Displaying publications 1 - 20 of 356 in total

Abstract:
Sort:
  1. Khoo LW, Kow ASF, Maulidiani M, Ang MY, Chew WY, Lee MT, et al.
    Phytochem Anal, 2019 Jan;30(1):46-61.
    PMID: 30183131 DOI: 10.1002/pca.2789
    INTRODUCTION: Clinacanthus nutans, a small shrub that is native to Southeast Asia, is commonly used in traditional herbal medicine and as a food source. Its anti-inflammation properties is influenced by the metabolites composition, which can be determined by different binary extraction solvent ratio and extraction methods used during plant post-harvesting stage.

    OBJECTIVE: Evaluate the relationship between the chemical composition of C. nutans and its anti-inflammatory properties using nuclear magnetic resonance (NMR) metabolomics approach.

    METHODOLOGY: The anti-inflammatory effect of C. nutans air-dried leaves extracted using five different binary extraction solvent ratio and two extraction methods was determined based on their nitric oxide (NO) inhibition effect in lipopolysaccharide-interferon-gamma (LPS-IFN-γ) activated RAW 264.7 macrophages. The relationship between extract bioactivity and metabolite profiles and quantifications were established using 1 H-NMR metabolomics and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The possible metabolite biosynthesis pathway was constructed to further strengthen the findings.

    RESULTS: Water and sonication prepared air-dried leaves possessed the highest NO inhibition activity (IC50  = 190.43 ± 12.26 μg/mL, P 

    Matched MeSH terms: Reference Standards
  2. Tameem AA, Saad B, Makahleh A, Salhin A, Saleh MI
    Talanta, 2010 Sep 15;82(4):1385-91.
    PMID: 20801345 DOI: 10.1016/j.talanta.2010.07.004
    A sorbent material based on a newly synthesized hydrazone ligand, 4-hydroxy-N'-[(E)-(2-hydroxyphenyl)methylidene]benzohydrazide was prepared by immobilizing the ligand into a silica sol-gel matrix. The capability of the sorbent material for the extraction of seven biogenic amines (BAs), i.e., tryptamine (TRY), beta-phenylethylamine (PEA), putrescine (PUT), cadaverine (CAD), histamine (HIS), tyramine (TYR), and spermidine (SPD) was studied. Under the adopted conditions, the sorbent showed good selectivity towards PUT, CAD, HIS and SPD (% extraction (%E)>96) while %E for TYR, TRY and PEA were 82.0, 78.9 and 46.4%, respectively. The sorbent could be used up to six extraction cycles for SPD, CAD and PUT and was applied to the determination of food samples ("budu", ketchup, orange juice, soy sauce) that were spiked with 20 mg L(-1) of the BAs. The extracted analytes were derivatized with dansyl chloride before the HPLC determination. With the exception of HIS and TYR in "budu" sample, reasonable recoveries were found for the other analytes in all the tested food samples.
    Matched MeSH terms: Reference Standards
  3. Mendel B, Christianto, Setiawan M, Prakoso R, Siagian SN
    Curr Cardiol Rev, 2021 Jun 03.
    PMID: 34082685 DOI: 10.2174/1573403X17666210603113430
    BACKGROUND: Junctional ectopic tachycardia (JET) is an arrhythmia originating from the AV junction, which may occur following congenital heart surgery, especially when the intervention is near the atrioventricular junction.

    OBJECTIVE: The aim of this systematic review and meta-analysis is to compare the effectiveness of amiodarone, dexmedetomidine and magnesium in preventing JET following congenital heart surgery.

    METHODS: This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement, where 11 electronic databases were searched from date of inception to August 2020. The incidence of JET was calculated with the relative risk of 95% confidence interval (CI). Quality assessment of the included studies was assessed using the Consolidated Standards of Reporting Trials (CONSORT) 2010 statement.

    RESULTS: Eleven studies met the predetermined inclusion criteria and were included in this meta-analysis. Amiodarone, dexmedetomidine and magnesium significantly reduced the incidence of postoperative JET [Amiodarone: risk ratio 0.34; I2= 0%; Z=3.66 (P=0.0002); 95% CI 0.19-0.60. Dexmedetomidine: risk ratio 0.34; I2= 0%; Z=4.77 (P<0.00001); 95% CI 0.21-0.52. Magnesium: risk ratio 0.50; I2= 24%; Z=5.08 (P<0.00001); 95% CI 0.39-0.66].

