Browse publications by year: 2019

  1. Awaluddin SM, Ahmad FH, Jeevananthan C, Ganapathy SS, Sooryanarayana R, Mohamad Anuar MF, et al.
    Asia Pac J Public Health, 2019 Nov;31(8_suppl):65S-72S.
    PMID: 31522523 DOI: 10.1177/1010539519872662
    Serious injury due to motor vehicle accidents (MVAs) significantly contributes to the adolescents' health status. The objective of this study was to estimate the prevalence of nonfatal injury due to MVAs and its associated factors among Malaysian school-going adolescents. Nationally representative samples were selected via 2-stage stratified cluster sampling. Data was collected using a validated self-administered questionnaire. Logistic regression analysis was conducted to examine the associations between the variables. A total of 1088 out of 27 497 adolescents reported that they had sustained serious injury due to MVAs with a prevalence of 4.1% (95% confidence interval [CI] = 3.7-4.5). Serious injury due to MVAs among adolescents was positively associated with being current cigarette smokers (adjusted odds ratio [aOR] = 2.5; 95% CI = 2.2-2.9), followed by Malay ethnicity (aOR = 2.4; 95% CI = 1.9-3.0), current drug users (aOR = 2.3; 95% CI = 1.9-3.0), boys (aOR = 2.1; 95% CI = 1.8-2.4), Indian ethnicity (aOR = 1.8; 95% CI = 1.2-2.5), and those who were in upper secondary school (aOR = 1.3; 95% CI = 1.2-1.5). Targeted intervention and curbing substance use among boys may reduce the morbidities from MVAs and its resulting complications.
  2. Awaluddin SMB, Ying Ying C, Yoep N, Paiwai F, Lodz NA, Muhammad EN, et al.
    Asia Pac J Public Health, 2019 Nov;31(8_suppl):57S-64S.
    PMID: 31523984 DOI: 10.1177/1010539519872642
    Parental protective factors do play an important role in preventing Internet addiction. A self-administered questionnaire was used to measure health risk behaviors among Malaysian adolescents. The prevalence of Internet addiction was significantly higher among adolescents with perceived lack of parental supervision (30.1% [95% confidence interval (CI) = 28.7-31.4]) and lack of parental connectedness (30.1% [95% CI = 28.5-31.7]), compared with their counterparts. Adolescents who perceived a lack of parental supervision, respect for privacy, connectedness, and bonding were more likely to have Internet addiction: (adjusted odds ratio [aOR] = 1.39; 95% CI = 1.27-1.52), (aOR = 1.23; 95% CI = 1.16-1.31), (aOR = 1.09; 95% CI = 1.02-1.16), (aOR = 1.06; 95% CI = 1.00-1.12), respectively. Among girls, Internet addiction was associated with those who perceived lack in all 4 parental factors, while among boys, those who perceived lack of parental supervision and respect for privacy were more prone to Internet addiction.
  3. Khor GL, Shariff ZM
    BMC Public Health, 2019 Dec 16;19(1):1685.
    PMID: 31842826 DOI: 10.1186/s12889-019-8055-8
    The purpose of this correspondence is to express our disappointment with the coverage of the BMC Public Health supplement: Vol 19 (4) titled "Health and Nutritional Issues Among Low Income Population in Malaysia", which neglected to include the fundamental health and nutrition issues that are adversely affecting the lives and livelihood of the indigenous peoples. The Supplement comprised 21 papers. Two of these papers included indigenous peoples as study subjects. These two papers addressed peripheral, albeit important health issues, namely visual impairment and quality of life, and not the persistent and rising health concerns impacting this population. We will provide evidence from research and reports to justify our critique that the Supplement missed the opportunity to spotlight on the serious extent of the health and nutritional deprivations of the indigenous peoples of Malaysia. As researchers of the indigenous peoples, we ought to lend our voice to the "silenced minority" by highlighting their plight in the media including scientific journals.
    MeSH terms: Humans; Malaysia/epidemiology; Nutrition Disorders/epidemiology*; Poverty/statistics & numerical data*; Health Status Disparities*; Research Report/standards*
  4. Kaltenbach T, Gattolliat JL
    Zookeys, 2019;895:1-117.
    PMID: 31844411 DOI: 10.3897/zookeys.895.38576
    Material collected between 2010 and 2014 on the Indonesian islands of Sumatra, Bali, Sumba, Sumbawa, Sulawesi, and Seram unveiled the enormous diversity of Labiobaetis Novikova & Kluge in this country. Five species were reported from Indonesia previously (L. fulmeki (Ulmer), L. obscurum (Ulmer), L. necopinatum (Müller-Liebenau), L. ulmeri (Müller-Liebenau), and L. boettgeri (Ulmer)); all were described from adults only and no species were previously known at larval stage. We identified 18 new species by integrative taxonomy using genetic distance (COI, Kimura-2-parameter) and morphology, and they are described and illustrated based on their larvae. Another species, L. multus (Müller-Liebenau) from Malaysia, was also found in Indonesia, increasing the total number of species in Indonesia to 24. Seven morpho-groups of species are proposed based on morphological characters and a key to the larvae of all species from Indonesia and adjacent countries is provided. The total number of Labiobaetis species worldwide is augmented to 123. The examination of the new species allowed us to slightly modify the generic attributes of the larvae. The interspecific K2P distances are usually between 11% and 24%, the intraspecific distances are usually between 0% and 3%. The remarkable richness of the genus in Indonesia is discussed.
  5. Chinnasamy V, Subramaniyan V, Chandiran S, Kayarohanam S, Kanniyan DC, Velaga VSSR, et al.
    Open Access Maced J Med Sci, 2019 Sep 15;7(17):2709-2714.
    PMID: 31844425 DOI: 10.3889/oamjms.2019.559
    AIM: To determine the ameliorative potential of aqueous extract of Achyranthesaspera(AEAA) against arthritis using swiss albino mice and Wistar rats, and its possible mechanism of action.

