56 results on '"Foo, KY"'
Search Results
2. AD HOC SYNCHRONISATION IN A MULTIPLE HOP UNDERWATER NETWORK
- Author
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FOO, KY, primary, ATKINS, PR, additional, ATKINS, SA, additional, and TILTMAN, CP, additional
- Published
- 2023
- Full Text
- View/download PDF
3. Multi-class classification of breast tissue using optical coherence tomography and attenuation imaging combined via deep learning
- Author
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Foo, KY, Newman, K, Fang, Q, Gong, P, Ismail, HM, Lakhiani, DD, Zilkens, R, Dessauvagie, BF, Latham, B, Saunders, CM, Chin, L, Kennedy, BF, Foo, KY, Newman, K, Fang, Q, Gong, P, Ismail, HM, Lakhiani, DD, Zilkens, R, Dessauvagie, BF, Latham, B, Saunders, CM, Chin, L, and Kennedy, BF
- Abstract
We demonstrate a convolutional neural network (CNN) for multi-class breast tissue classification as adipose tissue, benign dense tissue, or malignant tissue, using multi-channel optical coherence tomography (OCT) and attenuation images, and a novel Matthews correlation coefficient (MCC)-based loss function that correlates more strongly with performance metrics than the commonly used cross-entropy loss. We hypothesized that using multi-channel images would increase tumor detection performance compared to using OCT alone. 5,804 images from 29 patients were used to fine-tune a pre-trained ResNet-18 network. Adding attenuation images to OCT images yields statistically significant improvements in several performance metrics, including benign dense tissue sensitivity (68.0% versus 59.6%), malignant tissue positive predictive value (PPV) (79.4% versus 75.5%), and total accuracy (85.4% versus 83.3%), indicating that the additional contrast from attenuation imaging is most beneficial for distinguishing between benign dense tissue and malignant tissue.
- Published
- 2022
4. Quantitative Micro-Elastography Enables In Vivo Detection of Residual Cancer in the Surgical Cavity during Breast-Conserving Surgery
- Author
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Gong, P, Chin, SL, Allen, WM, Ballal, H, Anstie, JD, Chin, L, Ismail, HM, Zilkens, R, Lakhiani, DD, McCarthy, M, Fang, Q, Firth, D, Newman, K, Thomas, C, Li, J, Sanderson, RW, Foo, KY, Yeomans, C, Dessauvagie, BF, Latham, B, Saunders, CM, Kennedy, BF, Gong, P, Chin, SL, Allen, WM, Ballal, H, Anstie, JD, Chin, L, Ismail, HM, Zilkens, R, Lakhiani, DD, McCarthy, M, Fang, Q, Firth, D, Newman, K, Thomas, C, Li, J, Sanderson, RW, Foo, KY, Yeomans, C, Dessauvagie, BF, Latham, B, Saunders, CM, and Kennedy, BF
- Abstract
UNLABELLED: Breast-conserving surgery (BCS) is commonly used for the treatment of early-stage breast cancer. Following BCS, approximately 20% to 30% of patients require reexcision because postoperative histopathology identifies cancer in the surgical margins of the excised specimen. Quantitative micro-elastography (QME) is an imaging technique that maps microscale tissue stiffness and has demonstrated a high diagnostic accuracy (96%) in detecting cancer in specimens excised during surgery. However, current QME methods, in common with most proposed intraoperative solutions, cannot image cancer directly in the patient, making their translation to clinical use challenging. In this proof-of-concept study, we aimed to determine whether a handheld QME probe, designed to interrogate the surgical cavity, can detect residual cancer directly in the breast cavity in vivo during BCS. In a first-in-human study, 21 BCS patients were scanned in vivo with the QME probe by five surgeons. For validation, protocols were developed to coregister in vivo QME with postoperative histopathology of the resected tissue to assess the capability of QME to identify residual cancer. In four cavity aspects presenting cancer and 21 cavity aspects presenting benign tissue, QME detected elevated stiffness in all four cancer cases, in contrast to low stiffness observed in 19 of the 21 benign cases. The results indicate that in vivo QME can identify residual cancer by directly imaging the surgical cavity, potentially providing a reliable intraoperative solution that can enable more complete cancer excision during BCS. SIGNIFICANCE: Optical imaging of microscale tissue stiffness enables the detection of residual breast cancer directly in the surgical cavity during breast-conserving surgery, which could potentially contribute to more complete cancer excision.
- Published
- 2022
5. Optical palpation for tumor margin assessment in breast-conserving surgery
- Author
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Foo, KY, Kennedy, KM, Zilkens, R, Allen, WM, Fang, Q, Sanderson, RW, Anstie, J, Dessauvagie, BF, Latham, B, Saunders, CM, Chin, L, Kennedy, BF, Foo, KY, Kennedy, KM, Zilkens, R, Allen, WM, Fang, Q, Sanderson, RW, Anstie, J, Dessauvagie, BF, Latham, B, Saunders, CM, Chin, L, and Kennedy, BF
- Abstract
Intraoperative margin assessment is needed to reduce the re-excision rate of breast-conserving surgery. One possibility is optical palpation, a tactile imaging technique that maps stress (force applied across the tissue surface) as an indicator of tissue stiffness. Images (optical palpograms) are generated by compressing a transparent silicone layer on the tissue and measuring the layer deformation using optical coherence tomography (OCT). This paper reports, for the first time, the diagnostic accuracy of optical palpation in identifying tumor within 1 mm of the excised specimen boundary using an automated classifier. Optical palpograms from 154 regions of interest (ROIs) from 71 excised tumor specimens were obtained. An automated classifier was constructed to predict the ROI margin status by first choosing a circle diameter, then searching for a location within the ROI where the circle was ≥ 75% filled with high stress (indicating a positive margin). A range of circle diameters and stress thresholds, as well as the impact of filtering out non-dense tissue regions, were tested. Sensitivity and specificity were calculated by comparing the automated classifier results with the true margin status, determined from co-registered histology. 83.3% sensitivity and 86.2% specificity were achieved, compared to 69.0% sensitivity and 79.0% specificity obtained with OCT alone on the same dataset using human readers. Representative optical palpograms show that positive margins containing a range of cancer types tend to exhibit higher stress compared to negative margins. These results demonstrate the potential of optical palpation for margin assessment.
- Published
- 2021
6. Three-dimensional mapping of the attenuation coefficient in optical coherence tomography to enhance breast tissue microarchitecture contrast
- Author
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Foo, KY, Chin, L, Zilkens, R, Lakhiani, DD, Fang, Q, Sanderson, R, Dessauvagie, BF, Latham, B, McLaren, S, Saunders, CM, Kennedy, BF, Foo, KY, Chin, L, Zilkens, R, Lakhiani, DD, Fang, Q, Sanderson, R, Dessauvagie, BF, Latham, B, McLaren, S, Saunders, CM, and Kennedy, BF
- Abstract
Effective intraoperative tumor margin assessment is needed to reduce re-excision rates in breast-conserving surgery (BCS). Mapping the attenuation coefficient in optical coherence tomography (OCT) throughout a sample to create an image (attenuation imaging) is one promising approach. For the first time, three-dimensional OCT attenuation imaging of human breast tissue microarchitecture using a wide-field (up to ~45 × 45 × 3.5 mm) imaging system is demonstrated. Representative results from three mastectomy and one BCS specimen (from 31 specimens) are presented with co-registered postoperative histology. Attenuation imaging is shown to provide substantially improved contrast over OCT, delineating nuanced features within tumors (including necrosis and variations in tumor cell density and growth patterns) and benign features (such as sclerosing adenosis). Additionally, quantitative micro-elastography (QME) images presented alongside OCT and attenuation images show that these techniques provide complementary contrast, suggesting that multimodal imaging could increase tissue identification accuracy and potentially improve tumor margin assessment.
