22 research outputs found
Neural Cognition and Affective Computing on Cyber Language
Characterized by its customary symbol system and simple and vivid expression patterns, cyber language acts as not only a tool for convenient communication but also a carrier of abundant emotions and causes high attention in public opinion analysis, internet marketing, service feedback monitoring, and social emergency management. Based on our multidisciplinary research, this paper presents a classification of the emotional symbols in cyber language, analyzes the cognitive characteristics of different symbols, and puts forward a mechanism model to show the dominant neural activities in that process. Through the comparative study of Chinese, English, and Spanish, which are used by the largest population in the world, this paper discusses the expressive patterns of emotions in international cyber languages and proposes an intelligent method for affective computing on cyber language in a unified PAD (Pleasure-Arousal-Dominance) emotional space
Mild sp2Carbon-Oxygen Bond Activation by an Isolable Ruthenium(II) bis(Dinitrogen) Complex: Experiment and Theory
The isolable ruthenium(II) bis(dinitrogen) complex [Ru(H)2(N2)2(PCy3)2] (1) reacts with aryl ethers (Ar–OR, R = Me and Ar) containing a ketone directing group to effect sp2C–O bond activation at temperatures below 40 °C. DFT studies support a low-energy Ru(II)/Ru(IV) pathway for C–O bond activation: oxidative addition of the C–O bond to Ru(II) occurs in an asynchronous manner with Ru–C bond formation preceding C–O bond breaking. Alternative pathways based on a Ru(0)/Ru(II) couple are competitive but less accessible due to the high energy of the Ru(0) precursors. Both experimentally and by DFT calculations, sp2C–H bond activation is shown to be more facile than sp2C–O bond activation. The kinetic preference for C–H bond activation over C–O activation is attributed to unfavorable approach of the C–O bond toward the metal in the selectivity determining step of the reaction pathway
Epidemiological characteristics of respiratory viruses in hospitalized children during the COVID-19 pandemic in southwestern China
BackgroundMultinational studies have reported that the implementation of nonpharmaceutical interventions (NPIs) to control severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission coincided with the decline of other respiratory viruses, such as influenza viruses and respiratory syncytial virus.ObjectiveTo investigate the prevalence of common respiratory viruses during the coronavirus disease 2019 (COVID-19) pandemic.MethodsRespiratory specimens of children with lower respiratory tract infections (LRTIs) hospitalized at the Children’s Hospital of Chongqing Medical University from January 1, 2018 to December 31, 2021 were collected. Seven common pathogens, including respiratory syncytial virus (RSV), adenovirus (ADV), influenza virus A and B (Flu A, Flu B), and parainfluenza virus types 1–3 (PIV1–3), were detected by a multiplex direct immunofluorescence assay (DFA). Demographic data and laboratory test results were analyzed.Results1) A total of 31,113 children with LRTIs were enrolled, including 8141 in 2018, 8681 in 2019, 6252 in 2020, and 8059 in 2021.The overall detection rates decreased in 2020 and 2021 (P < 0.001). The detection rates of RSV, ADV, Flu A, PIV-1, and PIV-3 decreased when NPIs were active from February to August 2020, with Flu A decreasing most predominantly, from 2.7% to 0.3% (P < 0.05). The detection rates of RSV and PIV-1 resurged and even surpassed the historical level of 2018–2019, while Flu A continued decreasing when NPIs were lifted (P < 0.05). 2) Seasonal patterns of Flu A completely disappeared in 2020 and 2021. The Flu B epidemic was observed until October 2021 after a long period of low detection in 2020. RSV decreased sharply after January 2020 and stayed in a nearly dormant state during the next seven months. Nevertheless, the detection rates of RSV were abnormally higher than 10% in the summer of 2021. PIV-3 decreased significantly after the COVID-19 pandemic; however, it atypically surged from August to November 2020.ConclusionThe NPIs implemented during the COVID-19 pandemic affected the prevalence and seasonal patterns of certain viruses such as RSV, PIV-3, and influenza viruses. We recommend continuous surveillance of the epidemiological and evolutionary dynamics of multiple respiratory pathogens, especially when NPIs are no longer necessary
A study of the Canadian property boom
