Nanyang Technological University

About: Nanyang Technological University is a education organization based out in Singapore, Singapore. It is known for research contribution in the topics: Computer science & Catalysis. The organization has 48003 authors who have published 112815 publications receiving 3294199 citations. The organization is also known as: NTU & Universiti Teknologi Nanyang.

Charge-Convertible Carbon Dots for Imaging-Guided Drug Delivery with Enhanced in Vivo Cancer Therapeutic Efficiency

Abstract: Carbon dots (CDs) are remarkable nanocarriers due to their promising optical and biocompatible capabilities. However, their practical applicability in cancer therapeutics is limited by their insensitive surface properties to complicated tumor microenvironment in vivo. Herein, a tumor extracellular microenvironment-responsive drug nanocarrier based on cisplatin(IV) prodrug-loaded charge-convertible CDs (CDs–Pt(IV)@PEG-(PAH/DMMA)) was developed for imaging-guided drug delivery. An anionic polymer with dimethylmaleic acid (PEG-(PAH/DMMA)) on the fabricated CDs–Pt(IV)@PEG-(PAH/DMMA) could undergo intriguing charge conversion to a cationic polymer in mildly acidic tumor extracellular microenvironment (pH ∼ 6.8), leading to strong electrostatic repulsion and release of positive CDs–Pt(IV). Importantly, positively charged nanocarrier displays high affinity to negatively charged cancer cell membrane, which results in enhanced internalization and effective activation of cisplatin(IV) prodrug in the reductive cytos...

Graphene‐Based Electrochemical Sensors

Abstract: Graphene, one kind of emerging carbon nanomaterial, has attracted increasing attention recently. Due to its fascinating physical and electrochemical properties, graphene as a promising electrode material has been widely used in electrochemical sensing applications. In this review, different approaches for the fabrication of graphene and the preparation of graphene-modified electrodes for electrochemical sensors are introduced. Moreover, recent research results on different graphene-based materials as an electrochemical platform for the detection of various biomolecules and chemicals are reviewed and compared. More electrochemical studies on this novel material should show up in the near future.

Language Learning Strategy Use of Bilingual Foreign Language Learners in Singapore

Abstract: This study, using Oxford's 80-item Strategy Inventory for Language Learning (SILL), examines the self-reported language learning strategy use of 678 university students learning Japanese and French as foreign languages in Singapore. The study differs from previous SILL studies in that the participants were bilingual from a multicultural setting, and the use of all 80 strategies was examined. Relationships between background variables and overall strategyuse were investigated using ANOVA. Results were significant for motivation, self-rated proficiency, and language studied, with motivation significantly interacting with language studied. The use of each strategy by proficiency and also by gender was investigated using chi-square. Results showed more learning strategy use among learners with higher proficiency and, unexpectedly, more strategies used significantly more often by men.

Influence maximization: near-optimal time complexity meets practical efficiency

Abstract: Given a social network G and a constant $k$, the influence maximization problem asks for k nodes in G that (directly and indirectly) influence the largest number of nodes under a pre-defined diffusion model. This problem finds important applications in viral marketing, and has been extensively studied in the literature. Existing algorithms for influence maximization, however, either trade approximation guarantees for practical efficiency, or vice versa. In particular, among the algorithms that achieve constant factor approximations under the prominent independent cascade (IC) model or linear threshold (LT) model, none can handle a million-node graph without incurring prohibitive overheads. This paper presents TIM, an algorithm that aims to bridge the theory and practice in influence maximization. On the theory side, we show that TIM runs in O((k+ l) (n+m) log n/e2) expected time and returns a (1-1/e-e)-approximate solution with at least 1 - n-l probability. The time complexity of TIM is near-optimal under the IC model, as it is only a log n factor larger than the Ω(m + n) lower-bound established in previous work (for fixed k, l, and e). Moreover, TIM supports the triggering model, which is a general diffusion model that includes both IC and LT as special cases. On the practice side, TIM incorporates novel heuristics that significantly improve its empirical efficiency without compromising its asymptotic performance. We experimentally evaluate TIM with the largest datasets ever tested in the literature, and show that it outperforms the state-of-the-art solutions (with approximation guarantees) by up to four orders of magnitude in terms of running time. In particular, when k = 50, e = 0.2, and l = 1, TIM requires less than one hour on a commodity machine to process a network with 41.6 million nodes and 1.4 billion edges. This demonstrates that influence maximization algorithms can be made practical while still offering strong theoretical guarantees.

Developing measures of airport productivity and performance: an application of data envelopment analysis

Abstract: Many studies have investigated the financial results and economic productivity of airlines but few have investigated the productivity or performance of airports, and how changes in the industry may have affected them. Most airports measure performance strictly in accounting terms by looking at only total costs and revenues and the resulting surpluses or deficits. Few utilize any type of productivity measure or performance indicator. This paper applies Data Envelopment Analysis to assess the performance of airports. It is used to construct performance indices on the basis of the multiple outputs which airports produce and the multiple inputs which they utilize. In particular we develop productivity measures for terminals and airside operations. The performance measures are then used in a second stage Tobit regression in which environmental, structural and managerial variables are included. The regression results provide a ‘net’ performance index and also identify which variables the managers have some control over and what the relative importance of each variable is in affecting performance. The data set contains a panel of 21 U.S. airports over a five-year period.