- Published
- 2020
7. Camera-based optical palpation
- Author
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Sanderson, RW, Fang, Q, Curatolo, A, Adams, W, Lakhiani, DD, Ismail, HM, Foo, KY, Dessauvagie, BF, Latham, B, Yeomans, C, Saunders, CM, Kennedy, BF, Sanderson, RW, Fang, Q, Curatolo, A, Adams, W, Lakhiani, DD, Ismail, HM, Foo, KY, Dessauvagie, BF, Latham, B, Yeomans, C, Saunders, CM, and Kennedy, BF
- Abstract
Optical elastography is undergoing extensive development as an imaging tool to map mechanical contrast in tissue. Here, we present a new platform for optical elastography by generating sub-millimetre-scale mechanical contrast from a simple digital camera. This cost-effective, compact and easy-to-implement approach opens the possibility to greatly expand applications of optical elastography both within and beyond the field of medical imaging. Camera-based optical palpation (CBOP) utilises a digital camera to acquire photographs that quantify the light intensity transmitted through a silicone layer comprising a dense distribution of micro-pores (diameter, 30-100 µm). As the transmission of light through the micro-pores increases with compression, we deduce strain in the layer directly from intensity in the digital photograph. By pre-characterising the relationship between stress and strain of the layer, the measured strain map can be converted to an optical palpogram, a map of stress that visualises mechanical contrast in the sample. We demonstrate a spatial resolution as high as 290 µm in CBOP, comparable to that achieved using an optical coherence tomography-based implementation of optical palpation. In this paper, we describe the fabrication of the micro-porous layer and present experimental results from structured phantoms containing stiff inclusions as small as 0.5 × 0.5 × 1 mm. In each case, we demonstrate high contrast between the inclusion and the base material and validate both the contrast and spatial resolution achieved using finite element modelling. By performing CBOP on freshly excised human breast tissue, we demonstrate the capability to delineate tumour from surrounding benign tissue.
- Published
- 2020
8. Handheld volumetric manual compression-based quantitative microelastography
- Author
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Fang, Q, Frewer, L, Zilkens, R, Krajancich, B, Curatolo, A, Chin, L, Foo, KY, Lakhiani, DD, Sanderson, RW, Wijesinghe, P, Anstie, JD, Dessauvagie, BF, Latham, B, Saunders, CM, Kennedy, BF, Fang, Q, Frewer, L, Zilkens, R, Krajancich, B, Curatolo, A, Chin, L, Foo, KY, Lakhiani, DD, Sanderson, RW, Wijesinghe, P, Anstie, JD, Dessauvagie, BF, Latham, B, Saunders, CM, and Kennedy, BF
- Abstract
Compression optical coherence elastography (OCE) typically requires a mechanical actuator to impart a controlled uniform strain to the sample. However, for handheld scanning, this adds complexity to the design of the probe and the actuator stroke limits the amount of strain that can be applied. In this work, we present a new volumetric imaging approach that utilizes bidirectional manual compression via the natural motion of the user's hand to induce strain to the sample, realizing compact, actuator-free, handheld compression OCE. In this way, we are able to demonstrate rapid acquisition of three-dimensional quantitative microelastography (QME) datasets of a tissue volume (6 × 6 × 1 mm3 ) in 3.4 seconds. We characterize the elasticity sensitivity of this freehand manual compression approach using a homogeneous silicone phantom and demonstrate comparable performance to a benchtop mounted, actuator-based approach. In addition, we demonstrate handheld volumetric manual compression-based QME on a tissue-mimicking phantom with an embedded stiff inclusion and on freshly excised human breast specimens from both mastectomy and wide local excision (WLE) surgeries. Tissue results are coregistered with postoperative histology, verifying the capability of our approach to measure the elasticity of tissue and to distinguish stiff tumor from surrounding soft benign tissue.
- Published
- 2020
9. A Case of undiagnosed Pseudoaneurysm caused by an open tibial fracture
- Author
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Gunalan, R and Foo, KY
- Subjects
Letter to the Editor - Published
- 2016
10. Field Management of Hot Mix Asphalt Volumetric Properties
- Author
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Kandhal, PS, primary, Foo, KY, additional, and D'Angelo, JA, additional
- Full Text
- View/download PDF
11. Designing Recycled Hot Mix Asphalt Mixtures Using Superpave Technology
- Author
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Kandhal, PS, primary and Foo, KY, additional
- Full Text
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12. Adapting Superpave Technology to Design of Hot Recycled Mixes
- Author
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Petersen, DR, primary, Foo, KY, additional, and Kandhal, PS, additional
- Published
- 1998
- Full Text
- View/download PDF
13. Evaluation of Variability in Resilient Modulus Test Results (ASTM D 4123)
- Author
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Wolfenden, A, primary, Brown, ER, additional, and Foo, KY, additional
- Published
- 1991
- Full Text
- View/download PDF
14. Adapting Superpave Technology to Design of Hot Recycled Mixes
- Author
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Foo, KY and Kandhal, PS
- Abstract
Mix design procedures for recycled asphalt pavements require the selection of virgin asphalt or recycling agent and recycled hot mix asphalt (HMA) mix design. This research project was undertaken (a) to develop a procedure for selecting the performance grade (PG) of virgin asphalt binder based on the Superpave PG grading system and (b) to design hot recycled mix using Superpave technology. Blending charts were constructed and used to select the PG grade of virgin asphalt binder for mixes with 0, 20, 30, and 40 percent of recycled asphalt pavement material (RAP). Superpave volumetric mix design were conducted on mixes with 0, 20, 30, and 40 percent RAP. Evaluation of the volumetric properties of these mixes has indicated that the Superpave volumetric mix design procedures can be adapted to design recycled HMA mixtures with minimal modification.
- Published
- 1998
- Full Text
- View/download PDF
15. Evaluation of Variability in Resilient Modulus Test Results (ASTM D 4123)
- Author
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Brown, ER and Foo, KY
- Abstract
Samples of asphalt mixture were evaluated in the laboratory under various conditions to evaluate the repeatability of the resilient modulus test and the effect of stress on the measured resilient modulus. Some samples were prepared in the laboratory, others were obtained from in-place pavements that had been subjected to traffic. The independent variables included stress, test temperature, and maximum aggregate size.Tests were repeated a number of times, and the data were analyzed by Statistical Analysis System (SAS) to investigate their repeatability. This study quantified the repeatability of the ASTM D 4123 resilient modulus test as a function of stiffness. The repeatability of ASTM D 4123 is low. A significant increase in the number of samples or number of measurements is required to improve the repeatability. Tests conducted at different stresses showed the resilient modulus to be stress sensitive. This indicated that stress should be specified in the test procedure. A correction factor was established for stresses differing from the recommended stress (15% of tensile strength) for test temperatures of 25 and 40°C.
- Published
- 1991
- Full Text
- View/download PDF
16. Tumor spheroid elasticity estimation using mechano-microscopy combined with a conditional generative adversarial network.
- Author
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Foo KY, Shaddy B, Murgoitio-Esandi J, Hepburn MS, Li J, Mowla A, Sanderson RW, Vahala D, Amos SE, Choi YS, Oberai AA, and Kennedy BF
- Subjects
- Humans, MCF-7 Cells, Algorithms, Image Processing, Computer-Assisted methods, Neural Networks, Computer, Microscopy methods, Tomography, Optical Coherence methods, Finite Element Analysis, Elasticity, Spheroids, Cellular, Elasticity Imaging Techniques methods
- Abstract
Background and Objectives: Techniques for imaging the mechanical properties of cells are needed to study how cell mechanics influence cell function and disease progression. Mechano-microscopy (a high-resolution variant of compression optical coherence elastography) generates elasticity images of a sample undergoing compression from the phase difference between optical coherence microscopy (OCM) B-scans. However, the existing mechano-microscopy signal processing chain (referred to as the algebraic method) assumes the sample stress is uniaxial and axially uniform, such that violation of these assumptions reduces the accuracy and precision of elasticity images. Furthermore, it does not account for prior information regarding the sample geometry or mechanical property distribution. In this study, we investigate the feasibility of training a conditional generative adversarial network (cGAN) to generate elasticity images from phase difference images of samples containing a cell spheroid embedded in a hydrogel., Methods: To construct the cGAN training and simulated test sets, we generated 30,000 artificial elasticity images using a parametric model and computed the corresponding phase difference images using finite element analysis to simulate compression applied to the artificial samples. We also imaged real MCF7 breast tumor spheroids embedded in hydrogel using mechano-microscopy to construct the experimental test set and evaluated the cGAN using the algebraic elasticity images and co-registered OCM and confocal fluorescence microscopy (CFM) images., Results: Comparison with the simulated test set ground truth elasticity images shows the cGAN produces a lower root mean square error (median: 3.47 kPa, 95 % confidence interval (CI) [3.41, 3.52]) than the algebraic method (median: 4.91 kPa, 95 % CI [4.85, 4.97]). For the experimental test set, the cGAN elasticity images contain features resembling stiff nuclei at locations corresponding to nuclei seen in the algebraic elasticity, OCM, and CFM images. Furthermore, the cGAN elasticity images are higher resolution and more robust to noise than the algebraic elasticity images., Conclusions: The cGAN elasticity images exhibit better accuracy, spatial resolution, sensitivity, and robustness to noise than the algebraic elasticity images for both simulated and real experimental data., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships that may be considered as potential competing interests: BFK reports a relationship with OncoRes Medical Pty Ltd that includes equity or stocks. All other authors declare that there are no conflicts of interest related to this article., (Copyright © 2024. Published by Elsevier B.V.)