    METHODS: Swiss albino mice (25-30 g) and Wistar rats (150-180 g) under standard controlled conditions (24 ± 2°C, 50-70 humidity and 12 h light/dark cycle). The groups were divided into 6 groups (n = 6/group) and assigned as control, negative control, standard and, formaldehyde supplemented with two different test dose groups of A. aspera for 4 weeks. Arthritis induced by subplantar administration of 0.1 ml formaldehyde (2% v/v) into the left hind paw in all groups except normal control. Arthritis was assessed using serum Hb, ESR, paw volume, joint diameter, radiological and histopathological investigation.

    RESULTS: Oral administration of AEAA shown a significant (p < 0.01) dose-dependent protection against formaldehyde induced arthritis. At 21st day, A.asperashown an inhibition of paw volume in the different doses of 250 mg/kg and 500 mg/kg were found to be 30% and, 38.33% respectively. At 14th day the joint swelling was found to be 27.2% and 36.36 respectively. Diclofenac (10 mg/kg) had an effect of 36.61% inhibition of arthritis and joint swelling at 21st and 14th day.

    CONCLUSION: Thus, the present study revealed that the aqueous extract of A. aspera offered significant protection against arthritis and joint inflammation.

  6. Chu ECP, Chin WL, Bhaumik A
    Oxf Med Case Reports, 2019 Nov;2019(11):476-478.
    PMID: 31844531 DOI: 10.1093/omcr/omz115
    Cervical muscles have numerous connections with vestibular, visual and higher centres, and their interactions can produce effective proprioceptive input. Dysfunction of the cervical proprioception because of various neck problems can alter orientation in space and cause a sensation of disequilibrium. Cervicogenic dizziness (CGD) is a clinical syndrome characterized by the presence of dizziness and associated neck pain in patients with cervical pathology. Here, we report a 24-year-old female, who was diagnosed with CGD based on the correlating episodes of neck pain and dizziness. Both symptoms improved with targeted chiropractic adjustment and ultrasound therapy. CGD is a seemingly simple complaint for patients, but tends to be a controversial diagnosis because there are no specific tests to confirm its causality. For CGD to be considered, an appropriate management for the neck pain should not be denied any patient.
  7. Kusuma SAF, Parwati I, Rostinawati T, Yusuf M, Fadhlillah M, Ahyudanari RR, et al.
    Heliyon, 2019 Nov;5(11):e02741.
    PMID: 31844694 DOI: 10.1016/j.heliyon.2019.e02741
    MPT64 is a specific protein that is secreted by Mycobacterium tuberculosis complex (MTBC). The objective of this study was to obtain optimum culture conditions for MPT64 synthetic gene expression in Escherichia coli BL21 (DE3) by response surface methodology (RSM). The RSM was undertaken to optimize the culture conditions under different cultivation conditions (medium concentration, induction time and inducer concentration), designed by the factorial Box-Bhenken using Minitab 17 statistical software. From the randomized combination, 15 treatments and three center point repetitions were obtained. Furthermore, expression