106 results on '"Low SC"'
Search Results
2. Multidetector computed tomography diagnosis of splenic flexure volvulus: usefulness of multiplanar reformats
- Author
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Koh, S, primary, Low, SC, additional, and Quah, HM, additional
- Published
- 2013
- Full Text
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3. Diagnostic accuracy of contrast-enhanced ultrasound in differentiating benign and malignant focal liver lesions: a retrospective study.
- Author
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Ooi CC, Low SC, Schneider-Kolsky M, Lombardo P, Lim SY, Abu Bakar R, Lo RH, Ooi, Chin-Chin, Low, Su-Chong Albert, Schneider-Kolsky, Michal, Lombardo, Paul, Lim, Sze-Ying, Abu Bakar, Rafidah, and Lo, Richard Hoau-Gong
- Abstract
Purpose: The purpose of this study was to assess the diagnostic accuracy of our early experience with contrast-enhanced ultrasound (CEUS) in the characterisation of focal liver lesions (FLLs) using histopathology, contrast-enhanced computed tomography (CT), magnetic resonance imaging (MRI) or other imaging follow-up as the standard of reference.Materials and Methods: Seventy-three patients with 82 FLLs who underwent liver CEUS from January 2006 to December 2008 were retrospectively reviewed. CEUS was performed with up to 4.8 mL of SonoVue® (Bracco, Milan, Italy) using a low mechanical index mode. The CEUS findings were compared with histopathology, or where histopathology was not available, clinical and imaging follow-up over at least 12 months was used as the standard of reference.Results: Of the 82 FLLs, 50 were malignant and 32 were benign at final diagnosis. CEUS correctly identified 43 malignant FLLs, with final diagnosis confirmed by histopathology in 13 lesions and clinico-radiological follow-up in 30 lesions. Twenty-nine lesions were correctly identified as benign on CEUS, with all these lesions confirmed on clinico-radiological follow-up. CEUS demonstrated a sensitivity of 86.0% and a specificity of 90.6% in the characterisation of liver lesions as malignant, with an overall accuracy of 87.8% (P < 0.05).Conclusion: Our early experience has shown that CEUS can be accurate in differentiating malignant from benign FLLs and may become a useful first-line imaging tool where CT or MRI are not available or contra-indicated. [ABSTRACT FROM AUTHOR]- Published
- 2010
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4. Endoscopic submucosal dissection of gastric lesions by using a Master and Slave Transluminal Endoscopic Robot (MASTER)
- Author
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Ho K, Phee SJ, Shabbir A, Low SC, Huynh VA, Kencana AP, Yang K, Lomanto D, So BYJ, Wong YJ, and Chung SS
- Abstract
Background: Performing endoscopic submucosal dissection (ESD) by using standard endoscopy platforms is technically challenging because of the equipment''s lack of dexterity. Objective: To explore the feasibility of using the Master and Slave Transluminal Endoscopic Robot (MASTER), a novel robotics-enhanced endosurgical system, to perform ESD. Design: ESD was performed on simulated gastric lesions in 5 Erlangen porcine stomach models (ex vivo) and 5 live pigs (in vivo). Performance of ESD by using the MASTER was compared with that using the insulation-tipped (IT) diathermic knife. Setting: SMART Laboratory, Advance Surgical Training Centre, National University Hospital, Singapore. Subjects: Five Erlangen porcine stomach models and 5 pigs, 5 to 7 months old, each weighing about 35 kg. Interventions: ESD. Main Outcome Measurements: Lesion resection time, grasper and hook efficacy grade, completeness of resection, and presence of procedure-related perforation. Results: In the Erlangen stomach models, 15 simulated lesions from the cardia, antrum, and body were removed en bloc (mean dimension, 37.4 × 26.5 mm) by electrocautery excision using the MASTER. The mean ESD time was 23.9 minutes (range 7-48 minutes). There was no difference in the dissection times of lesions at different locations (P = .449). In the live pigs, the MASTER took a mean of 16.2 minutes (range 3-29 minutes) to complete the ESD of 5 gastric lesions, whereas the IT diathermic knife took 18.6 minutes (range 9-34 minutes). There was no significant difference in the times taken (P = .708). All lesions were excised en bloc; the mean dimensions of lesions resected by the MASTER and the IT diathermic knife were 37.2 × 30.1 mm and 32.78 × 25.6 mm, respectively. The MASTER exhibited good grasping and cutting efficiency throughout. Surgical maneuvers were achieved with ease and precision. There was no incidence of excessive bleeding or stomach wall perforation. Limitations: Exploratory study with limited sample size. Conclusions: Performing ESD by using the MASTER is feasible. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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5. MRI of ocular toxoplasmosis.
- Author
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Low SC and Chan LL
- Published
- 2006
- Full Text
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6. Biomimetic heat-localized and solar absorption-enhanced hollow structural nanofibrous membrane for clean water production from saline water and dye wastewater.
- Author
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Zhao J, Li W, Shi Y, Zheng X, Feng Q, Low SC, Tan SH, and Liu Z
- Abstract
The rational design of material structures can be an effective approach to enhance the performance of solar-driven clean water production. In this study, a hollow structural nanofibrous membrane was developed by mimicking the hollow structure of polar bear hair using coaxial electrospinning. The shell layer consisted of carbon nanoparticles (C NPs) decorated CuO nanosheets (C@CuO), that exhibited photothermal conversion capacity. Meanwhile, the core layer containing hydrophilic polyvinylpyrrolidone (PVP) was eliminated to generate the hollow structure. The C NPs enhanced the membrane's light absorption to increase thermal energy harvesting, while the CuO nanosheets improved the membrane's wettability enhancing the water supply. Furthermore, the hollow structure limited air convection, prevented heat conduction, and minimized heat radiation, enabling heat localization to be achieved inside the membrane to suppress heat loss during evaporation. For 3.5 wt% saline water and actual dye wastewater, the C@CuO nanofibrous membrane achieved high evaporation rates of 1.36 kg·m
-2 ·h-1 and 1.31 kg·m-2 ·h-1 , respectively, under 1 sun illumination. Moreover, even after continuous 6-h evaporation tests, the evaporation rate of the C@CuO membrane remained virtually unchanged, highlighting its long-term stability with regard to salt resistance in real-world applications. Additionally, the remarkable flexibility of the C@CuO membrane offers convenience during operation and guarantees dimensional stability when it is subjected to external stresses. These discoveries should inspire subsequent research on developing delicate architectural materials and exploring their potential applications in various fields, including energy generation, clean water production, and thermal insulation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2024
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7. Quantitative muscle ultrasound as a disease biomarker in hereditary transthyretin amyloidosis with polyneuropathy.
- Author
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Tan SY, Tan CY, Yahya MA, Low SC, Shahrizaila N, and Goh KJ
- Subjects
- Humans, Male, Female, Middle Aged, Aged, Biomarkers, Adult, Amyloid Neuropathies, Familial diagnostic imaging, Ultrasonography, Muscle, Skeletal diagnostic imaging, Muscle, Skeletal pathology, Polyneuropathies diagnostic imaging
- Abstract
Introduction: There is an increasing need for a reproducible and sensitive outcome measure in patients with hereditary transthyretin amyloidosis (ATTRv) with polyneuropathy (PN) due to the emergence of disease modifying therapies. In the current study, we aimed to investigate the role of quantitative muscle ultrasound (QMUS) as a disease biomarker in ATTRv-PN., Methods: Twenty genetically confirmed ATTRv amyloidosis patients (nine symptomatic, 11 pre-symptomatic) were enrolled prospectively between January to March 2023. Muscle ultrasound was performed on six muscles at standardized locations. QMUS parameters included muscle thickness (MT) and muscle echo intensity (EI). Twenty-five age- and sex-matched healthy controls were recruited for comparison. Significant QMUS parameters were correlated with clinical outcome measures., Results: Muscle volume of first dorsal interosseus (FDI) muscle [measured as cross-sectional area (CSA)] was significantly lower in symptomatic patients compared to healthy controls and pre-symptomatic carriers (98.3 ± 58.0 vs. 184.4 ± 42.5 vs. 198.3 ± 56.8, p < 0.001). EI of biceps and FDI for symptomatic ATTRv-PN patients were significantly higher compared to the other two groups (biceps: 76.4 ± 10.8 vs. 63.2 ± 11.5 vs. 59.2 ± 9.0, p = 0.002; FDI: 48.2 ± 7.5 vs. 38.8 ± 7.5 vs. 33.0 ± 5.3, p < 0.001). CSA of FDI and EI of biceps and FDI correlated with previous validated outcome measures [polyneuropathy disability score, neuropathy impairment score, Karnofsky performance scale, Rasch-built overall disability scale, European quality of life (QoL)-5 dimensions and Norfolk QoL questionnaire-diabetic neuropathy]., Conclusion: QMUS revealed significant difference between ATTRv amyloidosis patients and healthy controls and showed strong correlation with clinical outcome measures. QMUS serves as a sensitive and reliable biomarker of disease severity in ATTRv-PN., (© 2024. Fondazione Società Italiana di Neurologia.)
- Published
- 2024
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8. Editorial notes for the ESPR special issue on Green technology and Industrial Revolution 4.0 for a greener future.
- Author
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Low SC, Vo DN, Hameed BH, and Abd Rahman SB
- Subjects
- Promoter Regions, Genetic, Bacterial Proteins genetics, Technology
- Published
- 2023
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9. Antibiotics oxytetracycline removal by photocatalyst titanium dioxide and graphitic carbon nitride in aquaculture wastewater.
