Displaying publications 1 - 20 of 1484 in total

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  1. A'ziz ANA, Minhat FI, Pan HJ, Shaari H, Saelan WNW, Azmi N, et al.
    Sci Rep, 2021 Apr 26;11(1):8890.
    PMID: 33903697 DOI: 10.1038/s41598-021-88404-3
    Pulau Tioman is a famous tourist island off Peninsular Malaysia with beautiful coral reefs. This study aims to assess the health of the coral reefs surrounding Pulau Tioman based on the application of the Foraminifera in Reef Assessment and Monitoring Index (FI). Ten sampling sites around Pulau Tioman were studied with a total of 30 samples. Eight orders, 41 families, 80 genera, and 161 species of benthic foraminifera were identified. The agglutinated type of foraminifera constituted 2-8% of the total assemblages. Calcareous hyaline and porcelaneous groups represented 79% and 19% of the total assemblages, respectively. Symbiont-bearing taxa were the most common foraminifera. The results indicate that most of the sampling sites are conducive for coral reef growth with good recoverability from future stress to the ecosystem. However, several areas with higher coastal development and tourism have reduced water and sediment quality. Therefore, the limit on the number of visitors and tourists should be revised to enable coral growth and health. The FI values in this study showed a positive correlation with good water qualities and a negative correlation with organic matter enrichment. The FI is a good measure to assess the health of a coral reef and can be applied to other reef ecosystems around Malaysia.
  2. Ab Rahman N, Lim MT, Lee FY, Wo WK, Yeoh HS, Peariasamy KM, et al.
    Sci Rep, 2023 Nov 22;13(1):20471.
    PMID: 37993548 DOI: 10.1038/s41598-023-47486-x
    This study assessed the association between COVID-19 vaccines, SARS-CoV-2 infection and the risk of thrombocytopenia and venous thromboembolism (VTE). This self-controlled case series study used hospital records between 1st February 2021 and 28th February 2022 linked to the national immunisation registry and COVID-19 surveillance data in Malaysia. Conditional Poisson regression was used to estimate incidence rate ratios (IRR) of events in the risk period (day 1-21 post-exposure) relative to control period with the corresponding 95% confidence interval (CI) adjusted for calendar period. We found no significant increased risk of thrombocytopenia in 1-21 days following BNT162b2, CoronaVac and ChAdOx1 vaccines while the risk was increased following SARS-CoV-2 infection (IRR 15.52, 95% CI 13.38-18.00). Similarly, vaccination with BNT162b2, CoronaVac, or ChAdOx1 was not associated with an increased risk of VTE during the 1-21 days risk period. SARS-CoV-2 infection was associated with increased risk of VTE (IRR 39.84, 95% CI 27.45-32.44). Our findings showed low event rates of thrombocytopenia and VTE following booster vaccination with comparable safety profiles between those who received homologous and heterologous booster combinations. Our findings showed the risk of thrombocytopenia and VTE was not increased after COVID-19 vaccination while the risks were substantially higher after SARS-CoV-2 infection.
  3. Abbas G, Shah S, Hanif M, Shah A, Rehman AU, Tahir S, et al.
    Sci Rep, 2020 05 15;10(1):8064.
    PMID: 32415157 DOI: 10.1038/s41598-020-65065-2
    Intrauterine growth restriction (IUGR) is a clinical definition applied to neonates born with clinical features of malnutrition and in-utero growth retardation irrespective of their birth weight percentile. This study was aimed to determine the frequency of pulmonary hypertension (PH) in neonates with IUGR. In this descriptive cross-sectional study, we followed 96 neonates with IUGR (≤28 days) and 38 neonates without IUGR born in the department of the neonatal intensive care unit children hospital complex Multan, Pakistan. We analyzed certain factors such as gender, gestational age (GA) (weeks), birth weight (BW in kg), weight percentile (WP) for GA, meconium aspiration syndrome (MAS), birth asphyxia (BA) and respiratory distress syndrome (RDS) for pulmonary hypertension (PH) in IUGR and non-IUGR group. GA was measured by the Ballard scoring system. Echocardiography was performed for all patients by the pediatric cardiologist to measure pulmonary arterial (PA) pressure using Bernoulli's equation. Out of total 96 IUGR neonates, 33.3% (n = 32) suffered from PH, of which 65.3% (n = 18) were male and 43.7% (n = 14) were female. The percentages of IUGR neonates with BA, MAS and RDS were 34.4%, 18.8% and 22.9% respectively. The data were analyzed using the SPSS-16 software to test the statistical significance of the results. A p-value less than 0.05 was considered significant. When the chi-square test was applied, it depicted that MAS was significantly associated with PH in IUGR neonates (p = 0.0001) compared to non-IUGR neonates. Our findings suggested an increased chance of PH in IUGR neonates and MAS may be a strong factor.
