Displaying publications 161 - 180 of 2561 in total

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  1. Naomie Salim, Holliday J, Willett P
    This paper describes experiments to study on how well the whole range of topological indices-based non-binary similarity values represents the physicochemical similarities between compounds. Measured log P values have been compared with the log P values predicted from compounds at different range of similarities calculated based on various topological indices of the compounds. Analysis shows that the non-binary Cosine, Simpson and Pearson coefficients might give misleading results when certain compounds are compared. Similarity values involving 1% most similar compounds based on the non-binary Tanimoto or Euclidean coefficients has been found to be able to represent physicochemical similarities between the molecules compared. Therefore, for searches requiring around 1% most similar compounds, rational selection methods based on the non-binary Tanimoto or Euclidean coefficients are likely to produce better results than random selection. Similarity values involving 5% most dissimilar compounds based on the non-binary Tanimoto coefficients has also been found to be able to represent physicochemical dissimilarities between the molecules compared. Therefore, for diverse selection requiring less than 5% most dissimilar compounds, rational selection methods based on the non-binary Tanimoto coefficient is likely to produce better results than random selection. However, in both focused and diverse selection using the coefficients mentioned, as more and more compounds are selected, the selection becomes more and more like random selection in terms of physicochemical properties similarity and dissimilarity.
    Kertas kerja ini membincangkan mengenai kajian untuk melihat sejauh mana nilai keserupaan bukan binari yang dihasilkan melalui perbandingan indeks topologi sebatian mampu mewakili perbezaan atau keserupaan ciri fizikal dan kimia sebatian yang dibandingkan. Di dalam kajian ini, nilai log P yang diperolehi daripada ujikaji makmal telah dibandingkan dengan nilai log P jangkaan yang diambil daripada purata log P sebatian yang mempunyai pelbagai julat nilai keserupaan tertinggi berdasarkan perbandingan indeks tolopologi kesemua sebatian di dalam pangkalan data dengan sebatian berkenaan. Analisa menunjukkan yang pengiraan keserupaan bukan binari menggunakan angkali Cosine, Simpson dan Pearson boleh memberikan nilai keserupaan yang mengelirukan apabila sesetengah jenis sebatian dibandingkan. Nilai keserupaan yang melibatkan 1% sebatian paling serupa berdasarkan angkali Tanimoto atau Euclidean didapati mampu menggambarkan keserupaan ciri fizikal dan kimia sebatian yang dibandingkan. Justeru, carian atau pemilihan berfokus bagi mendapatkan 1% sebatian paling serupa dengan sesuatu sebatian menggunakan angkali Tanimoto dan Euclidean ke atas perwakilan bukan binari sebatian dijangka berkecenderungan memberikan hasil yang lebih memuaskan berbanding dengan pemilihan rambang. Nilai keserupaan yang melibatkan 5% sebatian paling berbeza berdasarkan angkali Tanimoto juga didapati mampu menggambarkan perbezaan ciri fizikal dan kimia molekul yang dibandingkan. Ini menunjukkan yang pemilihan rasional berdasarkan angkali Tanimoto bagi memilih subset yang terdiri daripada 5% molekul paling rencam dari sebuah pangkalan data molekul yang mempunyai perwakilan bukan binari berkecenderungan untuk memberikan hasil yang lebih baik daripadapemilihan secara rambang. Walau bagaimanapun. di dalam kedua-dua pemilihan berfokus atau rencam menggunakan angkali yang dinyatakan, semakin banyak sebatian yang dipilih, hasil yang didapati semakin menyerupai pemilihan secara rawak dari segi keserupaan atau kerencaman ciri fizikal dan kimia.
