Displaying publications 1 - 20 of 87 in total

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  1. Chen Wong Keong, Yusri Yusof
    MyJurnal
    Computer technology has become a very important element in an advanced manufacturing system. The good and systematic data model for the exchange of manufacturing information between different stages of development of product life cycle is paramount to ensure the product is manufactured and delivered to the market successfully. As a result, ISO 10303, an international standard, or well known as Standard for Exchange of Product Model Data (STEP) is not just for providing a neutral data format within the heterogenous CAD systems, its functionality has extended to the whole life cycle of product. STEP Part 21 is the first implementation method from EXPRESS modelling language and implemented successfully as neutral product data to integrate heterogeneous CAD platform. However, this CAD STEP Part21 text file is hardly to be applied in manufacturing processes since it consists of purely geometrical and topological data. In this research, a nonprocedural approach is presented to translate the EXPRESS language model of STEP CAD data into a new product database system model. A new nonprocedural approach of data enrichment and automated machining feature recognition is proposed and implemented on this newly developed product database system and provide a solution for the interrelated tasks of automated machining feature recognition: (1) extraction of geometrical feature from STEP CAD model data of the part (2) formation of part representation suitable for form feature identification (3) matching of form features. This paper proves the validity of this newly developed product database system by translating STEP Part21 file from a commercial CAD system to database system format, data enrichment, performing automated machining feature recognition and lastly generating STEP standard data according to AP224 for supporting STEP based process planning and manufacturing applications.
  2. Irfan Mohamad, Yusri Musa, M.
    MyJurnal
    Tracheocutaneous fistula (TCF) is a known complication of tracheostomy. It can cause problems such as saliva leak, predispose to infection from external skin into respiratory tract and cosmetically not acceptable. Treatment of the underlying infection is paramount important. Persistence of tract after sufficient duration of observation period should be surgically treated. Cases reported in the literature are mainly regarding paediatric TCF and the procedures are usually done under general anesthesia. We describe a case of surgical treatment of an adult TCF which was done under local anaesthesia.
  3. Sayed, I. S., Yusri, N. H.
    MyJurnal
    In radiography, radiation workers are responsible to protect patients and their caregivers from adverse effects of X-rays during diagnostic procedures. The X-ray examination rooms are designated as controlled areas where only authorised persons are allowed to enter. However, sometimes radiographers allow next in-line patients’ and caregivers in X-ray examination room and ask them to stand behind the mobile lead shielding when exposure is on. The objectives of this study were to determine the amount of scatter radiation dose at different heights with respect to the floor in the X-ray examination room and to educate and increase the awareness of radiation workers about the scattered radiation in minimizing the unnecessary radiation dose to patient’s caregivers. Siemens Multix Top X-ray system was used. Kyoto Kagaku PBU-50 whole body phantom was scanned. The phantom (torso) was positioned for anteroposterior (AP) lumbar projection on the examination table. The nanoDot OSLDs were fixed behind the lead shielding at different heights (120, 130, 140, 150, 160 and 170 cm) with respect to the floor 2.5 meters away from the central ray of X-ray beam. The phantom was exposed using different tube voltages 68 kVp, 79 kVp and 90 kVp at a constant tube current of 32 mAs fixing a 100 cm source to image distance (SID). Scatter radiation doses measured at different heights were different for each exposure. The highest scattered radiation dose measured was 6.4 mGy at 130 cm height for 79 kVp exposure. In conclusion the measured scattered radiation doses were within the acceptable annual dose limits as recommended by NCRP 116 and ICRP 103 for patient caregiver. However, a smallest amount of radiation dose may increase the risk of cancer. Thus, the negligence must not be overlooked because it exposes the caregiver to unnecessary radiation.
  4. Nik Azlan, N.M., Muhammad Yusri, Y.
    Medicine & Health, 2019;14(1):44-52.
