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Fulltext Subperiosteal Drainage versus Subdural Drainage in the management of Chronic Subdural Hematoma (A Comparative Study)

Chih AN, Hieng AW, Rahman NA, Abdullah JM

Malays J Med Sci, 2017 Mar;24(1):21-30.
PMID: 28381926 DOI: 10.21315/mjms2017.24.1.3

INTRODUCTION: Symptomatic chronic subdural hematomas (CSDH) remain one of the most frequent diagnoses in current neurosurgical practice. Burr-hole craniostomy with irrigation and placement of close-system drainage is the current recommended surgery for symptomatic CSDH. The aim of this study is to perform a direct comparison between two surgical techniques in the treatment of symptomatic CSDH, which have been proven in previous studies to be efficient. Our main objective was to compare the efficacy of placement of a subperiosteal drain (SPD) and a subdural drain (SDD) following single burr-hole craniostomy and irrigation, and to demonstrate any significant differences in terms of overall surgical complications, functional outcome at three months and mortality rate.
MATERIALS AND METHODS: The study was carried out in two local neurosurgical centres. The SPD group was performed in Hospital Umum Sarawak (HUS) and the SDD group was performed in Hospital Sultanah Aminah Johor Bahru (HSAJB), from 1 January 2012 till 30 January 2014 with a total of 30 patients in both treatment groups.
RESULTS: Overall, there were no statistically significant difference in terms of patient general characteristics, pre-operative and post-operative symptoms, Markwalder grades, post-operative hematoma volume and recurrence, mortality and functional outcome at discharge and at three month follow-up between both groups. Albeit not achieving statistical significance, we observed a lower rate of surgical complication especially for post-operative intracranial hematoma with placement of the SPD system.
CONCLUSIONS: Our study concludes that both treatment methods proved to be highly effective in the treatment of CSDH. However, with a lower overall surgical complication rate, treatment with single burr-hole craniostomy, irrigation and placement of the SPD system can be considered a treatment of choice for the management of symptomatic CSDH.
Door-to-Skin Time in Patient Undergoing Emergency Trauma Craniotomy

Chockalingam K, A Rahman NA, Idris Z, Theophilus SC, Abdullah JM, Ghani ARI, et al.

Malays J Med Sci, 2023 Aug;30(4):71-84.
PMID: 37655152 DOI: 10.21315/mjms2023.30.4.7

BACKGROUND: Traumatic brain injury (TBI) is the third leading cause of death and disability worldwide in 2020. For patients with TBI with significant intracranial bleeds, urgent surgical intervention remains the mainstay treatment. This study aims to evaluate the time to definite surgical intervention since admission and its association with patient outcomes in a neurosurgery referral centre in Malaysia.
METHODS: This retrospective study was conducted at Hospital Sultanah Aminah Johor Bahru from 1 January 2019 to 31 December 2019. All patients with TBI requiring urgent craniotomy were identified from the operating theatre registry, and the required data were extracted from their clinical notes, including the Glasgow Outcome Score (GCS) at discharge and 6 months later. Logistic regression was performed to identify the factors associated with poor outcomes.
RESULTS: A total of 154 patients were included in this study. The median door-to-skin time was 605 (interquartile range = 494-766) min. At discharge, 105 patients (68.2%) had poor outcomes. At the 6-month follow-up, only 58 patients (37.7%) remained to have poor outcomes. Simple logistic regression showed that polytrauma, hypotensive episode, ventilation, severe TBI, and the door-to-skin time were significantly associated with poor outcomes. After adjustments for the clinical characteristics in the analysis, the likelihood of having poor outcomes for every minute delay in the door-to-skin time increased at discharge (adjusted odds ratio [AOR] = 1.005; 95% confidence interval [CI] = 1.002-1.008) and the 6-month follow-up (AOR = 1.008; 95% CI = 1.005-1.011).
CONCLUSION: The door-to-skin time is directly proportional to poor outcomes in patients with TBI. Concerted efforts from all parties involved in trauma care are essential in eliminating delays in surgical interventions and improving outcomes.
Fulltext Prevalence and viral load of oncogenic human papillomavirus (HPV) in pterygia in multi-ethnic patients in the Malay Peninsula

Chong PP, Tung CH, Rahman NA, Yajima M, Chin FW, Yeng CL, et al.

