Displaying publications 1 - 20 of 23 in total

Abstract:
Sort:
  1. Ng YH, Chai YC, Mazli N, Jaafar NF, Ibrahim S
    Malays Orthop J, 2024 Mar;18(1):60-65.
    PMID: 38638655 DOI: 10.5704/MOJ.2403.008
    INTRODUCTION: To describe the duration of survival among bone tumour patients with endoprosthesis reconstruction and to determine frequency of implant failure, revision of surgery, and amputation after endoprosthesis reconstruction.

    MATERIALS AND METHODS: A retrospective cross-sectional review of all patients with either primary bone tumour or secondary bone metastases treated with en bloc resection and endoprosthesis reconstruction from January 2008 to December 2020.

    RESULTS: A total of 35 failures were recorded among the 27 (48.2%) patients with endoprostheses. Some of the patients suffered from one to three types of modes of failure on different timelines during the course of the disease. Up to eight patients suffered from more than one type of failure throughout the course of the disease. Out of all modes of failure, local recurrence (type 5 failure) was the most common, accounting for 25.0% of all failure cases. Four patients (7.1%) eventually underwent amputation, which were either due to infection (2 patients) or disease progression causing local recurrence (2 patients).

    CONCLUSION: The overall result of endoprosthesis reconstruction performed in our centre was compatible with other centres around the world. Moreover, limb salvage surgery should be performed carefully in a selected patient group to maximise the benefits of surgery.

  2. Ng YH, Moy FM, Hairi NN, Bulgiba A
    PeerJ, 2024;12:e16778.
    PMID: 38274329 DOI: 10.7717/peerj.16778
    BACKGROUND: Teachers are responsible for educating future generations and therefore play an important role in a country's education system. Teachers constitute about 2.6% of all employees in Malaysia, making it one of the largest workforces in the country. While health and well-being are crucial to ensuring teachers' work performance, reports on non-communicable diseases such as type 2 diabetes mellitus (T2DM) among Malaysian teachers are scarce. Hence, this study focused on the prevalence of T2DM, undiagnosed diabetes mellitus (DM), impaired fasting glucose (IFG), and underlying lifestyle factors associated with these outcomes among Malaysian teachers.

    METHODS: This is a cross-sectional study from the CLUSTer cohort. There were 14144 teachers from the Peninsular Malaysia included in this study. The teachers' sociodemographic and lifestyle characteristics were described using a weighted complex analysis. A matched age group comparison was carried out between teachers and the Malaysian general population on T2DM, undiagnosed DM, and IFG status. Next, the researchers examined the association of lifestyle factors with T2DM and IFG using multivariable logistic regression.

    RESULTS: The prevalence of T2DM, undiagnosed DM, and IFG among the Malaysian teachers were 4.1%, 5.1%, and 5.6%, respectively. The proportions of teachers with T2DM (both diagnosed and undiagnosed) and the IFG increased linearly with age. Teachers had a lower weighted prevalence of T2DM (known and undiagnosed) than the general population. However, teachers were more inclined to have IFG than the general population, particularly those aged 45 years and older. Among all lifestyle indicators, only waist circumference (aOR: 1.14, 95% CI: 1.08, 1.20) was found to be associated with T2DM, whereas waist circumference (aOR: 1.10, 95% CI: 1.05, 1.15) and physical activity [moderately active = (aOR: 0.71, 95% CI: 0.52, 0.98); highly active = (aOR: 0.56, 95% CI: 0.40, 0.80)] were associated with IFG.

    CONCLUSIONS: Modifiable lifestyle factors such as abdominal obesity and physical activity were associated with T2DM and IFG. Intervention programs targeting these factors could help reduce future treatment costs and increase productivity.

