Displaying publications 121 - 140 of 167 in total

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  1. Nik Mohd Fakhruddin NNI, Shahar S, Ismail IS, Ahmad Azam A, Rajab NF
    Nutrients, 2020 Sep 23;12(10).
    PMID: 32977370 DOI: 10.3390/nu12102900
    Food intake biomarkers (FIBs) can reflect the intake of specific foods or dietary patterns (DP). DP for successful aging (SA) has been widely studied. However, the relationship between SA and DP characterized by FIBs still needs further exploration as the candidate markers are scarce. Thus, 1H-nuclear magnetic resonance (1H-NMR)-based urine metabolomics profiling was conducted to identify potential metabolites which can act as specific markers representing DP for SA. Urine sample of nine subjects from each three aging groups, SA, usual aging (UA), and mild cognitive impairment (MCI), were analyzed using the 1H-NMR metabolomic approach. Principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were applied. The association between SA urinary metabolites and its DP was assessed using the Pearson's correlation analysis. The urine of SA subjects was characterized by the greater excretion of citrate, taurine, hypotaurine, serotonin, and melatonin as compared to UA and MCI. These urinary metabolites were associated with alteration in "taurine and hypotaurine metabolism" and "tryptophan metabolism" in SA elderly. Urinary serotonin (r = 0.48, p < 0.05) and melatonin (r = 0.47, p < 0.05) were associated with oat intake. These findings demonstrate that a metabolomic approach may be useful for correlating DP with SA urinary metabolites and for further understanding of SA development.
    Matched MeSH terms: Least-Squares Analysis
  2. Che Zain MS, Osman MF, Lee SY, Shaari K
    Molecules, 2021 Feb 19;26(4).
    PMID: 33669484 DOI: 10.3390/molecules26041084
    Luteolin and apigenin derivatives present in oil palm (Elaeis guineensis) leaves (OPL) are reported to possess excellent antioxidant properties relating to numerous health benefits. To meet the global demand for flavonoids, OPL, which is plentifully generated as an agricultural by-product from oil palm plantations, can be further exploited as a new source of natural antioxidant compounds. However, to produce a standardized herbal preparation, validation of the quantification method for these compounds is required. Therefore, in this investigation, we developed and validated an improved and rapid analytical method, ultra-high-performance liquid chromatography equipped with ultraviolet/photodiode array (UHPLC-UV/PDA) for the quantification of 12 luteolin and apigenin derivatives, particularly focusing on flavonoid isomeric pairs: orientin/isoorientin and vitexin/isovitexin, present in various OPL extracts. Several validation parameters were assessed, resulting in the UHPLC-UV/PDA technique offering good specificity, linearity, accuracy, precision, and robustness, where the values were within acceptable limits. Subsequently, the validated method was employed to quantify luteolin and apigenin derivatives from OPL subjected to different drying treatments and extraction with various solvent systems, giving total luteolin (TLC) and apigenin content (TAC) in the range of 2.04-56.30 and 1.84-160.38 µg/mg extract, respectively. Additionally, partial least square (PLS) analysis disclosed the combination of freeze dry-aqueous methanol yielded OPL extracts with high TLC and TAC, which are strongly correlated with antioxidant activity. Therefore, we provide the first validation report of the UHPLC-UV/PDA method for quantification of luteolin and apigenin derivatives present in various OPL extracts, suggesting that this approach could be employed in standardized herbal preparations by adopting orientin, isoorientin, vitexin, and isovitexin as chemical markers.
