Displaying publications 41 - 60 of 165 in total

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  1. Rahman NA, Ali Z, Zuharah WF, Fadzly N
    Trop Life Sci Res, 2016 Aug;27(2):1-12.
    PMID: 27688847 MyJurnal DOI: 10.21315/tlsr2016.27.2.1
    We conducted several aviary experiments to investigate the influence of colours in quantity judgments of two species of birds; house crow (Corvus splendens) and common myna (Acridotheres tristis). Different quantity (in seven different food proportions) of mealworms were presented nonsequentially to all birds using artificially coloured red mealworms, for experiment 1, and using artificially coloured green mealworms, for experiment 2. Both red and green coloured mealworms have no significant effect on house crow's quantity judgments (red:
  2. Zin CS, Rahman NA, Ismail CR, Choy LW
    Pain Pract, 2017 07;17(6):774-781.
    PMID: 27676695 DOI: 10.1111/papr.12525
    BACKGROUND: There are currently limited data available on the patterns of opioid prescribing in Malaysia. This study investigated the patterns of opioid prescribing and characterized the dosing and duration of opioid use in patients with noncancer and cancer pain.
    METHODS: This retrospective, cross-sectional study was conducted at an outpatient hospital setting in Malaysia. All prescriptions for opioids (dihydrocodeine, fentanyl, morphine, and oxycodone) issued between January 2013 and December 2014 were examined. The number of prescriptions and patients, the distribution of mean daily dose, annual total days covered with opioids, and annual total opioid dose at the individual level were calculated and stratified by noncancer and cancer groups.
    RESULTS: A total of 1015 opioid prescriptions were prescribed for 347 patients from 2013 to 2014. Approximately 41.5% of patients (N = 144/347) and 58.5% (N = 203/347) were associated with noncancer and cancer diagnosis, respectively. Oxycodone (38.0%) was the highest prescribed primarily for the noncancer group. The majority of patients in both noncancer (74.3%) and cancer (60.4%) groups were receiving mean daily doses of < 50 mg morphine equivalents. The chronic use of opioids (> 90 days per year) was associated with 21.8% of patients in the noncancer group and 17.5% in the cancer group.
    CONCLUSIONS: The finding from this study showed that 41.5% of opioid users at an outpatient hospital setting in Malaysia received opioids for noncancer pain and 21.8% of these users were using opioids for longer than 90 days. The average daily dose in the majority of patients in both groups of noncancer and cancer was modest.
    Study site: outpatient clinic, hospital, Malaysia
  3. Singh VA, Lim CY, Yan HC, Rahman NA
    J Foot Ankle Surg, 2017 06 26;56(6):1292-1297.
    PMID: 28659241 DOI: 10.1053/j.jfas.2017.05.005
    Melanoma is a well-known malignant neoplasm of the skin, although it can also arise from other structures. Bone metastasis is not an uncommon event associated with melanoma, although primary osseous melanoma is very rare. In the present report, we describe a case of primary melanoma arising from the left third metatarsal in an adult male. The lesion was treated with surgical excision without adjunct chemotherapy, and recurrence developed approximately 12 months after the foot surgery. The patient died of the cancer 34 months after it had been identified. Primary melanoma arising in a metatarsal is rare, and we wished to highlight this unusual presentation.
  4. Rahman NA, Sharudin A, Diah S, Muharram SH
    Microb Pathog, 2017 Sep;110:352-358.
    PMID: 28711510 DOI: 10.1016/j.micpath.2017.07.021
    INTRODUCTION: Pneumococcal infections have caused morbidity and mortality globally. Streptococcus pneumoniae (pneumococci) are commensal bacteria that colonize the nasopharynx, asymptomatically. From there, pneumococci can spread in the lungs causing pneumonia and disseminate in the bloodstream causing bacteremia (sepsis) and reach the brain leading to meningitis. Endothelial cells are one of the most important components of the blood-brain barrier that separates the blood from the brain and plays the first protective role against pneumococcal entry. Thus this study aimed to investigate on the ability of non-meningitis pneumococcal clinical strains to adhere and invade a brain endothelium model.

