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Chloroquine polymeric membrane electrodes: Development and applications

Saad B, Kanapathy K, Ahmad MN, Hussin AH, Ismail Z

Talanta, 1991 Dec;38(12):1399-402.
PMID: 18965315

Three main types of PVC solvent polymeric membrane ion-selective electrodes for chloroquine are described. They are based on three ion-pairing agents namely dipicrylamine (DPA), tetraphenylborate (TPB) or tetrakis(4-chlorophenyl)borate (TCPB) with either dioctylphenyl phosphonate (DOPP) or trioctyl phosphate (TOP) solvent mediator. All electrodes exhibit Nernstian responses, fast dynamic response times and a wide useful pH range. The best all-round electrode is based on TPB and TOP plasticizing solvent mediators with a limit of detection of 7.1 x 10(-6)M and was utilized for the assay of chloroquine in tablets. Direct potentiometric determinations with either the analyte addition method or the normal calibration method gave results comparable to the official method.

Matched MeSH terms: Calibration
Simple and rapid LC-MS/MS method for simultaneous determination of flavoxate and 3-methyl-flavone-8-carboxylic acid in human plasma: Application to a bioequivalence study

Loh GOK, Wong EYL, Tan YTF, Wee HC, Ng RS, Lee CY, et al.

J Pharm Biomed Anal, 2021 Feb 05;194:113758.
PMID: 33248861 DOI: 10.1016/j.jpba.2020.113758

A simple, rapid, sensitive, and reproducible LC-MS/MS method was developed for simultaneous quantification of flavoxate and 3-methyl-flavone-8-carboxylic (MFCA) in human plasma, using diphenhydramine HCl as internal standard (IS). The chromatographic separation was achieved using Agilent Poroshell 120 EC-C18 - Fast LC column (100 × 2.1mmID, 2.7 μm) fitted with UHPLC Guard Poroshell 120 EC-C18 (5 × 2.1 mmID, 2.7 μm). The mobile phase consisted of 0.1 % v/v formic acid and acetonitrile (30:70, v/v) run at a flow rate of 0.40 mL/min. The standard calibration curve was linear over the concentration range of 2.00 - 2,000.31 ng/mL and 240.00 - 24,000.04 ng/mL for flavoxate and MFCA. For flavoxate and MFCA, the within-run precision was 0.81-6.67 % and 1.68-4.37 %, while accuracy was 100.21-108.25 % and 103.99-110.28 %. The between-run precision was 2.01-9.14 % and 2.31-11.11 %, and accuracy was 96.09-103.33 % and 102.37-109.52 %. The extended run precision was 7.78-11.04 % and 2.22-3.33 %, while accuracy was 100.72-101.88 % and 102.34-105.60 %. Flavoxate and MFCA in plasma were stable 4 h at bench top (short term), 24 h in autosampler and instrumentation room (post-preparative), after 7 freeze-thaw cycles, and 89 days in the freezer. Both analytes and IS stock solutions were stable for 31 days when kept at room temperature (25 ± 4 °C) and refrigerated (2-8 °C). The validated method was successfully applied to a bioequivalence study of two flavoxate formulations involving 24 healthy volunteers.

Matched MeSH terms: Calibration
Fulltext Effects of antihypertensive drugs on alveolar bone loss in patients with chronic periodontitis: a retrospective study

AL-Bayaty, F.H., Omar Emad Ibrahim, William, C., Khairuddin, N.A.

Compendium of Oral Science, 2018;5(1):26-36.
MyJurnal

Objective: This retrospective study aims to evaluate the possible effects of antihypertensive drugs on alveolar bone loss in patients with chronic periodontitis. Methods: 50 patients on antihypertensive drugs selected as the experimental group and 50 patients with chronic periodontitis with no known systemic illnesses as control group were randomly selected as the study samples. Orthopantomographs were obtained, calibration and assessment of alveolar bone loss was performed by using the computer software program available in the faculty, through radiographic linear measurement procedure. Premolars, first and second molars of both maxilla and mandible were measured from the most apical point to the cementoenamel junction for mesial and distal aspects in the form of millimetres and percentile of the root length. Data was statistically analyzed using independent t-test and Analysis of Covariance in SPSS Version 23 with significance at P-value, p

Matched MeSH terms: Calibration
Fulltext Comparative Evaluation of pH and In Vitro Cytotoxicity of Zinc Oxide-Ozonated Eugenol and Conventional Zinc Oxide Eugenol as Endodontic Sealers

