117 research outputs found
Incidence, Prevalence, and Health Care Outcomes in Idiopathic Intracranial Hypertension
Objective: To characterise trends in incidence, prevalence, and healthcare outcomes in the idiopathic intracranial hypertension (IIH) population in Wales using routinely collected healthcare data.Methods: We used and validated primary and secondary care IIH diagnosis codes within the Secure Anonymised Information Linkage databank, to ascertain IIH cases and controls, in a retrospective cohort study between 2003 and 2017. We recorded body mass index (BMI), deprivation quintile, CSF diversion surgery and unscheduled hospital admissions in case and control cohorts.Results: We analysed 35 million patient years of data. There were 1765 cases of IIH in 2017 (85% female). The prevalence and incidence of IIH in 2017 was 76/100,000 and 7.8/100,000/year, a significant increase from 2003 (corresponding figures=12/100,000 and 2.3/100,000/year) (p<0.001). IIH prevalence is associated with increasing BMI and increasing deprivation. The odds ratio for developing IIH in the least deprived quintile compared to the most deprived quintile, adjusted for gender and BMI, was 0.65 (95% CI 0.55 to 0.76). 9% of IIH cases had CSF shunts with less than 0.2% having bariatric surgery. Unscheduled hospital admissions were higher in the IIH cohort compared to controls (rate ratio=5.28, p<0.001) and in individuals with IIH and CSF shunts compared to those without shunts (rate ratio=2.02, p<0.01).Conclusions: IIH incidence and prevalence is increasing considerably, corresponding to population increases in BMI, and is associated with increased deprivation. This has important implications for healthcare professionals and policy makers given the comorbidities, complications and increased healthcare utilization associated with II
COVID-19 vaccination uptake in people with epilepsy in wales
Purpose: People with epilepsy (PWE) are at increased risk of severe COVID-19. Assessing COVID-19 vaccine uptake is therefore important. We compared COVID-19 vaccination uptake for PWE in Wales with a matched control cohort. Methods: We performed a retrospective, population, cohort study using linked, anonymised, Welsh electronic health records within the Secure Anonymised Information Linkage (SAIL) Databank (Welsh population=3.1 million).We identified PWE in Wales between 1st March 2020 and 31st December 2021 and created a control cohort using exact 5:1 matching (sex, age and socioeconomic status). We recorded 1st, 2nd and booster COVID-19 vaccinations.Results: There were 25,404 adults with epilepsy (127,020 controls). 23,454 (92.3%) had a first vaccination, 22,826 (89.9%) a second, and 17,797 (70.1%) a booster. Comparative figures for controls were: 112,334 (87.8%), 109,057 (85.2%) and 79,980 (62.4%).PWE had higher vaccination rates in all age, sex and socioeconomic subgroups apart from booster uptake in older subgroups. Vaccination rates were higher in older subgroups, women and less deprived areas for both cohorts. People with intellectual disability and epilepsy had higher vaccination rates when compared with controls with intellectual disability. Conclusions: COVID-19 vaccination uptake for PWE in Wales was higher than that for a matched control group
Sintering of calcium phosphates with a femtosecond pulsed laser for hard tissue engineering
The authors acknowledge support from the sponsors of this work; the EPSRC LUMIN (EP/K020234/1) and EU-Marie-Curie-IAPP LUSTRE (324538) projects.Direct laser sintering on hard tissues is likely to open new pathways for personalised medicine. To minimise irradiation damage of the surrounding soft tissues, lasers operating at wavelengths that are âsafeâ for the tissues and biomaterials with improved optical properties are required. In this work laser sintering is demonstrated with the use of an ultrafast, femtosecond (100 fs) pulsed laser operating at a wavelength of 1045 nm and two existing calcium phosphate minerals (brushite and hydroxyapatite) which have been improved after doping with iron (10 mol%). Femtosecond laser irradiation caused transformation of the Fe3+-doped brushite and Fe3+-doped HAp samples into ÎČ-calcium pyrophosphate and calcium-iron-phosphate, respectively, with simultaneous evidence for microstructural sintering and densification. After estimating the temperature profile at the surface of the samples we suggest that soft tissues over 500 ÎŒm from the irradiated zone would be safe from thermal damage. This novel laser processing provides a means to control the phase constitution and the morphology of the finished surfaces. The porous structure of ÎČ-pyrophosphate might be suitable for applications in bone regeneration by supporting osteogenic cell activity while, the densified Fe3+-rich calcium-iron-phosphate may be promising for applications like dental enamel restoration.PostprintPeer reviewe
ÎČ-pyrophosphate: A potential biomaterial for dental applications
