Displaying publications 1 - 20 of 38 in total

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  1. Rahman Z, Hashim F, Rasid MFA, Othman M
    PLoS One, 2018;13(6):e0197087.
    PMID: 29874237 DOI: 10.1371/journal.pone.0197087
    Underwater Wireless Sensor Network (UWSN) has emerged as promising networking techniques to monitor and explore oceans. Research on acoustic communication has been conducted for decades, but had focused mostly on issues related to physical layer such as high latency, low bandwidth, and high bit error. However, data gathering process is still severely limited in UWSN due to channel impairment. One way to improve data collection in UWSN is the design of routing protocol. Opportunistic Routing (OR) is an emerging technique that has the ability to improve the performance of wireless network, notably acoustic network. In this paper, we propose an anycast, geographical and totally opportunistic routing algorithm for UWSN, called TORA. Our proposed scheme is designed to avoid horizontal transmission, reduce end to end delay, overcome the problem of void nodes and maximize throughput and energy efficiency. We use TOA (Time of Arrival) and range based equation to localize nodes recursively within a network. Once nodes are localized, their location coordinates and residual energy are used as a matrix to select the best available forwarder. All data packets may or may not be acknowledged based on the status of sender and receiver. Thus, the number of acknowledgments for a particular data packet may vary from zero to 2-hop. Extensive simulations were performed to evaluate the performance of the proposed scheme for high network traffic load under very sparse and very dense network scenarios. Simulation results show that TORA significantly improves the network performance when compared to some relevant existing routing protocols, such as VBF, HHVBF, VAPR, and H2DAB, for energy consumption, packet delivery ratio, average end-to-end delay, average hop-count and propagation deviation factor. TORA reduces energy consumption by an average of 35% of VBF, 40% of HH-VBF, 15% of VAPR, and 29% of H2DAB, whereas the packet delivery ratio has been improved by an average of 43% of VBF, 26% of HH-VBF, 15% of VAPR, and 25% of H2DAB. Moreover, the average end-to-end delay has been reduced by 70% of VBF, 69% of HH-VBF, 46% of VAPR, and 73% of H2DAB. Furthermore, average hope-count has been improved by 57%, 53%, 16% and 31% as compared to VBF, HHVBF, VAPR, and H2DAB, respectively. Also, propagation delay has been reduced by 34%, 30%, 15% and 23% as compared to VBF, HHVBF, VAPR, and H2DAB, respectively.
  2. Waran V, Devaraj P, Hari Chandran T, Muthusamy KA, Rathinam AK, Balakrishnan YK, et al.
    J Clin Neurosci, 2012 Apr;19(4):574-7.
    PMID: 22305869 DOI: 10.1016/j.jocn.2011.07.031
    In neurosurgery and ear, nose and throat surgery the application of computerised navigation systems for guiding operations has been expanding rapidly. However, suitable models to train surgeons in using navigation systems are not yet available. We have developed a technique using an industrial, rapid prototyping process from which accurate spatial models of the cranium, its contents and pathology can be reproduced for teaching. We were able to register, validate and navigate using these models with common available navigation systems such as the Medtronic StealthStation S7®.
  3. Waran V, Pancharatnam D, Thambinayagam HC, Raman R, Rathinam AK, Balakrishnan YK, et al.
    PMID: 23315670 DOI: 10.1055/s-0032-1330960
    Navigation in neurosurgery has expanded rapidly; however, suitable models to train end users to use the myriad software and hardware that come with these systems are lacking. Utilizing three-dimensional (3D) industrial rapid prototyping processes, we have been able to create models using actual computed tomography (CT) data from patients with pathology and use these models to simulate a variety of commonly performed neurosurgical procedures with navigation systems.
  4. Abdul Rahman Z, Hamzah SH, Hassan SA, Osman S, Md Noor SS
    J Infect Dev Ctries, 2013 Jun;7(6):448-52.
    PMID: 23771288 DOI: 10.3855/jidc.2535
    INTRODUCTION: Coagulase-negative staphylococci (CoNS) are a group of micro-organisms that are increasingly implicated as a cause of significant infection and the leading cause of bloodstream infection (BSI). One important predictor of true BSI is the isolation of CoNS from multiple blood cultures, presuming that the isolates represent the same species. Thus the objective of this study was to determine the significance of repeated CoNS isolated from blood cultures.
    METHODOLOGY: This was a prospective laboratory study which was initiated in June 2007 and lasted until July 2008. CoNS isolates were obtained from patients who had two positive blood cultures within a 14-day interval. CoNS were identified to the species level using an API-Staph, and antibiotics susceptibility testing was performed according to Clinical and Laboratory Standards Institute specifications. Strain relatedness was confirmed using pulsed-field gel electrophoresis.
