Displaying publications 1 - 20 of 167 in total

Abstract:
Sort:
  1. Zainordin NH, Abd Talib R, Shahril MR, Sulaiman S, A Karim N
    Asian Pac J Cancer Prev, 2020 Dec 01;21(12):3689-3696.
    PMID: 33369469 DOI: 10.31557/APJCP.2020.21.12.3689
    OBJECTIVE: Fear of cancer recurrent, side effects of treatment and belief in food taboos encourage cancer survivors to make changes in their dietary practices after diagnosis of cancer. The objective of this study was to determine the impact of dietary changes on quality of life (QoL) among Malay breast and gynaecological cancer survivors.

    METHODS: Questionnaire of dietary changes was modified from WHEL study and adapted to typical Malay's food intake in Malaysia. A total of 23 items were listed and categorized by types of food and cooking methods.  Four categories of changes "increased", "decreased", "no changes" or "stopped" were used to determine the changes in dietary practices. Score one (+1) is given to positive changes by reference to WCRF/AICR and Malaysia Dietary Guideline healthy eating recommendations. Malay EORTC QLQ-C30 were used to determine the QoL. Sociodemographic, clinical characteristics and anthropometric measurement were also collected.

    RESULTS: The mean age of the subjects (n=77) was 50.7±7.8 years old with duration of survivorship 4.0±3.1 years. Subjects mean BMI was 27.8±4.9 kg/m2 which indicate subjects were 31.2% overweight and 32.5% obese. The percentage score of positive dietary changes was 34.7±16.4%. Positive dietary changes were increased intake of green leafy vegetable (49.4%), cruciferous vegetable (46.8%) and boiling cooking methods (45.5%). Subjects reduced their intake of red meat (42.9%), sugar (53.2%) and fried cooking method (44.2%). Subjects stopped consuming milk (41.6%), c 2008-5862 heese (33.8%) and sweetened condensed milk (33.8%). With increasing positive dietary changes, there was a significant improvement on emotional function (rs=0.27; p=0.016) and reduced fatigue symptoms (rs=-0.24; p=0.033).

    CONCLUSION: Positive changes in dietary intake improved emotional function and reduced fatigue symptoms after cancer treatment. By knowing the trend of food changes after cancer treatment, enables the formation of healthy food intervention implemented more effective.

