Browse publications by year: 2020

  1. Tan JS, Teah KM, Hoe VC, Khairuddin A, Sellapan H, Hayati F, et al.
    Ann Med Surg (Lond), 2020 Nov;59:251-253.
    PMID: 33088499 DOI: 10.1016/j.amsu.2020.10.009
    Background: Adult intussusception is a relatively rare clinical entity. The majority of cases of intussusception in adults are due to a pathologic condition that serves as a lead point and requires surgery. Small bowel intussusception is usually caused by benign or malignant neoplasms appearing at the head of the invagination. Inflammatory fibroid polyp (IFP) of the small bowel is an unusual benign neoplastic lesion that has been rarely reported to cause intussusception, especially in the jejunum.

    Case presentation: We present a rare case of adult intussusception who presented with a triad of intestinal obstruction. Computed tomography revealed small bowel intussusception with bowel ischemia. Intraoperatively, she required resection of the small bowel and primary anastomosis. Macroscopic examination revealed a single pedunculated polyp, which is the lead point of intestinal obstruction and confirmed histologically.

    Conclusion: Inflammatory fibroid polyp should be considered as a cause of intussusception among adults with small bowel obstruction.

    MeSH terms: Adult; Anastomosis, Surgical; Female; Humans; Intestinal Obstruction; Intestine, Small; Intussusception; Jejunum; Leiomyoma; Tomography; Mesenteric Ischemia
  2. Du C, Zan MCH, Cho MJ, Fenton JI, Hsiao PY, Hsiao R, et al.
    Clocks Sleep, 2020 Sep;2(3):334-353.
    PMID: 33089208 DOI: 10.3390/clockssleep2030025
    High levels of perceived stress and anxiety among university students are a global concern and are known to negatively influence sleep. However, few studies have explored how stress response styles, like psychological resilience and rumination, might alter these relationships. Using validated tools, perceived stress, anxiety, stress response styles, and sleep behaviors of undergraduate and graduate students from seven countries during the height of the COVID-19 pandemic were characterized in order to examine the relationships between these factors using mediation and moderation analyses. Students enrolled in universities in China, Ireland, Malaysia, Taiwan, South Korea, the Netherlands, and the United States were recruited in May 2020. A total of 2254 students completed this cross-sectional study. Perceived stress and anxiety were negatively associated with sleep quality through the mediation of rumination. Increased psychological resilience weakened the relationships between perceived stress and anxiety on sleep quality. The majority of students reported that COVID-19 negatively influenced their mental health and sleep quality but not sleep duration. Based on these results, university students would likely benefit from sleep education and mental health promotion programs that include trainings to increase psychological resilience and reduce rumination, particularly during times of increased stress.
  3. Abdullah Z, Abdul Aziz SH, Sodri NA, Mohd Hanafiah AN, Ibrahim NI, Johari MZ
    J Prim Care Community Health, 2020 10 23;11:2150132720956478.
    PMID: 33089737 DOI: 10.1177/2150132720956478
    BACKGROUND: Primary healthcare is the earliest gateway for patient care, and improvisations are often needed to accommodate the ever-increasing demand in public health. The Enhanced Primary Healthcare (EnPHC) initiative is aimed at improving such needs, and one core intervention is the introduction of a care coordinator (CC). The purpose of this study was to identify barriers and facilitators in implementing a new intervention in primary healthcare clinics.

    METHODS: This qualitative exploration study. All healthcare providers who were involved in EnPHC at the intervention clinics were selected as participants. In-depth interviews and focus group discussions were carried out among healthcare providers working in the intervention clinic. Thematic analysis was used to categorize data, based on the consolidated framework for implementation research (CFIR) theoretical framework domains.

    RESULTS: A total of 61 healthcare providers participated. All 5 domains with 19 CFIR constructs emerged from the analysis. Inner setting played a significant role in facilitating CC intervention, in which culture, networking, and collaboration and leadership engagement played an essential role in supporting CC activities. Although CC tasks are complex, concerns of losing clinical skill and resource constraints were identified as potential barriers in CC implementations. Criteria for appointing new CCs emerged from the characteristics of individual constructs, in which the individual must be familiar and interested in community health, have good communication skills, and at least 3 years' experience in the primary healthcare setting.

