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  1. Cheong AT, Mohd Said S, Muksan N
    Asia Pac J Public Health, 2015 Mar;27(2):NP485-94.
    PMID: 23343640 DOI: 10.1177/1010539512472361
    This study aimed to examine the duration to achieve first blood pressure (BP) control after the diagnosis of hypertension. This was a retrospective cohort study on 195 hypertensive patients' (age ≥18 years) records from a primary health care clinic. The median time to achieve first BP control was 7.2 months (95% confidence interval [CI] = 4.99-9.35). Cox proportional hazards regression results showed female patients were 1.5 times more likely to achieve BP control when compared with male patients (hazard ratio [HR] = 1.50, 95% CI 1.09-2.09, P = .013). Those with monotherapy were 2 times more likely (HR = 2.09, 95% CI = 1.39-3.13, P < 0.001) and those on 2 drugs were 3.5 times more likely (HR = 3.49, 95% CI = 1.65-7.40, P = .001) to achieve BP control than those with nonpharmacological treatment. The median time to achieve BP control was longer than the recommended time. Doctors may need to consider starting the pharmacological treatment early and be more aggressive in hypertensive management for male patients.
  2. Rahman MD, Mohd Said S, Balamurugan S
    Sci Technol Adv Mater, 2015 Jun;16(3):033501.
    PMID: 27877782
    The blue phase liquid crystal (BPLC) is a highly ordered liquid crystal (LC) phase found very close to the LC-isotropic transition. The BPLC has demonstrated potential in next-generation display and photonic technology due to its exceptional properties such as sub-millisecond response time and wide viewing angle. However, BPLC is stable in a very small temperature range (0.5-1 °C) and its driving voltage is very high (∼100 V). To overcome these challenges recent research has focused on solutions which incorporate polymers or nanoparticles into the blue phase to widen the temperature range from around few °C to potentially more than 60 °C. In order to reduce the driving voltage, strategies have been attempted by modifying the device structure by introducing protrusion or corrugated electrodes and vertical field switching mechanism has been proposed. In this paper the effectiveness of the proposed solution will be discussed, in order to assess the potential of BPLC in display technology and beyond.
  3. Azizan N, Mohd Said S, Zainal Abidin Z, Jantan I
    Molecules, 2017 Dec 05;22(12).
    PMID: 29206142 DOI: 10.3390/molecules22122135
    In this study, the essential oils of Orthosiphon stamineus Benth and Ficus deltoidea Jack were evaluated for their antibacterial activity against invasive oral pathogens, namely Enterococcus faecalis, Streptococcus mutans, Streptococcus mitis, Streptococcus salivarius, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum. Chemical composition of the oils was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The antibacterial activity of the oils and their major constituents were investigated using the broth microdilution method (minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC)). Susceptibility test, anti-adhesion, anti-biofilm, checkerboard and time-kill assays were also carried out. Physiological changes of the bacterial cells after exposure to the oils were observed under the field emission scanning electron microscope (FESEM). O. stamineus and F. deltoidea oils mainly consisted of sesquiterpenoids (44.6% and 60.9%, respectively), and β-caryophyllene was the most abundant compound in both oils (26.3% and 36.3%, respectively). Other compounds present in O. stamineus were α-humulene (5.1%) and eugenol (8.1%), while α-humulene (5.5%) and germacrene D (7.7%) were dominant in F. deltoidea. The oils of both plants showed moderate to strong inhibition against all tested bacteria with MIC and MBC values ranging 0.63-2.5 mg/mL. However, none showed any inhibition on monospecies biofilms. The time-kill assay showed that combination of both oils with amoxicillin at concentrations of 1× and 2× MIC values demonstrated additive antibacterial effect. The FESEM study showed that both oils produced significant alterations on the cells of Gram-negative bacteria as they became pleomorphic and lysed. In conclusion, the study indicated that the oils of O. stamineus and F. deltoidea possessed moderate to strong antibacterial properties against the seven strains pathogenic oral bacteria and may have caused disturbances of membrane structure or cell wall of the bacteria.
  4. Shadisvaaran S, Chin KY, Mohd-Said S, Leong XF
    Front Nutr, 2023;10:1209248.
    PMID: 37781110 DOI: 10.3389/fnut.2023.1209248
    Chronic inflammation is the underlying mechanism for many diseases. Thus, inflammatory signaling pathways are valuable targets for new treatment modalities. Natural products have gained interest as a potential source of bioactive compounds which provide health benefits in combating inflammatory-related diseases. Recent reports have linked the medicinal values of Bixa orellana L. with its anti-inflammatory activities. Therefore, this review aims to examine the therapeutic potential of bixin, a major bioactive constituent found in the seeds of B. orellana, on inflammatory-related diseases based on existing in vitro and in vivo evidence. Additionally, the anti-inflammatory mechanism of bixin via signaling pathways is explored and possible toxic effects are addressed. The findings suggest that bixin may ameliorate inflammation via inhibition of toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-κB), phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) and thioredoxin-interacting protein/NOD-like receptor protein 3 (TXNIP/NLRP3) inflammasome mechanisms. More well-planned clinical studies should be performed to verify its effectiveness and safety profile.
  5. Ramli H, Mohd-Dom TN, Mohd-Said S
    BMC Oral Health, 2021 Dec 03;21(1):618.
    PMID: 34861857 DOI: 10.1186/s12903-021-01950-0
    BACKGROUND: Siwak is a chewing stick used as an oral hygiene aid associated with Muslim communities across the globe since more than 1500 years ago. Used either exclusively or in conjunction with a regular toothbrush, there is evidence supporting its clinical effectiveness in plaque control, but adverse effects on periodontal health remains inconclusive.

