Displaying publications 1 - 20 of 47 in total

Abstract:
Sort:
  1. Tiong SH, Nair A, Abd Wahid SA, Saparin N, Ab Karim NA, Ahmad Sabri MP, et al.
    PMID: 34407744 DOI: 10.1080/19440049.2021.1960430
    Chlorinated compounds such as sphingolipid-based organochlorine compounds are precursors for the formation of 3-monochlororopanediol (3-MCPD) esters in palm oil. This study evaluates the effects of several factors within the palm oil supply chain on the levels of sphingolipid-based organochlorine, which in turn may influence the formation of 3-MCPD esters during refining. These factors include application of inorganic chlorinated fertiliser in the oil palm plantation, bruising and degradation of oil palm fruits after harvest, recycling of steriliser condensate as water for dilution of crude oil during oil palm milling, water washing of palm oil and different refining conditions. It was observed that bruised and degraded oil palm fruits showed higher content of sphingolipid-based organochlorine than control. In addition, recycling steriliser condensate during milling resulted in elevated content of sphingolipid-based organochlorine in palm oil. However, the content of sphingolipid-based organochlorine compounds was reduced by neutralisation, degumming and bleaching steps during refining. Although water washing of crude palm oils (CPO) prior to refining did not reduce the content of sphingolipid-based organochlorine, it did reduce the formation of 3-MCPD esters through the removal of water-soluble chlorinated compounds. It was found that the use of inorganic chlorinated fertiliser in plantations did not increase the content of chlorinated compounds in oil palm fruits and extracted oil, and hence chlorinated fertiliser does not seem to play a role in the formation of 3-MCPD esters in palm oil. Overall, this study concluded that lack of freshness and damage to the fruits during transport to mills, combined with water and oil recycling in mills are the major contributors of chlorinated precursor for 3-MCPD esters formation in palm oil.
    Matched MeSH terms: Hydrocarbons, Chlorinated/analysis*
  2. El-Sheikh MA, Hadibarata T, Yuniarto A, Sathishkumar P, Abdel-Salam EM, Alatar AA
    Chemosphere, 2020 Nov 04.
    PMID: 33220978 DOI: 10.1016/j.chemosphere.2020.128873
    Since a few centuries ago, organochlorine compounds (OCs) become one of the threatened contaminants in the world. Due to the lipophilic and hydrophobic properties, OCs always discover in fat or lipid layers through bioaccumulation and biomagnification. The OCs are able to retain in soil, sediment and water for long time as it is volatile, OCs will evaporate from soil and condense in water easily and frequently, which pollute the shelter of aquatic life and it affects the function of organs and damage system in human body. Photocatalysis that employs the usage of semiconductor nanophotocatalyst and solar energy can be the possible alternative for current conventional water remediation technologies. With the benefits of utilizing renewable energy, no production of harmful by-products and easy operation, degradation of organic pollutants in rural water bodies can be established. Besides, nanophotocatalyst that is synthesized with nanotechnology outnumbered conventional catalyst with larger surface area to volume ratio, thus higher photocatalytic activity is observed. In contrast, disadvantages particularly no residual effect in water distribution network, requirement of post-treatment and easily affected by various factors accompanied with photocatalysis method cannot be ignored. These various factors constrained the photocatalytic efficiency via nanocatalysts which causes the full capacity of solar photocatalysis has yet to be put into practice. Therefore, further modifications and research are still required in nanophotocatalysts' synthesis to overcome limitations such as large band gaps and photodecontamination.
    Matched MeSH terms: Hydrocarbons, Chlorinated
  3. Marsin FM, Wan Ibrahim WA, Nodeh HR, Sanagi MM
    J Chromatogr A, 2020 Feb 08;1612:460638.