    Matched MeSH terms: Least-Squares Analysis
  3. Norasikin Ab Azis, Mohd Saleh Ahmad Kamal, Zurain Radjeni, Ahmed Mediani, Renu Agarwal
    MyJurnal
    Introduction: This study examined the association of losartan induced changes in urinary
    metabolomic profile with the changes in blood pressure (BP) and renin-angiotensinaldosterone system (RAAS) in spontaneously hypertensive rats (SHR). Methods: Male SHR
    were administered with either 0.5 mL of distilled water (control group, n=6) or 10 mg.kg-1 of
    losartan (group 2, n=6) daily by oral gavage for 4 weeks. Body weight, BP, food and water
    intake were measured weekly. At week 4, urine was collected for urinary electrolyte analysis
    and metabolite profiling, after which the animals were euthanised by decapitation and blood
    was collected for analysis of components of RAAS and electrolyte concentrations. Urine
    metabolite profile of SHR was determined using proton nuclear magnetic resonance (
    1H-NMR)
    spectrometry combined with multivariate data analysis. Results: At week 4, losartan-treated
    SHR had significantly lower BP than non-treated SHR. There were no differences in water
    and food intake, body weight, serum and urinary electrolyte concentrations or in their urinary
    excretions between the two groups. No differences were evident in the components of RAAS
    except that the angiotensinogen level was significantly higher in losartan-treated SHR
    compared to non-treated SHR. Orthogonal partial least squares discriminant analysis (OPLSDA) showed clear separation of urinary metabolites between control and losartan-treated
    SHR. Losartan-treated SHR group was separated from the control group by changes in the
    intermediates involved in glycine, serine and threonine metabolism. Conclusion:
    Antihypertensive effect of losartan in SHR seems to be associated with changes in urinary
    metabolite profile, particularly involving the metabolism of glycine, serine and threonine.
    Matched MeSH terms: Least-Squares Analysis
  4. Gopinath D, Kunnath Menon R, Chun Wie C, Banerjee M, Panda S, Mandal D, et al.
    J Oral Microbiol, 2020 Dec 09;13(1):1857998.
    PMID: 33391629 DOI: 10.1080/20002297.2020.1857998
    Objective: While some oral carcinomas appear to arise de novo, others develop within long-standing conditions of the oral cavity that have malignant potential, now known as oral potentially malignant disorders (OPMDs). The oral bacteriome associated with OPMD has been studied to a lesser extent than that associated with oral cancer. To characterize the association in detail we compared the bacteriome in whole mouth fluid (WMF) in patients with oral leukoplakia, oral cancer and healthy controls. Methods: WMF bacteriome from 20 leukoplakia patients, 31 patients with oral cancer and 23 healthy controls were profiled using the Illumina MiSeq platform. Sequencing reads were processed using DADA2, and taxonomical classification was performed using the phylogenetic placement method. Sparse Partial Least Squares Regression Discriminant Analysis model was used to identify bacterial taxa that best discriminate the studied groups. Results: We found considerable overlap between the WMF bacteriome of leukoplakia and oral cancer while a clearer separation between healthy controls and the former two disorders was observed. Specifically, the separation was attributed to 14 taxa belonging to the genera Megaspheara, unclassified enterobacteria, Prevotella, Porphyromonas, Rothia and Salmonella, Streptococcus, and Fusobacterium. The most discriminative bacterial genera between leukoplakia and oral cancer were Megasphaera, unclassified Enterobacteriae, Salmonella and Prevotella.Conclusion: Oral bacteria may play a role in the early stages of oral carcinogenesis as a dysbiotic bacteriome is associated with oral leukoplakia and this resembles that of oral cancer more than healthy controls. Our findings may have implications for developing oral cancer prevention strategies targeting early microbial drivers of oral carcinogenesis.
    Matched MeSH terms: Least-Squares Analysis
  5. Asef Raiyan Hoque, Mohd Yusof Ibrahim, Mohammad Zahirul Hoque
    MyJurnal
    Introduction: In recent years, the variation in total fertility rate (TFR) has sparked public interest for demographic concerns on the global population shift towards an older age structure. This study aims to investigate the determi-nants of total fertility rate among Brunei, Indonesia, Malaysia and Philippines East Asian Growth Area (BIMP-EAGA) region. Methods: Our empirical study consists of data collected from the United Nations Development Report of the UNDP, World Development Indicators (WDI) of the World Bank and World Health Organization (WHO) report 2018. We investigated the socio-economic determinants of fertility rate by analyzing a panel data set consisting of 28 years from 1990-2017 of the four countries. A statistical and econometric software EViews version 10 (HIS Global Inc., Irvine, CA, USA) were used to run a Pearson’s Correlation and a multiple regression analysis by panel least squares method. To investigate the determinants of TFR we have selected five socio- economic factors, these are- Infant mortality rate (IMR), Gross National Income Per Capita, PPP (GNI), Human Development Index (HDI), percentage of population living in urban areas (URB) and lastly Female Labor Force Participation Rate (FLP). Results:Pearson’s correlation showed that a statistically significant negative relationship exists between TFR and the 3 vari-ables- GNI, URB and HDI. A statistically strong positive relationship exists between IMR and TFR. However, our results from the empirical multiple regression model indicates that there is a statistically significant negative relation-ship exists between TFR and two of the independent variables GNI and FLP. Conclusion: The results of present study showed that an increase in the national income and female labor participation rate in the workforce could result in a decrease in total fertility rate. These findings may have implications for countries national policy for planning, development and resource allocation.
