Displaying publications 61 - 80 of 983 in total

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  1. SEM studies on differential morphology between the adult Malaysian schistosome and Schistosoma japonicum
    Phansri W, Ow-Yang CK, Lai PF, Greer GJ
    Southeast Asian J. Trop. Med. Public Health, 1984 Dec;15(4):525.
    PMID: 6535267
    Matched MeSH terms: Microscopy, Electron, Scanning
  2. Molecularly imprinted polymer for the removal of diclofenac from water: Synthesis and characterization
    Samah NA, Sánchez-Martín MJ, Sebastián RM, Valiente M, López-Mesas M
    Sci Total Environ, 2018 Aug 01;631-632:1534-1543.
    PMID: 29727977 DOI: 10.1016/j.scitotenv.2018.03.087
    Contaminants of Emerging Concerns (CECs) have been introduced as one type of recalcitrant pollutant sources in water. In this study, the non-steroidal anti-inflammatory drug diclofenac (DCF) has been removed from water solutions using Molecularly Imprinted Polymer (MIP), synthetized via bulk polymerization with allylthiourea (AT) as the functional monomer and using DCF as template (MIP-DCF). DCF detection has been performed by UV spectrophotometer. From the kinetic study in batch mode, approximately 100% of removal is observed by using 10mg of MIP-DCF, with an initial concentration of 5mg/L of DCF at pH7, within 3min and agitated at 25°C. In continuous flow mode study, using a cartridge pre-packed with 10mg of MIP-DCF, a high adsorption capacity of 160mgDCF/g MIP was obtained. To study the porosity of MIPs, scanning electron microscopy (SEM) has been used. In order to characterize the chemical interaction between monomer and template, the pre-polymerization mixture for MIP and DCF has also been studied by 1H NMR. One of the chemical shift observed has been related to the formation of a complex between amine protons of thiourea group of AT with carboxylic acid on DCF. In conclusion, the developed MIP works as a good adsorbent for DCF removal, and is selective to DCF in the presence of indomethacin and ibuprofen.
    Matched MeSH terms: Microscopy, Electron, Scanning
  3. Enhancement of high temperature performance of cement blocks via CO2 curing
    Meng Y, Ling TC, Mo KH, Tian W
    Sci Total Environ, 2019 Jun 25;671:827-837.
    PMID: 30947055 DOI: 10.1016/j.scitotenv.2019.03.411
    Carbonation for the curing of cement-based materials has been gaining increased attention in recent years, especially in light of emerging initiatives to reduce carbon dioxide (CO2) emissions. Carbonation method or CO2 curing is founded on the basis of the reaction between CO2 and cement products to form thermally stable and denser carbonate, which not only improves the physical and mechanical properties of cement-based materials, but also has the ability to utilize and store CO2 safely and permanently. This study aims to assess the effect of CO2 curing technology on the high-temperatures performance of cement blocks. Upon molding, dry-mix cement blocks were cured under statically accelerated carbonation condition (20% CO2 concentration with 70% relative humidity) for 28 days, followed by exposure to elevated temperatures of 300 °C to 800 °C in order to comprehensively study the principal phase changes and decompositions of cement hydrates. The results indicated that CO2 curing improved the performance of cement blocks, such as enhancement in the residual compressive strength and reducing the sorptivity. At 600 °C, the scanning electron microscopy (SEM) revealed a denser microstructure while thermal analisis and X-ray diffraction (XRD) analysis also clearly demonstrated that higher amounts of calcium carbonate were present in the cement blocks after CO2 curing, suggesting better high-temperature performance compared to natural cured cement blocks. In general, an improved high-temperature performance, specifically at 600 °C of the dry-mixed cement blocks was demonstrated by adopting the CO2 curing technology. This confirms the potential of utilizing CO2 curing technology in not only improving quality of cement blocks, new avenue for storing of CO2 in construction material can be realized at the same time.
    Matched MeSH terms: Microscopy, Electron, Scanning
  4. Environmental evaluation and nano-mineralogical study of fresh and unsaturated weathered coal fly ashes
    Akinyemi SA, Gitari WM, Petrik LF, Nyakuma BB, Hower JC, Ward CR, et al.
    Sci Total Environ, 2019 May 01;663:177-188.
