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Enhancement of flavonoid production by suppressing cinnamate-4-hydroxylase (C4H) gene expression using RNA and CRISPR interference systems in Nicotiana tabacum and Boesenbergia rotunda cell suspension cultures / Karlson Chou Khai Soong
No full textFlavonoids are an important natural compound in plants with many health benefits,
including antioxidant, anticancer, antiviral, and anti-inflammatory properties. However,
the scarcity of flavonoid chemicals in nature restricts their industrial applicability.
Cinnamate-4-hydroxylase (C4H) is a critical enzyme found at the very first branching
point in the flavonoid biosynthetic pathway. By silencing the branching pathway, the redirection
of the metabolic flux may enhance the desired flavonoid production in plants.
This study demonstrated how C4H silencing affects flavonoid production in Nicotiana
tabacum cell suspension cultures using RNAi and CRISPRi silencing systems. The main
aim of this study was to enhance the flavonoid production by silencing its C4H using (1)
RNAi system with a partial cDNA of C4H from Boesenbergia rotunda (designated as
BrC4H) and (2) CRISPRi system with guide RNAs (gRNAs) targeting the promoter
region of endogenous C4H. Prior to plant transformation, the previously constructed
partial pANDA-BrC4H plasmid containing BrC4H cDNA (1,302 kb) was verified by
PCR analysis and sequencing. To construct the CRISPRi vector, guide RNAs (gRNAs)
targeting the region at the C4H’s promoter were designed and cloned into a CRISPRi
vector. Both vectors were introduced separately into the established B. rotunda and N.
tabacum cell suspension cultures through Agrobacterium-mediated transformation.
About 76.2 % and 52.9 % N. tabacum cell suspension cultures transformed with CRISPRi
and RNAi vectors, respectively, survived under hygromycin selection media. In contrast,
9.2 % of the B. rotunda cell suspension cultures survived after transforming with an RNAi
vector. Attempts to transform B. rotunda cell suspension cultures with the CRISPRi
vector was unsuccessful as all cells were dead because of the nationwide lockdown due to the pandemic. All transformants that survived on antibiotic media were harvested for
PCR analysis. The PCR-positive cell lines were maintained for another three months
before being harvested for quantitative-real-time PCR (qPCR) analysis. The expression
of C4H for RNAi- and CRISPRi-silenced N. tabacum cell suspension cultures was 0.75-
and 0.44-fold, respectively, lower than wild type. However, for other flavonoid-related
genes, such as 4CL and CHS, the C4H-silenced cells using CRISPRi showed a higher
expression than RNAi-silenced and wild type. Similarly, the accumulation of flavonoids,
namely pinostrobin, naringenin, and chlorogenic acid, in the CRISPRi-silenced cells was
higher than in RNAi-silenced and wild type. These findings showed that the flavonoid
biosynthesis has altered after silencing the C4H via RNAi and CRISPRi, thus increasing
several targeted flavonoids
Tetrahedral meshing by finite element analysis for surface cracks with respect to corner point singularities for smooth and stepped round bars / Sharon Teh Ai Ping
No full textNumerous failure investigations involving failed round bars for various applications have been reported in literature. The cracks are predominantly initiated at high stress concentration regions. However, in the ensuing failure investigations, the use of numerical fracture mechanics was commonly omitted. The current advancement of computational development on the interactive numerical techniques allows the analysts to more accessibly figure out the fracture phenomena when performing engineering analyses nowadays. The stress intensity factors (SIFs) of a surface planar flaw at a stepped round bar are of practical interest, however, the SIF solutions along the flaw front have not yet been documented in literature. In this study, the practical abilities of the numerical fracture mechanics on the fracture analyses were demonstrated by evaluating a planar surface flaw at the shoulder fillet through numerical simulations by the finite element method (FEM) and the dual boundary element method (DBEM) for both smooth and stepped round bars. Crack front SIFs results from FEM studies have shown corner point singularity issues. The SIF data for relatively small crack sizes are valuable to gauge whether an existing crack would grow to a critical size. The stress contours along the front of planar flaws are also presented for visualization of crack front shape propagation.
