Displaying publications 3341 - 3360 of 3989 in total

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  1. Zhou JN, Lin BR, Shen HF, Pu XM, Chen ZN, Feng JJ
    Plant Dis, 2012 May;96(5):760.
    PMID: 30727539 DOI: 10.1094/PDIS-11-11-0942
    Phalaenopsis orchids, originally from tropical Asia, are mainly planted in Thailand, Singapore, Malaysia, the Philippines, and Taiwan and have gained popularity from consumers all over the world. The cultivation area of Phalaenopsis orchids has been rising and large-scale bases have been established in mainland China, especially South China because of suitable environmental conditions. In September 2011, a soft rot of Phalaenopsis aphrodita was found in a Phalaenopsis planting base in Guangzhou with an incidence of ~15%. Infected plants initially showed water-soaked, pale-to-dark brown pinpoint spots on leaves that were sometimes surrounded by a yellow halo. Spots expanded rapidly with rising humidity and temperatures, and in a few days, severely extended over the blade with a light tan color and darker brown border. Lesions decayed with odorous fumes and tissues collapsed with inclusions exuding. The bacterium advanced to the stem and pedicle. Finally, leaves became papery dry and the pedicles lodged. Six diseased samples were collected, and bacteria were isolated from the edge of symptomatic tissues after sterilization in 0.3% NaOCl for 10 min, rinsing in sterile water three times, and placing on nutrient agar for culture. Twelve representative isolates were selected for further characterization. All strains were gram negative, grew at 37°C, were positive for indole production, and utilized malonate, glucose, and sucrose but not glucopyranoside, trehalose, or palatinose. Biolog identification (version 4.20.05, Hayward, CA) was performed and Pectobacterium chrysanthemi (SIM 0.868) was confirmed for the tested isolates (transfer to genus Dickeya). PCR was used to amplify the 16S rDNAgene with primers 27f and 1492r, dnaX gene with primers dnaXf and dnaXr (3), and gyrB gene with primers gyrBf (5'-GAAGGYAAAVTKCATCGTCAGG-3') and gyrB-r1 (5'-TCARATATCRATATTCGCYGCTTTC-3') designed on the basis of the published gyrB gene sequences of genus Dickeya. BLASTn was performed online, and phylogeny trees (100% bootstrap values) were created by means of MEGA 5.05 for these gene sequences, respectively. Results commonly showed that the representative tested strain, PA1, was most homologous to Dickeya dieffenbachiae with 98% identity for 16S rDNA(JN940859), 97% for dnaX (JN989971), and 96% for gyrB (JN971031). Thus, we recommend calling this isolate D. dieffenbachiae PA1. Pathogenicity tests were conducted by injecting 10 P. aphrodita seedlings with 100 μl of the bacterial suspension (1 × 108 CFU/ml) and another 10 were injected with 100 μl of sterile water as controls. Plants were inoculated in a greenhouse at 28 to 32°C and 90% relative humidity. Soft rot symptoms were observed after 2 days on the inoculated plants, but not on the control ones. The bacterium was isolated from the lesions and demonstrated identity to the inoculated plant by the 16S rDNA sequence comparison. Previously, similar diseases of P. amabilis were reported in Tangshan, Jiangsu, Zhejiang, and Wuhan and causal agents were identified as Erwinia spp. (2), Pseudomonas grimontii (1), E. chrysanthemi, and E. carotovora subsp. carovora (4). To our knowledge, this is the first report of D. dieffenbachiae causing soft rot disease on P. aphrodita in China. References: (1) X. L. Chu and B. Yang. Acta Phytopathol. Sin. 40:90, 2010. (2) Y. M. Li et al. J. Beijing Agric. Coll. 19:41, 2004. (3) M. Sławiak et al. Eur. J. Plant Pathol. 125:245, 2009. (4) Z. Y. Wu et al. J. Zhejiang For. Coll. 27:635, 2010.
    Matched MeSH terms: Water
  2. Sulaiman R, Thanarajoo SS, Kadir J, Vadamalai G
    Plant Dis, 2012 May;96(5):767.
