2,347 research outputs found
Reaction of the chick to one atmosphere of oxygen
Experiment to determine chicken reaction to 100 percent oxygen at atmospheric pressur
Embryo development and chick growth in a helium - oxygen atmosphere
Embryo development and chick growth in helium- oxygen atmospher
Recommended from our members
Environmental Tobacco Smoke Exposure in Relation to Family Characteristics, Stressors and Chemical Co-Exposures in California Girls.
Childhood environmental tobacco smoke (ETS) exposure is a risk factor for adverse health outcomes and may disproportionately burden lower socioeconomic status groups, exacerbating health disparities. We explored associations of demographic factors, stressful life events, and chemical co-exposures, with cotinine levels, among girls in the CYGNET Study. Data were collected from families of girls aged 6-8 years old in Northern California, through clinic exams, questionnaires and biospecimens (n = 421). Linear regression and factor analysis were conducted to explore predictors of urinary cotinine and co-exposure body burdens, respectively. In unadjusted models, geometric mean cotinine concentrations were higher among Black (0.59 ug/g creatinine) than non-Hispanic white (0.27), Asian (0.32), or Hispanic (0.34) participants. Following adjustment, living in a rented home, lower primary caregiver education, and lack of two biologic parents in the home were associated with higher cotinine concentrations. Girls who experienced parental separation or unemployment in the family had higher unadjusted cotinine concentrations. Higher cotinine was also associated with higher polybrominated diphenyl ether and metals concentrations. Our findings have environmental justice implications as Black and socio-economically disadvantaged young girls experienced higher ETS exposure, also associated with higher exposure to other chemicals. Efforts to reduce ETS and co-exposures should account for other disparity-related factors
Impaired muscle oxygen use at onset of exercise in peripheral arterial disease
ObjectivesIn patients with peripheral arterial disease (PAD), abnormal muscle metabolism and impaired oxygen delivery distal to the arterial occlusions may contribute to the exercise limitation observed in this population. Muscle tissue hemoglobin saturation (StO2), measured with near-infrared spectroscopy, reflects the relative contributions of oxygen delivery and oxygen use. Thus differences in the kinetics of StO2 in response to exercise may yield important insight into the potential mechanisms associated with the PAD exercise impairment. The purposes of this study were to characterize the muscle oxygenation responses in patients with PAD and in healthy control subjects at the onset of exercise, and to compare the kinetics of StO2 desaturation. We hypothesized that at the onset of exercise the kinetics of StO2 desaturation would be slowed in PAD compared with control responses.Material and methodsSix patients with PAD and 6 healthy control subjects from a university center were examined in a prospective cross-sectional analysis that evaluated the desaturation kinetics of StO2 at the onset of walking exercise. On separate visits subjects performed graded treadmill exercise and 3 constant work rate treadmill tests equivalent to ∼60% (low), ∼80% (medium), and 100% (peak) of their peak exercise work rate. Gastrocnemious muscle StO2 response profiles (InSpectra tissue spectrometer) were measured at rest and across the rest to exercise transition. Muscle StO2 responses were characterized by an exponential mathematical model. The end point value was taken as the time constant of StO2 desaturation after onset of exercise (ie, equivalent to time to reach approximately 63% of StO2 decrease).ResultsThe patients with PAD and the control subjects were of similar age and activity level. The qualitative patterns of StO2 responses at onset of exercise were also similar between patients and control subjects at all work rates. However, the kinetic time constants of StO2 desaturation were prolonged in patients with PAD versus control subjects (averaged time constant across all work rates, 21.9 ± 9.4 seconds vs 4.9 ± 2.2 seconds; P < .01).ConclusionsThe slowed muscle StO2 kinetics in PAD are consistent with an impairment in muscle oxygen use at the onset of walking exercise. Impaired muscle metabolism may contribute to the altered physiologic responses to exercise and to exercise impairment in patients with PAD
Characteristics of Esophageal Cancer Cases in Tanzania.