For a relatively small ratio of the crack depth over shaft diameter, Modes I and II (in-plane) stress intensity factors (SIFs) at the corner points by FEM were observed to be satisfactorily predicted and in good agreements with those by dual boundary element method (DBEM) especially for points away from corner points. Effect of the crack aspect ratio and crack size on the corner point singularity, were noted in this study. The severity of singularity at stepped bars were intensified by the presence of stress concentration caused by geometry irregularity intensity. Mode III SIFs around the corner points by FEA generally diverge from those by DBEM, but for those around deepest points, the SIF calculations by FEA and DBEM showed good agreement for cases of higher crack aspect ratio. On the contrary, although the crack size is relatively small, Mode III SIFs around the corner points by FEA with ultra-fine meshing showed a significant influence of singularity. Hence, it needs more computational development for improvements. This research has demonstrated the viability of using tetrahedral meshing elements in FEM-based software ANSYS to model small cracks and evaluate the SIFs of both non-inclined and inclined semi-elliptical surface cracks in smooth and stepped cylinder bar subjected to axial tension
Pulse generation in 1.55 and 2.0 micron regions using passive saturable absorbers of bismuth telluride (Bi2Te3), nickel oxide (NiO) and spent coffee ground (SCG) materials / Muhammad Farid Mohd Rusdi
No full textIn this research, three types of two-dimensional (2D) materials have been studied
which are Bismuth (III) Telluride (Bi2Te3), Nickel oxide (NiO) and spent coffee ground
(SCG). 2D materials are widely used in the application of optical communication, remote
sensing and medical diagnostics. Sharing some advantages to photonic fields, the
developed fiber laser is more robust, has zero alignments and has less operational
technology. These materials have been prepared by mixing with the polyvinyl alcohol
(PVA) solution to form a thin film saturable absorber (SA). These fabricated SAs are
characterized in terms of nonlinear absorption parameters, linear absorption parameters,
field emission scanning electron microscope (FESEM), electron dispersion spectroscopy
(EDS), and Raman spectroscopy are being performed to confirm the presence of 2D
materials in the fabricated SA. To validate the fabricated SA’s performance, the SA is
integrated into the laser cavity by sandwiching a piece of SA in between two fiber
ferrules. Two ring cavities were established using Erbium-doped fiber (EDF) and
Thulium-doped fiber (TDF) as a gain medium as well to provide a sufficient nonlinearity
in the cavity that operates at 1.55- and 2.0-micron regions, respectively. To avoid a selfpulsing
instability, the free polarization isolator is used to suppress a multiwavelength
and Brillouin backscattering. With EDF and TDF as the gain medium, the laser are
successfully achieved with a stable Q-switched and mode-locked pulse for all materials.
For example, NiO-based mode-locked Erbium-doped fiber laser (EDFL) and Thuliumdoped
fiber laser (TDFL), the laser produces a stable pulse train at 1.89 MHz with a slope
efficiency of 8.44% and pulse energy of 1.94 nJ at 51 mW pump power. In this study, we
explore a new organic and waste material as SA, which is SCG. At a pump power of 56 mW, the stable mode-locked with a repetition rate of 1.81 MHz, slope efficiency of 9.18%
and pulse energy of 2.76 nJ are obtained. These findings show that 2D materials
especially organic materials have a great potential for photonics applications
In vitro and in vivo assessment of antiproliferative, apoptotic and antitumorigenic effects of cardamonin against hepg2 hepatocellular carcinoma cells / Nassrin Abdulgalel Badroon
No full textCardamonin (2′, 4′-dihydroxy-6′-methoxychalcone) is a natural bioactive chalcone that has been explored with keen interest by investigators because of its broad-spectrum biological activities. Previous studies revealed that Cardamonin (CADMN) has antiproliferative activities against several types of cancer cells, including lung, prostate, breast, nasopharynx, multiple myeloma, ovarian and colorectal. The present study investigated the antiproliferative, apoptotic and antitumorigenic effects of CADMN against HepG2 hepatocellular carcinoma cells in vitro and in vivo in HepG2 cells xenografts in nude mice. Results of the in vitro study showed that CADMN inhibited the growth of HepG2 cells with an IC50 4.6 ± 0.16 μg/ml after 72 h of treatment. Cell cycle analysis showed that CADMN arrests HepG2 cells at the G1 phase. Moreover, AO/PI double staining assay indicates gradual cell death via apoptosis as evidenced by the morphological changes sequential from 24 h to 72 h in CADMN-treated