    PMID: 30727556 DOI: 10.1094/PDIS-06-11-0482-PDN
    Physic nut (Jatropha curcas L.) is an important biofuel crop worldwide. Although it has been reported to be resistant to pests and diseases (1), stem cankers have been observed on this plant at several locations in Peninsular Malaysia since early February 2008. Necrotic lesions on branches appear as scars with vascular discoloration in the tissue below the lesion. The affected area is brownish and sunken in appearance. Disease incidence of these symptomatic nonwoody plants can reach up to 80% in a plantation. Forty-eight samples of symptomatic branches collected from six locations (University Farm, Setiu, Gemenceh, Pulau Carey, Port Dickson, and Kuala Selangor) were surface sterilized in 10% bleach, rinsed twice with sterile distilled water, air dried on filter paper, and plated on water agar. After 4 days, fungal colonies on the agar were transferred to potato dextrose agar (PDA) and incubated at 25°C. Twenty-seven single-spore fungal cultures obtained from all locations produced white, aerial mycelium that became dull gray after a week in culture. Pycnidia from 30-day-old pure cultures produced dark brown, oval conidia that were two celled, thin walled, and oval shape with longitudinal striations. The average size of the conidia was 23.63 × 12.72 μm with a length/width ratio of 1.86. On the basis of conidial morphology, these cultures were identified as Lasiodiplodia theobromae. To confirm the identity of the isolates, the internal transcribed spacer (ITS) region was amplified with ITS1/ITS4 primers and sequenced. The sequences were deposited in GenBank (Accession Nos. HM466951, HM466953, HM466957, GU228527, HM466959, and GU219983). Sequences from the 27 isolates were 99 to 100% identical to two L. theobromae accessions in GenBank (Nos. HM008598 and HM999905). Hence, both morphological and molecular characteristics confirmed the isolates as L. theobromae. Pathogenicity tests were performed in the glasshouse with 2-month-old J. curcas seedlings. Each plant was wound inoculated by removing the bark on a branch to a depth of 2 mm with a 10-mm cork borer. Inoculation was conducted by inserting a 10-mm-diameter PDA plug of mycelium into the wound and wrapping the inoculation site with wetted, cotton wool and Parafilm. Control plants were treated with plugs of sterile PDA. Each isolate had four replicates and two controls. After 6 days of incubation, all inoculated plants produced sunken, necrotic lesions with vascular discoloration. Leaves were wilted and yellow above the point of inoculation on branches. The control plants remained symptomless. The pathogen was successfully reisolated from lesions on inoculated branches. L. theobromae has been reported to cause cankers and dieback in a wide range of hosts and is common in tropical and subtropical regions of the world (2,3). To our knowledge, this is the first report of stem canker associated with L. theobromae on J. curcas in Malaysia. References: (1) S. Chitra and S. K. Dhyani. Curr. Sci. 91:162, 2006. (2) S. Mohali et al. For. Pathol. 35:385, 2005. (3) E. Punithalingam. Page 519 in: CMI Descriptions of Pathogenic Fungi and Bacteria. Commonwealth Mycological Institute, Kew, Surrey, UK. 1976.
    Matched MeSH terms: Water
  3. Hamzah N, Nagarajah M, Leo CP
    Water Sci Technol, 2018 Dec;78(12):2532-2541.
    PMID: 30767918 DOI: 10.2166/wst.2019.016
    Fat, oil and grease in wastewater generated from household kitchens, restaurants and food processing plants affect sewer systems, water resources and environment adversely. Hence, membrane distillation of saline and oily water was studied using a nearly superhydrophobic membrane developed in this work. Polyvinylidene fluoride (PVDF) membrane incorporated SiO2 nanoparticles was synthesized via phase inversion with dual baths and modified using hexadecyltrimethoxy silane. The volume ratio of silane to ethanol was varied between 1:200 to 1:25. The membrane characteristics were examined using a goniometer, a porometer, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The PVDF-SiO2 membrane modified using the volume ratio of 1:50 achieved the highest water contact angle of 141.6° and LEP of 2.642 bar. This membrane was further tested in membrane distillation to observe the permeate flux of distilled water, saline solution (1 M NaCl) as well as saline and oily solution (1 M NaCl; 1,000 ppm of palm oil). The modified PVDF/SiO2 showed high permeate flux which is nearly four times of the permeate flux of neat PVDF membrane, but still susceptible of salt and oil fouling as shown in SEM images.
