Performance and operational characteristics of point-of-care tests for the diagnosis of urogenital gonococcal infections.

BACKGROUND: In 2012, there was an estimated 78 million new cases of gonorrhoea globally. Untreated infection may lead to reproductive and neonatal morbidity and facilitate HIV transmission. Diagnosis and treatment are a priority for control and prevention, yet use of point-of-care tests (POCTs) for Neisseria gonorrhoeae (NG) is limited. OBJECTIVES: To review the performance and operational characteristics of NG POCTs for diagnosis of urogenital gonorrhoea. METHODS: We compiled and synthesised findings from two separate systematic reviews which included evaluations published until August 2015. RESULTS: Six tests were included: five were immunochromatographic tests (ICTs) or optical immunoassay (OIAs) based on antigen detection; with 5-7 steps and results in 25-40 min, and one (GeneXpert CT/NG) was a 'near-patient test' based on nucleic acid amplification technique (NAAT); with three steps, electricity required, and results in 90 min. When compared with laboratory-based NAATs as the reference tests, sensitivities of ICT and OIA-based POCTs ranged from 12.5% to 70% when cervical/vaginal swabs were tested. Specificities ranged from 89% to 99.8%. The near-patient NAAT had sensitivities of >95% and specificities of >99.8% consistently across all specimen types (urine, cervical and vaginal swabs). CONCLUSIONS: Based on a limited number of evaluations, antigen detection POCTs for NG lacked sufficient sensitivity to be used for screening. A near-patient NAAT has acceptable performance, only involved a few steps, but needs electricity, a temperature-controlled environment and has a 90 min run time. To achieve wider scale up of NG POCTs, we need strong evidence of cost-effectiveness, which should inform guidelines and ultimately increase test development, demand and reduce costs

Photon Pair Generation in Silicon Micro-Ring Resonator with Reverse Bias Enhancement

Photon sources are fundamental components for any quantum photonic technology. The ability to generate high count-rate and low-noise correlated photon pairs via spontaneous parametric down-conversion using bulk crystals has been the cornerstone of modern quantum optics. However, future practical quantum technologies will require a scalable integration approach, and waveguide-based photon sources with high-count rate and low-noise characteristics will be an essential part of chip-based quantum technologies. Here, we demonstrate photon pair generation through spontaneous four-wave mixing in a silicon micro-ring resonator, reporting a maximum coincidence-to-accidental (CAR) ratio of 602 (+-) 37, and a maximum photon pair generation rate of 123 MHz (+-) 11 KHz. To overcome free-carrier related performance degradations we have investigated reverse biased p-i-n structures, demonstrating an improvement in the pair generation rate by a factor of up to 2, with negligible impact on CAR.Comment: 5 pages, 3 figure

Comparison of the Electronic Structures and Energetics of Ferroelectric LiNbO3 and LiTaO3

This paper explains the origin of the ferroelectric instability in LiNbO3 and LiTaO3 and compares the electronic structures and energetics of the two materials.Comment: 31 pages, 11 Postscript figure

Squeezing Droplet Formation in a Flow-Focusing Micro Cross-Junction

Motivated by the increasing need of optimised micro-devices for droplet production in medical and biological applications, this paper introduces an integrated approach for the study of the liquid-liquid droplet creation in flow-focusing micro cross-junctions. The micro-junction considered is characterised by a restriction of the channels cross-sections in the junction, which has the function of focusing the flow in the region of the droplet formation. The problem is studied numerically in the OpenFOAM environment and validated by a comparison with experimental results obtained by high-speed camera images and micro-PIV measurements. The analysis of the forces acting on the dispersed phase during the droplet formation and the diameter of the droplets obtained numerically are considered for the development of a model of the droplet breakup under the squeezing regime. On the basis of energy balancing during the breakup, a relation between interfacial tension, the size of the cross-sections in the junction, and the time interval needed for droplet creation is obtained, which yields a novel correlation between the dimensionless length of the droplet and the dimensionless flow rate. This research expands our knowledge of the phenomenon of drop creation in micro-junctions with restrictions providing new aid for the optimal design of micro-drop generators

Pelargonidin-3-O-glucoside and its metabolites have modest anti-inflammatory effects in human whole blood cultures

