Browse publications by year: 2020

  1. Fisekovic Kremic MB
    Malays Fam Physician, 2020;15(3):54-61.
    PMID: 33329863
    Introduction: People with diabetes mellitus (DM) may have concurrent mental health disorders and have been shown to have poorer disease outcomes.

    Objective: The aim of this study to determine the prevalence of DASS in patients with diabetes mellitus without mental disorders, aged 20 years or more, in primary health care, and to determine any association between DASS and patients' sociodemographic and clinical attributes.

    Methods: This was a cross-sectional study conducted in a primary health care center, in the department of general practice. Patients with DM who visited the doctor and agreed to fill in the questionnaire were included in the study. Data were collected using the questionnaire DASS-21. Descriptive statistics, the Pearson chi-square test, and logistic regression analysis were used to analyze the data.

    Results: Out of a total of 102 respondents with DM, 29 (28.4%) had some form of psychological symptoms. The prevalence of DASS was 16.7%, 16.6%, and 23.5%, respectively. There was no significant difference between sociodemographic variables according to stress status. Respondents aged 40-49 years more often showed emotional states of depression and anxiety. There was a significant association between emotional status of DASS and HbA1c values. Logistic regression analysis indicated that age (OR=2.57, 95% CI: 1.59-4.13) was a predictor of depression and anxiety.

    Conclusion: Unpleasant emotional states DASS are common in patients with DM, depression (16.7%), anxiety (16.6%), and stress (23.5%). Age is the strongest predictor of DASS status. The screening and monitoring of unpleasant emotional states in people with diabetes should be performed from a young age.

    MeSH terms: Adult; Anxiety; Anxiety Disorders; Cross-Sectional Studies; Depression; Diabetes Mellitus; Humans; Mental Health; Middle Aged; Primary Health Care; Surveys and Questionnaires; Prevalence; Chi-Square Distribution; Logistic Models; Young Adult; General Practice
  2. Sahiran MF, Lee PY, Mawardi M, Mohd Azizi F
    Malays Fam Physician, 2020;15(3):62-73.
    PMID: 33329864
    Introduction: It is common, and many international and local studies confirm this, that women of reproductive age misperceive their body-weight status. This phenomenon can lead to their being less likely to adopt a healthy lifestyle which later exposes them to increased health problems and risks including those of a gynecological and obstetric nature. Generally, there have been inconsistent findings concerning the association between the self-perceived weight status and sociodemographic factors, physical activities, and previous weight loss attempts of women of reproductive age in an Asian population like Malaysia.

    Objective: This study aimed to determine the factors associated with body weight status misperception among reproductive-aged women at a primary care setting in Malaysia.

    Methods: This is a cross-sectional study conducted at Klinik Kesihatan Durian Tunggal in 2016-2017. The questionnaire included questions on the perception of weight status, sociodemographic factors, smoking status, level of physical activity, and weight loss attempts. Logistic regressions were used for statistical analysis to examine the association between body weight status misperception and related factors.

    Results: The study recruited 630 reproductive-aged women. The mean age and SD of the respondents was 32.7 + 8.9 years, and 84% of the respondents were Malays. More than three-quarters of the respondents (75.5%, n = 476) had received up to a secondary level of education. The majority of the respondents were in the overweight/obese group (59.4%, n = 374). The mean BMI of the respondents was 27.1 kg/m2 + 6.61. Approximately 65.4% (n = 412) of the respondents had an inactive lifestyle. However, 60% (n = 378) of the respondents reported that they had attempted to reduce their weight in the last year. A total of 141 respondents (22.4%) misperceived their weight status with 113 (80.1% ) of them underestimating their weight status. Women with primary-level education (OR: 3.545, 95% CI: 1.530-8.215, p = 0.003) and secondary-level education (OR: 1.933, 95% CI: 1.065-3.510, p = 0.030) had a greater likelihood of misperceiving their body weight status as compared to those who have a tertiary level of education. Women with no weight loss attempts were also at risk of body weight status misperception (OR: 1.850, 95% CI: 1.195, 2.865, p = 0.006).

