The effects of the annealing temperatures and thicknesses on the shapes, sizes and arrangement of platinum (Pt) nanoparticles (NPs) on graphene and their sensing performance for hydrogen (H2) detection were investigated. It shows strong dependency of the annealing temperatures and thicknesses on the properties of NPs. It was found that the proposed technique is able to form the NPs with good size controllability and uniformity even for thick deposited layer, thus eliminating the requirement of very thin layer of below 5 nm for the direct NP synthesis by evaporation or sputtering. The transport properties of Pt NPs/graphene structure and its sensing performance on H2 at room temperature under various H2 concentration were evaluated. The results showed an acceptable sensing response, indicating an innovative approach to fabricate Pt NPs embedded graphene for gas sensing application.
Effective and rapid methods for RNA extraction from conidia, germinating conidia and appressoria of the fungal plant pathogen, Colletotrichum gloeosporioides is reported in this study. The procedure for the RNA extraction from conidia and germinating conidia was carried out using TRI REAGENT® solution (Molecular Research Center, USA) and can be completed in less than one and a half hours. The procedure for RNA extraction from appressoria was carried out using a modified protocol employing guanidine isothiocyanate and mechanical cell disruption by glass beads. The efficiency of the RNA extraction procedures was evaluated by several measures to determine RNA integrity, purity and applicability in RT-PCR. RNA integrity was assessed by observing the integrity of the major RNA species (18S and 28S rRNA) on denaturing agarose gel electrophoresis. The ethidium bromide-staining pattern of intact total RNA extracted from the three fungal morphogenetic cells showed clearly defined 28S and 18S rRNA bands and no genomic DNA contamination. Spectrophotometric assessment of RNA from each sample indicated relatively high purity and absence of carbohydrate contamination. Finally, we have demonstrated that the methods used for RNA extraction of conidia, germinating conidia and appressoria produced RNA of sufficient quality suitable for RT-PCR in detecting the expression of protein kinase A regulatory subunit gene in C. gloeosporioides.
Delta 6-asid lemak desaturase dan delta 12-asid lemak desaturase merupakan enzim yang diperlukan bagi langkah desaturasi semasa proses biosintesis asid gamma-linolenik (GLA) oleh kulat oleaginus. Objektif kajian ini ialah untuk menganalisis profil pengekspresan gen mengekod enzim delta 6-asid lemak desaturase (des6) dan delta 12-asid lemak desaturase (des12) kulat oleaginus Cunninghamella bainieri semasa penghasilan GLA. Jujukan gen separa bersaiz 1372 pb bagi des6 dan 1008 pb bagi des12 telah dipencil daripada C. bainieri. Analisis pengekspresan gen menggunakan kaedah tindak balas berantai polimerase kuantitatif masa sebenar (RT-qPCR) menunjukkan perubahan kadar pengekspresan des6 adalah lebih tinggi berbanding kadar pengekspresan des12 semasa penghasilan GLA. Pengekspresan des6 adalah tertinggi selepas 24 jam dikultur dalam medium penghasilan GLA. Namun, kadar pengekspresannya menurun hingga jam ke-96 pertumbuhan tetapi meningkat semula pada jam ke-120. Bagi des12, kadar pengekspresannya adalah lebih sekata dengan pengekspresan tertinggi dikesan pada jam ke-120. Analisis penghasilan GLA menunjukkan jumlah GLA dalam sel berkolerasi dengan kadar pengekspresan des6. Hasil kajian mencadangkan bahawa aras pengekspresan des6 adalah penting dalam menentukan aras GLA dalam C. bainieri.
