Displaying publications 61 - 80 of 102 in total

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  1. Mohd Yusof N, Saleh AK, Abuomira IEAA, Attallah AA, Elshal EA, Khames AAA
    Orthop Res Rev, 2022;14:437-443.
    PMID: 36444242 DOI: 10.2147/ORR.S383863
    BACKGROUND AND AIM: Maintenance of stability using external fixation devices is an important principle to ensure successful treatment of osteomyelitis (OM). In this study, we report our experience with femoral OM treated with acute compression and bone transport using the Orthofix limb reconstruction system (LRS).

    PATIENTS AND METHODS: This prospective study included 30 consecutive patients with femoral OM. LRS insertion and corticotomy were done according to the standard technique. Radiographic evaluation was performed every 2 weeks during the distraction phase and every 2-4 weeks during the consolidation phase. The clinical outcome measurements included union time, limb length discrepancy, additional operative procedures, refracture and infection.

    RESULTS: The present study included 30 patients with femoral OM. They comprised 27 males (90.0%) and 3 females (10.0%) with an age of 28.1 ± 15.6 years. All, except one, achieved union with a mean union time of 8.6 months (range 4-20 months). The mean union time for acute compression was 7.6 months (range 4-20 months) while for patients with bone transport it was 14.5 months (range 12-18 months). The mean limb length discrepancy was 1.8 cm (range 0-4 cm). At the end of the follow=up, two patients were not able to ambulate without support; one due to non-union and one due to paraplegia.

    CONCLUSION: The present study identified treatment of femoral OM using LRS as a feasible and effective technique with good outcomes. Reported complications could be adequately managed in most cases.

