Displaying publications 1 - 20 of 44 in total

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  1. Hameed BH, Rahman AA
    J Hazard Mater, 2008 Dec 30;160(2-3):576-81.
    PMID: 18434009 DOI: 10.1016/j.jhazmat.2008.03.028
    Activated carbon derived from rattan sawdust (ACR) was evaluated for its ability to remove phenol from an aqueous solution in a batch process. Equilibrium studies were conducted in the range of 25-200mg/L initial phenol concentrations, 3-10 solution pH and at temperature of 30 degrees C. The experimental data were analyzed by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. Equilibrium data fitted well to the Langmuir model with a maximum adsorption capacity of 149.25mg/g. The dimensionless separation factor RL revealed the favorable nature of the isotherm of the phenol-activated carbon system. The pseudo-second-order kinetic model best described the adsorption process. The results proved that the prepared activated carbon was an effective adsorbent for removal of phenol from aqueous solution.
  2. Sirat HM, Jamil S, Rahman AA
    Nat Prod Commun, 2009 Sep;4(9):1171.
    PMID: 19831021
    From the rhizomes of Curcuma ochrorhiza, four sesquiterpenes, isofuranodiene, germacrene, furanogermenone and zederone, have been isolated, the structures of which have been elucidated by spectroscopic methods.
  3. Baharum MI, Kuppuswamy R, Rahman AA
    Forensic Sci Int, 2008 May 20;177(2-3):221-7.
    PMID: 18313246 DOI: 10.1016/j.forsciint.2008.01.004
    A study has been made of the characteristics of restoration of obliterated engraved marks on aluminium surfaces by etching technique. By etching different reagents on 0.61mm thick sheets of aluminium (99wt%) on which some engraved marks had been erased to different depths it was found that the reagent 60% hydrochloric acid and 40% sodium hydroxide on alternate swabbing on the surfaces was found to be the most sensitive one for these metal surfaces. This reagent was able to restore marks in the above plates erased down to 0.04mm below the bottom of the engraving. The marks also presented excellent contrast with the background. This reagent was further experimented with similar aluminium surfaces, but of relatively greater thickness of 1.5mm. It was noticed that the recovery depth increased slightly to 0.06mm; this suggested the dependence of recovery depth on the thickness of the sheet metal. Further, the depth of restoration decreased in cases where the original number was erased and over which a new number was engraved; the latter results are similar to those of steel surfaces reported earlier [M.A.M. Zaili, R. Kuppuswamy, H. Harun, Restoration of engraved marks on steel surfaces by etching technique, Forensic Sci. Int. 171 (2007) 27-32].
  4. Sirat HM, Rahman AA, Itokawa H, Morita H
    Planta Med, 1996 Apr;62(2):188-9.
    PMID: 17252439
  5. Tong T, Iqbal K, Rahman AA
    Front Psychol, 2022;13:959448.
    PMID: 35936275 DOI: 10.3389/fpsyg.2022.959448
    The purpose of this study was to examine the effect of core technology competence on the competitive advantage of high-tech SMEs (small- and mid-sized enterprises in China). Based on the 379 valid responses collected from a survey, structural equation modeling (SEM) was employed to examine the research model. Infrastructure and technology, state-of-the-art technology, innovative research and development (R&D) capability, and organizational flexibility all have a significant impact on the competitive advantage, while infrastructure and technology, state-of-the-art technology, and innovative R&D capability have a significant effect on organizational flexibility. Organizational flexibility plays a mediating role between innovative R&D capability's effect and competitive advantage. Under the continuous influence of COVID-19, we should promote development from the perspective of strengthening enterprise infrastructure and technology and improving organizational flexibility to gain a competitive advantage. This study reveals the internal relationship between core technology competence, organizational flexibility, and competitive advantage. The results of this study will help us to fully understand the survival status and competitive advantage of high-tech SMEs under COVID-19.
  6. Taha M, Naz H, Rahman AA, Ismail NH, Yousuf S
    Acta Crystallogr Sect E Struct Rep Online, 2012 Oct 1;68(Pt 10):o2846.
