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Charge balance materials for homojunction and heterojunction OLED applications

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Frontiers of Optoelectronics 2009年第4期2卷 435-441页

作者： Louis m.leung Yik-Chung LAW michael Y.WONG Tik-Ho LEE Kin ming LAI Lok-Yee TANG Department of Chemistry and Centre for Advanced Luminescence materials Hong Kong Baptist University

In a homojunction device, a single organic layer assumes the multiple roles of hole, electron transportation, and emitter. Its ease in processing is highly desirable from the manufacturing point of view. In this paper, we shall describe the synthesis of a range of bipolar small molecules and conductive vinyl polymers for application in homojunction and heterojunction organic light emitting diodes（OLEDs）. The bipolar materials, in general, consist of three basic building blocks: an arylamine, a 1,3,4-oxadiazole, and a polycyclic aromatic moiety. The achievement of charge balance can be validated either by direct measurement of electron/hole mobility or indirectly via optimization of device properties.A series of conductive vinyl copolymers containing hole transporting N-（4-methoxyphenyl）-N-（4-vinylphenyl）naphthalen-1-amine（4meONPA） and electron transporting 2-phenyl-5-（4-vinylphenyl）-1,3,4-oxadiazole（OXA）at different compositions was applied for heterojunction and homojunction OLEDs. For heterojunction devices employed the copolymers as the hole transporting layer and Alq3as the electron transporting and emitting layer,a maximum luminance and current efficiency of over 23000 cd/m2and 4.2 cd/A（PL of Alq3）, respectively, were achieved at the charge balance composition. Homojunction devices for the copolymers were demonstrated by the addition of rubrene as a dopant. The single layer devices at the optimal copolymer composition has ca 1500 cd/m2and 0.74 cd/A.

关键词： homojunction devices charge balance bipolar small molecules conductive vinyl copolymers

COVID-19 mortality and Vaccine Coverage——Hong Kong Special Administrative Region,China,January 6,2022-march 21,2022

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China CDC weekly 2022年第14期4卷 288-292页

作者： Dallas J.Smith Avi J.Hakim Gabriel m.leung Wenbo Xu WWilliam Schluter Ryan T.Novak Barbara marston Bradley S.Hersh CDC COVID-19 Response International Task Force Atlanta Epidemic Intelligence Service CDC Li Ka Shing Faculty of medicine University of Hong KongHong Kong Special Administrative RegionChina National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina CDC China BeijingChina

Summary What is already known about this topic?COVID-19 vaccines are important tools to protect populations from severe disease and *** is added by this report?Among persons aged≥60 years in Hong Kong,49%,had received≥2 doses of a COVID-19 vaccine,and vaccination coverage declined with *** January-march 2022,reported COVID-19-associated deaths rose rapidly in Hong *** these deaths,96%occurred in persons aged≥60 years;within this age group,the risk for death was 20 times lower among those who were fully vaccinated compared with those who were unvaccinated.

关键词： doses COV deaths

message from Deputy Editor-in-Chief Gabriel m.leung—International Trade and Global Health Protection

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China CDC weekly 2019年第4期1卷 45-46页

作者： Gabriel m.leung China CDC Weekly Dean of medicine The University of Hong KongHong Kong SARChina

It was external trade that first prompted the collection and reporting of surveillance data at the foreign ports from which the US imported *** established Bulletin of the Public Health—the first precursor to the US ... 详细信息

关键词： Trade prompt Health

320层CT冠状动脉成像预期稳定性冠状动脉疾病是否需要血管重建并作为行有创性血管造影的决定指标:储备血流分数的相关性研究

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国际医学放射学杂志 2014年第3期 298-298页

作者： B.S.Ko D.T.L.Wong J.D.Cameron D.P.Leong m.leung I.T.meredith 唐光健 monash Heart 246 Clayton RoadClayton 3168VICAustralia

