Displaying publications 1 - 20 of 56 in total

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  1. Ahmed Qasim Turki, Nashiren Farzilah Mailah, Ahmed H. Sabry
    MyJurnal
    This paper presents a transmission line (TL) modelling which is based upon vector fitting algorithm
    and RLC passive filter design. Frequency Response Analysis (FRA) is utilised for behaviour prediction and fault diagnosis. The utilities of the measured FRA data points need to be enhanced with suitable modelling category to facilitate the modelling and analysis process. This research proposes a new method for modelling the transmission line based on a rational approximation function which can be extracted through the Vector Fitting (VF) method, based on the frequency response measured data points. A set of steps needs to be implemented to achieve this by setting up an extracted partial fraction approximation, which results from a least square RMS error via VF. Active and passive filter design circuits are used to construct the model of the Transmission line. The RLC design representation was implemented for modelling the system physically while MATLAB Simulink was used to verify the results.
  2. Ahmed HM
    Int Endod J, 2013 Nov;46(11):1011-22.
    PMID: 23711096 DOI: 10.1111/iej.12134
    Paediatric endodontics is an integral part of dental practice that aims to preserve fully functional primary teeth in the dental arch. Pulpectomy of primary molars presents a unique challenge for dental practitioners. Negotiation and thorough instrumentation of bizarre and tortuous canals encased in roots programmed for physiological resorption are the main challenges for this treatment approach. Consequently, numerous in vitro and in vivo studies have been conducted to validate the application of some contemporary endodontic armamentarium for effective treatment in primary molars whilst maintaining favourable clinical outcomes. Electronic apex locators, rotary nickel-titanium files and irrigation techniques are at the forefront of endodontic armamentarium in paediatric dentistry. Hence, this review aims to map out the root and root canal morphology of primary molars, to discuss the application of electronic apex locators in primary molars and to provide an update on the preparation of their root canal systems.
  3. El Beltagi AH, El-Nil H, Alrabiah L, El Shammari N
    Clin Imaging, 2012 Mar-Apr;36(2):142-5.
    PMID: 22370135 DOI: 10.1016/j.clinimag.2011.07.004
    Leprosy is a granulomatous disease primarily affecting the skin and peripheral nerves caused by Mycobacterium leprae, but also significantly involving sinonasal cavities and cranial nerves. It continues to be a significant public health problem, and despite multidrug therapy, it can still cause significant morbidity. The awareness of cranial nerve, intracranial and orbital apex involvement as in our case is important for appropriate treatment measures.
  4. Alsharif AH, Salleh NZM, Al-Zahrani SA, Khraiwish A
    Behav Sci (Basel), 2022 Nov 23;12(12).
    PMID: 36546955 DOI: 10.3390/bs12120472
    In the past decade, neurophysiological and physiological tools have been used to explore consumer behaviour toward advertising. The studies into brain processes (e.g., emotions, motivation, reward, attention, perception, and memory) toward advertising are scant, and remain unclear in the academic literature. To fill the gap in the literature, this study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol to extract relevant articles. It extracted and analysed 76 empirical articles from the Web of Science (WoS) database from 2009-2020. The findings revealed that the inferior frontal gyrus was associated with pleasure, while the middle temporal gyrus correlated with displeasure of advertising. Meanwhile, the right superior-temporal is related to high arousal and the right middle-frontal-gyrus is linked to low arousal toward advertisement campaigns. The right prefrontal-cortex (PFC) is correlated with withdrawal behaviour, and the left PFC is linked to approach behaviour. For the reward system, the ventral striatum has a main role in the reward system. It has also been found that perception is connected to the orbitofrontal cortex (OFC) and ventromedial (Vm) PFC. The study's findings provide a profound overview of the importance of brain processes such as emotional processes, reward, motivation, cognitive processes, and perception in advertising campaigns such as commercial, social initiative, and public health.
  5. Alsharif AH, Salleh NZM, Alrawad M, Lutfi A
    Curr Psychol, 2023 Jun 03.