  2. Aziz ME, Yusof NR, Abdullah MS, Yusof AH, Yusof MI
    Singapore Med J, 2005 Aug;46(8):426-8.
    PMID: 16049615
    Persistent sciatic artery is a very uncommon embryological vascular variant. This case report highlights this rare vascular anomaly, diagnostic difficulty, complication and subsequent treatment in a 43-year-old man who presented with sudden onset of right leg pain for a few hours. He was unable to walk because of pain and numbness. Emergency right lower limb angiogram showed a large aneurysm that was initially thought to arise from the right common femoral artery, associated with thrombus formation within the right popliteal artery. A below knee amputation was performed due to worsening ischaemia of the right leg. The persistent right sciatic artery was later obliterated using percutaneous stenting and endovascular grafting, with deployment of two wallstents.
  3. Mansor A, Ariffin AF, Yusof N, Mohd S, Ramalingam S, Md Saad AP, et al.
    Cell Tissue Bank, 2023 Mar;24(1):25-35.
    PMID: 35610332 DOI: 10.1007/s10561-022-10013-9
    Bone processing and radiation were reported to influence mechanical properties of cortical bones due in part to structural changes and denaturation of collagen composition. This comparative study was to determine effects of bone processing on mechanical properties and organic composition, and to what extent the radiation damaging after each processing. Human femur cortical bones were processed by freezing, freeze-drying and demineralisation and then gamma irradiated at 5, 15, 20, 25 and 50 kGy. In the compression test, freeze drying significantly decreased the Young's Modulus by 15%, while demineralisation reduced further by 90% (P 
  4. Esmat SM, Sulong AF, Awang MS, Oon ZS, Mohd Yusof N
    Cureus, 2023 Aug;15(8):e43448.
    PMID: 37711923 DOI: 10.7759/cureus.43448
    Growth plate injuries over the distal femur typically occur due to high-energy trauma. It is commonly associated with serious complications such as growth disturbance. Its occurrence in children undergoing limb-lengthening procedures is uncommon. We report a case of distal femur growth plate injury in a 13-year-old boy undergoing a limb-lengthening procedure for femoral hypoplasia. Conservative treatment yielded a good functional outcome in this patient.
  5. Murizan NIS, Mustafa NS, Ngadiman NHA, Mohd Yusof N, Idris A
    Polymers (Basel), 2020 Nov 27;12(12).
    PMID: 33261121 DOI: 10.3390/polym12122818
    Nanocrystalline cellulose is an abundant and inexhaustible organic material on Earth. It can be derived from many lignocellulosic plants and also from agricultural residues. They endowed exceptional physicochemical properties, which have promoted their intensive exploration in biomedical application, especially for tissue engineering scaffolds. Nanocrystalline cellulose has been acknowledged due to its low toxicity and low ecotoxicological risks towards living cells. To explore this field, this review provides an overview of nanocrystalline cellulose in designing materials of bone scaffolds. An introduction to nanocrystalline cellulose and its isolation method of acid hydrolysis are discussed following by the application of nanocrystalline cellulose in bone tissue engineering scaffolds. This review also provides comprehensive knowledge and highlights the contribution of nanocrystalline cellulose in terms of mechanical properties, biocompatibility and biodegradability of bone tissue engineering scaffolds. Lastly, the challenges for future scaffold development using nanocrystalline cellulose are also included.
  6. Abdullah MN, Mustapha F, Yusof N', Khan T, Sebaey TA
