Displaying publications 1 - 20 of 390 in total

Abstract:
Sort:
  1. Zaharan NL, Muhamad NH, Jalaludin MY, Su TT, Mohamed Z, Mohamed MNA, et al.
    PMID: 29755414 DOI: 10.3389/fendo.2018.00209
    Background: Several non-synonymous single-nucleotide polymorphisms (nsSNPs) have been shown to be associated with obesity. Little is known about their associations and interactions with physical activity (PA) in relation to adiposity parameters among adolescents in Malaysia.

    Methods: We examined whether (a) PA and (b) selected nsSNPs are associated with adiposity parameters and whether PA interacts with these nsSNPs on these outcomes in adolescents from the Malaysian Health and Adolescents Longitudinal Research Team study (n = 1,151). Body mass indices, waist-hip ratio, and percentage body fat (% BF) were obtained. PA was assessed using Physical Activity Questionnaire for Older Children (PAQ-C). Five nsSNPs were included: beta-3 adrenergic receptor (ADRB3) rs4994, FABP2 rs1799883, GHRL rs696217, MC3R rs3827103, and vitamin D receptor rs2228570, individually and as combined genetic risk score (GRS). Associations and interactions between nsSNPs and PAQ-C scores were examined using generalized linear model.

    Results: PAQ-C scores were associated with % BF (β = -0.44 [95% confidence interval -0.72, -0.16], p = 0.002). The CC genotype of ADRB3 rs4994 (β = -0.16 [-0.28, -0.05], corrected p = 0.01) and AA genotype of MC3R rs3827103 (β = -0.06 [-0.12, -0.00], p = 0.02) were significantly associated with % BF compared to TT and GG genotypes, respectively. Significant interactions with PA were found between ADRB3 rs4994 (β = -0.05 [-0.10, -0.01], p = 0.02) and combined GRS (β = -0.03 [-0.04, -0.01], p = 0.01) for % BF.

    Conclusion: Higher PA score was associated with reduced % BF in Malaysian adolescents. Of the nsSNPs, ADRB3 rs4994 and MC3R rs3827103 were associated with % BF. Significant interactions with PA were found for ADRB3 rs4994 and combined GRS on % BF but not on measurements of weight or circumferences. Targeting body fat represent prospects for molecular studies and lifestyle intervention in this population.

    Matched MeSH terms: Linear Models
  2. Chaibakhsh N, Rahman MB, Basri M, Salleh AB, Abd-Aziz S
    Biotechnol J, 2010 Aug;5(8):848-55.
    PMID: 20632329 DOI: 10.1002/biot.201000063
    Dimethyl adipate (DMA) was synthesized by immobilized Candida antarctica lipase B-catalyzed esterification of adipic acid and methanol. To optimize the reaction conditions of ester production, response surface methodology was applied, and the effects of four factors namely, time, temperature, enzyme concentration, and molar ratio of substrates on product synthesis were determined. A statistical model predicted that the maximum conversion yield would be 97.6%, at the optimal conditions of 58.5 degrees C, 54.0 mg enzyme, 358.0 min, and 12:1 molar ratio of methanol to adipic acid. The R(2) (0.9769) shows a high correlation between predicted and experimental values. The kinetics of the reaction was also investigated in this study. The reaction was found to obey the ping-pong bi-bi mechanism with methanol inhibition. The kinetic parameters were determined and used to simulate the experimental results. A good quality of fit was observed between the simulated and experimental initial rates.
    Matched MeSH terms: Linear Models
  3. Tan CE, Hi MY, Azmi NS, Ishak NK, Mohd Farid FA, Abdul Aziz AF
    Cureus, 2020 Mar 24;12(3):e7390.
