Displaying publications 121 - 140 of 288 in total

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  1. Fulltext Biochemical Constituent of Ginkgo biloba (Seed) 80% Methanol Extract Inhibits Cholinesterase Enzymes in Javanese Medaka (Oryzias javanicus) Model
    Hassan I, Wan Ibrahim WN, Yusuf FM, Ahmad SA, Ahmad S
    J Toxicol, 2020;2020:8815313.
    PMID: 33029137 DOI: 10.1155/2020/8815313
    Background: Pathophysiological changes leading to the death of nerve cells present in the brain and spinal cord are referred to as neurodegenerative diseases. Presently, treatment of these diseases is not effective and encounters many challenges due to the cost of drug and side effects. Thus, the search for the alternative agents to replace synthetic drugs is in high demand. Therefore, the aim of this study is to evaluate the anticholinesterase properties of Ginkgo biloba seed.

    Methods: The seed was extracted with 80% methanol. Toxicity studies and evaluation of anticholinesterase activities were carried out in adult Javanese medaka (Oryzias javanicus). Phytochemical study to identify the bioactive lead constituents of the crude extract was also carried out using high performance liquid chromatography (HPLC).

    Results: The result shows activities with high significant differences at P < 0.001 between the treated and nontreated groups. A bioactive compound (vitaxin) was identified with the aid of HPLC method.

    Conclusion: The presence of bioactive compound vitaxin is among the major secondary metabolites that contribute to increasing activities of this plant extract. High anticholinesterase activities and low toxicity effect of this plant show its benefit to be used as natural medicine or supplements.