- Published
- 2024
- Full Text
- View/download PDF
17. Quantitative Micro-Elastography Enables In Vivo Detection of Residual Cancer in the Surgical Cavity during Breast-Conserving Surgery.
- Author
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Gong P, Chin SL, Allen WM, Ballal H, Anstie JD, Chin L, Ismail HM, Zilkens R, Lakhiani DD, McCarthy M, Fang Q, Firth D, Newman K, Thomas C, Li J, Sanderson RW, Foo KY, Yeomans C, Dessauvagie BF, Latham B, Saunders CM, and Kennedy BF
- Subjects
- Female, Humans, Breast Neoplasms pathology, Breast Neoplasms surgery, Margins of Excision, Elasticity Imaging Techniques methods, Mastectomy, Segmental methods, Neoplasm, Residual diagnostic imaging
- Abstract
Breast-conserving surgery (BCS) is commonly used for the treatment of early-stage breast cancer. Following BCS, approximately 20% to 30% of patients require reexcision because postoperative histopathology identifies cancer in the surgical margins of the excised specimen. Quantitative micro-elastography (QME) is an imaging technique that maps microscale tissue stiffness and has demonstrated a high diagnostic accuracy (96%) in detecting cancer in specimens excised during surgery. However, current QME methods, in common with most proposed intraoperative solutions, cannot image cancer directly in the patient, making their translation to clinical use challenging. In this proof-of-concept study, we aimed to determine whether a handheld QME probe, designed to interrogate the surgical cavity, can detect residual cancer directly in the breast cavity in vivo during BCS. In a first-in-human study, 21 BCS patients were scanned in vivo with the QME probe by five surgeons. For validation, protocols were developed to coregister in vivo QME with postoperative histopathology of the resected tissue to assess the capability of QME to identify residual cancer. In four cavity aspects presenting cancer and 21 cavity aspects presenting benign tissue, QME detected elevated stiffness in all four cancer cases, in contrast to low stiffness observed in 19 of the 21 benign cases. The results indicate that in vivo QME can identify residual cancer by directly imaging the surgical cavity, potentially providing a reliable intraoperative solution that can enable more complete cancer excision during BCS., Significance: Optical imaging of microscale tissue stiffness enables the detection of residual breast cancer directly in the surgical cavity during breast-conserving surgery, which could potentially contribute to more complete cancer excision., (©2022 The Authors; Published by the American Association for Cancer Research.)
- Published
- 2022
- Full Text
- View/download PDF
18. Multi-class classification of breast tissue using optical coherence tomography and attenuation imaging combined via deep learning.
- Author
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Foo KY, Newman K, Fang Q, Gong P, Ismail HM, Lakhiani DD, Zilkens R, Dessauvagie BF, Latham B, Saunders CM, Chin L, and Kennedy BF
- Abstract
We demonstrate a convolutional neural network (CNN) for multi-class breast tissue classification as adipose tissue, benign dense tissue, or malignant tissue, using multi-channel optical coherence tomography (OCT) and attenuation images, and a novel Matthews correlation coefficient (MCC)-based loss function that correlates more strongly with performance metrics than the commonly used cross-entropy loss. We hypothesized that using multi-channel images would increase tumor detection performance compared to using OCT alone. 5,804 images from 29 patients were used to fine-tune a pre-trained ResNet-18 network. Adding attenuation images to OCT images yields statistically significant improvements in several performance metrics, including benign dense tissue sensitivity (68.0% versus 59.6%), malignant tissue positive predictive value (PPV) (79.4% versus 75.5%), and total accuracy (85.4% versus 83.3%), indicating that the additional contrast from attenuation imaging is most beneficial for distinguishing between benign dense tissue and malignant tissue., Competing Interests: BL: OncoRes Medical (I), CMS: OncoRes Medical (I,S), LC: OncoRes Medical (I,E), BFK: OncoRes Medical (F,I). The other authors declare no conflicts of interest., (© 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.)
- Published
- 2022
- Full Text
- View/download PDF
19. One-step synthesis of carbonaceous adsorbent from soybean bio-residue by microwave heating: Adsorptive, antimicrobial and antifungal behavior.
- Author
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Lim KY and Foo KY
- Subjects
- Adsorption, Anti-Bacterial Agents, Charcoal, Heating, Hydrogen-Ion Concentration, Kinetics, Methylene Blue analysis, Microwaves, Glycine max, Antifungal Agents, Water Pollutants, Chemical analysis
- Abstract
In this work, the transformation of soybean industrial bio-residue with limited practical applications, into a multifunctional carbonaceous adsorbent (SBAC) via one-step microwave-irradiation has been succeeded. The surface porosity, chemical compositions, functionalities and surface chemistry were featured by microscopic pore-textural analysis, elemental constitution analysis, morphological characterization and Fourier transform infra-red spectroscopy. The adsorptive performance of SBAC was evaluated in a batch experiment by adopting different classes of water pollutants, specifically methylene blue (MB), acetaminophen and 2,4-dichlorophenoxyacetic acid (2,4-D). The equilibrium uptakes were analyzed with respect to the non-linearized Langmuir, Freundlich and Temkin isotherm equations. The unique features of SBAC, specifically the antimicrobial and antifungal efficacies were examined against gram-positive/negative bacteria and fungi species. An ordered microporous-mesoporous structure of SBAC, with the BET surface area and total pore volume of 1696 m
2 /g and 0.94 m3 /g, respectively, has been achieved. The equilibrium data of MB and acetaminophen were found to be in good agreement with the Langmuir isotherm model, with the monolayer adsorption capacities (Qo ) of 434.57 mg/g and 393.31 mg/g, respectively. The adsorptive experiment of 2,4-D was best fitted to the Freundlich isotherm equation, with the Qo of 253.17 mg/g. The regeneration performance of the spent SBAC under microwave-irradiation could maintain at 69.42-79.31%, even after five (5) adsorption-regeneration cycles. SBAC exhibited excellent inhibition efficiencies against gram-positive/negative bacteria and fungi species, with the inhibition zones at 14.0-28.0 mm. This newly developed SBAC appears to be a new powerful candidate for the remediation of different classes of water contaminants, and novel antibacterial and antifungal agents against biological contaminations. The novel concept of "turn waste into wealth" in a cost-effective and energy saving manner for environmental preservation has been successfully accomplished., (Copyright © 2021 Elsevier Inc. All rights reserved.)- Published
- 2022
- Full Text
- View/download PDF
20. Sodium salt-assisted low temperature activation of bentonite for the adsorptive removal of methylene blue.
- Author
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Shattar SFA and Foo KY
- Abstract
The sodium salt-assisted low temperature activation of bentonite (BB) was attempted. The unique features of the raw bentonite and BB were characterized with respect to the morphological, functional, and textural analysis. The adsorptive behaviour was evaluated by adopting methylene blue (MB) as the model pollutant via batch adsorption experiment. The experimental data were fitted to the non-linear isotherm equations (Freundlich, Langmuir, and Temkin), while the adsorption modelling was interpreted by the pseudo-first order, pseudo-second order and Elovich models. The adsorptive mechanism was ascertained according to intraparticle-diffusion and boyd models. The intercalation of sodium salt into the bentonite surface give rise to the specific surface area and total pore volume from 120.34 to 426.91, m
2 /g and 0.155 to 0.225 cm3 /g, respectively, indicating a large proportion of the newly formed surfaces may be connected to new pore walls, associated with the silanol (≡SiOH), and aluminol (≡AlOH), and hydroxyl (-OH) groups for the possible entrapment MB onto the adsorbent. The equilibrium data was satisfactory described by the Langmuir isotherm and pseudo-second order model, with a monolayer adsorption capacity for MB of 318.38 mg/g, while the thermodynamic study verified spontaneous, feasible, and endothermic of the adsorption process., (© 2022. The Author(s).)- Published
- 2022
- Full Text
- View/download PDF
21. Hydrothermal synthesis of phosphorylated chitosan and its adsorption performance towards Acid Red 88 dye.
- Author
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Subramaniam S, Foo KY, Md Yusof EN, Jawad AH, Wilson LD, and Sabar S
- Subjects
- Phosphorylation, Azo Compounds chemistry, Chitosan chemistry, Coloring Agents chemistry, Hot Temperature
- Abstract
Phosphorylated chitosan (P-CS) was successfully synthesized using a facile experimental setup of hydrothermal method that was applied to the adsorption of anionic Acid Red 88 (AR88) from aqueous media. The adsorption process obeyed the pseudo-second-order (PSO) kinetic model. In contrast, the adsorption isotherm conformed to the Langmuir model, with the maximum adsorption capacity (q
m = 230 mg g-1 ) at 303 K. Both external and intraparticle diffusion strongly influenced the rate of adsorption. The insights from this study reveal that P-CS could be easily prepared and regenerated for reusability applications. The adsorption mechanism and intermolecular interaction between P-CS and AR 88 were investigated using Fourier transform infrared (FTIR) spectroscopy and calculations via Density Functional Theory (DFT). The key modes of adsorption for the P-CS/AR 88 system are driven by electrostatic attractions, H-bonding, and n-π interactions. The findings herein reveal that P-CS is a promising adsorbent for the removal of anionic dyes such as AR88 or similar pollutants from water., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
22. Hazard identification and risk assessment of the organic, inorganic and microbial contaminants in the surface water after the high magnitude of flood event.
