Optimization of oxygen evolution electrocatalytic activity of metal oxide nanosheet via surface modification

Sidek Haslinda Binti Mohd,이지형,Jin Xiaoyan,황성주 대한화학회 2023 Bulletin of the Korean Chemical Society Vol.44 No.12

A surface modification route to high-performance oxygen evolution electrocatalysts was developed by immobilization of highly-oxidized SeO42− species on the surface of exfoliated MnO2 nanosheets. The enhanced stability of tetragonally-distorted MnO6 octahedron could be achieved by the weakening of axial Mn–O bond due to competition with highly covalent Se6+–O bonds. The selenate anchoring was found to be quite effective in improving the electrocatalyst functionality of MnO2 nanosheets for oxygen evolution reaction, which could be ascribed to the improvement of charge transfer kinetics and the enhancement of Mn3+ stability. This study emphasized that the fine-control of bonding nature via surface modification with selenate anchoring can offer useful means to explore efficient electrocatalysts.

Stabilization of Layered Double Oxide in Hybrid Matrix of Graphene and Layered Metal Oxide Nanosheets: An Effective Way To Explore Efficient CO₂ Adsorbent

Mohd Sidek, Haslinda Binti,Jo, Yun Kyung,Kim, In Young,Hwang, Seong-Ju American Chemical Society 2016 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.120 No.41

<P>A novel methodology to explore efficient CO2 adsorbent is developed by the stabilization of layered double oxide (LDO) in the hybrid matrix of reduced graphene oxide (rG-O) and layered titanate nanosheets. The electrostatically derived self-assembly between cationic Mg-Al-layered double hydroxide (LDH) nanosheet and anionic graphene oxide (G-O)/layered titanate nanosheets followed by heat treatment at high temperature leads to the cohybridization of LDO (MgO/MgAl2O4) nanocrystals with exfoliated rG-O and layered titanate nanosheets. The incorporation of LDO into the hybrid matrix of rG-O and layered titanate nanosheets is highly effective in increasing its surface area through the formation of mesoporous stacking structure. Of prime importance is that even at very low concentration of titanate (0.3 wt %), an addition of layered titanate nanosheet induces a remarkable surface area expansion of LDO-rG-O nanocomposite from 178 to 330 m(2) g(-1). This result is attributable to the depression of the self-aggregation of rG-O nanosheets due to the incorporation of layered titanate nanosheet. The resulting LDO-rG-O-layered titanate nanocomposite shows promising CO2 adsorption capability of 1.71 mmol g(-1) at 273 K, which is much greater than those of LDO (0.79 mmol g(-1)) and LDO-rG-O nanocomposites (1.19 mmol g(-1)), highlighting the remarkable advantage of titanate addition to improve the CO2 adsorptivity of LDO. The present study clearly proves that the restacked assembly of rG-O nanosheet and layered metal oxide one has potential applications as an efficient hybrid matrix for exploring high performance gas adsorbent.</P>

Enhancement of the Water Adsorptivity of Metal–Organic Frameworks upon Hybridization with Layered Double Hydroxide Nanosheets

Mohd Sidek, Haslinda Binti,Jo, Yun Kyung,Kim, Tae Woo,Hwang, Young Kyu,Chang, Jong-San,Hwang, Seong-Ju American Chemical Society 2017 The Journal of Physical Chemistry Part C Vol.121 No.28

<P>Efficient water adsorbents with improved hydrostability can be synthesized by the hybridization of metal-organic framework (MOF) compounds with exfoliated layered double hydroxide (LDH) 2D nanosheets. The self-assembly between copper benzene tricarboxylate (Cu-BTC) MOF nanocrystals and exfoliated Mg-Al-LDH nanosheets leads to the nanoscale mixing of the MOF and LDH components, as well as to the prevention of the formation of aggregated secondary MOF particles. In the resulting nanohybrids, spherical Cu-BTC nanocrystals with small particle sizes of similar to 5-10 nm are uniformly anchored on the surface of Mg-Al-LDH 2D nanosheets with the dimensions of several hundred nanometers. At the optimal composition, the surface area of the resulting nanohybrid becomes greater than that of pristine Cu-BTC, which is attributable to the suppression of the self-aggregation of MOF nanocrystals and to the formation of the mesoporous stacking structure of the LDH nanosheets. Of prime importance is that both the water adsorption ability and the hydrostability of Cu-BTC become notably improved upon hybridization with LDH nanosheets. The present study clearly demonstrates that exfoliated LDH nanosheets can be used as an effective hybridization matrix for exploring novel efficient MOF-based hybrid water adsorbents.</P>

Contribution of the MLH1 -93G>A Promoter Polymorphism in Modulating Susceptibility Risk in Malaysian Colorectal Cancer Patients