    METHODS: Two pneumococcal Brunei clinical strains were serotyped by multiplex PCR method using oligonucleotide sequences derived from Centers for Disease Control and Prevention. A validated immortalised mouse brain endothelial cell line (bEnd.3) was used as a brain endothelium model for the study of the pneumococcal breach of the blood-brain barrier using an adherence and invasion assay.

    RESULTS: Both of the pneumococcal clinical strains were found to be serotype 19F, a common circulating serotype in Southeast Asia and globally and possess the ability to adhere and invade the brain endothelial cells.

    CONCLUSION: In addition, this is the first report on the serotype identification of pneumococci in Brunei Darussalam and their application on a brain endothelium model. Further studies are required to understand the virulence capabilities of the clinical strains.

  5. Ahmad R, Rahman NA, Hasan R, Yaacob NS, Ali SH
    Spec Care Dentist, 2020 Jan;40(1):62-70.
    PMID: 31774579 DOI: 10.1111/scd.12436
    AIMS: To investigate the oral health and nutritional status of children with cerebral palsy (CP).

    METHODS AND RESULTS: Oral health assessment included dental caries and dental plaque maturity scores (DPMS) while the nutritional assessment included children's height-for-age Z-score (HAZ), body mass index-for-age Z-score (BAZ), mid-upper-arm circumference (MUAC), nutrient intake, cariogenic food frequency (CFF) and daily sugar exposure (DSE). Ninety-three CP children were recruited. The prevalence of caries was 81.7% (95% CI: 72.7%-88.3%). The median (IQR) of the DMFT and dft scores were 0.5(4.0) and 3.0(8.0), respectively. Most of the participants had acid-producing plaque (90.3%), severely stunted (81.4%), and 45% were severely thin with acute malnutrition. Intakes of calcium, iron, zinc, vitamin A, vitamin D and total fat were below 77% of the Recommended Nutrient Intakes for Malaysian children (RNI 2017). Nine types of cariogenic foods/drinks were consumed moderately, and DSE indicated that 45% of the children were at moderate risk of dental caries.

    CONCLUSION: Untreated dental caries, severe stunting and thinness were prevalent, and cariogenic foods/drinks were consumed moderately suggesting a moderate risk of caries. Therefore, controlling cariogenic food intake is crucial, but monitoring daily nutrient intake is needed for the optimum growth of children with CP.

  6. Omar F, Ab-Ghani Z, Rahman NA, Halim MS
    Eur J Dent, 2019 Oct;13(4):589-598.
    PMID: 31891975 DOI: 10.1055/s-0039-1700659
    OBJECTIVES:  This study evaluates the efficacy and safety of the professionally prescribed and nonprescription over-the-counter (OTC) bleaching agents.

    MATERIALS AND: METHODS:  Extracted human upper central incisors were prepared and stained with red wine for 14 days before being subjected to four different bleaching agents: professionally prescribed opalescence PF 15%, VOCO Perfect Bleach 10%, nonprescription OTC Crest 3D Whitestrips, and Whitelight Teeth Whitening System. Colorimetric measurement was performed with Vita Easyshade Handheld Spectrophotometer, enamel surface microhardness measured using Vickers Hardness machine, and surface roughness was evaluated with profilometer, before and after bleaching. Scanning electron microscope (SEM) evaluation and atomic force microscopy were conducted postbleaching.

    STATISTICAL ANALYSIS:  The data were analyzed with t-test, two-way ANOVA, one-way ANOVA, and Turkey's test at a significance level of 5%.

    RESULTS:  All bleaching products have the same efficacy to whiten stained enamel. Opalescence PF 15% showed significant increase in the microhardness (92.69 ± 68.316). All groups demonstrated significant increase in surface roughness (p < 0.05). SEM evaluation showed that Opalescence PF 15% resulted in same microscopic appearance as unbleached enamel, while VOCO Perfect Bleach 10%, Whitelight Teeth Whitening System and Crest 3D Whitestrips demonstrated mild to moderate irregularities and accentuated irregularities, respectively.