- Author
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Lim KY and Foo KY
- Subjects
- China, Ecosystem, Environmental Monitoring, Escherichia coli, Floods, Humans, Risk Assessment, Water, Metals, Heavy analysis, Water Pollutants, Chemical analysis
- Abstract
The present work has been oriented to the qualitative and quantitative assessments of the aftermath effects of 2014 flood tragedy on the organic, inorganic and microbial contaminants in the floodwater, with a particular emphasis on their relative health risks and microbial infectious hazards to the flood-affected population, using average daily dose, hazard quotient, hazard index (HI), cancer risk (CR) and quantitative microbial risk assessment. Statistical comparison of the organic and inorganic contents was performed using the paired t-tests, while the predominant socio-demographic profiles and health attributes of the respondents to flood-induced health risks (HI) were verified by the chi-square test and binary logistic regression analysis. Among all, Fe, Cu, Pb, Ni, Zn, Cr, Cd, chlorpyrifos, diazinon, polycyclic aromatic hydrocarbons, estriol, 17α-ethinylestradiol, estrone, β-estradiol and bisphenol A were detected at the study area after flooding. The microbiological quality of the floodwater samples has been tracked positive for Escherichia coli, Salmonella typhimurium and Shigella flexneri, with the mean concentrations of 6500, 50 and 180 CFU/100 mL, respectively. Exposure and health risk assessments revealed that the overall HI value for organic and inorganic contaminants in the water samples was 1.19, exceeding the USEPA maximum limit of 1, after the flood incidence. The largest CR contributors were Ni, Cr and Cd, while the infection risks (P
inf,single ) associated with the exposure of E. coli, Salmonella spp. and Shigella spp. were identified to be 3.1 × 10-2 , 1.2 × 10-4 and 3.2 × 10-5 for incidental scenario; and 8.3 × 10-1 , 3.9 × 10-1 and 1.9 × 10-1 for intentional scenario, respectively. The findings of these integrated tools are critically important to provide a more reliable quantitative assessment of human health hazards and microbial risks for different environmental settings, to safeguard water resource, and preservation of public health and the overall river ecosystem., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
23. Speckle-dependent accuracy in phase-sensitive optical coherence tomography.
- Author
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Hepburn MS, Foo KY, Wijesinghe P, Munro PRT, Chin L, and Kennedy BF
- Abstract
Phase-sensitive optical coherence tomography (OCT) is used to measure motion in a range of techniques, such as Doppler OCT and optical coherence elastography (OCE). In phase-sensitive OCT, motion is typically estimated using a model of the OCT signal derived from a single reflector. However, this approach is not representative of turbid samples, such as tissue, which exhibit speckle. In this study, for the first time, we demonstrate, through theory and experiment that speckle significantly lowers the accuracy of phase-sensitive OCT in a manner not accounted for by the OCT signal-to-noise ratio (SNR). We describe how the inaccuracy in speckle reduces phase difference sensitivity and introduce a new metric, speckle brightness, to quantify the amount of constructive interference at a given location in an OCT image. Experimental measurements show an almost three-fold degradation in sensitivity between regions of high and low speckle brightness at a constant OCT SNR. Finally, we apply these new results in compression OCE to demonstrate a ten-fold improvement in strain sensitivity, and a five-fold improvement in contrast-to-noise by incorporating independent speckle realizations. Our results show that speckle introduces a limit to the accuracy of phase-sensitive OCT and that speckle brightness should be considered to avoid erroneous interpretation of experimental data.
- Published
- 2021
- Full Text
- View/download PDF
24. Optical palpation for tumor margin assessment in breast-conserving surgery.
- Author
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Foo KY, Kennedy KM, Zilkens R, Allen WM, Fang Q, Sanderson RW, Anstie J, Dessauvagie BF, Latham B, Saunders CM, Chin L, and Kennedy BF
- Abstract
Intraoperative margin assessment is needed to reduce the re-excision rate of breast-conserving surgery. One possibility is optical palpation, a tactile imaging technique that maps stress (force applied across the tissue surface) as an indicator of tissue stiffness. Images (optical palpograms) are generated by compressing a transparent silicone layer on the tissue and measuring the layer deformation using optical coherence tomography (OCT). This paper reports, for the first time, the diagnostic accuracy of optical palpation in identifying tumor within 1 mm of the excised specimen boundary using an automated classifier. Optical palpograms from 154 regions of interest (ROIs) from 71 excised tumor specimens were obtained. An automated classifier was constructed to predict the ROI margin status by first choosing a circle diameter, then searching for a location within the ROI where the circle was ≥ 75% filled with high stress (indicating a positive margin). A range of circle diameters and stress thresholds, as well as the impact of filtering out non-dense tissue regions, were tested. Sensitivity and specificity were calculated by comparing the automated classifier results with the true margin status, determined from co-registered histology. 83.3% sensitivity and 86.2% specificity were achieved, compared to 69.0% sensitivity and 79.0% specificity obtained with OCT alone on the same dataset using human readers. Representative optical palpograms show that positive margins containing a range of cancer types tend to exhibit higher stress compared to negative margins. These results demonstrate the potential of optical palpation for margin assessment., Competing Interests: BFK: OncoRes Medical (F, I), CMS, BL, LC, KMK: OncoRes Medical (I). The other authors declare no conflicts of interest related to this article., (© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.)
- Published
- 2021
- Full Text
- View/download PDF
25. Integrated Assessment of Nickel Electroplating Industrial Wastewater Effluent as a Renewable Resource of Irrigation Water Using a Hydroponic Cultivation System.
- Author
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Chow YN, Lee LK, Zakaria NA, and Foo KY
- Abstract
Nickel, a micronutrient essential for plant growth and development, has been recognized as a metallic pollutant in wastewater. The concentration of nickel ions in the water course, exceeding the maximum tolerable limit, has called for an alarming attention, due to the bioaccumulative entry in the water-plant-human food chain, leaving a burden of deteriorative effects on visible characteristics, physiological processes, and oxidative stress response in plants. In this work, the renewable utilization of nickel electroplating industrial wastewater effluent (0, 5, 10, 25, 50, and 100%) as a viable source of irrigation water was evaluated using a hydroponic cultivation system, by adopting Lablab purpureus and Brassica chinensis as the plant models, in relation to the physical growth, physiological and morphological characteristics, photosynthetic pigments, proline, and oxidative responses. The elongation of roots and shoots in L. purpureus and B. chinensis was significantly inhibited beyond 25 and 5% of industrial wastewater. The chlorophyll- a , chlorophyll- b , total chlorophyll, and carotenoid contents, accompanied by alterations in the morphologies of xylem, phloem, and distortion of stomata, were recorded in the industrial wastewater-irrigated groups, with pronounced toxicity effects detected in B. chinensis . Excessive proline accumulation was recorded in the treated plant models. Ascorbate peroxidase (APX), guaiacol peroxidase (POD), and catalase (CAT) scavenging activities were drastically altered, with a profound upregulation effect in the POD activity in L. purpureus and both POD and APX in B. chinensis , predicting the nickel-induced oxidative stress. Conclusively, the diluted industrial wastewater effluent up to the optimum concentrations of 5 and 25%, respectively, could be feasibly reused as a renewable resource for B. chinensis and L. purpureus irrigation, verified by the minimal or negligible phytotoxic implications in the plant models. The current findings have shed light on the interruption of nickel-contaminated industrial wastewater effluent irrigation practice on the physical and biochemical features of food crops and highlighted the possibility of nutrient recycling via wastewater reuse in a sustainable soilless cultivation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Chow, Lee, Zakaria and Foo.)