    CONCLUSION: All three drugs show promise in reducing the incidence of JET. Our systematic review found that dexmedetomidine is better in reducing the length of ICU stays as well as mortality. In addition, dexmedetomidine also has the least pronounced side effects among the three. However, it should be noted that this conclusion was derived from studies with small sample sizes. Therefore, dexmedetomidine may be considered as the drug of choice for preventing JET.

    Matched MeSH terms: Reference Standards
  4. Jaafar F, Na-Nakorn U, Srisapoome P, Amornsakun T, Duong TY, Gonzales-Plasus MM, et al.
    Biology (Basel), 2021 Apr 01;10(4).
    PMID: 33915909 DOI: 10.3390/biology10040286
    The king of rivers or mahseer comprises three genera: Tor, Neolissochilus, and Naziritor, under the Cyprinidae family. The Tor genus has been classified as the true mahseer due to the presence of a median lobe among the three genera. The Tor species are widely distributed across Southeast (SE) Asia, and 13 Tor species have been reported previously: Tor ater, Tor dongnaiensis, Tor douronensis, Tor laterivittatus, Tor mosal, Tor mekongensis, Tor putitora, Tor sinensis, Tor soro, Tor tambra, Tor tambroides, Tor tor and Tor yingjiangensis. However, the exact number of valid Tor species remains debatable. Different and unstandardized approaches of applying genetic markers in taxonomic identification and morphology variation within the same species have further widened the gap and ameliorated the instability of Tor species taxonomy. Therefore, synchronized and strategized research among Tor species researchers is urgently required to improve and fill the knowledge gap. This review is a current update of SE Asia's Tor species, outlining their distribution, morphology, and genetic identification. In addition, the present review proposes that there are ten valid Tor species in the SE Asian region. This list will serve as a template and standard to improve the taxonomy of the SE Asian Tor species, which could serve as a basis to open new directions in Tor research.
    Matched MeSH terms: Reference Standards
  5. Lim SM, Choo JM, Li H, O'Rielly R, Carragher J, Rogers GB, et al.
    Foods, 2021 Jan 21;10(2).
    PMID: 33494480 DOI: 10.3390/foods10020220
    High amylose wheat (HAW) contains more resistant starch than standard amylose wheat (SAW) and may have beneficial effects on gastrointestinal health. However, it is currently unclear whether these effects differ according to the level of HAW included in the diet or between males and females. Male and female C57BL/6 mice (n = 8/group/sex) were fed SAW65 (65% SAW; control), HAW35 (35% HAW), HAW50 (50% HAW) or HAW65 (65% HAW) diet for eight weeks. Female but not male, mice consuming any amount of HAW exhibited accelerated gastric emptying compared to SAW65 group. In both sexes, relative colon weights were higher in the HAW65 group compared to SAW65 group and in females, relative weights of the small intestine and cecum were also higher in the HAW65 group. In females only, colonic expression of Pyy and Ocln mRNAs were higher in the HAW65 group compared to HAW35 and HAW50 groups. In both sexes, mice consuming higher amounts of HAW (HAW50 or HAW65) had increased fecal bacterial load and relative abundance of Bacteroidetes phylum and reduced relative abundance of Firmicutes compared to SAW65 group. These data are consistent with a beneficial impact of HAW on gastrointestinal health and indicate dose-dependent and sex-specific effects of HAW consumption.
    Matched MeSH terms: Reference Standards
  6. Lourdesamy Anthony AI, Zam Z, Hussin N
    Malays J Med Sci, 2020 Dec;27(6):79-88.
    PMID: 33447136 DOI: 10.21315/mjms2020.27.6.8
    Background: In real-life practice, only 20% of hospitalised pneumonia cases have an identified etiology. The usage of Legionella urine antigen test (LUAT) in developed nations revolutionised case detection rates. Accordingly, our objectives were to study the microbiological etiology for hospitalised pneumonia patients and the diagnosis of Legionella pneumonia.

    Methods: A prospective, observational single-centre study was conducted where all 504 cases that were consecutively admitted for pneumonia were enrolled. Blood and sputum samples obtained were used to identify pathogens using standard microbiological culture methods. The urine samples collected were tested using the ImmunocatchTMLegionella immunochromatographic (ICT) urine antigen test.

