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Fulltext Correlation between Fischer-Tropsch catalytic activity and composition of catalysts

Ali S, Mohd Zabidi NA, Subbarao D

Chem Cent J, 2011;5:68.
PMID: 22047220 DOI: 10.1186/1752-153X-5-68

This paper presents the synthesis and characterization of monometallic and bimetallic cobalt and iron nanoparticles supported on alumina. The catalysts were prepared by a wet impregnation method. Samples were characterized using temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), CO-chemisorption, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM-EDX) and N2-adsorption analysis. Fischer-Tropsch synthesis (FTS) was carried out in a fixed-bed microreactor at 543 K and 1 atm, with H2/CO = 2 v/v and space velocity, SV = 12L/g.h. The physicochemical properties and the FTS activity of the bimetallic catalysts were analyzed and compared with those of monometallic cobalt and iron catalysts at similar operating conditions.H2-TPR analysis of cobalt catalyst indicated three temperature regions at 506°C (low), 650°C (medium) and 731°C (high). The incorporation of iron up to 30% into cobalt catalysts increased the reduction, CO chemisorption and number of cobalt active sites of the catalyst while an opposite trend was observed for the iron-riched bimetallic catalysts. The CO conversion was 6.3% and 4.6%, over the monometallic cobalt and iron catalysts, respectively. Bimetallic catalysts enhanced the CO conversion. Amongst the catalysts studied, bimetallic catalyst with the composition of 70Co30Fe showed the highest CO conversion (8.1%) while exhibiting the same product selectivity as that of monometallic Co catalyst. Monometallic iron catalyst showed the lowest selectivity for C5+ hydrocarbons (1.6%).
Ab initio calculation of vibrational frequencies and Raman spectra of barium peroxide glass including comparison of tetrahedral BaO4 with GeO4 and SiO4

Rosli AN, Zabidi NA, Kassim HA, Shrivastava KN

Spectrochim Acta A Mol Biomol Spectrosc, 2011 Sep;79(5):1251-5.
PMID: 21571582 DOI: 10.1016/j.saa.2011.04.051

We have calculated the vibrational frequencies of clusters of atoms from the first principles by using the density-functional theory in the local density approximation (LDA). We are also able to calculate the electronic binding energy for all of the clusters of atoms from the optimized structure. We have made clusters of BanOm (n, m=1-6) and have determined the bond lengths, vibrational frequencies as well as intensities in each case. We find that the peroxide cluster BaO2 occurs with the O-O vibrational frequency of 836.3 cm(-1). We also find that a glass network occurs in the material which explains the vibrational frequency of 67 cm(-1). The calculated values agree with those measured from the Raman spectra of barium peroxide and Ba-B-oxide glass. We have calculated the vibrational frequencies of BaO4, GeO4 and SiO4 each in tetrahedral configuration and find that the vibrational frequencies in these systems depend on the inverse square root of the atomic mass.
Fulltext Enhancement of Versatile Extracellular Cellulolytic and Hemicellulolytic Enzyme Productions by Lactobacillus plantarum RI 11 Isolated from Malaysian Food Using Renewable Natural Polymers

Mohamad Zabidi NA, Foo HL, Loh TC, Mohamad R, Abdul Rahim R

Molecules, 2020 Jun 03;25(11).
PMID: 32503356 DOI: 10.3390/molecules25112607

Lactobacillus plantarum RI 11 was reported recently to be a potential lignocellulosic biomass degrader since it has the capability of producing versatile extracellular cellulolytic and hemicellulolytic enzymes. Thus, this study was conducted to evaluate further the effects of various renewable natural polymers on the growth and production of extracellular cellulolytic and hemicellulolytic enzymes by this novel isolate. Basal medium supplemented with molasses and yeast extract produced the highest cell biomass (log 10.51 CFU/mL) and extracellular endoglucanase (11.70 µg/min/mg), exoglucanase (9.99 µg/min/mg), β-glucosidase (10.43 nmol/min/mg), and mannanase (8.03 µg/min/mg), respectively. Subsequently, a statistical optimization approach was employed for the enhancement of cell biomass, and cellulolytic and hemicellulolytic enzyme productions. Basal medium that supplemented with glucose, molasses and soybean pulp (F5 medium) or with rice straw, yeast extract and soybean pulp (F6 medium) produced the highest cell population of log 11.76 CFU/mL, respectively. However, formulated F12 medium supplemented with glucose, molasses and palm kernel cake enhanced extracellular endoglucanase (4 folds), exoglucanase (2.6 folds) and mannanase (2.6 folds) specific activities significantly, indicating that the F12 medium could induce the highest production of extracellular cellulolytic and hemicellulolytic enzymes concomitantly. In conclusion, L. plantarum RI 11 is a promising and versatile bio-transformation agent for lignocellulolytic biomass.
Fulltext Inhibitory evaluation of Curculigo latifolia on α-glucosidase, DPP (IV) and in vitro studies in antidiabetic with molecular docking relevance to type 2 diabetes mellitus