    PMID: 31676087 DOI: 10.1016/j.chroma.2019.460638
    Magnetic solid phase extraction (MSPE) employing oil-palm fiber activated carbon (OPAC) modified with magnetite (Fe3O4) and polypyrrole (OPAC-Fe3O4-PPy) was successfully used for the determination of two organochlorine pesticides (OCPs), namely endosulfan and dieldrin in environmental water samples. Analysis was performed using gas chromatography with micro-electron capture detection (GC-μECD). The effects of three preparation variables, namely Fe3O4:OPAC ratio, amount of pyrrole monomer, and amount of FeCl3 oxidant were optimized using Box-Behnken design (BBD) (R2 < 0.99, p-value < 0.001%). The optimum conditions were as follows: Fe3O4:OPAC ratio of 2:1 w/w, 1 g of FeCl3 and 100 μL of pyrrole monomer. The experimental results obtained agreed satisfactorily with the model prediction (> 90% agreement). Optimized OPAC-Fe3O4-PPy composite was characterized using field emission scanning electron microscope, vibrating sample magnetometer and Fourier transform infrared spectroscopy. Four numerical parameters of MSPE procedure was optimized using BBD. The significance of the MSPE parameters were salt addition > sample solution pH > extraction time and desorption time. Under the optimized conditions (extraction time: 90 s, desorption time: 10 min, salt: 0%, and pH: 5.8), the method demonstrated good linearity (25-1000 ng L-1) with coefficients of determination, R2 > 0.991, and low detection limits for both endosulfan (7.3 ng L-1) and dieldrin (8.6 ng L-1). The method showed high analyte recoveries in the range of 98.6-103.5% for environmental water samples. The proposed OPAC-Fe3O4-PPy MSPE method offered good features such as sustainability, simplicity, and rapid extraction.
    Matched MeSH terms: Hydrocarbons, Chlorinated/analysis*
  4. Norrabiátul Adawiyah, A., Teh, L.K., Fathimah, M., Nuraliza, A.S.
    Medicine & Health, 2020;15(1):54-69.
    MyJurnal
    Penuaan ovari telah dikaitkan dengan tekanan oksidatif dan kehilangan fungsi ovari. Tokotrienol telah dibuktikan dapat memberi kesan yang baik terhadap sistem pembiakan wanita. Walau bagaimanapun, peranan tokotrienol ke atas metabolisma ovari dan seterusnya peningkatan kualiti oosit dalam mencit tua masih tidak diketahui. Oleh itu, hubungan antara perubahan aktiviti metabolik dalam ovari dan kualiti oosit dalam mencit tua selepas suplementasi fraksi kaya tokotrienol (TRF) telah dikaji. Mencit betina berusia enam minggu digunakan sebagai kumpulan Muda. Mencit betina berusia enam bulan dibahagikan kepada empat kumpulan iaitu kumpulan pertama yang diberikan minyak jagung-bebas tokoferol (kawalan) manakala tiga kumpulan yang lain diberi suplimen TRF pada dos 90, 120, dan 150 mg/kg. Rawatan diberikan secara oral selama dua bulan. Pada akhir rawatan, mencit dari semua kumpulan disuperovulasi dan kemudian dikorbankan. Kualiti oosit dinilai dan analisis metabolomik secara tidak disasarkan, pada tisu ovari dijalankan dengan menggunakan 'liquid chromatography tandem mass spectrometry of quadrupole time-of-flight' (LC-MS Q-TOF). Peratusan oosit normal adalah lebih tinggi (p
    Matched MeSH terms: Hydrocarbons, Chlorinated
  5. Sabihah, A., Shamsuriani, M.J., Mohd Hisham, M.I., Afliza, A.B., Nidzwani, M.M., Tan, T.L., et al.
    Medicine & Health, 2020;15(1):88-95.
    MyJurnal
    Pendidikan kemahiran resusitasi kardiopulmonari (CPR) kepada orang awam sangat penting dalam merendahkan kadar kematian serangan jantung. American Heart Association mencadangkan kemahiran tersebut harus dimasukkan ke dalam kurikulum sekolah. Pelatih rakan sebaya adalah kaedah yang berkos rendah dan berkesan dalam mencapai objektif ini. Objektif kajian terkawal 3 bulan ini adalah untuk membandingkan keberkesanan pengajaran kompresi CPR antara rakan sebaya dan jurulatih Basic Life Support (BLS) kepada pelajar sekolah menengah. Peningkatan pengetahuan dan kemahiran psikomotor pemampatan CPR adalah hasil utama yang dinilai. Dua belas pelatih rakan sebaya berusia 16 tahun dan dua belas pelatih BLS telah direkrut dalam kajian ini. Kompresi CPR diajarkan kepada 36 pelajar sekolah menengah secara rawak oleh pelatih rakan sebaya (Kumpulan P) atau pelatih BLS (Kumpulan B). Pra-ujian, pasca ujian serta ujian pengekalan 3 bulan mengenai pengetahuan dan kemahiran psikomotor telah dijalankan. Tidak terdapat perbezaan yang signifikan secara statistik dalam skor min pengetahuan dan psikomotor pada pra-ujian, pasca ujian serta ujian pengekalan 3 bulan antara Kumpulan P dan Kumpulan B. Terdapat peningkatan skor pengetahuan yang signifikan antara pra-ujian dan pasca ujian dalam Kumpulan P (perbezaan min 5.8+2.7, p
