4,363 research outputs found
Decacarbonyl[μ4-(ethane-1,2-diyldinitrilo)tetrakis(methanethiolato)]bis(triphenylphosphane)tetrairon(2 Fe—Fe)
In the title compound, [Fe4(C6H12N2S4)(C18H15P)2(CO)10], the unit cell contains one molecule, which exhibits a crystallographically imposed center of symmetry. The independent Fe2S2 fragment [Fe—Fe = 2.527 (1) Å] is in a butterfly conformation, and each Fe atom displays a pseudo-square-pyramidal coordination geometry. The phosphane group occupies an apical position [Fe—P = 2.2670 (14) Å]. In the crystal, weak intermolecular C—H⋯O hydrogen bonds link the molecules into chains along [110]
Conceptualized Representation Learning for Chinese Biomedical Text Mining
Biomedical text mining is becoming increasingly important as the number of
biomedical documents and web data rapidly grows. Recently, word representation
models such as BERT has gained popularity among researchers. However, it is
difficult to estimate their performance on datasets containing biomedical texts
as the word distributions of general and biomedical corpora are quite
different. Moreover, the medical domain has long-tail concepts and
terminologies that are difficult to be learned via language models. For the
Chinese biomedical text, it is more difficult due to its complex structure and
the variety of phrase combinations. In this paper, we investigate how the
recently introduced pre-trained language model BERT can be adapted for Chinese
biomedical corpora and propose a novel conceptualized representation learning
approach. We also release a new Chinese Biomedical Language Understanding
Evaluation benchmark (\textbf{ChineseBLUE}). We examine the effectiveness of
Chinese pre-trained models: BERT, BERT-wwm, RoBERTa, and our approach.
Experimental results on the benchmark show that our approach could bring
significant gain. We release the pre-trained model on GitHub:
https://github.com/alibaba-research/ChineseBLUE.Comment: WSDM2020 Health Da
Emulating Reader Behaviors for Fake News Detection
The wide dissemination of fake news has affected our lives in many aspects,
making fake news detection important and attracting increasing attention.
Existing approaches make substantial contributions in this field by modeling
news from a single-modal or multi-modal perspective. However, these modal-based
methods can result in sub-optimal outcomes as they ignore reader behaviors in
news consumption and authenticity verification. For instance, they haven't
taken into consideration the component-by-component reading process: from the
headline, images, comments, to the body, which is essential for modeling news
with more granularity. To this end, we propose an approach of Emulating the
behaviors of readers (Ember) for fake news detection on social media,
incorporating readers' reading and verificating process to model news from the
component perspective thoroughly. Specifically, we first construct
intra-component feature extractors to emulate the behaviors of semantic
analyzing on each component. Then, we design a module that comprises
inter-component feature extractors and a sequence-based aggregator. This module
mimics the process of verifying the correlation between components and the
overall reading and verification sequence. Thus, Ember can handle the news with
various components by emulating corresponding sequences. We conduct extensive
experiments on nine real-world datasets, and the results demonstrate the
superiority of Ember.Comment: 12 page
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Water-Soluble 3D Covalent Organic Framework that Displays an Enhanced Enrichment Effect of Photosensitizers and Catalysts for the Reduction of Protons to H2.
