Displaying publications 1 - 20 of 2561 in total

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  1. Tan TS, Sharifah Syed Hassan, Yap WB
    Sains Malaysiana, 2016;45:787-793.
    The use of cell lines such as Madin-Darby Canine Kidney (MDCK) and African Green Monkey Kidney (Vero) cells in
    influenza vaccine production is much advocated presently as a safer alternative to chicken embryonated eggs. It is
    thus essential to understand the influenza virus replication patterns in these cell lines prior to utilizing them in vaccine
    production. The infectivity of avian influenza A virus (A/Chicken/Malaysia/5858/2004) H5N1 in MDCK and Vero cell
    lines was first assessed by comparing the cytopathic effect (CPE) caused by the virus infection. The viral loads in both
    of the infected media and cells were also compared. The results showed that both of the MDCK and Vero cells began to
    exhibit significant CPE (p<0.05) after 48 h post-infection (h p.i). The MDCK cell line was more susceptible to the virus
    infection compared to Vero cell line throughout the incubation period. A higher viral load was also detected in the host
    cells compared to their respective culturing media. Interestingly, after reaching its maximum titer at 48 h p.i, the viral
    load in MDCK cells declined meanwhile the viral load in Vero cells increased gradually and peaked at 120 h p.i. Overall,
    both cell lines support efficient H5N1 virus replication. While the peak viral loads measured in the two cell lines did
    not differ much, a more rapid replication was observed in the infected MDCK samples. The finding showed that MDCK
    cell line might serve as a more time-saving and cost-effective cell culture-based system compared to Vero cell line for
    influenza vaccine production.
  2. Tan Hc, Tan Bc, Norzulaani Khalid, Wong Sm
    Sains Malaysiana, 2016;45:795-802.
    Boesenbergia rotunda is a medicinal ginger that has been found to contain several bioactive compounds such as
    boesenbergin A, panduratin A, cardamonin, pinostrobin and pinocembrin. These compounds are useful in treating various
    ailments, such as oral diseases, inflammation and have also been used as an aphrodisiac. In this study, an efficient
    protocol for developing and isolating protoplast cultures for B. rotunda has been established. Rhizome buds of B. rotunda
    were used as explants to initiate callus growth and the established cell suspension cultures were used to optimize their
    growth conditions. Our results indicated that embryogenic suspension cultures in liquid Murashige and Skoog (MS)
    medium supplemented with 3% (w/v) sucrose produced the highest growth rate (µ = 0.1125), whereas no promotive effect
    was seen in the presence of 2,4-dichlorophenoxyacetic acid and those that underwent sonication treatment. Amount of
    protoplasts isolated ranging from 1-5 × 105
    protoplast per mL were isolated using 0.25% (w/v) macerozyme and 1%
    (w/v) cellulase for 24 h under continuous agitation (50 rpm) in dark condition. Of the isolated protoplasts, 54.93% were
    viable according to fluorescein diacetate staining test. Micro-colonies were recovered in liquid MS medium containing
    9 g/L mannitol, 2 mg/L 1-naphthaleneacetic acid and 0.5 mg/L benzylaminopurine (BAP) for 4 weeks and subsequently
    transferred to solid MS medium supplemented with 0.5 mg/L BAP for callus initiation. The protoplast system established
    in this study would be useful for genetic manipulation and modern breeding program of B. rotund
  3. Syaliza Abdul Hammid, Zaini Assim, Fasihuddin Ahmad
    Sains Malaysiana, 2016;45:627-632.
    Cinnamomum species (Lauraceae) are well known for their fragrance and medicinal value. The essential oils of three Cinnamomum species (C. macrophyllum, C. crassinervium and C. griffithii) collected in Sarawak were obtained by hydrodistillation and analyzed by gas chromatograpy mass spectrometry (GC-MS). The analysis of the oils showed that most of the essential oils were mainly phenylpropanoids and monoterpenes with a small amount of sesquiterpenes present. Both C. griffithii and C. crassinervium contained similar major chemical composition such as β-linalool, methyl cinnamate and eugenol methyl ether. No presence of methyl cinnamate and β-linalool were found in the oil of C. macrophyllum. m-Eugenol was prominent in the leaf oil of C. macrophyllum, while cinnamaldehyde was found mainly in the bark oil of C. macrophyllum. High percentage of camphor was identified in the bark and root oil of C. macrophyllum, compared to small amount of camphor found in the both root oil of C. griffithii and C. crassinervium.
