1,213 research outputs found
Low frequency sound propagation in activated carbon
Activated carbon can adsorb and desorb gas molecules onto and off its surface. Research has examined
whether this sorption affects low frequency sound waves, with pressures typical of audible
sound, interacting with granular activated carbon. Impedance tube measurements were undertaken
examining the resonant frequencies of Helmholtz resonators with different backing materials. It
was found that the addition of activated carbon increased the compliance of the backing volume.
The effect was observed up to the highest frequency measured (500 Hz), but was most significant at
lower frequencies (at higher frequencies another phenomenon can explain the behavior). An apparatus
was constructed to measure the effective porosity of the activated carbon as well as the number
of moles adsorbed at sound pressures between 104 and 118 dB and low frequencies between 20
and 55 Hz. Whilst the results were consistent with adsorption affecting sound propagation, other
phenomena cannot be ruled out. Measurements of sorption isotherms showed that additional energy
losses can be caused by water vapor condensing onto and then evaporating from the surface of the
material. However, the excess absorption measured for low frequency sound waves is primarily
caused by decreases in surface reactance rather than changes in surface resistance
A randomized controlled trial of anesthesia guided by bispectral index versus standard care: Effects on cognition
© 2019 AANA Publishing Inc. All rights reserved. Postoperative cognitive dysfunction, a subtle deterioration of cognitive function after exposure to anesthetics, is reported in 10% to 50% of surgical cases. Delivery of excessive inhalation anesthetics based on minimum alveolar concentration produces greater deep hypnotic times, which may contribute to postoperative cognitive dysfunction. This study tested the impact on cognitive function of balanced anesthetic using electroencephalographic (EEG) guidance vs usual anesthesia. We studied 88 surgical patients: 45 randomly assigned to balanced anesthetic technique with EEG guidance and 43 to standard treatment. Cognitive function was evaluated with the Cambridge Neuropsychological Test Automated Battery-Mild Cognitive Impairment at 3 intervals (preoperatively, 3-5 days postoperatively, and 3-5 months postoperatively). Additionally, 37 age- and sex-matched individuals not undergoing surgery or anesthesia were evaluated at the same intervals. Better outcomes were seen in the intervention group compared with usual care in the short-term/visual memory cognitive domain (P = .02) at 3 to 5 days, but not at 3 to 5 months. Delivery of anesthesia using EEG monitoring systems can reduce cumulative deep hypnotic time without negatively affecting patient physiologic stress, surgical conditions, or cognitive function. Our findings provide data to support optimal anesthetic approaches to improve cognitive function after anesthesia with volatile anesthetics
The relationship between psychological states and health perception in individuals at risk for cardiovascular disease
© 2019 Lee et al. Backgrounds: Perceptions of health are important to motivate people to change behaviors. Non-adherence to healthy behaviors that prevent cardiovascular disease may result from inadequate health perceptions. However, there are few studies investigating relationships between health perceptions and psychological states. Objective: To determine whether psychological states (ie, depressive symptoms and anxi-ety) are associated with the congruency between health perception and estimated risk for cardiovascular disease in adults with 2 or more cardiovascular disease risk factors. Methods: Community dwellers at risk for cardiovascular disease were asked to complete the Patient Health Questionnaire-9 and the anxiety subscale of the Brief Symptom Inventory to measure depressive symptoms and anxiety, respectively. Participants rated their perceived health from excellent to poor. The estimated cardiovascular disease risks were measured with the 10-year cardiovascular disease Framingham risk scores. Participants were grouped into three health perception groups based on congruency between levels of health perception and cardiovascular disease risk. Multivariate multinomial logistic regression was done to examine the association between psychological states and health perception groups. Results: Of 828 participants 54.7%, 12.0%, and 33.3% had congruent, pessimistically biased, and optimistically biased health perception, respectively. Depressive symptoms were significantly associated with pessimistic bias (adjusted odds ratio: 1.070, 95% confidence interval 1.010–1.133), but not anxiety. Optimistic bias was not associated with either depressive symptoms or anxiety. Conclusions: A mismatch between individual health perceptions and cardiovascular disease risks was associated with depressive symptoms. As health perception is affected by depressive symptoms, clinicians should assess depressive symptoms when exploring health perceptions and engaging individuals in decision-making about a healthy lifestyle
Generational Differences in Faculty and Student Comfort With Technology Use.