    PMID: 32337117 DOI: 10.7759/cureus.7390
    Background Most family caregivers of stroke patients in Malaysia do not receive adequate prior preparation or training. This study aimed to determine levels of patient positioning knowledge and caregiving self-efficacy among caregivers of stroke patients. Methods This cross-sectional study was conducted at an urban teaching hospital involving 128 caregivers of stroke patients. The caregivers were conveniently sampled and completed the data collection forms, which comprised their socio-demographic data, patients' functional status, the Caregiving Knowledge For Stroke Questionnaire: Patient Positioning (CKQ-My© Patient Positioning) to measure caregiver's knowledge on patient positioning, and the Family Caregiver Activation Tool (FCAT©) to measure caregivers' self-efficacy in managing the patient. Descriptive and multivariate inferential statistics were used for data analysis. Results Among the caregivers sampled, 87.3% had poor knowledge of positioning (mean score 14.9 ± 4.32). The mean score for FCAT was 49.7 ± 6.0 from a scale of 10 to 60. There was no significant association between knowledge on positioning and self-efficacy. Multiple linear regression showed that caregivers' age (B = 0.146, p = 0.003) and caregiver training (B = 3.302, p = 0.007) were independently associated with caregivers' self-efficacy. Conclusion Caregivers' knowledge on the positioning of stroke patients was poor, despite a fairly good level of self-efficacy. Older caregivers and receiving caregiver training were independently associated with better caregiver self-efficacy. This supports the provision of caregiver training to improve caregiver self-efficacy.
    Matched MeSH terms: Linear Models
  4. Adzhar Rambli, Rossita Mohamad Yunus, Ibrahim Mohamed, Abdul Ghapor Hussin
    Sains Malaysiana, 2015;44:1027-1032.
    Recently, there is strong interest on the subject of outlier problem in circular data. In this paper, we focus on detecting outliers in a circular regression model proposed by Down and Mardia. The basic properties of the model are available including the exact form of covariance matrix of the parameters. Hence, we intend to identify outliers in the model by looking at the effect of the outliers on the covariance matrix. The method resembles closely the COVRATIO statistic for the case of linear regression problem. The corresponding critical values and the performance of the outlier detection procedure are studied via simulations. For illustration, we apply the procedure on the wind data set.
    Matched MeSH terms: Linear Models
  5. Basri, M.N., Janattul, A.J., Azrina, M.R., Abdul Hadi, M.
    MyJurnal
    Introduction: Our objectives are to identify the incidence of hypophosphatemia and the associated risk factors. We also want to establish intravenous replacement therapy that is effective for ICU patients. Methods: A prospective observational study assessing adults admitted to ICU in between March and May 2009. All patients without baseline phosphate level and renal failure were excluded. They were evaluated for the occurrence of common risk factors. Association with independent variables that includes age, gender and BMI were verified. Evaluation of IV replacement therapy was done in the treated patients. Results: From 50 patients that were reviewed, nine were excluded. There were 66% male and 34% female with mean age 46.88±17.89. The mean ICU stay was 8.00±6.41 days. The incidence of hypophosphatemia was 29% (n=12/41). Gender and
    creatinine clearance was found to be significantly different between normophosphatemia and
    hypophosphatemia patients. There was no significant association for each potential risk factor and the number of risk factors (≥3) with the incidence of hypophosphatemia. Multi-linear regression analysis showed that lactate, creatinine clearance and pH were significant predictors to the serum levels. A significant difference of mean serum phosphate was seen after repletion by total dose of 10, 20 and 40 mmols in the treatment subgroups. Conclusions: The incidence of hypophosphatemia in our ICU was high and comparable to previous studies. None of the commonly reported risk factors is associated with hypophosphatemia in this studied population. Among all significant correlated variables, only pH was found to be a significant predictor for serum phosphate. Baseline phosphate level may guide the initial replacement dose to prevent delay in normalization of serum levels.
    Matched MeSH terms: Linear Models
  6. Amir Hamzah A, Abu Bakar Z, Abdul Sani N, Tan JK, Ahmad Damanhuri M, Makpol S, et al.
    Sains Malaysiana, 2016;45:1371-1380.