    CONCLUSION:  Professionally prescribed bleaching agent of Opalescence PF 15% is effective tin whitening the teeth, while the other bleaching products may be effective but also have deleterious effects on the enamel.

  7. Mohd Yusof H, Mohamad R, Zaidan UH, Rahman NA
    Microb Cell Fact, 2020 Jan 15;19(1):10.
    PMID: 31941498 DOI: 10.1186/s12934-020-1279-6
    BACKGROUND: The use of microorganisms in the biosynthesis of zinc oxide nanoparticles (ZnO NPs) has recently emerged as an alternative to chemical and physical methods due to its low-cost and eco-friendly method. Several lactic acid bacteria (LAB) have developed mechanisms in tolerating Zn2+ through prevention against their toxicity and the production of ZnO NPs. The LAB's main resistance mechanism to Zn2+ is highly depended on the microorganisms' ability to interact with Zn2+ either through biosorption or bioaccumulation processes. Besides the inadequate studies conducted on biosynthesis with the use of zinc-tolerant probiotics, the understanding regarding the mechanism involved in this process is not clear. Therefore, this study determines the features of probiotic LAB strain TA4 related to its resistance to Zn2+. It also attempts to illustrate its potential in creating a sustainable microbial cell nanofactory of ZnO NPs.

    RESULTS: A zinc-tolerant probiotic strain TA4, which was isolated from local fermented food, was selected based on the principal component analysis (PCA) with the highest score of probiotic attributes. Based on the 16S rRNA gene analysis, this strain was identified as Lactobacillus plantarum strain TA4, indicating its high resistance to Zn2+ at a maximum tolerable concentration (MTC) value of 500 mM and its capability of producing ZnO NPs. The UV-visible spectroscopy analysis proved the formations of ZnO NPs through the notable absorption peak at 380 nm. It was also found from the dynamic light scattering (DLS) analysis that the Z-average particle size amounted to 124.2 nm with monodisperse ZnO NPs. Studies on scanning electron microscope (SEM), energy-dispersive X-ray (EDX) spectroscopy, and Fourier-transform infrared spectroscopy (FT-IR) revealed that the main mechanisms in ZnO NPs biosynthesis were facilitated by the Zn2+ biosorption ability through the functional groups present on the cell surface of strain TA4.

    CONCLUSIONS: The strong ability of zinc-tolerant probiotic of L. plantarum strain TA4 to tolerate high Zn2+ concentration and to produce ZnO NPs highlights the unique properties of these bacteria as a natural microbial cell nanofactory for a more sustainable and eco-friendly practice of ZnO NPs biosynthesis.