    CONCLUSION: The implementation of the CC intervention faces varying challenges in different settings. This is partially resolved through teamwork, guidance from mentors, and support from superiors. The complexity of the responsibility of the CC intervention is perceived as both a validation and a burden. Above all, it is seen as paramount in EnPHC intervention.

    MeSH terms: Health Personnel*; Humans; Malaysia; Primary Health Care*; Focus Groups; Qualitative Research
  4. Balamurugan S, Muthu BA, Peng SL, Wahab MHA
    Big Data, 2020 10;8(5):450-451.
    PMID: 33090023 DOI: 10.1089/big.2020.29038.cfp
    MeSH terms: Agriculture*; Data Interpretation, Statistical*; Disaster Planning*; Manuscripts as Topic; Editorial Policies
  5. Apuke OD, Omar B
    Health Educ Res, 2020 10 01;35(5):490-503.
    PMID: 33090215 DOI: 10.1093/her/cyaa030
    We proposed a conceptual model combining three theories: uses and gratification theory, social networking sites (SNS) dependency theory and social impact theory to understand the factors that predict fake news sharing related to COVID-19. We also tested the moderating role of fake news knowledge in reducing the tendency to share fake news. Data were drawn from social media users (n = 650) in Nigeria, and partial least squares was used to analyse the data. Our results suggest that tie strength was the strongest predictor of fake news sharing related to COVID-19 pandemic. We also found perceived herd, SNS dependency, information-seeking and parasocial interaction to be significant predictors of fake news sharing. The effect of status-seeking on fake news sharing, however, was not significant. Our results also established that fake news knowledge significantly moderated the effect of perceived herd, SNS dependency, information-seeking, parasocial interaction on fake news sharing related to COVID-19. However, tie strength and status-seeking effects were not moderated.
    MeSH terms: Adolescent; Adult; Aged; Female; Humans; Deception; Male; Middle Aged; Nigeria; Online Systems; Pneumonia, Viral*; Coronavirus Infections*; Young Adult; Pandemics*; Social Media
  6. Apuke OD, Omar B
    Health Educ Res, 2020 10 01;35(5):471-480.
    PMID: 33090216 DOI: 10.1093/her/cyaa031
    This study examined media coverage of COVID-19 in Nigeria with attention to the frequency and depth of coverage, story format, news sources, media tone and themes. Four widely read newspapers were content analysed between February 2020 and April 2020. Focus was on Daily Sun, Vanguard, Daily Trust and Leadership. Results indicated that the Nigerian media performed well in terms of covering the pandemic, which in turn created awareness. However, the coverage was not in-depth as most of the reported stories were short and were predominantly straight news. It was also observed that the media cited more of the Nigeria Centre for Disease Control (NCDC) and government officials. Further findings disclosed that most of the stories were alarming and induced panic. Most common topics were coverage of cases in Nigeria, death rates and concerns about Nigeria's preparedness. Public sensitization and education were sparingly covered. Ethics healthcare workers could adhere to received minimal attention. The media should focus more on sensitizing and educating the public on the necessary steps to take in curbing the virus. They should refrain from over usage of alarming and panic tone in presenting the stories of COVID-19 pandemic in Nigeria.
    MeSH terms: Awareness; Humans; Mass Media; Newspapers as Topic; Nigeria; Pneumonia, Viral/prevention & control*; Coronavirus Infections/prevention & control*; Pandemics/prevention & control*
  7. Hand RM, Senarathna SMDKG, Page-Sharp M, Gray K, Sika-Paotonu D, Sheel M, et al.
    Pharmacol Res Perspect, 2020 12;8(6):e00668.