  4. Abbasi M, Gholizadeh R, Kasaee SR, Vaez A, Chelliapan S, Fadhil Al-Qaim F, et al.
    Sci Rep, 2023 Apr 12;13(1):5987.
    PMID: 37046068 DOI: 10.1038/s41598-023-33095-1
    In recent years, mesoporous silica nanoparticles (MSNs) have been applied in various biomedicine fields like bioimaging, drug delivery, and antibacterial alternatives. MSNs could be manufactured through green synthetic methods as environmentally friendly and sustainable synthesis approaches, to improve physiochemical characteristics for biomedical applications. In the present research, we used Rutin (Ru) extract, a biocompatible flavonoid, as the reducing agent and nonsurfactant template for the green synthesis of Ag-decorated MSNs. Transmission electron microscopy (TEM), zeta-potential, x-ray powder diffraction (XRD), fourier transform infrared (FTIR) spectroscopy analysis, scanning electron microscopy (SEM), brunauer-emmett-teller (BET) analysis, and energy-dispersive system (EDS) spectroscopy were used to evaluate the Ag-decorated MSNs physical characteristics. The antimicrobial properties were evaluated against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and also different types of candida. The cytotoxicity test was performed by using the MTT assay. Based on the findings, the significant antimicrobial efficacy of Ru-Ag-decorated MSNs against both gram positive and gram negative bacteria and different types of fungi was detected as well as acceptable safety and low cytotoxicity even at lower concentrations. Our results have given a straightforward and cost-effective method for fabricating biodegradable Ag-decorated MSNs. The applications of these MSNs in the domains of biomedicine appear to be promising.
  5. Abd El-Aal AAA, Jayakumar FA, Lahiri C, Tan KO, Reginald K
    Sci Rep, 2023 Sep 06;13(1):14673.
    PMID: 37673929 DOI: 10.1038/s41598-023-41581-9
    Cryptides are a subfamily of bioactive peptides that exist in all living organisms. They are latently encrypted in their parent sequences and exhibit a wide range of biological activities when decrypted via in vivo or in vitro proteases. Cationic cryptides tend to be drawn to the negatively charged membranes of microbial and cancer cells, causing cell death through various mechanisms. This makes them promising candidates for alternative antimicrobial and anti-cancer therapies, as their mechanism of action is independent of gene mutations. In the current study, we employed an in silico approach to identify novel cationic cryptides with potential antimicrobial and anti-cancer activities in atypical and systematic strategy by reanalysis of a publicly available RNA-seq dataset of Pacific white shrimp (Penaus vannamei) in response to bacterial infection. Out of 12 cryptides identified, five were selected based on their net charges and potential for cell penetration. Following chemical synthesis, the cryptides were assayed in vitro to test for their biological activities. All five cryptides demonstrated a wide range of selective activity against the tested microbial and cancer cells, their anti-biofilm activities against mature biofilms, and their ability to interact with Gram-positive and negative bacterial membranes. Our research provides a framework for a comprehensive analysis of transcriptomes in various organisms to uncover novel bioactive cationic cryptides. This represents a significant step forward in combating the crisis of multi-drug-resistant microbial and cancer cells, as these cryptides neither induce mutations nor are influenced by mutations in the cells they target.
  6. Abd Halim S, Manurung YHP, Raziq MA, Low CY, Rohmad MS, Dizon JRC, et al.
    Sci Rep, 2023 Feb 21;13(1):3013.