  3. Moy FM, Ng YH, Tan SS
    J Nutr Sci Vitaminol (Tokyo), 2023;69(6):463-470.
    PMID: 38171819 DOI: 10.3177/jnsv.69.463
    Metabolic syndrome (MetS) poses increased risks for non-communicable diseases, increasing all-cause mortality, disability, and healthcare costs. Beta-carotene as the major carotenoid is identified to play an important role in the pathophysiology of MetS. The present study aimed to investigate the association between serum beta-carotene levels with metabolic syndrome and metabolic risk factors among a cohort of teachers in Peninsular Malaysia. This cross-sectional study investigated a sub-sample of 645 serum samples which were randomly selected for beta-carotene determination. Socio-demographic, lifestyle and metabolic risk factors were measured following standard protocols. There were equal proportions of males and females, with majority Malays (69%) followed by the Chinese (24%) and Indians (6.5%). The prevalence of MetS was 24.8% with abnormal waist circumference and high blood pressure as the most commonly reported metabolic risk factors. The median serum beta-carotene was 5.15 (5.07) μmol/L. Serum beta-carotene in the lowest quartile (Q1) was found to be significantly associated with MetS (OR: 5.81; 95% CI: 2.96, 11.38) and metabolic risk factors, namely triglycerides (OR: 6.38; 95% CI: 3.04, 13.35), fasting blood sugar (OR: 3.32; 95% CI: 1.48, 7.43), HDL-cholesterol (OR: 2.88; 95% CI: 1.58, 5.26) and waist circumference (OR: 2.94; 95% CI: 1.73, 5.01), after adjusted for potential confounders. In summary, participants with lower serum beta-carotene had higher odds for MetS and the above-mentioned metabolic risk factors.
  4. Lu L, Yap YC, Nguyen DQ, Chan YH, Ng JL, Zhang YC, et al.
    Clin Genet, 2022 Jan 22.
    PMID: 35064937 DOI: 10.1111/cge.14116
    Multinational studies have reported monogenic etiologies in 25%-30% of children with steroid-resistant nephrotic syndrome. Such large studies are lacking in Asia. We established Deciphering Diversities: Renal Asian Genetics Network (DRAGoN) and aimed to describe the genetic and clinical spectrums in Asians. We prospectively studied a cohort of 183 probands with suspected genetic glomerulopathies from South and Southeast Asia, of whom 17% had positive family history. Using multi-gene panel sequencing, we detected pathogenic variants in 26 (14%) probands, of whom one-third had COL4A4 or COL4A5 variants (n = 9, 5%). Of those with COL4A5 defects, only 25% had features suggestive of Alport syndrome. Besides traditional predictors for genetic disease (positive family history and extrarenal malformations), we identified novel predictors, namely older age (6.2 vs. 2.4 years; p = 0.001), hematuria (OR 5.6; 95% CI 2.1-14.8; p 60% when a second risk factor (positive family history or extrarenal manifestation) co-existed. The genetic spectrum of glomerulopathies appears different in Asia. Collagen IV genes may be included in sequencing panels even when suggestive clinical features are absent.
  5. Grace Ng YH, Aminuddin AA, Tan TL, Kuppusamy R, Tagore S, Yeo GSH
    Arch Gynecol Obstet, 2021 May 11.
    PMID: 33973051 DOI: 10.1007/s00404-021-06090-y
    OBJECTIVE: To evaluate the safety in the first 12 h, efficacy and maternal satisfaction of a double balloon catheter (DBC) with vaginal prostaglandin (PGE) for induction of labour (IOL).

    METHODS: We conducted a multicentre randomised controlled study of 420 patients from 1st January 2016 to 31st December 2017 to evaluate the use of DBC in IOL in an Asian population looking at the adverse effects in the first 12 h after insertion. Women were assigned randomly to cervical ripening with either a DBC or a prostaglandin pessary. The adverse events in the 12 h after DBC or first prostaglandin inserted, the efficacy of a DBC to a prostaglandin in labour induction and maternal satisfaction were evaluated.

    RESULTS: There were significantly less women with uterine hyperstimulation in the DBC (2 vs 24, p ≤ 0.0001) compared to the prostaglandin group. There were no women with uterine hyperstimulation and non-reassuring foetal status in the DBC while there were 5 women with uterine hyperstimulation and foetal distress in the prostaglandin group. Use of entonox was significantly less in the DBC group (p = 0.009). There were no significant differences in both groups in caesarean section, vaginal deliveries and time to delivery, although significant less time was needed to achieve cervical os dilation more than 4 cm in the DBC group (p ≤ 0.0001). Neonatal birth outcomes were similar. Women's pain scores were similar for both methods. 80.1% of women allocated the DBC and 76.8% of women allocated the PGE were keen to recommend their method of induction.

    CONCLUSION: Double balloon catheter remains a good alternative method for inducing women in view of a good safety profile with low risk of hyperstimulation and high maternal satisfaction.

    CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02620215.