HepG2 cells. Then, the CADMN-treated and vehicle-treated (control) HepG2 cells were stained with Annexin V-FITC and PI and analysed by flow cytometry. The CADMN-treated cells showed an increment of early and late apoptosis in a time-dependent manner, which peaked at 31.9% and 35.6%, respectively, after 72 h treatment. Findings also showed that apoptosis induction occurred via extrinsic and intrinsic pathways as demonstrated by a significant increase in caspases-3/7, -8, and -9 activities and overexpression of apoptotic proteins using proteome profiler array. The results of the confocal microscope revealed that CADMN induces alterations in cell membrane permeability and mitochondrial outer membrane permeabilization (MOMP) and significantly increases cytochrome C release into the cytosol. In addition, CADMN generated significantly reactive oxygen species (ROS) production in HepG2 cells after 2 h of treatment compared to control. Furthermore, CADMN inhibited NF-κβ translocation in HepG2 cells, which suggests the contribution of NF-κβ inhibitory mechanism in apoptosis through the ROS accumulation. Oral acute toxicity study in mice showed that CADMN is safe up to 2000 mg /kg. As compared to the untreated control group, the oral administration of 25 and 50 mg/kg/day of CADMN in xenograft nude mice showed significant suppression of tumour growth by 45.4% and 65.2%, respectively. Immunohistochemistry findings showed that Ki-67 and PCNA proliferating proteins were strongly overexpressed in the untreated control group. In contrast, these proteins were downregulated in mice treated with 25 and 50 mg/kg of mg/kg/day of CADMN. Immunofluorescence results of tumour tissues showed high expression levels of Bcl-2, p-NF-κβ, and Ikkβ, while 50 mg/kg/day of CADMN treatment significantly downregulated these proteins. In conclusion, these results suggest that CADMN has an anti-proliferative effect, apoptotic action and anti-tumorigenic activity on hepatocellular carcinoma HepG2 cells and can be considered as a potential alternative anticancer agent against hepatocellular carcinoma. However, further investigations should be conducted in different primary liver cancer cells to represent the heterogeneity of hepatocellular carcinoma
An acquisition and a modulated recognition system for driver profiling in Malaysia / Ward Ahmed Alaulddin Al-Hussein
No full textThe process of collecting driving data and using a computational model to generate a safety score for the driver is known as driver profiling. Previous studies in Malaysia relied on simulators, questionnaires, and surveys to collect driving data. Such methods were criticized for being biased and untrustworthy. Furthermore, due to the disparity in traffic laws and regulations between countries, what is deemed aggressive behavior in one place may not be the same in another. As a result, adopting existing profiles is not ideal. This research presents the first naturalistic driving study in Malaysia, in which thirty drivers were recruited to drive an instrumented vehicle for an accumulated distance of 750 kilometers. The data acquisition system consisted of various sensors, including On-Board Diagnostics II (OBDII), lidar, ultrasonic sensors, Inertial Measurement Unit (IMU), and Global Positioning System (GPS). The collected data were then utilized to establish credible driver profiles based on criteria developed in consultation with traffic experts. Following that, three deep-learning-based algorithms, namely, Deep Neural Network (DNN), Recurrent Neural Network (RNN), and Convolutional Neural Network (CNN), were modulated to classify the recorded driving data according to the established profiles. The results have shown that CNN outperformed the other two classification algorithms in terms of accuracy, precision, recall, and f-measure and was therefore selected for a recognition system that, in combination with the acquisition system, would assist traffic police and insurance firms in detecting unsafe driving behaviors. Furthermore, the study examined the effects of various factors on driving in Malaysia. The statistical results revealed that driving behavior is greatly influenced by drivers’ gender, age, and cultural background. There were also significant behavioral differences between those who drove on weekends and those who drove on weekdays. Finally, several recommendations were presented to government agencies based on the findings to improve road safety and help avoid future accidents
In vitro bioactivities of Tabernaemontana divaricata andTabernaemontana divaricata ‘Flore Pleno’ variant / Muhammad Nazzim Muaz Abdul Halim
