Kuala Lumpur, Malaysia
Kuala Lumpur, Malaysia

The University of Malaya is a public research university located in Kuala Lumpur, Malaysia. It is the oldest and most esteemed university in Malaysia. The university's name was abbreviated as Malaya during the pre-independence period.The university was founded in 1949 as a public-funded tertiary institution. Today, it has more than 2,500 faculty members. In 2012, UM was granted autonomy status by the Ministry of Higher Education.In 2014, the QS World University Rankings has ranked UM at the 151st place of the world. Wikipedia.

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Huang N.M.,University of Malaya
International journal of nanomedicine | Year: 2011

Graphene has attracted much attention from researchers due to its interesting mechanical, electrochemical, and electronic properties. It has many potential applications such as polymer filler, sensor, energy conversion, and energy storage devices. Graphene-based nanocomposites are under an intense spotlight amongst researchers. A large amount of graphene is required for preparation of such samples. Lately, graphene-based materials have been the target for fundamental life science investigations. Despite graphene being a much sought-after raw material, the drawbacks in the preparation of graphene are that it is a challenge amongst researchers to produce this material in a scalable quantity and that there is a concern about its safety. Thus, a simple and efficient method for the preparation of graphene oxide (GO) is greatly desired to address these problems. In this work, one-pot chemical oxidation of graphite was carried out at room temperature for the preparation of large-area GO with ~100% conversion. This high-conversion preparation of large-area GO was achieved using a simplified Hummer's method from large graphite flakes (an average flake size of 500 μm). It was found that a high degree of oxidation of graphite could be realized by stirring graphite in a mixture of acids and potassium permanganate, resulting in GO with large lateral dimension and area, which could reach up to 120 μm and ~8000 μm(2), respectively. The simplified Hummer's method provides a facile approach for the preparation of large-area GO.

Photodynamic therapy (PDT) has emerged as a capable therapeutic modality for the treatment of cancer. PDT is a targeted cancer therapy that reportedly leads to tumor cell apoptosis and/or necrosis by facilitating the secretion of certain pro-inflammatory cytokines and expression of multiple apoptotic mediators in the tumor microenvironment. In addition, PDT also triggers oxidative stress that directs tumor cell killing and activation of inflammatory responses. However, the cellular and molecular mechanisms underlying the role of PDT in facilitating tumor cell apoptosis remain ambiguous. Here, we investigated the ability of PDT in association with hypericin (HY) to induce tumor cell apoptosis by facilitating the induction of reactive oxygen species (ROS) and secretion of Th1/Th2/Th17 cytokines in human hepatocellular liver carcinoma cell line (HepG2) cells. To discover if any apoptotic mediators were implicated in the enhancement of cell death of HY-PDT-treated tumor cells, selected gene profiling in response to HY-PDT treatment was implemented. Experimental results showed that interleukin (IL)-6 was significantly increased in all HY-PDT-treated cells, especially in 1 μg/ml HY-PDT, resulting in cell death. In addition, quantitative real-time PCR analysis revealed that the expression of apoptotic genes, such as BH3-interacting-domain death agonist (BID), cytochrome complex (CYT-C) and caspases (CASP3, 6, 7, 8 and 9) was remarkably higher in HY-PDT-treated HepG2 cells than the untreated HepG2 cells, entailing that tumor destruction of immune-mediated cell death occurs only in PDT-treated tumor cells. Hence, we showed that HY-PDT treatment induces apoptosis in HepG2 cells by facilitating cytotoxic ROS, and potentially recruits IL-6 and apoptosis mediators, providing additional hints for the existence of alternative mechanisms of anti-tumor immunity in hepatocellular carcinoma, which contribute to long-term suppression of tumor growth following PDT.

Saidur R.,University of Malaya
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2010

Chillers consume a major share of total air conditioning energy use in commercial and industrial buildings for space conditioning to get thermal comfort for a country. In this paper, energy consumption by chillers has been estimated using data collected by walkthrough energy audit for Malaysian office buildings. It has been found that chillers use about 42,285MWh and 84,569MWh of electric energy for 50% and 100% loadings in an institutional buildings. As chillers are major energy users, energy savings measure such as use of energy efficient chillers and VSDs in chillers cooling load reductions have been applied to reduce their energy consumptions. It has been found that 90MWh-896MWh of energy can be saved for using energy efficient chillers for different percentage of loadings. Along with energy savings, US$57,314 as a bill savings can be achieved for high efficient chillers for 50% chillers loading. Study found that 35,975 MWh energy and US$2,302,431 bill can be saved for 60% of speed reductions using VSD. It was also found that payback periods for this energy saving option for chillers are economically viable. Along with energy savings, emission reductions and cost of avoided carbon associated with energy savings have been estimated and presented in this paper. © Sila Science.