- Author
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Chin JY, Ahmad AL, and Low SC
- Subjects
- Anti-Bacterial Agents chemistry, Wastewater, Titanium chemistry, Aquaculture, Oxytetracycline chemistry
- Abstract
The surge in the use of antibiotics, especially in aquaculture, has led to development of antibiotic resistance genes, which will harm environmental and public health. One of the most commonly used antibiotics in aquaculture is oxytetracycline (OTC). Employing photocatalysis, this study compared OTC degradation efficiency of two different types of common photocatalysts, TiO
2 and graphitic carbon nitride (GCN) in terms of their photochemical properties and underlying photocatalytic mechanism. For reference purpose, self-synthesized GCN from urea precursor (GCN-Urea) and commercial GCN (GCN-Commercial) were both examined. OTC adsorption-photocatalysis removal rates in pure OTC solution by TiO2 , GCN-Urea and GCN-Commercial were attained at 95%, 60% and 40% respectively. Photochemical properties evaluated included light absorption, band gap, valence and conduction band positions, photoluminescence, cyclic voltammetry, BET surface area and adsorption capability of the photocatalysts. Through the evaluations, this study provides novel insights towards current state-of-the-art heterogeneous photocatalytic processes. The electron-hole recombination examined by photoluminescence is not the key factor influencing the photocatalytic efficacies as commonly discussed. On the contrary, the dominating factors governing the higher OTC degradation efficiency of TiO2 compared to GCN are the high mobility of electrons that leads to high redox capability and the high pollutant-photocatalyst affinity. These claims are proven by 86% and 40% more intense anodic and cathodic cyclic voltammetry curve peaks of TiO2 as compared to both GCNs. OTC also demonstrated 1.7 and 2.3 times higher affinity towards TiO2 than GCN-Urea and GCN-Commercial. OTC removal by TiO2 in real aquaculture wastewater only achieved 50%, due to significant inhibition effect by dissolved solids, dissolved organic matters and high ionic contents in the wastewater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)- Published
- 2023
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10. Design and testing of a humanized porcine donor for xenotransplantation.
- Author
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Anand RP, Layer JV, Heja D, Hirose T, Lassiter G, Firl DJ, Paragas VB, Akkad A, Chhangawala S, Colvin RB, Ernst RJ, Esch N, Getchell K, Griffin AK, Guo X, Hall KC, Hamilton P, Kalekar LA, Kan Y, Karadagi A, Li F, Low SC, Matheson R, Nehring C, Otsuka R, Pandelakis M, Policastro RA, Pols R, Queiroz L, Rosales IA, Serkin WT, Stiede K, Tomosugi T, Xue Y, Zentner GE, Angeles-Albores D, Chris Chao J, Crabtree JN, Harken S, Hinkle N, Lemos T, Li M, Pantano L, Stevens D, Subedar OD, Tan X, Yin S, Anwar IJ, Aufhauser D, Capuano S, Kaufman DB, Knechtle SJ, Kwun J, Shanmuganayagam D, Markmann JF, Church GM, Curtis M, Kawai T, Youd ME, and Qin W
- Subjects
- Animals, Humans, Animals, Genetically Modified, Endothelial Cells immunology, Endothelial Cells metabolism, Polysaccharides deficiency, Transgenes genetics, Graft Rejection immunology, Graft Rejection prevention & control, Kidney Transplantation methods, Macaca fascicularis, Swine genetics, Transplantation, Heterologous methods
- Abstract
Recent human decedent model studies
1,2 and compassionate xenograft use3 have explored the promise of porcine organs for human transplantation. To proceed to human studies, a clinically ready porcine donor must be engineered and its xenograft successfully tested in nonhuman primates. Here we describe the design, creation and long-term life-supporting function of kidney grafts from a genetically engineered porcine donor transplanted into a cynomolgus monkey model. The porcine donor was engineered to carry 69 genomic edits, eliminating glycan antigens, overexpressing human transgenes and inactivating porcine endogenous retroviruses. In vitro functional analyses showed that the edited kidney endothelial cells modulated inflammation to an extent that was indistinguishable from that of human endothelial cells, suggesting that these edited cells acquired a high level of human immune compatibility. When transplanted into cynomolgus monkeys, the kidneys with three glycan antigen knockouts alone experienced poor graft survival, whereas those with glycan antigen knockouts and human transgene expression demonstrated significantly longer survival time, suggesting the benefit of human transgene expression in vivo. These results show that preclinical studies of renal xenotransplantation could be successfully conducted in nonhuman primates and bring us closer to clinical trials of genetically engineered porcine renal grafts., (© 2023. The Author(s).)- Published
- 2023
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11. Importance of carbon structure for nitrogen and sulfur co-doping to promote superior ciprofloxacin removal via peroxymonosulfate activation.
- Author
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Gasim MF, Veksha A, Lisak G, Low SC, Hamidon TS, Hussin MH, and Oh WD
- Subjects
- Nitrogen chemistry, Ciprofloxacin, Peroxides chemistry, Carbon, Nanotubes, Carbon
- Abstract
Herein, five N, S-co-doped carbocatalysts were prepared from different carbonaceous precursors, namely sawdust (SD), biochar (BC), carbon-nanotubes (CNTs), graphite (GP), and graphene oxide (GO) and compared. Generally, as the graphitization degree increased, the extent of N and S doping decreased, graphitic N configuration is preferred, and S configuration is unaltered. As peroxymonosulfate (PMS) activator for ciprofloxacin (CIP) removal, the catalytic performance was in order: NS-CNTs (0.037 min
-1 ) > NS-BC (0.032 min-1 ) > NS-rGO (0.024 min-1 ) > NS-SD (0.010 min-1 ) > NS-GP (0.006 min-1 ), with the carbonaceous properties, rather than the heteroatoms content and textural properties, being the major factor affecting the catalytic performance. NS-CNTs was found to have the supreme catalytic activity due to its remarkable conductivity (3.38 S m-1 ) and defective sites (ID /IG = 1.28) with high anti-interference effect against organic and inorganic matter and varying water matrixes. The PMS activation pathway was dominated by singlet oxygen (1 O2 ) generation and electron transfer regime between CIP and PMS activated complexes. The CIP degradation intermediates were identified, and a degradation pathway is proposed. Overall, this study provides a better understanding of the importance of selecting a suitable carbonaceous platform for heteroatoms doping to produce superior PMS activator for antibiotics decontamination., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)- Published
- 2023
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12. Efficacy and safety of vutrisiran for patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy: a randomized clinical trial.
- Author
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Adams D, Tournev IL, Taylor MS, Coelho T, Planté-Bordeneuve V, Berk JL, González-Duarte A, Gillmore JD, Low SC, Sekijima Y, Obici L, Chen C, Badri P, Arum SM, Vest J, and Polydefkis M
- Subjects
- Humans, Quality of Life, Prealbumin genetics, Amyloid Neuropathies, Familial drug therapy, Amyloid Neuropathies, Familial genetics, Amyloid Neuropathies, Familial complications, Polyneuropathies drug therapy, Polyneuropathies genetics, Polyneuropathies complications
- Abstract
Background: The study objective was to assess the effect of vutrisiran, an RNA interference therapeutic that reduces transthyretin (TTR) production, in patients with hereditary transthyretin (ATTRv) amyloidosis with polyneuropathy., Methods: HELIOS-A was a phase 3, global, open-label study comparing the efficacy and safety of vutrisiran with an external placebo group (APOLLO study). Patients were randomized 3:1 to subcutaneous vutrisiran 25 mg every 3 months (Q3M) or intravenous patisiran 0.3 mg/kg every 3 weeks (Q3W) for 18 months., Results: HELIOS-A enrolled 164 patients (vutrisiran, n = 122; patisiran reference group, n = 42); external placebo, n = 77. Vutrisiran met the primary endpoint of change from baseline in modified Neuropathy Impairment Score +7 (mNIS+7) at 9 months ( p = 3.54 × 10
-12 ), and all secondary efficacy endpoints; significant improvements versus external placebo were observed in Norfolk Quality of Life-Diabetic Neuropathy, 10-meter walk test (both at 9 and 18 months), mNIS+7, modified body-mass index, and Rasch-built Overall Disability Scale (all at 18 months). TTR reduction with vutrisiran Q3M was non-inferior to within-study patisiran Q3W. Most adverse events were mild or moderate in severity, and consistent with ATTRv amyloidosis natural history. There were no drug-related discontinuations or deaths., Conclusions: Vutrisiran significantly improved multiple disease-relevant outcomes for ATTRv amyloidosis versus external placebo, with an acceptable safety profile., Clinicaltrials.gov: NCT03759379.- Published
- 2023
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13. A Novel Tri-Functionality pH-Magnetic-Photocatalytic Hybrid Organic-Inorganic Polyoxometalates Augmented Microspheres for Polluted Water Treatment.