    Results: A microbiological diagnosis was only achieved in 104 cases (20.6%) and a Gram-negative infection predominance was observed. Culture-positive cases required longer hospitalisation (8.46 days versus 5.53 days; P < 0.001) and the higher usage of antipseudomonal antibiotics (23.1% versus 8.3%; P < 0.001). Only 3 cases (0.6%) were diagnosed with Legionella pneumonia.

    Conclusion: The local pathogen distribution is diverse compared to other regions. Culture-negative pneumonia is common and significantly differs from culture-positive pneumonia. Legionella pneumophila serotype 1 is not a common cause of pneumonia and LUAT did not help demystify the cause of culture-negative pneumonia.

    Matched MeSH terms: Reference Standards
  7. Mohammadi A, Karimzadeh S, Jalal SJ, Kamran KV, Shahabi H, Homayouni S, et al.
    Sensors (Basel), 2020 Dec 16;20(24).
    PMID: 33339435 DOI: 10.3390/s20247214
    Digital elevation model (DEM) plays a vital role in hydrological modelling and environmental studies. Many essential layers can be extracted from this land surface information, including slope, aspect, rivers, and curvature. Therefore, DEM quality and accuracy will affect the extracted features and the whole process of modeling. Despite freely available DEMs from various sources, many researchers generate this information for their areas from various observations. Sentinal-1 synthetic aperture radar (SAR) images are among the best Earth observations for DEM generation thanks to their availabilities, high-resolution, and C-band sensitivity to surface structure. This paper presents a comparative study, from a hydrological point of view, on the quality and reliability of the DEMs generated from Sentinel-1 data and DEMs from other sources such as AIRSAR, ALOS-PALSAR, TanDEM-X, and SRTM. To this end, pair of Sentinel-1 data were acquired and processed using the SAR interferometry technique to produce a DEM for two different study areas of a part of the Cameron Highlands, Pahang, Malaysia, a part of Sanandaj, Iran. Based on the estimated linear regression and standard errors, generating DEM from Sentinel-1 did not yield promising results. The river streams for all DEMs were extracted using geospatial analysis tool in a geographic information system (GIS) environment. The results indicated that because of the higher spatial resolution (compared to SRTM and TanDEM-X), more stream orders were delineated from AIRSAR and Sentinel-1 DEMs. Due to the shorter perpendicular baseline, the phase decorrelation in the created DEM resulted in a lot of noise. At the same time, results from ground control points (GCPs) showed that the created DEM from Sentinel-1 is not promising. Therefore, other DEMs' performance, such as 90-meters' TanDEM-X and 30-meters' SRTM, are better than Sentinel-1 DEM (with a better spatial resolution).
    Matched MeSH terms: Reference Standards
  8. Draman R, Yousuf R, Abdul Aziz S, Ding CH, Zainol S, Leong CF
    Indian J Hematol Blood Transfus, 2020 Jan;36(1):112-116.
    PMID: 32174694 DOI: 10.1007/s12288-019-01171-0
    Thawed fresh frozen plasma (FFP) if not used within 6 h, may have to be discarded due to the risk of contamination and uncertainty about its quality. The main objective of this study was to evaluate the levels of coagulation Factor II (FII), Factor VIII (FVIII), fibrinogen and bacterial growth in thawed refrozen FFP. Thirty FFP samples were collected from healthy donors. FFP were thawed in water bath at 37 °C for 20-25 min. Approximately 10 mL of plasma from each FFP unit was tested for FII, FVIII, fibrinogen and sterility. The thawed FFP units were then kept at 4 °C for 6 h before being refrozen and stored at - 20 °C. Two weeks later, the refrozen FFP were thawed again and representative samples were analysed as before. There was a significant decline in the mean FVIII level, from 155.77% to 85.6% at second thaw. The mean FII level increased significantly from 74.9% to 82%, whereas the mean fibrinogen level fell from 3.34g/L to 3.28 g/L, but the decline was not statistically significant. There was no bacterial contamination in all samples at both time points. Refrozen plasma may be considered as an alternative to the storage of thawed unused FFP provided they are kept in a controlled environment to reduce wastage. These thawed refrozen FFP can be used later in bleeding cases like other FFP as the levels of FVIII are still within the standard haematology range (0.5-2 IU/mL) and above the minimal level of 30% coagulation factors required for adequate haemostasis.
    Matched MeSH terms: Reference Standards
  9. Petito LC, McCabe ME, Pool LR, Krefman AE, Perak AM, Marino BS, et al.
    Am J Prev Med, 2024 Feb;66(2):216-225.
    PMID: 37751803 DOI: 10.1016/j.amepre.2023.09.019
    INTRODUCTION: Clinical cardiovascular health is a construct that includes 4 health factors-systolic and diastolic blood pressure, fasting glucose, total cholesterol, and body mass index-which together provide an evidence-based, more holistic view of cardiovascular health risk in adults than each component separately. Currently, no pediatric version of this construct exists. This study sought to develop sex-specific charts of clinical cardiovascular health for age to describe current patterns of clinical cardiovascular health throughout childhood.

