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Validated tool for early prediction of intensive care unit admission in COVID-19 patients

World Journal of Clinical Cases 2021年第28期9卷 8388-8403页

作者： Hao-Fan Huang Yong Liu Jin-Xiu Li Hui Dong Shan Gao Zheng-Yang Huang Shou-Zhi Fu Lu-Yu Yang Hui-Zhi Lu Liao-You Xia Song Cao Yi Gao Xia-Xia Yu School of Biomedical Engineering Health Science CenterShenzhen UniversityShenzhen 518060Guangdong ProvinceChina Expert Panel of shenzhen 2019-nCoV Pneumonia Shenzhen HospitalSouthern Medical UniversityShenzhen 518000Guangdong ProvinceChina Department of Critical Care Medicine Shenzhen Third People’s HospitalSecond Hospital Affiliated to Southern University of Science and TechnologyShenzhen 518112Guangdong ProvinceChina Department of ICU/Emergency Wuhan Third HospitalWuhan UniversityWuhan 430000Hubei ProvinceChina

BACKGROUND The novel coronavirus disease 2019(COVID-19)pandemic is a global threat caused by the severe acute respiratory syndrome *** To develop and validate a risk stratification tool for the early prediction of intensive care unit(ICU)admission among COVID-19 patients at hospital *** The training cohort included COVID-19 patients admitted to the Wuhan Third *** selected 13 of 65 baseline laboratory results to assess ICU admission risk,which were used to develop a risk prediction model with the random forest(RF)algorithm.A nomogram for the logistic regression model was built based on six selected *** predicted models were carefully calibrated,and the predictive performance was evaluated and compared with two previously published *** There were 681 and 296 patients in the training and validation cohorts,*** patients in the training cohort were older than those in the validation cohort(median age:63.0 vs 49.0 years,P<0.001),and the percentages of male gender were similar(49.6%vs 49.3%,P=0.958).The top predictors selected in the RF model were neutrophil-to-lymphocyte ratio,age,lactate dehydrogenase,C-reactive protein,creatinine,D-dimer,albumin,procalcitonin,glucose,platelet,total bilirubin,lactate and creatine *** accuracy,sensitivity and specificity for the RF model were 91%,88%and 93%,respectively,higher than those for the logistic regression *** area under the receiver operating characteristic curve of our model was much better than those of two other published methods(0.90 vs 0.82 and 0.75).Model A underestimated risk of ICU admission in patients with a predicted risk less than 30%,whereas the RF risk score demonstrated excellent ability to categorize patients into different risk *** predictive model provided a larger standardized net benefit across the major high-risk range compared with model *** Our model can identify ICU admission risk in COVID-19 patients at ad

关键词： COVID-19 Intensive care units Machine learning Prognostic predictive model Risk stratification

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Materials and structures for the electron transport layer of efficient and stable perovskite solar cells

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Science China Chemistry 2019年第7期62卷 800-809页

作者： Shizhao Zheng Gaopeng Wang Tongfa Liu Lingyun Lou Shuang Xiao Shihe Yang Guangdong Key Laboratory of Nano-Micro Material Research School of Chemical Biology and Biotechnology Shenzhen Graduate SchoolPeking University

The electron transport layer plays a vital function in extracting and transporting photogenerated electrons, modifying the interface, aligning the interfacial energy level and minimizing the charge recombination in perovskite solar cells. This review summarizes the recent research progress on electron transport materials of metal oxides, organic molecules and multilayers. The doped metal oxides as electron transport materials in regular perovskite solar cells show improved device performance relative to their non-doped counterpart due to enhanced electron mobility and energy level alignment. The non-fullerene organic electron transport materials with better electron mobility and tunable energy level alignment need to be further designed and developed despite their advantages of mechanical flexibility and wide range tunability. The multilayer electron transport materials are suggested to be an important direction of research for efficient and stable perovskite solar cells because of their favorable synergistic interaction.