Acta Ophthalmol, 2014 Nov;92(7):e569-79.
PMID: 25043991 DOI: 10.1111/aos.12427

The aim of the study was to determine the prevalence of human papillomavirus (HPV) in primary and recurrent pterygia samples collected from different ethnic groups in the equatorial Malay Peninsula.
Polyethylene glycol-coated porous magnetic nanoparticles for targeted delivery of chemotherapeutics under magnetic hyperthermia condition

Dabbagh A, Hedayatnasab Z, Karimian H, Sarraf M, Yeong CH, Madaah Hosseini HR, et al.

Int J Hyperthermia, 2019;36(1):104-114.
PMID: 30428737 DOI: 10.1080/02656736.2018.1536809

PURPOSE: Although magnetite nanoparticles (MNPs) are promising agents for hyperthermia therapy, insufficient drug encapsulation efficacies inhibit their application as nanocarriers in the targeted drug delivery systems. In this study, porous magnetite nanoparticles (PMNPs) were synthesized and coated with a thermosensitive polymeric shell to obtain a synergistic effect of hyperthermia and chemotherapy.
MATERIALS AND METHODS: PMNPs were produced using cetyltrimethyl ammonium bromide template and then coated by a polyethylene glycol layer with molecular weight of 1500 Da (PEG1500) and phase transition temperature of 48 ± 2 °C to endow a thermosensitive behavior. The profile of drug release from the nanostructure was studied at various hyperthermia conditions generated by waterbath, magnetic resonance-guided focused ultrasound (MRgFUS), and alternating magnetic field (AMF). The in vitro cytotoxicity and hyperthermia efficacy of the doxorubicin-loaded nanoparticles (DOX-PEG1500-PMNPs) were assessed using human lung adenocarcinoma (A549) cells.
RESULTS: Heat treatment of DOX-PEG1500-PMNPs containing 235 ± 26 mg·g-1 DOX at 48 °C by waterbath, MRgFUS, and AMF, respectively led to 71 ± 4%, 48 ± 3%, and 74 ± 5% drug release. Hyperthermia treatment of the A549 cells using DOX-PEG1500-PMNPs led to 77% decrease in the cell viability due to the synergistic effects of magnetic hyperthermia and chemotherapy.
CONCLUSION: The large pores generated in the PMNPs structure could provide a sufficient space for encapsulation of the chemotherapeutics as well as fast drug encapsulation and release kinetics, which together with thermosensitive characteristics of the PEG1500 shell, make DOX-PEG1500-PMNPs promising adjuvants to the magnetic hyperthermia modality.
Fulltext Prevalence and Factors Associated With Caesarean Delivery in Nepal: Evidence From a Nationally Representative Sample

Das P, Samad N, Sapkota A, Al-Banna H, A Rahman NA, Ahmad R, et al.