    PMID: 23125650 DOI: 10.1107/S1600536812036550
    The title compound, C(15)H(14)N(2)O(5)·CH(3)OH, displays an E conformation about the azomethine double bond [C=N = 1.277 (2) Å] and the benzene rings are inclined to one another by 18.28 (9)°. An intra-molecular O-H⋯O hydrogen bond occurs between the para-OH group and one of the meta-O atoms of the 3,4,5-trihy-droxy-benzyl-idene group. In the crystal, the components are linked into a three dimensional network by O-H⋯O, O-H⋯N and C-H⋯O hydrogen bonds.
  7. Rahman AA, Usman A, Chantrapromma S, Fun HK
    Acta Crystallogr C, 2003 Sep;59(Pt 9):i92-4.
    PMID: 12944636
    A sample of hydronium perchlorate, H(3)O(+) x ClO(4)(-), crystallized from ethanol at ambient temperature, was found to be orthorhombic (space group Pnma) at both 193 and 293 K, with no phase transition observed in this temperature range. This contrasts with the earlier observation [Nordman (1962). Acta Cryst. 15, 18-23] of a monoclinic phase (space group P2(1)/n) at 193 K for crystals grown at that temperature from perchloric acid. The hydronium and perchlorate ions lie across a mirror plane but it is not possible to define at either temperature a simple description of the H-atom positions due to the three-dimensional tumbling of the hydronium cation.
  8. Zulkifli S, Rahman AA, Kadir SHSA, Nor NSM
    Eur J Pediatr, 2021 Oct;180(10):3111-3127.
    PMID: 33893858 DOI: 10.1007/s00431-021-04085-0
    For the past two decades, growing research has been pointing to multiple repercussions of bisphenol A (BPA) exposure to human health. BPA is a synthetic oestrogen which primarily targets the endocrine system; however, the compound also disturbs other systemic organ functions, in which the magnitude of impacts in those other systems is as comparable to those in the endocrine system. To date, the discoveries on the association between BPA and health outcomes mainly came from animal and in vitro studies, with limited human studies which emphasised on children's health. In this comprehensive review, we summarised studies on human, in vivo and in vitro models to understand the consequences of pre-, post- and perinatal BPA exposure on the perinatal, children and adult health, encompassing cardiovascular, neurodevelopmental, endocrine and reproductive effects.Conclusion: Evidence from in vitro and animal studies may provide further support and better understanding on the correlation between environmental BPA exposure and its detrimental effects in humans and child development, despite the difficulties to draw direct causal relations of BPA effects on the pathophysiology of the diseases/syndromes in children, due to differences in body system complexity between children and adults, as well as between animal and in vitro models and humans. What is known: • Very limited reviews are available on how BPA adversely affects children's health. • Previous papers mainly covered two systems in children. What is new: • Comprehensive review on the detrimental effects of BPA on children health outcomes, including expectations on adult health outcomes following perinatal BPA exposure, as well as covering a small part of BPA alternatives. • Essentially, BPA exposure during pregnancy has huge impacts on the foetus in which it may cause changes in foetal epigenetic programming, resulting in disease onsets during childhood as well as adulthood.
  9. Omar M, Abdul Rahman AA, Mohd Hussein AM, Mustafa N
    Family Physician, 2005;13(3):15-15.
    MyJurnal
    Osteopoikilosis is a rare bone dysplasia which is inherited as an autosomal dominant trait with a prevalence of less than 0.1 per million.1 It is characterised by dense ovoid or circular spots in cancellous bone which may appear at birth or during skeletal growth. It is usually found in the metaphyseal and epiphyseal regions of long bones, the carpals and tarsals, the end of large turbular bones and around the acetabula. It is clinically asymptomatic and occasionally associated with hereditary multiple exostosis and dermatofibrosis lenticularis disseminata. It is not associated with spontaneous fractures and treatment is unnecessary. However a case of osteosarcoma developing in a man with osteopoikilosis has been reported. The first case of osteopoikilosis was reported in Malaysia four years ago in a 25 years old lady who is also of Indian descent. It would be interesting to know if these two patients are related. Since the bone lesions could easily be mistaken for metastatic disease, it is important that family physicians be aware of the benign nature of this condition.
  10. Mohamad NA, Rahman AA, Sheikh Abdul Kadir SH
    Oncol Lett, 2023 Jan;25(1):34.