This study hypothesized that the predominant strawberry anthocyanin, pelargonidin-3-O-glucoside (Pg-3-glc), and three of its plasma metabolites (4-hydroxybenzoic acid, protocatechuic acid and phloroglucinaldehyde [PGA]) would affect phagocytosis, oxidative burst and the production of selected pro- and anti-inflammatory cytokines in a whole blood culture model. For the assessment of phagocytosis and oxidative burst activity of monocytes and neutrophils, whole blood was pre-incubated in the presence or absence of the test compounds at concentrations up to 5 μM, followed by analysis of phagocytic and oxidative burst activity using commercially available test kits. For the cytokine analysis, diluted whole blood was stimulated with lipopolysaccharide in the presence or absence of the test compounds at concentrations up to 5 μM. Concentrations of selected cytokines (tumor necrosis factor-α [TNF-α], interleukin [IL]-1β, IL-6, IL-8 and IL-10) were determined using a cytometric bead array kit. There were no effects of any of the test compounds on phagocytosis of opsonized or non-opsonized E. coli or on oxidative burst activity. Pg-3-glc and PGA at 0.08 μM increased the concentration of IL-10 (P<0.01 and P<0.001, respectively), but there was no effect on TNF-α, IL-1β, IL-6 and IL-8 and there were no effects of the other compounds. In conclusion, this study demonstrated a lack of effect of these compounds on the opsonization, engulfment and subsequent destruction of bacteria. Pg-3-glc and PGA, at physiologically relevant concentrations, had anti-inflammatory properties; however, effects were modest, only observed at the lowest dose tested and limited to IL-10

Continuous and transparent multimodal authentication: reviewing the state of the art

Individuals, businesses and governments undertake an ever-growing range of activities online and via various Internet-enabled digital devices. Unfortunately, these activities, services, information and devices are the targets of cybercrimes. Verifying the user legitimacy to use/access a digital device or service has become of the utmost importance. Authentication is the frontline countermeasure of ensuring only the authorized user is granted access; however, it has historically suffered from a range of issues related to the security and usability of the approaches. They are also still mostly functioning at the point of entry and those performing sort of re-authentication executing it in an intrusive manner. Thus, it is apparent that a more innovative, convenient and secure user authentication solution is vital. This paper reviews the authentication methods along with the current use of authentication technologies, aiming at developing a current state-of-the-art and identifying the open problems to be tackled and available solutions to be adopted. It also investigates whether these authentication technologies have the capability to fill the gap between high security and user satisfaction. This is followed by a literature review of the existing research on continuous and transparent multimodal authentication. It concludes that providing users with adequate protection and convenience requires innovative robust authentication mechanisms to be utilized in a universal level. Ultimately, a potential federated biometric authentication solution is presented; however it needs to be developed and extensively evaluated, thus operating in a transparent, continuous and user-friendly manner

Rappresentare l’armatura culturale del territorio con QGIS: l’esperienza del PTRA della Franciacorta

Landscape features are the result of interrelated actions of man-and-nature and can provide ecosystem services that need to be protected. Since urban planning policies can impact negatively on the conservation of cultural ecosystem services, urban plans must map them and make provision for their protection. For the Plan of Franciacorta (22 municipalities in Lombardy), we chose QGIS to set up a geo-database and map cultural heritage information. QGIS can provide more flexibility than a typical map, thanks to its graphics tools. To plan the development of actions to protect the landscape and suggest a range of planning opportunities for municipalities, an integrated representation of the landscape and protected ecological elements can highlight some critical issues: municipal borders can prove an obstacle in the implementation of supra-municipal projects and protected areas can include enclaves potentially vulnerable to urban pressures. Such maps have proved useful in guiding the planning choices in the development of the landscape protection schemes. The geo-location of critical aspects has brought out a range of inter-municipal planning opportunities

A Neuro-Evolutionary Approach to Electrocardiographic Signal Classification

International audienceThis chapter presents an evolutionary Artificial Neural Networks (ANN) classifier system as a heartbeat classification algorithm designed according to the rules of the PhysioNet/Computing in Cardiology Challenge 2011 (Moody, Comput Cardiol Challenge 38:273-276, 2011), whose aim is to develop an efficient algorithm able to run within a mobile phone that can provide useful feedback when acquiring a diagnostically useful 12-lead Electrocardiography (ECG) recording. The method used to solve this problem is a very powerful natural computing analysis tool, namely evolutionary neural networks, based on the joint evolution of the topology and the connection weights relying on a novel similarity-based crossover. The chapter focuses on discerning between usable and unusable electrocardiograms tele-medically acquired from mobile embedded devices. A preprocessing algorithm based on the Discrete Fourier Transform has been applied before the evolutionary approach in order to extract an ECG feature dataset in the frequency domain. Finally, a series of tests has been carried out in order to evaluate the performance and the accuracy of the classifier system for such a challenge