- Published
- 2021
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26. One step acid activation of bentonite derived adsorbent for the effective remediation of the new generation of industrial pesticides.
- Author
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Shattar SFA, Zakaria NA, and Foo KY
- Abstract
Herein, the facile one step acid activation of bentonite derived functionalized adsorbent (AB) for the effective remediation of both ionic and non-ionic secondary pesticides, ametryn and metolachlor has been attempted. The surface characteristics of AB were examined by the nitrogen adsorption-desorption analysis, scanning electron microscopy (SEM), and Fourier Transforms Infrared (FTIR) Spectroscopy. The adsorptive behavior was evaluated with respect to the effect of contact time, initial concentrations and solution pH. The equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherm models, while the adsorption kinetic was analyzed using the pseudo-first order and pseudo-second order kinetic equations. Thermodynamic parameters including the standard enthalpy change (ΔH°), standard entropy change (ΔS°), and Gibbs free energy change (ΔG°) were established. Thermodynamic analysis illustrated that the adsorption process was feasible and exothermic in nature, while the characterization findings verified the alteration of FTIR bands, and a high specific surface area of 464.92 m
2 /g, with a series of pores distributed over the surface. Equilibrium data was best confronted to the pseudo-second order kinetic model, while the adsorptive removal of ametryn and metolachlor onto AB was satisfactory described by the Langmuir isotherm model, with the monolayer adsorption capacities for ametryn and metolachlor of 2.032 and 0.208 mmole/g respectively. The findings outlined the potential of the newly develop AB for the on-site treatment of pesticide polluted water.- Published
- 2020
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27. Camera-based optical palpation.
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Sanderson RW, Fang Q, Curatolo A, Adams W, Lakhiani DD, Ismail HM, Foo KY, Dessauvagie BF, Latham B, Yeomans C, Saunders CM, and Kennedy BF
- Abstract
Optical elastography is undergoing extensive development as an imaging tool to map mechanical contrast in tissue. Here, we present a new platform for optical elastography by generating sub-millimetre-scale mechanical contrast from a simple digital camera. This cost-effective, compact and easy-to-implement approach opens the possibility to greatly expand applications of optical elastography both within and beyond the field of medical imaging. Camera-based optical palpation (CBOP) utilises a digital camera to acquire photographs that quantify the light intensity transmitted through a silicone layer comprising a dense distribution of micro-pores (diameter, 30-100 µm). As the transmission of light through the micro-pores increases with compression, we deduce strain in the layer directly from intensity in the digital photograph. By pre-characterising the relationship between stress and strain of the layer, the measured strain map can be converted to an optical palpogram, a map of stress that visualises mechanical contrast in the sample. We demonstrate a spatial resolution as high as 290 µm in CBOP, comparable to that achieved using an optical coherence tomography-based implementation of optical palpation. In this paper, we describe the fabrication of the micro-porous layer and present experimental results from structured phantoms containing stiff inclusions as small as 0.5 × 0.5 × 1 mm. In each case, we demonstrate high contrast between the inclusion and the base material and validate both the contrast and spatial resolution achieved using finite element modelling. By performing CBOP on freshly excised human breast tissue, we demonstrate the capability to delineate tumour from surrounding benign tissue.
- Published
- 2020
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28. One-step synthesis of chitosan-polyethyleneimine with calcium chloride as effective adsorbent for Acid Red 88 removal.
- Author
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Yusof NH, Foo KY, Hameed BH, Hussin MH, Lee HK, and Sabar S
- Subjects
- Adsorption, Chemical Phenomena, Hydrogen-Ion Concentration, Kinetics, Thermodynamics, Water Pollutants, Chemical chemistry, Water Purification, Azo Compounds chemistry, Calcium Chloride chemistry, Chitosan chemistry, Polyethyleneimine chemistry
- Abstract
Chitosan-polyethyleneimine with calcium chloride as ionic cross-linker (CsPC) was synthesized as a new kind of adsorbent using a simple, green and cost-effective technique. The adsorption properties of the adsorbent for Acid Red 88 (AR88) dye, as a model analyte, were investigated in a batch system as the function of solution pH (pH 3-12), initial AR88 concentration (50-500 mg L
- 1 ), contact time (0-24 h), and temperature (30-50 °C). Results showed that the adsorption process obeyed the pseudo-first order kinetic model and the adsorption rate was governed by both intra-particle and liquid-film mechanism. Equilibrium data were well correlated with the Freundlich isotherm model, with the calculated maximum adsorption capacity (qm ) of 1000 mg g- 1 at 30 °C. The findings underlined CsPC to be an effective and efficient adsorbent, which can be easily synthesized via one-step process with promising prospects for the removal of AR88 or any other similar dyes from the aqueous solutions., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2020
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29. Handheld volumetric manual compression-based quantitative microelastography.
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Fang Q, Frewer L, Zilkens R, Krajancich B, Curatolo A, Chin L, Foo KY, Lakhiani DD, Sanderson RW, Wijesinghe P, Anstie JD, Dessauvagie BF, Latham B, Saunders CM, and Kennedy BF
- Subjects
- Female, Humans, Mastectomy, Phantoms, Imaging, Tomography, Optical Coherence, Breast Neoplasms, Elasticity Imaging Techniques
- Abstract
Compression optical coherence elastography (OCE) typically requires a mechanical actuator to impart a controlled uniform strain to the sample. However, for handheld scanning, this adds complexity to the design of the probe and the actuator stroke limits the amount of strain that can be applied. In this work, we present a new volumetric imaging approach that utilizes bidirectional manual compression via the natural motion of the user's hand to induce strain to the sample, realizing compact, actuator-free, handheld compression OCE. In this way, we are able to demonstrate rapid acquisition of three-dimensional quantitative microelastography (QME) datasets of a tissue volume (6 × 6 × 1 mm
3 ) in 3.4 seconds. We characterize the elasticity sensitivity of this freehand manual compression approach using a homogeneous silicone phantom and demonstrate comparable performance to a benchtop mounted, actuator-based approach. In addition, we demonstrate handheld volumetric manual compression-based QME on a tissue-mimicking phantom with an embedded stiff inclusion and on freshly excised human breast specimens from both mastectomy and wide local excision (WLE) surgeries. Tissue results are coregistered with postoperative histology, verifying the capability of our approach to measure the elasticity of tissue and to distinguish stiff tumor from surrounding soft benign tissue., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2020
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30. Three-dimensional mapping of the attenuation coefficient in optical coherence tomography to enhance breast tissue microarchitecture contrast.
- Author
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Foo KY, Chin L, Zilkens R, Lakhiani DD, Fang Q, Sanderson R, Dessauvagie BF, Latham B, McLaren S, Saunders CM, and Kennedy BF
- Subjects
- Breast diagnostic imaging, Breast surgery, Female, Humans, Mastectomy, Mastectomy, Segmental, Breast Neoplasms diagnostic imaging, Tomography, Optical Coherence
- Abstract
Effective intraoperative tumor margin assessment is needed to reduce re-excision rates in breast-conserving surgery (BCS). Mapping the attenuation coefficient in optical coherence tomography (OCT) throughout a sample to create an image (attenuation imaging) is one promising approach. For the first time, three-dimensional OCT attenuation imaging of human breast tissue microarchitecture using a wide-field (up to ~45 × 45 × 3.5 mm) imaging system is demonstrated. Representative results from three mastectomy and one BCS specimen (from 31 specimens) are presented with co-registered postoperative histology. Attenuation imaging is shown to provide substantially improved contrast over OCT, delineating nuanced features within tumors (including necrosis and variations in tumor cell density and growth patterns) and benign features (such as sclerosing adenosis). Additionally, quantitative micro-elastography (QME) images presented alongside OCT and attenuation images show that these techniques provide complementary contrast, suggesting that multimodal imaging could increase tissue identification accuracy and potentially improve tumor margin assessment., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2020
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31. Diagnostic Accuracy of Quantitative Micro-Elastography for Margin Assessment in Breast-Conserving Surgery.
