30 research outputs found

    Full-length genome and molecular characterization of dengue virus serotype 2 isolated from an imported patient from Myanmar

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    Abstract Background Dengue is the most common mosquito-borne infection worldwide and a serious threat to global public health. Sporadic dengue virus serotype 2 (DENV-2) imported cases from Myanmar have been documented almost every year in Yunnan Province of China since 2005. However, the complete genome sequences of DENV-2 isolates imported from Myanmar are not available. Methods The full-length genome of the DENV-2 strain (YNPE2), isolated from an imported case from Myanmar in 2013, was identified by the next-generation sequencing. The extreme ends of the viral genome were validated by 5′/3′ RACE and Sanger sequencing. Furthermore, phylogenetic, recombination and selection pressure analyses were conducted for the molecular characterization of YNPE2 strain. Results Whole-genome sequencing revealed that the full-length sequence of YNPE2 strain was 10,724 bases, with an open reading frame encoding for 3391 amino acids. The YNPE2 strain had 99.0% nucleotide identity and 99.8% amino acid identity with two closely related strains, ThD2_0078_01 strain (DQ181797) and DENV-2/TH/BID-V2157/200 strain (FJ639832). The phylogenetic analysis suggested that the YNPE2 strain belonged to Asian I genotype and was likely derived from Thailand strain (DQ181797). Moreover, selection pressure analysis revealed two amino acid sites of the NS4B and NS5 proteins, with important evidence of positive selection. Conclusion This study revealed the first complete genome sequence and molecular characterization of a DENV-2 strain (YNPE2) isolated from an imported case from Myanmar, thus providing a valuable reference genome source for future surveillance, epidemiology and vaccine development of DENV-2 virus in Yunnan, China

    Molecular characterization and phylogenetic analysis of a dengue virus serotype 3 isolated from a Chinese traveler returned from Laos

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    Abstract Background Dengue virus (DENV) infection caused by international visitors has become a public health concern in China. Although sporadic imported cases of DENV have been documented in Yunnan, China since 2000, a complete genome sequence of dengue virus serotype 3 (DENV-3) imported from Laos is still not available. Here, we report the first complete genome sequence and genomic characterization of a DENV-3 strain (YNPE3) isolated from a patient returned from Laos. Methods Viral isolation from the patient’s serum was performed using mosquitoes C6/36 cells. Reverse transcriptase polymerase chain reaction (RT-PCR) was used for identification and serotyping of the virus. The complete sequence was determined by Sanger dideoxy sequencing. Homology analysis was implemented by NCBI-BLAST. Multiple sequence alignment was performed using MegAlign module of the Lasergene 7 software package DNASTAR. MFOLD software was used to predict the RNA secondary structure of 5′ untranslated region (UTR) and 3′ UTR. Phylogenetic analysis, which was based on envelope gene and complete coding sequence, was performed by Maximum-Likelihood method. Results RT-PCR analysis confirmed that the virus belonged to dengue virus serotype 3, which was named YNPE3 strain. The full-length genome of the YNPE3 strain was 10,627 nucleotides (nts) with an open reading frame (ORF) encoding 3390 amino acids. Strain YNPE3 shared 98.6–98.8% nucleotide identity with the closely related strains isolated in India (JQ922556, KU216209, KU216208). We observed the deletion of about 40 nts in the 5′ UTR and 3′ UTR of strain YNPE3, and 11 nts (ACGCAGGAAGT) insertion that was present in the 3′ UTR of YNPE3. Compared with prototype strain H87, abundant amino acid substitutions in the YNPE3 strain were observed. Phylogenetic analysis revealed that the YNPE3 strain belonged to genotype III of DENV-3, and that it might be closely related with genotype III strains isolated in Laos and India. Conclusions This is the first report of the complete genome sequence and molecular characterization of a DENV-3 isolate imported from Laos. The presented results can further promote disease surveillance, and epidemiological and evolutionary studies of the DENV-3 in Yunnan province of China