  2. Zaharim WN, Ahmad SNA, Sulaiman S, Rozak H, Hasan Baseri DF, Mohamad Rosli NA, et al.
    ACS Omega, 2021 Nov 09;6(44):29641-29650.
    PMID: 34778635 DOI: 10.1021/acsomega.1c03956
    Density functional theory method at the B3LYP/6-31G level was used to determine the structure of 12mer single-strand guanine oligomers. The length and width of the optimized structure are 38.7 and 18.2 Å, respectively, and the observed high-resolution transmission electron microscopy image of the 12mer single-strand guanine sample shows similar oligomer dimensions with the calculated ones. Both HOMO and LUMO are significantly delocalized, and the calculated HOMO-LUMO gap is 3.31 eV. A total of 96 muonium trapping sites at C2, C4, C5, C6, C8, N3, N7, and O6 were investigated. All 12 C8 sites have lower energy than the other 84 sites and are clustered in the energy-muon hyperfine coupling constant scatter plot. The calculated muon hyperfine coupling constant at C8 sites range from 384.6 to 481.1 MHz, and the corresponding estimated ALC-μSR resonance for |ΔM| = 1 range from 1.419 to 1.775 T.
  3. Yusof YA, Ahmad N, Das S, Sulaiman S, Murad NA
    Afr J Tradit Complement Altern Med, 2008 Oct 25;6(1):87-93.
    PMID: 20162046
    Ginger (Zingiber officinale Rosco) is widely used in foods as a spice all around the world. It has been reported to have antioxidant and anticarcinogenic properties. We investigated the effect of ginger in ethionine induced rat hepatocarcinogenesis. Male Wistar rats were divided into 5 groups: group 1 and 2 served as controls and they received normal rat chow and olive oil respectively. Group 3 was fed with ginger oleoresin dissolved in olive oil at 100 mg/kg body wt. Group 4 was fed with choline deficient diet and 0.1% ethionine in drinking water (CDE diet), and group 5 received ginger with CDE diet. Blood samples were taken from the orbital sinus at 0 and 8 weeks of experiment for the determination of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase and lipid peroxidation end product, malondialdehyde (MDA). Rats were also killed at 8 weeks for the observation of liver tumor formation. CDE diet induced the formation of liver nodules in rats and increased SOD activity. However, it had no effect on catalase, GPx and MDA levels when compared to both controls at 8 weeks of experiment. When CDE rats were treated with ginger, the formation of liver tumour, SOD activity and MDA level reduced, catalase activity was increased but no change was observed for GPx activity when compared to CDE group. In conclusion, ginger supplementation suppressed liver carcinogenesis by scavenging the free radical formation, and by reducing lipid peroxidation.
  4. Yeow TC, Wong WF, Sabet NS, Sulaiman S, Shahhosseini F, Tan GM, et al.
    BMC Microbiol, 2016 Mar 18;16:45.
    PMID: 26987367 DOI: 10.1186/s12866-016-0671-1
    BACKGROUND: The 7.5 kb cryptic plasmid of Chlamydia trachomatis has been shown to be a virulence factor in animal models, but its significance in humans still remains unknown. The aim of this study was to investigate the prevalence and potential involvement of the C. trachomatis cryptic plasmid in causing various clinical manifestations; including infertility, reproductive tract disintegrity, menstrual disorder, and polycystic ovarian syndrome (PCOS) among genital C. trachomatis-infected patients.
    RESULTS:A tot l of 180 female patients of child bearing age (mean 30.9 years old, IQR:27-35) with gynecological complications and subfertility issues, who visited Obstetrics and Gynecology clinics in Kuala Lumpur, Malaysia were recruited for the study. Prevalence of genital chlamydial infection among these patients was alarmingly high at 51.1% (92/180). Of the 92 chlamydia-infected patients, 93.5% (86/92) were infected with plasmid-bearing (+) C. trachomatis while the remaining 6.5% (6/92) were caused by the plasmid-free (-) variant. Our data showed that genital C. trachomatis infection was associated with infertility issues, inflammation in the reproductive tract (mucopurulent cervicitis or endometriosis), irregular menstrual cycles and polycystic ovarian syndrome (PCOS). However, no statistical significance was detected among patients with plasmid (+) versus plasmid (-) C. trachomatis infection. Interestingly, plasmid (+) C. trachomatis was detected in all patients with PCOS, and the plasmid copy numbers were significantly higher among PCOS patients, relative to non-PCOS patients.
    CONCLUSION: Our findings show a high incidence of C. trachomatis infection among women with infertility or gynecological problems in Malaysia. However, due to the low number of plasmid (-) C. trachomatis cases, a significant role of the plasmid in causing virulence in human requires further investigation of a larger cohort.
    KEYWORDS: Chlamydia trachomatis; Infertility; Plasmid; Reproductive system disorders
    Study site: Obstetrics and Gynecology clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
  5. Yap KH, Sulaiman S
    Singapore Med J, 2009 Jul;50(7):e247-9.
    PMID: 19644610
    Pulmonary atelectasis may be caused by endobronchial lesions or by extrinsic compression of the bronchus. However, lung collapse due to compression from a thoracic aneurysm is uncommon. We report a 76-year-old hypertensive female patient who has pulmonary atelectasis due to an extrinsic compression from a descending thoracic aortic aneurysm, and discuss possible treatment options.
  6. We ACE, Aris A, Zain NAM, Muda K, Sulaiman S
    Chemosphere, 2021 Jan;263:128209.
    PMID: 33297168 DOI: 10.1016/j.chemosphere.2020.128209
    The present work investigates the feasibility of aerobic granulation for the treatment of low-medium strength domestic wastewater for long-term operation and effects of a static mixer on the properties and removal performances of the aerobic granules formed. The static mixer was installed in a sequential batch reactor to provide higher hydrodynamic shear force in enhancing the formation of the aerobic granules. Aerobic granules were successfully formed in the domestic wastewater, and the granulation treatment system was sustained for a period of 356 days without granules disintegration. Subsequent to the installation, aerobic granules with a low SVI30 of 41.37 mL/gTSS, average diameter 1.11 mm, granular strength with integrity coefficient 10.4% and regular shape with minimum filamentous outgrowth were formed. Mineral concentrations such as Fe, Mg, Ca and Na as well as composition of protein and polysaccharide in tightly bound-extracellular polymeric substance of the aerobic granules were found to be higher under the effect of the static mixer. However, no significant improvement was observed on the TCOD, NH4+-N and TSS removal performance. Good TCOD and TSS removal performance of above 85% and 90%, respectively and moderate NH4+-N removal performance of about 60% were observed throughout the study. Higher simultaneous nitrification and denitrification (SND) efficiency of 56% was observed after the installation of the static mixer, as compared to 21% prior. Therefore, it may be concluded that the installation of the static mixer significantly improved the properties of aerobic granules formation and SND efficiency but not the TCOD, NH4+-N and TSS removal performance.
  7. Teah YF, Abduraman MA, Amanah A, Adenan MI, Fariza Sulaiman S, Tan ML
    Data Brief, 2017 Oct;14:584-591.
    PMID: 28879216 DOI: 10.1016/j.dib.2017.08.008
    The data presented in this article are related to the research article entitled "The effects of deoxyelephantopin on the cardiac delayed rectifier potassium channel current (IKr) and human ether-a-go-go-related gene (hERG) expression" (Y.F. Teah, M.A. Abduraman, A. Amanah, M.I. Adenan, S.F. Sulaiman, M.L. Tan) [1], which the possible hERG blocking properties of deoxyelephantopin were investigated. This article describes the construction of human embryonic kidney 293 (HEK293) cells overexpressing HERG potassium channel and verification of the presence of hERG mRNA and protein expression in this recombinant cell line.
  8. Tay ST, Lotfalikhani A, Sabet NS, Ponnampalavanar S, Sulaiman S, Na SL, et al.
    Mycopathologia, 2014 Oct;178(3-4):307-14.
    PMID: 25022264 DOI: 10.1007/s11046-014-9778-9
    BACKGROUND: Candida nivariensis and C. bracarensis have been recently identified as emerging yeast pathogens which are phenotypically indistinguishable from C. glabrata. However, there is little data on the prevalence and antifungal susceptibilities of these species.