  2. Fulltext Antiviral and Immunomodulatory Effects of Phytochemicals from Honey against COVID-19: Potential Mechanisms of Action and Future Directions
    Al-Hatamleh MAI, Hatmal MM, Sattar K, Ahmad S, Mustafa MZ, Bittencourt MC, et al.
    Molecules, 2020 Oct 29;25(21).
    PMID: 33138197 DOI: 10.3390/molecules25215017
    The new coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has recently put the world under stress, resulting in a global pandemic. Currently, there are no approved treatments or vaccines, and this severe respiratory illness has cost many lives. Despite the established antimicrobial and immune-boosting potency described for honey, to date there is still a lack of evidence about its potential role amid COVID-19 outbreak. Based on the previously explored antiviral effects and phytochemical components of honey, we review here evidence for its role as a potentially effective natural product against COVID-19. Although some bioactive compounds in honey have shown potential antiviral effects (i.e., methylglyoxal, chrysin, caffeic acid, galangin and hesperidinin) or enhancing antiviral immune responses (i.e., levan and ascorbic acid), the mechanisms of action for these compounds are still ambiguous. To the best of our knowledge, this is the first work exclusively summarizing all these bioactive compounds with their probable mechanisms of action as antiviral agents, specifically against SARS-CoV-2.
  3. Fulltext Age-dependent electrocardiographic changes in Pgc-1β deficient murine hearts
    Ahmad S, Valli H, Salvage SC, Grace AA, Jeevaratnam K, Huang CL
    Clin Exp Pharmacol Physiol, 2018 02;45(2):174-186.
    PMID: 28949414 DOI: 10.1111/1440-1681.12863
    Increasing evidence implicates chronic energetic dysfunction in human cardiac arrhythmias. Mitochondrial impairment through Pgc-1β knockout is known to produce a murine arrhythmic phenotype. However, the cumulative effect of this with advancing age and its electrocardiographic basis have not been previously studied. Young (12-16 weeks) and aged (>52 weeks), wild type (WT) (n = 5 and 8) and Pgc-1β-/- (n = 9 and 6), mice were anaesthetised and used for electrocardiographic (ECG) recordings. Time intervals separating successive ECG deflections were analysed for differences between groups before and after β1-adrenergic (intraperitoneal dobutamine 3 mg/kg) challenge. Heart rates before dobutamine challenge were indistinguishable between groups. The Pgc-1β-/- genotype however displayed compromised nodal function in response to adrenergic challenge. This manifested as an impaired heart rate response suggesting a functional defect at the level of the sino-atrial node, and a negative dromotropic response suggesting an atrioventricular conduction defect. Incidences of the latter were most pronounced in the aged Pgc-1β-/- mice. Moreover, Pgc-1β-/- mice displayed electrocardiographic features consistent with the existence of a pro-arrhythmic substrate. Firstly, ventricular activation was prolonged in these mice consistent with slowed action potential conduction and is reported here for the first time. Additionally, Pgc-1β-/- mice had shorter repolarisation intervals. These were likely attributable to altered K+ conductance properties, ultimately resulting in a shortened QTc interval, which is also known to be associated with increased arrhythmic risk. ECG analysis thus yielded electrophysiological findings bearing on potential arrhythmogenicity in intact Pgc-1β-/- systems in widespread cardiac regions.
  4. Fulltext A Perspective Review on the Role of Nanomedicine in the Modulation of TNF-TNFR2 Axis in Breast Cancer Immunotherapy
    Al-Hatamleh MAI, Ahmad S, Boer JC, Lim J, Chen X, Plebanski M, et al.
    J Oncol, 2019;2019:6313242.
    PMID: 31239840 DOI: 10.1155/2019/6313242
    In the past decade, nanomedicine research has provided us with highly useful agents (nanoparticles) delivering therapeutic drugs to target cancer cells. The present review highlights nanomedicine applications for breast cancer immunotherapy. Recent studies have suggested that tumour necrosis factor (TNF) and its receptor 2 (TNFR2) expressed on breast cancer cells have important functional consequences. This cytokine/receptor interaction is also critical for promoting highly immune-suppressive phenotypes by regulatory T cells (Tregs). This review generally provides a background for nanoparticles as potential drug delivery agents for immunomodulators and further discusses in depth the potential of TNF antagonists delivery to modulate TNF-TNFR2 interactions and inhibit breast cancer progression.
  5. Fulltext Synthesis, characterization and advanced sustainable applications of titanium dioxide nanoparticles: A review
    Irshad MA, Nawaz R, Rehman MZU, Adrees M, Rizwan M, Ali S, et al.
    Ecotoxicol Environ Saf, 2021 Apr 01;212:111978.
    PMID: 33561774 DOI: 10.1016/j.ecoenv.2021.111978