    PMID: 36810419 DOI: 10.1038/s41598-023-29906-0
    Optimizing Resistance spot welding, often used as a time and cost-effective process in many industrial sectors, is very time-consuming due to the obscurity inherent within process with numerous interconnected welding parameters. Small changes in values will give effect to the quality of welds which actually can be easily analysed using application tool. Unfortunately, existing software to optimize the parameters are expensive, licensed and inflexible which makes small industries and research centres refused to acquire. In this study, application tool using open-sourced and customized algorithm based on artificial neural networks (ANN) was developed to enable better, fast, cheap and practical predictions of major parameters such as welding time, current and electrode force on tensile shear load bearing capacity (TSLBC) and weld quality classifications (WQC). A supervised learning algorithm implemented in standard backpropagation neural network gradient descent (GD), stochastic gradient descent (SGD) and Levenberg-Marquardt (LM) was constructed using TensorFlow with Spyder IDE in python language. All the display and calculation processes are developed and compiled in the form of application tool of graphical user interface (GUI). Results showed that this low-cost application tool Q-Check based on ANN models can predict with 80% training and 20% test set on TSLBC with an accuracy of 87.220%, 92.865% and 93.670% for GD, SGD and LM algorithms respectively while on WQC 62.5% for GD and 75% for both SGD and LM. It is also expected that tool with flexible GUI can be widely used and enhanced by practitioner with minimum knowledge in the domain.
  7. Abdal S, Hussain S, Siddique I, Ahmadian A, Ferrara M
    Sci Rep, 2021 Apr 08;11(1):7799.
    PMID: 33833251 DOI: 10.1038/s41598-021-86953-1
    It is a theoretical exportation for mass transpiration and thermal transportation of Casson nanofluid over an extending cylindrical surface. The Stagnation point flow through porous matrix is influenced by magnetic field of uniform strength. Appropriate similarity functions are availed to yield the transmuted system of leading differential equations. Existence for the solution of momentum equation is proved for various values of Casson parameter [Formula: see text], magnetic parameter M, porosity parameter [Formula: see text] and Reynolds number Re in two situations of mass transpiration (suction/injuction). The core interest for this study aroused to address some analytical aspects. Therefore, existence of solution is proved and uniqueness of this results is discussed with evaluation of bounds for existence of solution. Results for skin friction factor are established to attain accuracy for large injection values. Thermal and concentration profiles are delineated numerically by applying Runge-Kutta method and shooting technique. The flow speed retards against M, [Formula: see text] and [Formula: see text] for both situations of mass injection and suction. The thermal boundary layer improves with Brownian and thermopherotic diffusions.
  8. Abdaljaleel M, Barakat M, Alsanafi M, Salim NA, Abazid H, Malaeb D, et al.
    Sci Rep, 2024 Jan 23;14(1):1983.
    PMID: 38263214 DOI: 10.1038/s41598-024-52549-8
    Artificial intelligence models, like ChatGPT, have the potential to revolutionize higher education when implemented properly. This study aimed to investigate the factors influencing university students' attitudes and usage of ChatGPT in Arab countries. The survey instrument "TAME-ChatGPT" was administered to 2240 participants from Iraq, Kuwait, Egypt, Lebanon, and Jordan. Of those, 46.8% heard of ChatGPT, and 52.6% used it before the study. The results indicated that a positive attitude and usage of ChatGPT were determined by factors like ease of use, positive attitude towards technology, social influence, perceived usefulness, behavioral/cognitive influences, low perceived risks, and low anxiety. Confirmatory factor analysis indicated the adequacy of the "TAME-ChatGPT" constructs. Multivariate analysis demonstrated that the attitude towards ChatGPT usage was significantly influenced by country of residence, age, university type, and recent academic performance. This study validated "TAME-ChatGPT" as a useful tool for assessing ChatGPT adoption among university students. The successful integration of ChatGPT in higher education relies on the perceived ease of use, perceived usefulness, positive attitude towards technology, social influence, behavioral/cognitive elements, low anxiety, and minimal perceived risks. Policies for ChatGPT adoption in higher education should be tailored to individual contexts, considering the variations in student attitudes observed in this study.
  9. Abdel-Sattar OE, Allam RM, Al-Abd AM, Avula B, Katragunta K, Khan IA, et al.
    Sci Rep, 2023 Feb 15;13(1):2683.
