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老年遗忘型轻度认知障碍执行功能的神经机制及数字干预

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心理科学进展 2024年第6期32卷 873-885页

作者：刘海宁董现玲刘海虹刘艳丽李现文承德医学院心理学系河北承德067000 承德医学院生物医学工程系河北承德067000 南京医科大学护理学院南京211166

阿尔茨海默病具有极高的发病率和致死率。遗忘型轻度认知障碍(Amnestic Mild cognitive Impairment,aMcI)作为临床前驱期,探究其形成和发展机制有助于预防阿尔茨海默病的发生。现有研究显示,多个执行域缺陷与aMcI记忆衰退密切相关,但尚... 详细信息

阿尔茨海默病具有极高的发病率和致死率。遗忘型轻度认知障碍(Amnestic Mild cognitive Impairment,aMcI)作为临床前驱期,探究其形成和发展机制有助于预防阿尔茨海默病的发生。现有研究显示,多个执行域缺陷与aMcI记忆衰退密切相关,但尚未回答何种执行域是关键致病因子、关键干预治疗靶标等科学问题。为突破以往研究将执行功能视作整体抑或割裂元素的局限性,本研究拟从执行功能结构全貌着眼,在提出aMcI执行功能与记忆损害关系假说的基础上,利用脑电技术系统考察aMcI抑制、刷新和转换三种执行功能子成分的时域、时频和动态脑网络特征;并结合三维卷积神经网络筛选、识别执行功能缺陷的特异性神经靶标,探索将抑制域相关神经标记物加入aMcI早期识别的可能性;最后,通过纵向因果设计分析不同靶向数字干预对aMcI患者的训练效果及神经基础,以揭示抑制域相关额顶控制网络在干预中的重要作用。本研究有望从计算认知神经视角阐明抑制是aMcI执行功能缺损和干预的认知新靶点,进而为aMcI早期识别和制定精准化诊疗方案提供循证依据。

关键词：执行功能遗忘型轻度认知障碍认知神经机制数字干预深度学习

An unsupervised learning approach to study synchroneity of past events in the South china Sea

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Frontiers of Earth Science 2019年第3期13卷 628-640页

作者： Kevin c. Tse hon-chim chiu Man-Yin Tsang Yiliang Li Edmund Y. Lam Department of Earth Sciences The University of Hong KongPokfulamHong KongChina Department of Geography and centre for Geo-computation Studies Hong Kong Baptist UniversityKowloon TongHong KongChina Department of Earth Sciences University of TorontoCanada Department of Electrical and Electronic Engineering The University of Hong KongPokfulamHong KongChina

Unsupervised machine learning methods were applied on multivariate geophysical and geochemical datasets of ocean floor sediment cores collected from the South china Sea. The well-preserved and continuous core samples comprising high resolution cenozoic sediment records enable scientists to carry out paleoenvironment studies in detail. Bayesian age-depth chronological models constructed from biostratigraphic control points for the drilling sites are applied on cluster boundaries generated from two popular unsupervised learning methods: K-means and random forest. The unsupervised learning methods experimented have produced compact and unambiguous clusters from the datasets, indicating that previously unknown data patterns can be revealed when all variables from the datasets are taken into account simultaneously. A study of synchroneity of past events represented by the cluster boundaries across geographically separated ocean drilling sites is achieved through converting the fixed depths of cluster boundaries into chronological ranges represented by Gaussian density plots which are then compared with known past events in the region. A Gaussian density peak at around 7.2 Ma has been identified from results of all three sites and it is suggested to coincide with the initiation of the East Asian monsoon. contrary to traditional statistical approach, a priori assumptions are not required for unsupervised learning, and the clustering results serve as a novel data-driven proxy for studying the complex and dynamic processes of the paleoenvironment surrounding the ocean sediment. This work serves as a pioneering approach to extract valuable information of regional events and opens up a systematic and objective way to study the vast global ocean sediment datasets.

关键词： machine learning ocean sediments unsupervised classification

Unsupervised learning on scientific ocean drilling datasets from the South china Sea

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Frontiers of Earth Science 2019年第1期13卷 180-190页

作者： Kevin c.TSE hon-chim cHIU Man-Yin TSANG Yiliang LI Edmund Y.LAM Department of Earth Sciences The University of Hong KongPokfulamHong KongChina Department of Geography and centre for Geo-computation Studies Hong Kong Baptist UniversityKowloon TongHong KongChina Department of Earth Sciences University of TorontoTorontoON M5S 2M8Canada Department of Electrical and Electronic Engineering The University of Hong KongPokfulamHong KongChina

