Showing papers by "Hong Kong Polytechnic University published in 2002"

Targeted Drug Delivery via the Transferrin Receptor-Mediated Endocytosis Pathway

Abstract: The membrane transferrin receptor-mediated endocytosis or internalization of the complex of transferrin bound iron and the transferrin receptor is the major route of cellular iron uptake. This efficient cellular uptake pathway has been exploited for the site-specific delivery not only of anticancer drugs and proteins, but also of therapeutic genes into proliferating malignant cells that overexpress the transferrin receptors. This is achieved either chemically by conjugation of transferrin with therapeutic drugs, proteins, or genetically by infusion of therapeutic peptides or proteins into the structure of transferrin. The resulting conjugates significantly improve the cytotoxicity and selectivity of the drugs. The coupling of DNA to transferrin via a polycation or liposome serves as a potential alternative to viral vector for gene therapy. Moreover, the OX26 monoclonal antibody against the rat transferrin receptor offers great promise in the delivery of therapeutic agents across the blood-brain barrier to the brain.

The revolutionary creation of new advanced materials - Carbon nanotube composites

Abstract: Since the discovery of carbon nanotubes at the beginning of the last decade, extensive research related to the nanotubes in the fields of chemistry, physics, materials science and engineering, and electrical and electronic engineering has been found increasingly. The nanotubes, having an extreme small physical size (diameter ≈1 nm) and many unique mechanical and electrical properties depending on its hexagonal lattice arrangement and chiral vector have been appreciated as ideal fibres for nanocomposite structures. It has been reported that the nanotubes own a remarkable mechanical properties with theoretical Young's modulus and tensile strength as high as 1 TPa and 200 GPa, respectively. Since the nanotubes are highly chemical insert and able to sustain a high strain (10–30%) without breakage, it could be foreseen that nanotube-related structures could be designed for nanoinstrument to create ultra-small electronic circuits and used as strong, light and high toughness fibres for nanocomposite structures. In this paper, recent researches and applications on carbon nanotubes and nanotube composites are reviewed. The interfacial bonding properties, mechanical performance and reliability of nanotube/polymer composites will be discussed.

Investigating the Relationship Between Vocabulary Knowledge and Academic Reading Performance: An Assessment Perspective

Abstract: The present study was conducted in the context of Test of English as a Foreign Language (TOEFL) 2000 research to conceptually validate the roles of breadth and depth of vocabulary knowledge in reading comprehension in academic settings and to empirically evaluate a test measuring three elements of the depth dimension of vocabulary knowledge, namely, synonymy, polysemy, and collocation. A vocabulary size measure and a TOEFL vocabulary measure were also tested. The study found that the dimension of vocabulary depth is as important as that of vocabulary size in predicting performance on academic reading and that scores on the three vocabulary measures tested are similarly useful in predicting performance on the reading comprehension measure used as the criterion. The study confirms the importance of the vocabulary factor in reading assessment.

Cultural Tourism: The Partnership Between Tourism and Cultural Heritage Management