    Nanotechnology is capturing great interest worldwide due to their stirring applications in various fields. Among nanoparticles (NPs), titanium dioxide (TiO2) NPs have been widely used in daily life and can be synthesized through various physical, chemical, and green methods. Green synthesis is a non-toxic, cost-effective, and eco-friendly route for the synthesis of NPs. Plenty of work has been reported on the green, chemical, physical and biological synthesis of TiO2 NPs and these NPs can be characterized through high tech. instruments. In the present review, dense data have been presented on the comparative synthesis of TiO2 NPs with different characteristics and their wide range of applications. Among the TiO2 NPs synthesis techniques, the green methods have been proven to be efficient than chemical synthesis methods because of the less use of precursors, time-effectiveness, and energy-efficiency during the green synthesis procedures. Moreover, this review describes the types of plants (shrubs, herbs and trees), microorganisms (bacteria, fungi and algae), biological derivatives (proteins, peptides, and starches) employed for the synthesis of TiO2 NPs. The TiO2 NPs can be effectively used for the treatment of polluted water and positively affected the plant physiology especially under abiotic stresses but the response varied with types, size, shapes, doses, duration of exposure, metal species along with other factors. This review also highlights the regulating features and future standpoints for the measurable enrichment in TiO2 NPs product and perspectives of TiO2 NPs reliable application.
  6. Biological evaluation of curcumin and related diarylheptanoids
    Abas F, Hui LS, Ahmad S, Stanslas J, Israf DA, Shaari K, et al.
    Z Naturforsch C J Biosci, 2006 12 2;61(9-10):625-31.
    PMID: 17137104
    Nine derivatives of three natural diarylheptanoids, curcumin, demethoxycurcumin and bisdemethoxycurcumin, were prepared. Their antioxidant, free radical scavenging, nitric oxide (NO) inhibitory and cytotoxic activities were evaluated and compared with those of the respective natural compounds. Curcumin (1), demethoxycurcumin (2), demethyldemethoxy-curcumin (C3), diacetyldemethoxycurcumin (AC2) and triacetyldemethylcurcumin (AC5) exhibited higher antioxidant activity than quercetin while products from demethylation of 1 and 2 exhibited higher free radical scavenging activity. Compounds AC2 and AC5 were found to be most active in inhibiting breast cancer cells (MCF-7) proliferation with IC50 values of 6.7 and 3.6 microM, respectively. The activity of AC2 is almost doubled and of AC5 almost tripled as compared to curcumin. Their selectivity towards different cell lines is also more noticeable. Compounds AC2 and AC5 also showed increased activity against a human prostate cancer cell line (DU-145) and non-small lung cancer cell line (NCI-H460) with IC50 values of 20.4, 16.3 and 18.3, 10.7 microM, respectively.
  7. Fulltext FNG-IE: an improved graph-based method for keyword extraction from scholarly big-data
    Tahir N, Asif M, Ahmad S, Malik MSA, Aljuaid H, Butt MA, et al.
    PeerJ Comput Sci, 2021;7:e389.
    PMID: 33817035 DOI: 10.7717/peerj-cs.389
    Keyword extraction is essential in determining influenced keywords from huge documents as the research repositories are becoming massive in volume day by day. The research community is drowning in data and starving for information. The keywords are the words that describe the theme of the whole document in a precise way by consisting of just a few words. Furthermore, many state-of-the-art approaches are available for keyword extraction from a huge collection of documents and are classified into three types, the statistical approaches, machine learning, and graph-based methods. The machine learning approaches require a large training dataset that needs to be developed manually by domain experts, which sometimes is difficult to produce while determining influenced keywords. However, this research focused on enhancing state-of-the-art graph-based methods to extract keywords when the training dataset is unavailable. This research first converted the handcrafted dataset, collected from impact factor journals into n-grams combinations, ranging from unigram to pentagram and also enhanced traditional graph-based approaches. The experiment was conducted on a handcrafted dataset, and all methods were applied on it. Domain experts performed the user study to evaluate the results. The results were observed from every method and were evaluated with the user study using precision, recall and f-measure as evaluation matrices. The results showed that the proposed method (FNG-IE) performed well and scored near the machine learning approaches score.
  8. Fulltext Targeting dendritic cells through gold nanoparticles: A review on the cellular uptake and subsequent immunological properties
    Ahmad S, Zamry AA, Tan HT, Wong KK, Lim J, Mohamud R
    Mol Immunol, 2017 11;91:123-133.
    PMID: 28898717 DOI: 10.1016/j.molimm.2017.09.001
    Gold nanoparticles (NPs) have been proposed as a highly potential tool in immunotherapies due to its advantageous properties including customizable size and shapes, surface functionality and biocompatibility. Dendritic cells (DCs), the sentinels of immune response, have been of interest to be manipulated by using gold NPs for targeted delivery of immunotherapeutic agent. Researches done especially in human DCs showed a variation of gold NPs effects on cellular uptake and internalization, DC maturation and subsequent T cells priming as well as cytotoxicity. In this review, we describe the synthesis and physiochemical properties of gold NPs as well as the importance of gold NPs in immunotherapies through their actions on human DCs.
  9. Fulltext Use of the Arabin pessary in women at high risk for preterm birth: long-term experience at a single tertiary center in Malaysia
    Rahman RA, Atan IK, Ali A, Kalok AM, Ismail NAM, Mahdy ZA, et al.
    BMC Pregnancy Childbirth, 2021 May 10;21(1):368.
    PMID: 33971828 DOI: 10.1186/s12884-021-03838-x
    BACKGROUND: Spontaneous preterm birth is a global issue that contributed to perinatal morbidities and mortalities worldwide. The study aimed to describe the experience at UKM Medical Center in managing women at high risk for spontaneous preterm birth using the Arabin pessary.