    Conclusion: Bodyweight status misperception among reproductive-aged women was associated with a low level of education and with those who had made no weight loss attempts. Identifying women who are at risk of misperceiving their weight status would enable early counseling on weight management.

    MeSH terms: Adult; Body Weight; Counseling; Cross-Sectional Studies; Female; Humans; Malaysia; Obesity; Surveys and Questionnaires; Smoking; Weight Loss; Exercise; Body Mass Index; Logistic Models; Bombacaceae; Overweight; Young Adult; Healthy Lifestyle
  3. Muhd H, Zuhaimy H, Ismail MF, Arshad F, Azmi S, Sahak NH
    Malays Fam Physician, 2020;15(3):74-78.
    PMID: 33329865
  4. Boo WH, Chan YC
    Malays Fam Physician, 2020;15(3):79-82.
    PMID: 33329866
    The discovery of a solitary pulmonary nodule (SPN) on chest imaging can be alarming for both the clinician and the patient. In the absence of a uniform guideline, managing SPN is nothing short of challenging for primary care physicians (PCPs). We present a case here of a patient presenting with prolonged cough who also displayed unilateral SPN on her chest radiograph. Through further examination, this presence was later shown to be a nipple shadow simulating SPN, and the patient was spared unnecessary testing and psychological distress.
    MeSH terms: Solitary Pulmonary Nodule; Cough; Female; Humans; Nipples; Pneumonia, Pneumocystis; Thorax; Physicians, Primary Care
  5. Muthanna AM, Al-Qubati YA
    Malays Fam Physician, 2020;15(3):83-85.
    PMID: 33329867
    A keloid represents an excessive overgrowth of skin beyond the boundaries of an injury. Earlobe keloids usually follow ear piercing and can become large, sometimes producing remarkable disfigurement. Surgical excision, pressure dressing, intralesional corticosteroid injection, cryosurgery, radiation, and lasers have all been used to treat earlobe keloids. However, none has produced uniformly satisfactory results. Combinations of more than one modality have also been employed to yield successful outcomes. We describe cryotherapy as a single modality to treat seven-year-old, multiple earlobe keloids. Three cryotherapy sessions with two freezing-thawing cycles of 30-40 seconds' freezing time and two minutes' thawing time, undertaken one month apart, resulted in complete flatness of the keloids and no recurrence after 5 years. We also evaluate keloid-related and operational factors that determine the success of cryotherapy as a monotherapy for earlobe keloids.
    MeSH terms: Adrenal Cortex Hormones; Bandages; Cryosurgery; Freezing; Keloid; Recurrence; Skin; Injections, Intralesional; Cryotherapy; Body Piercing
  6. Low QJ, Lau WK, Lim TH, Lee RA, Cheo SW
    Malays Fam Physician, 2020;15(3):86-89.
    PMID: 33329868
    Primary care providers should be alert to travel-related infections. Around 10-40% of returning travelers from all destinations and 15-70% of travelers from tropical settings experience ill health, either overseas or upon returning home.1 A systematic approach concentrating on possible infections should be undertaken based on the patient's travel location, immunization history, presence of malaria chemoprophylaxis at the destination, other potential exposures, incubation period, and clinical presentation.2-3 The World Health Organization (WHO) website is constantly being updated on specific travel-related infections and recent geographical outbreaks. In this paper, we report a case of severe falciparum malaria in a returned traveler.
    MeSH terms: Disease Outbreaks; Humans; Immunization; Malaria; Primary Health Care; Travel; World Health Organization; Malaria, Falciparum; Chemoprevention
  7. Siti BC, Zulkifli MM, Mohd Yusoff SS, Muhamad R, Ahmad TM
    Malays Fam Physician, 2020;15(3):90-94.
    PMID: 33329869
    Schizencephaly is a very rare congenital birth defect. It is characterized by a cortical brain malformation that manifests as a grey-matter-lined cleft extending from the ependyma to the pia mater. It is a rare condition, and few cases have been reported in the literature. The exact cause is unknown. Herein, we report a case of an infant presenting with left side hemiparesis. The CT scan of her brain revealed right fronto-temporal and left parieto-temporal open-lip schizencephaly; thus, urgent referral to a pediatric neurologist was made for early intervention.
    MeSH terms: Brain; Child; Ependyma; Female; Humans; Infant; Nervous System Malformations; Paresis; Pia Mater; Referral and Consultation; Tomography, X-Ray Computed; Schizencephaly; Gray Matter; Neurologists
  8. Kounis NG, Koniari I, Tsigkas G, Soufras GD, Plotas P, Davlouros P, et al.
    Malays Fam Physician, 2020;15(3):97-98.
    PMID: 33329871
  9. Rajendran SD, Wahab SN, Yeap SP
    Saf Health Work, 2020 Dec;11(4):537-542.
    PMID: 33329921 DOI: 10.1016/j.shaw.2020.06.007
    Background: Personal protective equipment (PPE) has been designed in such a way to reduce accident rates. Unfortunately, existing PPE is rather ineffective as it is not able to provide warning signals when hazard is around. The integration of intelligent systems is envisaged to increase the efficiency of existing PPE.