    Matched MeSH terms: Least-Squares Analysis
  6. Basri KN, Hussain MN, Bakar J, Sharif Z, Khir MFA, Zoolfakar AS
    Spectrochim Acta A Mol Biomol Spectrosc, 2017 Feb 15;173:335-342.
    PMID: 27685001 DOI: 10.1016/j.saa.2016.09.028
    Short wave near infrared spectroscopy (NIR) method was used to detect the presence of lard adulteration in palm oil. MicroNIR was set up in two different scan modes to study the effect of path length to the performance of spectral measurement. Pure and adulterated palm oil sample were classified using soft independent modeling class analogy (SIMCA) algorithm with model accuracy more than 0.95 reported for both transflectance and transmission modes. Additionally, by employing partial least square (PLS) regression, the coefficient of determination (R2) of transflectance and transmission were 0.9987 and 0.9994 with root mean square error of calibration (RMSEC) of 0.5931 and 0.6703 respectively. In order to remove the uninformative variables, variable selection using cumulative adaptive reweighted sampling (CARS) has been performed. The result of R2 and RMSEC after variable selection for transflectance and transmission were improved significantly. Based on the result of classification and quantification analysis, the transmission mode has yield better prediction model compared to the transflectance mode to distinguish the pure and adulterated palm oil.
    Matched MeSH terms: Least-Squares Analysis
  7. Chua VL, Smith BT, Burner RC, Rahman MA, Lakim M, Prawiradilaga DM, et al.
    Mol Phylogenet Evol, 2017 Aug;113:139-149.
    PMID: 28545973 DOI: 10.1016/j.ympev.2017.05.016
    The mountains of Borneo are well known for their high endemicity and historical role in preserving Southeast Asian rainforest biodiversity, but the diversification of populations inhabiting these mountains is poorly studied. Here we examine the genetic structure of 12 Bornean montane passerines by comparing complete mtDNA ND2 gene sequences of populations spanning the island. Maximum likelihood and Bayesian phylogenetic trees and haplotype networks are examined for common patterns that might signal important historical events or boundaries to dispersal. Morphological and ecological characteristics of each species are also examined using phylogenetic generalized least-squares (PGLS) for correlation with population structure. Populations in only four of the 12 species are subdivided into distinct clades or haplotype groups. Although this subdivision occurred at about the same time in each species (ca. 0.6-0.7Ma), the spatial positioning of the genetic break differs among the species. In two species, northeastern populations are genetically divergent from populations elsewhere on the island. In the other two species, populations in the main Bornean mountain chain, including the northeast, are distinct from those on two isolated peaks in northwestern Borneo. We suggest different historical forces played a role in shaping these two distributions, despite commonality in timing. PGLS analysis showed that only a single characteristic-hand-wing index-is correlated with population structure. Birds with longer wings, and hence potentially more dispersal power, have less population structure. To understand historical forces influencing montane population structure on Borneo, future studies must compare populations across the entirety of Sundaland.
    Matched MeSH terms: Least-Squares Analysis
  8. Zakaria SR, Saim N, Osman R, Abdul Haiyee Z, Juahir H
    Molecules, 2018 Sep 16;23(9).
    PMID: 30223605 DOI: 10.3390/molecules23092365
    This study analyzed the volatile organic compounds (VOCs) of three mango varieties (Harumanis, Tong Dam and Susu) for the discrimination of authentic Harumanis from other mangoes. The VOCs of these mangoes were extracted and analysed nondestructively using Head Space-Solid Phase Micro Extraction (HS-SPME) coupled to Gas Chromatography-Mass Spectrometry (GC-MS). Prior to the analytical method, two simple sensory analyses were carried out to assess the ability of the consumers to differentiate between the Harumanis and Tong Dam mangoes as well as their preferences towards these mangoes. On the other hand, chemometrics techniques, such as principal components analysis (PCA), hierarchical clustering analysis (HCA), and discriminant analysis (DA), were used to visualise grouping tendencies of the volatile compounds detected. These techniques were successful in identifying the grouping tendencies of the mango samples according to the presence of their respective volatile compounds, thus enabling the identification of the groups of substances responsible for the discrimination between the authentic and unauthentic Harumanis mangoes. In addition, three ocimene compounds, namely beta-ocimene, trans beta-ocimene, and allo-ocimene, can be considered as chemical markers of the Harumanis mango, as these compounds exist in all Harumanis mango, regardless the different sources of the mangoes obtained.