    OBJECTIVE: This study aims to systematically review the wide range of data and literatures related to siwak practice and its effect on periodontal health.

    METHOD: The review was conducted based on scoping review techniques, searching literature in EBSCOHOST, PubMed, SCOPUS and Google scholar databases using the following search terms: "siwak' or 'miswak' or 'chewing stick" for intervention, and "periodontium or 'periodontal' or 'periodontal health' or 'periodontal disease" for outcome. Articles published between January 1990 to March 2021 and written in English language were included.

    RESULTS: A total of 721 articles collected from the search and 21 of them were eligible for the final analysis. Results of this study was described based on clinical and antibacterial reporting of siwak, method of siwak practice and its adverse effect on oral health. Siwak was found effective at removing dental plaque and improving periodontal health over time although its effect on subgingival microbiota was inconclusive. Presence of gingival recession and clinical attachment loss were much more commonly reported in siwak users, attributable to variations in the methods employed for tooth cleaning using the siwak.

    CONCLUSION: There is substantial evidence that the lack of standardised reporting for effective siwak use may have resulted in contradictory findings about its oral hygiene benefits and adverse effects. As such, future work on safe and effective siwak practice is to be advocated among its users.

  6. Megat Hasnan MM, Mohd Sabri MF, Mohd Said S, Nik Ghazali NN
    ScientificWorldJournal, 2014;2014:912683.
    PMID: 25165751 DOI: 10.1155/2014/912683
    This paper presents the design and evaluation of a high force density fishbone shaped electrostatic comb drive actuator. This comb drive actuator has a branched structure similar to a fishbone, which is intended to increase the capacitance of the electrodes and hence increase the electrostatic actuation force. Two-dimensional finite element analysis was used to simulate the motion of the fishbone shaped electrostatic comb drive actuator and compared against the performance of a straight sided electrostatic comb drive actuator. Performances of both designs are evaluated by comparison of displacement and electrostatic force. For both cases, the active area and the minimum gap distance between the two electrodes were constant. An active area of 800 × 300 μm, which contained 16 fingers of fishbone shaped actuators and 40 fingers of straight sided actuators, respectively, was used. Through simulation, improvement of drive force of the fishbone shaped electrostatic comb driver is approximately 485% higher than conventional electrostatic comb driver. These results indicate that the fishbone actuator design provides good potential for applications as high force density electrostatic microactuator in MEMS systems.
  7. Kamarudin MA, Sahamir SR, Datta RS, Long BD, Mohd Sabri MF, Mohd Said S
    ScientificWorldJournal, 2013;2013:713640.
    PMID: 24324378 DOI: 10.1155/2013/713640
    Thermoelectricity, by converting heat energy directly into useable electricity, offers a promising technology to convert heat from solar energy and to recover waste heat from industrial sectors and automobile exhausts. In recent years, most of the efforts have been done on improving the thermoelectric efficiency using different approaches, that is, nanostructuring, doping, molecular rattling, and nanocomposite formation. The applications of thermoelectric polymers at low temperatures, especially conducting polymers, have shown various advantages such as easy and low cost of fabrication, light weight, and flexibility. In this review, we will focus on exploring new types of polymers and the effects of different structures, concentrations, and molecular weight on thermoelectric properties. Various strategies to improve the performance of thermoelectric materials will be discussed. In addition, a discussion on the fabrication of thermoelectric devices, especially suited to polymers, will also be given. Finally, we provide the challenge and the future of thermoelectric polymers, especially thermoelectric hybrid model.