- Author
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Kennedy KM, Zilkens R, Allen WM, Foo KY, Fang Q, Chin L, Sanderson RW, Anstie J, Wijesinghe P, Curatolo A, Tan HEI, Morin N, Kunjuraman B, Yeomans C, Chin SL, DeJong H, Giles K, Dessauvagie BF, Latham B, Saunders CM, and Kennedy BF
- Subjects
- Adenocarcinoma, Mucinous pathology, Adenocarcinoma, Mucinous surgery, Adult, Aged, Breast Neoplasms pathology, Breast Neoplasms surgery, Carcinoma, Ductal, Breast pathology, Carcinoma, Ductal, Breast surgery, Elasticity Imaging Techniques standards, Female, Humans, Mastectomy, Segmental standards, Middle Aged, Reoperation, Tomography, Optical Coherence, Adenocarcinoma, Mucinous diagnostic imaging, Breast Neoplasms diagnostic imaging, Carcinoma, Ductal, Breast diagnostic imaging, Elasticity Imaging Techniques methods, Margins of Excision, Mastectomy, Segmental methods
- Abstract
Inadequate margins in breast-conserving surgery (BCS) are associated with an increased likelihood of local recurrence of breast cancer. Currently, approximately 20% of BCS patients require repeat surgery due to inadequate margins at the initial operation. Implementation of an accurate, intraoperative margin assessment tool may reduce this re-excision rate. This study determined, for the first time, the diagnostic accuracy of quantitative micro-elastography (QME), an optical coherence tomography (OCT)-based elastography technique that produces images of tissue microscale elasticity, for detecting tumor within 1 mm of the margins of BCS specimens. Simultaneous OCT and QME were performed on the margins of intact, freshly excised specimens from 83 patients undergoing BCS and on dissected specimens from 7 patients undergoing mastectomy. The resulting three-dimensional images (45 × 45 × 1 mm) were coregistered with postoperative histology to determine tissue types present in each scan. Data from 12 BCS patients and the 7 mastectomy patients served to build a set of images for reader training. One hundred and fifty-four subimages (10 × 10 × 1 mm) from the remaining 71 BCS patients were included in a blinded reader study, which resulted in 69.0% sensitivity and 79.0% specificity using OCT images, versus 92.9% sensitivity and 96.4% specificity using elasticity images. The quantitative nature of QME also facilitated development of an automated reader, which resulted in 100.0% sensitivity and 97.7% specificity. These results demonstrate high accuracy of QME for detecting tumor within 1 mm of the margin and the potential for this technique to improve outcomes in BCS. SIGNIFICANCE: An optical imaging technology probes breast tissue elasticity to provide accurate assessment of tumor margin involvement in breast-conserving surgery., (©2020 American Association for Cancer Research.)
- Published
- 2020
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32. Clinical feasibility of optical coherence micro-elastography for imaging tumor margins in breast-conserving surgery.
- Author
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Allen WM, Foo KY, Zilkens R, Kennedy KM, Fang Q, Chin L, Dessauvagie BF, Latham B, Saunders CM, and Kennedy BF
- Abstract
It has been demonstrated that optical coherence micro-elastography (OCME) provides additional contrast of tumor compared to optical coherence tomography (OCT) alone. Previous studies, however, have predominantly been performed on mastectomy specimens. Such specimens typically differ substantially in composition and geometry from the more clinically relevant wide-local excision (WLE) specimens excised during breast-conserving surgery. As a result, it remains unclear if the mechanical contrast observed is maintained in WLE specimens. In this manuscript, we begin to address this issue by performing a feasibility study of OCME on 17 freshly excised, intact WLE specimens. In addition, we present two developments required to sustain the progression of OCME towards intraoperative deployment. First, to enable the rapid visualization of en face images required for intraoperative assessment, we describe an automated segmentation algorithm to fuse en face micro-elastograms with OCT images to provide dual contrast images. Secondly, to validate contrast in micro-elastograms, we present a method that enables co-registration of en face images with histology of WLE specimens, sectioned in the orthogonal plane, without any modification to the standard clinical workflow. We present a summary of the observations across the 17 specimens imaged in addition to representative micro-elastograms and OCT images demonstrating contrast in a number of tumor margins, including those involved by invasive ductal carcinoma, mucinous carcinoma, and solid-papillary carcinoma. The results presented here demonstrate the potential of OCME for imaging tumor margins., Competing Interests: BFK: OncoRes Medical (F, I), KMK, LC, BL, and CMS: OncoRes Medical (I). The other authors declare that there are no conflicts of interest related to this article.
- Published
- 2018
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33. A Case of undiagnosed Pseudoaneurysm caused by an open tibial fracture.
- Author
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Gunalan R and Foo KY
- Published
- 2016
34. Interaction between Flavivirus and Cytoskeleton during Virus Replication.
- Author
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Foo KY and Chee HY
- Subjects
- Biological Transport, Active, Humans, Cytoskeleton metabolism, Flavivirus physiology, Flavivirus Infections metabolism, Virus Internalization, Virus Release, Virus Replication physiology
- Abstract
Flaviviruses are potentially human pathogens that cause major epidemics worldwide. Flavivirus interacts with host cell factors to form a favourable virus replication site. Cell cytoskeletons have been observed to have close contact with flaviviruses, which expands the understanding of cytoskeleton functions during virus replication, although many detailed mechanisms are still unclear. The interactions between the virus and host cytoskeletons such as actin filaments, microtubules, and intermediate filaments have provided insight into molecular alterations during the virus infection, such as viral entry, in-cell transport, scaffold assembly, and egress. This review article focuses on the utilization of cytoskeleton by Flavivirus and the respective functions during virus replication.
- Published
- 2015
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35. Effects of familial climate on the adolescents' driving habits: a recent literature.
- Author
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Foo KY
- Subjects
- Adolescent, Aggression, Alcohol Drinking, Attention Deficit Disorder with Hyperactivity psychology, Automobile Driving education, Humans, Intergenerational Relations, Parents psychology, Adolescent Behavior, Automobile Driving psychology, Parent-Child Relations
- Abstract
Driving is a functional task that requires a complex interaction of visual perception, cognitive and motor skills. Next to circulatory diseases and cancer, road accidents remain the third epidemic cause of death internationally, with approximately half a million teen drivers killed annually. Driver behaviour has been cited as the pervasive marker of automotive crashes. A reliable and firm relationship between the positive parental model, message, and communication has been established. Specifically, the familial climate is proposed to be an important element of reinforcement, modelling, support and environmental determinant in interpreting personal perceptions, habits, values, and belief system. Confirming the assertion, this bibliographic review presents the most recent research findings on the contributions of families to the driving habits of teens. The emphasis is speculated on parental alcohol use, aggressiveness, attention-deficit/hyperactivity disorder, relationship, and intergenerational transmission of driving styles. Besides, the effects of familial supervision, monitoring, education and awareness, and genders, partners, and demographic influence on the driving habits are discussed and outlined.
- Published
- 2015
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36. Recent insights on the significance of transcriptomic and metabolomic analysis of male factor infertility.
- Author
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Lee LK and Foo KY
- Subjects
- Biomarkers metabolism, Humans, Male, Metabolomics methods, Infertility, Male metabolism, Metabolome, Transcriptome
- Abstract
Infertility is a worldwide reproductive health problem which affects approximately 15% of couples, with male factor infertility dominating nearly 50% of the affected population. The nature of the phenomenon is underscored by a complex array of transcriptomic, proteomic and metabolic differences which interact in unknown ways. Many causes of male factor infertility are still defined as idiopathic, and most diagnosis tends to be more descriptive rather than specific. As such, the emergence of novel transcriptomic and metabolomic studies may hold the key to more accurately diagnose and treat male factor infertility. This paper provides the most recent evidence underlying the role of transcriptomic and metabolomic analysis in the management of male infertility. A summary of the current knowledge and new discovery of noninvasive, highly sensitive and specific biomarkers which allow the expansion of this area is outlined., (Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
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37. Preparation of tamarind fruit seed activated carbon by microwave heating for the adsorptive treatment of landfill leachate: A laboratory column evaluation.
- Author
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Foo KY, Lee LK, and Hameed BH
- Subjects
- Adsorption, Biodegradation, Environmental, Biological Oxygen Demand Analysis, Laboratories, Models, Theoretical, Nitrogen isolation & purification, Porosity, Charcoal chemistry, Fruit chemistry, Microwaves, Seeds chemistry, Tamarindus chemistry, Water Pollutants, Chemical isolation & purification, Water Purification methods
- Abstract
The preparation of tamarind fruit seed granular activated carbon (TSAC) by microwave induced chemical activation for the adsorptive treatment of semi-aerobic landfill leachate has been attempted. The chemical and physical properties of TSAC were examined. A series of column tests were performed to determine the breakthrough characteristics, by varying the operational parameters, hydraulic loading rate (5-20 mL/min) and adsorbent bed height (15-21 cm). Ammonical nitrogen and chemical oxygen demand (COD), which provide a prerequisite insight into the prediction of leachate quality was quantified. Results illustrated an encouraging performance for the adsorptive removal of ammonical nitrogen and COD, with the highest bed capacity of 84.69 and 55.09 mg/g respectively, at the hydraulic loading rate of 5 mL/min and adsorbent bed height of 21 cm. The dynamic adsorption behavior was satisfactory described by the Thomas and Yoon-Nelson models. The findings demonstrated the applicability of TSAC for the adsorptive treatment of landfill leachate., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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38. Preparation of activated carbon from sugarcane bagasse by microwave assisted activation for the remediation of semi-aerobic landfill leachate.
