Displaying publications 81 - 100 of 180 in total

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  1. Lee JM, Wasserman RJ, Gan JY, Wilson RF, Rahman S, Yek SH
    Ecohealth, 2020 03;17(1):52-63.
    PMID: 31786667 DOI: 10.1007/s10393-019-01457-9
    Knowledge of the interrelationship of mosquito communities and land use changes is of paramount importance to understand the potential risk of mosquito disease transmission. This study examined the effects of land use types in urban, peri-urban and natural landscapes on mosquito community structure to test whether the urban landscape is implicated in increased prevalence of potentially harmful mosquitoes. Three land use types (park, farm, and forest nested in urban, peri-urban and natural landscapes, respectively) in Klang Valley, Malaysia, were surveyed for mosquito larval habitat, mosquito abundance and diversity. We found that the nature of human activities in land use types can increase artificial larval habitats, supporting container-breeding vector specialists such as Aedes albopictus, a dengue vector. In addition, we observed a pattern of lower mosquito richness but higher mosquito abundance, characterised by the high prevalence of Ae. albopictus in the urban landscape. This was also reflected in the mosquito community structure whereby urban and peri-urban landscapes were composed of mainly vector species compared to a more diverse mosquito composition in natural landscape. This study suggested that good environmental management practices in the tropical urban landscape are of key importance for effective mosquito-borne disease management.
  2. Nandakumal G, Ismail F, Mohamad NF, Lott PW, Chew KS, Ab Rahman S, et al.
    J Pediatr Hematol Oncol, 2021 04 01;43(3):101-103.
    PMID: 33560075 DOI: 10.1097/MPH.0000000000002077
    Hemolacria is a rare condition that causes a person to produce tears that are partially composed of blood. It can be a presenting feature of certain ocular and systemic conditions. Here, the authors describe an interesting case of a 12-year-old boy with an underlying beta-thalassemia trait, who presented with a 2-day history of bilateral blood-stained tears, and an episode of epistaxis. Ocular examination was normal, and syringing showed no nasolacrimal duct blockage. Systemic examination was unremarkable. Laboratory investigations confirmed type 2 von Willebrand disease. Management of hemolacria remains a clinical challenge given the rare occurrence of the disease. In this case report, the authors discuss the differential diagnosis and management approach to hemolacria.
  3. Ramli N, Abdul Rahman S, Hassan O, Mohd Yatim A, Said M, Lim LS, et al.
    Malays J Nutr, 2000 Mar;6(1):55-63.
    PMID: 22692392