    RESULTS: During the study period, 202 CoNS-positive samples were isolated from 101 patients. The most common species isolated was Staphylococcus epidermidis (59.0%), and 83.2% of the patients isolated the same species of CoNS from repeated blood cultures. Among the isolates of the same species, only 40.7% had the same antibiogram. CoNS with the same species and antibiogram had 93.3% probability of belonging to the same strain. Most (65.5%) of the patients were treated with antibiotics, primarily from the glycopeptides group.
    CONCLUSION: Speciation and antibiogram of CoNS from repeated blood cultures are adequate in determining the significance of repeated CoNS isolated from blood cultures.
  5. Atan AA, Ab Rahman Z, Zayzan KR, Bahaudin N, Ahmad AR
    Cureus, 2021 Nov;13(11):e19918.
    PMID: 34976521 DOI: 10.7759/cureus.19918
    Simultaneous ipsilateral fractures involving all the bones around the shoulder girdle, namely, the scapula, clavicle and humerus, are rare. We describe an interesting case of a 31-year-old patient who presented after a motor vehicle accident with excruciating pain over his left shoulder and a flail left upper limb. Radiographs and computed tomography (CT) scan revealed the presence of comminuted left scapula, clavicle and proximal humerus fractures. He was also diagnosed with a complete brachial plexus injury of the left shoulder. The patient underwent a tedious surgery involving screw fixation and plating of the scapula, clavicle and proximal humerus. Despite achieving stable fixations of the shoulder and radiographic union of all the fractures, he did not recover from the complete brachial plexus injury 14 months after the trauma. The presence of ipsilateral clavicle, scapula and humerus fracture suggests involvement in high-energy trauma, and therefore, associated injuries especially neurovascular compromise should not be missed. Despite its rarity, management of this complex injury should always be individualised to ensure optimal functional outcomes are achieved.
  6. Ismail F, Couvin D, Farakhin I, Abdul Rahman Z, Rastogi N, Suraiya S
    PLoS One, 2014;9(12):e114832.
    PMID: 25502956 DOI: 10.1371/journal.pone.0114832
    Tuberculosis (TB) still constitutes a major public health problem in Malaysia. The identification and genotyping based characterization of Mycobacterium tuberculosis complex (MTBC) isolates causing the disease is important to determine the effectiveness of the control and surveillance programs.
  7. Rathakrishnan B, Bikar Singh SS, Kamaluddin MR, Yahaya A, Mohd Nasir MA, Ibrahim F, et al.
    PMID: 34444042 DOI: 10.3390/ijerph18168291
    This study was conducted to examine the relationship between smartphone addiction, sleep quality, and academic performance. The study presented quantitative research on 323 students in a public university in Sabah to explore the relationship between smartphone addiction, sleep quality, and academic performance. A simple random sampling was used in the study. The Smartphone Addiction Scale Short Version (SAS-SV) and the Pittsburgh Sleep Quality Index (PSQI) were used in this study. SPSS was used as a tool of analysis for descriptive and inferential analysis. Pearson correlation was involved to test the hypothesis of the study. The result indicated that the greater the smartphone addiction, the lower the academic performance of university students. The finding also proved that students with poor sleep quality might exhibit low academic performance. Smartphone addiction was found to be associated with sleep quality where overusing smartphones was related to poor sleep quality in university students. On this basis, the problem of smartphone addiction and sleep quality should be tackled in order to improve the academic performance of university students and their overall health.
  8. Abdullah J, Saffie N, Sjasri FA, Husin A, Abdul-Rahman Z, Ismail A, et al.
    Braz J Microbiol, 2014;45(4):1385-91.
    PMID: 25763045
    An in-house loop-mediated isothermal amplification (LAMP) reaction was established and evaluated for sensitivity and specificity in detecting the presence of Salmonella Typhi (S. Typhi) isolates from Kelantan, Malaysia. Three sets of primers consisting of two outer and 4 inner were designed based on locus STBHUCCB_38510 of chaperone PapD of S. Typhi genes. The reaction was optimised using genomic DNA of S. Typhi ATCC7251 as the template. The products were visualised directly by colour changes of the reaction. Positive results were indicated by green fluorescence and negative by orange colour. The test was further evaluated for specificity, sensitivity and application on field samples. The results were compared with those obtained by gold standard culture method and Polymerase Chain Reaction (PCR). This method was highly specific and -10 times more sensitive in detecting S. Typhi compared to the optimised conventional polymerase chain reaction (PCR) method.