  2. Ratnawati H, Widowati W
    Hypercholesterolemia is the main risk factor of atherosclerosis which is directly related to coronary heart disease. Velvet bean (Mucuna pruriens L.) is predicted to have potential anticholesterolemia since a previous study showed that this plant had high antioxidant activity. The purpose of this research was to determine the anticholesterol activity of crude extract and ethyl acetate fraction of velvet bean compared to simvastatin and vitamin E in decreasing the plasma level of total cholesterol, LDL and triglyceride and increasing the HDL level on hypercholesterolemic rats. Thirty male Wistar rats were divided into ten groups. Group I was fed with standard diet as negative control group and all the other groups were fed with high-fat diet and were given fructose solution. High-fat diet and fructose solution increased the level of total cholesterol, LDL-cholesterol and triglyceride and decreased the level of HDL-cholesterol significantly compared to the negative control group. The treatment groups were given 3 various doses of crude extract (50, 100, 200 mg/kgBW) and ethyl acetate fraction (15, 30, 60 mg/kgBW) of velvet bean, simvastatin 2.7 mg/kgBW and vitamin E 60 mg/kgBW daily for ten days. The data were analyzed by one way Analysis of Variance (ANOVA) and Duncan’s Post Hoc Test. The best results were shown by 15 mg/kgBW of ethyl acetate fraction in decreasing total cholesterol and 60 mg/kgBW of ethyl-acetate fraction for the LDL-cholesterol, 200 mg/kgBW of crude extract in increasing HDL-cholesterol and 50 and 200 mg/kgBW of crude extract and 60 mg of ethyl acetate fraction in lowering the triglyceride.
  3. Varavut Tanamool, Piyorot Hongsachart, Wichai Soemphol
    Sains Malaysiana, 2018;47:481-488.
    Acetic acid bacteria (AAB) isolated from natural resources and fermented plant beverages were screened to produce
    1,3-dihydroxyacetone (DHA) from non-detoxified crude glycerol. Among them, the isolate NKC115 was identified as
    Gluconobacter frateurii and produced the highest amounts of DHA. Subsequently, the effects of growth-medium conditions
    (initial pH, crude glycerol concentration and nitrogen sources) on growth and DHA-production capability were examined.
    The results showed that the crude glycerol concentration increase to above 100 g/L suppressed growth and DHA production.
    The highest amount of DHA obtained was 27.50 g/L, from an initial crude glycerol concentration of 100 g/L. Meanwhile,
    an initial pH of 5.5-7.5 in the YPGc medium did not significantly affect the bacterial growth and DHA production. The
    optimal nitrogen source was peptone, with DHA production at 34.70 g/L. Furthermore, overexpression of the nhaK2 gene
    encoding for the Na+(K+)/H+ antiporter from Acetobactor tropicalis SKU1100 in G. frateurii NKC115 improved growth
    and increased the accumulation of DHA (37.25 g/L) from an initial crude glycerol concentration of 20%. These results
    indicated that the expression of this antiporter might maintain an optimal intracellular pH and concentration of Na+ or
    K+, leading to the cells’ ability to tolerate high concentrations of crude glycerol.
  4. Suratman S, Hussein A, Mohd Tahir N, Latif M, Mostapa R, Weston K
    Sains Malaysiana, 2016;45:551-558.
    This paper presents the results for surface water quality parameters measured in the Setiu Wetland, on the east coast of Malaysia, which feeds into the southern part of the South China Sea. There are no previous studies dealing with the seasonal and spatial variation of water quality in this area, despite numerous anthropogenic inputs into this ecologically and economically important wetland. The parameters measured were salinity, temperature, dissolved oxygen (DO), pH, biological oxygen demand (BOD) and total suspended solids (TSS). These parameters were sampled monthly from October 2009 to September 2010, during both the wet and dry seasons, at ten sampling stations distributed throughout the area. The physical water quality parameters were measured in situ whilst TSS and BOD were determined using the standard methods. A deterioration of water quality in the Setiu Wetland was observed in areas near agriculture and aquaculture activities. This was expected to be as a result of the use of fertilisers, waste from fish farm food and the waste products of aquaculture. The parameters measured showed lower mean values of surface salinity, temperature, DO, pH and TSS during the wet season relative to the dry season. In contrast, the concentration of BOD was high during the wet season and lowest in the dry season. Results obtained from this study clearly showed the surface physical water quality for the Setiu Wetland was highly influenced by anthropogenic activities and seasonal variation. Therefore, both factors must be considered to move towards proper management of this wetland.