- Author
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Yee LY, Ng QH, Enche Ab Rahim SK, Hoo PY, Chang PT, Ahmad AL, Low SC, and Shuit SH
- Abstract
The severe water pollution from effluent dyes threatens human health. This study created pH-magnetic-photocatalytic polymer microspheres to conveniently separate the photocatalyst nanoparticles from the treated water by applying an external magnetic field. While fabricating magnetic nanoparticles' (MNPs) microspheres, incorporating 0.5 wt.% iron oxide (Fe
3 O4 ) showed the best magnetophoretic separation ability, as all the MNPs microspheres were attracted toward the external magnet. Subsequently, hybrid organic-inorganic polyoxometalates (HPOM), a self-synthesized photocatalyst, were linked with the functionalized magnetic nanoparticles (f-MNPs) to prepare augmented magnetic-photocatalytic microspheres. The photodegradation dye removal efficiency of the augmented magnetic-photocatalytic microspheres (f-MNPs-HPOM) was then compared with that of the commercial titanium dioxide (TiO2 ) photocatalyst (f-MNPs-TiO2 ). Results showed that f-MNPs-HPOM microspheres with 74 ± 0.7% photocatalytic removal efficiency better degraded methylene orange (MO) than f-MNPs-TiO2 (70 ± 0.8%) at an unadjusted pH under UV-light irradiation for 90 min. The excellent performance was mainly attributed to the lower band-gap energy of HPOM (2.65 eV), which required lower energy to be photoactivated under UV light. The f-MNPs-HPOM microspheres demonstrated excellent reusability and stability in the photo-decolorization of MO, as the microspheres retained nearly the same removal percentage throughout the three continuous cycles. The degradation rate was also found to follow the pseudo-first-order kinetics. Furthermore, f-MNPs-HPOM microspheres were pH-responsive in the photodegradation of MO and methylene blue (MB) at pH 3 (acidic) and pH 9 (alkaline). Overall, it was demonstrated that using HPOM photocatalysts in the preparation of magnetic-photocatalytic microspheres resulted in better dye degradation than TiO2 photocatalysts.- Published
- 2023
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14. Environmental monitoring of trace metal pollutants using cellulosic-paper incorporating color change of azo-chromophore.
- Author
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Low SC, Azmi NAB, Ong CS, and Lim JK
- Subjects
- Dithizone chemistry, Environmental Monitoring, Ions analysis, Lead analysis, Resorcinols chemistry, Water analysis, Chitosan, Environmental Pollutants analysis, Metals, Heavy analysis, Trace Elements analysis
- Abstract
An essential requirement for colorimetric paper-sensor is to allow the target analytes (heavy metal ions) to access the chromophore while maintaining strong chromophore immobilization on the porous substrate surface. This work evaluates the selection of sensitive chromophores (dithizone, 1-(2-pyridylazo) 2-naphthol and 4-(2-pyridylazo)-resorcinol) and their immobilization strategies on paper sensors. Dithizone (DTz) are capable of producing a significant color transition at unadjusted pH, observed by UV-Vis absorption spectroscopy and visible recognition. After immobilizing DTz on a paper substrate (cellulose acetate/chitosan substrate), the DTz-paper sensor showed a distinctive color change from blue-green to peach-pink upon reaction with Pb
2+ ions, and the color intensity was proportional to the metal concentration. Quantitative analysis using RGB (R:Red; G:Green; B:Blue) plots showed that increasing DTz concentration on the CA/CS paper sensor increases the difference in total color intensity (∆IT ) and the difference in red code intensity (∆IR ). This is due to the formation of more DTz-Pb2+ complexes on the CA/CS paper substrate. The CA/CS paper strips immobilized with 100 ppm DTz showed practical potential for rapid detection of heavy metal ions. The DTz-CA/CS paper sensor showed significant color change when detecting spiked heavy metals ions (0.1 ppm Pb2+ , 2.0 ppm Zn2+ , and 0.2 ppm Cu2+ ) in river water samples that prepared at the maximum permissible limit for industrial effluent in Malaysia., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2022
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15. Multimodality Imaging in the Diagnosis and Assessment of Cardiac Amyloidosis.
- Author
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Velaga J, Liew C, Choo Poh AC, Lee PT, Lath N, Low SC, and Bharadwaj P
- Abstract
Amyloidosis is a rare disorder where abnormal protein aggregates are deposited in tissues forming amyloid fibrils, leading to progressive organ failure. Although any organ can be affected, cardiac involvement is the main cause of morbidity and mortality associated with amyloidosis as diagnosis is often delayed due to the indolent nature of the disease in some forms. An early diagnosis of disease and knowledge of the type/subtype of cardiac amyloidosis (CA) are essential for appropriate management and better outcome. Echocardiography is often the first line of investigation for patients suspected of CA and offers superior hemodynamic assessment. Although cardiovascular magnetic resonance (CMR) imaging is not diagnostic of CA, it provides vital clues to diagnosis and has a role in disease quantification and prognostication. Radiolabeled bone seeking tracers are the mainstay of diagnosis of CA and when combined with screening of monoclonal light chains, bone scintigraphy offers high sensitivity in diagnosing transthyretin type of CA. This review aims to describe the noninvasive imaging assessment and approach to diagnosis of patients with suspected CA. Imaging features of echocardiography, nuclear scintigraphy, and CMR are described with a brief mention on computed tomography., Competing Interests: Conflict of Interest None declared., (World Association of Radiopharmaceutical and Molecular Therapy (WARMTH). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)
- Published
- 2022
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16. Saccade rate is associated with recall of items in working memory.
- Author
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Low SC, Verschure PFMJ, and Santos-Pata D
- Subjects
- Eye-Tracking Technology, Hippocampus, Humans, Mental Recall physiology, Memory, Short-Term physiology, Saccades
- Abstract
Working memory has been shown to rely on theta oscillations' phase synchronicity for item encoding and recall. At the same time, saccadic eye movements during visual exploration have been observed to trigger theta-phase resets, raising the question of whether the neuronal substrates of mnemonic processing rely on motor-evoked responses. To quantify the relationship between saccades and working memory load, we recorded eye tracking and behavioral data from human participants simultaneously performing an n-back Sternberg auditory task and a hue-based catch detection task. In addition to task-specific interference in performance, we also found that saccade rate was modulated by working memory load in the Sternberg task's preresponse stage. Our results support the possibility of interplay between saccades and hippocampal theta during working memory retrieval of items., (© 2022 Low et al.; Published by Cold Spring Harbor Laboratory Press.)
- Published
- 2022
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17. Applications of Alginate-Based Nanomaterials in Enhancing the Therapeutic Effects of Bee Products.
- Author
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Al-Hatamleh MAI, Alshaer W, Hatmal MM, Lambuk L, Ahmed N, Mustafa MZ, Low SC, Jaafar J, Ferji K, Six JL, Uskoković V, and Mohamud R
- Abstract
Since the ancient times, bee products (i.e., honey, propolis, pollen, bee venom, bee bread, and royal jelly) have been considered as natural remedies with therapeutic effects against a number of diseases. The therapeutic pleiotropy of bee products is due to their diverse composition and chemical properties, which is independent on the bee species. This has encouraged researchers to extensively study the therapeutic potentials of these products, especially honey. On the other hand, amid the unprecedented growth in nanotechnology research and applications, nanomaterials with various characteristics have been utilized to improve the therapeutic efficiency of these products. Towards keeping the bee products as natural and non-toxic therapeutics, the green synthesis of nanocarriers loaded with these products or their extracts has received a special attention. Alginate is a naturally produced biopolymer derived from brown algae, the desirable properties of which include biodegradability, biocompatibility, non-toxicity and non-immunogenicity. This review presents an overview of alginates, including their properties, nanoformulations, and pharmaceutical applications, placing a particular emphasis on their applications for the enhancement of the therapeutic effects of bee products. Despite the paucity of studies on fabrication of alginate-based nanomaterials loaded with bee products or their extracts, recent advances in the area of utilizing alginate-based nanomaterials and other types of materials to enhance the therapeutic potentials of bee products are summarized in this work. As the most widespread and well-studied bee products, honey and propolis have garnered a special interest; combining them with alginate-based nanomaterials has led to promising findings, especially for wound healing and skin tissue engineering. Furthermore, future directions are proposed and discussed to encourage researchers to develop alginate-based stingless bee product nanomedicines, and to help in selecting suitable methods for devising nanoformulations based on multi-criteria decision making models. Also, the commercialization prospects of nanocomposites based on alginates and bee products are discussed. In conclusion, preserving original characteristics of the bee products is a critical challenge in developing nano-carrier systems. Alginate-based nanomaterials are well suited for this task because they can be fabricated without the use of harsh conditions, such as shear force and freeze-drying, which are often used for other nano-carriers. Further, conjunction of alginates with natural polymers such as honey does not only combine the medicinal properties of alginates and honey, but it could also enhance the mechanical properties and cell adhesion capacity of alginates., Competing Interests: Author VU is the cofounder of TardigradeNano LLC, a biotech startup with no commercial or financial interest in the topic elaborated here. The remaining 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 © 2022 Al-Hatamleh, Alshaer, Hatmal, Lambuk, Ahmed, Mustafa, Low, Jaafar, Ferji, Six, Uskoković and Mohamud.)
- Published
- 2022
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18. Can biochar and hydrochar be used as sustainable catalyst for persulfate activation?
- Author
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Gasim MF, Lim JW, Low SC, Lin KA, and Oh WD
- Subjects
- Adsorption, Biomass, Catalysis, Charcoal
- Abstract
Over the past decade, there has been a surge of interest in using char (hydrochar or biochar) derived from biomass as persulfate (PS, either peroxymonosulfate or peroxydisulfate) activator for anthropogenic pollutants removal. While extensive investigation showed that char could be used as a PS activator, its sustainability over prolonged application is equivocal. This review provides an assessment of the knowledge gap related to the sustainability of char as a PS activator. The desirable char properties for PS activation are identified, include the high specific surface area and favorable surface chemistry. Various synthesis strategies to obtain the desirable properties during biomass pre-treatment, hydrochar and biochar synthesis, and char post-treatment are discussed. Thereafter, factors related to the sustainability of employing char as a PS activator for anthropogenic pollutants removal are critically evaluated. Among the critical factors include performance uncertainty, competing adsorption process, char stability during PS activation, biomass precursor variation, scalability, and toxic components in char. Finally, some potential research directions are provided. Fulfilling the sustainability factors will provide opportunity to employ char as an economical and efficient catalyst for sustainable environmental remediation., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2022
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19. Slippery membrane surface tuning with polypropylene coating to treat real aquaculture wastewater in membrane distillation.
