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Lui DTW, Wong CH, Ip A, Ng AKY. Ticagrelor was associated with lower fracture risk than clopidogrel in the dual anti-platelet regimen among patients with acute coronary syndrome treated with percutaneous coronary intervention. J Endocrinol Invest 2024; 47:895-902. [PMID: 37776493 DOI: 10.1007/s40618-023-02205-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/18/2023] [Indexed: 10/02/2023]
Abstract
PURPOSE Patients with coronary artery disease have increased fracture risks. P2Y12 inhibitors may impact fracture risks. We compared the fracture risks associated with ticagrelor and clopidogrel in dual anti-platelet therapy (DAPT). METHODS We identified all adults who underwent first-ever percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) between 2010 and 2017 from a territory-wide PCI registry in Hong Kong. Following 1:1 propensity-score matching for baseline characteristics, patients were followed up till event occurrence, death, or 30 June 2022. Outcomes of interest were major osteoporotic fractures (MOF) identified by validated ICD-9-CM codes. Cox proportional hazards regression was used to compute the hazard ratio (HR) for MOF associated with ticagrelor versus clopidogrel use. RESULTS 3018 ticagrelor users and 3018 clopidogrel users were identified after propensity-score matching (mean age: 61.4 years; 84.1% men). Upon median follow-up of 6.5 years, 59 ticagrelor users and 119 clopidogrel users sustained MOF (annualized fracture risks: 0.34% and 0.56%, respectively). Ticagrelor use was associated with lower risks of MOF (HR 0.60, 95%CI 0.44-0.83; p = 0.002). Consistent HRs were observed for fractures over vertebrae, hip and upper limbs. Subgroup analyses showed no interaction according to age, sex, presence of diabetes, presence of chronic kidney disease and prior fracture history. CONCLUSION Among adults who underwent first-ever PCI for ACS, ticagrelor use in the DAPT was associated with a lower risk of MOF compared with clopidogrel. Our results support the use of ticagrelor in the DAPT from the perspective of bone health.
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Affiliation(s)
- D T W Lui
- Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - C H Wong
- Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - A Ip
- Critical Care Unit, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - A K Y Ng
- Cardiac Medical Unit, Grantham Hospital, Hong Kong SAR, China.
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2
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Siu PLK, Choy CT, Chan HHY, Leung RKK, Chan UK, Zhou J, Wong CH, Lee YW, Chan HW, Lo CJY, Tsui JCC, Loo SKF, Tsui SKW. A Novel Multi-Strain E3 Probiotic Formula Improved the Gastrointestinal Symptoms and Quality of Life in Chinese Psoriasis Patients. Microorganisms 2024; 12:208. [PMID: 38276193 PMCID: PMC10820679 DOI: 10.3390/microorganisms12010208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/12/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024] Open
Abstract
Psoriasis is a chronic immune-mediated inflammatory disease affecting the skin and other systems. Gastrointestinal disease was found to be correlated with psoriasis in previous studies and it can significantly affect the quality of life of psoriasis patients. Despite the importance of the gut microbiome in gut and skin health having already been demonstrated in many research studies, the potential effect of probiotics on GI comorbidities in psoriasis patients is unclear. To investigate the effects of probiotics on functional GI comorbidities including irritable bowel syndrome, functional constipation, and functional diarrhea in psoriasis patients, we conducted a targeted 16S rRNA sequencing and comprehensive bioinformatic analysis among southern Chinese patients to compare the gut microbiome profiles of 45 psoriasis patients over an 8-week course of novel oral probiotics. All the participants were stratified into responders and non-responders according to their improvement in GI comorbidities, which were based on their Bristol Stool Form Scale (BSFS) scores after intervention. The Dermatological Life Quality Index (DLQI) score revealed a significant improvement in quality of life within the responder group (DLQI: mean 10.4 at week 0 vs. mean 15.9 at week 8, p = 0.0366). The proportion of psoriasis patients without GI comorbidity manifestation at week 8 was significantly higher than that at week 0 (week 0: Normal 53.33%, Constipation/Diarrhea 46.67%; week 8: Normal 75.56%, Constipation/Diarrhea 24.44%, p = 0.0467). In addition, a significant difference in the gut microbiome composition between the responders and non-responders was observed according to alpha and beta diversities. Differential abundance analysis revealed that the psoriasis patients exhibited (1) an elevated relative abundance of Lactobacillus acidophilus, Parabacteroides distasonis, and Ruminococcus bromii and (2) a reduced relative abundance of Oscillibacter, Bacteroides vulgatus, Escherichia sp., and Biophila wadsworthia after the 8-week intervention. The responders also exhibited a higher relative abundance of Fusicatenibacter saccharivorans when compared to the non-responders. In summary, our study discovers the potential clinical improvement effects of the novel probiotic formula in improving GI comorbidities and quality of life in psoriasis patients. We also revealed the different gut microbiome composition as well as the gut microbial signatures in the patients who responded to probiotics. These findings could provide insight into the use of probiotics in the management of psoriasis symptoms.
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Affiliation(s)
- Pui Ling Kella Siu
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Chi Tung Choy
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Helen Hoi Yin Chan
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Ross Ka Kit Leung
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Un Kei Chan
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Junwei Zhou
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Chi Ho Wong
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Yuk Wai Lee
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Ho Wang Chan
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Claudia Jun Yi Lo
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Joseph Chi Ching Tsui
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
| | - Steven King Fan Loo
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
- Hong Kong Institute of Integrative Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Dermatology Centre, CUHK Medical Centre, The Chinese University of Hong Kong, Hong Kong, China
| | - Stephen Kwok Wing Tsui
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China; (P.L.K.S.)
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Centre for Microbial Genomics and Proteomics, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong, China
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Chan HHY, Siu PLK, Choy CT, Chan UK, Zhou J, Wong CH, Lee YW, Chan HW, Tsui JCC, Loo SKF, Tsui SKW. Novel Multi-Strain E3 Probiotic Formulation Improved Mental Health Symptoms and Sleep Quality in Hong Kong Chinese. Nutrients 2023; 15:5037. [PMID: 38140296 PMCID: PMC10745623 DOI: 10.3390/nu15245037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Mental health issues have emerged as a significant concern in public health, given their association with physical and psychological comorbidities and the resultant socioeconomic burdens. Recent studies have highlighted the interplay between gut microbes and brain functions through the gut-brain axis. To investigate this further, we conducted a targeted 16S rRNA sequencing and comprehensive bioinformatic analysis among Southern Chinese individuals to explore the role of the gut microbiome in depression, anxiety, and sleep disturbance. We analyzed the differences in the gut microbiome profile of 68 participants with sleep disturbance and mood symptoms before and after an 8-week course of a novel oral E3 multi-strain probiotics formula. The results revealed a significant improvement in subjective sleep quality (PSQI: mean 8.79 at baseline vs. 7.10 at week 8, p < 0.001), depressive symptoms (PHQ9: mean 6.17 at baseline vs. 4.76 at week 8, p < 0.001), and anxious symptoms (GAD7: mean 4.90 at baseline vs. 3.76 at week 8, p < 0.001). Additionally, there were notable differences in beta diversity (weighted UniFrac; p = 0.045) and increased Firmicutes/Bacteroidetes (F/B) ratio (p = 4 × 10-4) were observed in the gut microbiome analysis. Furthermore, the relative abundance of Bifidobacterium bifidum (p < 0.001), Lactobacillus acidophilus (p < 0.001), Lactobacillus helveticus (p < 0.001) and Lactobacillus plantarum (p < 0.001) were significantly increased after the 8-week probiotic supplementation. Our study suggests that the gut microbial landscape varies between responders and non-responders at multiple levels, including genera, species, functional, and network interaction. Notably, the use of probiotics in populations with depressive or anxious symptoms and poor sleeping quality remodeled the gut microbiome and demonstrated improved mood and sleep quality.