    PMID: 36589673 DOI: 10.3892/ol.2022.13620
    Piper betle leaves are widely cultivated in Malaysia, India, Indonesia and Thailand. They have been used as a traditional medicine for centuries due to their medicinal properties, including antioxidant, antiproliferative, antibacterial, antifungal and anti-inflammatory properties, which are attributable to their high phenolic contents. Hydroxychavicol (HC), a primary constituent of P. betle leaves, is known to possess antiproliferative activity at micromolar doses on various cancer cell lines of different origins while leaving normal cells unharmed. The present review summarises the mechanisms of action of HC reported in the literature, reviews the scope of work done thus far and outlines the direction of future research on the potential of HC as an anticancer agent. PubMed, Scopus and Web of Science were searched using the keywords (hydroxychavicol OR 4-allylpyrocatechol OR 4-allylcatechol) AND (cancer OR carcinogenesis OR tumour OR carcinoma) to acquire research articles. In vitro studies reported several possible mechanisms for the chemopreventive effects of HC against cancer cell lines, including chronic myelogenous leukaemia (CML), prostate, glioma, breast and colorectal cancers, while in vivo studies encompassed investigations on Ehrlich ascites carcinoma cells in Swiss albino mice and a CML mouse model. These studies suggest that HC exerts its anticancer effect via the modulation of mitochondrial membrane potential and the c-Jun N-terminal kinase, mitogen-activated protein kinase and endoplasmic reticulum-unfolded protein responses pathways and the generation of reactive oxygen species. In summary, future research should focus on combinations of HC with other anticancer drugs and testing in animal models to evaluate its bioavailability, potency and tissue and dose selectivity.
  11. Jingwen Y, Rahman AA, Tong T, Kamarulzaman NH, Sidek SB
    PLoS One, 2025;20(1):e0310854.
    PMID: 39869571 DOI: 10.1371/journal.pone.0310854
    Small and medium-sized enterprises (SMEs) can gain a competitive advantage by implementing business model innovation (BMI), which is characterized as irreversible changes to a company's business model. However, BMI is often associated with high risk, uncertainty, and ambiguity. In this study, the effectiveness of BMI on improving SME performance is examined using structural equation modeling (SEM) based on data collected from 330 Chinese SMEs. The purpose of this paper is to examine how enterprise risk management (ERM), organizational agility (OA), and entrepreneurial orientation (EO) affect SME performance. The results reveal that ERM, OA, and EO all have a positive impact on efficiency-centered BMI and SME performance; efficiency-centered BMI mediates this pathway. Building on dynamic capabilities theory, this paper combines ERM, OA, and EO into one framework to assess their impact on SME performance. Additionally, a case study is presented to provide suggestions for making decisions about BMI implementation.
  12. Rahman AA, Makpol S, Jamal R, Harun R, Mokhtar N, Ngah WZ
    Molecules, 2014 Sep 12;19(9):14528-41.
    PMID: 25221872 DOI: 10.3390/molecules190914528
    Plant bioactives [6]-gingerol (GING), epigallocatechin gallate (EGCG) and asiaticoside (AS) and vitamin E, such as tocotrienol-rich fraction (TRF), have been reported to possess anticancer activity. In this study, we investigated the apoptotic properties of these bioactive compounds alone or in combination on glioma cancer cells. TRF, GING, EGCG and AS were tested for cytotoxicity on glioma cell lines 1321N1 (Grade II), SW1783 (Grade III) and LN18 (Grade IV) in culture by the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) (MTS) assay. With the exception of AS, combinations of two compounds were tested, and the interactions of each combination were evaluated by the combination index (CI) using an isobologram. Different grades of glioma cancer cells showed different cytotoxic responses to the compounds, where in 1321N1 and LN18 cells, the combination of EGCG + GING exhibited a synergistic effect with CI = 0.77 and CI = 0.55, respectively. In contrast, all combinations tested (TRF + GING, TRF + EGCG and EGCG + GING) were found to be antagonistic on SW1783 with CI values of 1.29, 1.39 and 1.39, respectively. Combined EGCG + GING induced apoptosis in both 1321N1 and LN18 cells, as evidenced by Annexin-V FITC/PI staining and increased active caspase-3. Our current data suggests that the combination of EGCG + GING synergistically induced apoptosis and inhibits the proliferation 1321N1 and LN18 cells, but not SW1783 cells, which may be due to their different genetic profiles.