  8. Rahman NA, Harun MH, Rahman SA, Mohammad NSA
    J Taibah Univ Med Sci, 2020 Apr;15(2):160-165.
    PMID: 32368214 DOI: 10.1016/j.jtumed.2020.02.005
    Gorham disease (GD) is an extremely rare disorder that is characterised by massive osteolysis of the affected bone with unknown aetiology and an unpredictable prognosis. Additionally, no standard treatment is available for GD. This article describes a case report of a 61-year-old Malay woman who was diagnosed with GD of the anterior mandible without a prior history of trauma. She presented with pain and mobility of the dentoalveolar segment for 3 months. The radiographic findings showed "floating teeth" with widening of the periodontal ligament space and localized area of bony destruction. Histopathologically, there was proliferation of numerous dilated endothelial-lined channels within the intertrabecular tissue. Some areas of bone were replaced by fibrous connective tissue giving rise to the appearance of a benign fibroosseous lesion. The patient was managed with simple removal of the affected bone segment under local anaesthesia, followed by prosthodontic rehabilitation. Healing of the surgical site was uneventful, and no recurrence was reported at the 3-year follow-up.
  9. Fauzi FH, Hamzan NI, Rahman NA, Suraiya S, Mohamad S
    J Zhejiang Univ Sci B, 2021 4 13;21(12):961-976.
    PMID: 33843162 DOI: 10.1631/jzus.B2000161
    Worldwide there has been a significant increase in the incidence of oropharyngeal squamous cell carcinoma (OPSCC) etiologically attributed to oncogenic human papillomavirus (HPV). Reliable and accurate identification and detection tools are important as the incidence of HPV-related cancer is on the rise. Several HPV detection methods for OPSCC have been developed and each has its own advantages and disadvantages in regard to sensitivity, specificity, and technical difficulty. This review summarizes our current knowledge of molecular methods for detecting HPV in OPSCC, including HPV DNA/RNA polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), p16 immunohistochemistry (IHC), and DNA/RNA in situ hybridization (ISH) assays. This summary may facilitate the selection of a suitable method for detecting HPV infection, and therefore may help in the early diagnosis of HPV-related carcinoma to reduce its mortality, incidence, and morbidity.
  10. Abd Rahman NA, Li S, Schmid S, Shaharudin S
    Phys Ther Sport, 2023 Jan;59:60-72.
    PMID: 36516512 DOI: 10.1016/j.ptsp.2022.11.011
    Low back pain (LBP) can result in increased direct medical and non-medical costs to patients, employers, and health care providers. This systematic review aimed to provide a better understanding of the biomechanical factors associated with chronic non-specific LBP in adults. SCOPUS, ScienceDirect, MEDLINE, and Web of Science databases were searched. In total, 26 studies were included and significant differences were noted between healthy controls and LBP patients in various motion. Biomechanical factors among adults with non-specific LBP were altered and differed as compared to healthy controls in various motion might be to compensate the pain during those motions. This review highlighted the biomechanical differences across those with non-specific LBP and healthy adults. Both groups showed a similar level of pain during functional tasks but LBP patients suffered from a moderate level of disability. Future studies should not rely on questionnaire-based pain scale only. The biomechanical factors summarized in this review can be used to diagnose non-specific LBP accurately, and as modifiable targets for exercise-based intervention.
  11. Tay KS, Rahman NA, Abas MR
    Environ Sci Pollut Res Int, 2013 May;20(5):3115-21.
    PMID: 23054788 DOI: 10.1007/s11356-012-1223-3
    This study investigated the degradation pathway of metoprolol, a widely used β-blocker, in the ozonation via the identification of generated ozonation by-products (OPs). Structure elucidation of OPs was performed using HPLC coupled with quadrupole time-of-flight high-resolution mass spectrometry. Seven OPs were identified, and four of these have not been reported elsewhere. Identified OPs of metoprolol included aromatic ring breakdown by-products; aliphatic chain degraded by-products and aromatic ring mono-, di-, and tetrahydroxylated derivatives. Based on the detected OPs, metoprolol could be degraded through aromatic ring opening reaction via reaction with ozone (O3) and degradation of aliphatic chain and aromatic ring via reaction with hydroxyl radical (•OH).
  12. Muhamad M, Kee LY, Rahman NA, Yusof R
    Int J Biol Sci, 2010 May 23;6(3):294-302.
    PMID: 20567498