    METHODS: Data were used from children and adolescents aged 8-19 years in six pooled childhood cohorts (19,261 participants, collected between 1972 and 2010) to create reference standards for fasting glucose and total cholesterol. Using the models for glucose and cholesterol as well as previously published reference standards for body mass index and blood pressure, clinical cardiovascular health charts were developed. All models were estimated using sex-specific random-effects linear regression, and modeling was performed during 2020-2022.

    RESULTS: Models were created to generate charts with smoothed means, percentiles, and standard deviations of clinical cardiovascular health for each year of childhood. For example, a 10-year-old girl with a body mass index of 16 kg/m2 (30th percentile), blood pressure of 100/60 mm Hg (46th/50th), glucose of 80 mg/dL (31st), and total cholesterol of 160 mg/dL (46th) (lower implies better) would have a clinical cardiovascular health percentile of 62 (higher implies better).

    CONCLUSIONS: Clinical cardiovascular health charts based on pediatric data offer a standardized approach to express clinical cardiovascular health as an age- and sex-standardized percentile for clinicians to assess cardiovascular health in childhood to consider preventive approaches at early ages and proactively optimize lifetime trajectories of cardiovascular health.

    Matched MeSH terms: Reference Standards
  10. Algamili AS, Khir MHM, Dennis JO, Ahmed AY, Alabsi SS, Ba Hashwan SS, et al.
    Nanoscale Res Lett, 2021 Jan 26;16(1):16.
    PMID: 33496852 DOI: 10.1186/s11671-021-03481-7
    Over the last couple of decades, the advancement in Microelectromechanical System (MEMS) devices is highly demanded for integrating the economically miniaturized sensors with fabricating technology. A sensor is a system that detects and responds to multiple physical inputs and converting them into analogue or digital forms. The sensor transforms these variations into a form which can be utilized as a marker to monitor the device variable. MEMS exhibits excellent feasibility in miniaturization sensors due to its small dimension, low power consumption, superior performance, and, batch-fabrication. This article presents the recent developments in standard actuation and sensing mechanisms that can serve MEMS-based devices, which is expected to revolutionize almost many product categories in the current era. The featured principles of actuating, sensing mechanisms and real-life applications have also been discussed. Proper understanding of the actuating and sensing mechanisms for the MEMS-based devices can play a vital role in effective selection for novel and complex application design.
    Matched MeSH terms: Reference Standards
  11. Kho CM, Enche Ab Rahim SK, Ahmad ZA, Abdullah NS
    Mol Neurobiol, 2017 07;54(5):3506-3527.
    PMID: 27189617 DOI: 10.1007/s12035-016-9929-8
    Microdialysis is a sampling technique first introduced in the late 1950s. Although this technique was originally designed to study endogenous compounds in animal brain, it is later modified to be used in other organs. Additionally, microdialysis is not only able to collect unbound concentration of compounds from tissue sites; this technique can also be used to deliver exogenous compounds to a designated area. Due to its versatility, microdialysis technique is widely employed in a number of areas, including biomedical research. However, for most in vivo studies, the concentration of substance obtained directly from the microdialysis technique does not accurately describe the concentration of the substance on-site. In order to relate the results collected from microdialysis to the actual in vivo condition, a calibration method is required. To date, various microdialysis calibration methods have been reported, with each method being capable to provide valuable insights of the technique itself and its applications. This paper aims to provide a critical review on various calibration methods used in microdialysis applications, inclusive of a detailed description of the microdialysis technique itself to start with. It is expected that this article shall review in detail, the various calibration methods employed, present examples of work related to each calibration method including clinical efforts, plus the advantages and disadvantages of each of the methods.
