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Fulltext Performance and Characterization of Bi-Metal Compound on Activated Carbon for Hydrogen Sulfide Removal in Biogas

Zulkefli NN, Noor Azam AMI, Masdar MS, Baharuddin NA, Wan Isahak WNR, Mohd Sofian N

Molecules, 2022 Dec 17;27(24).
PMID: 36558155 DOI: 10.3390/molecules27249024

This study reports on the synthesis of bi-metal compound (BMC) adsorbents based on commercial coconut activated carbon (CAC), surface-modified with metal acetate (ZnAc2), metal oxide (ZnO), and the basic compounds potassium hydroxide (KOH) and sodium hydroxide (NaOH). The adsorbents were then characterized by scanning electron microscopy and elemental analysis, microporosity analysis through Brunauer-Emmett-Teller (BET) analysis, and thermal stability via thermogravimetric analysis. Adsorption-desorption test was conducted to determine the adsorption capacity of H2S via 1 L adsorber and 1000 ppm H2S balanced 49.95% for N2 and CO2. Characterization results revealed that the impregnated solution homogeneously covered the adsorbent surface, morphology, and properties. The adsorption test result reveals that the ZnAc2/ZnO/CAC_B had a higher H2S breakthrough adsorption capacity and performed at larger than 90% capability compared with a single modified adsorbent (ZnAc2/CAC). Therefore, the synthesized BMC adsorbents have a high H2S loading, and the abundance and low cost of CAC may lead to favorable adsorbents in H2S captured.
Moving into a new era of periodontal genetic studies: relevance of large case-control samples using severe phenotypes for genome-wide association studies

Vaithilingam RD, Safii SH, Baharuddin NA, Ng CC, Cheong SC, Bartold PM, et al.

J Periodontal Res, 2014 Dec;49(6):683-95.
PMID: 24528298 DOI: 10.1111/jre.12167

Studies to elucidate the role of genetics as a risk factor for periodontal disease have gone through various phases. In the majority of cases, the initial 'hypothesis-dependent' candidate-gene polymorphism studies did not report valid genetic risk loci. Following a large-scale replication study, these initially positive results are believed to be caused by type 1 errors. However, susceptibility genes, such as CDKN2BAS (Cyclin Dependend KiNase 2B AntiSense RNA; alias ANRIL [ANtisense Rna In the Ink locus]), glycosyltransferase 6 domain containing 1 (GLT6D1) and cyclooxygenase 2 (COX2), have been reported as conclusive risk loci of periodontitis. The search for genetic risk factors accelerated with the advent of 'hypothesis-free' genome-wide association studies (GWAS). However, despite many different GWAS being performed for almost all human diseases, only three GWAS on periodontitis have been published - one reported genome-wide association of GLT6D1 with aggressive periodontitis (a severe phenotype of periodontitis), whereas the remaining two, which were performed on patients with chronic periodontitis, were not able to find significant associations. This review discusses the problems faced and the lessons learned from the search for genetic risk variants of periodontitis. Current and future strategies for identifying genetic variance in periodontitis, and the importance of planning a well-designed genetic study with large and sufficiently powered case-control samples of severe phenotypes, are also discussed.
Identification of biomarkers for periodontal disease using the immunoproteomics approach

Kerishnan JP, Mohammad S, Alias MS, Mu AK, Vaithilingam RD, Baharuddin NA, et al.

PeerJ, 2016;4:e2327.
PMID: 27635317 DOI: 10.7717/peerj.2327

Periodontitis is one of the most common oral diseases associated with the host's immune response against periodontopathogenic infection. Failure to accurately diagnose the stage of periodontitis has limited the ability to predict disease status. Therefore, we aimed to look for reliable diagnostic markers for detection or differentiation of early stage periodontitis using the immunoprotemic approach.
Fulltext Impact of non-surgical periodontal therapy on serum Resistin and periodontal pathogen in periodontitis patients with obesity

Md Tahir K, Ab Malek AH, Vaithilingam RD, Saub R, Safii SH, Rahman MT, et al.

