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Fulltext Effect of beta phase on tensile and creep fracture of as cast gamma titanium aluminide

Hamzah, E., Kanniah, M., Harun, M.

Journal of Nuclear and Related Technologies, 2006;2006(1):35-40.
MyJurnal

The microstructure, tensile fracture and creep fracture of as-cast beta phase contained γ-TiAl with nominal composition of Ti-48Al-4Cr (at.%) was investigated. The effect of beta phase on tensile and creep strength was determined from fracture analysis. Tensile test were performed at room temperature whereas constant load tensile creep test were performed at temperature 800 0 C and initial stress of 150MPa. Initial as-cast microstructure, microstructure and fracture surface after tensile and creep test were examined using scanning electron microscopy technique. Analysis shows brittle fracture after room temperature tensile test whereas ductile fracture after high temperature creep test. The role of beta phase was discussed. It is concluded that beta phase is sensitive to temperature and detrimental at both room and high temperature.
Fulltext Effect of microwave-assisted acid or alkali pretreatment on sugar release from Dragon fruit foliage

Ethaib, S., Omar, R., Mazlina, M., Radiah, A., Syafiie, S., Harun, M. Y.

International Food Research Journal, 2016;23(101):149-154.
MyJurnal

Agriculture residues are a promising feedstock for value-added products from lignocellulosic waste. However, pretreatment of lignocellulosic materials is essential to facilitate enzymatic
hydrolysis and improve sugar yield. The objective of this study is to evaluate the effect of acid or alkali during microwave-assisted pretreatment of dragon fruit foliage (DFF) that
would make hydrolysis process more efficient. In the present study, distilled water and three chemicals were examined for their effects on releasing monomeric sugar during microwave
treatment. Microwave-assisted pretreatment namely microwave-distilled water (M-H2O) (control); microwave-sulfuric acid (M-H2SO4); microwave-sodium hydroxide (M-NaOH); and
microwave-sodium bicarbonate (M-NaHCO3) pretreatment were performed using 5% (w/v) of DFF as substrate at 800 watt microwave power for 5 minutes exposure time. Highest yield
of monomeric sugar was found at 15.56 mg/g using M-NaOH pretreatment at 0.1N NaOH. For M-H2SO4 pretreatment, 0.1N H2SO4 produced 8.2 mg/g of monomeric sugar. Application
of M-NaHCO3 pretreatment using 0.05N NaHCO3 solution released 6.45 mg/g of monomeric sugar. While, soaking DFF in distilled water and subjecting to microwave irradiation released
6.6 mg/g of monomeric sugar. Treatments with the lowest concentration (0.01 N) of the three chemicals released only small quantities of total monomeric sugars and less than that with distilled water. The changes in the physical structure of DFF prior to and after the microwaveassisted pretreatment are also reported.
Fulltext Congenital posterior mediastinal teratoma--a case report

Harun MH, Yaacob I

Singapore Med J, 1993 Dec;34(6):567-8.
PMID: 8153729

Almost all mediastinal teratomas are found in the anterior mediastinum. We describe a case of a 41-day-old baby girl who had teratoma in the posterior mediastinum. She presented at the age of 6 days with the problem of progressive jaundice and was found to have septicaemia. During septic screening, chest X-ray revealed a mass in the right mediastinum. Ultrasound and CT-scan of the chest showed a multiloculated mass at the right posterior mediastinum. Fine needle aspiration biopsy of the mass confirmed a teratoma.
Study site: Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia
Fulltext Spontaneous pneumothorax: a review of 29 admissions into Hospital Universiti Sains Malaysia 1984-90