The ability of a locally isolated clinical strain of C. albicans to adapt and response towards oxidative stress were investigated in this study. Treatment of C. albicans with hydrogen peroxide (H2O2) will exert an oxidative stress to C. albicans cells and affect the growth rate of this opportunistic pathogen. Cells that were grown in Yeast Peptone Dextrose (YPD) medium with the presence of 4.0 mM H2O2 gave a doubling time of 51 min/generation compared to 44 min/generation for those grown in 0.4 mM H2O2 and without H2O2. In order to determine the resistance level of C. albicans towards oxidative stress, cells were exposed to different concentration of H2O2. Results showed that percentage of cells viability decreased with the increased concentration of H2O2. These data indicated that C. albicans could overcome oxidative stress to a certain level before they were killed. To determine whether this strain exhibited a stress induce protection, cells were treated with mild oxidative stress for one hour before exposed to a stronger oxidative stress. Data obtained shows that cells that were pre-treated with mild oxidative stress showed higher percentage of survival compared to non pre-treated cells. This strongly suggested that stress induce protection was present in this C. albicans. Finally, in order to determine whether oxidative stress can induce yeast to hyphal morphogenesis in C. albicans, cells were then exposed to 0.4 mM H2O2 at 37 ºC and the number of hyphal formed were compared to hyphal formation when the cells were grown at 37 ºC only. However the results showed that oxidative stress failed to induce yeast to hyphal morphogenesis in this clinically isolated C. albicans strain.
Keywords: Candida albicans; oxidative stress
The sorption parameters of two heavy metals (i.e. Pb and Cu) in clay soils from Selangor were studied using batch equilibrium test. The test was conducted in two separate systems, i.e. single and mix solutions. The sorption isotherms data from this test were then used to calculate the sorption parameters, i.e. distribution coefficient (Kd) and maximum adsorption capacity (Am). Langmuir sorption equation was used to model the sorption data with the correlation coefficients (r2) higher than 0.6. The study has revealed that different soils have different sorption capacity for different heavy metals. The Kd values are proportional to the sorption capacity of the soils. The sorption of Pb and Cu in single solution is higher than in mix solution, due to the competition for sorption sites among heavy metals in mix solution. The Kd values for Pb in single solution ranging from 36.18-334.48 L/g and for Cu is 9.29-66.19 L/g. In mix solution, the Kd values for Pb and Cu are much smaller, ranging from 23.13-31.79 L/g and 3.95-18.53 L/g respectively. The Am values in single solution for both Pb and Cu are ranging from 0.48-1.09 mg/g dan 0.18-0.70 mg/g respectively. While in mix solution, the values of Am for Pb ranging from 0.20-1.11 mg/g and Cu within 0.18-0.60 mg/g.
Analisis kimia air telah dilakukan terhadap larutan yang diekstrak dari 85 sampel tanah yang dipungut di kawasan ternakan udang harimau di Kerpan. Sampel tanah dikorek pada kedalaman 2 m bermula dari garis pantai sehingga 20 km ke arah daratan. Selain daripada tanah, air bawah tanah juga disampel dengan penggerudian yang berkedalaman 10 hingga 25 m untuk dilakukan analisis kimia air. Hasil analisis hidrokimia larutan yang diekstrasi dari sampel tanah yang diambil pada kedalaman 1-2 m menunjukkan kepekatan klorida berjulat dari 12 hingga 6500 mg/L. Berdasarkan kepekatan ion tersebut, kawasan kajian telah dibahagikan kepada beberapa zon-zon iaitu zon masin dan payau. Kepekatan pepejal terlarut yang diukur adalah dalam julat 100 hingga 40,000 mg/L dengan julat ini merangkumi zon berair segar hingga masin. Zon berair masin yang ditafsir berdasarkan kepekatan pepejal terlarut adalah dalam lingkungan 1 km dari pantai manakala berdasarkan kepekatan klorida sempadan ini adalah disekitar 4-5 km. Kehadiran air masin boleh berasal dari penerobosan langsung dari laut ataupun melalui proses air pasang-surut dimana air laut masuk melalui sungai atau terusan berhampiran ke kawasan kajian. Kehadiran air masin juga disokong oleh pertambahan kepekatan unsur-unsur seperti naterium, kalium dan kalsium ke arah laut. Berdasarkan peta taburan spatial kepekatan klorida, pola kontur kemasinan tinggi didapati mengikut bentuk kolam ternakan udang. Oleh itu besar kemungkinan pengaruh air masin adalah dari proses infiltrasi air kolam ke kawasan sekitar. Untuk melihat samada proses penerobosan juga turut memainkan peranan dalam mempengaruhi kemasinan di kawasan kajian, sampel air dari lubang gerudi pada kedalaman 10-25 meter juga turut dibuat. Sampel air yang dipam dari lubang gerudi menunjukkan kepekatan klorida dalam julat 2030 hingga 13,000 mg/L manakala kepekatan pepejal terlarut berjulat 3233 hingga 9280 mg/L. Berdasarkan nilai kepekatan klorida dan pepejal terlarut sampel air lubang gerudi, kawasan di sekitar lubang gerudi khususnya pada jarak hampir 1 km dari pantai telah tercemar dengan kesan penerobosan air laut.
