Displaying publications 1 - 20 of 40 in total

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  1. Fulltext Knowledge and practice of breast self-examination among students in a private higher learning institution in Malaysia
    Nimir, Amal R., Al-Dubai, Sami A. R., Alshagga, Mustafa A., Saliem, Ahmed M.
    Malaysian Journal of Public Health Medicine, 2014;14(3):0-0.
    MyJurnal
    Breast cancer is one of the most frequently encountered malignancies among young females in Malaysia, which accounts for 30.4% of newly diagnosed cancers. All women at or above the age of 20 are considered at risk of developing breast cancer. This is a cross-sectional study. The study was conducted in a private medical university in Malaysia during year 2012. Two hundred students were recruited in this study using universal sampling. Data collection was done using a selfadministration questionnaire. Chi-square test was used to assess the association between the practice of breast selfexamination and socio-demographic variables. Only 19.5% of the study sample has sufficient knowledge about BSE which is acquired mostly from local media. Having a family history of malignancy other than breast cancer seems to be the only significant variable associated with knowledge about BSE (P=0.002). Other variables such as demographic data, menstrual history and social history were also tested, but found to be not significant. Frequent community-based awareness programs are needed so that all women can know and practice BSE, which in turn helps to alert the women to any abnormal changes in the breasts so that they will be able to seek medical advice immediately.
  2. The monitoring of pesticides and alkylphenols in selected rivers in the State of Selangor, Malaysia
    Tan BL, Mustafa AM
    Asia Pac J Public Health, 2004;16(1):54-63.
    PMID: 18839869
    Alkylphenols and most pesticides, especially organochlorine pesticides are endocrine-disrupting chemicals and they usually mimic the female hormone, estrogen. Using these chemicals in our environment would eventually lead us to consume them somehow in the food web. Several rivers in the State of Selangor, Malaysia were selected to monitor the level of alkylphenols and pesticides contamination for several months. The compounds were extracted from the water samples using liquid-liquid extraction method with dichloromethane and ethyl acetate as the extracting solvents. The alkylphenols and pesticides were analyzed by selected ion monitoring (SIM) mode using the quadrapole detector in Shimadzu QP-5000 gas chromatograph-mass spectrometer (GCMS). Recovery of most alkylphenols and pesticides were in the range of 50% to 120%. Trace amounts of the compounds were detected in the river water samples, mainly in the range of parts per trillion. This technique of monitoring the levels of endocrine-disruptors in river water is consistent and cost effective.
  3. Leaching of bisphenol A from new and old babies' bottles, and new babies' feeding teats
    Tan BL, Mustafa AM
    Asia Pac J Public Health, 2003;15(2):118-23.
    PMID: 15038686
    Bisphenol A is the monomer used in the manufacture of polycarbonate. Bisphenol A is also known to mimic the female hormone estrogen. In this study, the possibility of the leaching of bisphenol A from polycarbonate babies' bottles and feeding teats was investigated. Bisphenol A was extracted from water samples exposed to the bottles and teats using liquid-liquid extraction. Bisphenol A was analysed by gas chromatograph-mass spectrometer with quadrapole detector in selected ion monitoring mode. Mean leaching of bisphenol A from 100 used babies' bottles when filled with water at 25 degrees C and 80 degrees C were 0.71 +/- 1.65 ng/cm2 (mean +/- standard deviation) and 3.37 +/- 5.68 ng/cm2 respectively. Mean leaching of bisphenol A from 30 new babies' bottles when filled with water at 25 degrees C and 80 degrees C were 0.03 +/- 0.02 ng/cm2 and 0.18 degrees 0.30 ng/cm2 respectively. Bisphenol A was observed to have leached from babies' feeding teats into 37 degrees C water ranged from non-detectable to 22.86 ng/g. The technique employed in this study is fast, reliable and economical.
  4. Mating calls description of five species of frogs from the genus Hylarana tschudi 1838 (amphibia, anura, ranidae) from Sarawak, Malaysia
    Ramlah Zainudin, Mustafa A. Rahman, Badrul Munir M. Zain, Shukor MN, Norhayati A, Inger RF
    Sains Malaysiana, 2010;39.
