545 research outputs found

    SENTIMENT ANALYSIS OF CHINESE MICROBLOG MESSAGE USING NEURAL NETWORK-BASED VECTOR REPRESENTATION FOR MEASURING REGIONAL PREJUDICE

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    Regional prejudice is prevalent in Chinese cities in which native residents and migrants lack a basic level of trust in the other group. Like Twitter, Sina Weibo is a social media platform where people actively engage in discussions on various social issues. Thus, it provides a good data source for measuring individuals’ regional prejudice on a large scale. We find that a resentful tone dominates in Weibo messages related to migrants. In this paper, we propose a novel approach, named DKV, for recognizing polarity and direction of sentiment for Weibo messages using distributed real-valued vector representation of keywords learned from neural networks. Such a representation can project rich context information (or embedding) into the vector space, and subsequently be used to infer similarity measures among words, sentences, and even documents. We provide a comprehensive performance evaluation to demonstrate that by exploiting the keyword embeddings, DKV paired with support vector machines can effectively recognize a Weibo message into the predefined sentiment and its direction. Results demonstrate that our method can achieve the best performances compared to other approaches

    Dynamic Effects of Axial Loading on the Lumbar Spine During Magnetic Resonance Imaging in Patients with Suspected Spinal Stenosis

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    BackgroundPrevious studies have shown that axial compression in extension (ACE) of the spine during magnetic resonance imaging (MRI) has revealed unexpected pathological features compared with the conventional psoas-relaxed position (PRP) used in imaging. The purpose of this study was to evaluate the dynamic effect of axial loading on lumbar spinal stenosis using MRI in patients with spinal stenosis.MethodsA total of 14 women and 11 men with lumbar spinal stenosis were examined in both PRP and ACE positions. We calculated the dural-sac cross-sectional area (DCSA) to evaluate severity of spinal canal stenosis. DCSA, as well as the dural-sac anteroposterior diameter (DAPD) and dural-sac transverse diameter (DTD) in both positions were measured using a digital image view station. A paired t test determined the differences in DCSA, DAPD and DTD between the two positions at each intervertebral disc level.ResultsAxial loading increased severity of lumbar spinal stenosis during MRI, as demonstrated by a decrease in DCSA from 20.5% to 6.3% (mean, 11.40 ± 3.66%) between the PRP and ACE positions (p < 0.01). Significant differences were also noted in DAPD and DTD between the PRP and ACE positions (p < 0.01). A significant correlation was found between the decrease in mean DCSA and that in DAPD and DTD. The decrease in mean DCSA, DAPD and DTD following axial compression was greatest at the L4/5 and L5/S1 levels.ConclusionAxial loading increases severity of lumbar canal stenosis and the effect of axial loading on MRI examination is greatest at the L4/5 and L5/S1 levels

    A mixture of anatase and rutile TiO2 nanoparticles induces histamine secretion in mast cells

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    <p>Abstract</p> <p>Background</p> <p>Histamine released from mast cells, through complex interactions involving the binding of IgE to FcεRI receptors and the subsequent intracellular Ca<sup>2+ </sup>signaling, can mediate many allergic/inflammatory responses. The possibility of titanium dioxide nanoparticles (TiO<sub>2 </sub>NPs), a nanomaterial pervasively used in nanotechnology and pharmaceutical industries, to directly induce histamine secretion without prior allergen sensitization has remained uncertain.</p> <p>Results</p> <p>TiO<sub>2 </sub>NP exposure increased both histamine secretion and cytosolic Ca<sup>2+ </sup>concentration ([Ca<sup>2+</sup>]<sub>C</sub>) in a dose dependent manner in rat RBL-2H3 mast cells. The increase in intracellular Ca<sup>2+ </sup>levels resulted primarily from an extracellular Ca<sup>2+ </sup>influx via membrane L-type Ca<sup>2+ </sup>channels. Unspecific Ca<sup>2+ </sup>entry via TiO<sub>2 </sub>NP-instigated membrane disruption was demonstrated with the intracellular leakage of a fluorescent calcein dye. Oxidative stress induced by TiO<sub>2 </sub>NPs also contributed to cytosolic Ca<sup>2+ </sup>signaling. The PLC-IP<sub>3</sub>-IP<sub>3 </sub>receptor pathways and endoplasmic reticulum (ER) were responsible for the sustained elevation of [Ca<sup>2+</sup>]<sub>C </sub>and histamine secretion.</p> <p>Conclusion</p> <p>Our data suggests that systemic circulation of NPs may prompt histamine release at different locales causing abnormal inflammatory diseases. This study provides a novel mechanistic link between environmental TiO<sub>2 </sub>NP exposure and allergen-independent histamine release that can exacerbate manifestations of multiple allergic responses.</p

    Atomically-thin metallic Si and Ge allotropes with high Fermi velocities

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    Silicon and germanium are the well-known materials used to manufacture electronic devices for the integrated circuits but they themselves are not considered as promising options for interconnecting the devices due to their semiconducting nature. We have discovered that both Si and Ge atoms can form unexpected metallic monolayer structures which are more stable than the extensively studied semimetallic silicene and germanene, respectively. More importantly, the newly discovered two-dimensional allotropes of Si and Ge have Fermi velocities superior to the Dirac fermions in graphene, indicating that the metal wires needed in the silicon-based integrated circuits can be made of Si atom itself without incompatibility, allowing for all-silicon-based integrated circuits.Comment: 10 pages, 3 figures, 1 tabl