    Matched MeSH terms: Reference Standards
  12. Ruhana Hassan, Nur Fatimah Mohd Azizi, Muhammad Amirul Arib Md Adzhar, Mohd Izwan Zulaini Abdul Gani, Rambli Ahmad, Charles Leh Moi Ung
    MyJurnal
    This study documented details of the dentitions, skulls and other skeletal remains of Crocodylus porosus and Tomistoma schlegelii, from western part of Sarawak, Malaysian Borneo. The remains of both reptiles were exhumed, followed by standard cleaning procedures and then detail morphological assessments were carried out accordingly. Both species show similar structure of vertebral columns, but T. schlegelii has the following unique structures: a long and narrower snout, D-shaped eye sockets, long and sharp pointed protruding quadratojugal bones, straight maxillae and dentary, a smooth surfaced skull, elongated triangular suborbital fenestrae, round shaped internal nares and visible supraoccipital from a dorsal view. C. porosus has heterodont dentition with blunt-pointed and irregular size of teeth whereas T. schlegelii has almost homodont dentition with sharp and similar size teeth. This is the first collection of teeth, skulls and other skeletal remains of both species obtained from Sarawak, and the materials have been used regularly to educate the public through science exhibitions, hoping they will spark the interests of young budding scientists to be involved in wildlife taphonomic studies in the future.
    Matched MeSH terms: Reference Standards
  13. Johnson, D., Badi’ah, Y.
    MyJurnal
    Introduction Clinical guidelines recommend the use of a single antipsychotic drug at standard doses. In clinical practise high-dose and combined antipsychotics are common. Methods A clinical audit of antipsychotic prescribing for patients in a forensic ward in a Malaysian hospital was undertaken using Prescribing Observatory for Mental Health-UK (POMH) standards and compared to POMH data. Results The level of high dose prescribing between Malaysian and the UK was comparable. There were low levels of the use of ‘as required’ (PRN) medication in Malaysia compared to the UK. The use of combined prescribing was more common in Malaysia. Discussion Levels of high dose antipsychotic prescribing are unsatisfactory across both jurisdictions. Specific quality improvements in Malaysia need to centre on the use of combination antipsychotics.
    Matched MeSH terms: Reference Standards
  14. Awosolu OB, Yahaya ZS, Farah Haziqah MT, Simon-Oke IA, Fakunle C
    Heliyon, 2021 Jan;7(1):e05975.
    PMID: 33521357 DOI: 10.1016/j.heliyon.2021.e05975
    Background: Malaria is a severe global public health challenge that causes significant morbidity and mortality worldwide, particularly in sub-Saharan Africa. This study was designed to determine the prevalence, parasite density, and risk factors associated with malaria infection transmission among residents of two urban communities of Ibadan, southwestern Nigeria.

    Materials and methods: A cross-sectional hospital-based study was carried out on 300 participants. Blood samples were obtained. Thick and thin blood films were prepared and viewed using the standard parasitological technique of microscopy. Moreover, data on sociodemographic and environmental variables were obtained using a pre-tested standard questionnaire.

    Results: Of the 300 participants examined, a total of 165 (55.0%) were found positive for Plasmodium falciparum with a mean (S.D) parasite density of 1814.70 (1829.117) parasite/μL of blood. The prevalence and parasite density of malaria infection vary significantly (P < 0.05) with age group. Children <5 years old were more likely to have malaria infection and high parasite densities than adults (p < 0.05). Similarly, in relation to gender, males significantly (P < 0.05) had a higher prevalence (60.2%) and mean (S.D) parasite density of malaria infection [2157.73 (1659.570) parasite/μL of blood] compared to females. Additionally, those without formal education had the highest prevalence (73.0%) and mean (S.D) parasite density of infection [2626.96 (2442.195) parasite/μL of blood]. The bivariate logistic regression analysis shows that age group 6-10 (Crude Odds Ratio, COR 0.066, 95% CI: 0.007-0.635), presence of streams/rivers (COR 0.225, 95% CI: 0.103-0.492), distance from streams/rivers within ≤1 km (COR 0.283, 95% CI: 0.122-0.654) and travel to rural area (COR 4.689, 95% CI: 2.430-9.049) were the significant risk factors.