    METHODS: This is a retrospective observational study involving 58 pregnancies from 1st January 2013 to 31st December 2019. Inclusion criteria were previous mid-trimester miscarriage and/or preterm birth, previous cervical surgery or short cervical length on routine sonogram. The demographic data, characteristics of each pregnancy and details of outcomes and management were described.

    RESULTS: The majority of women were Malay with mean age and body mass index of 32.9 ± 4.2 years and 27.1 ± 6.3 kg/m2 respectively. The most frequent indications for Arabin pessary insertion were previous mid-trimester miscarriage (46.4%) and early preterm birth (17.2%). A total of 73.4% of these women had the pessary inserted electively at a mean cervical length of 31.6 ± 9.1 mm at median gestation of 15.0 weeks. They were managed as outpatient (56.9%), inpatient (24.1%) or mixed (19.0%) with combination of progestogen (81.0%) and 53.4% received antenatal corticosteroids. Spontaneous preterm birth at or more than 34 weeks gestation occurred in 74.1% with birthweight at or more than 2000 g (82.4%). Despite cervical funneling in 12 women (20.7%), 66.7% delivered at or later than 34 weeks gestation and 2 (16.7%) resulted in miscarriage.

    CONCLUSIONS: Insertion of the Arabin pessary is beneficial to prevent spontaneous preterm birth in pregnant women who are at high risk. In particular, early insertion and close monitoring allows the best possible outcomes.

    TRIAL REGISTRATION: This study was retrospectively registered with ClinicalTrials.gov ( NCT04638023 ) on 20/11/2020.

  10. Fulltext Force-Invariant Improved Feature Extraction Method for Upper-Limb Prostheses of Transradial Amputees
    Islam MJ, Ahmad S, Haque F, Reaz MBI, Bhuiyan MAS, Islam MR
    Diagnostics (Basel), 2021 May 07;11(5).
    PMID: 34067203 DOI: 10.3390/diagnostics11050843
    A force-invariant feature extraction method derives identical information for all force levels. However, the physiology of muscles makes it hard to extract this unique information. In this context, we propose an improved force-invariant feature extraction method based on nonlinear transformation of the power spectral moments, changes in amplitude, and the signal amplitude along with spatial correlation coefficients between channels. Nonlinear transformation balances the forces and increases the margin among the gestures. Additionally, the correlation coefficient between channels evaluates the amount of spatial correlation; however, it does not evaluate the strength of the electromyogram signal. To evaluate the robustness of the proposed method, we use the electromyogram dataset containing nine transradial amputees. In this study, the performance is evaluated using three classifiers with six existing feature extraction methods. The proposed feature extraction method yields a higher pattern recognition performance, and significant improvements in accuracy, sensitivity, specificity, precision, and F1 score are found. In addition, the proposed method requires comparatively less computational time and memory, which makes it more robust than other well-known feature extraction methods.
  11. Fulltext Internet pornography exposures amongst young people in Malaysia: A cross-sectional study looking into the role of gender and perceived realism versus the actual sexual activities
    Zohor Ali AA, Muhammad NA, Jamil TR, Ahmad S, Abd Aziz NA
    Addict Behav Rep, 2021 Dec;14:100350.
    PMID: 34041356 DOI: 10.1016/j.abrep.2021.100350
    Despite the wide accessibility to internet, pornography activities among youths are not well described in conservative countries like Malaysia. This study aimed to determine the prevalence, elicit gender differences and identify associated factors of pornographic exposure including perceived realism among college students. This cross-sectional study was conducted among students aged 18 to 25 years from seven colleges in Penang, Malaysia. A self-administered questionnaire was used to obtain data on socio-demographic characteristics, pornography exposure, pattern of use, sexual exposure and perceived realism. Among 986 participants, the prevalence of lifetime pornography exposure was 74.5%. More males (71.7%) were exposed to pornography, had started at earlier age, were frequent users and using the internet alone at home (p 