    PMID: 33090729 DOI: 10.1002/prp2.668
    Benzathine penicillin G (BPG) is used as first-line treatment for most forms of syphilis and as secondary prophylaxis against rheumatic heart disease (RHD). Perceptions that poor quality of BPG is linked to reported adverse effects and therapeutic failure may impact syphilis and RHD control programs. Clinical networks and web-based advertising were used to obtain vials of BPG from a wide range of countries. The quality of BPG was assessed using a high performance liquid chromatography assay capable of detecting relevant impurities and degradation products. Tests for water content, presence of heavy metals and physical characteristics of BPG, including particle size analysis and optical microscopy, also were conducted. Thirty-five batches of BPG were sourced from 16 countries across 4 WHO regions. All batches passed the US Pharmacopeia requirements for BPG injection (content), with no evidence of breakdown products or other detected contaminants. Water content and heavy metal analysis (n = 11) indicated adherence to regulatory standards and Good Manufacturing Practice. Particle size analysis (n = 20) found two batches with aggregated particles (>400 µm) that were dispersed following sonication. Current batches of BPG were of satisfactory pharmaceutical quality but aggregated particles were found in a modest proportion of samples. Future studies should focus on the physical characteristics of BPG which may contribute to variations in plasma penicillin concentrations an observed needle blockages in clinical practice. Pharmacopeial monographs could be revised to include standards on particle size and crystal morphology of BPG.
    MeSH terms: Anti-Bacterial Agents/standards*; Anti-Bacterial Agents/therapeutic use; Chemistry, Pharmaceutical/methods; Chemistry, Pharmaceutical/standards*; Cross-Sectional Studies; Humans; Penicillin G Benzathine/standards*; Penicillin G Benzathine/therapeutic use; Quality Control*; Rheumatic Heart Disease/drug therapy; Internationality*
  8. Chaudakshetrin P, Cardosa MS, Goh CR, Javier FO, Musba AMT, Prateepavanich P, et al.
    Pain, 2020 09;161 Suppl 1:S87-S94.
    PMID: 33090741 DOI: 10.1097/j.pain.0000000000001871
    MeSH terms: Asia, Southeastern; Pain Clinics*; Pain Management*
  9. Ahmad MF, Abu MA, Abdul Karim AK
    J Adolesc Young Adult Oncol, 2020 12;9(6):693-694.
    PMID: 33090942 DOI: 10.1089/jayao.2020.0105
    MeSH terms: Fertility/immunology*; Humans; Malaysia; Neoplasms/complications*; Neoplasms/pathology
  10. Oyeleye AO, Mohd Yusoff SF, Abd Rahim IN, Leow ATC, Saidi NB, Normi YM
    PLoS One, 2020;15(10):e0241074.
    PMID: 33091044 DOI: 10.1371/journal.pone.0241074
    Conventional refolding methods are associated with low yields due to misfolding and high aggregation rates or very dilute proteins. In this study, we describe the optimization of the conventional methods of reverse dilution and affinity chromatography for obtaining high yields of a cysteine rich recombinant glycoside hydrolase family 19 chitinase from Streptomyces griseus HUT6037 (SgChiC). SgChiC is a potential biocontrol agent and a reference enzyme in the study and development of chitinases for various applications. The overexpression of SgChiC was previously achieved by periplasmic localization from where it was extracted by osmotic shock and then purified by hydroxyapatite column chromatography. In the present study, the successful refolding and recovery of recombinant SgChiC (r-SgChiC) from inclusion bodies (IB) by reverse dilution and column chromatography methods is respectively described. Approximately 8 mg of r-SgChiC was obtained from each method with specific activities of 28 and 52 U/mg respectively. These yields are comparable to that obtained from a 1 L culture volume of the same protein isolated from the periplasmic space of E. coli BL21 (DE3) as described in previous studies. The higher yields obtained are attributed to the successful suppression of aggregation by a stepwise reduction of denaturant from high, to intermediate, and finally to low concentrations. These methods are straight forward, requiring the use of fewer refolding agents compared with previously described refolding methods. They can be applied to the refolding of other cysteine rich proteins expressed as inclusion bodies to obtain high yields of actively folded proteins. This is the first report on the recovery of actively folded SgChiC from inclusion bodies.