Ravivarman C, Jeyasenthil A, Ajay R, Nilofernisha N, Karthikeyan R, Rajkumar D

J Pharm Bioallied Sci, 2020 Aug;12(Suppl 1):S73-S77.
PMID: 33149434 DOI: 10.4103/jpbs.JPBS_21_20

Background: Eugenol released from zinc oxide eugenol (ZOE)-based sealants may cause irritation to the periapical tissues and has cytotoxic potential. Ozone therapy has numerous clinical applications with humans because of its bactericidal action, detoxifying effect, stimulation of angiogenesis, and wound-healing capacity. Therefore ozone can be incorporated in ZOE sealer to exploit these properties.
Materials and Methods: Eugenol was ozonated using ozonator machine and the samples were divided into two groups: Group I: zinc oxide eugenol (n = 10) and Group II: zinc oxide-ozonated eugenol (OZOE; n = 10). The pH of the fresh sealer samples and the set samples was measured using calibrated pH meter after predetermined time intervals. Cytotoxicity of the set sealer was evaluated on mouse L929 fibroblasts using cellular metabolic assay.
Results: pH of the samples in Group II was higher when compared to Group I. Group II showed higher cell viability than the Group I.
Conclusion: OZOE sealers can be used as an alternative to the conventional ZOE sealers.

Matched MeSH terms: Calibration
Enantioseparation of ketoconazole and miconazole by capillary electrophoresis and a study on their inclusion interactions with β-cyclodextrin and derivatives

Azhari NR, Yahaya N, Mohd Suah FBM, Prabu S, Yih Hui B, Shahriman MS, et al.

Chirality, 2021 01;33(1):37-50.
PMID: 33197086 DOI: 10.1002/chir.23285

A chiral separation method coupled with capillary electrophoresis (CE) analysis for ketoconazole and miconazole enantiomers using chiral selectors such as β-cyclodextrin (β-CD) and hydroxypropyl-β-CD (HP-β-CD) was developed in this study, which included the optimisation, validation and application of the method on the antifungal cream samples. The formation of inclusion complex between the hosts (β-CD and HP-β-CD) and guests (ketoconazole and miconazole) were compared and analysed using ultraviolet-visible spectrophotometry, nuclear magnetic resonance (NMR) spectroscopy and molecular docking methods. Results from the study showed that in a concentration that ranged between 0.25 and 50 mg L-1 , the linear calibration curves of each enantiomer had a high coefficient of regression (R2 > 0.999), low limit of detection (0.075 mg L-1 ) and low limit of quantification (0.25 mg L-1 ). The relative standard deviation (RSD) of the intraday and interday analyses ranged from 0.79% to 8.01% and 3.30% to 11.43%, respectively, while the recoveries ranged from 82.0% to 105.7% (RSD < 7%, n = 3). The most probable structure of the inclusion complexes was proposed based on the findings from the molecular docking studies conducted using the PatchDock server.

Matched MeSH terms: Calibration
Fulltext A New Sensor for Methyl Paraben Using an Electrode Made of a Cellulose Nanocrystal-Reduced Graphene Oxide Nanocomposite

Wan Khalid WEF, Mat Arip MN, Jasmani L, Lee YH

Sensors (Basel), 2019 Jun 18;19(12).
PMID: 31216625 DOI: 10.3390/s19122726

A new cellulose nanocrystal-reduced graphene oxide (CNC-rGO) nanocomposite was successfully used for mediatorless electrochemical sensing of methyl paraben (MP). Fourier-transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FESEM) studies confirmed the formation of the CNC-rGO nanocomposite. Cyclic voltammetry (CV) studies of the nanocomposite showed quasi-reversible redox behavior. Differential pulse voltammetry (DPV) was employed for the sensor optimization. Under optimized conditions, the sensor demonstrated a linear calibration curve in the range of 2 × 10-4-9 × 10-4 M with a limit of detection (LOD) of 1 × 10-4 M. The MP sensor showed good reproducibility with a relative standard deviation (RSD) of about 8.20%. The sensor also exhibited good stability and repeatability toward MP determinations. Analysis of MP in cream samples showed recovery percentages between 83% and 106%. Advantages of this sensor are the possibility for the determination of higher concentrations of MP when compared with most other reported sensors for MP. The CNC-rGO nanocomposite-based sensor also depicted good reproducibility and reusability compared to the rGO-based sensor. Furthermore, the CNC-rGO nanocomposite sensor showed good selectivity toward MP with little interference from easily oxidizable species such as ascorbic acid.