  8. Abdullah N, Mohd Said S, Marlina A, Roslan MF, Azil A, Nordin AR
    ScientificWorldJournal, 2015;2015:860537.
    PMID: 25879076 DOI: 10.1155/2015/860537
    A dimeric iron(II) complex, trans-[Fe2(CH3COO)4(L1)2] (1), and a trinuclear iron(II) complex, [Fe3(CH3COO)4(H2O)4(L2)] (2), were studied as potential dye-sensitised solar cell materials. The structures of both complexes were deduced by a combination of instrumental analyses and molecular modelling. Variable-temperature magnetic susceptibility data suggested that 1 was made up of 56.8% high-spin (HS) and 43.2% low-spin (LS) Fe(II) atoms at 294 K and has a moderate antiferromagnetic interaction (J=-81.2 cm(-1)) between the two Fe(II) centres, while 2 was made up of 27.7% HS and 72.3% LS Fe(II) atoms at 300 K. The optical band gaps (Eo) for 1 were 1.9 eV (from absorption spectrum) and 2.2 eV (from fluorescence spectrum), electrochemical bandgap (Ee) was 0.83 eV, excited state lifetime (τ) was 0.67 ns, and formal redox potential (E'(FeIII/FeII)) was +0.63 V. The corresponding values for 2 were 3.5 eV (from absorption spectrum), 1.8 eV (from fluorescence spectrum), 0.69 eV, 2.8 ns, and +0.41 V.
  9. Damulak PP, Ismail S, Abdul Manaf R, Mohd Said S, Agbaji O
    PMID: 33802322 DOI: 10.3390/ijerph18052477
    Optimal adherence to antiretroviral therapy (ART) remains the bedrock of effective therapy and management of human immunodeficiency virus (HIV). This systematic review examines the effect of interventions in improving ART adherence in sub-Saharan Africa (SSA), which bears the largest global burden of HIV infection. In accordance with PRISMA guidelines, and based on our inclusion and exclusion criteria, PUBMED, MEDLINE, and Google Scholar databases were searched for published studies on ART adherence interventions from 2010 to 2019. Thirty-one eligible studies published between 2010 to 2019 were identified, the categories of interventions were structural, behavioral, biological, cognitive, and combination. Study characteristics varied across design, intervention type, intervention setting, country, and outcome measurements. Many of the studies were behavioral interventions conducted in hospitals with more studies being randomized controlled trial (RCT) interventions. Despite the study variations, twenty-four studies recorded improvements. Notwithstanding, more quality studies such as RCTs should be conducted, especially among key affected populations (KAPs) to control transmission of resistant strains of the virus. Reliable objective measures of adherence should replace the conventional subjective self-report. Furthermore, long-term interventions with longer duration should be considered when evaluating the effectiveness of interventions.
  10. Mat-Baharin NH, Razali M, Mohd-Said S, Syarif J, Muchtar A
    J Prosthodont Res, 2020 Oct;64(4):490-497.
    PMID: 32063537 DOI: 10.1016/j.jpor.2020.01.004
    PURPOSE: Not all elements with β-stabilizing properties in titanium alloys are suitable for biomaterial applications, because corrosion and wear processes release the alloying elements to the surrounding tissue. Chromium and molybdenum were selected as the alloying element in this work as to find balance between the strength and modulus of elasticity of β-titanium alloys. This study aimed to investigate the effect of Titanium-10Molybdenum-10Chromium (Ti-10Mo-10Cr), Titanium-10Chromium (Ti-10Cr) and Titanium-10Molybdenum (Ti-10Mo) on the elemental leachability in tissue culture environment and their effect on the viability of human gingival fibroblasts (HGFs).

    METHODS: Each alloy was immersed in growth medium for 0-21 days, and the elution was analyzed to detect the released metals. The elution was further used as the treatment medium and exposed to seeded HGFs overnight. The HGFs were also cultured directly to the titanium alloy for 1, 3 and 7 days. Cell viability was then determined.