  9. Irekeola AA, Shueb RH, E A R ENS, Wada Y, Abdul Rahman Z, Ahmad S, et al.
    Cancers (Basel), 2021 Apr 14;13(8).
    PMID: 33919987 DOI: 10.3390/cancers13081886
    For more than 50 years, nasopharyngeal carcinoma (NPC) has been associated with dermatomyositis (DM), a rare idiopathic inflammatory disorder that mainly affects the skin and muscles. Although the association between these rare diseases is well-documented, the actual prevalence of NPC in DM patients remains unknown. Here, a systematic review and meta-analysis of published data was conducted in accordance with the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Electronic databases including PubMed, Scopus, ScienceDirect, and Google Scholar were searched without year or language restrictions for studies reporting the occurrence of NPC in DM patients. The study protocol was lodged with PROSPERO (CRD42021225335). A total of 95 studies covering 303 cases of NPC among 16,010 DM patients was included. Summary estimates were calculated using the random-effects model. The pooled prevalence of NPC in DM was 3.3% (95% CI, 2.5-4.3). When stratified according to study location, higher prevalence estimates were obtained for Hong Kong (36.5%), Malaysia (27.7%), and Singapore (11.9%). There was a predominance of cases among male DM patients compared with females, and most patients were aged 40 and above. Many of the NPC cases were found to be diagnosed after the diagnosis of DM. It is therefore pertinent to screen for NPC in DM patients, especially among older DM patients in the Asian region.
  10. Hassan SA, Othman N, Idris FM, Abdul Rahman Z, Maning N, Abdul Rahman R, et al.
    Med J Malaysia, 2012 Aug;67(4):402-5.
    PMID: 23082450 MyJurnal
    This study describes the prevalence of Clostridium difficile toxin (CDT) in loose stool samples from inpatients aged more than two years of a tertiary hospital. A total of 175 samples that had been examined were from stool samples that were sent to the Medical Microbiology & Parasitology Laboratory for various clinical indications. The toxin was detected by a commercial immunochromatograhic test, and the patients' demography, clinical features, treatment and outcomes were analyzed from their medical records. Clostridium difficile toxin was positive in 24 (13.7%) of the stool samples. Male and female were 11 (45.8%) and 13 (54.2%) respectively, with the majority of them aged more than 50 years. Most were from medical wards (n = 21, 87.5%), with the rest from surgical wards (n = 2, 8.3%) and intensive care units (n = 1, 3.4%). All the CDT positive patients had history of prior antibiotic usage within 6 weeks before the detection of the toxin. The mean duration of antibiotics usage was 17.75 (+/- 13.75) days, while the mean duration of diarrhea was 5.21((+/- 5.85) days. Eighteen patients had underlying medical illnesses that were diabetes mellitus, chronic renal disease, hypertension, ischaemic heart disease, cerebrovascular disease and malignancy; with seven of them being CDT positive while on chemotherapy. Stool occult blood test was positive in 15 patients whereas presence of pus cells in the CD positive stool samples were detected in 21 patients. The duration of hospitalization among the patients was 27.96 (+/- 23.22) days.
  11. Chua WC, Mazlan MZ, Ali S, Che Omar S, Wan Hassan WMN, Seevaunnantum SP, et al.
    IDCases, 2017;9:91-94.
    PMID: 28725564 DOI: 10.1016/j.idcr.2017.05.002
    We report a fatal case of post-partum streptococcal toxic shock syndrome in a patient who was previously healthy and had presented to the emergency department with an extensive blistering ecchymotic lesions over her right buttock and thigh associated with severe pain. The pregnancy had been uncomplicated, and the mode of delivery had been spontaneous vaginal delivery with an episiotomy. She was found to have septicemic shock requiring high inotropic support. Subsequently, she was treated for necrotizing fasciitis, complicated by septicemic shock and multiple organ failures. A consensus was reached for extensive wound debridement to remove the source of infection; however, this approach was abandoned due to the patient's hemodynamic instability and the extremely high risks of surgery. Both the high vaginal swab and blister fluid culture revealed Group A beta hemolytic streptococcus infection. Intravenous carbapenem in combination with clindamycin was given. Other strategies attempted for streptococcal toxic removal included continuous veno-venous hemofiltration and administration of intravenous immunoglobulin. Unfortunately, the patient's condition worsened, and she succumbed to death on day 7 of hospitalization.