Matched MeSH terms: Calibration
Expansion and systematics redefinition of the most threatened freshwater mussel family, the Margaritiferidae

Lopes-Lima M, Bolotov IN, Do VT, Aldridge DC, Fonseca MM, Gan HM, et al.

Mol Phylogenet Evol, 2018 10;127:98-118.
PMID: 29729933 DOI: 10.1016/j.ympev.2018.04.041

Two Unionida (freshwater mussel) families are present in the Northern Hemisphere; the Margaritiferidae, representing the most threatened of unionid families, and the Unionidae, which include several genera of unresolved taxonomic placement. The recent reassignment of the poorly studied Lamprotula rochechouartii from the Unionidae to the Margaritiferidae motivated a new search for other potential species of margaritiferids from members of Gibbosula and Lamprotula. Based on molecular and morphological analyses conducted on newly collected specimens from Vietnam, we here assign Gibbosula crassa to the Margaritiferidae. Additionally, we reanalyzed all diagnostic characteristics of the Margaritiferidae and examined museum specimens of Lamprotula and Gibbosula. As a result, two additional species are also moved to the Margaritiferidae, i.e. Gibbosula confragosa and Gibbosula polysticta. We performed a robust five marker phylogeny with all available margaritiferid species and discuss the taxonomy within the family. The present phylogeny reveals the division of Margaritiferidae into four ancient clades with distinct morphological, biogeographical and ecological characteristics that justify the division of the Margaritiferidae into two subfamilies (Gibbosulinae and Margaritiferinae) and four genera (Gibbosula, Cumberlandia, Margaritifera, and Pseudunio). The systematics of the Margaritiferidae family is re-defined as well as their distribution, potential origin and main biogeographic patterns.

Matched MeSH terms: Calibration
Fulltext Smartphone-based laser glucometer for non-invasive measurement of glucose level of diabetic patients

Tamrin, K.F., Adilah, A.N., Hamdi, M.M., Jong, R.P.

Borneo International Journal, 2018;1(1):27-32.
MyJurnal

A glucose meter (or glucometer) is a medical device for determining the approximate concentration of glucose in the
blood by pricking a finger to draw blood sample using a sharp needle. However, diabetic patient has quite slow level in
wound healing process which causes their fingers constantly in a state of wounded and exposed to bacteria. More
importantly, two main factors for the weakness of invasive technique is a painful process and cost often because constant
monitoring of glucose level is very expensive. The main objective of this research is to design and develop a non-invasive
optical measuring technique to measure body glucose level automatically and painlessly using a laser pointer and a
smartphone. Images captured by the smartphone is analysed using a Matlab software to determine the refractive index of
the urine sample. Calibration of the system is performed by correlating the results with that of the glucometer. Both
results compare well with R-squared value of 92.9%. The system can be potentially used for remote health and patient
monitoring.

Matched MeSH terms: Calibration
Prognostic factors and nomogram for survival prediction in patients with primary pulmonary lymphoma: a SEER population-based study

Low SK, Zayan AH, Istanbuly O, Nguyen Tran MD, Ebied A, Mohamed Tawfik G, et al.

Leuk Lymphoma, 2019 12;60(14):3406-3416.
PMID: 31322026 DOI: 10.1080/10428194.2019.1633636

Primary pulmonary lymphomas (PPLs) are rare lymphoproliferative malignancies arising from the lungs. The prognostic factors and optimal management of PPL have not been clearly defined due to its rarity. This study sought to characterize the significant prognostic factors and develop a validated nomogram for individualized prediction of survival outcomes in patients with PPL. A total of 2325 patients diagnosed with PPL between 1983 and 2010 were identified using the Surveillance, Epidemiology, and End Results (SEER) database. Older age at diagnosis, males, Hispanic race, non-marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue histology, Ann Arbor stage IV were significantly associated with worse OS on multivariable analysis. All treatment modalities, including chemotherapy, surgery, and radiotherapy were independent predictors of survival on univariable analysis. The nomogram built demonstrated good discriminative ability and calibration, with the C-index of 0.690 and 0.730 in the training and validation cohorts, respectively.

Matched MeSH terms: Calibration
Nano-silica embedded polydimethylsiloxane on interdigitated sensor as adhesive polymer for detecting lung cancer mutation

Abulaiti A, Salai A, Sun X, Yibulayin W, Gao Y, Gopinath SCB, et al.