methods were carried out in the flask scale fermentation in accordance with the predetermined design. Then, the MPT64 protein in the cytoplasm of E. coli cell was isolated and characterized using sodium dodecyl sulfate polyacrilamide electrophoresis (SDS-PAGE) then quantified using the ImageJ program. The optimum conditions were two-fold medium concentration (tryptone 20 mg/mL, yeast extract 10 mg/mL, and sodium chloride 20 mg/mL), 5 h of induction time and 4 mM rhamnose. The average concentration of recombinant MPT64 at optimum conditions was 0.0392 mg/mL, higher than the predicted concentration of 0.0311 mg/mL. In conclusion, the relationship between the selected optimization parameters strongly influenced the level of MPT64 gene expression in E. coli BL21 (DE3).
    MeSH terms: Cytoplasm; Electrophoresis, Polyacrylamide Gel; Escherichia coli; Fermentation; Genes, Synthetic; Mycobacterium tuberculosis; Rhamnose; Sodium Chloride; Sodium Dodecyl Sulfate; Sodium Radioisotopes; Software
  8. Fatimah I, Prakoso NI, Sahroni I, Musawwa MM, Sim YL, Kooli F, et al.
    Heliyon, 2019 Nov;5(11):e02766.
    PMID: 31844705 DOI: 10.1016/j.heliyon.2019.e02766
    In this work, TiO2/SiO2 composite photocatalysts were prepared using biogenic silica extracted from bamboo leaves and titanium tetraisopropoxide as a titania precursor via a sol-gel mechanism. A study of the physicochemical properties of materials as a function of their titanium dioxide content was conducted using Fourier transform infrared spectroscopy, a scanning electron microscope, a diffuse reflectance ultraviolet-visible (UV-vis) spectrophotometer, and a gas sorption analyzer. The relationship between physicochemical parameters and photocatalytic performance was evaluated using the methylene blue (MB) photocatalytic degradation process under UV irradiation with and without the addition of H2O2 as an oxidant. The results demonstrated that increasing the TiO2 helps enhance the parameters of specific surface area, the pore volume, and the particle size of titanium dioxide, while the band gap energy reaches a maximum of 3.21 eV for 40% and 60% Ti content. The composites exhibit photocatalytic activity with the MB degradation with increasing photocatalytic efficiency since the composites with 40 and 60% wt. of TiO2 demonstrated the higher degradation rate compared with TiO2 in the presence and absence of H2O2. This higher rate is correlated with the higher specific surface area and band gap energy compared with those of TiO2.
    MeSH terms: Hydrogen Peroxide; Methylene Blue; Microscopy, Electron, Scanning; Particle Size; Silicon Dioxide; Spectrophotometry, Ultraviolet; Titanium; Ultraviolet Rays; Oxidants; Spectroscopy, Fourier Transform Infrared; Plant Leaves
  9. Chen AH, Abu Bakar NF, Arthur P
    J Curr Ophthalmol, 2019 Dec;31(4):357-365.
    PMID: 31844783 DOI: 10.1016/j.joco.2019.07.006
    PURPOSE: Incorporating mass pediatric vision screening programs as part of a national agenda can be challenging. This review assessed the implementation strategy of the existing pediatric vision screening program.

