King Abdulazis University

Jeddah, Saudi Arabia

King Abdulazis University

Jeddah, Saudi Arabia
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Ewais H.A.,King Abdulaziz University | Ewais H.A.,Beni Suef University | Ismail I.M.I.,King Abdulaziz University | Ismail I.M.I.,King Abdulazis University | And 2 more authors.
Oxidation Communications | Year: 2014

The oxidation of the ternary complex, [Cr(III)(Gu)(Asp)(H 2O)2]2+ (Gu = guanosine and Asp = DL-Aspartic acid) by periodate in aqueous solution to chromium(VI) has been studied spectrophotometrically over the 25-45°C range. The reaction is first order with respect to both [IO4 -] and [Cr(III)], and increases with pH over the 2.38-3.68 range. The experimental rate law is consistent with the derived mechanism and the reaction follows the rate law: d[Cr(III)]/dt = (k1K5 + k2K6K1/[H +])[IO4 -][Cr(III)]T/{1 + K 1/[H+] + (K5 + K1K 6/[H+])[IO4 -]}, where K1, K5 and K6 are the deprotonation of [Cr(III)(Gu)(Asp) (H2O)2]2+ and preequilibrium formation constants for [Cr(III)(Gu)(Asp)(H2O)(OIO3)]+ and [Cr(III)(Gu) (Asp)(OH)OIO3] precursor complexes, respectively. The reaction may follow a 2-step inner-sphere electron transfer mechanism via coordination of IO4 - to chromium(III). Thermodynamic activation parameters have been calculated.

Taruno W.P.,Spectra - Physics | Baidillah M.R.,Spectra - Physics | Sulaiman R.I.,Spectra - Physics | Ihsan M.F.,Spectra - Physics | And 4 more authors.
Proceedings - International Symposium on Biomedical Imaging | Year: 2013

A real time, volumetric (4D) imaging for human brain activity based on Electrical Capacitance Volume Tomography (ECVT) has been proposed, for the first time, in this work. The ECVT has been used to measure electrical signals generated from human brain activity and reconstruct volumetric image of the brain signal in real time. The ECVT system comprises of a helmet shaped capacitive sensor, 32-channel data acquisition system and a computer system to control the measurement, process the image reconstruction and display the brain activities on the scalp and inside the brain. Tests with simulation as well as experimental data showed different images of charged as compared to non-charged phantoms. The charged phantoms used an electrical source of 100mV with 250Hz positive pulses to simulate the action potentials of the brain. The ECVT has also been applied to monitor activity of the brain during different stimulations. Electrical signals measured from capacitance electrodes clearly showed significant differences when the brain was in rest and in high tasks such as listening to music, moving hands and solving a mathematical problem. Preliminary results have shown that ECVT was able to detect brain activities related to human motoric and language functions. © 2013 IEEE.

Taruno W.P.,Spectra - Physics | Ihsan M.F.,Spectra - Physics | Baidillah M.R.,Spectra - Physics | Tandian T.,Bandung Institute of Technology | And 2 more authors.
Middle East Conference on Biomedical Engineering, MECBME | Year: 2014

In this study we performed brain activity observation related to simple tasks of executed movement (EM) and imagined movement (IM) using Electrical Capacitance Volume Tomography (ECVT). ECVT has been previously applied to brain activity imaging and brain cancer detection. This study is intended to elaborate further the previous studies on the brain functional imaging. Experiment on human subjects was conducted by measuring brain signals using ECVT during five conditions: (1) relax: baseline condition, (2) actual movement with the right hands and left hands, (3) imagined movement with right and left hands. Signal normalization was used to extract the ECVT brain activity signals related to a particular condition. Qualitative and quantitative analysis was performed on the ECVT images of brain activity related to EM and IM tasks. The results indicate that lateral brain activation can be observed using ECVT in concordance with fMRI studies. © 2014 IEEE.

Taruno W.P.,Edwar Technology Co. | Baidillah M.R.,Edwar Technology Co. | Sulaiman R.I.,Edwar Technology Co. | Yusuf A.,Edwar Technology Co. | And 3 more authors.
Proceedings of IEEE Sensors | Year: 2012

In this study, we proposed a novel sensor for real time 3D imaging of cancerous mass within human breast using the capacitance measurement method, namely Electrical Capacitance Volume Tomography developed earlier. The sensor works based on the fact that cancerous mass has much higher relative permittivity as compared with normal breast tissue. The electrical capacitance volume tomography (ECVT) imaging technique is capable of generating volumetric image of permittivity distribution of the breast in real time. The 3D sensor constitutes a half-sphere of sensing region to capture the whole permittivity image of the breast. The sensor consists of 24 electrodes with combined triangular and rectangular shapes. Simulated phantoms as well as actual phantom of human breast constituting paraffin as normal human breast tissue and rubber as breast cancer tissue have been used to test the reliability of the sensor system to evaluate the performance of the ECVT technique for breast cancer imaging. The reconstructed images using simulated objects as well as actual measurement using the actual phantom have shown accurate permittivity distributions. The results obtained showed a great feasibility of the 4D tomography imaging as an alternative for a robust and high speed nonradiation technique for breast cancer screening. © 2012 IEEE.