Survei keberintangan geoelektrik ini telah dijalankan di kawasan Bukit Tenggek, Setiu, Terengganu untuk mengesan kemungkinan wujudnya terowong lama yang dipercayai berada di kawasan berkenaan. Kaedah keberintangan geoelektrik ini bukanlah asing dan didapati amat berkesan di dalam eksplorasi mencari bahan arkeologi dan struktur terkambus di bawah tanah (terowong dan bahan artifak). Survei keberintangan geoelektrik ini dijalankan dengan menggunakan peralatan ABEM Terrameter SAS1000 dan susun atur elektrod jenis Wenner. Kawasan kajian terletak di kawasan lembah yang lembap dan terdapat anak sungai yang merentasi kawasan tersebut. Imej keberintangan 2-D menunjukkan wujudnya beberapa kawasan beranomali yang boleh dikaitkan dengan struktur yang dicari. Nilai keberintangan yang rendah mewakili kawasan yang dianggarkan wujudnya terowong lama. Manakala anomali yang menunjukkan bentuk gugusan dianggarkan berasosiasi dengan lokasi tong/bahan artifak. Profil keberintangan 3-D menunjukkan anomali yang mungkin disebabkan oleh wujudnya satu terowong mendatar dan dua terowong menegak. Namun, kerja galicari perlu dilakukan bagi menentukan punca sebenar anomali tersebut.
This study looked into the rate and pattern of neuropsychological impairment in patients with traumatic brain injury patients at three months post injury. Forty patients attending the neurosurgery outpatient clinic were included in the study. Benton visual retention test (BVRT), rey auditory verbal learning test (RAVLT), digit span test, trail making test (TMT) and mini mental state examination (MMSE) were used for assessment. Forty five percent (n=18) sustained moderate to severe head injury. Twenty five percent (n=10) have abnormal MMSE result. Forty two and a half percent (n=17) have abnormal BVRT result. Seventy five percent (n=30) have abnormal RAVLT result while 35% (n=14) have abnormal digit span test result. Seventy seven and a half percent (n=31) have at least one neurological deficit. There was significant association between severity of head injury (GCS score) and neuropsychological deficit. This study highlights the point that in post head injury patients, there are high occurrences of cognitive dysfunction. MMSE and GCS play a significant and important role in assessing cognitive dysfunction. Severity of head injury as determined by GCS scores also influence the outcome in patients with head injury
Some numerical methods for solving diffusion-convection equations in two dimensional space are formulated. Iterative scheme for each method is studied and numerical test to model problem is conducted. Comparison of methods is given in table form.
Beberapa kaedah berangka bagi menyelesaikan persamaan resapan-olakan dalam ruang dua dimensi telah dirumuskan. Skema lelaran untuk setiap satunya dikaji dan pengujian berangka kepada masalah model dilakukan. Perbandingan antara kaedah telah diberikan secara berjadual.