- Author
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Chin JY, Teoh GH, Ahmad AL, and Low SC
- Subjects
- Aquaculture, Membranes, Artificial, Polypropylenes, Wastewater, Distillation, Water Purification
- Abstract
Surging growth of aquaculture industry has alarmed the public when the wastewater discharged had an adverse effect on the environment. This current study is a pioneer in the use of membrane distillation (MD) to treat real aquaculture wastewater. In addition to excellent hydrophobicity, the slippery surface of membrane used for MD is another key factor that enhances the performance of MD. The slippery surface of the membrane was tuned by layering high-viscosity and low-viscosity polypropylene (PP) polymers on the electrospun membrane by solvent-exchanged method. While the high-viscosity PP coating (PP/HV) rendered the membrane surface slippery, the low-viscosity PP coating (PP/LV) caused the fish farm wastewater to have stick-slip movement on the membrane surface. In the long-term 70-hour direct contact membrane distillation (DCMD) separation, PP/HV and PP/LV membranes can perfectly eliminate the undesirable components in the fish farm wastewater. The PP/HV membrane has registered a flux of 19.1 kg/m
2 ·h, while the flux of PP/LV membrane was only 7.3 kg/m2 ·h. The PP/HV membrane also showed excellent anti-scaling properties in relative to the PP/LV membrane. This is because the PP/HV membrane promotes effortless gliding of the feed water along the surface of the membrane, while the surface of the PP/LV membrane has a static water boundary. Therefore, it can be concluded that the application of MD using the membrane coated with high-viscosity PP polymer is a feasible technology for the treatment of aquaculture wastewater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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20. Multicomponent Spiral Wound Membrane Separation Model for CO 2 Removal from Natural Gas.
- Author
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Abdul Latif AA, Lau KK, Low SC, and Azeem B
- Abstract
A spiral wound membrane (SWM) is employed to separate acid gases (mainly CO
2 ) from natural gas due to its robustness, lower manufacturing cost, and moderate packing density compared to hollow fiber membranes. Various mathematical models are available to describe the separation performance of SWMs under different operating conditions. Nevertheless, most of the mathematical models deal with only binary gas mixtures (CO2 and CH4 ) that may lead to an inaccurate assessment of separation performance of multicomponent natural gas mixtures. This work is aimed to develop an SWM separation model for multicomponent natural gas mixtures. The succession stage method is employed to discretize the separation process within the multicomponent SWM module for evaluating the product purity, hydrocarbon loss, stage cut, and permeate acid gas composition. Our results suggest that multicomponent systems tend to generate higher product purity, lower hydrocarbon loss, and augmented permeate acid gas composition compared to the binary system. Furthermore, different multicomponent systems yield varied separation performances depending on the component of the acid gas. The developed multicomponent SWM separation model has the potential to design and optimize the spiral wound membrane system for industrial application.- Published
- 2021
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21. Isotherm and Electrochemical Properties of Atrazine Sensing Using PVC/MIP: Effect of Porogenic Solvent Concentration Ratio.
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Che Lah NF, Ahmad AL, Low SC, and Zaulkiflee ND
- Abstract
Widespread atrazine use is associated with an increasing incidence of contamination of drinking water. Thus, a biosensor using molecularly imprinted polymers (MIPs) was developed to detect the amount of atrazine in water to ensure prevention of exposure levels that could lead to reproductive effects in living organisms. In this study, the influence of the porogen on the selectivity of MIPs was investigated. The porogen plays a pivotal role in molecular imprinting as it affects the physical properties and governs the prepolymerization complex of the resulting polymer, which in turn firmly defines the recognition properties of the resulting molecularly imprinted polymer (MIP). Therefore, bulk MIPs against atrazine (Atr) were synthesized based on methacrylic acid (MAA) as a functional monomer and ethyleneglycol dimethacrylate (EGDMA) as a crosslinker; they were prepared in toluene and dimethyl sulfoxide (DMSO). The imprinting factor, binding capacity, and structural stability were evaluated using the respective porogenic solvents. Along with the characterization of the morphology of the obtained polymers via SEM and BET analysis, the kinetic and adsorption analyses were demonstrated and verified. The highest imprinting factor, binding capacity, and the highest structural stability were found to be on polymer synthesized in a medium of MAA and EGDMA, which contained 90% toluene and 10% DMSO as porogen. Moreover, the response for Atr concentrations by the PVC-based electrochemical sensor was found to be at a detection limit of 0.0049 μM (S/N = 3). The sensor proved to be an effective sensor with high sensitivity and low Limit of Detection (LOD) for Atr detection. The construction of the sensor will act as a baseline for a fully functionalized membrane sensor.
- Published
- 2021
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22. Modified Zeolite/Polysulfone Mixed Matrix Membrane for Enhanced CO 2 /CH 4 Separation.
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Anbealagan LD, Ng TYS, Chew TL, Yeong YF, Low SC, Ong YT, Ho CD, and Jawad ZA
- Abstract
In recent years, mixed matrix membranes (MMMs) have received worldwide attention for their potential to offer superior gas permeation and separation performance involving CO
2 and CH4 . However, fabricating defect-free MMMs still remains as a challenge where the incorporation of fillers into MMMs has usually led to some issues including formation of undesirable interfacial voids, which may jeopardize the gas separation performance of the MMMs. This current work investigated the incorporation of zeolite RHO and silane-modified zeolite RHO (NH2 -RHO) into polysulfone (PSf) based MMMs with the primary aim of enhancing the membrane's gas permeation and separation performance. The synthesized zeolite RHO, NH2 -RHO, and fabricated membranes were characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared-attenuated total reflection (FTIR-ATR), thermogravimetric analysis (TGA) and field emission scanning election microscopy (FESEM). The effects of zeolite loading in the MMMs on the CO2 /CH4 separation performance were investigated. By incorporating 1 wt% of zeolite RHO into the MMMs, the CO2 permeability and ideal CO2 /CH4 selectivity slightly increased by 4.2% and 2.7%, respectively, compared to that of a pristine PSf membrane. On the other hand, a significant enhancement of 45% in ideal CO2 /CH4 selectivity was attained by MMMs incorporated with 2 wt% of zeolite NH2 -RHO compared to a pristine PSf membrane. Besides, all MMMs incorporated with zeolite NH2 -RHO displayed higher ideal CO2 /CH4 selectivity than that of the MMMs incorporated with zeolite RHO. By incorporating 1-3 wt% zeolite NH2 -RHO into PSf matrix, MMMs without interfacial voids were successfully fabricated. Consequently, significant enhancement in ideal CO2 /CH4 selectivity was enabled by the incorporation of zeolite NH2 -RHO into MMMs.- Published
- 2021
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23. Hereditary transthyretin amyloidosis in multi-ethnic Malaysians.
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Low SC, Md Sari NA, Tan CY, Ahmad-Annuar A, Wong KT, Law WC, Sim RS, Lin KP, Shahrizaila N, and Goh KJ
- Subjects
- Adult, Aged, Asian People genetics, Female, Humans, Malaysia, Male, Middle Aged, Mutation, Neurologic Examination, Phenotype, Amyloid Neuropathies, Familial genetics, Ethnicity genetics
- Abstract
We report the clinical and genetic characteristics of hereditary transthyretin amyloidosis in the multi-ethnic Malaysian population. Subjects with genetically confirmed transthyretin amyloidosis seen between 2001 till August 2020 were included. There were 30 patients and 14 asymptomatic carriers, of which 26 (59.1%) were men. The majority (86.7%) were ethnic Chinese while two (6.7%) each were Malay and Sri Lankan Tamil ethnicity respectively. Among patients, mean age of symptom-onset was 55.9 ± 9.8 years with mean duration from symptom-onset to diagnosis of 3.2 ± 2.5 years. Common presenting symptoms were sensory symptoms of upper limbs (43.3%), symmetric sensory symptoms of both lower limbs (16.7%) and autonomic symptoms (16.7%). Nerve conduction studies showed sensorimotor polyneuropathy in 25 (83.3%) patients (22, axonal). Abnormal echocardiograms were seen in 24 (80%) patients, although 15 were asymptomatic. Of six different TTR mutations found, Ala97Ser was the commonest, and found exclusively in 84.6% of Chinese patients. Other mutations among Chinese patients were Val30Met, Ala25Thr and Asp39Val. Our Malay and Tamil patients had Glu54Lys and Gly47Val mutations respectively. In conclusion, TTR Ala97Ser is the commonest mutation among ethnic Chinese Malaysians which presented with late-onset progressive sensorimotor polyneuropathy, autonomic dysfunction and subclinical cardiac involvement., Competing Interests: Declarations of Competing Interest None of the authors has any declaration of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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24. Magnetophoresis of Magnetic Pickering Emulsions Under Low Field Gradient: Macroscopic and Microscopic Motion.