  4. Goh SL, Lim FP, Ibrahim Mohamed, Noorizam Daud
    Sains Malaysiana, 2016;45:499-506.
    This paper discussed methods for outlier detection in standard 2 × 2 crossover studies. Two outlier detection procedures were carried out based on residuals. Under a simplified model of 2 × 2 crossover design, we present the classical calculation of studentized residual (SR1) and propose a new studentized residual using median absolute deviation (SR2) to identify possible outlying subjects. The performances of both procedures in detecting subject outliers were compared. We show via simulation that a proposed procedure using SR2 is more powerful than that using SR1 for outlier detection. As an illustration, these procedures were applied to two real data sets from studies of bioavailability and kinesiology, respectively.
  5. Jau CL, Wan Aizan Wan Abdul Rahman, Avérous L, Teck HL
    Sains Malaysiana, 2016;45:633-641.
    This paper reports the post-processing ageing phenomena of thermoplastic sago starch (TPS) and plasticised sago pith waste (SPW), which were processed using twin-screw extrusion and compression moulding techniques. Wide angle X-ray diffraction (XRD) analyses showed that after processing, starch molecules rearranged into VH-type (which was formed rapidly right post processing and concluded within 4 days) and B-type (which was formed slowly over a period of months) crystallites. Evidence from Fourier transform infrared spectroscopy (FTIR) analyses corroborated the 2-stage crystallisation process, which observed changes in peak styles and peak intensities (at 1043 and 1026 cm-1) and bandnarrowing. Thermogravimetric analysis (TGA) studies showed that the thermal stability of plasticised SPW declined continuously for 90 days before gradual increments ensued. For all formulations tested, post-processing ageing led to drastic changes in the tensile strength (increased) and elongation at break (decreased). Glycerol and fibres restrained the retrogradation of starch molecules in TPS and SPW.
  6. Amira FS, Kamaruzzaman BY, Jalal KCA, Rahman MM, Hossain MY, Khan NS
    Sains Malaysiana, 2016;45:79-86.
    A study was conducted to understand the relative abundance and growth of male and female Nemipterus furcosus population in the Pahang coastal water, Malaysia. The sampling was done monthly for a period of one year. A total of 1446 fish specimens were studied in this research. The results showed that male N. furcosus population was significantly more than female (p<0.01) N. furcosus population. The growth coefficient (b value) varied between 2.6808 and 3.2396 for male and 2.0926 and 3.2838 for female N. furcosus. The growth co-efficients of male N. furcosus were significantly different than the growth co-efficients of female N. furcosus in all months (p<0.05). They showed negative allometric growths in February- June and September. Female N. furcosus showed positive allometric growths in November-January and August. Isometric growths of female were observed only in October and July. As for male N. furcosus, negative allometric growths were observed in March-June, November and January. Male N. furcosus showed positive allometric growths in August, September, October, December and February. Male N. furcosus showed isometric growth only in July. The overall mean condition factor of male and female was statistically similar (p>0.05). The condition factor (K) ranged from 1.2559 to 1.3917 for male while 1.2503 to 1.3926 for female N. furcosus. Overall, higher mean condition factor was observed in smaller fish of both sexes. This study is useful for policy makers and fishery biologists for sustainable fishery management in the Pahang coastal water, Malaysia.
  7. Zulkifli Yusop, Harisaweni, Fadhilah Yusof
    Sains Malaysiana, 2016;45:87-97.
