157 research outputs found
Comparative Studies of Detecting Abusive Language on Twitter
The context-dependent nature of online aggression makes annotating large
collections of data extremely difficult. Previously studied datasets in abusive
language detection have been insufficient in size to efficiently train deep
learning models. Recently, Hate and Abusive Speech on Twitter, a dataset much
greater in size and reliability, has been released. However, this dataset has
not been comprehensively studied to its potential. In this paper, we conduct
the first comparative study of various learning models on Hate and Abusive
Speech on Twitter, and discuss the possibility of using additional features and
context data for improvements. Experimental results show that bidirectional GRU
networks trained on word-level features, with Latent Topic Clustering modules,
is the most accurate model scoring 0.805 F1.Comment: ALW2: 2nd Workshop on Abusive Language Online to be held at EMNLP
2018 (Brussels, Belgium), October 31st, 201
Glycogen synthase kinase 3 beta suppresses polyglutamine aggregation by inhibiting Vaccinia-related kinase 2 activity
Huntington's disease (HD) is a neurodegenerative disorder caused by an abnormal expansion of polyglutamine repeats in the N-terminal of huntingtin. The amount of aggregate-prone protein is controlled by various mechanisms, including molecular chaperones. Vaccinia-related kinase 2 (VRK2) is known to negatively regulate chaperonin TRiC, and VRK2-facilitated degradation of TRiC increases polyQ protein aggregation, which is involved in HD. We found that VRK2 activity was negatively controlled by glycogen synthase kinase 3 beta (GSK3 beta). GSK3 beta directly bound to VRK2 and inhibited the catalytic activity of VRK2 in a kinase activity-independent manner. Furthermore, GSK3 beta increased the stability of TRiC and decreased the formation of HttQ103-GFP aggregates by inhibiting VRK2. These results indicate that GSK3 beta signaling may be a regulatory mechanism of HD progression and suggest targets for further therapeutic trials for HD.1131Ysciescopu
Development and evaluation of gellan gum/silk fibroin/chondroitin sulfate ternary injectable hydrogel for cartilage tissue engineering
Hydrogel is in the spotlight as a useful biomaterial in the field of drug delivery and tissue engineering due to its similar biological properties to a native extracellular matrix (ECM). Herein, we proposed a ternary hydrogel of gellan gum (GG), silk fibroin (SF), and chondroitin sulfate (CS) as a biomaterial for cartilage tissue engineering. The hydrogels were fabricated with a facile combination of the physical and chemical crosslinking method. The purpose of this study was to find the proper content of SF and GG for the ternary matrix and confirm the applicability of the hydrogel in vitro and in vivo. The chemical and mechanical properties were measured to confirm the suitability of the hydrogel for cartilage tissue engineering. The biocompatibility of the hydrogels was investigated by analyzing the cell morphology, adhesion, proliferation, migration, and growth of articular chondrocytes-laden hydrogels. The results showed that the higher proportion of GG enhanced the mechanical properties of the hydrogel but the groups with over 0.75% of GG exhibited gelling temperatures over 40 °C, which was a harsh condition for cell encapsulation. The 0.3% GG/3.7% SF/CS and 0.5% GG/3.5% SF/CS hydrogels were chosen for the in vitro study. The cells that were encapsulated in the hydrogels did not show any abnormalities and exhibited low cytotoxicity. The biochemical properties and gene expression of the encapsulated cells exhibited positive cell growth and expression of cartilage-specific ECM and genes in the 0.5% GG/3.5% SF/CS hydrogel. Overall, the study of the GG/SF/CS ternary hydrogel with an appropriate content showed that the combination of GG, SF, and CS can synergistically promote articular cartilage defect repair and has considerable potential for application as a biomaterial in cartilage tissue engineering.This research was supported by the International Research and Development Program of
the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future
Planning (NRF-2017K1A3A7A03089427) and by the bilateral cooperation Program of the National
Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning
(NRF-2019K2A9A1A06098563)
Deleterious effects in reproduction and developmental immunity elicited by pulmonary iron oxide nanoparticles
With the extensive application of iron oxide nanoparticles (FeNPs), attention about their potential risks to human health is also rapidly raising, particularly in sensitive subgroups such as pregnant women and babies. In this study, we a single instilled intratracheally FeNPs (1, 2, and 4 mg/kg) to the male and female parent mice, mated, then assessed reproductive toxicity according to the modified OECD TG 421. During the pre-mating period (14 days), two female parent mice died at 4 mg/kg dose, and the body weight gain dose-dependently decreased in male and female parent mice exposed to FeNPs. Additionally, iron accumulation and the enhanced expression of MHC class II molecules were observed in the ovary and the testis of parent mice exposed to the highest dose of FeNPs, and the total sex ratio (male/female) of the offspring mice increased in the groups exposed to FeNPs. Following, we a single instilled intratracheally to their offspring mice with the same doses and evaluated the immunotoxic response on day 28. The increased mortality and significant hematological- and biochemical- changes were observed in offspring mice exposed at 4 mg/kg dose, especially in female mice. More interestingly, balance of the immune response was shifted to a different direction in male and female offspring mice. Taken together, we conclude that the NOAEL for reproductive and developmental toxicity of FeNPs may be lower than 2 mg/kg, and that female mice may show more sensitive response to FeNPs exposure than male mice. Furthermore, we suggest that further studies are necessary to identify causes of both the alteration in sex ratio of offspring mice and different immune response in male and female offspring mice.