Cureus, 2021 Dec;13(12):e20326.
PMID: 35028222 DOI: 10.7759/cureus.20326

Background Caesarian sections (CS) are life-saving management for a pregnant mother and fetus subject to obstetric complications. The World Health Organization (WHO) expected CS rates not to exceed 10 to 15 per 100 live births in any country. This study aimed to assess the prevalence of CS and its associated factors from the 2016 Nepal Demographic and Health Survey (NDHS), building on previous studies mentioned in detail in the latter part of the paper. Methods This study analyzed the secondary data from the 2016 Nepal Demographic and Health Survey (NDHS), conducted from June 19, 2016, to January 31, 2017. The survey is undertaken every five years; consequently, the data capture the information in the previous five years from the data collection period. We used the 2016 NDHS, which is implemented by the new Enumeration Area (EA) under the support of the Ministry of Health (MOH) and funded by the U.S. Agency for International Development (USAID). In the rural areas, the sample is stratified and selected in two stages. In the first stage, wards are selected as the primary sampling units (PSU), with households subsequently chosen from the PSUs. In the urban areas, the sample is nominated in three stages. In the first stage, wards are selected as PSUs; in the second stage, one EA is chosen from each PSU, and finally, households are selected from the EAs. Then data were collected from the women in the reproductive age group within the selected households. Results The prevalence of CS in Nepal conforms to the WHO standard with 7.8, 7.5, and 8.1 per 100 deliveries, or 9.8, 8.9, and 9.1 per women's last births in the previous one, three, and five years, respectively. Older mothers of 30 years old or more, having high incomes, being overweight and obese, using the internet, ante-natal care (ANC) visits of more than four times, ANC by doctors, twin delivery, and having babies of 4 kg or more, had higher odds for a CS while having two or more children seemed to be protective towards CS. Conclusion These findings can be used to update health policies surrounding CS delivery to limit unnecessary CS and ensure better health as CS is not without complications.
Fabrication of electrospun cellulose/chitosan/ball-milled bone char membranes for efficient and selective sorption of Pb(II) from aqueous solutions

Du X, Rashid SA, Abdullah LC, Rahman NA

Environ Sci Pollut Res Int, 2023 Nov;30(51):110417-110430.
PMID: 37783997 DOI: 10.1007/s11356-023-30213-4

Separation materials have received increasing attention given their broad applications in the management of environmental pollution. It is desired to balance the contradiction between high separation efficiency and selectivity of separation materials. The integration of ball-milled bone chars with electrospun membranes might achieve this balance. In this study, electrospun cellulose/chitosan/ball-milled bone char (CL/CS/MB) membranes were by well-dispersing ball-milled bone chars with nanoscale size (98.9-167.5 nm) and developed porosity (40.2-373.1 m2/g) in the electrospinning solvent. The synergistic integration of distributed MBs (5.4-31.5 wt.% of loading hydroxyapatite on the membrane matrix) allowed the efficient sorption of Pb(II) with fast kinetics (20.0 min), excellent capacity (219.9 mg/g at pH 5.0, T 298 K), and favorable selectivity coefficients (2.76-6.79). The formation of minerals was dominant for the selective sorption of Pb(II) by combining the spectral analysis and quantitative determination. The surface complexation with O-/reductive N-species, the cation exchange with inorganic Ca2+, the electrostatic attraction with deprotonated O-, and the cation-π coordination with the aromatic carbon via the π-electrons should be not ignored for the capture of Pb(II). This work demonstrated the feasibility of electrospun CL/CS/MB membranes as a promising candidate for the remediation of aquatic pollutants.
Fulltext Detection of human papillomavirus in oropharyngeal squamous cell carcinoma

Fauzi FH, Hamzan NI, Rahman NA, Suraiya S, Mohamad S

J Zhejiang Univ Sci B, 2021 4 13;21(12):961-976.
PMID: 33843162 DOI: 10.1631/jzus.B2000161

Worldwide there has been a significant increase in the incidence of oropharyngeal squamous cell carcinoma (OPSCC) etiologically attributed to oncogenic human papillomavirus (HPV). Reliable and accurate identification and detection tools are important as the incidence of HPV-related cancer is on the rise. Several HPV detection methods for OPSCC have been developed and each has its own advantages and disadvantages in regard to sensitivity, specificity, and technical difficulty. This review summarizes our current knowledge of molecular methods for detecting HPV in OPSCC, including HPV DNA/RNA polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), p16 immunohistochemistry (IHC), and DNA/RNA in situ hybridization (ISH) assays. This summary may facilitate the selection of a suitable method for detecting HPV infection, and therefore may help in the early diagnosis of HPV-related carcinoma to reduce its mortality, incidence, and morbidity.
Fulltext Validation of quantitative structure-activity relationship (QSAR) model for photosensitizer activity prediction