    Materials (Basel), 2024 Mar 11;17(6).
    PMID: 38541452 DOI: 10.3390/ma17061298
    This study aims to develop suitable formulations of geopolymer concrete (GPC) by varying the percentages of the geopolymer with aggregates and evaluating the performances in thermal and mechanical properties of palm kernel shell ash (PKSA)-GPC compared to rice husk ash (RHA)-GPC and ordinary Portland cement concrete (OPCC). Preliminary tests were conducted to select the best mix design ratios before casting the specimens. Then, the performance of the PKSA-GPC, RHA-GPC and OPCC specimens was evaluated based on their thermal performance and drying shrinkage. The mix designs of PKSA-GPC 70:30, PKSA-GPC 60:40, PKSA-GPC 50:50 and PKSA-GPC 66.6:33.3 were found to produce an acceptable consistency, rheological and thixotropic behaviour for the development of the GPC. PKSA-GPC showed a better thermal performance than the RHA-GPC and OPCC due to their strong and dense intumescent layers and slow temperature increment upon exposure to a high flame temperature from ambient temperature to 169 °C. The low molar ratio of the Si/Al present in the PKSA-GPC created a thermally stable intumescent layer. In the drying shrinkage test, PKSA-GPC 60:40 and RHA-GPC 60:40 shared an equal drying shrinkage performance (5.040%) compared to the OPCC (8.996%). It was observed that microcrack formation could significantly contribute to the high shrinkage in the PKSA-GPC 50:50 and RHA-GPC 70:30 specimens. The findings of this study show that PKSA could be incorporated into GPC as a fire-retardant material due to its capability of prolonging the spread of fire upon ignition and acting as an alternative to the conventional OPCC.
  7. Wan Ikhsan SN, Yusof N, Mat Nawi NI, Bilad MR, Shamsuddin N, Aziz F, et al.
    Polymers (Basel), 2021 Jan 30;13(3).
    PMID: 33573140 DOI: 10.3390/polym13030441
    Membrane filtration is an attractive process in water and wastewater treatment, but largely restricted by membrane fouling. In this study, the membrane fouling issue is addressed by developing polyethersulfone (PES)-based mixed matrix membranes (MMMs) with the incorporation of hydrophilic nanoparticles as an additive. Ultrafiltration MMMs were successfully fabricated by incorporating different loadings of halloysite nanotube-ferrihydrates (HNT-HFO) into a polyethersulfone (PES) matrix and their performance was evaluated for the separation of bovine serum albumin (BSA) solution and oil/water emulsion. The results show that wettability is endowed to the membrane by introducing the additive aided by the presence of abundant -OH groups from the HFO. The loading of additive also leads to more heterogeneous surface morphology and higher pure water fluxes (516.33-640.82 L/m2h) more than twice that of the pristine membrane as reference (34.69 L/m2h) without affecting the rejection. The MMMs also provide much enhanced antifouling properties. The filtration results indicate that the flux recovery ratio of the modified membrane reached 100% by washing with only distilled water and a total flux recovery ratio of >98% ± 0.0471 for HNT-HFO-loaded membranes in comparison with 59% ± 0.0169 for pristine PES membrane.
  8. Nur Asyura Adznam S, Shahar S, Rahman SA, Yusof NA, Arshad F, Yassin Z, et al.
    J Nutr Health Aging, 2009 Dec;13(10):925-30.
    PMID: 19924355
    OBJECTIVE: Prior to the development of a healthy ageing and risk reduction of chronic diseases intervention package for older people in Malaysia, a need assessment study was conducted to identify nutritional knowledge status and information needs, as part of an action research process.

