11,092 research outputs found

    Using Linguistic Features to Estimate Suicide Probability of Chinese Microblog Users

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    If people with high risk of suicide can be identified through social media like microblog, it is possible to implement an active intervention system to save their lives. Based on this motivation, the current study administered the Suicide Probability Scale(SPS) to 1041 weibo users at Sina Weibo, which is a leading microblog service provider in China. Two NLP (Natural Language Processing) methods, the Chinese edition of Linguistic Inquiry and Word Count (LIWC) lexicon and Latent Dirichlet Allocation (LDA), are used to extract linguistic features from the Sina Weibo data. We trained predicting models by machine learning algorithm based on these two types of features, to estimate suicide probability based on linguistic features. The experiment results indicate that LDA can find topics that relate to suicide probability, and improve the performance of prediction. Our study adds value in prediction of suicidal probability of social network users with their behaviors

    A Novel NFC Antenna for Metal Cover Smartphone Applications

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    © 2018 IEEE. A miniaturized dual-loop near field communication antenna of size 15 mm×25 mm is proposed for metal cover smartphone applications. By embedded it with a small rectangular slot of size 8 mm×16 mm loaded metal cover, the direction of the eddy current induced on metal cover will be the same with the current flow the on the dual loop NFC antenna coil. It's worth noting that the proposed NFC antenna design was certified by the Europay, Mastercard and Visa (EMV) test

    Relationship between climatic conditions and the relative abundance of modern C<inf>3</inf> and C<inf>4</inf> plants in three regions around the North Pacific

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    Using -24‰ and -14‰ as the endpoints of stable carbon isotopic composition of total organic carbon (δ13CTOC) of surface soil under pure C3 and C4 vegetation, and surface soil δ13CTOC data from eastern China, Australia and the Great Plains of North America, we estimate the relative abundance of C3/C4 plants (i. e., the ratio of C3 or C4 biomass to local primary production) in modern vegetation for each region. The relative abundance of modern C3/C4 vegetation from each region is compared to the corresponding climatic parameters (mean annual temperature and precipitation) to explore the relationship between relative C4 abundance and climate. The results indicate that temperature controls the growth of C4 plants. However, even where temperature is high enough for the growth of C4 plants, they will only dominate the landscape when precipitation declines as temperatures increase. Our results are consistent with those of other investigations of the geographic distribution of modern C4 plant species. Therefore, our results provide an important reference for interpretation of past C3/C4 relative abundance records in these three regions. © 2010 Science China Press and Springer-Verlag Berlin Heidelberg

    Direct multiple shoot induction and plant regeneration from dormant buds of Codonopsis pilosula (Franch.) Nannf.

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    An efficient and reproducible protocol for in vitro plant multiplication system via direct organogenesis from dormant buds of Codonopsis pilosula Nannf was developed. Multiple shoots were induced at a frequency of 75% after nine weeks on Murashige and Skoog (MS) medium supplemented with BAP (1.0 mg/l), NAA (0.5 mg/l), 3% sucrose and 0.7% agar. Approximately, 15 to 18 shoots were formed at the base of each dormant bud. Higher concentrations of BAP and NAA resulted in callus formation. Further development of shoot elongation and multiplication were also studied. Well-grown shoots of 2.8 cm height and 3.8 proliferation coefficient were achieved by sub-culturing on MS medium supplemented with 0.2 mg/l BAP and 0.05 mg/l IBA. At higher concentrations, BAP (0.5 mg/l) promoted higher shoot proliferation coefficient (4.2); however, it negatively affected shoot elongation. Further, low NAA concentration was beneficial to shoot proliferation. All in vitro-derived shoots measuring 2.5 to 3 cm in length, rooted when grown on ½MS (half of all MS elements) basal medium containing 1.5 mg/l IBA within 3 weeks, 100% of shoots developed roots and test-tube seedlings grew stout.Key words: Codonopsis pilosula, dormant bud, direct organogenesis, multiple shoot, shoot elongation, rooting

    Field-induced polarisation of Dirac valleys in bismuth

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    Electrons are offered a valley degree of freedom in presence of particular lattice structures. Manipulating valley degeneracy is the subject matter of an emerging field of investigation, mostly focused on charge transport in graphene. In bulk bismuth, electrons are known to present a threefold valley degeneracy and a Dirac dispersion in each valley. Here we show that because of their huge in-plane mass anisotropy, a flow of Dirac electrons along the trigonal axis is extremely sensitive to the orientation of in-plane magnetic field. Thus, a rotatable magnetic field can be used as a valley valve to tune the contribution of each valley to the total conductivity. According to our measurements, charge conductivity by carriers of a single valley can exceed four-fifth of the total conductivity in a wide range of temperature and magnetic field. At high temperature and low magnetic field, the three valleys are interchangeable and the three-fold symmetry of the underlying lattice is respected. As the temperature lowers and/or the magnetic field increases, this symmetry is spontaneously lost. The latter may be an experimental manifestation of the recently proposed valley-nematic Fermi liquid state.Comment: 14 pages + 5 pages of supplementary information; a slightly modified version will appear as an article in Nature physic