    MyJurnal
    Door to needle (DTN) time for thrombolysis in the Emergency Department, Universiti Kebangsaan Malaysia Medical Centre (ED, UKMMC) is an indicator that can reduce mortality and morbidity of patients with ST Elevation Myocardial Infarction (STEMI). This study was conducted to determine factors that influence DTN time for acute ST Elevation Myocardial Infarction (STEMI) and whether it has achieved the recommended time of 30 minutes. A cross-sectional study was conducted among patients diagnosed with acute STEMI and thrombolysed in ED, UKMMC from June 2016 until March 2017. A data collection sheet was used to collect patient’s demographic data and clinical data which included time of arrival to ED, time of initial electrocardiogram (ECG), time of drug preparation and time of thrombolytic delivery to the patient. A total of 98 patients were included in this study. Majority of patients (77.6%) were thrombolysed more than 30 minutes following ED arrival. Mean DTN in ED, UKKMC was 59.28 + 36.01 minutes. The mean door to ECG time was 7.19 + 8.08 minutes and the mean drug preparation time was 9.86 + 7.51 minutes. Out of 76 (77.6%) patients that were thrombolysed after 30 minutes of ED arrival, 59.2% (n=45) were due to multiple disciplinary referral. Other factors were delay in performing initial ECG 19.8% (n=15), incorrect initial ECG interpretation 9.2% (n=7) and unavoidable need for prior resuscitation 9.2% (n=7). As a conclusion this study showed that there was an unacceptable delay in hospital thrombolysis for acute STEMI.
  5. Kayode JS, Yusup Y
    Data Brief, 2018 Aug;19:798-803.
    PMID: 29900375 DOI: 10.1016/j.dib.2018.05.090
    A secondary dataset was generated from the Euldph-λ semi-automatic Algorithm, (ESA) developed to automatically computes various depths to the magnetic anomalies using a primary data set from gridded aeromagnetic data obtained in the study area. Euler Deconvolution techniques, (EDT), was adopted in the identification and definition of the magnetic anomaly source rocks in the study area. The aim is to use the straightforward technique to pinpoint magnetic anomalies at a depth which substantiate mineralization potential of the area. The ESA was integrated with the imaging function of Oasis Montaj 2014 source parameter from Geosoft® Inc. From the data, it could be summarized that similar tectonic processes during the deformation and metamorphic activities, the subsurface structures of the study area produce corresponding trending form.
  6. Irfan M, Shahid H, Yusri MM, Venkatesh RN
    Med J Malaysia, 2011 Jun;66(2):150-1.
    PMID: 22106700 MyJurnal
    Schwannoma in the head and neck region is very rare. The tumour occurring in the intraparotid facial nerve is even rarer. A patient presenting with a parotid swelling with facial nerve paralysis is not pathognomonic of a facial nerve schwannoma. However it may occur because enlargement of the parotid, by any kind of tumour especially a malignant one can cause facial nerve paralysis. We report a case of an intraparotid facial nerve schwannoma, in a patient who presented with parotid enlargement and facial nerve paralysis.
  7. PEI YING LEE, YUSRI YUSOF, MELISSA BEATA MARTIN
    MyJurnal
    This study focuses on the parasites in Dascyllus trimaculatus fish in Bidong Island. Though D. trimaculatus is a common reef fish, there is lack on parasites studies of this fish in Malaysia. The objectives of this study are to identify metazoan parasites and analyse the prevalence and mean intensity the parasites in D. trimaculatus. Sampling was randomly conducted on a coral colony of 100 meters within a 15m depth at Pantai Pasir Cina,BidongIsland.ThisresearchresultedintheidentificationofacopepodLernaeocera branchialis and a nematode from the family Camallanidae. The copepods collected in this study infected 20 out of 42 D. trimaculatus specimens, whereas the nematode-like parasites collected infected 18 of out of 42 D. trimaculatus. All copepods found in the gills of D. trimaculatus had a prevalence of 4.95 and mean intensity of 47.62%, while the nematode-like parasite, which were found in the brain, had 2.72 prevalence and 42.86% mean intensity. This elucidates that both parasites are categorised as having light levelbut common frequency of infection, and the current IUCN status of D. trimaculatus has not been reported to be harmedby parasites. Though the mean intensity of both parasites isnot harmful, the prevalence are concerning and might increase in the future, with further incorporation and monitoring of climate change factors that may affect the damselfish.
