Displaying publications 1721 - 1740 of 10006 in total

Abstract:
Sort:
  1. Investigating membrane morphology and quantity of immobilized protein for the development of lateral flow immunoassay
    Ahmad AL, Low SC, Shukor SR, Ismail A
    J Immunoassay Immunochem, 2012 Jan;33(1):48-58.
    PMID: 22181820 DOI: 10.1080/15321819.2011.591479
    This study was aimed at gaining a quantitative understanding of the effect of protein quantity and membrane pore structure on protein immobilization. The concentration of immobilized protein was measured by staining with Ponceau S and measuring its color intensity. In this study, both membrane morphology and the quantity of deposited protein significantly influenced the quantity of protein immobilization on the membrane surface. The sharpness and intensity of the red protein spots varied depending on the membrane pore structure, indicating a dependence of protein immobilization on this factor. Membranes with smaller pores resulted in a higher color density, corresponding to enhanced protein immobilization and an increased assay sensitivity level. An increased of immobilized volume has a significant jagged outline on the protein spot but, conversely, no difference in binding capacity.
  2. Fulltext Chemical compositions, antioxidant and antimicrobial activities of essential oils of Piper caninum Blume
    Salleh WM, Ahmad F, Yen KH, Sirat HM
    Int J Mol Sci, 2011;12(11):7720-31.
    PMID: 22174627 DOI: 10.3390/ijms12117720
    Chemical composition, antioxidant and antimicrobial activities of the fresh leaves and stems oils of Piper caninum were investigated. A total of forty eight constituents were identified in the leaves (77.9%) and stems (87.0%) oil which were characterized by high proportions of phenylpropanoid, safrole with 17.1% for leaves and 25.5% for stems oil. Antioxidant activities were evaluated by using β-carotene/linoleic acid bleaching, DPPH radical scavenging and total phenolic content. Stems oil showed the highest inhibitory activity towards lipid peroxidation (114.9 ± 0.9%), compared to BHT (95.5 ± 0.5%), while leaves oil showed significant total phenolic content (27.4 ± 0.5 mg GA/g) equivalent to gallic acid. However, the essential oils showed weak activity towards DPPH free-radical scavenging. Evaluation of antimicrobial activity revealed that both oils exhibited strong activity against all bacteria strains with MIC values in the range 62.5 to 250 μg/mL, but weak activity against fungal strains. These findings suggest that the essential oils can be used as antioxidant and antimicrobial agents for therapeutic, nutraceutical industries and food manufactures.
  3. Fulltext Fabrication and characterization of gelatin stabilized silver nanoparticles under UV-light
    Darroudi M, Ahmad MB, Zak AK, Zamiri R, Hakimi M
    Int J Mol Sci, 2011;12(9):6346-56.
    PMID: 22016663 DOI: 10.3390/ijms12096346
    Silver nanoparticles (Ag-NPs) were successfully synthesized using the UV irradiation of aqueous solutions containing AgNO(3) and gelatin as a silver source and stabilizer, respectively. The UV irradiation times influence the particles' diameter of the Ag-NPs, as evidenced from surface plasmon resonance (SPR) bands and transmission electron microscopy (TEM) images. When the UV irradiation time was increased, the mean size of particles continuously decreased as a result of photoinduced Ag-NPs fragmentation. Based on X-ray diffraction (XRD), the UV-irradiated Ag-NPs were a face-centered cubic (fcc) single crystal without any impurity. This study reveals that the UV irradiation-mediated method is a green chemistry and promising route for the synthesis of stable Ag-NPs for several applications (e.g., medical and surgical devices). The important advantages of this method are that it is cheap, easy, and free of toxic materials.
  4. Computerised image analysis of vitiligo lesion: evaluation using manually defined lesion areas
    Nugroho H, Ahmad Fadzil MH, Shamsudin N, Hussein SH
    Skin Res Technol, 2013 Feb;19(1):e72-7.