    Thirty-two samples of chocolate products were analysed by HPLC for caffeine and theobromine contents. Defatted residues of samples were extracted with 80% aqueous acetone. After extraction into boiling water, the methylxanthines were identified and quantified with the use of μ-Bondapak column and mobile phase of methanol:water:acetic acid (20:79:1). Levels of caffein and theobromine in 32 samples of chocolate products averaged 0.62-1.14 mg/g and 0.026-0.153 mg/g respectively. Mean values for theobromine and caffeine content for chocolate coating were 0.82 and 0.07 mg/g respectively. The chocolate coating made from fat substitute had theobromine and caffeine levels ranging from 0.36-0.70 mg/g and 0.027-0.061 mg/g respectively, with mean values of 0.49 mg theobromine/g and 0.039 mg caffeine/g. In local chocolate, the mean theobromine and caffeine levels respectively were 0.72 mg/g and 0.04 mg/g in milk chocolate, and 0.85 mg/g and 0.06 mg/g in dark chocolate. Meanwhile, for imported chocolate, the mean theobromine and caffeine levels respectively were 1.05 mg/g and 0.12 mg/g in dark chocolate; 0.76 mg/g and 0.04 mg/g in milk chocolate; and 0.74 mg/g and 0.03 mg/g in white chocolate. Compared with the local chocolates, imported chocolates had higher levels of theobromine and caffeine at 1.141 mg/g and 0.1533mg/g. The average theobromine and caffeine concentrations in local chocolate were 0.082mg/g and 0.066mg/g. Theobromine concentration in chocolate samples is within the range of 0.62mg/g-1.141mg/g and the range of caffeine concentration is 0.026mg/g-0.153mg/g respectively. Bittersweet chocolates were found to have higher theobromine and caffeine concentrations than normal sweet chocolates and milk chocolates.
  4. Alam T, Rahman SM, Alam T, Habib N, Umar BU, Banna QR, et al.
    JNMA J Nepal Med Assoc, 2014 Jul-Sep;52(195):892-6.
    PMID: 26982662
    Long term physical training has been considered to adversely affect the performance of athletes especially the females. It may be due to the iron depletion caused by hemolysis or hemodilution results from plasma volume expansion. This study aims to assess the effect of heavy exercise on hemoglobin concentration and some other hematological parameters in female athletes.
  5. Daniel DS, Gan HM, Lee SM, Dykes GA, Rahman S
    Genome Announc, 2017 Jun 15;5(24).
    PMID: 28619812 DOI: 10.1128/genomeA.00553-17
    Enterococcus faecalis is known to cause a variety of nosocomial infections, including urinary tract infections. Antibiotic resistance and virulence properties in this species are of public concern. The draft genome sequences of six E. faecalis strains isolated from clinical and environmental sources in Malaysia are presented here.
  6. Tengku Shaeran TA, Shaari R, Abdul Rahman S, Alam MK, Muhamad Husin A
    J Oral Biol Craniofac Res, 2017 Jan-Apr;7(1):7-12.
    PMID: 28316914 DOI: 10.1016/j.jobcr.2016.10.007
    BACKGROUND: Bilateral sagittal split osteotomy (BSSO) is the most versatile procedure and adopted by many surgeons to relocate the mandible in patients having mandibular prognathism (MP). Injury to the inferior alveolar nerve (IAN) and unfavorable splits are two surgical complications of BSSO which are associated with mandibular morphology. Uses of cone beam computed tomography (CBCT) in providing 3-D images has gained a wider acceptance in surgical field nowadays. Its advantages are including reduced cost, lesser radiation dose and smaller physical footprint comparing to the conventional computed tomography.