    Matched MeSH terms: Hydrocarbons, Chlorinated
  6. Shamsuriani, M.J., Norhidayah, M.S.
    Medicine & Health, 2020;15(1):218-224.
    MyJurnal
    Pengurusan kendiri asma menggunakan pelan tindakan asma secara bertulis (WAAP) penting dalam memastikan pengurusan asma yang berkesan kerana ia mengurangkan kadar kehadiran ke hospital. Kajian ini menilai peningkatan pengetahuan dan kawalan asma menggunakan WAAP di kalangan pesakit asma di Jabatan Kecemasan. Kajian cubaan kawalan rawak ini dijalankan selama 19 bulan di Jabatan Perubatan Kecemasan sebuah hospital universiti. Kajian ini melibatkan pesakit dewasa serangan asma ringan dan sederhana. Pesakit dibahagikan secara rawak kepada dua kumpulan iaitu kumpulan intervensi dan kawalan. Soal selidik pengetahuan penyakit asma diberikan pada pesakit. Pesakit dari kedua kumpulan menerima kaunseling tentang penyakit asma berdasarkan risalah asma yang telah disediakan. Kumpulan intervensi, kemudiannya menerima kaunseling WAAP mengikut keperluan individu tersebut. Kumpulan kawalan menerima kaunseling lisan berdasarkan perawatan. Susulan kajian dijalankan pada 1 dan 3 bulan. Pengetahuan penyakit asma dan kawalan penyakit asma dinilai melalui tinjauan telefon. Lima puluh pesakit telah dibahagikan secara rawak kepada kumpulan intervensi dan kawalan. Setiap kumpulan menerima 25 pesakit. Skor pengetahuan kumpulan intervensi jauh lebih tinggi daripada kawalan (16.88+0.44 vs 13.36+3.72; p19) pada 1 bulan berbanding kumpulan kawalan (20.64+3.26 vs 17.72+4.17). Kedua-dua kumpulan mencapai kawalan yang baik pada 3 bulan. Pengurusan kendiri asma dengan menggunakan WAAP di Jabatan Kecemasan meningkatkan pengetahuan dan kawalan asma di kalangan pesakit yang mendapat serangan asma ringan dan sederhana.
    Matched MeSH terms: Hydrocarbons, Chlorinated
  7. Adamu A, Abdul Wahab R, Aliyu F, Abdul Razak FI, Mienda BS, Shamsir MS, et al.
    J Mol Graph Model, 2019 11;92:131-139.
    PMID: 31352207 DOI: 10.1016/j.jmgm.2019.07.012
    Dehalogenases continue to garner interest of the scientific community due to their potential applications in bioremediation of halogen-contaminated environment and in synthesis of various industrially relevant products. Example of such enzymes is DehL, an L-2-haloacid dehalogenase (EC 3.8.1.2) from Rhizobium sp. RC1 that catalyses the specific cleavage of halide ion from L-2-halocarboxylic acids to produce the corresponding D-2-hydroxycarboxylic acids. Recently, the catalytic residues of DehL have been identified and its catalytic mechanism has been fully elucidated. However, the enantiospecificity determinants of the enzyme remain unclear. This information alongside a well-defined catalytic mechanism are required for rational engineering of DehL for substrate enantiospecificity. Therefore, using quantum mechanics/molecular mechanics and molecular mechanics Poisson-Boltzmann surface area calculations, the current study theoretically investigated the molecular basis of DehL enantiospecificity. The study found that R51L mutation cancelled out the dehalogenation activity of DehL towards it natural substrate, L-2-chloropropionate. The M48R mutation, however introduced a new activity towards D-2-chloropropionate, conveying the possibility of inverting the enantiospecificity of DehL from L-to d-enantiomer with a minimum of two simultaneous mutations. The findings presented here will play important role in the rational design of DehL dehalogenase for improving substrate utility.