Frimayanti N, Yam ML, Lee HB, Othman R, Zain SM, Rahman NA

Int J Mol Sci, 2011;12(12):8626-44.
PMID: 22272096 DOI: 10.3390/ijms12128626

Photodynamic therapy is a relatively new treatment method for cancer which utilizes a combination of oxygen, a photosensitizer and light to generate reactive singlet oxygen that eradicates tumors via direct cell-killing, vasculature damage and engagement of the immune system. Most of photosensitizers that are in clinical and pre-clinical assessments, or those that are already approved for clinical use, are mainly based on cyclic tetrapyrroles. In an attempt to discover new effective photosensitizers, we report the use of the quantitative structure-activity relationship (QSAR) method to develop a model that could correlate the structural features of cyclic tetrapyrrole-based compounds with their photodynamic therapy (PDT) activity. In this study, a set of 36 porphyrin derivatives was used in the model development where 24 of these compounds were in the training set and the remaining 12 compounds were in the test set. The development of the QSAR model involved the use of the multiple linear regression analysis (MLRA) method. Based on the method, r(2) value, r(2) (CV) value and r(2) prediction value of 0.87, 0.71 and 0.70 were obtained. The QSAR model was also employed to predict the experimental compounds in an external test set. This external test set comprises 20 porphyrin-based compounds with experimental IC(50) values ranging from 0.39 μM to 7.04 μM. Thus the model showed good correlative and predictive ability, with a predictive correlation coefficient (r(2) prediction for external test set) of 0.52. The developed QSAR model was used to discover some compounds as new lead photosensitizers from this external test set.
Fulltext Design of new competitive dengue NS2B/NS3 protease inhibitors-a computational approach

Frimayanti N, Chee CF, Zain SM, Rahman NA

Int J Mol Sci, 2011;12(2):1089-100.
PMID: 21541045 DOI: 10.3390/ijms12021089

Dengue is a serious disease which has become a global health burden in the last decade. Currently, there are no approved vaccines or antiviral therapies to combat the disease. The increasing spread and severity of the dengue virus infection emphasizes the importance of drug discovery strategies that could efficiently and cost-effectively identify antiviral drug leads for development into potent drugs. To this effect, several computational approaches were applied in this work. Initially molecular docking studies of reference ligands to the DEN2 NS2B/NS3 serine protease were carried out. These reference ligands consist of reported competitive inhibitors extracted from Boesenbergia rotunda (i.e., 4-hydroxypanduratin A and panduratin A) and three other synthesized panduratin A derivative compounds (i.e., 246DA, 2446DA and 20H46DA). The design of new lead inhibitors was carried out in two stages. In the first stage, the enzyme complexed to the reference ligands was minimized and their complexation energies (i.e., sum of interaction energy and binding energy) were computed. New compounds as potential dengue inhibitors were then designed by putting various substituents successively on the benzyl ring A of the reference molecule. These substituted benzyl compounds were then computed for their enzyme-ligand complexation energies. New enzyme-ligand complexes, exhibiting the lowest complexation energies and closest to the computed energy for the reference compounds, were then chosen for the next stage manipulation and design, which involved substituting positions 4 and 5 of the benzyl ring A (positions 3 and 4 for 2446DA) with various substituents.
Fulltext Molecular Dynamics Simulations in Designing DARPins as Phosphorylation-Specific Protein Binders of ERK2