    PURPOSE: This study aims to identify the differences in morphology of prognathic and non-prognathic mandible at BSSO sites using cone beam computed tomography images.

    METHODS: This retrospective study involved 51 CBCT images of patients having mandibular prognathism and without mandibular prognathism. The latter group made up from patients with Class I skeletal pattern. Samples were taken using purposive sampling method from two clinical centers.

    RESULT: Prognathic mandible has higher lingula level, superiorly and buccally placed inferior alveolar nerve canal at distal second molar, thinner mediolateral width of ramus at anterior and posterior part and thinner anteroposterior width of the ramus.

    CONCLUSION: Morphology of mandible in patients with mandibular prognathism (MP) was significantly different from patients without mandibular prognathism (WMP) for most of the parameters. The high risk parameters may be highlighted to the patients using cone beam computed tomography images.
  7. Al-Mamun A, Jafary T, Baawain MS, Rahman S, Choudhury MR, Tabatabaei M, et al.
    Environ Res, 2020 04;183:109273.
    PMID: 32105886 DOI: 10.1016/j.envres.2020.109273
    Developing cost-effective technology for treatment of sewage and nitrogen-containing groundwater is one of the crucial challenges of global water industries. Microbial fuel cells (MFCs) oxidize organics from sewage by exoelectrogens on anode to produce electricity while denitrifiers on cathode utilize the generated electricity to reduce nitrogen from contaminated groundwater. As the exoelectrogens are incapable of oxidizing insoluble, polymeric, and complex organics, a novel integration of an anaerobic sequencing batch reactor (ASBR) prior to the MFC simultaneously achieve hydrolytic-acidogenic conversion of complex organics, boost power recovery, and remove Carbon/Nitrogen (C/N) from the sewage and groundwater. The results obtained revealed increases in the fractions of soluble organics and volatile fatty acids in pretreated sewage by 52 ± 19% and 120 ± 40%, respectively. The optimum power and current generation with the pretreated sewage were 7.1 W m-3 and 45.88 A m-3, respectively, corresponding to 8% and 10% improvements compared to untreated sewage. Moreover, the integration of the ASBR with the biocathode MFC led to 217% higher carbon and 136% higher nitrogen removal efficiencies compared to the similar system without ASBR. The outcomes of the present study represent the promising prospects of using ASBR pretreatment and successive utilization of solubilized organics in denitrifying biocathode MFCs for simultaneous energy recovery and C/N removal from both sewage and nitrate nitrogen-contaminated groundwater.
  8. Muniandy K, Tan MH, Shehnaz S, Song BK, Ayub Q, Rahman S
    Planta, 2020 Feb 01;251(2):57.
    PMID: 32008119 DOI: 10.1007/s00425-020-03349-7
    MAIN CONCLUSION: The rice leaf mitochondrial DNA is  more methylated compared to the rice grain mitochondrial DNA. The old rice leaf mitochondrial DNA has also a higher methylation level than the young rice leaf mitochondrial DNA. The presence of DNA methylation in rice organelles has not been well characterized. We have previously shown that cytosine methylation of chloroplast DNA is different between leaf and grain, and varies between young and old leaves in rice. However, the variation in cytosine methylation of mitochondrial DNA is still poorly characterized. In this study, we have investigated cytosine methylation of mitochondrial DNA in the rice grain and leaf. Based on CpG, CHG, and CHH methylation analyses, the leaf mitochondrial DNA was found to be  more methylated compared to the grain mitochondrial DNA. The methylation of the leaf mitochondrial DNA was also higher in old compared to young leaves. Differences in methylation were observed at different cytosine positions of the mitochondrial DNA between grain and leaf, although there were also positions with a similar level of high methylation in all the tissues examined. The differentially methylated cytosine positions in rice mitochondrial DNA were observed mostly in the intergenic region and in some mitochondrial-specific genes involved in ATP production, transcription, and translation. The functional importance of cytosine methylation in the life cycle of rice mitochondria is still to be determined.
  9. Ab Rahman S, Ahmed Shokri A, Ahmad MR, Ismail AF, Termizi NS
    Adv Orthop, 2020;2020:4539792.
    PMID: 32411483 DOI: 10.1155/2020/4539792
    Background: Implants used for total knee arthroplasty (TKA) in Asian patients are mostly produced based on anthropometry of the Western population, thus causing problem with patella sizing, especially in Asian females where the patellae are regarded to be smaller. This study is to define intraoperative patella dimensions in our female populations and compare them with current prosthetic systems available at our institution.

    Methods: This is a cross-sectional study involving 156 TKA female patients with normal patellae. The patella height, width, thickness, medial and lateral articular facets' width and thickness, and the dome position were measured. The smallest implant size from 3 manufacturers was compared to the data obtained. Analysis using descriptive statistics was used to get the mean and median of anatomical patella dimensions, whereas the independent T test and one-way ANOVA test were used to compare the Malaysian female's patella dimensions with various implant sizes.

    Results: The articular surface of the patella was found to have an oval shape with a width-height ratio of 1.31. The mean (SD) patella thickness, width, and height were 20.7 (1.85) mm, 40.7 (3.79) mm, and 31.3 (2.81) mm, respectively. Only 17.9% fit for smallest implant size from all 3 manufacturers. The oval-shape implant was suitable in 53.8% patients based on their width-height ratio. The dome position is 2.2 mm medial to centre.

    Conclusion: These female patients have thinner and smaller patella, which are generally unable to accommodate patellar components based on the Caucasian database. Therefore, orthopaedic implant manufacturers should consider optimizing the thicknesses as well as widths of their patellar prostheses.