    Conclusions: Malaria infection is prevalent in the study area and was greatly influenced by traveling activities from the rural areas to urban centers and vice versa. Multifaceted and integrated control strategy should be adopted. Health education on mosquito prevention and chemoprophylaxis before and during travel to rural areas are essential.

    Matched MeSH terms: Reference Standards
  15. Muhammad Danial Abu Hasan, Zair Asrar Ahmad, Mohd Salman Leong, Lim, Meng Hee
    MyJurnal
    The present paper deals with the novel approach for clustering using the image feature of stabilization diagram for automated operational modal analysis in parametric model which is stochastic subspace identification (SSI)-COV. The evolution of automated operational modal analysis (OMA) is not an easy task, since traditional methods of modal analysis require a large amount of intervention by an expert user. The stabilization diagram and clustering tools are introduced to autonomously distinguish physical poles from noise (spurious) poles which can neglect any user interaction. However, the existing clustering algorithms require at least one user-defined parameter, the maximum within-cluster distance between representations of the same physical mode from different system orders and the supplementary adaptive approaches have to be employed to optimize the selection of cluster validation criteria which will lead to high demanding computational effort. The developed image clustering process is based on the input image of the stabilization diagram that has been generated and displayed separately into a certain interval frequency. and standardized image features in MATLAB was applied to extract the image features of each generated image of stabilisation diagrams. Then, the generated image feature extraction of stabilization diagrams was used to plot image clustering diagram and fixed defined threshold was set for the physical modes classification. The application of image clustering has proven to provide a reliable output results which can effectively identify physical modes in stabilization diagrams using image feature extraction even for closely spaced modes without the need of any calibration or user-defined parameter at start up and any supplementary adaptive approach for cluster validation criteria.
    Matched MeSH terms: Reference Standards
  16. Chin WK, Thuraisingam AS, Kanagasabapathy S
    Account Res, 2021 May 05.
    PMID: 33857400 DOI: 10.1080/08989621.2021.1917397
    Clinical trials play a critical role in the development of life-enhancing and life-sustaining biomedical advances. It is costly and, regardless of how well-designed and ethically conducted, there are always inherent uncertainties which subsequently expose human participants to the risk of injuries or even death. In Malaysia, compensation for clinical trial-related injury has not been incorporated into standard national regulations or policies. Therefore, when clinical trial-related injuries do occur, such participants cannot be compensated by researchers, and with the absence of specific statutory laws governing trial-related injury within the local legal framework, aggrieved parties need to seek legal redress and can only depend on the existing tort laws. To propose a viable compensation framework, the existing compensation regulations and policies implemented in India and South Africa are analyzed, and their best principles have been recommended. This study proposes the implementation of a no-fault compensation framework in Malaysia which should be disbursed efficiently at minimum administrative cost. This proposed approach should be mandated by the amendment of current laws governing biomedical research and, in the interim, should be adopted voluntarily by research sponsors, institutions and investigators conducting clinical trials in Malaysia.
    Matched MeSH terms: Reference Standards
  17. Tey HY, See HH
    J Chromatogr A, 2021 Jan 04;1635:461731.
    PMID: 33285415 DOI: 10.1016/j.chroma.2020.461731
    Conventional sampling of biological fluids often involves a bulk quantity of samples that are tedious to collect, deliver and process. Miniaturized sampling approaches have emerged as promising tools for sample collection due to numerous advantages such as minute sample size, patient friendliness and ease of shipment. This article reviews the applications and advances of microsampling techniques in therapeutic drug monitoring (TDM), covering the period January 2015 - August 2020. As whole blood is the gold standard sampling matrix for TDM, this article comprehensively highlights the most historical microsampling technique, the dried blood spot (DBS), and its development. Advanced developments of DBS, ranging from various automation DBS, paper spray mass spectrometry (PS-MS), 3D dried blood spheroids and volumetric absorptive paper disc (VAPD) and mini-disc (VAPDmini) are discussed. The volumetric absorptive microsampling (VAMS) approach, which overcomes the hematocrit effect associated with the DBS sample, has been employed in recent TDM. The sample collection and sample preparation details in DBS and VAMS are outlined and summarized. This review also delineates the involvement of other biological fluids (plasma, urine, breast milk and saliva) and their miniaturized dried matrix forms in TDM. Specific features and challenges of each microsampling technique are identified and comparison studies are reviewed.