    RESULTS: Six metal elements were detected in the immersion of titanium alloys. Among these elements, molybdenum released from Ti-10Mo-10Cr had the highest concentration throughout the immersion period. Significant difference in the viability of fibroblast cells treated with growth medium containing metals and with direct exposure technique was not observed. The duration of immersion did not significantly affect cell viability. Nevertheless, cell viability was significantly affected after 1 and 7 days of exposure, when the cells were grown directly onto the alloy surfaces.

    CONCLUSIONS: Within the limitation of this study, the newly developed β-titanium alloys are non-cytotoxic to human gingival fibroblasts.

  11. Jamil NA, Mohd-Said S, Hwa CS, Sameeha MJ, Kruger E
    Int J Integr Care, 2021 09 15;21(3):10.
    PMID: 34611460 DOI: 10.5334/ijic.5952
    Introduction: The diabetes mellitus-periodontitis relationship has advocated several strategic management approaches on effective glycaemic control and oral health improvement for diabetic patients and periodontitis patients with diabetes. We aimed to identify the challenges of providing health education to patients with diabetes and/or periodontitis among healthcare professionals and needs for an integrated nutrition-oral health education module.

    Methods: This study involved semi-structure in-depth interview with fifteen healthcare professionals from a training hospital focused on: (i) the existing issues and challenges encountered while managing patients for their nutrition and care and (ii) issues related to the current practice among healthcare professionals. Details pertaining to the participants' verbal and non-verbal responses were recorded, transcribed ad verbatim and analysed using themes codes.

    Results: Patients' attitude and behaviour, language barriers and prioritising time were found as the common problems with patients, while limited knowledge on the relationship between diabetes-periodontitis, limited availability of appropriate and cultural-based health educational tools, lack of inter-professional multidisciplinary collaboration in managing patients, and constrains in time as well as costly therapy were common issues in the current practice.

    Conclusions: Cost-effective efforts must be focused on overcoming these issues besides emphasizing the needs on developing an integrated module to achieve better management outcomes.

  12. Zahid NI, Mahmood MS, Subramanian B, Mohd Said S, Abou-Zied OK
    J Phys Chem Lett, 2017 Nov 16;8(22):5603-5608.
    PMID: 29094952 DOI: 10.1021/acs.jpclett.7b02601
    Fluorescence upconversion and transient absorption techniques are used to explain the source of the intense red/near-infrared emission of crystalline 4-dimethylamino-2'-hydroxychalcone. We found that the initially excited enol form undergoes tautomerization in 3 ps to form the keto tautomer. The latter is stable in the ground state as a consequence of J-type aggregation in the crystal packing and is manifested in an absorption peak at 550 nm that spectrally overlaps with the short-lived enol emission, leading to self-reabsorption and adding a factor to the complete depletion of the enol emission. Relaxation of the keto tautomer takes place in the form of intense fluorescence (600-750 nm) with 1.7 ns lifetime. The different spectroscopy in solution is due to vibrational cooling (300 fs), followed by solvation dynamics (5 ps in methanol) and twisting of the hydroxyphenyl ring (16 ps), before relaxation of the enol tautomer in the form of weak green fluorescence with 350 ps lifetime.
  13. Ramli H, Nor Aripin KN, Mohd Said S, Mohamad Hanafiah R, Mohd Dom TN
    J Ethnopharmacol, 2022 Nov 15;298:115598.
    PMID: 35944735 DOI: 10.1016/j.jep.2022.115598
    ETHNOPHARMACOLOGICAL RELEVANCE: Salvadora persica L. and Azadirachtaindica A.Juss. are listed within the most common sources of miswak or chewing stick that widely used among Western Asia and Muslim populations worldwide. Miswak use in conjunction with toothbrush (adjunctive) has become apparent among the adults. Furthermore, miswak has been reported to have mechanical and pharmacological activities, and benefits to the oral health, by many studies.

    AIM OF THE STUDY: To assess the effectiveness of miswak in maintaining periodontal health among adults.

    MATERIALS AND METHODS: We searched for randomised controlled trials (RCTs) investigating the effect of miswak published in PubMed, EBSCOHOST (Dentistry & Oral Sciences), SCOPUS, and Cochrane Database for Systematic Review (CDSR) from inception to May 08, 2022. The primary outcomes of interest were changes in the periodontal health measured with plaque and gingivitis scores as well as subgingival bacteria load. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach while the estimates of effect were pooled using a random-effects model.