Harun MH, Yaacob I, Mohd Kassim Z

Singapore Med J, 1993 Apr;34(2):150-2.
PMID: 8266158

Twenty-nine patients (16 males, 13 females) with spontaneous pneumothorax admitted into Hospital Universiti Sains Malaysia, Kubang Kerian, from September 1984 to September 1990 were reviewed. Their ages ranged from newborn to 75 years. The commonest chief presenting symptom was dyspnoea (69%), followed by chest pain (35%). Four patients had chronic obstructive airway disease, 7 had pneumonia, 2 had pulmonary tuberculosis, one patient had emphysema while 4 patients had multiple underlying lung disorders. The left and right lungs were involved with equal frequency. Bilateral pneumothorax occurred in one patient. Most patients had a single episode of pneumothorax but recurrent pneumothoraces occurred in 3 patients (10%). Six patients were observed conservatively, 20 patients required chest tube insertion alone and 3 patients also required pleurodesis. Death occurred in 8 patients (28%) mainly due to coexisting infection and respiratory failure.
Fulltext Experimental optimization in polymer BLEND composite preparation based on mix level of taguchi robust design

Aziz Mohamed, A., Hafizal Yazid, Sahrim Ahmad, Rozaidi Rasid, Jaafar Abdullah, Dahlan, M., et al.

Journal of Nuclear and Related Technologies, 2012;2012(1):23-32.
MyJurnal

L18 orthogonal array in mix level of Taguchi robust design method was carried out to optimize experimental conditions for the preparation of polymer blend composite. Tensile strength and neutron absorption of the composite were the properties of interest. Filler size, filler loading, ball mixing time and dispersion agent concentration were selected as parameters or factors which are expected to affect the composite properties. As a result of Taguchi analysis, filler loading was the most influencing parameter on the tensile strength and neutron absorption. The least influencing was ball-mixing time. The optimal conditions were determined by using mix-level Taguchi robust design method and a polymer composite with tensile strength of 6.33 MPa was successfully prepared. The composite was found to fully absorb thermal neutron flux of 1.04 x 105n/cm2/s with only 2 mm in thickness. In addition, the filler was also characterized by scanning electron microscopy (SEM) and elemental analysis (EDX).
Energy Efficiency Policies in Malaysia: A Critical Evaluation from the Sustainable Development Perspective

Aktar MA, Alam MM, Harun M

Environ Sci Pollut Res Int, 2022 Jan 13.
PMID: 35028847 DOI: 10.1007/s11356-021-18257-w

Reduced electricity demand through the implementation of an energy efficiency policy is a central pillar of the Malaysian government's energy strategy. Energy efficiency first emerged as part of Malaysia's energy policy agenda in 1979 but only came into force during the 2000s. Initially, it was seen from global fears about the shortage of fossil fuels, then as a way of combating climate change. This paper offers a comprehensive review of Malaysia's energy policies with a focus on adopting policies to improve energy efficiency. Starting with Malaysia's preliminary policy in response to the OPEC-driven global oil crisis in 1973, the paper discusses how policymakers are considering energy efficiency from Malaysia's sustainable development perspective and what relevant government efforts have been made to improve it. The review evaluates the progress that has been made over the past 25 years to address energy efficiency in the economy and highlights the achievements and remaining difficulties. Findings show that the level of energy efficiency while having shown improvement during 1990-2015 was lower than expected. In terms of electricity intensity of GDP, Malaysia has a relatively large position among the ASEAN countries and the world's largest electricity consumers. Researchers, scientists, and practitioners will benefit from the extensive review material of this study, which will help them better understand energy efficiency and the sustainability strategy implemented in Malaysia to date.
Two dimensional-QSAR and molecular dynamics studies of a selected class of aldoxime- and hydroxy-functionalized chalcones as monoamine oxidase-B inhibitors

Mathew B, Ravichandran V, Raghuraman S, Rangarajan TM, Abdelgawad MA, Ahmad I, et al.