Thesis: S.M. in Management Studies, Massachusetts Institute of Technology, Sloan School of Management, May, 2020Cataloged from the official PDF of thesis.Includes bibliographical references (pages 30-33).Canadian real estate has experienced unprecedented rapid growth since the early 2000s. People are buying homes out of concern and hope that prices may continue to rise. The immediate consequence of this trend is the changes in affordability for Canadian households. Increasing number of individuals have had to shoulder debt burdens that exceed their capacity to pay as a result of the price inflation. This has generated significant risk for the financial system and the strength of the economy. The vulnerabilities due to the housing market performance may undermine economic fundamentals and weaken the economy's ability to withstand disruptions. In this paper, the present economic conditions are examined to understand the general health of the Canadian economy. A comparison between the housing market boom in Canada and the exuberance of the 2006 US housing is drawn to gauge the degree to which the former market performance is heated. In addition, an analysis of the key variables that has fed into the growth in home prices will be presented to address how these elements contributed to the price appreciation. The optimism around Canada's housing market is worrying and the impact could be debilitating to the country's economic well-being. In light of the novel Covid-19 pandemic and its effects on the economy, where home prices will go is ever-more relevant. The paper will discuss the vulnerabilities that undermine Canada's economic resilience and conclude that the present stability is unsustainable.by Shirley Xueer Zhou.S.M. in Management StudiesS.M.inManagementStudies Massachusetts Institute of Technology, Sloan School of Managemen
Non-coding RNAs in exosomes and adipocytes cause fat loss during cancer cachexia
Cancer Cachexia (CC) is a disease that changes various metabolisms in human body. Fat metabolism is significantly affected in CC, leading to fat loss. Non-coding RNAs (ncRNAs) in adipocytes and exosomes secreted by tumor play an important role in fat loss. However, there is no related reviews summarizing how ncRNAs contribute to fat loss during CC. This review screens recent articles to summarize how ncRNAs are packaged, transported in exosomes, and play the role in fat loss. Not only does this review summarize the mechanisms, we also point out the research orientations in the future
Cooperative N–H bond activation by amido-Ge(ii) cations
N-heterocyclic carbene (NHC) and tertiary phosphine-stabilized germylium-ylidene cations, [R(L)Ge:]+, featuring tethered amido substituents at R have been synthesized via halide abstraction. Characterization in the solid state by X-ray crystallography shows these systems to be monomeric, featuring a two-coordinate C,N- or P,N-ligated germanium atom. The presence of the strongly Lewis acidic cationic germanium centre and proximal amide function allows for facile cleavage of N–H bonds in 1,2-fashion: the products resulting from reactions with carbazole feature a tethered secondary amine donor bound to a three-coordinate carbazolyl-GeII centre. In each case, addition of the components of the N–H bond occurs to the same face of the germanium amide function, consistent with a coordination/proton migration mechanism. Such as sequence is compatible with the idea that substrate coordination via the pπ orbital at germanium reduces the extent of N-to-Ge π donation from the amide, thereby enhancing the basicity of the proximal N-group.peerReviewe
Mild sp<sup>2</sup>Carbon-Oxygen Bond Activation by an Isolable Ruthenium(II) Bis(dinitrogen) Complex:Experiment and Theory
The isolable ruthenium(II) bis(dinitrogen) complex [Ru(H)2(N2)2(PCy3)2] (1) reacts with aryl ethers (Ar-OR, R = Me and Ar) containing a ketone directing group to effect sp2C-O bond activation at temperatures below 40 °C. DFT studies support a low-energy Ru(II)/Ru(IV) pathway for C-O bond activation: oxidative addition of the C-O bond to Ru(II) occurs in an asynchronous manner with Ru-C bond formation preceding C-O bond breaking. Alternative pathways based on a Ru(0)/Ru(II) couple are competitive but less accessible due to the high energy of the Ru(0) precursors. Both experimentally and by DFT calculations, sp2C-H bond activation is shown to be more facile than sp2C-O bond activation. The kinetic preference for C-H bond activation over C-O activation is attributed to unfavorable approach of the C-O bond toward the metal in the selectivity determining step of the reaction pathway.</p
Mild sp<sup>2</sup>Carbon-Oxygen Bond Activation by an Isolable Ruthenium(II) Bis(dinitrogen) Complex:Experiment and Theory
The isolable ruthenium(II) bis(dinitrogen) complex [Ru(H)2(N2)2(PCy3)2] (1) reacts with aryl ethers (Ar-OR, R = Me and Ar) containing a ketone directing group to effect sp2C-O bond activation at temperatures below 40 °C. DFT studies support a low-energy Ru(II)/Ru(IV) pathway for C-O bond activation: oxidative addition of the C-O bond to Ru(II) occurs in an asynchronous manner with Ru-C bond formation preceding C-O bond breaking. Alternative pathways based on a Ru(0)/Ru(II) couple are competitive but less accessible due to the high energy of the Ru(0) precursors. Both experimentally and by DFT calculations, sp2C-H bond activation is shown to be more facile than sp2C-O bond activation. The kinetic preference for C-H bond activation over C-O activation is attributed to unfavorable approach of the C-O bond toward the metal in the selectivity determining step of the reaction pathway.</p