    PMID: 22233154 DOI: 10.1111/j.1600-0846.2011.00610.x
    Vitiligo is a cutaneous pigmentary disorder characterized by depigmented macules and patches that result from loss of epidermal melanocytes. Physician evaluates the efficacy of treatment by comparing the extent of vitiligo lesions before and after treatment based on the overall visual impression of the treatment response. This method is called the physician's global assessment (PGA) which is subjective. In this article, we present an innovative digital image processing method to determine vitiligo lesion area in an objective manner.
  5. Fulltext Antioxidant, anti-inflammatory and cytotoxicity of Phaleria macrocarpa (Boerl.) Scheff Fruit
    Hendra R, Ahmad S, Oskoueian E, Sukari A, Shukor MY
    BMC Complement Altern Med, 2011;11:110.
    PMID: 22070850 DOI: 10.1186/1472-6882-11-110
    Phaleria macrocarpa (Scheff.) Boerl (Thymelaceae) originates from Papua Island, Indonesia and grows in tropical areas. The different parts of the fruit of P. macrocarpa were evaluated for antioxidant, anti-inflammatory, and cytotoxic activities.
  6. Inhibitory effect of compounds from Goniothalamus tapis Miq. and Goniothalamus uvaroides King on platelet-activating factor receptor binding
    Moharam BA, Jantan I, Jalil J, Ahmad F
    Phytother Res, 2012 May;26(5):687-91.
    PMID: 22002630 DOI: 10.1002/ptr.3620
    Phytochemical investigation on the bark of Goniothalamus tapis Miq. and G. uvaroides King has resulted in the isolation of eight styryl-lactones, (-)-cryptomeridiol, liriodenine, 3-methyl-1H-benz[f]indole-4,9-dione, (-)-stigmasterol and dimethyl terephthalate. The structures of the compounds were elucidated by spectroscopic techniques. The compounds were evaluated for their effect on platelet-activating factor (PAF) receptor binding on rabbit platelets using (3) H-PAF as a ligand. Among the compounds tested, (-)-cryptomeridiol, (+)-goniothalamin and (+)-isoaltholactone exhibited a significant and concentration-dependent inhibitory effect on PAF receptor binding, with inhibitory concentration (IC)(50) values of 17.5, 19.7 and 46.5 µm, respectively. The inhibitory effects of the first two compounds were comparable to that obtained from the positive control, cedrol. The results indicated that these compounds were strong PAF receptor binding inhibitors.
  7. Fulltext Flavonoid analyses and antimicrobial activity of various parts of Phaleria macrocarpa (Scheff.) Boerl fruit
    Hendra R, Ahmad S, Sukari A, Shukor MY, Oskoueian E
    Int J Mol Sci, 2011;12(6):3422-31.
    PMID: 21747685 DOI: 10.3390/ijms12063422
    Phaleria macrocarpa (Scheff.) Boerl (Thymelaceae) is commonly known as 'Crown of God', 'Mahkota Dewa', and 'Pau'. It originates from Papua Island, Indonesia and it grows in tropical areas. Empirically, it is potent in treating the hypertensive, diabetic, cancer and diuretic patients. It has a long history of ethnopharmacological usage, and the lack of information about its biological activities led us to investigate the possible biological activities by characterisation of flavonoids and antimicrobial activity of various part of P. macrocarpa against pathogenic bacteria and fungi. The results showed that kaempferol, myricetin, naringin, and rutin were the major flavonoids present in the pericarp while naringin and quercetin were found in the mesocarp and seed. Furthermore, the antibacterial activity of different parts of P. macrocarpa fruit showed a weak ability to moderate antibacterial activity against pathogenic tested bacteria (inhibition range: 0.93-2.17 cm) at concentration of 0.3 mg/disc. The anti fungi activity was only found in seed extract against Aspergillus niger (1.87 cm) at concentration of 0.3 mg/well. From the results obtained, P. macrocarpa fruit could be considered as a natural antimicrobial source due to the presence of flavonoid compounds.