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Affiliation(s)
- Helen Hoi Yin Chan
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
| | - Pui Ling Kella Siu
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
| | - Chi Tung Choy
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
| | - Un Kei Chan
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
| | - Junwei Zhou
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
| | - Chi Ho Wong
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
| | - Yuk Wai Lee
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
| | - Ho Wang Chan
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
| | - Joseph Chi Ching Tsui
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
| | - Steven King Fan Loo
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
- Hong Kong Institute of Integrative Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Dermatology Centre, CUHK Medical Centre, The Chinese University of Hong Kong, Hong Kong, China
| | - Stephen Kwok Wing Tsui
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China (P.L.K.S.); (U.K.C.); (J.Z.); (C.H.W.); (Y.W.L.); (H.W.C.); (J.C.C.T.)
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Centre for Microbial Genomics and Proteomics, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong, China
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Lam RCT, Hui CWC, Wong CH, Lo KW, Tsang ACM, Hui EP, Chan ATC, Ma BBY. Preclinical evaluation of the VEGF/Ang2 bispecific nanobody BI 836880 in nasopharyngeal carcinoma models. Invest New Drugs 2023; 41:699-709. [PMID: 37572231 DOI: 10.1007/s10637-023-01384-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/11/2023] [Indexed: 08/14/2023]
Abstract
Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) is endemic to parts of Asia and overexpression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α are common in NPC. Anti-vascular agents have known clinical activity in patients with recurrent/ metastatic NPC and in this study, we investigated the anti-tumor effect of BI 836880, a humanized bispecific nanobody against VEGF and angiopoietin-2 (Ang2), in preclinical models of EBV-positive and EBV-negative NPC. The efficacy of BI 836880 was also compared with bevacizumab, a recombinant humanized monoclonal antibody against VEGF. We found that BI 836880 could exert growth-inhibitory effect on endothelial cells (HUVEC-C) and the EBV-negative NPC cell line (HK1), but to a lesser extent in the EBV-positive NPC cell lines, C17C and C666-1. In patients-derived xenograft (PDX) models of NPC - Xeno-2117 and Xeno-666, BI 836880 could suppress tumor growth and Ki67, as well as induce tumor necrosis and reduce microvessel density. Moreover, treatment with BI 836880 increased the level of macrophage infiltration in both PDX tumor models of NPC, suggesting that BI 836880 may exert immunomodulatory effect on the NPC immune microenvironment. When compared with bevacizumab, BI 836880 appeared to show at least comparable activity as bevacizumab in terms of its anti-proliferative and anti-angiogenic effects. This study showed that BI 836880 has anti-proliferative, anti-angiogenic and possibly immunomodulatory effect in clinical models of NPC, therefore the dual targeting of VEGF and Ang2 signaling in NPC should be further investigated.
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Affiliation(s)
- Rachel C T Lam
- Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong , SAR, China
| | - Connie W C Hui
- State Key Laboratory of Translational Oncology, Sir YK Pao Centre for Cancer, Department of Clinical Oncology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong, SAR, China
- Cancer Drug Testing Unit, Li Ka Shing Institute of Health Sciences, Hong Kong Cancer Institute, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - C H Wong
- State Key Laboratory of Translational Oncology, Sir YK Pao Centre for Cancer, Department of Clinical Oncology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong, SAR, China
- Cancer Drug Testing Unit, Li Ka Shing Institute of Health Sciences, Hong Kong Cancer Institute, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - K W Lo
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Anna C M Tsang
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Edwin P Hui
- State Key Laboratory of Translational Oncology, Sir YK Pao Centre for Cancer, Department of Clinical Oncology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong, SAR, China
| | - Anthony T C Chan
- State Key Laboratory of Translational Oncology, Sir YK Pao Centre for Cancer, Department of Clinical Oncology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong, SAR, China
- Cancer Drug Testing Unit, Li Ka Shing Institute of Health Sciences, Hong Kong Cancer Institute, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Brigette B Y Ma
- State Key Laboratory of Translational Oncology, Sir YK Pao Centre for Cancer, Department of Clinical Oncology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong, SAR, China.
- Cancer Drug Testing Unit, Li Ka Shing Institute of Health Sciences, Hong Kong Cancer Institute, The Chinese University of Hong Kong, Hong Kong, SAR, China.
- Department of Clinical Oncology, Prince of Wales Hospital, Shatin, NT, Hong Kong SAR, China.
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Choy CT, Siu PLK, Zhou J, Wong CH, Lee YW, Chan HW, Tsui JCC, Lo CJY, Loo SKF, Tsui SKW. Improvements in Gut Microbiome Composition Predict the Clinical Efficacy of a Novel Synbiotics Formula in Children with Mild to Moderate Atopic Dermatitis. Microorganisms 2023; 11:2175. [PMID: 37764019 PMCID: PMC10536305 DOI: 10.3390/microorganisms11092175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 09/29/2023] Open
Abstract
Atopic dermatitis (AD) is a common chronic inflammatory skin disease with a significant association with various type-2 inflammation-related comorbidities. Ongoing research suggests the crucial involvement of gut microbiome, especially in childhood onset AD, and hence, probiotics have emerged as a potential non-steroid-based therapeutics option to complement existing AD management plans. In order to delineate the impact of probiotics in the gut microbiome of pediatric AD patients from southern China, targeted 16S rRNA sequencing and thorough bioinformatic analysis were performed to analyze the gut microbiome profiles of 24 AD children after taking an orally administered novel synbiotics formula with triple prebiotics for 8 weeks. A notable improvement in Eczema Area and Severity Index (EASI) (p = 0.008) was observed after taking an 8-week course of probiotics, with no adverse effects observed. The relative abundances of key microbial drivers including Bacteroides fragilis and Lactobacillus acidophilus were significantly increased at week 8. We also found that the positive responsiveness towards an 8-week course of probiotics was associated with improvements in the gut microbiome profile with a higher relative abundance of probiotic species. Over-represented functional abundance pathways related to vitamin B synthesis and peptidoglycan recycling may imply the underlying mechanism. In summary, our study suggests how the gut microbial landscape shifts upon probiotic supplementation in AD children, and provides preliminary evidence to support targeted probiotic supplementation for the management of childhood AD.