Gautam V, Nimmanpipug P, Zain SM, Rahman NA, Lee VS

Molecules, 2021 Jul 27;26(15).
PMID: 34361694 DOI: 10.3390/molecules26154540

Extracellular signal-regulated kinases 1 and 2 (ERK1/2) play key roles in promoting cell survival and proliferation through the phosphorylation of various substrates. Remarkable antitumour activity is found in many inhibitors that act upstream of the ERK pathway. However, drug-resistant tumour cells invariably emerge after their use due to the reactivation of ERK1/2 signalling. ERK1/2 inhibitors have shown clinical efficacy as a therapeutic strategy for the treatment of tumours with mitogen-activated protein kinase (MAPK) upstream target mutations. These inhibitors may be used as a possible strategy to overcome acquired resistance to MAPK inhibitors. Here, we report a class of repeat proteins-designed ankyrin repeat protein (DARPin) macromolecules targeting ERK2 as inhibitors. The structural basis of ERK2-DARPin interactions based on molecular dynamics (MD) simulations was studied. The information was then used to predict stabilizing mutations employing a web-based algorithm, MAESTRO. To evaluate whether these design strategies were successfully deployed, we performed all-atom, explicit-solvent molecular dynamics (MD) simulations. Two mutations, Ala → Asp and Ser → Leu, were found to perform better than the original sequence (DARPin E40) based on the associated energy and key residues involved in protein-protein interaction. MD simulations and analysis of the data obtained on these mutations supported our predictions.
Screening of Transforming Growth Factor Beta 3 and Jagged2 Genes in the Malay Population With Nonsyndromic Cleft Lip With or Without Cleft Palate

Ghazali N, Rahman NA, Kannan TP, Jaafar S

Cleft Palate Craniofac J, 2015 07;52(4):e88-94.
PMID: 26151095 DOI: 10.1597/14-024

OBJECTIVE: To determine the prevalence of mutations in transforming growth factor beta 3 (TGFβ3) and Jagged2 genes and their association with nonsyndromic cleft lip with or without cleft palate (CL±P) patients.

DESIGN: Cross-sectional study on nonsyndromic CL±P and noncleft patients.

SETTING: Reconstructive clinic and outpatient dental clinic, Hospital Universiti Sains Malaysia.

PATIENTS: Blood samples of 96 nonsyndromic CL±P and 96 noncleft subjects.

MAIN OUTCOME MEASURE: Prevalence and association of mutations in TGFβ3 and Jagged2 genes with nonsyndromic CL±P.

RESULTS: Most of the nonsyndromic CL±P patients (53.1%) had left unilateral CLP. There were slightly more females (56.6%) compared with males. The prevalence of the mutations in the TGFβ3 gene was 17.7% (95% confidence interval [CI]: 9.5, 24.5) and in the Jagged2 gene was 12.5% (95% CI: 5.5, 18.5), which was higher compared with the noncleft group. For the TGFβ3 gene, there was no mutation in the coding region in either of the groups. All variants were single nucleotide polymorphisms located within the intronic flanking region. Two variants were identified (g.15812T>G and g.15966A>G) in both nonsyndromic CL±P and noncleft patients. However, the association was not significant (P > .05). Three variants (g.19779C>T, g.19547G>A, and g.19712C>T) were identified in the Jagged2 gene among nonsyndromic CL±P and noncleft patients. Only g.19712C>T showed a significant association with nonsyndromic CL±P patients (P = .039).

CONCLUSION: g.19712C>T might play a crucial role in the development of cleft lip and palate. To the best of our knowledge, this is the first report of the mutation found within intron 13 of the Jagged2 gene among nonsyndromic CL±P Malay patients.

Study site:Reconstructive and outpatient dental clinic, Hospital Universiti Sains Malaysia (HUSM)
Identification of copy neutral loss of heterozygosity on chromosomes 1p, 1q, and 6p among nonsyndromic cleft lip and/or without cleft palate with hypodontia

Ghazali N, Rahman NA, Kannan TP, Ahmad A, Sulong S

BMC Oral Health, 2023 Nov 29;23(1):945.
PMID: 38031027 DOI: 10.1186/s12903-023-03464-3

