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Differential-based biosensor arrays for detecting carcinogens in heat-processed foods / Wong Siew Fang
No full textFood contamination is a severe issue owing to the large concentration of chemicals in foods that causes serious health problems. Protecting public health and preventing contaminated foods are a high priority. Foodborne chloropropanols and amides, specifically 3-chloropropane-1,2-diol (3-MCPD) and acrylamide, are vitally important for food safety and food security, as they are the most popular food toxicants and suspected human carcinogens. Chloropropanols are challenging analytes because of the scarcity of functional group diversity and difficulty in aiming the hydroxyl groups in aqueous conditions. In addition, due to their small molecular size, time-consuming, labor-intensive, and costly derivatization methods are often required for acquiring desirable chromatographic patterns and enhancing the detectability and stability of the analytes. Similarly, an intricate sample pretreatment procedures and requirement for sophisticated instrumentation in the existing analytical approaches unfortunately render difficulties in the rapid, simplistic, on-the-spot sensitive determination of acrylamide. Therefore, achieving physical chromatographic determination is challenging. Apart from chromatographic techniques, electrochemical method with higher detection limit and lower sensitivity hinders the detection of trace concentrations of 3-MCPD and acrylamide in foods. Considering these potential limitations, an array-based differential optical biosensing methods were proposed. The concept of differential sensing is primarily based on fingerprint patterns generated from the interactions between the analytes and the cross-reactive receptors with multifarious binding affinities, thus facilitating the detection of small-molecule analytes. As compared to conventional chemosensor, differential biosensor array has the added advantage of precluding the strenuous procedures for developing a highly specific receptors in detecting small analytes. Employing serum albumins, ascorbic acid, and PRODAN, a differential-based fluorescent biosensor array was developed to differentiate and detect chloropropanols. The sensor array integrated with linear discriminant analysis effectively differentiated four chloropropanols based on the number of hydroxyl groups and their isomerism properties, even at ultra-low concentration (5 nM). The sensor array was then applied for chloropropanols quantification and differentiation in synthetic soy sauce samples. Leave-one-out cross-validation analysis revealed 100% accurate classification for all experiments. In contrast, exploring molecular interactions at the bio-nano interfaces facilitated the development of array-based detection system with gold nanoparticles as a colorimetric probe. A combination of distinct proteins as cross-reactive bioreceptors and the subsequent fine-tuning of the protein surface coverage on the gold nanosurface with dithiothreitol resulted in a differential-based colorimetric nanobiosensor array for the detection, differentiation, and quantification of acrylamide and six analogues. Using the principal component analysis and hierarchical cluster analysis, acrylamide and six analogues were successfully detected and discriminated based on their amine subgroups, IARC carcinogen classifications, and food additive types, at concentrations as low as 500 pM. Furthermore, the sensor array has the capability to identify and differentiate non-targeted analytes by the types of sweeteners and food ingredients, apart from distinguishing and quantifying individual analytes and mixtures of them in the coffee samples. Considering the benefits of high sensitivity and simple design, the differential-based biosensor arrays show great promise for food safety monitoring in the food and beverage industry
Synthesis of new anilinoquinazoline derivatives as potential anticancer agents: Antiproliferative activity, molecular docking and molecular dynamics studies / Muhammad Kumayl Abdul Wahab
No full textCurrent reversible epidermal growth factor (EGFR) tyrosine kinase inhibitors of the non-small cell lung cancer (NSCLC) have been resisted by T790M mutation, while irreversible inhibitors introduced to overcome the mutation have faced resistance from C797S mutation. In the effort to discover potential reversible EGFR inhibitors, two series of anilinoquinazoline derivatives were synthesized and characterized, studied for their in vitro antiproliferative activity against NSCLC cell lines, namely A549, H1650 and H1975, and studied for the plausible binding mode in epidermal growth factor receptor kinases with different mutations through molecular docking. In the first series, the anilinoquinazoline scaffold was derivatized through the addition of amide group at the 2nd carbon of the aniline ring. Seven derivatives were synthesized and characterized through 1H NMR, 13C NMR, and HREIMS. Compound 3.7 exhibited the highest activity against all three cell lines, with the IC50 values of 24.60 ± 0.75 μM in A549, 14.83 ± 0.54 μM in H1650, and 21.72 ± 1.21 μM in H1975. The molecular