Abstract: Contents * Preface * Acknowledgments * Chapter 1. Introduction * Defining Cultural Tourism * Conceptualizing Cultural Tourism--A Thematic Approach * The Key Issue: Linking Cultural Heritage Management and Tourism Management * Chapter 2. Challenges in Achieving Sustainable Cultural Tourism * Introduction * Culture and Tourism--Collaborators or Competitors? * The Independent Evolution of Tourism and Cultural Heritage * Seven Possible Relationships Between Tourism and Cultural Heritage Management * The Consequences * The Solution? * Chapter 3. How Tourism Works * Introduction * The Nature of Tourism * Attractions Drive Tourism * Factors Influencing Visitation Levels * Tourist Behavior * Cultural Tourism * Conclusion * Chapter 4. Cultural Heritage Management * Introduction * Core Concepts * Cultural Heritage Management and Tourism * Negative and Positive Impacts of Tourism * Conclusion * Chapter 5. Tangible Heritage * Introduction * Process-Driven Conservation of Tangible Cultural Heritage * The Scope of Tangible Heritage Assets * Cultural Significance of Heritage Assets * Authenticity * Tourism, Authenticity, and Commodification * Visitor Accessibility to Tangible Heritage Assets * Consultation As an Important Element of the Management Process * Chapter 6. Intangible Heritage and Its Management * Introduction * Recognition of Intangible Cultural Heritage Management * Intangible Heritage Assets--Management and Tourism Issues * Authenticity and Cultural Space * Tourism and Changes to Intangible Heritage * Culturally Appropriate and Sustainable Use of Assets * Stakeholder Consultation in Setting Management Priorities * Chapter 7. Cultural Tourism Products--A Regional Perspective * Introduction * Products * Benefits of Adopting a Marketing Approach to Product Development * Hierarchy of Attractions * Developing Cultural Tourism Attractions * Conclusions * Chapter 8. Commodification, Environmental Bubbles, and Cultural Tourism Products * Introduction * Consumption--Strangeness versus Familiarity and the Environmental Bubble * Creating Cultural Tourism Products or Attractions * Tactics * Conclusions * Chapter 9. The Cultural Tourism Market: A Cultural Tourism Typology * Introduction * Who Are Cultural Tourists? * A Typology of Cultural Tourists: Recognizing Different Shades of Cultural Tourists * Five Types of Cultural Tourists * Testing the Model: Hong Kong As a Case Study * Implications for Cultural Tourism * Chapter 10. Gatekeepers * Introduction * Using Cultural and Heritage Assets to Brand a Destination * The Role of Gatekeepers in Conveying Messages * Effect of Many Gatekeepers on the Message Passed to the Tourist * Chapter 11. Assessment * Introduction * Assessing the Tourism Potential of Assets * Considering the Wider Context * Understanding the Asset in Its Setting * Asset Specific Issues: "Place" and Cultural Spaces * Stakeholder and Consultation Issues * People, Skills, and Financial Resources * Conclusions * Chapter 12. Asset Auditing and Planning * Introduction * An Audit Model * An Audit Procedure * Testing the Procedure--Hong Kong * Planning * Chapter 13. Marketing * Introduction * Marketing As a Management Tool * Unique Features of Marketing in Cultural Tourism * Thinking Strategically * Sustainable Competitive Advantages * Role of Research * Putting It Together--The Marketing Plan * The Four Ps--The Marketing Mix * Conclusions * Chapter 14. Presentation and Management of Heritage Assets * Introduction * Reinvestment of Revenue in Conservation As One Benefit of Tourism * Fees and Levies Raised at the Source * Epilogue * References * Index

Stock market linkages: Evidence from Latin America

Abstract: This study investigates the dynamic interdependence of the major stock markets in Latin America. Using data from 1995 to 2000, we examine the stock market indexes of Argentina, Brazil, Chile, Colombia, Mexico and Venezuela. The index level series are non-stationary and so we employ cointegration analysis and error correction vector autoregressions (VAR) techniques to model the interdependencies. We find that there is one cointegrating vector which appears to explain the dependencies in prices. The results are robust to sensitivity tests based on translating indexes to US dollars (i.e., a common currency for all the markets) and to partitioning the sample into periods before and after the Asian and Russian financial crises of 1997 and 1998, respectively. Our results suggest that the potential for diversifying risk by investing in different Latin American markets is limited.

The Determination of Capital Structure: Is National Culture a Missing Piece to the Puzzle?

Abstract: Why does knowing the nationality of the company help predict its financial leverage? Differences in institutional backgrounds provide only a partial answer to this question. This study suggests that national culture affects corporate capital structures. Empirical hypotheses, drawn from financial models and cross-cultural psychology, are tested against a sample of 5591 firms across 22 countries. Results show that countries with high scores on the cultural dimensions of “conservatism” and “mastery” tend to have lower corporate debt ratios. The effects are strong and remain significant even after accounting for differences in economic performance, legal systems, financial institutions, and some other well-known determinants of debt ratios.

Strategic dimensions of maintenance management

Abstract: The contemporary business environment has raised the strategic importance of the maintenance function in organizations which have significant investment in physical assets. Four strategic dimensions of maintenance management are identified, namely service‐delivery options, organization and work structuring, maintenance methodology and support systems. The alternatives available are reviewed: the guidelines for selection of these alternatives, the key decision areas in each of the four dimensions, as well as the critical success factors for the transformation process are discussed. The two factors that permeate in these strategic dimensions are human factors and information flow; the latter can be made more efficient by embracing the e‐maintenance model.

Towards a classification of cultural tourists

Abstract: This paper proposes a model to segment the cultural tourism market according to two dimensions: (i) the importance of cultural motives in the decision to visit a destination and (ii) depth of experience. The model is tested empirically using Hong Kong as a case study. The test identified five discrete cultural tourism market segments that exhibited substantially different behaviour. Copyright © 2002 John Wiley & Sons, Ltd.