  12. Unequal distribution of COVID-19 vaccine: A looming crisis
    Sawal I, Ahmad S, Tariq W, Tahir MJ, Essar MY, Ahmed A
    J Med Virol, 2021 09;93(9):5228-5230.
    PMID: 33942326 DOI: 10.1002/jmv.27031
  13. Neuroprotective and antioxidant effect of Curcuma longa (Rhizome) methanolic extract on SH-SY5Y cells and Javanese medaka
    Hassan IM, Wan Ibrahim WN, Yusuf FM, Ahmad SA, Ahmad S
    Pak J Pharm Sci, 2021 Jan;34(1):47-56.
    PMID: 34248002
    Diseases caused by oxidative stress can be prevented by antioxidant. Current treatments for those neurodegenerative diseases are not effective and cause many side effects. Thus, the search for alternative medicines is in high demand. Therefore, the main purposed of this study is to evaluate the neuroprotective effects of Curcuma longa (rhizome) 80% methanol extract. Antioxidant using dichlorofuoresence diacetate (DCF-DA) assay on SH-SY5Y cells revealed high activities of Curcuma longa (rhizome) extract with IC50 of 105.9±0.8 µg/mL. Sub-acute and chronic toxicity tests of the plant extract on adult Javanese medaka (Oryzias javanicus) showed high toxicity effect with LC50 of 24.15±0.8 mg/L and 13.69±0.7 mg/L respectively. Neuroprotective tests using cholinesterase assay disclose significant differences at P<0.05 between the group that are exposed to arsenic and treated with the crude extract and the group that are exposed to only arsenic. Identification of vitexin and isovitexin justified the high antioxidant potential of this plant leaf and it highest benefit to be used as medicinal supplement.
  14. Molecular evidence and hematological alterations associated with the occurrence of coronavirus in domestic dogs in Pakistan
    Sulehria MU, Ahmad SS, Ijaz M, Mushtaq MH, Khan AY, Ghaffar A
    Trop Biomed, 2020 Dec 01;37(4):963-972.
    PMID: 33612749 DOI: 10.47665/tb.37.4.963
    Canine Enteric Coronavirus (CCoV) is one of the major enteric pathogen affecting dogs. This study aims to investigate the molecular prevalence, phylogenetic analysis, associated risk factors, and haemato-biochemical alterations in Canine Coronavirus in dogs in district Lahore, Pakistan. 450 fecal samples were collected from symptomatic dogs originating from various pet-clinics and kennels during 2018-2019. Samples were initially analyzed by sandwich lateral flow immunochromatographic assay and then further processed by RT-PCR (reverse transcriptase polymerase chain reaction) targeting the M gene followed by sequencing. RT-PCR based positive (n=20) and negative (n=20) dogs were samples for their blood for the haemato-biochemical analysis. A questionnaire was used to collect data from pet owners, in order to analyze the data for risk factors analysis by chi square test on SPSS. The prevalence of CCoV was 35.1%, and 23.8 % through Sandwich lateral flow immunochromatographic and RT-PCR respectively. Various risk factors like breed, age, sex, vomiting, diarrhea, sample source, body size, cohabitation with other animals, living environment, food, deworming history, contact with other animals or birds feces, and season were significantly associated with CCoV. The CCoV identified in Pakistan were 98% similar with the isolates from China (KT 192675, 1), South Korea (HM 130573, 1), Brazil (GU 300134, 1), Colombia (MH 717721, 1), United Kingdom (JX 082356, 1) and Tunisia (KX156806). Haematobiochemical alterations in CCoV affected dogs revealed anaemia, leucopenia, lymphopenia, neutrophilia, and decreased packed cell volume, and a significant increase in alkaline phosphate and alanine transaminase. It is concluded that infection with canine coronavirus appears widespread among dog populations in district Lahore, Pakistan. This study is the first report regarding the molecular detection and sequence analysis of CCoV in Pakistan.
  15. Five decades of the International Endodontic Journal: Bibliometric overview 1967-2020
    Khan AS, Ur Rehman S, Ahmad S, AlMaimouni YK, Alzamil MAS, Dummer PMH
    Int Endod J, 2021 Oct;54(10):1819-1839.
    PMID: 34196006 DOI: 10.1111/iej.13595
    AIM: The International Endodontic Journal (IEJ) has served as a platform for research and clinical practice in Endodontics since 1967. This study provides a bibliographic analysis and overview of the publications that have appeared in the IEJ from 1967 to 2020.