  6. Wu H, Kong XY, Wen X, Chai SP, Lovell EC, Tang J, et al.
    Angew Chem Int Ed Engl, 2021 Apr 06;60(15):8455-8459.
    PMID: 33368920 DOI: 10.1002/anie.202015735
    Improving the stability of cuprous oxide (Cu2 O) is imperative to its practical applications in artificial photosynthesis. In this work, Cu2 O nanowires are encapsulated by metal-organic frameworks (MOFs) of Cu3 (BTC)2 (BTC=1,3,5-benzene tricarboxylate) using a surfactant-free method. Such MOFs not only suppress the water vapor-induced corrosion of Cu2 O but also facilitate charge separation and CO2 uptake, thus resulting in a nanocomposite representing 1.9 times improved activity and stability for selective photocatalytic CO2 reduction into CH4 under mild reaction conditions. Furthermore, direct transfer of photogenerated electrons from the conduction band of Cu2 O to the LUMO level of non-excited Cu3 (BTC)2 has been evidenced by time-resolved photoluminescence. This work proposes an effective strategy for CO2 conversion by a synergy of charge separation and CO2 adsorption, leading to the enhanced photocatalytic reaction when MOFs are integrated with metal oxide photocatalyst.
  7. Samsudin MFR, Ullah H, Tahir AA, Li X, Ng YH, Sufian S
    J Colloid Interface Sci, 2021 Mar 15;586:785-796.
    PMID: 33198982 DOI: 10.1016/j.jcis.2020.11.003
    Herein, we performed an encyclopedic analysis on the photoelectrocatalytic hydrogen production of BiVO4/g-C3N4 decorated with reduced graphene oxide (RGO) or graphene quantum dots (GQDs). The differences between RGO and GQDs as an electron mediator was revealed for the first time in the perspective of theoretical DFT analysis and experimental validation. It was found that the incorporation of GQDs as an electron mediator promotes better photoelectrocatalytic hydrogen performance in comparison to the RGO. The addition of GQD can significantly improve the activity by 25.2 and 75.7% in comparison to the BiVO4/RGO/g-C3N4 and binary composite samples, respectively. Correspondingly, the BiVO4/GQD/g-C3N4 attained the highest photocurrent density of 19.2 mA/cm2 with an ABPE of 0.57% without the presence of any sacrificial reagents. This enhancement is stemming from the low photocharge carrier transfer resistance which was further verified via DFT study. The DFT analysis revealed that the BiVO4/GQD/g-C3N4 sample shared their electronic cloud density through orbital hybridization while the BiVO4/RGO/g-C3N4 sample show less mutual sharing. Additionally, the charge redistribution of the GQDs-composite at the heterostructure interface articulates a more stable and stronger heterojunction than the RGO-composite. Notably, this study provides new insights on the effect of different carbonaceous materials (RGO and GQDs) which are often used as an electron mediator to enhance photocatalytic activity.
  8. Moy FM, Ng YH
    Sci Prog, 2021;104(3):368504211029812.
    PMID: 34260295 DOI: 10.1177/00368504211029812
    The COVID-19 pandemic has disrupted the lives of all including university students. With the preventive measures to reduce the transmission of COVID-19, all face-to-face teaching and learning are converted to e-learning. The COVID-19 pandemic and the implementation of e-learning may influence these students' mental conditions. This study aimed to determine the association of factors with mental health status (depression, anxiety and stress) among university students in Malaysia. Study participants were tertiary education students from both the private and public universities in Malaysia. Participants were recruited via university emails and social media. The survey was administered via the online REDCap platform, from April to June 2020, during the movement control order period in the country. The questionnaire captured data on socio-demographic characteristics, academic information, implementation of e-learning, perception towards e-learning and COVID-19; as well as DASS 21 to screen for depression, anxiety and stress. The levels of stress, anxiety and depression were 56.5% (95% CI: 50.7%, 62.1%), 51.3% (95% CI: 45.6%, 57.0%) and 29.4% (95% CI: 24.3%, 34.8%) respectively. Most participants had good perception towards e-learning but negative perception on COVID-19. From the multivariate analysis, participants with positive perception on COVID-19 were protective towards stress (aOR: 0.96; 95% CI: 0.92, 0.99), anxiety (aOR: 0.94, 95% CI: 0.90, 0.98) and depression (aOR: 0.95; 95% CI: 0.91, 0.99). Older students were 14% (aOR: 0.86, 95% CI: 0.79, 0.94) and 11% (aOR: 0.89: 95% CI: 0.80, 0.99) less likely for anxiety and depression, respectively. Students originated from the Malay ethnicity had higher odds (aOR: 1.93; 95% CI: 1.05, 3.56) for depression. These findings demonstrated that the mental status of university students was greatly affected during the COVID-19 pandemic. Timely and credible information should be disseminated to alleviate their negative perception towards COVID-19.
  9. Chiu CK, Chan CYW, Tan PH, Goh SH, Ng SJ, Chian XH, et al.
    Spine (Phila Pa 1976), 2020 Mar 15;45(6):E319-E328.
    PMID: 31593064 DOI: 10.1097/BRS.0000000000003275
    STUDY DESIGN: Retrospective study.