    PMID: 36792619 DOI: 10.1038/s41598-023-29566-0
    The members of the genus Phyllanthus have long been used in the treatment of a broad spectrum of diseases. They exhibited antiproliferative activity against various human cancer cell lines. Breast cancer is the most diagnosed cancer and a leading cause of cancer death among women. Doxorubicin (DOX) is an anticancer agent used to treat breast cancer despite its significant cardiotoxicity along with resistance development. Therefore, this study was designed to assess the potential cytotoxicity of P. niruri extracts (and fractions) alone and in combination with DOX against naïve (MCF-7) and doxorubicin-resistant breast cancer cell lines (MCF-7ADR). The methylene chloride fraction (CH2Cl2) showed the most cytotoxic activity among all tested fractions. Interestingly, the CH2Cl2-fraction was more cytotoxic against MCF-7ADR than MCF-7 at 100 µg/mL. At sub-cytotoxic concentrations, this fraction enhanced the cytotoxic effect of DOX against the both cell lines under investigation (IC50 values of 0.054 µg/mL and 0.14 µg/mL vs. 0.2 µg/mL for DOX alone against MCF-7) and (1.2 µg/mL and 0.23 µg/mL vs. 9.9 µg/mL for DOX alone against MCF-7ADR), respectively. Further, TLC fractionation showed that B2 subfraction in equitoxic combination with DOX exerted a powerful synergism (IC50 values of 0.03 µg/mL vs. 9.9 µg/mL for DOX alone) within MCF-7ADR. Untargeted metabolite profiling of the crude methanolic extract (MeOH) and CH2Cl2 fraction exhibiting potential cytotoxicity was conducted using liquid chromatography diode array detector-quadrupole time-of-flight mass spectrometry (LC-DAD-QTOF). Further studies are needed to separate the active compounds from the CH2Cl2 fraction and elucidate their mechanism(s) of action.
  10. Abdul Aziz AF, Ali MF, Yusof MF, Che' Man Z, Sulong S, Aljunid SM
    Sci Rep, 2018 12 19;8(1):17965.
    PMID: 30568180 DOI: 10.1038/s41598-018-36154-0
    Data on post stroke outcomes in developing countries are scarce due to uncoordinated healthcare delivery systems. In Malaysia, the national stroke clinical practice guideline does not address transfer of care and longer term post stroke care beyond tertiary care. Hence, post stroke care delivery may be delivered at either tertiary or primary care facilities. This study aimed at describing patients' characteristics and outcomes of post stroke care delivered by the primary care teams at public primary care healthcentres across Peninsular Malaysia. Multi staged sampling was done to select public primary care health centres to recruit post stroke patients. At each health centre, convenience sampling was done to recruit adult patients (≥18 years) who received post stroke care between July-December 2012. Baseline measurements were recorded at recruitment and retrospective medical record review was done simultaneously, for details on medical and / or rehabilitation treatment at health centre. Changes in the measurements for post stroke care were compared using paired t-tests and Wilcoxon Rank test where appropriate. Total of 151 patients were recruited from ten public primary care healthcentres. The mean age at stroke presentation was 55.8 ± 9.8 years. Median duration of follow up was 2.3 (IQR 5.1) years. Majority co-resided with a relative (80.8%), and a family member was primary caregiver (75.%). Eleven percent were current smokers. Almost 71.0% of patients achieved BP ≤ 140/90 mmHg. Only 68.9% of the patients had been referred for neurorehabilitation. Percentage of recorded data was highest for blood pressure (88.1%) while lowest was HbA1c (43.0%). For clinical outcomes, systolic and diastolic blood pressure, triglyceride level and calculated GFR (eGFR) showed statistically significant changes during follow up (p 
  11. Abdul Rani KN, Abdulmalek M, A Rahim H, Siew Chin N, Abd Wahab A
    Sci Rep, 2017 Apr 20;7:46521.
    PMID: 28425443 DOI: 10.1038/srep46521
    This research proposes the various versions of modified cuckoo search (MCS) metaheuristic algorithm deploying the strength Pareto evolutionary algorithm (SPEA) multiobjective (MO) optimization technique in rectangular array geometry synthesis. Precisely, the MCS algorithm is proposed by incorporating the Roulette wheel selection operator to choose the initial host nests (individuals) that give better results, adaptive inertia weight to control the positions exploration of the potential best host nests (solutions), and dynamic discovery rate to manage the fraction probability of finding the best host nests in 3-dimensional search space. In addition, the MCS algorithm is hybridized with the particle swarm optimization (PSO) and hill climbing (HC) stochastic techniques along with the standard strength Pareto evolutionary algorithm (SPEA) forming the MCSPSOSPEA and MCSHCSPEA, respectively. All the proposed MCS-based algorithms are examined to perform MO optimization on Zitzler-Deb-Thiele's (ZDT's) test functions. Pareto optimum trade-offs are done to generate a set of three non-dominated solutions, which are locations, excitation amplitudes, and excitation phases of array elements, respectively. Overall, simulations demonstrates that the proposed MCSPSOSPEA outperforms other compatible competitors, in gaining a high antenna directivity, small half-power beamwidth (HPBW), low average side lobe level (SLL) suppression, and/or significant predefined nulls mitigation, simultaneously.