    METHODOLOGY: A literature search was performed in Elsevier's Scopus database to locate all the publications of the International Endodontic Journal. Various bibliometric software packages including the open-source visualization software Gephi and Biblioshiny (version 2.0) were employed for data visualization and analysis.

    RESULTS: A total of 3739 records with citation and bibliographic details were selected and retrieved to allow a bibliometric analysis to be performed. The bibliometric analysis indicates that the IEJ has grown both in terms of productivity and influence. Over time, the journal has been associated with an increase in the number of manuscripts published and the citations they have attracted, but with minor downward fluctuations in citations in the last few years. Bibliographic coupling of the IEJ articles revealed that the major research themes published in the journal include 'endodontics', 'root canal treatment', 'calcium hydroxide', 'apical periodontitis', 'mineral trioxide aggregate', 'microbiology', 'cyclic fatigue', 'cone-beam computed tomography' and 'micro-computed tomography'. Authors affiliated to institutions in the UK were the major contributors to the journal and were linked with other countries such as Brazil, USA and Malaysia. The largest number of publications were from the University of São Paulo, Brazil.

    CONCLUSION: The IEJ is one of the leading journals in Endodontology and has been providing a platform for innovative research and clinical reports for more than 50 years. Publications have been associated with a wide range of authors, institutions and countries around the world.