    Dengue viruses, mosquito-borne members of the Flaviviridae family, are the causative agents of dengue fever and its associated complications, dengue haemorrhagic fever and dengue shock syndrome. To date, more than 2.5 billion people in over 100 countries are at risk of infection, and approximately 20 million infections were reported annually. There is currently no treatment or vaccine available for dengue infection. This study employed a whole-cell organism model or in vitro methods to study the inhibitory property of the flavanoid-derived compounds against DENV2 activity. Results showed that at concentration not exceeding the maximum non-toxic dose (MNTD), these compounds completely prevented DENV2 infection in HepG2 cells as indicated by the absence of cytophatic effects. The in vitro antiviral activity assessed in HepG2 cells employing virus inhibition assay showed high inhibitory activity in a dose dependent manner. At concentration below MNTD, compounds exhibited inhibitory activity against DENV2 with a range of potency strengths of 72% to 100%. The plaque forming unit per ml (pfu/ml) was reduced prominently with a maximum reduction of 98% when the infected HepG2 cells were treated with the highest non-toxic dose of compounds. The highly potent activity of the compounds against DENV2 infection strongly suggests their potential as a lead antiviral agent for dengue.
  13. Mohd Yusof H, Mohamad R, Zaidan UH, Abdul Rahman NA
    PMID: 31321032 DOI: 10.1186/s40104-019-0368-z
    In recent years, zinc oxide nanoparticles (ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles (NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods. Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, non-toxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal's body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.
  14. Du X, Rashid SA, Abdullah LC, Rahman NA
    Environ Sci Pollut Res Int, 2023 Nov;30(51):110417-110430.
    PMID: 37783997 DOI: 10.1007/s11356-023-30213-4
    Separation materials have received increasing attention given their broad applications in the management of environmental pollution. It is desired to balance the contradiction between high separation efficiency and selectivity of separation materials. The integration of ball-milled bone chars with electrospun membranes might achieve this balance. In this study, electrospun cellulose/chitosan/ball-milled bone char (CL/CS/MB) membranes were by well-dispersing ball-milled bone chars with nanoscale size (98.9-167.5 nm) and developed porosity (40.2-373.1 m2/g) in the electrospinning solvent. The synergistic integration of distributed MBs (5.4-31.5 wt.% of loading hydroxyapatite on the membrane matrix) allowed the efficient sorption of Pb(II) with fast kinetics (20.0 min), excellent capacity (219.9 mg/g at pH 5.0, T 298 K), and favorable selectivity coefficients (2.76-6.79). The formation of minerals was dominant for the selective sorption of Pb(II) by combining the spectral analysis and quantitative determination. The surface complexation with O-/reductive N-species, the cation exchange with inorganic Ca2+, the electrostatic attraction with deprotonated O-, and the cation-π coordination with the aromatic carbon via the π-electrons should be not ignored for the capture of Pb(II). This work demonstrated the feasibility of electrospun CL/CS/MB membranes as a promising candidate for the remediation of aquatic pollutants.
  15. Abd Rahman NA, Mohamed Sahari KS, Baharuddin MZ
    Appl Radiat Isot, 2023 Oct;200:110968.
    PMID: 37544032 DOI: 10.1016/j.apradiso.2023.110968
    The sensor coverage problem aims to maximize the coverage of a target area with a fixed or minimum number of sensors. However, the sampling point coverage for radiation mapping has yet to be specified or adequately established. When dealing with unknown radiation fields, it is critical that the placements of sampling points will ensure that all hotspots are detected and accurately identified. Therefore, the concept of coverage and detection limit for a sampling point in radiation mapping is proposed in this paper. The proposed concept relates the angular dependency of the radiation measurement instruments with the detector detection limit or minimum detectable amount (MDA). To demonstrate the implementation, the concept is used to compute the sensitivity of the radiation map for coverage radiation mapping with mobile robot. Simulation results showed that hotspots with intensity equal to or above the sampling point detection limit were successfully detected regardless of their position within the coverage circle. Moreover, the experimental results of coverage radiation mapping showed that the concept can be used to compute the resolution of the radiation map. This will help the user to efficiently configure the appropriate grid size that suit their mapping situation and requirements.
  16. Ghazali N, Rahman NA, Kannan TP, Ahmad A, Sulong S
    BMC Oral Health, 2023 Nov 29;23(1):945.
    PMID: 38031027 DOI: 10.1186/s12903-023-03464-3
    BACKGROUND: Nonsyndromic cleft lip and/or without cleft palate (NSCL/P) with or without hypodontia is a common developmental aberration in humans and animals. This study aimed to identify the loss of heterozygosity (LOH) involved in hypodontia and NSCL/P pathogenesis.