    MeSH terms: Bacterial Proteins/chemistry; Chromatography, Affinity; Cysteine/chemistry; Glycoside Hydrolases/chemistry*; Recombinant Proteins/chemistry; Streptomyces griseus/enzymology*; Streptomyces griseus/chemistry; Protein Refolding*
  11. Nasir, Len, Amalia, Madihie, Salmah, Mohamad Yusoff
    MyJurnal
    The purpose of this paper is to evaluate the validity and reliability of Cognitive Therapy Group Intervention (CTGI) which focuses on the elements of resilience among adolescents with behavioural problems. It is developed based on Cognitive Theory (comment: it’d be more sufficient if you can mention whose theory) and Sidek Module Development Model and consists of eight interventions. Cognitive Therapy Intervention (CTI) manuscripts and a five-item questionnaires were distributed to five content experts to determine the intervention’s validity. The findings reported the validity index of 0.87. The target group were thirty-two adolescents chosen to measure the reliability of each intervention by evaluating the objectives in each intervention session. As a result, a reliability index of 0.85 was obtained. From these two indexes, it is proven that the Cognitive Therapy Group Intervention (CTGI) possesses high validity and good reliability and is ready to be put to use. This implies that, counselling interventions in schools are required in working with adolescents with at risk behaviours.
    MeSH terms: Problem Behavior; Adolescent; Cognition; Counseling; Humans; Psychotherapy, Group; Surveys and Questionnaires; Risk-Taking; Schools; Reproducibility of Results
  12. Higuchi T, Ishigooka J, Iyo M, Hagi K
    Asia Pac Psychiatry, 2020 Mar;12(1):e12377.
    PMID: 31837113 DOI: 10.1111/appy.12377
    INTRODUCTION: This study was designed to evaluate the long-term safety and effectiveness of lurasidone in the treatment of schizophrenia among Asian patients.

    METHODS: Patients (N = 281) with schizophrenia who had completed a randomized, double-blind (DB), 6-week comparison of lurasidone (40 and 80 mg/day) and placebo were enrolled in a 26-week extension study in which all patients received open-label (OL), flexible doses of lurasidone (40 or 80 mg/day). Effectiveness was measured using the Positive and Negative Syndrome Scale (PANSS) scale.

    RESULTS: Fifty-seven percent of patients completed the OL extension study; 16.7% discontinued early due to lack of effectiveness; and 10.3% due to adverse events. The most common adverse events were insomnia (11.3%), akathisia (11.0%), and nasopharyngitis (10.6%). Adverse events related to weight gain, metabolic parameters, prolactin, and ECG measures were uncommon. Mean change in the PANSS total score from the DB baseline to OL endpoint was -28.4, with mean improvement of -7.5 observed from baseline to OL endpoint, and with a PANSS responder rate of 73.7%.

    DISCUSSION: The results of the current 26-week extension study found lurasidone to be a generally safe, well-tolerated, and effective long-term treatment for schizophrenia in Asian patients.

    MeSH terms: Lurasidone Hydrochloride/administration & dosage; Lurasidone Hydrochloride/adverse effects; Lurasidone Hydrochloride/pharmacology*; Adult; Female; Humans; Japan; Malaysia; Male; Middle Aged; Schizophrenia/drug therapy*; Taiwan; Antipsychotic Agents/administration & dosage; Antipsychotic Agents/adverse effects; Antipsychotic Agents/pharmacology*; Outcome Assessment (Health Care); Republic of Korea
  13. Mohd Fauzi MF, Mohd Yusoff H, Muhamad Robat R, Mat Saruan NA, Ismail KI, Mohd Haris AF
    PMID: 33050004 DOI: 10.3390/ijerph17197340