    OBJECTIVE: This study investigated the occurrence of C. nivariensis and C. bracarensis in a culture collection of 185 C. glabrata isolates at a Malaysian teaching hospital.

    METHODS: C. nivariensis was discriminated from C. glabrata using a PCR assay as described by Enache-Angoulvant et al. (J Clin Microbiol 49:3375-9, 2011). The identity of the isolates was confirmed by sequence analysis of the D1D2 domain and internal transcribed spacer region of the yeasts. The isolates were cultured on Chromogenic CHROMagar Candida (®) agar (Difco, USA), and their biochemical and enzymic profiles were determined. Antifungal susceptibilities of the isolates against amphotericin B, fluconazole, voriconazole and caspofungin were determined using E tests. Clotrimazole MICs were determined using a microbroth dilution method.

    RESULTS: There was a low prevalence (1.1 %) of C. nivariensis in our culture collection of C. glabrata. C. nivariensis was isolated from a blood culture and vaginal swab of two patients. C. nivariensis grew as white colonies on Chromogenic agar and demonstrated few positive reactions using biochemical tests. Enzymatic profiles of the C. nivariensis isolates were similar to that of C. glabrata. The isolates were susceptible to amphotericin B, fluconazole, voriconazole and caspofungin. Clotrimazole resistance is suspected in one isolate.

    CONCLUSION: This study reports for the first time the emergence of C. nivariensis in our clinical setting.

