91 research outputs found
Improving Social Media Popularity Prediction with Multiple Post Dependencies
Social Media Popularity Prediction has drawn a lot of attention because of
its profound impact on many different applications, such as recommendation
systems and multimedia advertising. Despite recent efforts to leverage the
content of social media posts to improve prediction accuracy, many existing
models fail to fully exploit the multiple dependencies between posts, which are
important to comprehensively extract content information from posts. To tackle
this problem, we propose a novel prediction framework named Dependency-aware
Sequence Network (DSN) that exploits both intra- and inter-post dependencies.
For intra-post dependency, DSN adopts a multimodal feature extractor with an
efficient fine-tuning strategy to obtain task-specific representations from
images and textual information of posts. For inter-post dependency, DSN uses a
hierarchical information propagation method to learn category representations
that could better describe the difference between posts. DSN also exploits
recurrent networks with a series of gating layers for more flexible local
temporal processing abilities and multi-head attention for long-term
dependencies. The experimental results on the Social Media Popularity Dataset
demonstrate the superiority of our method compared to existing state-of-the-art
models
Perceptions of the benefits of the basic medical insurance system among the insured: a mixed methods research of a northern city in China
BackgroundThe perceptions of the benefits of the basic medical insurance system among the insured not only reflect the system's performance but also the public's basic medical insurance policy literacy, valuable information for countries that have entered the stage of deepening reform. This study aims to examine the factors that affect the perceptions of the benefits of the basic medical insurance system in China, diagnose the key problems, and propose corresponding measures for improvement.MethodsA mixed method design was used. Data for the quantitative study were obtained from a cross-sectional questionnaire survey (n = 1,045) of residents of Harbin who had enrolled for basic medical insurance system. A quota sampling method was further adopted. A multivariate logistic regression model was then employed to identify the factors influencing the perceptions of the benefits of the basic medical insurance system, followed by semi-structured interviews with 30 conveniently selected key informants. Interpretative phenomenological analysis was used to analyze the interview data.ResultsApproximately 44% of insured persons reported low perceptions of benefits. The logistic regression model showed that low perceptions of the benefits of the basic medical insurance system was positively correlated with the experience of daily drug purchases (OR = 1.967), perceptions of recognition with basic medical insurance system (OR = 1.948), perceptions of the financial burden of participation costs (OR = 1.887), perceptions of the convenience of using basic medical insurance for medical treatment (OR = 1.770), perceptions of the financial burden of daily drug purchases costs (OR = 1.721), perceptions of the financial burden of hospitalization costs (OR = 1.570), and type of basic medical insurance system (OR = 1.456). The results of the qualitative analysis showed that the key problem areas of perceptions of the benefits of the basic medical insurance system were: (I) system design of basic medical insurance; (II) intuitive cognition of the insured; (III) rational cognition of the insured; and (IV) the system environment.ConclusionsImproving the perceptions of the benefits of the basic medical insurance system of the insured requires joint efforts in improving system design and implementation, exploring effective publicity methods of basic medical insurance system information, supporting public policy literacy, and promoting the health system environment
New Capoamycin-Type Antibiotics and Polyene Acids from Marine Streptomyces fradiae PTZ0025
Capoamycin-type antibiotics (2–5) and polyene acids (6, 7) were isolated from marine Streptomyces fradiae strain PTZ0025. Their structures were established by extensive nuclear magnetic resonance (NMR) and high resolution electron spray ionization mass spectroscopy (HRESIMS) analyses and chemical degradation. Compounds 3, 4, 6, 7 were found to be new and named as fradimycins A (3) and B (4), and fradic acids A (6) and B (7). Compounds 3–5 showed in vitro antimicrobial activity against Staphylococcus aureus with a minimal inhibitory concentration (MIC) of 2.0 to 6.0 μg/mL. Interestingly, Compounds 3–5 also significantly inhibited cell growth of colon cancer and glioma with IC50 values ranging from 0.13 to 6.46 μM. Fradimycin B (4), the most active compound, was further determined to arrest cell cycle and induce apoptosis in tumor cells. The results indicated that fradimycin B (4) arrested the cell cycle at the G0/G1 phase and induced apoptosis and necrosis in colon cancer and glioma cells. Taken together, the results demonstrated that the marine natural products 3–5, particularly fradimycin B (4), possessed potent antimicrobial and antitumor activities
New Metabolites and Bioactive Actinomycins from Marine-Derived Streptomyces sp. ZZ338
An extract prepared from the culture of a marine-derived actinomycete Streptomyces sp. ZZ338 was found to have significant antimicrobial and antiproliferative activities. A chemical investigation of this active extract resulted in the isolation of three known bioactive actinomycins (1–3) and two new metabolites (4 and 5). The structures of the isolated compounds were identified as actinomycins D (1), V (2), X0β (3), 2-acetylamino-3-hydroxyl-4-methyl-benzoic acid methyl ester (4), and N-1S-(4-methylaminophenylmethyl)-2-oxo-propyl acetamide (5) based on their nuclear magnetic resonance (NMR) and high resolution electrospray ionization mass spectroscopy (HRESIMS) data as well as their optical rotation. This class of new compound 5 had never before been found from a natural resource. Three known actinomycins showed activities in inhibiting the proliferation of glioma cells and the growth of methicillin-resistant Staphylococcus aureus, Escherichia coli, and Candida albicans and are responsible for the activity of the crude extract. Actinomycin D (1) was also found to downregulate several glioma metabolic enzymes of glycolysis, glutaminolysis, and lipogenesis, suggesting that targeting multiple tumor metabolic regulators might be a new anti-glioma mechanism of actinomycin D. This is the first report of such a possible mechanism for the class of actinomycins
Indium-Tin-Oxide for High-performance Electro-optic Modulation
Advances in opto-electronics are often led by discovery and development of
materials featuring unique properties. Recently, the material class of
transparent conductive oxides (TCO) has attracted attention for active photonic
devices on-chip. In particular, indium tin oxide (ITO) is found to have
refractive index changes on the order of unity. This property makes it possible
to achieve electrooptic modulation of sub-wavelength device scales, when thin
ITO films are interfaced with optical light confinement techniques such as found
in plasmonics; optical modes are compressed to nanometer scale to create strong
light-matter interactions. Here we review efforts towards utilizing this novel
material for high performance and ultra-compact modulation. While high
performance metrics are achieved experimentally, there are open questions
pertaining to the permittivity modulation mechanism of ITO. Finally, we review a
variety of optical and electrical properties of ITO for different processing
conditions, and show that ITO-based plasmonic electro-optic modulators have the
potential to significantly outperform diffractionlimited devices
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