Biofilm is a microbial community that attaches to a surface and is enclosed in extracellular polymeric substance (EPS) matrix. Formation of biofilm often develops resistance towards a wide spectrum of antimicrobial agents. Since the biofilm-mediated diseases are commonly difficult to treat, there is need to find new anti-biofilm agent. The studies on anti-biofilm activities of plant species have received a great deal of attention over the last few decades. In Malaysia, plant species have been used as alternatives to the conventional antimicrobial therapy. Several Malaysian plant species are known to control biofilm infection by inhibition of quorum sensing pathway, disruption of EPS matrix, alteration of cell permeability and reduction in cell surface hydrophobicity. This review demonstrates that Malaysian plant species may become excellent therapeutic agents in combating the biofilm infection.
Cell- based targeted delivery is recently gain attention as a promising platform for delivery of anticancer drug in selective and efficient manner. As a new biotechnology platform, bacterial ghosts (BGs) have novel biomedical application as targeted drug delivery system (TDDS). In the current work, Salmonellas' BGs was utilized for the first time as hepatocellular cancer (HCC) in-vitro targeted delivery system. Successful BGs loading and accurate analysis of doxorubicin (DOX) were necessary steps for testing the applicability of DOX loaded BGs in targeting the liver cancer cells. Loading capacity was maximized to reach 27.5 µg/mg (27.5% encapsulation efficiency), by incubation of 10 mg BGs with 1 mg DOX at pH 9 in constant temperature (25 °C) for 10 min. In-vitro release study of DOX loaded BGs showed a sustained release (182 h) obeying Higuchi sustained kinetic release model. The death rate (tested by MTT assay) of HepG2 reached to 64.5% by using of 4 μg/ml, while it was about 51% using the same concentration of the free DOX (P value
To examine the changes in the short-term auditory memory following the use of frequency-modulated (FM) system in children with suspected auditory processing disorders (APDs), and also to compare the advantages of bilateral over unilateral FM fitting.
This study involves the adoption of the Geographic Information System (GIS) modeling approach to determine the quickest routes for fresh vegetable delivery. During transport, fresh vegetables mainly deteriorate on account of temperature and delivery time. Nonetheless, little attention has been directed to transportation issues in most areas within Kuala Lumpur. In addition, perishable food normally has a short shelf life, thus timely delivery significantly affects delivery costs. Therefore, selecting efficient routes would consequently reduce the total transportation costs. The regression model is applied in this study to determine the parameters that affect route selection with respect to the fastest delivery of fresh vegetables. For the purpose of this research, ArcGIS software with network analyst extension is adopted to solve the problem of complex networks. The final output of this research is a map of quickest routes with the best delivery times based on all variables. The variables tested from regression analysis are the most effective parameters to make the flow of road networks slower. The objective is to improve the delivery services by achieving the least drive time. The main findings of this research are that Land use such as residential area and population as variables are the effective parameters on drive time.
Biodiesel, one of the renewable energy sources has gained attention for decades as the alternative fuel due to its remarkable properties. However, there are several drawbacks from the industrial production of biodiesel such as the spike in the production cost, environmental issues related to the usage of homogeneous catalyst and profitability in long term. One of the solutions to eliminate the problem is by utilizing low cost starting material such as palm fatty acid distillate (PFAD). PFAD is a byproduct from the refining of crude palm oil and abundantly available. Esterification of PFAD to biodiesel will be much easier with the presence of heterogeneous acid catalyst. Most of acid catalyst preparation involves series of heating process using conventional method. In this study, microwave was utilized in catalyst preparation, significantly reducing the reaction time from conventional heating method. The catalyst produced was characterized using X-Ray Diffraction (XRD), Brunauer Emmet and Teller (BET), Scanning Electron Microscopy (SEM), Temperature-Programmed Desorption - Ammonia (TPD-NH3) and Fourier Transform Infrared (FTIR) while percentage yield and conversion of the PFAD were analysed by gas chromatography - flame ionization detector (GC-FID) and acid-base titration, respectively. It has been demonstrated that the percentage yield of biodiesel from the PFAD by employing sulfonated glucose acid catalyst (SGAC) reached 98.23% under the following conditions: molar ratio of methanol to PFAD of 10:1, catalyst loading of 2.5% and reaction temperature of 70oC. The microwave-assisted SGAC showed its potential to replace the SGAC produced via conventional heating method.