  12. Abdul Satar NM, Ogawa S, Parhar IS
    Sci Rep, 2020 11 09;10(1):19361.
    PMID: 33168887 DOI: 10.1038/s41598-020-75777-0
    The habenula is a phylogenetically conserved epithalamic structure, which conveys negative information via inhibition of mesolimbic dopamine neurons. We have previously shown the expression of kisspeptin (Kiss1) in the habenula and its role in the modulation of fear responses in the zebrafish. In this study, to investigate whether habenular Kiss1 regulates fear responses via dopamine neurons in the zebrafish, Kiss1 peptides were intracranially administered close to the habenula, and the expression of dopamine-related genes (th1, th2 and dat) were examined in the brain using real-time PCR and dopamine levels using LC-MS/MS. th1 mRNA levels and dopamine levels were significantly increased in the telencephalon 24-h and 30-min after Kiss1 administration, respectively. In fish administered with Kiss1, expression of neural activity marker gene, npas4a and kiss1 gene were significantly decreased in the ventral habenula. Application of neural tracer into the median raphe, site of habenular Kiss1 neural terminal projections showed tracer-labelled projections in the medial forebrain bundle towards the telencephalon where dopamine neurons reside. These results suggest that Kiss1 negatively regulates its own neuronal activity in the ventral habenula via autocrine action. This, in turn affects neurons of the median raphe via interneurons, which project to the telencephalic dopaminergic neurons.
  13. Abdul-Aziz Ahmed K, Jabbar AAJ, Abdulla MA, Zuhair Alamri Z, Ain Salehen N, Abdel Aziz Ibrahim I, et al.
    Sci Rep, 2024 Jan 08;14(1):813.
    PMID: 38191592 DOI: 10.1038/s41598-023-50947-y
    Mangiferin (MF) is a natural C-glucosylxantone compound that has many substantial curative potentials against numerous illnesses including cancers. The present study's goal is to appraise the chemo preventive possessions of MF on azoxymethane (AOM)-mediated colonic aberrant crypt foci (ACF) in rats. Rats clustered into 5 groups, negative control (A), inoculated subcutaneously with normal saline twice and nourished on 0.5% CMC; groups B-E injected twice with 15 mg/kg azoxymethane followed by ingestion of 0.5% CMC (B, cancer control); intraperitoneal inoculation of 35 mg/kg 5-fluorouracil (C, reference rats) or nourished on 30 mg/kg (D) and 60 mg/kg (E) of MF. Results of gross morphology of colorectal specimens showed significantly lower total colonic ACF incidence in MF-treated rats than that of cancer controls. The colon tissue examination of cancer control rats showed increased ACF availability with bizarrely elongated nuclei, stratified cells, and higher depletion of the submucosal glands compared to MF-treated rats. Mangiferin treatment caused increased regulation of pro-apoptotic (increased Bax) proteins and reduced the β-catenin) proteins expression. Moreover, rats fed on MF had significantly higher glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), and lower malondialdehyde (MDA) concentrations in their colonic tissue homogenates. Mangiferin supplementation significantly down-shifted pro-inflammatory cytokines (transforming growth factor-α and interleukine-6) and up-shifted anti-inflammatory cytokines (interleukine-10) based on serum analysis. The chemo-protective mechanistic of MF against AOM-induced ACF, shown by lower ACF values and colon tissue penetration, could be correlated with its positive modulation of apoptotic cascade, antioxidant enzymes, and inflammatory cytokines originating from AOM oxidative stress insults.
  14. Abdulbari HA, Basheer EAM
    Sci Rep, 2019 08 29;9(1):12576.