    OBJECTIVE: The primary objective of this study was to assess the conformity of the radiological neck and shoulder balance parameters throughout a follow-up period of more than 2 years.

    SUMMARY OF BACKGROUND DATA: Postoperative shoulder and neck imbalance are undesirable features among Adolescent Idiopathic Scoliosis patients who underwent Posterior Spinal Fusion. There are many clinical and radiological parameters used to assess this clinical outcome. However, we do not know whether these radiological parameters conform throughout the entire follow-up period.

    METHODS: This was a retrospective study done in a single academic institution. Inclusion criteria were patients with scoliosis who underwent posterior instrumented spinal fusion with pedicle screw fixation and attended all scheduled follow-ups for at least 24 months postoperatively. Radiological shoulder parameters were measured from both preoperative antero-posterior and postoperative antero-posterior radiographs. Lateral shoulder parameters were: Radiographic Shoulder Height, Clavicle Angle (Cla-A), Clavicle-Rib Intersection Difference, and Coracoid Height Difference. Medial shoulder and neck parameters were: T1 Tilt and Cervical Axis (CA).

    RESULTS: The radiographs of 50 patients who had surgery done from November 2013 to November 2015 were analyzed. Mean age of this cohort was 16.3 ± 7.0 years. There were 38 (76%) female patients and 12 (24%) male patients. Mean final follow-up was 38.6 ± 5.8 months. When conformity assessment of the radiological parameter using the interclass coefficient correlation was done, we found that all parameters had significant correlation (P 

  10. Kwan MK, Chiu CK, Goh SH, Ng SJ, Tan PH, Chian XH, et al.
    Clin Spine Surg, 2019 Jul;32(6):256-262.
    PMID: 30640749 DOI: 10.1097/BSD.0000000000000769
    STUDY DESIGN: Retrospective study.

    OBJECTIVE: This study looked into whether crossbar can reliably measure Upper Instrumend Vertebra (UIV) tilt angle intraoperatively and accurately predict the UIV tilt angle postoperatively and at final follow-up.

    SUMMARY OF BACKGROUND DATA: Postoperative shoulder imbalance is a common cause of poor cosmetic appearance leading to patient dissatisfaction. There were no reports describing the technique or method in measuring the UIV tilt angle intraoperatively. Therefore, this study was designed to look into the reliability and accuracy of the usage of intraoperative crossbar in measuring the UIV tilt angle intraoperatively.

    METHODS: Lenke 1 and 2 Adolescent Idiopathic Scoliosis patients who underwent instrumented Posterior Spinal Fusion using pedicle screw constructs with minimum follow-up of 24 months were recruited for this study. After surgical correction, intraoperative UIV tilt angle was measured using a crossbar. Immediate postoperative and final follow up UIV tilt angle was measured on the standing anteroposterior radiographs.

    RESULTS: A total of 100 patients were included into this study. The reliability of the intraoperative crossbar to measure the optimal UIV tilt angle intraoperatively was determined by repeated measurements by assessors and measurement by different assessors. We found that the intra observer and inter observer reliability was very good with intraclass correlation coefficient values of >0.9. The accuracy of the intraoperative crossbar to measure the optimal UIV tilt angle intraoperatively was determined by comparing this measurement with the postoperative UIV tilt angle. We found that there was no significant difference (P>0.05) between intraoperative, immediate postoperative, and follow-up UIV tilt angle.

    CONCLUSIONS: The crossbar can be used to measure the intraoperative UIV tilt angle consistently and was able to predict the postoperative UIV tilt angle. It was a cheap, simple, reliable, and accurate instrument to measure the intraoperative UIV tilt angle.