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Affiliation(s)
- Chi Tung Choy
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong
| | - Pui Ling Kella Siu
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong
| | - Junwei Zhou
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong
| | - Chi Ho Wong
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong
| | - Yuk Wai Lee
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong
| | - Ho Wang Chan
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong
| | | | - Claudia Jun Yi Lo
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong
| | - Steven King Fan Loo
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong
- Hong Kong Institute of Integrative Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
- Dermatology Centre, CUHK Medical Centre, The Chinese University of Hong Kong, Hong Kong
| | - Stephen Kwok Wing Tsui
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
- Centre for Microbial Genomics and Proteomics, The Chinese University of Hong Kong, Hong Kong
- Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong
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Wong CH, Lortz R. Preliminary Tc Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO 3 Superconductors. Materials (Basel) 2023; 16:4674. [PMID: 37444987 DOI: 10.3390/ma16134674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/21/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023]
Abstract
Many theoretical models of iron-based superconductors (IBSC) have been proposed, but the superconducting transition temperature (Tc) calculations based on these models are usually missing. We have chosen two models of iron-based superconductors from the literature and computed the Tc values accordingly; recently two models have been announced which suggest that the superconducting electron concentration involved in the pairing mechanism of iron-based superconductors may have been underestimated and that the antiferromagnetism and the induced xy potential may even have a dramatic amplification effect on electron-phonon coupling. We use bulk FeSe, LiFeAs and NaFeAs data to calculate the Tc based on these models and test if the combined model can predict the superconducting transition temperature (Tc) of the nanostructured FeSe monolayer well. To substantiate the recently announced xy potential in the literature, we create a two-channel model to separately superimpose the dynamics of the electron in the upper and lower tetrahedral plane. The results of our two-channel model support the literature data. While scientists are still searching for a universal DFT functional that can describe the pairing mechanism of all iron-based superconductors, we base our model on the ARPES data to propose an empirical combination of a DFT functional for revising the electron-phonon scattering matrix in the superconducting state, which ensures that all electrons involved in iron-based superconductivity are included in the computation. Our computational model takes into account this amplifying effect of antiferromagnetism and the correction of the electron-phonon scattering matrix, together with the abnormal soft out-of-plane lattice vibration of the layered structure. This allows us to calculate theoretical Tc values of LiFeAs, NaFeAs and FeSe as a function of pressure that correspond reasonably well to the experimental values. More importantly, by taking into account the interfacial effect between an FeSe monolayer and its SrTiO3 substrate as an additional gain factor, our calculated Tc value is up to 91 K and provides evidence that the strong Tc enhancement recently observed in such monolayers with Tc reaching 100 K may be contributed from the electrons within the ARPES range.
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Affiliation(s)
- Chi Ho Wong
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
- Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, China
- Research Institute for Advanced Manufacturing, The Hong Kong Polytechnic University, Hong Kong, China
| | - Rolf Lortz
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
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Wong CH, Buntov EA, Yip WS, To S, Guseva MB, Zatsepin AF. Thermal Disorder in Finite-Length Carbon Nanowire. Int J Mol Sci 2023; 24:ijms24098149. [PMID: 37175856 PMCID: PMC10178940 DOI: 10.3390/ijms24098149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 04/28/2023] [Accepted: 04/28/2023] [Indexed: 05/15/2023] Open
Abstract
Enhancement in chemisorption is one of the active research areas in carbon materials. To remedy the thermally degraded chemisorption occurring at high temperatures, we report a comprehensive study of kink structures in free-standing monoatomic carbon nanowires upon heating. Our Monte Carlo simulation considers multi-monoatomic carbon chains laterally interacting by van der Waals forces. Our study reveals that carbon nanowires maintain their linearity regardless of chain length at low temperatures, but this is not the case at high temperatures. Disordered kink structure is observed in short carbon chains, especially above the Peierls transition temperature. A severe kink structure may increase the possibility of attaching negatively charged atoms, thereby contributing to the development of next-generation materials for chemisorption at high temperatures. We have also provided an important indication that any physical property of the finite-length carbon chain predicted by ab initio calculation should reconsider the atomic rearrangement due to thermal instability at high temperatures.
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Affiliation(s)
- C H Wong
- Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong
- Research Institute for Advanced Manufacturing, The Hong Kong Polytechnic University, Hong Kong
| | - E A Buntov
- Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg, Russia
| | - W S Yip
- Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong
- State Key Laboratory of Ultra-precision Machining Technology, Department of Industrial and System Engineering, The Hong Kong Polytechnic University, Hong Kong
| | - S To
- Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong
- State Key Laboratory of Ultra-precision Machining Technology, Department of Industrial and System Engineering, The Hong Kong Polytechnic University, Hong Kong
| | - M B Guseva
- Faculty of Physics, Lomonosov Moscow State University, 125009 Moscow, Russia
| | - A F Zatsepin
- Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg, Russia
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Choy CT, Chan UK, Siu PLK, Zhou J, Wong CH, Lee YW, Chan HW, Tsui JCC, Loo SKF, Tsui SKW. A Novel E3 Probiotics Formula Restored Gut Dysbiosis and Remodelled Gut Microbial Network and Microbiome Dysbiosis Index (MDI) in Southern Chinese Adult Psoriasis Patients. Int J Mol Sci 2023; 24:ijms24076571. [PMID: 37047542 PMCID: PMC10094986 DOI: 10.3390/ijms24076571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/05/2023] Open
Abstract
Psoriasis is a common chronic immune-mediated inflammatory skin disease with the association of various comorbidities. Despite the introduction of highly effective biologic therapies over the past few decades, the exact trigger for an immune reaction in psoriasis is unclear. With the majority of immune cells residing in the gut, the effect of gut microbiome dysbiosis goes beyond the gastrointestinal site and may exacerbate inflammation and regulate the immune system elsewhere, including but not limited to the skin via the gut-skin axis. In order to delineate the role of the gut microbiome in Southern Chinese psoriasis patients, we performed targeted 16S rRNA sequencing and comprehensive bioinformatic analysis to compare the gut microbiome profile of 58 psoriasis patients against 49 healthy local subjects presumably with similar lifestyles. Blautia wexlerae and Parabacteroides distasonis were found to be enriched in psoriasis patients and in some of the healthy subjects, respectively. Metabolic functional pathways were predicted to be differentially abundant, with a clear shift toward SCFA synthesis in healthy subjects. The alteration of the co-occurrence network was also evident in the psoriasis group. In addition, we also profiled the gut microbiome in 52 of the 58 recruited psoriasis patients after taking 8 weeks of an orally administrated novel E3 probiotics formula (with prebiotics, probiotics and postbiotics). The Dermatological Life Quality Index (p = 0.009) and Psoriasis Area and Severity Index (p < 0.001) were significantly improved after taking 8 weeks of probiotics with no adverse effect observed. We showed that probiotics could at least partly restore gut dysbiosis via the modulation of the gut microbiome. Here, we also report the potential application of a machine learning-derived gut dysbiosis index based on a quantitative PCR panel (AUC = 0.88) to monitor gut dysbiosis in psoriasis patients. To sum up, our study suggests the gut microbial landscape differed in psoriasis patients at the genera, species, functional and network levels. Additionally, the dysbiosis index could be a cost-effective and rapid tool to monitor probiotics use in psoriasis patients.