    Matched MeSH terms: Hydrocarbons, Chlorinated/chemistry*
  8. Elia-Amira NMR, Chen CD, Low VL, Lau KW, Haziqah-Rashid A, Amelia-Yap ZH, et al.
    J Med Entomol, 2019 10 28;56(6):1715-1725.
    PMID: 31290534 DOI: 10.1093/jme/tjz117
    Resistance status of Aedes albopictus (Diptera: Culicidae) collected from Sabah, East Malaysia, was evaluated against four major classes of adulticides, namely pyrethroid, carbamate, organochlorine, and organophosphate. Adult bioassays conforming to WHO standard protocols were conducted to assess knockdown and mortality rates of Ae. albopictus. Among tested pyrethroid adulticides, only cyfluthrin, lambda-cyaholthrin, and deltamethrin were able to inflict total knockdown. The other adulticide classes mostly failed to cause any knockdown; the highest knockdown rate was only 18.33% for propoxur. With regards to mortality rate, Ae. albopictus was unanimously susceptible toward all pyrethroids, dieldrin, and malathion, but exhibited resistance toward bendiocarb, propoxur, dichlorodiphenyltrichloroethane, and fenitrothion. Additionally, correlation analysis demonstrated cross-resistance between bendiocarb and propoxur, and malathion and propoxur. In conclusion, this study has disclosed that pyrethroids are still generally effective for Aedes control in Sabah, Malaysia. The susceptibility status of Ae. albopictus against pyrethroids in descending order was cyfluthrin > lambda-cyhalothrin > deltamethrin > etofenprox > permethrin.
    Matched MeSH terms: Hydrocarbons, Chlorinated/pharmacology
  9. Oscar Crehan, James Mair, Siang Hii Yii, Che Din Mohd Safuan, Zainudin Bachok
    Trop Life Sci Res, 2019;30(2):1-18.
    MyJurnal
    Terumbu karang adalah ekosistem yang paling mempunyai kepelbagaian biologi di planet ini. Terumbu karang hanya dijumpai dalam lingkungan pengecilan parameter julat yang sempit, yang meletakkan terumbu karang berisiko di seluruh dunia. Terumbu karang dipengaruhi oleh kesan antropogenik dan alam sekitar yang mengubah taburan genera karang. Memahami di mana jenis karang yang berbeza terletak dan bagaimana setiap genus terjejas oleh tekanan tempatan dan global adalah penting untuk pemuliharaan. Teknik coral video transect mula digunakan pada bulan Mei 2016 untuk membandingkan taburan genera karang di tapak yang dipengaruhi oleh faktor-faktor yang berbeza. Tapak yang mempunyai impak paling sedikit mencatatkan pelitupan karang yang paling tinggi, tapak yang berkaitan dengan sedimen mencatatkan pelitupan yang paling rendah, dan tapak yang mempunyai aktiviti pelancongan yang tinggi mempunyai pelitupan alga yang paling besar. Acropora didapati dominan di Kepulauan Bidong dan Pulau Redang, manakala Favia, Fungia dan Porites mempunyai perlindungan karang yang agak tinggi di setiap tapak
    Matched MeSH terms: Hydrocarbons, Chlorinated
  10. Osman BE, Khalik WMAWM
    Data Brief, 2018 Oct;20:999-1003.
    PMID: 30225314 DOI: 10.1016/j.dib.2018.08.178
    The main goal of this research work is to measure the concentration levels of organochlorine residue in soil. The potential health risk of this pollutant on human was also determined. 10 samples were taken from a lowland paddy field situated in Kelantan, Malaysia. Physical parameters namely soil pH, organic carbon content, water content and particle size were identified to evaluate the quality of soil from the agriculture site. Soxhlet extraction and florisil clean-up process were applied to isolate 10 targeted organochlorine compounds prior to the final determination using a gas chromatography-electron capture detector. Soil from the lowland has characteristics such as slightly acidic, low organic carbon content, high water content and texture dominated by the sandy type. Concentration levels of six detected organochlorine pesticides were calculated in µg/kg. Hazard quotient value in all samples was less than the acceptable risk level HQ ≤ 1, thus reflecting the status of soil in the subjected area as unlikely to pose any adverse health effects.