  8. Baba Md Deros, Ahmad Rasdan Ismail, Mohd Yusri Mohd Yusof
    MyJurnal
    Regulation on occupational safety and health in Malaysia had evolved from the prescriptive Factory and Machinery Act (1967) to a self-regulated Occupational Safety and Health Act (1994). However, from the authors’ observation the high standards of occupational safety and health culture that surpass the legal requirement were not widely practiced by small and medium enterprises (SMEs). The two main objectives of this study are: first, to identify and determine the level of conformity; and second, to investigate the reasons of nonconformity to Occupational Safety and Health Act (1994) regulation in SMEs involved the chemical industry sub-sectors. The survey questionnaire was distributed to 150 SMEs in chemical industry sub-sectors. Forty one of the survey questionnaires were completed and returned, giving a response rate of 27.3% for the survey. The survey results revealed that an overwhelming majority (92.7%) of the respondents from SMEs are likely not conforming to the basic requirement of Occupational Safety and Health Act (1994). In addition to this, the survey also found that only 3.1% of the management personnel can be considered competent in terms of knowledge, skill and ability in carrying out occupational safety and health regulation within their respective organization. While, 96.9% of the respondents that participated in the survey can be considered not competent. The authors hope the result of this survey could assist the relevant authorities in formulating a better policy and strategy for implementing occupational safety and health in SMEs involved in chemical industry sub-sectors.
  9. Ghasak Ghazi Faisal, Faridah Md Khalid, Yusri Yazid
    MyJurnal
    Introduction: Smoking is a well-known cause of oral disease and oral cancer. Several dysplastic cytological changes occur before the appearance of the clinical lesion. This study aimed to investigate the cytopathological effects of smoking in clinically normal oral mucosa of cigarette smokers.
    Materials and Methods: A total of 40 cigarette smokers and 40 nonsmokers (control group) were included in this study. All participants had clinically normal oral mucosa. Oral smears were obtained from the side of the tongue and floor of the mouth using a Cytobrush. The smears were stained by Papanicolaou stain and examined under light microscope for inflammation, hyperkeratinization and dysplasia.
    Results: There was a significantly higher rate(p<0.005) of inflammation 63%, hyperkeratiniztion 62% and mild dysplasia 26% among smokers than non-smokers where the rates were 35%, 12% and 2% respectively.
    Conclusion: Smoking causes significant cytopathological changes in normal oral mucosa, the detection of which is important to prevent progression into carcinoma. The procedure is fast, painless and inexpensive.
    KEYWORDS: Papanicolaou stain, brush biopsy, cigarette smokers, dysplasia, oral mucosa
  10. MOHD YUSRI MOHD YUSOF, BABA MD. DEROS, AHMAD RASDAN ISMAIL
    Sains Malaysiana, 2013;42:1815-1818.
    Working environmental conditions in automotive industry are very challenging to the human workers. Meanwhile, products quality is very much dependent on workers’ health, safety and comfort in their working environment. Environmental factors, such as temperature, illuminance and humidity levels have significant effect on workers’ performance at the production line. In this experiment, temperature, humidity, illuminance levels and productivity rate were observed in a control room. An automotive manufacturing firm production line was chosen to be simulated in the control room to observe the temperature, relative humidity, illuminance and worker’s productivity rate. The experimental data collected was analyzed using Response Surface Method (RSM). RSM is an analysis technique, which combined statistical systems and mathematical methods. It can be applied for research and development, reform and optimize a process, which involves several design variables. As a result, the combined effect of temperature, illuminance and humidity toward productivity can be clearly seen. Optimum environmental factor cannot be predicted using first order RSM analysis because it gives low reliability for obtaining the optimum level. Thus, a second order RSM analysis was generated for obtaining the optimum level of environmental factors.
  11. Yusri NM, Chan KW, Iqbal S, Ismail M
    Molecules, 2012 Oct 25;17(11):12612-21.