  9. Tan SL, Sulaiman S, Pingguan-Murphy B, Selvaratnam L, Tai CC, Kamarul T
    Cell Tissue Bank, 2011 Feb;12(1):59-70.
    PMID: 19953328 DOI: 10.1007/s10561-009-9164-x
    This study investigates the feasibility of processed human amnion (HAM) as a substrate for chondrogenic differentiation of mesenchymal stem cells (MSCs). HAM preparations processed by air drying (AD) and freeze drying (FD) underwent histological examination and MSC seeding in chondrogenic medium for 15 days. Monolayer cultures were used as control for chondrogenic differentiation and HAMs without cell seeding were used as negative control. Qualitative observations were made using scanning electron microscopy analysis and quantitative analyses were based on the sulfated glycosaminoglycans (GAG) assays performed on day 1 and day 15. Histological examination of HAM substrates before seeding revealed a smooth surface in AD substrates, while the FD substrates exhibited a porous surface. Cell attachment to AD and FD substrates on day 15 was qualitatively comparable. GAG were significantly highly expressed in cells seeded on FD HAM substrates. This study indicates that processed HAM is a potentially valuable material as a cell-carrier for MSC differentiation.
  10. Tan PC, Khine PP, Sabdin NH, Vallikkannu N, Sulaiman S
    J Ultrasound Med, 2011 Feb;30(2):227-33.
    PMID: 21266561
    OBJECTIVES: The purpose of this study was to evaluate cervical length changes after membrane sweeping and the effect of cervical shortening on pregnancy outcomes.

    METHODS: Low-risk women at 40 weeks' gestation undergoing membrane sweeping to expedite labor were recruited. Participants were scheduled for labor induction at 41 weeks' gestation. Transvaginal ultrasonography was performed immediately before and after membrane sweeping to measure the cervical length. Three presweep and postsweep cervical lengths were measured. The shortest lengths before and after the sweep were taken as the representative lengths. The effect of membrane sweeping on cervical length was analyzed. Multivariable logistic regression analysis was performed to evaluate the effect of cervical shortening on labor induction and the mode of delivery.

    RESULTS: For the 160 participants, the mean presweep cervical length ± SD was 21.0 ± 10.0 mm; the postsweep length was 23.8 ± 10.9 mm, an average increase of 2.8 ± 0.6 mm (P < .001). Cervical shortening after membrane sweeping was noted in 53 of 160 cases (33%). Cervical shortening was associated with a reduction in all-cause cesarean delivery but not labor induction on bivariate analysis. After adjustment for maternal age, parity, presweep Bishop score, postsweep cervical length, oxytocin augmentation, epidural analgesia, and meconium-stained fluid, cervical shortening after membrane sweeping was independently predictive of a reduction in cesarean deliveries (adjusted odds ratio, 0.24; 95% confidence interval, 0.06-0.90; P = .034).

    CONCLUSIONS: Membrane sweeping was associated with lengthening of the cervix. A shortened cervix after sweeping was independently predictive of vaginal delivery.

  11. Tan PC, Soe MZ, Sulaiman S, Omar SZ
    Obstet Gynecol, 2013 Feb;121(2 Pt 1):253-259.
    PMID: 23344273 DOI: 10.1097/AOG.0b013e31827e7fd9
    OBJECTIVE: To compare immediate with delayed (4 hours) oxytocin infusion after amniotomy on vaginal delivery within 12 hours and patient satisfaction with the birth process.

    METHODS: Parous women with favorable cervixes after amniotomy for labor induction were randomized to immediate titrated oxytocin or placebo intravenous infusion in a double-blind noninferiority trial. After 4 hours, study infusions were stopped, the women were assessed, and open-label oxytocin was started if required. Maternal satisfaction with the birth process was assessed with a 10-point visual numerical rating scale (lower score, greater satisfaction).