    Matched MeSH terms: Hydrocarbons, Chlorinated
  11. Elia-Amira NMR, Chen CD, Lau KW, Lee HL, Low VL, Norma-Rashid Y, et al.
    J Econ Entomol, 2018 09 26;111(5):2488-2492.
    PMID: 29982497 DOI: 10.1093/jee/toy184
    The present study aims to investigate the susceptibility status of Aedes albopictus (Skuse) collected from residential areas in Sabah, Malaysia towards eight WHO-recommended dosages of larvicides representing the classes of organophosphates and organochlorines. Field and reference strains of Ae. albopictus larvae were bioassayed in accordance to WHO standard methods using diagnostic dosages of bromophos, malathion, fenthion, fenitrothion, temephos, chlorpyrifos, dichlorodiphenyltrichloroethane (DDT), and dieldrin. The results revealed that Ae. albopictus was resistant (mortality < 90%) towards malathion, temephos, and DDT. In addition, most of the Ae. albopictus strains exhibited a wide range of susceptibilities against bromophos, with mortality ranged from 49.33 to 93.33%. On the contrary, only dieldrin was able to induce 100% mortality against all strains of Ae. albopictus. Tolerance to fenitrothion, fenthion, and chlorpyrifos, with mortality ranging from 81.33 to 97.33%, was also observed in this study.
    Matched MeSH terms: Hydrocarbons, Chlorinated*
  12. Leong CS, Vythilingam I, Wong ML, Wan Sulaiman WY, Lau YL
    Acta Trop, 2018 Sep;185:115-126.
    PMID: 29758171 DOI: 10.1016/j.actatropica.2018.05.008
    The resistance status of Selangor Aedes aegypti (Linnaeus) larvae against four major groups of insecticides (i.e., organochlorines, carbamates, organophosphates and pyrethroids) was investigated. Aedes aegypti were susceptible against temephos (organophosphate), although resistance (RR50 = 0.21-2.64) may be developing. The insecticides susceptibility status of Ae. aegypti larvae were found heterogeneous among the different study sites. Results showed that Ae. aegypti larvae from Klang, Sabak Bernam and Sepang were susceptible against all insecticides tested. However, other study sites exhibited low to high resistance against all pyrethroids (RR50 = 1.19-32.16). Overall, the application of synergists ethacrynic acid, S.S.S.- tributylphosphorotrithioate and piperonyl butoxide increased the toxicity of insecticides investigated. However, the application failed to increase the mortality to susceptible level (>97%) for certain populations, therefore there are chances of alteration of target site resistance involved. Biochemical assays revealed that α-esterase, (Gombak, Kuala Langat, Kuala Selangor and Sabak Bernam strains) β-esterase (Klang and Sabak Bernam strains), acetylcholinesterase (Kuala Selangor and Sabak Bernam strains), glutathione-S-transferase (Kuala Selangor and Sabak Bernam strains) and mono-oxygenases (Gombak, Hulu Langat, Hulu Selangor and Kuala Langat strains) were elevated. Spearman rank-order correlation indicated a significant correlation between resistance ratios of: DDT and deltamethrin (r = 0.683, P = 0.042), cyfluthrin and deltamethrin (r = 0.867, P =0.002), cyflyuthrin and lambdacyhalothrin (r = 0.800, P =0.010), cyfluthrin and permethrin (r = 0.770, P =0.015) deltamethrin and permethrin (r = 0.803, P =0.088), propoxur and malathion (r = 0.867, P = 0.002), malathion and temephos (r = 0.800, P = 0.010), etofenprox and MFO enzyme (r = 0.667, P =0.050). The current study provides baseline information for vector control programs conducted by local authorities. The susceptibility status of Ae. aegypti should be monitored sporadically to ensure the effectiveness of current vector control strategy in Selangor.
    Matched MeSH terms: Hydrocarbons, Chlorinated
  13. Farina Y, Munawar N, Abdullah MP, Yaqoob M, Nabi A
    Environ Monit Assess, 2018 Jun 09;190(7):386.
