1,086 research outputs found
Synthesized Tripodal Amine as Potential Anti-Cancer Therapeutic
Cancer remains a prevalent disease today. This disease may manifest itself in many different ways and affect a variety of tissues with everything from the brain to the blood. With this wide diversity of cancer types, treatment can be complicated since there is not a âone size fits allâ treatment for the disease. Surgery, radiation, and chemotherapy are all options that must be weighed with their benefits and side effects. Ultimately though, there are not enough effective treatment options available for every type of cancer. This leaves many with the grim prognosis of never being cured. With this clear need for more anti-cancer medicine, research is warranted into novel treatments and drugs. A novel tris-indolyl iron-chelating drug GS02 was synthesized and tested for its potential anti-cancer properties. The LD50 was determined using MTS assays against human cancer cell lines and apoptosis assays were carried out with the PC3 cell line. Images of the cells were collected using confocal imaging microscopy. Current results show a decrease in cell viability and suggest that GS02 is inducing apoptosis in the PC3 cell line. Furthermore, the compound was shown to be toxic within a specific concentration range which may be of interest for the potential of a new chemotherapy agent. Given these results, GS02 warrants continued investigations into its potential to trigger apoptosis in more human cancer cell lines
Exponential sum approximations for
Given and , the function may be approximated
for in a compact interval by a sum of terms of the form
, with parameters and . One such an approximation, studied
by Beylkin and Monz\'on, is obtained by applying the trapezoidal rule to an
integral representation of , after which Prony's method is applied
to reduce the number of terms in the sum with essentially no loss of accuracy.
We review this method, and then describe a similar approach based on an
alternative integral representation. The main difference is that the new
approach achieves much better results before the application of Prony's method;
after applying Prony's method the performance of both is much the same.Comment: 18 pages, 5 figures. I have completely rewritten this paper because
after uploading the previous version I realised that there is a much better
approach. Note the change to the title. Have included minor corrections
following revie
Distinct replay signatures for prospective decision-making and memory preservation
Theories of neural replay propose that it supports a range of functions, most prominently planning and memory consolidation. Here, we test the hypothesis that distinct signatures of replay in the same task are related to model-based decision-making (âplanningâ) and memory preservation. We designed a reward learning task wherein participants utilized structure knowledge for model-based evaluation, while at the same time had to maintain knowledge of two independent and randomly alternating task environments. Using magnetoencephalography and multivariate analysis, we first identified temporally compressed sequential reactivation, or replay, both prior to choice and following reward feedback. Before choice, prospective replay strength was enhanced for the current task-relevant environment when a model-based planning strategy was beneficial. Following reward receipt, and consistent with a memory preservation role, replay for the alternative distal task environment was enhanced as a function of decreasing recency of experience with that environment. Critically, these planning and memory preservation relationships were selective to pre-choice and post-feedback periods, respectively. Our results provide support for key theoretical proposals regarding the functional role of replay and demonstrate that the relative strength of planning and memory-related signals are modulated by ongoing computational and task demands
Simple and Nearly Optimal Polynomial Root-finding by Means of Root Radii Approximation
We propose a new simple but nearly optimal algorithm for the approximation of
all sufficiently well isolated complex roots and root clusters of a univariate
polynomial. Quite typically the known root-finders at first compute some crude
but reasonably good approximations to well-conditioned roots (that is, those
isolated from the other roots) and then refine the approximations very fast, by
using Boolean time which is nearly optimal, up to a polylogarithmic factor. By
combining and extending some old root-finding techniques, the geometry of the
complex plane, and randomized parametrization, we accelerate the initial stage
of obtaining crude to all well-conditioned simple and multiple roots as well as
isolated root clusters. Our algorithm performs this stage at a Boolean cost
dominated by the nearly optimal cost of subsequent refinement of these
approximations, which we can perform concurrently, with minimum processor
communication and synchronization. Our techniques are quite simple and
elementary; their power and application range may increase in their combination
with the known efficient root-finding methods.Comment: 12 pages, 1 figur
Effect of vitamin K2 on postural sway in older people who fall:a randomized controlled trial
