242 research outputs found
Quantification of optical pulsed-plane-wave-shaping by chiral sculptured thin films
The durations and average speeds of ultrashort optical pulses transmitted
through chiral sculptured thin films (STFs) were calculated using a
finite-difference time-domain algorithm. Chiral STFs are a class of
nanoengineered materials whose microstructure comprises parallel helicoidal
nanowires grown normal to a substrate. The nanowires are 10-300 nm in
diameter and m in length. Durations of transmitted pulses tend to
increase with decreasing (free-space) wavelength of the carrier plane wave,
while average speeds tend to increase with increasing wavelength. An increase
in nonlinearity, as manifested by an intensity-dependent refractive index in
the frequency domain, tends to increase durations of transmitted pulses and
decrease average speeds. The circular Bragg phenomenon exhibited by a chiral
STFs manifests itself in the frequency domain as high reflectivity for normally
incident carrier plane waves whose circular polarization state is matched to
the structural handedness of the film and whose wavelength falls in a range
known as the Bragg regime; films of the opposite structural handedness reflect
such plane waves little. This effect tends to distort the shapes of transmitted
pulses with respect to the incident pulses, and such shaping can cause sharp
changes in some measures of average speed with respect to carrier wavelength. A
local maximum in the variation of one measure of the pulse duration with
respect to wavelength is noted and attributed to the circular Bragg phenomenon.
Several of these effects are explained via frequency-domain arguments. The
presented results serve as a foundation for future theoretical and experimental
studies of optical pulse propagation through causal, nonlinear, nonhomogeneous,
and anisotropic materials.Comment: To appear in Journal of Modern Optic
Clinical-pathological study on β-APP, IL-1β, GFAP, NFL, Spectrin II, 8OHdG, TUNEL, miR-21, miR-16, miR-92 expressions to verify DAI-diagnosis, grade and prognosis
Traumatic brain injury (TBI) is one of the most important death and disability cause, involving substantial costs, also in economic terms, when considering the young age of the involved subject. Aim of this paper is to report a series of patients treated at our institutions, to verify neurological results at six months or survival; in fatal cases we searched for βAPP, GFAP, IL-1β, NFL, Spectrin II, TUNEL and miR-21, miR-16, and miR-92 expressions in brain samples, to verify DAI diagnosis and grade as strong predictor of survival and inflammatory response. Concentrations of 8OHdG as measurement of oxidative stress was performed. Immunoreaction of β-APP, IL-1β, GFAP, NFL, Spectrin II and 8OHdG were significantly increased in the TBI group with respect to control group subjects. Cell apoptosis, measured by TUNEL assay, were significantly higher in the study group than control cases. Results indicated that miR-21, miR-92 and miR-16 have a high predictive power in discriminating trauma brain cases from controls and could represent promising biomarkers as strong predictor of survival, and for the diagnosis of postmortem traumatic brain injury
Financial impact of reducing door-to-balloon time in ST-elevation myocardial infarction: a single hospital experience