  10. Rahmat S, Yati IES, Musa R, A Rahman S, Ahmad NS, Dzulkarnain AAA
    Med J Malaysia, 2021 09;76(5):672-679.
    PMID: 34508373
    OBJECTIVE: The aims of this study are to measure the psychometric properties of the newly developed preliminary version of hearing impairment inventory for religious duties for Muslim adults, i.e., the Inventori Persepsi Bagi Muslim Yang Memiliki Masalah Pendengaran (IPM3P), and to produce a final version of IPM3P.

    METHODS: The preliminary version of IPM3P that is used to investigate the perception of Muslim adults with hearing impairment towards Islamic understanding and practice has been tested in this study. The preliminary version of IPM3P consists of three domains (obligation, practice, and difficulty) with 59 items in total. Four phases of validity and reliability testing involved were: i) Content validation, ii) Pretesting, face validity and proofreading, iii) Pilot study, and iv) Psychometric evaluation.

    RESULTS: The final version of IPM3P consists of 36 items. The findings from the present study suggest that the final version of IPM3P has excellent psychometric properties manifested by: i) good content validity, ii) excellently pretested, iii) good face validity, iv) good construct validity shown by principal component analysis and convergent validity, and v) good discriminant validity showed by divergent validity.

    CONCLUSION: IPM3P shows good potential to be used as a tool in investigating perception of Muslim adults towards Islamic understanding and practice.

  11. Rahman S, Ismail AA, Ismail SB, Naing NN, Abdul Rahman AR
    Eur J Clin Pharmacol, 2007 Aug;63(8):733-41.
    PMID: 17565489 DOI: 10.1007/s00228-007-0315-3
    OBJECTIVE: To investigate whether pharmacological interventions with rosiglitazone/ramipril can reverse preclinical vasculopathy in newly diagnosed untreated patients with type 2 diabetes (T2DM) and impaired glucose tolerance (IGT).

    METHODS: In this randomised, double-blind, placebo-controlled study, 33 T2DM and 33 IGT patients were randomised to 4 mg rosiglitazone or 5 mg ramipril or placebo for 1 year. The subjects were newly diagnosed, untreated, normotensive, nonobese, nonsmoker, and nonhyperlipidaemic. Haemodynamic variables were measured at three treatment phases and pulse wave velocity (PWV) and augmentation index (AI) were measured throughout the treatment period.

    RESULTS: Rosiglitazone showed a significant reduction in PWV (p=0.039) and AI (p=0.031) and ramipril demonstrated a significant reduction of AI (p=0.025) in IGT in comparison to placebo on the 12th month of treatment. No significant difference was observed in PWV and AI in T2DM with rosiglitazone/ramipril in comparison to placebo during overall treatment period.

    CONCLUSIONS: Rosiglitazone significantly reversed preclinical vasculopathy in IGT as evident by significant decrease in PWV and AI after 1 year of treatment. Ramipril also reduced large artery stiffness as shown by significant decrease of AI after 1 year of treatment in IGT. Further trials are needed for a longer period of time, maybe with higher doses, to show whether rosiglitazone/ramipril can reverse preclinical vasculopathy in T2DM.
  12. Salmi MS, Ahmed U, Aslfattahi N, Rahman S, Hardy JG, Anwar A
    RSC Adv, 2022 Nov 15;12(51):33142-33155.
    PMID: 36425203 DOI: 10.1039/d2ra04944a
    Two dimensional (2D) nanomaterials display properties with significant biological utility (e.g., antimicrobial activity). In this study, MXene-functionalized graphene (FG) nanocomposites with Ti3C2T x in varying ratios (FG : Ti3C2T x , 25 : 75%, 50 : 50%, and 75 : 25%) were prepared and characterized via scanning electron microscopy, scanning electron microscopy-energy dispersive X-ray (SEM-EDX), high-resolution transmission electron microscopy (HRTEM), and zeta potential analysis. Their cytotoxicity was assessed using immortalized human keratinocytes (HaCaT) cells at three different timepoints, and antibacterial activity was assessed using Gram-positive Methicillin resistant Staphylococcus aureus, MRSA, and Gram-negative neuro-pathogenic Escherichia coli K1 (E. coli K1) in vitro. The nanomaterials and composites displayed potent antibacterial effects against both types of bacteria and low cytotoxicity against HaCaT cells at 200 μg mL-1, which is promising for their utilization for biomedical applications.
  13. Wahyudi F, Aghakhanian F, Rahman S, Teo YY, Szpak M, Dhaliwal J, et al.
    BMC Bioinformatics, 2021 Dec 18;22(1):604.
    PMID: 34922440 DOI: 10.1186/s12859-021-04506-9
    BACKGROUND: In population genomics, polymorphisms that are highly differentiated between geographically separated populations are often suggestive of Darwinian positive selection. Genomic scans have highlighted several such regions in African and non-African populations, but only a handful of these have functional data that clearly associates candidate variations driving the selection process. Fine-Mapping of Adaptive Variation (FineMAV) was developed to address this in a high-throughput manner using population based whole-genome sequences generated by the 1000 Genomes Project. It pinpoints positively selected genetic variants in sequencing data by prioritizing high frequency, population-specific and functional derived alleles.