Kondo-like behaviors in magnetic and thermal properties of single crystal Tm5Si2Ge2
We grew the single crystal of stoichiometric Tm5Si2.0Ge2.0 using a Bridgeman
method and performed XRD, EDS, magnetization, ac and dc magnetic
susceptibilities, specific heat, electrical resistivity and XPS experiments. It
crystallizes in orthorhombic Sm5Ge4-type structure. The mean valence of Tm ions
in Tm5Si2.0Ge2.0 is almost trivalent. The 4f states is split by the crystalline
electric field. The ground state exhibits the long range antiferromagnetic
order with the ferromagnetically coupled magnetic moments in the ac plane below
8.01 K, while the exited states exhibit the reduction of magnetic moment and
magnetic entropy and -log T-behaviors observed in Kondo materials.Comment: 8 pages, 13 figure
Biological Toxicity and Inflammatory Response of Semi-Single-Walled Carbon Nanotubes
The toxicological studies on carbon nanotubes (CNTs) have been urgently needed from the emerging diverse applications of CNTs. Physicochemical properties such as shape, diameter, conductance, surface charge and surface chemistry of CNTs gained during manufacturing processes play a key role in the toxicity. In this study, we separated the semi-conductive components of SWCNTs (semi-SWCNTs) and evaluated the toxicity on days 1, 7, 14 and 28 after intratracheal instillation in order to determine the role of conductance. Exposure to semi-SWCNTs significantly increased the growth of mice and significantly decreased the relative ratio of brain weight to body weight. Recruitment of monocytes into the bloodstream increased in a time-dependent manner, and significant hematological changes were observed 28 days after exposure. In the bronchoalveolar lavage (BAL) fluid, secretion of Th2-type cytokines, particularly IL-10, was more predominant than Th1-type cytokines, and expression of regulated on activation normal T cell expressed and secreted (RANTES), p53, transforming growth factor (TGF)-β, and inducible nitric oxide synthase (iNOS) increased in a time-dependent manner. Fibrotic histopathological changes peaked on day 7 and decreased 14 days after exposure. Expression of cyclooxygenase-2 (COX-2), mesothelin, and phosphorylated signal transducer and activator of transcription 3 (pSTAT3) also peaked on day 7, while that of TGF-β peaked on days 7 and 14. Secretion of histamine in BAL fluid decreased in a time-dependent manner. Consequently, we suggest that the brain is the target organ of semi-SWCNTs brought into the lung, and conductance as well as length may be critical factors affecting the intensity and duration of the inflammatory response following SWCNT exposure
Investigation of the mechanism of the anomalous Hall effects in Cr2Te3/(BiSb)2(TeSe)3 heterostructure
The interplay between ferromagnetism and the non-trivial topology has
unveiled intriguing phases in the transport of charges and spins. For example,
it is consistently observed the so-called topological Hall effect (THE)
featuring a hump structure in the curve of the Hall resistance (Rxy) vs. a
magnetic field (H) of a heterostructure consisting of a ferromagnet (FM) and a
topological insulator (TI). The origin of the hump structure is still
controversial between the topological Hall effect model and the multi-component
anomalous Hall effect (AHE) model. In this work, we have investigated a
heterostructure consisting of BixSb2-xTeySe3-y (BSTS) and Cr2Te3 (CT), which
are well-known TI and two-dimensional FM, respectively. By using the so-called
minor-loop measurement, we have found that the hump structure observed in the
CT/BSTS is more likely to originate from two AHE channels. Moreover, by
analyzing the scaling behavior of each amplitude of two AHE with the
longitudinal resistivities of CT and BSTS, we have found that one AHE is
attributed to the extrinsic contribution of CT while the other is due to the
intrinsic contribution of BSTS. It implies that the proximity-induced
ferromagnetic layer inside BSTS serves as a source of the intrinsic AHE,
resulting in the hump structure explained by the two AHE model
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