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Performance of air-cathode microbial fuel cell with wood charcoal as electrodes

Chai, L.F., Chai, L.C., Suhaimi, N., Son, R.

International Food Research Journal, 2010;17(2):485-490.
MyJurnal

Local wood charcoal was used as the main component of the electrodes of an air-cathode microbial
fuel cell (air-cathode MFC) in current study. The air cathode was build with finely milled charcoal powder and cement plaster as binder; while anode was made up of a packed bed of charcoal granules. Mangrove estuary brackish water was inoculated in the anodic chamber as the fuel and a source of exoelectrogens. The constructed fuel cell was monitored by measuring the potential over time. The MFC generated a stable power density at 33mW/m2 (0.5V) under a load of 200Ω after 72 hours of operation. An open circuit voltage (OCV) of 0.7mV was obtained after 15 hours operating under open circuit. The result of power generation by the constructed fuel cell indicating that wood charcoal could be used as electrode in an MFC and that brackish water contained potential exoelectrogens. However, further investigation and modification is required to increase the performance of the fuel cell.
Fulltext Unveiling high specific energy supercapacitor from layer-by-layer assembled polypyrrole/graphene oxide|polypyrrole/manganese oxide electrode material

Kulandaivalu S, Suhaimi N, Sulaiman Y

Sci Rep, 2019 Mar 20;9(1):4884.
PMID: 30894621 DOI: 10.1038/s41598-019-41203-3

A novel layer-by-layer (LBL) based electrode material for supercapacitor consists of polypyrrole/graphene oxide and polypyrrole/manganese oxide (PPy/GO|PPy/MnO2) has prepared by electrochemical deposition. The formation of LBL assembled nanocomposite is confirmed by Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction. The field emission scanning electron microscopy images clearly showed that PPy/MnO2 was uniformly coated on PPy/GO. The PPy/GO|PPy/MnO2 symmetrical supercapacitor has revealed outstanding supercapacitive performance with a high specific capacitance of 786.6 F/g, an exceptionally high specific energy of 52.3 Wh/kg at a specific power of 1392.9 W/kg and preserve a good cycling stability over 1000 cycles. It is certain that PPy/GO|PPy/MnO2 has an extraordinary perspective as an electrode for future supercapacitor developments. This finding contributes to a significant impact on the evolution of electrochemical supercapacitor.
Combating chlorhexidine allergy in perioperative setting

Shamsher S, Suhaimi NHI, Noor Ali R, Zulkifli K

Med J Malaysia, 2023 Jan;78(1):126-127.
PMID: 36715203

Chlorhexidine is labelled as hidden allergen as the health care professionals (HCPs) are unaware of the wide range of products containing chlorhexidine. Adverse events from chlorhexidine allergy can be reduced by appropriate perioperative management especially heeding on positive history during preoperative assessment, awareness regarding this hidden allergen, and educating HCPs on possible chlorhexidine-containing products. The regulatory agencies all over the world have issued recommendations regarding safety and risk of hypersensitivity reactions with chlorhexidine-containing products. The onus lies on HCPs to disseminate this knowledge to the stakeholders. We present a brief update to combat chlorhexidine allergy in perioperative setting.
Fulltext Interdisciplinary and inter-institutional differences in learning preferences among Malaysian medical and health sciences students

Wong RSY, Siow HL, Kumarasamy V, Shaherah Fadhlullah Suhaimi N

J Adv Med Educ Prof, 2017 Oct;5(4):164-171.
PMID: 28979910

INTRODUCTION: The learner-centred approach in medical and health sciences education makes the study of learning preferences relevant and important. This study aimed to investigate the interdisciplinary, inter-institutional, gender and racial differences in the preferred learning styles among Malaysian medical and health sciences students in three Malaysian universities, namely SEGi University (SEGi), University of Malaya (UM) and Universiti Tunku Abdul Rahman (UTAR). It also investigated the differences in the preferred learning styles of these students between high achievers and non-high achievers.
METHODS: This cross-sectional study was carried out on medical and health sciences students from three Malaysian universities following the approval of the Research and Ethics Committee, SEGi University. Purposive sampling was used and the preferred learning styles were assessed using the VARK questionnaire. The questionnaire was validated prior to its use. Three disciplines (medicine, pharmacy and dentistry) were chosen based on their entry criteria and some similarities in their course structure. The three participating universities were Malaysian universities with a home-grown undergraduate entry medical program and students from a diverse cultural and socioeconomic background. The data were analysed using the Statistical Package for the Social Sciences (SPSS) software, version 22. VARK subscale scores were expressed as mean+standard deviation. Comparisons of the means were carried out using t-test or ANOVA. A p value of <0.05 was considered as statistically significant, and <0.001 as highly significant.
RESULTS: Both statistically significant interdisciplinary and inter-institutional differences in learning preferences were observed. Out of the 337 students, a majority of the participants were unimodal learners (n=263, 78.04%). The most common type of learners was the reading/writing type (n=92, 27.30%) while the kinesthetic subscale (M=6.98, SD=2.85) had the highest mean score. Female students (M=6.86, SD=2.86) scored significantly higher than male students (M=6.08, SD=2.41; t(249), p=0.014) in the auditory subscale, whereas Chinese students (M=5.87, SD=2.65) scored significantly higher than Malay students (M=4.70, SD=2.87; p=0.04) in the visual subscale. However, the mean VARK subscale scores did not differ significantly between high achievers and non-high achievers (p>0.05).
CONCLUSION: This study gives an insight into the learner characteristics of more than one medical school in Malaysia. Such multi-institutional studies are lacking in the published literature and this study gives a better representation of the current situation in the learning preferences among medical students in Malaysia.
Fulltext Bioprocess optimization for pectinase production using Aspergillus niger in a submerged cultivation system