BACKGROUND: Nonsyndromic cleft lip and/or without cleft palate (NSCL/P) with or without hypodontia is a common developmental aberration in humans and animals. This study aimed to identify the loss of heterozygosity (LOH) involved in hypodontia and NSCL/P pathogenesis.
METHODS: This is a cross-sectional study that conducted genome-wide copy number analysis using CytoScan 750K array on salivary samples from Malay subjects with NSCL/P with or without hypodontia aged 7-13 years. To confirm the significant results, simple logistic regression was employed to conduct statistical data analysis using SPSS software.
RESULTS: The results indicated the most common recurrent copy neutral LOH (cnLOH) observed at 1p33-1p32.3, 1q32.2-1q42.13 and 6p12.1-6p11.1 loci in 8 (13%), 4 (7%), and 3 (5%) of the NSCL/P subjects, respectively. The cnLOHs at 1p33-1p32.3 (D1S197), 1q32.2-1q42.13 (D1S160), and 6p12.1-6p11.1 (D1S1661) were identified observed in NSCL/P and noncleft children using microsatellite analysis markers as a validation analysis. The regions affected by the cnLOHs at 1p33-1p32.3, 1q32.2-1q42.13, and 6p12.1-6p11.1 loci contained selected genes, namely FAF1, WNT3A and BMP5, respectively. There was a significant association between the D1S197 (1p33-32.3) markers containing the FAF1 gene among NSCL/P subjects with or without hypodontia compared with the noncleft subjects (p-value = 0.023).
CONCLUSION: The results supported the finding that the genetic aberration on 1p33-32.3 significantly contributed to the development of NSCL/P with or without hypodontia. These results have an exciting prospect in the promising field of individualized preventive oral health care.
Screening of Transforming Growth Factor Beta 3 and Jagged2 Genes in the Malay Population With Nonsyndromic Cleft Lip With or Without Cleft Palate

Ghazali N, Rahman NA, Kannan TP, Jaafar S

Cleft Palate Craniofac J, 2014 Nov 05.
PMID: 25372553

OBJECTIVE: To determine the prevalence of mutations in transforming growth factor beta 3 (TGFβ3) and Jagged2 genes and their association with nonsyndromic cleft lip with or without cleft palate (CL±P) patients.
DESIGN: Cross-sectional study on nonsyndromic CL±P and noncleft patients.
SETTING: Reconstructive clinic and outpatient dental clinic, Hospital Universiti Sains, Malaysia.
PATIENTS: Blood samples of 96 nonsyndromic CL±P and 96 noncleft subjects.
MAIN OUTCOME MEASURE: Prevalence and association of mutations in TGFβ3 and Jagged2 genes with nonsyndromic CL±P.
RESULTS: Most of the nonsyndromic CL±P patients (53.1%) had left unilateral CLP. There were slightly more females (56.6%) compared with males. The prevalence of the mutations in the TGFβ3 gene was 17.7 (95% confidence interval [CI]: 9.5, 24.5) and in the Jagged2 gene was 12.5% (95% CI: 5.5, 18.5), which was higher compared with the noncleft group. For the TGFβ3 gene, there was no mutation in the coding region in either of the groups. All variants were single nucleotide polymorphisms located within the intronic flanking region. Two variants were identified (g.15812T>G and g.15966A>G) in both nonsyndromic CL±P and noncleft patients. However, the association was not significant (P > .05). Three variants (g.19779C>T, g.19547G>A, and g.19712C>T) were identified in the Jagged2 gene among nonsyndromic CL±P and noncleft patients. Only g.19712C>T showed a significant association with nonsyndromic CL±P patients (P = .039).
CONCLUSION: g.19712C>T might play a crucial role in the development of cleft lip and palate. To the best of our knowledge, this is the first report of the mutation found within intron 13 of the Jagged2 gene among nonsyndromic CL±P Malay patients.
Helicobacter pylori eradication with short-term therapy leads to duodenal ulcer healing without the need for continued acid suppression therapy

Goh KL, Navaratnam P, Peh SC, Wong NW, Chuah SY, Rahman NA, et al.