With the rapid civilization and industrialization, water pollution is becoming more and more intricate. Heterogeneous photocatalysis using metal oxide loaded ZnO nanorods is a well-known environmental technology to degrade toxic organic pollutants. In this study, Cr2O3 particles anchored on the ZnO nanorods (Cr2O3/ZnO) were successfully synthesized by a hydrothermal-deposition technique. Microscopic and crystallographic analyses indicated that the synthesized samples consisted of two-phase heterostructure of Cr2O3 and ZnO. The photocatalytic results showed that the phenol degradation by Cr2O3 /ZnO heterostructures was higher than those of pure ZnO and commercial TiO2. The synergetic effect between Cr2O3 and ZnO was the pivotal reason for the improvement of photoactivity as proven by the photoluminescence and terephthalic acid–photoluminescence analyses.
The purpose of this study was to examine the effect of viscous dissipation on mixed convection flow of viscoelastic
nanofluid past a horizontal circular cylinder. Carboxymethyl cellulose solution (CMC) is chosen as the base fluid and
copper as a nanoparticle with the Prandtl number Pr = 6.2. The transformed boundary layer equations for momentum
and temperature subject to the appropriate boundary conditions are solved numerically by using Keller-box method. The
influenced of the dimensionless parameters such as Eckert number, mixed convection parameter, nanoparticles volume
fraction and viscoelastic parameter on the flow and heat transfer characteristics is analyzed in detail and presented
graphically. The results come out with the velocity profiles are increased while the temperature profiles are decreased
by increasing the values of nanoparticles volume fraction and viscoelastic parameter, respectively. The graph shows
that, increasing Eckert number the skin friction is also increases. The values of skin friction are increased by increasing
mixed convection parameter, but the values of Nusselt number produce an opposite behavior. The present study has many
applications especially in heat exchangers technology and oceanography. Therefore, in future, it is hoping to study the
viscoelastic nanofluid flow past a different geometric such as sphere and cylindrical cone.
This article investigates the performance of two-sample pseudo-median based procedure in testing differences between groups. The procedure is a modification of the one-sample Wilcoxon procedure using the pseudo-median of differences between group values as the central measure of location. The test was conducted on two groups with moderate sample
sizes of symmetric and asymmetric distributions. The performance of the procedure was measured in terms of Type I error and power rates computed via Monte Carlo methods. The performance of the procedure was compared against the t-test and Mann-Whitney-Wilcoxon test. The findings from this study revealed that the pseudo-median procedure performed very
well in controlling Type I error rates close to the nominal value. The pseudo-median procedure outperformed the MannWhitney-Wilcoxon test and is comparable to the t-test in controlling Type I error and maintaining adequate power.
Ujian Alexander-Govern merupakan ujian kesamaan sukatan memusat yang teguh pada keadaan varians heterogen. Malangnya ujian ini tidak teguh pada keadaan data tidak normal. Adaptasi penganggar teguh seperti penganggar M satu langkah terubah suai (MOM) sebagai sukatan memusat menggantikan min didapati berupaya meningkatkan keteguhan ujian ini apabila dijalankan pada data terpencong. Penganggar ini mempunyai kelebihan berbanding min kerana tidak dipengaruhi oleh data yang tidak normal. Kajian ini mendapati bahawa ujian Alexander-Govern yang telah diubah suai ini berupaya mengawal Ralat Jenis I dengan baik pada data terpencong untuk semua keadaan. Kadar Ralat Jenis I yang dihasilkan kebanyakannya berada di dalam selang kriteria teguh ketat (0.045 hingga 0.055) pada aras keertian 0.05. Berbeza dengan kaedah pengujian asal yang mana pada kebanyakan keadaan, ujian teguh tetapi hanya dengan kriteria liberal (0.025 hingga 0.075), malahan ada kedaan yang mana ujian tidak teguh. Prestasi kaedah yang diubah suai ini juga setanding dengan keadah asal pada keadaan data normal. Kajian ini juga membandingkan kaedah Alexander Govern yang diubah suai dengan kaedah pengujian klasik seperti ujian-t dan ANO VA dan menyaksikan bahawa kaedah klasik tidak teguh pada keadaan varians heterogen.