    Automatic Analysis of Affective States: Visual Attention Based Approach

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    International audienceComputing environment is moving from computer centered designs to human-centered designs. Human’s tend to communicate wealth of information through affective states or expressions. Thus automatic analysis of user affective states have become inevitable for computer vision community. In this paper first we focus on understanding human visual system (HVS) when it decodes or recognizes facial expressions. To understand HVS, we have conducted psycho-visual experimental study with an eye-tracker, to find which facial region is perceptually more attractive or salient for a particular expression. Secondly, based on results obtained from psycho-visual experimental study we have proposed a novel framework for automatic analysis of affective states. Framework creates discriminative feature space by processing only salient facial regions to extract Pyramid Histogram of Orientation Gradients (PHOG) features. The proposed framework achieved automatic expression recognition accuracy of 95.3 % on extended Cohn-Kanade (CK+) facial expression database for six universal facial expressions. We have also discussed generalization capabilites of proposed framework on unseen data. In the last paper discusses effectiveness of proposed framework against low resolution image sequences

    Electrochemical investigation of Li-excess layered oxide cathode materials/mesocarbon microbead in 18650 batteries

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    The electrochemical performance of the 18650 lithium-ion batteries for layered Li-excess oxide Li1.144Ni0.136CO0.136Mn0.544O2 (LNCMO) cathode material and mesocarbon microbead (MCMB) anode material is investigated. The battery shows an excellent rate capability with the capacity of 227 mAh g(-1) at 8 C-rate (the cut-off voltage is 4.5 V). Furthermore, it exhibits excellent cycle performance that the capacity retention over 300 cycles in the voltage ranges of 2.5-4.5 V (vs. MCMB) and at 0.2 C-rate is about 85%. Although the medium voltage of the battery greatly reduces during the first 30 cycles, it keeps stable in the following cycles. The mechanisms of the capacity fade and voltage decay are also studied based on energy dispersive spectrometry, X-ray photoelectron spectroscopy, charge-discharge curves, and dQ/dV plots. (C) 2014 Elsevier Ltd. All rights reserved

    Polymorphism in a high-entropy alloy.

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    Polymorphism, which describes the occurrence of different lattice structures in a crystalline material, is a critical phenomenon in materials science and condensed matter physics. Recently, configuration disorder was compositionally engineered into single lattices, leading to the discovery of high-entropy alloys and high-entropy oxides. For these novel entropy-stabilized forms of crystalline matter with extremely high structural stability, is polymorphism still possible? Here by employing in situ high-pressure synchrotron radiation X-ray diffraction, we reveal a polymorphic transition from face-centred-cubic (fcc) structure to hexagonal-close-packing (hcp) structure in the prototype CoCrFeMnNi high-entropy alloy. The transition is irreversible, and our in situ high-temperature synchrotron radiation X-ray diffraction experiments at different pressures of the retained hcp high-entropy alloy reveal that the fcc phase is a stable polymorph at high temperatures, while the hcp structure is more thermodynamically favourable at lower temperatures. As pressure is increased, the critical temperature for the hcp-to-fcc transformation also rises

    Intake of soy foods and soy isofl avones by rural adult women

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    This study evaluated the intake of soy foods and soy isoflavones by rural adult women and potential determinant factors. Soy food consumption and information on age, education and medical history were collected on 1,188 subjects in Gansu Province and Hebei Province, China using a food frequency questionnaire to gather data on food intake over the past year. Weight and height were simultaneously measured. The results showed that 1139 (95.9%) rural women consumed soy foods in the past year. The average intake of soy foods and isoflavones was 38.7 ± 58.2 (median = 23.5) g/d and 17.7 ± 26.6 (median=8.9) mg/d, respectively. Tofu accounted for the most contribution to their intake. The soy isoflavone intake ranged between 0-35 mg/day in 89.2% of subjects. Gansu women had higher intakes of soy foods and isoflavones than Henbei women (P<0.05). Women aged 41-50 years consumed less soy foods and isoflavones than the 20-30-year olds and 31-40 year olds (P <0.05). The intake of soy foods (P<0.01) and isoflavones (P<0.01) by women who experienced secondary education or above was significantly higher than illiterate women. Women without a medical history had a higher soy isoflavone intake than women with a medical history, but the difference was not statistically significant. These results suggest that the intake of soy isoflavones by Chinese rural adult women was much higher than women in Western countries. The distribution of intake was skewed to the right and varied among women in regard to region, age group and education level
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