Unsupervised learning methods were applied to explore data patterns in multivariate geophysical datasets collected from ocean floor sediment core samples coming from scientific ocean drilling in the South china *** to studies on similar datasets,but using supervised learning methods which are designed to make predictions based on sample training data,unsupervised learning methods require no a priori information and focus only on the input *** this study,popular unsupervised learning methods including K-means,self-organizing maps,hierarchical clustering and random forest were coupled with different distance metrics to form exploratory data *** resulting data clusters were externally validated with lithologic units and geologic time scales assigned to the datasets by conventional methods. compact and connected data clusters displayed varying degrees of correspondence with existing classification by lithologic units and geologic time scales.K-means and self-organizing maps were observed to perform better with lithologic units while random forest corresponded best with geologic time *** study sets a pioneering example of how unsupervised machine learning methods can be used as an automatic processing tool for the increasingly high volume of scientific ocean drilling data.

关键词： machine learning unsupervised learning ODP IODP clustering

Luminescent cyclometalated iridium(Ⅲ) dipyridoquinoxaline indole complexes as biological probes

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Science china chemistry 2010年第10期53卷 2091-2098页

作者： LO Kenneth Kam-Wing LEUNG Arthur Ho-hon Department of Biology and chemistry City University of Hong Kong

Four luminescent cyclometalated iridium(Ⅲ) dipyridoquinoxaline complexes appended with an indole moiety [Ir(N^c)2(N^N)] (PF6) (HN^c = 2-phenylpyridine, Hppy; N^N = 2-(N-(2-(indole-3-acetamido)ethyl)aminocarbonyl)dipyrido[3,2-f:2′,3′-h]quinox- aline, dpqc2indole (1a), N^N = 2-(N-(6-(indole-3-acetamido)hexyl)aminocarbonyl)dipyrido[3,2-f:2′,3′-h]quinoxaline, dpqc6indole (1b); HN^c = 7,8-benzoquinoline, Hbzq, N^N = dpqc2indole (2a), N^N = dpqc6indole (2b)) have been synthesized and characterized. Upon irradiation, all the complexes displayed moderately intense and long-lived luminescence under ambient condi-tions and in 77 K glass. On the basis of the photophysical data, the emission of the complexes has been assigned to an excited state of triplet metal-to-ligand charge-transfer (3MLcT) ((dπ(Ir)→π*(N^N)) character. cyclic voltammetric studies revealed indole-based and iridium-based oxidations at ca. +1.10 V and +1.24 V vs. ScE, respectively, and ligand-based reductions at ca. -1.07 to-2.29 V vs. ScE. The interactions of the complexes with an indole-binding protein, bovine serum albumin (BSA), have been examined by emission titrations.

关键词： binding indole iridium luminescence probes

TAKOTSUBO SYNDROME WITH TRANSIENT cOMPLETE ATRIOVENTRIcULAR BLOcK

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chinese Medical Journal 2006年第1期119卷 73-76页

作者： LEE wai Luen Stephen MIAO Li-fu cHAN hon Wah Ryamond cHEN Ming-zhe Division of cardiology Department of Medicine Queen Mary Hospital Hong Kong China center of cardiology First Hospital of Tsinghua University Beijing 100016 China

Takotsubo syndrome （transient left ventricular apical ballooning syndrome） is a novel cardiac syndrome of left ventricular apical ballooning involving reversible left ventricular apical ballooning （during systole） of acute onset with chest pain, electrocardiographic changes, and minimal elevation of cardiac enzymes resembling acute myocardial infarction, but without evidence of myocardial ischemia or injury.

关键词： Takotsubo syndrome transient left ventricular apical ballooning syndrome

chronic hepatitis B and metabolic risk factors:A call for rigorous longitudinal studies

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World Journal of Gastroenterology 2019年第3期25卷 282-286页

作者： wai-Kay Seto Department of Medicine the University of Hong Kong Queen Mary Hospital Department of Medicine the University of Hong Kong-Shenzhen Hospital State Key Laboratory for Liver Research the University of Hong Kong

Long-term nucleos(t)ide analogue therapy in chronic hepatitis B virus(HBV)infection is effective in suppressing viral replication and reducing liver-related complications. However, HBV-related liver events can still occur in different patient sub-groups. There is emerging evidence that, similar to chronic hepatitis c virus infection, metabolic risk factors may play a role in the disease process of chronic HBV. While the mechanistic nature of metabolic-HBV interactions remains uncertain, studies in different HBV-infected populations have demonstrated that hepatic steatosis, increased body-mass index, diabetes, or a combination of different metabolic risk factors are associated with an increased risk of hepatocellular carcinoma and cirrhosis. The impact of metabolic risk factors is especially prominent in patients with quiescent virological activity,including on-treatment patients with effective viral suppression. As the proportion of on-treatment chronic HBV patients increases worldwide,longitudinal studies determining the relative risks of different metabolic parameters with respect to clinical outcomes are needed. Future studies should also determine if metabolic-directed interventions can improve disease outcomes in chronic HBV.