J Biomol Struct Dyn, 2023 Nov;41(19):9256-9266.
PMID: 36411738 DOI: 10.1080/07391102.2022.2146198

Candidates generated from unsaturated ketone (chalcone) demonstrated as strong, reversible and specific monoamine oxidase-B (MAO-B) inhibitory activity. For the research on MAO-B inhibition, our team has synthesized and evaluated a panel of aldoxime-chalcone ethers (ACE) and hydroxylchalcones (HC). The MAO-B inhibitory activity of several candidates is in the micro- to nanomolar range in these series. The purpose of this research was to develop predictive QSAR models and look into the relation between MAO-B inhibition by aldoxime and hydroxyl-functionalized chalcones. It was shown that the molecular descriptors ETA Shape P, MDEO-12, ETA dBetaP, SpMax1 Bhi and ETA EtaP B are significant in the inhibitory action of the MAO-B target. Using the current 2D QSAR models, potential chalcone-based MAO-B inhibitors might be created. The lead molecules were further analyzed by the detailed molecular dynamics study to establish the stability of the ligand-enzyme complex.Communicated by Ramaswamy H. Sarma.
Production of eco-friendly adsorbent of kaolin clay and cellulose extracted from peanut shells for removal of methylene blue and congo red removal dyes

Reghioua A, Atia D, Hamidi A, Jawad AH, Abdulhameed AS, Mbuvi HM

Int J Biol Macromol, 2024 Apr;263(Pt 1):130304.
PMID: 38382796 DOI: 10.1016/j.ijbiomac.2024.130304

This present work targets the production of an eco-friendly adsorbent (hereinafter KA/CEL) from kaolin clay functionalized with cellulose extract obtained from peanut shells. The adsorbents were used for decolorization of two different types of organic dyes (cationic: methylene blue, MB; anionic: Congo red, CR) from an aqueous environment. Several analytical methods, including Brunauer-Emmett-Teller (surface properties), Fourier Transforms infrared (functionality), scanning electron microscope, Energy dispersive X-Ray (morphology), and pHpzc test (surface charge), were used to attain the physicochemical characteristics of KA/CEL. The Box-Behnken Design (BBD) was applied to determine the crucial factors affecting adsorption performance. These included cellulose loading at 25 %, an adsorbent dose of 0.06 g, solution pH set at 10 for MB and 7 for CR, a temperature of 45 °C, and contact times of 12.5 min for MB and 20 min for CR dye. The adsorption data exhibited better agreement with the pseudo-second-order kinetic and Freundlich models. The Langmuir model estimated the monolayer capacity to be 291.5 mg/g for MB and 130.7 mg/g for CR at a temperature of 45 °C. This study's pivotal finding underscores the promising potential of KA/CEL as an effective adsorbent for treating wastewater contaminated with organic dyes.
Effect of physical pretreatment on dilute acid hydrolysis of water hyacinth (Eichhornia crassipes)

Harun MY, Dayang Radiah AB, Zainal Abidin Z, Yunus R

Bioresour Technol, 2011 Apr;102(8):5193-9.
PMID: 21333529 DOI: 10.1016/j.biortech.2011.02.001

Effects of different physical pretreatments on water hyacinth for dilute acid hydrolysis process (121 ± 3 °C, 5% H(2)SO(4), 60 min) were comparatively investigated. Untreated sample had produced 24.69 mg sugar/g dry matter. Steaming (121 ± 3 °C) and boiling (100 ± 3 °C) for 30 min had provided 35.9% and 52.4% higher sugar yield than untreated sample, respectively. The highest sugar yield (132.96 mg sugar/g dry matter) in ultrasonication was obtained at 20 min irradiation using 100% power. The highest sugar production (155.13 mg sugar/g dry matter) was obtained from pulverized samples. Hydrolysis time was reduced when using samples pretreated by drying, mechanical comminution and ultrasonication. In most methods, prolonging the pretreatment period was ineffective and led to sugar degradations. Morphology inspection and thermal analysis had provided evidences of structure disruption that led to higher sugar recovery in hydrolysis process.
Macular haemorrhage in adult acute leukaemia patients at presentation and the risk of subsequent intracranial haemorrhage