Due to their high ionic conductivity, solid polymer electrolyte (SPE) systems have attracted wide spread attention as the most appropriate choice to fabricate all-solid-state electrochemical devices, namely batteries, sensors and fuel cells. In this work, ion conductive polymer electrolyte membranes have been prepared for battery fabrication. However, fractals were found to grow in these polymer electrolyte membranes weeks after they were prepared. It was believed that the formation of fractal aggregates in these membranes were due to ionic movement. The discovery of fractal growth pattern can be used to understand the effects of such phenomenon in the polymer electrolyte membranes. Digital images of the fractal growth patterns were taken and a simulation model was developed based on the Brownian motion theory and a fractal dialect known as L-system. A computer coding has been designed to simulate and visualize the fractal growth.
Neurological soft signs (NSS) are subtle indicators of brain dysfunction which are present in excess among patients with Schizophrenia. Its clinical significance remains unclear despite extensive researches in this area. The objective of this work was to determine the proportion of schizophrenia patients who have motor NSS and then to compare the clinical features between these two groups; with and without motor NSS. This cross-sectional study which utilized the brief motor scale (BMS) was used to investigate the presence of motor NSS in 80 schizophrenia patients who attended Universiti Kebangsaan Malaysia Medical Centre (UKMCC) Psychiatric clinic. The diagnosis of schizophrenia was confirmed by mini international neuropsychiatic interview (MINI). Symptomatology and abnormal motor movement were assessed using the brief psychiatric rating scale (BPRS) and abnormal involuntary movement scale (AIMS), respectively. A brief battery of cognitive tests covering aspects of attention, working memory and executive function was administered. The bivariate analyses were applied to look for any relationship between the study factors. Majority of schizophrenia patients (68.8%) in this study have motor NSS. The motor NSS were associated with ethnic group, level of education, age of onset, duration of illness and performance in cognitive assessment; verbal fluency, digit span forward, digit span backward
and trail making B (p<0.05) but not with trail making A. The assessment of motor NSS represents a brief, inexpensive and meaningful tool in assessing the cognitive functions in schizophrenia. It has the potential as an illness marker and a link between neurobiological research and clinical practice.
Atomic force microscopes (AFM) as one of the scanning probe microscopy (spm) modes have become useful tools, not only for observing surface morphology and nanostructure topography but also for fabrication of various nanostructures itself. In this work, silicon oxide (SiOx) patterns were formed on Si(100) surface by means of AFM anodization, where a non-contact mode used to oxidize Si wafer at the nanoscale size. The oxide patterns could serve as masks for the chemical etching of Si surface in alkaline solution in order to create the Si nanodots. A special attention is paid to finding relations between the size of dots and operational parameters as tip bias voltage and tip writing speed Dot arrays with 10 nm high and less than 50 nm in diameter have been successfully fabricated. The ability to control oxidation and scanning speed can be utilized in fabrication of complex nanostructures and make scanning probe lithography (SPL) as a very promising lithographic technique in nanoelectronic devices, nanophotonics and other high-tech areas.
Tool life of the cutting tools is considered as one of the factors which has effects on machining costs and the quality of machined parts. The topic of tool life prediction has been an interesting and important research topic attracting the attention of a wide number of researchers in this particular area. In terms of the suitable methods used in this research topic, it is stated that both statistical and artificial intelligence (AI) approaches can be employed to model tool life. For further justifying the capability of the ANN model in predicting tool life, the current study was based on conducting experimental work for collecting the experimental data. After carrying out the experiment, 17 data sets were collected and they were divided into two subsets; the first one for training and the second for testing. Since the data sets seemed to be lower than the number of data sets used in previous studies, we attempted to make verification of the ability of the ANN model in learning and adapting with low training and testing data. Diverse topologies accompanied with single and two hidden layers were created for modeling the tool life. For choosing the best and most effective network, the study adopted the mean square error function as criteria for the evaluation of the network selection. Thus, based on the data generated from the same experiment, a regression model (RM) was constructed employing the SPSS software. A comparison between the ANN model and RMs in terms of their accuracy was carried out and the findings revealed that the accuracy of the ANN was higher than that of the RM.
