317 research outputs found
Pilot-scale production and physicochemical characterisation of spray-dried nanoparticulated whey protein powders
Spray-dried whey protein isolate (WPI) powders were prepared at pilot-scale from solutions without heat (WPIUH), heated (WPIH) or heated with calcium (WPIHCa), which were analysed and compared with a control sample (WPIC). WPIC, WPIUH, WPIH and WPIHCa solutions had whey protein denaturation levels of 0.0, 3.2, 64.4 and 74.4%, respectively. Computerised tomography scanning showed that 52.6, 84.0, 74.5 and 41.9% of WPIC, WPIUH, WPIH and WPIHCa powder particles had diameters of ≤30 µm. WPIHCa and WPIH powders were cohesive, while WPIC and WPIUH powders were easy flowing. Marked differences in microstructure were observed between WPIH and WPIHCa. There were no measured differences in wall friction, bulk density or colour
Consistent Application of Maximum Entropy to Quantum-Monte-Carlo Data
Bayesian statistics in the frame of the maximum entropy concept has widely
been used for inferential problems, particularly, to infer dynamic properties
of strongly correlated fermion systems from Quantum-Monte-Carlo (QMC) imaginary
time data. In current applications, however, a consistent treatment of the
error-covariance of the QMC data is missing. Here we present a closed Bayesian
approach to account consistently for the QMC-data.Comment: 13 pages, RevTeX, 2 uuencoded PostScript figure
Bayesian Inference in Processing Experimental Data: Principles and Basic Applications
This report introduces general ideas and some basic methods of the Bayesian
probability theory applied to physics measurements. Our aim is to make the
reader familiar, through examples rather than rigorous formalism, with concepts
such as: model comparison (including the automatic Ockham's Razor filter
provided by the Bayesian approach); parametric inference; quantification of the
uncertainty about the value of physical quantities, also taking into account
systematic effects; role of marginalization; posterior characterization;
predictive distributions; hierarchical modelling and hyperparameters; Gaussian
approximation of the posterior and recovery of conventional methods, especially
maximum likelihood and chi-square fits under well defined conditions; conjugate
priors, transformation invariance and maximum entropy motivated priors; Monte
Carlo estimates of expectation, including a short introduction to Markov Chain
Monte Carlo methods.Comment: 40 pages, 2 figures, invited paper for Reports on Progress in Physic
Relationship between erythema effective UV radiant exposure, total ozone, cloud cover and aerosols in southern England, UK
Evidence of an underlying trend in the dependence of erythema effective ultraviolet
(UV) radiant exposure (Her) on changes in the total ozone, cloud cover and
aerosol optical depth (AOD) has been studied using solar ultraviolet
radiation measurements collected over a 25-year period (1991–2015) at Chilton
in the south of England in the UK.
The monthly mean datasets of these measures corrected for underlying
seasonal variation were analysed. When a single linear trend was fitted over
the whole study period between 1991 and 2015, the analyses revealed that the
long-term variability of Her can be best characterised in two
sub-periods (1991–2004 and 2004–2015), where the estimated linear trend was
upward in the first period (1991–2004) but downward in the second period
(2004–2015).
Both cloud cover (CC) and total ozone (TO) were found to have a highly
statistically significant influence on Her, but the influence of the
AOD measure was very small. The radiation amplification factor (RAF) for the
erythema action spectrum due to TO was −1.03 at constant levels of CC over
the whole study period; that is, for a 1.0 % increase in TO, Her
decreases by 1.03 %. Over the first period (1991–2004), the RAF related to
CC was slightly higher at 0.97 compared to that for TO at 0.79. The
proportion of the change in Her explained by the change in CC (47 %)
was much greater than the proportion explained by changes in TO (8 %). For
the second period (2004–2015), the pattern reversed, with the observed RAF
related to TO being −1.25, almost double that of CC (−0.65). Furthermore, in
this period the proportion of variation in Her explained by TO
variation was 33 %, double that of CC at 16 %, while AOD changes had a
negligible effect (1 %).
When the data were examined separately for each season, for the first period
(1991–2004) the greatest effect of TO and CC on Her (i.e. the largest
RAF value) was found during spring. Spring was also the season during which TO and
CC variation explained the greatest proportion of variability in Her
(82 %). In the later period (2004–2015), the RAF and greatest
influence of TO and CC were observed in winter (67 %) and the AOD effect
explained a further 5 % variability in Her.
This study provides evidence that both the increasing trend in Her for
1991–2004 and the decreasing trend in Her for 2004–2015 occur in
response to variation in TO, which exhibits a small increasing tendency over
these periods. CC plays a more important role in the increasing trend in
Her for 1991–2004 than TO, whereas for 2004–2015, the decreasing trend
in Her is less associated with changes in CC and AOD.</p
The multiple sclerosis risk sharing scheme monitoring study - early results and lessons for the future
Background: Risk sharing schemes represent an innovative and important approach to the problems of rationing and achieving cost-effectiveness in high cost or controversial health interventions. This study aimed to assess the feasibility of risk sharing schemes, looking at long term clinical outcomes, to determine the price at which high cost treatments would be acceptable to the NHS.