BackgroundNavigating through online education courses continues to be a struggle for some nursing students. At the same time, integrating technology into online courses can be difficult for nursing faculty.PurposeThe purpose of this study was to assess faculty technology integration practices, student attitudes about technology use, and generational differences related to faculty and student technology use.MethodsA descriptive cross-sectional survey design was used to obtain data for this study.ResultsIntegration of technology into online courses and student attitudes about technology use were not significantly different by generation. Faculty and students from the Baby Boomer and Generation X reported less comfort using technology and higher levels of anxiety using technology than did individuals from Generation Y.ConclusionSignificant generational variations were not noted in relation to technology integration into courses and overall student attitudes about technology in this study, but differences were noted in relation to comfort with use of technology and anxiety when using technology. Student learning outcomes and satisfaction with learning may be influenced by the student's comfort using technology and faculty's confidence in integrating and using technology to provide online instruction
Rationale, design and conduct of a randomised controlled trial evaluating a primary care-based complex intervention to improve the quality of life of heart failure patients: HICMan (Heidelberg Integrated Case Management) : study protocol
Background: Chronic congestive heart failure (CHF) is a complex disease with rising prevalence, compromised quality of life (QoL), unplanned hospital admissions, high mortality and therefore high burden of illness. The delivery of care for these patients has been criticized and new strategies addressing crucial domains of care have been shown to be effective on patients' health outcomes, although these trials were conducted in secondary care or in highly organised Health Maintenance Organisations. It remains unclear whether a comprehensive primary care-based case management for the treating general practitioner (GP) can improve patients' QoL. Methods/Design: HICMan is a randomised controlled trial with patients as the unit of randomisation. Aim is to evaluate a structured, standardized and comprehensive complex intervention for patients with CHF in a 12-months follow-up trial. Patients from intervention group receive specific patient leaflets and documentation booklets as well as regular monitoring and screening by a prior trained practice nurse, who gives feedback to the GP upon urgency. Monitoring and screening address aspects of disease-specific selfmanagement, (non)pharmacological adherence and psychosomatic and geriatric comorbidity. GPs are invited to provide a tailored structured counselling 4 times during the trial and receive an additional feedback on pharmacotherapy relevant to prognosis (data of baseline documentation). Patients from control group receive usual care by their GPs, who were introduced to guidelineoriented management and a tailored health counselling concept. Main outcome measurement for patients' QoL is the scale physical functioning of the SF-36 health questionnaire in a 12-month follow-up. Secondary outcomes are the disease specific QoL measured by the Kansas City Cardiomyopathy questionnaire (KCCQ), depression and anxiety disorders (PHQ-9, GAD-7), adherence (EHFScBS and SANA), quality of care measured by an adapted version of the Patient Chronic Illness Assessment of Care questionnaire (PACIC) and NTproBNP. In addition, comprehensive clinical data are collected about health status, comorbidity, medication and health care utilisation. Discussion: As the targeted patient group is mostly cared for and treated by GPs, a comprehensive primary care-based guideline implementation including somatic, psychosomatic and organisational aspects of the delivery of care (HICMAn) is a promising intervention applying proven strategies for optimal care. Trial registration: Current Controlled Trials ISRCTN30822978
Pregnant women with bronchial asthma benefit from progressive muscle relaxation: A randomized, prospective, controlled trial
Background: Asthma is a serious medical problem in pregnancy and is often associated with stress, anger and poor quality of life. The aim of this study was to determine the efficacy of progressive muscle relaxation (PMR) on change in blood pressure, lung parameters, heart rate, anger and health-related quality of life in pregnant women with bronchial asthma. Methods: We treated a sample of 64 pregnant women with bronchial asthma from the local population in an 8-week randomized, prospective, controlled trial. Thirty-two were selected for PMR, and 32 received a placebo intervention. The systolic blood pressure, forced expiratory volume in the first second, peak expiratory flow and heart rate were tested, and the State-Trait Anger Expression Inventory and Health Survey (SF-36) were employed. Results: According to the intend-to-treat principle, a significant reduction in systolic blood pressure and a significant increase in both forced expiratory volume in the first second and peak expiratory flow were observed after PMR. The heart rate showed a significant increase in the coefficient of variation, root mean square of successive differences and high frequency ranges, in addition to a significant reduction in low and middle frequency ranges. A significant reduction on three of five State-Trait Anger Expression Inventory scales, and a significant increase on seven of eight SF-36 scales were observed. Conclusions: PMR appears to be an effective method to improve blood pressure, lung parameters and heart rate, and to decrease anger levels, thus enhancing health-related quality of life in pregnant women with bronchial asthma. Copyright (c) 2006 S. Karger AG, Basel