  13. Abidin NZ, Zulkifli A, Abidin EZ, Rasdi I, Ismail SN, Rahman AA, et al.
    Int J Tuberc Lung Dis, 2014 Jul;18(7):856-61.
    PMID: 24902566 DOI: 10.5588/ijtld.13.0906
    OBJECTIVE: To identify the relationship between knowledge, attitude and perception regarding environmental tobacco smoke (ETS) and smoking among Malaysian adolescents living in states with complete or partial smoke-free legislation (SFL).
    METHODS: A total of 898 respondents aged 13-14 years were randomly selected from 21 secondary schools. The Malay version of the modified Global Youth Tobacco Survey questionnaire was used. Hierarchical logistic regression was performed in examining predictors of smoking attempt among adolescents.
    RESULTS: Participants exposed to ETS >5 h/day were more likely to have smoked compared to those exposed to ETS <1 h/day (OR 4.1, 95%CI 1.03-16.0). Living in a state with partial SFL was associated with a two-fold increase in self-reported smoking attempts (OR 1.95, 95%CI 1.10-3.43) compared to living in a state with complete SFL. Negative attitudes and perceptions towards smoking and ETS exposure were linked to lower smoking attempts in states with complete SFL.
    CONCLUSIONS: Adolescents with limited ETS exposure who lived in a state with complete SFL were less likely to attempt smoking compared to those exposed more regularly to ETS and living in a state with partial SFL. Preventing adolescents from becoming smokers is the key to reducing national prevalence rates in smoking. There is a need to implement comprehensive smoke-free legislation nationally across Malaysia.
  14. Yusof MS, Razali NR, Arshad S, Rahman AA, Razak IA
    PMID: 24046599 DOI: 10.1107/S1600536813014268
    In the title mol-ecule, C23H22N2OS, the di-phenyl-acetyl and ethyl-benzene groups adopt a trans-cis conformation, respectively, with respect to the S atom across the (S=)C-N bonds. This conformation is stabilized by an intra-molecular N-H⋯O hydrogen bond and a weak C-H⋯S hydrogen bond. The ethyl-substituted benzene ring forms dihedral angles of 87.53 (15) and 73.94 (15)° with the phenyl rings. In the crystal, N-H⋯O hydrogen bonds link mol-ecules into chains along [100]. A weak C-H⋯π inter-action is also observed.
  15. Yusof MS, Razali NR, Arshad S, Rahman AA, Razak IA
    PMID: 24109341 DOI: 10.1107/S1600536813018680
    The title mol-ecule, C22H17F3N2OS, adopts a trans-cis conformation with respect to the positions of the carbonyl and tri-fluoro-methyl-benzene groups against the thio-carbonyl group across the C-N bonds. The mol-ecular structure is stabilized by an intra-molecular N-H⋯O hydrogen bond with an S(6) ring motif. The tri-fluoro-methyl-substituted benzene ring forms dihedral angles of 66.05 (9) and 47.19 (9)° with the terminal phenyl rings and is twisted from the O=C-N-(C=S)-N carbonyl-thio-urea plane [maximum deviation = 0.0535 (12) Å], making a dihedral angle of 63.59 (8)°. In the crystal, N-H⋯O and C-H⋯F hydrogen bonds link the mol-ecules into a layer parallel to the bc plane. A C-H⋯π inter-action is also observed.
  16. Yusof MS, Razali NR, Arshad S, Rahman AA, Razak IA
    PMID: 23795124 DOI: 10.1107/S1600536813013354
    In the title compound, C25H26N2OS, the diethyl-substituted benzene ring forms dihedral angles of 67.38 (9) and 55.32 (9)° with the terminal benzene rings. The mol-ecule adopts a trans-cis conformation with respect to the orientations of the di-phenyl-methane and 1,3-di-ethyl-benzene groups with respect to the S atom across the C-N bonds. This conformation is stabilized by an intra-molecular N-H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, pairs of N-H⋯S hydrogen bonds link the mol-ecules into inversion dimers, forming R 2 (2)(6) loops. The dimer linkage is reinforced by a pair of C-H⋯S hydrogen bonds, which generate R 2 (2)(8) loops. Weak C-H⋯π and π-π [centroid-centroid seperation = 3.8821 (10) Å] inter-actions also occur in the crystal structure.