    The COVID-19 pandemic potentially increases doctors' work demands and limits their recovery opportunity; this consequently puts them at a high risk of adverse mental health impacts. This study aims to estimate the level of doctors' fatigue, recovery, depression, anxiety, and stress, and exploring their association with work demands and recovery experiences. This was a cross-sectional study among all medical doctors working at all government health facilities in Selangor, Malaysia. Data were collected in May 2020 immediately following the COVID-19 contagion peak in Malaysia by using self-reported questionnaires through an online medium. The total participants were 1050 doctors. The majority of participants were non-resident non-specialist medical officers (55.7%) and work in the hospital setting (76.3%). The highest magnitude of work demands was mental demand (M = 7.54, SD = 1.998) while the lowest magnitude of recovery experiences was detachment (M = 9.22, SD = 5.043). Participants reported a higher acute fatigue level (M = 63.33, SD = 19.025) than chronic fatigue (M = 49.37, SD = 24.473) and intershift recovery (M = 49.97, SD = 19.480). The majority of them had no depression (69.0%), no anxiety (70.3%), and no stress (76.5%). Higher work demands and lower recovery experiences were generally associated with adverse mental health. For instance, emotional demands were positively associated with acute fatigue (adj. b = 2.73), chronic fatigue (adj. b = 3.64), depression (adj. b = 0.57), anxiety (adj. b = 0.47), and stress (adj. b = 0.64), while relaxation experiences were negatively associated with acute fatigue (adj. b = -0.53), chronic fatigue (adj. b = -0.53), depression (adj. b = -0.14), anxiety (adj. b = -0.11), and stress (adj. b = -0.15). However, higher detachment experience was associated with multiple mental health parameters in the opposite of the expected direction such as higher level of chronic fatigue (adj. b = 0.74), depression (adj. b = 0.15), anxiety (adj. b = 0.11), and stress (adj. b = 0.11), and lower level of intershift recovery (adj. b = -0.21). In conclusion, work demands generally worsen, while recovery experiences protect mental health during the COVID-19 pandemic with the caveat of the role of detachment experiences.
    MeSH terms: Adaptation, Psychological; Mental Disorders/epidemiology*; Cross-Sectional Studies; Humans; Malaysia/epidemiology; Physicians/psychology*; Pneumonia, Viral/epidemiology; Pneumonia, Viral/therapy*; Workload/psychology; Coronavirus Infections/epidemiology; Coronavirus Infections/therapy*; Pandemics*
  14. Calcetas OA, Adorada JR, Navasero MV
    Zootaxa, 2020 Oct 08;4859(4):zootaxa.4859.4.4.
    PMID: 33056182 DOI: 10.11646/zootaxa.4859.4.4
    Motschulsky (1859), a Russian Imperial Army Colonel and entomologist, established the genus Exopholis, described E. birmannica and transferred Melolontha hypoleuca Wiedemann, 1819 to it. Brenske (1896) described Exopholis philippinica from the "Philippinen" from a single female specimen. Dalla Torre (1912), listed eight species under the genus Exopholis Motschulsky, 1859 from South East Asia: E. hypoleuca (Weidemann, 1819) (Myanmar, Malaysia, Borneo, Java, Sumatra, Nias, Ambon), E. costata (Burmeister, 1855) (Java, Nias), E. birmanica Motschulsky, 1859 (Myanmar), E. lacordairei Waterhouse, 1867 (Borneo), E. pinguis Lansberge, 1879 (Sumatra), E. brenskei Nonfried, 1891, E. borneensis Brenske, 1894 (both from Borneo) and E. philippinica Brenske, 1896 (Philippines). This paper aims to review the taxonomy of Exopholis from the Philippines. Specifically, to focus on the diagnosis of Exopholis philippinica and its geographic distribution.
    MeSH terms: Animals; Beetles*; Female; Philippines
  15. Lindquist EE, Oconnor BM, Shaw MD, Sidorchuk EA
    Zootaxa, 2020 Sep 28;4857(1):zootaxa.4857.1.4.