Biotechnol Appl Biochem, 2021 Feb 12.
PMID: 33576539 DOI: 10.1002/bab.2122

Non-small cell lung cancer (NSCLC) incited by epidermal growth factor receptor (EGFR) mutation makes up ∼85% of lung cancer diagnosed and death cases worldwide. The presented study introduced an alternative approach in detecting EGFR mutation using nano-silica integrated with polydimethylsiloxane (PDMS) polymer on interdigitated electrode (IDE) sensor. A 400 μm gap-sized aluminum IDE was modified with nano-polymer layer, which was made up of silica nanoparticles and PDMS polymer. IDE and PDMS-coated IDE (PDMS/IDE) were imaged using electron microscopes that reveals its smooth and ideal sensor morphology. The nano-silica-integrated PDMS/IDE surface was immobilized with EGFR probe and target to specify the lung cancer detection. The sensor specificity was justified through the insignificant current readouts with one-base mismatch and noncomplementary targets. The sensitivity of nano-silica-integrated PDMS/IDE was examined with mutant target spiked in human serum, where the resulting current affirms the detection of EGFR mutation. Based on the slope of the calibration curve, the sensitivity of nano-silica-integrated PDMS/IDE was 2.24E-9 A M-1 . The sensor recognizes EGFR mutation lowest at 1 aM complementary mutant target; however, the detection limit obtained based on 3σ calculation is 10 aM with regression value of 0.97.

Matched MeSH terms: Calibration
Lead contamination in Eugenia dyeriana herbal preparations from different commercial sources in Malaysia

Ang HH

Food Chem Toxicol, 2008 Jun;46(6):1969-75.
PMID: 18328612 DOI: 10.1016/j.fct.2008.01.037

The Drug Control Authority (DCA) of Malaysia implemented the phase three registration of traditional medicines on 1 January, 1992. A total of 100 products in various pharmaceutical dosage forms of a herbal preparation, containing Eugenia dyeriana, either single or combined preparations (more than one medicinal plant), were analyzed for the presence of lead contamination, using atomic absorption spectrophotometry. These samples were bought from different commercial sources in the Malaysian market, after performing a simple random sampling. Results showed that 22% of the above products failed to comply with the quality requirement for traditional medicines in Malaysia. Although this study showed that 78% of the products fully complied with the quality requirement for traditional medicines in Malaysia pertaining to lead, however, they cannot be assumed safe from lead contamination because of batch-to-batch inconsistency.

Matched MeSH terms: Calibration
Characterization of soy-lignin bonded Rhizophora spp. particleboard as substitute phantom material for radiation dosimetric studies - Investigation of CT number, mass attenuation coefficient and effective atomic number

Zuber SH, Hashikin NAA, Mohd Yusof MF, Aziz MZA, Hashim R

Appl Radiat Isot, 2021 Apr;170:109601.
PMID: 33515930 DOI: 10.1016/j.apradiso.2021.109601

Experimental particleboards are made from Rhizophora spp. wood trunk with three different percentages of lignin and soy flour (0%, 6% and 12%) as adhesives. The objective was to investigate the equivalence of Rhizophora spp. particleboard as phantom material with human soft tissue using Computed Tomography (CT) number. The linear and mass attenuation coefficient of Rhizophora spp. particleboard at low energy range was also explored using X-ray Fluorescence (XRF) configuration technique. Further characterization of the particleboard was performed to determine the effective atomic number, Zeff using Energy Dispersive X-Ray (EDX) method. Adhesive-bonded Rhizophora spp. particleboard showed close similarities with water, based on the average CT numbers, electron density calibration curve and the analysis of CT density profile, compared to the binderless particleboard. The effective atomic number obtained from the study indicated that the attenuation properties of all the particleboards at different percentages of adhesives were almost similar to water. The mass attenuation coefficient calculated from XRF configuration technique showed good agreement with water from XCOM database, suggesting its potential as phantom material for radiation study.