    Methods: This project designed a safety vest incorporated with metal detectors which can provide immediate warning to the field workers when there is metal hazard around. This product has greater freedom of design via smart manufacturing as it involves the assembly of few commercially available parts into a single entity. Briefly, the metal detector is a do it yourself (DIY) kit, and the safety vest is purchasable from any local market. The DIY kit was connected to a copper coil and being sewed into the safety vest.

    Results: The metal detector induces beeping sound when there is metal hazard around. A total of 121 engineering students were introduced to the prototype before being requested to answer a survey associated with the design. Respondents have rated >3.00/5.00 for the design simplicity, ease of usage, and light weight. Meanwhile, respondents suggested that the design should be further improved by increasing the metal detection range.

    Conclusion: It is envisaged that the introduction of this smart safety vest will allow the workers to carry out their duties securely by reducing the accident rates. Particularly, such design is expected to reduce workplace accident especially during night time at construction sites where the visibility is low.

    MeSH terms: Accidents, Occupational; Personal Protective Equipment; Copper; Freedom; Humans; Metals; Surveys and Questionnaires; Students; Workplace
  10. Rasool MF, Rehman AU, Imran I, Abbas S, Shah S, Abbas G, et al.
    Front Public Health, 2020;8:531038.
    PMID: 33330300 DOI: 10.3389/fpubh.2020.531038
    Introduction: Medication error is unintentional and can be reduced by reducing the risk factors. Patients suffering from chronic diseases are at an increased risk of medication errors. Objective: This work aims to assess the risk factors associated with medication errors among patients suffering from chronic disorders in hospitals of South Punjab, Pakistan. Methodology: Multiple logistic regression analysis was used to assess the impact of different risk factors on the prevalence of medication errors in patients suffering from chronic diseases. Results: A greater risk for the occurrence of medication errors was associated with age ≥60 years (odds ratio, OR = 1.9; 95% CI = 1.3-3.1; p = 0.001), overburdened healthcare system (OR = 2.2; 95% CI = 1.64-3.56; p < 0.000), number of prescribed drugs ≥5 (OR = 1.74; 95% CI = 1.02-2.64; p < 0.000), comorbidities (OR = 2.6; 95% CI = 1.72-3.6; p = 0.003), Charlson comorbidity index (OR = 1.31; 95% CI = 0.49-1.84; p = 0.004), and multiple prescribers to one patient (OR = 1.12; 95% CI = 0.64-1.76; p = 0.001). Conclusion: Older age, overburdened healthcare system, number of prescribed drugs, comorbidities, Charlson comorbidity index, and multiple prescribers to one patient are significant risk factors for the occurrence of medication errors.
    MeSH terms: Aged; Chronic Disease; Humans; Medication Errors*; Middle Aged; Pakistan/epidemiology; Risk Factors; Comorbidity
  11. Rahman NA, Katayama T, Wahid MEA, Kasan NA, Khatoon H, Yamada Y, et al.
    Front Bioeng Biotechnol, 2020;8:581628.
    PMID: 33330417 DOI: 10.3389/fbioe.2020.581628
