336 research outputs found
A Non-Scaling FFAG Gantry Design for the PAMELA Project
A gantry is reÂquired for the PAMELA proÂject using non-scalÂing Fixed Field AlÂterÂnatÂing GraÂdiÂent (NS-FFAG) magÂnets. The NS-FFAG prinÂciÂple ofÂfers the posÂsiÂbilÂiÂty of a gantry much smallÂer, lighter and cheapÂer than conÂvenÂtionÂal deÂsigns, with the added abilÂiÂty to acÂcept a wide range of fast changÂing enÂerÂgies. This paper will build on preÂviÂous work to inÂvesÂtiÂgate a deÂsign which could be used for the PAMELA proÂject
An FFAG Transport Line for the PAMELA Project
The PAMELA project to design an accelerator for
hadron therapy using non-scaling Fixed Field Alternating
Gradient (NS-FFAG) magnets requires a transport line
and gantry to take the beam to the patient. The NS-FFAG
principle offers the possibility of a gantry much smaller,
lighter and cheaper than conventional designs, with the
added ability to accept a wide range of fast changing
energies. This paper will build on previous work to
investigate a transport line which could be used for the
PAMELA project. The design is presented along with a
study and optimisation of its acceptance
Endometrial injury in women undergoing assisted reproductive techniques
ACKNOWLEDGEMENTS We would like to express our appreciation to Dra Abha Maheshwari for her important authorial contribution to the previous version of this review. We also acknowledge the important help provided by the Cochrane Menstrual Disorders and Subfertility Group team, specially by Marian Showell, Trials Search Co-ordinator; by Helen Nagels, Managing Editor; and by Prof. Cindy Farquhar, Co-ordinating Editor. Finally, we would like to express our gratitude to the following investigators, who provided essential information for the preparation of this review: TK Aleyamma, Erin F Wolff, Lukasz Polanski, Nava Dekel, Neeta Singh, Suleyman Guven and Tracy YeungPeer reviewedPublisher PD
Identifying Acute Coronary Syndrome Patients Approaching End-of-Life
Background: Acute coronary syndrome (ACS) is common in patients approaching the end-of-life (EoL), but these patients rarely receive palliative care. We compared the utility of a palliative care prognostic tool (Gold Standards Framework (GSF)) and the Global Registry of Acute Coronary Events (GRACE) score, to help identify patients approaching EoL. Methods and Findings: 172 unselected consecutive patients with confirmed ACS admitted over an eight-week period were assessed using prognostic tools and followed up for 12 months. GSF criteria identified 40 (23%) patients suitable for EoL care while GRACE identified 32 (19%) patients with $10 % risk of death within 6 months. Patients meeting GSF criteria were older (p = 0.006), had more comorbidities (1.660.7 vs. 1.260.9, p = 0.007), more frequent hospitalisations before (p = 0.001) and after (0.0001) their index admission, and were more likely to die during follow-up (GSF+ 20 % vs GSF- 7%, p = 0.03). GRACE score was predictive of 12-month mortality (C-statistic 0.75) and this was improved by the addition of previous hospital admissions and previous history of stroke (C-statistic 0.88). Conclusions: This study has highlighted a potentially large number of ACS patients eligible for EoL care. GSF or GRACE could be used in the hospital setting to help identify these patients. GSF identifies ACS patients with more comorbidity and at increased risk of hospital readmission
Heparin for assisted reproduction (Review)
Abstract
BACKGROUND:
Heparin as an adjunct in assisted reproduction (peri-implantation heparin) is given at or after egg collection or at embryo transfer during assisted reproduction. Heparin has been advocated to improve embryo implantation and clinical outcomes. It has been proposed that heparin enhances the intra-uterine environment by improving decidualisation with an associated activation of growth factors and a cytokine expression profile in the endometrium that is favourable to pregnancy.
OBJECTIVES:
To investigate whether the administration of heparin around the time of implantation (peri-implantation heparin) improves clinical outcomes in subfertile women undergoing assisted reproduction.
SEARCH METHODS:
A comprehensive and exhaustive search strategy was developed in consultation with the Trials Search Co-ordinator of the Cochrane Menstrual Disorders and Subfertility Group (MDSG). The strategy was used in an attempt to identify all relevant studies regardless of language or publication status (published, unpublished, in press, and in progress). Relevant trials were identified from both electronic databases and other resources (last search 6 May 2013).
SELECTION CRITERIA:
All randomised controlled trials (RCTs) were included where peri-implantation heparin was given during assisted reproduction. Peri-implantation low molecular weight heparin (LMWH) during IVF/ICSI was given at or after egg collection or at embryo transfer in the included studies. Live birth rate was the primary outcome.
DATA COLLECTION AND ANALYSIS:
Two review authors independently assessed the eligibility and quality of trials and extracted relevant data. The quality of the evidence was evaluated using GRADE methods.
MAIN RESULTS:
Three RCTs (involving 386 women) were included in the review.Peri-implantation LMWH administration during assisted reproduction was associated with a significant improvement in live birth rate compared with placebo or no LMWH (odds ratio (OR) 1.77, 95% confidence interval (CI) 1.07 to 2.90, three studies, 386 women, I(2) = 51%, very low quality evidence with high heterogeneity). There was also a significant improvement in the clinical pregnancy rate with use of LMWH (OR 1.61, 95% CI 1.03 to 2.53, three studies, 386 women, I(2) = 29%, very low quality evidence with low heterogeneity).However these findings should be interpreted with extreme caution as they were dependent upon the choice of statistical method: they were no longer statistically significant when a random-effects model was used.Adverse events were poorly reported in all included studies, with no comparative data available. However, LMWH did cause adverse effects including bruising, ecchymosis, bleeding, thrombocytopenia and allergic reactions. It appeared that these adverse effects were increased if heparin therapy was used over a longer duration.
AUTHORS' CONCLUSIONS:
The results of this Cochrane review of three randomised controlled trials with a total of 386 women suggested that peri-implantation LMWH in assisted reproduction treatment (ART) cycles may improve the live birth rate in women undergoing assisted reproduction. However, these results were dependent on small low quality studies with substantial heterogeneity, and were sensitive to the choice of statistical model. There were side effects reported with use of heparin, including bruising and bleeding, and no reliable data on long-term effects. The results do not justify this use of heparin outside well-conducted research trials.These findings need to be further investigated with well-designed, adequately powered, double-blind, randomised, placebo-controlled, multicentre trials. Further investigations could also focus on the effects of the local (uterine) and not systemic application of heparin during ART
Nickel: A very fast diffuser in silicon
Nickel is increasingly used in both IC and photovoltaic device fabrication, yet it has the potential to create highly recombination-active precipitates in silicon. For nearly three decades, the accepted nickel diffusivity in silicon has been DNi(T)=2.3Ă10expâ3 exp(â0.47 eV/kBT) cm2/s, a surprisingly low value given reports of rapid nickel diffusion in industrial applications. In this paper, we employ modern experimental methods to measure the higher nickel diffusivity DNi(T)=(1.69±0.74)Ă10expâ4 exp(â0.15±0.04 eV/kBT) âcm2/s. The measured activation energy is close to that predicted by first-principles theory using the nudged-elastic-band method. Our measured diffusivity of nickel is higher than previously published values at temperatures below 1150â°C, and orders of magnitude higher when extrapolated to room temperature.Peer reviewe
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