    Recordings of frog calls from the genus Hylarana were conducted at seven study sites in Sarawak, Malaysia. The results showed that each species differs in terms of call characteristics, in which a high number of pulsed note belongs to H. baramica, while high repetition note belongs to the sibling species, H. glandulosa. Higher pitched and number of amplitude spectrum, however, belong to H. signata. Pulsed note and note repetition differed significantly among species, except for spectrum amplitude. Advertisement calls for each species were described in detail. This study provide a baseline data on advertisement call characteristics of frogs from the genus Hylarana for future studies of these frogs particularly and the Oriental frogs generally.
  5. Simultaneous determination of organochlorine pesticides and bisphenol A in edible marine biota by GC-MS
    Santhi VA, Hairin T, Mustafa AM
    Chemosphere, 2012 Mar;86(10):1066-71.
    PMID: 22197311 DOI: 10.1016/j.chemosphere.2011.11.063
    A study to assess the level of organochlorine pesticides (OCPs) and bisphenol A (BPA) in edible marine biota collected from coastal waters of Malaysia was conducted using GC-MS and SPE extraction. An analytical method was developed and validated to measure the level of 15 OCPs and BPA simultaneously from five selected marine species. It was observed that some samples had low levels of p,p'-DDE, p,p'-DDT and p,p'- DDD ranging from 0.50 ng g(-1) to 22.49 ng g(-1) dry weight (d.w) but significantly elevated level of endosulfan I was detected in a stingray sample at 2880 ng g(-1) d.w. BPA was detected in 31 out of 57 samples with concentration ranging from below quantification level (LOQ: 3 ng g(-1)) to 729 ng g(-1) d.w. The presence of OCPs is most likely from past use although there is also indication of illegal use in recent times. The study also reveals that BPA is more widely distributed in coastal species caught off the coast of the most developed state. The potential health risk from dietary intakes of OCPs and BPA from the analysed fish species was negligible.
  6. Fulltext Frequencies of glutathione s-transferase (GSTM1, GSTM3 AND GSTT1) polymorphisms in a Malaysian population
    Alshagga MA, Mohamed N, Nazrun Suhid A, Abdel Aziz Ibrahim I, Zulkifli Syed Zakaria S
    Arch Med Sci, 2011 Aug;7(4):572-8.
    PMID: 22291790 DOI: 10.5114/aoms.2011.24123
    Glutathione S-transferase (GST) is a xenobiotic metabolising enzyme (XME), which may modify susceptibility in certain ethnic groups, showing ethnic dependent polymorphism. The aim of this study was to determine GSTM1, GSTM3 and GSTT1 gene polymorphisms in a Malaysian population in Kuala Lumpur.
  7. Revisiting Wallace's haunt: coalescent simulations and comparative niche modeling reveal historical mechanisms that promoted avian population divergence in the Malay Archipelago
    Lim HC, Rahman MA, Lim SL, Moyle RG, Sheldon FH
    Evolution, 2011 Feb;65(2):321-34.
    PMID: 20796023 DOI: 10.1111/j.1558-5646.2010.01105.x
    Sundaland, a biogeographic region of Southeast Asia, is a major biodiversity hotspot. However, little is known about the relative importance of Pleistocene habitat barriers and rivers in structuring populations and promoting diversification here. We sampled 16 lowland rainforest bird species primarily from peninsular Malaysia and Borneo to test the long-standing hypothesis that animals on different Sundaic landmasses intermixed extensively when lower sea-levels during the Last Glacial Maximum (LGM) exposed land-bridges. This hypothesis was rejected in all but five species through coalescent simulations. Furthermore, we detected a range of phylogeographic patterns; Bornean populations are often genetically distinct from each other, despite their current habitat connectivity. Environmental niche modeling showed that the presence of unsuitable habitats between western and eastern Sundaland during the LGM coincided with deeper interpopulation genetic divergences. The location of this habitat barrier had been hypothesized previously based on other evidence. Paleo-riverine barriers are unlikely to have produced such a pattern, but we cannot rule out that they acted with habitat changes to impede population exchanges across the Sunda shelf. The distinctiveness of northeastern Borneo populations may be underlied by a combination of factors such as rivers, LGM expansion of montane forests and other aspects of regional physiography.
  8. Detrimental effects of bisphenol A on development and functions of the male reproductive system in experimental rats
    Gurmeet K, Rosnah I, Normadiah MK, Das S, Mustafa AM
    EXCLI J, 2014;13:151-60.