    Matched MeSH terms: Least-Squares Analysis
  9. Arunachalam GR, Chiew YS, Tan CP, Ralib AM, Nor MBM
    Comput Methods Programs Biomed, 2020 Jan;183:105103.
    PMID: 31606559 DOI: 10.1016/j.cmpb.2019.105103
    BACKGROUND AND OBJECTIVE: Mechanical ventilation therapy of respiratory failure patients can be guided by monitoring patient-specific respiratory mechanics. However, the patient's spontaneous breathing effort during controlled ventilation changes airway pressure waveform and thus affects the model-based identification of patient-specific respiratory mechanics parameters. This study develops a model to estimate respiratory mechanics in the presence of patient effort.

    METHODS: Gaussian effort model (GEM) is a derivative of the single-compartment model with basis function. GEM model uses a linear combination of basis functions to model the nonlinear pressure waveform of spontaneous breathing patients. The GEM model estimates respiratory mechanics such as Elastance and Resistance along with the magnitudes of basis functions, which accounts for patient inspiratory effort.

    RESULTS AND DISCUSSION: The GEM model was tested using both simulated data and a retrospective observational clinical trial patient data. GEM model fitting to the original airway pressure waveform is better than any existing models when reverse triggering asynchrony is present. The fitting error of GEM model was less than 10% for both simulated data and clinical trial patient data.

    CONCLUSION: GEM can capture the respiratory mechanics in the presence of patient effect in volume control ventilation mode and also can be used to assess patient-ventilator interaction. This model determines basis functions magnitudes, which can be used to simulate any waveform of patient effort pressure for future studies. The estimation of parameter identification GEM model can further be improved by constraining the parameters within a physiologically plausible range during least-square nonlinear regression.

    Matched MeSH terms: Least-Squares Analysis
  10. Muhammad Zul Fayyadh Azizo Rahman, Chong, Hui Wen, Lim, Vuanghao
    MyJurnal
    Adulterated premixed coffees have turned into an issue in Malaysia lately and have caught the eye of the authorities due to death reports linked to these products. The major cause of this issue is reported that these premixed coffees have passed food inspection test and eventually released to the market for public consumption. These coffees were claimed to be spiked with several sexual enhancers like sildenafil, tadalafil, and vardenafill, which are common drugs used to treat erectile dysfunction. Methods: Chemometrics approach using UV-Vis spectroscopy was developed to detect the selected sexual enhancer drugs found in commercial coffees by employing SIMCA-P software for the multivariate statistical analysis. Seven brands of coffee samples were purchased from local stores, and 30 sachets each were tested, hence totalling to 210 samples. Each sample was named H, J, G, W, N, T, and K, respectively. Results: Three multivariate models were generated, namely principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and partial least squares discriminant analysis (PLS-DA). OPLS-DA was selected as the best model for the overall results as it displayed minimal discriminate. Sildenafil, tadalafil, and vardenafil were detected in sample H, while vardenafil in brand J, and none in samples G, W, N, T, and K. Conclusion: OPLS-DA analysis showed discrimination for the sexual enhancer drugs in two brands of premixed coffee. The UV-Vis spectroscopy-based chemometrics method proved to be reliable and efficient in determining the selected drugs, as well as in saving time and cost.
    Matched MeSH terms: Least-Squares Analysis
  11. Jamal N, Ng KH, McLean D, Looi LM, Moosa F
    AJR Am J Roentgenol, 2004 Mar;182(3):713-7.
    PMID: 14975974
    This study was undertaken to estimate mammographic breast glandularity in Malaysian women from radiographic data.
    Matched MeSH terms: Least-Squares Analysis
  12. Samsudin H, Auras R, Burgess G, Dolan K, Soto-Valdez H
    Food Res Int, 2018 03;105:920-929.
