University of Macau

About: University of Macau is a education organization based out in Macao, Macau, China. It is known for research contribution in the topics: Computer science & Population. The organization has 6636 authors who have published 18324 publications receiving 327384 citations. The organization is also known as: UM & UMAC.

Two natural glucomannan polymers, from Konjac and Bletilla, as bioactive materials for pharmaceutical applications

Abstract: Next-generation biomaterials are expected to possess both desirable mechanical features and unique biological functions. Recently, two plant-derived glucomannans (GMs)—Konjac glucomannan (KGM) and the polysaccharide of Bletilla striata (BSP)—have emerged as new sources for development of biomaterials. They have been fabricated into drug delivery vehicles and wound healing dressings in varying shapes and sizes, and demonstrated strong gelling properties, high biocompatibility and remarkable convenience for processing and modification. Notably, they demonstrate bioactivities such as response to enzymes produced in special biological niches and/or affinity for carbohydrate receptors on specific cells. All these mechanical and biological advantages suggest these two GMs have great potential for future development and broader application in various biomedical and pharmaceutical fields.

A Novel En-Route Filtering Scheme Against False Data Injection Attacks in Cyber-Physical Networked Systems

Abstract: In Cyber-Physical Networked Systems (CPNS), the adversary can inject false measurements into the controller through compromised sensor nodes, which not only threaten the security of the system, but also consume network resources. To deal with this issue, a number of en-route filtering schemes have been designed for wireless sensor networks. However, these schemes either lack resilience to the number of compromised nodes or depend on the statically configured routes and node localization, which are not suitable for CPNS. In this paper, we propose a Polynomial-based Compromise-Resilient En-route Filtering scheme (PCREF), which can filter false injected data effectively and achieve a high resilience to the number of compromised nodes without relying on static routes and node localization. PCREF adopts polynomials instead of Message Authentication Codes (MACs) for endorsing measurement reports to achieve resilience to attacks. Each node stores two types of polynomials: authentication polynomial and check polynomial, derived from the primitive polynomial, and used for endorsing and verifying the measurement reports. Through extensive theoretical analysis and experiments, our data shows that PCREF achieves better filtering capacity and resilience to the large number of compromised nodes in comparison to the existing schemes.

A reciprocal relationship between reactive oxygen species and mitochondrial dynamics in neurodegeneration.

Abstract: Mitochondrial fragmentation due to fission/fusion imbalance has often been linked to mitochondrial dysfunction and apoptosis in neurodegeneration. Conventionally, it is believed that once mitochondrial morphology shifts away from its physiological tubular form, mitochondria become defective and downstream apoptotic signaling pathways are triggered. However, our study shows that beta-amyloid (Aβ) induces morphological changes in mitochondria where they become granular-shaped and are distinct from fragmented mitochondria in terms of both morphology and functions. Accumulation of mitochondrial reactive oxygen species triggers granular mitochondria formation, while mitoTEMPO (a mitochondria-targeted superoxide scavenger) restores tubular mitochondrial morphology within Aβ-treated neurons. Interestingly, modulations of mitochondria fission and fusion by genetic and pharmacological tools attenuated not only the induction of granular mitochondria, but also mitochondrial superoxide levels in Aβ-treated neurons. Our study shows a reciprocal relationship between mitochondrial dynamics and reactive oxygen species and provides a new potential therapeutic target at early stages of neurodegenerative disease pathogenesis.

Outage Performance Analysis for the Advanced SIC Receiver in Wireless NOMA Systems

Abstract: In this correspondence, an uplink nonorthogonal multiple access (NOMA) system where the base station (BS) trends to decode the independent information of users occupying the same radio resource simultaneously is considered. Different from the traditional successive interference cancellation (SIC) decoding scheme where the later decoding can only be processed after the successful decoding of the previous users, an advanced SIC decoding strategy is proposed to achieve outage balancing for the later decoded users. Under the proposed SIC decoding mechanism, the BS regards the unsuccessfully decoded users’ information as the interference on the following users, i.e., even the outage occurs for any of the previous decoded users, the BS will still try to decode the following users’ information. The outage performance with the new decoding strategy is theoretically analyzed. The closed-form expressions of the outage probability for each user are derived for an uplink 2-user NOMA system. The accuracy of the theoretical results is verified by the simulations.