  8. Burden of care among caregivers of patients with Parkinson disease: a cross-sectional study
    Razali R, Ahmad F, Rahman FN, Midin M, Sidi H
    Clin Neurol Neurosurg, 2011 Oct;113(8):639-43.
    PMID: 21684679 DOI: 10.1016/j.clineuro.2011.05.008
    Parkinson disease (PD) affects the lives of both the individuals and their family members. This study aims at investigating for clinical as well as socio-demographic factors associated with the perception of burden among the caregivers of individuals with PD in Malaysia.
  9. Analysis of melamine migration from melamine food contact articles
    Chik Z, Haron DE, Ahmad ED, Taha H, Mustafa AM
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2011;28(7):967-73.
    PMID: 21607892 DOI: 10.1080/19440049.2011.576401
    Migration of melamine has been determined for 41 types of retail melamine-ware products in Malaysia. This study was initiated by the Ministry of Health, Malaysia, in the midst of public anxiety on the possibility of melamine leaching into foods that come into contact with the melamine-ware. Thus, the objective of this study was to investigate the level of melamine migration in melamine utensils available on the market. Samples of melamine tableware, including cups and plates, forks and spoons, tumblers, bowls, etc., were collected from various retail outlets. Following the test guidelines for melamine migration set by the European Committee for Standardisation (CEN 2004) with some modifications, the samples were exposed to two types of food simulants (3% acetic acid and distilled water) at three test conditions (25°C (room temperature), 70 and 100°C) for 30 min. Melamine analysis was carried out using LC-MS/MS with a HILIC column and mobile phase consisting of ammonium acetate/formic acid (0.05%) in water and ammonium acetate/formic acid (0.05%) in acetonitrile (95 : 5, v/v). The limit of quantification (LOQ) was 5 ng/ml. Melamine migration was detected from all samples. For the articles tested with distilled water, melamine migration were [median (interquartile range)] 22.2 (32.6), 49.3 (50.9), 84.9 (89.9) ng/ml at room temperature (25°C), 70 and 100°C, respectively. In 3% acetic acid, melamine migration was 31.5 (35.7), 81.5 (76.2), 122.0 (126.7) ng/ml at room temperature (25°C), 70 and 100°C, respectively. This study suggests that excessive heat and acidity may directly affect melamine migration from melamine-ware products. However the results showed that melamine migration in the tested items were well below the specific migration limit (SML) of 30 mg/kg (30,000 ng/ml) set out in European Commission Directive 2002/72/EC.
  10. Fulltext Green synthesis and characterization of gelatin-based and sugar-reduced silver nanoparticles
    Darroudi M, Ahmad MB, Abdullah AH, Ibrahim NA
    Int J Nanomedicine, 2011;6:569-74.
    PMID: 21674013 DOI: 10.2147/IJN.S16867
    Silver nanoparticles (Ag-NPs) have been successfully prepared with simple and "green" synthesis method by reducing Ag(+) ions in aqueous gelatin media with and in the absence of glucose as a reducing agent. In this study, gelatin was used for the first time as a reducing and stabilizing agent. The effect of temperature on particle size of Ag-NPs was also studied. It was found that with increasing temperature the size of nanoparticles is decreased. It was found that the particle size of Ag-NPs obtained in gelatin solutions is smaller than in gelatin-glucose solutions, which can be related to the rate of reduction reaction. X-ray diffraction, ultraviolet-visible spectra, transmission electron microscopy, and atomic force microscopy revealed the formation of monodispersed Ag-NPs with a narrow particle size distribution.
  11. Interaction of isothermal phase inversion and membrane formulation for pathogens detection in water
    Low SC, Ahmad AL, Ideris N, Ng QH
    Bioresour Technol, 2012 Jun;113:219-24.