  5. Suratman S, Hussein A, Latif M, Weston K
    Sains Malaysiana, 2014;43:1127-1131.
    Setiu Wetland is located in the southern part of South China Sea, Malaysia. This wetland has diverse ecosystems that represent a vast array of biological diversity and abundance in utilizable natural resources. However, there are large scales of aquaculture activities within and nearby the wetland which could threaten the ecosystems of this area. Thus, the main goal of the study was to assess the impact of these activities through the measurement of physico-chemical water quality parameters and then compare this to a previous study carried out in the same study area. The parameters (salinity, temperature, pH, dissolved oxygen, biological oxygen demand and total suspended solids) were monitored monthly at the surface water from July to October 2008. The results showed that the impact of aquaculture activities on the water quality in the area with dissolved oxygen and total suspended solids concentrations were considerably lower than those observed previously. With respect to the Malaysian Marine Water Quality Criteria and Standard, most of the level of parameters measured remained Class 1, suggesting the physico-chemical environment were in line with sustainable conservation of the marine protected areas and marine parks of this wetland area.
  6. Dongsheng Li, Wenfei Xi
    Sains Malaysiana, 2017;46:2119-2124.
    The DEM construction of high and steep slope has great importance to slope disaster monitoring. The conventional method used to construct high and steep slope DEM model requires larger field surveying workload. First of all, the high and steep slope image was obtained through unmanned aerial vehicle (UAV) platform; Then the SIFT algorithm is used to extract the feature points which are going to be matched accurately by using RANSAC algorithm. Finally, stereo pair splicing method is used to generate orthogonal images and construct DEM model. After comparing the DEM model with actual slope measurement result collected by total station finding, it is shown that elevation error between the DEM model constructed by unmanned aerial vehicle (UAV) and actual measurement is minimal and its efficiency is proven.
  7. Roszaini Md Salleh, Abdul Rahman Mohamed, Raihana Bahru, Wei-Ming Yeoh
    Sains Malaysiana, 2018;47:393-402.
    A simple method of growing carbon nanostructures (CNS), a mixture of carbon nanotube (CNT) and carbon nanofiber (CNF),
    directly on a nickel catalyst layer electroplated on the copper substrate at low reaction temperature and atmospheric
    pressure via chemical vapor deposition (CVD) was investigated in this study. The nickel catalyst was prepared using
    electroplating methods and the current density was varied to give the nickel catalyst layer with different thicknesses
    and grain sizes prior to the growth of CNS which was carried out at 600°C and under a mixture of 25 sccm: 100 sccm of
    acetylene to nitrogen for 40 min. A nickel catalyst layer electroplated at 1 mA/cm2, which possess a smaller grain size and
    thinner layer of nickel catalyst, enables the synthesis of high quality and dense CNS as well as high ratio of CNT over CNF.
  8. Wararit Panichkitkosolkul
    Sains Malaysiana, 2014;43:1623-1633.
    A unit root test based on the modified least squares (MLS) estimator for first-order autoregressive process is proposed and compared with unit root tests based on the ordinary least squares (OLS), the weighted symmetric (WS) and the modified weighted symmetric (MWS) estimators. The percentiles of the null distributions of the unit root test are also reported. The empirical probabilities of type I error and powers of the unit root tests were estimated via Monte Carlo simulation. The simulation results showed that all unit root tests can control the probability of type I error for all situations. The empirical power of the test is higher than the other unit root tests, and Apart from that, the and tests also provide the highest empirical power. As an illustration, the monthly series of U.S. nominal interest rates on three-month treasury bills is analyzed.
  9. Kaewbuddee C, Chanpiwat P, Kidkhunthod P, Wantala K
    Sains Malaysiana, 2016;45:1155-1167.