No full textTwo Tabernaemontana species, Tabernaemontana divaricata (TD) and Tabernaemontana divaricata ‘Flore Pleno’ variant (TDF) were chosen to be studied for their bioactivities in relation to wound healing properties. Methanol (M) and aqueous (A) extracts of these Tabernaemontana species were used in this study for wound healing potential assessment on adult normal human dermal fibroblasts (HDFa) cells, total phenolic contents (TPC), antioxidant potential, protective effects against hydrogen peroxide (H2O2) and anti-inflammatory properties by means of nitric oxide (NO) production from RAW264.7 murine macrophage cells. TD-A extract reported the highest wound closure (58.50%) followed by TDF-A extract (53.54%) with the highest total phenolic content (31.96 mg GAE/g). The free radical scavenging activities carried out by ABTS and DPPH assay showed that TDF-A extract was able to exhibit the highest antioxidant values at IC50 = 1.11 μg/ml and IC50 = 2.44 μg/ml respectively compared to the other extracts. Reducing activity on TDF-A extract assessed by FRAP assay also reported high value of [18.07 mM Fe (II)/g] with other extracts. Pre-treatment and post-treatment assessment showed at 25 μg/ml of TDF-M extract concentration were able to provide protectivity towards HDFa cells against H2O2 with cell viability at 93.92% and 89.69% respectively. At 500 μg/ml of TD-A and TDF-A extract concentration, the extracts were able to inhibit NO production by RAW264.7 murine macrophage cells at 5.22 μM and 5.11 μM respectively. Based on these findings, it is shown the two Tabernaemontana species studied exhibit multiple bioactivities that may contribute to the wound healing process in general. Keywords
Performance analysis of convolutional neural networks extended with predefined kernels in image classification / Arash Fatehi
No full textWhile Machine Learning aims to solve more challenging problems, Artificial Neural Networks (ANN) become deeper and more accurate. Convolutional Neural Network (CNN) is not an exception and state-of-art architectures consist of millions of learnable parameters. Aiming for better performance, these networks become more complex and computation intensive. Also, with the rise of IoT devices and edge computing, the importance of model acceleration and reduction of needed computing resources become more curial for training neural networks. Model acceleration and compression techniques often target reducing inference latency and memory usage, and research about reducing the training time was limited to two previous studies. Considering numerous use cases of CNNs, reducing the training time and processing cost is beneficial. CNNs are universal functions and in the case of supervised learning, they will converge to a specific desired function after training. In this research, predefined image processing kernels were merged into CNN's architecture to help the network to converge faster for the use case of image classification. This method can be applied to any classification task of multi-channel sensory data. The efficiency of the method was tested through an experiment on ImageNet, Cifar10, and Cifar100 datasets. The effects on performance were architecture dependent. In the case of CNNs with residual blocks and skip connections, the model was not able to leverage the provided information by image processing filters to converge faster, but CNNs based on VGG had a significantly (up to 125%) faster training time, which is beneficial for training models on embedded devices and edge computing
Three-tiered architecture for access control in internet of medical things / Mahi Uddin
No full textThe Internet of Things (IoT) has made a successful impact on our personal and professional life. More specifically, the internet of medical things (IoMT) is capturing a crucial role in improving healthcare and providing medical facilities to human-being worldwide. Different smart sensors are connected to patients and transfer important data to the healthcare system to monitor and provide better patient treatment. As a result, the number of users is increasing drastically. Connected Internet of Things devices will be 52.2 billion by 2022. Although IoMT is counted as a promising apart in healthcare, the security of patients’ information is still a challenging issue that should be thoroughly addressed. Access control is one of the leading security mechanisms introduced to healthcare to limit access to patients’ information to only authorized individuals. In healthcare, access to the medical record of patients within a minimal time is also extremely important because less time maybe save a life. In this research, designed a three-tiered architecture for access control (T-TAFAC) on IoMT. That uses a hybrid approach by combining a fine-grained attribute-based access control model (ACM), role-based access control model (RBAC), capability-based access control model (CBAC), and using fog computing. Fog computing is a new era of cloud computing that provides computation, storage, and application services to end-users. This implemented schema is eXtensible Access Control Markup Language (XACML) driven. This T-TAFAC reduces the existing processing time. T-TAFAC is emulated as a testbed, provide a performance evaluation of this architecture, and making it compatible for practical use
