Origin of the giant magnetic moments of Fe impurities on and in Cs films

To explore the origin of the observed giant magnetic moments ($\sim 7 \mu_B$) of Fe impurities on the surface and in the bulk of Cs films, we have performed the relativistic LSDA + U calculations using the linearized muffin-tin orbital (LMTO) band method. We have found that Fe impurities in Cs behave differently from those in noble metals or in Pd. Whereas the induced spin polarization of Cs atoms is negligible, the Fe ion itself is found to be the source of the giant magnetic moment. The 3d electrons of Fe in Cs are localized as the 4f electrons in rare-earth ions so that the orbital magnetic moment becomes as large as the spin magnetic moment. The calculated total magnetic moment of $M = 6.43 \mu_B$, which comes mainly from Fe ion, is close to the experimentally observed value.Comment: 4 pages including 3 figures and 1 table. Submitted to PR

Evaluation of renal Kt/V as a marker of renal function in predialysis patients

Evaluation of renal Kt/V as a marker of renal function in predialysis patients.BackgroundThe use of renal Kt/V (r-Kt/V) as an indicator for the need of dialysis initiation has been recommended in the NKF-DOQI guidelines. In analogy to clinical practice in peritoneal dialysis, a fall of r-Kt/V below a threshold of 2.0 per week may indicate inadequate renal toxin elimination. However, there are no studies linking r-Kt/V with other parameters of glomerular filtration rate (GFR) in predialysis patients, and the validity of r-Kt/V as parameter for timing of dialysis initiation is unknown.MethodsRenal function was assessed repeatedly in 125 patients (N = 465 measurements). In predialysis patients (r-Kt/V <2.5 per week) r-Kt/V was compared with creatinine [CCr], urea [CUr], averaged creatinine/urea clearance [CCr/Ur], Cockcroft-Gault formula [CCG], and MDRD prediction equation 6 (MDRD6-GFR). The diagnostic performance of r-Kt/V as a parameter for timing the initiation of dialysis was evaluated.ResultsRenal Kt/V <2.5 was prevalent in 24.9% of cases (N = 116, mean 1.92 ± 0.34). In this group mean CCr was 13.8 ± 4.9, mean CUr 6.7 ± 1.3, and CCr/Ur 10.2 ± 2.9mL/min/1.73m2. There was no correlation of r-Kt/V with serum creatinine and MDRD6-GFR, but a significantly positive correlation with CCr/Ur (r2 = 0.3382, P < 0.001). Sensitivity of r-Kt/V to detect CCr/Ur < 10.5mL/min/1.73m2, defined as the threshold for dialysis initiation, was 73.6% with a specificity of 91.9%.ConclusionsThese results suggest that r-Kt/V is a parameter of acceptable specificity but poor sensitivity for the timing of dialysis initiation. Additional measures of renal function, such as the average of measured creatinine and urea clearance, also should be taken into consideration when deciding on the timing of dialysis initiation prior to the development of clinical signs of uremia and malnutrition

Event-Free Survival in Adults With Heart Failure who Engage in Self-Care Management

Background Self-care management in heart failure (HF) involves decision-making to evaluate, and actions to ameliorate symptoms when they occur. This study sought to compare the risks of all-cause mortality, hospitalization, or emergency-room admission among HF patients who practice above-average self-care management, those who practice below-average self-care management, and those who are symptom-free. Methods A secondary analysis was conducted of data collected on 195 HF patients. A Cox proportional hazards model was used to examine the association between self-care management and event risk. Results The sample consisted of older (mean ± standard deviation = 61.3 ± 11 years), predominantly male (64.6%) adults, with an ejection fraction of 34.7% ± 15.3%; 60.1% fell within New York Heart Association class III or IV HF. During an average follow-up of 364 ± 288 days, 4 deaths, 82 hospitalizations, and 5 emergency-room visits occurred as first events. Controlling for 15 common confounders, those who engaged in above-average self-care management (hazard ratio, .44; 95% confidence interval, .22 to .88; P \u3c .05) and those who were symptom-free (hazard ratio, 0.48; 95% confidence interval, .24 to .97; P \u3c .05) ran a lower risk of an event during follow-up than those engaged in below-average self-care management. Conclusion Symptomatic HF patients who practice above-average self-care management have an event-free survival benefit similar to that of symptom-free HF patients