    The aims of this work were to investigate the characteristics of nanoscale zero valent irons (nZVI) coupled with mesoporous
    materials (RH-MCM-41) adsorbent and to study the removal mechanisms of Pb (II) from synthetical solutions using full
    pictorial design batch experiments. Synthetic nZVI coupled with RH MCM-41 as Pb (II) adsorbent were characterized
    by XRD, TEM, BET and XANES. The results of XANES analyses confirmed the ability of RH-MCM-41 to prevent oxidations of
    Fe0
    to Fe2+ and Fe3+. XANES results also verified the oxidation states of Pb (II). The solution pH was the most significant
    positive effect in controlling Pb (II) adsorption. The equilibrium and kinetic adsorption isotherms well fitted with the
    Langmuir isotherm. The pseudo-second order kinetic adsorption indicated that the adsorption process is the rate limiting
    step for Pb (II) removal. Furthermore, Langmuir-Hinshelwood confirmed the obvious Pb (II) adsorption at the active
    site of adsorbents. The reduction rate constant (kr
    = 5,000 mg/L.min) was higher than the adsorption rate constant (Kad
    = 0.0002 L/mg). Regarding the research results, four pathways including: reduction process, adsorption on FeOOH,
    adsorption on RH-MCM-41 and complex reaction between Fe and Pb ions were suggested for Pb (II) removal by nZVI
    coupled with RH-MCM-41.
  10. De Luna M, Millanar J, Yodsa-Nga A, Wantala K
    Sains Malaysiana, 2017;46:274-283.
    Toluene and benzene are hazardous air pollutants commonly found in the atmosphere at relatively high concentrations. Due to this, a need to remove these pollutants became a necessity. In this study, octahedral molecular sieve type manganese oxide (K-OMS 2) prepared by hydrothermal method was utilized to decompose toluene and benzene. X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmet-Teller (BET), X-ray absorption near edge structure (XANES) analysis were used to investigate the crystallinity, morphology, surface area and oxidation state of K-OMS 2, respectively. It was confirmed that K-OMS 2 was successfully produced from hydrothermal method. Central composite design (CCD) was used to investigate the main and interaction effects of gas hourly space velocity (GHSV) and reaction temperature on the thermal catalytic oxidation of benzene and toluene. Both factors were found to have significant main and interaction effects on toluene oxidation. However, only the main effects of the factors were significant for benzene. This result was due to the difference in the stability of the structures of the two VOCs. The K-OMS 2 obtained has excellent efficiency on toluene and benzene removal. Toluene was completely decomposed at a temperature as low as 250°C while benzene decomposition reached around 98% at 292.4°C.
  11. Chansiriwat W, Tanangteerapong D, Wantala K
    Sains Malaysiana, 2016;45:1723-1731.
    The aim of this research was to synthesize zeolite from coal fly ash by hydrothermal method. The effect of aging temperature
    and time on zeolite P1 synthesis (Na-P1) from Mae Moh coal fly ash (MFA) without adding any alumina and silica sources
    were examined during the synthesized process. The central composite design (CCD) was used for experimental design
    to obtain the optimal process parameters of the aging temperature (105-195ºC) and time (12-84 h) where the specific
    surface area was used as a response. The chemical and physical properties of Na-P1 such as specific surface area,
    crystalline phase, compositions and morphology were examined. The response results showed that the specific surface
    area of Na-P1 decreased with an increase of both aging temperature and time, whereas the XRD intensity of Na-P1
    increased with an increase of both aging temperature and time. The composition of SiO2
    /Al2
    O3
    in mass ratio of coal fly
    ash was observed, which was suitable to Na-P1 synthesis. The maximum specific surface area of zeolite products was
    found at the designed condition of aging temperature of 105ºC and time of 12 h. Thus, zeolite P1 can be prepared by
    hydrothermal method without adding any alumina and silica sources.
  12. Khoomsab K, Wannasri S
    Sains Malaysiana, 2017;46:851-858.
