28 research outputs found

    Antibodies against H10N8 avian influenza virus among animal workers in Guangdong Province before November 30, 2013, when the first human H10N8 case was recognized

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    BACKGROUND: Considered an epicenter of pandemic influenza virus generation, southern China has recently seen an increasing number of human H7N9 infections. However, it is not the only threat. On 30 November 2013, a human H10N8 infection case was first described in China. The origin and genetic diversity of this novel virus is similar to that of H7N9 virus. As H10N8 avian influenza virus (AIV) was first identified from a duck in Guangdong Province during 2012 and there is also evidence of H10N8 infected dogs in this region, we sought to examine archived sera from animal workers to see if there was evidence of subclinical human infections before the first human H10N8 cases. METHODS: We studied archived serum samples (cross-sectional study, convenience sample) collected between May and September 2013 from 710 animal workers and 107 non-animal exposed volunteers living in five cities of Guangdong Province. Study participants’ sera were tested by horse red blood cells (RBCs) hemagglutination inhibition (HI) and microneutralization (MN) assays according to World Health Organization guidelines. The A/Jiangxi-Donghu/346-1/2013(H10N8) virus was used. Sera which have an HI assay ≥1:20 were further tested with the MN assay. Questionnaire data were examined for risk factor associations with positive serological assays. Risk factor analyses failed to identify specific factors associated with probable H10N8 infections. RESULTS: Among the 827 sera, only 21 animal workers had an HI titer ≥1:20 (18 had an HI titer of 1:20 and 3 had an HI titer of 1:40). None of these 21 subjects reported experiencing any influenza symptoms during the three months before enrollment. Among the three subjects with HI titers of 1:40, two had MN antibody titers of 1:40, and one had a MN antibody titer of 1:80 (probable H10N8 infections). CONCLUSIONS: Study data suggest that animal workers may have been infected with the H10N8 virus before the first recognized H10N8 human infection cases. It seems prudent to continue surveillance for H10N8 viruses among animal workers

    The Digital Predistortion of the SC-FDMA Signals in LTE Uplink System

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    The single-carrier frequency-division multiple access (SC-FDMA) is used in the uplink of the long-term evolution (LTE) and LTE-advanced systems because of the lower peak-to-average-power ratio (PAPR) compared with the widely used orthogonal frequency-division multiplexing (OFDM) scheme. However, the non-linearity caused by the characteristic of the radio frequency (RF) power amplifiers (PAs) is still a critical problem, and there are few researches about the linearisation for the SC-FDMA signals. The digital predistorter is widely applied by employing digital baseband distortion ahead of the amplifier to compensate for the non-linearity effects and provide efficiency enhancements for high PAs in the different communication systems. This letter presents an efficient and flexible inverse autoregressive moving-average (ARMA) model-based digital predistorter to linearise the PA distortion with memory in the LTE uplink system. The proposed digital predistortion (DPD) algorithm is for the first time applied to SC-FDMA signals and verified with a series of experimental measurements. The spectrum regrowth of SC-FDMA signals is improved by up to 12 dB from both simulation and measurement. The proposed predistorter has been shown to solve the distortion problem caused by the memory effect effectively in RF PA

    Machine-learning and water energy harvesting based wireless water consumption sensing system in buildings

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    In recent years, smart wireless remote water meters have become popular, but this kind of smart water meter needs an external power supply, and every 100 to 200 installed this type of water meter, needs to set up an independent collector. This kind of water meter is expensive, and the external power supply will increase the energy consumption of the building, which is not conducive to the circuit safety of the old community. In order to reduce the burden of manual meter reading and reduce the building's ''carbon emissions''. A wireless water consumption sensing system for buildings based on machine learning and water energy collection is designed. Images are collected and recognized by visual sensors to realize the visual reading of water meter data. The system is powered by a 12V micro water generator and transferred to lithium battery energy storage to realize the self-energy supply of the whole system. The lightweight YOLOv5 was used to implement the model training process. Then, on the premise of the small sample data set, the data set was expanded by a data enhancement method which randomly changed the image brightness and hue. Finally, the training model is deployed on MCU through the TensorFlow Lite framework to realize edge AI detection. Experiments show that the size of the lightweight YOLOv5 is reduced by 87.1% and the mAP reaches 92.3%. The system can complete the water meter wireless meter reading and realize the system self-power stably. In addition, the system can be expanded for other meter reading tasks based on visual features

    Experimental measurement and clustered equal diameter particle model of permeability with methane hydrate in glass beads

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    Permeability is a key parameter for gas recovery from marine hydrate reservoirs. In this study, two kinds of BZ02 and BZ04 glass beads provided skeleton structure for methane hydrate synthesis in pressure vessel. Based on the observation of Scanning Electron Microscopy (SEM), the glass beads in the pressure vessel were considered to be equal diameter spheres and stacked in the form of orthorhombic. The water effective permeability KW of glass beads with different hydrate saturations (S-H) were carried out by steady-state water injection method. Experimental results indicated that the presence of methane hydrate could cause significant decrease of K-W, and the gas produced by hydrate dissociation would reduce the resistance of fluid flow in pores. The permeability ratio in the presence and absence of hydrate Kr-W was exponentially decreasing with the SH. A clustered equal diameter particle (CEDP) model was proposed that methane hydrate was clustered as equal diameter spheres and occupied in the center of pore space. The internal surface area of pore space with and without hydrate was simplified and the KrW-SH relationship was deduced in detail. When the saturation exponent n of BZ02 and BZ04 were recommended to be 10 and 18, respectively, the K-rW in the CEDP model was fitted well with the experimental results. This model also revealed that the radius of glass beads and hydrate particles had a stronger effect on the KrW