    METHODS: A search was performed on PubMed, EBSCO host MEDLINE Complete, and Scopus databases encompassing the past ten years for mass pediatric screening practice patterns that met the selection criteria regarding their objectives and implementation. Results were analyzed from 18 countries across five continents.

    RESULTS: Eight countries (44%) offered screening for distance visual acuity only, where the majority of the countries (88%) used either Snellen or Tumbling E chart. High-income countries initiated screening earlier and applied a more comprehensive approach, targeting conditions other than reduced vision only, compared with middle-income countries. Chart-based testing was most commonly performed, with only three countries incorporating an instrument-based approach. Lack of eyecare and healthcare practitioners frequently necessitated the involvement of non-eyecare personnel (94%) as a vision screener including parent, trained staff, and nurse.

    CONCLUSIONS: Implementation of a vision screening program was diverse within countries preceded by limited resources issues. Lack of professional eyecare practitioners implied the need to engage a lay screener. The limitation of existing tests to detect a broader range of visual problems at affordable cost advocated the urgent need for the development of an inexpensive and comprehensive screening tool.

  10. Tan MP, Wong LL, Razali SA, Afiqah-Aleng N, Mohd Nor SA, Sung YY, et al.
    Evol Bioinform Online, 2019;15:1176934319892284.
    PMID: 31839703 DOI: 10.1177/1176934319892284
    Aquatic ecosystems that form major biodiversity hotspots are critically threatened due to environmental and anthropogenic stressors. We believe that, in this genomic era, computational methods can be applied to promote aquatic biodiversity conservation by addressing questions related to the evolutionary history of aquatic organisms at the molecular level. However, huge amounts of genomics data generated can only be discerned through the use of bioinformatics. Here, we examine the applications of next-generation sequencing technologies and bioinformatics tools to study the molecular evolution of aquatic animals and discuss the current challenges and future perspectives of using bioinformatics toward aquatic animal conservation efforts.
    MeSH terms: Animals; Genome; Ecosystem; Evolution, Molecular; Computational Biology; Genomics; Biodiversity; Aquatic Organisms; High-Throughput Nucleotide Sequencing
  11. Mulimani P, Ballas SK, Abas AB, Karanth L
    Cochrane Database Syst Rev, 2019 Dec 16;12(12):CD011633.
    PMID: 31841224 DOI: 10.1002/14651858.CD011633.pub3
    BACKGROUND: Sickle cell disease is the most common single gene disorder and the commonest haemoglobinopathy found with high prevalence in many populations across the world. Management of dental complications in people with sickle cell disease requires special consideration for three main reasons. Firstly, dental and oral tissues are affected by the blood disorder resulting in several oro-facial abnormalities. Secondly, living with a haemoglobinopathy and coping with its associated serious consequences may result in individuals neglecting their oral health care. Finally, the treatment of these oral complications must be adapted to the systemic condition and special needs of these individuals, in order not to exacerbate or deteriorate their general health. Guidelines for the treatment of dental complications in this population who require special care are unclear and even unavailable in many aspects. Hence this review was undertaken to provide a basis for clinical care by investigating and analysing the existing evidence in the literature for the treatment of dental complications in people with sickle cell disease. This is an update of a previously published review.

    OBJECTIVES: To assess methods of treating dental complications in people with sickle cell disease.

    SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Review Group's Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. Date of last search: 01 August 2019. Additionally, we searched nine online databases (PubMed, Google Scholar, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, Literature in the Health Sciences in Latin America and the Caribbean database, African Index Medicus, Index Medicus for South East Asia Region, Index Medicus for the Eastern Mediterranean Region, Indexing of Indian Medical Journals). We also searched the reference lists of relevant articles and reviews and contacted haematologists, experts in fields of dentistry, organizations, pharmaceutical companies and researchers working in this field. Date of last search: 07 November 2019.

    SELECTION CRITERIA: We searched for published or unpublished randomised controlled studies of treatments for dental complications in people with sickle cell disease.

    DATA COLLECTION AND ANALYSIS: Two review authors intended to independently extract data and assess the risk of bias of the included studies using standard Cochrane methodologies; however, no studies were identified for inclusion in the review.

    MAIN RESULTS: No randomised controlled studies were identified.