    PMID: 31467344 DOI: 10.1038/s41598-019-49071-7
    Directional solvent extraction is one of the promising membrane-less seawater desalination method. This technique was not extensively investigated due the poor mixing and separation performances of its bench-scale system. It is believed that, overcoming these drawbacks is possible now with the rapid development of microfluidics technology that enabled high-precession micro mixing and separation. This work presents microfluidics chip for extracting and separating salt from seawater. The chip was designed with two sections for extraction and separation. In both sections, the liquids were separated using capillary channels perpendicular to the main stream. The main channels were designed to be 400 µm in width and 100 µm in height. Two streams inlets were introduced through a Y-junction containing octanoic acid as the organic phase and saltwater as the aqueous phase. The desalination performance was investigated at four different temperatures and five different solvent flow rates. Water product salinity was recorded to be as low as 0.056% (w/w) at 60 °C and 40 mL/h. A maximum water yield of 5.2% was achieved at 65 °C and 40 mL/h with a very low solvent residual (70 ppm). The chip mass transfer efficiency was recorded to be as high as 68% under similar conditions. The fabricated microfluidic desalination system showed a significant improvement in terms of water yield and separation efficiency over the conventional macroscale. The high performance of this microsystem resulted from its ability to achieve a high mixing efficiency and separate phases selectively and that will provide a good platform in the near future to develop small desalination kits for personal use.
  15. Abdullah B, Chew SC, Aziz ME, Shukri NM, Husain S, Joshua SW, et al.
    Sci Rep, 2020 03 12;10(1):4600.
    PMID: 32165705 DOI: 10.1038/s41598-020-61610-1
    Keros and Gera classifications are widely used to assess the risk of skull base injury during endoscopic sinus surgery. Although, both classifications are useful preoperatively to stratify risk of patients going for surgery, it is not practical to measure the respective lengths during surgery. In this study, we aimed to propose a new radiological classification (Thailand-Malaysia-Singapore (TMS)) to assess the anatomical risk of anterior skull base injury using the orbital floor (OF) as a reference. A total of 150 computed tomography images of paranasal sinuses (300 sides) were reviewed. The TMS classification was categorized into 3 types by measuring OF to cribriform plate and OF to ethmoid roof. Most patients were classified as TMS type 1, Keros type 2 and Gera class II, followed by patients classified as TMS type 3, Keros type 1 and Gera class 1. TMS has significant correlation with Keros classification (p 
  16. Abdullah B, Rasid NSA, Lazim NM, Volgger V, Betz CS, Mohammad ZW, et al.
    Sci Rep, 2020 04 24;10(1):6941.
    PMID: 32332848 DOI: 10.1038/s41598-020-64011-6
    The diagnostic procedure for upper aerodigestive tract (UADT) tumours is by white light endoscopy (WLE) combined with biopsy. However, WLE has difficulty identifying minute epithelial changes which hinders early diagnosis. Storz Professional Image Enhancement System (SPIES) is designed to enhance the visualization of microvasculature on the mucosal surface and detect any epithelial changes. In this study, we aimed to evaluate the use of Ni endoscopic classification with SPIES endoscopy in the detection of UADT tumours. Fifty-nine patients with suspected UADT tumours underwent WLE followed by SPIES endoscopy. All the tumours were biopsied and sent for histopathological examination (HPE). The kappa index (κ) was used to evaluate the agreement between the methods. The level of agreement between SPIES using Ni classification and HPE showed almost perfect agreement as compared to moderate agreement between WLE and HPE. The sensitivity and specificity for WLE and HPE were 77.5% and 84.2% respectively with positive predictive value (PPV) of 91.2% and negative predictive value (NPV) of 64%. The sensitivity and specificity for SPIES endoscopy using Ni classification and HPE were 97.5% and 94.7% respectively with PPV of 97.5% and NPV of 94.7%. SPIES endoscopy using Ni classification is a valid tool for earlier tumour detection.
  17. Abdullah GMS, Ahmad M, Babur M, Badshah MU, Al-Mansob RA, Gamil Y, et al.
    Sci Rep, 2024 Jan 28;14(1):2323.