    Rainfall intensity is the main input variable in various hydrological analysis and modeling. Unfortunately, the quality of rainfall data is often poor and reliable data records are available at coarse intervals such as yearly, monthly and daily. Short interval rainfall records are scarce because of high cost and low reliability of the measurement and the monitoring systems. One way to solve this problem is by disaggregating the coarse intervals to generate the short one using the stochastic method. This paper describes the use of the Bartlett Lewis Rectangular Pulse (BLRP) model. The method was used to disaggregate 10 years of daily data for generating hourly data from 5 rainfall stations in Kelantan as representative area affected by monsoon period and 5 rainfall stations in Damansara affected by inter-monsoon period. The models were evaluated on their ability to reproduce standard and extreme rainfall model statistics derived from the historical record over disaggregation simulation results. The disaggregation of daily to hourly rainfall produced monthly and daily means and variances that closely match the historical records. However, for the disaggregation of daily to hourly rainfall, the standard deviation values are lower than the historical ones. Despite the marked differences in the standard deviation, both data series exhibit similar patterns and the model adequately preserve the trends of all the properties used in evaluating its performances.
  8. Huixing Liang, Aihui Chen, Zhaoxia Li, Muhammad Aqeel Ashraf, Cheng Ding
    Sains Malaysiana, 2016;45:129-134.
    In order to explore the response of the soil microbial community to 1,2-dichlorobenzene exposure in Wetland soil, a short-term (7 weeks) mesocosm study was conducted at four 1,2-dichlorobenzene concentrations of (100, 400 and 800) μg g -1. Dry soil, sterile and unsterile controls were also compared. The results obtained showed a significant effect of 1,2-dichlorobenzene on the development of bacterial populations in soils contaminated with different concentrations of 1,2-dichlorobenzene at the early time after application. In general, however, the number of populations of the same soil sample treated with the same concentration of 1,2-dichlorobenzene differed significantly with the increasing incubation time within the early 5 weeks. The scale of differences in banding patterns-showed that the microbial community structures of 1,2-dichlorobenzene-treated and non-1,2-dichlorobenzene-treated soils were not significantly different after 7 weeks of incubation. DNA in application-responsive bands from the 1,2-dichlorobenzene treatments was recovered and amplified using the universal primers. PCR products were recovered and cloned into pGEM-T Easy (Promega) and two clones were obtained. The two clones were sequenced using the automated Model 3730 DNA sequencing system. The two cloned sequences had very high similarities to an uncultured bacterium reported previously in the database of NCBI.
  9. Nor Hafizah Zakaria, Mohammad Mustafizur Rahman, Ahmed Jalal Khan Chowdhury, Zaima Azira Zainal Abidin
    Sains Malaysiana, 2016;45:135-140.
    The application of microbial techniques in aquaculture has been playing a vital role to increase the production yield by improving the nutritional values of the targeted fish. Phototrophic purple bacteria as single cell protein (SCP) appears to be a promising substitution for protein rich supplement for aquaculture feeds making them a promising growth enhancer in aquaculture industry. Two species of phototrophic purple bacteria, Marichromatium sp. and Rhodopseudomonas sp. were used in the commercial diet to compare the growth, survival rate and feed utilizationon for Tor tambroides juvenile. Purple bacteria were isolated from mangrove sediment and fish tank and mass cultured using 112 synthetic media under anaerobic light condition. Bacterial cells were included in the diets by mixing the fresh biomass with the crushed commercial pellet, re-pelleted and air-dried. The experimental diets were fed to the fingerlings twice per day for 10 weeks to satiation level. The results showed that there were trends of increased growth, better survival rate and improved feed conversion ratio when fed with diet 1 (Marichromatium sp.) compared with other diets. There was significant difference (p<0.05) between the sampling days. The specific growth rate and weight gain of the fish fed with diet 1 were 0.49 % and 4.92 g, respectively, compared to 0.42% and 4.11 g from the control. This study suggested that purple bacteria could be used in feed formulation as a supplement to promote growth and survival of freshwater fishes in Malaysia.
  10. Anis Syuhada Mohd Saidi, Chin HC, Sharifah Nabihah Syed Jaafar, Farah Nadia Mohammad Padzil, Sarani Zakaria
    Sains Malaysiana, 2016;45:263-270.