In recent years, by-products of fruit processing have received a great deal of attention, which is primarily due to their nutritional and economic exploitation through utilization of emerging technologies. Mango peel waste, a by-product from pulp processing units, is an important source of high quality antioxidant dietary fibre, pectin, polyphenols and carotenoids. It also possess significant biotechnological potential since it has been found suitable for several bioprocesses including ethanol, biogas, lactic acid, enzymes and single cell production. Valorization of mango peel through different routes not only can increase the profitability of fruit processing industries, but also help reduce environmental pollution. This review intends to provide a broad view on available technologies for mango peel waste utilization, with an emphasis on its biotechnological conversion into added value products beside other ways of utilization.
In recent years, issues regading safety and wellness of dietary oils and fats have received major attention. This is particularly so in the case of structured modified fats, which are being used extensively to meet the product-specific demand primarily in bakery industry as shortenings, cocoa butter substitutes in confectionary industry, and in margarine preparation, as butter substitute. During modification stages, native oils and fats are subjected to different physical and chemical treatments such as fractionation, hydrogenation and interesterification in order to produce fats with desirable
physical as well as functional properties. Numerous studies have demonstrated the adverse health effects of these modified oils and fats, especially trans fatty acids, using animal models as well as human volunteers. Consequently, the decadesold process of partial hydrogenation of oils has been abandoned in most nations. However, alternative technologies to hydrogenation are on rise, creating new trends in modified oils and fats synthesis to cater food industry needs that may have unforeseeable consequences on human health.
Water deficit and environmental pollution owing to excessive nitrogen use have caused considerable attention. In a field experiment, a combination of three water levels (20, 40 and 60 cm) and nitrogen fertilizer rates (0, 85 and 170 kg ha-1) was applied. The main objectives of this study were to optimize water and nitrogen application and exploit their interactive effects on the growth characteristics, yield and water and nitrogen use efficiency of spinach. The results showed that water and nitrogen significantly influenced average plant height and leaf area. Total aboveground biomass (TB) was affected by nitrogen fertilizer and TB decreased in water deficit. Adding nitrogen fertilizer amount resulted in higher leaf chlorophyll content and chlorophyll content obtained the maximum value in N2 treatment, but chlorophyll content was not affected by water deficit. Spinach yield was higher at N1 compared with N0 and N2 at all water levels. Abundant water supply resulted in the highest spinach yield, but yield reduced at lower water level (W3). The correlation analysis between spinach yield and leaf number was relatively weak (R2=0.58). On the contrast, the correlation analysis between spinach yield and leaf weight showed a correlationship (R2=0.91), indicating that leaf weight was the primary reason for yield increase in all treatments. Nitrogen fertilization significantly decreased NUE in all the treatments. WUE of spinach increased with adding nitrogen application in most conditions.
Public perceptions, understanding and acceptance of modern biotechnology can both promote and hamper their commercial introduction and adoption. Various studies have shown that consumer acceptance of modern biotechnology tend to be conditional and dependent on several factors. Public perceptions of biotechnology have received extensive attention in recent years in most Western countries such as Europe, USA and Canada but there have been limited similar surveys in developing countries. Most of the earlier studies used uni-dimensional or bi-dimensional instrument with multi-items or the most is four dimensions with single item. In this study, public attitude towards genetically modified (GM) soybean that is already available in the Malaysian market. A survey was carried out on 577 general public respondents in the Klang Valley region. In order to detect the structure of attitude amongst the expert group in the Klang Valley region, structural equation modeling (SEM) using AMOS version 5.1 was carried out. Result of the survey has confirmed that attitude towards complex issues such as biotechnology should be seen as multi-faceted/ multidimensional process. The most important factors predicting encouragement of GM soybean are the specific application-linked perceptions about the benefits and acceptance of risk while moral concern, risk and familiarity are significant predictors of intermediate factors. Researchers, policy makers and industries interested in developing and marketing GM products in Malaysia should consider the various factors mentioned in this in order to gain public approval.
Natural organic and abundant resources biopolymers received more attention due to their low cost, availability and degradability after usage. Cassava skin was used as natural fillers to the polyvinyl alcohol (PVA). Cassava skin/poly vinyl alcohol blends were compounded using melt extrusion twin screw extruder and test samples were prepared using the compression method. Various ratios of cassava skin and glycerol were investigated to identify suitable composition based on the water absorption and tensile properties. The water absorption of the cassava skins/PVA samples increased at higher composition of cassava skin due to their hydrophilic properties but decrease with glycerol content. The strength of the cassava skins/PVA samples increased with the higher composition of cassava skin up to 70 wt% while gradually decreased with the increasing composition of glycerol. The Young modulus increased with glycerol content but decreased with fibre loading up to 70 wt%. Elongation at break decreased with fibre loading and glycerol up to 70 wt% and 30 phr, respectively.