Eur J Gastroenterol Hepatol, 1996 May;8(5):421-3.
PMID: 8804868

To determine whether duodenal ulcers continue to heal following successful Helicobacter pylori eradication with short-term eradication therapy without further acid suppression therapy.
Enhanced fermentable sugar production from kitchen waste using various pretreatments

Hafid HS, Rahman NA, Md Shah UK, Baharudin AS

J Environ Manage, 2015 Jun 1;156:290-8.
PMID: 25900092 DOI: 10.1016/j.jenvman.2015.03.045

The kitchen waste fraction in municipal solid waste contains high organic matter particularly carbohydrate that can contribute to fermentable sugar production for subsequent conversion to bioethanol. This study was carried out to evaluate the influence of single and combination pretreatments of kitchen waste by liquid hot water, mild acid pretreatment of hydrochloric acid (HCl) and sulphuric acid (H2SO4) and enzymatic hydrolysis (glucoamylase). The maximum total fermentable sugar produced after combination pretreatment by 1.5% HCl and glucoamylase consisted of 93.25 g/L glucose, 0.542 g/L sucrose, 0.348 g/L maltose, and 0.321 g/L fructose. The glucose released by the combination pretreatment method was 0.79 g glucose/g KW equivalent to 79% of glucose conversion. The effects of the pre-treatment on kitchen waste indicated that the highest solubilization was 40% by the combination method of 1.5% HCl and glucoamylase. The best combination pre-treatment gave concentrations of lactic acid, acetic acid, and propionic acid of 11.74 g/L, 6.77 g/L, and 1.02 g/L, respectively. The decrease of aliphatic absorbance bands of polysaccharides at 2851 and 2923 cm(-1) and the increase on structures of carbonyl absorbance bands at 1600 cm(-1) reflects the progress of the kitchen waste hydrolysis to fermentable sugars. Overall, 1.5% HCl and glucoamylase treatment was the most profitable process as the minimum selling price of glucose was USD 0.101/g kitchen waste. Therefore, the combination pretreatment method was proposed to enhance the production of fermentable sugar, particularly glucose from kitchen waste as the feedstock for bioethanol production.
Fulltext Machine learning models development for accurate multi-months ahead drought forecasting: Case study of the Great Lakes, North America

Hameed MM, Razali SFM, Mohtar WHMW, Rahman NA, Yaseen ZM

PLoS One, 2023;18(10):e0290891.
PMID: 37906556 DOI: 10.1371/journal.pone.0290891

The Great Lakes are critical freshwater sources, supporting millions of people, agriculture, and ecosystems. However, climate change has worsened droughts, leading to significant economic and social consequences. Accurate multi-month drought forecasting is, therefore, essential for effective water management and mitigating these impacts. This study introduces the Multivariate Standardized Lake Water Level Index (MSWI), a modified drought index that utilizes water level data collected from 1920 to 2020. Four hybrid models are developed: Support Vector Regression with Beluga whale optimization (SVR-BWO), Random Forest with Beluga whale optimization (RF-BWO), Extreme Learning Machine with Beluga whale optimization (ELM-BWO), and Regularized ELM with Beluga whale optimization (RELM-BWO). The models forecast droughts up to six months ahead for Lake Superior and Lake Michigan-Huron. The best-performing model is then selected to forecast droughts for the remaining three lakes, which have not experienced severe droughts in the past 50 years. The results show that incorporating the BWO improves the accuracy of all classical models, particularly in forecasting drought turning and critical points. Among the hybrid models, the RELM-BWO model achieves the highest level of accuracy, surpassing both classical and hybrid models by a significant margin (7.21 to 76.74%). Furthermore, Monte-Carlo simulation is employed to analyze uncertainties and ensure the reliability of the forecasts. Accordingly, the RELM-BWO model reliably forecasts droughts for all lakes, with a lead time ranging from 2 to 6 months. The study's findings offer valuable insights for policymakers, water managers, and other stakeholders to better prepare drought mitigation strategies.
Rational discovery of dengue type 2 non-competitive inhibitors