OBJECTIVES: Vitamin K is thought to be involved in both bone health and maintenance of neuromuscular function. We tested the effect of vitamin K2 supplementation on postural sway, falls, healthcare costs, and indices of physical function in older people at risk of falls.DESIGN: Parallel-group double-blind randomized placebo-controlled trial.SETTING: Fourteen primary care practices in Scotland, UK.PARTICIPANTS: A total of 95 community-dwelling participants aged 65 and older with at least two falls, or one injurious fall, in the previous year.INTERVENTION: Once/day placebo, 200 ÎŒg or 400 ÎŒg of oral vitamin K2 for 1 year.MEASUREMENTS: The primary outcome was anteroposterior sway measured using sway plates at 12âmonths, adjusted for baseline. Secondary outcomes included the Short Physical Performance Battery, Berg Balance Scale, Timed Up & Go Test, quality of life, health and social care costs, falls, and adverse events.RESULTS: Mean participant age was 75 (standard deviation [SD] = 7) years. Overall, 58 of 95 (61%) were female; 77 of 95 (81%) attended the 12-month visit. No significant effect of either vitamin K2 dose was seen on the primary outcome of anteroposterior sway (200 ÎŒg vs placebo: -.19âcm [95% confidence interval [CI] -.68 to .30; P = .44]; 400 ÎŒg vs placebo: .17âcm [95% CI -.33 to .66; P = .50]; or 400 ÎŒg vs 200 ÎŒg: .36âcm [95% CI -.11 to .83; P = .14]). Adjusted falls rates were similar in each group. No significant treatment effects were seen for other measures of sway or secondary outcomes. Costs were higher in both vitamin K2 arms than in the placebo arm.CONCLUSION: Oral vitamin K2 supplementation did not improve postural sway or physical function in older people at risk of falls.</p
Elucigene FH20 and LIPOchip for the diagnosis of familial hypercholesterolaemia : a systematic review and economic evaluation
PMID: 22469073 [PubMed - indexed for MEDLINE] Free full textPeer reviewedPublisher PD
The Cost-Effectiveness of Reclassification Sampling for Prevalence Estimation
Typically, a two-phase (double) sampling strategy is employed when classifications are subject to error and there is a gold standard (perfect) classifier available. Two-phase sampling involves classifying the entire sample with an imperfect classifier, and a subset of the sample with the gold-standard.In this paper we consider an alternative strategy termed reclassification sampling, which involves classifying individuals using the imperfect classifier more than one time. Estimates of sensitivity, specificity and prevalence are provided for reclassification sampling, when either one or two binary classifications of each individual using the imperfect classifier are available. Robustness of estimates and design decisions to model assumptions are considered. Software is provided to compute estimates and provide advice on the optimal sampling strategy.Reclassification sampling is shown to be cost-effective (lower standard error of estimates for the same cost) for estimating prevalence as compared to two-phase sampling in many practical situations
Relativistic deformed mean-field calculation of binding energy differences of mirror nuclei
Binding energy differences of mirror nuclei for A=15, 17, 27, 29, 31, 33, 39
and 41 are calculated in the framework of relativistic deformed mean-field
theory. The spatial components of the vector meson fields and the photon are
fully taken into account in a self-consistent manner. The calculated binding
energy differences are systematically smaller than the experimental values and
lend support to the existency of the Okamoto--Nolen-Schiffer anomaly found
decades ago in nonrelativistic calculations. For the majority of the nuclei
studied, however, the results are such that the anomaly is significantly
smaller than the one obtained within state-of-the-art nonrelativistic
calculations.Comment: 13 pages, REVTeX, no figure
The Off Shell - Mixing in the QCD Sum Rules
The dependence of the mixing amplitude is analyzed with
the use of the QCD sum rules and the dispersion relation. Going off shell the
mixing decreases, changes sign at and is
negative in the space like region. Implications of this result to the isospin
breaking part of the nuclear force are discussed.Comment: 26 pages + 11 figures (PostScript
Ethics, Nanobiosensors and Elite Sport: The Need for a New Governance Framework
Individual athletes, coaches and sports teams seek continuously for ways to improve performance and accomplishment in elite competition. New techniques of performance analysis are a crucial part of the drive for athletic perfection. This paper discusses the ethical importance of one aspect of the future potential of performance analysis in sport, combining the field of biomedicine, sports engineering and nanotechnology in the form of âNanobiosensorsâ. This innovative technology has the potential to revolutionise sport, enabling real time biological data to be collected from athletes that can be electronically distributed. Enabling precise real time performance analysis is not without ethical problems. Arguments concerning (1) data ownership and privacy; (2) data confidentiality; and (3) athlete welfare are presented alongside a discussion of the use of the Precautionary Principle in making ethical evaluations. We conclude, that although the future potential use of Nanobiosensors in sports analysis offers many potential benefits, there is also a fear that it could be abused at a sporting system level. Hence, it is essential for sporting bodies to consider the development of a robust ethically informed governance framework in advance of their proliferated use
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