    Higher level of education is associated with better cognitive performance and lower risk of developing dementia. However, the effect of education on cognitive performance varies across different cognitive domains and in different populations. The aim of this study was to determine the relationship between education and performance of different cognitive domains among healthy Malay adults. A total of 53 individuals aged 29 to 77 years participated in a battery of neurophysiological tests consisting of Mini-Mental State Examination, Montreal Cognitive Assessment, digit span, visual reproduction and digit symbol speed test (DSST). Blood test was performed for each participant to obtain their biochemical profile. Educational level was divided into level 1 (PMR), level 2 (SPM), level 3 (STPM), level 4 (Diploma) and level 5 (Degree). Simple linear regression indicated that years of education was positively associated with scores of delayed visual reproduction (b=1.348, p=0.002) and DSST (b=3.257, p=0.012). However, scores of all the tests were not significantly different among different levels of education after controlling for age, gender and blood test profile by ANCOVA. Multiple linear regression analysis showed that MMSE score was associated with red cell distribution width (b=-0.628, p=0.005), age (b=-0.119, p<0.001) and there was interaction between high density lipoprotein (HDL) with age (b=0.047, p<001). MoCA score was associated with age (b=-0.121, p<0.001), gender (male compared to female, b=1.870, p=0.020) and HDL (b=1.681, p=0.047). Age was associated with backward digit span (b=-0098, p<0.001) and immediate visual reproduction (b=-0.348, p<0.001), resp. Delayed visual reproduction was associated with age (b=-0.323, p<0.001) and potassium level (b=-4.471, p=0.016). DSST was associated with age (b=-0.911, p<0.001) and alanine aminotransferase (b=-0.754, p=0.002). The lack of association between educational level and cognitive performance after adjusting for confounders in this study maybe due to multiple factors influencing cognitive performance and further studies with a larger sample size are needed to further identify the factors involved.
    Keywords: Cognitive performance; education; healthy Malay adults
    ABSTRAK
    Tahap pendidikan yang tinggi telah dikaitkan dengan prestasi kognitif yang lebih baik dan risiko perkembangan dementia yang lebih rendah. Namun, kesan pendidikan terhadap prestasi kognitif berbeza antara domain kognitif dan populasi yang berlainan. Kajian ini bertujuan untuk menentukan hubungan antara pendidikan dengan prestasi pada domain kognitif yang berlainan pada individu dewasa Melayu yang sihat. Seramai 53 individu yang berumur antara 29 hingga 77 tahun telah menyertai ujian neuropsikologi yang terdiri daripada Pemeriksaan Keadaan Mental Mini, Penilaian Kognitif Montreal, digit span, penghasilan semula visual dan ujian kelajuan simbol digit (DSST). Tahap pendidikan dibahagikan kepada tahap 1 (PMR), tahap 2 (SPM), tahap 3 (STPM), tahap 4 (Diploma) dan tahap 5 (Ijazah Sarjana Muda). Regresi linear mudah menunjukkan bahawa tahap pendidikan berhubung kait secara positif dengan penghasilan semula visual tertunda (b=1.348, p=0.002) dan DSST (b=3.257, p=0.012). Namun, semua skor ujian menjadi tidak berbeza antara tahap pendidikan yang berbeza selepas mengambil kira kesan konpengasas dengan menggunakan ANCOVA. Regresi linear berganda menunjukkan bahawa skor MMSE berhubung kait dengan lebar taburan sel merah (b=-0.628, p=0.005), umur (b=-0.119, p<0.001) dan interaksi antara lipoprotein ketumpatan tinggi (HDL) dan umur (b=0.047, p<001). MoCA didapati berhubung kait dengan umur (b=-0.121, p<0.001), jantina (lelaki berbanding perempuan, b=1.870, p=0.020) dan HDL (b=1.681, p=0.047). Umur juga berhubung kait dengan digit span ke belakang (b=-0098, P<0.001) dan penghasilan semula visual segera (b=-0.348, p<0.001). Penghasilan semula visual tertunda berhubung kait dengan umur (b=-0.323, p<0.001) dan tahap kalium (b=-4.471, p=0.016). DSST berhubung kait dengan umur (b=-0.911, p<0.001) dan alanin aminotransferase (b=-0.754, p=0.002). Hubungan antara tahap pendidikan dan prestasi kognitif tidak dikesan selepas mengambil kira kesan konpengasas yang mencadangkan bahawa prestasi kognitif mungkin dipengaruhi oleh pelbagai faktor dan kajian lanjut dengan bilangan sampel yang lebih besar diperlukan untuk mengenal pasti faktor ini.