Nizam, Zahary Mohd,Abdul Aziz, Ahmad Aizat,Kaur, Gurjeet,Abu Hassan, Muhammad Radzi,Mohd Sidek, Ahmad Shanwani,Lee, Yeong Yeh,Mazuwin, Maya,Ankathil, Ravindran Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Background: Colorectal cancer (CRC) exists in a more common sporadic form and less common hereditary forms, associated with the Lynch syndrome, familial adenomatous polyposis (FAP) and other rare syndromes. Sporadic CRC is believed to arise as a result of close interaction between environmental factors, including dietary and lifestyle habits, and genetic predisposition factors. In contrast, hereditary forms such as those related to the Lynch syndrome result from inheritance of germline mutations of mismatch repair (MMR) genes. However, in certain cases, the influence of low penetrance alleles in familial colorectal cancer susceptibility is also undeniable. Aim: To investigate the genotype frequencies of MLH1 promoter polymorphism -93G>A and to determine whether it could play any role in modulating familial and sporadic CRC susceptibility risk. Methods: A case-control study comprising of 104 histopathologically confirmed CRC patients as cases (52 sporadic CRC and 52 Lynch syndrome patients) and 104 normal healthy individuals as controls was undertaken. DNA was extracted from peripheral blood and the polymorphism was genotyped employing PCR-RFLP methods. The genotypes were categorized into homozygous wild type, heterozygous and homozygous variants. The risk association between these polymorphisms and CRC susceptibility risk was calculated using binary logistic regression analysis and deriving odds ratios (ORs). Results: When risk association was investigated for all CRC patients as a single group, the heterozygous (G/A) genotype showed a significantly higher risk for CRC susceptibility with an OR of 2.273, (95%CI: 1.133-4.558 and p-value=0.021). When analyzed specifically for the 2 types of CRC, the heterozygous (G/A) genotype showed significantly higher risk for sporadic CRC susceptibility with and OR of 3.714, (95%CI: 1.416-9.740 and p-value=0.008). Despite high OR value was observed for Lynch syndrome (OR: 1.600, 95%CI: 0.715-3.581), the risk was not statistically significant (P=0.253). Conclusion: Our results suggest an influence of MLH1 promoter polymorphism -93G>A in modulating susceptibility risk in Malaysian CRC patients, especially those with sporadic disease.

Stages of Smoking Cessation among Malaysian Adults - Findings from National Health Morbidity Survey 2006

Lim, Kuang Hock,Ibrahim, Normala,Ghazali, Sumarni Mohd,Kee, Chee Cheong,Lim, Kuang Kuay,Chan, Ying Ying,Teh, Chien Huey,Tee, Eng Ong,Lai, Wai Yee,Nik Mohamad, Mohd. Haniki,Sidek, Sherina Mohd Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Increasing the rate of smoking cessation will reduce the burden of diseases related to smoking, including cancer. Understanding the process of smoking cessation is a pre-requisite to planning and developing effective programs to enhance the rate of smoking cessation.The aims of the study were to determine the demographic distribution of smokers across the initial stages of smoking cessation (the pre-contemplation and contemplation stages) and to identify the predictors of smoking cessation among Malaysian adult smokers. Data were extracted from a population-based, cross-sectional survey carried out from April 2006 to July 2006. The distribution of 2,716,743 current smokers across the pre-contemplation stage (no intention to quit smoking in the next six months) or contemplation stage (intended to quit smoking in the next six months) was described. Multivariable logistic regression analysis was used to examine the relationship between socio-demographic variables and the stages of smoking cessation. Of the 2,716,743 current smokers, approximately 30% and 70% were in the pre-contemplative and contemplative stages of smoking cessation respectively. Multivariable analysis showed that male gender, low education level, older age group, married and those from higher income group and number of cigarettes smoked were associated with higher likelihood of pre-contemplation to cease smoking in the next six months. The majority of current smokers in Malaysia were in the contemplative stage of smoking cessation. Specific interventions should be implemented to ensure the pre-contemplative smokers proceed to the contemplative stage and eventually to the preparation stage.