    PMID: 29884954 DOI: 10.1007/s10661-018-6762-8
    Occurrence and distribution of organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), and pyrethroid pesticides (PYRs) residues in the leafy vegetables were analyzed together with the soil samples using gas chromatography-electron capture detector. Edible tissues of vegetables showed detectable residues of these compounds indicating the influence of the conventional farms and nearby organic farms. In the vegetables, the OCPs concentrations were recorded as nd-133.3 ng/g, OPPs as nd-200 ng/g, and PYRs as nd-33.3 ng/g. In the soil, the OCPs concentrations were recorded as nd-30.6 ng/g, OPPs as nd-26.6 ng/g, and for PYRs as nd-6.7 ng/g. Bioconcentration factor (BCF) was higher for the OPPs (0.3) than the OCPs and PYRs (1.1). The OCPs concentration in the vegetables decreased in the following order: spinach > celery > broccoli > cauliflower > cabbage > lettuce > mustard. For OPPs, the concentration decreased in the following order: cauliflower > spinach > celery > cabbage > broccoli > lettuce > mustard and for PYRs as spinach > celery > lettuce > cabbage > broccoli. Principal component analysis indicates that the sources of these pesticides are not the same, and the pesticide application on the vegetables depends on the type of crop. There is a significant positive correlation between OPPs and the soil (r = 0.65) as compared to OCPs and PYRs (r = 0.1) as the vegetables accumulated OPPs more efficiently than OCPs and PYRs.
    Matched MeSH terms: Hydrocarbons, Chlorinated/analysis
  14. Tiong SH, Saparin N, Teh HF, Ng TLM, Md Zain MZB, Neoh BK, et al.
    J Agric Food Chem, 2018 Jan 31;66(4):999-1007.
    PMID: 29260544 DOI: 10.1021/acs.jafc.7b04995
    During high-temperature refining of vegetable oils, 3-monochloropropanediol (3-MCPD) esters, possible carcinogens, are formed from acylglycerol in the presence of a chlorine source. To investigate organochlorine compounds in vegetable oils as possible precursors for 3-MCPD esters, we tested crude palm, soybean, rapeseed, sunflower, corn, coconut, and olive oils for the presence of organochlorine compounds. Having found them in all vegetable oils tested, we focused subsequent study on oil palm products. Analysis of the chlorine isotope mass pattern exhibited in high-resolution mass spectrometry enabled organochlorine compound identification in crude palm oils as constituents of wax esters, fatty acid, diacylglycerols, and sphingolipids, which are produced endogenously in oil palm mesocarp throughout ripening. Analysis of thermal decomposition and changes during refining suggested that these naturally present organochlorine compounds in palm oils and perhaps in other vegetable oils are precursors of 3-MCPD esters. Enrichment and dose-response showed a linear relationship to 3-MCPD ester formation and indicated that the sphingolipid-based organochlorine compounds are the most active precursors of 3-MCPD esters.
    Matched MeSH terms: Hydrocarbons, Chlorinated
  15. Noordeyana T, Rozmi I, Muhammad Ajib Abdul R, Mohd Nasir S, Nurul Shafini S, Norhayati I, et al.
    Jurnal Psikologi Malaysia, 2018;32:94-103.
    Artikel ini bertujuan mengkaji keberkesanan program SHIELDS daripada perspektif pelajar dan urusetia yang telah turut terlibat. Program SHIELDS adalah satu bentuk program campbased yang diperkenalkan hasil kerjasama antara Kementerian Pendidikan dan Pihak Agensi Anti Dadah Kebangsaan (AADK). Nama SHEILDS ini adalah akronim yang bermaksud Sayangi Hidup, Elak Derita Selamanya. Sehubungan itu, program ini bertujuan meningkatkan kesedaran dan mengupayakan ketahanan diri murid (lingkungan umur 13 hingga 18 tahun) yang dikenalpasti berisiko dalam penyalahgunaan dadah. Kajian kuantitatif ini melibatkan dua fasa iaitu fasa pertama adalah mengedarkan soal selidik sebelum dan selepas program SHIELDS dijalankan. Manakala, fasa kedua pula adalah sesi follow up selepas 3 bulan terhadap 50 pelajar yang telah terlibat dengan program SHIELDS terlebih dahulu. Hasil kajian menunjukkan secara keseluruhan perspektif pelajar seramai 559 orang yang terlibat dengan program SHIELDS ini adalah baik dengan min=4.48. Kesimpulannya, dapatan ini menunjukkan bahawa program SHIELDS ini sewajarnya diteruskan dengan beberapa penambahbaikan untuk kelangsungan program dan kebaikan semua pihak yang terlibat.