The Fusarium species are notoriously known for causing various plants and animal diseases and producing a number of harmful mycotoxins. The mycotoxins production by species recovered from non-agricultural hosts such as wild grasses have hitherto never been given attention. We examined 30 strains representing 12 Fusarium species i.e. F. oxysporum, F. solani, F. semitectum, F. nelsonii, F. compactum, F. equiseti, F. chlamydosporum, F. proliferatum, F. subglutinans, F. sacchari, F. lateritium and F. incarnatum-equiseti species complex isolated from wild grasses in Peninsular Malaysia for the production of four major mycotoxins i.e. moniliformin (MON), fumonisin BI (FB1), zearalenone (ZEN) and beauvericin (BEA) using TLC and HPLC techniques. BEA was the highest frequency of mycotoxin detected, followed by MON, ZEN and FB1. This study also presented the first report of BEA production by F. solani, F. compactum and F. chlamydosporum. All mycotoxins were not produced by F. nelsonii and F. lateritium. All Fusarium species were isolated from asymptomatic grasses, hence they are likely to exist as endophytes or latent pathogens.
Fenitrothion (FNT) usage has received much attention for its potential to promote free radicals generation and interfere with antioxidant defense system. The aim of the present study was to investigate the effect of palm oil tocotrienol rich fraction (TRF) supplementation on oxidative stress and histological changes in rat brain induced by FNT. A total of 32 male Sprague Dawley rats divided into four groups: control group which received corn oil; TRF group was received palm oil TRF (200 mg/kg bw); FNT group administered with FNT (20 mg/kg bw) and TRF+FNT group pretreated with palm oil TRF (200 mg/kg bw) 30 min prior to administration of FNT (20 mg/kg bw). FNT and TRF were dissolved in corn oil and all supplementations were given by oral gavage once daily for 28 days. After four weeks of supplementation, TRF+FNT rats had significantly lower malondialdehyde (MDA) content and superoxide dismutase (SOD) activity but higher reduced glutathione (GSH) level and total protein level compared to FNT rats (p<0.05). However, protein carbonyl (PC) level was insignificantly lower for TRF+FNT group compared to FNT group. In conclusion, this study suggested that palm oil TRF was effective in preventing brain damage in rats.
Freshwater fish has been studied and reported numerously. However, little attention has been made and limited studies available on local marine fish in Malaysia. Thus, in this study, concentrations of heavy metals (Cd, Cr, Pb and Cu) were studied in four major local marine fish Megalaspis cordyla (hardtail scad), Rastrelliger kanagurta (Indian mackerel), Selaroides leptolepis (yellowstripe scad) and Sardinella fimbriata (fringescale sardinella). The study was also intended to estimate potential health risk assessment from these heavy metals to the consumption of fish and assess maximum allowable fish consumption rate. The range of heavy metal concentrations were 0.053-0.096 mg/kg for Cd, 1.16-2.34 mg/kg for Cr, 8.34-12.44 mg/kg for Pb and 1.40-3.21 mg/kg for Cu in four major self-caught saltwater fish. Heavy metal levels of Cd and Cu in the local marine fish from Port Dickson are below the limit enforced by Food Regulations (1985) while the levels of Cr and Pb have exceeded the limit. Potential health risks associated with Cd, Cr, Cu and Pb were assessed based on target hazard quotients. HQ values calculated for Cd, Cr and Cu were less than 1, thus indicate that no adverse effects while HQ values for Pb exceeded 1 for all the fish species assessed with the exception of Megalaspis spp and Sardinella sppa. Cr was the highest while Pb concentrations were the lowest in all the studied fish samples for maximum allowable fish consumption rate. A long term monitoring program is crucial to be done in coastal areas with high consumption of local marine fish along Port Dickson to obtain real consumption rates and other cofounders factors in local population.
