科研成果

2021
Niu Y (PHD Student), Liu Y, Wu X, Chen J *. Categorical perception of lexical tones based on acoustic-electric stimulation. JASA Express Letters. 2021;1(8):084405.
Deng Y, Zhou X-H. Caution about truncation-by-death in clinical trial statistical analysis: a lesson from Remdesivir. China CDC Weekly [Internet]. 2021;3(25):538-540. 访问链接Abstract
Clinical trials may often be encountered with truncation-by-death problem, where subjects enrolled in the experiment dies before their outcomes are collected. It is worth noting that truncation by death is a totally different concept from censoring. Censoring refers to the cases that subjects do have an outcome (such as time to recovery), but this outcome is masked by loss of follow-up, while truncation by death leaves the outcome undefined. In this article, we address the truncation-by death issue by reviewing two clinical trials on remdesivir for COVID-19, and provide some instructions to deal with the truncation-by-death problem.
Li X, Qin H, Zhou Z, Li Y, Wang J, Lin M, Dong X, Yang M, Li L. Cellular evaluation of the metal-organic framework PCN-224 associated with inflammation and autophagy. Toxicol In VitroToxicol In Vitro. 2021;70:105019.Abstract
Metal-organic frameworks (MOFs) are innovative porous structures consisting of metal ions and organic ligands, which have been verified for extraordinary applications in nanomedicine and pharmaceuticals. PCN-224 is a type of Zr-based MOFs, which has recently emerged as one of the most attractive nanomaterials for various applications, such as drug delivery, bioimaging and cancer therapy due to its favorable and fascinating physical-chemical properties. However, the safety evaluation and the potential toxicological properties remain unclear. In this study, the general cytotoxicity of PCN-224 were examined in both human hepatocytes L-02 cells and mouse macrophages RAW264.7. Furthermore, the effect of inflammation and autophagy were measured in L-02 cells. The results indicated that PCN-224 was engulfed in L-02 cells and subsequently resulted in morphological changes, cell membrane destruction, and oxidative stress in L-02 cells. PCN-224 might trigger inflammation by promoting the secretion of inflammatory factors such as Tumor necrosis factors (TNF-alpha) and Interleukin (IL-6). PCN-224 might induce autophagosome accumulation and subsequently autophagic dysfunction. Additionally, PCN-224 induced cytotoxicity in RAW264.7 cells and increased the protein levels of the inflammasome component NLR Family Pyrin Domain Containing 3 (NLRP3) molecular, which indicated its cellular effects in different cell types. All of these results will support the reasonable use of PCN-224.
Chang J, Wang X, Zhou Z, Chen H, Niu Y. CFD modeling of hydrodynamics, combustion and NOx emission in a tangentially fired pulverized-coal boiler at low load operating conditions. Advanced Powder Technology [Internet]. 2021;32:290-303. 访问链接Abstract
With deep peak-load regulations, utility boilers are frequently operated under variable/low load conditions. However, their hydrodynamics, combustion and NOx emission characteristics are uncertain and relevant theoretical guidance are lacking. For this purpose, a comprehensive CFD model including flow, coal combustion and NOx formation is established for a 630 MW tangentially fired pulverized-coal boiler, aiming at solving the problem of decreasing combustion stability and increasing NOx emission in low-load operation. Based on the grid independence and model validation, the flow field, temperature profile, species concentration profile and NOx emission are predicted, and the influences of angle/arrangement of burners are further evaluated. Simulation results indicate that under low-load conditions, residual airflow rotation still persists at the top of boiler regardless of how to adjust the angle/arrangement of burners. With tilting the burner angle upward, flame is more concentrated, combustion becomes more stable, and heat flux rises in the upper zone; the burner arrangement of ABDE gives more uniform temperature distribution in the combustion zone. CO species shows higher content in the combustion zone; the 0° tilt angle gives maximum CO content, followed by the 15° angle, and finally the −15° angle; compared to the ACDE and ABCE arrangement, the ABDE arrangement mode gives much lower CO contents. Burner tilt angle of −15° benefits for lower NOx emission (183 mg/m3) but goes against stable combustion; the burner arrangement mode of ABDE is optimal for the present boiler, which ensures both stable combustion and lower NOx emission (209 mg/m3).