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Tham FK, Ng WM, Leong SS, Yeap SP, Low SC, Lee HL, and Lim J
- Abstract
Monodispersed iron oxide nanoparticles (IONPs) coated with polystyrenesulfonate (PSS) and cetrimonium bromide (CTAB) have been used to stabilize magnetic Pickering emulsions (MPEs). Magnetophoresis of MPEs under the influence of a low gradient magnetic field (∇ B < 100 T/m) was investigated at the macroscopic and microscopic scale. At the macroscopic scale, for the case of pH 7, the MPE achieved a magnetophoretic velocity of 70.9 μm/s under the influence of ∇ B at 93.8 T/m. The magnetic separation efficiency of the MPE at 90% was achieved within 30 min for pH 3, 7, and 10. At pH 10, the colloidal stability of the MPE was the lowest compared to that for pH 3 and 7. Thus, MPE at pH 10 required the shortest time for achieving the highest separation efficiency, as the MPE experienced cooperative magnetophoresis at alkaline pH. The creaming rate of the MPE at all conditions was still lower compared to magnetophoresis and was negligible in influencing its separation kinetics profiles. At the microscopic scale, the migration pathways of the MPEs (with diameters between 2.5 and 7.5 μm) undergoing magnetophoresis at ∇ B ∼ 13.0 T/m were recorded by an optical microscope. From these experiments, and taking into consideration the MPE size distribution from the dynamic light scattering (DLS) measurement, we determined the averaged microscopic magnetophoretic velocity to be 7.8 ± 5.5 μm/s. By making noncooperative magnetophoresis assumptions (with negligible interactions between the MPEs along their migration pathways), the calculated velocity of individual MPEs was 9.8 μm/s. Such a value was within the percentage error of the experimental result of 7.8 ± 5.5 μm/s. This finding allows for an easy and quick estimation of the magnetophoretic velocity of MPEs at the microscale by using macroscopic separation kinetics data.
- Published
- 2021
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25. Probiotics for Constipation in Parkinson Disease: A Randomized Placebo-Controlled Study.
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Tan AH, Lim SY, Chong KK, A Manap MAA, Hor JW, Lim JL, Low SC, Chong CW, Mahadeva S, and Lang AE
- Subjects
- Aged, Constipation etiology, Constipation physiopathology, Double-Blind Method, Feces chemistry, Female, Humans, Leukocyte L1 Antigen Complex metabolism, Male, Middle Aged, Parkinson Disease complications, Constipation therapy, Parkinson Disease physiopathology, Patient Satisfaction, Probiotics therapeutic use, Quality of Life
- Abstract
Objective: To determine whether probiotics are effective for constipation, a common and often difficult-to-treat problem, in Parkinson disease (PD)., Methods: In this double-blind, randomized, placebo-controlled, single-center trial, 280 patients with PD were screened, and 72 eligible patients were block-randomized (1:1) to receive either multistrain probiotics capsules (n = 34) or identical-appearing placebo (n = 38), for 4 weeks. The primary endpoint was the change in the average number of spontaneous bowel movements (SBM) per week during the last 2 weeks of intervention compared with the 2-week preintervention phase, recorded by daily stool diary. Secondary outcome measures included changes in stool consistency, constipation severity score, and quality of life related to constipation. Satisfaction with intervention received was assessed. Change in levels of fecal calprotectin, a marker of intestinal inflammation, was an exploratory outcome., Results: SBM increased by 1.0 ± 1.2 per week after treatment with probiotics and decreased by 0.3 ± 1.0 per week in the placebo group (mean difference 1.3, 95% confidence interval 0.8-1.8, p < 0.001). Significant improvements were also seen for secondary outcomes after correction for multiple comparisons, including stool consistency ( p = 0.009) and quality of life related to constipation ( p = 0.001). In the treatment group, 65.6% reported satisfaction with the intervention vs only 21.6% in the placebo group ( p < 0.001). One patient (2.9%) in the treatment group withdrew due to a nonserious adverse event. Fecal calprotectin did not change significantly during the study., Conclusions: Multistrain probiotics treatment was effective for constipation in PD. Further studies are needed to investigate the long-term efficacy and safety of probiotics in PD, as well as their mechanisms of action., Clinicaltrialsgov Identifier: NCT03377322., Classification of Evidence: This study provides Class I evidence that, for people with PD, multistrain probiotics significantly increased the average number of SBM per week., (© 2020 American Academy of Neurology.)
- Published
- 2021
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26. Superhydrophobic surface coating on electrospun polypropylene membrane to treat high salinity water in membrane distillation.
- Author
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Chin JY, Teoh GH, Ahmad AL, and Low SC
- Subjects
- Membranes, Artificial, Polypropylenes, Salinity, Water, Distillation, Water Purification
- Abstract
Membrane distillation (MD) is an advantageous separation process compared with pressure-driven technologies and was subsequently introduced to treat aquaculture wastewater. Harnessing a superhydrophobic membrane in an MD process is of extreme importance to prevent membrane wetting. In this work, the electrospun polypropylene (PP) membrane was surface modified by depositing an additional coating of PP via the solvent-exchange method, thereby improving the membrane's superhydrophobicity. Layer-by-layer deposition of PP caused the formation of uniform polymer spherulites on the membrane surface, which levelled up the membrane's surface roughness. A superhydrophobic surface was achieved by applying a single-layered PP coating, with static water contact angle of 152.2° and sliding angle of 12.5°. While all membranes achieved almost perfect salt rejection (up to 99.99%), the MD permeate flux improved by 30%, average of 13.0 kg/m
2 h, when the single-layered PP-coated membrane was used to treat the high salinity water in both 2 and 60 hr MD processes. Further layers of coating resulted in larger size of PP spherulites with higher sliding angle, followed by lowered flux in MD. The evenness of the surface coating and the size of the aggregate PP spherulites (nano-scaled) are two predominant factors contributing to the superhydrophobicity character of a membrane.- Published
- 2020
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27. Unified View of Magnetic Nanoparticle Separation under Magnetophoresis.
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Leong SS, Ahmad Z, Low SC, Camacho J, Faraudo J, and Lim J
- Abstract
The migration process of magnetic nanoparticles and colloids in solution under the influence of magnetic field gradients, which is also known as magnetophoresis, is an essential step in the separation technology used in various biomedical and engineering applications. Many works have demonstrated that in specific situations, separation can be performed easily with the weak magnetic field gradients created by permanent magnets, a process known as low-gradient magnetic separation (LGMS). Due to the level of complexity involved, it is not possible to understand the observed kinetics of LGMS within the classical view of magnetophoresis. Our experimental and theoretical investigations in the last years unravelled the existence of two novel physical effects that speed up the magnetophoresis kinetics and explain the observed feasibility of LGMS. Those two effects are (i) cooperative magnetophoresis (due to the cooperative motion of strongly interacting particles) and (ii) magnetophoresis-induced convection (fluid dynamics instability originating from inhomogeneous magnetic gradients). In this feature article, we present a unified view of magnetophoresis based on the extensive research done on these effects. We present the physical basis of each effect and also propose a classification of magnetophoresis into four distinct regimes. This classification is based on the range of values of two dimensionless quantities, namely, aggregation parameter N * and magnetic Grashof number Gr
m , which include all of the dependency of LGMS on various physical parameters (such as particle properties, thermodynamic parameters, fluid properties, and magnetic field properties). This analysis provides a holistic view of the classification of transport mechanisms in LGMS, which could be particularly useful in the design of magnetic separators for engineering applications.- Published
- 2020
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28. Lithium chloride (LiCl)-modified polyethersulfone (PES) substrate surface pore architectures on thin poly(dimethylsiloxane) (PDMS) dense layer formation and the composite membrane's performance in gas separation.
- Author
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Mohd Shafie ZMH, Ahmad AL, Low SC, Rode S, and Belaissaoui B
- Abstract
The use of pore forming agents has been notable for improving the water flux in a water-based separation membrane but are rarely being studied as a methodology to influence the substrate's surface architectures for composite membrane fabrication in gas separation. In this study, the influence of lithium chloride (LiCl) on the surface pore architectures and hence, the gas permeance, has been studied in both bare and composite forms with poly(dimethylsiloxane) (PDMS). 1-4 wt% of LiCl was mixed with the dope solution of PES/NMP in the ratio 0.19 and was casted via the dry-wet phase inversion method. Bare substrates were noted to possess increasingly larger surface pore sizes but at a diminishing surface pore density with maximum surface porosity at 2 wt% LiCl. The permeances were, however, significantly reduced with the increase in the LiCl content from 105 300 to 4300 GPU for N
2 gas, presumably due to the thicker skin layer. Nevertheless, the porous surface morphology was confirmed and exhibited Knudsen selectivity with a CO2 /N2 selectivity of about 0.8, signifying minimal gas flow resistance by the substrates. Upon coating with a similar amount of thin PDMS layer, the composite permeances retain the same trend with values from 361.9 GPU for 0 wt% LiCl substrates to 68.8 GPU for 4 wt% LiCl substrates for CO2 gas at a consistent selectivity of about 14. As the PDMS layer of the same volumes were used and no significant difference in the coating thickness was noted, the mixed influence of pore intrusion and lateral diffusion is hypothesised at the substrate-coating interface owing to the different surface pore architectures of the substrates., Competing Interests: The authors have no other competing interests., (This journal is © The Royal Society of Chemistry.)- Published
- 2020
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29. Assessment of different strategies for scalable production and proliferation of human myoblasts.