    Antioxidants found in microalgae play an essential role in both animals and humans, against various diseases and aging processes by protecting cells from oxidative damage. In this study, 26 indigenous tropical marine microalgae were screened. Out of the 26 screened strains, 10 were selected and were further investigated for their natural antioxidant compounds which include carotenoids, phenolics, and fatty acids collected in their exponential and stationary phases. The antioxidant capacity was also evaluated by a total of four assays, which include ABTS, DPPH, superoxide radical (O2•-) scavenging capacity, and nitric oxide (•NO-) scavenging capacity. This study revealed that the antioxidant capacity of the microalgae varied between divisions, strains, and growth phase and was also related to the content of antioxidant compounds present in the cells. Carotenoids and phenolics were found to be the major contributors to the antioxidant capacity, followed by polyunsaturated fatty acids linoleic acid (LA), eicosapentaenoic acid (EPA), arachidonic acid (ARA), and docosahexaenoic acid (DHA) compared to other fatty acids. The antioxidant capacity of the selected bacillariophytes and haptophytes was found to be positively correlated to phenolic (R2-value = 0.623, 0.714, and 0.786 with ABTS, DPPH, and •NO-) under exponential phase, and to carotenoid fucoxanthin and β-carotene (R2 value = 0.530, 0.581 with ABTS, and 0.710, 0.795 with O2•-) under stationary phase. Meanwhile, antioxidant capacity of chlorophyte strains was positively correlated with lutein, β-carotene and zeaxanthin under the exponential phase (R2 value = 0.615, 0.615, 0.507 with ABTS, and R2 value = 0.794, 0.659, and 0.509 with •NO-). In the stationary phase, chlorophyte strains were positively correlated with violaxanthin (0.755 with •NO-), neoxanthin (0.623 with DPPH, 0.610 with •NO-), and lutein (0.582 with •NO-). This study showed that antioxidant capacity and related antioxidant compound production of tropical microalgae strains are growth phase-dependent. The results can be used to improve the microalgal antioxidant compound production for application in pharmaceutical, nutraceutical, food, and feed industry.
    MeSH terms: Antioxidants; Carotenoids; Docosahexaenoic Acids; Humans; Nitric Oxide; Superoxides; Lutein; Eicosapentaenoic Acid; beta Carotene; Microalgae; Haptophyta; Zeaxanthins
  12. Singh VA, Puri A
    J Orthop Surg (Hong Kong), 2020 12 18;28(3):2309499020979750.
    PMID: 33331233 DOI: 10.1177/2309499020979750
    Giant cell tumour of the bone (GCTB) has been classically treated surgically. With the advent of denosumab, there is potential to use it as a targeted therapy to downstage the tumour and control its progression. Like all new therapies, the dosage, duration, and long-term effects of treatment can only be determined over the time through numerous trials and errors. The current recommendation of use of the monoclonal antibody is 3-4 months of neoadjuvant denosumab in patients with advanced GCTB for cases who were not candidates for primary curettage initially, and prolonged use for surgically unsalvageable GCTB. The use of Denosumab in the adjuvant setting to prevent recurrence is not established.
    MeSH terms: Denosumab/pharmacology*; Bone Neoplasms/therapy*; Humans; Giant Cell Tumor of Bone/therapy*; Neoadjuvant Therapy; Bone Density Conservation Agents/pharmacology
  13. Lin Y, Hu Z, Zhao Q, Alias H, Danaee M, Wong LP
    PLoS Negl Trop Dis, 2020 12;14(12):e0008961.
    PMID: 33332359 DOI: 10.1371/journal.pntd.0008961
    BACKGROUND: This study attempts to understand coronavirus disease 2019 (COVID-19) vaccine demand and hesitancy by assessing the public's vaccination intention and willingness-to-pay (WTP). Confidence in COVID-19 vaccines produced in China and preference for domestically-made or foreign-made vaccines was also investigated.

    METHODS: A nationwide cross-sectional, self-administered online survey was conducted on 1-19 May 2020. The health belief model (HBM) was used as a theoretical framework for understanding COVID-19 vaccination intent and WTP.