Ye L, Wang Z, Liu Y, Chen P, Li H, Zhang H, Wu M, He W, Shen L, Zhang Y, et al. The Challenges and Emerging Technologies for Low-Power Artificial Intelligence IoT Systems. IEEE Transactions on Circuits and Systems I: Regular Papers. 2021;68:4821-4834.Abstract
The Internet of Things (IoT) is an interface with the physical world that usually operates in random-sparse-event (RSE) scenarios. This article discusses main challenges of IoT chips: power consumption, power supply, artificial intelligence (AI), small-signal acquisition, and evaluation criteria. To overcome these challenges, many works recently aimed at IoT system design have emerged. This work reviews the architecture and circuit innovations that have contributed to IoT developments. This paper does not cover security of IoT. Event-driven architectures and nonuniform sampling ADCs significantly reduce the long-term average power. Besides, embedding AI engines in IoT nodes (AIoT) is one critical trend. The computing-in-memory technique improves the energy efficiency of the AI engine. Asynchronous spike neural networks (ASNNs) AI engines show low power potential. In addition to data processing, small-signal acquisition is also critical. The charge-domain analog-front-end (AFE) techniques such as floating inverter-based amplifiers improve energy efficiency. In addition to the above low power and high energy efficiency technologies, energy harvesting can also enhance the lifetime of AIoT devices. This article discusses recent ambient RF and natural energy harvesting approaches and high-efficiency DC-DC with a wide load range. Finally, novel evaluation criteria are introduced to establish benchmark standards for AIoT chips.
Zhao X, Yu Y-H, Peng M-M, Luo W, Hu S-H, Yang X, Liu B, Zhang T, Gao R, Chan CL-W. Change of poverty and outcome of persons with severe mental illness in rural China, 1994-2015. International Journal of Social Psychiatry. 2021;67(4):315-323.
Wang T, Han Y, Li H, Wang Y, Xue T, Chen X, Chen W, Fan Y, Qiu X, Gong J, et al. Changes in bioactive lipid mediators in response to short-term exposure to ambient air particulate matter: A targeted lipidomic analysis of oxylipin signaling pathways. Environment InternationalEnvironment International. 2021;147.
Cao S, Wen D, Li S, Guo Q, Duan X, Gong J, Xu X, Meng X, Qin N, Wang B, et al. Changes in children's lung function over two decades in relation to socioeconomic, parental and household factors in Wuhan, China. Journal of Thoracic DiseaseJournal of Thoracic Disease. 2021;13:4601-+.
Li X, Fan H, Wu X, Xu N, Guo S, Hu M. Characteristics and Sources of PAHs in PM2.5 during Winter Heavy Pollution Episodes in Dezhou and Beijing. Research of Environmental SciencesResearch of Environmental SciencesResearch of Environmental Sciences. 2021;34:54-62.Abstract
Particulate PAHs are of significant concern due to their carcinogenic and mutagenic properties. In order to investigate the characteristics and sources of particulate PAHs during heavy pollution episodes, PM2.5 samples were collected in Beijing and Dezhou in the North China Plain from November 17th, 2018 to January 19th, 2019. 26 species of PAHs in PM2.5 during six heavy pollution episodes were measured by gas chromatography-mass spectrometer (GC-MS). The results showed that: (1) The total concentration of PAHs during six heavy pollution episodes ranged from 62 to 191 ng/m3 in Dezhou, and from 61 to 129 ng/m3 in Beijing. (2) The ratios of ∑26PAHs/PM2.5 were higher in Beijing, although PM2.5 concentrations were lower. (3) The dominant components of PAHs were benzo[b]fluoranthene, benzo[a]pyrene (Bap), benzo[a]anthracene, methyl-fluoranthene and retene, accounting for about 50% of ∑26PAHs. (4) The diagnostic ratios indicated vehicle exhaust, coal combustion and biomass burning were the main sources of PAHs at both sites. A more obvious influence of biomass burning in Dezhou was found via a tracer-based approach and using the ratio of PAHs to levoglucosan in fresh biomass burning aerosols. (5) The Bap toxic equivalent concentrations (TEQ) were 6.5-17.2 ng/m3, with higher values in Dezhou than those in Beijing. The BaP concentration ranged from 5.2 to 13.1 ng/m3 and exceeded BaP standard (24 h average: 2.5 ng/m3) in China (Ambient Air Quality Standard, GB 3095-2012), indicating a potential hazardous effect on human health. The studies have shown that both sites have similar distribution characteristics and sources, while the enrichment ratios of ∑26PAHs/PM2.5 in Beijing were higher. PAHs emission control needs to be further strengthened to reduce the risk of human exposure to heavy pollution episodes and the PM2.5 pollution levels. © 2021, Editorial Board, Research of Environmental Sciences. All right reserved.