关键词： perovskite solar cells electron transport layer metal oxide organic molecules multilayer

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planar Magnetic Metamaterial Slabs for Magnetic Resonance Imaging Applications

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Chinese Physics Letters 2014年第7期31卷 184-187页

作者：李春来郭洁张澎余铨强马伟涛缪锡根赵治亚栾琳 shenzhen Key Laboratory of Optical and Terahertz Meta-RF Kuang-Chi Institute of Advanced Technology Shenzhen 518057 Shenyang Aircraft Design and Research Institute Shenyang 110035

A type of planar magnetic metamaterial is proposed with a square winding microstructure as a superlens for magnetic resonance imaging （MRI） applications. A direct magnetic field mapping measurement demonstrates that the radio-frequency magnetic field passing through the superlens is increased by as high as 46.9% at the position of about 3 cm behind the superlens. The resonance frequency of the fabricated slabs is found to be in good agreement with the target frequency （63.6 MHz） for a 1.5 T MRI system. MRI experiments with the magnetic superlens show that the intensity of the image and the SNR （signal-to-noise ratio） are both enhanced, implying promising MRI applications of our planar magnetic superlens.

关键词： MAGNETIC materials MAGNETIC resonance imaging MAGNETIC fields SIGNAL-to-noise ratio MICROSTRUCTURE

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Current progress in developing metal oxide nanoarrays-based photoanodes for photoelectrochemical water splitting

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Science Bulletin 2019年第18期64卷 1348-1380页

作者： Yongcai Qiu Zhenghui Pan Haining Chen Daiqi Ye Lin Guo Zhiyong Fan Shihe Yang Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control School of Environment and EnergySouth China University of TechnologyGuangzhou 510006China State Key Laboratory of Luminescent Materials and Devices South China University of TechnologyGuangzhou 510640China Department of Materials Science and Engineering National University of SingaporeSingapore 117574Singapore School of Materials Science and Engineering Beihang UniversityBeijing 100191China School of Chemistry and Environment Beihang UniversityBeijing 100191China Department of Electronic and Computer Engineering The Hong Kong University of Science and TechnologyHong KongChina Department of Chemistry The Hong Kong University of Science and TechnologyHong KongChina Guangdong Key Lab of Nano-Micro Material Research School of Chemical Biology and Biotechnology Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China

Solar energy driven photoelectrochemical(PEC) water splitting is a clean and powerful approach for renewable hydrogen production. The design and construction of metal oxide based nanoarray photoanodes is one of the promising strategies to make the continuous breakthroughs in solar to hydrogen conversion efficiency of PEC cells owing to their owned several advantages including enhanced reactive surface at the electrode/electrolyte interface, improved light absorption capability, increased charge separation efficiency and direct electron transport pathways. In this Review, we first introduce the structure,work principle and their relevant efficiency calculations of a PEC cell. We then give a summary of the state-of the-art research in the preparation strategies and growth mechanism for the metal oxide based nanoarrays, and some details about the performances of metal oxide based nanoarray photoanodes for PEC water splitting. Finally, we discuss key aspects which should be addressed in continued work on realizing high-efficiency metal oxide based nanoarray photoanodes for PEC solar water splitting systems.

关键词： Photoelectrochemical water splitting Metal oxide based nanoarray photoanodes Preparation strategies and growth mechanism

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Hierarchical graphite foil/CoNi2S4 flexible electrode with superior thermal conductivity for high-performance supercapacitors

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Journal of Energy Chemistry 2018年第2期27卷 463-471页

作者： Yunming Li Jiahui Chen Yaqiang Ji Wenhu Yang Xian-Zhu Fu Rong Sun Ching-Ping Wong shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 Guangdong China shenzhen College of Advanced Technology University of Chinese Academy of Sciences Shenzhen 518055 Guangdong China School of New Energy Science and Engineering Xinyu University Xinyu 338004 Jiangxi China School of Electronics and Information Engineering Guangdong Ocean University Zhanjiang 524088 Guangdong China College of Materials Science and Engineering Shenzhen University Shenzhen 518061 Guangdong China Department of Electronic Engineering Faculty of Engineering The Chinese University of Hong Kong Hong Kong 999077 China

Effective heat dissipation is a crucial issue in electrochemical energy storage devices. Thus, it is highly desirable to develop high-performance electrode materials with high thermal conductivity. Here, we report a facile one-step electrodeposition method to synthesize ternary cobalt nickel sulfide（CoNi2S4）flower-like nanosheets which are grown on graphite foil（GF） as binder-free electrode materials for supercapacitors. The as-fabricated GF/CoNi2S4 integrated electrode manifested an excellent thermal conductivity of 620.1 W·m-1·K-1 and a high specific capacitance of 881 F·g-2 at 5 mA cm-2, as well as good rate capability and cycling stability. Ultimately, the all-solid-state symmetric supercapacitor based on these advanced electrodes demonstrated superior heat dissipation performance during the galvanostatic charge-discharge processes. This novel strategy provides a new example of effective thermal management for potential applications in energy storage devices.