A bibliographic review of the crystallographic literature has been conducted on gold(I) compounds bearing functional groups capable of forming conventional hydrogen bonding interactions, namely, primary amide, secondary amide and carboxylic acid. The clear majority of structures featured hydrogen bonding interactions leading to well defined zero- or one-dimensional supramolecular architectures; rarely were two-dimensional architectures formed. Conversely, aurophilic, Au⋯Au, were the exception rather than the rule. This observation is correlated with steric hindrance: small atoms associated via directional hydrogen bonding compared with encumbered gold-atom environments (due to bulky ligands). Amide-{⋯HNCO}2 and carboxylic acid-{⋯HOCO}2 synthons featured in significantly more of the gold(I) structures compared with all-organic systems, particularly for non-ionic structures where charged-assisted hydrogen bonding precluded the formation of these cyclic synthons. This suggests a crystal engineering strategy of functionalising metal complexes with hydrogen bonding potential to improve opportunities of rational design of crystal structures. © 2014.

Furuoka F.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2016

This paper examined the relationship between natural gas consumption and economic development in two largest natural gas consumers in Asia, namely, China and Japan for the period of 1980-2012. It used the autoregressive distributed lags (ARDL) method for the empirical analysis. The findings revealed some similarities in the natural gas consumption and economic development nexus in China and Japan. Thus, a cointegration relationship between natural gas consumption and economic development was found to exist both in China and Japan. However, there was an important difference in the findings. In the case of China, the findings indicated the existence of a unidirectional causality from natural gas consumption to economic development, which was in line with the growth hypothesis. In Japan, there was a bidirectional causality between natural gas consumption and economic development, which supported the feedback hypothesis. © 2015 Elsevier Ltd.

Tiekink E.R.T.,University of Malaya
Chemical Communications | Year: 2014

In this Viewpoint, the impact of the paper published by Gautam R. Desiraju and Angelo Gavezzotti (J. Chem. Soc., Chem. Commun., 1989, 621) upon the development of Crystal Engineering, now recognised a key discipline in contemporary chemical/pharmaceutical/materials science, is discussed. © 2014 the Partner Organisations.

Tiekink E.R.T.,University of Malaya
Dalton Transactions | Year: 2012

Despite being disparaged for their malodorous and toxic demeanour, compounds of selenium, a bio-essential element, and tellurium, offer possibilities as therapeutic agents. Herein, their potential use as drugs, for example, as anti-viral, anti-microbial, anti-inflammatory agents, etc., will be surveyed along with a summary of the established biological functions of selenium. The natural biological functions of tellurium remain to be discovered. © 2012 The Royal Society of Chemistry.

Saidur R.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2010

The industrial sector is the largest users of energy around the world. Industrial motor uses a major fraction of total industrial energy uses. This paper describes a comprehensive literature review about electric motor energy analysis. This paper compiles latest literatures in terms of thesis (MS and PhD), journal articles, conference proceedings, web materials, reports, books, handbooks on electrical motor energy use, losses, efficiency, energy savings strategies. Different types of losses that occur in a motor have been identified and ways to overcome these losses explained. An energy audit that helps to identify motor energy wastages have been discussed extensively. As motors are the major energy users, different energy savings strategies such as use of high-efficient motor, variable speed drive (VSD), and capacitor bank to improve the power factor to reduce their energy uses have reviewed. Different policy measures (i.e. regulatory, voluntary and incentives based) to save motor energy use have been reviewed and presented in this paper. In this review, computer tools that can be used to analyze electric motors energy used has been discussed. Cost parameters to carry out economic analysis have been shown as well. Moreover, payback period for different energy savings strategies have been identified. © 2009 Elsevier Ltd. All rights reserved.

The present invention disclosed a method to produce a slow release lipid nanoparticles comprising steps of determining a log P value of an active ingredient; mixing fatty acid, non-ionic surfactant and the active ingredient to form a mixture; melting the mixture; homogenizing the mixture to form a nanoemulsion; sonicating the homogenized nanoemulsion; and pouring the nanoemulsion into cold water to form the liquid nanoparticles. The lipid nanoparticles with active ingredient and the selected log P value has a prolong release property. In specific embodiment, the active ingredients are the chemical compound with the log P value selected from the range 0 to 4.0.

University of Malaya | Date: 2015-09-15

The present invention relates to a composition having antiviral activity for prophylaxis or treatment of flavivirus infection or a disease resulting therefrom in humans or animals, characterised in that the composition comprises quercetin, or analogues, or derivatives thereof. The composition may further comprise a pharmaceutically acceptable carrier. The antiviral activity may include inhibition of virus attachment to host cells and inhibition of intracellular virus replication. The flavivirus may comprise dengue virus type-1, dengue virus type-2, dengue virus type-3, and dengue virus type-4.

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