Jackson N, Reddy SC, Harun MH, Quah SH, Low HC

Br J Haematol, 1997 Jul;98(1):204-9.
PMID: 9233585

Retinal changes are common in adult acute leukaemia patients at presentation, but whether they correlate with the risk of subsequent intracranial haemorrhage is unknown. A 4-year study has been carried out in 82 newly-diagnosed acute leukaemia patients, aged 12-77 years, who were studied prospectively for the presence of intra-retinal haemorrhages (IRH), white-centred haemorrhages (WCH), cotton-wool spots (CWS) and macular haemorrhages (MH). Groups with and without these features were compared for their risk of intra-cranial haemorrhage (ICH) within the first 30 d following diagnosis. There was no association between the incidence of ICH and the presence of IRH, WCH or CWS. However, 6/13 of those with MH developed ICH, compared to 6/69 of those without MH (relative risk 5.0, CI 95% [2.03-12.33], P=0.003). The only other identifiable risk factor for ICH was the M3 subtype of AML, but if the four cases of M3-AML were discounted from analysis, MH remained a highly significant risk factor for ICH. Patients with MH should be monitored intensively for the development of ICH, and receive priority in the allocation of platelets where these are in short supply.
The use of graphic rules in grade one to help identify children at risk of handwriting difficulties

Khalid PI, Yunus J, Adnan R, Harun M, Sudirman R, Mahmood NH

Res Dev Disabil, 2010 Nov-Dec;31(6):1685-93.
PMID: 20554150 DOI: 10.1016/j.ridd.2010.04.005

Previous researches on elementary grade handwriting revealed that pupils employ certain strategy when writing or drawing. The relationship between this strategy and the use of graphic rules has been documented but very little research has been devoted to the connection between the use of graphic rules and handwriting proficiency. Thus, this study was conducted to investigate the relative contribution of the use of graphic rules to the writing ability. A sample of 105 first graders who were average printers and 65 first graders who might experience handwriting difficulty, as judged by their teachers, of a normal primary school were individually tested on their use of graphic rules. It has been found that pupils who are below average printers use more non-analytic strategy than average printers to reproduce the figures. The results also reveal that below average printers do not acquire the graphic principles that foster an analytic approach to production skills. Although the findings are not sufficient to allow definitive conclusions about handwriting ability, it can be considered as one of the screening measures in identifying pupils who are at risk of handwriting difficulties.
Effect of torsional loading on compressive fatigue behaviour of trabecular bone

Fatihhi SJ, Rabiatul AA, Harun MN, Kadir MR, Kamarul T, Syahrom A

J Mech Behav Biomed Mater, 2016 Feb;54:21-32.
PMID: 26410762 DOI: 10.1016/j.jmbbm.2015.09.006

The present study reports the effects of combined torsional and compressive cyclic loading on trabecular bone in order to mimic true physiological conditions and thereby provides improved data that represents clinical and real life conditions. However, only compressive behaviour is evaluated in most previous studies of bone mechanics. From the monotonic evaluation, it is observed that lower stress is needed for the onset of microcrack in the sample under torsional loading, compared to the stress needed in compression. Trabecular bone samples were subjected to a combination of torsion and compression fatigue at different stress levels during which they were compared to compressive axial fatigue. The stress levels were determined by considering the monotonic strength at 25-50% for both compressive and shear stresses. Significant decrease in fatigue lifetime is observed in between samples of pure compression fatigue and those with superpositioned torsional loading (p<0.05). The reduction in fatigue lifetime became more evident at a high torsional stress level. In this case, the failure of the sample is said to be 'torsional dominant'. Fatigue behaviour of bovine trabecular bone begins with plastic deformation, followed by strain accumulation and modulus reduction. As the strain rate increases, more energy dissipates and the sample finally failed. Further, the analysis of fractograph revealed something on the trabeculae by bending in sample with superpositioned torsional loading. In conclusion, torsional loading decreases the quality of the trabecular properties in terms of stiffness, life and structural integrity. It is hoped that results from this study will improve the understanding of the behaviour of trabecular bone under combined fatigue and help to develop future assessments of trabecular failure.
Uniaxial and Multiaxial Fatigue Life Prediction of the Trabecular Bone Based on Physiological Loading: A Comparative Study

Fatihhi SJ, Harun MN, Abdul Kadir MR, Abdullah J, Kamarul T, Öchsner A, et al.