    PMID: 22153291 DOI: 10.1016/j.biortech.2011.11.048
    The aim of this study was to explore the utilization of polymeric membrane for bio-sensing application in most efficient and rapid way. Customization of membrane formulation via phase separation study to modify its morphologies and properties enable the detection of different pathogens in a specific manner. Experimental findings (FESEM, through-pore distribution, porosity, capillary flow test and protein binding test) verified the predictions of faster capillary flow time and higher membrane's protein binding by the addition of cellulose acetate and nitrocellulose to the membrane casting dope, respectively. Throughout the phase separation study, the potential phase behavior was investigated, which was correlating various membrane structures to its performances for potential pathogens detection in water.
  12. Oil palm biomass-based adsorbents for the removal of water pollutants--a review
    Ahmad T, Rafatullah M, Ghazali A, Sulaiman O, Hashim R
    J Environ Sci Health C Environ Carcinog Ecotoxicol Rev, 2011 Jul;29(3):177-222.
    PMID: 21929380 DOI: 10.1080/10590501.2011.601847
    This article presents a review on the role of oil palm biomass (trunks, fronds, leaves, empty fruit bunches, shells, etc.) as adsorbents in the removal of water pollutants such as acid and basic dyes, heavy metals, phenolic compounds, various gaseous pollutants, and so on. Numerous studies on adsorption properties of various low-cost adsorbents, such as agricultural wastes and its based activated carbons, have been reported in recent years. Studies have shown that oil palm-based adsorbent, among the low-cost adsorbents mentioned, is the most promising adsorbent for removing water pollutants. Further, these bioadsorbents can be chemically modified for better efficiency and can undergo multiple reuses to enhance their applicability at an industrial scale. It is evident from a literature survey of more than 100 recent papers that low-cost adsorbents have demonstrated outstanding removal capabilities for various pollutants. The conclusion is been drawn from the reviewed literature, and suggestions for future research are proposed.
  13. CYP3A4*18 polymorphisms and anti-hepatitis A virus seroprevalence
    Ahmad F, Che Hamzah NA, Mustaffa N, Hua GS
    Hepatogastroenterology, 2011 07 15;58(110-111):1725-9.
    PMID: 21940338 DOI: 10.5754/hge11107
    BACKGROUND/AIMS: CYP3A4 is the major cytochrome in humans which shows reduced activity in chronic liver disease as well as in hepatic cirrhosis. The detection of this polymorphism may give an indication on the prognosis of patients having chronic viral hepatitis with superimposed hepatitis A infection. The aim of this study is to correlate the seroprevalence of anti-HAV antibodies in chronic liver disease patients having CYP3A4*18 polymorphisms.

    METHODOLOGY: This is a prospective study where patients (n=119) blood was tested for anti-HAVIgG and CYP3A4*18 polymorphism.

    RESULTS: The overall anti-HAV seroprevalence was 88.2%. The etiology of CLD was hepatitis B in 96 patients (80.7%) and hepatitis C in 23 patients (19.3%). There was a significant increase in the age of the prevalence of this disease after 30 years of age (p=0.008). CYP3A4*18 polymorphism was detected in 3 (2.5%) of the patients with chronic liver disease. However, there was no significant association between CP3A4*18 mutation and anti-HAV serology.

    CONCLUSIONS: Age was the most important factor in determining anti-HAV positivity. It is concluded that CYP3A4*18 genetic polymorphism does not play a main role in influencing the seroprevalence of anti-hepatitis A among chronic viral hepatitis B and C liver disease patients.

  14. Patterns of intracranial hemorrhage in petrous temporal bone fracture
    Asha'ari ZA, Ahmad R, Rahman J, Yusof RA, Kamarudin N
    Auris Nasus Larynx, 2012 Apr;39(2):151-5.
    PMID: 21592698 DOI: 10.1016/j.anl.2011.02.010
    To study the relationship pattern of intracranial hemorrhage in cases of traumatic petrous temporal bone fracture.