    DESIGN: A cross sectional study was conducted among 267 elderly people, 54 care givers and 66 health professionals in two rural areas of Peninsular of Malaysia (i.e Sabak Bernam, Selangor and Kuala Pilah, Negeri Sembilan). Information on nutritional knowledge was obtained from an interview based questionnaire for older subjects and caregiver and through self administered questionnaire from the health professionals. Anthropometric and functional measurements were also conducted among elderly subjects.

    RESULTS: It was found that the elderly subjects had poor nutritional knowledge with 43.8% of them classified as having unsatisfactory nutritional knowledge, followed by moderately satisfactory (33.7%), very unsatisfactory (15.7%) and good (6.7%). Talks, counselling sessions with health professionals and electronic media such as television and radio were the most preferred nutrition education sources among elderly subjects and their care givers. The majority of health professionals studied (98.5%) had good nutritional knowledge. Although most of them (93.6%) were involved in management of the elderly, only 45.5% incorporated nutritional information component in this activity. Most of the health professionals used the guidelines for management of elderly patients (63.6%). However, nutritional knowledge was very minimal in these guidelines. Multiple regression analysis indicated that 'level education', involvement in 'social activities', presence of 'hearing problems', the Instrumental Activities of Daily Living (IADL) score, having previous 'nutritional information' and 'participation in healthy eating programme' were the major predictors of nutritional knowledge score among elderly subjects.

    CONCLUSION: Based on the above findings it is thus, imperative that an appropriate nutritional intervention package and programme be developed so as to help improve nutritional knowledge and subsequently the nutritional status of the rural elderly Malays.

  9. Mohd Zohdi R, Abu Bakar Zakaria Z, Yusof N, Mohamed Mustapha N, Abdullah MN
    PMID: 21941590 DOI: 10.1155/2012/843025
    A novel cross-linked honey hydrogel dressing was developed by incorporating Malaysian honey into hydrogel dressing formulation, cross-linked and sterilized using electron beam irradiation (25 kGy). In this study, the physical properties of the prepared honey hydrogel and its wound healing efficacy on deep partial thickness burn wounds in rats were assessed. Skin samples were taken at 7, 14, 21, and 28 days after burn for histopathological and molecular evaluations. Application of honey hydrogel dressings significantly enhanced (P < 0.05) wound closure and accelerated the rate of re-epithelialization as compared to control hydrogel and OpSite film dressing. A significant decrease in inflammatory response was observed in honey hydrogel treated wounds as early as 7 days after burn (P < 0.05). Semiquantitative analysis using RT-PCR revealed that treatment with honey hydrogel significantly (P < 0.05) suppressed the expression of proinflammatory cytokines (IL-1α, IL-1β, and IL-6). The present study substantiates the potential efficacy of honey hydrogel dressings in accelerating burn wound healing.
  10. Yang Harmony TC, Yusof N, Ramalingam S, Baharin R, Syahrom A, Mansor A
    Clin Orthop Relat Res, 2022 Feb 01;480(2):407-418.
    PMID: 34491235 DOI: 10.1097/CORR.0000000000001968
    BACKGROUND: Gamma irradiation, which minimizes the risk of infectious disease transmission when human bone allograft is used, has been found to negatively affect its biomechanical properties. However, in those studies, the deep-freezing temperature during irradiation was not necessarily maintained during transportation and sterilization, which may have affected the findings. Prior reports have also suggested that controlled deep freezing may mitigate the detrimental effects of irradiation on the mechanical properties of bone allograft.