    RESULTS: We developed a stand-alone software that implements the FineMAV statistic. To graphically visualise the FineMAV scores, it outputs the statistics as bigWig files, which is a common file format supported by many genome browsers. It is available as a command-line and graphical user interface. The software was tested by replicating the FineMAV scores obtained using 1000 Genomes Project African, European, East and South Asian populations and subsequently applied to whole-genome sequencing datasets from Singapore and China to highlight population specific variants that can be subsequently modelled. The software tool is publicly available at https://github.com/fadilla-wahyudi/finemav .

    CONCLUSIONS: The software tool described here determines genome-wide FineMAV scores, using low or high-coverage whole-genome sequencing datasets, that can be used to prioritize a list of population specific, highly differentiated candidate variants for in vitro or in vivo functional screens. The tool displays these scores on the human genome browsers for easy visualisation, annotation and comparison between different genomic regions in worldwide human populations.

  14. Abdul Rahman S, Jeffree MS, Kamaludin F, Din IA, Yusof M, Ahmed K
    J Immigr Minor Health, 2018 Oct;20(5):1294-1297.
    PMID: 29159485 DOI: 10.1007/s10903-017-0674-5
    In February 2012, a district health authority received three inmates with bilateral leg swelling and difficulty in breathing from a detention camp for unauthorized immigrants. A case control study was conducted. Fasting blood samples of case and control groups were collected according to instructions of the laboratory for determining thiamine level, and their 1 week dietary intake was analyzed. 9% (21/226) of inmates had bilateral leg swelling, and 75% (6/8) of them had low thiamine level (
  15. Daniel DS, Lee SM, Gan HM, Dykes GA, Rahman S
    J Infect Public Health, 2017 02 21;10(5):617-623.
    PMID: 28254461 DOI: 10.1016/j.jiph.2017.02.006
    Enterococcus faecalis ranks as one of the leading causes of nosocomial infections. A strong epidemiological link has been reported between E. faecalis inhabiting animals and environmental sources. This study investigates the genetic diversity, antibiotic resistance and virulence determinants in E. faecalis from three sources in Malaysia. A total of 250 E. faecalis isolates were obtained consisting of 120 isolates from farm animals, 100 isolates from water sources and 30 isolates from hospitalized patients. Pulse-field gel electrophoresis-typing yielded 63 pulsotypes, with high diversity observed in all sources (D=≥0.901). No pulsotype was common to all the three sources. Each patient room had its own unique PFGE pattern which persisted after six months. Minimum inhibitory concentrations of Vancomycin, Gentamicin, Penicillin, Tetracycline, Nitrofurantoin, Levofloxacin, Ciprofloxacin and Fosfomycin were evaluated. Resistance to Tetracycline was most prevalent in isolates from farm animals (62%) and water sources (49%). Water isolates (86%) had a higher prevalence of the asa1 gene, which encodes for aggregation substance, whereas clinical (78%) and farm animal isolates (87%) had a higher prevalence of the esp gene, encoding a surface exposed protein. This study generates knowledge on the genetic diversity of E. faecalis with antibiotic resistance and virulence characteristics from various sources in Malaysia.
  16. Mat Eil Ismail MS, Sharifudin MA, Shokri AA, Ab Rahman S
    Singapore Med J, 2016 Mar;57(3):138-43.
    PMID: 26996450 DOI: 10.11622/smedj.2016055
    INTRODUCTION: Physiotherapy is an important part of rehabilitation following arthroplasty, but the impact of preoperative physiotherapy on functional outcomes is still being studied. This randomised controlled trial evaluated the effect of preoperative physiotherapy on the short-term functional outcomes of primary total knee arthroplasty (TKA).