  12. Rahman ZA, Hitam S, Al-Mansoori MH, Abas AF, Mahdi MA
    Opt Express, 2011 Oct 24;19(22):21238-45.
    PMID: 22108976 DOI: 10.1364/OE.19.021238
    A multiwavelength widely tunable Brillouin optical comb with an enhanced reverse-S-shaped feedback coupling assisted by out-of-cavity optical amplifier is demonstrated. The enhancement is done by locating the amplifier and the Brillouin pump into the reverse-S-shaped fiber section. The oscillating modes in the cavity are directly influenced solely by the Brillouin gain. A wide tuning range of 45 nm is obtained that is only limited by the erbium amplification bandwidth. An average of eleven laser lines that can be tuned to over 45 nm wavelengths is obtained at 40% optimum output coupling ratio.
  13. Moxness Reksten A, Rahman Z, Kjellevold M, Garrido Gamarro E, Thilsted SH, Pincus LM, et al.
    Foods, 2021 May 20;10(5).
    PMID: 34065408 DOI: 10.3390/foods10051147
    Fish represent an important part of the Sri Lankan and Bangladeshi diet. However, fish is also a source of contaminants that may constitute a health risk to consumers. The aim of this study was to analyse the contents of arsenic, cadmium, mercury, and lead in 24 commonly consumed marine fish species from the Bay of Bengal and to assess the potential health risk associated with their consumption. Mercury and lead contents did not exceed the maximum limits for any of the sampled species, and consumer exposure from estimated daily consumption was assessed to be minimal for adults and children. Numerous samples exceeded the maximum limit for cadmium (58%), particularly those of small size (≤25 cm). However, consumer exposure was insignificant, and health assessment showed no risk connected to consumption. These data represent an important contribution to future risk/benefit assessments related to the consumption of fish.
  14. Abdullah JM, Rahman ZA, Ariff AR, Jaafar H, Phang KS
    Singapore Med J, 2004 Jun;45(6):286-8.
    PMID: 15181525
    Rhabdoid tumour is a rare childhood tumour with poor prognosis. We report a 13-month-old Malay girl suffering from this tumour that was located at the left fronto-temporo-parietal region of the brain. Computed tomography showed a large irregular enhancing mass that caused obstructive hydrocephalus. The tumour did not reduce in size after three operations and finally the patient succumbed to the disease four months after diagnosis.
  15. Abdul Rahman Z, Mohamad SA, Abdul Hamid H
    Cureus, 2024 Mar;16(3):e55811.
    PMID: 38586634 DOI: 10.7759/cureus.55811
    This is a report on remarkable visual recovery from blindness in a case of isolated optic perineuritis (OPN). A 68-year-old Chinese lady presented with a two-week history of progressive painless bilateral vision loss. Her vision was 6/18 on the right eye and no perception of light (NPL) on the left eye with positive relative afferent pupillary defect (RAPD). Fundus showed hyperaemic and swollen optic disc bilaterally. MRI of the brain and orbit revealed hyperintense periventricular white matter lesions, possibly early changes of multiple sclerosis (MS), and perineural enhancement of optic nerve bilaterally, consistent with OPN. All other investigations were negative. Intravenous methylprednisolone 1g/day for three days was started, followed with oral prednisolone, tapered in three months. At the third month of follow-up, her vision had improved to 6/12 on the left and 6/9 on the right. The hyperaemic and swollen disc has resolved. Intravenous megadose corticosteroid treatment is an effective first-line treatment for OPN.
  16. Salmuna ZN, Hashim S, Hasan H, Harun A, Abdul Rahman Z, Ismail N, et al.
    IIUM Medical Journal Malaysia, 2019;18(3):144-152.
    MyJurnal
    Influenza-like illnesses (ILI) were defined as a triad of cough, sore throat and fever. The aim of this study is to determine the changes in knowledge, perceptions and practices towards preventive measures of succumbing to ILI before and after hajj among Malaysian hajj pilgrims.Methodology: An open-labeled randomized control trial study performed on five hundred Malaysian hajj pilgrims in the year 2013. After validated pre-hajj questionnaires completed, 250 subjects were given health education, benzalkonium-based handrub and demonstration of the handrub usage together with pamphlets and labelled as an intervention group. Another 250 subjects from another flight batch were given the same questionnaires without health education with unmedicated hand lotion as a control group. The knowledge, perception, practices and compliances to the handrub practice in both groups were compared with the pre-hajj results. Results: No significant difference between pre and post hajj knowledge and practice among hajj pilgrims in intervention group. Pre hajj perception score [ M (IQR) = 30 (5.00), Z= -2.441, p < 0.05 ] is much higher compared to post hajj perception [ M (IQR) = 29 (6.00), Z = -2.441, p < O.O5 ]. No significant difference between pre and post hajj knowledge, perception and practices among hajj pilgrims in control group. Hand hygiene compliance was not improved with provision of health education and free handrub supply. Conclusion: No significant changes in knowledge, perceptions and practices of Malaysian hajj pilgrims pre and post-hajj in both groups. Provision of handrub did not improved hajj pilgrims compliance.