Ann Biomed Eng, 2015 Oct;43(10):2487-502.
PMID: 25828397 DOI: 10.1007/s10439-015-1305-8

Fatigue assessment of the trabecular bone has been developed to give a better understanding of bone properties. While most fatigue studies are relying on uniaxial compressive load as the method of assessment, in various cases details are missing, or the uniaxial results are not very realistic. In this paper, the effect of three different load histories from physiological loading applied on the trabecular bone were studied in order to predict the first failure surface and the fatigue lifetime. The fatigue behaviour of the trabecular bone under uniaxial load was compared to that of multiaxial load using a finite element simulation. The plastic strain was found localized at the trabecular structure under multiaxial load. On average, applying multiaxial loads reduced more than five times the fatigue life of the trabecular bone. The results provide evidence that multiaxial loading is dominated in the low cycle fatigue in contrast to the uniaxial one. Both bone volume fraction and structural model index were best predictors of failure (p
Effects of Toxoplasma gondii infection on the function and integrity of human cerebrovascular endothelial cells and the influence of verapamil treatment in vitro

Harun MSR, Marsh V, Elsaied NA, Webb KF, Elsheikha HM

Brain Res, 2020 11 01;1746:147002.
PMID: 32592740 DOI: 10.1016/j.brainres.2020.147002

Toxoplasma gondii can cause parasitic encephalitis, a life-threatening infection that predominately occurs in immunocompromised individuals. T. gondii has the ability to invade the brain, but the mechanisms by which this parasite crosses the blood-brain-barrier (BBB) remain incompletely understood. The present study reports the changes associated with infection and replication of T. gondii within human brain microvascular endothelial cells (BMECs) in vitro. Our results indicated that exposure to T. gondii had an adverse impact on the function and integrity of the BMECs - through induction of cell cycle arrest, disruption of the BMEC barrier integrity, reduction of cellular viability and vitality, depolarization of the mitochondrial membrane potential, increase of the DNA fragmentation, and alteration of the expression of immune response and tight junction genes. The calcium channel/P-glycoprotein transporter inhibitor verapamil was effective in inhibiting T. gondii crossing the BMECs in a dose-dependent manner. The present study showed that T. gondii can compromise several functions of BMECs and demonstrated the ability of verapamil to inhibit T. gondii crossing of the BMECs in vitro.
Current advances of nanocellulose application in biomedical field

Leong MY, Kong YL, Harun MY, Looi CY, Wong WF

Carbohydr Res, 2023 Oct;532:108899.
PMID: 37478689 DOI: 10.1016/j.carres.2023.108899

Nanocellulose (NC) is a natural fiber that can be extracted in fibrils or crystals form from different natural sources, including plants, bacteria, and algae. In recent years, nanocellulose has emerged as a sustainable biomaterial for various medicinal applications including drug delivery systems, wound healing, tissue engineering, and antimicrobial treatment due to its biocompatibility, low cytotoxicity, and exceptional water holding capacity for cell immobilization. Many antimicrobial products can be produced due to the chemical functionality of nanocellulose, such disposable antibacterial smart masks for healthcare use. This article discusses comprehensively three types of nanocellulose: cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), and bacterial nanocellulose (BNC) in view of their structural and functional properties, extraction methods, and the distinctive biomedical applications based on the recently published work. On top of that, the biosafety profile and the future perspectives of nanocellulose-based biomaterials have been further discussed in this review.
Fulltext The Incidence and Variation of Corona Mortis in Multiracial Asian: An Insight from 82 Cadavers

Khirul-Ashar NA, Ismail II, Hussin P, Nizlan NM, Harun MH, Mawardi M, et al.