    Matched MeSH terms: Water Purification
  4. Nur Fitrah Che Nan, Norhazlin Zainuddin, Mansor Ahmad
    MyJurnal
    Carboxymethylcellulose (CMC) is a water-soluble polymer, which is widely used in various
    fields such as food additives, textiles, pharmaceuticals and cosmetics. In this study, hydrogel
    was prepared from CMC by using calcium chloride as a crosslinking agent. Optimization
    of the reaction was done through investigation of four different parameters which had
    different percentage of CMC (w/v), percentage of calcium chloride (w/v), reaction time and
    temperature. The gel content and swelling properties of the CMC hydrogel were studied.
    The highest gel content was 85.33% at 7% of CMC (w/v) with 2% of calcium chloride (w/v)
    in 24 hours reaction time at room temperature. The gel content increased with the increasing
    concentration of CMC and CaCl2. This was due to the higher number of functional groups
    of COO- that were available in more concentrated CMC which could crosslink with CaCl2
    to give higher gel content. Increasing the percentage of CaCl2 will increase the electrostatic
    attraction between anionic charges of polymer chains and multivalent cation (Ca2+) that
    leads to increase in ionic crosslinking of CMC. The swelling properties of CMC hydrogel
    showed that the optimum degree of swelling was 45.33 (g/g). The swelling capacity of the
    hydrogel in water decreased with the increase of the gel content of CMC hydrogel. This
    could be due to the increase in the degree of crosslinking of the CMC hydrogel.
    Matched MeSH terms: Water
  5. Tran TV, Nguyen DTC, Le HTN, Bach LG, Vo DN, Hong SS, et al.
    Nanomaterials (Basel), 2019 Feb 10;9(2).
    PMID: 30744163 DOI: 10.3390/nano9020237
    Chloramphenicol (CAP) is commonly employed in veterinary clinics, but illegal and uncontrollable consumption can result in its potential contamination in environmental soil, and aquatic matrix, and thereby, regenerating microbial resistance, and antibiotic-resistant genes. Adsorption by efficient, and recyclable adsorbents such as mesoporous carbons (MPCs) is commonly regarded as a "green and sustainable" approach. Herein, the MPCs were facilely synthesized via the pyrolysis of the metal⁻organic framework Fe₃O(BDC)₃ with calcination temperatures (x °C) between 600 and 900 °C under nitrogen atmosphere. The characterization results pointed out mesoporous carbon matrix (MPC700) coating zero-valent iron particles with high surface area (~225 m²/g). Also, significant investigations including fabrication condition, CAP concentration, effect of pH, dosage, and ionic strength on the absorptive removal of CAP were systematically studied. The optimal conditions consisted of pH = 6, concentration 10 mg/L and dose 0.5 g/L for the highest chloramphenicol removal efficiency at nearly 100% after 4 h. Furthermore, the nonlinear kinetic and isotherm adsorption studies revealed the monolayer adsorption behavior of CAP onto MPC700 and Fe₃O(BDC)₃ materials via chemisorption, while the thermodynamic studies implied that the adsorption of CAP was a spontaneous process. Finally, adsorption mechanism including H-bonding, electrostatic attraction, π⁻π interaction, and metal⁻bridging interaction was proposed to elucidate how chloramphenicol molecules were adsorbed on the surface of materials. With excellent maximum adsorption capacity (96.3 mg/g), high stability, and good recyclability (4 cycles), the MPC700 nanocomposite could be utilized as a promising alternative for decontamination of chloramphenicol antibiotic from wastewater.
    Matched MeSH terms: Waste Water
  6. Salati M, Wong MY, Sariah M, Nik Masdek H
    Plant Dis, 2010 May;94(5):642.