    AUTHORS' CONCLUSIONS: This Cochrane Review did not identify any randomised controlled studies assessing interventions for the treatment of dental complications in people with sickle cell disease. There is an important need for randomised controlled studies in this area, so as to identify the most effective and safe method for treating dental complications in people with sickle cell disease.

    MeSH terms: Anemia, Sickle Cell/complications*; Dental Care/methods*; Humans; Tooth Diseases/etiology*; Tooth Diseases/therapy; Randomized Controlled Trials as Topic; Craniofacial Abnormalities/complications
  12. Mohd Taha MD, Mohd Jaini MF, Saidi NB, Abdul Rahim R, Md Shah UK, Mohd Hashim A
    PLoS One, 2019;14(12):e0224431.
    PMID: 31841519 DOI: 10.1371/journal.pone.0224431
    Dieback disease caused by Erwinia mallotivora is a major threat to papaya plantation in Malaysia. The current study was conducted to evaluate the potential of endophytic lactic acid bacteria (LAB) isolated from papaya seeds for disease suppression of papaya dieback. Two hundred and thirty isolates were screened against E. mallotivora BT-MARDI, and the inhibitory activity of the isolates against the pathogen was ranging from 11.7-23.7 mm inhibition zones. The synergistic experiments revealed that combination of W. cibaria PPKSD19 and Lactococcus lactis subsp. lactis PPSSD39 increased antibacterial activity against the pathogen. The antibacterial activity was partially due to the production of bacteriocin-like inhibitory substances (BLIS). The nursery experiment confirmed that the application of bacterial consortium W. cibaria PPKSD19 and L. lactis subsp. lactis PPSSD39 significantly reduced disease severity to 19% and increased biocontrol efficacy to 69% of infected papaya plants after 18 days of treatment. This study showed that W. cibaria PPKSD19 and L. lactis subsp. lactis PPSSD39 are potential candidate as biocontrol agents against papaya dieback disease.
    MeSH terms: Antibiosis/drug effects; Anti-Bacterial Agents; Bacteria/drug effects; Bacteriocins/pharmacology*; Biological Phenomena; Erwinia/drug effects*; Erwinia/pathogenicity; Food Microbiology; Malaysia; Seeds/drug effects; Carica/drug effects*; Carica/metabolism; Lactobacillales/drug effects
  13. Idrus II, Abdul Latef T, Aridas NK, Abu Talip MS, Yamada Y, Abd Rahman T, et al.
    PLoS One, 2019;14(12):e0226499.
    PMID: 31841536 DOI: 10.1371/journal.pone.0226499
    Researchers are increasingly showing interest in the application of a Butler matrix for fifth-generation (5G) base station antennas. However, the design of the Butler matrix is challenging at millimeter wave because of the very small wavelength. The literature has reported issues of high insertion losses and incorrect output phases at the output ports of the Butler matrix, which affects the radiation characteristics. To overcome these issues, the circuit elements of the Butler matrix such as the crossover, the quadrature hybrid and the phase shifter must be designed using highly accurate dimensions. This paper presents a low-loss and compact single-layer 8 × 8 Butler matrix operating at 28 GHz. The optimum design of each circuit element is also demonstrated in detail. The designed Butler matrix was fabricated to validate the simulated results. The measured results showed return losses of less than -10 dB at 28 GHz. The proposed Butler matrix achieved a low insertion loss and a low phase error of ± 2 dB and ± 10°, respectively. In sum, this work obtained a good agreement between the simulated and measured results.
    MeSH terms: Algorithms; Computer Simulation; Electrodes; Software; Wireless Technology/economics; Wireless Technology/instrumentation*; Electromagnetic Radiation*
  14. Lee SC, Tang MS, Easton AV, Devlin JC, Chua LL, Cho I, et al.
    PLoS Pathog, 2019 12;15(12):e1008066.
    PMID: 31841569 DOI: 10.1371/journal.ppat.1008066
