7,101 research outputs found
Development of ultraviolet lasers
The pulsed electron accelerator selected for use in the development of ultraviolet laser capability suitable for use in photoexcitation and photoionization studies of the upper atmosphere is reported. Performance figures, installation specifications, and total cost of the equipment are briefly shown, and plans for further studies are outlined
Recent trends in the incidence of anxiety diagnoses and symptoms in primary care.
Anxiety is common, with significant morbidity, but little is known about presentations and recording of anxiety diagnoses and symptoms in primary care. This study aimed to determine trends in incidence and socio-demographic variation in General Practitioner (GP) recorded diagnoses of anxiety, mixed anxiety/depression, panic and anxiety symptoms
Quantum dynamics of the avian compass
The ability of migratory birds to orient relative to the Earth's magnetic
field is believed to involve a coherent superposition of two spin states of a
radical electron pair. However, the mechanism by which this coherence can be
maintained in the face of strong interactions with the cellular environment has
remained unclear. This Letter addresses the problem of decoherence between two
electron spins due to hyperfine interaction with a bath of spin 1/2 nuclei.
Dynamics of the radical pair density matrix are derived and shown to yield a
simple mechanism for sensing magnetic field orientation. Rates of dephasing and
decoherence are calculated ab initio and found to yield millisecond coherence
times, consistent with behavioral experiments
Smoking as a predictor of frailty: a systematic review
BACKGROUND: Evidence on longitudinal associations between smoking and frailty is scarce. The objective of this study was to systematically review the literature on smoking as a predictor of frailty changes among community-dwelling middle-aged and older population. METHODS: A systematic search was performed using three electronic databases: MEDLINE, Embase and Scopus for studies published from 2000 through May 2015. Reference lists of relevant articles, articles shown as related citations in PubMed and articles citing the included studies in Google Scholar were also reviewed. Studies were included if they were prospective observational studies investigating smoking status as a predictor and subsequent changes in frailty, defined by validated criteria among community-dwelling general population aged 50 or older. A standardised data collection tool was used to extract data. Methodological quality was examined using the Newcastle-Ottawa Scale for cohort studies. RESULTS: A total of 1020 studies were identified and systematically reviewed for their titles, abstracts and full-text to assess their eligibilities. Five studies met inclusion criteria and were included in this review. These studies were critically reviewed and assessed for validity of their findings. Despite different methodologies and frailty criteria used, four of the five studies consistently showed baseline smoking was significantly associated with developing frailty or worsening frailty status at follow-up. Although not significant, the other study showed the same trend in male smokers. It is of note that most of the estimate measures were either unadjusted or only adjusted for a limited number of important covariates. CONCLUSIONS: This systematic review provides the evidence of smoking as a predictor of worsening frailty status in community-dwelling population. Smoking cessation may potentially be beneficial for preventing or reversing frailty
Permeability characteristics of the human nail plate
The permeation of chemicals across the nail plate and their consequent effects are discussed in relation to cosmetic toxicity and possible clinical efficacy. The reviewed data are then assessed and placed in context with recent observations on the direct assessment of permeability of the human nail plate. Although marked differences between the diffusional barrier characteristics of nail and stratum corneum are shown, a reasonably unified picture of nail plate permeability is drawn from the collective observations. The cosmetic and clinical implications of chemical penetration of the nail plate are briefly outlined and places where knowledge needs to be strengthened are identified. La permÉabilitÉ de l'ongie humainPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72442/1/j.1467-2494.1983.tb00348.x.pd
Association between frailty and quality of life among community-dwelling older people: a systematic review and meta-analysis