  15. Expansion and preservation of multipotentiality of rabbit bone-marrow derived mesenchymal stem cells in dextran-based microcarrier spin culture
    Boo L, Selvaratnam L, Tai CC, Ahmad TS, Kamarul T
    J Mater Sci Mater Med, 2011 May;22(5):1343-56.
    PMID: 21461701 DOI: 10.1007/s10856-011-4294-7
    The use of mesenchymal stem cells (MSCs) in tissue repair and regeneration despite their multipotentiality has been limited by their cell source quantity and decelerating proliferative yield efficiency. A study was thus undertaken to determine the feasibility of using microcarrier beads in spinner flask cultures for MSCs expansion and compared to that of conventional monolayer cultures and static microcarrier cultures. Isolation and characterization of bone marrow derived MSCs were conducted from six adult New Zealand white rabbits. Analysis of cell morphology on microcarriers and culture plates at different time points (D0, D3, D10, D14) during cell culture were performed using scanning electron microscopy and bright field microscopy. Cell proliferation rates and cell number were measured over a period of 14 days, respectively followed by post-expansion characterization. MTT proliferation assay demonstrated a 3.20 fold increase in cell proliferation rates in MSCs cultured on microcarriers in spinner flask as compared to monolayer cultures (p < 0.05). Cell counts at day 14 were higher in those seeded on stirred microcarrier cultures (6.24 ± 0.0420 cells/ml) × 10(5) as compared to monolayer cultures (0.22 ± 0.004 cells/ml) × 10(5) and static microcarrier cultures (0.20 ± 0.002 cells/ml) × 10(5). Scanning electron microscopy demonstrated an increase in cell colonization of the cells on the microcarriers in stirred cultures. Bead-expanded MSCs were successfully differentiated into osteogenic and chondrogenic lineages. This system offers an improved and efficient alternative for culturing MSCs with preservation to their phenotype and multipotentiality.
  16. Analysis of retinal fundus images for grading of diabetic retinopathy severity
    Ahmad Fadzil MH, Izhar LI, Nugroho H, Nugroho HA
    Med Biol Eng Comput, 2011 Jun;49(6):693-700.
    PMID: 21271293 DOI: 10.1007/s11517-011-0734-2
    Diabetic retinopathy (DR) is a sight threatening complication due to diabetes mellitus that affects the retina. In this article, a computerised DR grading system, which digitally analyses retinal fundus image, is used to measure foveal avascular zone. A v-fold cross-validation method is applied to the FINDeRS database to evaluate the performance of the DR system. It is shown that the system achieved sensitivity of >84%, specificity of >97% and accuracy of >95% for all DR stages. At high values of sensitivity (>95%), specificity (>97%) and accuracy (>98%) obtained for No DR and severe NPDR/PDR stages, the computerised DR grading system is suitable for early detection of DR and for effective treatment of severe cases.
  17. Determinants of smoking behaviour among secondary school students in Bangladesh
    Rahman MM, Ahmad SA, Karim MJ, Chia HA
    J Community Health, 2011 Oct;36(5):831-8.
    PMID: 21359500 DOI: 10.1007/s10900-011-9382-6
    Despite established country's tobacco control law, cigarette smoking by the young people and the magnitude of nicotine dependence among the students is alarming in Bangladesh. This study was aimed to determine the prevalence of smoking and factors influencing it among the secondary school students. A two-stage cluster sampling was used for selection of schools with probability proportional to enrollment size followed by stratified random sampling of government and private schools. The 70-item questionnaire included 'core GYTS' (Global Youth Tobacco Survey) and other additional questions were used to collect relevant information. Analysis showed that the prevalence of smoking was 12.3% among boys and 4.5% among girls, respectively. The mean age at initiation of smoking was 10.8 years with standard deviation of 2.7 years. Logistic regression analysis revealed that boys are 2.282 times likely to smoked than girls and it was 1.786 times higher among the students aged 16 years and above than their younger counterparts. Smoking by teachers appeared to be the strong predictor for students smoking behaviour (OR 2.206, 95% CI: 1.576, 3.088) followed by peer influence (OR 1.988, 95% CI: 1.178, 3.356). Effective smoking prevention program should to be taken to reduce smoking behaviour. The school curricula had less impact in preventing smoking except teacher's smoking behaviour.