A Systematic Review of Biological Mechanisms of Fatigue in Chronic Illness

Fatigue, a commonly reported symptom, is defined as an overwhelming, debilitating, and sustained sense of exhaustion that decreases the ability to function and carry out daily activities. To date, cancer researchers have been in the forefront in investigating the possible biological mechanisms of fatigue, identifying inflammation, dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis, and activation of the autonomic nervous system. The purpose of this systematic review is to describe fatigue and what is known about the biological mechanisms described in cancer in five chronic, noninfectious illnesses: heart failure, multiple sclerosis, chronic kidney disease, rheumatoid arthritis, and chronic obstructive pulmonary disease. We searched PubMed and EMBASE using fatigue as a major Medical subject headings (MeSH) heading with each individual disease added as a search term followed by each biological mechanism. We included only primary research articles published in English between 1996 and 2016 describing studies conducted in adult humans. We identified 26 relevant articles. While there is some evidence that the biological mechanisms causing fatigue in cancer are also associated with fatigue in other chronic illnesses, more research is needed to explore inflammation, the HPA axis, and the autonomic nervous system, and other mechanisms in relation to fatigue in a variety of chronic illnesses

Development and initial testing of the self‐care of chronic illness inventory

Aim The aim was to develop and psychometrically test the self‐care of chronic illness Inventory, a generic measure of self‐care. Background Existing measures of self‐care are disease‐specific or behaviour‐specific; no generic measure of self‐care exists. Design Cross‐sectional survey. Methods We developed a 20‐item self‐report instrument based on the Middle Range Theory of Self‐Care of Chronic Illness, with three separate scales measuring Self‐Care Maintenance, Self‐Care Monitoring, and Self‐Care Management. Each of the three scales is scored separately and standardized 0–100 with higher scores indicating better self‐care. After demonstrating content validity, psychometric testing was conducted in a convenience sample of 407 adults (enrolled from inpatient and outpatient settings at five sites in the United States and ResearchMatch.org). Dimensionality testing with confirmatory factor analysis preceded reliability testing. Results The Self‐Care Maintenance scale (eight items, two dimensions: illness‐related and health‐promoting behaviour) fit well when tested with a two‐factor confirmatory model. The Self‐Care Monitoring scale (five items, single factor) fitted well. The Self‐Care Management scale (seven items, two factors: autonomous and consulting behaviour), when tested with a two‐factor confirmatory model, fitted adequately. A simultaneous confirmatory factor analysis on the combined set of items supported the more general model. Conclusion The self‐care of chronic illness inventory is adequate in reliability and validity. We suggest further testing in diverse populations of patients with chronic illnesses

Critical Care Nurses\u27 Beliefs About and Reported Management of Anxiety

Background: Anxiety is associated with increased morbidity and mortality. Critical care nurses are uniquely positioned to reduce anxiety in their patients. Critical care nurses\u27 beliefs about and frequency of use of strategies to reduce anxiety have not been studied. Objectives: To explore critical care nurses\u27 beliefs about the importance of anxiety management and to describe nurses\u27 reported use of strategies to manage anxiety in their patients. Methods: A random sample (N = 2500) of members of the American Association of Critical-Care Nurses was asked to complete the Critical Care Nurse Anxiety Identification and Management Survey. Results: Respondents (n = 783) were primarily female (92%), white (88.5%) staff nurses (74.1%) who thought that anxiety is potentially harmful (mean, 4.1; SD, 0.8; range, 1 = no harm to 5 = life-threatening harm), that anxiety management is important (mean, 4.8; SD 0.6; range, 1 = no benefit to 5 = profound benefit). A majority commonly used pharmacological management; most also used information and communication interventions. Fewer subjects used the presence of patients\u27 family members to alleviate patients\u27 anxiety; few reported using stress-reduction techniques. Conclusion: Most respondents thought that treating anxiety is important and beneficial. Commonly used strategies included pharmacological relief of anxiety and pain and information and communication interventions. Although these strategies are useful, they may not effectively reduce anxiety in all patients

Evaluation of Transmitral Pressure Gradients in the Intraoperative Echocardiographic Diagnosis of Mitral Stenosis after Mitral Valve Repair