Tooth hypersensitivity is a growing problem affecting both the young and ageing population worldwide. Since an effective and permanent solution is not yet available, we propose a new methodology for the restoration of dental enamel using femtosecond lasers and novel calcium phosphate biomaterials. During this procedure the irradiated mineral transforms into a densified layer of acid resistant iron doped ÎČ-pyrophosphate, bonded with the surface of eroded enamel. Our aim therefore is to evaluate this densified mineral as a potential replacement material for dental hard tissue. To this end, we have tested the hardness of ÎČ-pyrophosphate pellets (sintered at 1000 °C) and its mineral precursor (brushite), the wear rate during simulated tooth-brushing trials and the cytocompatibility of these minerals in powder form. It was found that the hardness of the ÎČ-pyrophosphate pellets is comparable with that of dental enamel and significantly higher than dentine while, the brushing trials prove that the wear rate of ÎČ-pyrophosphate is much slower than that of natural enamel. Finally, cytotoxicity and genotoxicity tests suggest that iron doped ÎČ-pyrophosphate is cytocompatible and therefore could be used in dental applications. Taken together and with the previously reported results on laser irradiation of these materials we conclude that iron doped ÎČ-pyrophosphate may be a promising material for restoring acid eroded and worn enamel
Removing Orbital Debris with Lasers
Orbital debris in low Earth orbit (LEO) are now sufficiently dense that the
use of LEO space is threatened by runaway collisional cascading. A problem
predicted more than thirty years ago, the threat from debris larger than about
1 cm demands serious attention. A promising proposed solution uses a high power
pulsed laser system on the Earth to make plasma jets on the objects, slowing
them slightly, and causing them to re-enter and burn up in the atmosphere. In
this paper, we reassess this approach in light of recent advances in low-cost,
light-weight modular design for large mirrors, calculations of laser-induced
orbit changes and in design of repetitive, multi-kilojoule lasers, that build
on inertial fusion research. These advances now suggest that laser orbital
debris removal (LODR) is the most cost-effective way to mitigate the debris
problem. No other solutions have been proposed that address the whole problem
of large and small debris. A LODR system will have multiple uses beyond debris
removal. International cooperation will be essential for building and operating
such a system.Comment: 37 pages, 15 figures, in preparation for submission to Advances in
Space Researc
2-D Electronic Spectroscopy on the light-dependent enzyme protochlorophyllide oxidoreductase
In photosynthesis, quantum coherence in light harvesting
complexes could form the basis for the highly efficient propagation
of excited states within the photosynthetic membranes
of bacteria and plants. Recent studies on Photosystem
II reaction centres extends the possible relevance of
electronic coherence to the photochemical steps of photosynthesis;
it was shown that coherent states are sufficiently
long-lived, at room temperature, to persist during the initial
steps of electron transfer. This extension of quantum coherence,
from the energy transfer to the energy trapping steps of
photosynthesis, made it timely to investigate if quantum coherence
also plays a role in the formation of product states in
enzyme catalysis. Given the short timescales involved it was
necessary to study an enzyme where the catalytic cycle can
be triggered by femtosecond light pulses, so protochlorophyllide
oxidoreductase (POR) was selected as an ideal model
system. 2-dimensional electronic spectroscopy (2DES) was
used to investigate the presence of quantum coherence in
the intermediates of the light-dependent reduction of protochlorophyllide
(Pchlide) to chlorophyllide (Chlide) catalysed
by POR
Exogenous mineralization of hard tissues using photo-absorptive minerals and femto-second lasers; the case of dental enamel
A radical new methodology for the exogenous mineralization of hard tissues is demonstrated in the context of laser-biomaterials interaction. The proposed approach is based on the use of femtosecond pulsed lasers (fs) and FeÂłâș-doped calcium phosphate minerals (specifically in this work fluorapatite powder containing FeâOâ nanoparticles (NP)). A layer of the synthetic powder is applied to the surface of eroded bovine enamel and is irradiated with a fs laser (1040 nm wavelength, 1 GHz repetition rate, 150 fs pulse duration and 0.4 W average power). The FeâOâ NPs absorb the light and may act as thermal antennae, dissipating energy to the vicinal mineral phase. Such a photothermal process triggers the sintering and densification of the surrounding calcium phosphate crystals thereby forming a new, dense layer of typically 20 ÎŒm in thickness, which is bonded to the underlying surface of the natural enamel. The dispersed iron oxide NPs, ensure the localization of temperature excursion, minimizing collateral thermal damage to the surrounding natural tissue during laser irradiation. Simulated brushing trials (pH cycle and mechanical force) on the synthetic layer show that the sintered material is more acid resistant than the natural mineral of enamel. Furthermore, nano-indentation confirms that the hardness and Youngâs modulus of the new layers are significantly more closely matched to enamel than current restorative materials used in clinical dentistry. Although the results presented herein are exemplified in the context of bovine enamel restoration, the methodology may be more widely applicable to human enamel and other hard-tissue regenerative engineering