    QUESTION/PURPOSE: Does a controlled deep-freezing temperature during irradiation help preserve the compressive mechanical properties of human femoral cortical bone allografts?

    METHODS: Cortical bone cube samples, each measuring 64 mm3, were cut from the mid-diaphyseal midshaft of five fresh-frozen cadaver femurs (four male donors, mean [range] age at procurement 42 years [42 to 43]) and were allocated via block randomization into one of three experimental groups (with equal numbers of samples from each donor allocated into each group). Each experimental group consisted of 20 bone cube samples. Samples irradiated in dry ice were subjected to irradiation doses ranging from 26.7 kGy to 27.1 kGy (mean 26.9 kGy) at a deep-freezing temperature below -40°C (the recommended long-term storage temperature for allografts). Samples irradiated in gel ice underwent irradiation doses ranging from 26.2 kGy and 26.4 kGy (mean 26.3 kGy) in a freezing temperature range between -40°C and 0°C. Acting as controls, samples in a third group were not subjected to gamma irradiation. The mechanical properties (0.2% offset yield stress, ultimate compression stress, toughness, and the Young modulus) of samples from each group were subsequently evaluated via axial compression loading to failure along the long axis of the bone. The investigators were blinded to sample group during compression testing.

    RESULTS: The mean ultimate compression stress (84 ± 27 MPa versus 119 ± 31 MPa, mean difference 35 [95% CI 9 to 60]; p = 0.005) and toughness (3622 ± 1720 kJ/m3 versus 5854 ± 2900 kJ/m3, mean difference 2232 [95% CI 70 to 4394]; p = 0.009) of samples irradiated at a higher temperature range (-40°C to 0°C) were lower than in those irradiated at deep-freezing temperatures (below -40°C). The mean 0.2% offset yield stress (73 ± 28 MPa versus 109 ± 38 MPa, mean difference 36 [95% CI 11 to 60]; p = 0.002) and ultimate compression stress (84 ± 27 MPa versus 128 ± 40 MPa, mean difference 44 [95% CI 17 to 69]; p < 0.001) of samples irradiated at a higher temperature range (-40°C to 0°C) were lower than the nonirradiated control group samples. The mean 0.2% offset yield stress (73 ± 28 MPa versus 101 ± 28 MPa, mean difference 28 [95% CI 3 to 52]; p = 0.02; effect size = 1.0 [95% CI 0.8 to 1.2]) of samples irradiated at higher temperature range (-40°C to 0°C) were no different with the numbers available to those irradiated at deep-freezing temperature. The mean toughness (3622 ± 1720 kJ/m3 versus 6231 ± 3410 kJ/m3, mean difference 2609 [95% CI 447 to 4771]; p = 0.02; effect size = 1.0 [95% CI 0.8 to 1.2]) of samples irradiated at higher temperature range (-40°C to 0°C) were no different with the numbers available to the non-irradiated control group samples. The mean 0.2% offset yield stress, ultimate compression stress, and toughness of samples irradiated in deep-freezing temperatures (below -40°C) were not different with the numbers available to the non-irradiated control group samples. The Young modulus was not different with the numbers available among the three groups.

    CONCLUSION: In this study, maintenance of a deep-freezing temperature below -40°C, using dry ice as a cooling agent, consistently mitigated the adverse effects of irradiation on the monotonic-compression mechanical properties of human cortical bone tissue. Preserving the mechanical properties of a cortical allograft, when irradiated in a deep-freezing temperature, may have resulted from attenuation of the deleterious, indirect effects of gamma radiation on its collagen architecture in a frozen state. Immobilization of water molecules in this state prevents radiolysis and the subsequent generation of free radicals. This hypothesis was supported by an apparent loss of the protective effect when a range of higher freezing temperatures was used during irradiation.