    RESULTS: Vaginal delivery rates at 12 hours were 91 of 96 (94.8%) compared with 91 of 94 (96.8%) (relative risk 0.98, 95% confidence interval [CI] 0.92-1.04, P=.72), and maternal satisfaction on a visual numerical rating scale (median [interquartile range]) was 3 [3-4] compared with 3 [3-5], P=.36 for immediate compared with delayed arm, respectively). Cesarean delivery, maternal fever, postpartum hemorrhage, uterine hyperactivity, and adverse neonatal outcome rates were similar between arms. The immediate oxytocin arm had a shorter amniotomy-to-delivery interval of 5.3±3.1 compared with 6.9±2.9 hours (P

  12. Tan ML, Muhammad TS, Najimudin N, Sulaiman SF
    J Ethnopharmacol, 2005 Jan 15;96(3):375-83.
    PMID: 15619555
    Epipremnum pinnatum (L.) Engl. hexane extract produced a significant growth inhibition against T-47D breast carcinoma cells and analysis of cell death mechanisms indicated that the extract elicited a non-apoptotic programmed cell death. T-47D cells exposed to the extract at EC(50) concentration (72 h) for 24 h failed to demonstrate typical DNA fragmentation associated with apoptosis, as carried out using a modified TUNEL assay. In addition, acute exposure to the extract produced an insignificant regulation of caspase-3 and p53 mRNA expression but increased in the c-myc mRNA expression. Ultrastructural analysis using transmission electron microscope demonstrated distinct vacuolated cells, which strongly indicated a Type II non-apoptotic cell death although the changes in chromatin were also detected. The presence of non-apoptotic programmed cell death was then reconfirmed with annexin-V and propidium iodide staining. These findings suggested that up-regulation of c-myc mRNA expression may have contributed to the growth arrest and Type II non-apoptotic programmed cell death in the Epipremnum pinnatum (L.) Engl. hexane extract-treated T-47D cells.
  13. Tan ML, Sulaiman SF, Najimuddin N, Samian MR, Muhammad TS
    J Ethnopharmacol, 2005 Jan 4;96(1-2):287-94.
    PMID: 15588681
    Currently, breast cancer is the leading cause of cancer-related death in women. Therefore, there is an urgent need to develop alternative therapeutic measures against this deadly disease. Here, we report the cytotoxicity activity and the mechanism of cell death exhibited by the methanol extract prepared from Pereskia bleo (Kunth) DC. (Cactaceae) plant against human breast carcinoma cell line, T-47D. In vitro cytotoxicity screening of methanol extract of Pereskia bleo plant indicated the presence of cytotoxicity activity of the extract against T-47D cells with EC50 of 2.0 microg/ml. T-47D cell death elicited by the extract was found to be apoptotic in nature based a clear indication of DNA fragmentation which is a hallmark of apoptosis. In addition, ultrastructural analysis also revealed apoptotic characteristics (the presence of chromatin margination and apoptotic bodies) in the extract-treated cells. RT-PCR analysis showed the mRNA expression levels of c-myc, and caspase 3 were markedly increased in the cells treated with the plant extract. However, p53 expression was only slightly increased as compared to caspase 3 and c-myc. Thus, the results from this study strongly suggest that the methanol extract of Pereskia bleo may contain bioactive compound(s) that caused breast carcinoma, T-47D cell death by apoptosis mechanism via the activation of caspase-3 and c-myc pathways.
  14. Tan KK, Sy AK, Tandoc AO, Khoo JJ, Sulaiman S, Chang LY, et al.
    Sci Rep, 2015 Jul 23;5:12279.
    PMID: 26201250 DOI: 10.1038/srep12279
    Outbreaks involving the Asian genotype Chikungunya virus (CHIKV) caused over one million infections in the Americas recently. The outbreak was preceded by a major nationwide outbreak in the Philippines. We examined the phylogenetic and phylogeographic relationships of representative CHIKV isolates obtained from the 2012 Philippines outbreak with other CHIKV isolates collected globally. Asian CHIKV isolated from the Philippines, China, Micronesia and Caribbean regions were found closely related, herein denoted as Cosmopolitan Asian CHIKV (CACV). Three adaptive amino acid substitutions in nsP3 (D483N), E1 (P397L) and E3 (Q19R) were identified among CACV. Acquisition of the nsP3-483N mutation in Compostela Valley followed by E1-397L/E3-19R in Laguna preceded the nationwide spread in the Philippines. The China isolates possessed two of the amino acid substitutions, nsP3-D483N and E1-P397L whereas the Micronesian and Caribbean CHIKV inherited all the three amino acid substitutions. The unique amino acid substitutions observed among the isolates suggest multiple independent virus dissemination events. The possible biological importance of the specific genetic signatures associated with the rapid global of the virus is not known and warrant future in-depth study and epidemiological follow-up. Molecular evidence, however, supports the Philippines outbreak as the possible origin of the CACV.
  15. Tan KK, Zulkifle NI, Sulaiman S, Pang SP, NorAmdan N, MatRahim N, et al.
    BMC Evol. Biol., 2018 04 24;18(1):58.
    PMID: 29699483 DOI: 10.1186/s12862-018-1175-4
    BACKGROUND: Dengue virus type 3 genotype III (DENV3/III) is associated with increased number of severe infections when it emerged in the Americas and Asia. We had previously demonstrated that the DENV3/III was introduced into Malaysia in the late 2000s. We investigated the genetic diversity of DENV3/III strains recovered from Malaysia and examined their phylogenetic relationships against other DENV3/III strains isolated globally.