Framework of Success Criteria for Design/Build Projects

Abstract: Success has always been the ultimate goal of every activity, and a construction project is no exception. Due to the ambiguous definition of project success and the different perceptions of participants toward this concept, it may be difficult to tell whether a project is successful as there is a lack of consensus. Time, cost, and quality have long been the success criteria used to evaluate the performance of a construction project. However, such a list has been criticized as not being comprehensive. Even studies of the project success of a particular construction method, such as the design/build procurement system, are lacking in most previous research considering construction projects in general. This paper sets out to establish criteria for project success for a design/build project in construction, first by identifying relevant measures of project success for a construction project in past studies, with particular emphasis on design/build projects, and then by establishing a comprehensive assessment fr...

How Does Government Ownership Affect Firm Performance? Evidence from China’s Privatization Experience

Abstract: The effect of government ownership on firm performance remains a controversial issue, especially in a transitional economy like China. Government ownership is typically viewed as adversely affecting firm performance. This study of that of Mainland China’s privatization experience indicates the opposite. No matter whether it is in the form of state ownership or legal person ownership, government ownership has a positive impact on partially privatized state-owned enterprises. However, this relationship is nonlinear and shows an inverted U-shape. Given the situation of highly indebted, non-performing state-owned enterprises, we argue that too much government control is indeed bad for enterprises. But too little government ownership may not be good either. It might mean a lack of the government’s political support and business connections, which are valuable and necessary to vitalize performance.

Measures for evaluating supply chain performance in transport logistics

Abstract: This study aims to investigate the construct of, and develop a measurement instrument for, supply chain performance (SCP) in transport logistics. Based on the supply chain operations reference model and various established measures, a measurement model and a measurement instrument for SCP in transport logistics are developed. A 26-item SCP measurement instrument was constructed, reflecting service effectiveness for shippers, operations efficiency for transport logistics service providers, and service effectiveness for consignees. The empirical findings suggest that the measurement instrument is reliable and valid for evaluating SCP in transport logistics.

A fuzzy ahp approach to the determination of importance weights of customer requirements in quality function deployment

Abstract: Quality function deployment (QFD) is an important tool in product planning that could contribute to increase in customer satisfaction and shorten product design and development time During the QFD process, determination of the importance weights of customer requirements is a crucial and essential step The analytic hierarchy process (AHP) has been used in weighting the importance However, due to the vagueness and uncertainty existing in the importance attributed to judgement of customer requirements, the crisp pairwise comparison in the conventional AHP seems to be insufficient and imprecise to capture the degree of importance of customer requirements In this paper, fuzzy number is introduced in the pairwise comparison of AHP An AHP based on fuzzy scales is proposed to determine the importance weights of customer requirements The new approach can improve the imprecise ranking of customer requirements which is based on the conventional AHP Finally, an example of bicycle splashguard design is used to illustrate the proposed approach

Transferrin/transferrin receptor‐mediated drug delivery

Abstract: Since transferrin was discovered more than half a century ago, a considerable effort has been made towards understanding tranferrin-mediated iron uptake. However, it was not until recently with the identification and characterization of several new genes related to iron homeostasis, such as the hemochromatosis protein HFE and the iron transporter DMT1, that our knowledge has been advanced dramatically. A major pathway for cellular iron uptake is through internalization of the complex of iron-bound transferrin and the transferrin receptor, which is negatively modulated by HFE, a protein related to hereditary hemochromatosis. Iron is released from transferrin as the result of the acidic pH in endosome and then is transported to the cytosol by DMT1. The iron is then utilized as a cofactor by heme and ribonucleotide reductase or stored in ferritin. Apart from iron, many other metal ions of therapeutic and diagnostic interests can also bind to transferrin at the iron sites and their transferrin complexes can be recognized by many cells. Therefore, transferrin has been thought as a "delivery system" for many beneficial and harmful metal ions into the cells. Transferrin has also be widely applied as a targeting ligand in the active targeting of anticancer agents, proteins, and genes to primary proliferating malignant cells that overexpress transferrin receptors. This is achieved by conjugation of transferrin with drugs, proteins, hybride systems with marcomolecules and as liposomal-coated systems. Conjugates of anticancer drugs with transferrin can significantly improve the selectivity and toxicity and overcome drug resistance, thereby leading to a better treatment. The coupling of DNA to transferrin via a polycation such as polylysine or via cationic liposomes can target and transfer of the extrogenous DNA particularly into proliferating cells through receptor-mediated endocytosis. These kinds of non-viral vectors are potential alternatives to viral vectors for gene therapy, if the transfection efficiency can be improved. Moreover, transferrin receptors have shown potentials in delivery of therapeutic drugs or genes into the brain across blood-brain barrier.