    PMID: 30754434 DOI: 10.1094/PDIS-94-5-0642A
    In December 2008, infected leaves of Trichosanthes cucumerina were observed on commercial cucurbit farms located in Pontian, Johor (south of West Malaysia). Bright yellow and small necrotic lesions were observed on the adaxial surface of the leaves, whereas sporangiophores were observed on pale yellowish brown-to-brown lesions on the abaxial surface. The length and width of the sporangia ranged from 19 to 36 μm (28.6) and 11 to 23 μm (17.6), respectively. The length of the sporangiophores ranged from 310 to 450 μm, with an average length of 380 μm. The pathogen was identified as Pseudoperonospora cubensis on the basis of the morphological criteria described by Palti and Cohen (2). To confirm the morphological findings, DNA was extracted from symptomatic tissue and the internal transcribed spacer (ITS) region was PCR amplified using primers ITS5-P2 and ITS4 (3). The appropriate-sized amplicon was gel excised and column purified and then submitted for direct sequencing. The resulting 802 bp amplified ITS region was 100% identical to published P. cubensis sequences (GenBank Accession Nos. EU876603, EU876584, and AY198306). This sequence was deposited with NCBI GenBank under the Accession No. GU233293. In this study, pathogenicity tests were conducted using detached leaf disc assays (1) and a P. cubensis isolate obtained from T. cucumerina. For this purpose, leaf discs were excised from 6- to 8-week-old leaves of T. cucumerina using a 20-mm cork borer. Five leaf discs were placed with their abaxial surface facing upward on moist filter paper in petri dishes. Each of four leaf discs was inoculated with four 10-μl droplets of a 1 × 105 per ml sporangial suspension, whereas the fifth disc was inoculated with water droplets and served as a control. Three replications were completed. The leaf discs were placed in darkness at 14 ± 2°C for 24 h and subsequently incubated with a 12-h photoperiod. After 10 days, sporulation was observed on the sporangia-inoculated leaf discs with similar morphological features to the initial field samples. To our knowledge, this is the first report of P. cubensis causing downy mildew of T. cucumerina in Malaysia. References: (1) A. Lebeda and M. P. Widrlechner. J. Plant Dis. Prot. 110:337, 2003. (2) J. Palti and Y. Cohen. Phytoparasitica 8:109, 1980. (3) H. Voglmayr and O. Constantinescu. Mycol. Res. 112:487, 2008.
    Matched MeSH terms: Water
  7. Ibrahim KA, Naz MY, Shukrullah S, Sulaiman SA, Ghaffar A, AbdEl-Salam NM
    Sci Rep, 2020 Apr 03;10(1):5927.
    PMID: 32246028 DOI: 10.1038/s41598-020-62793-3
    The world does not have too much time to ensure that the fast-growing population has enough land, food, water and energy. The rising food demand has brought a positive surge in fertilizers' demand and agriculture-based economy. The world is using 170 million tons of fertilizer every year for food, fuel, fiber, and feed. The nitrogenous fertilizers are being used to meet 48% of the total food demand of the world. High fertilizer inputs augment the reactive nitrogen levels in soil, air, and water. The unassimilated reactive nitrogen changes into a pollutant and harms the natural resources. The use of controlled-release fertilizers for slowing down the nutrients' leaching has recently been practiced by farmers. However, to date, monitoring of the complete discharge time and discharge rate of controlled released fertilizers is not completely understood by the researchers. In this work, corn starch was thermally processed into a week gel-like coating material by reacting with urea and borate. The granular urea was coated with native and processed starch in a fluidized bed reactor having bottom-up fluid delivery system. The processed starch exhibited better thermal and mechanical stability as compared to the native starch. Unlike the pure starch, the storage modulus of the processed starch dominated the loss modulus. The release time of urea, coated with processed starch, remained remarkably larger than the uncoated urea.
    Matched MeSH terms: Water
  8. Iqhrammullah M, Marlina, Hedwig R, Karnadi I, Kurniawan KH, Olaiya NG, et al.
    Polymers (Basel), 2020 Apr 13;12(4).
    PMID: 32294999 DOI: 10.3390/polym12040903
    The use of polymeric material in heavy metal removal from wastewater is trending. Heavy metal removal from wastewater of the industrial process is of utmost importance in green/sustainable manufacturing. Production of absorbent materials from a natural source for industrial wastewater has been on the increase. In this research, polyurethane foam (PUF), an adsorbent used by industries to adsorb heavy metal from wastewater, was prepared from a renewable source. Castor oil-based polyurethane foam (COPUF) was produced and modified for improved adsorption performance using fillers, analyzed with laser-induced breakdown spectroscopy (LIBS). The fillers (zeolite, bentonite, and activated carbon) were added to the COPUF matrix allowing the modification on its surface morphology and charge. The materials were characterized using Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), and thermal gravimetry analysis (TGA), while their adsorption performance was studied by comparing the LIBS spectra. The bentonite-modified COPUF (B/COPUF) gave the highest value of the normalized Pb I (405.7 nm) line intensity (2.3), followed by zeolite-modified COPUF (Z/COPUF) (1.9), and activated carbon-modified COPUF (AC/COPUF) (0.2), which indicates the adsorption performance of Pb2+ on the respective materials. The heavy metal ions' adsorption on the B/COPUF dominantly resulted from the electrostatic attraction. This study demonstrated the potential use of B/COPUF in adsorption and LIBS quantitative analysis of aqueous heavy metal ions.