docking study of compound 3.7 indicated that the compound formed the hydrogen bonding with MET793 and ASP855 in wild-type EGFR kinase (WT-EGFR) and MET793 in L858R+T790M mutated EGFR kinase (LRTM-EGFR). In the second series, the anilinoquinazoline scaffold was further derivatized, by extending the chain next to the amide group to include an aromatic ring. Seven derivatives were synthesized and characterized in the series. Compound 3.18 exhibited the significantly highest activity against A549 cell line (IC50: 17.60 ± 1.70 μM), surpassing compound 3.7 (IC50: 24.60 ± 0.75 μM) and the standard drug, gefitinib (IC50: 34.32 ± 1.30 μM), while compound 3.20 exhibited the significantly highest activity against H1975 cell line (IC50: 9.75 ± 1.06 μM), surpassing compound 3.7 (IC50: 21.72 ± 1.21 μM) and gefitinib (IC50: 31.12 ± 0.38 μM). The molecular docking of compound 3.18 in WT-EGFR and compound 3.20 in LRTM-EGFR showed that for both compounds, hydrogen bonding with MET793 and π-π interaction with PHE723 were observed, while the molecular dynamic simulations showed that hydrogen bonding with ASP855 was observed during the simulations of the compounds in the respective EGFR kinases
Design and development of a multimodal self adjusting vibration energy harvesting system / Lim Chin Seong
No full textVibration energy harveting devices have the potential to replace batteries in powering remote sensors. However,the bandwidth of such devices is typically very narrow, and thus. only abble to generate sufficient power when the excitation frequency is at the natural frequency of the device. This research aims to design, build and test the behavior of a antilever beam that has the capability to self-tune its natural frequency mechanically.The self-turning mechanism is designed based on the observation that vibration causes freely supported disc to rotate, and the mass distribution of an asymmetrical disc changes with the rotary position of the disc, which in turn changes the natural frequency of the cantilever beam. Teh self-tuning mechanism is found to increase the bandwidth of the testing apparatus as compared to the bandwith without self-tuning. An improvement of up to 318% was observed between the measured vibration magnitudes of the self-tuning system vs the system without self-tuning. The vibration magnitude is characterized by RMS Acceleration and Displacement as measured by accelerometers and laser displacement sensor. It is expectedthat higher Acceleration and Displacement would couse more electrical power to be generated when the self-tuning mechanism is combinedwith energy conversion devices such as piezo-electric elements
Hearing loss qualitative assessment among work from home earphone users / Jotham Ngu Ong Hu
Get PDFEarphones have become a common and trendy hearing device among people in the world. The outbreak of Covid-19 pandemic has caused many workers in Malaysia to work from home. Working from home may prolong the usage of earphones and potentially cause hearing loss among workers and appear as an occupational health hazard. Thus, this research has been carried out to examine the effect of earphones towards hearing loss among work from home workers and investigate the reason and the cause of the hearing loss experienced. A hearing loss qualitative assessment has been generated and 20 respondents participated in the assessment. The qualitative assessment comprises interview questions and 3 tests namely the whispering test, the speech in noise test and the single-sided ear test. The interview analyzes the cause of hearing loss while the tests examine the ear health and detect hearing loss. As a result, the unhealthy respondents have the common characteristics, in which they are all using earphones for more than 5 hours per working day and having their earphone volume more than 65%. Hence, if the workers do not practice good earphones using habit, prolonged earphone usage during work from home possesses risks in ear health. If companies and their workers do not have proper awareness on earphones usage during the work from home period, it will eventually emerge as an occupational hearing health issue in the future
Three-dimensional visualization of brain tumor computed tomography images / Nurizzaty Khairi Mohamed
Get PDFOpen-source software used to reconstruct and visualize 3D image from 2D computed tomography (CT) images. This research used Visualization toolkit (VTK) and 3D slicer software to reconstruct 3D image from a set of 2D brain tumor CT image. Each software practiced four different methods to visualize 3D image from a set of 2D image. Methods used in VTK software are surface rendering, multiplanar rendering, volume rendering and volume rendering with additional features while 3D slicer software display surface of 3D model, multiplanar 3D model, volume 3D model and volume with measurement 3D model. A set of 2D brain segment images obtained from CT scan used as source data. The reconstructed 3D images expected to visualize 2D brain tumor CT images into 3D image and measure 3D volume of brain tumor. Result of 3D slicer will be used for comparison purposes. The result shows that both software capable to reconstruct and visualize 3D image from a set of 2D images. However, volume rendering with additional features method by using VTK shows the best result in reconstructing 3D image from a set of 2D images because of lower noise and artifacts present in the 3D image. Plus, the method able to crop the 3D image and allow user to observe cross-section of the 3D image for measuring the brain tumor size. In conclusion, 3D reconstruction software ease physicians and radiologists to diagnose abnormalities faster and precisely