  18. Catalytic cracking of bio-oil to organic liquid product (OLP)
    Hew KL, Tamidi AM, Yusup S, Lee KT, Ahmad MM
    Bioresour Technol, 2010 Nov;101(22):8855-8.
    PMID: 20621470 DOI: 10.1016/j.biortech.2010.05.036
    The main objective of this paper is to find the optimum operating condition to upgrade the EFB-derived pyrolysis oil (bio-oil) to liquid fuel, mainly gasoline using Taguchi Method. From the analysis that has been done, it is found that the optimum operating condition for heterogeneous catalytic cracking process is at 400 degrees C, 15min of reaction time using 30g of catalyst weight where operating at this condition produced the highest yield of gasoline fraction which is 91.67 wt.%. This observation proves that EFB-derived pyrolysis oil could be upgraded via heterogeneous catalytic cracking to produce gasoline.
  19. Determination of foveal avascular zone in diabetic retinopathy digital fundus images
    Ahmad Fadzil MH, Izhar LI, Nugroho HA
    Comput Biol Med, 2010 Jul;40(7):657-64.
    PMID: 20573343 DOI: 10.1016/j.compbiomed.2010.05.004
    Monitoring FAZ area enlargement enables physicians to monitor progression of the DR. At present, it is difficult to discern the FAZ area and to measure its enlargement in an objective manner using digital fundus images. A semi-automated approach for determination of FAZ using color images has been developed. Here, a binary map of retinal blood vessels is computer generated from the digital fundus image to determine vessel ends and pathologies surrounding FAZ for area analysis. The proposed method is found to achieve accuracies from 66.67% to 98.69% compared to accuracies of 18.13-95.07% obtained by manual segmentation of FAZ regions from digital fundus images.
  20. Enhanced growth of lactobacilli in soymilk upon immobilization on agrowastes
    Teh SS, Ahmad R, Wan-Abdullah WN, Liong MT
    J Food Sci, 2010 Apr;75(3):M155-64.
    PMID: 20492305 DOI: 10.1111/j.1750-3841.2010.01538.x
    Cell immobilization is an alternative to microencapsulation for the maintenance of cells in a liquid medium. The objective of this study was to evaluate the effects of agrowastes from durian (Durio zibethinus), cempedak (Artocarpus champeden), and mangosteen (Garcinia mangostana) as immobilizers for lactobacilli grown in soymilk. Rinds from the agrowastes were separated from the skin, dried, and ground (150 microm) to form powders and used as immobilizers. Scanning electron microscopy revealed that lactobacilli cells were attached and bound to the surface of the immobilizers. Immobilized cells of Lactobacillus acidophilus FTDC 1331, L. acidophilus FTDC 2631, L. acidophilus FTDC 2333, L. acidophilus FTDC 1733, and L. bulgaricus FTCC 0411 were inoculated into soymilk, stored at room temperature (25 degrees C) and growth properties were evaluated over 168 h. Soymilk inoculated with nonimmobilized cells was used as the control. Utilization of substrates, concentrations of lactic and acetic acids, and changes in pH were evaluated in soymilk over 186 h. Immobilized lactobacilli showed significantly better growth (P < 0.05) compared to the control, accompanied by higher production of lactic and acetic acids in soymilk. Soymilk containing immobilized cells showed greater reduction of soy sugars such as stachyose, raffinose, sucrose, fructose, and glucose compared to the control (P < 0.05).
Related Terms
Filters
Contact Us

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

External Links