El Enshasy HA, Elsayed EA, Suhaimi N, Malek RA, Esawy M

BMC Biotechnol, 2018 11 09;18(1):71.
PMID: 30413198 DOI: 10.1186/s12896-018-0481-7

BACKGROUND: Pectinase enzymes present a high priced category of microbial enzymes with many potential applications in various food and oil industries and an estimated market share of $ 41.4 billion by 2020.
RESULTS: The production medium was first optimized using a statistical optimization approach to increase pectinase production. A maximal enzyme concentration of 76.35 U/mL (a 2.8-fold increase compared with the initial medium) was produced in a medium composed of (g/L): pectin, 32.22; (NH4)2SO4, 4.33; K2HPO4, 1.36; MgSO4.5H2O, 0.05; KCl, 0.05; and FeSO4.5H2O, 0.10. The cultivations were then carried out in a 16-L stirred tank bioreactor in both batch and fed-batch modes to improve enzyme production, which is an important step for bioprocess industrialization. Controlling the pH at 5.5 during cultivation yielded a pectinase production of 109.63 U/mL, which was about 10% higher than the uncontrolled pH culture. Furthermore, fed-batch cultivation using sucrose as a feeding substrate with a rate of 2 g/L/h increased the enzyme production up to 450 U/mL after 126 h.
CONCLUSIONS: Statistical medium optimization improved volumetric pectinase productivity by about 2.8 folds. Scaling-up the production process in 16-L semi-industrial stirred tank bioreactor under controlled pH further enhanced pectinase production by about 4-folds. Finally, bioreactor fed-batch cultivation using constant carbon source feeding increased maximal volumetric enzyme production by about 16.5-folds from the initial starting conditions.
The diversity of rhizospheric bacterial communities associated with Trichoderma-treated rice fields

Abdullah NS, Doni F, Chua KO, Mispan MS, Saiman MZ, Mohd Yusuf Y, et al.

Lett Appl Microbiol, 2022 Dec;75(6):1645-1650.
PMID: 36073093 DOI: 10.1111/lam.13832

Microbial-based fertilizer has been widely used as a healthier and better alternative to agrochemical products. However, the effects of biofertilizers on the rhizospheric microbiota has rarely been investigated. Thus, the aim of this study was to investigate the effects of symbiotic fungus Trichoderma asperellum SL2-based inoculant on the soil bacterial population through next generation sequencing using a metabarcoding approach. The treatment plots were treated with T. asperellum SL2 spore suspension, while the control plots were treated with sterilized distilled water. The results showed similar bacterial microbiome profiles in the soil of control and T. asperellum SL2-treated plots. In conclusion, the application of the T. asperellum SL2 inoculant had not exerted a negative impact towards the bacterial population as similar observation was reflected in control plots. Nonetheless, future research should be conducted to investigate the effects of repeated application of T. asperellum SL2 over a longer period on the rice microbiota communities.
Fulltext Enhancement of astaxanthin accumulation using black light in Coelastrum and Monoraphidium isolated from Malaysia

Kaha M, Iwamoto K, Yahya NA, Suhaimi N, Sugiura N, Hara H, et al.

Sci Rep, 2021 06 03;11(1):11708.
PMID: 34083633 DOI: 10.1038/s41598-021-91128-z

Microalgae are important microorganisms which produce potentially valuable compounds. Astaxanthin, a group of xanthophyll carotenoids, is one of the most powerful antioxidants mainly found in microalgae, yeasts, and crustaceans. Environmental stresses such as intense light, drought, high salinity, nutrient depletion, and high temperature can induce the accumulation of astaxanthin. Thus, this research aims to investigate the effect of black light, also known as long-wave ultraviolet radiation or UV-A, as a stressor on the accumulation of astaxanthin as well as to screen the antioxidant property in two tropical green algal strains isolated from Malaysia, Coelastrum sp. and Monoraphidium sp. SP03. Monoraphidium sp. SP03 showed a higher growth rate (0.66 day-1) compared to that of Coelastrum sp. (0.22 day-1). Coelastrum sp. showed significantly higher accumulation of astaxanthin in black light (0.999 g mL culture-1) compared to that in control condition (0.185 g mL-1). Similarly, Monoraphidium sp. SP03 showed higher astaxanthin content in black light (0.476 g mL culture-1) compared to that in control condition (0.363 g mL culture-1). Coelastrum sp. showed higher scavenging activity (30.19%) when cultured in black light condition, indicating a correlation between the antioxidant activity and accumulation of astaxanthin. In this study, black light was shown to possess great potential to enhance the production of astaxanthin in microalgae.
Fulltext Effectiveness of Pre-procedural Mouth Rinses in Reducing Aerosol Contamination During Periodontal Prophylaxis: A Systematic Review

