The Egyptian Cardiothoracic Surgeon (ECTS - E-Journal)
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An integrated genomic approach identifies that the PI3K/AKT/FOXO pathway is involved in breast cancer tumor initiation
No full textTherapy resistance is one of the major impediments to successful cancer treatment. In breast cancer, a small subpopulation of cells with stem cell features, named breast cancer stem cells (BCSC), is responsible for metastasis and recurrence of the tumor. BCSC have the unique ability to grow under non-adherent conditions in “mammospheres”. To prevent breast cancer recurrence and metastasis it will be crucial to eradicate BCSC.We used shRNA genetic screening to identify genes that upon knockdown enhance mammosphere formation in breast cancer cells. By integration of these results with gene expression profiles of mammospheres and NOTCH-activated cells, we identified FOXO3A. Modulation of FOXO3A activity results in a change in mammosphere formation, expression of mammary stem cell markers and breast cancer initiating potential. Importantly, lack of FOXO3A expression in breast cancer patients is associated with increased recurrence rate. Our findings provide evidence for a role for FOXO3A downstream of NOTCH and AKT that may have implications for therapies targeting BCSCs
Which are the most useful scales for predicting repeat self-harm? A systematic review evaluating risk scales using measures of diagnostic accuracy.
No full textOBJECTIVES: The aims of this review were to calculate the diagnostic accuracy statistics of risk scales following self-harm and consider which might be the most useful scales in clinical practice. DESIGN: Systematic review. METHODS: We based our search terms on those used in the systematic reviews carried out for the National Institute for Health and Care Excellence self-harm guidelines (2012) and evidence update (2013), and updated the searches through to February 2015 (CINAHL, EMBASE, MEDLINE, and PsychINFO). Methodological quality was assessed and three reviewers extracted data independently. We limited our analysis to cohort studies in adults using the outcome of repeat self-harm or attempted suicide. We calculated diagnostic accuracy statistics including measures of global accuracy. Statistical pooling was not possible due to heterogeneity. RESULTS: The eight papers included in the final analysis varied widely according to methodological quality and the content of scales employed. Overall, sensitivity of scales ranged from 6% (95% CI 5% to 6%) to 97% (CI 95% 94% to 98%). The positive predictive value (PPV) ranged from 5% (95% CI 3% to 9%) to 84% (95% CI 80% to 87%). The diagnostic OR ranged from 1.01 (95% CI 0.434 to 2.5) to 16.3 (95%CI 12.5 to 21.4). Scales with high sensitivity tended to have low PPVs. CONCLUSIONS: It is difficult to be certain which, if any, are the most useful scales for self-harm risk assessment. No scales perform sufficiently well so as to be recommended for routine clinical use. Further robust prospective studies are warranted to evaluate risk scales following an episode of self-harm. Diagnostic accuracy statistics should be considered in relation to the specific service needs, and scales should only be used as an adjunct to assessment
High-Shear Mixing: Applications in the Food Industry
No full textAbstract High-shear mixing is used widely in the food industry. This article introduces the subject, explaining why it is used, and gives examples of its applications, including emulsification, encapsulation, thickeners, and powders. A common high-shear mixing device, rotor???stator mixer, is described, and the pros and cons of their different possible arrangements are explained. The method of calculating power draw of the system, a fundamental measurement in mixing, is given
The mutual construction of urban retrofit and scale: Governing ON, IN and WITH in Greater Manchester
No full textIn this article, we focus on the mutually interrelated processes of constructing urban retrofit and the city-region as a scale for action. Urban retrofitting – the systematic reconfiguration of sociotechnologies of energy in the existing built environment and infrastructure – is critical to the achievement of ambitious carbon reduction targets. To realise the ecological and economic benefits of retrofit cities are continually searching for a ‘fix’ that allows them to upscale retrofit from a largely ad hoc and piecemeal activity of repair and maintenance into strategic and systemic retrofit programmes that transform existing cities. This article is primarily concerned with understanding the politics and purpose of such experimentation and analyses efforts to integrate retrofit and governing in Greater