关键词： Electrode materials Thermal conductivity Heat dissipation Energy storage Supercapacitors

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Ferroelectric materials for vibrational energy harvesting

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Science China(Technological Sciences) 2016年第7期59卷 1012-1022页

作者： SONG JunDong WANG Jin Division of Energy and Environment in Graduate School at shenzhen Tsinghua University

Energy harvesting is an appealing technology that makes use of the ambient energy which is otherwise wasted. Piezoelectric materials directly convert the elastic energy to the electric energy, and thus have a great advantage in scavenging vibrational energy for simplicity in device structure with relatively high power density. This paper provides an overview on the research of piezoelectric materials in energy harvesting in recent decades, from basics of piezoelectricity and working principle of energy harvesting with piezoelectric materials, to the progress of development of high-performance piezoelectrics including ceramics, single crystals and polymers, then to experimental attempts on the device fabrication and optimization, finally to perspective applications of piezoelectric energy harvesting(PEH). The criteria for selection of materials for PEH applications are introduced. Not only the figure of merit but also maximum allowable stress of materials are taken into account in the evaluation of their potential in achieving high energy density and output power density. The influence of the device configuration on the performance is also acknowledged and discussed. The magnitude and distribution of induced stress in the piezoelectric unit upon excitation by the vibration source play an important role in determining the output power density and can be tuned via proper design of device configuration without changing its resonant frequency. Approaches to address the issue of frequency match accompanying with the resonant mode are illustrated with literature examples. Usage of PEH devices can be extended to a variety of vibration sources in everyday life as well as in nature. Some appealing applications of PEH, such as in implantable and wearable devices, are reviewed.

关键词： energy harvesting ferroelectric materials piezoelectricity figure of merit applications

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Temperature evolution and grain defect formation during single crystal solidification of a blade cluster

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China Foundry 2017年第5期14卷 456-460页

作者： De-xin Ma Fu Wang Qiang Wu Jian-zheng Guo Fu-ze Xu Zhao-feng Liu Shou-zhu Ou Wedge Central South Research Institute Shenzhen 518045China Foundry Institute RWTH Aachen UniversityAachen 52072Germany ALD Vacuum Technologies GmbH Hanau 63450Germany

In order to investigate the asymmetry of thermal conditions during directional solidification, the temperature evolution and correspondingly developed undercooling in a simplified single crystal blade cluster were numerically simulated. Simulation results demonstrate that the temperature distribution at the blade platforms is obviously asymmetrical. On the outside of the blade which directly faces the heating element, the liquidus(TL) isotherms progress relatively smoothly. On the inside of the blades facing the central rod, however, the TLisotherms are in concave shape and the slope goes upwards to the platform extremities. The average undercooling extent ?T and undercooling time ?t at the inside are much higher than those at the outside. It was then predicted that the inside platform extremities have significantly higher probabilities of stray grain formation compared to the outside ones. A corresponding experiment was carried out and the metallographic examination exhibited the same side-and height-dependence of stray grain formation in the blades as predicted. On the inside of the blades, all platforms are occupied by stray grains, while the platforms on the outside are nearly stray grain free. The simulation result agrees very well with the experimental observation.

关键词： superalloy directional solidification single crystal (SC) simulation stray grain (SG)

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Remarkable anodic performance of lead titanate 1D nanostructures via in-situ irreversible formation of abundant Ti^3＋ as conduction pathways

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Nano Research 2016年第2期9卷 353-362页

作者： Zhiyong Shi Jin Wang Wenxi Wang Yixiang Zhang Bo Li Zhouguang Lu Yadong Li Division of Energy and Environment in Graduate School at shenzhen Tsinghua University Shenzhen 518055 China Department of Materials Science and Engineering South University of Science and Technology of China Shenzhen 518055 China Department of Chemistry Tsinghua University Beijing 100084 China