Zhang Y, Chen Z, Zong Y, Zhong Z, Chen L, Wu Y, Chen J, Liu Y*. Characteristics of Electrocochleography in Patients with Presbycusis and DifferentLevels of Speech Recognition Ability. Journal of Otology (中华耳科学杂志). 2021;19(3):447-451.
Su Z, Wen D. Characterization of antibiotic resistance across Earth's microbial genomes. Science of the Total Environment [Internet]. 2021;816:151613. 访问链接Abstract
Widespread antibiotic resistance across Earth's habitats has become a critical health concern. However, large-scale investigation on the distribution of antibiotic resistance genes (ARGs) in the microbiomes from most types of ecosystem is still lacking. In this study, we provide a comprehensive characterization of ARGs for 52,515 microbial genomes covering various Earth's ecosystems, and conduct the risk assessment for ARG-carrying species based on further identification of mobile genetic elements (MGEs) and virulence factor genes (VFGs). We identify a total of 6159 ARG-carrying metagenome-assembled genomes (ACMs), and most of them are recovered from human gut and city subway. Our results show that efflux pump is the most common mechanism for bacteria to acquire multidrug resistance genes in Earth's microbiomes. Enterobacteriaceae species are the largest hosts of ARGs, accounting for 14% of total ACMs with 64% of the total ARG hits. Most of ARG-carrying species are unique in the different ecosystem categories, while 33 potential background ARGs are commonly shared by all ecosystem categories. We then detect 36 high-risk ARGs that likely threat public health in all ACMs. Based on ranking the importance of ARG-carrying species in the different ecosystem categories, several bacterial taxa such as Escherichia coliEnterococcus faecalis, and Pseudomonas_A stutzeri are recognized as priority species for surveillance and control. Overall, our study gives a broad view of ARG-host associations in the environments.
Wu H, Fu P, Morris JP, Mattson ED, Neupane G, Smith MM, J.Hawkins A, Zhang Y, Kneafsey T. Characterization of flow and transport in a fracture network at the EGS Collab field experiment through stochastic modeling of tracer recovery. Journal of Hydrology [Internet]. 2021;593:125888. 访问链接
Wang H, Tian L, Kang K, Zhang B, Li G, Zhang K. Characterization of Ultrasonic-Induced Wettability Alteration under Subsurface Conditions. Langmuir [Internet]. 2021;38(1):514-522. 访问链接Abstract
Understanding and manipulating wettability alterations has tremendous implications in theoretical research and industrial applications. This study proposes a novel idea of applying ultrasonic for wettability alterations and also provides its quantitative characterizations and in-depth analyses. More specifically, with pretreatment of ultrasonic, mechanisms of wettability alteration were characterized from the contact angle measurements, as well as the in-depth analyses from atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). After ultrasonic treatments, the wettability of mineral with low permeability is determined to altered from strong hydrophilic to intermediate wettability. The mechanism interpretations are conducted by means of the AFM, XRD, and FTIR. Basically, as the time of ultrasonic treatment increases, the AFM results indicate that the roughness of rock surface and oil/rock interface (contact area) with surroundings of brine is enhanced. Meanwhile, the XRD results show the diffusions of clays from the rock surface to the aqueous phase, and FTIR indicates that the number of functional groups of Si–O–Si, C–O–C, C–O, C═O, and OH decreases while the number of COOH and C═C═O groups increases. This study clearly reveals the surface chemistry of oil-rock wettability alteration in the subsurface conditions, which would provide technical support for subsurface usage of geo-energy productions and carbon sequestrations.