BACKGROUND: With growing numbers of older people worldwide, improving and maintaining quality of life during the extended years of life are a major focus for healthcare providers and policymakers. Some studies have suggested frailty may be associated with worse quality of life. OBJECTIVES: To review the associations between frailty and quality of life among community-dwelling older people. METHODS: A systematic literature search was performed using five databases for cross-sectional and longitudinal studies examining associations between frailty and quality of life among community-dwelling older people published in 2000 or later. Reference lists of relevant studies were also manually searched. Authors were requested for data for a meta-analysis if necessary. Meta-analysis was attempted for studies using the same frailty criteria and quality-of-life instrument. Methodological quality, heterogeneity and publication bias were assessed. RESULTS: The systematic review identified 5145 studies, among which 11 cross-sectional studies and two longitudinal studies were included in this review. Meta-analysis including four cross-sectional studies using the Fried Phenotype and 36-Item Short Form Health Survey showed that those classified as frail and prefrail had significantly lower mental and physical quality-of-life scores than those classified as non-frail. High heterogeneity and possible publication bias were noted. CONCLUSIONS: This systematic review and meta-analysis has demonstrated the evidence of a consistent inverse association between frailty/prefrailty and quality of life among community-dwelling older people. Interventions targeted at reducing frailty may have the additional benefit of improving corresponding quality of life. More longitudinal analysis is required to determine this effect
Frailty as a Predictor of Alzheimer Disease, Vascular Dementia, and All Dementia Among Community-Dwelling Older People: A Systematic Review and Meta-Analysis
OBJECTIVE: To perform a systematic search of the literature for currently available evidence on frailty as a predictor of dementia and to conduct a meta-analysis to synthesize the pooled risk estimates among community-dwelling older people. DESIGN: A systematic review and meta-analysis. DATA SOURCES: Embase, MEDLINE, CINAHL Plus, PsycINFO, and the Cochrane Library from 2000 to January 2016, and reference lists of relevant articles. ELIGIBILITY CRITERIA: Any studies that prospectively examined the incident risks of dementia with frailty among community-dwelling older people without language restriction. RESULTS: Of 2565 studies identified through the systematic review, 7 studies were included in this review. Of these, 4 studies reported hazard ratios (HR) of incident dementia for physical frailty defined by Cardiovascular Health Study criteria and were included in a meta-analysis. Frailty was a significant predictor of incident Alzheimer disease (4 studies: pooled HR = 1.28, 95% confidence interval (95% CI) = 1.00-1.63, P = .05), vascular dementia (2 studies: pooled HR 2.70, 95% CI 1.40-5.23, P = .003), and all dementia (3 studies: pooled HR 1.33, 95% CI 1.07-1.67, P = .01). Heterogeneity across the studies was low to modest (I(2) = 0%-51%). A random-effects meta-regression analysis showed that the female proportion of the cohort primarily mediated the association of frailty with Alzheimer disease (female proportion coefficient = 0.04, 95%CI = 0.01-0.08, P = .01). CONCLUSION: This systematic review and meta-analysis suggests that frailty was a significant predictor of Alzheimer disease, vascular dementia, and all dementia among community-dwelling older people. Frail women may have a higher risk of incident Alzheimer disease than frail men
Number of Pregnancies and Trajectory of Frailty Index: English Longitudinal Study of Ageing
OBJECTIVES: Women are frailer than men across different populations and age groups. However, the mechanisms are still not fully understood. One possible cause is pregnancy and motherhood. The objective of this study was to examine trajectories of Frailty Index over time according to the number of pregnancies. DESIGN: A prospective study with repeated measures over 14 years. SETTING AND PARTICIPANTS: A total of 2060 community-dwelling older women aged ≥60 years in England. METHODS: The number of pregnancies was calculated as a sum of the number of live births and the number of miscarriages, still-births, or abortions. The Frailty Index (FI) was constructed using 60 deficits and repeatedly calculated every 2 years over 14 years. Trajectories of FI according to the number of pregnancies were estimated by a mixed effects model. RESULTS: Mean FI was 0.15 at baseline. A mixed effects model adjusted for age, smoking, alcohol use, education, and wealth showed that FI increased over time. A higher number of pregnancies were significantly associated with a higher FI (estimate = 0.0047, 95% confidence interval = 0.0020, 0.0074). CONCLUSIONS AND IMPLICATIONS: The current study showed that a higher number of pregnancies were significantly associated with a higher degree of frailty at baseline and over time. Pregnancy and child rearing may explain some of the observed excess risk of frailty in women. Pregnancy-related factors, such as pregnancy loss, types of delivery, length of pregnancy, childbearing, and child rearing, should be examined in relation to frailty in future studies
- …