In Malaysia, nests of Aerodramus fuciphagus (white-nest swiftlet) and Aerodramus maximus (black-nest swiftlet) are
harvested for commercial purposes, as one of the most valuable animal products. The taxonomy of a species is crucial,
as delineating species boundaries is fundamental to discover life’s diversity. However, swiftlet taxonomy has been
controversial, due to numerous undefined parameters. Although there are these limitations, morphological taxonomy
cannot be the unique approach for species identification and it is a valuable component in taxonomy studies. We have
undertaken a morphological approach to analyse community relationships among species of swiftlets. In this study, we
selected three different swiftlet species to generate two sets of comparisons: Within species and among different habitats.
This study found that A. fuciphagus from man-made habitats is generally larger in size compared to the natural habitat and
A. maximus is larger compared with A. fuciphagus. We postulate the difference in body size is due to dietary behaviour
and genetic variations of the swiftlets.
This study was aimed to determine the effect of polysaccharide from guava fruit on paracetamol (PCM)-induced liver injury. Aqueous extract of Psidium guajava fruit was treated with 95% ethanol to collect the water soluble polysaccharide precipitates. Thirty-eight male Sprague Dawley rats were divided into control (C), PPG400, PCM, PPG200+PCM and PPG400+PCM. The control and PCM groups received 0.9% normal saline orally while the rest were given 200 and 400 mg/kg of freeze-dried polysaccharide (PPG) per oral for fourteen days. At day 15, the animals were orally received PCM (2 g/kg) except the control and PPG400 groups which received 5% dimethyl sulfoxide. At day 16, the blood was collected to determine serum liver enzymes such as transaminases (AST and ALT). The liver tissue was harvested for determination of superoxide dismutase (SOD), glutathione (GSH), tumour necrosis factor-α (TNF-α), interleukin-6(IL6), microscopic changes and glycogen content. The PCM group showed significant higher level of AST, ALT, TNF-α and IL6 than those of group C. The PCM group showed glycogen depletion, vacuolisation, loss of cell membrane, inflammatory cells infiltration and distorted hepatocelluar cords and narrow sinusoidal spaces. However, those PCM-induced alterations were attenuated by the PPG supplementation. Therefore, the polysaccharide of Psidium guajava possesses hepatoprotective activity and can be used as a dietary supplementation for protection of liver.
Environmental health in general is referring to the aspect of concern on healthy environment, and the interrelations between environment and human health. Due to the urbanization, urban development is changing the natural environment into a man-made environment. Along with the process, level of environmental quality and human health are decreased. Air quality as reference shows that urban ambient air is more polluted than rural. Due to high density of human population and their activities in urban areas, it produces air pollutants with higher rate as compared to less-developed areas. Air pollutants contribute to various health problems. People suffering from respiratory diseases are the most likely to be affected by air pollution. This paper aimed to examine the rate of respiratory infection among residents in an urban growth corridor (Petaling Jaya-Shah Alam-Klang) and the relationship with the urban land uses, traffic volume and air quality. There were four major types of data used in this study i.e., respiratory infection of the respondents, air quality, land use and traffic volume. A health questionnaire survey was carried out besides the secondary data collection from the various government departments. Relationship analysis was performed between respiratory health and the urban factors (air quality, traffic volume and land uses). The study found out that the relationship between the respiratory health and the urban factors is different in city-wide land use and traffic factors, as compared to the localised air quality and land use factors. To conclude, the urban factors are potentially affecting the respiratory health.
There are many treatment options for localized prostate cancer, and there is clinical equipoise in relation to the treatment outcomes. This study aimed to explore doctors’ approaches to decision support in counseling patients with localized prostate cancer in a country with a less established system of support and care delivery for cancer treatment. Four in-depth
interviews and three focus group discussions were conducted with seven government policy makers/consultant urologists, three oncologists, four private urologists and six urology trainees in Malaysia between 2012 and 2013. Doctors facilitated the treatment decision by explaining about the disease and the treatment options, which included monitoring,
side effects and complications of each treatment option. Paper-based (charts and diagram drawings) or electronic (ipad apps and websites) illustrations and physical models were used as patient education aids. Further reading materials and websites links were often provided to patients. Patients were given time till subsequent follow up to decide on the
treatment and family involvement was encouraged. Referral to other healthcare professionals (oncologist, radiotherapist or other urologist) for second opinion was offered to the patients. The doctors would recommend patients to speak to prostate cancer survivors for peer support but official support groups were not easily accessible. This study highlighted
a multi-faceted approach to support patients with localized prostate cancer in making a treatment decision. It not only involved the doctors (urologist or oncologist) themselves, but also empowered the patients and their social network to support the decision making process.