    Matched MeSH terms: Waste Water
  9. Akinfalabi SI, Rashid U, Arbi Nehdi I, Yaw Choong TS, Sbihi HM, Gewik MM
    R Soc Open Sci, 2020 Jan;7(1):191592.
    PMID: 32218977 DOI: 10.1098/rsos.191592
    The optimum conditions to produce palm fatty acid distillate (PFAD)-derived-methyl esters via esterification have been demonstrated with the aid of the response surface methodology (RSM) with central composite rotatable design in the presence of heterogeneous acid catalyst. The effect of four reaction variables, reaction time (30-110 min), reaction temperature (30-70°C), catalyst concentration (1-3 wt.%) and methanol : PFAD molar ratio (3 : 1-11 : 1), were investigated. The reaction time had the most influence on the yield response, while the interaction between the reaction time and the catalyst concentration, with an F-value of 95.61, contributed the most to the esterification reaction. The model had an R2-value of 0.9855, suggesting a fit model, which gave a maximum yield of 95%. The fuel properties of produced PFAD methyl ester were appraised based on the acid value, iodine value, cloud and pour points, flash point, kinematic viscosity, density, ash and water contents and were compared with biodiesel EN 14214 and ASTM D-6751 standard limits. The PFAD methyl ester was further blended with petro-diesel from B0, B3, B5, B10, B20 and B100, on a volumetric basis. The blends were characterized by TGA, DTG and FTIR. With an acid value of 0.42 (mg KOH g-1), iodine value of 63 (g.I2/100 g), kinematic viscosity of 4.31 (mm2 s-1), the PFAD methyl ester has shown good fuel potential, as all of its fuel properties were within the permissible international standards for biodiesel.
    Matched MeSH terms: Water
  10. Hilaluddin F, Yusoff FM, Natrah FMI, Lim PT
    Mar Environ Res, 2020 Jun;158:104935.
    PMID: 32217292 DOI: 10.1016/j.marenvres.2020.104935
    To assess the effects of environmental changes on phytoplankton community structure in a mangrove ecosystem, phytoplankton distribution in Matang mangrove, Malaysia was examined. Phytoplankton and water samples, and in situ environmental parameters from three estuaries with differing levels of disturbance were examined monthly for one year. Two species, Cyclotella choctawhatcheeana and Skeletonema costatum, were dominant in the least disturbed and moderately disturbed areas, respectively. Skeletonema costatum was also the most dominant in the most disturbed area. Significant differences in phytoplankton density and biodiversity between the least and most disturbed areas were also observed. Principle component 1 (salinity, conductivity, total solids/water transparency and nitrogenous compounds) and PC2 (dissolved oxygen, pH and temperature) explained 60.4% of the total variance. This study illustrated that changes in phytoplankton community structure in Matang mangrove estuaries were significantly correlated with environmental parameters which were in turn influenced by ecosystem disturbance levels as well as seasonal changes.
    Matched MeSH terms: Water
  11. Tanveer Ahmed Khan, Mohd Raihan Taha, Ali Asghar Firoozi, Ali Akbar Firoozi
    Sains Malaysiana, 2017;46:1269-1267.
    Environmental concerns have significantly influenced the construction industry regarding the identification and use of environmentally sustainable construction materials. In this context, enzymes (organic materials) have been introduced recently for ground improvement projects such as pavements and embankments. The present experimental study was carried out in order to evaluate the compressive strength of a sedimentary residual soil treated with three different types of enzymes, as assessed through a California bearing ratio (CBR) test. Controlled untreated and treated soil samples containing four dosages (the recommended dose and two, five and 10 times the recommended dose) were prepared, sealed and cured for four months. Following the curing period, samples were soaked in water for four days before the CBR tests were administered. These tests showed no improvement in the soil is compressive strength; in other words, samples prepared even at higher dosages did not exhibit any improvement. Nuclear magnetic resonance (NMR) spectroscopy tests were carried out on three enzymes in order to study the functional groups present in them. Furthermore, X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) tests were executed for untreated and treated soil samples to determine if any chemical reaction took place between the soil and the enzymes. Neither of the tests (XRD nor FESEM) revealed any change. In fact, the XRD patterns and FESEM images for untreated and treated soil samples were indistinguishable.