    METHODS: This is a cross-sectional study that conducted genome-wide copy number analysis using CytoScan 750K array on salivary samples from Malay subjects with NSCL/P with or without hypodontia aged 7-13 years. To confirm the significant results, simple logistic regression was employed to conduct statistical data analysis using SPSS software.

    RESULTS: The results indicated the most common recurrent copy neutral LOH (cnLOH) observed at 1p33-1p32.3, 1q32.2-1q42.13 and 6p12.1-6p11.1 loci in 8 (13%), 4 (7%), and 3 (5%) of the NSCL/P subjects, respectively. The cnLOHs at 1p33-1p32.3 (D1S197), 1q32.2-1q42.13 (D1S160), and 6p12.1-6p11.1 (D1S1661) were identified observed in NSCL/P and noncleft children using microsatellite analysis markers as a validation analysis. The regions affected by the cnLOHs at 1p33-1p32.3, 1q32.2-1q42.13, and 6p12.1-6p11.1 loci contained selected genes, namely FAF1, WNT3A and BMP5, respectively. There was a significant association between the D1S197 (1p33-32.3) markers containing the FAF1 gene among NSCL/P subjects with or without hypodontia compared with the noncleft subjects (p-value = 0.023).

    CONCLUSION: The results supported the finding that the genetic aberration on 1p33-32.3 significantly contributed to the development of NSCL/P with or without hypodontia. These results have an exciting prospect in the promising field of individualized preventive oral health care.

  17. Ghazali N, Rahman NA, Kannan TP, Jaafar S
    PMID: 25372553
    OBJECTIVE:   To determine the prevalence of mutations in transforming growth factor beta 3 (TGFβ3) and Jagged2 genes and their association with nonsyndromic cleft lip with or without cleft palate (CL±P) patients.

    DESIGN:   Cross-sectional study on nonsyndromic CL±P and noncleft patients.

    SETTING:   Reconstructive clinic and outpatient dental clinic, Hospital Universiti Sains, Malaysia.

    PATIENTS:   Blood samples of 96 nonsyndromic CL±P and 96 noncleft subjects.

    MAIN OUTCOME MEASURE:   Prevalence and association of mutations in TGFβ3 and Jagged2 genes with nonsyndromic CL±P.

    RESULTS:   Most of the nonsyndromic CL±P patients (53.1%) had left unilateral CLP. There were slightly more females (56.6%) compared with males. The prevalence of the mutations in the TGFβ3 gene was 17.7 (95% confidence interval [CI]: 9.5, 24.5) and in the Jagged2 gene was 12.5% (95% CI: 5.5, 18.5), which was higher compared with the noncleft group. For the TGFβ3 gene, there was no mutation in the coding region in either of the groups. All variants were single nucleotide polymorphisms located within the intronic flanking region. Two variants were identified (g.15812T>G and g.15966A>G) in both nonsyndromic CL±P and noncleft patients. However, the association was not significant (P > .05). Three variants (g.19779C>T, g.19547G>A, and g.19712C>T) were identified in the Jagged2 gene among nonsyndromic CL±P and noncleft patients. Only g.19712C>T showed a significant association with nonsyndromic CL±P patients (P = .039).

    CONCLUSION:   g.19712C>T might play a crucial role in the development of cleft lip and palate. To the best of our knowledge, this is the first report of the mutation found within intron 13 of the Jagged2 gene among nonsyndromic CL±P Malay patients.

