10 research outputs found

    A copper-mediated reverse aromatic Finkelstein reaction in ionic liquid

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    We have developed a general method for reverse aromatic Finkelstein reactions. Good reaction yields were obtained when aryl iodides or aryl bromides were treated with copper halide salts as promoters in a 1-butyl-3-methylimidazolium bromide ([BMIM]Br) ionic liquid (IL) solvent at 140 °C for 8 h. Preliminary investigation supported that the copper salts were also the halide sources in halogen exchange reactions. The optimized conditions are applicable to a variety of substrates and have excellent functional group tolerance. Additionally, the [BMIM]Br solvent showed good stability for at least 10 consecutive runs. Results indicated that the [BMIM]Br solvent was recyclable for reverse aromatic Finkelstein reactions

    A novel approach combining particle swarm optimization and deep learning for flash flood detection from satellite images

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    Flood is one of the deadliest natural hazards worldwide, with the population affected being more than 2 billion between 1998–2017 with a lack of warning systems according to WHO. Especially, flash floods have the potential to generate fatal damages due to their rapid evolution and the limited warning and response time. An effective Early Warning Systems (EWS) could support detection and recognition of flash floods. Information about a flash flood can be mainly provided from observations of hydrology and from satellite images taken before the flash flood happens. Then, predictions from satellite images can be integrated with predictions based on sensors’ information to improve the accuracy of a forecasting system and subsequently trigger warning systems. The existing Deep Learning models such as UNET has been effectively used to segment the flash flood with high performance, but there are no ways to determine the most suitable model architecture with the proper number of layers showing the best performance in the task. In this paper, we propose a novel Deep Learning architecture, namely PSO-UNET, which combines Particle Swarm Optimization (PSO) with UNET to seek the best number of layers and the parameters of layers in the UNET based architecture; thereby improving the performance of flash flood segmentation from satellite images. Since the original UNET has a symmetrical architecture, the evolutionary computation is performed by paying attention to the contracting path and the expanding path is synchronized with the following layers in the contracting path. The UNET convolutional process is performed four times. Indeed, we consider each process as a block of the convolution having two convolutional layers in the original architecture. Training of inputs and hyper-parameters is performed by executing the PSO algorithm. In practice, the value of Dice Coefficient of our proposed model exceeds 79.75% (8.59% higher than that of the original UNET model). Experimental results on various satellite images prove the advantages and superiority of the PSO-UNET approach. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Anaemia and its relation to demographic, socio-economic and anthropometric factors in rural primary school children in Hai Phong City, Vietnam

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    © 2019 by the authors. Licensee MDPI, Basel, Switzerland. Little is known about the prevalence of anaemia and associated factors in school children in Vietnam. In this cross-sectional study, we aimed to determine the prevalence of anaemia and its subtypes, and the associations of types of anaemia with demographic, socio-economic and anthropometric factors among 6–9-year-old primary school children in rural areas of Hai Phong City, Vietnam. Haemoglobin (Hb) and mean corpuscular volume (MCV) were measured, and demographic, socio-economic and anthropometric data were collected in 893 children from eight primary schools. The prevalence of anaemia (Hb < 115 g/L) was 12.9% (95% CI: 8.1%, 19.9%), microcytic anaemia (Hb < 115 g/L and MCV < 80 fL) was 7.9% (95% CI: 5.3%, 11.6%) and normocytic anaemia (Hb < 115 g/L and MCV 80–90 fL) was 5.3% (95% CI: 2.9%, 9.5%). No child presented with macrocytic anaemia (Hb < 115 g/L and MCV > 90 fL). Children who were underweight, wasted, or in anthropometric failure (either underweight, stunted or wasted) were more likely to be anaemic (all p ≤ 0.004), and specifically, to have normocytic anaemia (all p ≤ 0.006), than those who were not underweight, wasted or in anthropometric failure. Stunted children were more likely to be anaemic (p = 0.018) than those who were not stunted. Overweight/obese children were less likely to be anaemic (p = 0.026) or have normocytic anaemia (p = 0.038) compared with children who were not overweight/obese. No anthropometric status indicator was associated with the risk of microcytic anaemia. No demographic or socio-economic factor was associated with any type of anaemia. Anaemia remains a public health issue in rural areas in Hai Phong City, Vietnam, and future approaches for its prevention and control should target undernourished primary school children

    Validation and utilization of an internally controlled multiplex Real-time RT-PCR assay for simultaneous detection of enteroviruses and enterovirus A71 associated with hand foot and mouth disease

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    Background: Hand foot and mouth disease (HFMD) is a disease of public health importance across the Asia-Pacific region. The disease is caused by enteroviruses (EVs), in particular enterovirus A71 (EV-A71). In EV-A71-associated HFMD, the infection is sometimes associated with severe manifestations including neurological involvement and fatal outcome. The availability of a robust diagnostic assay to distinguish EV-A71 from other EVs is important for patient management and outbreak response. Methods: We developed and validated an internally controlled one-step single-tube real-time RT-PCR in terms of sensitivity, linearity, precision, and specificity for simultaneous detection of EVs and EV-A71. Subsequently, the assay was then applied on throat and rectal swabs sampled from 434 HFMD patients. Results: The assay was evaluated using both plasmid DNA and viral RNA and has shown to be reproducible with a maximum assay variation of 4.41 % and sensitive with a limit of detection less than 10 copies of target template per reaction, while cross-reactivity with other EV serotypes was not observed. When compared against a published VP1 nested RT-PCR using 112 diagnostic throat and rectal swabs from 112 children with a clinical diagnosis of HFMD during 2014, the multiplex assay had a higher sensitivity and 100 % concordance with sequencing results which showed EVs in 77/112 (68.8 %) and EV-A71 in 7/112 (6.3 %). When applied to clinical diagnostics for 322 children, the assay detected EVs in throat swabs of 257/322 (79.8 %) of which EV-A71 was detected in 36/322 (11.2 %) children. The detection rate increased to 93.5 % (301/322) and 13.4 % (43/322) for EVs and EV-A71, respectively, when rectal swabs from 65 throat-negative children were further analyzed. Conclusion: We have successfully developed and validated a sensitive internally controlled multiplex assay for rapid detection of EVs and EV-A71, which is useful for clinical management and outbreak control of HFMD

    Effect of double dose oseltamivir on clinical and virological outcomes in children and adults admitted to hospital with severe influenza: Double blind randomised controlled trial

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    10.1136/bmj.f3039BMJ (Online)3467911-BMJO

    Upper Devonian conodonts of northeastern European Russia

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