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Airborne transmission during short-term events: Direct route over indirect route

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Building Simulation 2022年第12期15卷 2097-2110页

作者： Xiujie Li Zhengtao Ai Jinjun Ye Cheuk ming Mak Hai ming wong Department of Building Environment and Energy Engineering The Hong Kong Polytechnic UniversityHong KongChina Department of Civil Engineering Hunan UniversityChangshaChina National Center for International Research Collaboration in Building Safety and Environment Hunan UniversityChangshaChina Faculty of Dentistry The University of Hong KongHong KongChina

Numerous short-term exposure events in public spaces were reported during the COVID-19 pandemic,especially during the spread of Delta and ***,the currently used exposure risk assessment models and mitigation measures are mostly based on the assumption of steady-state and complete-mixing *** present study investigates the dynamics of airborne transmission in short-term events when a steady state is not reached before the end of the ***-eddy simulation(LES)is performed to predict the airborne transmission in short-term events,and three representative physical distances between two occupants are *** time-averaged and phase-averaged exposure indices are used to evaluate the exposure *** results present that the exposure index in the short-term events constantly varies over time,especially within the first 1/ACH(air changes per hour)hour of exposure between occupants in close proximity,posing high uncertainty to the spatial and temporal evolutions of the risk of *** decoupling analysis of the direct and indirect airborne transmission routes indicates that the direct airborne transmission is the predominated route in short-term *** suggests also that the general dilution ventilation has a relatively limited efficiency in mitigating the risk of direct airborne transmission,but determines largely the occurrence time of the indirect *** the randomness,discreteness,localization,and high-risk characteristics of direct airborne transmission,a localized method that has a direct interference on the respiratory flows would be better than dilution ventilation for short-term events,in terms of both efficiency and cost.

关键词： airborne transmission short-term events direct exposure transient computational fluid dynamics(CFD) exposure risk

Development and accuracy of artificial intelligence-generated prediction of facial changes in orthodontic treatment:a scoping review

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2023年第11期24卷 974-984页

作者： Jiajun ZHU Yuxin YANG Hai ming wong Stomatology Hospital School of StomatologyZhejiang University School of MedicineZhejiang Provincial Clinical Research Center for Oral DiseasesKey Laboratory of Oral Biomedical Research of Zhejiang ProvinceCancer Center of Zhejiang UniversityEngineering Research Center of Oral Biomaterials and Devices of Zhejiang ProvinceHangzhou310000China Faculty of Dentistry The University of Hong KongHong KongChina

Artificial intelligence(AI)has been utilized in soft-tissue analysis and prediction in orthodontic treatment planning,although its reliability has not been systematically *** scoping review was conducted to outline the development of AI in terms of predicting soft-tissue changes after orthodontic treatment,as well as to comprehensively evaluate its prediction *** electronic databases(PubMed,EBSCOhost,Web of Science,Embase,Cochrane Library,and Scopus)were searched up to March 14,*** studies investigating the performance of AI-based systems in predicting post-orthodontic soft-tissue alterations were *** Quality Assessment of Diagnostic Accuracy Studies-2(QUADAS-2)and Joanna Briggs Institute(JBI)appraisal checklist for diagnostic test accuracy studies were applied to assess risk of bias,while the Grading of Recommendation,Assessment,Development,and Evaluation(GRADE)assessment was conducted to evaluate the certainty of *** screening 2500 studies,four non-randomized clinical trials were finally included for full-text *** found a low level of evidence indicating an estimated high overall accuracy of AI-generated prediction,whereas the lower lip and chin seemed to be the least predictable ***,the facial morphology simulated by AI via the fusion of multimodality images was considered to be reasonably *** all of the included studies that were not randomized clinical trials(non-RCTs)showed a moderate to high risk of bias,more well-designed clinical trials with sufficient sample size are needed in future work.

关键词： Facial morphology Soft-tissue changes Artificial intelligence(AI) Orthodontic treatment

Design of a Five-Band Dual-Port Rectenna for RF Energy Harvesting

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Computers, Materials & Continua 2021年第10期69卷 487-501页

作者： Surajo Muhammad Jun Jiat Tiang Sew kin wong Jamel Nebhen Amjad Iqbal Centre for Wireless Technology Faculty of EngineeringMultimedia UniversityCyberjaya63100Malaysia College of Computer Science and Engineering Prince Sattam Bin Abdulaziz UniversityAlkharj11942Saudi Arabia