  17. Yazid SN, Ahmad K, Razak MSFA, Rahman ZA, Ramachandran K, Mohamad SNA, et al.
    Braz J Biol, 2021;84:e248359.
    PMID: 34730685 DOI: 10.1590/1519-6984.248359
    Bacterial leaf blight (BLB) is one of the major rice diseases in Malaysia. This disease causes substantial yield loss as high as 70%. Development of rice varieties which inherited BLB resistant traits is a crucial approach to promote and sustain rice industry in Malaysia. Hence, this study aims were to enhance BLB disease resistant characters of high yielding commercial variety MR219 through backcross breeding approach with supporting tool of marker-assisted selection (MAS). Broad spectrum BLB resistance gene, Xa7 from donor parent IRBB7 were introgressed into the susceptible MR219 (recurrent parent) using two flanking markers ID7 and ID15. At BC3F4, we managed to generate 19 introgressed lines with homozygous Xa7 gene and showed resistant characteristics as donor parent when it was challenged with Xanthomonas oryzae pv. oryzae through artificial inoculation. Recurrent parent MR219 and control variety, MR263 were found to be severely infected by the disease. The improved lines exhibited similar morphological and yield performance characters as to the elite variety, MR219. Two lines, PB-2-107 and PB-2-34 were chosen to be potential lines because of their outstanding performances compared to parent, MR219. This study demonstrates a success story of MAS application in development of improved disease resistance lines of rice against BLB disease.
  18. Salim NL, Azhany Y, Abdul Rahman Z, Yusof R, Liza-Sharmini AT
    Case Rep Ophthalmol Med, 2015;2015:249419.
    PMID: 26064735 DOI: 10.1155/2015/249419
    Fungal endophthalmitis is rare but may complicate glaucoma drainage device surgery. Management is challenging as the symptoms and signs may be subtle at initial presentation and the visual prognosis is usually poor due to its resistant nature to treatment. At present there is lesser experience with intravitreal injection of voriconazole as compared to Amphotericin B. We present a case of successfully treated Aspergillus endophthalmitis following Baerveldt glaucoma drainage device implantation with intravitreal and topical voriconazole.
  19. Md Setamam N, Jaafar Sidik N, Abdul Rahman Z, Che Mohd Zain CR
    BMC Res Notes, 2014 Jun 30;7:414.
    PMID: 24981787 DOI: 10.1186/1756-0500-7-414
    BACKGROUND: Capsicum annuum and Capsicum frutescens, also known as "chilies", belong to the Solanaceae family and have tremendous beneficial properties. The application of hairy root culture may become an alternative method for future development of these species by adding value, such as by increasing secondary metabolites and improving genetic and biochemical stability compared with normal Capsicum plants. Therefore, in this research, different types of explants of both species were infected with various Agrobacterium rhizogenes strains to provide more information about the morphology and induction efficiency of hairy roots. After 2 weeks of in vitro seed germination, young seedling explants were cut into three segments; the cotyledon, hypocotyl, and radical. Then, the explants were co-cultured with four isolated A. rhizogenes strains in Murashige & Skoog culture media (MS) containing decreasing carbenicillin disodium concentrations for one month.

    RESULTS: In this experiment, thick and short hairy roots were induced at all induction sites of C. annuum while thin, elongated hairy roots appeared mostly at wound sites of C. frutescens. Overall, the hairy root induction percentages of C. frutescens were higher compared with C. annuum. Hairy root initiation was observed earliest using radicles (1st week), followed by cotyledons (2nd week), and hypocotyls (3rd week). Cotyledon explants of both species had the highest induction frequency with all strains compared with the other explants types. Strains ATCC 13333 and ATCC 15834 were the most favourable for C. frutescens while ATCC 43056 and ATCC 43057 were the most favourable for C. annuum. The interactions between the different explants and strains showed significant differences with p-values < 0.0001 in both Capsicum species.

    CONCLUSIONS: Both Capsicum species were amenable to A. rhizogenes infection and hairy root induction is recommended for use as an alternative explants in future plant-based studies.

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