    Cellulose was extracted from kenaf core pulp (KCP) by a series of bleaching processes (D) and alkali treatment (E) in the sequence of (DEED) and pretreated with acid hydrolysis in room temperature for 6 hours. The pretreated and non-treated cellulose were dissolved in lithium hydroxide/urea (LiOH/urea) and subsequently used to produce cellulose membrane cross linked with various percentages of glyoxal from 2.5 to 20%. The effects of acid hydrolysis pretreatment on solubility, crystallinity and morphology were investigated. The acid hydrolysis pretreatment leads to higher solubility of the cellulose solution. The formation of cellulose II and crystallinity index of the cellulose membrane were examined by X-ray diffraction (XRD). Cellulose membrane without acid hydrolysis pretreatment cross linked with higher percentage of glyoxal has higher tensile strength compared with the treated cellulose.
  11. Ebenezer Akin Oluwasola, Md. Maniruzzaman A. Aziz, Naquiddin M. Warid M, Mohd Rosli Hainin
    Sains Malaysiana, 2016;45:278-287.
    This study focuses on the potential of electric arc furnace (EAF) steel slag and copper mine tailings as asphalt paving materials with respect to issues of volumetric properties and leaching. In this study, four different asphalt mixes were investigated; each contained EAF steel slag and copper mine tailings of various proportions. Apart from the microstructure analysis of the materials, a toxicity characteristics leaching procedure (TCLP) test was conducted on both the mixes and the aggregates. All the mixes were evaluated by the following parameters: Voids in the mineral aggregates (VMA), voids in total mix (VTM), voids filled with asphalt (VFA), Marshall stability and flow and specific gravity. F-test ANNOVA was used to evaluate the degree of significance of the mixes with each of the evaluated standards. It was observed that the mixes containing either EAF steel slag or copper mine tailings or both gave better results than the control mix. In terms of the TCLP test, none of the detected hazardous elements exceeded the standard limits, which indicates the possibility of using them as construction materials.
  12. Liu Hui
    Sains Malaysiana, 2016;45:99-107.
    Investigation of meteorological disasters caused by small-scale topography shows that flashover due to wind age yaw occurred quite often where col topography existed. Considering that the distribution pattern of wind profile at different locations of a col topography is not clear, this paper, with wind tunnel tests, studied the influenced of such topographic features of a col as hill slope and valley mouth width on the wind profile at different locations. The results of wind tunnel tests indicated that over-hill wind has a stronger effect on wind velocity correction coefficient than does valley wind, that compared to flat terrain wind velocity, the maximum speed-up amplitude of wind velocity at valley throat and hill summit reach 33 and 53%, respectively, apparently higher than 10% specified in Codes, that wind velocity at valley throat increases with the increase of hill slope and decreases with the increase of valley mouth width, that wind velocity in the valley basically does not go up when the slope of one hill side is smaller than 0.1 and that wind velocity at the same non-dimensional height of a 3D hill summit increases with the increase of hill height.
  13. Xu-hui Zhang, Lei Liang, Xiao-yan Wang, Li Zhang, Yan-xin Zheng, Hong-zhu Deng, et al.
    Sains Malaysiana, 2016;45:109-113.
    We investigated the antitumor effects of the combination of matrine-a purified alkaloid extracted from Sophora flavescence-and 5-fluorouracil (5-FU) on SW480 cells. This combination inhibited the growth of SW480 cells in a synergistic or additive manner by disrupting their progression through the cell cycle. Exposure of SW480 cells to matrine and 5-FU was followed by an increased rate of expression for caspase-3, caspase-9 and poly-ADP ribose polymerase (PARP) and inhibited the subcutaneous transplantation of SW480 tumors into Balb/c nude mice. Histopathological analysis showed that this effect was most pronounced in the spleens of treated animals. Typical cytotoxic effects observed in 5-FU-treated mice included fibrosis and lymphopenia, whereas in mice treated with 5-FU combined with matrine, the spleen ultrastructure remained intact. These findings indicate that matrine may enhance the therapeutic effectiveness of 5-FU in SW480 tumors by enhancing apoptosis and overcome the threat to immunocompetence associated with 5-FU.