    Matched MeSH terms: Linear Models
  7. Zyoud TYT, Abdul Rashid SN, Suppiah S, Mahmud R, Kabeer A, Abd Manaf R, et al.
    Malays J Pathol, 2020 Dec;42(3):423-431.
    PMID: 33361724
    INTRODUCTION: Post-mortem computed tomography (PMCT) provides information that helps in the determination of the cause of death and corpse identification of disaster victims. One of the methods for corpse identification includes assessment of the body stature. There is a lack of post-mortem imaging studies that focus on the anthropometric assessment of corpses. Our aim was to identify the relationship between cadaveric spine length and autopsy length (AL) among and autopsy length (AL) among a Malaysian population and derive a regression formula for the estimation of corpse body height using PMCT.

    MATERIALS AND METHODS: We retrospectively assessed 107 cadavers that had undergone conventional autopsy and PMCT. We made 5 measurements from the PMCT that included cervical length (CL), thoracic length (TL), lumbosacral length (LS), total column length of the spine, excluding the sacrum and coccyx (TCL), and ellipse line measurement of the whole spine, excluding the sacrum and coccyx (EL). We compared these anthropometric PMCT measurements with AL and correlated them using linear regression analysis.

    RESULTS: The results showed a significant linear relationship existed between TL and LS with AL, which was higher in comparison with the other parameters than the rest of the spine parameters. The linear regression formula derived was: 48.163 + 2.458 (TL) + 2.246 (LS).

    CONCLUSIONS: The linear regression formula derived from PMCT spine length parameters particularly thoracic and lumbar spine gave a finer correlation with autopsy body length and can be used for accurate estimation of cadaveric height. To the best of our knowledge, this is the first ever linear regression formula for cadaveric height assessment using only post mortem CT spine length measurements.

    Matched MeSH terms: Linear Models
  8. Saman SA, Chang KH, Abdullah AFL
    J Forensic Sci, 2021 Mar;66(2):608-618.
    PMID: 33202056 DOI: 10.1111/1556-4029.14625
    Abuse of solvent-based adhesives jeopardizes world population, especially the young generation. Adhesive-related exhibits encountered in forensic cases might need to be determined if they could have come from a particular source or to establish link between cases or persons. This study was aimed to discriminate solvent-based adhesives, especially to aid forensic investigation of glue sniffing activities. In this study, thirteen brands with three samples each, totaling at 39 adhesive samples, were analyzed using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy followed by chemometric methods. Experimental output showed that adhesive samples utilized in this study were less likely to change in their ATR-FTIR profiles over time, at least up to 2 months. No interference from plastic materials was noticed based on ATR-FTIR profile comparison. Physical examination could differentiate the samples into two groups, namely contact adhesives and cement adhesives. A principal component analysis-score linear discriminative analysis (PC-score LDA) model resulted in 100% and 98.6% correct classification in discriminating the two groups of adhesive samples, forming seven discriminative clusters. Test set with adhesive samples applied glass slide and plastic substrates also demonstrated a 100% correct classification into their respective groups. As a conclusion, the method allowed for discrimination of adhesive samples based on the spectral features, displaying relationship among samples. It is hoped that this comparative information is beneficial to trace the possible source of solvent-based adhesives, whenever they are recovered from a crime scene, for forensic investigation.
    Matched MeSH terms: Linear Models
  9. Muazu Musa R, P P Abdul Majeed A, Taha Z, Chang SW, Ab Nasir AF, Abdullah MR
    PLoS One, 2019;14(1):e0209638.