- Author
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Chua MJ, Yildirim ED, Tan JE, Chua YB, Low SC, Ding SLS, Li CW, Jiang Z, Teh BT, Yu K, and Shyh-Chang N
- Subjects
- Cell Differentiation, Cell Line, Cell Proliferation, Cell Transformation, Viral, Cells, Cultured, Cyclin D1 genetics, Cyclin-Dependent Kinase 4 genetics, Genetic Markers, Human Embryonic Stem Cells cytology, Humans, Muscle Development, MyoD Protein genetics, Myoblasts physiology, Myoblasts transplantation, Regeneration, Satellite Cells, Skeletal Muscle cytology, Telomerase genetics, Myoblasts cytology
- Abstract
Objectives: Myoblast transfer therapy (MTT) is a technique to replace muscle satellite cells with genetically repaired or healthy myoblasts, to treat muscular dystrophies. However, clinical trials with human myoblasts were ineffective, showing almost no benefit with MTT. One important obstacle is the rapid senescence of human myoblasts. The main purpose of our study was to compare the various methods for scalable generation of proliferative human myoblasts., Methods: We compared the immortalization of primary myoblasts with hTERT, cyclin D1 and CDK4
R24C , two chemically defined methods for deriving myoblasts from pluripotent human embryonic stem cells (hESCs), and introduction of viral MyoD into hESC-myoblasts., Results: Our results show that, while all the strategies above are suboptimal at generating bona fide human myoblasts that can both proliferate and differentiate robustly, chemically defined hESC-monolayer-myoblasts show the most promise in differentiation potential., Conclusions: Further efforts to optimize the chemically defined differentiation of hESC-monolayer-myoblasts would be the most promising strategy for the scalable generation of human myoblasts, for applications in MTT and high-throughput drug screening., (© 2019 John Wiley & Sons Ltd.)- Published
- 2019
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30. Ala97Ser mutation is common among ethnic Chinese Malaysians with transthyretin familial amyloid polyneuropathy.
- Author
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Low SC, Tan CY, Md Sari NA, Ahmad-Annuar A, Wong KT, Lin KP, Shahrizaila N, Tan CT, and Goh KJ
- Subjects
- Adult, Aged, Amyloid Neuropathies, Familial epidemiology, Amyloid Neuropathies, Familial pathology, China epidemiology, Female, Humans, Male, Middle Aged, Mutation, Amyloid Neuropathies, Familial genetics, Prealbumin genetics
- Published
- 2019
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31. Chorea in Sporadic Creutzfeldt-Jakob Disease.
- Author
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Tan AH, Toh TH, Low SC, Fong SL, Chong KK, Lee KW, Goh KJ, and Lim SY
- Published
- 2018
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32. Artificial Magnetotaxis of Microbot: Magnetophoresis versus Self-Swimming.
- Author
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Ng WM, Che HX, Guo C, Liu C, Low SC, Chieh Chan DJ, Mohamud R, and Lim J
- Abstract
An artificial magnetotactic microbot was created by integrating the microalgal cell with magnetic microbead for its potential application as biomotor in microscale environment. Here, we demonstrate the remote magnetotactic control of the microbot under a low gradient magnetic field (<100 T/m). We characterize the kinematic behavior of the microbots carrying magnetic microbeads of two different sizes, with diameter of 2 and 4.5 μm, in the absence and presence of magnetic field. In the absence of magnetic field, we observed the microbot showed a helical motion as a result of the misalignment between the thrust force and the symmetry axis after the attachment. The microbot bound with a larger magnetic microbead moved with higher translational velocity but rotated slower about its axis of rotation. The viscous force was balanced by the thrust force of the microbot, resulting in a randomized swimming behavior of the microbot at its terminal velocity. Meanwhile, under the influence of a low gradient magnetic field, we demonstrated that the directional control of the microbot was based on following principles: (1) magnetophoretic force was insignificant on influencing its perpendicular motion and (2) its parallel motion was dependent on both self-swimming and magnetophoresis, in which this cooperative effect was a function of separation distance from the magnet. As the microbot approached the magnet, the magnetophoretic force suppressed its self-swimming behavior, leading to a positive magnetotaxis of the microbot toward the source of magnetic field. Our experimental results and kinematic analysis revealed the contribution of mass density variation of particle-and-cell system on influencing its dynamical behavior.
- Published
- 2018
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33. Size Matters: How Scaling Affects the Interaction between Grid and Border Cells.
- Author
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Santos-Pata D, Zucca R, Low SC, and Verschure PFMJ
- Abstract
Many hippocampal cell types are characterized by a progressive increase in scale along the dorsal-to-ventral axis, such as in the cases of head-direction, grid and place cells. Also located in the medial entorhinal cortex (MEC), border cells would be expected to benefit from such scale modulations. However, this phenomenon has not been experimentally observed. Grid cells in the MEC of mammals integrate velocity related signals to map the environment with characteristic hexagonal tessellation patterns. Due to the noisy nature of these input signals, path integration processes tend to accumulate errors as animals explore the environment, leading to a loss of grid-like activity. It has been suggested that border-to-grid cells' associations minimize the accumulated grid cells' error when rodents explore enclosures. Thus, the border-grid interaction for error minimization is a suitable scenario to study the effects of border cell scaling within the context of spatial representation. In this study, we computationally address the question of (i) border cells' scale from the perspective of their role in maintaining the regularity of grid cells' firing fields, as well as (ii) what are the underlying mechanisms of grid-border associations relative to the scales of both grid and border cells. Our results suggest that for optimal contribution to grid cells' error minimization, border cells should express smaller firing fields relative to those of the associated grid cells, which is consistent with the hypothesis of border cells functioning as spatial anchoring signals.
- Published
- 2017
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34. Teaching Video NeuroImages: Purposeless groaning in progressive supranuclear palsy.
- Author
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Low SC, Tan AH, and Lim SY
- Subjects
- Humans, Male, Middle Aged, Neuroimaging methods, Supranuclear Palsy, Progressive diagnostic imaging, Supranuclear Palsy, Progressive physiopathology, Video Recording methods
- Published
- 2017
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35. Integrating Patient Concerns into Parkinson's Disease Management.
- Author
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Lim SY, Tan AH, Fox SH, Evans AH, and Low SC
- Subjects
- Caregivers, Humans, Patient Satisfaction, Precision Medicine, Quality of Life, Parkinson Disease therapy
- Abstract
Parkinson's disease (PD) is a complex motor and non-motor disorder and management is often challenging. In this review, we explore emerging approaches to improve the care of patients, drawing from the literature regarding patient-centred care, patient and caregiver perspectives and priorities, gaps in knowledge among patients and caregivers and the need for accurate information, individual variability in disease manifestations, prognostication of disease course, new developments in health technologies and personalized medicine, specialty care, pharmacological and non-pharmacological management, financial burden, lifestyle and work-related issues, support groups and palliative care.
- Published
- 2017
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36. "Ictal catatonia": Rare but not to be missed!
- Author
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Tan AH, Low SC, Tan CY, Lim KS, Tan CT, and Lim SY
- Subjects
- Catatonia drug therapy, Catatonia etiology, Electroencephalography, Humans, Male, Middle Aged, Seizures complications, Catatonia physiopathology, Seizures physiopathology
- Published
- 2016
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37. Phase I Study of PSMA-Targeted Docetaxel-Containing Nanoparticle BIND-014 in Patients with Advanced Solid Tumors.
- Author
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Von Hoff DD, Mita MM, Ramanathan RK, Weiss GJ, Mita AC, LoRusso PM, Burris HA 3rd, Hart LL, Low SC, Parsons DM, Zale SE, Summa JM, Youssoufian H, and Sachdev JC
- Subjects
- Adult, Aged, Aged, 80 and over, Antigens, Surface, Docetaxel, Drug Administration Schedule, Drug Carriers adverse effects, Female, Humans, Male, Middle Aged, Nanoparticles adverse effects, Neoplasms pathology, Drug Carriers pharmacokinetics, Drug Carriers therapeutic use, Glutamate Carboxypeptidase II antagonists & inhibitors, Nanoparticles therapeutic use, Neoplasms drug therapy, Taxoids therapeutic use
- Abstract
Purpose: First-in-human phase I trial to determine the safety, pharmacokinetics, and antitumor activity of BIND-014, a novel, tumor prostate-specific membrane antigen (PSMA)-targeted nanoparticle, containing docetaxel., Experimental Design: Patients with advanced solid tumors received BIND-014 every three weeks (n = 28) or weekly (n = 27), with dose levels ranging from 3.5 to 75 mg/m(2) and 15 to 45 mg/m(2), respectively., Results: BIND-014 was generally well tolerated, with no unexpected toxicities. The most common drug-related toxicities (>20% of patients) on either schedule included neutropenia, fatigue, anemia, alopecia, and diarrhea. BIND-014 demonstrated a dose-linear pharmacokinetic profile, distinct from docetaxel, with prolonged persistence of docetaxel-encapsulated circulating nanoparticles. Of the 52 patients evaluable for response, one had a complete response (cervical cancer on the every three week schedule) and five had partial responses (ampullary adenocarcinoma, non-small cell lung, and prostate cancers on the every-three-week schedule, and breast and gastroesophageal cancers on the weekly schedule). Responses were noted in both PSMA-detectable and -undetectable tumors., Conclusions: BIND-014 was generally well tolerated, with predictable and manageable toxicity and a unique pharmacokinetic profile compared with conventional docetaxel. Clinical activity was noted in multiple tumor types. The recommended phase II dose of BIND-014 is 60 mg/m(2) every three weeks or 40 mg/m(2) weekly. Clin Cancer Res; 22(13); 3157-63. ©2016 AACR., (©2016 American Association for Cancer Research.)
- Published
- 2016
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38. Mixing characteristics of sludge simulant in a model anaerobic digester.