    PMID: 33056345 DOI: 10.11646/zootaxa.4857.1.4
    The gamasine genus Berlesia Canestrini, 1884, is revived and further diagnosed, based on descriptions of adult females, males and nymphs of three new species (B. hospitabilis sp. nov., B. multisetosa sp. nov., B. vorontsovi sp. nov.) ectoparasitic on raspy crickets of three genera of Gryllacrididae (Ensifera) from Australia and the Philippines. A tight sister relationship of Berlesia with the monobasic genus Katydiseius Fain Lukoschus, 1983, known only from a pseudophylline katydid in Malaysia, is proposed. The subfamily Katydiseiinae Fain Lukoschus, 1983 (previously included in the family Otopheidomenidae in the superfamily Phytoseioidea) is redefined to include only those two genera, and moved to the dermanyssoid family Laelapidae, while its previously other monobasic genus, Eickwortius Zhang, 1995, is retained tentatively in the family Otopheidomenidae. Among other taxa relevant to Katydiseiinae reviewed here, Berlesia cultrigera Berlese, 1910a is transferred to the genus Orthopteroseius Mo, 1996, at present Otopheidomenidae, as Orthopteroseius cultrigerum (Berlese) comb. nov., and Berlesia nuda Berlese, 1910b is transferred to the genus Prasadiseius Wainstein, 1972, at present Otopheidomenidae, as Prasadiseius nudum (Berlese) comb. nov. A key to the two genera and five species recognized as belonging in Katydiseiinae is presented. Notable morphological traits of Berlesia, including only deutonymphs equipped with well-developed claws and males with dimorphically more elongated salivary stylets, are discussed. The one known life cycle of a species of Berlesia, B. hospitabilis sp. nov., includes protonymphipary, followed by a fully functioning deutonymph, and male copulation with pharate females-traits, rarely or not known among gamasine mite associates of invertebrates. The possible significance of elongate spermatodactyls and male reduced feeding are explored.
    MeSH terms: Animals; Female; Gryllidae*; Male; Mites*
  16. Som HE, Grismer LL, Wood PLJ, Quah ESH, Brown RM, Diesmos AC, et al.
    Zootaxa, 2020 Apr 21;4766(3):zootaxa.4766.3.6.
    PMID: 33056593 DOI: 10.11646/zootaxa.4766.3.6
    Liopeltis is a genus of poorly known, infrequently sampled species of colubrid snakes in tropical Asia. We collected a specimen of Liopeltis from Pulau Tioman, Peninsular Malaysia, that superficially resembled L. philippina, a rare species that is endemic to the Palawan Pleistocene Aggregate Island Complex, western Philippines. We analyzed morphological and mitochondrial DNA sequence data from the Pulau Tioman specimen and found distinct differences to L. philippina and all other congeners. On the basis of these corroborated lines of evidence, the Pulau Tioman specimen is described as a new species, L. tiomanica sp. nov. The new species occurs in sympatry with L. tricolor on Pulau Tioman, and our description of L. tiomanica sp. nov. brings the number of endemic amphibians and reptiles on Pulau Tioman to 12.
    MeSH terms: Animals; Malaysia; Colubridae*
  17. Solangi M, Kanwal, Mohammed Khan K, Saleem F, Hameed S, Iqbal J, et al.
    Bioorg Med Chem, 2020 Nov 01;28(21):115605.
    PMID: 33065441 DOI: 10.1016/j.bmc.2020.115605
    One of the most prevailing metabolic disorder diabetes mellitus has become the global health issue that has to be addressed and cured. Different marketed drugs have been made available for the treatment of diabetes but there is still a need of introducing new therapeutic agents that are economical and have lesser or no side effects. The current study deals with the synthesis of indole acrylonitriles (3-23) and the evaluation of these compounds for their potential for α-glucosidase inhibition. The structures of these synthetic molecules were deduced by using different spectroscopic techniques. Acarbose (IC50 = 2.91 ± 0.02 μM) was used as standard in this study and the synthetic molecules (3-23) have shown promising α-glucosidase inhibitory activity. Compounds 4, 8, 10, 11, 14, 18, and 21 displayed superior inhibition of α-glucosidase enzyme in the range of (IC50 = 0.53 ± 0.01-1.36 ± 0.04 μM) as compared to the standard acarbose. Compound 10 (IC50 = 0.53 ± 0.01 μM) was the most effective inhibitor of this library and displayed many folds enhanced activity in contrast to the standard. Molecular docking of synthetic compounds was performed to verify the binding interactions of ligand with the active site of enzyme. This study had identified a number of potential α-glucosidase inhibitors that can be used for further research to identify a potent therapeutic agent against diabetes.