Government management on food service industry and the intention to practice standard operating measures during COVID-19 / Wang Xiaohui
No full textThe COVID-19 global pandemic has changed the relationship between consumers and food, increased the frequency of cooking at home, and adopted strict precautions when
shopping, delivering meals and eating out. This time, we took the form of an online questionnaire survey, which led and received effective responses from 200 interviewees.
Use descriptive statistics to analyze data and use SPSS data processing methods to pass reliability analysis, validity analysis, factor analysis, and correlation analysis, the average score of food safety knowledge of Malaysian respondents is 8.92 (11 .00 = highest score),
indicating that consumers have a high level of food safety knowledge and sufficient knowledge reserves, which can effectively prevent COVID-19 infection. The Alpha
coefficient is 0.882, the test KMO=0.700 (KMO>0.7), Sig.<0.001, and the total variance explanation chart, we explored the relationship between the two variables (health and safety knowledge and people’s attitude/behavior ability to respond to the epidemic) The correlation, the result (sig = 0.796), shows that the relationship between the two is to play a positive role, the higher people's health and safety knowledge. During the COVID-19 period, regarding Malaysia and China’s safety policies for the catering service industry, in terms of the effectiveness of epidemic prevention, the containment strategy adopted by
China is more effective in terms of epidemic control
Evaluation of safety and health improvement in population by the implementation strategy of China government during COVID-19 pandemic / Yan Xiangyu
No full textEvaluation of Safety and Health Improvement in Population by The Implementation Strategy of China Government during Covid-19 Pandemic Abstract Confirmed case of COVID-19 gradually appeared all over the world as the first case of COVID-19 was diagnosed and COVID-19 has begun to become uncontrollable in 2020. As the first discovered and hardest hit area in China, the epidemic was effectively controlled within three months. Therefore, this study conducted investigations in three cities in China, Wuhan, Beijing and Yinchuan, in order to obtain relevant policies for epidemic control and effects of people during epidemic. This research provides a template for epidemic prevention and control for other hard-hit countries. This study collected government policy data and compared and analyzed 186 questionnaire surveys in the three cities to find out how to implement different policy in different regions can effectively control COVID-19. Through the collection of policy data, it is found that the Chinese government is more inclined to reduce the spread of the epidemic and solve the problem of material shortages in the hardest-hit areas. For low-risk areas, the government pays more attention to how to reduce foreign infections, increase the cure rate, and establish relevant responsible persons. Through survey data analysis, it is found that the mental health of more than 70% of people is affected. Enhancing knowledge of people of the hazards of COVID-19 will increase satisfaction with epidemic prevention and control, and people will be more willing to comply with relevant epidemic prevention regulations. Therefore, timely provision of adequate supplies and personnel to the hardest-hit areas will reduce their medical pressure, and effective travel control will reduce the risk of transmission from the source. Establishing responsible persons and raising awareness of epidemic prevention in low-risk areas can reduce human-to-human transmission and
reduce personnel violations of epidemic prevention regulations. Online psychological assistance from hospitals and governments can reduce people's mental health problems
Greening flaring process in oil and gas industries / Yuharajan Baskaran
No full textThe process of burning excess natural gas in the atmosphere is known as gas flaring in the oil and gas industry. It occurs at the onshore and offshore oil and gas production platforms, as well as the processing plant. As a result, a significant proportion of natural gas is squandered. It would be ideal to recover energy from flared natural gas and use it to generate electricity, particularly in an offshore area when electricity is scarce. As a result, more attention should be paid to the efficient use of flared natural gas in offshore oil and gas installations. The energy recovery system, as one of the promising approaches for generating power from flared natural gas in the Central Processing Platform 1, has gotten a lot of attention (CPP1).