    PMID: 30605456 DOI: 10.1371/journal.pone.0209638
    k-nearest neighbour (k-NN) has been shown to be an effective learning algorithm for classification and prediction. However, the application of k-NN for prediction and classification in specific sport is still in its infancy. The present study classified and predicted high and low potential archers from a set of physical fitness variables trained on a variation of k-NN algorithms and logistic regression. 50 youth archers with the mean age and standard deviation of (17.0 ± 0.56) years drawn from various archery programmes completed a one end archery shooting score test. Standard fitness measurements of the handgrip, vertical jump, standing broad jump, static balance, upper muscle strength and the core muscle strength were conducted. Multiple linear regression was utilised to ascertain the significant variables that affect the shooting score. It was demonstrated from the analysis that core muscle strength and vertical jump were statistically significant. Hierarchical agglomerative cluster analysis (HACA) was used to cluster the archers based on the significant variables identified. k-NN model variations, i.e., fine, medium, coarse, cosine, cubic and weighted functions as well as logistic regression, were trained based on the significant performance variables. The HACA clustered the archers into high potential archers (HPA) and low potential archers (LPA). The weighted k-NN outperformed all the tested models at itdemonstrated reasonably good classification on the evaluated indicators with an accuracy of 82.5 ± 4.75% for the prediction of the HPA and the LPA. Moreover, the performance of the classifiers was further investigated against fresh data, which also indicates the efficacy of the weighted k-NN model. These findings could be valuable to coaches and sports managers to recognise high potential archers from a combination of the selected few physical fitness performance indicators identified which would subsequently save cost, time and energy for a talent identification programme.
    Matched MeSH terms: Linear Models
  10. Taha Z, Musa RM, P P Abdul Majeed A, Alim MM, Abdullah MR
    Hum Mov Sci, 2018 Feb;57:184-193.
    PMID: 29248809 DOI: 10.1016/j.humov.2017.12.008
    Support Vector Machine (SVM) has been shown to be an effective learning algorithm for classification and prediction. However, the application of SVM for prediction and classification in specific sport has rarely been used to quantify/discriminate low and high-performance athletes. The present study classified and predicted high and low-potential archers from a set of fitness and motor ability variables trained on different SVMs kernel algorithms. 50 youth archers with the mean age and standard deviation of 17.0 ± 0.6 years drawn from various archery programmes completed a six arrows shooting score test. Standard fitness and ability measurements namely hand grip, vertical jump, standing broad jump, static balance, upper muscle strength and the core muscle strength were also recorded. Hierarchical agglomerative cluster analysis (HACA) was used to cluster the archers based on the performance variables tested. SVM models with linear, quadratic, cubic, fine RBF, medium RBF, as well as the coarse RBF kernel functions, were trained based on the measured performance variables. The HACA clustered the archers into high-potential archers (HPA) and low-potential archers (LPA), respectively. The linear, quadratic, cubic, as well as the medium RBF kernel functions models, demonstrated reasonably excellent classification accuracy of 97.5% and 2.5% error rate for the prediction of the HPA and the LPA. The findings of this investigation can be valuable to coaches and sports managers to recognise high potential athletes from a combination of the selected few measured fitness and motor ability performance variables examined which would consequently save cost, time and effort during talent identification programme.
    Matched MeSH terms: Linear Models
  11. Sanagi MM, Loh SH, Wan Ibrahim WA, Hasan MN, Aboul Enein HY
    J Chromatogr Sci, 2013 Feb;51(2):112-6.
    PMID: 22776739 DOI: 10.1093/chromsci/bms113
    In this work, a two-phase hollow fiber liquid-phase microextraction (HF-LPME) method combined with gas chromatography-mass spectrometry (GC-MS) is developed to provide a rapid, selective and sensitive analytical method to determine polycyclic aromatic hydrocarbons (PAHs) in fresh milk. The standard addition method is used to construct calibration curves and to determine the residue levels for the target analytes, fluorene, phenanthrene, fluoranthene, pyrene and benzo[a]pyrene, thus eliminating sample pre-treatment steps such as pH adjustment. The HF-LPME method shows dynamic linearity from 5 to 500 µg/L for all target analytes with R(2) ranging from 0.9978 to 0.9999. Under optimized conditions, the established detection limits range from 0.07 to 1.4 µg/L based on a signal-to-noise ratio of 3:1. Average relative recoveries for the determination of PAHs studied at 100 µg/L spiking levels are in the range of 85 to 110%. The relative recoveries are slightly higher than those obtained by conventional solvent extraction, which requires saponification steps for fluorene and phenanthrene, which are more volatile and heat sensitive. The HF-LPME method proves to be simple and rapid, and requires minimal amounts of organic solvent that supports green analysis.