    MeSH terms: Acrylonitrile; alpha-Glucosidases; Diabetes Mellitus; Indoles; Libraries; Global Health; Inhibitory Concentration 50; Catalytic Domain; Acarbose; Molecular Docking Simulation; Glycoside Hydrolase Inhibitors
  18. Khan R, H Ya H, Pao W, Majid MAA, Ahmed T, Ahmad A, et al.
    Materials (Basel), 2020 Oct 16;13(20).
    PMID: 33081078 DOI: 10.3390/ma13204601
    Erosion-corrosion of elbow configurations has recently been a momentous concern in hydrocarbon processing and transportation industries. The carbon steel 90° elbows are susceptible to the erosion-corrosion during the multiphase flow, peculiarly for erosive slug flows. This paper studies the erosion-corrosion performance of 90° elbows at slug flow conditions for impact with 2, 5, and 10 wt.% sand fines concentrations on AISI 1018 carbon steel exploiting quantitative and qualitative analyses. The worn surface analyses were effectuated by using laser confocal and scanning electron microscopy. The experiment was conducted under air and water slug flow containing sand fines of 50 µm average size circulated in the closed flow loop. The results manifest that with the increase of concentration level, the erosion-corrosion magnitude increases remarkably. Sand fines instigate the development of perforation sites in the form of circular, elongated, and coalescence pits at the elbow downstream and the corrosion attack is much more obvious with the increase of sand fines concentration. Another congruent finding is that cutting and pitting corrosion as the primitive causes of material degradation, the 10 wt.% sand fines concentration in carrier phase increases the erosion-corrosion rate of carbon steel up to 93% relative to the 2 wt.% sand fines concentration in slug flow.
    MeSH terms: Abnormalities, Multiple; Carbon; Cleft Lip; Cleft Palate; Corrosion; Cysts; Elbow; Hydrocarbons; Lip; Microscopy, Electron, Scanning; Steel
  19. Ibrahim Lakin I, Abbas Z, Azis RS, Abubakar Alhaji I
    Materials (Basel), 2020 Oct 16;13(20).
    PMID: 33081082 DOI: 10.3390/ma13204602
    This study was aimed at fabricating composites of polylactic acid (PLA) matrix-reinforced oil palm empty fruit bunch (OPEFB) fiber filled with chemically reduced graphene oxide (rGO). A total of 2-8 wt.% rGO/OPEFB/PLA composites were characterized for their complex permittivity using an open-ended coaxial probe (OEC) technique. The shielding efficiency properties were calculated using the measured transmission (S21) and the reflection (S11) coefficient results. All the measurements and calculations were performed in the 8-12 GHz frequency range. The morphological and microstructural study included X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and Fourier transform infrared spectroscopy (FTIR). The results indicated that the incorporation of rGO as filler into the composites enhanced their complex permittivity properties. The composites showed a total shielding efficiency (SET) of about 31.2 dB at a frequency range of 8-12 GHz, which suggests their usefulness for microwave absorption.
    MeSH terms: Dietary Fiber; Fruit; Graphite; Microscopy, Electron, Scanning; Microwaves; Polyesters; X-Ray Diffraction; Spectroscopy, Fourier Transform Infrared; Physical Phenomena
  20. Ansarudin F, Abd Rahman T, Yamada Y, Rahman NHA, Kamardin K
    Sensors (Basel), 2020 Oct 16;20(20).
    PMID: 33081110 DOI: 10.3390/s20205849
    In the 5G mobile system, new features such as millimetre wave operation, small cell size and multi beam are requested at base stations. At millimetre wave, the base station antennas become very small in size, which is about 30 cm; thus, dielectric lens antennas that have excellent multi beam radiation pattern performance are suitable candidates. For base station application, the lens antennas with small thickness and small curvature are requested for light weight and ease of installation. In this paper, a new lens shaping method for thin and small lens curvature is proposed. In order to develop the thin lens antenna, comparisons of antenna structures with conventional aperture distribution lens and Abbe's sine lens are made. Moreover, multi beam radiation pattern of three types of lenses are compared. As a result, the thin and small curvature of the proposed lens and an excellent multi beam radiation pattern are ensured.
    MeSH terms: Eye Abnormalities; Lens, Crystalline; Lenses; Radiation; Cell Size
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