Covalent organic frameworks (COFs) are emerging porous polymers that have 2D or 3D long-range ordering. Currently available COFs are typically insoluble or decompose upon dissolution, which remarkably restricts their practical implementations. For 3D COFs, the achievement of noninterpenetration, which maximizes their porosity-derived applications, also remains a challenge synthetically. Here, we report the synthesis of the first highly water-soluble 3D COF (sCOF-101) from irreversible polymerization of a preorganized supramolecular organic framework through cucurbit[8]uril (CB[8])-controlled [2 + 2] photodimerization. Synchrotron X-ray scattering and diffraction analyses confirm that sCOF-101 exhibits porosity periodicity, with a channel diameter of 2.3 nm, in both water and the solid state and retains the periodicity under both strongly acidic and basic conditions. As an ordered 3D polymer, sCOF-101 can enrich [Ru(bpy)3]2+ photosensitizers and redox-active polyoxometalates in water, which leads to remarkable increase of their photocatalytic activity for proton reduction to produce H2
Characteristics of the complete mitochondrial genome of Suhpalacsa longialata (Neuroptera, Ascalaphidae) and its phylogenetic implications
The owlflies (Family Ascalaphidae) belong to the Neuroptera but are often mistaken as dragonflies because of morphological characters. To date, only three mitochondrial genomes of Ascalaphidae, namely Libelloides macaronius; Ascaloptynx appendiculatus; Ascalohybris subjacens, are published in GenBank, meaning that they are greatly under-represented in comparison with the 430 described species reported in this family. In this study, we sequenced and described the complete mitochondrial genome of Suhpalacsa longialata (Neuroptera, Ascalaphidae). The total length of the S. longialata mitogenome was 15,911 bp, which is the longest known to date among the available family members of Ascalaphidae. However, the size of each gene was similar to the other three Ascalaphidae species. The S. longialata mitogenome included a transposition of tRNACys and tRNATrp genes and formed an unusual gene arrangement tRNACys-tRNATrp-tRNATyr (CWY). It is likely that the transposition occurred by a duplication of both genes followed by random loss of partial duplicated genes. The nucleotide composition of the S. longialata mitogenome was as follows: A = 41.0%, T = 33.8%, C = 15.5%, G = 9.7%. Both Bayesian inference and ML analyses strongly supported S. longialata as a sister clade to (Ascalohybris subjacens + L. macaronius), and indicated that Ascalaphidae is not monophyletic
Effect of estradiol on proliferation and differentiation of side population stem/progenitor cells from murine endometrium
<p>Abstract</p> <p>Background</p> <p>In our previous study, endometrium side population cells (SP cells) were isolated from postpartum murine uterus, and characterized by a heterogeneous population of stem/progenitor cells. In this study, we investigated the effect of estrogen on the proliferation and differentiation of SP cells.</p> <p>Methods</p> <p>SP and non-SP cells of postpartum murine endometrium were isolated by DNA dye Hoechst 33342. The expression of estrogen receptor 1 (ESR1) was measured by reverse transcription polymerase chain reaction (RT-PCR), Real-time PCR, Western blot, immunofluorescence and immunohistochemistry. The proliferation and differentiation of SP cells treated with different concentrations [10(-8) M-10(-6) M] of estradiol (E2) and E2+ ICI182780 (Faslodex, inhibitor of ESR1) were measured by 3-(4, 5-dimethylthiazoly1-2)-2,5-diphenyltetrazolium bromide(MTT) and clonogenic assays.</p> <p>Results</p> <p>(1) SP cells expressed ESR1 at a higher level than non-SP cells. (2) The level of E2 in the serum and the expression of ESR1 in the uterus of postpartum murine changed in the same manner with the ratio of SP cells to total uterus cells at a different postpartum time point. ESR1, as ABCG2 is also predominantly located in the stroma and the glandular epithelium of the uterus. (3) 10(-6) M E2 notably promoted the proliferation of SP cells after treatment for 24 h. This effect could be inhibited by ICI182780. E2 at the concentration of 10(-7) M or 10(-8) M was sent to impair the large cloning efficiency (CE) of SP cells.</p> <p>Conclusions</p> <p>The effect of estrogen on the proliferation and differentiation of endometrium SP cells via ESR1 was observed and it was in a concentration dependent fashion. Clearly, more work is needed to understand the <it>in vivo </it>effect of E2 at the physiological concentration on the differentiation of SP cells.</p
An improved method for genome wide DNA methylation profiling correlated to transcription and genomic instability in two breast cancer cell lines
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