    PMID: 30711584 DOI: 10.1016/j.scitotenv.2019.01.308
    Coal combustion and the disposal of combustion wastes emit enormous quantities of nano-sized particles that pose significant health concerns on exposure, particularly in unindustrialized countries. Samples of fresh and weathered class F fly ash were analysed through various techniques including X-ray fluorescence (XRF), X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), field-emission gun scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM) coupled with energy dispersive x-ray spectroscopy (EDS), and Raman Spectroscopy. The imaging techniques showed that the fresh and weathered coal fly ash nanoparticles (CFA-NPs) are mostly spherical shaped. The crystalline phases detected were quartz, mullite, ettringite, calcite, maghemite, hematite, gypsum, magnetite, clay residues, and sulphides. The most abundant crystalline phases were quartz mixed with Al-Fe-Si-K-Ti-O-amorphous phases whereas mullite was detected in several amorphous phases of Al, Fe, Ca, Si, O, K, Mg, Mn, and P. The analyses revealed that CFA-NPs are 5-500 nm in diameter and encapsulate several potentially hazardous elements (PHEs). The carbon species were detected as 5-50 nm carbon nanoballs of graphitic layers and massive fullerenes. Lastly, the aspects of health risks related to exposure to some detected ambient nanoparticles are also discussed.
    Matched MeSH terms: Microscopy, Electron, Scanning
  5. Fulltext Effects of salivary pH on coating durability of two different aesthetic archwire coatings under a simulated intraoral environment
    Abdulkader YC, Kamaruddin AF, Mydin RBSMN
    Saudi Dent J, 2020 Sep;32(6):306-313.
    PMID: 32874071 DOI: 10.1016/j.sdentj.2019.09.010
    Objectives: This study compared the effects of normal salivary pH, and acidic pH found in patients with poor oral hygiene, on the durability of aesthetic archwire coated with epoxy resin and polytetrafluoroethylene (PTFE).

    Methods: The posterior parts of the archwires were sectioned into 20 mm segments (N = 102) and divided among six groups. Four groups were treated with different pH levels and two served as controls. The specimens were immersed in individual test tubes containing 10 ml of artificial saliva adjusted to a pH of 6.75 or 3.5. The tubes were sealed and stored in a 37 °C water bath for 28 days. After 28 days, the specimens were ligated to brackets embedded in an acrylic block and subjected to mechanical stress using an electronic toothbrush for 210 s. The specimens were photographed, and images were measured for coating loss using AutoCAD® software. Surface morphology was observed using a scanning electron microscope (SEM).

    Results: Significant coating loss (p 

    Matched MeSH terms: Microscopy, Electron, Scanning
  6. Fulltext Characterization and safety assessment of bioengineered limbal epithelium
    Lim MN, Umapathy T, Baharuddin PJ, Zubaidah Z
    Med J Malaysia, 2011 Oct;66(4):335-41.
    PMID: 22299553 MyJurnal
    Transplantation of cultivated limbal epithelium on substrates such as amniotic membrane is an established treatment for severe ocular surface disease with limbal stem cell deficiency. In this study, we adapted an established method to generate sheets of limbal epithelium on amniotic membrane and characterized the cells contained in these sheets and tested them for safety with regard to microbial contamination. Human limbal biopsies were cultivated on denuded amniotic membranes. After three weeks of culture, the phenotypes of cultivated cells were analyzed by immunohistochemistry and real-time RT-PCR for the expression of a panel of specific markers. Cultivated limbal epithelial cell sheets were also analyzed by scanning (SEM) and transmission (TEM) electron microscopy. Sterility tests and mycoplasma assays were conducted for the safety of product. A confluent layer of polygonal cells was formed in 2 weeks and 1-3 stratified layer of cells were observed after three weeks of culture. Cultivated cells were positive for p63, K3, K19, and involucrin but negative for K14, integrin alpha9 and ABCG2 when analyzed by immunohistochemistry. Expression of molecular markers was detectable with real-time RT-PCR. SEM showed multilayer of flat squamous polygonal epithelial cells. Desmosomal and hemidesmosomal attachments were evident. Our study showed that cultivated limbal epithelium consists of limbal progenitors as well as differentiated corneal epithelial cells. SEM and TEM analysis showed cultivated cells demonstrated typical features of corneal epithelium. The risk of contamination is low and can be prevented by culturing the cells in a clean room facility complying to Good Manufacturing Practice standard.