    PMID: 23099617 DOI: 10.3390/molecules171112612
    A sequential solvent extraction scheme was employed for the extraction of antioxidant compounds from kenaf (Hibiscus cannabinus L.) seeds. Yield of extracts varied widely among the solvents and was the highest for hexane extract (16.6% based on dry weight basis), while water extract exhibited the highest total phenolic content (18.78 mg GAE/g extract), total flavonoid content (2.49 mg RE/g extract), and antioxidant activities (p < 0.05). DPPH and hydroxyl radical scavenging, β-carotene bleaching, metal chelating activity, ferric thiocyanate and thiobarbituric acid reactive substances assays were employed to comprehensively assess the antioxidant potential of different solvent extracts prepared sequentially. Besides water, methanolic extract also exhibited high retardation towards the formation of hydroperoxides and thiobarbituric acid reactive substances in the total antioxidant activity tests (p < 0.05). As conclusion, water and methanol extracts of kenaf seed may potentially serve as new sources of antioxidants for food and nutraceutical applications.
  12. Win TT, Jaafar H, Yusuf Y
    South Asian J Cancer, 2014 Jul;3(3):171-4.
    PMID: 25136525 DOI: 10.4103/2278-330X.136799
    Angiogenesis and apoptosis play an essential role in tumor development and progression. Previous studies on apoptosis and angiogenesis of soft-tissue sarcoma (STS) were done separately. This is the first study of the relationship between apoptotic and angiogenic activity. Correlation of expression of anti-apoptotic protein (Bcl-2) and pro-apoptotic protein (Bax) in the tumor cells (TCs) with their expression in endothelial cell (EC) of the tumor blood vessels in STS were also carried out.
  13. Mohd Yusop AY, Xiao L, Fu S
    Data Brief, 2019 Aug;25:104234.
    PMID: 31384643 DOI: 10.1016/j.dib.2019.104234
    This paper presents the data on the optimisation and validation of a liquid chromatography-high-resolution mass spectrometry (LC-HRMS) to establish the presence of phosphodiesterase 5 (PDE5) inhibitors and their analogues as adulterants in instant coffee premixes. The method development data covered chromatographic optimisation for better analyte separation and isomeric resolution, mass spectrometry optimisation for high sensitivity and sample preparation optimisation for high extraction recovery (RE) and low matrix effect (ME). The validation data covered specificity, linearity, range, accuracy, limit of detection, limit of quantification, precisions, ME, and RE. The optimisation and validation data presented here is related to the article: "Determination of phosphodiesterase 5 (PDE5) inhibitors in instant coffee premixes using liquid chromatography-high-resolution mass spectrometry (LC-HRMS)" Mohd Yusop et al., 2019.
  14. Mohd Yusop AY, Xiao L, Fu S
    Talanta, 2019 Nov 01;204:36-43.
    PMID: 31357306 DOI: 10.1016/j.talanta.2019.05.078
    As a widely consumed beverage, coffee tends to be a target for intentional adulteration. This study describes the application of modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) coupled to liquid chromatography-high-resolution mass spectrometry (LC-HRMS) for simultaneous screening, identification, and quantification of undeclared phosphodiesterase 5 (PDE5) inhibitors in instant coffee premixes (ICPs). The mass spectrometer was operated in auto MS/MS acquisition for simultaneous MS and MS/MS experiments. Qualitative establishments from the suspected-target screening and targeted identification processes led to an unambiguous analyte assignment from the protonated molecule ([M+H]+) precursor ion which is subsequently used for quantification of 23 targeted PDE5 inhibitors. The analytical method validation covered specificity, linearity, range, accuracy, limit of detection (LOD), limit of quantification (LOQ), precisions, matrix effect (ME), and extraction recovery (RE). The specificity was established using the optimised chromatographic separation as well as the distinguishable [M+H]+ precursor ion. The linearity of each target analyte was demonstrated with a coefficient of determination (r2) of >0.9960 over the expected range of sample concentrations. The accuracy ranged from 88.1%-119.3% with LOD and LOQ of <70 ng/mL and 80 ng/mL, respectively. Excellent precisions were established within 0.4%-9.1% of the relative standard deviation. An insignificant ME within -5.2% to +8.7% was achieved using three different strategies of chromatography, sample extraction, and sample dilution. The RE was good for all target analytes within 84.7%-123.5% except for N-desethylacetildenafil at low (53.8%) and medium (65.1%) quality control levels. The method was successfully applied to 25 samples of ICPs where 17 of them were found to be adulterated with PDE5 inhibitors and their analogues. Further quantification revealed the total amount of these adulterants ranged from 2.77 to 121.64 mg per sachet.