Zabidi NA, Ishak NA, Hamid M, Ashari SE, Mohammad Latif MA

J Enzyme Inhib Med Chem, 2021 Dec;36(1):109-121.
PMID: 33249946 DOI: 10.1080/14756366.2020.1844680

The inhibition of α-glucosidase and DPP enzymes capable of effectively reducing blood glucose level in the management of type 2 diabetes. The purpose of the present study is to evaluate the inhibitory potential of α-glucosidase and DPP (IV) activity including with the 2-NBDG uptake assay and insulin secretion activities through in vitro studies. The selected of active compounds obtained from the screening of compounds by LC-MS were docked with the targeted enzyme that involved in the mechanism of T2DM. From the results, root extracts displayed a better promising outcome in α-glucosidase (IC50 2.72 ± 0.32) as compared with the fruit extracts (IC50 3.87 ± 0.32). Besides, root extracts also displayed a better activity in the inhibition of DPP (IV), enhance insulin secretion and glucose uptake activity. Molecular docking results revealing that phlorizin binds strongly with α-glucosidase, DPP (IV) and Insulin receptor (IR) enzymes with achieving the lowest binding energy value. The present work suggests several of the compounds have the potential that contribute towards inhibiting α-glucosidase and DPP (IV) and thus effective in lowering post-prandial hyperglycaemia.
Reshaping the Curriculum for Academy in Factory in Malaysia

Jamaludin KA, Ealangov S, Saleh SNHM, Zabidi NA, Alias N, Yasin MHM, et al.

Front Psychol, 2023;14:1120611.
PMID: 37082577 DOI: 10.3389/fpsyg.2023.1120611

Academy in Factory (AiF) was recently introduced in Malaysia to cater to the talent development and education attainment for a future-ready workforce. Though ideally expected to be an effective initiative, a lack of a strong curriculum framework hinders its implementation. To date the literature on AiF is very limited. It was found that its vague definition and characteristics, non-harmonised interaction between industry and academia, and non-existing curriculum framework are among contributing factors to its ineffective implementation. Thus, this study is aimed at reshaping a curriculum framework that is responsive to its aims and objectives. Building upon an extensive review of literature on AiF, industry-based curriculum, employability and human capital development, and best practices in the international context, the proposed framework is hoped to serve as a reference to improve its current practice.
Fulltext Protocol of health screening related to occupational diseases in 100 000 workers in critical sectors: a cross-sectional study with worksite risk assessment

Yasin SM, Ismail N, Masngut MI, Abdullah NN, Yasin NE, Omar M, et al.

BMJ Open, 2024 Aug 29;14(8):e083796.
PMID: 39209791 DOI: 10.1136/bmjopen-2023-083796

BACKGROUND: Occupational diseases are one of the most important health problems related to employment However, in Malaysia, there are few epidemiological studies discussing these issues, especially among workers in the industry. For that, this study aimed to screen workers from high-risk industrial sectors, identify hazards in the workplace and recommend improvement measures in the workplace to prevent occupational diseases.
METHODS AND ANALYSIS: This is a 3-year project in which a survey of 100 000 workers from all 13 states in Malaysia will be conducted using a web-based screening tool that is comprised of two parts: occupational disease screening tool and hazard identification, risk assessment and risk control method. Data will be collected using a multistage stratified sampling method from 500 companies, including seven critical industrial sectors. The independent variables will be sociodemographic characteristics, comorbidities, previous medical history, high-risk behaviour and workplace profile. The dependent variable will be the types of occupational diseases (noise-induced hearing loss, respiratory, musculoskeletal, neurotoxic, skin and mental disorders). Subsequently, suggestions of referral for medium and high-risk workers to occupational health clinics will be attained. The approved occupational health service clinics/providers will make a confirmatory diagnosis of each case as deemed necessary. Subsequently, a walk-through survey to identify workplace hazards and recommend workplace improvement measures to prevent these occupational diseases will be achieved. Both descriptive and inferential statistics will be used in this study. Simple and adjusted binary regression will be used to find the determinants of occupational diseases.
ETHICS AND DISSEMINATION: This study has been approved by the MARA University of Technology Research Ethics Board. Informed, written consent will be obtained from all study participants. Findings will be disseminated to the Department of Occupational Health and Safety, involved industries, and through peer-reviewed publications.