  17. Hamat RA, Rahman AA, Osman M, Unyah NZ, Abdullah WO, Isa NH
    Trans R Soc Trop Med Hyg, 2010 Feb;104(2):170-2.
    PMID: 19732927 DOI: 10.1016/j.trstmh.2009.07.019
    Cutaneous larva migrans is a common parasitic skin disease that can be easily prevented by wearing 'protective' footwear. However, this has been under-emphasized in terms of what constitutes the protective footwear. Even though the disease resolves spontaneously, the significant duration of the disease along with severity of pruritus make treatment unavoidable. Here, we present a very long-standing creeping eruption, which puzzled many attending clinicians handling the case, and the possibility of long socks as a causal effect on the development of cutaneous larva migrans infection.
  18. Mustafa IS, Kamari HM, Yusoff WM, Aziz SA, Rahman AA
    Int J Mol Sci, 2013;14(2):3201-14.
    PMID: 23380963 DOI: 10.3390/ijms14023201
    Spectrophotometric studies of lead borotellurite glasses were carried out before and after gamma irradiation exposure. The increasing peak on the TeO(4) bi-pyramidal arrangement and TeO(3+1) (or distorted TeO(4)) is due to augmentation of irradiation dose which is attributed to an increase in degree of disorder of the amorphous phase. The structures of lead tellurate contain Pb(3)TeO(6) consisting of TeO(3) trigonal pyramid connected by PbO(4) tetragonal forming a three-dimensional network. The decrease of glass rigidity is due to irradiation process which is supported by the XRD diffractograms results. The decreasing values of absorption edge indicate that red shift effect occur after irradiation processes. A shift in the optical absorption edge attributed to an increase of the conjugation length. The values of optical band gap, E(opt) were calculated and found to be dependent on the glass composition and radiation exposure. Generally, an increase and decrease in Urbach's energy can be considered as being due to an increase in defects within glass network.
  19. Habsah M, Amran M, Mackeen MM, Lajis NH, Kikuzaki H, Nakatani N, et al.
    J Ethnopharmacol, 2000 Oct;72(3):403-10.
    PMID: 10996279
    Dichloromethane and methanol extracts of 13 Zingiberaceae species from the Alpinia, Costus and Zingiber genera were screened for antimicrobial and antioxidant activities. The antimicrobial activity of most of the extracts was antibacterial with only the methanol extract of Costus discolor showing very potent antifungal activity against only Aspergillus ochraceous (MID, 15.6 microg per disc). All the extracts showed strong antioxidant activity comparable with or higher that of alpha-tocopherol.
  20. Yusof F, Mehde AA, Mehdi WA, Raus RA, Ghazali H, Rahman AA
    Biomed Environ Sci, 2015 Sep;28(9):660-5.
    PMID: 26464253 DOI: 10.3967/bes2015.092
    OBJECTIVE: Nephrolithiasis is one of the most common disorders of the urinary tract. The aim of this study was to examine a possible relationship between DNase I/II activity and E3 SUMO-protein ligase NSE2 in the sera of nephrolithiasis patients to evaluate the possibility of a new biomarker for evaluating kidney damage.
    METHODS: Sixty nephrolithiasis patients and 50 control patients were enrolled in a case-control study. Their blood urea, creatinine, protein levels and DNase I/II activity levels were measured by spectrometry. Serum NSMCE2 levels were measured by ELISA. Blood was collected from patients of the government health clinics in Kuantan-Pahang and fulfilled the inclusion criteria.
    RESULTS: The result indicated that mean levels of sera NSMCE2 have a significantly increase (P<0.01) in patients compared to control group. Compared with control subjects, activities and specific activities of serum DNase I and II were significantly elevated in nephrolithiasis patients (P$lt;0.01).
    CONCLUSION: This study suggests that an increase in serum concentrations of DNase I/II and E3 SUMO-protein ligase NSE2 level can be used as indicators for the diagnosis of kidney injury in patients with nephrolithiasis.
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