    CLINICAL RELEVANCE: Deep-freezing temperatures below -40°C during gamma irradiation may be a promising approach to better retain the native mechanical properties of cortical bone allografts. A further study of the effect of deep-freezing during gamma radiation sterilization on sterility and other important biomechanical properties of cortical bone (such as, tensile strength, fracture toughness, and fatigue) is needed to confirm these findings.

  11. Azhar Hilmy SH, Nordin N, Yusof MYPM, Soh TYT, Yusof N
    Nutr J, 2024 Jan 17;23(1):11.
    PMID: 38233923 DOI: 10.1186/s12937-023-00884-3
    Excessive sugar consumption is well documented as a common risk factor for many Non-Communicable Diseases (NCDs). Thus, an adequate intervention description is important to minimise research waste and improve research usability and reproducibility. A systematic review was conducted to identify components in published evidence interventions pertaining to the health promotions on reducing sugar intake among adults. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and used the Mixed Methods Appraisal Tool (MMAT) for quality appraisal. The period for the selected study was from 2000 to 2022, and articles were retrieved from Web of Science (WOS), Medline, Scopus, and PubMed. The target population was adults aged 18 years old and above who underwent intervention to assess the changes in their sugar intake. Data sources and all human epidemiologic studies were included. Out of the 9,333 papers identified, 25 were included. The overall quality of evidence of the studies was considered moderate. Apart from the characteristics of the reviewed studies, components of interventions are including the basis of theoretical or model for the intervention, which majority use Social Cognitive Theory, followed by PRECEDE-PROCEED model, socio-ecological and process-improvement theories and Transtheoretical Model; providers, who are commercial provider, qualified nutritionist, professor of nutrigenomics and nutrigenetics, doctor, dietitian nutritionist, lifestyle coaches, and junior public health nurses; duration of the intervention and follow-up time, varies from as short as one month to as long as 24 months; material provided either softcopy or hardcopy; tailoring approach, based on the individual goals, the process of change, genotype analysis, beliefs, barriers, and sociocultural norms; delivery mechanism either face-to-face or technology-mediated; and tools to measure the sugar consumption outcome mostly used Food Frequency Questionnaire (FFQ), besides 24-h dietary recalls, and food diaries. There are various components in downstream health promotion to reduce sugar intake among adults that can be adapted according to the local health promotion and intervention context. More well-designed interventions using integration components are encouraged in further studies.
  12. Razali NAM, Salleh WNW, Mohamed MA, Aziz F, Jye LW, Yusof N, et al.
    PMID: 38958863 DOI: 10.1007/s11356-024-34081-4
    The investigations of real industrial wastewater, such as palm oil mill effluent (POME), as a recalcitrant pollutant remain a subject of global water pollution concern. Thus, this work introduced the preparation and modification of g-C3N4 and WO3 at optimum calcination temperature, where they were used as potent visible light-driven photocatalysts in the degradation of POME under visible light irradiation. Herein, g-C3N4-derived melamine and WO3 photocatalyst were obtained at different calcination temperatures in order to tune their light absorption ability and optoelectronics properties. Both photocatalysts were proven to have their distinct phases, crystallinity levels, and elements with increasing temperature, as demonstrated by the ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) results. Significantly, g-C3N4 (580 °C) and WO3 (450 °C) unitary photocatalysts exhibited the highest removal efficiency of POME without dilution due to good crystallinity, extended light absorption, high separation, and less recombination efficiency of electron-hole pairs. Furthermore, surprisingly, the superior energy storage photocatalytic performance with outstanding stability by WO3 achieved an approximately 10% increment during darkness, compared with g-C3N4 under visible light irradiation. Moreover, it has been proven that the WO3 and g-C3N4 photocatalysts are desirable photocatalysts for various pollutant degradations, with excellent visible-light utilization and favorable energy storage application.
  13. Zu Nurain Ahmad S, Salleh WNW, Yusof N, Yusop MZM, Hamdan R, Ismail AF
    PMID: 38727970 DOI: 10.1007/s11356-024-33322-w
    Simple and efficient removal of Pb(II) ion from aqueous solution through adsorption has accelerated the development of many new composites to improve this popular method. In this study, the composites of graphene oxide (GO), zeolitic imidazolate framework-8 (ZIF-8), and magnetic materials were synthesized via coprecipitation method utilizing a different molar ratio between FeCl2 and FeCl3 of 1:0.5, 2:1, 3:1.5, and 4:2. The ZIF-8/GO was prepared via room temperature synthesis method prior to its further modification with magnetic materials for ease of separation. It was observed that the MZIF-8/GO2 of molar ratio 2:1 showed the best performance in adsorbing Pb(II) ion. As confirmed by FESEM image, it appeared to be ZIF-8 particles that have grown all over the GO platform and overlayed with Fe3O4 granular-shaped particles. The MZIF-8/GO2 successfully achieved 99% removal of Pb(II) within 10 min. The optimum values obtained for the initial concentration of Pb (II) were 100 mg/L, pH of 4 to 6, and adsorbent dosage used was 10 mg. The Langmuir isotherm and the pseudo-second-order kinetic model were deemed suitable to evaluate the adsorption of Pb(II) using MZIF-8/GO2. Results showed that MZIF-8GO2 achieved a maximum adsorption capacity of 625 mg/g of Pb(II) adsorption. All parent materials demonstrated a good synergistic effects, while exhibiting a significant contribution in providing active sites for Pb(II) adsorption. Therefore, this ternary composite of MZIF-8/GO2 is expected to be a promising adsorbent for Pb(II) adsorption from aqueous solution with an added value of ease of post phase separation using external magnetic field.
  14. Bab NB, Rahman RNARA, Mohamed S, Radzi NAM, Yusof N
    Spec Care Dentist, 2024;44(4):1002-1025.
    PMID: 38480484 DOI: 10.1111/scd.12990
    BACKGROUND: The rising percentage of children and adolescents experiencing mental disorders brought attention to the emerging opportunities for proactive oral health interventions in this population. Currently, existing guidelines focus mainly on oral health in general practice and on adults residing in care homes. This report aims to provide a broad overview of the effectiveness of oral health interventions for children and adolescents with mental disorders.