    Matched MeSH terms: Water
  12. Wong YL
    JUMMEC, 2002;7:59-61.
    The majority of migrant workers studied in this survey were males Muslims from Bangladesh. The mean age was 30 and the majority were aged between 21-30 years. Although almost all of them had 7-13 years of schooling, the majority were working in the service industry. More than two thrids of the migrant workers were provided with various forms of housing by their employers. Majority of them stated that they had better amenities, such as piped drinking water and sanitary toilets, in Malaysia compared to those in their home countries. From their reports, it appears that the majority did not engage in risk behaviours such as, smoking, alcohol and drug abuse.
    Matched MeSH terms: Water
  13. Aina Aqila Arman Alim, Rizafizah Othaman
    Sains Malaysiana, 2018;47:1517-1525.
    Epoxidized natural rubber/polyvinyl chloride/microcrystalline cellulose (ENR/PVC/MCC) composite membranes were
    prepared and used to treat palm oil mill effluent (POME). The loadings of MCC were varied at 0, 5, 10 and 15 w/w%. The
    increment of MCC loads has intensified the hydroxyl peak of the membranes in FTIR spectrum, indicating the increase
    in membrane hydrophilicity. MCC acted as a pore forming agent since the ENR/PVC/10% MCC gave the highest water
    flux and well-distributed pores. After first treatment of POME, the levels of chemical oxygen demand (COD), biochemical
    oxygen demand (BOD) and total suspended solid (TSS) were reduced to 99.9%, 70.3%, and 16.9%, respectively. These
    data showed that ENR/PVC/MCC membrane has the potential to treat POME.
    Matched MeSH terms: Water
  14. Lee ZS, Chin SY, Cheng CK
    Heliyon, 2019 Jun;5(6):e01792.
    PMID: 31245637 DOI: 10.1016/j.heliyon.2019.e01792
    This study evaluates the effects of subcritical hydrothermal treatment on palm oil mill effluent (POME) and its concomitant formations of solid hydrochar, liquid product and gaseous product. The reactions were carried out at temperatures ranged 493 K-533 K for 2 h. The highest reduction of chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were 58.8% and 62.5%, respectively, at 533 K. In addition, the removal of total suspended solids (TSS) achieved up to 99%, with the pH of POME reaching 6 from the initial pH 4. The gas chromatography coupled with mass spectroscopy (GC-MS) analysis showed that the fresh POME contained n-Hexadecanoic acid as the dominant component, which gradually reduced in the liquid product in the reaction with increased temperature, in addition to the attenuation of carboxyl compounds and elevation of phenolic components. The gaseous products contained CO2, CO, H2, and C3 - C6 hydrocarbons. Traces of CH4 were only found at 533 K. CO2 is the dominant species, where the highest of 3.99 vol% per 500 mL working volume of POME recorded at 533 K. The solid hydrochars showed negligible morphological changes across the reaction temperature. The O/C atomic ratio of the hydrochar range from 0.157 to 0.379, while the H/C atomic ratio was in the range from 0.930 to 1.506. With the increase of treatment temperature, the higher heating value (HHV) of the hydrochar improved from 24.624 to 27.513 MJ kg-1. The characteristics of hydrochar make it a fuel source with immense potential. POME decomposed into water-soluble compounds, followed by deoxygenation (dehydration and decarboxylation) in producing hydrochar with lower oxygen content and higher aromatic compounds in the liquid product. Little gaseous hydrocarbons were produced due to subcritical hydrothermal gasification at low temperature.
    Matched MeSH terms: Water
  15. Nikathirah Yusoff, Li-ngee Ho, Soon-an Ong, Yee-shian Wong, Wanfadhilah Khalik, Muhammad Fahmi Ridzwan
    Sains Malaysiana, 2017;46:2507-2514.