    Matched MeSH terms: Hydrocarbons, Chlorinated
  16. Sharip Z, Hashim N, Suratman S
    Environ Monit Assess, 2017 Oct 15;189(11):560.
    PMID: 29034408 DOI: 10.1007/s10661-017-6274-y
    This study investigates the presence and distribution of organochlorine pesticides in streams and the lake in the Sembrong Lake Basin in Malaysia. The catchment of Sembrong Lake has been converted to agricultural areas over the past 30 years, with oil palm plantations and modern agricultural farming being the main land use. Surface water samples were collected from eight sites comprising the stream and lake and analysed for 19 organochlorine pesticides (OCPs). In situ measurement of temperature, dissolved oxygen, pH and conductivity were also undertaken at each site. Aldrin, endrin, δ-BHC, 4,4-DDT, methoxychlor and endosulfan were the main OCPs detected in the lake basin. The total OCP concentration ranged between 5.42 and 349.2 ng/L. The most frequently detected OCPs were δ-BHC, heptachlor and aldrin. The maximum values detected were 23.0, 43.2 and 50.4 ng/L respectively. The highest concentration of OCPs was attributed to 4,4-DDT, but such high residue was rare and only detected once. Other OCP residues were low. Significant differences in the mean values were observed between lake and stream for dichlorodiphenyldichloroethylene (DDE) and α-endosulfan concentration (p 
    Matched MeSH terms: Hydrocarbons, Chlorinated/analysis*
  17. Amirah Audadi Madzen, Lam KC
    Sains Malaysiana, 2017;46:421-428.
    Fenologi tumbuhan menggambarkan fasa kitaran hidup atau aktiviti tumbuhan dan adalah penting untuk memahami
    interaksinya dengan iklim. Kajian dilakukan untuk mengenal pasti respons fenologi tumbuhan dan metrik fenologi
    hutan dipterokarpa, kelapa sawit dan pokok getah menggunakan data indeks tumbuhan Enhanced Vegetation Index
    (EVI) daripada MODIS-Aqua (produk MYD13Q1) dan purata hujan bulanan sepanjang tahun 2007 dan 2009 di negeri
    Johor. Pola hujan pada tahun 2007 menunjukkan taburan hujan normal, manakala tahun 2009 mengalami kekurangan
    hujan sepanjang tempoh sebelas tahun (2000-2010). Hasil mendapati tren EVI hutan dipterokarpa lebih bervariasi pada
    2009 dengan nilai EVI antara 0.39-0.64 berbanding tren pada 2007 yang tekal dengan nilai EVI antara 0.33-0.57. Tren
    fenologi kelapa sawit pada 2007 lebih kerap mengalami turun naik berbanding pada 2009, masing-masing dengan EVI
    antara 0.45-0.71 dan 0.5-0.74. Corak fenologi pokok getah pada kedua-dua tahun kajian adalah sama dan julat EVI
    pada 2009 adalah lebih kecil berbanding 2007, masing-masing dengan EVI antara 0.39-0.62 dan 0.30-0.73. Pengaruh
    masa susulan ke atas tahap kehijauan tumbuhan telah dikesan, khususnya selepas peristiwa hujan lebat dalam dua
    tahun tersebut dan sedikit sebanyak mempengaruhi nilai korelasi antara pemboleh ubah purata hujan bulanan dengan
    EVI tumbuh-tumbuhan. Permulaan dan pengakhiran musim pertumbuhan hutan dipterokarpa bagi kedua-dua tahun
    berlaku dalam bulan yang sama, iaitu Februari (permulaan musim) dan Disember (pengakhiran musim). Tidak wujud
    perbezaan yang ketara antara panjang musim pertumbuhan kelapa sawit bagi kedua-dua tahun, iaitu hanya 32 hari
    lebih panjang pada 2007 berbanding 2009. Musim pertumbuhan pokok getah pula adalah lebih panjang pada 2007 dan
    lebih singkat pada 2009, masing-masing 176 hari dan 113 hari.
