crisis intervention for psychiatric patients referred to the emergency department. Patients were assessed with the General Health Questionnaire (GHQ-28) at the time of referral to the emergency department and again 1 month later. Patients referred for a psychiatric crisis intervention were compared with patients receiving short-term psychiatric inpatient treatment in another hospital. Patients referred to the emergency department showed a considerable degree of psychiatric disturbance. The General Health Questionnaire appeared to be a good measure for assessment of the "state" aspect of a psychiatric disturbance. The state of distress was significantly reduced one month after referral in both treatment conditions. Nevertheless, an important proportion of patients remained in a state of considerable distress. The results indicate that a short hospital-based crisis intervention approach is comparable with more traditional acute inpatient treatment. However, in the case of more severely distressed patients it may be insufficient. Several limitations of this study are also discussed (risk of overestimation of improvement, influence of time or pre-existing differences).  相似文献   

13.
Psychodynamic theories of short-term treatment are reviewed and applied to counseling college students. J. Mann's (1973) conceptualization of unconscious-yearning "Mother Time" and reality-limited "Father Time" lays the dynamic groundwork. The explorations of dynamic interpretations using D. H. Malan's (1979) triangle of persons and triangle of conflict are followed by methods of intensifying the work, comparing "homework" as suggested by S. H. Budman (1981) with the anxiety-arousing, confrontational techniques of P. O. Sifneos (1972) and H. Davanloo (1980). (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

14.
The most controversial issue related to prolonged estrogen therapy is the possible relationship of this therapy to the etiology and pathogenesis of breast and uterine cancer. The imprecise nature of the relevant data does not allow full definition of the rish. To maintain proper perspective, smoking 20 cigarettes a day increases the risk of death from lung cancer 17 times; the risk from estrogens is less than that. There is no controversy over the use of estrogens for short-term relief of menopausal symptoms. The Mulley and Mitchell paper referred to was opinion based on no direct research and an inadequate knowledge of the literature. The early symptoms of estrogen dificiency, hot flushes and atrophic vaginitis, respond to short-term estrogen therapy, which in addition, provides a "mental tonic" effect. It is not justifiable to withhold such therapy from the normal informed patient requesting it, provided no contraindications exist. The patient should be reevaluated at frequent intervals, and the proper selection of drug, dosage, and therepeutic regimen administered. This can be accomplished, including research, through a menopause clinic.  相似文献   

15.
"The following three measures of vocabulary performance varying in sensitivity were obtained from groups of short-term schizophrenics, long-term schizophrenics, and normals equated for art and education: gesticulation (nonverbal), conventional vocabulary achievement, and level of verbal communication. No differences were found between the short-term schizophrenics and the normals of any of the measures. The long-term schizophrenics were significantly lower than normals and short-term schizophrenics on all of the measures. The decrement on gesticulation for the long-term schizophrenics was significantly less than that for the other measures." (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

16.
OBJECTIVE: To assess the coping ability and the social support of relatives looking after patients who have had a stroke. Of special interest was to ascertain how coping behaviour and social support differed between short-term (caring period of 3-6 months) and long-term (caring period longer than 2 years) carers. Differences in social networking between relatives and a control group (no caring tasks) were also assessed. SUBJECTS AND METHODS: A questionnaire based on the well-established "Berne coping forms" and another on social support were filled in by 20 relatives (18 women, two men; mean age 50.6 years) after a short-term caring period of up to 6 months and 20 relatives after a caring period longer than 2 years (14 women, six men; mean age 64.9 years) and a control group (27 women, 10 men; mean age 57.8 years). RESULTS: Among the total group of relatives the coping strategies (listed by order of importance) were: "passive cooperation", "acceptance", and "lending a hand". The short- and long-term carers showed no significant differences in these strategies. However, there were significant deficits in social support between the relatives and the controls as to practical support (P < 0.05), social integration (P < 0.01), social support received (P < 0.01), social burden (P < 0.01) and the caring persons (P < 0.05). There was no difference regarding social support between the short- and long-term carers. CONCLUSIONS: The results confirm the importance of social support for relatives who look after stroke patients. Every form of psychosocial help should be given at the time the patient is discharged to home care. This would require day clinics and short-term places in nursing homes.  相似文献   

17.
A short-term test to determine renal concentrating ability without any water deprivation has been described. It consists of osmolatity determinations in three onehour urine portions from spontaneous voidings following an intranasal application of 7 microng of the synthetic analogue of vasopressin-DDAVP per 0,5 m2 body surface. The values of maximal urine osmalatity over 900 mosm/Kg H2O following DDAVP are considered normal whereas values under 600 mosm are consistent with impaired renal function. If, however, the maximal urine osmolality is in the so called "uncertain range" i.e. from 600 to 900 mosm, it is advisable to perform in the same patients also the classical concentration test based on a prolonged dehydration (26 h).  相似文献   

18.
The knowledge and skills of psychology can be useful in developing countries where indigenous mental health resources are sometimes scarce. Although it may be useful for psychologists to provide short-term training in developing countries, the potential for long-term change is best accomplished by investing in training students from developing countries, especially those committed to returning to their homeland after completing their training. Three "investment strategies" are suggested for training students from developing countries: faculty awareness, intentional mentoring, and facilitated launching. Challenges and implications for professional psychologists are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
Considers the concepts of quantitative and structural change as these have been characterized from a multivariate perspective, and introduces a 3rd type-quantistructural change, a hybrid of the original 2 types. These 3 types of change properties, together with the possibility for stability, are applied to 3 separate situations: the latent structure of a factorially complex criterion variable that is "extra" the original factor analysis; a factor defined in terms of salient variables; and hierarchical factor models. This provides for 2 separate 2-level analyses of change. The trait-state factor distinction and long-term vs short-term time spans are also considered and are seen to imply certain restrictions as to the possible types of multivariate ontogenetic change. (51 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
Criticizes 2 influential premises underlying most of current research on schizophrenia and attention: (a) belief in the existence of a specific information-processing deficit and (b) acceptance of a framework of "cold cognition." Capacity theory is proposed as an alternative theoretical framework within which the various phenotypically diverse attentional deficits in schizophrenia reflect a deficit in the control function that governs the mobilization and allocation of attention. Attentional deficits, therefore, are most manifest when effortful processing in short-term storage is required. Research on short-term memory processes in schizophrenics shows that the magnitude of the attention deficit correlates positively with the attentional requirements of the cognitive operations involved. The dysfunction is thought to reflect the high levels of arousal characteristic of schizophrenics. Parallels in the performance of schizophrenics and essentially normal but hyperaroused Ss are outlined in support of this hypothesis. The failure to consider the possible mediating effects of hyperarousal in attentional performance of schizophrenics is an omission in the research on schizophrenic cognition. Causality between arousal and information processing is addressed. (101 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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