  15. Mohd Yusop AY, Xiao L, Fu S
    Drug Test Anal, 2021 May;13(5):965-976.
    PMID: 32441056 DOI: 10.1002/dta.2861
    The lucrative market of herbal remedies spurs rampant adulteration, particularly with pharmaceutical drugs and their unapproved analogues. A comprehensive screening strategy is, therefore, warranted to detect these adulterants and, accordingly, to safeguard public health. This study uses the data-dependent acquisition of liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS) to screen phosphodiesterase 5 (PDE5) inhibitors in herbal remedies using suspected-target and non-targeted strategies. For the suspected-target screening, we used a library comprising 95 PDE5 inhibitors. For the non-targeted screening, we adopted top-down and bottom-up approaches to flag novel PDE5 inhibitor analogues based on common fragmentation patterns. LC-QTOF-MS was optimised and validated for capsule and tablet dosage forms using 23 target analytes, selected to represent different groups of PDE5 inhibitors. The method exhibited excellent specificity and linearity with limit of detection and limit of quantification of <40 and 80 ng/mL, respectively. The accuracy ranged from 79.0% to 124.7% with a precision of <14.9% relative standard deviation. The modified, quick, easy, cheap, effective, rugged, and safe extraction provided insignificant matrix effect within -9.1%-8.0% and satisfactory extraction recovery of 71.5%-105.8%. These strategies were used to screen 52 herbal remedy samples that claimed to enhance male sexual performance. The suspected-target screening resulted in 33 positive samples, revealing 10 target analytes and 2 suspected analytes. Systematic MS and tandem MS interrogations using the non-targeted screening returned insignificant signals, indicating the absence of potentially novel analogues. The target analytes were quantified from 0.03 to 121.31 mg per dose of each sample. The proposed strategies ensure that all PDE5 inhibitors are comprehensively screened, providing a useful tool to curb the widespread adulteration of herbal remedies.
  16. Mohd Yusop AY, Xiao L, Fu S
    Drug Test Anal, 2021 May;13(5):953-964.
    PMID: 32959983 DOI: 10.1002/dta.2926
    The surge in the consumption of food products containing herbal aphrodisiacs has driven their widespread adulteration. A rapid screening strategy is, therefore, warranted to curb this problem. This study established an enzyme inhibition assay to screen phosphodiesterase 5 (PDE5) inhibitors as adulterants in selected food products. Fluorescein-labelled cyclic-3',5'-guanosine monophosphate was utilised as substrates for the PDE5A1 enzyme, aided by the presence of nanoparticle phosphate-binding beads on their fluorescence polarisation. The sample preparation was optimised to improve the enzyme inhibition efficiency and applied to calculate the threshold values of six blank food matrices. The assay was validated using sildenafil, producing an IC50 of 4.2 nM. The applicability of the assay procedure was demonstrated by screening 55 distinct food samples. The results were subsequently verified using confirmatory liquid chromatography-high-resolution mass spectrometry (LC-HRMS) analysis. Altogether, 49 samples inhibited the PDE5 enzyme above the threshold values (75.7%-105.5%) and were registered as potentially adulterated samples. The remaining six samples were marked as nonadulterated with percentage inhibition below the threshold values (-3.3%-18.2%). The LC-HRMS analysis agreed with the assay results for all food products except for the instant coffee premix (ICP) samples. False-positive results were obtained for the ICP samples at 32% (8/25), due to possible PDE5 inhibition by caffeine. Contrarily, all other food samples were found to produce 0% (0/30) false-positive or false-negative results. The broad-based assay, established via a simple mix-incubate-read format, exhibited promising potential for high-throughput screening of PDE5 inhibitors in various food products, except those with naturally occurring phosphodiesterase inhibitors such as caffeine.
  17. Mohd Yusop AY, Xiao L, Fu S
    Forensic Sci Int, 2021 May;322:110748.