  14. Tayeb MA, Ismail BS, Khairiatul Mardiana J, Goh CT
    Sains Malaysiana, 2016;45:237-245.
    Glufosinate ammonium or ammonium salt (ammonium-(2RS)-2-amino-4- (methylphosphinato) butyric acid; C5H15N2O4P) is a commonly used polar herbicide in Malaysia and present in a variety of environmental waters at the sub-ppb level. Thus, glufosinate ammonium is analyzed in soil and water using high-performance liquid chromatography (HPLC), which is a complex yet the most powerful analysis tool. HPLC is tremendously sensitive and highly automated and HPLC instrumentation and machinery have improved over the years. However, typical problems are still encountered. HPLC users and advanced learners require help in identifying, separating and correcting typical problems. All HPLC systems consist of similar basic components. Although it is a modular system, trouble can occur in each component and change the overall performance. Resolving these problems may be expensive. This review describes the different aspects of HPLC, particularly troubleshooting, common problems and easy guidelines for maintenance.
  15. Nabil FL, Anwar UMK, Bakar ES, Zaidon A, Lee SH, Paridah MT
    Sains Malaysiana, 2016;45:255-262.
    The aimed of this study was to evaluate the resistance of sesenduk (Endospermum diadenum) wood, treated using admixture
    of low molecular weight phenol formaldehyde (LmwPF) resin and nanoclay, against white rot fungus (Pycnoporus
    sanguineus) and subterranean termites (Coptotermes curvignathus Holmgren). Seven sample groups including untreated
    sesenduk wood and treated sesenduk wood using 10, 15 and 20% LmwPF resin and the admixture of the 1.5% nanoclay
    with every level of resin concentrations. Air-dried samples were impregnated using vacuum-pressure process. After
    impregnation, the treated samples were heated in an oven at 150°
    C for 30 min. Five test blocks from each treatment
    group were tested separately against P. sanguineus and C. curvignathus in accordance with AWPA E10-12 and AWPA E1-13
    standards, respectively. The results showed that both treatments had significant effects on the percentage weight loss and
    decay rate of the samples. The weight loss due to termite attack was found reduce with the increasing PF concentration.
    Generally, the addition of 1.5% nanoclay in PF resin slightly increased the resistance against both deteriorating agents
    compared to the wood treated using PF alone. It was found that the PF resin can be used as an effective method to improve
    the durability of sesenduk wood.
  16. Abdul Ghani Rafek, Azimah Hussin, Lee KE, Ailie Sofyiana Serasa, Goh TL
    Sains Malaysiana, 2016;45:185-193.
    The uniaxial compressive strength (UCS) is one of the most common mechanical parameters required in geotechnical engineering to characterize the compressive strength of rock material. Measurements of UCS are expensive, time consuming, destructive and thus, not favorable in the presence of limited samples. Therefore, a simple yet practical application is needed for the estimation of UCS. This research presents two correlations to predict UCS values for granite and schist by using ultrasonic velocity travel time (tp) from ultrasonic tests. The validity of the practical approach presented in this research is confirmed based on the strong correlations developed from the experimental tests conducted. For the entire data set, the correlation between UCS and ultrasonic velocity travel time was expressed as UCS = 217.2 e-0.016(tp) for granite and UCS = 1110.6 e-0.037(tp) for schist and the coefficient of determination (R2) value for both granite and schist is 0.93. These correlations may be useful for applications related to geotechnical engineering designs.
  17. Zeng Zhou Tan, Mohammad Zakir Hossain, Md Shahidul Ahsan, Yew Choy Chew, Swe Swe Win, Suan Phaik Khoo
    Sains Malaysiana, 2016;45:201-205.