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Affiliation(s)
- Chi Tung Choy
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China
| | - Un Kei Chan
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China
| | - Pui Ling Kella Siu
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China
| | - Junwei Zhou
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China
| | - Chi Ho Wong
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China
| | - Yuk Wai Lee
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China
| | - Ho Wang Chan
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China
| | | | - Steven King Fan Loo
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China
- Hong Kong Institute of Integrative Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Dermatology Centre, CUHK Medical Centre, The Chinese University of Hong Kong, Hong Kong, China
| | - Stephen Kwok Wing Tsui
- Microbiome Research Centre, BioMed Laboratory Company Limited, Hong Kong, China
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Centre for Microbial Genomics and Proteomics, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong, China
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9
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Wong CH, Yeung YM, Zhao X, Law WC, Tang CY, Mak CL, Leung CW, Shi L, Lortz R. A Simulation of the Effect of External and Internal Parameters on the Synthesis of a Carbyne with More than 6000 Atoms for Emerging Continuously Tunable Energy Barriers in CNT-Based Transistors. Nanomaterials (Basel) 2023; 13:1048. [PMID: 36985943 PMCID: PMC10058369 DOI: 10.3390/nano13061048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/10/2023] [Accepted: 03/11/2023] [Indexed: 06/18/2023]
Abstract
Transistors made up of carbon nanotube CNT have demonstrated excellent current-voltage characteristics which outperform some high-grade silicon-based transistors. A continuously tunable energy barrier across semiconductor interfaces is desired to make the CNT-based transistors more robust. Despite that the direct band gap of the carbyne inside a CNT can be widely tuned by strain, the size of the carbyne cannot be controlled easily. The production of a monoatomic chain with more than 6000 carbon atoms is an enormous technological challenge. To predict the optimal chain length of a carbyne in different molecular environments, we have developed a Monte Carlo model in which a finite-length carbyne with a size of 4000-15,000 atoms is encapsulated by a CNT at finite temperatures. Our simulation shows that the stability of the carbyne@nanotube is strongly influenced by the nature and porosity of the CNT, the external pressure, the temperature, and the chain length. We have observed an initiation of the chain-breaking process in a compressed carbyne@nanotube. Our work provides much-needed input for optimizing the carbyne length to produce carbon chains much longer than 6000 atoms at ~300 K. Design rules are proposed for synthesizing ~1% strained carbyne@(6,5)CNT as a component in CNT-based transistors to tune the energy barriers continuously.
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Affiliation(s)
- Chi Ho Wong
- Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong 999077, China
- Research Institute for Advanced Manufacturing, The Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Yan Ming Yeung
- School of Science, The Hong Kong University of Science and Technology, Hong Kong 999077, China
| | - Xin Zhao
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Wing Cheung Law
- Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Chak Yin Tang
- Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Chee Leung Mak
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Chi Wah Leung
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Lei Shi
- State Key Laboratory of Optoelectronic Materials and Technologies, Nanotechnology Research Center, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Rolf Lortz
- Department of Physics, The Hong Kong University of Science and Technology, Hong Kong 999077, China
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10
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Chan TH, Wong CH, Shen J, Yin G. Source-Aware Embedding Training on Heterogeneous Information Networks. Data Intelligence 2023. [DOI: 10.1162/dint_a_00200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
Abstract
Heterogeneous information networks (HINs) have been extensively applied to real-world tasks, such as recommendation systems, social networks, and citation networks. While existing HIN representation learning methods can effectively learn the semantic and structural features in the network, little awareness was given to the distribution discrepancy of subgraphs within a single HIN. However, we find that ignoring such distribution discrepancy among subgraphs from multiple sources would hinder the effectiveness of graph embedding learning algorithms. This motivates us to propose SUMSHINE (Scalable Unsupervised Multi-Source Heterogeneous Information Network Embedding) — a scalable unsupervised framework to align the embedding distributions among multiple sources of an HIN. Experimental results on real-world datasets in a variety of downstream tasks validate the performance of our method over the state-of-the-art heterogeneous information network embedding algorithms.
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Affiliation(s)
- Tsai Hor Chan
- Department of Statistics and Actuarial Science The University of Hong Kong Hong Kong, China ,
| | - Chi Ho Wong
- Department of Computer Science and Engineering The Hong Kong University of Science and Technology Hong Kong, China
| | - Jiajun Shen
- TCL Corporate Research (Hong Kong) Hong Kong, China
| | - Guosheng Yin
- Department of Statistics and Actuarial Science The University of Hong Kong Hong Kong, China ,
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11
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Wong CH, Man MS, Lau TKW, Wong CY, Fong LK, Luo VD. Adoption of the 2017 American College of Cardiology/American Heart Association (ACC/AHA) Hypertension Guideline in Hong Kong and implications for local practice. Hong Kong Med J 2022; 28:88-90. [DOI: 10.12809/hkmj219636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- CH Wong
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong
| | - MS Man
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong
| | - Thomas KW Lau
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong
| | - CY Wong
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong
| | - LK Fong
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong
| | - Valeria Deng Luo
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong
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12
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Wong THT, Wong CH, Zhang X, Zhou Y, Xu J, Yuen KC, Wan JMF, Louie JCY. The Association Between Coffee Consumption and Metabolic Syndrome in Adults: A Systematic Review and Meta-Analysis. Adv Nutr 2020; 12:708-721. [PMID: 33118010 PMCID: PMC8166542 DOI: 10.1093/advances/nmaa132] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/31/2020] [Accepted: 09/21/2020] [Indexed: 12/20/2022] Open
Abstract
Previous meta-analyses that found an inverse association between coffee consumption and metabolic syndrome pooled data from cross-sectional and longitudinal studies, which could lead to potentially misleading conclusions. Hence, this work aimed to reassess this association by analyzing data from the 2 types of studies separately and including recent studies. Online databases including PubMed, Scopus, Embase, The Cumulative Index to Nursing and Allied Health Literature (CINAHL) Plus, and Science Direct were searched for relevant studies published up to July 2020. Both cross-sectional and longitudinal studies were included if published after 1999, reported both effect estimates and CIs, and presented results adjusted for confounding variables. Data of the highest coffee consumption level in each study, as well as those of medium consumption levels in studies with ≥3 consumption categories, were pooled using random-effect models, with sex-stratified and sex-adjusted results being analyzed separately. Results were obtained based on data from 13 cross-sectional studies involving 280,803 participants and 2 longitudinal studies involving 17,014 participants. The overall sex-adjusted association of the highest consumption level was not significant (n = 9 studies; OR: 0.88; 95% CI: 0.70, 1.10; I2: 91.5%) and the 2 longitudinal studies both yielded no association. Subgroup analysis revealed inverse associations in both males and females, as well as in Caucasians with medium coffee consumption (n = 4 studies, OR: 0.88; 95% CI: 0.84, 0.93; I2: 0%). Although residual confounding could affect the results of this meta-analysis, our findings suggested with a low certainty that coffee consumption may not be associated with metabolic syndrome, a finding that is different from those of previous meta-analyses and could be due to variation in characteristics of study participants. More longitudinal studies are also needed to further assess the temporal association between coffee consumption and metabolic syndrome. This meta-analysis was registered at https://www.crd.york.ac.uk/prospero as CRD42018110650.