    RESULTS: Phylogenetic analysis revealed at least four distinct DENV3/III lineages. Two of the lineages (DENV3/III-B and DENV3/III-C) are current actively circulating whereas the DENV3/III-A and DENV3/III-D were no longer recovered since the 1980s. Selection pressure analysis revealed strong evidence of positive selection on a number of amino acid sites in PrM, E, NS1, NS2a, NS2b, NS3, NS4a, and NS5. The Malaysian DENV3/III isolates recovered in the 1980s (MY.59538/1987) clustered into DENV3/III-B, which was the lineage with cosmopolitan distribution consisting of strains actively circulating in the Americas, Africa, and Asia. The Malaysian isolates recovered after the 2000s clustered within DENV3/III-C. This DENV3/III-C lineage displayed a more restricted geographical distribution and consisted of isolates recovered from Asia, denoted as the Asian lineage. Amino acid variation sites in NS5 (NS5-553I/M, NS5-629 T, and NS5-820E) differentiated the DENV3/III-C from other DENV3 viruses. The codon 629 of NS5 was identified as a positively selected site. While the NS5-698R was identified as unique to the genome of DENV3/III-C3. Phylogeographic results suggested that the recent Malaysian DENV3/III-C was likely to have been introduced from Singapore in 2008 and became endemic. From Malaysia, the virus subsequently spread into Taiwan and Thailand in the early part of the 2010s and later reintroduced into Singapore in 2013.

    CONCLUSIONS: Distinct clustering of the Malaysian old and new DENV3/III isolates suggests that the currently circulating DENV3/III in Malaysia did not descend directly from the strains recovered during the 1980s. Phylogenetic analyses and common genetic traits in the genome of the strains and those from the neighboring countries suggest that the Malaysian DENV3/III is likely to have been introduced from the neighboring regions. Malaysia, however, serves as one of the sources of the recent regional spread of DENV3/III-C3 within the Asia region.