Malays Orthop J, 2024 Mar;18(1):26-32.
PMID: 38638662 DOI: 10.5704/MOJ.2403.004

INTRODUCTION: Corona Mortis (CMOR) is a term used to describe an anatomical vascular variant of retropubic anastomosis located posterior to superior pubic ramus. We aim to provide sufficient data on the incidence, morphology and mean location of 'crown of death' in Asian population. Other objectives include to assess the relationship between CMOR incidence with gender, race and age.
MATERIALS AND METHODS: This is a cross-sectional cadaveric study involving 164 randomly selected fresh multiracial Asian hemipelves (82 cadavers). Hemipelves were dissected to expose and evaluate the vascular elements posterior to superior pubic rami. Data were analysed using Chi-Square, t-test and with the help of IBM SPSS Statistics v26 software.
RESULTS: CMOR was found in 117 hemipelves (71.3%). No new morphological subtype was found. The mean distance of CMOR to symphysis pubis was 54.72mm (SD 9.35). Based on the results, it is evident that precaution needed to be taken at least within 55mm from symphysis pubis during any surgical intervention. The lack of statistically significant correlation between CMOR occurrence and gender, race and age suggest that the incidence of CMOR could be sporadic in manner.
CONCLUSION: We conclude that CMOR is not just aberrant vessel as the incidence is high and this finding is comparable to other studies. The mean location of CMOR obtained in this study will guide surgeons from various disciplines in Asia to manage traumatic vascular injury and to perform a safe surgical procedure involving the pelvis area.
Fluid-structure interaction (FSI) modeling of bone marrow through trabecular bone structure under compression

Rabiatul AAR, Fatihhi SJ, Md Saad AP, Zakaria Z, Harun MN, Kadir MRA, et al.

Biomech Model Mechanobiol, 2021 Jun;20(3):957-968.
PMID: 33547975 DOI: 10.1007/s10237-021-01423-x

The present study has sought to investigate the fluid characteristic and mechanical properties of trabecular bone using fluid-structure interaction (FSI) approach under different trabecular bone orientations. This method imposed on trabecular bone structure at both longitudinal and transverse orientations to identify effects on shear stress, permeability, stiffness and stress regarded to the trabeculae. Sixteen FSI models were performed on different range trabecular cubes of 27 mm3 with eight models developed for each longitudinal and transverse direction. Results show that there was a moderate correlation between permeability and porosity, and surface area in the longitudinal and transverse orientations. For the longitudinal orientation, the permeability values varied between 3.66 × 10-8 and 1.9 × 10-7 and the sheer stress values varied between 0.05 and 1.8 Pa, whilst for the transverse orientation, the permeability values varied between 5.95 × 10-10 and 1.78 × 10-8 and the shear stress values varied between 0.04 and 3.1 Pa. Here, transverse orientation limits the fluid flow from passing through the trabeculae due to high shear stress disturbance generated within the trabecular bone region. Compared to physiological loading direction (longitudinal orientation), permeability is higher within the range known to trigger a response in bone cells. Additionally, shear stresses also increase with bone surface area. This study suggests the shear stress within bone marrow in real trabecular architecture could provide the mechanical signal to marrow cells that leads to bone anabolism and can depend on trabecular orientation.
Parametric study of coagulant recovery from water treatment sludge towards water circular economy

Shawal NBM, Razali NA, Hairom NHH, Yatim NII, Rasit N, Harun MHC, et al.

Water Sci Technol, 2023 Dec;88(12):3142-3150.
PMID: 38154800 DOI: 10.2166/wst.2023.398

This study aims to recover the used coagulants from two water treatment plants via acidification technique. The water treatment sludge (WTS) was acidified with sulfuric acid (H2SO-4) at variable normalities (0.5, 1, 1.5, 2.0 and 2.5 N). The surface morphology and functionalities of both recovered coagulants were analysed using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The performance of recovered coagulants was tested for turbidity removal in surface water treatment at different coagulant dosages and pH. It was found that the optimum normality of H2SO4 for recovered alum was 1.5 N, where 66% turbidity removal was recorded. The recovered PAC treated with 1.0 N H2SO4 indicated high turbidity removal percentage, which was 50.5%. The turbidity removal increased with increasing coagulant dosage. More than 80% turbidity removal was achieved with 40 mg/L dosage of recovered alum and recovered PAC. Maximum removal (85%) was observed with 50 mg/L dosage of recovered alum. For commercial coagulant, the turbidity removal was higher, with a difference of up to 6% in favor of recovered alum. The potential reuse of coagulants can be explored in order to reduce the operating costs and promotes the reduction of WTS disposal.

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