    PMID: 29433289 DOI: 10.1016/j.foodres.2017.11.065
    A two-step solution based on the boundary conditions of Crank's equations for mass transfer in a film was developed. Three driving factors, the diffusion (D), partition (Kp,f) and convective mass transfer coefficients (h), govern the sorption and/or desorption kinetics of migrants from polymer films. These three parameters were simultaneously estimated. They provide in-depth insight into the physics of a migration process. The first step was used to find the combination of D, Kp,f and h that minimized the sums of squared errors (SSE) between the predicted and actual results. In step 2, an ordinary least square (OLS) estimation was performed by using the proposed analytical solution containing D, Kp,f and h. Three selected migration studies of PLA/antioxidant-based films were used to demonstrate the use of this two-step solution. Additional parameter estimation approaches such as sequential and bootstrap were also performed to acquire a better knowledge about the kinetics of migration. The proposed model successfully provided the initial guesses for D, Kp,f and h. The h value was determined without performing a specific experiment for it. By determining h together with D, under or overestimation issues pertaining to a migration process can be avoided since these two parameters are correlated.
    Matched MeSH terms: Least-Squares Analysis
  13. Se KW, Ghoshal SK, Wahab RA, Ibrahim RKR, Lani MN
    Food Res Int, 2018 03;105:453-460.
    PMID: 29433236 DOI: 10.1016/j.foodres.2017.11.012
    In this study, we propose an easy approach by combining the Fourier transform infrared and attenuated total reflectance (FTIR-ATR) spectroscopy together with chemometrics analysis for rapid detection and accurate quantification of five adulterants such as fructose, glucose, sucrose, corn syrup and cane sugar in stingless bees (Heterotrigona itama) honey harvested in Malaysia. Adulterants were classified using principal component analysis and soft independent modeling class analogy, where the first derivative of the spectra in the wavenumber range of 1180-750cm-1 was utilized. The protocol could satisfactorily discriminate the stingless bees honey samples that were adulterated with the concentrations of corn syrup above 8% (w/w) and cane sugar over 2% (w/w). Feasibility of integrating FTIR-ATR with chemometrics for precise quantification of the five adulterants was affirmed using partial least square regression (PLSR) analysis. The study found that optimal PLSR analysis achieved standard error of calibrations and standard error of predictions within an acceptable range of 0.686-1.087% and 0.581-1.489%, respectively, indicating good predictive capability. Hence, the method developed here for detecting and quantifying adulteration in H. itama honey samples is accurate and rapid, requiring only 7-8min to complete as compared to 3h for the standard method, AOAC method 998.12.
    Matched MeSH terms: Least-Squares Analysis
  14. Man CN, Ismail S, Harn GL, Lajis R, Awang R
    PMID: 19109080 DOI: 10.1016/j.jchromb.2008.12.014
    Hair nicotine is a known biomarker for monitoring long-term environmental tobacco smoke (ETS) exposure and smoking status. In general, hair nicotine assay involves alkaline digestion, extraction and instrumental analysis. The gas chromatography-mass spectrometry (GC-MS) assay currently developed has shown to be of high throughput with average approximately 100 hair samples being extracted and analyzed per day. This was achieved through simplified extraction procedure and shortened GC analysis time. The extraction was improved by using small volume (0.4 mL) of organic solvent that does not require further evaporation and salting steps prior to GC-MS analysis. Furthermore, the amount of hair utilized in the extraction was very little (5 mg) while the sensitivity and selectivity of the assay is equal, if not better than other established methods. The linearity of the assay (r(2)>0.995), limit of quantitation (0.04 ng/mg hair), within- and between-assays accuracies and precisions (<11.4%) and mean recovery (92.6%) were within the acceptable range.
    Matched MeSH terms: Least-Squares Analysis
  15. Ashiq Ur Rahman M, Khan SA, Lyla PS, Kadharsha K, Chander PM, John BA
    Pak J Biol Sci, 2013 Apr 01;16(7):345-50.
