762 research outputs found
Microarrays and breast cancer clinical studies: forgetting what we have not yet learnt
This review takes a sceptical view of the impact of breast cancer studies that have used microarrays to identify predictors of clinical outcome. In addition to discussing general pitfalls of microarray experiments, we also critically review the key breast cancer studies to highlight methodological problems in cohort selection, statistical analysis, validation of results and reporting of raw data. We conclude that the optimum use of microarrays in clinical studies requires further optimisation and standardisation of methodology and reporting, together with improvements in clinical study design
Towards a reduction of greenhouse gas emission from wastewater treatment plants: a new plant wide experimental and modelling approach
The increasing interest in greenhouse gas (GHG) emissions from wastewater treatment plants (WWTPs) has led to the development of new tools for their design and management. Studies about gas emissions show that the sewer collection and the wastewater treatment plant are anthropogenic GHG potential sources, so they contribute to the climate change and air pollution. A wastewater treatment plant receives wastewater from sewers and, while produces treated water for discharge into surface water, emits the three major greenhouse gases, CO2, CH4, and N2O, during the treatment processes, and additional amounts of CO2 and CH4 from the energy demands (Bani Shahabadi et al., 2009). Indeed, energy consumption can be considered as an indirect source of GHGs. Greenhouse-gas emissions are generated by water-line and sludge- line processes and by the on-site combustion of biogas and fossil fuels for energy generation. GHGs may also be produced during sludge disposal or reuse (transportation and degradation of remaining biosolids off-site), off-site energy production and off-site chemicals production. In recent years, increasing attention is given to the assessment of N2O emissions from WWTPs. N2O is a powerful greenhouse gas that is almost 300 times stronger than CO2. Nevertheless, the source and magnitude of N2O are relatively unknown and the knowledge is still incomplete. This paper presents the first results of an ongoing research project aiming at setting-up an innovative mathematical model platform (Decision Support System—DSS) for the design and management of WWTPs. The project is constituted by four research units (UOs) and its final goal is to minimize, by means of this platform, the environmental impact of WWTPs through their optimization in terms of energy consumptions and pollutants, sludge and GHG emissions
Chinese-chi and Kundalini yoga Meditations Effects on the Autonomic Nervous System: Comparative Study
Cardiac disease is one of the major causes for death
all over the world. Heart rate variability (HRV) is a significant
parameter that used in assessing Autonomous Nervous System
(ANS) activity. Generally, the 2D Poincare′ plot and 3D Poincaré
plot of the HRV signals reflect the effect of different external stimuli
on the ANS. Meditation is one of such external stimulus, which
has different techniques with different types of effects on the ANS.
Chinese Chi-meditation and Kundalini yoga are two different
effective meditation techniques. The current work is interested with
the analysis of the HRV signals under the effect of these two based on
meditation techniques. The 2D and 3D Poincare′ plots are generally
plotted by fitting respectively an ellipse/ellipsoid to the dense region
of the constructed Poincare′ plot of HRV signals. However, the
2D and 3D Poincaré plots sometimes fail to describe the proper
behaviour of the system. Thus in this study, a three-dimensional
frequency-delay plot is proposed to properly distinguish these two
famous meditation techniques by analyzing their effects on ANS.
This proposed 3D frequency-delay plot is applied on HRV signals
of eight persons practicing same Chi-meditation and four other
persons practising same Kundalini yoga. To substantiate the result
for larger sample of data, statistical Student t-test is applied, which
shows a satisfactory result in this context. The experimental results
established that the Chi-meditation has large impact on the HRV
compared to the Kundalini yoga
Inclined reinforcement around web opening in concrete beams
YesTwelve reinforced-concrete continuous deep beams
having web openings within interior shear spans were
tested to failure. The main variables investigated were
the opening size and the amount of inclined
reinforcement around openings. An effective inclined
reinforcement factor combining the influence of the
amount of inclined web reinforcement and opening size
is proposed and used to analyse the structural behaviour
of continuous deep beams tested. It was observed that
the end support reaction, diagonal crack width and load
capacity of beams tested were significantly dependent on
the proposed effective inclined reinforcement factor. As
this factor increased, the end support reaction and
increasing rate of diagonal crack width were closer to
those of companion solid deep beams. In addition, a
higher load capacity was exhibited by beams having an
effective inclined reinforcement factor above 0.077 than
the companion solid deep beam. A numerical procedure
based on the upper-bound analysis of the plasticity
theory was proposed to estimate the load capacity of
beams tested. Comparisons between the measured and
predicted load capacities showed good agreement
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High resolution melting for mutation scanning of TP53 exons 5-8.