    Matched MeSH terms: Linear Models
  12. Al Azzam KM, Saad B, Aboul-Enein HY
    Electrophoresis, 2010 Sep;31(17):2957-63.
    PMID: 20690150 DOI: 10.1002/elps.201000266
    Binding constants for the enantiomers of modafinil with the negatively charged chiral selector sulfated-β-CD (S-β-CD) using CE technique is presented. The calculations of the binding constants employing three different linearization plots (double reciprocal, X-reciprocal and Y-reciprocal) were performed from the electrophoretic mobility values of modafinil enantiomers at different concentrations of S-β-CD in the BGE. The highest inclusion affinity of the modafinil enantiomers were observed for the S-enantiomer-S-β-CD complex, in agreement with the computational calculations performed previously. Binding constants for each enantiomer-S-β-CD complex at different temperatures, as well as thermodynamic parameters for binding, were calculated. Host-guest binding constants using the double reciprocal fit showed better linearity (r(2)>0.99) at all temperatures studied (15-30°C) and compared with the other two fit methods. The linear van't Hoff (15-30°C) plot obtained indicated that the thermodynamic parameters of complexation were temperature dependent for the enantiomers.
    Matched MeSH terms: Linear Models
  13. Al Azzam KM, Saad B, Adnan R, Aboul-Enein HY
    Anal Chim Acta, 2010 Aug 3;674(2):249-55.
    PMID: 20678638 DOI: 10.1016/j.aca.2010.06.046
    A capillary electrophoretic method for the separation of the enantiomers of both ofloxacin and ornidazole is described. Several parameters affecting the separation were studied, including the type and concentration of chiral selector, buffer pH, voltage and temperature. Good chiral separation of the racemic mixtures was achieved in less than 16 min with resolution factors Rs=5.45 and 6.28 for ofloxacin and ornidazole enantiomers, respectively. Separation was conducted using a bare fused-silica capillary and a background electrolyte (BGE) of 50 mM H(3)PO(4)-1 M tris solution; pH 1.85; containing 30 mg mL(-1) of sulfated-beta-cyclodextrin (S-beta-CD). The separation was carried out in reversed polarity mode at 25 degrees C, 18 kV, detection wavelength at 230 nm and using hydrodynamic injection for 15 s. Acceptable validation criteria for selectivity, linearity, precision, and accuracy were studied. The limits of detection (LOD) and limits of quantitation (LOQ) of the enantiomers (ofloxacin enantiomer 1 (OF-E1), ofloxacin enantiomer 2 (OF-E2), ornidazole enantiomer 1 (OR-E1) and ornidazole enantiomer 2 (OR-E2)) were (0.52, 0.46, 0.54, 0.89) and (1.59, 1.40, 3.07, 2.70) microg mL(-1), respectively. The proposed method was successfully applied to the assay of enantiomers of both ofloxacin and ornidazole in pharmaceutical formulations. The computational calculations for the enantiomeric inclusion complexes rationalized the reasons for the different migration times between the ofloxacin and ornidazole enantiomers.
    Matched MeSH terms: Linear Models
  14. Elbashir AA, Saad B, Ali AS, Saleh MI, Aboul-Enein HY
    Biomed Chromatogr, 2009 Mar;23(3):295-301.
    PMID: 18816453 DOI: 10.1002/bmc.1113
    A capillary electrophoretic (CE) method for the baseline separation of the enantiomers of primaquine diphosphate (PQ) and quinocide (QC) (a major contaminant) in pharmaceutical formulations is proposed. Both components were separated under the following conditions: 50 mm tris phosphate buffer (pH 3.0) containing 15 mm hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD) as background electrolyte; applied voltage, 16 kV; capillary temperature, 25 degrees C; detection wavelength, 254 nm; hydrostatic injection, 10 s. The separations were conducted using a 35 cm length and 50 microm i.d. uncoated fused silica capillary column. Under the optimized conditions, the components were successfully separated in about 5 min. Intraday precision of migration time and corrected peak areas when expressed as relative standard deviation ranged from 0.17 to 0.45 and 2.60 to 3.94%, respectively, while the interday precision ranged from 2.59 to 4.20 and 3.15 to 4.21%, respectively. After the validation exercise, the proposed method was applied for the determination of QC impurity in PQ formulations.