- Author
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Low SC, Eshtiaghi N, Slatter P, Baudez JC, and Parthasarathy R
- Subjects
- Models, Chemical, Sewage chemistry
- Abstract
This study aims to investigate the mixing characteristics of a transparent sludge simulant in a mechanically agitated model digester using flow visualisation technique. Video images of the flow patterns were obtained by recording the progress of an acid-base reaction and analysed to determine the active and inactive volumes as a function of time. The doughnut-shaped inactive region formed above and below the impeller in low concentration simulant decreases in size with time and disappears finally. The 'cavern' shaped active mixing region formed around the impeller in simulant solutions with higher concentrations increases with increasing agitation time and reaches a steady state equilibrium size, which is a function of specific power input. These results indicate that the active volume is jointly determined by simulant rheology and specific power input. A mathematical correlation is proposed to estimate the active volume as a function of simulant concentration in terms of yield Reynolds number.
- Published
- 2016
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39. Optimization of polyvinylidene fluoride (PVDF) membrane fabrication for protein binding using statistical experimental design.
- Author
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Ahmad AL, Ideris N, Ooi BS, Low SC, and Ismail A
- Subjects
- Immunoblotting, Models, Statistical, Protein Binding, Temperature, Membrane Proteins chemistry, Polyvinyls chemical synthesis, Polyvinyls chemistry
- Abstract
Statistical experimental design was employed to optimize the preparation conditions of polyvinylidenefluoride (PVDF) membranes. Three variables considered were polymer concentration, dissolving temperature, and casting thickness, whereby the response variable was membrane-protein binding. The optimum preparation for the PVDF membrane was a polymer concentration of 16.55 wt%, a dissolving temperature of 27.5°C, and a casting thickness of 450 µm. The statistical model exhibits a deviation between the predicted and actual responses of less than 5%. Further characterization of the formed PVDF membrane showed that the morphology of the membrane was in line with the membrane-protein binding performance.
- Published
- 2016
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40. Morphology and kinetic modeling of molecularly imprinted organosilanol polymer matrix for specific uptake of creatinine.
- Author
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Ang QY and Low SC
- Subjects
- Adsorption, Computer Simulation, Kinetics, Materials Testing, Surface Properties, Creatinine chemistry, Models, Chemical, Molecular Imprinting methods, Polymers chemistry, Silanes chemistry
- Abstract
Molecular imprinting is an emerging technique to create imprinted polymers that can be applied in affinity-based separation, in particular, biomimetic sensors. In this study, the matrix of siloxane bonds prepared from the polycondensation of hydrolyzed tetraethoxysilane (TEOS) was employed as the inorganic monomer for the formation of a creatinine (Cre)-based molecularly imprinted polymer (MIP). Doped aluminium ion (Al(3+)) was used as the functional cross-linker that generated Lewis acid sites in the confined silica matrix to interact with Cre via sharing of lone pair electrons. Surface morphologies and pore characteristics of the synthesized MIP were determined by field emission scanning electron microscopy (FESEM) and Brunauer-Emmet-Teller (BET) analyses, respectively. The imprinting efficiency of MIPs was then evaluated through the adsorption of Cre with regard to molar ratios of Al(3+). A Cre adsorption capacity of up to 17.40 mg Cre g(-1) MIP was obtained and adsorption selectivity of Cre to its analogues creatine (Cr) and N-hydroxysuccinimide (N-hyd) were found to be 3.90 ± 0.61 and 4.17 ± 3.09, respectively. Of all the studied MIP systems, chemisorption was predicted as the rate-limiting step in the binding of Cre. The pseudo-second-order chemical reaction kinetic provides the best correlation of the experimental data. Furthermore, the equilibrium adsorption capacity of MIP fit well with a Freundlich isotherm (R (2) = 0.98) in which the heterogeneous surface was defined.
- Published
- 2015
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41. Eosinophilic gastroenteritis: Clinical profiles and treatment outcomes, a retrospective study of 18 adult patients in a Singapore Tertiary Hospital.
- Author
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Wong GW, Lim KH, Wan WK, Low SC, and Kong SC
- Abstract
Background: Eosinophilic gastroenteritis (EG) can mimic symptoms of common gastrointestinal (GI) disorders but responds well to appropriate treatment. Accurate diagnosis is central to effective management. Data on EG in Southeast Asia is lacking. We aim to describe the clinical profiles and treatment outcomes of adult patients with EG in a Singapore Tertiary Hospital., Materials and Methods: This retrospective study involved archival search of patients with GI biopsies that showed eosinophilic infiltration from January 2004 to December 2012. Patients' clinical data from computerised hospital records and clinical notes was reviewed. Diagnostic criteria for EG included presence of GI symptoms with more than 30 eosinophils/high power field on GI biopsies. Patients with secondary causes for eosinophilia were excluded., Results: Eighteen patients with EG were identified (mean age 52 years; male/female: 11/7). Fifteen patients (83%) had peripheral blood eosinophilia. Seven patients (39%) had atopic conditions. Most common symptoms were diarrhoea and abdominal pain. Small intestine was the most common site involved. Endoscopic finding was non-specific. Ten patients were treated with corticosteroids (nine prednisolone, one budesonide): eight patients (89%) responded clinically to prednisolone but four patients (50%) relapsed following tapering-off of prednisolone and required maintenance dose. One patient each responded to diet elimination and montelukast respectively. Half of the remaining six patients who were treated with proton-pump inhibitors, antispasmodic or antidiarrheal agents still remained symptomatic., Conclusion: Prednisolone is an effective treatment though relapses are common. Small intestine is most commonly involved. EG should be considered in the evaluation of unexplained chronic recurrent GI symptoms.
- Published
- 2015
42. The impact of green stormwater infrastructure installation on surrounding health and safety.
- Author
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Kondo MC, Low SC, Henning J, and Branas CC
- Subjects
- Crime prevention & control, Crime psychology, Crime statistics & numerical data, Drainage, Sanitary methods, Ecosystem, Humans, Nature, Philadelphia, Plants, Rain, Regression Analysis, Residence Characteristics, Sewage, Stress, Psychological complications, Stress, Psychological prevention & control, Drainage, Sanitary standards, Environment Design, Safety, Urban Health statistics & numerical data, Water Quality standards
- Abstract
Objectives: We investigated the health and safety effects of urban green stormwater infrastructure (GSI) installments., Methods: We conducted a difference-in-differences analysis of the effects of GSI installments on health (e.g., blood pressure, cholesterol and stress levels) and safety (e.g., felonies, nuisance and property crimes, narcotics crimes) outcomes from 2000 to 2012 in Philadelphia, Pennsylvania. We used mixed-effects regression models to compare differences in pre- and posttreatment measures of outcomes for treatment sites (n=52) and randomly chosen, matched control sites (n=186) within multiple geographic extents surrounding GSI sites., Results: Regression-adjusted models showed consistent and statistically significant reductions in narcotics possession (18%-27% less) within 16th-mile, quarter-mile, half-mile (P<.001), and eighth-mile (P<.01) distances from treatment sites and at the census tract level (P<.01). Narcotics manufacture and burglaries were also significantly reduced at multiple scales. Nonsignificant reductions in homicides, assaults, thefts, public drunkenness, and narcotics sales were associated with GSI installation in at least 1 geographic extent., Conclusions: Health and safety considerations should be included in future assessments of GSI programs. Subsequent studies should assess mechanisms of this association.
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- 2015
- Full Text
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43. External and internal bone micro-architecture in normal and Kienböck's lunates: a whole-bone micro-computed tomography study.
- Author
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Low SC, Bain GI, Findlay DM, Eng K, and Perilli E
- Subjects
- Adolescent, Adult, Aged, Humans, Lunate Bone diagnostic imaging, Middle Aged, Osteonecrosis diagnostic imaging, X-Ray Microtomography, Lunate Bone pathology, Osteonecrosis pathology
- Abstract
Kienböck's disease is idiopathic osteonecrosis of the lunate, leading to its fracture and collapse. This study compares internal and external bone micro-architecture of normal and fractured lunates (Kienböck's), by using high-resolution three-dimensional (3D) micro-computed tomography (micro-CT) on the whole bone of the two lunate types, and histology. Fractured Kienböck-diseased lunates were obtained from patients undergoing proximal-row-carpectomy, while normal cadaveric lunates served as controls. 3D-micro-CT-imaging of control lunates revealed an encircling cortex surrounding trabecular bone. Trabeculae were arranged in a radial pattern, spanning from the distal to the proximal subchondral plate. Kienböck's lunates exhibited clear fracture lines, with fragmented bone, both proximally and distally, in areas the radially-patterned trabeculae and enveloping cortex were absent, producing height loss. In trabecular bone, Kienböck's lunates revealed increased bone volume fraction, trabecular thickness and number, and decreased trabecular separation and structure model index. Histologically, Kienböck's lunates revealed osteonecrosis, as well as remodeling fronts with osteoblasts and osteoid surrounding bone marrow. Whole-bone high-resolution 3D examination of normal and Kienböck's diseased lunates contributes to a better understanding of micro-architectural changes occurring in the pathology., (© 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)
- Published
- 2014
- Full Text
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44. Magnetophoresis of iron oxide nanoparticles at low field gradient: the role of shape anisotropy.
- Author
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Lim J, Yeap SP, Leow CH, Toh PY, and Low SC
- Subjects
- Ferric Compounds chemistry, Kinetics, Magnetics, Microscopy, Electron, Transmission, Nanospheres, Nanotubes, Ferric Compounds isolation & purification, Metal Nanoparticles
- Abstract
Magnetophoresis of iron oxide magnetic nanoparticle (IOMNP) under low magnetic field gradient (<100 T/m) is significantly enhanced by particle shape anisotropy. This unique feature of magnetophoresis is influenced by the particle concentration and applied magnetic field gradient. By comparing the nanosphere and nanorod magnetophoresis at different concentration, we revealed the ability for these two species of particles to achieve the same separation rate by adjusting the field gradient. Under cooperative magnetophoresis, the nanorods would first go through self- and magnetic field induced aggregation followed by the alignment of the particle clusters formed with magnetic field. Time scale associated to these two processes is investigated to understand the kinetic behavior of nanorod separation under low field gradient. Surface functionalization of nanoparticles can be employed as an effective strategy to vary the temporal evolution of these two aggregation processes which subsequently influence the magnetophoretic separation time and rate., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2014
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45. Synthesis, characterization, X-ray structure and biological activities of C-5-bromo-2-hydroxyphenylcalix[4]-2-methyl resorcinarene.