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Affiliation(s)
- Tommy H T Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Chi Ho Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Xiaoyu Zhang
- Department of Statistics and Actuarial Science, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Yunpeng Zhou
- Department of Statistics and Actuarial Science, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Jinfeng Xu
- Department of Statistics and Actuarial Science, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Kam Chuen Yuen
- Department of Statistics and Actuarial Science, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Jennifer M F Wan
- School of Biological Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
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13
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Zatsepin AF, Kuznetsova YA, Wong CH. Creation of Si quantum dots in a silica matrix due to conversion of radiation defects under pulsed ion-beam exposure. Phys Chem Chem Phys 2019; 21:25467-25473. [PMID: 31714553 DOI: 10.1039/c9cp04715h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In this work we present an innovative method of creating Si quantum dots under pulsed ion-beam exposure. The evolution of defect structure ODC(II) → E'→ ODC(I) → Si QDs in glassy SiO2 under ion-beam implantation was established by optical absorption and photoluminescence spectroscopies. Depending on the mode of ion exposure, it is possible to easily control the type and concentration of defects in the host and modify its optical properties for novel applications. Ab initio calculations confirm that bond softening in SiO2 is attainable via the use of Gd ion implantation. According to our experimental and theoretical results, the three-stage interaction of primary oxygen-deficient centers leads to the formation of stable silicon quantum dots with a size of 3.6 nm and luminescence at 1.8 eV excited by incoherent light.
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Affiliation(s)
- A F Zatsepin
- Photonics and VUV-Spectroscopy Lab, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russia.
| | - Yu A Kuznetsova
- Photonics and VUV-Spectroscopy Lab, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russia.
| | - C H Wong
- Photonics and VUV-Spectroscopy Lab, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russia.
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14
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Wang MX, Wong CH, Kim JE. Impact of whole egg intake on blood pressure, lipids and lipoproteins in middle-aged and older population: A systematic review and meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis 2019; 29:653-664. [PMID: 31076323 DOI: 10.1016/j.numecd.2019.04.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 04/10/2019] [Accepted: 04/16/2019] [Indexed: 01/14/2023]
Abstract
BACKGROUND AND AIM Effects of whole egg consumption on cardiovascular diseases (CVD) risk in the middle-aged and older population remain unclear due to inconsistent findings from observational and randomized controlled trials (RCTs). This meta-analysis aimed to assess the impacts of whole egg and egg category (whole eggs versus egg substitutes) intake quantity on CVD risk factors from systematically searched RCTs. Egg substitutes were hypothesized to have minimal effects of the blood lipid and lipoprotein profile as they are void of dietary cholesterol. METHODS AND RESULTS As many as 434 studies identified from PubMed, Cochrane Library, CINAHL and Medline (Ovid) databases were screened and data were extracted from 8 selected RCTs. Quality of the selected studies were assessed and the overall effect sizes of weighted mean differences (WMD) were calculated using a random effects model. Non-differential effects in blood pressures, lipids and lipoproteins were observed when >4 whole eggs/week compared to ≤4 whole eggs/week were consumed. Intake of >4 whole eggs/week compared to equivalent amounts of egg substitutes caused greater elevations in blood total cholesterol (WMD: 0.198 mmol/L; 95% CIs: 0.056, 0.339), HDL cholesterol (WMD: 0.068 mmol/L; 95% CIs: 0.006, 0.130) and LDL cholesterol (WMD: 0.171 mmol/L; 95% CIs: 0.028, 0.315) but did not differentially affect triglycerides concentration. CONCLUSION Overall, the results support the notion that quantity of whole egg intake does not affect CVD risk factors and consuming egg substitutes may also be beneficial compared to whole eggs on lowering CVD risk in the middle-aged and older population.
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Affiliation(s)
- M X Wang
- Food Science and Technology Program, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore; Centre for Infectious Disease Epidemiology and Research, Saw Swee Hock School of Public Health, National University of Singapore, Tahir Foundation Building, 12 Science Drive 2, 117549, Singapore.
| | - C H Wong
- Food Science and Technology Program, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore.
| | - J E Kim
- Food Science and Technology Program, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore.
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15
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Wong CH, Buntov EA, Zatsepin AF, Lyu J, Lortz R, Zatsepin DA, Guseva MB. Room temperature p-orbital magnetism in carbon chains and the role of group IV, V, VI, and VII dopants. Nanoscale 2018; 10:11186-11195. [PMID: 29873371 DOI: 10.1039/c8nr02328j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The study of magnetism without the involvement of transition metals or rare earth ions is considered the key to the fabrication of next generation spintronic devices. Several recent reports claim that optimizing the occupation number of the mixed p-orbitals is the correct way to reinforce p-orbital magnetism in bulk crystals. We provide experimental evidence that the kinked monoatomic carbon chains, the so-called linear-chained carbon, generate intrinsic ferromagnetism even above room temperature. According to our ab initio calculations, unconventional magnetism has its origin in the p-shells. In contrast, the linear monoatomic carbon chains are non-magnetic. Although the optimized differential spin density of states at the Fermi level (SDOS) of the kinked carbon chains is higher than that of bulk Fe, the magnetic moment is as low as 0.3μB. In order to enhance the magnetic response, we decided to tune the p-orbital magnetism by adding dopants from groups IV to VII of the periodic table. We observed that the strength of the p-orbital magnetism and the sign of the exchange interaction depend not only on the kink angle, but also on the concentration of lone pair electrons, free radical electrons, lateral chain spacing, internal electric dipole, dative covalent bonds and the Bohr radius of the dopants. Surprisingly, the V and VII-doped carbon chains show a strong non-zero SDOS, which has its origin in the p-shells. The VII-doped carbon chains give the SDOS of the opposite sign. Our best system, the arsenic-doped carbon chain, exhibits a strong local magnetic moment of 1.5μB, which is comparable to that of the bulk Fe of 2.2μB, with the mean exchange-correlation energy reaching a 63% ratio relative to that of the bulk Fe.
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Affiliation(s)
- C H Wong
- Institute of Physics and Technology, Ural Federal University, Yekaterinburg, Russia.
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16
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Wong CH, Lortz R, Buntov EA, Kasimova RE, Zatsepin AF. A theoretical quest for high temperature superconductivity on the example of low-dimensional carbon structures. Sci Rep 2017; 7:15815. [PMID: 29150653 PMCID: PMC5693954 DOI: 10.1038/s41598-017-16038-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/07/2017] [Indexed: 11/13/2022] Open
Abstract
High temperature superconductivity does not necessarily require correlated electron systems with complex competing or coexisting orders. Instead, it may be achieved in a phonon-mediated classical superconductor having a high Debye temperature and large electronic density of states at the Fermi level in a material with light atoms and strong covalent bonds. Quasi-1D conductors seem promising due to the Van Hove singularities in their electronic density of states. In this sense, quasi-1D carbon structures are good candidates. In thin carbon nanotubes, superconductivity at ~15 K has been reported, and it is likely the strong curvature of the graphene sheet which enhances the electron-phonon coupling. We use an ab-initio approach to optimize superconducting quasi-1D carbon structures. We start by calculating a Tc of 13.9 K for (4.2) carbon nanotubes (CNT) that agrees well with experiments. Then we reduce the CNT to a ring, open the ring to form chains, optimize bond length and kink structure, and finally form a new type of carbon ring that reaches a Tc value of 115 K.