    PMID: 37359681 DOI: 10.1007/s12144-023-04812-w
    This study aims to select the physiological and neurophysiological studies utilized in advertising and to address the fragmented comprehension of consumers' mental responses to advertising held by marketers and advertisers. To fill the gap, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework was employed to select relevant articles, and bibliometric analysis was conducted to determine global trends and advancements in advertising and neuromarketing. The study selected and analyzed forty-one papers from the Web of Science (WoS) database from 2009-2020. The results indicated that Spain, particularly the Complutense University of Madrid, was the most productive country and institution, respectively, with 11 and 3 articles. The journal Frontiers in Psychology was the most prolific, with eight articles. The article "Neuromarketing: The New Science of Consumer Behavior" had the most citations (152 T.Cs). Additionally, the researchers discovered that the inferior frontal and middle temporal gyri were associated with pleasant and unpleasant emotions, respectively, while the right superior temporal and right middle frontal gyrus was connected to high and low arousal. Furthermore, the right prefrontal cortex (PFC) and left PFC were linked to withdrawal and approach behaviors. In terms of the reward system, the ventral striatum played a critical role, while the orbitofrontal cortex and ventromedial PFC were connected to perception. As far as we know, this is the first paper that focused on the global academic trends and developments of neurophysiological and physiological instruments used in advertising in the new millennium, emphasizing the significance of intrinsic and extrinsic emotional processes, endogenous and exogenous attentional processes, memory, reward, motivational attitude, and perception in advertising campaigns.
  6. Ahmed HM, Abbott PV
    Int Endod J, 2012 Oct;45(10):883-97.
    PMID: 22621247 DOI: 10.1111/j.1365-2591.2012.02071.x
    Advances in endodontic materials and techniques are at the forefront of endodontic research. Despite continuous improvements, tooth discolouration, especially in anterior teeth, is considered an undesirable consequence following endodontic treatment as it creates a range of aesthetic problems. This article aims to discuss the intrinsic and internalized tooth discolouration caused by endodontic procedures, and to address the discolouration potential of materials used during root canal treatment, including root canal irrigants, intra-canal medicaments, endodontic and post-endodontic filling materials. In addition, the discolouration patterns caused by combined endodontic and nonendodontic aetiological factors are discussed. The recommended guidelines that should be followed by dental practitioners to prevent and manage tooth discolouration are also outlined.
  7. Ahmed HM, Abbott PV
    Aust Dent J, 2012 Jun;57(2):123-31; quiz 248.
    PMID: 22624750 DOI: 10.1111/j.1834-7819.2012.01678.x
    Maxillary molar teeth may have accessory roots. The aim of this paper is to review and discuss the endodontic implications of this anatomical variation. A review of the literature was undertaken to identify studies and reported cases where accessory roots have been recorded in maxillary molar teeth. The results show that although the prevalence of accessory roots in maxillary molar teeth is low, they can exist in all three types of maxillary molar teeth, and they may be located palatally, buccally, mesially or distally. Hence, it is essential that dentists undertaking root canal treatment thoroughly assess all teeth to determine how many roots are present in order to provide the best possible outcome of treatment for the patient.
  8. Ahmed HM, Hashem AA
    Int Endod J, 2016 Aug;49(8):724-36.
    PMID: 26174943 DOI: 10.1111/iej.12508
    Anterior teeth may have aberrant anatomical variations in the number of roots and root canals. A review of the literature was conducted using appropriate key words in major endodontic journals to identify the available reported cases as well as experimental and clinical investigations on accessory roots and root canals in anterior teeth. After retrieving the full text of related articles, cross-citations were identified, and the pooled data were then discussed. Results revealed a higher prevalence in accessory root/root canal variations in mandibular anterior teeth than in maxillary counterparts. However, maxillary incisor teeth revealed the highest tendency for accessory root/root canal aberrations caused by anomalies such as dens invaginatus and palato-gingival groove. Primary anterior teeth may also exhibit external and internal anatomical variations in the root, especially maxillary canines. Therefore, dental practitioners should thoroughly assess all teeth scheduled for root canal treatment to prevent the undesirable consequences caused by inadequate debridement of accessory configurations of the root canal system.
  9. Ahmed HM, Cohen S, Lévy G, Steier L, Bukiet F
    Aust Dent J, 2014 Dec;59(4):457-63.
    PMID: 25091028 DOI: 10.1111/adj.12210
    Proper isolation is an essential prerequisite for successful endodontic treatment. This article aims to provide an update on the prevalence of rubber dam (RD) use, and the role of education along with attitudes of general dental practitioners (GDPs) and patients towards the application of RD in endodontics. Critical ethical issues are also highlighted. Using certain keywords, an electronic search was conducted spanning the period from January 1983 to April 2013 to identify the available related investigations, and the pooled data were then analysed. The results show that although RD is the Standard of Care in endodontic practice, there is a clear discrepancy in what GDPs are taught in dental school and what they practice after graduation. There is little scientific evidence to support the application of RD; however, patient safety and clinical practice guidelines indicate that it is unnecessary and unethical to consider a cohort study to prove what is already universally agreed upon. A few clinical situations may require special management which should be highlighted in the current guidelines. This would pave the way for clear and straightforward universal guidelines.