    RESULTS: A total of 3,541 complete responses were received. The majority reported a probably yes intent (54.6%), followed by a definite yes intent (28.7%). The perception that vaccination decreases the chances of getting COVID-19 under the perceived benefit construct (OR = 3.14, 95% CI 2.05-4.83) and not being concerned about the efficacy of new COVID-19 vaccines under the perceived barriers construct (OR = 1.65, 95% CI 1.31-2.09) were found to have the highest significant odds of a definite intention to take the COVID-19 vaccine. The median (interquartile range [IQR]) of WTP for COVID-19 vaccine was CNY¥200/US$28 (IQR CNY¥100-500/USD$14-72). The highest marginal WTP for the vaccine was influenced by socio-economic factors. The majority were confident (48.7%) and completely confident (46.1%) in domestically-made COVID-19 vaccine. 64.2% reported a preference for a domestically-made over foreign-made COVID-19 vaccine.

    CONCLUSIONS: The findings demonstrate the utility of HBM constructs in understanding COVID-19 vaccination intent and WTP. It is important to improve health promotion and reduce the barriers to COVID-19 vaccination.

    MeSH terms: Adolescent; Adult; Aged; China/epidemiology; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Patient Acceptance of Health Care/psychology; Patient Acceptance of Health Care/statistics & numerical data*; Surveys and Questionnaires; Vaccination/economics; Vaccination/psychology*; Intention; Young Adult
  14. Hasan NI, Mohd Taib A, Muhammad NS, Mat Yazid MR, Mutalib AA, Abang Hasbollah DZ
    PLoS One, 2020;15(12):e0243293.
    PMID: 33332375 DOI: 10.1371/journal.pone.0243293
    The main cause of problematic soil failure under a certain load is due to low bearing capacity and excessive settlement. With a growing interest in employing shallow foundation to support heavy structures, it is important to study the soil improvement techniques. The technique of using geosynthetic reinforcement is commonly applied over the last few decades. This paper aims to determine the effect of using geogrid Tensar BX1500 on the bearing capacity and settlement of strip footing for different types of soils, namely Al-Hamedat, Ba'shiqah, and Al-Rashidia in Mosul, Iraq. The analysis of reinforced and unreinforced soil foundations was conducted numerically and analytically. A series of conditions were tested by varying the number (N) and the width (b) of the geogrid layers. The results showed that the geogrid could improve the footing's bearing capacity and reduce settlement. The soil of the Al-Rashidia site was sandy and indicated better improvement than the other two sites' soils (clayey soils). The optimum geogrid width (b) was five times the footing width (B), while no optimum geogrid number (N) was obtained. Finally, the numerical results of the ultimate bearing capacity were compared with the analytical results, and the comparison showed good agreement between both the analyses and the optimum range published in the literature. The significant findings reveal that the geogrid reinforcement may induce improvement to the soil foundation, however, not directly subject to the width and number of the geogrid alone. The varying soil properties and footing size also contribute to both BCR and SRR values supported by the improvement factor calculations. Hence, the output complemented the benefit of applying reinforced soil foundations effectively.
    MeSH terms: Biological Phenomena; Data Collection; Iraq; Publications; Soil; Reconstructive Surgical Procedures
  15. Kemung HM, Tan LT, Chan KG, Ser HL, Law JW, Lee LH, et al.
    Biomed Res Int, 2020;2020:6402607.
    PMID: 32258133 DOI: 10.1155/2020/6402607
    The mangrove ecosystem of Malaysia remains yet to be fully explored for potential microbes that produce biologically active metabolites. In the present study, a mangrove-derived Streptomyces sp. strain MUSC 14 previously isolated from the state of Pahang, Malaysia Peninsula, was studied for its potential in producing antioxidant metabolites. The identity of Streptomyces sp. strain MUSC14 was consistent with the genotypic and phenotypic characteristics of the Streptomyces genus. The antioxidant potential of Streptomyces sp. strain MUSC 14 was determined through screening of its methanolic extract against sets of antioxidant assays. The results were indicative of Streptomyces sp. strain MUSC 14 displaying strong antioxidant activity against ABTS, DPPH free radicals and metal chelating activity of 62.71 ± 3.30%, 24.71 ± 2.22%, and 55.82 ± 2.35%, respectively. The result of ferric reducing activity measured in terms of dose was equivalent to 2.35-2.45 μg of positive control ascorbic acid. Furthermore, there was a high correlation between the total phenolic content and the antioxidant activities with r = 0.979, r = 0.858, and r = 0.983 representing ABTS, DPPH, and metal chelation, respectively. Overall, the present study suggests that Streptomyces sp. strain MUSC 14 from mangrove forest soil has potential to produce antioxidant metabolites that can be further exploited for therapeutic application.
    MeSH terms: Antioxidants/analysis*; Malaysia; Soil Microbiology*; Wetlands*
  16. Ahmed P, Bukhari IA, Albaijan R, Sheikh SA, Vohra F
    Photodiagnosis Photodyn Ther, 2020 Dec;32:102077.
    PMID: 33157330 DOI: 10.1016/j.pdpdt.2020.102077
    AIM: The current clinical trial aimed to assess the effectiveness of adjunctive photodynamic therapy (aPDT) and adjunctive antibiotic gel therapy (aAGT) to treat peri-implantitis among patients with type 2 diabetes mellitus (T2DM).