- Author
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Abosadiya HM, Hasbullah SA, Mackeen MM, Low SC, Ibrahim N, Koketsu M, and Yamin BM
- Subjects
- Animals, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, Antioxidants chemistry, Antiviral Agents chemistry, Antiviral Agents pharmacology, Chlorocebus aethiops, Crystallography, X-Ray, Herpesvirus 1, Human drug effects, Molecular Structure, Phenylalanine chemistry, Phenylalanine pharmacology, Thermogravimetry, Vero Cells, Calixarenes chemistry, Calixarenes pharmacology, Phenylalanine analogs & derivatives
- Abstract
C-5-bromo-2-hydroxyphenylcalix[4]-2-methylresorcinarene (I) was synthesized by cyclocondensation of 5-bromo-2-hydroxybenzaldehyde and 2-methylresorcinol in the presence of concentrated HCl. Compound I was characterized by infrared and nuclear magnetic resonance spectroscopic data. X-ray analysis showed that this compound crystallized in a triclinic system with space group of Pī, a = 15.9592(16)Å, b = 16.9417(17)Å, c = 17.0974(17)Å, α = 68.656(3)°, β = 85.689(3)°, γ = 81.631(3)°, Z = 2 and V = 4258.6(7)Å3. The molecule adopts a chair (C2h) conformation. The thermal properties and antioxidant activity were also investigated. It was strongly antiviral against HSV-1 and weakly antibacterial against Gram-positive bacteria. Cytotoxicity testing on Vero cells showed that it is non-toxic, with a CC50 of more than 0.4 mg/mL.
- Published
- 2013
- Full Text
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46. Electrophoretic interactions between nitrocellulose membranes and proteins: Biointerface analysis and protein adhesion properties.
- Author
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Low SC, Shaimi R, Thandaithabany Y, Lim JK, Ahmad AL, and Ismail A
- Subjects
- Adsorption, Animals, Cattle, Electrophoresis, Hydrogen-Ion Concentration, Particle Size, Photometry, Surface Properties, Collodion chemistry, Serum Albumin, Bovine chemistry
- Abstract
Protein adsorption onto membrane surfaces is important in fields related to separation science and biomedical research. This study explored the molecular interactions between protein, bovine serum albumin (BSA), and nitrocellulose films (NC) using electrokinetic phenomena and the effects of these interactions on the streaming potential measurements for different membrane pore morphologies and pH conditions. The data were used to calculate the streaming ratios of membranes-to-proteins and to compare these values to the electrostatic or hydrophobic attachment of the protein molecules onto the NC membranes. The results showed that different pH and membrane pore morphologies contributes to different protein adsorption mechanisms. The protein adsorption was significantly reduced under conditions where the membrane and protein have like-charges due to electrostatic repulsion. At the isoelectric point (IEP) of the protein, the repulsion between the BSA and the NC membrane was at the lowest; thus, the BSA could be easily attached onto the membrane/solution interface. In this case, the protein was considered to be in a compact layer without intermolecular protein repulsions., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
47. Characterization of magnetic nanoparticle by dynamic light scattering.
- Author
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Lim J, Yeap SP, Che HX, and Low SC
- Abstract
Here we provide a complete review on the use of dynamic light scattering (DLS) to study the size distribution and colloidal stability of magnetic nanoparticles (MNPs). The mathematical analysis involved in obtaining size information from the correlation function and the calculation of Z-average are introduced. Contributions from various variables, such as surface coating, size differences, and concentration of particles, are elaborated within the context of measurement data. Comparison with other sizing techniques, such as transmission electron microscopy and dark-field microscopy, revealed both the advantages and disadvantages of DLS in measuring the size of magnetic nanoparticles. The self-assembly process of MNP with anisotropic structure can also be monitored effectively by DLS.
- Published
- 2013
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48. Excessive motor overflow reveals abnormal inter-hemispheric connectivity in Friedreich ataxia.
- Author
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Low SC, Corben LA, Delatycki MB, Ternes AM, Addamo PK, and Georgiou-Karistianis N
- Subjects
- Adult, Fingers physiopathology, Humans, Middle Aged, Neural Pathways physiopathology, Psychomotor Performance physiology, Brain physiopathology, Corpus Callosum physiopathology, Friedreich Ataxia physiopathology, Functional Laterality physiology, Movement physiology
- Abstract
This study sought to characterise force variability and motor overflow in 12 individuals with Friedreich ataxia (FRDA) and 12 age- and gender-matched controls. Participants performed a finger-pressing task by exerting 30 and 70 % of their maximum finger force using the index finger of the right and left hand. Control of force production was measured as force variability, while any involuntary movements occurring on the finger of the other, passive hand, was measured as motor overflow. Significantly greater force variability in individuals with FRDA compared with controls is indicative of cortico-cerebellar disruption affecting motor control. Meanwhile, significantly greater motor overflow in this group provides the first evidence of possible abnormal inter-hemispheric activity that may be attributable to asymmetrical neuronal loss in the dentate nucleus. Overall, this study demonstrated a differential engagement in the underlying default processes of the motor system in FRDA.
- Published
- 2013
- Full Text
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49. Biochemical and functional characterization of a recombinant monomeric factor VIII-Fc fusion protein.
- Author
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Peters RT, Toby G, Lu Q, Liu T, Kulman JD, Low SC, Bitonti AJ, and Pierce GF
- Subjects
- Amino Acid Sequence, Animals, Binding Sites, Cloning, Molecular, Coagulants chemistry, Coagulants pharmacokinetics, Cysteine Endopeptidases metabolism, Disease Models, Animal, Factor VIII chemistry, Factor VIII genetics, Factor VIII pharmacokinetics, Half-Life, Hemophilia A blood, Humans, Immunoglobulin Fc Fragments chemistry, Immunoglobulin Fc Fragments genetics, Male, Mass Spectrometry, Mice, Neoplasm Proteins metabolism, Partial Thromboplastin Time, Peptide Mapping methods, Protein C metabolism, Protein Conformation, Protein Engineering, Protein Stability, Recombinant Fusion Proteins pharmacokinetics, Recombinant Fusion Proteins pharmacology, Structure-Activity Relationship, Thrombelastography, von Willebrand Factor metabolism, Blood Coagulation drug effects, Coagulants pharmacology, Factor VIII pharmacology, Hemophilia A drug therapy, Immunoglobulin Fc Fragments metabolism
- Abstract
Background: Hemophilia A results from a deficiency in factor VIII activity. Current treatment regimens require frequent dosing, owing to the short half-life of FVIII. A recombinant FVIII-Fc fusion protein (rFVIIIFc) was molecularly engineered to increase the half-life of FVIII, by 1.5-2-fold, in several preclinical animal models and humans., Objective: To perform a biochemical and functional in vitro characterization of rFVIIIFc, with existing FVIII products as comparators., Methods: rFVIIIFc was examined by utilizing a series of structural and analytic assays, including mass spectrometry following lysyl endopeptidase or thrombin digestion. rFVIIIFc activity was determined in both one-stage clotting (activated partial thromboplastin time) and chromogenic activity assays, in the context of the FXase complex with purified components, and in both in vitro and ex vivo rotational thromboelastometry (ROTEM) assays performed in whole blood., Results: rFVIIIFc contained the predicted primary structure and post-translational modifications, with an FVIII moiety that was similar to other recombinant FVIII products. The von Willebrand factor-binding and specific activity of rFVIIIFc were also found to be similar to those of other recombinant FVIII molecules. Both chromogenic and one-stage assays of rFVIIIFc gave similar results. Ex vivo ROTEM studies demonstrated that circulating rFVIIIFc activity was prolonged in mice with hemophilia A in comparison with B-domain-deleted or full-length FVIII. Clot parameters at early time points were similar to those for FVIII, whereas rFVIIIFc showed prolonged improvement of clot formation., Conclusions: rFVIIIFc maintains normal FVIII interactions with other proteins necessary for its activity, with prolonged in vivo activity, owing to fusion with the Fc region of IgG(1) ., (© 2012 International Society on Thrombosis and Haemostasis.)
- Published
- 2013
- Full Text
- View/download PDF
50. Interaction of isothermal phase inversion and membrane formulation for pathogens detection in water.
- Author
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Low SC, Ahmad AL, Ideris N, and Ng QH
- Subjects
- Animals, Spectroscopy, Fourier Transform Infrared, Cryptosporidium isolation & purification, Escherichia coli isolation & purification, Giardia isolation & purification, Membranes, Artificial
- Abstract
The aim of this study was to explore the utilization of polymeric membrane for bio-sensing application in most efficient and rapid way. Customization of membrane formulation via phase separation study to modify its morphologies and properties enable the detection of different pathogens in a specific manner. Experimental findings (FESEM, through-pore distribution, porosity, capillary flow test and protein binding test) verified the predictions of faster capillary flow time and higher membrane's protein binding by the addition of cellulose acetate and nitrocellulose to the membrane casting dope, respectively. Throughout the phase separation study, the potential phase behavior was investigated, which was correlating various membrane structures to its performances for potential pathogens detection in water., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
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