Epilepsy and the risk of COVID â19ârelated hospitalization and death: A population study
Objective: People with epilepsy (PWE) may be at an increased risk of severe COVIDâ19. It is important to characterize this risk to inform PWE and for future health and care planning. We assessed whether PWE were at higher risk of being hospitalized with, or dying from, COVIDâ19. Methods: We performed a retrospective cohort study using linked, populationâscale, anonymized electronic health records from the SAIL (Secure Anonymised Information Linkage) databank. This includes hospital admission and demographic data for the complete Welsh population (3.1 million) and primary care records for 86% of the population. We identified 27 279 PWE living in Wales during the study period (March 1, 2020 to June 30, 2021). Controls were identified using exact 5:1 matching (sex, age, and socioeconomic status). We defined COVIDâ19 deaths as having International Classification of Diseases, 10th Revision (ICDâ10) codes for COVIDâ19 on death certificates or occurring within 28 days of a positive SARSâCoVâ2 polymerase chain reaction (PCR) test. COVIDâ19 hospitalizations were defined as having a COVIDâ19 ICDâ10 code for the reason for admission or occurring within 28 days of a positive SARSâCoVâ2 PCR test. We recorded COVIDâ19 vaccinations and comorbidities known to increase the risk of COVIDâ19 hospitalization and death. We used Cox proportional hazard models to calculate hazard ratios. Results: There were 158 (.58%) COVIDâ19 deaths and 933 (3.4%) COVIDâ19 hospitalizations in PWE, and 370 (.27%) deaths and 1871 (1.4%) hospitalizations in controls. Hazard ratios for COVIDâ19 death and hospitalization in PWE compared to controls were 2.15 (95% confidence interval [CI] = 1.78â2.59) and 2.15 (95% CI = 1.94â2.37), respectively. Adjusted hazard ratios (adjusted for comorbidities) for death and hospitalization were 1.32 (95% CI = 1.08â1.62) and 1.60 (95% CI = 1.44â1.78). Significance: PWE are at increased risk of being hospitalized with, and dying from, COVIDâ19 when compared to ageâ, sexâ, and deprivationâmatched controls, even when adjusting for comorbidities. This may have implications for prioritizing future COVIDâ19 treatments and vaccinations for PWE
Health care utilization and mortality for people with epilepsy during COVID â19: A population study
Objective: This study was undertaken to characterize changes in health care utilization and mortality for people with epilepsy (PWE) during the COVIDâ19 pandemic. Methods: We performed a retrospective study using linked, individualâlevel, populationâscale anonymized health data from the Secure Anonymised Information Linkage databank. We identified PWE living in Wales during the study âpandemic periodâ (January 1, 2020âJune 30, 2021) and during a âprepandemicâ period (January 1, 2016âDecember 31, 2019). We compared prepandemic health care utilization, status epilepticus, and mortality rates with corresponding pandemic rates for PWE and people without epilepsy (PWOE). We performed subgroup analyses on children (65 years old), those with intellectual disability, and those living in the most deprived areas. We used Poisson models to calculate adjusted rate ratios (RRs). Results: We identified 27 279 PWE who had significantly higher rates of hospital (50.3 visits/1000 patient months), emergency department (55.7), and outpatient attendance (172.4) when compared to PWOE (corresponding figures: 25.7, 25.2, and 87.0) in the prepandemic period. Hospital and epilepsyârelated hospital admissions, and emergency department and outpatient attendances all reduced significantly for PWE (and all subgroups) during the pandemic period. RRs [95% confidence intervals (CIs)] for pandemic versus prepandemic periods were .70 [.69â.72], .77 [.73â.81], .78 [.77â.79], and .80 [.79â.81]. The corresponding rates also reduced for PWOE. New epilepsy diagnosis rates decreased during the pandemic compared with the prepandemic period (2.3/100 000/month cf. 3.1/100 000/month, RR = .73, 95% CI = .68â.78). Both allâcause deaths and deaths with epilepsy recorded on the death certificate increased for PWE during the pandemic (RR = 1.07, 95% CI = .997â1.145 and RR = 2.44, 95% CI = 2.12â2.81). When removing COVID deaths, RRs were .88 (95% CI = .81â.95) and 1.29 (95% CI = 1.08â1.53). Status epilepticus rates did not change significantly during the pandemic (RR = .95, 95% CI = .78â1.15). Significance: Allâcause nonâCOVID deaths did not increase but nonâCOVID deaths associated with epilepsy did increase for PWE during the COVIDâ19 pandemic. The longer term effects of the decrease in new epilepsy diagnoses and health care utilization and increase in deaths associated with epilepsy need further research
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