    PMID: 24498802
    Determination of Length-weight Relationship (LWR) of any commercially important fish is crucial to validate the wild stock level, to predict their wellbeing in the natural habitat and for various sustainable fishery management practices. Liza subviridis (Valenciennes) is noted to be highly abundant along the coast of Parangipettai, South east coast of India. Hence, the present study was aimed to establish Length-weight relationship and condition factor of Greenback mullet, Liza subviridis (Valenciennes) occurring in Vellar estuary, Parangipettai (lat. 11 degrees 30' N, long. 79 degrees 46' E) using least square method. To determine the actual relationship between length and weight of L. subviridis exponent coefficient or equilibrium constant (b) and relative condition factor (Kn) analysis were adopted. The females were found to be heavier than males at similar length. The equilibrium constant 'b' was found to be 2.7106 in males and 2.8927 in females. The corresponding parabolic representation for male was W = 0.0462L(2.7106) and for female W = 0.0382L(2.8927). The equilibrium constant did not obey the cube law as it deviated significantly from 3 in the case of males. The relative condition factor around 1 and little over it revealed the well-being of L. subviridis in Parangipettai waters.
    Matched MeSH terms: Least-Squares Analysis
  16. Shamsudin S, Selamat J, Sanny M, A R SB, Jambari NN, Khatib A
    Molecules, 2019 Oct 29;24(21).
    PMID: 31671885 DOI: 10.3390/molecules24213898
    Stingless bee honey produced by Heterotrigona itama from different botanical origins was characterised and discriminated. Three types of stingless bee honey collected from acacia, gelam, and starfruit nectars were analyzed and compared with Apis mellifera honey. The results showed that stingless bee honey samples from the three different botanical origins were significantly different in terms of their moisture content, pH, free acidity, total soluble solids, colour characteristics, sugar content, amino acid content and antioxidant properties. Stingless bee honey was significantly different from Apis mellifera honey in terms of physicochemical and antioxidant properties. The amino acid content was further used in the chemometrics analysis to evaluate the role of amino acid in discriminating honey according to botanical origin. Partial least squares-discriminant analysis (PLS-DA) revealed that the stingless bee honey was completely distinguishable from Apis mellifera honey. Notably, a clear distinction between the stingless bee honey types was also observed. The specific amino acids involved in the distinction of honey were cysteine for acacia and gelam, phenylalanine and 3-hydroxyproline for starfruit, and proline for Apis mellifera honey. The results showed that all honey samples were successfully classified based on amino acid content.
    Matched MeSH terms: Least-Squares Analysis
  17. Javadi N, Abas F, Abd Hamid A, Simoh S, Shaari K, Ismail IS, et al.
    J Food Sci, 2014 Jun;79(6):C1130-6.
    PMID: 24888400 DOI: 10.1111/1750-3841.12491
    Cosmos caudatus, which is known as "Ulam Raja," is an herbal plant used in Malaysia to enhance vitality. This study focused on the evaluation of the α-glucosidase inhibitory activity of different ethanolic extracts of C. caudatus. Six series of samples extracted with water, 20%, 40%, 60%, 80%, and 100% ethanol (EtOH) were employed. Gas chromatography-mass spectrometry (GC-MS) and orthogonal partial least-squares (OPLS) analysis was used to correlate bioactivity of different extracts to different metabolite profiles of C. caudatus. The obtained OPLS scores indicated a distinct and remarkable separation into 6 clusters, which were indicative of the 6 different ethanol concentrations. GC-MS can be integrated with multivariate data analysis to identify compounds that inhibit α-glucosidase activity. In addition, catechin, α-linolenic acid, α-D-glucopyranoside, and vitamin E compounds were identified and indicate the potential α-glucosidase inhibitory activity of this herb.
    Matched MeSH terms: Least-Squares Analysis
  18. Rohman A, Ariani R
    ScientificWorldJournal, 2013;2013:740142.
    PMID: 24319381 DOI: 10.1155/2013/740142
    Fourier transform infrared spectroscopy (FTIR) combined with multivariate calibration of partial least square (PLS) was developed and optimized for the analysis of Nigella seed oil (NSO) in binary and ternary mixtures with corn oil (CO) and soybean oil (SO). Based on PLS modeling performed, quantitative analysis of NSO in binary mixtures with CO carried out using the second derivative FTIR spectra at combined frequencies of 2977-3028, 1666-1739, and 740-1446 cm(-1) revealed the highest value of coefficient of determination (R (2), 0.9984) and the lowest value of root mean square error of calibration (RMSEC, 1.34% v/v). NSO in binary mixtures with SO is successfully determined at the combined frequencies of 2985-3024 and 752-1755 cm(-1) using the first derivative FTIR spectra with R (2) and RMSEC values of 0.9970 and 0.47% v/v, respectively. Meanwhile, the second derivative FTIR spectra at the combined frequencies of 2977-3028 cm(-1), 1666-1739 cm(-1), and 740-1446 cm(-1) were selected for quantitative analysis of NSO in ternary mixture with CO and SO with R (2) and RMSEC values of 0.9993 and 0.86% v/v, respectively. The results showed that FTIR spectrophotometry is an accurate technique for the quantitative analysis of NSO in binary and ternary mixtures with CO and SO.