    Airflow Dynamics of Coughing in Healthy Human Volunteers by Shadowgraph Imaging: An Aid to Aerosol Infection Control

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    Cough airflow dynamics have been previously studied using a variety of experimental methods. In this study, real-time, non-invasive shadowgraph imaging was applied to obtain additional analyses of cough airflows produced by healthy volunteers. Twenty healthy volunteers (10 women, mean age 32.2±12.9 years; 10 men, mean age 25.3±2.5 years) were asked to cough freely, then into their sleeves (as per current US CDC recommendations) in this study to analyze cough airflow dynamics. For the 10 females (cases 1–10), their maximum detectable cough propagation distances ranged from 0.16–0.55 m, with maximum derived velocities of 2.2–5.0 m/s, and their maximum detectable 2-D projected areas ranged from 0.010–0.11 m2, with maximum derived expansion rates of 0.15–0.55 m2/s. For the 10 males (cases 11–20), their maximum detectable cough propagation distances ranged from 0.31–0.64 m, with maximum derived velocities of 3.2–14 m/s, and their maximum detectable 2-D projected areas ranged from 0.04–0.14 m2, with maximum derived expansion rates of 0.25–1.4 m2/s

    Association of consciousness impairment and mortality in people with COVID-19

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    BACKGROUND: To investigate the association between impairment of consciousness and risk of death in people with COVID-19. METHODS: In this multicentre retrospective study, we enrolled people with confirmed COVID-19 from 44 hospitals in Wuhan and Sichuan, China, between 18 January and 30 March 2020. We extracted demographics, clinical, laboratory data and consciousness level (as measured by the Glasgow Coma Scale (GCS) score) from medical records. We used Cox proportional hazards regression, structural equation modelling and survival time analysis to compare people with different progressions of impaired consciousness. RESULTS: We enrolled 1,143 people (average age 51.3 ± standard deviation 17.1-year-old; 50.3% males), of whom 76 died. Increased mortality risk was identified in people with GCS score between 9 and 14 (hazard ratio (HR) 46.76, p 2 days, p = .028) had shorter survival times. CONCLUSION: Altered consciousness and its progression had a direct link with death in COVID-19. Interactions with age, oxygen saturation level and pH suggest possible pathophysiology. Further work to confirm these findings explore prevention strategies and interventions to decrease mortality is warranted

    Treatment of insomnia in myasthenia gravis-A prospective study on non-benzodiazepine hypnotics in the treatment of myasthenia gravis patients with insomnia

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    Objectives: This study aimed to evaluate the efficacy and safety of non-benzodiazepine hypnotics in the treatment of myasthenia gravis (MG) patients with insomnia. Methods: This is a prospective longitudinal study. Outpatients who met the criteria for stable MG and insomnia diagnosis according to the International Classification of Sleep Disorders (third edition) were included in the study. They took a regular dose of non-benzodiazepine hypnotics (zolpidem 10 mg per night or zopiclone 7.5 mg per night) based on their own preferences. Patients received psychotherapy (including sleep health education) and were followed up for 4–5 weeks. Cases with lung diseases, respiratory disorders, or inappropriate use of hypnotic medications were excluded. The primary outcome is the difference in total Pittsburgh Sleep Quality Index (PSQI) score between baseline and the end of follow-up period. Secondary outcomes include the difference in Myasthenia Gravis Activities of Daily Living (MG-ADL) score, 7-item Generalized Anxiety Disorder Questionnaire (GAD-7), and the Patient Health Questionnaire-9 (PHQ-9) between baseline and the end of follow-up period and the safety of medication. Results: A total of 75 MG patients with insomnia were included in this study. After 4–5 weeks of treatment, the total PSQI score and MG-ADL score were lower than baseline (p < 0.01). No patients had an increased MG-ADL score. The incidence rate of adverse events was 16.0% (12 cases), including dizziness (6 cases, 8.0%), drowsiness (3 cases, 4.0%), fatigue (2 cases, 2.7%), and nausea (1 case, 1.3%), all of which were mild. No patients had new onset breathing disorders. Conclusion: Non-benzodiazepine hypnotics are safe and effective for stable MG patients who need insomnia treatment
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