    Matched MeSH terms: Microscopy, Electron, Scanning
  7. Scanning electron microscopy of cornea re-epithelization after transplanted with bilayered corneal construct
    Masrudin SS, Ghafar NA, Saidi M, Aminuddin BS, Rahmat A, Ruszymah BH, et al.
    Med J Malaysia, 2008 Jul;63 Suppl A:109-10.
    PMID: 19025009
    The present work was to determine the development and re-epithelization of bilayered corneal construct (BCC) in vitro and in vivo using scanning electron microscopy (SEM). The in vitro BCC was transplanted to the rabbit's eye and after 90 days the BCC was harvested and analyzed. The corneas were processed for morphology studies. The result indicates that the BICC that was transplanted for 90 days showed good development and re-epithelization of epithelial layer similar to the normal cornea.
    Matched MeSH terms: Microscopy, Electron, Scanning*
  8. Cytotoxicity and scanning electron microscopy study of gentamycin-coated HA effect on biofilm
    Au LF, Othman F, Mustaffa R, Vidyadaran S, Rahmat A, Besar I, et al.
    Med J Malaysia, 2008 Jul;63 Suppl A:16-7.
    PMID: 19024962
    Biofilms are adherent, multi-layered colonies of bacteria that are typically more resistant to the host immune response and routine antibiotic therapy. HA biomaterial comprises of a single-phased hydroxyapatite scaffold with interconnected pore structure. The device is designed as osteoconductive space filler to be gently packed into bony voids or gaps following tooth extraction or any surgical procedure. Gentamycin-coated biomaterial (locally made hydroxyapatite) was evaluated to reduce or eradicate the biofilm on the implant materials. The results indicated that the HA coated with gentamycin was biocompatible to human osteoblast cell line and the biofilm has been reduced after being treated with different concentrations of gentamycin-coated hydroxyapatite (HA).
    Matched MeSH terms: Microscopy, Electron, Scanning/instrumentation*; Microscopy, Electron, Scanning/methods
  9. A scanning electron microscopic study of in vivo tissue engineered respiratory epithelium in sheep
    Heikal MY, Aminuddin BS, Jeevanan J, Chen HC, Sharifah S, Ruszymah BH
    Med J Malaysia, 2008 Jul;63 Suppl A:34.
    PMID: 19024970
    Normal tracheal mucociliary clearance is the key to maintaining the health and defense of respiratory airway. Therefore the present of cilia and mucous blanket are important for tracheal epithelium to function effectively. In the present study, we prepared a tissue engineered respiratory epithelium construct (TEREC) made of autologous respiratory epithelium cells, fibroblast and fibrin from sheep owns blood which replaced a created tracheal mucosal defect. Scanning electron microscopy (SEM) showed encouraging result where immature cilia were present on the surface of TEREC. This result indicates that engineered respiratory epithelium was able to function as normal tissue.
    Matched MeSH terms: Microscopy, Electron, Scanning*
  10. Comparison of chitosan scaffold and chitosan-collagen scaffold: a preliminary study
    Norazril SA, Aminuddin BS, Norhayati MM, Mazlyzam AL, Fauziah O, Ruszymah BH
    Med J Malaysia, 2004 May;59 Suppl B:186-7.
    PMID: 15468880
    Chitosan has similar structure to glycosaminoglycans in the tissue, thus may be a good candidates as tissue engineering scaffold. However, to improve their cell attachment ability, we try to incorporate this natural polymer with collagen by combining it via cross-linking process. In this preliminary study we evaluate the cell attachment ability of chitosan-collagen scaffold versus chitosan scaffold alone. Chitosan and collagen were dissolved in 1% acetic acid and then were frozen for 24 hours before the lyophilizing process. Human skin fibroblasts were seeded into both scaffold and were cultured in F12: DMEM (1:1). Metabolic activity assay were used to evaluate cell attachment ability of scaffold for a period of 1, 3, 7 and 14 days. Scanning electron micrographs shows good cell morphology on chitosan-collagen hybrid scaffold. In conclusion, the incorporation of collagen to chitosan will enhance its cell attachment ability and will be a potential scaffold in tissue engineering.