BACKGROUND: p53 is commonly inactivated by mutations in the DNA-binding domain in a wide range of cancers. As mutant p53 often influences response to therapy, effective and rapid methods to scan for mutations in TP53 are likely to be of clinical value. We therefore evaluated the use of high resolution melting (HRM) as a rapid mutation scanning tool for TP53 in tumour samples. METHODS: We designed PCR amplicons for HRM mutation scanning of TP53 exons 5 to 8 and tested them with DNA from cell lines hemizygous or homozygous for known mutations. We assessed the sensitivity of each PCR amplicon using dilutions of cell line DNA in normal wild-type DNA. We then performed a blinded assessment on ovarian tumour DNA samples that had been previously sequenced for mutations in TP53 to assess the sensitivity and positive predictive value of the HRM technique. We also performed HRM analysis on breast tumour DNA samples with unknown TP53 mutation status. RESULTS: One cell line mutation was not readily observed when exon 5 was amplified. As exon 5 contained multiple melting domains, we divided the exon into two amplicons for further screening. Sequence changes were also introduced into some of the primers to improve the melting characteristics of the amplicon. Aberrant HRM curves indicative of TP53 mutations were observed for each of the samples in the ovarian tumour DNA panel. Comparison of the HRM results with the sequencing results revealed that each mutation was detected by HRM in the correct exon. For the breast tumour panel, we detected seven aberrant melt profiles by HRM and subsequent sequencing confirmed the presence of these and no other mutations in the predicted exons. CONCLUSION: HRM is an effective technique for simple and rapid scanning of TP53 mutations that can markedly reduce the amount of sequencing required in mutational studies of TP53.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
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Flexural toughness and calculation model of super-fine stainless wire reinforced reactive powder concrete
YesAs a type of excellent reinforcing filler, super-fine stainless wire (SSW) can form widely distributed network in reactive powder concrete (RPC) to transfer crack tip stresses as well as inhibit the initiation and propagation of cracks, leading to significant improvement of flexural toughness of RPC. In this paper, the flexural toughness of RPC beams and plates reinforced with 1% and 1.5% by vol. of SSWs was investigated, and its calculation model was established according to the composite material theory. Experimental results showed that the flexural toughness of unnotched beams fabricated with RPC containing 1.5% SSWs is 146.5% higher than that of control RPC without SSWs according to load-deflection relationships. The equivalent flexural strength of notched RPC beams is enhanced by 80.0% as SSW content increases from 1% to 1.5%. The limitation ability of SSWs on crack mouth opening can be used to evaluate the flexural toughness of composites. An addition of 1.5% SSWs leads to 201.9% increase of flexural toughness of RPC plates in accordance with load-deflection relationships. The calculation model based on the composite material theory can accurately describe the toughening effect of SSWs on RPC beams and plates. The enhancement of flexural toughness of RPC caused by SSWs is beneficial for improving the safety of structures as well as broadening the engineering applications of composites.National Key Research and Development Program of China (2018YFC0705601) and China Postdoctoral Science Fundation (2019M651116)
Application of Plasticity Theory to Reinforced Concrete Deep Beams
yesThis paper reviews the application of the plasticity theory to reinforced concrete deep beams. Both the truss analogy and mechanism approach were employed to predict the capacity of reinforced concrete deep beams. In addition, most current codes of practice, for example Eurocode 1992 and ACI 318-05, recommend the strut-and-tie model for designing reinforced concrete deep beams.
Compared with methods based on empirical or semi-empirical equations, the strut-and-tie model and mechanism analyses are more rational, adequately accurate and sufficiently simple for estimating the load capacity of reinforced concrete deep beams. However, there is a problem of selecting the effectiveness factor of concrete as reflected in the wide range of values reported in the literature for deep beams
Angular momenta creation in relativistic electron-positron plasma
Creation of angular momentum in a relativistic electron-positron plasma is
explored. It is shown that a chain of angular momentum carrying vortices is a
robust asymptotic state sustained by the generalized nonlinear Schrodinger
equation characteristic to the system. The results may suggest a possible
electromagnetic origin of angular momenta when it is applied to the MeV epoch
of the early Universe.Comment: 20 pages, 6 figure
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