    Matched MeSH terms: Least-Squares Analysis
  19. Siddiqui MF, Reza AW, Kanesan J
    PLoS One, 2015;10(8):e0135875.
    PMID: 26280918 DOI: 10.1371/journal.pone.0135875
    A wide interest has been observed in the medical health care applications that interpret neuroimaging scans by machine learning systems. This research proposes an intelligent, automatic, accurate, and robust classification technique to classify the human brain magnetic resonance image (MRI) as normal or abnormal, to cater down the human error during identifying the diseases in brain MRIs. In this study, fast discrete wavelet transform (DWT), principal component analysis (PCA), and least squares support vector machine (LS-SVM) are used as basic components. Firstly, fast DWT is employed to extract the salient features of brain MRI, followed by PCA, which reduces the dimensions of the features. These reduced feature vectors also shrink the memory storage consumption by 99.5%. At last, an advanced classification technique based on LS-SVM is applied to brain MR image classification using reduced features. For improving the efficiency, LS-SVM is used with non-linear radial basis function (RBF) kernel. The proposed algorithm intelligently determines the optimized values of the hyper-parameters of the RBF kernel and also applied k-fold stratified cross validation to enhance the generalization of the system. The method was tested by 340 patients' benchmark datasets of T1-weighted and T2-weighted scans. From the analysis of experimental results and performance comparisons, it is observed that the proposed medical decision support system outperformed all other modern classifiers and achieves 100% accuracy rate (specificity/sensitivity 100%/100%). Furthermore, in terms of computation time, the proposed technique is significantly faster than the recent well-known methods, and it improves the efficiency by 71%, 3%, and 4% on feature extraction stage, feature reduction stage, and classification stage, respectively. These results indicate that the proposed well-trained machine learning system has the potential to make accurate predictions about brain abnormalities from the individual subjects, therefore, it can be used as a significant tool in clinical practice.
    Matched MeSH terms: Least-Squares Analysis
  20. Nipun TS, Khatib A, Ahmed QU, Redzwan IE, Ibrahim Z, Khan AYF, et al.
    Molecules, 2020 Sep 11;25(18).
    PMID: 32932994 DOI: 10.3390/molecules25184161
    The plant Psychotria malayana Jack belongs to the Rubiaceae family and is known in Malaysia as "meroyan sakat/salung". A rapid analytical technique to facilitate the evaluation of the P. malayana leaves' quality has not been well-established yet. This work aimed therefore to develop a validated analytical technique in order to predict the alpha-glucosidase inhibitory action (AGI) of P. malayana leaves, applying a Fourier Transform Infrared Spectroscopy (FTIR) fingerprint and utilizing an orthogonal partial least square (OPLS). The dried leaf extracts were prepared by sonication of different ratios of methanol-water solvent (0, 25, 50, 75, and 100% v/v) prior to the assessment of alpha-glucosidase inhibition (AGI) and the following infrared spectroscopy. The correlation between the biological activity and the spectral data was evaluated using multivariate data analysis (MVDA). The 100% methanol extract possessed the highest inhibitory activity against the alpha-glucosidase (IC50 2.83 ± 0.32 μg/mL). Different bioactive functional groups, including hydroxyl (O-H), alkenyl (C=C), methylene (C-H), carbonyl (C=O), and secondary amine (N-H) groups, were detected by the multivariate analysis. These functional groups actively induced the alpha-glucosidase inhibition effect. This finding demonstrated the spectrum profile of the FTIR for the natural herb P. malayana Jack, further confirming its medicinal value. The developed validated model can be used to predict the AGI of P. malayana, which will be useful as a tool in the plant's quality control.
    Matched MeSH terms: Least-Squares Analysis
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