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Fulltext Influence of Silica Modulus and Curing Temperature on the Strength of Alkali-Activated Volcanic Ash and Limestone Powder Mortar

Adewumi AA, Mohd Ariffin MA, Maslehuddin M, Yusuf MO, Ismail M, Al-Sodani KAA

Materials (Basel), 2021 Sep 10;14(18).
PMID: 34576445 DOI: 10.3390/ma14185204

This present study evaluates the effect of silica modulus (Ms) and curing temperature on strengths and the microstructures of binary blended alkali-activated volcanic ash and limestone powder mortar. Mortar samples were prepared using mass ratio of combined Na2SiO3(aq)/10 M NaOH(aq) of 0.5 to 1.5 at an interval of 0.25, corresponding to Ms of 0.52, 0.72, 0.89, 1.05 and 1.18, respectively, and sole 10 M NaOH(aq). Samples were then subjected to ambient room temperature, and the oven-cured temperature was maintained from 45 to 90 °C at an interval of 15 °C for 24 h. The maximum achievable 28-day strength was 27 MPa at Ms value of 0.89 cured at 75 °C. Samples synthesised with the sole 10 M NaOH(aq) activator resulted in a binder with a low 28-day compressive strength (15 MPa) compared to combined usage of Na2SiO3(aq)/10 M NaOH(aq) activators. Results further revealed that curing at low temperatures (25 °C to 45 °C) does not favour strength development, whereas higher curing temperature positively enhanced strength development. More than 70% of the 28-day compressive strength could be achieved within 12 h of curing with the usage of combined Na2SiO3(aq)/10 M NaOH(aq). XRD, FTIR and SEM + EDX characterisations revealed that activation with combined Na2SiO3(aq)/10 M NaOH(aq) leads to the formation of anorthite (CaAl2Si2O8), gehlenite (CaO.Al2O3.SiO2) and albite (NaAlSi3O8) that improve the amorphosity, homogeneity and microstructural density of the binder compared to that of samples synthesised with sole 10 M NaOH(aq).
Comparing the efficacy and safety between propofol and dexmedetomidine for sedation in claustrophobic adults undergoing magnetic resonance imaging (PADAM trial)

Loh PS, Ariffin MA, Rai V, Lai LL, Chan L, Ramli N

J Clin Anesth, 2016 Nov;34:216-22.
PMID: 27687378 DOI: 10.1016/j.jclinane.2016.03.074

STUDY OBJECTIVE: To determine the efficacy of sedation with dexmedetomidine compared to propofol for claustrophobic adults undergoing magnetic resonance imaging (MRI) in our institution.
DESIGN: Randomized, prospective, double-blinded study.
SETTING: University-based tertiary referral center.
PATIENTS: Thirty claustrophobic adults with American Society of Anesthesiologists physical status I and II who were planned for MRI.
INTERVENTIONS: Patients were randomly assigned to target-controlled infusion propofol or dexmedetomidine loading followed by maintenance dose for procedural sedation.
MEASUREMENTS AND MAIN RESULTS: The primary end point was adequate reduction in patient anxiety levels to allow successful completion of the MRI sequence. Both methods of sedation adequately reduced anxiety levels in visual analog scale scores and Spielberger Strait Test Anxiety Inventory (P
Fulltext Experimental and Modelling of Alkali-Activated Mortar Compressive Strength Using Hybrid Support Vector Regression and Genetic Algorithm

Al-Sodani KAA, Adewumi AA, Mohd Ariffin MA, Maslehuddin M, Ismail M, Salami HO, et al.