  10. Ahmed HMA, Neelakantan P, Dummer PMH
    Int Endod J, 2018 Feb;51(2):164-176.
    PMID: 28635100 DOI: 10.1111/iej.12800
    Thorough knowledge of anatomical complexities of the root canal system has a direct impact on the effectiveness of canal preparation and filling, and is an essential prerequisite for successful root canal treatment. A wide range of complex variations in root canal anatomy exists, including root canal configuration type, developmental anomalies and minor canal morphology such as accessory canals and apical deltas. Accessory canals and apical deltas have been associated with pulp disease, primary canal infection, canal reinfection and post-treatment disease. The current definitions of accessory canal anatomy are not standardized and potentially confusing. Given their role in endodontic disease and their impact on treatment outcomes, there is a need to have a simple classification of their anatomy to provide an accurate description of their position and path from the canal to the external surface of the root. The purpose of this article is to introduce a new system for classifying accessory canal morphology for use in research, clinical practice and training.
  11. Ahmed HMA, Dummer PMH
    Int Endod J, 2018 Apr;51(4):389-404.
    PMID: 29023779 DOI: 10.1111/iej.12867
    Understanding the normal anatomical features as well as the more unusual developmental anomalies of teeth, roots and root canals is essential for successful root canal treatment. In addition to various types of root canal configuration and accessory canal morphology, a wide range of developmental tooth, root and canal anomalies exists, including C-shaped canals, dens invaginatus, taurodontism, root fusion, dilacerations and palato-gingival grooves. There is a direct association between developmental anomalies and pulp and periradicular diseases that usually require a multidisciplinary treatment approach to achieve a successful outcome. A number of classifications have categorized tooth, root and canal anomalies; however, several important details are often missed making the classifications less than ideal and potentially confusing. Recently, a new coding system for classifying root, root canal and accessory canal morphology has been introduced. The purpose of this article is to introduce a new system for classifying tooth, root and canal anomalies for use in research, clinical practice and training, which can serve as complementary codes to the recently described system for classifying root, as well as main and accessory canal morphology.
  12. Hilles AH, Abu Amr SS, Hussein RA, El-Sebaie OD, Arafa AI
    J Environ Manage, 2016 Jan 15;166:493-8.
    PMID: 26580899 DOI: 10.1016/j.jenvman.2015.10.051
    A combination of persulfate and hydrogen peroxide (S2O8(2-)/H2O2) was used to oxidizelandfill leachate. The reaction was performed under varying S2O8(2-)/H2O2 ratio (g/g), S2O8(2-)/H2O2 dosages (g/g), pH, and reaction time (minutes), so as to determine the optimum operational conditions. Results indicated that under optimum operational conditions (i.e. 120 min of oxidation using a S2O8(2-)/H2O2 ratio of 1 g/1.47 g at a persulfate and hydrogen peroxide dosage of 5.88 g/50 ml and8.63 g/50 ml respectively, at pH 11) removal of 81% COD and 83% NH3-N was achieved. In addition, the biodegradability (BOD5/COD ratio) of the leachate was improved from 0.09 to 0.17. The results obtained from the combined use of (S2O8(2-)/H2O2) were compared with those obtained with sodium persulfate only, hydrogen peroxide only and sodium persulfate followed by hydrogen peroxide. The combined method (S2O8(2-)/H2O2) achieved higher removal efficiencies for COD and NH3-N compared with the other methods using a single oxidizing agent. Additionally, the study has proved that the combination of S2O8(2-)/H2O2 is more efficient than the sequential use of sodium persulfate followed by hydrogen peroxide in advanced oxidation processes aiming at treatingstabilizedlandfill leachate.
  13. Hilles AH, Abu Amr SS, Hussein RA, Arafa AI, El-Sebaie OD
    Water Sci Technol, 2016;73(1):102-12.