Heh CH, Othman R, Buckle MJ, Sharifuddin Y, Yusof R, Rahman NA

Chem Biol Drug Des, 2013 Jul;82(1):1-11.
PMID: 23421589 DOI: 10.1111/cbdd.12122

Various works have been carried out in developing therapeutics against dengue. However, to date, no effective vaccine or anti-dengue agent has yet been discovered. The development of protease inhibitors is considered as a promising option, but most previous works have involved competitive inhibition. In this study, we focused on rational discovery of potential anti-dengue agents based on non-competitive inhibition of DEN-2 NS2B/NS3 protease. A homology model of the DEN-2 NS2B/NS3 protease (using West Nile Virus NS2B/NS3 protease complex, 2FP7, as the template) was used as the target, and pinostrobin, a flavanone, was used as the standard ligand. Virtual screening was performed involving a total of 13 341 small compounds, with the backbone structures of chalcone, flavanone, and flavone, available in the ZINC database. Ranking of the resulting compounds yielded compounds with higher binding affinities compared with the standard ligand. Inhibition assay of the selected top-ranking compounds against DEN-2 NS2B/NS3 proteolytic activity resulted in significantly better inhibition compared with the standard and correlated well with in silico results. In conclusion, via this rational discovery technique, better inhibitors were identified. This method can be used in further work to discover lead compounds for anti-dengue agents.
Fulltext Effect of TGF-beta1 antisense oligodeoxynucleotide on renal function in chronic renal failure rats

Hiong LC, Voon KL, Abdullah NA, Sattar MA, Rahman NA, Khan AH, et al.

Acta Pharmacol Sin, 2008 Apr;29(4):451-7.
PMID: 18358091 DOI: 10.1111/j.1745-7254.2008.00772.x

The aim of the present study was to investigate the effectiveness of transforming growth factor (TGF)-beta1 antisense oligodeoxynucleotides (ODN) in ameliorating deteriorated kidney function in rats with puromycin-induced chronic renal failure (CRF).
Maxillofacial trauma with emphasis on soft-tissue injuries in Malaysia

Hussaini HM, Rahman NA, Rahman RA, Nor GM, Ai Idrus SM, Ramli R

Int J Oral Maxillofac Surg, 2007 Sep;36(9):797-801.
PMID: 17630250

Soft-tissue injuries with or without facial bone involvement are the most common presentation following maxillofacial trauma. The objective of this study was to look at the distribution, pattern and type of soft-tissue injury in relation to aetiology. Records of patients over a period of 5 years (1998-2002), who sustained maxillofacial injuries and were treated at Kajang Hospital, a secondary referral hospital, were reviewed. Out of 313 patients with maxillofacial injuries, 295 patients sustained soft-tissue injuries. Males (79%) between 21 and 30 years old (34%) were the majority of patients. Road-traffic accident was the main cause of soft-tissue injuries (75%) with motorcycle accident being the most frequent (40%). The upper lips (23%) and the lower lips (18%) were the most common extraoral site involved, while the labial mucosa and sulcular areas, both accounting for 21%, were the most common intraoral sites. Stringent road-traffic regulations should be practiced in developing countries, as morbidity arising from road-traffic accidents poses a national economic and social problem.
Combustion characteristics of Malaysian oil palm biomass, sub-bituminous coal and their respective blends via thermogravimetric analysis (TGA)

Idris SS, Rahman NA, Ismail K

Bioresour Technol, 2012 Nov;123:581-91.
PMID: 22944493 DOI: 10.1016/j.biortech.2012.07.065

The combustion characteristics of Malaysia oil palm biomass (palm kernel shell (PKS), palm mesocarp fibre (PMF) and empty fruit bunches (EFB)), sub-bituminous coal (Mukah Balingian) and coal/biomass blends via thermogravimetric analysis (TGA) were investigated. Six weight ratios of coal/biomass blends were prepared and oxidised under dynamic conditions from temperature 25 to 1100°C at four heating rates. The thermogravimetric analysis demonstrated that the EFB and PKS evolved additional peak besides drying, devolatilisation and char oxidation steps during combustion. Ignition and burn out temperatures of blends were improved in comparison to coal. No interactions were observed between the coal and biomass during combustion. The apparent activation energy during this process was evaluated using iso-conversional model free kinetics which resulted in highest activation energy during combustion of PKS followed by PMF, EFB and MB coal. Blending oil palm biomass with coal reduces the apparent activation energy value.

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