<p>Abstract</p> <p>Background</p> <p>The impact of reducing door-to-balloon time on hospital revenues, costs, and net income is unknown.</p> <p>Methods</p> <p>We prospectively determined the impact on hospital finances of (1) emergency department physician activation of the catheterization lab and (2) immediate transfer of the patient to an immediately available catheterization lab by an in-house transfer team consisting of an emergency department nurse, a critical care unit nurse, and a chest pain unit nurse. We collected financial data for 52 consecutive ST-elevation myocardial infarction patients undergoing emergency percutaneous intervention from October 1, 2004–August 31, 2005 and compared this group to 80 consecutive ST-elevation myocardial infarction patients from September 1, 2005–June 26, 2006 after protocol implementation.</p> <p>Results</p> <p>Per hospital admission, insurance payments (hospital revenue) decreased (36,670 vs. 16,185, P = 0.039) along with total hospital costs (31,453 vs. 9,242, P = 0.009). Hospital net income per admission was unchanged (7134, P = 0.95) as the drop in hospital revenue equaled the drop in costs. For every 1077 for private payers and 70,430 ± 53,514 ± 100,000 (7.7% vs. 0%, P = 0.022) all contributed to decreasing ST-elevation myocardial infarction hospitalization revenue. One-year post-discharge financial follow-up revealed similar results: Insurance payments: 53,741 vs. 23,125, P = 0.044; Total hospital costs: 37,434 vs. 15,561, P = 0.007; Net Income: 9159, P = 0.855.</p> <p>Conclusion</p> <p>All of the financial benefits of reducing door-to-balloon time in ST-elevation myocardial infarction go to payers both during initial hospitalization and after one-year follow-up.</p> <p>Trial Registration</p> <p><b>ClinicalTrials.gov ID</b>: NCT00800163</p
Preliminary outcomes of a paediatric highly active antiretroviral therapy cohort from KwaZulu-Natal, South Africa
BACKGROUND: Few studies address the use of paediatric highly active antiretroviral therapy (HAART) in Africa. METHODS: We performed a retrospective cohort study to investigate preliminary outcomes of all children eligible for HAART at Sinikithemba HIV/AIDS clinic in KwaZulu-Natal, South Africa. Immunologic, virologic, clinical, mortality, primary caregiver, and psychosocial variables were collected and analyzed. RESULTS: From August 31, 2003 until October 31, 2005, 151 children initiated HAART. The median age at HAART initiation was 5.7 years (range 0.3–15.4). Median follow-up time of the cohort after HAART initiation was 8 months (IQR 3.5–13.5). The median change in CD4% from baseline (p < 0.001) was 10.2 (IQR 5.0–13.8) at 6 months (n = 90), and 16.2 (IQR 9.6–20.3) at 12 months (n = 59). Viral loads (VLs) were available for 100 children at 6 months of which 84% had HIV-1 RNA levels ≤ 50 copies/mL. At 12 months, 80.3% (n = 61) had undetectable VLs. Sixty-five out of 88 children (73.8%) reported a significant increase (p < 0.001) in weight after the first month. Eighty-nine percent of the cohort (n = 132) reported ≤ 2 missed doses during any given treatment month (> 95%adherence). Seventeen patients (11.3%) had a regimen change; two (1.3%) were due to antiretroviral toxicity. The Kaplan-Meier one year survival estimate was 90.9% (95%confidence interval (CI) 84.8–94.6). Thirteen children died during follow-up (8.6%), one changed service provider, and no children were lost to follow-up. All 13 deaths occurred in children with advanced HIV disease within 5 months of treatment initiation. In multivariate analysis of baseline variables against mortality using Cox proportional-hazards model, chronic gastroenteritis was associated with death [hazard ratio (HR), 12.34; 95%CI, 1.27–119.71) and an HIV-positive primary caregiver was found to be protective against mortality [HR, 0.12; 95%CI, 0.02–0.88). Age, orphanhood, baseline CD4%, and hemoglobin were not predicators of mortality in our cohort. Fifty-two percent of the cohort had at least one HIV-positive primary caregiver, and 38.4% had at least one primary caregiver also on HAART at Sinikithemba clinic. CONCLUSION: This report suggests that paediatric HAART can be effective despite the challenges of a resource-limited setting
Practicing physiotherapy in Danish private practice: an ethical perspective.