Through greenhouse gases and other pollutants, gas flaring is one of the most serious environmental issues. These emissions contribute to climate change by having a high global warming potential. Flared gas and its emissions must be measured, and this has proven to be a difficult task. The reduction and recovery of flare gases is a high priority since it satisfies both environmental and economic efficiency goals. In industry, there are several different forms of FGRS, including gas collection and compression, gas-to-liquid, and power generation. A variety of technical problems have hampered FGRS, including a combination of extremely variable flow rates and composition, poor heating value, and low pressure of waste gases. FGRS has enhanced noise and thermal radiation reduction, operating and maintenance expenses, air pollution and gas emission reduction, and reduced fuel gas and steam usage due to environmental and economic concerns.
Therefore, in this study, a simulation model was created using the HYSYS simulation software to anticipate the potential energy in terms of power generated from gas flaring in DCPP using a microturbine. The focus has been on recovering and evaluating potential energy from gas flaring, with the case study taking place at the Central Processing
Platform 1, the total amount of gas burned at CPP1 is currently 1.48MMscf/d. With the help of the simulation model, a total of 245kW of power may be created. Based on the amount of energy generated and the money required to set up the system, a complete economic analysis was conducted. It is found that the energy recovery system is extremely desirable, with a potential annual savings of RM217,344 during a 7-year payback time. To make use of the gas flaring, it is recommended that an energy recovery system consisting of a microturbine be placed in the Central Processing Platform 1
Analysis of inflammation, metabolic and clinical markers in predicting fat mass in HIV-positive males using artificial neural network / Nurul Farhah Shamsuddin
No full textIncreased inflammation has been discovered in people living with Human Immunodeficiency Virus (HIV), which has been associated with the development and advancement of metabolic diseases. Immune activation and inflammation have been revealed to affect the redistribution of fat in people living with HIV (PLWH) whether the individual is on treatment with antiretroviral therapy (ART) or treatment naïve. Therefore, the assessment of body fat composition of PLWH based on markers of inflammation is important to develop keen diagnosis and prognosis of medical conditions facing by these patients, for example lipodystrophy syndrome, metabolic syndrome, dyslipidemia and diabetes mellitus. The purpose of this study is to investigate the relationship among inflammation marker, interleukin-6 (IL-6), clinical and metabolic factors with fat mass (FM) in males living with HIV (MLWH) using artificial neural network (ANN) and to assess the contribution of metabolic and clinical factors alongside inflammation marker, IL-6 to body fat composition in MLWH. Five sets of ANN models were constructed, and each set of network model was produced and manipulated based on inclusion of inflammation marker, IL-6 as an independent variable and on statistically significant association of independent variables with dependent variable, FM. First set of ANN models used inflammation, metabolic and clinical variables as input, the second set of ANN models used metabolic and clinical variables as input, the third set of ANN models used body mass index (BMI) and waist-hip-ratio (WHR) as input, the fourth and fifth set of ANN models used statistically significant parameters associated with FM but each set applied different training split ratio. Dependent variable consisted of body