Service quality framework for mobile government services in Kingdom of Bahrain / Abdulla Jaafar Mohamed Hasan Ali
No full textService quality is the success of any organizations. The advancement of technology encourages the services providers to use electronic forms as new channels to deliver services for the public. Popularity of using smart devices by most of people, leads the government authority to use smart devices as a portal to deliver government services, which is called Mobile Government. The mGovernment authority face difficulties at measuring the service quality at the services delivered through smart devices, that leads the government service provider to use other service quality measurement scales to be used at the context of mGovernment portal. It is difficult to use other measurement scales at the environment of mGovernment services, because each of online service portal has its own features and criteria. The issue here is; there is a lack of integrated, compatible, and comprehensive service quality framework that can be used by government authorities to measure the service quality at mGovernment portal. Therefore, the study targeted the service category of (Government To Citizens – G2C) through the main research objectives of: a) To investigate the service quality dimensions of mGovernment services, b) To develop a service quality framework of mGovernment services, and c) To validate the service quality framework of mGovernment services. Using the Mixed-Method Approach, the researcher applied the Exploratory Sequential Design to integrate both qualitative and quantitative data to investigate the most appropriate factors for mGovernment Service Quality Framework. For qualitative method, interviews with experts were conducted to evaluate the proposed mGovernment quality dimensions with related constructs. While for quantitative method, online questionnaire survey was distributed at the Kingdom of Bahrain and a total valid sample of (934) were collected. Factor analysis were conducted using both Exploratory Factor Analysis (E.F.A.) and Confirmatory Factor Analysis (C.F.A.). The E.F.A. serves at the present study for correlations between variables, factor extraction, factor rotation, and to measure the reliability of the factors. The factor structure of mGovernment framework was verified using C.F.A. The final results show that the mGovernment Service Quality Framework consists of four main dimensions that are “a) Efficiency and Usability, b) Interaction, c) Information and Service Availability, and d) Privacy and Security” with a total of (28) quality constructs. The researcher recommends to conduct advanced analysis for each of the individual quality constructs related to mGovernment service quality
Gallium-doped zinc oxide nanorods for photocatalytic performance under solar irradiation / Sulaiman S.A. Alghafri
No full textIn this thesis, a rapid microwave-assisted method has been used to synthesize pristine and gallium (Ga) doped ZnO nanorods on the glass substrates. With different percentages of the concentration of the gallium nitrate compound in the seeding and growth solutions, the samples were labeled to 0.5%, 1%, 3% and 5% Ga-doped ZnO nanorods. These samples were used to degrade artificial water pollutants by adding methylene blue dye in water and to track the percentage of analysis for each sample. Prepared samples were characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX), Atomic Force Microscopy (AFM), UV-Vis spectroscopy, Photoluminescence (Shtepliuk) spectroscopy, Fourier Transform Infra-red (FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and methylene blue degradation photo-catalyst efficiency analysis. The degradation of methylene blue in the presence of a prepared sample has been followed systematically. The results showed that the diameter and length of the nanorods significantly change with Ga doping from 0% to 5% from 63.2 ± 0.2 to 85.2 ± 0.2 nm diameter and from 0.64 ± 0.01 to 2.08 ± 0.02 μm length. Comparably, the crystal orientation and surface oxidation states from mean crystallite grain size (D) and the FWHM values at the peak position are also Ga content dependent. The existence of Ga-O bonds in the ZnO lattice is evidenced by XRD, which confirms the effective Ga-doping of ZnO NRs. The 1% Ga doping sample showed significant enhancement in visible light absorption, effective change carrier separation, and rapid degradation rate (60 min) compared to the pristine sample