Matched MeSH terms: Calibration
Fulltext Projected Streamflow in the Kurau River Basin of Western Malaysia under Future Climate Scenarios

Adib MNM, Rowshon MK, Mojid MA, Habibu I

Sci Rep, 2020 05 20;10(1):8336.
PMID: 32433561 DOI: 10.1038/s41598-020-65114-w

Climate change-induced spatial and temporal variability of stremflow has significant implications for hydrological processes and water supplies at basin scale. This study investigated the impacts of climate change on streamflow of the Kurau River Basin in Malaysia using a Climate-Smart Decision Support System (CSDSS) to predict future climate sequences. For this, we used 25 reliazations consisting from 10 Global Climate Models (GCMs) and three IPCC Representative Concentration Pathways (RCP4.5, RCP6.0 and RCP8.5). The generated climate sequences were used as input to Soil and Water Assessment Tool (SWAT) to simulate projected changes in hydrological processes in the basin over the period 2021-2080. The model performed fairly well for the Kurau River Basin, with coefficient of determination (R2), Nash-Sutcliffe Efficiency (NSE) and Percent Bias (PBIAS) of 0.65, 0.65 and -3.0, respectively for calibration period (1981-1998) and 0.60, 0.59 and -4.6, respectively for validation period (1996-2005). Future projections over 2021-2080 period show an increase in rainfall during August to January (relatively wet season, called the main irrigation season) but a decrease in rainfall during February to July (relatively dry season, called the off season). Temperature projections show increase in both the maximum and minimum temperatures under the three RCP scenarios, with a maximum increase of 2.5 °C by 2021-2080 relative to baseline period of 1976-2005 under RCP8.5 scenario. The model predicted reduced streamflow under all RCP scenarios compared to the baseline period. Compared to 2021-2050 period, the projected streamflow will be higher during 2051-2080 period by 1.5 m3/s except in February for RCP8.5. The highest streamflow is predicted during August to December for both future periods under RCP8.5. The seasonal changes in streamflow range between -2.8% and -4.3% during the off season, and between 0% (nil) and -3.8% during the main season. The assessment of the impacts of climatic variabilities on the available water resources is necessary to identify adaptation strategies. It is supposed that such assessment on the Kurau River Basin under changing climate would improve operation policy for the Bukit Merah reservoir located at downstream of the basin. Thus, the predicted streamflow of the basin would be of importance to quantify potential impacts of climate change on the Bukit Merah reservoir and to determine the best possible operational strategies for irrigation release.

Matched MeSH terms: Calibration
Fulltext Estimation of Caffeine Content in Coffee of Malaysian Market Using Fourier Transform Infrared (FTIR) Spectroscopy

Francis Davin Nyoro, Siong Fong Sim, Amelia Laccy Jeffrey Kimura

Trends in Undergraduate Research, 2018;1(1):0-0.
MyJurnal

This study reports the caffeine content in seven locally available coffee. The caffeine was extracted with chloroform and analysed using Fourier Transform Infrared (FTIR). The method reports an average recovery of 101% with the limit of determination established at 0.1%. The absorption band at 1654 cm-1 was used to construct the calibration curve for quantification of caffeine where the regression was fitted with satisfactory linearity. An average of 0.55% of caffeine was detected in the seven coffee products with Arabica coffee demonstrating lower caffeine concentration. The study evidenced that caffeine content in coffee is determined by the coffee types. The caffeine content found in the local coffee products was relatively lower likely due to the solvent types, extraction procedure and analytical method used.

Matched MeSH terms: Calibration
Fulltext Performance of dental undergraduate students using international caries detection and assessment system (icdas)

Sanus,M,A,, Nordin,M,A,, Rusli,M,R,, Mohamed,Z,N,h,

Compendium of Oral Science, 2020;7(1):13-19.
MyJurnal

Abstract
Objectives: This study aimed to assess intra- and inter-examiner reliability of International Caries Detection
and Assessment System (ICDAS) and modified epidemiology ICDAS (MOD) code by undergraduate dental
students with different clinical experiences.
Methods: A total of 150 dental undergraduate students with varying clinical experiences (0, 1 and 2 years of
clinical experience) were recruited. Participants received training through a theoretical lecture on ICDAS criteria
by an experienced National Benchmark Group (NBG) examiner and underwent e-learning program prior to
ICDAS calibration. Visual examination on extracted permanent teeth (N= 45) with different location and stages
of caries progression ranging from ICDAS scores 0 to 6, was performed using the ICDAS criteria. The
assessments were repeated after one hour. The data were analysed to evaluate inter-examiner and
intra-examiner reliability in the form of kappa scores using SPSS 23 Software.
Results: Mean kappa values for intra- and inter-examiner reliability for ICDAS code, were between 0.41 to
0.60, and 0.61 to 0.80 respectively. For MOD code, mean kappa values for intra- and inter-examiner reliability
were between 0.61 to 0.80. Good intra-examiner agreement (>0.61) was observed in both ICDAS and MOD
code for all groups.
Conclusion: All students performed similar agreement, therefore, clinical experience within 2 years does not
influence the performance of visual inspection in detecting caries using ICDAS. The results of the study shows
that ICDAS and modified epidemiology ICDAS codes has good reproducibility and is feasible to be used as a
tool in clinical practice as well as patient education.