Taruno W.P.,Edwar Technology Co. | Baidillah M.R.,Edwar Technology Co. | Sulaiman R.I.,Edwar Technology Co. | Ihsan M.F.,Edwar Technology Co. | And 3 more authors.
International IEEE/EMBS Conference on Neural Engineering, NER | Year: 2013

In this study, for the first time, we have used the ECVT technique, developed earlier for real-time and volumetric imaging of brain activity, to detect the presence of brain tumor. The ECVT sensor system measures the capacitance of electrical signals of the brain on the cortex, and generates a volumetric map of the brain activity on the cortex and inside the brain through a tomography image reconstruction algorithm based on a Neural-Network Multi-criteria Optimization Image Reconstruction Technique (NN-MOIRT). The ECVT is able to detect brain tumors through an examination of the brain functional abnormalities, as the tumors block the propagation of neuro-signals and cause abnormalities in the brain activity image. The ECVT sensor design has been optimized for the detection of the brain tumors in different sensitivity regions of the brain. Case studies have been carried out to five volunteers suffering from different brain tumors including ependymoma, oligodendroglioma, cranio-pharyngioma, germinoma pineal, and cerebellopontine angle tumors. Comparisons with their respective CT and MRI results have also been performed. The study has shown a great feasibility of the 4D imaging technique as a complementary alternative for a high speed non-radiation technique for brain cancer detection and functional imaging. © 2013 IEEE.

Hedia H.S.,King Abdulazis University | Aldousari S.M.,King Abdulazis University | Khairy A.,King Abdulazis University | Aljabarti E.,King Abdulazis University | Aljabarti E.,Saudi Electricity Company
Materialpruefung/Materials Testing | Year: 2012

Recently, nano-materials have received increasingly more attention for their potential applications as structural and functional materials. The unique mechanical properties of CNTs, their high strength and stiffness and the enormous aspect ratio provide potentials for the improvement of the mechanical properties of structural materials. The aim of this research is to investigate experimentally the effect of nanocomposite coating on the fatigue life of carbon steel AISI 1045 specimens with different surface finishes. Nanoadhesives of epoxy resin are synthesized and evaluated. They are originally modified by multiwalled carbon nanotubes (MWCNT) with 0.5 wt.-% as reinforcement. Fatigue tests are conducted on the respective specimens by a rotating bending machine of the cantilever type. Comparing the results for specimens coated with 0.5 wt.-% MWCNT-epoxy composition with the base materials it is found that fatigue life increased five times for a roughness of 0.3 urn and three times for an average specimen roughness of 0.8, 1.6 and 2.5 urn, respectively. © Carl Hanser Verlag, München.

Fleige C.,University of Munster | Steinbuchel A.,University of Munster | Steinbuchel A.,King Abdulazis University
Applied Microbiology and Biotechnology | Year: 2014

Amycolatopsis sp. ATCC 39116 is able to synthesize the important flavoring agent vanillin from cheap natural substrates. The bacterium is therefore of great interest for the industry and used for the fermentative production of vanillin. In order to improve the production of natural vanillin with Amycolatopsis sp. ATCC 39116, the strain has been genetically engineered to optimize the metabolic flux towards the desired product. Extensive metabolic engineering was hitherto hampered, due to the lack of genetic tools like functional promoters and expression vectors. In this study, we report the establishment of a plasmid-based gene expression system for Amycolatopsis sp. ATCC 39116 that allows a further manipulation of the genotype. Four new Escherichia coli-Amycolatopsis shuttle vectors harboring different promoter elements were constructed, and the functionality of these regulatory elements was proven by the expression of the reporter gene gusA, encoding a β-glucuronidase. Glucuronidase activity was detected in all plasmid-harboring strains, and remarkable differences in the expression strength of the reporter gene depending on the used promoter were observed. The new expression vectors will promote the further genetic engineering of Amycolatopsis sp. ATCC 39116 to get insight into the metabolic network and to improve the strain for a more efficient industrial use. © 2014 Springer-Verlag.

Fleige C.,University of Munster | Hansen G.,University of Munster | Kroll J.,University of Munster | Steinbuchel A.,University of Munster | Steinbuchel A.,King Abdulazis University
Applied and Environmental Microbiology | Year: 2013

The actinomycete Amycolatopsis sp. strain ATCC 39116 is capable of synthesizing large amounts of vanillin from ferulic acid, which is a natural cell wall component of higherplants. The desired intermediate vanillin is subject to undesired catabolism caused by the metabolic activity of a hitherto unknown vanillin dehydrogenase (VDHATCC 39116). In order to prevent the oxidation of vanillin to vanillic acid and thereby to obtainhigher yields and concentrations of vanillin, the responsible vanillin dehydrogenase in Amycolatopsis sp. ATCC 39116 was investigated for the first time by using data from our genome sequence analysis and further bioinformatic approaches. The vdh gene was heterologously expressed in Escherichia coli, and the encoded vanillin dehydrogenase was characterized in detail. VDHATCC 39116 was purified to apparent electrophoretic homogeneity and exhibited NAD+-dependent activity toward vanillin, coniferylaldehyde, cinnamaldehyde, and benzaldehyde. The enzyme showed its highest level of activity toward vanillin atpH 8.0 and at a temperature of 44°C. In a next step, a precise vdh deletion mutant ofAmycolatopsis sp. ATCC 39116 was generated. The mutant lost its ability to grow on vanillin and did not show vanillin dehydrogenase activity. A 2.3-times-higher vanillin concentration and a substantially reduced amount of vanillic acid occurred with the Amycolatopsissp. ATCC 39116 δvdh::Kmr mutant when ferulic acid was provided for biotransformation in a cultivation experiment on a 2-liter-bioreactor scale. Based on these results and taking further metabolic engineering into account, the Amycolatopsis sp. ATCC 39116 δvdh::Kmr mutant represents an optimized and industrially applicable platform for the biotechnological production of natural vanillin. © 2012, American Society for Microbiology.

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