198 research outputs found
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was used in an attempt to identify all relevant studies regardless of language or publication status (published, unpublished, in press, and in progress).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
Effective lifetimes exceeding 300 μs in gettered p-type epitaxial kerfless silicon for photovoltaics
We evaluate defect concentrations and investigate the lifetime potential of p-type single-crystal kerfless silicon produced via epitaxy for photovoltaics. In gettered material, low interstitial iron concentrations (as low as (3.2 ± 2.2) × 10[superscript 9] cm[superscript −3]) suggest that minority-carrier lifetime is not limited by dissolved iron. An increase in gettered lifetime from 300 μs is observed after increasing growth cleanliness. This improvement coincides with reductions in the concentration of Mo, V, Nb, and Cr impurities, but negligible change in the low area-fraction (23%.United States. Dept. of Energy (Contract DE-EE0005314)National Science Foundation (U.S.) (United States. Dept. of Energy NSF CA EEC-1041895)American Society for Engineering Education. National Defense Science and Engineering Graduate FellowshipAlexander von Humboldt-Stiftung (Feodor Lynen Postdoctoral Fellowship
ISUOG updated consensus statement on the impact of cfDNA aneuploidy testing on screening policies and prenatal ultrasound practice
Pamela: development of the RF system for a non-relativistic non-scaling FFAG
The PAMELA project(Particle Accelerator For MEdical
Applications) currently consists of the design of a particle
therapy facility. The project, which is in the design phase,
contains Non-Scaling FFAG, particle accelerator capable
of rapid beam acceleration, giving a pulse repetition rate of
1kHz, far beyond that of a conventional synchrotron. To
realise the repetition rate, a key component of the accelerator
is the rf accelerating system. The combination of a high
energy gain per turn and a high repetition rate is a significant
challenge. In this paper, options for the rf system of
the proton ring and the status of development are presented
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)=2.3×10exp−3 exp(−0.47 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)×10exp−4 exp(−0.15±0.04 eV/kBT)  cm2/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 1150 °C, and orders of magnitude higher when extrapolated to room temperature.Peer reviewe
Precipitated iron: a limit on gettering efficacy in multicrystalline silicon
A phosphorus diffusion gettering model is used to examine the efficacy of a standard gettering process on interstitial and precipitated iron in multicrystalline silicon. The model predicts a large concentration of precipitated iron remaining after standard gettering for most as-grown iron distributions. Although changes in the precipitated iron distribution are predicted to be small, the simulated post-processing interstitial iron concentration is predicted to depend strongly on the as-grown distribution of precipitates, indicating that precipitates must be considered as internal sources of contamination during processing. To inform and validate the model, the iron distributions before and after a standard phosphorus diffusion step are studied in samples from the bottom, middle, and top of an intentionally Fe-contaminated laboratory ingot. A census of iron-silicide precipitates taken by synchrotron-based X-ray fluorescence microscopy confirms the presence of a high density of iron-silicide precipitates both before and after phosphorus diffusion. A comparable precipitated iron distribution was measured in a sister wafer after hydrogenation during a firing step. The similar distributions of precipitated iron seen after each step in the solar cell process confirm that the effect of standard gettering on precipitated iron is strongly limited as predicted by simulation. Good agreement between the experimental and simulated data supports the hypothesis that gettering kinetics is governed by not only the total iron concentration but also by the distribution of precipitated iron. Finally, future directions based on the modeling are suggested for the improvement of effective minority carrier lifetime in multicrystalline silicon solar cells
Schoolwide Application of Positive Behavior Support in an Urban High School:. Journal Of Positive Behavior Interventions
Abstract: The nuances of the application of schoolwide positive behavior supports (PBS) in an urban high school setting were investigated. Impact of implementation was measured using qualitative interviews and observations, including the School-wide Evaluation Tool (SET), Effective Behavior Support Survey, Student Climate Survey, and office disciplinary referrals. The results indicated that schoolwide PBS was implemented in an urban high school setting with some success. The overall level of implementation of PBS reached 80% as measured by the SET. Staff and teachers increased their level of perceived priority for implementing PBS in their school. A decrease in monthly discipline referrals to the office and the proportion of students who required secondary and tertiary supports was noted. These findings seem to indicate that PBS may be an important process for improving outcomes for teachers and students in urban high school settings
Clarifying the role of three-dimensional transvaginal sonography in reproductive medicine: an evidenced-based appraisal
This overview describes and illustrates the clinical applications of three-dimensional transvaginal sonography in reproductive medicine. Its main applications include assessment of uterine anomalies, intrauterine pathology, tubal patency, polycystic ovaries, ovarian follicular monitoring and endometrial receptivity. It is also useful for detailed evaluation of failed and/or ectopic pregnancy. Three-dimensional color Doppler sonography provides enhanced depiction of uterine, endometrial, and ovarian vascularity
Conceptual design of a nonscaling fixed field alternating gradient accelerator for protons and carbon ions for charged particle therapy
Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.The conceptual design for a nonscaling fixed field alternating gradient accelerator suitable for charged particle therapy (the use of protons and other light ions to treat some forms of cancer) is described.EPSR
Quantifying the effects of temperature and noise on attention-level using EDA and EEG sensors
Most people with Autism Spectrum Disorder (ASD) experience atypical sensory modality and need help to self-regulate their sensory responses. Results of a pilot study are presented here where temperature, noise types and noise levels are used as independent variables. Attention-based tests (ABTs), Electrodermal Activity (EDA) and Electroencephalography (EEG) sensors are used as dependent variables to quantify the effects of temperature and noise. Based on the outcome of the analyses, it is feasible to use off-the-shelf sensors to recognize physiological changes, indicating a possibility to develop sensory management recommendation interventions to support people with ASD
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