composition variable, FM collected from whole-body DEXA scan was selected as output. Comparison of model performance were assessed through the model error function, error sum of squares (SSE), relative error (RE) and mean predictive accuracy percentage (MPA%). The MPA% obtained by Set A was 84.84% with ten hidden nodes in its single-hidden layer ANN, 84.02% with ten hidden nodes for Set B, 80.09% with eight hidden nodes for Set C, 85.26% with four hidden nodes for Set D and 85.48% with two hidden nodes for Set E. Through independent sample t-test conducted on Set A and Set B ANN performance to discover the influence of the inflammation marker, IL-6, no significant difference was found in the MPA% between ANN models using clinical, metabolic and inflammation data and ANN models using clinical and metabolic variables, t (13) = 0.75, p< .05, 95% C.I. [-0.95% – 1.96%]. However, statistically significant difference in prediction accuracy was found on fat mass in MLWH at the p <.05 level for the five ANN models sets [F (4, 45) = 8.802, p = 0.00]. The findings show that ANN technique was able to triangulate the relationship between body fat composition and clinical, metabolic and inflammation data of MLWH even though the addition of inflammation marker, IL-6 did not significantly improve the ANN performance
Analysis of periodontal parameters, subgingival bacteria and levels of LL-37 in periodontitis subjects with rheumatoid arthritis / Cheah Chia Wei
No full textAssociations between rheumatoid arthritis (RA), a chronic inflammatory autoimmune
disease of the joints, and periodontitis (PD), a chronic inflammatory disease affecting
tooth supporting tissues have been reported. Antimicrobial peptide cathelicidin LL-37
besides being antibacterial, is also involved in inflammatory process. It has been
suggested as a possible mechanistic link for these diseases. This study aimed to
investigate the subgingival microbial profile of RA subjects and its correlation with levels
of salivary and serum LL-37. A total of 104 subjects were allocated into RA (n=49) or
non-RA (NRA) (n=55) groups. Three subgroups, PD, gingivitis (G) and periodontal
health (H) were further established. Demographic, periodontal parameters and
rheumatology data were collected. Subgingival plaque, saliva and serum was sampled.
Extracted plaque DNA was amplified and sequenced on MiSeq platform targeting the 16s
rRNA V3-V4 region. Sequenced data was processed and analysed in CLC Genomic
Workbench (Qiagen) to study characteristics of bacterial communities. Correlations
between bacteria were explored using network analysis and differentially abundant
bacteria were investigated. Serum and salivary LL-37 levels were measured using
enzyme-linked immunosorbent assay (ELISA). The associations between bacteria genera
with disease parameters and LL-37 were explored. Bacterial communities were highly
diverse in all groups while the samples clustered together according to PD conditions.
Phyla Firmicutes, Fusobacteria, Bacteroidetes, Actinobacteria, Proteobacteria,
Patescibacteria and Epsilonbacteraeota were 99% of the total abundance. In the PD
groups, there were higher abundance in phyla Spirochaetes and Synergistetes and
reduction in phyla Actinobacteria and Proteobateria. Highly dense inter-generic
iv
networks were noted between the genera in the RA-PD group compared to NRA-PD, RA?H or NRA-H. More periodontal disease-associated bacteria genera were observed in RA?PD group. For levels of salivary and serum LL-37, RA-PD showed statistically higher
salivary level compared to all groups. All RA groups and NRA-PD showed statistically
higher serum LL-37 levels compared to NRA-G and NRA-H, but not across the four
groups. Salivary LL-37 positively correlated with ESR and negatively correlated with
CAL in RA-H. Serum LL-37 negatively correlated with number of teeth in NRA-PD; RA
disease duration in RA-H; positively correlated with ESR in RA-G and CRP in RA-H.
Periodontal disease-associated genus positively correlated with periodontal parameters in
NRA-H groups. However, in the rest of the groups, both health- and disease-associated
genera correlated positively with disease parameters. For correlations with salivary and
serum LL-37 similar presentations were exhibited. In conclusion, subgingival microbial
profile was influenced by PD condition. The aberrant immune system in RA-PD
presented as dense network of subgingival microbiota. Severe periodontitis denoted by
fewer number of teeth in NRA-PD showed positive association with serum LL-37.
Positive correlations for serum LL-37 with inflammation were based on associations with
ESR and CRP in RA groups. A dysbiotic oral microbial community was associated with
the inflammatory conditions present in RA and PD. These inflamed conditions increased
the levels of circulating inflammatory cytokines such as LL-37 that may further
dysregulate the host immune balance. The mechanism of subgingival microbial dysbiosis
on LL-37 and the development of RA needs to be further studied.
Keywords: subgingival microbiota, rheumatoid arthritis, periodontitis, LL-3