关键词： Hepatitis B virus Diabetes Obesity Steatosis Non-alcoholic fatty liver disease Body-mass index

An Uncommon Potentially Fatal complication in a Patient without Predisposing Factor Following Oral Bowel Preparation commonly Used for colonoscopy

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Open Journal of Emergency Medicine 2016年第1期4卷 6-10页

作者： Iris wai Sum Li Ling Pong Leung Sik hon Tsui Queen Mary Hospital Hospital Authority Hong Kong China Emergency Medicine Unit Li Ka Shing Faculty of Medicine The University of Hong Kong Hong Kong China Department of Accident & Emergency Queen Mary Hospital Hospital Authority Hong Kong Special Administrative Region Hong Kong China

We described the case report of a patient presented with no known predisposing factor, generalized malaise with vomiting, locked jaw, perioral paraesthesia, carpopedal spasm and a positive chvostek’s sign which resulted from severe electrolyte disturbance at 5 hours after use of oral sodium phosphate solution (NaPO4) as bowel preparation for colonoscopy. On presentation, she developed hyperphosphatemia and symptomatic hypocalcaemia with serum phosphate of 1.84 mmol/L and adjusted calcium level 1.67 mmol/L respectively. Her symptoms subsided after immediate intravenous calcium gluconate followed by oral calcium supplement. The electrolyte disturbances were normalized with an uneventful clinical course. The potentially fatal complications of sodium phosphate solution which commonly prescribed as bowel preparation for conventional colonoscopy could develop though previously reported as uncommon in patients without predisposing factors, and should not be overlooked. Urgent assessment and immediate correction of electrolyte disturbances are needed. Recommendations on patient selection of use of sodium phosphate to minimize risk of developing adverse events are needed to incorporate in clinical protocols.

关键词： Symptomatic Hypocalcaemia Hyperphosphatemia Sodium Phosphate Solution Bowel

Small Molecule Organic Nanostructures—Fabrication and Properties

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Journal of Materials Science & Technology 2008年第4期24卷 563-568页

作者： A.B.Djurii A.M.c.Ng Kai-Yin cHEUNG Man-Kin FUNG wai-Kin cHAN Department of Physics University of Hong KongPokfulam RoadHong KongHong Kong SARChina Department of chemistry University of Hong KongPokfulam RoadHong KongHong Kong SARChina

Organic materials are of great interest for the development of low cost electronic and optoelectronic devices. Although majority of research on organic materials is concerned with synthesis of novel compounds and organic thin films, organic nanostructures are attracting increasing interest in recent years. We briefly review different growth methods of organic nanostructures, which can be roughly divided into vapor deposition methods and self-assembly techniques in solution. Then we highlight some interesting properties of organic nanostructures, as well as possible applications, includinf field emission, electronic and optoelectronic devices.

关键词： Organic nanostructures Self-assembly Vapor deposition

Responses in gas exchange and water status between drought-tolerant and-susceptible soybean genotypes with ABA application

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The crop Journal 2015年第6期3卷 500-506页

作者： Md.Mokter Hossain hon-Ming Lam Jianhua Zhang School of Life Sciences and center for Soybean Research of the State Key Laboratory of Agrobiotechnology The Chinese University of Hong Kong

The purpose of this study was to investigate the physiological responses of drought-tolerant and drought-susceptible soybean genotypes to exogenous abscisic acid(ABA) application during progressive soil drying at seedling stages. Five-day old soybean seedlings were transplanted into PVc tubes filled with soil mixture. Seedlings were watered daily with similar water volumes until second trifoliate leaves emerged, and thereafter soil drying with or without exogenous ABA application was imposed. Half of the seedlings of each genotype were left for regular watering as control plants. Soil water status declined significantly over seven days of withholding water supply for both genotypes. Leaf expansion rate, stomatal conductance(g_s), leaf water potential(ψ_w), and relative water content of leaves(%RWc) declined significantly under soil drying as well as soil drying with ABA application, compared to their values for well-watered soybean genotypes. However, a drought-tolerant genotype(c12) responded more rapidly than a drought-susceptible genotype(c08) after imposition of soil drying and soil drying with exogenous ABA. In addition, application of exogenous ABA to water-restricted soybeans resulted in higher %RWc and ψwin the drought-tolerant than in the drought-susceptible genotype. compared to the drought-susceptible genotype, the drought-tolerant genotype was more responsive to exogenous ABA application, resulting in a higher root-to-shoot ratio.

关键词： Drought stress Exogenous ABA Leaf relative water content Stomatal conductance Soybean genotypes