The issue of age difference in hospital admission should be given special attention since it affects the structure of hospital care and treatments. Patients of different age groups should be given different priority in service provision. Due to crucial time and limited resources, healthcare managers need to make wise decisions in identifying priorities in age of admission. This paper aimed to propose a construction of a daily composite hospital admission index (CHAI) as an indicator that captures relevant information about the overall performance of hospital admission over time. It involves five different age groups of total patients admitted to seven major public hospitals in the Klang Valley, Malaysia for respiratory and cardiovascular diseases for a period of three years, 2008 - 2010. The criteria weights were predetermined by aggregating the subjective weight based on rank ordered centroid (ROC) method and objective weight based on entropy - kernel method. The highest and lowest scores of CHAI were marked, while the groups of patients were prioritized according to the criteria weight ranking orders.
Due to the increasing production and use of nanoparticles in various sectors such as electronic industries and healthcare,
concerns about the unknown effects caused by the presence of these materials in the natural environment and agricultural
systems were on the rise. Because of the growing trend of ZnO nanoparticles (nZnO) which is one of the most widely
used nanoparticles being released into the environment, it has attracted the attention for more studies to be done on
the effects of this nanoparticle on organisms. This study was carried out to investigate the phytotoxicity effect of nZnO
on groundnut seedlings in Murashige and Skoog (MS) medium. The experimental treatments of this study include eight
concentrations of nZnO (10, 30, 50, 100, 200, 400, 1000 & 2000 mg.L-1) added to MS medium and MS medium without
nanoparticles have been used as control treatment. For the first 6 days after sowing, germination percent and germination
rate index were calculated by counting the germinated seeds every day. Groundnut seedlings were incubated for 3 weeks
in optimum condition and after that, seedling characteristics such as length, wet and dry weight of radicle and plumule
were measured. The water content of radicle and plumule were also calculated. The results of this study showed that
radicle and plumule length of groundnut seedlings were affected by nZnO exposure, in a way that length of radicles in 50
mg.L-1 nZnO and higher concentrations was significantly lower than that of control treatment and the shortest plumule
length was observed in 2000 mg.L-1 nZnO concentration treatment. Both the radicle and plumule wet weight were also
decreased as the nanoparticle concentration was increased. However, despite the decreasing in radicle and plumule dry
weight with increasing in nZnO concentration, this increase was not significant. However radicle dry weight in 10 mg.L-1
nZnO was significantly higher than nZnOtreatments with 200 mg.L-1 concentration and higher concentrations. Moreover,
observations of this study did not show any significant difference between the water content of nZnO concentration
treatments and control treatment.
Polymer-based nanocomposites have attracted a lot of attention for amperometric biosensor development due to their general physical and chemical properties including biocompatibility, film-forming ability, stability and different functional groups that can be bonded with other biomolecues. In this study, poly-4-vinlyridine homopolymer (P4VP) and polylactic acid-block-poly(2-vinylpyridine) block copolymer (PLA-b-P2VP) were used to hybridize with gold precursors (Au3+) based on the association between the nitrogen of the pyridine group of P4VP or P2VP block with gold precursors. P4VP/Au3+ and PLA-b-P2VP/Au3+ nanocomposites were prepared with ratio of gold to P2VP or P4VP (10:1). The Au3+ in both polymers was reduced to gold nanoparticles (AuNPs) via in-situ approach by using hydrazine. Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM) and cyclic voltammetry (CV) were used to characterize the structural, morphological and electrochemical properties of the nanocomposites. The peak currents of P4VP/AuNPs and PLA-b-P2VP/AuNPs nanocomposites modified electrode were 6.685 nA and 69.432 nA, respectively, which are much lower than bare electrode (205.019 nA) due to the non-conductivity of P4VP and PLA-b-P2VP. In order to improve the electron transfer capability of electrode, graphene oxide (GO) was blended and electrochemically reduced to obtain P4VP/AuNPs/rGO and PLA-b-P2VP/AuNPs/rGO nanocomposites. After immobilization of these two nanocomposites on electrode through drop casting method, the peak currents of P4VP/AuNPs/rGO and PLA-b-P2VP/AuNPs/rGO nanocomposites modified electrode were 871.172 nA and 663.947 nA, respectively, which are much higher than bare electrode (205.019 nA) and shown good capability to accelerate electron transfer. Based on these characterizations, P4VP/AuNPs/rGO has potential as the nanocomposite to modify the electrode for enzymatic biosensor development.