    PMID: 38282061 DOI: 10.1038/s41598-024-52825-7
    The present research employs new boosting-based ensemble machine learning models i.e., gradient boosting (GB) and adaptive boosting (AdaBoost) to predict the unconfined compressive strength (UCS) of geopolymer stabilized clayey soil. The GB and AdaBoost models were developed and validated using 270 clayey soil samples stabilized with geopolymer, with ground-granulated blast-furnace slag and fly ash as source materials and sodium hydroxide solution as alkali activator. The database was randomly divided into training (80%) and testing (20%) sets for model development and validation. Several performance metrics, including coefficient of determination (R2), mean absolute error (MAE), root mean square error (RMSE), and mean squared error (MSE), were utilized to assess the accuracy and reliability of the developed models. The statistical results of this research showed that the GB and AdaBoost are reliable models based on the obtained values of R2 (= 0.980, 0.975), MAE (= 0.585, 0.655), RMSE (= 0.969, 1.088), and MSE (= 0.940, 1.185) for the testing dataset, respectively compared to the widely used artificial neural network, random forest, extreme gradient boosting, multivariable regression, and multi-gen genetic programming based models. Furthermore, the sensitivity analysis result shows that ground-granulated blast-furnace slag content was the key parameter affecting the UCS.
  18. Abdullah HSTSH, Chia PW, Omar D, Chuah TS
    Sci Rep, 2021 07 09;11(1):14227.
    PMID: 34244589 DOI: 10.1038/s41598-021-93662-2
    Herbicide resistance is a worldwide problem in weed control. This prompts researchers to look for new modes of action to slow down the evolution of herbicide-resistant weeds. This research aims to determine the herbicidal action of thiazolo[3,2-a]pyrimidines derivatives, which are well known as antihypertensive drugs. The phytotoxic effects of ten compounds were investigated using leaf disc discoloration test and seed germination bioassay. At concentrations of 125 to 250 mg/L, the 5-(3-Fluoro-phenyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester (c) was highly active against Oldenlandia verticillata and Eleusine indica. At application rates of 1.25 to 2.5 kg ai/ha, formulated c demonstrated selective post-emergence and pre-emergence herbicidal activity against O. verticillata, E. indica and Cyperus iria. In the crop tolerance test, formulated c outperformed the commercial herbicide diuron, with aerobic Oryza sativa being the most tolerant, followed by Zea mays, and Brassica rapa. The addition of calcium chloride partially nullified compound c's inhibitory effects on weed shoot growth, indicating that it has potential as a calcium channel blocker. Compound c acted by triggering electrolyte leakage without affecting photosystem II. These findings imply that c could be explored further as a template for developing new herbicides with novel modes of action.
  19. Abdullah MK, Hassan LH, Moghavvemi M
    Sci Rep, 2022 Dec 24;12(1):22279.
    PMID: 36566331 DOI: 10.1038/s41598-022-26751-5
    Three static techniques (i.e. Power flow, Continuation Power Flow (CPF) and the Q-V curve) are used to assess the voltage stability of the power grid with a Solar Photovoltaic Generator (SPVG) and FACTS devices under nominal and heavy loading conditions. A static model is proposed for the power system that includes conventional power generation units and SPVGs with FACTS devices. Two models of SPVG were used (i.e., PV-model and PQ-model) to elucidate the effect of the SPVGs on the stability of the voltage under various operating conditions. The best location for FACTS devices was obtained under nominal and heavy load conditions using static techniques. A comparison between series and shunt FACTS devices under nominal and heavy loading conditions was carried out using the three static techniques. The interaction between SPVGs and FACTS devices was detailed in this paper. The proposed approach was tested on the New England 39-bus standard test system, and the results confirmed the effectiveness of the proposed approach under various operating conditions.
  20. Abdullah NH, Mustaffa MS, Hamidon MN, Shafie FN, Ismail I, Ibrahim IR
    Sci Rep, 2021 Oct 04;11(1):19642.
    PMID: 34608254 DOI: 10.1038/s41598-021-99236-6
    A new approach through heat treatment has been attempted by establishing defects by the process of quenching towards electrical and magnetic properties in the nickel zinc ferrite (Ni0.5Zn0.5Fe2O4) sample. The measured property values in permeability and hysteresis characteristic gave their recovery behaviour in which the values, after quenching were recovered after undergoing the annealing. Interestingly, a different trend observed in the permittivity value whereas the value was increased after quenching and subsequently recovered after annealing. The mechanisms which produced the changes is believed to be involved by defects in the form of vacancies, interstitials, microcracks and dislocations created during quenching which gave rise to changes in the values of the complex permeability and permittivity components and hysteresis behaviour.
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