  18. Yehye WA, Rahman NA, Ariffin A, Ng SW
    Acta Crystallogr Sect E Struct Rep Online, 2008 Aug 23;64(Pt 9):o1824.
    PMID: 21201799 DOI: 10.1107/S1600536808026846
    In the crystal structure of the title Schiff-base, C(20)H(21)N(3)O(4), the amino group forms an N-H⋯O hydrogen bond to the acetyl group of an adjacent mol-ecule, forming a zigzag chain. The 2-hydr-oxy group is inter-nally hydrogen bonded to the amido group though an O-H⋯O hydrogen bond.
  19. Zubair NA, Rahman NA, Lim HN, Sulaiman Y
    Nanoscale Res Lett, 2017 Dec;12(1):113.
    PMID: 28209034 DOI: 10.1186/s11671-017-1888-0
    Electrically conductive nanofiber is well known as an excellent nanostructured material for its outstanding performances. In this work, poly(3,4-ethylenedioxythiophene) (PEDOT)-coated polyvinyl alcohol-graphene oxide (PVA-GO)-conducting nanofibers were fabricated via a combined method using electrospinning and electropolymerization techniques. During electrospinning, the concentration of PVA-GO solution and the applied voltage were deliberately altered in order to determine the optimized electrospinning conditions. The optimized parameters obtained were 0.1 mg/mL of GO concentration with electrospinning voltage of 15 kV, which displayed smooth nanofibrous morphology and smaller diameter distribution. The electrospun PVA-GO nanofiber mats were further modified by coating with the conjugated polymer, PEDOT, using electropolymerization technique which is a facile approach for coating the nanofibers. SEM images of the obtained nanofibers indicated that cauliflower-like structures of PEDOT were successfully grown on the surface of the electrospun nanofibers during the potentiostatic mode of the electropolymerization process. The conductive nature of PEDOT coating strongly depends on the different electropolymerization parameters, resulting in good conductivity of PEDOT-coated nanofibers. The optimum electropolymerization of PEDOT was at a potential of 1.2 V in 5 min. The electrochemical measurements demonstrated that the fabricated PVA-GO/PEDOT composite nanofiber could enhance the current response and reduce the charge transfer resistance of the nanofiber.
  20. Abdullah AC, Adnan JS, Rahman NA, Palur R
    Malays J Med Sci, 2017 Mar;24(1):104-112.
    PMID: 28381933 DOI: 10.21315/mjms2017.24.1.11
    INTRODUCTION: Computed tomography (CT) is the preferred diagnostic toolkit for head and brain imaging of head injury. A recent development is the invention of a portable CT scanner that can be beneficial from a clinical point of view.

    AIM: To compare the quality of CT brain images produced by a fixed CT scanner and a portable CT scanner (CereTom).

    METHODS: This work was a single-centre retrospective study of CT brain images from 112 neurosurgical patients. Hounsfield units (HUs) of the images from CereTom were measured for air, water and bone. Three assessors independently evaluated the images from the fixed CT scanner and CereTom. Streak artefacts, visualisation of lesions and grey-white matter differentiation were evaluated at three different levels (centrum semiovale, basal ganglia and middle cerebellar peduncles). Each evaluation was scored 1 (poor), 2 (average) or 3 (good) and summed up to form an ordinal reading of 3 to 9.

    RESULTS: HUs for air, water and bone from CereTom were within the recommended value by the American College of Radiology (ACR). Streak artefact evaluation scores for the fixed CT scanner was 8.54 versus 7.46 (Z = -5.67) for CereTom at the centrum semiovale, 8.38 (SD = 1.12) versus 7.32 (SD = 1.63) at the basal ganglia and 8.21 (SD = 1.30) versus 6.97 (SD = 2.77) at the middle cerebellar peduncles. Grey-white matter differentiation showed scores of 8.27 (SD = 1.04) versus 7.21 (SD = 1.41) at the centrum semiovale, 8.26 (SD = 1.07) versus 7.00 (SD = 1.47) at the basal ganglia and 8.38 (SD = 1.11) versus 6.74 (SD = 1.55) at the middle cerebellar peduncles. Visualisation of lesions showed scores of 8.86 versus 8.21 (Z = -4.24) at the centrum semiovale, 8.93 versus 8.18 (Z = -5.32) at the basal ganglia and 8.79 versus 8.06 (Z = -4.93) at the middle cerebellar peduncles. All results were significant with P-value < 0.01.

    CONCLUSIONS: Results of the study showed a significant difference in image quality produced by the fixed CT scanner and CereTom, with the latter being more inferior than the former. However, HUs of the images produced by CereTom do fulfil the recommendation of the ACR.

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