摘要目的明确以储备血流分数(FFR)作为参考标准,320层多层CT冠状动脉血管成像(m320-CCTA)检出稳定性冠状动脉疾病功能性狭窄与预期血管重建的准确性。方法

关键词：冠状动脉疾病血管重建分数 CCTA 有创血流储备 CT

Interaction between gut microbiota and COVID-19 and its vaccines

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World Journal of Gastroenterology 2022年第40期28卷 5801-5806页

作者： John S m.leung Cardiothoracic Unit St.Paul’s HospitalHong KongChina

The whole world has been continuously afflicted by the coronavirus disease 2019(COVID-19)pandemic for the past 3 *** countries have tried many methods to control this virus infection with varying successes and *** gut microbiota is a biosystem spanning the entire length of the digestive tract and playing important roles in health and *** is much affected by *** return it also substantially impacts *** particular,the gut microbiota has established a bidirectional interaction with the COVID-19 vaccines,enhancing or reducing vaccine efficacy by virtue of its varying ***,COVID-19 vaccines also make a substantial impact on the gut microbiota,reducing its overall population and *** is hoped that by exploring and harnessing this bidirectional interaction we may break new ground and develop new methods to prevent and treat this formidable virus infection.

关键词： Gut microbiota COVID-19 vaccines Vaccine interactions Gut microbiota alterations

Biased activity of soluble guanylyl cyclase:the Janus face of thymoquinone

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Acta Pharmaceutica Sinica B 2017年第4期7卷 401-408页

作者： Charlotte Detremmerie Paul m.Vanhoutte Susan leung Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology Li Ka Shing Faculty of Medicinethe University of Hong KongHong KongChina

The natural compound thymoquinone, extracted from Nigella sativa(black cumin), is widely used in humans for its anti-oxidative properties. Thymoquinone is known for its acute endotheliumindependent vasodilator effects in isolated rat aortae and pulmonary arteries, depending in part on activation of adenosine triphosphate-sensitive potassium channels and inhibition of voltage-dependent calcium channels. The compound also improves endothelial dysfunction in mesenteric arteries of ageing rodents and in aortae of rabbits treated with pyrogallol, by inhibiting oxidative stress. Serendipitously,thymoquinone was found to augment contractions in isolated arteries with endothelium of both rats and pigs. The endothelium-dependent augmentation it causes counterintuitively depends on biased activation of soluble guanylyl cyclase(sGC) producing inosine 3',5'-cyclic monophosphate(cyclic ImP) rather than guanosine 3',5'-cyclic monophosphate. This phenomenon shows a striking mechanistic similarity to the hypoxic augmentation previously observed in porcine coronary arteries. The cyclic ImP preferentially produced under thymoquinone exposure causes an increased contractility of arterial smooth muscle by interfering with calcium homeostasis. This brief review summarizes the vascular pharmacology of thymoquinone, focussing in particular on how the compound causes endothelium-dependent contractions by biasing the activity of sGC.

关键词： Thymoquinone Endothelium-dependentcontraction Nitric oxide Soluble guanylyl cyclase Cyclic ImP NADPH:quinone oxidoreductase

Innovating for Health in China’s Greater Bay Area

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China CDC weekly 2022年第1期4卷 1-3页

作者： Feichau Pang Puihong Chung Gabriel m.leung School of Public Health LKS Faculty of MedicineThe University of Hong KongHong KongChina

The Success of World metropolitan and Bay Areas The Tokyo Bay Area,the New York metropolitan Area,and the San Francisco Bay Area are leading regions for science and *** share an economic transformation from industrial or manufacturing bases to predominantly service-based economies with this sector contributing 75%of their gross domestic product(GDP)in *** companies in these locations accounted for 60%of the revenue of the top 100 global tech companies in 2018(1).The success of these locations stems from the convergence of academia,technology giants,government support,and a high density of investors,as well as innovative entrepreneurs(2).