    PMID: 26417249
    Bisphenol A (BPA) is widely used in manufacturing industries. It is commonly detected in the environment and was reported to exert oestrogenic effects which may be harmful to the reproductive system. The present study was carried out to observe the effects of oral administration of BPA on the development of the reproductive organs and plasma sex hormone levels in prepubertal male Sprague-Dawley (SD) rats. Prepubertal male SD rats (n=8 in each group) were administered BPA in the doses of 1, 5, 10 and 100 mg/kg BW (body weight) via oral gavage for a period of 6 weeks. The control animals received the vehicle for BPA (Tween 80 in distilled water). Following 6 weeks of BPA exposure, the rats exhibited less evidence of spermatogenesis. There was seminiferous epithelial damage which included disruption of intercellular junctions and sloughing of germ cells into the seminiferous tubular lumen. Furthermore, the lumina of the seminiferous tubules and the epididymis of these animals were filled with immature germ cells and cellular debris. This damage may lead to the significant reduction in the seminiferous tubular diameter in BPA-treated animals. These findings were associated with the significant lower plasma testosterone and 17β-oestradiol levels. There was no significant difference between the body weight gain, the absolute as well as relative testis weight or epididymal weight of BPA-treated animals when compared to the control animals. The findings provided further evidence of the detrimental effects of BPA on the male reproductive system.
  9. Fulltext Stochastic frontier model approach for measuring stock market efficiency with different distributions
    Hasan MZ, Kamil AA, Mustafa A, Baten MA
    PLoS One, 2012;7(5):e37047.
    PMID: 22629352 DOI: 10.1371/journal.pone.0037047
    The stock market is considered essential for economic growth and expected to contribute to improved productivity. An efficient pricing mechanism of the stock market can be a driving force for channeling savings into profitable investments and thus facilitating optimal allocation of capital. This study investigated the technical efficiency of selected groups of companies of Bangladesh Stock Market that is the Dhaka Stock Exchange (DSE) market, using the stochastic frontier production function approach. For this, the authors considered the Cobb-Douglas Stochastic frontier in which the technical inefficiency effects are defined by a model with two distributional assumptions. Truncated normal and half-normal distributions were used in the model and both time-variant and time-invariant inefficiency effects were estimated. The results reveal that technical efficiency decreased gradually over the reference period and that truncated normal distribution is preferable to half-normal distribution for technical inefficiency effects. The value of technical efficiency was high for the investment group and low for the bank group, as compared with other groups in the DSE market for both distributions in time-varying environment whereas it was high for the investment group but low for the ceramic group as compared with other groups in the DSE market for both distributions in time-invariant situation.
  10. Occurrence of bisphenol A in surface water, drinking water and plasma from Malaysia with exposure assessment from consumption of drinking water
    Santhi VA, Sakai N, Ahmad ED, Mustafa AM
    Sci Total Environ, 2012 Jun 15;427-428:332-8.
    PMID: 22578698 DOI: 10.1016/j.scitotenv.2012.04.041
    This study investigated the level of bisphenol A (BPA) in surface water used as potable water, drinking water (tap and bottled mineral water) and human plasma in the Langat River basin, Malaysia. BPA was present in 93% of the surface water samples at levels ranging from below limit of quantification (LOQ; 1.3 ng/L) to 215 ng/L while six fold higher levels were detected in samples collected near industrial and municipal sewage treatment plant outlets. Low levels of BPA were detected in most of the drinking water samples. BPA in tap water ranged from 3.5 to 59.8 ng/L with the highest levels detected in samples collected from taps connected to PVC pipes and water filter devices. Bottled mineral water had lower levels of BPA (3.3±2.6 ng/L) although samples stored in poor storage condition had significantly higher levels (11.3±5.3 ng/L). Meanwhile, only 17% of the plasma samples had detectable levels of BPA ranging from 0.81 to 3.65 ng/mL. The study shows that BPA is a ubiquitous contaminant in surface, tap and bottled mineral water. However, exposure to BPA from drinking water is very low and is less than 0.01% of the tolerable daily intake (TDI).
  11. Fulltext Stochastic Frontier approach and Data Envelopment Analysis to Total Factor Productivity and efficiency measurement of Bangladeshi rice
    Hossain MK, Kamil AA, Baten MA, Mustafa A
    PLoS One, 2012;7(10):e46081.