Methods: This case study of the first NHS risk sharing scheme, a long term prospective cohort study of beta interferon and glatiramer acetate in multiple sclerosis ( MS) patients in 71 specialist MS centres in UK NHS hospitals, recruited adults with relapsing forms of MS, meeting Association of British Neurologists (ABN) criteria for disease modifying therapy. Outcome measures were: success of recruitment and follow up over the first three years, analysis of baseline and initial follow up data and the prospect of estimating the long term cost-effectiveness of these treatments.
Results: Centres consented 5560 patients. Of the 4240 patients who had been in the study for a least one year, annual review data were available for 3730 (88.0%). Of the patients who had been in the study for at least two years and three years, subsequent annual review data were available for 2055 (78.5%) and 265 (71.8%) patients respectively. Baseline characteristics and a small but statistically significant progression of disease were similar to those reported in previous pivotal studies.
Conclusion: Successful recruitment, follow up and early data analysis suggest that risk sharing schemes should be able to deliver their objectives. However, important issues of analysis, and political and commercial conflicts of interest still need to be addressed
Principles for non-ionizing radiation protection
In this statement, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) presents its principles for protection against adverse health effects from exposure to non-ionizing radiation. These are based upon the principles for protection against ionizing radiation of the International Commission for Radiological Protection (ICRP) in order to come to a comprehensive and consistent system of protection throughout the entire electromagnetic spectrum. The statement further contains information about ICNIRP and the processes it uses in setting exposure guidelines
Light-emitting diodes (LEDS): Implications for safety
Since the original ICNIRP Statement was published in 2000, there have been significant improvements in the efficiency and radiance (i.e., optical radiation emission) of LEDs. The most important improvement is the development of 'white' LEDs that can be used as general lighting sources, which are more efficient than traditional lighting sources. LEDs emitting in the ultraviolet wavelength region have also become available and have made their way into consumer products. All these changes have led to a rise in concern for the safety of the optical radiation emissions from LEDs. Several in vitro and animal studies have been conducted, which indicate that blue and white LEDs can potentially cause retinal cell damage under high irradiance and lengthy exposure conditions. However, these studies cannot be directly extrapolated to normal exposure conditions for humans, and equivalent effects can also be caused by the optical radiation from other light sources under extreme exposure conditions. Acute damage to the human retina from typical exposure to blue or white LEDs has not been demonstrated. Concern for potential long-term effects, e.g. age-related macular degeneration (AMD), remains based on epidemiological studies indicating a link between high levels of exposure to sunlight and AMD. When evaluating the optical radiation safety of LEDs, it has now been established that published safety standards for lamps, not lasers, should be applied. Thus far, the only clear, acute adverse health effects from LEDs are those due to temporal light modulation (including flicker). Glare can also create visual disturbances when LED light fixtures are not properly designed. Further research is needed on potential health effects from short- and long-term exposure to new and emerging lighting technologies
Efficacy and Safety of Medicines Targeting Neurotrophic Factors in the Management of Low Back Pain: Protocol for a Systematic Review and Meta-Analysis (Preprint)
BACKGROUND
Low back pain (LBP) is the leading cause of years lived with disability worldwide. Most people with LBP receive the diagnosis of nonspecific LBP or sciatica. Medications are commonly prescribed but have limited analgesic effects and are associated with adverse events. A novel treatment approach is to target neurotrophins such as nerve growth factor (NGF) to reduce pain intensity. NGF inhibitors have been tested in some randomized controlled trials (RCTs) in recent years, showing promise for the treatment of chronic LBP; however, their efficacy and safety need to be evaluated to guide regulatory actions.
OBJECTIVE
The aim of this study is to evaluate the efficacy and safety of medicines targeting neurotrophins in patients with LBP and sciatica.
METHODS
In this systematic review, we will include published and unpublished records of parallel RCTs and the first phase of crossover RCTs that compare the effects of medicines targeting neurotrophins with any control group. We will search the CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, EU Clinical Trials Register, and WHO International Clinical Registry Platform databases from inception. Pairs of authors will independently screen the records for eligibility, and we will independently extract data in duplicate. We will conduct a quantitative synthesis (meta-analysis) with the studies that report sufficient data and compare the medicines of interest versus placebo. We will use random-effects models and calculate estimates of effects and heterogeneity for each outcome. We will assess the risk of bias for each study using the Cochrane Collaboration tool, and form judgments of confidence in the evidence according to GRADE recommendations. We will use the PRISMA statement to report the findings. We plan to conduct subgroup analyses by condition, type of medication, and time point. We will also assess the impact of a potential new trial on an existing meta-analysis. Data from studies that meet inclusion criteria but cannot be included in the meta-analysis will be reported narratively.
RESULTS
The protocol was registered on the Open Science Framework on May 19, 2020. As of December 2020, we have identified 1932 records.
CONCLUSIONS
This systematic review and meta-analysis will assess the evidence for the efficacy and safety of NGF inhibitors for pain in patients with nonspecific LBP and sciatica. The inclusion of new studies and unpublished data may improve the precision of the effect estimates and guide regulatory actions of the medications for LBP and sciatica.
CLINICALTRIAL
Open Science Framework; https://osf.io/b8adn/
INTERNATIONAL REGISTERED REPORT
DERR1-10.2196/22905
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Present and Future CP Measurements
We review theoretical and experimental results on CP violation summarizing
the discussions in the working group on CP violation at the UK phenomenology
workshop 2000 in Durham.Comment: 104 pages, Latex, to appear in Journal of Physics
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