关键词： companies revenue bases

Sedated vs unsedated colonoscopy:A prospective study

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World Journal of Gastroenterology 2014年第17期20卷 5113-5118页

作者： Abdulrahman m Aljebreen majid A Almadi Felix W leung Gastroenterology Division King Khalid University HospitalKing Saud UniversityRiyadh 11461Saudi Arabia Gastroenterology Division McGill University Health Center mcGill University MontrealQuebec H3G 1A4Canada Research and medical Services Sepulveda Ambulatory Care CenterVeterans Affairs Greater Los Angeles Healthcare Systemand David Geffen School of Medicine at UCLALos AngelesCaliforniaCA 91343United States

AIm:To compare sedated to unsedated colonoscopy in terms of duration,pain and the patient’s willingness to repeat the ***:Consecutive patients who underwent colonoscopies over a 2-year period were invited to *** patients who were to undergo our endoscopy unit were offered sedation with standard intravenous sedatives and analgesics,or an unsedated colonoscopy was *** details were *** patient anxiety level prior to the procedure,time to reach the cecum,total discharge time,patient and endoscopist pain assessments,satisfaction after the examination and the patient’s willingness to return for the same procedure in the future were ***:Among the 403 observed patients,more males were observed in the unsedated group(66.2%vs 55.2%,P=0.04).Additionally,the unsedated group patients were less anxious prior to the procedure(5.1vs 6.0,Pmpletion rates were comparable between the 2 groups(85.9%vs84.2%,P=0.66).The time to reach the cecum was also comparable(12.2 min vs 11.8 min);however,the total discharge times were shorter in the unsedated group(20.7 min vs 83.0 min,Pmoreover,the average patient pain score(3.4 vs 5.7,Pms of willingness to repeat the procedure if another was required in the future(83.3%vs 77.3%,P=0.17).CONCLUSION:Unsedated colonoscopy is feasible in willing *** option saves the endoscopy units up to one hour per patient and does not affect the patient willingness to return to the same physician again for additional colonoscopies if a repeated procedure is needed.

关键词： Sedation Colonoscopy Unsedated Screening Endoscopy

Evaluation and management of the child with hypothyroidism

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World Journal of Pediatrics 2019年第2期15卷 124-134页

作者： Alexander K.C.leung Alexander A.C.leung Department of Pediatrics The University of Calgaryand The Alberta Children's Hospital#200233-16th Avenue NWCalgaryAB T2M 0H5Canada Department of medicine The University of CalgaryCalgaryABCanada

Background Thyroid hormones are critical for early neurocognitive development as well as growth and development throughout *** recognition and treatment of hypothyroidism is,therefore,of utmost importance to optimize physical and neurodevelopmental *** sources A Pubmed search was completed in Clinical Queries using the key terms 'hypothyroidism'.Results Hypothyroidism may be present at birth (congenital hypothyroidism) or develop later in life (acquired hypothyroidism).Thyroid dysgenesis and dyshormonogenesis account for approximately 85% and 15% of permanent cases of congenital primary hypothyroidism,*** than 95% of infants with congenital hypothyroidism have few,if any,clinical manifestations of *** screening programs allow early detection of congenital *** developed countries,Hashimoto thyroiditis is the most common cause of goiter and acquired hypothyroidism in children and ***,iodine deficiency associated with goiter is the most common cause of *** hypothyroidism is uncommon and may be associated with other congenital syndromes and deficiencies of other pituitary *** of the clinical features would allow prompt diagnosis and institution of *** To optimize neurocognitive outcome in infants with congenital hypothyroidism,treatment with levothyroxine should be started as soon as possible,preferably within the first 2 weeks of *** with acquired hypothyroidism should also be treated early to ensure normal growth and development as well as cognitive *** target is to keep serum TSH mIU/L and to maintain serum free T4 or total T4 within the upper half of the age-specific reference range,with elimination of all symptoms and signs of hypothyroidism.

关键词： Dysgenesis Dyshormonogenesis Hashimoto thyroiditis Hypothyroidism Iodine deficiency Levothyroxine mental retardation Stunted growth