The dynamic relationship between stock returns and trading volume: Domestic and cross-country evidence

Abstract: This paper examines the dynamic relations – causal relations and the sign and magnitude of dynamic effects – between stock market trading volume and returns (and volatility) for both domestic and cross-country markets by using the daily data of the three largest stock markets: New York, Tokyo, and London. Major findings are as follows: First, trading volume does not Granger-cause stock market returns on each of three stock markets. Second, there exists a positive feedback relationship between trading volume and return volatility in all three markets. Third, regarding the cross-country relationships, US financial market variables, in particular US trading volume, contains an extensive predictive power for UK and Japanese financial market variables. Fourth, sub-sample analyses show evidence of stronger spillover effects after the 1987 market crash and an increased importance of trading volume as an information variable after the introduction of options in the US and Japan.

Lead phytoextraction from contaminated soil with high-biomass plant species.

Abstract: In this study, cabbage [Brassica rapa L. subsp. chinensis (L.) Hanelt cv. Xinza No 1], mung bean [Vigna radiata (L.) R. Wilczek var. radiata cv. VC-3762], and wheat (Triticum aestivum L. cv. Altas 66) were grown in Pb-contaminated soils. Application of ethylenediaminetetraacetic acid (EDTA) (3.0 mmol of EDTA/kg soil) to the soil significantly increased the concentrations of Pb in the shoots and roots of all the plants. Lead concentrations in the cabbage shoots reached 5010 and 4620 mg/kg dry matter on Days 7 and 14 after EDTA application, respectively. EDTA was the best in solubilizing soil-bound Pb and enhancing Pb accumulation in the cabbage shoots among various chelates (EDTA, diethylenetriaminepentaacetic acid [DTPA], hydroxyethylenediaminetriacetic acid [HEDTA], nitrilotriacetic acid [NTA], and citric acid). Results of the sequential chemical extraction of soil samples showed that the Pb concentrations in the carbonate-specifically adsorbed and Fe-Mn oxide phases were significantly decreased after EDTA treatment. The results indicated that EDTA solubilized Pb mainly from these two phases in the soil. The relative efficiency of EDTA enhancing Pb accumulation in shoots (defined as the ratio of shoot Pb concentration to EDTA concentration applied) was highest when 1.5 or 3.0 mmol EDTA/kg soil was used. Application of EDTA in three separate doses was most effective in enhancing the accumulation of Pb in cabbage shoots and decreased mobility of Pb in soil compared with one- and two-dose application methods. This approach could help to minimize the amount of chelate applied in the field and to reduce the potential risk of soluble Pb movement into ground water.

Total antioxidant and ascorbic acid content of fresh fruits and vegetables: implications for dietary planning and food preservation.

Abstract: Epidemiological evidence links high intake of ascorbic acid (AA) and other antioxidant micronutrients to health promotion. It would be useful to know the overall, or 'total' antioxidant capacity of foods, to establish the contribution of AA to this, and to assess how this information may translate into dietary intakes to meet the new US daily reference intake for AA. In this study, the total antioxidant capacity, as the ferric reducing-antioxidant power (FRAP) value, and AA content of thirty-four types of fruits and vegetables were measured using a modified version of the FRAP assay, known as FRASC. This measures AA (reduced form only) simultaneously with the FRAP value. Results covered a wide range: 880-15940 micromol/kg fresh wet weight and <20-540 mg/kg fresh wet weight respectively, for FRAP and AA, which comprised < 1-73 % and < 1-59 % total antioxidant capacity of fruits and vegetables respectively. We estimate that 100 mg AA is contained in one orange, a few strawberries, one kiwi fruit, 1-2 slices of pineapple, several florets of raw cauliflower or a handful of uncooked spinach leaves. Apples, bananas, pears and plums, the most commonly consumed fruits in the UK, contain very little AA. Results indicate also that the antioxidant capacity of vegetables decreases rapidly and significantly after fragmentation. Results of this, and future studies, using FRASC as a biomonitoring tool will be useful in food production, preparation, preservation, and aid dietary choices to increase antioxidant and AA intake. Furthermore, FRASC will facilitate bioavailability studies of antioxidants from different foods of known antioxidant capacity and AA content.