- Author
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Foo KY, Lee LK, and Hameed BH
- Subjects
- Adsorption, Aerobiosis, Ammonia isolation & purification, Biodegradation, Environmental, Hydrogen-Ion Concentration, Kinetics, Nitrogen isolation & purification, Phosphates isolation & purification, Porosity, Solutions, Temperature, Time Factors, Cellulose chemistry, Charcoal chemistry, Microwaves, Saccharum chemistry, Water Pollutants, Chemical isolation & purification, Water Purification methods
- Abstract
This study evaluates the sugarcane bagasse derived activated carbon (SBAC) prepared by microwave heating for the adsorptive removal of ammonical nitrogen and orthophosphate from the semi-aerobic landfill leachate. The physical and chemical properties of SBAC were examined by pore structural analysis, scanning electron microscopy, Fourier transform infrared spectroscopy and elemental analysis. The effects of adsorbent dosage, contact time and solution pH on the adsorption performance were investigated in a batch mode study at 30°C. Equilibrium data were favorably described by the Langmuir isotherm model, with a maximum monolayer adsorption capacity for ammonical nitrogen and orthophosphate of 138.46 and 12.81 mg/g, respectively, while the adsorption kinetic was best fitted to the pseudo-second-order kinetic model. The results illustrated the potential of sugarcane bagasse derived activated carbon for the adsorptive treatment of semi-aerobic landfill leachate., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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39. Utilization of oil palm biodiesel solid residue as renewable sources for preparation of granular activated carbon by microwave induced KOH activation.
- Author
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Foo KY and Hameed BH
- Subjects
- Adsorption, Arecaceae radiation effects, Biofuels, Industrial Waste, Kinetics, Microwaves, Thermodynamics, Arecaceae chemistry, Charcoal chemical synthesis, Hydroxides chemistry, Potassium Compounds chemistry
- Abstract
In this work, preparation of granular activated carbon from oil palm biodiesel solid residue, oil palm shell (PSAC) by microwave assisted KOH activation has been attempted. The physical and chemical properties of PSAC were characterized using scanning electron microscopy, volumetric adsorption analyzer and elemental analysis. The adsorption behavior was examined by performing batch adsorption experiments using methylene blue as dye model compound. Equilibrium data were simulated using the Langmuir, Freundlich and Temkin isotherm models. Kinetic modeling was fitted to the pseudo-first-order, pseudo-second-order and Elovich kinetic models, while the adsorption mechanism was determined using the intraparticle diffusion and Boyd equations. The result was satisfactory fitted to the Langmuir isotherm model with a monolayer adsorption capacity of 343.94mg/g at 30°C. The findings support the potential of oil palm shell for preparation of high surface area activated carbon by microwave assisted KOH activation., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
40. Constrained-beam inverse planning for intensity-modulated radiation therapy of prostate cancer patients with bilateral hip prostheses.
- Author
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Martin DA, Hruby G, Whitaker MK, and Foo KY
- Subjects
- Aged, Humans, Male, Radiotherapy Dosage, Treatment Outcome, Hip Prosthesis, Prostatic Neoplasms radiotherapy, Radiotherapy Planning, Computer-Assisted methods, Radiotherapy, Conformal methods
- Abstract
Hip prostheses present a technical challenge in the planning of curative external beam radiation treatment for patients with prostate cancer. Bilateral prostheses compel planners to compromise between target coverage and avoidance of beam entry through the prostheses. Inverse planning systems given objectives to avoid dose to prostheses are overly restricted from allowing exit dose to them. We report a novel inverse planning technique for intensity-modulated radiation therapy of patients with prostate cancer and bilateral hip prostheses, by constraining beam characteristics rather than dose in the inverse planning process., (© 2012 The Authors. Journal of Medical Imaging and Radiation Oncology © 2012 The Royal Australian and New Zealand College of Radiologists.)
- Published
- 2012
- Full Text
- View/download PDF
41. Microwave-assisted regeneration of activated carbon.
- Author
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Foo KY and Hameed BH
- Subjects
- Adsorption radiation effects, Dose-Response Relationship, Radiation, Materials Testing, Microwaves, Porosity radiation effects, Radiation Dosage, Charcoal chemistry, Charcoal radiation effects, Conservation of Natural Resources methods
- Abstract
Microwave heating was used in the regeneration of methylene blue-loaded activated carbons produced from fibers (PFAC), empty fruit bunches (EFBAC) and shell (PSAC) of oil palm. The dye-loaded carbons were treated in a modified conventional microwave oven operated at 2450 MHz and irradiation time of 2, 3 and 5 min. The virgin properties of the origin and regenerated activated carbons were characterized by pore structural analysis and nitrogen adsorption isotherm. The surface chemistry was examined by zeta potential measurement and determination of surface acidity/basicity, while the adsorptive property was quantified using methylene blue (MB). Microwave irradiation preserved the pore structure, original active sites and adsorption capacity of the regenerated activated carbons. The carbon yield and the monolayer adsorption capacities for MB were maintained at 68.35-82.84% and 154.65-195.22 mg/g, even after five adsorption-regeneration cycles. The findings revealed the potential of microwave heating for regeneration of spent activated carbons., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
42. Preparation of activated carbon by microwave heating of langsat (Lansium domesticum) empty fruit bunch waste.
- Author
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Foo KY and Hameed BH
- Subjects
- Adsorption drug effects, Fruit drug effects, Kinetics, Meliaceae drug effects, Methylene Blue isolation & purification, Models, Chemical, Sodium Hydroxide pharmacology, Surface Properties drug effects, Temperature, Time Factors, Charcoal chemical synthesis, Fruit chemistry, Heating methods, Meliaceae chemistry, Microwaves, Waste Products analysis
- Abstract
The feasibility of langsat empty fruit bunch waste for preparation of activated carbon (EFBLAC) by microwave-induced activation was explored. Activation with NaOH at the IR ratio of 1.25, microwave power of 600 W for 6 min produced EFBLAC with a carbon yield of 81.31% and adsorption uptake for MB of 302.48 mg/g. Pore structural analysis, scanning electron microscopy and Fourier transform infrared spectroscopy demonstrated the physical and chemical characteristics of EFBLAC. Equilibrium data were best described by the Langmuir isotherm, with a monolayer adsorption capacity of 402.06 mg/g, and the adsorption kinetics was well fitted to the pseudo-second-order equation. The findings revealed the potential to prepare high quality activated carbon from langsat empty fruit bunch waste by microwave irradiation., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
43. Mesoporous activated carbon from wood sawdust by K2CO3 activation using microwave heating.
- Author
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Foo KY and Hameed BH
- Subjects
- Adsorption, Hydrogen-Ion Concentration, Microscopy, Electron, Scanning, Carbon chemistry, Carbonates chemistry, Microwaves, Potassium chemistry, Wood
- Abstract
Wood sawdust was converted into a high-quality activated carbon (WSAC) via microwave-induced K(2)CO(3) activation. The operational variables including chemical impregnation ratio, microwave power and irradiation time on the carbon yield and adsorption capability were identified. The surface physical characteristics of WSAC were examined by pore structural analysis, scanning electron microscopy and nitrogen adsorption isotherms. The adsorptive behavior of WSAC was quantified using methylene blue as model dye compound. The best conditions resulted in activated carbon with a monolayer adsorption capacity of 423.17 mg/g and carbon yield of 80.75%. The BET surface area, Langmuir surface area and total pore volume were corresponded to 1496.05 m(2)/g, 2245.53 m(2)/g and 0.864 cm(3)/g, respectively. The findings support the potential to prepare high surface area and mesoporous activated carbon from wood sawdust by microwave assisted chemical activation., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
44. Potential of jackfruit peel as precursor for activated carbon prepared by microwave induced NaOH activation.
- Author
-
Foo KY and Hameed BH
- Subjects
- Adsorption drug effects, Diffusion drug effects, Electricity, Hydrogen-Ion Concentration drug effects, Kinetics, Methylene Blue chemistry, Models, Chemical, Nitrogen chemistry, Porosity drug effects, Surface Properties drug effects, Temperature, Time Factors, Artocarpus chemistry, Artocarpus drug effects, Charcoal chemistry, Microwaves, Sodium Hydroxide pharmacology, Waste Products analysis
- Abstract
The feasibility of preparing activated carbon (JPAC) from jackfruit peel, an industrial residue abundantly available from food manufacturing plants via microwave-assisted NaOH activation was explored. The influences of chemical impregnation ratio, microwave power and radiation time on the properties of activated carbon were investigated. JPAC was examined by pore structural analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, nitrogen adsorption isotherm, elemental analysis, surface acidity/basicity and zeta potential measurements. The adsorptive behavior of JPAC was quantified using methylene blue as model dye compound. The best conditions resulted in JPAC with a monolayer adsorption capacity of 400.06 mg/g and carbon yield of 80.82%. The adsorption data was best fitted to the pseudo-second-order equation, while the adsorption mechanism was well described by the intraparticle diffusion model. The findings revealed the versatility of jackfruit peels as good precursor for preparation of high quality activated carbon., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
45. Microwave-assisted preparation and adsorption performance of activated carbon from biodiesel industry solid reside: influence of operational parameters.