    PMID: 23077500 DOI: 10.1371/journal.pone.0046081
    The objective of this paper is to apply the Translog Stochastic Frontier production model (SFA) and Data Envelopment Analysis (DEA) to estimate efficiencies over time and the Total Factor Productivity (TFP) growth rate for Bangladeshi rice crops (Aus, Aman and Boro) throughout the most recent data available comprising the period 1989-2008. Results indicate that technical efficiency was observed as higher for Boro among the three types of rice, but the overall technical efficiency of rice production was found around 50%. Although positive changes exist in TFP for the sample analyzed, the average growth rate of TFP for rice production was estimated at almost the same levels for both Translog SFA with half normal distribution and DEA. Estimated TFP from SFA is forecasted with ARIMA (2, 0, 0) model. ARIMA (1, 0, 0) model is used to forecast TFP of Aman from DEA estimation.
  12. Fulltext A Cobb Douglas stochastic frontier model on measuring domestic bank efficiency in Malaysia
    Hasan MZ, Kamil AA, Mustafa A, Baten MA
    PLoS One, 2012;7(8):e42215.
    PMID: 22900009 DOI: 10.1371/journal.pone.0042215
    Banking system plays an important role in the economic development of any country. Domestic banks, which are the main components of the banking system, have to be efficient; otherwise, they may create obstacle in the process of development in any economy. This study examines the technical efficiency of the Malaysian domestic banks listed in the Kuala Lumpur Stock Exchange (KLSE) market over the period 2005-2010. A parametric approach, Stochastic Frontier Approach (SFA), is used in this analysis. The findings show that Malaysian domestic banks have exhibited an average overall efficiency of 94 percent, implying that sample banks have wasted an average of 6 percent of their inputs. Among the banks, RHBCAP is found to be highly efficient with a score of 0.986 and PBBANK is noted to have the lowest efficiency with a score of 0.918. The results also show that the level of efficiency has increased during the period of study, and that the technical efficiency effect has fluctuated considerably over time.
  13. 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.
  14. Mechanisms of the anti-hypertensive effect of Hibiscus sabdariffa L. calyces
    Ajay M, Chai HJ, Mustafa AM, Gilani AH, Mustafa MR
    J Ethnopharmacol, 2007 Feb 12;109(3):388-93.
    PMID: 16973321
    Previous studies have demonstrated the anti-hypertensive effects of Hibiscus sabdariffa L. (HS) in both humans and experimental animals. To explore the mechanisms of the anti-hypertensive effect of the HS, we examined the effects of a crude methanolic extract of the calyces of HS (HSE) on vascular reactivity in isolated aortas from spontaneously hypertensive rats. HSE relaxed, concentration-dependently, KCl (high K(+), 80 mM)- and phenylephrine (PE, 1 microM)-pre-contracted aortic rings, with a greater potency against the alpha(1)-adrenergic receptor agonist. The relaxant effect of HSE was partly dependent on the presence of a functional endothelium as the action was significantly reduced in endothelium-denuded aortic rings. Pretreatment with atropine (1 microM), L-NAME (10 microM) or methylene blue (10 microM), but not indomethacin (10 microM), significantly blocked the relaxant effects of HSE. Endothelium-dependent and -independent relaxations induced by acetylcholine and sodium nitroprusside, respectively, were significantly enhanced in aortic rings pretreated with HSE when compared to those observed in control aortic rings. The present results demonstrated that HSE has a vasodilator effect in the isolated aortic rings of hypertensive rats. These effects are probably mediated through the endothelium-derived nitric oxide-cGMP-relaxant pathway and inhibition of calcium (Ca(2+))-influx into vascular smooth muscle cells. The present data further supports previous in vivo findings and the traditional use of HS as an anti-hypertensive agent.
  15. Fulltext (6E,10E) Isopolycerasoidol and (6E,10E) Isopolycerasoidol Methyl Ester, Prenylated Benzopyran Derivatives from Pseuduvaria monticola Induce Mitochondrial-Mediated Apoptosis in Human Breast Adenocarcinoma Cells
    Taha H, Looi CY, Arya A, Wong WF, Yap LF, Hasanpourghadi M, et al.
    PLoS One, 2015;10(5):e0126126.