Materials (Basel), 2021 Jun 03;14(11).
PMID: 34205101 DOI: 10.3390/ma14113049

This paper presents the outcome of work conducted to develop models for the prediction of compressive strength (CS) of alkali-activated limestone powder and natural pozzolan mortar (AALNM) using hybrid genetic algorithm (GA) and support vector regression (SVR) algorithm, for the first time. The developed hybrid GA-SVR-CS1, GA-SVR-CS3, and GA-SVR-CS14 models are capable of estimating the one-day, three-day, and 14-day compressive strength, respectively, of AALNM up to 96.64%, 90.84%, and 93.40% degree of accuracy as measured on the basis of correlation coefficient between the measured and estimated values for a set of data that is excluded from training and testing phase of the model development. The developed hybrid GA-SVR-CS28E model estimates the 28-days compressive strength of AALNM using the 14-days strength, it performs better than hybrid GA-SVR-CS28C model, hybrid GA-SVR-CS28B model, hybrid GA-SVR-CS28A model, and hybrid GA-SVR-CS28D model that respectively estimates the 28-day compressive strength using three-day strength, one day-strength, all the descriptors and seven day-strength with performance improvement of 103.51%, 124.47%, 149.94%, and 262.08% on the basis of root mean square error. The outcome of this work will promote the use of environment-friendly concrete with excellent strength and provide effective as well as efficient ways of modeling the compressive strength of concrete.
Fulltext An electrochemical biosensor for the rapid genetic identification of Musang King durian

Azizi MMF, Romeli S, Razali H, Ariffin EY, Tajol Ariffin MA, Heng LY, et al.

Sci Rep, 2022 Nov 11;12(1):19324.
PMID: 36369187 DOI: 10.1038/s41598-022-20998-8

More than 200 different cultivars of durian exist worldwide but Durio zibethinus or Musang King (MK) is the most premium and prized durian fruit among the recommended varieties. Early identification of this premium variety is critical to protect from non-authentic MK durian cultivars. However, the MK variety's morphological traits are nearly identical to other varieties. Currently, the identification of durian varieties is mostly performed via evaluation of leaf shape, fruit shape, aroma, taste and seed shape and this requires trained personnel for the morphology observation. To enable the rapid identification of the MK variety, PCR amplification of ten durian varieties using six gene candidates from the chloroplast genome was first performed to obtain DNA probes that were specific to the MK durian variety. PCR amplification of ten durian varieties using primers designed confirmed that the nadhA gene sequence showed an obvious difference in the MK variety from other durian varieties. The unique sequence of MK was used as a DNA probe to develop an electrochemical biosensor for the direct identification of the MK durian variety. The electrochemical biosensor was based on the hybridization response of the immobilized DNA probe with the target DNA from the MK variety and was monitored via differential pulse voltammetry technique. Under optimal conditions, the DNA electrochemical biosensor showed a low detection limit at 10% of MK genomic DNA concentration with a wide linear calibration range of 0.05-1.5 µM (R2 = 0.9891) and RSD value of 3.77% (n = 3). The results of the developed DNA biosensor provide high promise for the development of portable sensors employed in the determination of MK variety in the field.
A modified Delphi consensus on the use of intramuscular midazolam for early status epilepticus treatment (ESET) in Malaysia

Yow HY, Lim KS, Fong SL, Lim AJ, Chow CT, Azizah Ariffin MA, et al.

Seizure, 2025 Feb 18;127:16-24.
PMID: 40022772 DOI: 10.1016/j.seizure.2025.02.009

OBJECTIVES: Despite intramuscular (IM) midazolam being recommended as a primary treatment for status epilepticus (SE), its usage in Malaysian prehospital settings remains suboptimal. This study aimed to explore the awareness, practice, and barriers among healthcare professionals regarding the use of IM midazolam as a rescue medication for prehospital SE in Malaysia and provide a consensus for its implementation.
METHODS: An online cross-sectional survey and modified Delphi study was conducted among healthcare professionals across Malaysia from 22 March to 31 August 2024. A modified Delphi process was used to develop a consensus from existing literature, with two Delphi rounds assessing the relevance, clarity, and importance of each question. Consensus was achieved if 90 % or more participants agreed.
RESULTS: Among 137 responses, 89.1 % of healthcare professionals were aware of rescue medications. However, only 62.0 % recognized the superior absorption and bioavailability of IM midazolam over rectal diazepam, and 78.1 % were aware of its efficacy in terminating seizures. Of those (69.3 %) involved in SE management, 29.5 % (n = 28) were engaged in prehospital management of SE. Only 35.7 % (n = 10) reported that prehospital personnel were permitted to use IM midazolam for SE management and all required physician endorsement. Notably, 78.9 % of participants reported that 25 % or fewer patients with SE were treated with IM midazolam. The main barriers include unfamiliarity (64.2 %) and lack of protocols (62.1 %). A strong consensus was reached on the recommendation of IM midazolam as a first-line treatment for SE management.
CONCLUSION: While Malaysian healthcare professionals are aware of rescue medications for prehospital seizure emergencies, they lack an understanding of IM midazolam's benefits. Key barriers include unfamiliarity and lack of protocols despite strong consensus on its first-line use.
Fulltext Precursors to non-invasive clinical dengue screening: Multivariate signature analysis of in-vivo diffuse skin reflectance spectroscopy on febrile patients in Malaysia

Poh AH, Mahamd Adikan FR, Moghavvemi M, Syed Omar SF, Poh K, Mahyuddin MBH, et al.