PurposeAge-standardized incidence rates for esophageal cancer (EC) in East Africa have been reported as disproportionately high compared with the worldwide incidence of nine per 100,000 population. This study aimed to characterize EC cases seen at Muhimbili National Hospital and Ocean Road Cancer Institute in Dar es Salaam, Tanzania.MethodsDemographic, clinical, and treatment variables were abstracted from charts of patients who received care for a diagnosis of EC at one or both institutions between 2011 and 2013. Categorical data were summarized as frequency counts and percentages. Continuous data were presented as medians and ranges. To compare men and women, Pearson's χ2 and two-sample t tests were applied.ResultsSeven hundred thirty-eight unique cases of EC were identified, of whom 68% were men and the median age was 60 years (range, 19 to 95 years). Notably, 93 cases (13%) were ≤ 40 years old at diagnosis. Squamous cell carcinoma was the dominant histology, comprising 90% of cases with documented histopathology. However, 34% of cases with a diagnosis of EC were not pathologically confirmed. The stage was documented as locoregional in 4% of cases, locally advanced in 20% of cases, metastatic in 14% of cases, and unknown in 63% of cases. Of 430 patients who received treatment at Ocean Road Cancer Institute, 76% were treated with radiation, 44% were treated with chemotherapy, 3% underwent a cancer-related surgical procedure, and 10% of cases received no cancer-directed therapy. The median overall survival for all patients was 6.9 months (95% CI, 5.0 to 12.8), regardless of stage at presentation.ConclusionBetween 2011 and 2013, cases of EC represented a large clinical burden at both institutions
The relationship of multicultural awareness and belief of rape myths with intellectual empathy and empathic emotion for victims of acquaintance and stranger rape among undergraduate women and men
Title from PDF of title page, viewed on September 26, 2011Dissertation advisor: Changming DuanVitaIncludes bibliographical references (p. 92-100)Thesis (Ph.D.)--School of Education. University of Missouri--Kansas City, 2008.The purpose of this dissertation was to evaluate the contribution of observer sex, type of rape, multicultural awareness and belief in rape myths to intellectual empathy and empathic emotions of male and female college students toward acquaintance or stranger rape victims. This study also sought to explore if there were interactions between and among these variables which would predict additional variance in intellectual empathy and empathic emotion. The results of the study showed that observers' who read the stranger rape scenario held significantly more intellectual empathy for rape victims than observers who read the acquaintance rape scenario. Participants who endorsed lower levels of belief in rape myths also held more intellectual empathy for rape victims than participants who endorsed higher levels of belief in rape myths. The study did not find support for the hypothesis that type of rape scenario, sex, belief in rape myths, and multicultural awareness contributed to empathic emotion for rape victims. Interactions of the study variables did not predict additional variance in intellectual empathy nor emphatic emotion for victims of rape.Introduction -- Literature review -- Methods -- Results -- Discussion -- Appendix A. Consent form -- Appendix B. Debriefing sheets -- Appendix C. Measures -- Appendix D. Stimulus materials
Screening Mammography Use in Older Women According to Health Status: A Systematic Review and Meta-Analysis
Background: The extent to which screening mammography (SM) recommendations in older women incorporate life expectancy factors is not well established.
Objective: The objective of this review was to evaluate evidence on SM utilization in older women by life expectancy factors.
Data sources: We searched Medline, Embase and Web of Science from January 1991 to March 2016.
Study selection: We included studies examining SM utilization in women ages ≥ 65 years that measured life expectancy using comorbidity, functional limitations or health or prognostic status.
Data extraction and synthesis: ORs and 95% CIs were extracted and grouped by life expectancy category. Findings were aggregated into pooled ORs and 95% CIs and meta-analyzed by life expectancy category.
Main outcomes and measures: The primary outcome was SM utilization within the last 5 years. Life expectancy factors included number of comorbidities, Charlson Comorbidity Index (CCI), activities of daily living, instrumental activities of daily living, self-reported health status and 5-year prognostic indices.
Results: Of 2,606 potential titles, we identified 25 meeting the inclusion criteria (comorbidity: eight studies, functional status: 11 studies and health/prognostic status: 13 studies). Women with higher CCI scores had decreased SM utilization (pooled OR: 0.75, 95% CI: 0.67–0.85), but increased absolute number of comorbidities were weakly associated with increased SM utilization (pooled OR: 1.17, 95% CI: 1.00–1.36). Women with more functional limitations had lower SM use odds than women with no limitations (pooled OR: 0.72, 95% CI: 0.62–0.83). Screening utilization odds were lower among women with poor vs excellent health (pooled OR: 0.85, 95% CI: 0.74–0.96).
Conclusion: Greater CCI score, functional limitations and lower perceived health were associated with decreased SM use, whereas higher absolute number of comorbidities was associated with increased SM use. SM guidelines should consider these factors to improve assessments of potential benefits and harms in older women
- …