    The biological aspects of Channa limbata were studied between November 2013 and October 2014. A total of 346 fish specimens, 185 male and 161 female, were collected from Ta Bo, Huai Yai Wildlife Sanctuary, Phetchabun Province, Thailand. Specimens range from 7.3-17.2 cm in length with body weight 8-31 g; sex ratio between males and females was 1: 0.7. The length (L), weight (W) relationship for mixed sexes was W = 0.2064 L1.85 (R2=0.90). Gonadosomatic indices for males and females were measured monthly and varied from 0.21-0.65% and 1.96-3.74%, respectively. Condition factors for males and females ranged between 0.54 - 2.20 and 0.58 - 2.72, respectively, with fecundity range 956 to 4,652 eggs in females. Fecundity (F) to weight relationship was F = 189.53 W0.59 (R2 = 0.71) and fecundity to length relationship was F = 68.82 L1.15 (R2 = 0.77). The ratio between the intestine length and total length was 1:2, indicating that C. limbata was a carnivorous feeder. Analysis of the stomach contents gave 84% insects and 16% aquatic weed. These results can be applied to conserve efforts to prevent the extinction of C. limbata in protected areas.
  13. Nizam M, Rohani S, Wanjuliana W
    Sains Malaysiana, 2012;41:1-10.
    A study was conducted at Kenong Forest Park, Kuala Lipis, Pahang, to determine species composition and floristic variation of tree communities in two distinct habitats. Two plots of one hectare each were established adjacent to a limestone cave (BK) and in a lowland area (TR) of the forest park. A total of 2091 tree individuals with diameter at breast height (dbh) of 5.0 cm and above were enumerated in both plots where 1091 trees and 1000 trees occurred in the plots BK and TR, respectively. Floristic composition of tree communities at BK plot comprised of 45 families, 110 genera and 199 species, whilst the TR plot contained 232 tree species and 133 genera from 50 families. Altogether, combination of both plots produced floristic composition of 322 species, 161 genera and 54 families. Euphorbiaceae was the most speciose family for both plots, represented by 30 and 27 species in BK and TR plots, respectively. The most dominant species in the BK plot was Streblus ilicifolius (Moraceae) with Importance Value Index (IVi) of 19.18%, whilst in the TR plot, Intsia palembanica (Leguminosae) was the most dominant species with IVi of 14.58%. Total tree basal area for BK and TR plots was 26.91 m2/ha and 29.23 m2/ha, respectively, with Leguminosae dominated basal area in both plots. The Shannon-Weiner diversity Index (H’) of tree communities in both plots show high diversity values where the BK plot indicates H’ value of 4.42 (H’max= 5.26) while the TR plot shows H’ value of 4.79 (Hmax= 5.44), of which the values were different significantly (P<0.05). Community similarity between the two plots was moderate with Sorenson Similarity Index for species composition showed a value of 0.48 (48%). The ordination diagram constructed using Detrended Correspondence Analysis (DCA) demonstrated floristic variation between the two study plots. The DCA obviously separated plots between sites and this indicated a gradient of species change from the BK to the TR sites.
  14. Liu JH, Yong XH, Zhen Li, Du SF, Zhang ZW, Meng XF, et al.
    Sains Malaysiana, 2015;44:347-354.
    The effect of maternal mowing on seed traits of an invasive weed, Erigeron annuus, in farmland was discussed by
    comparing mowing plants with intact (no-mowing) plants. The maternal mowing effect resulted in the decrease of seed
    mass, achene size, pappus length and germination percentage and the increase of variation in achene size, pappus length,
    dispersal distance and germination non-uniformity. To some extent, the individuals suffered mowing might accelerate
    the environmental adaptation through the increase of these variations. Our study indicated the mean of mowing in
    farmland will restrain the growth and reproduction of weed E. annuus. However, it also increases the diversity of seeds
    through a more unequal provision to seeds that shares the risk and increases fitness to a wider range of heterogeneity
    of farmland condition.
  15. Li QY, Tao JP, Zhong ZC, Wang YJ
    Sains Malaysiana, 2014;43:161-168.