Matched MeSH terms: Calibration
Repeat analysis of intraoral digital imaging performed by undergraduate students using a complementary metal oxide semiconductor sensor: An institutional case study

Yusof MYPM, Rahman NLA, Asri AAA, Othman NI, Wan Mokhtar I

Imaging Sci Dent, 2017 Dec;47(4):233-239.
PMID: 29279822 DOI: 10.5624/isd.2017.47.4.233

Purpose: This study was performed to quantify the repeat rate of imaging acquisitions based on different clinical examinations, and to assess the prevalence of error types in intraoral bitewing and periapical imaging using a digital complementary metal-oxide-semiconductor (CMOS) intraoral sensor.
Materials and Methods: A total of 8,030 intraoral images were retrospectively collected from 3 groups of undergraduate clinical dental students. The type of examination, stage of the procedure, and reasons for repetition were analysed and recorded. The repeat rate was calculated as the total number of repeated images divided by the total number of examinations. The weighted Cohen's kappa for inter- and intra-observer agreement was used after calibration and prior to image analysis.
Results: The overall repeat rate on intraoral periapical images was 34.4%. A total of 1,978 repeated periapical images were from endodontic assessment, which included working length estimation (WLE), trial gutta-percha (tGP), obturation, and removal of gutta-percha (rGP). In the endodontic imaging, the highest repeat rate was from WLE (51.9%) followed by tGP (48.5%), obturation (42.2%), and rGP (35.6%). In bitewing images, the repeat rate was 15.1% and poor angulation was identified as the most common cause of error. A substantial level of intra- and interobserver agreement was achieved.
Conclusion: The repeat rates in this study were relatively high, especially for certain clinical procedures, warranting training in optimization techniques and radiation protection. Repeat analysis should be performed from time to time to enhance quality assurance and hence deliver high-quality health services to patients.

Matched MeSH terms: Calibration
Fulltext A custom made phantom for dosimetric audit and quality assurance of three-dimensional conformal radiotherapy

Radaideh, K.M., Matalqah, L.M., Tajuddin, A.A., Lee Luen, F.W., Bauk, S., Abdel Munem, E.M.E

Jurnal Sains Nuklear Malaysia, 2012;24(1):0-0.
MyJurnal

The ultimate check of the actual dose delivered to a patient in radiotherapy can be achieved by using dosimetric measurements. The aims of this study were to develop and evaluate a custom handmade head and neck phantom for evaluation of Three-Dimensional Conformal Radiation Therapy (3D-CRT) dose planning and delivery. A phantom of head and neck region of a medium built male patient with nasopharyngeal cancer was constructed from Perspex material. Primary and secondary Planning Target Volume (PTV) and twelve Organs at Risk (OAR) were delineated using Treatment Planning System (TPS) guided by computed tomography printout transverse images. One hundred and seven (107) holes distributed among the organs were loaded with Rod-shaped Thermoluminescent dosimeters (LiF:Mg,Ti TLDs) after common and individual calibration. Head and neck phantom was imaged, planned and irradiated conformally (3D-CRT) by linear accelerator (LINAC Siemens Artiste). The planned predicted doses by TPS at PTV and OAR regions were obtained and compared with the TLD measured doses using the phantom. Repeated TLD measurements were reproducible with a percent standard deviation of < 3.5%. Moreover, the average of dose discrepancies between TLDs reading and TPS predicted doses were found to be < 5.3%. The phantom’s preliminary results have proved to be a valuable tool for 3D-CRT treatment dose verification.