Wang H, Lu K, Chen S, Li X, Zeng L, Hu M, Zhang Y. Characterizing nitrate radical budget trends in Beijing during 2013–2019. Science of The Total Environment. 2021;795:148869.
Xu N, Wang TT, Li X, Tang RZ, Guo S, Hu M. Chemical Characteristics and Source Apportionment of Organic Aerosols in Atmospheric PM2.5 in Winter in Beijing. Huanjing Kexue/Environmental ScienceHuanjing Kexue/Environmental ScienceHuanjing Kexue/Environmental Science. 2021;42:2101-2109.Abstract
To explore the concentrations, characteristics, and sources of organic aerosols in winter in Beijing, atmospheric fine particulate matter (PM2.5) samples were collected from November 10, 2016 to December 10, 2016. One hundred and twenty-nine particulate organic matters (POM) were quantified by gas chromatography-mass spectrometry, accounting for approximately 9.3%±1.2% of the total concentration of organic matter. The most abundant class was sugar, among which levoglucosan alone accounted for 18% of the quantified organic matter mass. The next most abundant classes were alkanoic acids, normal alkanes, dicarboxylic acids, and polycyclic aromatic hydrocarbons. The influence of winter heating and biomass burning emissions on organic aerosols in winter in Beijing was analyzed by the characteristics of the molecular markers in the POM. Compared with those during the non-heating period, the concentrations and proportions of hopane species, which are tracers for fossil fuels, increased in the organic matters during the heating period. Moreover, the influence of coal burning emissions on the distribution of hopane species was enhanced. The species with the maximum concentration and carbon predominance index in n-alkanes also reflected the influence of enhanced fossil fuel emissions. The results of the concentration-weighted trajectory model for levoglucosan, a tracer for biomass combustion, suggested that straw burning pollution in the surrounding areas of Beijing would affect the composition of organic aerosols in Beijing via airmass transport. A molecular marker-based chemical mass balance model was used to apportion the sources of organic carbon in the winter of 2016 in Beijing, and the results were compared with those of research in 2006 to quantify the changes in the source contributions over 10 years. The contribution of motor vehicles increased significantly in 2016 compared with that in 2006, whereas the contribution of coal burning and wood burning decreased to a large extent. The contribution of cooking emissions could not be ignored. Therefore, the control of motor vehicle and cooking emissions is of great importance to reduce the problem of PM2.5 pollution in winter in Beijing. © 2021, Science Press. All right reserved.
Chen X, Ren Z-Y, Li D-L, Liu T, Wang K, Shen Z-Q, Ellingsen SP, Sobolev AM, Mei Y, Li J-J, et al. Chemically Fresh Gas Inflows Detected in a Nearby High-mass Star-forming Region. \apjl. 2021;923:L20.
Li S, Cao S, Duan X, Zhang Y, Gong J, Xu X, Guo Q, Meng X, Bertrand M, Zhang JJ. Children's lung function in relation to changes in socioeconomic, nutritional, and household factors over 20 years in Lanzhou. Journal of Thoracic DiseaseJournal of Thoracic Disease. 2021;13:4574-4588.
Song X, Liu C, Zhang Y. Chinese College Students’ Source Selection and Use in Searching for Health and Wellness Information Online. Information Processing and Management [Internet]. 2021;58(3):102489. 访问链接
Zheng Y, Mou N, Zhang L, Makkonen T, Yang T. Chinese tourists in Nordic countries: An analysis of spatio-temporal behavior using geo-located travel blog data. Computers Environment and Urban Systems. 2021;85:101561.
Min C, Chen Q, Yan E, Bu Y, Sun J. Citation cascade and the evolution of topic relevance. Journal of the Association for Information Science and Technology. 2021;72(1):110-127.

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