What Can a Pilot Congestive Heart Failure Disease Management Program Tell Us about Likely Return on Investment?: A Case Study from a Program Offered to Federal Employees
In 1999, the Blue Cross and Blue Shield Federal Employee Program (FEP) implemented a pilot disease management program to manage congestive heart failure (CHF) among members. The purpose of this project was to estimate the financial return on investment in the pilot CHF program, prior to a full program rollout. A cohort of 457 participants from the state of Maryland was matched to a cohort of 803 nonparticipants from a neighboring state where the CHF program was not offered. Each cohort was followed for 12 months before the program began and 12 months afterward. The outcome measures of primary interest were the differences over time in medical care expenditures paid by FEP and by all payers. Independent variables included indicators of program participation, type of heart disease, comorbidity measures, and demographics. From the perspective of the funding organization (FEP), the estimated return on investment for the pilot CHF disease management program was a savings of 1.15 in medical expenditures per dollar spent on the program. The amount of savings depended upon CHF risk levels. The value of a pilot initiative and evaluation is that lessons for larger-scale efforts can be learned prior to full-scale rollout. (Disease Management 2005;8:346-360)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63402/1/dis.2005.8.346.pd
The impact of personality factors on delay in seeking treatment of acute myocardial infarction
<p>Abstract</p> <p>Background</p> <p>Early hospital arrival and rapid intervention for acute myocardial infarction is essential for a successful outcome. Several studies have been unable to identify explanatory factors that slowed decision time. The present study examines whether personality, psychosocial factors, and coping strategies might explain differences in time delay from onset of symptoms of acute myocardial infarction to arrival at a hospital emergency room.</p> <p>Methods</p> <p>Questionnaires on coping strategies, personality dimensions, and depression were completed by 323 patients ages 26 to 70 who had suffered an acute myocardial infarction. Tests measuring stress adaptation were completed by 180 of them. The patients were then categorised into three groups, based on time from onset of symptoms until arrival at hospital, and compared using logistic regression analysis and general linear models.</p> <p>Results</p> <p>No correlation could be established between personality factors (i.e., extraversion, neuroticism, openness, agreeableness, conscientiousness) or depressive symptoms and time between onset of symptoms and arrival at hospital. Nor was there any significant relationship between self-reported patient coping strategies and time delay.</p> <p>Conclusions</p> <p>We found no significant relationship between personality factors, coping strategies, or depression and time delays in seeking hospital after an acute myocardial infraction.</p
synaptojanin1 Is Required for Temporal Fidelity of Synaptic Transmission in Hair Cells
To faithfully encode mechanosensory information, auditory/vestibular hair cells utilize graded synaptic vesicle (SV) release at specialized ribbon synapses. The molecular basis of SV release and consequent recycling of membrane in hair cells has not been fully explored. Here, we report that comet, a gene identified in an ENU mutagenesis screen for zebrafish larvae with vestibular defects, encodes the lipid phosphatase Synaptojanin 1 (Synj1). Examination of mutant synj1 hair cells revealed basal blebbing near ribbons that was dependent on Cav1.3 calcium channel activity but not mechanotransduction. Synaptojanin has been previously implicated in SV recycling; therefore, we tested synaptic transmission at hair-cell synapses. Recordings of post-synaptic activity in synj1 mutants showed relatively normal spike rates when hair cells were mechanically stimulated for a short period of time at 20 Hz. In contrast, a sharp decline in the rate of firing occurred during prolonged stimulation at 20 Hz or stimulation at a higher frequency of 60 Hz. The decline in spike rate suggested that fewer vesicles were available for release. Consistent with this result, we observed that stimulated mutant hair cells had decreased numbers of tethered and reserve-pool vesicles in comparison to wild-type hair cells. Furthermore, stimulation at 60 Hz impaired phase locking of the postsynaptic activity to the mechanical stimulus. Following prolonged stimulation at 60 Hz, we also found that mutant synj1 hair cells displayed a striking delay in the recovery of spontaneous activity. Collectively, the data suggest that Synj1 is critical for retrieval of membrane in order to maintain the quantity, timing of fusion, and spontaneous release properties of SVs at hair-cell ribbon synapses
- …