This paper proposed the design of a dual-port rectifier with multifrequency *** RF rectifier is achieved using a combination of L-section inductive impedance matching network(IMN)at Port-1 with a multiple stubs impedance transformer at *** fabricated prototype can harvest RF signal from GSM/900,GSM/1800,UMTS/2100,Wi-Fi/2.45 and LTE/2600 frequency bands at(0.94,1.80,2.10,2.46,and 2.63 GHz),*** rectifier occupies a small portion of a PCB board at 0.20λg×0.15λ*** proposed circuit realized a measured peak RF-to-dc(radio frequency direct current)power conversion efficiency(PCE)of(21%,22.76%,25.33%,21.57%,and 22.14%)for an input power of−20 *** RF harvester attains a measured peak RF-to-dc PCE of 72.70%and an output dc voltage of 154 mV for an input power of 3 dBm at 2.46 *** of the proposed rectifier in the ambiance gives a peak dc output voltage of 376.1 mV from the five signal ***,a low-powered bq25504-674 evaluation module(EVM)is integrated with the *** module boost and drive the rectifier output dc voltage to 945 *** performance of the proposed rectifier in the ambiance environment makes it a suitable module for low-powered RF applications.

关键词： RF energy harvesting impedance matching network power conversion efficiency multi-band rectifier

Radar-based Characteristics and Formation Environment of Supercells in the Landfalling Typhoon Mujigae in 2015

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Advances in Atmospheric Sciences 2022年第5期39卷 802-818页

作者： Lanqiang BAI Zhiyong MENG Ruilin ZHOU Guixing CHEN Naigeng WU Wai-kin wong School of Atmospheric Sciences Sun Yat-sen Universityand Key Laboratory of Tropical Atmosphere-Ocean SystemMinistry of Educationand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China Institute of Tropical and Marine Meteorology China Meteorological AdministrationGuangzhou 510640China Hong Kong Observatory Hong Kong 999077China

This study presents the radar-based characteristics and formation environment of supercells spawned by the tornadic landfalling Typhoon Mujigae(2015)in October *** than 100 supercells were identified within a 24-hour period around the time of the typhoon’s landfall,of which three were tornadic with a rotational intensity clearly stronger than those of non-tornadic *** identified supercells were concentrated within a relatively small area in the northeast quadrant beyond 140 km from the typhoon *** supercells were found more likely to form over flat topography and were difficult to maintain in mountainous *** the study period,more supercells formed offshore than *** mesocyclones of the identified supercells were characterized by a small diameter generally less than 5 km and a shallow depth generally less than 4 km above ground *** environmental analysis revealed that the northeast quadrant had the most favorable conditions for the genesis of supercell in this typhoon *** nondimensional supercell composite parameter(SCP)and entraining-SCP(E-SCP)were effective in separating supercell from non-supercell *** though the atmosphere in the typhoon’s northeast quadrant was characterized by an E-SCP/SCP value supportive of supercell organization,orography was an impeditive factor for the supercell *** findings support the use of traditional parameters obtained from midlatitude supercells to assess the supercell potential in a tropical cyclone envelope.

关键词： supercell tropical cyclone atmospheric environment radar meteorology

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Electronic transmission of three-terminal pyrene molecular bridge

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Chinese Physics B 2009年第2期18卷 501-505页

作者：王利光张秀梅 Terence kin Shun wong Katsunori Tagami Masaru Tsukada School of Science Jiangnan University School of Electrical and Electronic Engineering Nanyang Technological University Nano Technology Research Centre Waseda University

This paper investigates theoretically the electronic transmission spectra of the three terminal pyrene molecular bridge and the quantum current distribution on each bond by the tight-binding model based on nonequilibrium Green＇s function and the quantum current density approach, in which one π molecular orbital is taken into account per carbon atom when the energy levels and HOMO-LUMO gap are obtained. The transmission spectra show that the electronic transmission of the three terminal pyrene molecular bridge depends obviously on the incident electronic energy and the pyrene eigenenergy. The symmetrical and oscillation properties of the transmission spectra are illustrated. A novel plus-minus energy switching function is found. The quantum current distribution shows that the loop currents inside the pyrene are induced, and some bond currents are much larger than the input and the output currents. The reasons why the loop currents and the larger bond currents are induced are the phase difference of the atomic orbits and the degeneracy of the molecular orbits. The calculations illustrate that the quantum current distributions are in good agreement with Kirchhoff quantum current conservation law.

关键词： pyrene three terminals electronic transmission current distribution

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Remifentanil mimics cardioprotective effect of ischemic preconditioning via protein kinase C activation in open chest of rats

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Acta Pharmacologica Sinica 2005年第05期26卷 546-550页

作者： Michael G IRWIN Tak-ming wong Department of Anesthesiology Department of Physiology the University of Hong Kong Hong Kong China

Aim:To examine whether the protective effect of remifentanil preconditioning（RPC）on postischemic hearts is mediated by protein kinase（PKC）activation incomparison with ischemic preconditioning（IPC）.Methods:Male Sprague-Dawleyrats were anesthetized and their chests were *** experiment was per-formed with chelerythrine（CHE,2mg/kg）,GF109203X（0.05 mg/kg）protein kinaseC（PKC）inhibitors administered before RPC(remifentanil 6μ***-1·min-1×3 cycle)orIPC,*** size（IS）,as a percentage of the area at risk（AAR）,wasdetermined by triphenyltetrazolium ***:In groups subjected to IPCand RPC the IS/AAR were significantly reduced（IS/AAR from 52.7%±5.5% to12.9%±3.4%,P0.05 vs CON）or IPC（CHE+IPC 53.7%±4.3%,GF+IPC54.1%±6.2%,P>0.05 vs CON）.The difference was not significant in any of thehemodynamic parameters between control and treatment groups during ischemiaand ***:Remifentanil confers myocardial protection againstischemic injury through a mechanism that is similar to IPC and involves PKCactivation.