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Affiliation(s)
- C H Wong
- Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russia
| | - R Lortz
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
| | - E A Buntov
- Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russia
| | - R E Kasimova
- Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russia
| | - A F Zatsepin
- Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russia.
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17
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Deng J, Zhu X, Chen Z, Fan CH, Kwan HS, Wong CH, Shek KY, Zuo Z, Lam TN. A Review of Food–Drug Interactions on Oral Drug Absorption. Drugs 2017; 77:1833-1855. [DOI: 10.1007/s40265-017-0832-z] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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18
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Wong CH, Phuah ACL, Naik NSY, Choo WS, Ting HSY, Kuan SML, Teng CL, Sivalingam N. Views of faculty members in a medical school with regards to error disclosure and reporting to parents and/or higher authorities. Med J Malaysia 2016; 71:244-249. [PMID: 28064289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
BACKGROUND Little is known about the views of faculty members who train medical students concerning open disclosure. OBJECTIVES The objectives of this study were to determine the views of faculty in a medical school on: 1 what constitutes a medical error and the severity of such an error in relation to medication use or diagnosis; 2 information giving following such an adverse event, based on severity; and 3 acknowledgement of responsibility, remedial action, compensation, disciplinary action, legal action, and reporting to a higher body in relation to such adverse event. METHODS We adapted and contextualized a questionnaire developed from a previous study. The questionnaire had 4 case vignettes that described 1 clear medication error with lifelong disability; 2 possible diagnostic error with lifelong disability; 3 possible diagnostic error without harm; and 4 clear medication error without harm. We invited all faculty members attached to the medical school at the International Medical University to participate in the study. RESULTS Seventy faculty members took part. Faculty members viewed a medical error as having taken place depending on how clearly an error had occurred (94% and 73% versus 53% and 27%). They viewed cases as more severe based on the severity of complications (85% and 46% versus 5% and 10%). With increasing severity, they tended to attribute responsibility for the event and the duty to disclose towards more senior clinicians. They were also more agreeable with remedial action, compensation, disciplinary action, and reporting to a higher agency. There was no strong evidence of association between these areas and the demographics of faculty members. CONCLUSIONS Faculty members are more likely to perceive an error had occurred depending on the clarity of the circumstances. They viewed severity based on the presence of complications. Severity determined how they attributed responsibility, duty to disclose, and other areas related to open disclosure.
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Affiliation(s)
- C H Wong
- International Medical University, IMU Clinical School, Department of Family Medicine, Jalan Rasah, Negeri Sembilan, Malaysia.
| | - A C L Phuah
- International Medical University, IMU Clinical School, Jalan Rasah, Negeri Sembilan, Malaysia
| | - N S Y Naik
- International Medical University, IMU Clinical School, Jalan Rasah, Negeri Sembilan, Malaysia
| | - W S Choo
- International Medical University, IMU Clinical School, Jalan Rasah, Negeri Sembilan, Malaysia
| | - H S Y Ting
- International Medical University, IMU Clinical School, Jalan Rasah, Negeri Sembilan, Malaysia
| | - S M L Kuan
- International Medical University, IMU Clinical School, Jalan Rasah, Negeri Sembilan, Malaysia
| | - C L Teng
- International Medical University, IMU Clinical School, Jalan Rasah, Negeri Sembilan, Malaysia
| | - N Sivalingam
- International Medical University, IMU Clinical School, Jalan Rasah, Negeri Sembilan, Malaysia
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19
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Zhang Y, Wong CH, Shen J, Sze ST, Zhang B, Zhang H, Dong Y, Xu H, Yan Z, Li Y, Hu X, Lortz R. Dramatic enhancement of superconductivity in single-crystalline nanowire arrays of Sn. Sci Rep 2016; 6:32963. [PMID: 27595646 PMCID: PMC5011740 DOI: 10.1038/srep32963] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 08/15/2016] [Indexed: 11/24/2022] Open
Abstract
Sn is a classical superconductor on the border between type I and type II with critical temperature of 3.7 K. We show that its critical parameters can be dramatically increased if it is brought in the form of loosely bound bundles of thin nanowires. The specific heat displays a pronounced double phase transition at 3.7 K and 5.5 K, which we attribute to the inner ‘bulk’ contribution of the nanowires and to the surface contribution, respectively. The latter is visible only because of the large volume fraction of the surface layer in relation to the bulk volume. The upper transition coincides with the onset of the resistive transition, while zero resistance is gradually approached below the lower transition. In contrast to the low critical field Hc = 0.03 T of Sn in its bulk form, a magnetic field of more than 3 T is required to fully restore the normal state.
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Affiliation(s)
- Ying Zhang
- State Key Laboratory for Heavy Oil Processing, PetroChina Key Laboratory of Catalysis, China University of Petroleum, Qingdao 266580, China
| | - Chi Ho Wong
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.,Institute of Physics and Technology, Ural Federal University, Russia
| | - Junying Shen
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Sin Ting Sze
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Bing Zhang
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Haijing Zhang
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Yan Dong
- State Key Laboratory for Heavy Oil Processing, PetroChina Key Laboratory of Catalysis, China University of Petroleum, Qingdao 266580, China
| | - Hui Xu
- State Key Laboratory for Heavy Oil Processing, PetroChina Key Laboratory of Catalysis, China University of Petroleum, Qingdao 266580, China
| | - Zifeng Yan
- State Key Laboratory for Heavy Oil Processing, PetroChina Key Laboratory of Catalysis, China University of Petroleum, Qingdao 266580, China
| | - Yingying Li
- Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Xijun Hu
- Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Rolf Lortz
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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20
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Wong CH, Tan TR, Heng Hy HY, Ramesh T, Ting PW, Lee WS, Teng CL, Sivalingam N, Tan KK. Parental preferences with regards to disclosure following adverse events occurring in relation to medication use or diagnosis in the care of their children - perspectives from Malaysia. Med J Malaysia 2016; 71:186-192. [PMID: 27770117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
INTRODUCTION Open disclosure is poorly understood in Malaysia but is an ethical and professional responsibility. The objectives of this study were to determine: (1) the perception of parents regarding the severity of medical error in relation to medication use or diagnosis; (2) the preference of parents for information following the medical error and its relation to severity; and (3) the preference of parents with regards to disciplinary action, reporting, and legal action. METHODS We translated and contextualised a questionnaire developed from a previous study. The questionnaire consisted of four case vignettes that described the following: medication error with a lifelong complication; diagnostic error with a lifelong complication; diagnostic error without lifelong effect; and medication error without lifelong effect. Each case vignette was followed by a series of questions examining the subject's perception on the above areas. We also determined the content validity of the questionnaire. We invited parents of Malaysian children admitted to the paediatric wards of Tuanku Jaafar Hospital to participate in the study. RESULTS One hundred and twenty-three parents participated in the study. The majority of parents wanted to be told regarding the event. As the severity of the case vignettes increased, the desire for information, remedial action, acknowledgement of responsibility, compensation, punishment, legal action, and reporting to a higher agency also increased. The findings did not have strong evidence of a relationship with subject's demographics. CONCLUSION This study gives insights into previously unexplored perspectives and preferences of parents in Malaysia regarding open disclosure. It also highlights the opportunity for more research in this area with potentially broad applications.