Oil palm empty fruit bunch graft poly (acrylic acid-co-acrylamide) superabsorbent composite (OPEFB-g-(PAA-co-PAM) SAPC) was synthesized by graft copolymerization of the acrylic acid (AA) and acrylamide (AM) comonomer onto OPEFB fibre using ammonium persulfate (APS) and N,N-methylene bisacarylamide (MBA) as an initiator and crosslinker, respectively. The absorbency in various chloride salt solutions indicated that the absorbency decreased with increasing ionic strength of the salt solutions. Moreover, the absorbency under load (AUL) of SAPC was investigated at various applied loading and results show that, AUL decreased with increasing applied loading. Infrared Spectroscopy (IR) and Thermogravimetric Analysis (TGA) were carried out to confirm the chemical structure and thermal properties of the synthesized superabsorbent, respectively.
Rat bioassay was used to evaluate the nutritional quality of beef burger as influenced by the addition of selected herbs and vegetables. The selected herbs and vegetables used were pucuk ubi (Mannihot esculenta), pucuk gajus (Anacardium occidentale), pegaga (Centella asiatica) and jantung pisang (Musa paradisiaca) as treatment group with casein and skimmed milk as reference. The rats were fed with herbs and vegetables at the rate of 0.5 (low dose) and 25 (high dose) g/kg body weight. The samples were analyzed for proximate analysis, protein quality and protein digestibility. The rats fed with pucuk ubi (high dose) (364.30 ± 25.34 g) indicated the highest mean of increased body weight (121.05 ± 14.65 g) while rats fed with skimmed milk (310.98 ± 18.92 g) showed the lowest mean increase in body weight (88.33 ± 14.25 g). As for the Protein Efficiency Ratio (PER) value, all the rats fed with herbs diet showed PER values that were significantly lower (p<0.05) compared to the casein. As for the in vivo apparent protein digestibility test, casein showed the highest digestibility value (86.33 ± 4.20) while pucuk gajus (high dose) (59.59 ± 5.41) showed the lowest. As for the in vitro digestibility analyses, casein indicated the highest value for in vitro digestibility (93.84 ± 0.33). Administration of herbs and vegetables at low and high doses show significant effects (p<0.05) on nutritional quality of beef burger. In conclusion, it was found that antinutritional factors in selected herbs and vegetables might affect the nutritional quality of beef burger.
In order to optimize the extraction of gelatin from pangasius catfish skin, a response surface method (RSM) involving a Central Composite Design (CCD) was applied. Four variables, namely NaOH concentration (0-0.3 N), acetic acid concentration (0.025-0.125 N), extraction time (2-4 h) and extraction temperature (40-80°C) were selected as independent variables for the optimization using RSM. The dependent variable was calculated by hydroxyproline recovery. The optimum conditions for extraction were produced by a pre-treatment of 0.2 N NaOH and 0.1 N acetic acid along with hot water extraction at 63.7°C for 2.41 h. The results showed that the predicted response by RSM (68.53%) closely matched the experimental response of 68.16%. The results indicated that the extracted gelatin possessed high gel strength (438 g) and high content of imino acid (proline and hydroxyproline) (18.01%) with a viscosity of 4.67 mPa s. The results showed that RSM was a great optimizing tool for extraction of gelatin from pangasius catfish skin. The gelatin was also proven to have significantly (p<0.05) higher quality of physicochemical properties than those from bovine skin gelatin.