OBJECTIVE: Acute mitral stenosis (MS) following mitral valve (MV) repair is a rare but severe complication. We hypothesize that intraoperative echocardiography can be utilized to diagnose iatrogenic MS immediately after MV repair. METHODS: The medical records of 552 consecutive patients undergoing MV repair at a single institution were reviewed. Post-cardiopulmonary bypass peak and mean transmitral pressure gradients (TMPG), and pressure half time (PHT) were obtained from intraoperative transesophageal echocardiographic (TEE) examinations in each patient. RESULTS: Nine patients (9/552 = 1.6%) received a reoperation for primary MS, prior to hospital discharge. Interestingly, all of these patients already showed intraoperative post-CPB mean and peak TMPGs that were significantly higher compared to values for those who did not: 10.7±4.8 mmHg vs 2.9±1.6 mmHg; p<0.0001 and 22.9±7.9 mmHg vs 7.6±3.7 mmHg; p<0.0001, respectively. However, PHT varied considerably (87±37 ms; range: 20-439 ms) within the entire population, and only weakly predicted the requirement for reoperation (113±56 vs. 87±37 ms, p = 0.034). Receiver operating characteristic curves showed strong discriminating ability for mean gradients (AUC = 0.993) and peak gradients (area under the curve, AUC = 0.996), but poor performance for PHT (AUC = 0.640). A value of ≥7 mmHg for mean, and ≥17 mmHg for peak TMPG, best separated patients who required reoperation for MS from those who did not. CONCLUSIONS: Intraoperative TEE diagnosis of a peak TMPG ≥17 mmHg or mean TMPG ≥7 mmHg immediately following CPB are suggestive of clinically relevant MS after MV repair

Gender Differences in and Factors Related to Self-Care Behaviors: A Cross-Sectional, Correlational Study of Patients With Heart Failure

Background Although self-care may reduce exacerbations of heart failure, reported rates of effective self-care in patients with heart failure are low. Modifiable factors, including psychosocial status, knowledge, and physical factors, are thought to influence heart failure self-care, but little is known about their combined impact on self-care. Objectives The objective of this study was to identify factors related to self-care behaviors in patients with heart failure. Design A cross-sectional, correlational study design was used. Participants and settings One hundred twenty-two patients (77 men and 45 women, mean age 60 ± 12 years old, 66% New York Heart Association functional class III/IV) were recruited from the outpatient clinics of an academic medical center and two community hospitals. Methods Data on self-care behaviors (Self-Care of Heart Failure Index), depressive symptoms, perceived control, self-care confidence, knowledge, functional status, and social support were collected. Factors related to self-care were examined using hierarchical multiple regression. Results Mean self-care behavior scores were less than 70 indicating the majority of men and women with HF did not consistently engage in self-care behaviors. Higher self-care confidence and perceived control and better heart failure management knowledge were associated with better self-care (r2 = .25, p \u3c .001). Higher perceived control and better knowledge were related to better self-care behaviors in men (r2 = .18, p = .001), while higher self-care confidence and poorer functional status were related to better self-care behaviors in women (r2 = .35, p \u3c .001). Conclusion This study demonstrates the substantial impact of modifiable factors such as confidence in one’s self-care abilities, perceived control, and knowledge on self-care behaviors. This study demonstrates that there are gender differences in factors affecting self-care, even though at baseline men and women have similar knowledge levels, physical, psychological, and behavioral status. Effective interventions focusing on modifiable factors and the unique characteristics of men and women should be provided to improve self-care behaviors in patients with heart failure

Utilizing automatically collected smart card data to enhance travel demand surveys

Thesis (S.M. in Transportation)--Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 119-120).Public transport agencies have used manual surveys to collect demographic and travel diary information in order to understand their customers' travel behavior for many years. Recently many agencies have also begun to use automated sources of data from fare collection, vehicle location, and passenger counting systems to improve the understanding of their customers' detailed geographic and temporal travel behavior as well as frequency of usage, and travel pattern variation at a much larger scale than is possible with manually collected survey data. Transport for London (TfL), the public body responsible for all transportation services in London, was chosen as a case study to determine how and to what extent automatic fare card (Oyster) data can be used to enhance and validate the London Travel Demand Survey (LTDS) single day travel diary responses. This thesis found that combining survey responses with linked Oyster data for specific households could greatly enhance the validity of the single travel day and improve the understanding of the variability of weekly public transport (PT) use. However, it was difficult to match the survey diary responses and Oyster card records after the interview had taken place. This was evidenced by the fact that only 51.1% of Oyster journey stages had matching survey journey stages, only 45.6% of survey stages had matching Oyster stages, and only 44% of the sample had perfectly matching survey and Oyster stages. Even when there were matches, there were large differences in many journey start times and durations with an average start time difference of 61.2 minutes. This suggests that it would be advantageous to integrate the Oyster records earlier in the survey process, using some type of prompted recall methods with Oyster records in the near term, and new location tracking smart phone applications in the future. Analysis of the weekly variation in PT travel found that the single day survey overestimates typical PT use overall, but it underestimates the intensity of PT use on days when the survey sample chose to use the PT mode. Additionally, the reported frequency of PT use in the LTDS was significantly higher than the actual use as captured by the Oyster system, and therefore the LTDS is generally overestimating the PT use overall for London residents.by Laura K. Riegel.S.M.in Transportatio