    PMID: 26744940 DOI: 10.2166/wst.2015.468
    The objective of this study was to investigate the performance of employing H2O2 reagent in persulfate activation to treat stabilized landfill leachate. A central composite design (CCD) with response surface methodology (RSM) was applied to evaluate the relationships between operating variables, such as persulfate and H2O2 dosages, pH, and reaction time, to identify the optimum operating conditions. Quadratic models for the following two responses proved to be significant with very low probabilities (<0.0001): chemical oxygen demand (COD) and NH3-N removal. The obtained optimum conditions included a reaction time of 116 min, 4.97 g S2O8(2-), 7.29 g H2O2 dosage and pH 11. The experimental results were corresponding well with predicted models (COD and NH3-N removal rates of 81% and 83%, respectively). The results obtained in the stabilized leachate treatment were compared with those from other treatment processes, such as persulfate only and H2O2 only, to evaluate its effectiveness. The combined method (i.e., /S2O8(2-)/H2O2) achieved higher removal efficiencies for COD and NH3-N compared with other studied applications.
  14. Hilles AH, Abu Amr SS, Hussein RA, Arafa AI, El-Sebaie OD
    Waste Manag, 2015 Oct;44:172-7.
    PMID: 26248486 DOI: 10.1016/j.wasman.2015.07.046
    The current study investigated the effects of S2O8(2-) and S2O8(2-)/H2O2 oxidation processes on the biodegradable characteristics of an anaerobic stabilized leachate. Total COD removal efficiency was found to be 46% after S2O8(2-) oxidation (using 4.2 g S2O8(2-)/1g COD0, at pH 7, for 60 min reaction time and at 350 rpm shaking speed), and improved to 81% following S2O8(2-)/H2O2 oxidation process (using 5.88 g S2O8(2-) dosage, 8.63 g H2O2 dosage, at pH 11 and for 120 min reaction time at 350 rpm). Biodegradability in terms of BOD5/COD ratio of the leachate enhanced from 0.09 to 0.1 and to 0.17 following S2O8(2-) and S2O8(2-)/H2O2 oxidation processes, respectively. The fractions of COD were determined before and after each oxidation processes (S2O8(2-) and S2O8(2-)/H2O2). The fraction of biodegradable COD(bi) increased from 36% in raw leachate to 57% and 68% after applying S2O8(2-) and S2O8(2-)/H2O2 oxidation, respectively. As for soluble COD(s), its removal efficiency was 39% and 78% following S2O8(2-) and S2O8(2-)/H2O2 oxidation, respectively. The maximum removal for particulate COD was 94% and was obtained after 120 min of S2O8(2-)/H2O2 oxidation. As a conclusion, S2O8(2-)/H2O2 oxidation could be an efficient method for improving the biodegradability of anaerobic stabilized leachate.
  15. Abudula T, Gauthaman K, Hammad AH, Joshi Navare K, Alshahrie AA, Bencherif SA, et al.
    Polymers (Basel), 2020 May 29;12(6).
    PMID: 32485817 DOI: 10.3390/polym12061233
    Lack of suitable auto/allografts has been delaying surgical interventions for the treatment of numerous disorders and has also caused a serious threat to public health. Tissue engineering could be one of the best alternatives to solve this issue. However, deficiency of oxygen supply in the wounded and implanted engineered tissues, caused by circulatory problems and insufficient angiogenesis, has been a rate-limiting step in translation of tissue-engineered grafts. To address this issue, we designed oxygen-releasing electrospun composite scaffolds, based on a previously developed hybrid polymeric matrix composed of poly(glycerol sebacate) (PGS) and poly(ε-caprolactone) (PCL). By performing ball-milling, we were able to embed a large percent of calcium peroxide (CP) nanoparticles into the PGS/PCL nanofibers able to generate oxygen. The composite scaffold exhibited a smooth fiber structure, while providing sustainable oxygen release for several days to a week, and significantly improved cell metabolic activity due to alleviation of hypoxic environment around primary bone-marrow-derived mesenchymal stem cells (BM-MSCs). Moreover, the composite scaffolds also showed good antibacterial performance. In conjunction to other improved features, such as degradation behavior, the developed scaffolds are promising biomaterials for various tissue-engineering and wound-healing applications.
  16. Essam Y, Huang YF, Birima AH, Ahmed AN, El-Shafie A
    Sci Rep, 2022 01 07;12(1):302.