    METHOD: This review followed the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses 2020) statement. The initial electronic search yielded a total of 3710 articles. The search identified 2354 potential papers after removing duplicates and 2301 articles were excluded by title and abstract. The full texts of the remaining 53 articles and nine articles from the citation searching were screened and 15 articles matched the inclusion criteria. The Mixed-Method Appraisal Tool (MMAT) was used for quality appraisal.

    RESULTS: The thematic analysis resulted in four main themes which were educational intervention, physical intervention, clinical intervention, and a combination of both educational and clinical intervention.

    CONCLUSION: We presented the findings in a narrative synthesis with the primary outcomes which served as answers to our main research question that prompted this systematic review.

  15. Azma RZ, Othman A, Azman N, Alauddin H, Ithnin A, Yusof N, et al.
    Malays J Pathol, 2012 Jun;34(1):57-62.
    PMID: 22870600
    Haemoglobin Constant Spring (Hb CS) mutation and single gene deletions are common underlying genetic abnormalities for alpha thalassaemias. Co-inheritance of deletional and non-deletional alpha (alpha) thalassaemias may result in various thalassaemia syndromes. Concomitant co-inheritance with beta (beta) and delta (delta) gene abnormalities would result in improved clinical phenotype. We report here a 33-year-old male patient who was admitted with dengue haemorrhagic fever, with a background history of Grave's disease, incidentally noted to have mild hypochromic microcytic red cell indices. Physical examination revealed no thalassaemic features or hepatosplenomegaly. His full blood picture showed hypochromic microcytic red cells with normal haemoglobin (Hb) level. Quantitation of Hb using high performance liquid chromatography (HPLC) and capillary electrophoresis (CE) revealed raised Hb F, normal Hb A2 and Hb A levels. There was also small peak of Hb CS noted in CE. H inclusions was negative. Kleihauer test was positive with heterocellular distribution of Hb F among the red cells. DNA analysis for alpha globin gene mutations showed a single -alpha(-3.7) deletion and Hb CS mutation. These findings were suggestive of compound heterozygosity of Hb CS and a single -alpha(-3.7) deletion with a concomitant heterozygous deltabeta thalassaemia. Co-inheritance of Hb CS and a single -alpha(-3.7) deletion is expected to result at the very least in a clinical phenotype similar to that of two alpha genes deletion. However we demonstrate here a phenotypic modification of alpha thalassemia presumptively as a result of co-inheritance with deltabeta chain abnormality as suggested by the high Hb F level.
  16. Yusof N, Hassan MA, Yee PL, Tabatabaei M, Othman MR, Mori M, et al.
    Waste Manag Res, 2011 Jun;29(6):602-11.
    PMID: 21447612 DOI: 10.1177/0734242X10397581
    Nitrification of mature sanitary landfill leachate with high-strength of N-NH(4) + (1080-2350 mg L(-1)) was performed in a 10 L continuous nitrification activated sludge reactor. The nitrification system was acclimatized with synthetic leachate during feed batch operation to avoid substrate inhibition before being fed with actual mature leachate. Successful nitrification was achieved with an approximately complete ammonium removal (99%) and 96% of N-NH(4) + conversion to N-NO(-) (3) . The maximum volumetric and specific nitrification rates obtained were 2.56 kg N-NH(4) (+) m(-3) day(-1) and 0.23 g N-NH(4) ( +) g(-1) volatile suspended solid (VSS) day(-1), respectively, at hydraulic retention time (HRT) of 12.7 h and solid retention time of 50 days. Incomplete nitrification was encountered when operating at a higher nitrogen loading rate of 3.14 kg N-NH(4) (+) m(-3) day(-1). The substrate overloading and nitrifiers competition with heterotrophs were believed to trigger the incomplete nitrification. Fluorescence in situ hybridization (FISH) results supported the syntrophic association between the ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria. FISH results also revealed the heterotrophs as the dominant and disintegration of some AOB cell aggregates into single cells which further supported the incomplete nitrification phenomenon.
  17. Sastu UR, Abdullah NR, Norahmad NA, Saat MN, Muniandy PK, Jelip J, et al.
    Malar J, 2016;15:63.
    PMID: 26850038 DOI: 10.1186/s12936-016-1109-9