PX-phase PbTiO3 （PT） nanowires with open channels running along the length direction have been investigated as an anode material for lithium ion batteries. This material shows a stabilized reversible specific capacity of about 410 mAh·g^-1 up to 200 cycles with a charge/discharge voltage plateau of around 0.3-0.65 V. In addition, it exhibits superior high-rate performance, with 90% and 77% capacity retention observed at 1 and 2 A·g^-1, respectively. At a very high current rate of 10 A·g^-1, a specific capacity of over 170 mAh·g^-1 is retained up to 100 cycles, significantly outperforming the rate capability reported for Pb and Pb oxides. The results of X-ray photoelectron spectroscopy （XPS） and transmission electron microscopy （TEM） analyses along with the cyclic voltammogram results reveal that the PX-phase PT nanowires undergo irreversible structural amorphization and reduction reactions during the initial cycle, which allow them to transform into a composite structure composed of 2-5 nm Pb nanoparticles uniformly dispersed in the 1D amorphous Li2O·TiO2·LiTiO2 matrix. In this composite structure, the presence of abundant amounts of Ti^3＋ in both the charged and discharged states enhances the electrical conductance of the system, whereas the presence of ultrafine Pb nanoparticles imparts high reversible capacity. The structurally stable TiO2-based amorphous matrix can also considerably buffer the volume variation during the charge/discharge process, thereby facilitating extremely stable cycling performance. This compound combines the high specific capacity of Pb-based materials and the good rate capability of Ti^3＋-based wiring. Our results might furnish a possible route for achieving superior cycling and rate performance and contribute towards the search for next-generation anode materials.

关键词： PbTiO3 nanowires lithium ion anode materials amorphous Ti^3+-rich matrix composite structure

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Stable stitching method for stereoscopic panoramic video

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CAAI Transactions on Intelligence Technology 2018年第1期3卷 1-7页

作者： Zhuo Tan Shenghao Zhang Ronggang Wang School of Electronic and Computer Engineering Peking University Shenzhen Graduate School Shenzhen 518055People's Republic of China

This paper proposes a stable method of generating a stereoscopic panoramic video with the omnidirectional stereo （ODS） format. Different from the traditional image stitching method which can only be applied to generate a monocular panorama, we adopt an optical flow-based blending method to create two panoramas for binocular vision. In addition, traditional image stitching methods based on seam-finding tend to cause the problem of temporal flicker. We address this problem by restricting the optical flow field of the new frame with its previous frame＇s optical flow field. Thus, the generated video is stable and out of temporal flicker. There are four key operations in our approach. First, we adopt the ODS format which is the basis of stereoscopic panorama. Second, we do effective exposure compensation, making the brightness of the two eyes＇ panoramas consistent. Third, we employ an optical flow-based blending method to synthesis the final panorama effectively. Fourth, we take the previous frame＇s optical flow field as the restriction of the present frame＇s optical flow field to acquire a stable video. The final output videos can deliver a pleasant and impressive stereoscopic viewing experience to the audience when the audience watches the videos in the virtual reality headset.

关键词：图像拼接人工智能智能技术发展现状

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Aerobic N_2O emission for activated sludge acclimated under different aeration rates in the multiple anoxic and aerobic process

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Journal of Environmental Sciences 2016年第5期28卷 70-79页

作者： Huoqing Wang Yuntao Guan Min Pan Guangxue Wu Key Laboratory of Microorganism Application and Risk Control of shenzhen Graduate School at Shenzhen Tsinghua University Environmental Science and Technology Xiamen University of Technology

Nitrous oxide（N_2O） is a potent greenhouse gas that can be emitted during biological nitrogen removal. N_2O emission was examined in a multiple anoxic and aerobic process at the aeration rates of 600 m L/min sequencing batch reactor（SBRL） and 1200 m L/min（SBRH）.The nitrogen removal percentage was 89% in SBRLand 71% in SBRH, respectively. N_2O emission mainly occurred during the aerobic phase, and the N_2O emission factor was 10.1%in SBRLand 2.3% in SBRH, respectively. In all batch experiments, the N_2O emission potential was high in SBRLcompared with SBRH. In SBRL, with increasing aeration rates, the N_2O emission factor decreased during nitrification, while it increased during denitrification and simultaneous nitrification and denitrification（SND）. By contrast, in SBRHthe N_2O emission factor during nitrification, denitrification and SND was relatively low and changed little with increasing aeration rates. The microbial competition affected the N_2O emission during biological nitrogen removal.

关键词： Aeration rate Nitrous oxide Biological nitrogen removal Multiple anoxic and aerobic Nitrite accumulation

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