    RESULTS: Ten eligible articles were identified, of which 9 could be analysed quantitatively. The remaining report was included as part of the qualitative analysis. The meta-analysis showed that miswak was comparable with the toothbrush in reducing the mean plaque score (p= 0.08, SMD: 0.39, and 95% CI: -0.05 to 0.83) and mean gingivitis score (p= 0.37, SMD: 0.13, and 95% CI: -0.16 to 0.43). Even higher certainty of evidence for the effect of miswak on mean plaque reduction on labial surface of anterior teeth. However, the adjunctive effect of miswak was significantly more superior for reducing plaque (p= 0.01, SMD: 0.68, and 95% CI: 0.14 to 1.22) and gingivitis score (p= 0.04, SMD: 0.66, and 95% CI: 0.03 to 1.29).

    CONCLUSIONS: Miswak effectively reduced plaque and gingivitis scores to a level comparable to toothbrush when used exclusively. Adjunctive miswak use was particularly effective in improving periodontal health. However, the included studies inadequately reported on the method of toothbrushing using miswak and the frequency of miswak use. Therefore, further clinical studies are recommended to explore on the advantages and proper method of miswak practice for optima outcome and safety.

  14. Mohd-Said S, Mohd-Dom TN, Suhaimi N, Rani H, McGrath C
    Front Med (Lausanne), 2021;8:600769.
    PMID: 34179030 DOI: 10.3389/fmed.2021.600769
    Background: Aerosol-producing dental procedures are of concern in the spread of infections, especially during the COVID-19 pandemic. Periodontal prophylaxis is the most common aerosol-producing procedure conducted in dental practice globally. During COVID-19, many national and international organizations advocated the use of pre-procedural mouth rinsing to prevent the spread of infections from aerosol-generating procedures in the dental setting; however, many questioned the scientific basis for such recommendations. Objective: This systematic review aimed to evaluate the effectiveness of pre-procedural rinsing when preforming periodontal prophylaxis in reducing aerosol contamination in the dental setting. Methods: A comprehensive standardized search strategy was employed, informed by a defined PICO question across four electronic databases. The review of the literature was conducted using the PRISMA framework. Agreement between assessors was determined throughout. Synthesis of study characteristics and key outcomes were conducted. Cochrane's risk-of-bias tool for randomized trials (RoB 2) was employed to assess the quality/bias among studies. Results: The initial search yielded 731 citations across the four databases; 95 potentially effective studies were identified, with 56 effective studies found. Thirty randomized control trial studies were identified, 21 with a focus on effectiveness of pre-procedural mouth rinsing, involving 984 participants (aged 18-70). Agreement between assessors was high (Kappa >0.80). Various pre-procedural mouth rinses were tested, most frequently chlorhexidine (CHX) in 18 studies. The concentrations, volume, and prescribed duration of rinsing varied among studies, hampering meta-analyses. Nonetheless, all studies identified significant reductions in bacterial contamination, as measured by colony forming units (cfu). The effectiveness of CHX over other agents was evident with more than half of the studies (7/15) reporting over a 70% reduction in bacterial contamination (cfu). There were concerns over the risk of bias in most studies (76.2%); 19.0% had a high risk of bias and 4.8% were of low risk of bias. Conclusion: There is substantial evidence to support pre-procedural mouth rinsing, such as with chlorohexidine, to effectively reduce aerosol contamination when performing periodontal prophylaxis compared to mouth rinsing with water or not rinsing.
  15. Muhammad F, Tahir M, Zeb M, Kalasad MN, Mohd Said S, Sarker MR, et al.
    Sci Rep, 2020 Mar 16;10(1):4828.
    PMID: 32179797 DOI: 10.1038/s41598-020-61602-1
    This paper reports the potential application of cadmium selenide (CdSe) quantum dots (QDs) in improving the microelectronic characteristics of Schottky barrier diode (SBD) prepared from a semiconducting material poly-(9,9-dioctylfluorene) (F8). Two SBDs, Ag/F8/P3HT/ITO and Ag/F8-CdSe QDs/P3HT/ITO, are fabricated by spin coating a 10 wt% solution of F8 in chloroform and 10:1 wt% solution of F8:CdSe QDs, respectively, on a pre-deposited poly(3-hexylthiophene) (P3HT) on indium tin oxide (ITO) substrate. To study the electronic properties of the fabricated devices, current-voltage (I-V) measurements are carried out at 25 °C in dark conditions. The I-V curves of Ag/F8/P3HT/ITO and Ag/F8-CdSe QDs/P3HT/ITO SBDs demonstrate asymmetrical behavior with forward bias current rectification ratio (RR) of 7.42 ± 0.02 and 142 ± 0.02, respectively, at ± 3.5 V which confirm the formation of depletion region. Other key parameters which govern microelectronic properties of the fabricated devices such as charge carrier mobility (µ), barrier height (ϕb), series resistance (Rs) and quality factor (n) are extracted from their corresponding I-V characteristics. Norde's and Cheung functions are also applied to characterize the devices to study consistency in various parameters. Significant improvement is found in the values of Rs, n, and RR by 3, 1.7, and 19 times, respectively, for Ag/F8-CdSe QDs/P3HT/ITO SBD as compared to Ag/F8/P3HT/ITO. This enhancement is due to the incorporation of CdSe QDs having 3-dimensional quantum confinement and large surface-to-volume area. Poole-Frenkle and Richardson-Schottky conduction mechanisms are also discussed for both of the devices. Morphology, optical bandgap (1.88 ± 0.5 eV) and photoluminescence (PL) spectrum of CdSe QDs with a peak intensity at 556 nm are also reported and discussed.
  16. Jamil NA, Chau SH, Abdul Razak NI, Shamsul Kamar II, Mohd-Said S, Rani H, et al.
    BMC Med Educ, 2021 May 17;21(1):278.
    PMID: 34001119 DOI: 10.1186/s12909-021-02721-9
    BACKGROUND: A good understanding of the bi-directional relationship between diabetes and periodontitis is essential to ensure the successful management of both diseases. This study aimed to develop and evaluate an integrated diabetes-periodontitis nutrition and health education module.

