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991.
C. J. Snijders PhD A. Vleeming PhD R. Stoeckart PhD 《Clinical biomechanics (Bristol, Avon)》1993,8(6):285-294
This study deals primarily with the stability of the base of the spine. The sacroiliac joints are vulnerable to shear loading on account of their predominantly flat surfaces. This raises the question of what mechanisms are brought into action to prevent dislocation of the sacroiliac joints when they are loaded by the weight of the upper part of the body and by trunk muscle forces. First a model is introduced to compare load transfer in joints with spherical and with flat joint surfaces. Next we consider a biomechanical model for the equilibrium of the sacrum under load, describing a self-bracing effect that protects the sacroiliac joints against shear according to ‘the sacroiliac joint compression theory’, which has been demonstrated in vitro. The model shows joint stability by the application of bending moments and the configuration of the pelvic arch. The model includes a large number of muscles (e.g. the gluteus maximus and piriformis muscles), ligaments (e.g. the sacrotuberous, sacrospinal, and dorsal and interosseous sacroiliac ligaments) as well as the coarse texture and the ridges and grooves of the joint surfaces. 相似文献
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CAROL J. LAMMI-KEEFE PhD RD ELAINE S. LICKTEIG MS RD NAMANJEET AHLUWALIA PhD N.REBECCA HALEY MD 《Journal of the American Dietetic Association》1996,96(3):247-251
Objective To determine the day-to-day variation in biochemical measures of iron status in a group of elderly women with rheumatoid arthritis compared with a group of healthy elderly women.Design Venous blood samples were collected from each subject on 3 nonconsecutive days during a 2-week study period; subjects had fasted overnight. Variability in hemoglobin level, hematocrit value, serum iron concentration, total iron-binding capacity, transferrin saturation, serum ferritin concentration, and plasma transferrin receptor level was determined.Subjects Two groups of women, one with rheumatoid arthritis (n=10) and another that was apparently healthy (n=10).Statistical analyses Variance component analysis was used to estimate the biological variation (σ2day) and analytic variation (σ2rep) for each iron index. The coefficient of variation (CV) for each variance component was calculated: coefficient of biological variation = CVday, coefficient of analytic variation = CVrep, and coefficient of a single future determination = CVfd.Results The CVrep for all iron indexes was smaller than the CVday in both groups. The CVday was considerably higher for serum iron concentration and for transferrin saturation than for the other indexes in both groups (16.6% arid 16.6% in healthy subjects and 33.6% and 28.2%, respectively, in subjects with rheumatoid arthritis). The higher CVday for serum iron concentration and transferrin saturation translated into a higher CVfd for these indexes. Because of the higher variance for these two indexes, more sampling days were required for reliable estimates. CVda and CVfd for plasma transferrin receptor level were relatively low.Conclusions These findings corroborate our previous finding that variation of serum ferritin concentration in the elderly is lower than that demonstrated in younger populations. This aging effect persists in the presence of rheumatoid arthritis. Fasting appeared to improve reliability in the determinations for serum iron concentration and transferrin saturation. Variability estimates for the indexes other than serum iron concentration and transferrin saturation were not altered by the inflammation of rheumatoid arthritis. Plasma transferrin receptor level is a reliable index for assessing iron status in populations with rheumatoid arthritis. J Am Diet Assoc. 1996; 96:247-251. 相似文献
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JEANNIE McKENZIE DrPH RD LORIBETH DIXON PhD HELEN SMICIKLAS-WRIGHT PhD DIANE MITCHELL MS RD BARBARA SHANNON PhD RD ANDREW TERSHAKOVEC MD 《Journal of the American Dietetic Association》1996,96(9):865-873
Objective To determine change in nutrient intakes, number of servings, and contributions of total fat from food groups in children who lowered their dietary fat intake.Design A research and demonstration study designed to lower plasma low-density lipoprotein cholesterol level. There were four study groups: two intervention and two control groups. All children had hypercholesterolemia except for those in one control group. Three 24-hour dietary recalls were collected on randomly assigned days over a 2-week period at baseline and 3 months after the intervention.Subjects Three hundred three 4- to 10-year old children from suburbs north of Philadelphia, Pa.Interventions One intervention involved a home-based, parent-child autotutorial program (PCAT group) with audiotaped stories and print materials for the children and their families; the other intervention involved one face-to-face counseling session with a registered dietitian (counseling group).Outcome measures Change in mean nutrient intakes compared with the Recommended Dietary Allowance (RDA); change in number of servings and mean grams of total fat contributed from 10 different food groups.Statistical analyses performed Analyses of variance and χ2 analyses.Results Children in every study group had mean intakes of all nutrients (except vitamin D) greater than 67% of the RDA 3 months after the baseline measurement. Several food groups (ie, meats, dairy products, fats/oils, and desserts) provided less total fat to the diets of children who reduced their dietary lipid intake after 3 months (ie, PCAT and counseling groups). These children also reduced the mean number of servings selected from these food groups. Within these same food groups, some children consumed fewer servings of higher fat foods and more servings of lower fat foods.Applications/conclusions Children who lowered their dietary fat intake after intervention reported both quantitative and qualitative changes in food choices from several food groups. These choices did not significantly reduce their nutrient intakes. J Am Diet Assoc. 1996; 96:865-873. 相似文献
1000.
Lynn Clark Callister PhD RN 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》1995,24(4):327-334
In no known culture in the world is childbearing treated with indifference. Cultural beliefs about and values associated with childbearing touch all aspects of social life in any given culture. Such beliefs and values lend perspective to the meaning of childbirth to the childbearing woman. Having the opportunity to share the woman's perceptions of the meaning of childbearing may foster the self-actualization, promote maternal role attainment, and improve her relationship with her significant other and enrich the family perspective. Nursing interventions across the childbearing year should be culturally sensitive to promote positive outcomes for the woman and her family. 相似文献