    Growth performance, sexual reproduction and clonal propagation of I. japonica population in contrast reciprocal habitats; Open Area of Forest Edge (OAFE) and Bamboo Forest (BF) on Jinyun Mountain were studied to understand the adaptability of growth and reproductive of I. japonica in different habitats. The results were as follows: quantitative characteristics of growth and clonal propagation of I. japonica at genet (a group of genetically identical individuals, consists of whole ramets) level and at ramet (a unit composed of a shoot and root, with independent morphological and physiological traits in the same genet) level were higher in BF. However, quantitative characteristics of sexual reproduction at genet and ramet level were higher in OAFE. Biomass and allocation also showed the same trend as quantitative characteristics. Reproductive components (at ramet level) were significantly different and had trade- off in contrast reciprocal habitats. Allocation to clonal propagation and sexual reproduction of mother ramet was significantly negative correlation with allocation to daughter ramet (especially in BF). There was a trade-off between reproduction components (allocation to sexual reproduction and clonal propagation of mother ramet) in OAFE. Therefore, it showed predominantly sexual reproduction in OAFE and clonal propagation in BF. The results indicated that the contrast environmental stress shaping growth performance and reproduction variation of I. japonica in genet and ramet level in contrasting habitats might pronounce adaptive population differentiation among forest habitats.
  16. Li QY, Zhang ZW, Tao JP, Liu JH, Yong XH, Meng XF, et al.
    Sains Malaysiana, 2014;43:1119-1125.
    Due to widespread distribution of dwarf bamboo, Chimonobambusa utilis, in mountain environment, the effects of elevation (low and high) and canopy condition (forest understorey and forest edge) on the clonal morphology and leaf fluctuating asymmetry were investigated in an evergreen broadleaves forest of Jinfo Mountain Nature Reserve. Elevation and canopy condition were significant for all morphological traits of C. utilis (except for effect of elevation on node number under branch). Traits of clonal morphology such as height, basal diameter, height under branch tended to be higher in forest understorey and in high elevation. Forest understorey in high elevation was favour of shooting number. Interaction of elevation and canopy conditions had a significant effect on growth of node. Single leaf area (SLA) and all indices of fluctuating asymmetry were significantly higher in low elevation than that in high elevation of forest understorey. Thus, elevation and canopy condition formed environmental stress that lead to the adaptation of morphological traits and leaf fluctuating asymmetry of C. utilis populations to mountain forest habitats.
  17. Musalmah Mazlan, Rehanna Mansor, Wan Zurinah Wan Ngah
    Sains Malaysiana, 2010;39:315-320.
    Recent studies suggest that reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) may exert beneficial effects on health. Therefore this study evaluated the effects of H2O2 and gamma-tocotrienol (GTT), an antioxidant, on D-[2-3H]Glucose uptake by myotubes compared to insulin. Results showed that H2O2 and insulin significantly increased D-[2-3H]Glucose uptake. This was associated with an increased in Vmax but Michaelis constant (Km) of the transport system remained unchanged indicating that an increase in amount, rather than affinity, of the glucose transporter was involved in the process. Western blot studies confirmed that H2O2 increased the expressions of insulin sensitive glucose transporter, GLUT4 and also hexokinase (an enzyme which phosphorylates glucose and indirectly stimulates glucose uptake by cells). H2O2 and insulin also stimulated increased in PPAR-γ and IRS-1, which are proteins of the insulin transduction pathway. The present data however showed that GTT did not exert any effect on glucose uptake. Thus, the study showed that H2O2 mimicked insulin action in stimulating glucose uptake in myotube cells by influencing the insulin signaling pathway.
  18. Muhammad Faizan A. Shukor, Noor Akmal Shareela Ismail, Wan Zurinah Wan Ngah
    Sains Malaysiana, 2018;47:2543-2556.