    Matched MeSH terms: Microscopy, Electron, Scanning
  11. Evaluation of suitable biodegradable scaffolds for engineered bone tissue
    Phang MY, Ng MH, Tan KK, Aminuddin BS, Ruszymah BH, Fauziah O
    Med J Malaysia, 2004 May;59 Suppl B:198-9.
    PMID: 15468886
    Tricalcium phosphate/hydroxyapatite (TCP/HA), hydroxyapatite (HA), chitosan and calcium sulphate (CaSO4) were studied and evaluated for possible bone tissue engineered construct acting as good support for osteogenic cells to proliferate, differentiate, and eventually spread and integrate into the scaffold. Surface morphology visualized by SEM showed that scaffold materials with additional fibrin had more cell densities attached than those without, depicting that the presence of fibrin and collagen fibers were truly a favourite choice of cells to attach. In comparison of various biomaterials used incorporated with fibrin, TCP/HA had the most cluster of cells attached.
    Matched MeSH terms: Microscopy, Electron, Scanning
  12. Tissue-engineered bone via seeding bone marrow stem cell derived osteoblasts into coral: a rat model
    Al-Salihi KA
    Med J Malaysia, 2004 May;59 Suppl B:200-1.
    PMID: 15468887
    In the present study, natural coral of porites species was used as scaffold combined with in vitro expanded bone marrow stem cell derived osteoblasts (BMSC-DO), to develop a tissue-engineered bone graft in a rat model. Coral was molded into the shape of rat mandible seeded with 5x10(6) /ml BMSC-DO subsequently implanted subcutaneously in the back of 5 week Sprague dawely rats for 3 months. Coral alone was implanted as a control. The implants were harvest and processed for gross inspection and histological observations. The results showed that newly bone grafts were successfully formed coral seeded with cells group showed smooth highly vascularized like bone tissue. Histological sections revealed mature bone formation and lots of blood vessel, the bone formation occurred in the manner resemble intramembraneous bone formation. This study demonstrates that coral can be use as a suitable scaffold material for delivering bone marrow mesenchymal stem cells in tissue engineering.
    Matched MeSH terms: Microscopy, Electron, Scanning
  13. Collagen fibers an important entity in skin tissues remodeling
    Norhayati MM, Mazlyzam AL, Asmah R, Fuzina H, Aminuddin BS, Ruszymah BH, et al.
    Med J Malaysia, 2004 May;59 Suppl B:184-5.
    PMID: 15468879
    Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) evaluation were carried out in the in vivo skin construct using fibrin as biomaterial. To investigate its progressive remodeling, nude mice were grafted and the Extracellular Matrix (ECM) components were studied at four and eight weeks post-grafting. It was discovered that by 4 weeks of remodeling the skin construct acquired its native structure.
    Matched MeSH terms: Microscopy, Electron, Scanning
  14. The influence of sintering temperature on the porosity and strength of porous hydroxyapatite ceramics
    Rusnah M, Andanastuti M, Idris B
    Med J Malaysia, 2004 May;59 Suppl B:158-9.
    PMID: 15468866
    The present paper reports on the influence of sintering temperature on the porosity and strength of porous hydroxyapatite (HA). HA powder was first prepared by the sol-gel precipitation method using calcium hydroxide and ortho-phosporic acid. The fine HA powder, measuring <50 microm was then mixed into a slurry with the addition of binder agent, being a mixture of sago and PVA. A small amount of sodium dodecyl sulphate was also used as a foaming agent. Porous HA samples were then prepared via slip casting technique. The surface morphology of the sintered samples was observed under scanning electron microscopy at 20 kV and the compositions were determined via SEM-EDX. A universal testing machine was used to determine the compaction strength of the sintered samples.
    Matched MeSH terms: Microscopy, Electron, Scanning
  15. Locally produced bovine bone sponge as a haemostatic agent
    Ang CY, Samsudin AR, Karima AM, Nizam A
    Med J Malaysia, 2004 May;59 Suppl B:149-50.
    PMID: 15468862
    The aim of this study was to evaluate the morphological and biological properties of a locally produced "Bovine Bone Sponge" for use in dentistry. Bovine bone sponge was prepared from local calf bone. Endotoxin level and surface properties were investigated. The pore size and water uptake ability were measured and results were compared with the commercial haemostatic agent. The material was tested for its haemostatic property and its inhibition of alveolar bone resorption in a sheep model following dental extraction. Results revealed a significant difference in haemostatic effect, and a shorter bleeding time and a lower rate of alveolar bone resorption in bovine bone sponge compare to a commercial haemostatic agent.