    METHODS: The module was developed as an iterative and review process by five experts in nutrition and dietetics, periodontics, and dental public health. It consisted of three phases: (i) needs assessment on module contents and characteristics, (ii) module development and (iii) module evaluation by experts. Twelve healthcare professionals aged between 30 and 53 years (average 13.5 years of working experience) validated the module contents and its comprehensibility using the Patient Education Materials Assessment Tool for printable materials (PEMAT-P) and audio-visual materials (PEMAT-A/V). Scores of 0 (disagree) or 1 (agree) were given for sets of understandability and actionability statements and presented as a total percentage.

    RESULTS: Seventeen infographic-flip charts and 13 short-videos were developed in the Malay language and grouped into four topics: (i) Introduction to Diabetes and Periodontitis, (ii) Diabetes and Periodontitis Care, (iii) Lifestyle Modification, and (iv) Myths and Facts. Flip charts were rated between 76-100% for understandability and 80-100% for actionability, while videos rated between 90-100% for understandability and 100% for actionability, respectively.

    CONCLUSION: Overall, the newly developed module ranked high median scores for understandability and actionability. This finding reflects positive acceptance of the integrated module among the various healthcare professionals involved in managing patients with diabetes and periodontitis.

  17. Ali S, Tahir M, Mehboob N, Wahab F, J Langford S, Mohd Said S, et al.
    Materials (Basel), 2020 Feb 21;13(4).
    PMID: 32098037 DOI: 10.3390/ma13040960
    This work reports synthesis, thin film characterizations, and study of an organic semiconductor 2-aminoanthraquinone (AAq) for humidity and temperature sensing applications. The morphological and phase studies of AAq thin films are carried out by scanning electron microscope (SEM), atomic force microscope (AFM), and X-ray diffraction (XRD) analysis. To study the sensing properties of AAq, a surface type Au/AAq/Au sensor is fabricated by thermally depositing a 60 nm layer of AAq at a pressure of ~10-5 mbar on a pre-patterned gold (Au) electrodes with inter-electrode gap of 45 µm. To measure sensing capability of the Au/AAq/Au device, the variations in its capacitance and resistance are studied as a function of humidity and temperature. The Au/AAq/Au device measures and exhibits a linear change in capacitance and resistance when relative humidity (%RH) and temperature are varied. The AAq is a hydrophobic material which makes it one of the best candidates to be used as an active material in humidity sensors; on the other hand, its high melting point (575 K) is another appealing property that enables it for its potential applications in temperature sensors.
  18. Rusly NFS, Jamil NA, Mohd-Dom TN, Rani H, Mohd-Said S, Mohd-Norwir NA, et al.
    Healthcare (Basel), 2022 Oct 26;10(11).
    PMID: 36360470 DOI: 10.3390/healthcare10112129
    There were massive interruptions, including patient visits for dietary advice and dental services, during the COVID-19 outbreak. This study assessed the feasibility of an online diabetes wellness programme among periodontitis patients with type II diabetes mellitus. Patients were grouped into the intervention group (IG) and control group (CG). At baseline and week 12, all patients answered online questionnaires on diabetes-related knowledge, physical activity, and oral impacts on daily performances (OIDP). Body weight and waist circumference were self-measured with guided instructions. Diet recalls were used to estimate dietary and added sugar intake. All patients received a weekly educational video, but the IG attended three