    The benefits of integrated eye tracking with airborne image recorders in the flight deck: a rejected landing case study

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    Aircraft accident investigation has played a pivotal role in improving the safety of aviation. Advances in recorder technology, specifically Cockpit Voice Recorders (CVRs) and Flight Data Recorders (FDR) have made a huge contribution to the understanding of occurrences for accident investigators. However, even these recorders have limitations such as the evidence they provide about pilots' situation awareness or behaviours. Supplementing audio and data recordings with video has been discussed for many years and whilst there continues to be debate among regulators, operators, manufacturers and pilot unions, the International Civil Aviation Organization (ICAO) has mandated Airborne Image Recorders (AIR) from 2023. The purpose of installing such systems is to provide evidence of crew operational behaviours in terms of both human-human and human-computer interactions (HCI) on the flight deck. Video alone is unlikely to provide sufficient evidence for investigators. This study examines the additional value that eye-tracking technology may provide through the case study of an accident involving an Airbus A330-300 aircraft which experienced a rejected landing. Currently, the investigation of such events, where crew interaction with automation is critical to their situation awareness, relies heavily on interview data. Such data may be unavailable (in the case of serious injury) or unreliable (based on hindsight bias). By integrating eye tracking technology into an AIR, accident investigators will potentially gain a better understanding of pilots’ visual scan patterns across flight deck instrumentation. This has implications for flight deck and procedural design as well as training and simulation

    Inhibition of Mitochondria- and Endoplasmic Reticulum Stress-Mediated Autophagy Augments Temozolomide-Induced Apoptosis in Glioma Cells

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    Autophagy is a crucial process for cells to maintain homeostasis and survival through degradation of cellular proteins and organelles, including mitochondria and endoplasmic reticula (ER). We previously demonstrated that temozolomide (TMZ), an alkylating agent for brain tumor chemotherapy, induced reactive oxygen species (ROS)/extracellular signal-regulated kinase (ERK)-mediated autophagy to protect glioma cells from apoptosis. In this study, we investigated the role of mitochondrial damage and ER stress in TMZ-induced cytotoxicity. Mitochondrial depolarization and mitochondrial permeability transition pore (MPTP) opening were observed as a prelude to TMZ-induced autophagy, and these were followed by the loss of mitochondrial mass. Electron transport chain (ETC) inhibitors, such as rotenone (a complex I inhibitor), sodium azide (a complex IV inhibitor), and oligomycin (a complex V inhibitor), or the MPTP inhibitor, cyclosporine A, decreased mitochondrial damage-mediated autophagy, and therefore increased TMZ-induced apoptosis. TMZ treatment triggered ER stress with increased expression of GADD153 and GRP78 proteins, and deceased pro-caspase 12 protein. ER stress consequently induced autophagy through c-Jun N-terminal kinases (JNK) and Ca2+ signaling pathways. Combination of TMZ with 4-phenylbutyrate (4-PBA), an ER stress inhibitor, augmented TMZ-induced cytotoxicity by inhibiting autophagy. Taken together, our data indicate that TMZ induced autophagy through mitochondrial damage- and ER stress-dependent mechanisms to protect glioma cells. This study provides evidence that agents targeting mitochondria or ER may be potential anticancer strategies

    The Relationship between Brown Adipose Tissue Activity and Neoplastic Status: an 18F-FDG PET/CT Study in the Tropics

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    <p>Abstract</p> <p>Background</p> <p>Brown adipose tissue (BAT) has thermogenic potential. For its activation, cold exposure is considered a critical factor though other determinants have also been reported. The purpose of this study was to assess the relationship between neoplastic status and BAT activity by 2-deoxy-2-[18F]fluoro-D-glucose (<sup>18</sup>F-FDG) positron emission tomography/computed tomography (PET/CT) in people living in the tropics, where the influence of outdoor temperature was low.</p> <p>Methods</p> <p><sup>18</sup>F-FDG PET/CT scans were reviewed and the total metabolic activity (TMA) of identified activated BAT quantified. The distribution and TMA of activated BAT were compared between patients with and without a cancer history. The neoplastic status of patients was scored according to their cancer history and <sup>18</sup>F-FDG PET/CT findings. We evaluated the relationships between the TMA of BAT and neoplastic status along with other factors: age, body mass index, fasting blood sugar, gender, and outdoor temperature.</p> <p>Results</p> <p>Thirty of 1740 patients had activated BAT. Those with a cancer history had wider BAT distribution (<it>p </it>= 0.043) and a higher TMA (<it>p </it>= 0.028) than those without. A higher neoplastic status score was associated with a higher average TMA. Multivariate analyses showed that neoplastic status was the only factor significantly associated with the TMA of activated BAT (<it>p </it>= 0.016).</p> <p>Conclusions</p> <p>Neoplastic status is a critical determinant of BAT activity in patients living in the tropics. More active neoplastic status was associated with more vigorous TMA of BAT.</p
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