    Zinc oxide (ZnO) utilization in advanced oxidation process (AOP) via solar-photocatalytic process was a promising method for alternative treating wastewater containing phenol. The ZnO photocatalyst semiconductor was synthesized by sol-gel method. The morphology of the ZnO nanostructures was observed by using scanning electron microscope (SEM) and the crystallite phase of the ZnO was confirmed by x-ray diffraction (XRD). The objective of this study was to synthesis ZnO nanoparticles through a sol-gel method for application as a photocatalyst in the photodegradation of phenol under solar light irradiation. The photodegradation rate of phenol increased with the increasing of ZnO loading from 0.2 until 1.0 g. Only 2 h were required for synthesized ZnO to fully degrade the phenol. The synthesized ZnO are capable to totally degrade high initial concentration up until 45 mg L-1 within 6 h of reaction time. The photodegradation of phenol by ZnO are most favoured under the acidic condition (pH3) where the 100% removal achieved after 2 h of reaction. The mineralization of phenol was monitored through chemical oxygen demand (COD) reduction and 92.6% or removal was achieved. This study distinctly utilized natural sunlight as the sole sources of irradiation which safe, inexpensive; to initiate the photocatalyst for degradation of phenol.
    Matched MeSH terms: Waste Water
  16. Fahad Masoud Wattoo, Rashid Mehmood Rana, Sajid Fiaz, Syed Adeel Zafar, Mehmood Ali Noor, Shoaib ur Rehman, et al.
    Sains Malaysiana, 2018;47:295-302.
    Maize is an imperative grain crop used as a staple food in several countries around the world. Water deficiency is a serious
    problem limiting its growing area and production. Identification of drought tolerant maize germplasm is comparatively
    easy and sustainable approach to combat this issue. Present research was conducted to evaluate 50 maize genotypes
    for drought tolerance at early growth stage. Drought tolerance was assessed on the basis of several morphological
    and physiological parameters. Analysis of variance showed significant variation among the tested maize genotypes for
    recorded parameters. Principal component analysis revealed important morpho-physiological traits that were playing
    key role in drought tolerance. Correlation studies depicted significant positive correlation among the attributes such as
    fresh shoot length (FSL), fresh root length (FRL), dry shoot weight (DSW), dry root weight (DRW), relative water contents
    (RWC) and total dry matter (TDM) while a strongly negative correlation was observed among RWC and excised leaf
    water loss. Results concluded that the parameters fresh shoot weight, fresh root weight, FRL, DRW, TDM, cell membrane
    thermo stability (CMT) and RWC can be useful for rapid screening of maize germplasm for drought tolerance at early
    growth stages. Furthermore, the genotypes 6, 16, 18, 40, 45 and 50 can be used as a drought tolerant check in breeding
    programs. Moreover, biplot analysis along with other indices was proved to be a useful approach for rapid and cost
    efficient screening of large number of genotypes against drought stress condition.
    Matched MeSH terms: Water
  17. Nudrat Aisha Akram, Shamim Kausar, Naila Farid, Muhammad Ashraf, Muhammad Ashraf, Fahad Al-Qurainy
    Sains Malaysiana, 2018;47:661-670.
    The production of wheat crop is below average in many regions of the world which is ascribed to adverse environmental
    conditions including drought stress. The present study was conducted to appraise the beneficial role of exogenouslyapplied
    5-aminolevulinic acid (ALA) on growth, yield and some key physio-biochemical characteristics of two commercially
    important wheat cultivars (Shafaq-06 and Uqab-2000) under well watered [100% field capacity (FC)] and water-deficit
    (60 and 80% FC) conditions. Imposition of varying water regimes significantly decreased fresh and dry weights of shoots,
    photosynthetic pigments (a and b), non-photochemical quenching of chlorophyll fluorescence (NPQ), quenching coefficient
    for non-photochemical (N) of chlorophyll fluorescence (qN), K+ (potassium ion), Ca2+ (calcium ion) and P (phosphorus)
    accumulation in shoot and root and yield-related attributes. In contrast, water deficit regimes caused improvement in
    Fv/Fm (chlorophyll fluorescence measurement), coefficient of photochemical quenching (qP), proline, glycinebetaine
    (GB) and hydrogen peroxide (H2O2) contents. Foliar spray of ALA at the rate of 50, 100 and 150 mg/Lalong with control
    (no spray (NS) and/or water spray (WS)) significantly enhanced chlorophyll a and b pigments, qN, NPQ, qP, K+, Ca2+
    and P accumulation in both roots and shoots, proline, GB, total phenolics and malondialdehyde (MDA) contents and
    yield. The wheat Shafaq-06 was better in shoot dry weight, qN, NPQ and Fv/Fm, shoot and root K+, root Ca2+, proline,
    GB accumulation and yield attributes, while Uqab-2000 was better in chlorophyll a contents, root P and MDA contents.