PLoS One, 2020;15(4):e0228923.
PMID: 32236132 DOI: 10.1371/journal.pone.0228923

Dengue diagnostics have come a long way. Attempts at breaking away from lab-oriented dengue detection, such as NS1 antigen, IgM or IgG antibodies detection have extensively received numerous coverage. As a result, rapid detection tests (RDTs) have started to gain inroads in medical practice. Rapid detection tests notwithstanding, analysis of blood serum is still a relatively complicated task. This includes the necessity of phlebotomy, centrifugation for blood serum, and other reagent-based tests. Therefore, a non-invasive method of dengue detection was considered. In this study, we present the utility of diffuse reflectance skin spectroscopy (bandwidth of 200-2500nm) on the forearm during the triaging period for dengue screening potential. This is performed with multivariate analysis of 240 triaged febrile/suspected dengue patients. The data is then scrutinized for its clinical validity to be included as either confirmed or probable dengue, or a control group. Based on discriminant analysis of several data normalization models, we can predict the patients' clinical dengue-positivity at ranges of accuracy between ~93-98% depending on mode of the data, with a probably optimal sensitivity and specificity to the clinical diagnosis of ~89% and ~100% respectively. From the outcomes of this study, we recommend further trials with cautious optimism. With these findings, it is hoped that the elusive non-invasive detection of tropical diseases may gain platform in the near future.
Fulltext COVID-19 aerosol box as protection from droplet and aerosol contaminations in healthcare workers performing airway intubation: a randomised cross-over simulation study

Noor Azhar M, Bustam A, Poh K, Ahmad Zahedi AZ, Mohd Nazri MZA, Azizah Ariffin MA, et al.

Emerg Med J, 2021 Feb;38(2):111-117.
PMID: 33219133 DOI: 10.1136/emermed-2020-210514

BACKGROUND: Concerns over high transmission risk of SARS-CoV-2 have led to innovation and usage of an aerosol box to protect healthcare workers during airway intubation in patients with COVID-19. Its efficacy as a barrier protection in addition to the use of a standard personal protective equipment (PPE) is not fully known. We performed a simulated study to investigate the relationship between aerosol box usage during intubation and contaminations on healthcare workers pre-doffing and post-doffing of PPE.
METHODS: This was a randomised cross-over study conducted between 9 April to 5 May 2020 in the ED of University Malaya Medical Centre. Postgraduate Emergency Medicine trainees performed video laryngoscope-assisted intubation on an airway manikin with and without an aerosol box in a random order. Contamination was simulated by nebulised Glo Germ. Primary outcome was number of contaminated front and back body regions pre-doffing and post-doffing of PPE of the intubator and assistant. Secondary outcomes were intubation time, Cormack-Lehane score, number of intubation attempts and participants' feedback.
RESULTS: Thirty-six trainees completed the study interventions. The number of contaminated front and back body regions pre-doffing of PPE was significantly higher without the aerosol box (all p values<0.001). However, there was no significant difference in the number of contaminations post-doffing of PPE between using and not using the aerosol box, with a median contamination of zero. Intubation time was longer with the aerosol box (42.5 s vs 35.5 s, p<0.001). Cormack-Lehane scores were similar with and without the aerosol box. First-pass intubation success rate was 94.4% and 100% with and without the aerosol box, respectively. More participants reported reduced mobility and visibility when intubating with the aerosol box.
CONCLUSIONS: An aerosol box may significantly reduce exposure to contaminations but with increased intubation time and reduced operator's mobility and visibility. Furthermore, the difference in degree of contamination between using and not using an aerosol box could be offset by proper doffing of PPE.