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Affiliation(s)
- C H Wong
- International Medical University, Department of Family Medicine, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia.
| | - T R Tan
- International Medical University, IMU Clinical School, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - H Y Heng Hy
- International Medical University, IMU Clinical School, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - T Ramesh
- International Medical University, IMU Clinical School, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - P W Ting
- International Medical University, IMU Clinical School, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - W S Lee
- International Medical University, IMU Clinical School, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - C L Teng
- International Medical University, Department of Family Medicine, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - N Sivalingam
- International Medical University, Department of Obstetrics and Gynaecology, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - K K Tan
- Tuanku Jaafar Hospital, Department of Paediatrics, Seremban, Malaysia
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Rahman Z, Wong CH, Dexter M, Olsson G, Wong M, Gebsky V, Nahar N, Wood A, Byth K, King M, Bleasel AB. Epilepsy in patients with primary brain tumors: The impact on mood, cognition, and HRQOL. Epilepsy Behav 2015; 48:88-95. [PMID: 26136184 DOI: 10.1016/j.yebeh.2015.03.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 02/12/2015] [Accepted: 03/15/2015] [Indexed: 01/10/2023]
Abstract
BACKGROUND A primary brain tumor (PBT) is often a fatal disease of the nervous system and has a serious impact on health-related quality of life (HRQOL). Presence of epilepsy and adverse reactions from tumor and epilepsy treatments may cause additional decline in HRQOL. OBJECTIVES We aimed to study the impact of epileptic seizures on cognition, mood, and HRQOL in patients with brain tumor-related epilepsy. MATERIALS AND METHOD Patients were grouped on an ordinal scale according to epilepsy burden from none to severe based on the presence of epileptic seizures and seizure frequency: L1, no epilepsy; L2, with epilepsy, seizure-free in the last 6 months with antiepileptic drugs; and L3, with epilepsy, at least one seizure in the last 6 months with AEDs. Health-related quality of life was measured by Functional Assessment of Cancer Therapy-Brain (FACT-Br) and Quality of Life in Epilepsy-31 (QOLIE-31) tools, cognition by the Montreal Cognitive Assessment (MoCA) tool and Frontal Assessment Battery (FAB), mood by the Hospital Anxiety and Depression Scale (HADS), activities of daily living (ADLs) by the Barthel Index (BI), and performance status by the Karnofsky Performance Status (KPS) scale in patients with primary brain tumors at least one month following neurosurgery with or without radiotherapy and chemotherapy. RESULTS Eighty-one patients with a diagnosis of primary brain tumors were recruited. Sixty-eight percent of patients were diagnosed with primary brain tumor-related epilepsy, 50.61% patients had cognitive impairment, 33% had abnormal scores in the anxiety scale, and 34% had abnormal scores in the depression scale. There were no statistically significant differences in these scores among L1, L2, and L3 groups. There were statistically significant differences in duration of disease and KPS and BI scores between L1 and L3 groups. The L3 group has significantly longer duration of disease and scored low in both the BI and KPS scale when compared to the L1 group. All patients with primary brain tumors scored significantly low in FACT-Br 'physical well-being' (PWB) and 'emotional well-being' (EWB) and high in 'social well-being' (SWB) when compared to healthy controls. When scores of each group were individually compared to healthy controls, the L3 group showed the lowest scores in PWB, EWB, and 'functional well-being'. In SWB, L1 and L2 groups showed statistically significantly high scores when compared to normative data. The QOLIE-31 applied to groups with epilepsy showed statistically significantly lower scores in the L3 group when compared to the L2 group in 'cognitive' and 'social functioning' domains. On multivariate analysis, both poor performance status and frequency of seizures were found to be independent risk factors for poor HRQOL when FACT-Br mean scores were compared. Level of seizures was found to be an independent risk factor for poor HRQOL when QOLIE-31 scores were compared between L2 and L3 groups. DISCUSSION Presence of brain tumors could be attributed to cognitive impairment irrespective of the presence of epilepsy in our cohort. High seizure burden is an independent risk factor for poor HRQOL in patients with primary brain tumors. The QOLIE-31 is a more sensitive tool than the FACT-Br because of the presence of a seizure-related questionnaire.
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Affiliation(s)
- Z Rahman
- Westmead Hospital, Darcy Road, Westmead, NSW 2145, Australia.
| | - C H Wong
- Westmead Hospital, Darcy Road, Westmead, NSW 2145, Australia; The Children's Hospital at Westmead, Hawkesbury Road, Westmead 2145, Australia
| | - M Dexter
- Westmead Hospital, Darcy Road, Westmead, NSW 2145, Australia; The Children's Hospital at Westmead, Hawkesbury Road, Westmead 2145, Australia
| | - G Olsson
- Westmead Hospital, Darcy Road, Westmead, NSW 2145, Australia; The Children's Hospital at Westmead, Hawkesbury Road, Westmead 2145, Australia
| | - M Wong
- Westmead Hospital, Darcy Road, Westmead, NSW 2145, Australia
| | - V Gebsky
- The University of Sydney, NSW 2006, Australia
| | - N Nahar
- Westmead Hospital, Darcy Road, Westmead, NSW 2145, Australia
| | - A Wood
- Westmead Hospital, Darcy Road, Westmead, NSW 2145, Australia
| | - K Byth
- Westmead Hospital, Darcy Road, Westmead, NSW 2145, Australia
| | - M King
- The University of Sydney, NSW 2006, Australia
| | - A B Bleasel
- Westmead Hospital, Darcy Road, Westmead, NSW 2145, Australia
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He M, Wong CH, Shi D, Tse PL, Scheidt EW, Eickerling G, Scherer W, Sheng P, Lortz R. 1D to 3D dimensional crossover in the superconducting transition of the quasi-one-dimensional carbide superconductor Sc3CoC4. J Phys Condens Matter 2015; 27:075702. [PMID: 25643644 DOI: 10.1088/0953-8984/27/7/075702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The transition metal carbide superconductor Sc(3)CoC(4) may represent a new benchmark system of quasi-one-dimensional (quasi-1D) superconducting behavior. We investigate the superconducting transition of a high-quality single crystalline sample by electrical transport experiments. Our data show that the superconductor goes through a complex dimensional crossover below the onset T(c) of 4.5 K. First, a quasi-1D fluctuating superconducting state with finite resistance forms in the [CoC(4)](∞) ribbons which are embedded in a Sc matrix in this material. At lower temperature, the transversal Josephson or proximity coupling of neighboring ribbons establishes a 3D bulk superconducting state. This dimensional crossover is very similar to Tl(2)Mo(6)Se(6), which for a long time has been regarded as the most appropriate model system of a quasi-1D superconductor. Sc(3)CoC(4) appears to be even more in the 1D limit than Tl(2)Mo(6)Se(6).