    Helminth infection and dietary intake can affect the intestinal microbiota, as well as the immune system. Here we analyzed the relationship between fecal microbiota and blood profiles of indigenous Malaysians, referred to locally as Orang Asli, in comparison to urban participants from the capital city of Malaysia, Kuala Lumpur. We found that helminth infections had a larger effect on gut microbial composition than did dietary intake or blood profiles. Trichuris trichiura infection intensity also had the strongest association with blood transcriptional profiles. By characterizing paired longitudinal samples collected before and after deworming treatment, we determined that changes in serum zinc and iron levels among the Orang Asli were driven by changes in helminth infection status, independent of dietary metal intake. Serum zinc and iron levels were associated with changes in the abundance of several microbial taxa. Hence, there is considerable interplay between helminths, micronutrients and the microbiota on the regulation of immune responses in humans.
    MeSH terms: Gastrointestinal Microbiome*; Diet*; Helminthiasis/blood*; Helminthiasis/microbiology*; Host-Parasite Interactions/physiology; Humans; Iron/blood; Malaysia; RNA/blood; Zinc/blood
  15. Ridha NJ, Alosfur FK, Jumali MHH, Radiman S
    Nanotechnology, 2019 Dec 16.
    PMID: 31842006 DOI: 10.1088/1361-6528/ab6235
    High porous ZnO nanoflakes were successfully prepared using microwave assisted hydrothermal method. The presence of aluminum changes the environment of preparation reaction which controlled the crystallographic orientation. The unique morphology and properties of ZnO nanoflakes may due to the effect of microwave irradiation and the ambient condition. The approach is very simple and rapid that grows around 3 μm ZnO within 30 minutes. The mechanism of the construction of unique ZnO nanoflakes growth using the present approach will be proposed. Hence, the prospective performance of ethanol vapor sensing for the rapid growth of ZnO porous nanostructures was investigated.
  16. Suhaimi NH, Yeong YF, Ch'ng CWM, Jusoh N
    Polymers (Basel), 2019 Dec 09;11(12).
    PMID: 31835373 DOI: 10.3390/polym11122042
    CO2 separation from CH4 by using mixed matrix membranes has received great attention due to its higher separation performance compared to neat polymeric membrane. However, Robeson's trade-off between permeability and selectivity still remains a major challenge for mixed matrix membrane in CO2/CH4 separation. In this work, we report the preparation, characterization and CO2/CH4 gas separation properties of mixed matrix membranes containing 6FDA-durene polyimide and ZIF-8 particles functionalized with different types of amine groups. The purpose of introducing amino-functional groups into the filler is to improve the interaction between the filler and polymer, thus enhancing the CO2 /CH4 separation properties. ZIF-8 were functionalized with three differents amino-functional group including 3-(Trimethoxysilyl)propylamine (APTMS), N-[3-(Dimethoxymethylsilyl)propyl ethylenediamine (AAPTMS) and N1-(3-Trimethoxysilylpropyl) diethylenetriamine (AEPTMS). The structural and morphology properties of the resultant membranes were characterized by using different analytical tools. Subsequently, the permeability of CO2 and CH4 gases over the resultant membranes were measured. The results showed that the membrane containing 0.5 wt% AAPTMS-functionalized ZIF-8 in 6FDA- durene polymer matrix displayed highest CO2 permeability of 825 Barrer and CO2/CH4 ideal selectivity of 26.2, which successfully lies on Robeson upper bound limit.
    MeSH terms: Attention; Benzene Derivatives; Carbon Dioxide; Ethylenediamines; Gases; Permeability; Polyamines; Polymers; Propylamines
  17. Khan MI, Huat HY, Dun MHBM, Sutanto MH, Jarghouyeh EN, Zoorob SE
    Materials (Basel), 2019 Dec 10;12(24).
    PMID: 31835533 DOI: 10.3390/ma12244133
    In this study the effect of irradiated and non-irradiated waste polyethylene terephthalate (PET) as replacement of cement and fly-ash in ordinary Portland cement (OPC) and geopolymeric cement (GPC) based cementitious grouts on flexural strength of semi-flexible pavement specimens were evaluated. The porous asphalt gradation was selected based on Malaysian specifications for semi-flexible pavements with a target of 30% air voids. The cement content in the OPC grouts and the fly-ash content in the GPC based grouts were partially replaced with 1.25% PET (using both irradiated and non-irradiated PET). Beam specimens were prepared and tested for flexural strength properties using center point loading configuration. The grouts modified with recycled waste plastic (PET) showed approximately the same results as obtained from the control specimens. Although the replacement amount was low (1.25% by weight of cement), nonetheless, significant impact on reducing CO2 emissions is expected when preparing grouts for mass construction of semi-flexible pavement surfaces. Similarly, effective recycling of waste plastics in road construction and replacing OPC with plastic and geopolymers will have a positive effect on the environment and will furthermore contribute to sustainable pavement construction.