Analysis of Runoff Aggregation Structures with Different Flow Direction Methods under the Framework of Power Law Distribution

Kok, Kahhoong,Mohd Sidek, Lariyah,Jung, Kwansue,Kim, JooCheol Springer-Verlag 2018 Water resources management Vol.32 No.14

Development of an Acceleration Plethysmogram based Cardioid Graph Biometric Identification

Khairul Azami Sidek,Munieroh Osman,Siti Nurfarah Ain Mohd Azam,Nur Izzati Zainal 보안공학연구지원센터 2016 International Journal of Bio-Science and Bio-Techn Vol.8 No.3

The increasing identity theft cases are alarming which puts biometric as the alternative solution to combat identity crime. Recently, biosignals are proposed as biometric modalities. Thus, in this study, the development of an Acceleration Plethysmogram (APG) based Cardioid graph biometric identification is presented. A total of 10 Photoplethysmogram (PPG) data from MIMIC II Waveform Database (MIMIC2WDB) with sampling frequency of 125 Hz were obtained. The datasets are later converted to APG signal by the second order differentiation and preprocessed with Butterworth filter. Then, Cardioid based graph of APG signal was generated. Its centroid and Euclidean distance are calculated. Finally, classification is done by applying these extracted features to Multilayer Perceptron (MLP) and Naïve Bayes neural networks classifiers. Our experimentation results show that subject recognition is possible by obtaining classification accuracy of 95% for APG based Cardioid graph for both classifiers while only 85% and 70% for PPG signal in MLP and Naïve Bayes classifiers. These outcomes indicate that APG based Cardioid graph biometric identification is a feasible solution to overcome identity fraud.

Listening to Sentences in Noise: Revealing Binaural Hearing Challenges in Patients with Schizophrenia

Noor Alaudin Abdul Wahab,Mohd. Normani Zakaria,Abdul Hamid Abdul Rahman,Dinsuhaimi Sidek,Suzaily Wahab 대한신경정신의학회 2017 PSYCHIATRY INVESTIGATION Vol.14 No.6

Objective: The present, case-control, study investigates binaural hearing performance in schizophrenia patients towards sentences presented in quiet and noise. Methods: Participants were twenty-one healthy controls and sixteen schizophrenia patients with normal peripheral auditory functions. The binaural hearing was examined in four listening conditions by using the Malay version of hearing in noise test. The syntactically and semantically correct sentences were presented via headphones to the randomly selected subjects. In each condition, the adaptively obtained reception thresholds for speech (RTS) were used to determine RTS noise composite and spatial release from masking. Results: Schizophrenia patients demonstrated significantly higher mean RTS value relative to healthy controls (p=0.018). The large effect size found in three listening conditions, i.e., in quiet (d=1.07), noise right (d=0.88) and noise composite (d=0.90) indicates statistically significant difference between the groups. However, noise front and noise left conditions show medium (d=0.61) and small (d=0.50) effect size respectively. No statistical difference between groups was noted in regards to spatial release from masking on right (p=0.305) and left (p=0.970) ear. Conclusion: The present findings suggest an abnormal unilateral auditory processing in central auditory pathway in schizophrenia patients. Future studies to explore the role of binaural and spatial auditory processing were recommended.

Laboratory evaluation to field application of ultrasound: A state-of-theart review on the effect of ultrasonication on enhanced oil recovery mechanisms

Augustine Agi,Radzuan Junin,Mohd Zaidi Jaafar,Mohd Akhmal Sidek,Faruk Yakasai,Afeez Gbadamosi,Jeffrey Oseh 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.110 No.-

Ultrasonic applications have proven to be successful in the laboratory and in the field. However, a reviewon the influence of ultrasound on enhanced oil recovery (EOR) mechanisms, is still lacking in the literature. Herein, the state-of-the-art review on the impact of ultrasound on EOR mechanisms is presented. Ultrasound oil recovery mechanisms were identified. Main factors affecting oil recovery mechanismswere elucidated. The effects of ultrasound on EOR mechanisms were clarified. Laboratory and field applicationsof ultrasound were reviewed. Lastly, hitches encountered in ultrasound EOR have opened newavenues for research and solutions proposed. Experimental findings demonstrate that oil recovery byultrasound ranges from 5-82% original oil in place, with extra oil recovery occurring between 10–20 minutesof ultrasonication. Oilfield results indicate that oil production increased in the range of 26.5–91%,water cut decreased by 4–28%, the success rate was between 75–90%, and the effect can last for 3–24 months.

Formulation of bionanomaterials: A review of particle design towards oil recovery applications

Augustine Agi,Radzuan Junin,Mohd Zaidi Jaafar,Mohd Akhmal Sidek,Faruk Yakasai,Afeez Gbadamosi,Jeffrey Oseh 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.98 No.-

To minimize environmental impact and costs, bionanomaterials have been proffered. However, theirperformance hinges on material and intensification of synthesis methods. Herein, design ofbionanomaterials towards oil recovery applications are presented. Methods of synthesizing bionanomaterialswere discussed. Process intensification of synthesis methods was elucidated and basic drivingforce during synthesis were identified. Challenges prevalent during design and application ofbionanomaterials have opened new opportunities for research and are incorporated with proposedsolutions. In absence of Ostwald ripening, nucleation rate and growth processes can control size andshape of nanocrystal. Hence, designing bionanomaterials, nucleation rate should be determinedalongside supersaturation.