BMC Oral Health, 2020 02 14;20(1):52.
PMID: 32059714 DOI: 10.1186/s12903-020-1039-3

BACKGROUND: Non-surgical periodontal therapy (NSPT) known as gold standard treatment in managing periodontitis. The aim of this study was to investigate the response of NSPT in periodontitis subjects who were obese. Clinical parameters of periodontitis, changes in serum resistin and periodontal pathogens in subgingival plaque were compared before and after NSPT in periodontitis subjects who were obese and with normal weight.
METHODS: A total of 48 periodontitis subjects (obese, n = 18; normal weight, n = 30) were recruited (hereafter will be referred as participants) to participate into a prospective, before and after clinical trial. Obesity status is defined by body mass index (BMI) criteria (obese: ≥30 kg/ m2; normal weight
Fulltext Parametric Study and Electrocatalyst of Polymer Electrolyte Membrane (PEM) Electrolysis Performance

Noor Azam AMI, Li NK, Zulkefli NN, Masdar MS, Majlan EH, Baharuddin NA, et al.

Polymers (Basel), 2023 Jan 21;15(3).
PMID: 36771861 DOI: 10.3390/polym15030560

An investigation was conducted to determine the effects of operating parameters for various electrode types on hydrogen gas production through electrolysis, as well as to evaluate the efficiency of the polymer electrolyte membrane (PEM) electrolyzer. Deionized (DI) water was fed to a single-cell PEM electrolyzer with an active area of 36 cm2. Parameters such as power supply (50-500 mA/cm2), feed water flow rate (0.5-5 mL/min), water temperature (25-80 °C), and type of anode electrocatalyst (0.5 mg/cm2 PtC [60%], 1.5 mg/cm2 IrRuOx with 1.5 mg/cm2 PtB, 3.0 mg/cm2 IrRuOx, and 3.0 mg/cm2 PtB) were varied. The effects of these parameter changes were then analyzed in terms of the polarization curve, hydrogen flowrate, power consumption, voltaic efficiency, and energy efficiency. The best electrolysis performance was observed at a DI water feed flowrate of 2 mL/min and a cell temperature of 70 °C, using a membrane electrode assembly that has a 3.0 mg/cm2 IrRuOx catalyst at the anode side. This improved performance of the PEM electrolyzer is due to the reduction in activation as well as ohmic losses. Furthermore, the energy consumption was optimal when the current density was about 200 mA/cm2, with voltaic and energy efficiencies of 85% and 67.5%, respectively. This result indicates low electrical energy consumption, which can lower the operating cost and increase the performance of PEM electrolyzers. Therefore, the optimal operating parameters are crucial to ensure the ideal performance and durability of the PEM electrolyzer as well as lower its operating costs.
Establishing and managing a periodontal biobank for research: the sharing of experience

Vaithilingam RD, Safii SH, Baharuddin NA, Karen-Ng LP, Saub R, Ariffin F, et al.

Oral Dis, 2015 Jan;21(1):e62-9.
PMID: 24930489 DOI: 10.1111/odi.12267

Periodontal bio-repositories, which allow banking of clinically validated human data and biological samples, provide an opportunity to derive biomarkers for periodontal diagnosis, prognosis and therapeutic activities which are expected to improve patient management. This article presents the establishing of the Malaysian Periodontal Database and Biobank System (MPDBS) which was initiated in 2011 with the aim to facilitate periodontal research. Partnerships were established with collaborating centres. Policies on specimen access, authorship and acknowledgement policies were agreed upon by all participating centres before the initiation of the periodontal biobank. Ethical approval for the collection of samples and data were obtained from institutional ethics review boards. A broad-based approach for informed consent was used, which covered areas related to quality of life impacts, genetics and molecular aspects of periodontal disease. Sample collection and processing was performed using a standardized protocol. Biobanking resources such as equipment and freezers were shared with the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS). In the development of the MPDBS, challenges that were previously faced by the MOCDTBS were considered. Future challenges in terms of ethical and legal issues will be faced when international collaborations necessitate the transportation of specimens across borders.