关键词： remifentanil myocardial ischemia preconditioning myocardial reperfusion injury protein kinase C chelerythrine GF109203X

Optical coherence tomography-guided percutaneous transluminal angioplasty in renal artery fibromuscular dysplasia

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Journal of Geriatric Cardiology 2020年第3期17卷 173-174页

作者： Wai kin Chi Tan Guang ming Bryan P Yan Division of Cardiology Department of Medicine and TherapeuticsPrince of Wales Hospitalthe Chinese University of Hong KongHong KongChina

A 40-year-old woman was referred for resistant hypertension despite three anti-hypertensive medications including a diuretic at maximum tolerated *** has no family history of fibromuscular dysplasia(FMD).Contrast-enha... 详细信息

关键词： Fibromuscular dysplasia Optical coherence tomography Renal artery stenosis

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Multiplex real-time PCR revealed very high prevalence of soil-transmitted helminth infections among aborigines in Peninsular Malaysia

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Asian Pacific Journal of Tropical Medicine 2020年第12期13卷 550-556页

作者： Nurulhasanah Othman Noorizan Miswan Weng-kin wong Boon-huat Lim Rahmah Noordin Institute for Research in Molecular Medicine Universiti Sains Malaysia11800 PenangMalaysia School of Health Sciences Universiti Sains Malaysia16150 KelantanMalaysia

Objective:To determine the true prevalence of soil-transmitted helminth infections in the Malaysian aborigines using real-time ***:A total of 122 aborigines from seven tribes were recruited from settlements and nearby hospitals which served the communities,located in four states in Peninsular *** stool samples were examined for the presence of soil-transmitted helminth using real-time PCR and *** latter included the direct wet mount and formalin-ether concentration technique(FECT).The infection load in FECT-positive samples was determined by the Kato-Katz *** real-time analyzer detected five helminth species using two sets of ***:The real-time PCR detected soil-transmitted helminth in 98.4% samples(n=122),which were 1.56 times higher than by *** lumbricoides and Trichuris trichiura were detected in more than 90% of the samples,while hookworm was detected in 46.7%(Necator americanus) and 13.9%(Ancylostoma sp.)of the *** with previous reports on the Malaysian aborigines showed that the real-time PCR markedly improved the detection of Ascaris lumbricoides,hookworm and Strongyloides *** real-time PCR detected poly-helminths in 92.6%of the samples compared to 28.7% by *** addition,27 samples(22.1%) showed amplification of Strongyloides stercoralis ***:The real-time PCR showed very high prevalence rates of soil-transmitted helminth infections in the aborigines and is the recommended method for epidemiological investigation of soiltransmitted helminth infections in this population.

关键词： prevalence infections markedly

Chronic ulcerative gastroduodenitis as a first gastrointestinal manifestation of Hermansky-Pudlak syndrome in a 10-year-old child

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World Journal of Gastroenterology 2008年第18期14卷 2939-2941页

作者： Anselm Chi-Wai Lee kin-Hung Poon Wing-Hong Lo Lap-Gate wong Department of Pediatrics & Adolescent Medicine Tuen Mun Hospital New Territories Hong Kong 999077 China Department of Clinical Pathology Tuen Mun Hospital New Territories Hong Kong 999077 China

A 10-year-old Chinese boy who had a history of congenital thrombocytopathy presented with severe iron deficiency anemia secondary to chronic gastric inflammation and duodenal ulcerations. Subtle oculocutaneous albinism led to the finding of diminished dense bodies in the platelets under electron microscopy, hence the diagnosis of Hermansky-Pudlak syndrome (HPS). Biopsies from the stomach and duodenum revealed a lymphocytic infiltration in the submucosa, but H pylori infection was absent. The gastroduodenitis responded to the treatment with omeprazole while iron deficiency anemia was corrected by oral iron therapy. HPS is a rare cause of congenital bleeding disorder with multisystemic manifestations. Upper gastrointestinal involvement is rare and should be distinguished from a mere manifestation of the bleeding diathesis.

关键词： Albinism Duodenal ulceration Hermansky-Pudlak syndrome Inflammatory bowel disease Thrombocytopathy