    Malaria cases persist in some remote areas in Sabah and Sarawak despite the ongoing and largely successful malaria control programme conducted by the Vector Borne Disease Control Programme, Ministry Of Health, Malaysia. Point mutations in the genes that encode the two enzymes involved in the folate biosynthesis pathway, dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) enzymes confer resistance to pyrimethamine and sulfadoxine respectively, in both Plasmodium falciparum and P. vivax. The aim of the current study was to determine the mutation on both pvdhfr at codon 13, 33, 57, 58, 61, 117, and 173 and pvdhps genes at codon 383 and 553, which are potentially associated with resistance to pyrimethamine and sulfadoxine in P. vivax samples in Sabah.
  18. Che Othman FE, Yusof N, Yub Harun N, Bilad MR, Jaafar J, Aziz F, et al.
    Polymers (Basel), 2020 Sep 10;12(9).
    PMID: 32927881 DOI: 10.3390/polym12092064
    Various types of activated carbon nanofibers' (ACNFs) composites have been extensively studied and reported recently due to their extraordinary properties and applications. This study reports the fabrication and assessments of ACNFs incorporated with graphene-based materials, known as gACNFs, via simple electrospinning and subsequent physical activation process. TGA analysis proved graphene-derived rice husk ashes (GRHA)/ACNFs possess twice the carbon yield and thermally stable properties compared to other samples. Raman spectra, XRD, and FTIR analyses explained the chemical structures in all resultant gACNFs samples. The SEM and EDX results revealed the average fiber diameters of the gACNFs, ranging from 250 to 400 nm, and the successful incorporation of both GRHA and reduced graphene oxide (rGO) into the ACNFs' structures. The results revealed that ACNFs incorporated with GRHA possesses the highest specific surface area (SSA), of 384 m2/g, with high micropore volume, of 0.1580 cm3/g, which is up to 88% of the total pore volume. The GRHA/ACNF was found to be a better adsorbent for CH4 compared to pristine ACNFs and reduced graphene oxide (rGO/ACNF) as it showed sorption up to 66.40 mmol/g at 25 °C and 12 bar. The sorption capacity of the GRHA/ACNF was impressively higher than earlier reported studies on ACNFs and ACNF composites. Interestingly, the CH4 adsorption of all ACNF samples obeyed the pseudo-second-order kinetic model at low pressure (4 bar), indicating the chemisorption behaviors. However, it obeyed the pseudo-first order at higher pressures (8 and 12 bar), indicating the physisorption behaviors. These results correspond to the textural properties that describe that the high adsorption capacity of CH4 at high pressure is mainly dependent upon the specific surface area (SSA), pore size distribution, and the suitable range of pore size.
  19. Ma ZF, Yusof N, Hamid N, Lawenko RM, Mohammad WMZW, Liong MT, et al.
    Benef Microbes, 2019 Mar 13;10(2):111-120.
    PMID: 30525951 DOI: 10.3920/BM2018.0008
    Individuals in a community who developed irritable bowel syndrome (IBS) after major floods have significant mental health impairment. We aimed to determine if Bifidobacterium infantis M-63 was effective in improving symptoms, psychology and quality of life measures in flood-affected individuals with IBS and if the improvement was mediated by gut microbiota changes. Design was non-randomised, open-label, controlled before-and-after. Of 53 participants, 20 with IBS were given B. infantis M-63 (1×109 cfu/sachet/day) for three months and 33 were controls. IBS symptom severity scale, hospital anxiety and depression scale, SF-36 Questionnaire, hydrogen breath testing for small intestinal bacterial overgrowth and stools for 16S rRNA metagenomic analysis were performed before and after intervention. 11 of 20 who were given probiotics (M-63) and 20 of 33 controls completed study as per-protocol. Mental well-being was improved with M-63 vs controls for full analysis (P=0.03) and per-protocol (P=0.01) populations. Within-group differences were observed for anxiety and bodily pain (both P=0.04) in the M-63 per-protocol population. Lower ratio of Firmicutes/Bacteroidetes was observed with M-63 vs controls (P=0.01) and the lower ratio was correlated with higher post-intervention mental score (P=0.04). B. infantis M-63 is probably effective in improving mental health of victims who developed IBS after floods and this is maybe due to restoration of microbial balance and the gut-brain axis. However, our conclusion must be interpreted within the context of limited sample size. The study was retrospectively registered on 12 October 2017 and the Trial Registration Number (TRN) was NCT03318614.
  20. Faisal UH, Sabri NSA, Yusof N, Tahir AA, Said NNM, Riyadi FA, et al.
    Microbiol Resour Announc, 2021 May 13;10(19).
    PMID: 33986086 DOI: 10.1128/MRA.00259-21
    We report the draft genome sequence of Agrobacterium sp. strain S2, isolated from a decaying oil palm empty fruit bunch (OPEFB) in Negeri Sembilan, Malaysia, which yields potential genes encoding lignin degradation enzymes. This genome of 9,722,071 bp exhibited 58.9% GC content, 10,416 coding genes, and 12 RNAs.
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