  11. Kwan MK, Chiu CK, Tan PH, Chian XH, Ler XY, Ng YH, et al.
    Spine J, 2018 12;18(12):2239-2246.
    PMID: 29733900 DOI: 10.1016/j.spinee.2018.05.007
    BACKGROUND CONTEXT: In Lenke 1C and 2C curves, the choice between selective thoracic fusion (STF) versus non-selective thoracic fusion as the optimal surgical treatment is controversial.

    OBJECTIVE: This study aimed to assess the radiological and clinical outcome of patients with Lenke 1C and 2C curves treated with STF.

    STUDY DESIGN: This is a retrospective study.

    PATIENT SAMPLE: A total of 44 patients comprised the study sample.

    METHODS: Forty-four patients with Lenke 1C and 2C curves with adolescent idiopathic scoliosis who underwent STF were reviewed. Radiological parameters and Scoliosis Research Society (SRS)-22r scores were assessed preoperatively, postoperatively, and on final follow-up. The incidence of coronal decompensation, lumbar decompensation, and adding-on phenomenon were reported.

    RESULTS: Mean follow-up duration was 45.1±12.3 months and mean age was 17.0±5.1 years. The preoperative middle thoracic and thoracolumbar/lumbar (MT:TL/L) Cobb angle ratio was 1.4±0.3 and the MT:TL/L apical vertebra translation (AVT) ratio was 1.6±0.8. Final follow-up coronal balance was -13.0±11.5 mm, main thoracic AVT was 6.9±11.8 mm, and lumbar AVT was -20.4±13.8 mm (p

  12. Chan CYW, Chiu CK, Ler XY, Ng YH, Chian XH, Tan PH, et al.
    Spine (Phila Pa 1976), 2018 Oct 01;43(19):E1143-E1151.
    PMID: 29557927 DOI: 10.1097/BRS.0000000000002645
    STUDY DESIGN: Retrospective study.

    OBJECTIVE: To investigate the association between postoperative upper instrumented vertebrae (UIV) tilt angle with postoperative medial shoulder and neck imbalance.

    SUMMARY OF BACKGROUND DATA: Studies had found that current recommendations for UIV selection were not predictive of good postoperative shoulder balance.

    METHODS: A total of 98 patients with adolescent idiopathic scoliosis with Lenke 1/2 curves who underwent posterior spinal fusion between 2013 and 2014 with minimum follow-up of 2 years were recruited. Radiological parameters: UIV tilt angle, T1 tilt, cervical axis, and clavicle angle were measured preoperatively, postoperatively, and at final follow-up.

    RESULTS: Mean age was 16.2 ± 6.2 years. Mean follow-up was 37.9 ± 6.5 months. There were 73.5% Lenke 1 and 26.5% Lenke 2 curves. Significant factors affecting postoperative T1 Tilt were postoperative UIV tilt angle, preoperative T1 tilt, and preoperative UIV tilt angle. Postoperative UIV tilt angle and preoperative cervical axis were significant factors affecting cervical axis at final follow-up. UIV level was not significant independent factor that affected postoperative T1 tilt and cervical axis. There was strong correlation between postoperative UIV tilt angle and T1 tilt for the whole cohort (P 