    PMID: 34997183 DOI: 10.1038/s41598-021-04419-w
    High loads of suspended sediments in rivers are known to cause detrimental effects to potable water sources, river water quality, irrigation activities, and dam or reservoir operations. For this reason, the study of suspended sediment load (SSL) prediction is important for monitoring and damage mitigation purposes. The present study tests and develops machine learning (ML) models, based on the support vector machine (SVM), artificial neural network (ANN) and long short-term memory (LSTM) algorithms, to predict SSL based on 11 different river data sets comprising of streamflow (SF) and SSL data obtained from the Malaysian Department of Irrigation and Drainage. The main objective of the present study is to propose a single model that is capable of accurately predicting SSLs for any river data set within Peninsular Malaysia. The ANN3 model, based on the ANN algorithm and input scenario 3 (inputs consisting of current-day SF, previous-day SF, and previous-day SSL), is determined as the best model in the present study as it produced the best predictive performance for 5 out of 11 of the tested data sets and obtained the highest average RM with a score of 2.64 when compared to the other tested models, indicating that it has the highest reliability to produce relatively high-accuracy SSL predictions for different data sets. Therefore, the ANN3 model is proposed as a universal model for the prediction of SSL within Peninsular Malaysia.
  17. Adli Zakaria MN, Ahmed AN, Abdul Malek M, Birima AH, Hayet Khan MM, Sherif M, et al.
    Heliyon, 2023 Jul;9(7):e17689.
    PMID: 37456046 DOI: 10.1016/j.heliyon.2023.e17689
    Accurate water level prediction for both lake and river is essential for flood warning and freshwater resource management. In this study, three machine learning algorithms: multi-layer perceptron neural network (MLP-NN), long short-term memory neural network (LSTM) and extreme gradient boosting XGBoost were applied to develop water level forecasting models in Muda River, Malaysia. The models were developed using limited amount of daily water level and meteorological data from 2016 to 2018. Different input scenarios were tested to investigate the performance of the models. The results of the evaluation showed that the MLP model outperformed both the LSTM and the XGBoost models in predicting water levels, with an overall accuracy score of 0.871 compared to 0.865 for LSTM and 0.831 for XGBoost. No noticeable improvement has been achieved after incorporating meteorological data into the models. Even though the lowest reported performance was reported by the XGBoost, it is the faster of the three algorithms due to its advanced parallel processing capabilities and distributed computing architecture. In terms of different time horizons, the LSTM model was found to be more accurate than the MLP and XGBoost model when predicting 7 days ahead, demonstrating its superiority in capturing long-term dependencies. Therefore, it can be concluded that each ML model has its own merits and weaknesses, and the performance of different ML models differs on each case because these models depends largely on the quantity and quality of data available for the model training.
  18. Al-Shahethi AH, Zaki RA, Al-Serouri AWA, Bulgiba A
    Women Birth, 2019 Apr;32(2):e204-e215.
    PMID: 30030021 DOI: 10.1016/j.wombi.2018.06.016
    BACKGROUND: Perinatal mortality remains a major international problem responsible for nearly six million stillbirths and neonatal deaths.

    OBJECTIVES: To estimate the perinatal mortality rate in Sana'a, Yemen and to identify risk factors for perinatal deaths.

    METHODS: A community-based prospective cohort study was carried out between 2015 and 2016. Nine-hundred and eighty pregnant women were identified and followed up to 7 days following birth. A multi-stage cluster sampling was used to select participants from community households', residing in the five districts of the Sana'a City, Yemen.

    RESULTS: Total of 952 pregnant women were tracked up to 7 days after giving birth. The perinatal mortality rate, the stillbirth rate and the early neonatal mortality rate, were 89.3 per 1000, 46.2 per 1000 and 45.2 per 1000, respectively. In multivariable analysis older age (35+ years) of mothers at birth (Relative Risk=2.83), teenage mothers' age at first pregnancy (<18 years) (Relative Risk=1.57), primipara mothers (Relative Risk=1.90), multi-nuclear family (Relative Risk=1.74), mud house (Relative Risk=2.02), mothers who underwent female genital mutilation (Relative Risk=2.92) and mothers who chewed khat (Relative Risk=1.60) were factors associated with increased risk of perinatal death, whereas a positive mother's tetanus vaccination status (Relative Risk=0.49) were significant protective factors against perinatal deaths.

    CONCLUSION: Rates of perinatal mortality were higher in Sana'a City compared to perinatal mortality at the national level estimated by World Health Organization. It is imperative there be sustainable interventions in order to improve the country's maternal and newborn health.

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