Manchester. To do this, the article draws on a programme of interviews with national, city-regional, local authority and neighbourhood scale actors, documentary analysis and observations. We address on who is constructing retrofit responses in Greater Manchester and also why they are being constructed: Is it to transform the city-region and, if so, in what ways? And ask, in what ways are governance frameworks mediating and interpreting wider sets of global pressures at city-regional scale and which of these – economic, ecological, governing, social justice, etc. – pressures are more and less prioritised? We set out dominant city-regional responses (ON), alternative responses (IN) and assess the possibilities for integrated responses (WITH)
Study of energy transfer by different light curing units into a class III restoration as a function of tilt angle and distance, using a MARC Patient Simulator (PS)
No full texttObjective. The MARC Patient Simulator (MARC PS) enables researchers to observe the influence of handling errors on the radiant exposure that is delivered by light curing units (LCUs).Changes in the tilt angle and distance of the light guide exit face in relation to the surface ofthe composite increment have a distinct effect on the total amount of light delivered during polymerization and may cause insufficient conversion of the material. Therefore, the aimof the present study was to determine the influence of the tilt angle and distance of irradiance on the efficiency of light application by recording the total amount of energy using the anterior tooth sensor of the MARC PS.Methods. The influence of the tilt angle and distance of the light guide to the sensor surface on the delivered radiant exposure was examined for three different LCUs (Celalux 2 [C2],Bluephase [BP] and Translux Powerblue [TPB]). The measurements were performed for 20 s each with five different tilt angles (˛ = 0◦, 5◦, 10◦, 15◦, 20◦) and nine different distances (L = 1,2, 3, 4, 5, 6, 7, 8, 9 mm).Results. For all LCUs, a distinct influence of the tilt angle on the delivered amount of fluence was found. At 0◦tilt the C2 delivered a total light energy of 38.55 J/cm2. By increasing the tilt of the light guide the amount of energy applied significantly decreased. At 20◦tilt a reduction by 31.2% of the original light fluence was recorded. However, the C2 was the most powerfulLCU measured. Even under optimum measurement conditions, the BP delivered a fluence of only 14.8 J/cm2. At a tilt angle of 20◦, though, the light sensor still registered 92.7% of the original output power. Under the same conditions, the TPB delivered 81.4%.With increasing distance of the light guide exit face to the surface of the sensor all LCUs showed a significant loss in delivered light energy. At a distance of 2 mm the C2 showed axxxreduction by 46.7%, whereas total fluence of BP and TPB were reduced by 3.8% and 4.8%,respectively.Significance. The choice of LCU and the application of an appropriate curing time are impor-tant for successful polymerization. Nevertheless, a perpendicular positioning of the lightguide as close as possible to the surface of the composite increment is of essential importance in order to ensure sufficient delivery of light
Improved Accuracy Average Value Models of Modular Multilevel Converters
No full textModular Multilevel Converters (MMC) have become the converter topology of choice for VSC-HVDC systems. Excellent work has previously been conducted to develop much needed Average Value Models (AVM) for these complex converters, however there a number of limitations as highlighted in this paper. This work builds on the existing models, proposing numerous modifications and resulting in an enhanced MMC-AVM which is significantly more accurate and which can be used for a wider range of studies, including DC faults
Ultrafast Exciton Dynamics in Cd<sub>x</sub>Hg<sub>(1-x)</sub>Te alloy Quantum Dots
No full textUltrafast transient absorption spectroscopy is used to investigate sub-nanosecond exciton dynamics in CdxHg(1-x)Te alloy colloidal quantum dots. A bleach was observed at the band gap due to state-filling, the mono-exponential decay of which had a characteristic lifetime of 91±1 ps and was attributed to biexciton recombination; no evidence of surface-related trapping was observed. The rise time of the bleach, which is determined by the rate at which hot electrons cool to the band-edge, ranged between 1 and 5 ps depending on the pump photon energy. Measuring the magnitude of the bleach decay for different pump fluences and wavelengths allowed the quantum yield of multiple exciton generation to be determined, and was 115±1% for pump photons with energy equivalent to 2.6 times the band gap