    METHODS: Selected T2DM participants with peri-implantitis were distributed into 3 groups: Group-1: received a single session of adjunctive (aPDT); Group-2: received a single session of adjunctive (aAGT) (metronidazole 400 mg and amoxicillin 500 mg); and Group-3: received MD alone. Clinical (probing depth [PD], bleeding on probing [BOP], and plaque scores [PS]) and radiographic (crestal bone loss [CBL]) peri-implant variables were recorded. Levels of interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) were assessed after the collection of peri-implant sulcular fluid (PISF). All the evaluations were carried out at baseline, 3- and 6-months. The significance level was set to p < 0.05.

    RESULTS: At 3-and 6-months of follow-up, all the three groups showed significant alleviation in PS (p < 0.05), BOP (p < 0.05), and PD (p < 0.05) when compared with the baseline. At baseline, no significant variation was observed in all clinical and radiographic peri-implant parameters among all three research groups. At 3-months follow-up, a considerable alleviation of in PS, BOP, PD, and CBL was noticeable in group-1 patients when compared with the baseline. At 6-months follow-up, a comparable difference was observed in BOP, PD, and CBL between group-1 and group-2. At baseline, no significant variation was observed in the PISF levels of IL-6 and TNF-α among all three research groups. At 3- and 6-months follow-up, a considerable alleviation of TNF-α and IL-6 levels was observed in group-1 and group-2 patients, respectively, when compared with the baseline.

    CONCLUSION: The application of aPDT demonstrated improved clinical, radiographic, and immunological peri-implant parameters for the treatment of peri-implantitis among T2DM patients.