    Angiogenesis has an important role in the invasion, metastasis and growth of tumors. Increased microvessel density (MVD) has been described in oral squamous cell carcinoma (OSCC) compared to oral dysplasia and normal oral tissue. A morphometric study was designed to evaluate the MVD and to evaluate the presence of any association between MVD and keratin pearl in the three histopathological grades of OSCC (as defined in Bryne’s grading system). Forty-five samples of OSCC were graded into well differentiated (WDSCC), moderately differentiated (MDSCC) and poorly-differentiated (PDSCC) oral squamous cell carcinoma. Morphometric analysis showed that MVD was significantly lower in WDSCC compared to MDSCC (p<0.001) and PDSCC (p<0.001). The density in MDSCC was significant lower than PDSCC. The keratin pearl count was significantly higher in WDSCC compared to MDSCC (p<0.001) and PDSCC (p<0.001). Between MDSCC and PDSCC, the keratin pearl count was significantly higher for MDSCC (p=0.001). Pearson correlation test showed a significant negative correlation between keratin pearl and MVD (r=-0.805, p<0.001). The findings suggested that vascularity in OSCC is associated with its cellular differentiation and also associated with keratin pearl formation.
  18. Tang Mei, Liu Cao, Liang Zi, Hu Die, Gong Mingfu
    Sains Malaysiana, 2016;45:115-118.
    In order to separate lumbrokinase in Pheretima praepinguis and to study the enzymatic properties, with Pheretima praepinguis as material, lumbrokinase was separated with the salting out method. Lumbrokinase activity was measured with casein medium plate method. The effect of pH and temperature on lumbrokinase activity was studied. The activity of lumbrokinase separated from Pheretima praepinguis was relatively high. Lumbrokinase activity in neutral or slightly alkaline environment was higher. Lumbrokinase had tolerance ability to high temperature, with highly enzymatic activity under 60° and wide range of temperature adaptation.
  19. Mohammed A. Jasim, Mohd Sofian-azirun, Yusoff, Motior Rahman M
    Sains Malaysiana, 2016;45:119-127.
    In this paper we have studied the acute toxicity effect of Hg on hybrid tilapia (Oreochromis niloticus). For this, the tissues of tilapia have been digested by means of acids in microwave oven and was analyzed by flameless atomic absorption spectrophotometer (FAAS). We have identified that the levels of Hg varied significantly in different tissues and the metal concentration was in the following order: liver > gills > muscles; of which the maximum level recorded for Hg was 0.799 mg/kg. We have also observed the alterations towards histopathological aspects in the gills and liver of treated fishes were studied using light and electron microscopy, subjected to the exposure of Hg for 24 h and furthermore we have also noticed the extent of the increased alterations during the 96 h of exposure to median lethal concentration LC50 (0.3 mg/L) a severe disorganization of epithelial cells and modifications of the structure of the secondary lamellae. Moreover the severity has also found to increase to sub-lethal concentration (0.03 mgHg/L) in 21 days of exposure; Liver was slightly affected by the contamination of Hg. Ultimately, histopathology is considered as a sensitive technique of bioaccumulation and for the observing the potential damage from Hg exposure.
  20. Mehmet Yildirim, Zeki Yakut, Firat Kurt, Ferhat Kizilgeci, Cuma Akinci
    Sains Malaysiana, 2016;45:221-228.
    The effects of nitrogen (N) fertilization at different growth stages were investigated on durum wheat (Triticum durum L.) grain yield and yield components (with irrigated bed planting) in Diyarbakir, Turkey. N was applied at a rate of 140 kg ha–1 and distributed to one, two and three applications at various combinations with five different growth stages (i.e. sowing, seedling growth, early tillering, stem elongation and booting). This study included 13 treatments, including the control (zero nitrogen). The N application timings (NAT) of the 50% sowing + 50% early tillering and 66% sowing + 33% early tillering treatments were most suitable for durum wheat. The results showed that NAT had significant effect on flowering time, SPAD readings of the early milky ripe stage, plant density, thousand kernel weights, grain filling duration, grain filling rate, grain N content, grain yield, harvest index and grain N yield. In summary, the highest values of parameters studied were obtained from the 50% sowing + 50% first tillering and 66% sowing + 33% early tillering treatments. N fertilization application rate and time of durum wheat genotypes should consist of applying 50-60% of the total N fertilizer at sowing and 40–50% at the early tillering stage under irrigated conditions and with bed planting.
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