    Overall, better growth and yield of Shafaq-06 than Uqab-2000 under water deficit regimes was found to be associated
    with ALA improved leaf fluorescence (qN, NPQ and Fv/Fm), shoot and root K+, root Ca2+, proline and GB accumulation.
    Matched MeSH terms: Water
  18. Lina A, Shaharuddin M
    The purpose of this study was to determine aluminium (Al) concentrations in groundwater used for drinking and cooking and its related health risk among population of 28th Mile Orang Asli village in Jenderam Hilir, Selangor, Malaysia. A total of 100 respondents were recruited, comprising 51 (51.0 %) male and 49 (49.0 %) female residents. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine Al concentration, while the LAMOTTE TRACER ORP PockeTester was used to measure pH levels. Statistical Package for Social Science (SPSS) was used to analyze the data. Results showed that Al concentration ranged from 0.041 - 0.136 mg/L with a mean of 0.136 + SD 0.041 mg/L, hence the values obtained were below the standard value (0.2 mg/L). pH levels ranged from 3.82 to 5.84, with a mean of 4.163 + SD 0.411, which is acidic and below the range permitted by the health authorities. The acidic nature may have an impact on the Al concentration in the water. The Hazard Index (HI) was found to be less than 1, thus there was no health risk of Al exposure in drinking water for the respondents involved. The study area was considered safe from having health risk associated with Al exposure.
    Matched MeSH terms: Drinking Water
  19. Wong YL, Fauza AG
    JUMMEC, 1998;3:60-60.
    The majority of migrant workers studied in this pilot survey were male, from Bangladesh and Muslim. The mean age was 30 years and the majority were aged between 21-30 years. Although almost half of them had 7-13 years of schooling, or an equivalent to secondary education, the majority were work- ing in the Service industry, predominantly in cleaning services. It is noted that this enlployment trend varied from the national situation, whereby majority of legal migrant workers (Indonesian and Thai) are found in the agricultural sector. More than two thirds of the migrant workers were provided with various forms of housing by the employer. However, it is not known if such acconunodation was adequate or not, as there were no questions about housing structures aod extent of overcrowding. Majority of them stated that they had better amenities, such as piped drinking water and sanitaly toilets, here in Malaysia compared to those in their home countries. Yet, the real extent of better sani- tation is difficult to assess since verification of such amenities could not be done. From their self- reports, it appears that the majority did not engage in risk behaviours, such as smoking, alcohol and drug abuse. It is pertinent, however, to include other risk behaviours in the study, particularly the area of sexual behaviour. The pilot study yielded 28 female Indonesian migrant workers. More than two thirds of them were married. Although none of the married women reported that they were pregnant at the time of the survey, more than two thirds of then1 had betweenl-3 children in Malaysia. Since the age range of these children would be an important indicator of the need for preventive health care, it is proposed that age range of the accompanying children and their immunisation status be included in the questionnaire. Just below half of them were currently practising family planning, and more than two thirds were using modern methods, such as, pill, Norplant and IUD. It is recotnmended that in addition to pregnancy and family planning information, the study could also collect data on gynaeco- logical health and the health seeking behaviour for these problems.
    Matched MeSH terms: Water
  20. Mustafa AM, Yap CG
    JUMMEC, 1998;3:63-64.
    Screening for drugs of abused were conducted by using Gas chromatography-Mass spectrometry (GCMS) fitted with capillary column. Urine samples supplied by Centre of Inmigrant Studies, University of Malaya were processed upon arrival and screened for the following drugs. Amphetamines, methamphetamines, aphedrine, hydroxy-amphetamines, ecstasy, benzamphetamines, codeine, morphine, heroine, cocaine and diazepam. The analysis was done using Shimadzu QP5000 Gas chromatograph-mass spectrometer by selected ion monitoring with BPX35 column, 15 m length, 0.32 ID, helium gas as carrier and quadropole mass detector at 1.60 kV electron gain. Analysis were performed using selected ion monitoring (SIM) mode and quantitations were based on area under the curve of individual standards at various concentrations. The method is sensitive to nanogram levels and are able to detect the presence of these drugs in both urine and plasma. From this study (n-100), none of the urine were found positive for the drugs screened. The major problem encountered were adulterated with water based on the clearness and the colour of the urine. Based on this suspicion we would like to suggest that the testing be done on blood samples as this would be more confirmative and quantitative.
    Matched MeSH terms: Water
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