    MeSH terms: Anti-Bacterial Agents/therapeutic use; Debridement; Humans; Dental Implants*; Photosensitizing Agents/therapeutic use
  17. Tamrin NAM, Zainudin R, Esa Y, Alias H, Isa MNM, Croft L, et al.
    Animals (Basel), 2020 Dec 10;10(12).
    PMID: 33321745 DOI: 10.3390/ani10122359
    Taste perception is an essential function that provides valuable dietary and sensory information, which is crucial for the survival of animals. Studies into the evolution of the sweet taste receptor gene (TAS1R2) are scarce, especially for Bornean endemic primates such as Nasalis larvatus (proboscis monkey), Pongo pygmaeus (Bornean orangutan), and Hylobates muelleri (Muller's Bornean gibbon). Primates are the perfect taxa to study as they are diverse dietary feeders, comprising specialist folivores, frugivores, gummivores, herbivores, and omnivores. We constructed phylogenetic trees of the TAS1R2 gene for 20 species of anthropoid primates using four different methods (neighbor-joining, maximum parsimony, maximum-likelihood, and Bayesian) and also established the time divergence of the phylogeny. The phylogeny successfully separated the primates into their taxonomic groups as well as by their dietary preferences. Of note, the reviewed time of divergence estimation for the primate speciation pattern in this study was more recent than the previously published estimates. It is believed that this difference may be due to environmental changes, such as food scarcity and climate change, during the late Miocene epoch, which forced primates to change their dietary preferences. These findings provide a starting point for further investigation.
    MeSH terms: Animals; Bayes Theorem; Diet; Food; Hylobates; Phylogeny; Pongo pygmaeus; Primates; Taste; Taste Perception; Climate Change; Herbivory
  18. Mohamad Kasim AS, Ariff AB, Mohamad R, Wong FWF
    Nanomaterials (Basel), 2020 Dec 10;10(12).
    PMID: 33321788 DOI: 10.3390/nano10122475
    Silver nanoparticles (AgNPs) have been found to have extensive biomedical and biological applications. They can be synthesised using chemical and biological methods, and coated by polymer to enhance their stability. Hence, the changes in the physico-chemical characteristics of AgNPs must be scrutinised due to their importance for biological activity. The UV-Visible absorption spectra of polyethylene glycol (PEG) -coated AgNPs displayed a distinctive narrow peak compared to uncoated AgNPs. In addition, High-Resolution Transmission Electron Microscopy analysis revealed that the shapes of all AgNPs, were predominantly spherical, triangular, and rod-shaped. Fourier-Transform Infrared Spectroscopy analysis further confirmed the role of PEG molecules in the reduction and stabilisation of the AgNPs. Moreover, dynamic light scattering analysis also revealed that the polydispersity index values of PEG-coated AgNPs were lower than the uncoated AgNPs, implying a more uniform size distribution. Furthermore, the uncoated and PEG-coated biologically synthesised AgNPs demonstrated antagonisms activities towards tested pathogenic bacteria, whereas no antagonism activity was detected for the chemically synthesised AgNPs. Overall, generalisation on the interrelations of synthesis methods, PEG coating, characteristics, and antimicrobial activity of AgNPs were established in this study.
    MeSH terms: Dynamic Light Scattering; Anti-Infective Agents; Bacteria; Polyethylene Glycols; Polymers; Silver; Spectrum Analysis; Microscopy, Electron, Transmission; Metal Nanoparticles; Physical Phenomena; Chemical Phenomena
  19. Murali G, Amran M, Fediuk R, Vatin N, Raman SN, Maithreyi G, et al.
    Materials (Basel), 2020 Dec 11;13(24).
    PMID: 33322254 DOI: 10.3390/ma13245648
    Ferrocement panels, while offering various benefits, do not cover instances of low and moderated velocity impact. To address this problem and to enhance the impact strength against low-velocity impact, a fibrous ferrocement panel is proposed and investigated. This study aims to assess the flexural and low-velocity impact response of simply supported ferrocement panels reinforced with expanded wire mesh (EWM) and steel fibers. The experimental program covered 12 different ferrocement panel prototypes and was tested against a three-point flexural load and falling mass impact test. The ferrocement panel system comprises mortar reinforced with 1% and 2% dosage of steel fibers and an EWM arranged in 1, 2, and 3 layers. For mortar preparation, a water-cement (w/c) ratio of 0.4 was maintained and all panels were cured in water for 28 days. The primary endpoints of the investigation are first crack and ultimate load capacity, deflection corresponding to first crack and ultimate load, ductility index, flexural strength, crack width at ultimate load, a number of impacts needed to induce crack commencement and failure, ductility ratio, and failure mode. The finding revealed that the three-layers of EWM inclusion and steel fibers resulted in an additional impact resistance improvement at cracking and failure stages of ferrocement panels. With superior ultimate load capacity, flexural strength, crack resistance, impact resistance, and ductile response, as witnessed in the experiment program, ferrocement panel can be a positive choice for many construction applications subjected to repeated low-velocity impacts.
    MeSH terms: Accidental Falls; Construction Materials; Dental Materials; Glass Ionomer Cements; Steel; Surgical Mesh; Tensile Strength; Water
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