e-consultation sessions with a dietitian (weeks 1, 3, and 8) and a dentist (week 8) via video call. A semi-structured interview was conducted to collate qualitative feedback among the IG participants at the end of the programme. A total of 24 periodontitis patients (14 IG and 10 CG) participated in this study. Among the IG patients, significant improvements in diabetes knowledge, body weight, BMI, calories, carbohydrates, fat, and added sugar intakes were observed at week 12. The CG patients only had a significant reduction in carbohydrate intake post intervention. No changes were reported in physical activity level and OIDP for both groups. Feedback received from the IG participants included convenience, practical, preferred approach during the pandemic, increased awareness and knowledge, and favourable lifestyle changes. This study demonstrates that an online diabetes wellness programme with healthcare professionals is feasible and can facilitate knowledge and lifestyle improvements that can be adapted during the crisis situation.
  19. Shah SNA, Shahabuddin S, Mohd Sabri MF, Mohd Salleh MF, Mohd Said S, Khedher KM, et al.
    Nanomaterials (Basel), 2020 Jul 09;10(7).
    PMID: 32659972 DOI: 10.3390/nano10071340
    Developing stable nanofluids and improving their thermo-physical properties are highly important in heat transfer applications. In the present work, the stability, thermal conductivity, and rheological properties of tungsten disulphide (WS2) nanoparticles (NPs) with ethylene glycol (EG) were profoundly examined using a particle size analyzer, zeta-sizer, thermal property analyzer, rheometer, and pH measuring system. WS2 NPs were characterized by various techniques, such as XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared Spectroscopy), FESEM (Field emission scanning electron microscopy), and high-resolution transmission electron microscopy (HRTEM). The nanofluids were obtained with the two-step method by employing three volume concentrations (0.005%, 0.01%, and 0.02%) of WS2. The influence of different surfactants (Sodium dodecyl sulphate (SDS), Sodium dodecylbenzenesulfonate (SDBS), Cetyltrimethylammonium bromide (CTAB)) with various volume concentrations (0.05-2%) on the measured properties has also been evaluated. Pristine WS2/EG nanofluids exhibit low zeta potential values, i.e., -7.9 mV, -9.3 mV, and -5 mV, corresponding to 0.005%, 0.01%, and 0.02% nanofluid, respectively. However, the zeta potential surpassed the threshold (±30 mV) and the maximum values reached of -52 mV, -45 mV, and 42 mV for SDS, SDBS, and CTAB-containing nanofluids. This showed the successful adsorption of surfactants onto WS2, which was also observed through the increased agglomerate size of up to 1720 nm. Concurrently, particularly for 0.05% SDS with 0.005% WS2, thermal conductivity was enhanced by up to 4.5%, with a corresponding decrease in viscosity of up to 10.5% in a temperature range of (25-70 °C), as compared to EG. Conversely, the viscoelastic analysis has indicated considerable yield stress due to the presence of surfactants, while the pristine nanofluids exhibited enhanced fluidity over the entire tested deformation range. The shear flow behavior showed a transition from a non-Newtonian to a Newtonian fluid at a low shear rate of 10 s-1. Besides this, the temperature sweep analysis has shown a viscosity reduction in a range of temperatures (25-70 °C), with an indication of a critical temperature limit. However, owing to an anomalous reduction in the dynamic viscosity of up to 10.5% and an enhancement in the thermal conductivity of up to 6.9%, WS2/EG nanofluids could be considered as a potential candidate for heat transfer applications.
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