  16. Fulltext Testosterone deficiency syndrome among males with type 2 diabetes mellitus in East Malaysia
    Ahmad S, Jerampang P, Tohid H, Ali MF, Jamil TR, Kong CHC
    Nagoya J Med Sci, 2020 Nov;82(4):613-621.
    PMID: 33311792 DOI: 10.18999/nagjms.82.4.613
    Type 2 diabetes mellitus (T2DM) may be independently associated with testosterone deficiency syndrome (TDS). Both conditions are linked with reduced quality of life and cardiovascular comorbidities. The magnitude of TDS among T2DM men and its predictors has still not been well established in Malaysia. This study aimed to determine the prevalence of TDS and its predictors among men with T2DM attending a government health clinic in Kuching, Sarawak. TDS severity and level of serum total testosterone were also explored. A cross-sectional study was conducted involving 360 respondents. Aging Males Symptoms Scale (AMS) score > 26 and serum total testosterone ≤ 12 nmol/L were used to diagnose TDS. The prevalence of TDS in current study was 19.7%. Multivariate analysis showed that determinants for TDS included age (Adjusted OR 1.061: 95% CI 1.020; 1.103), Iban ethnicity (Adjusted OR 2.469: 95% CI 1.154; 5.283) and a waist circumference equal or greater than 90 cm (Adjusted OR 3.655: 95% CI 1.472; 9.081). However, there was no significant association between TDS and the level of serum total testosterone (p = 0.581). We concluded that the prevalence of TDS in this study was relatively low. The severity of this condition may not be influenced by testosterone level. Physicians might consider a diagnosis of TDS if elder diabetic men with abdominal obesity present to primary care clinics with clinical features of hypogonadism. Health care providers also might consider lowering their threshold to screen for TDS among Iban men with T2DM.
  17. Linguistic validation of stigmatisation degree, self-esteem and knowledge questionnaire among asthma patients using Rasch analysis
    Ahmad S, Ismail AI, Khan TM, Akram W, Mohd Zim MA, Ismail NE
    J Asthma, 2017 04;54(3):318-324.
    PMID: 27410725 DOI: 10.1080/02770903.2016.1208222
    BACKGROUND AND OBJECTIVE: The stigmatisation degree, self-esteem and knowledge either directly or indirectly influence the control and self-management of asthma. To date, there is no valid and reliable instrument that can assess these key issues collectively. The main aim of this study was to test the reliability and validity of the newly devised and translated "Stigmatisation Degree, Self-Esteem and Knowledge Questionnaire" among adult asthma patients using the Rasch measurement model.
    METHODOLOGY: This cross-sectional study recruited thirty adult asthma patients from two respiratory specialist clinics in Selangor, Malaysia. The newly devised self-administered questionnaire was adapted from relevant publications and translated into the Malay language using international standard translation guidelines. Content and face validation was done. The data were extracted and analysed for real item reliability and construct validation using the Rasch model.
    RESULTS AND CONCLUSION: The translated "Stigmatisation Degree, Self-Esteem and Knowledge Questionnaire" showed high real item reliability values of 0.90, 0.86 and 0.89 for stigmatisation degree, self-esteem, and knowledge of asthma, respectively. Furthermore, all values of point measure correlation (PTMEA Corr) analysis were within the acceptable specified range of the Rasch model. Infit/outfit mean square values and Z standard (ZSTD) values of each item verified the construct validity and suggested retaining all the items in the questionnaire. The reliability analyses and output tables of item measures for construct validation proved the translated Malaysian version of "Stigmatisation Degree, Self-Esteem and Knowledge Questionnaire" as a valid and highly reliable questionnaire.
    Study site: Respiratory clinics, Hospital Selayang, Hospital Sungai Buloh, Selangor, Malaysia
  18. EMG Processing Based Measures of Fatigue Assessment during Manual Lifting
    Shair EF, Ahmad SA, Marhaban MH, Mohd Tamrin SB, Abdullah AR
    Biomed Res Int, 2017;2017:3937254.
    PMID: 28303251 DOI: 10.1155/2017/3937254
    Manual lifting is one of the common practices used in the industries to transport or move objects to a desired place. Nowadays, even though mechanized equipment is widely available, manual lifting is still considered as an essential way to perform material handling task. Improper lifting strategies may contribute to musculoskeletal disorders (MSDs), where overexertion contributes as the highest factor. To overcome this problem, electromyography (EMG) signal is used to monitor the workers' muscle condition and to find maximum lifting load, lifting height and number of repetitions that the workers are able to handle before experiencing fatigue to avoid overexertion. Past researchers have introduced several EMG processing techniques and different EMG features that represent fatigue indices in time, frequency, and time-frequency domain. The impact of EMG processing based measures in fatigue assessment during manual lifting are reviewed in this paper. It is believed that this paper will greatly benefit researchers who need a bird's eye view of the biosignal processing which are currently available, thus determining the best possible techniques for lifting applications.
  19. Fulltext UV/O3 treatment as a surface modification of rice husk towards preparation of novel biocomposites
    Rajendran Royan NR, Sulong AB, Yuhana NY, Chen RS, Ab Ghani MH, Ahmad S
    PLoS One, 2018;13(5):e0197345.
    PMID: 29847568 DOI: 10.1371/journal.pone.0197345
    The use of rice husks (RH) to reinforce polymers in biocomposites are increasing tremendously. However, the incompatibility between the hydrophilic RH fibers and the hydrophobic thermoplastic matrices leads to unsatisfactory biocomposites. Surface modification of the fiber surface was carried out to improve the adhesion between fiber and matrix. In this study, the effect of surface modification of RH via alkali, acid and ultraviolet-ozonolysis (UV/O3) treatments on the properties of composites recycled high density polyethylene (rHDPE) composites was investigated. The untreated and treated RH were characterized by Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM). The composites containing 30 wt% of RH (treated and untreated) were then prepared via extrusion and followed by compression molding. As compared to untreated RH, all surface treated RH exhibited rougher surface and showed improved adhesion with rHDPE matrix. Tensile strength of UV/O3-treated RH composites showed an optimum result at 18.37 MPa which improved about 5% in comparison to the composites filled with untreated RH. UV/O3 treatment promotes shorter processing time and lesser raw material waste during treatment process where this is beneficial for commercialization in the future developments of wood plastic composites (WPCs). Therefore, UV/O3 treatment can be served as an alternative new method to modify RH surface in order to improve the adhesion between hydrophilic RH fibre and hydrophobic rHDPE polymer matrix.
  20. Inhibition of UVB-induced pro-inflammatory cytokines and MMP expression by Zanthoxylum rhetsa bark extract and its active constituent hesperidin
    Santhanam RK, Fakurazi S, Ahmad S, Abas F, Ismail IS, Rukayadi Y, et al.
    Phytother Res, 2018 Aug;32(8):1608-1616.
    PMID: 29672974 DOI: 10.1002/ptr.6092
    The antiphoto aging property of Zanthoxylum rhetsa obtained from Pangkor Island, Malaysia, was evaluated. Solvent fractions of different polarity obtained from the methanolic extract of the bark material were initially tested for anticollagenase and antielastase activities. The ethyl acetate fraction showed bioactivity against the protease enzymes. Hence, it was subjected to further purification via column chromatography, to yield a major constituent, hesperidin. Subsequently, the ethyl acetate fraction and hesperidin were tested for their effects against UVB-induced cytotoxicity and expressions of inflammatory cytokines (IL-6, IL-1β, and TNF-α), NF-κB, and MMPs (MMP1, 3, and 9) in human dermal fibroblasts (HDF). Both fraction and pure compound prevented UVB-induced cytotoxicity in HDF cells, in a dose dependent manner. Moreover, the ethyl acetate fraction inhibited the increase of pro-inflammatory cytokines induced by UVB to a level similar to the control (without UV treatment). Additionally, the fraction significantly inhibited the expressions of NF-κB, MMP 1, MMP 3, and MMP 9 in HDF cells treated with UVB. Similar effects were observed with hesperidin. The results obtained suggested that the ethyl acetate fraction of Z. rhetsa and its bioactive constituent, hesperidin, have the potential to be used as active ingredients in sunscreen and antiphoto aging formulations.
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