    PMID: 25946039 DOI: 10.1371/journal.pone.0126126
    Phytochemicals from Pseuduvaria species have been reported to display a wide range of biological activities. In the present study, a known benzopyran derivative, (6E,10E) isopolycerasoidol (1), and a new benzopyran derivative, (6E,10E) isopolycerasoidol methyl ester (2), were isolated from a methanol extract of Pseuduvaria monticola leaves. The structures of the isolated compounds were elucidated by spectroscopic methods including 1D and 2D NMR, IR, UV, and LCMS-QTOF, and by comparison with previously published data. The anti-proliferative and cytotoxic effects of these compounds on human breast cancer cell-lines (MCF-7 and MDA-MB-231) and a human normal breast epithelial cell line (MCF-10A) were investigated. MTT results revealed both (1) and (2) were efficient in reducing cell viability of breast cancer cells. Flow cytometry analysis demonstrated that (1) and (2) induced cell death via apoptosis, as demonstrated by an increase in phosphotidylserine exposure. Both compounds elevated ROS production, leading to reduced mitochondrial membrane potential and increased plasma membrane permeability in breast cancer cells. These effects occurred concomitantly with a dose-dependent activation of caspase 3/7 and 9, a down-regulation of the anti-apoptotic gene BCL2 and the accumulation of p38 MAPK in the nucleus. Taken together, our data demonstrate that (1) and (2) induce intrinsic mitochondrial-mediated apoptosis in human breast cancer cells, which provides the first pharmacological evidence for their future development as anticancer agents.
  16. Fulltext Low complexity smart grid security protocol based on elliptic curve cryptography, biometrics and hamming distance
    Mutlaq KA, Nyangaresi VO, Omar MA, Abduljabbar ZA, Abduljaleel IQ, Ma J, et al.
    PLoS One, 2024;19(1):e0296781.
    PMID: 38261555 DOI: 10.1371/journal.pone.0296781
    The incorporation of information and communication technologies in the power grids has greatly enhanced efficiency in the management of demand-responses. In addition, smart grids have seen considerable minimization in energy consumption and enhancement in power supply quality. However, the transmission of control and consumption information over open public communication channels renders the transmitted messages vulnerable to numerous security and privacy violations. Although many authentication and key agreement protocols have been developed to counter these issues, the achievement of ideal security and privacy levels at optimal performance still remains an uphill task. In this paper, we leverage on Hamming distance, elliptic curve cryptography, smart cards and biometrics to develop an authentication protocol. It is formally analyzed using the Burrows-Abadi-Needham (BAN) logic, which shows strong mutual authentication and session key negotiation. Its semantic security analysis demonstrates its robustness under all the assumptions of the Dolev-Yao (DY) and Canetti- Krawczyk (CK) threat models. From the performance perspective, it is shown to incur communication, storage and computation complexities compared with other related state of the art protocols.
  17. Fulltext Smart city energy efficient data privacy preservation protocol based on biometrics and fuzzy commitment scheme
    Nyangaresi VO, Abduljabbar ZA, Mutlaq KA, Bulbul SS, Ma J, Aldarwish AJY, et al.
    Sci Rep, 2024 Jul 13;14(1):16223.
    PMID: 39003319 DOI: 10.1038/s41598-024-67064-z
    Advancements in cloud computing, flying ad-hoc networks, wireless sensor networks, artificial intelligence, big data, 5th generation mobile network and internet of things have led to the development of smart cities. Owing to their massive interconnectedness, high volumes of data are collected and exchanged over the public internet. Therefore, the exchanged messages are susceptible to numerous security and privacy threats across these open public channels. Although many security techniques have been designed to address this issue, most of them are still vulnerable to attacks while some deploy computationally extensive cryptographic operations such as bilinear pairings and blockchain. In this paper, we leverage on biometrics, error correction codes and fuzzy commitment schemes to develop a secure and energy efficient authentication scheme for the smart cities. This is informed by the fact that biometric data is cumbersome to reproduce and hence attacks such as side-channeling are thwarted. We formally analyze the security of our protocol using the Burrows-Abadi-Needham logic logic, which shows that our scheme achieves strong mutual authentication among the communicating entities. The semantic analysis of our protocol shows that it mitigates attacks such as de-synchronization, eavesdropping, session hijacking, forgery and side-channeling. In addition, its formal security analysis demonstrates that it is secure under the Canetti and Krawczyk attack model. In terms of performance, our scheme is shown to reduce the computation overheads by 20.7% and hence is the most efficient among the state-of-the-art protocols.
  18. Fulltext Palladium/Graphene Oxide Nanocomposite for Hydrogen Gas Sensing Applications Based on Tapered Optical Fiber
    Alkhabet MM, Yaseen ZM, Eldirderi MMA, Khedher KM, Jawad AH, Girei SH, et al.