  13. Ibrahim I, Lim HN, Mohd Zawawi R, Ahmad Tajudin A, Ng YH, Guo H, et al.
    J Mater Chem B, 2018 Jul 28;6(28):4551-4568.
    PMID: 32254398 DOI: 10.1039/c8tb00924d
    Discovering the distinctive photophysical properties of semiconductor nanoparticles (NPs) has made these a popular subject in recent advances in nanotechnology-related analytical methods. Semiconductor NPs are well-known materials that have been widely used in photovoltaic devices such as optical sensors and bioimaging, and dye-sensitized solar cells (DSSCs), as well as for light-emitting diodes (LEDs). The use of a narrow-bandgap semiconductor such as CdS NPs in the photoelectrochemical (PEC) detection of chemicals and biological molecules plays a key role as a photosensitizer and promotes some specific advantages in light-harvesting media. Their size-controlled optical and electrical properties make NPs fascinating and promising materials for a variety of nanoscale photovoltaic devices. Moreover, charge injection from the narrow bandgap to the adjacent material leads to efficient charge separation and prolongs the electron lifetime by the elimination of the charge carrier recombination probability. In this regard, a single photon enables the production of multiple photogenerated charge carriers in CdS NPs, which subsequently boosts the effectiveness of the photovoltaic devices. In particular, the present review article highlights the recent emerging PEC detection methods based on CdS NPs, specifically related to the direct and indirect interactions of NPs with target analytes. The current opportunities and challenges in achieving real-world applications of CdS-based PEC sensing are also presented.
  14. Ng KH, Khan MR, Ng YH, Hossain SS, Cheng CK
    J Environ Manage, 2017 Jul 01;196:674-680.
    PMID: 28365553 DOI: 10.1016/j.jenvman.2017.03.078
    In this study, we have employed a photocatalytic method to restore the liquid effluent from a palm oil mill in Malaysia. Specifically, the performance of both TiO2 and ZnO was compared for the photocatalytic polishing of palm oil mill effluent (POME). The ZnO photocatalyst has irregular shape, bigger in particle size but smaller BET specific surface area (9.71 m2/g) compared to the spherical TiO2 photocatalysts (11.34 m2/g). Both scavenging study and post-reaction FTIR analysis suggest that the degradation of organic pollutant in the TiO2 system has occurred in the bulk solution. In contrast, it is necessary for organic pollutant to adsorb onto the surface of ZnO photocatalyst, before the degradation took place. In addition, the reactivity of both photocatalysts differed in terms of mechanisms, photocatalyst loading and also the density of photocatalysts. From the stability test, TiO2 was found to offer higher stability, as no significant deterioration in activity was observed after three consecutive cycles. On the other hand, ZnO lost around 30% of its activity after the 1st-cycle of photoreaction. The pH studies showed that acidic environment did not improve the photocatalytic degradation of the POME, whilst in the basic environment, the reaction media became cloudy. In addition, longevity study also showed that the TiO2 was a better photocatalyst compared to the ZnO (74.12%), with more than 80.0% organic removal after 22 h of UV irradiation.
  15. Loi E, Ng RW, Chang MM, Fong JF, Ng YH, Ng SM
    Luminescence, 2017 Feb;32(1):114-118.
    PMID: 27166514 DOI: 10.1002/bio.3157
    Carbon dots, a new class of nanomaterial with unique optical property and have great potential in various applications. This work demonstrated the possibility of tuning the emission wavelength of carbon dots by simply changing the acid type used during synthesis. In particular, sulfuric and phosphoric acids and a mixture of the two were used to carbonize the same starting precursor, sucrose. This resulted in the isolation of carbon dots with blue (440 nm) and green (515 nm) emission. Interestingly, the use of an acid mixture at various ratios did not shift the initial emission profile, but did obviously alter the fluorescence efficiency of the peaks. This clearly showed that acid type can be used as an alternative tool to produce carbon dots that have different emissions using the same starting precursor. Copyright © 2016 John Wiley & Sons, Ltd.
  16. Lim SP, Lim YS, Pandikumar A, Lim HN, Ng YH, Ramaraj R, et al.
    Phys Chem Chem Phys, 2017 Jan 04;19(2):1395-1407.
    PMID: 27976767 DOI: 10.1039/c6cp05950c
    In the present investigation, gold-silver@titania (Au-Ag@TiO2) plasmonic nanocomposite materials with different Au and Ag compositions were prepared using a simple one-step chemical reduction method and used as photoanodes in high-efficiency dye-sensitized solar cells (DSSCs). The Au-Ag incorporated TiO2 photoanode demonstrated an enhanced solar-to-electrical energy conversion efficiency of 7.33%, which is ∼230% higher than the unmodified TiO2 photoanode (2.22%) under full sunlight illumination (100 mW cm-2, AM 1.5G). This superior solar energy conversion efficiency was mainly due to the synergistic effect between the Au and Ag, and their surface plasmon resonance effect, which improved the optical absorption and interfacial charge transfer by minimizing the charge recombination process. The influence of the Au-Ag composition on the overall energy conversion efficiency was also explored, and the optimized composition with TiO2 was found to be Au75-Ag25. This was reflected in the femtosecond transient absorption dynamics in which the electron-phonon interaction in the Au nanoparticles was measured to be 6.14 ps in TiO2/Au75:Ag25, compared to 2.38 ps for free Au and 4.02 ps for TiO2/Au100:Ag0. The slower dynamics indicates a more efficient electron-hole separation in TiO2/Au75:Ag25 that is attributed to the formation of a Schottky barrier at the interface between TiO2 and the noble metal(s) that acts as an electron sink. The significant boost in the solar energy conversion efficiency with the Au-Ag@TiO2 plasmonic nanocomposite showed its potential as a photoanode for high-efficiency DSSCs.