    Data_Sheet_1_Associations between diet and incidence risk of lung cancer: A Mendelian randomization study.docx

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    BackgroundObservational studies have revealed associations between diet and lung cancer. However, it is unclear whether the association is disturbed by confounding factors. We used a two-sample Mendelian randomization (MR) method to characterize the associations between diet and the lung cancer risk (including 3 subtypes: lung adenocarcinoma (LA), squamous cell lung carcinoma (SqCLC), and small cell lung cancer (SCLC)).Materials and methodsData on 20 diets were screened from the UK Biobank. Lung cancer data came from a large meta-analysis of 85,716 individuals. The inverse-variance weighted method was used as the main analysis. Sensitivity analysis was also used to explain the different multiplicity patterns of the final model.ResultsOur results showed significant evidence that 3 diets were associated with lung cancer [odds ratio (OR): 0.271, 95% confidence interval (CI): 0.150–0.488, p = 1.46 × 10−4, dried fruit; OR: 3.010, 95% CI: 1.608–5.632, p = 5.70 × 10−4, beer] and SqCLC (OR: 0.135, 95% CI: 0.062–0.293, p = 2.33 × 10−5, dried fruit; OR: 0.485, 95% CI: 0.328–0.717, p = 2.9 × 10−4, cheese). There were also suggestive correlations between 5 dietary intakes and lung cancer (OR: 0.441, 95% CI: 0.250–0.778, p = 0.008, cereal; OR: 2.267, 95% CI: 1.126–4.564, p = 0.022, beef), LA (OR: 0.494, 95% CI: 0.285–0.858, p = 0.012, dried fruit; OR: 3.536, 95% CI: 1.546–8.085, p = 0.003, beer) and SCLC (OR: 0.006, 95% CI: 0.000–0.222, p = 0.039, non-oily fish; OR: 0.239, 95% CI: 0.086–0.664, p = 0.006, dried fruit). No other association between diet and lung cancer was observed.ConclusionOur study preliminary found that cheese, dried fruit, and beer intake were significantly associated with the risk of lung cancer or its subtypes, while cereal, beef, and non-oily fish intake were suggestively associated with the risk of lung cancer or its subtypes. Well-designed prospective studies are still needed to confirm our findings in the future.</p

    Structures of Anabaena Calcium-binding Protein CcbP INSIGHTS INTO CA(2+) SIGNALING DURING HETEROCYST DIFFERENTIATION

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    Ca2+-binding proteins play pivotal roles in both eukaryotic and prokaryotic cells. CcbP from cyanobacterium Anabaena sp. strain PCC 7120 is a major Ca2+-binding protein involved in heterocyst differentiation, a process that forms specialized nitrogen-fixing cells. The three-dimensional structures of both Ca2+-free and Ca2+-bound forms of CcbP are essential for elucidating the Ca2+-signaling mechanism. However, CcbP shares low sequence identity with proteins of known structures, and its Ca2+-binding sites remain unknown. Here, we report the solution structures of CcbP in both Ca2+-free and Ca2+-bound forms determined by nuclear magnetic resonance spectroscopy. CcbP adopts an overall new fold and contains two Ca2+-binding sites with distinct Ca2+-binding abilities. Mutation of Asp(38) at the stronger Ca2+-binding site of CcbP abolished its ability to regulate heterocyst formation in vivo. Surprisingly, the beta-barrel subdomain of CcbP, which does not participate in Ca2+-binding, topologically resembles the Src homology 3 (SH3) domain and might act as a protein-protein interaction module. Our results provide the structural basis of the unique Ca2+ signaling mechanism during heterocyst differentiation

    Seroprevalence of human enterovirus 71 and coxsackievirus A16 in Guangdong, China, in pre- and post-2010 HFMD epidemic period.

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    BACKGROUND: Human Enterovirus 71 and Coxsackie A16 have caused many outbreaks in the last decade in mainland China, resulting in thousands of fatal cases. Seroepidemiology which provides important information to document population immunity is rare in China. METHODOLOGY/PRINCIPAL FINDINGS: A cross sectional study of Enterovirus 71 (EV71) and Coxsackie A16 (CA16) seroprevalence was carried out in Guangdong, China, pre- and post- the 2010 hand, foot and mouth disease (HFMD) epidemic period. The levels of EV71 and CA16 specific antibodies were evaluated by a microneutralization test and the geometric mean titer (GMT) was calculated and compared. Our results indicated frequent infection by EV71 and CA16 in Guangdong before the 2010 epidemic. Only EV71 neutralizing antibody but not CA16 seroprevalence was significantly increased after the 2010 HFMD epidemic. Children less than 3 years old especially those aged 2 years showed the lowest positive rates for EV71 and CA16 NA before epidemic and the most significantly increased EV71 seroprevalence after epidemic. CA16 GMT values declined after the 2010 epidemic. CONCLUSIONS: These results indicate EV71 was the major pathogen of HFMD in Guangdong during the 2010 epidemic. The infection occurs largely in children less than 3 years, who should have first priority to receive an EV71 vaccine
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