- Author
-
Foo KY and Hameed BH
- Subjects
- Adsorption, Fruit chemistry, Hydrogen-Ion Concentration, Kinetics, Methylene Blue chemistry, Models, Chemical, Palm Oil, Plant Oils chemistry, Porosity, Temperature, Time Factors, Biofuels analysis, Biotechnology methods, Charcoal chemistry, Industrial Waste analysis, Microwaves
- Abstract
Preparation of activated carbon has been attempted using KOH as activating agent by microwave heating from biodiesel industry solid residue, oil palm empty fruit bunch (EFBAC). The significance of chemical impregnation ratio (IR), microwave power and activation time on the properties of activated carbon were investigated. The optimum condition has been identified at the IR of 1.0, microwave power of 600 W and activation time of 7 min. EFBAC was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and nitrogen adsorption isotherm. The surface chemistry was examined by zeta potential measurement, determination of surface acidity/basicity, while the adsorptive property was quantified using methylene blue as dye model compound. The optimum conditions resulted in activated carbon with a monolayer adsorption capacity of 395.30 mg/g and carbon yield of 73.78%, while the BET surface area and total pore volume were corresponding to 1372 m2/g and 0.76 cm3/g, respectively., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
46. Preparation, characterization and evaluation of adsorptive properties of orange peel based activated carbon via microwave induced K2CO3 activation.
- Author
-
Foo KY and Hameed BH
- Subjects
- Adsorption, Carbonates radiation effects, Charcoal radiation effects, Computer Simulation, Feasibility Studies, Kinetics, Microwaves, Potassium radiation effects, Radiation Dosage, Carbonates chemistry, Charcoal chemical synthesis, Citrus sinensis chemistry, Citrus sinensis radiation effects, Fruit chemistry, Fruit radiation effects, Models, Chemical, Potassium chemistry
- Abstract
This work explores the feasibility of orange peel, a citrus processing biomass as an alternative precursor for preparation of activated carbon (OPAC) via microwave assisted K(2)CO(3) activation. The operational parameters, chemical impregnation ratio, microwave power and irradiation time on the carbon yield and adsorption capability were investigated. The virgin characteristics of OPAC were examined by pore structural analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, nitrogen adsorption isotherm, elemental analysis, surface acidity/basicity and zeta potential measurement. The optimum conditions resulted in OPAC with a monolayer adsorption capacity of 382.75 mg/g for methylene blue and carbon yield of 80.99%. The BET surface area, Langmuir surface area and total pore volume were identified to be 1104.45 m(2)/g, 1661.04 m(2)/g and 0.615 m(3)/g, respectively. Equilibrium data were simulated using the Langmuir, Freundlich, Dubinin-Radushkevich, Redlich-Peterson, and Toth isotherms, and kinetic data were fitted to the pseudo-first-order, pseudo-second-order and Elovich kinetic models., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
47. Utilization of rice husks as a feedstock for preparation of activated carbon by microwave induced KOH and K2CO3 activation.
- Author
-
Foo KY and Hameed BH
- Subjects
- Adsorption, Methylene Blue chemistry, Microscopy, Electron, Scanning, Spectroscopy, Fourier Transform Infrared, Carbon metabolism, Carbonates chemistry, Hydroxides chemistry, Microwaves, Oryza, Potassium chemistry, Potassium Compounds chemistry
- Abstract
Rice husk (RH), an abundant by-product of rice milling, was used for the preparation of activated carbon (RHAC) via KOH and K(2)CO(3) chemical activation. The activation process was performed at the microwave input power of 600 W for 7 min. RHACs were characterized by low temperature nitrogen adsorption/desorption, scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption behavior was examined using methylene blue as adsorbate. The K(2)CO(3)-activated sample showed higher yield and better pore structures and adsorption capacity development than the KOH-activated sample, with a BET surface area, total pore volume and monolayer adsorption capacity of 1165 m(2)/g, 0.78 cm(3)/g and 441.52 mg/g, respectively. The results revealed the feasibility of microwave heating for preparation of high surface area activated carbons from rice husks via K(2)CO(3) activation., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
48. Phase calibration of sonar systems using standard targets and dual-frequency transmission pulses.
- Author
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Islas-Cital A, Atkins PR, Foo KY, and Picó R
- Subjects
- Calibration, Cobalt, Equipment Design, Models, Theoretical, Motion, Signal Processing, Computer-Assisted, Time Factors, Transducers, Tungsten Compounds, Ultrasonics instrumentation, Vibration, Sound, Ultrasonics standards
- Abstract
The phase angle component of the complex frequency response of a sonar system operating near transducer resonance is usually distorted. Interpretation and classification of the received sonar signal benefits from the preservation of waveform fidelity over the full bandwidth. A calibration process that measures the phase response in addition to the amplitude response is thus required. This paper describes an extension to the standard-target calibration method to include phase angle, without affecting the experimental apparatus, by using dual-frequency transmission pulses and frequency-domain data processing. This approach reduces the impact of unknown range and sound speed parameters upon phase calibration accuracy, as target phase is determined from the relationship of the two frequency components instead of relying on a local phase reference. Tungsten carbide spheres of various sizes were used to simultaneously calibrate the amplitude and phase response of an active sonar system in a laboratory tank. Experimental measurements of target phase spectra are in good agreement with values predicted from a theoretical model based upon full-wave analysis, over an operating frequency of 50-125 kHz., (© 2011 Acoustical Society of America)
- Published
- 2011
- Full Text
- View/download PDF
49. Preparation and characterization of activated carbon from sunflower seed oil residue via microwave assisted K2CO3 activation.
- Author
-
Foo KY and Hameed BH
- Subjects
- Adsorption, Kinetics, Methylene Blue chemistry, Spectroscopy, Fourier Transform Infrared, Sunflower Oil, Thermodynamics, Carbon chemistry, Carbonates chemistry, Microwaves, Plant Oils chemistry, Potassium chemistry
- Abstract
Sunflower seed oil residue, a by-product of sunflower seed oil refining, was utilized as a feedstock for preparation of activated carbon (SSHAC) via microwave induced K(2)CO(3) chemical activation. SSHAC was characterized by Fourier transform infrared spectroscopy, nitrogen adsorption-desorption and elemental analysis. Surface acidity/basicity was examined with acid-base titration, while the adsorptive properties of SSHAC were quantified using methylene blue (MB) and acid blue 15 (AB). The monolayer adsorption capacities of MB and AB were 473.44 and 430.37 mg/g, while the Brunauer-Emmett-Teller surface area, Langmuir surface area and total pore volume were 1411.55 m(2)/g, 2137.72 m(2)/g and 0.836 cm(3)/g, respectively. The findings revealed the potential to prepare high surface area activated carbon from sunflower seed oil residue by microwave irradiation., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
50. The environmental applications of activated carbon/zeolite composite materials.
- Author
-
Foo KY and Hameed BH
- Abstract
Over the past couple of years, the resurgence of placing an effective and sustainable amendment to combat against the auxiliary industrial entities, remains a highly contested agenda from a global point. With the renaissance of activated carbon, there has been a steadily growing interest in the research field. Recently, the adoption of zeolite composite, a prestigious advanced catalyst which formulates the enhancement of adsorption rate and hydrogen storage capability, has fore fronted to be a new growing branch in the scientific community. Confirming the assertion, this paper presents a state of art review of activated carbon/zeolite composite technology, its fundamental background studies, and environmental implications. Moreover, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of activated carbon/zeolite composite represents a potentially viable and powerful tool, leading to the plausible improvement of environmental preservation., (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
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