  17. Ong WJ, Tan LL, Ng YH, Yong ST, Chai SP
    Chem Rev, 2016 06 22;116(12):7159-329.
    PMID: 27199146 DOI: 10.1021/acs.chemrev.6b00075
    As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and "earth-abundant" nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g-C3N4 and g-C3N4-based nanocomposites, including (1) nanoarchitecture design of bare g-C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template-free synthesis routes, (2) functionalization of g-C3N4 at an atomic level (elemental doping) and molecular level (copolymerization), and (3) modification of g-C3N4 with well-matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The construction and characteristics of each classification of the heterojunction system will be critically reviewed, namely metal-g-C3N4, semiconductor-g-C3N4, isotype g-C3N4/g-C3N4, graphitic carbon-g-C3N4, conducting polymer-g-C3N4, sensitizer-g-C3N4, and multicomponent heterojunctions. The band structures, electronic properties, optical absorption, and interfacial charge transfer of g-C3N4-based heterostructured nanohybrids will also be theoretically discussed based on the first-principles density functional theory (DFT) calculations to provide insightful outlooks on the charge carrier dynamics. Apart from that, the advancement of the versatile photoredox applications toward artificial photosynthesis (water splitting and photofixation of CO2), environmental decontamination, and bacteria disinfection will be presented in detail. Last but not least, this comprehensive review will conclude with a summary and some invigorating perspectives on the challenges and future directions at the forefront of this research platform. It is anticipated that this review can stimulate a new research doorway to facilitate the next generation of g-C3N4-based photocatalysts with ameliorated performances by harnessing the outstanding structural, electronic, and optical properties for the development of a sustainable future without environmental detriment.
  18. Foo CY, Lim HN, Pandikumar A, Huang NM, Ng YH
    J Hazard Mater, 2016 Mar 5;304:400-8.
    PMID: 26595899 DOI: 10.1016/j.jhazmat.2015.11.004
    A newly developed CdS/rGO/CC electrode was prepared based on a flexible carbon cloth (CC) substrate with cadmium sulfide (CdS) nanoparticles and reduced graphene oxide (rGO). The CdS was synthesized using an aerosol-assisted chemical vapor deposition (AACVD) method, and the graphene oxide was thermally reduced on the modified electrode surface. The existence of rGO in the CdS-modified electrode increased the photocurrent intensity of the CdS/rGO/CC-modified electrode by three orders of magnitude, compared to that of the CdS/ITO electrode and two orders of magnitude higher than the CdS/CC electrode. A new visible-light-prompt photoelectrochemical sensor was developed based on the competitive binding reaction of Cu(2+) and CdS on the electrode surface. The results showed that the effect of the Cu(2+) on the photocurrent response was concentration-dependent over the linear ranges of 0.1-1.0 μM and 1.0-40.0 μM with a detection limit of 0.05 μM. The results of a selectivity test showed that this modified electrode has a high response toward Cu(2+) compared to other heavy metal ions. The proposed CdS/rGO/CC electrode provided a significantly high potential current compared to other reported values, and could be a practical tool for the fast, sensitive, and selective determination of Cu(2+).
  19. Ng YH, Fong MY, Subramaniam V, Shahari S, Lau YL
    Res Vet Sci, 2015 Dec;103:201-4.
    PMID: 26679818 DOI: 10.1016/j.rvsc.2015.10.009
    Sarcocystis species are pathogenic parasites that infect a wide range of animals, including cattle. A high prevalence of cattle sarcocystosis has been reported worldwide, but its status is unknown in Malaysia. This study focused on utilizing 18S rDNA to identify Sarcocystis species in Malaysian cattle and to determine their genetic variants. In this study, only Sarcocystis cruzi was detected in Malaysian cattle. The intra-species S. cruzi phylogenetic tree analysis and principal coordinate analysis (PCoA), respectively displayed two minor groups among the parasite isolates. This finding was supported by high Wright FST value (FST=0.647). The definitive hosts (dogs) may play a fundamental role in the development of S. cruzi genetic variants. Additionally, the existence of microheterogeneity within the S. cruzi merozoites and/or distinct genetic variants arisen from independent merozoites in mature sarcocysts, possibly contributed to the existence of intra-species variations within the population.
Related Terms
Filters
Contact Us

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

External Links