Mohd-Said S, Mohd-Dom TN, Suhaimi N, Rani H, McGrath C

Front Med (Lausanne), 2021;8:600769.
PMID: 34179030 DOI: 10.3389/fmed.2021.600769

Background: Aerosol-producing dental procedures are of concern in the spread of infections, especially during the COVID-19 pandemic. Periodontal prophylaxis is the most common aerosol-producing procedure conducted in dental practice globally. During COVID-19, many national and international organizations advocated the use of pre-procedural mouth rinsing to prevent the spread of infections from aerosol-generating procedures in the dental setting; however, many questioned the scientific basis for such recommendations. Objective: This systematic review aimed to evaluate the effectiveness of pre-procedural rinsing when preforming periodontal prophylaxis in reducing aerosol contamination in the dental setting. Methods: A comprehensive standardized search strategy was employed, informed by a defined PICO question across four electronic databases. The review of the literature was conducted using the PRISMA framework. Agreement between assessors was determined throughout. Synthesis of study characteristics and key outcomes were conducted. Cochrane's risk-of-bias tool for randomized trials (RoB 2) was employed to assess the quality/bias among studies. Results: The initial search yielded 731 citations across the four databases; 95 potentially effective studies were identified, with 56 effective studies found. Thirty randomized control trial studies were identified, 21 with a focus on effectiveness of pre-procedural mouth rinsing, involving 984 participants (aged 18-70). Agreement between assessors was high (Kappa >0.80). Various pre-procedural mouth rinses were tested, most frequently chlorhexidine (CHX) in 18 studies. The concentrations, volume, and prescribed duration of rinsing varied among studies, hampering meta-analyses. Nonetheless, all studies identified significant reductions in bacterial contamination, as measured by colony forming units (cfu). The effectiveness of CHX over other agents was evident with more than half of the studies (7/15) reporting over a 70% reduction in bacterial contamination (cfu). There were concerns over the risk of bias in most studies (76.2%); 19.0% had a high risk of bias and 4.8% were of low risk of bias. Conclusion: There is substantial evidence to support pre-procedural mouth rinsing, such as with chlorohexidine, to effectively reduce aerosol contamination when performing periodontal prophylaxis compared to mouth rinsing with water or not rinsing.
The clinical implications of Porphyromonas gingivalis and its detection methods - a systematic review

Shalihin MSE, Suhaimi NAN, Hamzah HA, Abidin S, Aidid ME, Musa R

Med J Malaysia, 2023 Nov;78(6):830-844.
PMID: 38031228

INTRODUCTION: Mounting evidence has shown the significant correlation between periodontitis and the development of other comorbidities, such as cardiovascular disease due to periodontopathogenic bacterial migration and colonisation. As the main etiologic agent of periodontitis, the role of Porphyromonas gingivalis (P. gingivalis) has been widely explored as the main culprit and its early detection is crucial to control the exacerbation of diseases. This review aims to identify and summarise all clinical diseases that potentially developed due to the presence of P. gingivalis and discover all its detection methods that have been developed.
MATERIALS AND METHODS: Full-text articles of case report, case control, cohort and cross-sectional studies that were published from 1st January 2012 until 30th June 2022, were searched using PubMed, CINAHL and Scopus. Periodontal related diseases were excluded in this review due to its wellknown associated disease with P. gingivalis. A comparison studies of detection methods were also excluded in this review.
RESULTS: Out of 612 articles that were screened, only 106 met the eligibility criteria to be selected for further review. Risk of bias was performed using FEAT principles and reviewers' discussion. A total of 21 final articles that were reviewed showed significant correlation with P. gingivalis and were classified into several clinical domains. Twelve out of 13 detection methods showed high sensitivity and specificity with short duration analysis.
CONCLUSION: Due to asymptomatic periodontal disease and the high prevalence of P. gingivalis-associated clinical diseases, this review suggests the need for oral public health awareness and early screening for the bacterium detection especially among elderly groups to maintain their quality of life.
Fulltext Chromosome-scale genome assembly of an acidophilic microalga Tetratostichococcus sp. P1 isolated from a tropical peatland in Malaysia

Maeda Y, Hirakawa T, Suzuki S, Suhaimi N, Shamsol Anuar NS, Yoneda K, et al.

Microbiol Resour Announc, 2024 Feb 15;13(2):e0081623.
PMID: 38179908 DOI: 10.1128/MRA.00816-23

Tetratostichococcus sp. P1 shows an acidophilic phenotype which could allow mass-scale monoculture of this green microalga without severe contamination by environmental microorganisms. In this study, we report a chromosome-scale genome assembly for Tetratostichococcus sp. P1.