    Matched MeSH terms: Linear Models
  15. Elbashir AA, Saad B, Ali AS, Saleh MI, Aboul-Enein HY
    Biomed Chromatogr, 2009 May;23(5):464-71.
    PMID: 19016231 DOI: 10.1002/bmc.1137
    A capillary zone electrophoretic method has been developed and validated for the determination of the impurity quinocide (QC) in the antimalarial drug primaquine (PQ). Different buffer additives such as native cyclodextrins and crown ethers were evaluated. Promising results were obtained when either beta-cyclodextrin (beta-CD) or 18-crown-6 ether (18C6) were used. Their separation conditions such as type of buffer and its pH, buffer additive concentration, applied voltage capillary temperature and injection time were optimized. The use of 18C6 offers slight advantages over beta-CD such as faster elution times and improved resolution. Nevertheless, migration times of less than 5 min and resolution factors (R(s)) in the range of 2-4 were obtained when both additives were used. The method was validated with respect to selectivity, linearity, limits of detection and quantitation, analytical precision (intra- and inter-day variability) and repeatability. Concentrations of 2.12 and 2.71% (w/w) of QC were found in pharmaceutical preparations of PQ from two different manufacturers. A possible mechanism for the successful separation of the isomers is also discussed.
    Matched MeSH terms: Linear Models
  16. Abboud AS, Sanagi MM, Ibrahim WAW, Keyon ASA, Aboul-Enein HY
    J Chromatogr Sci, 2018 Feb 01;56(2):177-186.
    PMID: 29186451 DOI: 10.1093/chromsci/bmx095
    In this study, caged calcium alginate-caged multiwalled carbon nanotubes dispersive microsolid phase extraction was described for the first time for the extraction of polycyclic aromatic hydrocarbons (PAHs) from water samples prior to gas chromatographic analysis. Fluorene, phenanthrene and fluoranthene were selected as model compounds. The caged calcium alginate-caged multiwalled carbon nanotubes was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and thermal gravimetry analyses. The effective parameters namely desorption solvent, solvent volume, extraction time, desorption time, the mass of adsorbent and sample volume were optimized. Under the optimum extraction conditions, the developed method showed good linearity in the range of 0.5-50 ng mL-1 (R2 ≥ 0.996), low limits of detection and quantification (0.42-0.22 ng mL-1) (0.73-1.38 ng mL-1) respectively, good relative recoveries (71.2-104.2%) and reproducibility (RSD 1.8-12.4%, n = 3) for the studied PAHs in water sample. With high enrichment factor (1,000), short extraction time (<30 min), low amounts of adsorbent (100 mg) and low amounts of solvent (0.1 mol) have proven that the microsolid phase extraction method based on calcium alginate-caged multiwalled carbon nanotubes are environmentally friendly and convenient extraction method to use as an alternative adsorbent in the simultaneous preconcentration of PAHs from environmental water samples.
    Matched MeSH terms: Linear Models
  17. Hafidh RR, Hussein SZ, MalAllah MQ, Abdulamir AS, Abu Bakar F
    Curr Cancer Drug Targets, 2018;18(8):807-815.
    PMID: 29141549 DOI: 10.2174/1568009617666171114144236
    BACKGROUND: Citrus bioactive compounds, as active anticancer agents, have been under focus by several studies worldwide. However, the underlying genes responsible for the anticancer potential have not been sufficiently highlighted.

    OBJECTIVES: The current study investigated the gene expression profile of hepatocellular carcinoma, HepG2, cells after treatment with Limonene.