    METHODS: 50 patients with primary knee osteoarthritis who underwent unilateral primary TKA were randomised into two groups: the physiotherapy group (n = 24), whose patients performed physical exercises for six weeks immediately prior to surgery, and the nonphysiotherapy group (n = 26). All patients went through a similar physiotherapy regime in the postoperative rehabilitation period. Functional outcome assessment using the algofunctional Knee Injury and Osteoarthritis Outcome Score (KOOS) scale and range of motion (ROM) evaluation was performed preoperatively, and postoperatively at six weeks and three months.
    RESULTS: Both groups showed a significant difference in all algofunctional KOOS subscales (p < 0.001). The mean score difference at six weeks and three months was not significant in the sports and recreational activities subscale for both groups (p > 0.05). Significant differences were observed in the time-versus-treatment analysis between groups for the symptoms (p = 0.003) and activities of daily living (p = 0.025) subscales. No significant difference in ROM was found when comparing preoperative measurements and those at three months following surgery, as well as in time-versus-treatment analysis (p = 0.928).
    CONCLUSION: Six-week preoperative physiotherapy showed no significant impact on short-term functional outcomes (KOOS subscales) and ROM of the knee following primary TKA.
    KEYWORDS: algofunctional Knee Injury and Osteoarthritis Outcome Score; functional outcome; prehabilitation; preoperative physiotherapy; total knee arthroplasty
  17. Iqbal F, Wilson R, Ayub Q, Song BK, Krzeminska-Ahmedzai U, Talei A, et al.
    Environ Sci Pollut Res Int, 2023 Mar;30(13):35715-35726.
    PMID: 36536201 DOI: 10.1007/s11356-022-24712-z
    Urban-dwelling birds can be useful biomonitors to assess the impact of the urbanisation on both public and wildlife health. Widely distributed urban bird species, the House crow, was studied for heavy metal accumulation levels from nine cities of South Asia, Southeast Asia and Africa that border the Indian Ocean. Feathers were spectroscopically investigated for the deposition of ten heavy metals, i.e. As, Zn, Pb, Cd, Ni, iron Fe, Mn, Cr, Cu and Li. Fe and Zn were found to be the most prevalent metals in all sites. Measured concentrations of Pb (4.38-14.77 mg kg-1) overall, and Fe (935.66 mg kg-1) and Cu (67.17 mg kg-1) at some studied sites were above the toxicity levels reported lethal in avian toxicological studies. Multivariate analysis and linear models supported geographical location as a significant predictor for the level of most of the metals. Zn and Cu, generally and Pb, Cd, Mn, Cr at some sites exhibited potential bioaccumulation from surrounding environments. Inter-species comparisons strengthen the inference that the House crow is a reliable bioindicator species for the qualitative assessment of local urban environmental pollution and could be a useful tool for inter-regional monitoring programs.
  18. Sripadmanabhan Indira S, Aravind Vaithilingam C, Oruganti KSP, Mohd F, Rahman S
    Nanomaterials (Basel), 2019 May 20;9(5).
    PMID: 31137520 DOI: 10.3390/nano9050773
    A sustainable power source to meet the needs of energy requirement is very much essential in modern society as the conventional sources are depleting. Bioenergy, hydropower, solar, and wind are some of the well-established renewable energy sources that help to attain the need for energy at mega to gigawatts power scale. Nanogenerators based on nano energy are the growing technology that facilitate self-powered systems, sensors, and flexible and portable electronics in the booming era of IoT (Internet of Things). The nanogenerators can harvest small-scale energy from the ambient nature and surroundings for efficient utilization. The nanogenerators were based on piezo, tribo, and pyroelectric effect, and