    Matched MeSH terms: Reference Standards
  18. Semail NF, Noordin SS, Keyon ASA, Waras MN, Saad B, Kamaruzaman S, et al.
    Biomed Chromatogr, 2021 May;35(5):e5050.
    PMID: 33314228 DOI: 10.1002/bmc.5050
    A simple and sensitive preconcentration strategy using sequential electrokinetic and hydrodynamic injection modes in micellar electrokinetic chromatography with diode array detection was developed and applied for the separation and determination of anticancer agent, 5-fluorouracil and its metabolite, 5-fluoro-2'-deoxyuridine, in human plasma. Sequential injection modes with increased analyte loading capacity using the anionic pseudo-stationary phase facilitated collection of the dispersed neutral and charged analytes into narrow zones and improved sensitivity. Several important parameters affecting sample enrichment performance were evaluated and optimized in this study. Under the optimized experimental conditions, 614- and 643-fold and 782- and 803-fold sensitivity improvement were obtained for 5-fluorouracil and its metabolite when compared with normal hydrodynamic and electrokinetic injection, respectively. The method has good linearity (1-1,000 ng/ml) with acceptable coefficient of determination (r2  > 0.993), low limits of detection (0.11-0.14 ng/ml) and satisfactory analyte relative recovery (97.4-99.7%) with relative standard deviations of 4.6-9.3% (n = 6). Validation results as well as the application to analysis of human plasma samples from cancer patients demonstrate the applicability of the proposed method to clinical studies.
    Matched MeSH terms: Reference Standards
  19. Muhammad Danial Abu Hasan, Zair Asrar Ahmad, Mohd Salman Leong, Lim, Meng Hee
    MyJurnal
    This paper presents parameters analysis for the estimated modal damping ratio using a new version of the automated enhanced frequency domain decomposition (AEFDD). The purpose of this study is to provide a better choice of a maximum number of points of time segments and modal assurance criterion (MAC) index number regarding to the variable level of system damping (low and high damped structure) and degree of freedom of the system. According current literature, frequency domain (FD) methods seem to have the problem with providing a correct identification of the modal damping ratio, since the correct estimate of modal damping is still an open problem and often leads to biased estimates. This technique is capable of providing consistent modal parameters estimation, particularly for modal frequencies and mode shapes. As a necessary fundamental condition, the algorithm has been assessed first from computed numerical responses according to random white noise, acting on different shear-type frame structures and corrupted with noise. Results indicate that reducing the value of natural frequencies and modal damping ratios of the modes under analysis demands longer time segments and a high value of the maximum number of points for adequate information on the decaying correlation functions when computing a modal damping ratio. In addition, the results also prove that the MAC index does not significantly affect the results for the low damped system. However, the use of a high MAC index value for the high damped system significantly introduces large error bound and it becomes worse, particularly for the higher modes, as the standard deviation of percentage error increases gradually. Furthermore, the use of a MAC index for a high number of points of time segments significantly increases the standard deviation of the percentage error.
    Matched MeSH terms: Reference Standards
  20. Rassiah P, Ng KH, DeWerd LA, Kunugi K
    Australas Phys Eng Sci Med, 2004 Mar;27(1):25-9.
    PMID: 15156705
    A thermoluminescent dosimetry (TLD) postal dose inter-comparison was carried out amongst radiotherapy centres in Malaysia. The aim of this TLD inter-comparison was to compare the uniformity involved in the measurement of absorbed dose among the participating centres. A set of 5 TLD chips placed within acrylic trays were mailed to all participating centres for irradiation to an absorbed dose to water of 2 Gy. Measurements were made for 6 MV and 60Co photon beams. Results show an agreement of +/- 5% for all but three radiotherapy centres. The ratios of the TLD readings to that of the reference centre are comparable with other national/regional dose inter-comparisons. The importance of a proper ongoing quality assurance program is essential in maintaining the consistency and uniformity of doses delivered.
    Matched MeSH terms: Reference Standards
Filters
Contact Us

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

External Links