    Matched MeSH terms: Microscopy, Electron, Scanning
  16. Plasma-sprayed coating of hydroxyapatite on metal implants--a review
    Talib RJ, Toff MR
    Med J Malaysia, 2004 May;59 Suppl B:153-4.
    PMID: 15468864
    Metal implants such as titanium, stainless steel and Co-Cr-Mo are used for load bearing purposes such as hip joint prostheses, fixing plates and dental root implants. For practical application, plasma-sprayed coatings of hydroxyapatite (HA) on metal implants are applied to promote early formation of strong bonds between metal implant and living bone. Plasma spray coating involves heating of HA material to a semi-molten or molten state and then propels its to a metal substrate. The plasma flame temperature is in the range of 6,000 degrees C to 16,000 degrees C but the surface temperature of the substrate rarely exceeds 150 degrees C. The HA materials are feed into the spray gun in the form of powders. Furthermore, this paper will discuss the processes of plasma-sprayed coating of HA on various types of metal implants.
    Matched MeSH terms: Microscopy, Electron, Scanning
  17. Comparative study between dense and porous hydroxyapatite using light and scanning electron microscopy
    Pohchi A, Suzina AH, Samsudin AR, Al-Salihi KA
    Med J Malaysia, 2004 May;59 Suppl B:151-2.
    PMID: 15468863
    This in vivo study revealed that porous hydroxyapatite (PHA) and dense hydroxyapatite (DHA) are good implant materials that can accelerate bone healing and resorbed in acceptable time. But there were differences in the mechanism of the resorption of DHA and PHA due to variability in the physical properties and osteogenicity.
    Matched MeSH terms: Microscopy, Electron, Scanning*
  18. Synthesis of nano-sized hydroxyapatite
    Tan SA, Ahmad Fauzi MN, Luay BH, Radzali O
    Med J Malaysia, 2004 May;59 Suppl B:162-3.
    PMID: 15468868
    In this work, nanometer HA crystals have been synthesized via wet chemical precipitation and characterized. This research studies how key synthesis parameters affect the size and phase purity of the produced HA. Characterization work was carried out using X-ray powder diffraction method and scanning electron microscopy for phase identification and particle sizing, respectively.
    Matched MeSH terms: Microscopy, Electron, Scanning
  19. In vivo study of CORAGRAF: a preliminary results
    Rosdan S, Al-Salihi KA, Suzina AH, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:111-2.
    PMID: 15468843
    The main objective of the study was to determine the biodegradability, resorption and osteoconductivity potency of coral implant. Coral blocks (CORAGRAF) were prepared from sea coral Porites species. The blocks were implanted in the right mandible of rabbit model. Implants were harvested at 2 and 4 weeks intervals and subjected for light and scanning electron microscopy. Dense hydroxyapatite (DHA) was implanted in the left mandible as a control. The results of this study demonstrated that CORAGRAF is a good implant material that can accelerates bone healing and be resorbed in an acceptable time. The mechanisms of the resorption seemed to be the same (crumbling process), a first step where the edge of the coral become powdery then a second step which could be phagocytosis and dissolution in extracellular fluid.
    Matched MeSH terms: Microscopy, Electron, Scanning
  20. Preparation of naltrexone hydrochloride loaded poly (DL-lactide-co-glycolide) microspheres and the effect of polyvinyl alcohol (PVA) as surfactant on the characteristics of the microspheres
    Suhaida MG, Yahya IB, Darmawati MY
    Med J Malaysia, 2004 May;59 Suppl B:63-4.
    PMID: 15468820
    The aim of this study was to investigate the effect of the surfactant properties of polyvinyl alcohol (PVA) in enhancing the yield of small size microspheres. Naltrexone microspheres were prepared by solvent-solvent extraction evaporation process. PVA of various concentrations were added into the aqueous phase prior to the mixing process. The addition of PVA was expected to influence the shape, size distribution, drug loading and drug release profile. The results indicated that it is desirable to increase the weight fraction of the microspheres with size range below 106 mm for the highest possible yield.
    Matched MeSH terms: Microscopy, Electron, Scanning
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