the first of its kind was developed in the year 2006 by Wang et al. The invention of nanogenerators is a breakthrough in the field of ambient energy-harvesting techniques as they are lightweight, easily fabricated, sustainable, and care-free systems. In this paper, a comprehensive review on fundamentals, performance, recent developments, and application of nanogenerators in self-powered sensors, wind energy harvesting, blue energy harvesting, and its integration with solar photovoltaics are discussed. Finally, the outlook and challenges in the growth of this technology are also outlined.
  19. Irfan M, Ghalib SA, Waqas S, Khan JA, Rahman S, Faraj Mursal SN, et al.
    ACS Omega, 2023 May 23;8(20):17869-17879.
    PMID: 37251131 DOI: 10.1021/acsomega.3c00868
    Rice husk ash (RHA), a low-cost biomaterial, was utilized to form bio-oil from pyrolysis in a batch-stirred reactor, followed by its upgradation using the RHA catalyst. In the present study, the effect of temperature (ranging from 400 to 480 °C) on bio-oil production produced from RHA was studied to obtain the maximum bio-oil yield. Response surface methodology (RSM) was applied to investigate the effect of operational parameters (temperature, heating rate, and particle size) on the bio-oil yield. The results showed that a maximum bio-oil output of 20.33% was obtained at 480 °C temperature, 80 °C/min heating rate, and 200 μm particle size. Temperature and heating rate positively impact the bio-oil yield, while particle size has little effect. The overall R2 value of 0.9614 for the proposed model proved in good agreement with the experimental data. The physical properties of raw bio-oil were determined, and 1030 kg/m3 density, 12 MJ/kg calorific value, 1.40 cSt viscosity, 3 pH, and 72 mg KOH/g acid value were obtained, respectively. To enhance the characteristics of the bio-oil, upgradation was performed using the RHA catalyst through the esterification process. The upgraded bio-oil stemmed from a density of 0.98 g/cm3, an acid value of 58 mg of KOH/g, a calorific value of 16 MJ/kg, and a viscosity 10.5 cSt, respectively. The physical properties, GC-MS and FTIR, showed an improvement in the bio-oil characterization. The findings of this study indicate that RHA can be used as an alternative source for bio-oil production to create a more sustainable and cleaner environment.
  20. Lee JM, Wasserman RJ, Wilson RF, Cuthbert RN, Rahman S, Yek SH
    Ecohealth, 2023 Mar;20(1):65-73.
    PMID: 37129695 DOI: 10.1007/s10393-023-01629-8
    Fogging with insecticides is one of the main control measures for adult mosquito populations employed in countries that are affected by dengue. In many such countries, urban communities are increasingly characterised by high-density residence in high-rise condominia. Although fogging is typically applied at the ground level, its efficacy in three-dimensional urban environments is poorly understood. Here, we investigated the effect of fogging on vector mosquito distribution and abundance in high-rise condominia by conducting a before-after fogging survey. We showed that although mosquitoes were significantly concentrated at the lower levels in high-rise condominia, they were found throughout the three-dimensional environments. Fogging did not significantly alter this distribution or abundance pattern across any floor level. Thus, any fogging effect was short-lived as mosquito populations recovered within a few days before the subsequent scheduled treatment. In addition, increasing fogging frequency within practicable limits did not prolong the intended control effect. As urban mosquitoes are increasingly insusceptible to fogging due to insecticide resistance and vertical avoidance, this study demonstrates the need to implement other mosquito control strategies for high-rise condominia to manage mosquito populations.
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