  18. Md Zin N, Al-Fakih A, Nikbakht E, Teo W, Anwar Gad M
    Materials (Basel), 2019 Dec 11;12(24).
    PMID: 31835775 DOI: 10.3390/ma12244159
    An experimental study is conducted to determine the influence of secondary reinforcement on the behaviour of corbels fabricated with three different types of high-performance fiber-reinforced cementitious composites, including engineered cementitious concrete (ECC); high-performance steel fiber-reinforced composite (HPSFRC); and hybrid fiber-reinforced composite (HyFRC). Two shear span-to-depth ratios (a/d = 0.75 and 1.0) are explored. The mechanical properties of the composites in terms of tensile, compressive, and flexural strengths are investigated. Next, the structural behaviour of the high-performance cementitious composite corbels in terms of ultimate load capacity, ductility, and failure modes under the three-point bending test are investigated. The secondary reinforcement is proven to significantly affect stiffness and ultimately load capacity of all three high-performance composite corbels with an aspect ratio of 0.75. However, the secondary reinforcement was more impactful for the HPSFRC corbels, with 51% increase of ultimate strength. Moreover, in terms of damage, fewer cracks occurred in ECC corbels. HPSFRC corbels displayed the highest level of ductility and deformation capacity compared to the other specimens. The results were comparatively analyzed against the predicted results using truss and plastic truss models which provided relatively reliable shear strength.
    MeSH terms: Dental Materials; Plastics; Pressure; Steel; Tensile Strength; Shear Strength
  19. Kagaya W, Gitaka J, Chan CW, Kongere J, Md Idris Z, Deng C, et al.
    Sci Rep, 2019 12 13;9(1):19060.
    PMID: 31836757 DOI: 10.1038/s41598-019-55437-8
    Although WHO recommends mass drug administration (MDA) for malaria elimination, further evidence is required for understanding the obstacles for the optimum implementation of MDA. Just before the long rain in 2016, two rounds of MDA with artemisinin/piperaquine (Artequick) and low-dose primaquine were conducted with a 35-day interval for the entire population of Ngodhe Island (~500 inhabitants) in Lake Victoria, Kenya, which is surrounded by areas with moderate and high transmission. With approximately 90% compliance, Plasmodium prevalence decreased from 3% to 0% by microscopy and from 10% to 2% by PCR. However, prevalence rebounded to 9% by PCR two months after conclusion of MDA. Besides the remained local transmission, parasite importation caused by human movement likely contributed to the resurgence. Analyses of 419 arrivals to Ngodhe between July 2016 and September 2017 revealed Plasmodium prevalence of 4.6% and 16.0% by microscopy and PCR, respectively. Risk factors for infection among arrivals included age (0 to 5 and 11 to 15 years), and travelers from Siaya County, located to the north of Ngodhe Island. Parasite importation caused by human movement is one of major obstacles to sustain malaria elimination, suggesting the importance of cross-regional initiatives together with local vector control.
    MeSH terms: Anemia/complications; Animals; Antimalarials/adverse effects; Antimalarials/pharmacology; Antimalarials/therapeutic use; Geography; Hemoglobins/metabolism; Humans; Kenya/epidemiology; Malaria/drug therapy*; Malaria/epidemiology*; Malaria/parasitology; Parasites/drug effects; Primaquine/adverse effects; Primaquine/pharmacology; Primaquine/therapeutic use; Recurrence; Risk Factors; Prevalence; Medication Adherence; Islands*
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