Matched MeSH terms: Calibration
Magnetized graphene layers synthesized on the carbon nanofibers as novel adsorbent for the extraction of polycyclic aromatic hydrocarbons from environmental water samples

Rezvani-Eivari M, Amiri A, Baghayeri M, Ghaemi F

J Chromatogr A, 2016 Aug 16.
PMID: 27578405 DOI: 10.1016/j.chroma.2016.08.034

The application of magnetized graphene (G) layers synthesized on the carbon nanofibers (CNFs) (m-G/CNF) was investigated as novel adsorbent for the magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) in water samples followed by gas chromatography-flame ionization detector (GC-FID). Six important parameters, affecting the extraction efficiency of PAHs, including: amount of adsorbent, adsorption and desorption times, type and volume of the eluent solvent and salt content of the sample were evaluated. The optimum extraction conditions were obtained as: 5min for extraction time, 20mg for sorbent amount, dichloromethane as desorption solvent, 1mL for desorption solvent volume, 5min for desorption time and 15% (w/v) for NaCl concentration. Good performance data were obtained at the optimized conditions. The calibration curves were linear over the concentration ranges from 0.012 to 100ngmL(-1) with correlation coefficients (r) between 0.9950 and 0.9967 for all the analytes. The limits of detection (LODs, S/N=3) of the proposed method for the studied PAHs were 0.004-0.03ngmL(-1). The relative standard deviations (RSDs) for five replicates at two concentration levels (0.1 and 50ngmL(-1)) of PAHs were ranged from 3.4 to 5.7%. Appropriate relative recovery values, in the range of 95.5-99.9%, were also obtained for the real water sample analysis.

Matched MeSH terms: Calibration
Fulltext Ascorbic acid quantification in Benincasa hispida fruit extracted using different solvents

Fatariah, Z., Tengku Zulkhairuazha, T.Y., Wan Rosli, W.I.

International Food Research Journal, 2015;22(1):208-212.
MyJurnal

Ascorbic acid or vitamin C is mostly found in natural products such as fruits and vegetables. High performance liquid chromatography (HPLC) method has been developed and validated to compare the ascorbic acid content in Benincasa hispida (Bh) fruit extract with three different extraction solvents; i) 3% metaphosphoric acid, ii) 3% citric acid and iii) distilled water. The compound has been detected and quantified by the use of HPLC coupled with UV-Vis detector. The amount of ascorbic acid detected in Bh fruit extract prepared with different extraction solvents; 3% metaphosphoric acid, 3% citric acid and distilled water were 13.18, 7.91 and 9.42 mg/100g respectively. Total run time was 6 min and the retention time was 2.60 min. Calibration curve was linear with the concentration range 1.00 – 16.00 μg/ml. Limits of detection was 0.24 μg/ml, limit of quantification was 0.81 μg/ml and recovery was 93.52%. The result showed ascorbic acid content is higher in Bh fruit extract with 3% metaphosphoric acid, followed by extract with distilled water and 3% citric acid. Thus, Bh is another novel fruit/ vegetable potentially used as food ingredient as it contains a good source of ascorbic acid that can be good for one’s health.

Matched MeSH terms: Calibration
"Edge-on" MOSkin detector for stereotactic beam measurement and verification

Jong WL, Ung NM, Vannyat A, Jamalludin Z, Rosenfeld A, Wong JH

Phys Med, 2017 Jan;33:127-135.
PMID: 28089106 DOI: 10.1016/j.ejmp.2016.12.020

Dosimetry in small radiation field is challenging and complicated because of dose volume averaging and beam perturbations in a detector. We evaluated the suitability of the "Edge-on" MOSkin (MOSFET) detector in small radiation field measurement. We also tested the feasibility for dosimetric verification in stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT). "Edge-on" MOSkin detector was calibrated and the reproducibility and linearity were determined. Lateral dose profiles and output factors were measured using the "Edge-on" MOSkin detector, ionization chamber, SRS diode and EBT2 film. Dosimetric verification was carried out on two SRS and five SRT plans. In dose profile measurements, the "Edge-on" MOSkin measurements concurred with EBT2 film measurements. It showed full width at half maximum of the dose profile with average difference of 0.11mm and penumbral width with difference of ±0.2mm for all SRS cones as compared to EBT2 film measurement. For output factor measurements, a 1.1% difference was observed between the "Edge-on" MOSkin detector and EBT2 film for 4mm SRS cone. The "Edge-on" MOSkin detector provided reproducible measurements for dose verification in real-time. The measured doses concurred with the calculated dose for SRS (within 1%) and SRT (within 3%). A set of output correction factors for the "Edge-on" MOSkin detector for small radiation fields were derived from EBT2 film measurement and presented. This study showed that the "Edge-on" MOSkin detector is a suitable tool for dose verification in small radiation field.

Matched MeSH terms: Calibration

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