    PMID: 33711768 DOI: 10.1016/j.forsciint.2021.110748
    The presence of erectile dysfunction (ED) drugs in adulterated dietary supplements, mainly in pharmaceutical dosage forms, is frequently addressed in the literature. Little attention is given to food products despite their increasing adulteration trend. To address this knowledge gap targeted, suspected-target, and non-targeted strategies were utilised to analyse ED drugs and their analogues in powdered drink mix (PDM), honey, jelly, hard candy, and sugar-coated chewing gum using liquid chromatography-high-resolution mass spectrometry (LC-HRMS). The method was optimised and validated using 23 target analytes, representing different ED drugs with structural similarities. The modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction exhibited insignificant matrix effect (ME) within - 9.2-8.8% and provided complete coverage of target analytes with acceptable extraction recovery (RE) within 75.5-123.9%, except for carbodenafil in the PDM matrix. Based on the ME and RE performance, the analytical method was validated to analyse 25 food samples that claimed to enhance male sexual performance. The method exhibited good specificity and linearity with a limit of detection within 10-70 ng/mL and limit of quantification of 80 ng/mL. Similarly, the accuracy and precision were satisfactory within 77.4-122.0% and
  18. Yusup Y, Kayode JS, Alkarkhi AFM
    MethodsX, 2018;5:448-453.
    PMID: 30090703 DOI: 10.1016/j.mex.2018.05.003
    The southern South China coastal oceans within the South East Asian region are much lacking in the perception of the surface energy budget and evaporation over the ocean waters in response to climatic changes. The eddy covariance method was used to measure the energy fluxes, microclimate variables, and surface water temperature from November 2015 to October 2017 at the Straits of Malacca, South China Sea; Pulau Pinang, Malaysia, situated at latitude 5°28'06″N, and longitude 100°12'01″E. This work focused on the methodological approach to the air-sea energy fluxes data collection and analysis. In this regard, the method applied for the direct measurements and analysis of energy fluxes and other meteorological parameters in the site is considered and reported. •The paper summarizes the analysis of energy fluxes, microclimate variables, and surface water temperature data in a tropical coastal ocean station using the eddy covariance method.•The methodological approach illustrates the method of analysis applied in this study which can be compared and used for similar studies in other places.•The reproducible data analysis technique matches similar comparative methods such as Matlab and Python.
  19. Yusup Y, Kayode JS, Alkarkhi AFM
    Data Brief, 2018 Aug;19:1477-1481.
    PMID: 30229020 DOI: 10.1016/j.dib.2018.06.020
    Air-sea flux exchanges influence the climate condition and the global carbon-moisture cycle. It is imperative to understand the fundamentals of the natural systems at the tropical coastal ocean and how the transformation takes place over the time. Hence, latent and sensible heat fluxes, microclimate variables, and surface water temperature data were collected using eddy covariance instruments mounted on a platform at a tropical coastal ocean station from November 2015 to October 2017. The research data is to gain the needful knowledge of the energy exchanges in the tropical climatic environment to further improve predictive algorithms or models. Therefore, it is intended that this data report will offer appropriate information for the Monsoonal, and diurnal patterns of latent (LE) and sensible (H) heats and hence, establish the relationship between microclimate variables on the energy fluxes at the peninsular Malaysian tropical coastal ocean.
  20. Yusup Y, Kayode JS, Alkarkhi AFM
    Data Brief, 2018 Dec;21:13-17.
    PMID: 30310834 DOI: 10.1016/j.dib.2018.09.108
    Data on the micrometeorological parameters and Energy Fluxes at an intertidal zone of a Tropical Coastal Ocean was carried out on an installed eddy covariance instruments at a Muka head station in the north-western end of the Pinang Island (5°28'06''N, 100°12'01''E), Peninsula Malaysia. The vast source of the supply of energy and heat to the hydrologic and earth׳s energy cycles principally come from the oceans. The exchange of energies via air-sea interactions is crucial to the understanding of climate variability, energy, and water budget. The turbulent energy fluxes are primary mechanisms through which the ocean releases the heat absorbed from the solar radiations to the environment. The eddy covariance (EC) system is the direct technique of measuring the micrometeorological parameters which allow the measurement of these turbulent fluxes in the time scale of half-hourly basis at 20 Hz over a long period. The data being presented is the comparison of the two-year seasonality patterns of monsoons variability on the measured microclimate variables in the southern South China Sea coastal area.
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