Despite an increasingly growth of professional guidelines, textbooks and research about ethics in health care, awareness about ethics in Danish physiotherapy private practice seen vague. This article explores how physiotherapists in Danish private practice, from an ethical perspective, perceive to practice physiotherapy. The empirical data consists of interviews with twenty-one physiotherapists. The interviews are analysed from a hermeneutic approach, inspired by Ricoeur's textual interpretation of distanciation. The analysis follows three phases: naïve reading, structural analysis and comprehensive analysis. Four main themes are constructed: Beneficence as the driving force; Disciplining the patient through the course of physiotherapy; Balancing between being a trustworthy professional and a businessperson; The dream of a code of practice. Private practice physiotherapy is embedded in a structural frame directed by both political and economical conditions that shape the conditions for practicing physiotherapy. It means that beneficence in practice is a balance between the patient, the physiotherapists themselves and the business. Beneficence towards the patient is expressed as an implicit demand. Physiotherapeutic practice is expressed as being an integration of professionalism and personality which implies that the physiotherapists also have to benefit themselves. Private practice seems to be driven by a paternalistic approach towards the patient, where disciplining the patient is a crucial element of practice, in order to optimise profit. Physiotherapists wish for a more beneficent practice in the future by aiming at bridging 'to be' and 'ought to be'
The Implementation of Mindfulness-Based Cognitive Therapy: Learning From the UK Health Service Experience
Generation and acceleration of electron bunches from a plasma photocathode
Plasma waves generated in the wake of intense, relativistic laser1,2 or particle beams3,4 can accelerate electron bunches to gigaelectronvolt energies in centimetre-scale distances. This allows the realization of compact accelerators with emerging applications ranging from modern light sources such as the free-electron laser to energy frontier lepton colliders. In a plasma wakefield accelerator, such multi-gigavolt-per-metre wakefields can accelerate witness electron bunches that are either externally injected5,6 or captured from the background plasma7,8. Here we demonstrate optically triggered injection9–11 and acceleration of electron bunches, generated in a multi-component hydrogen and helium plasma employing a spatially aligned and synchronized laser pulse. This ‘plasma photocathode’ decouples injection from wake excitation by liberating tunnel-ionized helium electrons directly inside the plasma cavity, where these cold electrons are then rapidly boosted to relativistic velocities. The injection regime can be accessed via optical11 density down-ramp injection12–16 and is an important step towards the generation of electron beams with unprecedented low transverse emittance, high current and 6D-brightness17. This experimental path opens numerous prospects for transformative plasma wakefield accelerator applications based on ultrahigh-brightness beams
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Duloxetine compared with fluoxetine and venlafaxine: use of meta-regression analysis for indirect comparisons
BACKGROUND: Data comparing duloxetine with existing antidepressant treatments is limited. A comparison of duloxetine with fluoxetine has been performed but no comparison with venlafaxine, the other antidepressant in the same therapeutic class with a significant market share, has been undertaken. In the absence of relevant data to assess the place that duloxetine should occupy in the therapeutic arsenal, indirect comparisons are the most rigorous way to go. We conducted a systematic review of the efficacy of duloxetine, fluoxetine and venlafaxine versus placebo in the treatment of Major Depressive Disorder (MDD), and performed indirect comparisons through meta-regressions. METHODS: The bibliography of the Agency for Health Care Policy and Research and the CENTRAL, Medline, and Embase databases were interrogated using advanced search strategies based on a combination of text and index terms. The search focused on randomized placebo-controlled clinical trials involving adult patients treated for acute phase Major Depressive Disorder. All outcomes were derived to take account for varying placebo responses throughout studies. Primary outcome was treatment efficacy as measured by Hedge's g effect size. Secondary outcomes were response and dropout rates as measured by log odds ratios. Meta-regressions were run to indirectly compare the drugs. Sensitivity analysis, assessing the influence of individual studies over the results, and the influence of patients' characteristics were run. RESULTS: 22 studies involving fluoxetine, 9 involving duloxetine and 8 involving venlafaxine were selected. Using indirect comparison methodology, estimated effect sizes for efficacy compared with duloxetine were 0.11 [-0.14;0.36] for fluoxetine and 0.22 [0.06;0.38] for venlafaxine. Response log odds ratios were -0.21 [-0.44;0.03], 0.70 [0.26;1.14]. Dropout log odds ratios were -0.02 [-0.33;0.29], 0.21 [-0.13;0.55]. Sensitivity analyses showed that results were consistent. CONCLUSION: Fluoxetine was not statistically different in either tolerability or efficacy when compared with duloxetine. Venlafaxine was significantly superior to duloxetine in all analyses except dropout rate. In the absence of relevant data from head-to-head comparison trials, results suggest that venlafaxine is superior compared with duloxetine and that duloxetine does not differentiate from fluoxetine
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