    Materials (Basel), 2022 Nov 17;15(22).
    PMID: 36431654 DOI: 10.3390/ma15228167
    Gaseous pollutants such as hydrogen gas (H2) are emitted in daily human activities. They have been massively studied owing to their high explosivity and widespread usage in many domains. The current research is designed to analyse optical fiber-based H2 gas sensors by incorporating palladium/graphene oxide (Pd/GO) nanocomposite coating as sensing layers. The fabricated multimode silica fiber (MMF) sensors were used as a transducing platform. The tapering process is essential to improve the sensitivity to the environment through the interaction of the evanescent field over the area of the tapered surface area. Several characterization methods including FESEM, EDX, AFM, and XRD were adopted to examine the structure properties of the materials and achieve more understandable facts about their functional performance of the optical sensor. Characterisation results demonstrated structures with a higher surface for analyte gas reaction to the optical sensor performance. Results indicated an observed increment in the Pd/GO nanocomposite-based sensor responses subjected to the H2 concentrations increased from 0.125% to 2.00%. The achieved sensitivities were 33.22/vol% with a response time of 48 s and recovery time of 7 min. The developed optical fiber sensors achieved excellent selectivity and stability toward H2 gas upon exposure to other gases such as ammonia and methane.
  19. EPA-coated titanium implants promote osteoconduction in white New Zealand rabbits
    Mustafa A, Lung CY, Mustafa NS, Mustafa BA, Kashmoola MA, Zwahlen RA, et al.
    Clin Oral Implants Res, 2016 Mar;27(3):303-9.
    PMID: 25393376 DOI: 10.1111/clr.12525
    OBJECTIVES: To investigate the effect of eicosapentaenoic acid (EPA)-coated Ti implants on osteoconduction in white New Zealand rabbit mandibles.

    MATERIAL AND METHODS: Sandblasted and cleansed planar titanium specimens with a size of 5 × 5 × 1 mm were coated on one side with 0.25 vol% eicosapentaenoic acid (EPA). The other side of the specimens was kept highly polished (the control side). These specimens were inserted in rabbit mandibles. Twelve rabbits were randomly assigned into three study groups (n = 4). The rabbits were sacrificed at 4, 8, and 12 weeks. The harvested specimens with the implants were assessed for new bone formation on both sides of the implant using CBCT, conventional radiographs, and the biaxial pullout test. The results were statistically analyzed by a nonparametric Kruskal-Wallis test and Friedman's test as multiple comparisons and by Brunner-Langer nonparametric mixed model approach (R Software).

    RESULTS: A significant osteoconductive bone formation was found on the EPA-coated Ti implant surface (P < 0.05) at 8 weeks when compared to the polished surface (control). Biaxial pullout test results showed a significant difference (P < 0.05) after 8 and 12 weeks with a maximum force of 243.8 N, compared to 143.25 N after 4 week.

    CONCLUSION: EPA implant coating promoted osteoconduction on the Ti implant surfaces, enhancing the anchorage of the implant to the surrounding bone in white New Zealand rabbits.

  20. Fulltext Modelling pedestrian travel time and the design of facilities: a queuing approach
    Rahman K, Ghani NA, Kamil AA, Mustafa A, Kabir Chowdhury MA
    PLoS One, 2013;8(5):e63503.
    PMID: 23691055 DOI: 10.1371/journal.pone.0063503
    Pedestrian movements are the consequence of several complex and stochastic facts. The modelling of pedestrian movements and the ability to predict the travel time are useful for evaluating the performance of a pedestrian facility. However, only a few studies can be found that incorporate the design of the facility, local pedestrian body dimensions, the delay experienced by the pedestrians, and level of service to the pedestrian movements. In this paper, a queuing based analytical model is developed as a function of relevant determinants and functional factors to predict the travel time on pedestrian facilities. The model can be used to assess the overall serving rate or performance of a facility layout and correlate it to the level of service that is possible to provide the pedestrians. It has also the ability to provide a clear suggestion on the designing and sizing of pedestrian facilities. The model is empirically validated and is found to be a robust tool to understand how well a particular walking facility makes possible comfort and convenient pedestrian movements. The sensitivity analysis is also performed to see the impact of some crucial parameters of the developed model on the performance of pedestrian facilities.
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