    Matched MeSH terms: Hydrocarbons, Chlorinated
  18. Ghani Z, Anuar A, Majid Z, Yoneda M
    Sains Malaysiana, 2017;46:2383-2392.
    This study describes the development of a multimedia environmental fate and transport model of dichlorodiphenyltrichloroethane (DDT) at Sungai Sayong watershed. Based on the latest estimated DDT emission, the DDT concentrations in air, soil, water and sediment as well as the transfer processes were simulated under the equilibrium and steady-state assumption. Model predictions suggested that soil and sediment was the dominant sink of DDT. The results showed that the model predicted was generally good agreement with field data. Compared with degradation reaction, advection outflow was more important processes occurred in the model. Sensitivities of the model estimates to input parameters were tested. The result showed that vapour pressure (Ps) and organic carbon water partition coefficient (KOC) were the most influential parameters for the model output. The model output-concentrations of DDT in multimedia environment is very important as it can be used in future for human exposure and risk assessment of organochlorine pesticides (OCPs) at Sungai Sayong Basin.
    Matched MeSH terms: Hydrocarbons, Chlorinated
  19. Mohd. Suhaimi Ahmad, Muhammad Ridwan Fahmi, Mustaqqim Abdul Rahim, Naimah Ibrahim
    Sains Malaysiana, 2016;45:1857-1867.
    Suatu kajian untuk menilai kesan gabungan aktiviti guna tanah dan perubahan musim terhadap kualiti sumber air telah dijalankan di Terusan Utara, Kedah. Kajian ini dijalankan di lima stesen terpilih selama 12 bulan berdasarkan Indeks Kualiti Air (WQI) dan Piawaian Interim Kualiti Air Kebangsaan (INWQS). Kajian mendapati kualiti air di Terusan Utara berada pada Kelas III dan berlaku peningkatan kualiti air dari hulu ke hilir. Hampir semua stesen berpotensi sebagai punca pencemaran berdasarkan aktiviti guna tanah terutamanya di Pelubang, Jitra serta Tunjang. Kajian menunjukkan terdapat perbezaan yang signifikan ketika perubahan musim pada DO, TSS serta BOD, namun tidak pada ammonia, pH dan COD. Secara amnya, kombinasi aktiviti guna tanah dan perubahan musim boleh mempengaruhi atau memberi kesan terhadap kualiti sumber air. Oleh itu, tindakan segera perlu dilakukan untuk mengawal punca pencemaran bagi memastikan kualiti sumber air di Terusan Utara kekal terpelihara.
    Matched MeSH terms: Hydrocarbons, Chlorinated
  20. Tursun M, Kumar CS, Bilge M, Rhyman L, Fun HK, Parlak C, et al.
    PMID: 25829021 DOI: 10.1016/j.saa.2015.03.022
    Molecular structure and properties of 2-fluoro-4-bromobenzaldehyde (FBB, C7H4BrFO) was experimentally investigated by X-ray diffraction technique and vibrational spectroscopy. Experimental results on the molecular structure of FBB were supported with computational studies using the density functional theory, with the Becke-3-Lee-Yang-Parr functional and the 6-311+G(3df,p) basis set. Molecular dimer formed by the intermolecular hydrogen bonding was investigated. Potential energy distribution analysis of normal modes was performed to identify characteristic frequencies. FBB crystallizes in orthorhombic space group P2(1)2(1)2(1) with the O-trans conformation. In order to investigate halogen effect, the chloro- (CBB) and bromo- (BBB) analogs of FBB have also been studied theoretically. It is observed that all compounds prefer the stable O-trans conformation. Although the free energy difference between the O-cis and O-trans conformers is less than 2.5 kcal/mol, the free energy rotational barrier is at least 7.4 kcal/mol. There is a good agreement between the experimentally determined structural parameters, and vibrational frequencies of FBB and those predicted theoretically.
    Matched MeSH terms: Hydrocarbons, Chlorinated/chemistry*
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links