    Coronary artery disease (CAD) predominantly manifests in older population above the age of 60 years old. The incidence
    of CAD in younger individuals has been reported and is called premature CAD (pCAD). The prevalence for pCAD in
    individuals below 45 years old is about 3-10% worldwide. Advances in risk prediction are of great importance as
    absolute values of risk factors sometimes correlate poorly with individuals. The measurement of traditional risk factors
    such as cholesterol level and blood pressure might be inadequate to predict risk for pCAD and therefore new biomarkers
    are required. The introduction of omics technology offers insight into the mechanism and interactions involved during
    disease progression and open the possibilities of discovering new biomarkers. Currently, new potential biomarkers for
    pCAD have been explored such as homocysteine, apolipoproteins, microRNAs and single nucleotide polymorphisms. In
    this review, we discussed the associated risk factors for pCAD, several reported and newly proposed biomarkers and
    their potential to be used clinically.
  19. Goon JA, Haryati Ahmad Hairi, Suzana Makpol, Mariati Abdul Rahman, Saiful Anuar Karsani, Wan Zurinah Wan Ngah
    Sains Malaysiana, 2011;40:1247-1253.
    Replicative senescence of human diploid fibroblasts (HDFs) occurs when cells lose their capacity to proliferate and enter a phase of irreversible growth arrest. Stress-induced premature senescence (SIPS) on the other hand is caused by subcytotoxic concentrations of various oxidants which trigger accelerated cellular senescence. In this study, a SIPS model was established by exposing human diploid fibroblasts (HDFs) to 20 μM H2O2 for 2 weeks. A proteomic comparison between young, senescent and SIPS cells was done using two dimensional gel electrophoresis (2DGE) to elucidate the changes in protein expression associated with cellular aging. Our analysis showed that 28 protein spots were differentially expressed in senescent cells whereas 10 protein spots were differentially expressed in SIPS as compared to young cells. Three similar protein spots were differentially expressed in both senescent and SIPS cells when compared to the young cells. These results indicate that a difference in protein expression exists between senescent cells and SIPS cells compared to young cells.
  20. Nur ‘Aishah Zarime, Wan Zuhairi Wan Yaacob
    Sains Malaysiana, 2016;45:1905-1912.
    Penyelidikan ini mengkaji tingkah laku cadmium (Cd) melalui tanah baki granit yang dipadatkan. Sampel tanah baki granit telah diambil di kawasan Broga, Selangor dan dikaji menggunakan tiga kaedah ujian utama iaitu; ujian fizikal (taburan saiz butiran, had-had Atterberg, graviti tentu, pemadatan dan kebolehtelapan), ujian kimia (pH, bahan organik, luas permukaan spesifik (SSA) dan kadar pertukaran kation (CEC) serta ujian mini kolum turasan. Melalui ujian kolum turasan, konsep kebolehtelapan turus menurun digunakan yang melibatkan tiga faktor iaitu halaju/daya-G, ketebalan sampel dan jenis larutan yang digunakan. Graf lengkung bulus menunjukkan kepekatan Cd dalam tanah baki granit semakin meningkat dengan peningkatan halaju. Urutan kapasiti penjerapan semakin meningkat terhadap kadar putaran alat emparan/daya tarikan graviti (G); 230G>520G>920G>1440G. Pergerakan logam berat melalui tanah baki juga meningkat dengan peningkatan halaju/daya-G. Lengkung bulus juga menunjukkan pergerakan Cd secara songsang dengan ketebalan lapisan tanah di dalam kolum. Masa penembusan bagi ketebalan 20 mm juga lebih lama berbanding ketebalan 15 dan 10 mm. Manakala jumlah Cd yang terjerap oleh tanah baki granit dalam larutan campuran adalah rendah berbanding larutan tunggal (masa yang singkat untuk menembusi lengkung bulus). Tanah baki granit juga mempunyai kapasiti penampanan yang rendah (pHfinal = 4 - 7). Kajian ini menunjukkan bahawa pencirian fiziko-kimia dan sifat penjerapan tanah dengan menggunakan ujian mini kolum turasan mempunyai kaitan yang kuat untuk mencirikan tanah baki granit untuk dijadikan pelapik lempung tereka bentuk.
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