    METHODS: The concentration that killed 50% of HepG2 cells was used to elucidate the genetic mechanisms of limonene anticancer activity. The apoptotic induction was detected by flow cytometry and confocal fluorescence microscope. Two of the pro-apoptotic events, caspase-3 activation and phosphatidylserine translocation were manifested by confocal fluorescence microscopy. Highthroughput real-time PCR was used to profile 1023 cancer-related genes in 16 different gene families related to the cancer development.

    RESULTS: In comparison to untreated cells, limonene increased the percentage of apoptotic cells up to 89.61%, by flow cytometry, and 48.2% by fluorescence microscopy. There was a significant limonene- driven differential gene expression of HepG2 cells in 15 different gene families. Limonene was shown to significantly (>2log) up-regulate and down-regulate 14 and 59 genes, respectively. The affected gene families, from the most to the least affected, were apoptosis induction, signal transduction, cancer genes augmentation, alteration in kinases expression, inflammation, DNA damage repair, and cell cycle proteins.

    CONCLUSION: The current study reveals that limonene could be a promising, cheap, and effective anticancer compound. The broad spectrum of limonene anticancer activity is interesting for anticancer drug development. Further research is needed to confirm the current findings and to examine the anticancer potential of limonene along with underlying mechanisms on different cell lines.

    Matched MeSH terms: Linear Models
  18. Sanagi MM, Ling SL, Nasir Z, Hermawan D, Ibrahim WA, Abu Naim A
    J AOAC Int, 2010 2 20;92(6):1833-8.
    PMID: 20166602
    LOD and LOQ are two important performance characteristics in method validation. This work compares three methods based on the International Conference on Harmonization and EURACHEM guidelines, namely, signal-to-noise, blank determination, and linear regression, to estimate the LOD and LOQ for volatile organic compounds (VOCs) by experimental methodology using GC. Five VOCs, toluene, ethylbenzene, isopropylbenzene, n-propylbenzene, and styrene, were chosen for the experimental study. The results indicated that the estimated LODs and LOQs were not equivalent and could vary by a factor of 5 to 6 for the different methods. It is, therefore, essential to have a clearly described procedure for estimating the LOD and LOQ during method validation to allow interlaboratory comparisons.
    Matched MeSH terms: Linear Models
  19. Wong LP, Shakir SM, Atefi N, AbuBakar S
    PLoS One, 2015;10(4):e0122890.
    PMID: 25836366 DOI: 10.1371/journal.pone.0122890
    Efforts to stamp dengue in many dengue endemic countries has met little success. There is a need to re-examine and understand how the public at large view the dengue prevention efforts. This study aimed to examine the demographic factors, theoretical constructs of the Health Belief Model and knowledge about dengue and how these influence the practice of dengue prevention.
    Matched MeSH terms: Linear Models
  20. Nazif A, Mohammed NI, Malakahmad A, Abualqumboz MS
    Environ Sci Pollut Res Int, 2018 Jan;25(1):283-289.
    PMID: 29032528 DOI: 10.1007/s11356-017-0407-2
    The devastating health effects of particulate matter (PM10) exposure by susceptible populace has made it necessary to evaluate PM10 pollution. Meteorological parameters and seasonal variation increases PM10 concentration levels, especially in areas that have multiple anthropogenic activities. Hence, stepwise regression (SR), multiple linear regression (MLR) and principal component regression (PCR) analyses were used to analyse daily average PM10 concentration levels. The analyses were carried out using daily average PM10 concentration, temperature, humidity, wind speed and wind direction data from 2006 to 2010. The data was from an industrial air quality monitoring station in Malaysia. The SR analysis established that meteorological parameters had less influence on PM10 concentration levels having coefficient of determination (R 2) result from 23 to 29% based on seasoned and unseasoned analysis. While, the result of the prediction analysis showed that PCR models had a better R 2 result than MLR methods. The results for the analyses based on both seasoned and unseasoned data established that MLR models had R 2 result from 0.50 to 0.60. While, PCR models had R 2 result from 0.66 to 0.89. In addition, the validation analysis using 2016 data also recognised that the PCR model outperformed the MLR model, with the PCR model for the seasoned analysis having the best result. These analyses will aid in achieving sustainable air quality management strategies.
    Matched MeSH terms: Linear Models
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links