  16. Tan KK, Nellis S, Zulkifle NI, Sulaiman S, AbuBakar S
    Epidemiol Infect, 2018 10;146(13):1635-1641.
    PMID: 29860959 DOI: 10.1017/S0950268818001425
    Dengue virus type 3 genotype III (DENV-3/III) is widely distributed in most dengue-endemic regions. It emerged in Malaysia in 2008 and autochthonously spread in the midst of endemic DENV-3/I circulation. The spread, however, was limited and the virus did not cause any major outbreak. Spatiotemporal distribution study of DENV-3 over the period between 2005 and 2011 revealed that dengue cases involving DENV-3/III occurred mostly in areas without pre-existing circulating DENV-3. Neutralisation assays performed using sera of patients with the respective infection showed that the DENV-3/III viruses can be effectively neutralised by sera of patients with DENV-3 infection (50% foci reduction neutralisation titres (FRNT50) > 1300). Sera of patients with DENV-1 infection (FRNT50 ⩾ 190), but not sera of patients with DENV-2 infection (FRNT50 ⩽ 50), were also able to neutralise the virus. These findings highlight the possibility that the pre-existing homotypic DENV-3 and the cross-reacting heterotypic DENV-1 antibody responses could play a role in mitigating a major outbreak involving DENV-3/III in the Klang Valley, Malaysia.
  17. Tan KK, Zulkifle NI, Abd-Jamil J, Sulaiman S, Yaacob CN, Azizan NS, et al.
    Infect Genet Evol, 2017 Oct;54:271-275.
    PMID: 28698156 DOI: 10.1016/j.meegid.2017.07.008
    Dengue is hyperendemic in most of Southeast Asia. In this region, all four dengue virus serotypes are persistently present. Major dengue outbreak cycle occurs in a cyclical pattern involving the different dengue virus serotypes. In Malaysia, since the 1980s, the major outbreak cycles have involved dengue virus type 3 (DENV3), dengue virus type 1 (DENV1) and dengue virus type 2 (DENV2), occurring in that order (DENV3/DENV1/DENV2). Only limited information on the DENV3 cycles, however, have been described. In the current study, we examined the major outbreak cycle involving DENV3 using data from 1985 to 2016. We examined the genetic diversity of DENV3 isolates obtained during the period when DENV3 was the dominant serotype and during the inter-dominant transmission period. Results obtained suggest that the typical DENV3/DENV1/DENV2 cyclical outbreak cycle in Malaysia has recently been disrupted. The last recorded major outbreak cycle involving DENV3 occurred in 2002, and the expected major outbreak cycle involving DENV3 in 2006-2012 did not materialize. DENV genome analyses revealed that DENV3 genotype II (DENV3/II) was the predominant DENV3 genotype (67%-100%) recovered between 1987 and 2002. DENV3 genotype I (DENV3/I) emerged in 2002 followed by the introduction of DENV3 genotype III (DENV3/III) in 2008. These newly emerged DENV3 genotypes replaced DENV3/II, but there was no major upsurge of DENV3 cases that accompanied the emergence of these viruses. DENV3 remained in the background of DENV1 and DENV2 until now. Virus genome sequence analysis suggested that intrinsic differences within the different dengue virus genotypes could have influenced the transmission efficiency of DENV3. Further studies and continuous monitoring of the virus are needed for better understanding of the DENV transmission dynamics in hyperendemic regions.
  18. Tamjidy M, Baharudin BTHT, Paslar S, Matori KA, Sulaiman S, Fadaeifard F
    Materials (Basel), 2017 May 15;10(5).
    PMID: 28772893 DOI: 10.3390/ma10050533
    The development of Friction Stir Welding (FSW) has provided an alternative approach for producing high-quality welds, in a fast and reliable manner. This study focuses on the mechanical properties of the dissimilar friction stir welding of AA6061-T6 and AA7075-T6 aluminum alloys. The FSW process parameters such as tool rotational speed, tool traverse speed, tilt angle, and tool offset influence the mechanical properties of the friction stir welded joints significantly. A mathematical regression model is developed to determine the empirical relationship between the FSW process parameters and mechanical properties, and the results are validated. In order to obtain the optimal values of process parameters that simultaneously optimize the ultimate tensile strength, elongation, and minimum hardness in the heat affected zone (HAZ), a metaheuristic, multi objective algorithm based on biogeography based optimization is proposed. The Pareto optimal frontiers for triple and dual objective functions are obtained and the best optimal solution is selected through using two different decision making techniques, technique for order of preference by similarity to ideal solution (TOPSIS) and Shannon's entropy.
  19. Talha NS, Sulaiman S
    Waste Manag, 2018 Aug;78:929-937.
    PMID: 32559988 DOI: 10.1016/j.wasman.2018.07.015
    In this study, solid coconut waste and CaO/PVA was used as raw material and catalyst respectively to produce biodiesel through in situ transesterification. Both, raw material and catalyst were packed in a packed bed reactor. The reaction was fixed for 3 h and the mixing was kept constant at 350 rpm. The highest biodiesel yield of 95% was obtained at reaction temperature of 61 °C with catalyst loading (CaO/PVA) of 2.29 wt% and methanol to solid ratio of 12:1. CaO-waste derived catalyst has been successfully proven to be utilized as heterogeneous base catalyst for the production of biodiesel from solid coconut waste.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links