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Affiliation(s)
- Mingquan He
- Department of Physics and the William Mong Institute of Nano Science and Technology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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Teng CL, Wong CH. Does negative IgM dengue serology rule out dengue fever in an adult with fever for three days? Malays Fam Physician 2013; 8:26-27. [PMID: 25883762 PMCID: PMC4391515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- CL Teng
- Department of Family Medicine, International Medical University
| | - CH Wong
- Department of Family Medicine, International Medical University
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Abstract
BACKGROUND Necrotizing fasciitis is a rapidly progressing skin infection characterized by necrosis of the fascia and subcutaneous tissue, accompanied by severe systemic toxicity. The objective of this systematic review was to identify clinical features and investigations that will aid early diagnosis. METHODS A systematic literature search of PubMed was undertaken using the keywords 'necrotising fasciitis', 'necrotising skin infection', 'diagnosis' and 'outcome'. Case series of 50 or more subjects with information on symptoms and signs at initial presentation, investigations and clinical outcome were included. RESULTS Nine case series were selected, with a total of 1463 patients. Diabetes mellitus was a co-morbidity in 44.5 per cent of patients. Contact with marine life or ingestion of seafood in patients with liver disease were risk factors in some parts of Asia. The top three early presenting clinical features were: swelling (80.8 per cent), pain (79.0 per cent) and erythema (70.7 per cent). These being non-specific features, initial misdiagnosis was common and occurred in almost three-quarters of patients. Clinical features that helped early diagnosis were: pain out of proportion to the physical findings; failure to improve despite broad-spectrum antibiotics; presence of bullae in the skin; and gas in the soft tissue on plain X-ray (although this occurred in only 24.8 per cent of patients). CONCLUSION A high index of suspicion of necrotizing fasciitis is needed in a patient presenting with cutaneous infection causing swelling, pain and erythema, with co-morbidity of diabetes or liver disease. The presence of bullae, or gas on plain X-ray can be diagnostic. Early surgical exploration is the best approach in the uncertain case.
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Affiliation(s)
- T Goh
- Department of Plastic, Reconstructive and Aesthetic Surgery, Singapore General Hospital, Singapore
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Savic S, Ouboussad L, Dickie LJ, Wong CH, Doble R, Miriam W, McDermott MF. PW02-013 - The role of IL6 and LPS in pathogenesis of TRAPS. Pediatr Rheumatol Online J 2013. [PMCID: PMC3952452 DOI: 10.1186/1546-0096-11-s1-a153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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He M, Wong CH, Tse PL, Zheng Y, Zhang H, Lam FLY, Sheng P, Hu X, Lortz R. "Giant" enhancement of the upper critical field and fluctuations above the bulk Tc in superconducting ultrathin lead nanowire arrays. ACS Nano 2013; 7:4187-4193. [PMID: 23565799 DOI: 10.1021/nn400604v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We have produced ultrathin lead (Pb) nanowires in the 6 nm pores of SBA-15 mesoporous silica substrates by chemical vapor deposition. The nanowires form regular and dense arrays. We demonstrate that bulk Pb (a type-I superconductor below Tc = 7.2 K with a critical field of 800 Oe) can be tailored by nanostructuring to become a type-II superconductor with an upper critical field (Hc2) exceeding 15 T and signs of Cooper pairing 3-4 K above the bulk Tc. The material undergoes a crossover from a one-dimensional fluctuating superconducting state at high temperatures to three-dimensional long-range-ordered superconductivity in the low-temperature regime. We show with our data in an impressive way that superconductivity in elemental metals can be greatly enhanced by nanostructuring.
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Affiliation(s)
- Mingquan He
- Department of Physics and the William Mong Institute of Nano Science and Technology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, People's Republic of China
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Wong CH, Duine RA. Topological transport in spin-orbit coupled bosonic Mott insulators. Phys Rev Lett 2013; 110:115301. [PMID: 25166549 DOI: 10.1103/physrevlett.110.115301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Indexed: 06/03/2023]
Abstract
We investigate topological transport in spin-orbit coupled bosonic Mott insulators. We show that interactions can lead to anomalous quasiparticle dynamics even when the spin-orbit coupling is Abelian. To illustrate the latter, we consider the spin-orbit coupling realized in the experiment of Lin et al. [Nature (London) 471, 83 (2011)]. For this spin-orbit coupling, we compute the quasiparticle dispersions and spectral weights, the interaction-induced momentum-space Berry curvature, and the momentum-space distribution of spin density, and propose experimental signatures. Furthermore, we find that, for a generic spin orbit coupling, in our approximation for the single-particle propagator, the ground state can in principle support an integer Hall conductivity if the sum of the Chern numbers of the hole bands is nonzero.
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Affiliation(s)
- C H Wong
- Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands
| | - R A Duine
- Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands
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Wong CH, van Driel HJ, Kittinaradorn R, Stoof HTC, Duine RA. Spin caloritronics in noncondensed Bose gases. Phys Rev Lett 2012; 108:075301. [PMID: 22401219 DOI: 10.1103/physrevlett.108.075301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Indexed: 05/31/2023]
Abstract
We consider coupled spin and heat transport in a two-component atomic Bose gas in the noncondensed state. We find that the transport coefficients show a temperature dependence reflecting the bosonic enhancement of scattering and discuss experimental signatures of the spin-heat coupling in spin accumulation, spin separation, and total dissipation. Close to the critical temperature for Bose-Einstein condensation, we find that the spin-heat coupling is strongly reduced, which is also reflected in the spin caloritronics figure of merit that determines the thermodynamic efficiency of spin-heat conversion.
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Affiliation(s)
- C H Wong
- Institute for Theoretical Physics, Utrecht University, Utrecht, The Netherlands
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Abstract
We report a rare case of self-injection of mercury into the subcutaneous tissue of the upper limb. A multi-disciplinary management approach was adopted including cooperation between toxicologists, orthopaedic surgeons, radiologists and environment safety personnel. Surgical removal of mercury under radiological screening and systemic intoxication treated by chelating agents, namely dimercaprol and succimer. Serial serum and urine mercury levels showed an initial rise despite surgical removal and returned to normal after a prolonged period of time. Safety precautions were taken during surgery to avoid inadvertent intoxication of staff. Contamination of the operation theatre was monitored by the amount of mercury vapour released into the air. All personnels involved in the management of the patient did not show any evidence of mercury intoxication.
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Affiliation(s)
- F Wong
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
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Hung YT, Hung LK, Griffith JF, Wong CH, Ho PC. ULTRASOUND FOR THE DETECTION OF VEGETATIVE FOREIGN BODY IN HAND — A CASE REPORT. Hand Surg 2011; 9:83-7. [PMID: 15368632 DOI: 10.1142/s021881040400198x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2003] [Accepted: 12/02/2003] [Indexed: 11/18/2022]
Abstract
Foreign bodies in soft tissues are commonly encountered in daily orthopaedic practice. While most of the metals and glass foreign bodies can be detected by plain radiograph, organic substances such as wood and vegetative materials are radiolucent. Unfortunately, these radiolucent foreign bodies are usually more prone to cause an inflammatory reaction and infection. The detection can be even more difficult in cases of multiple foreign bodies and in penetrating injuries with small innocuous skin wounds. Ultrasonography is a sensitive and reliable investigation for detection of foreign bodies in soft tissue. We present a case of penetration injury to thumb with residual radiolucent foreign bodies and demonstrate the proper role of ultrasonography in the management of foreign bodies in soft tissues.
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Affiliation(s)
- Y T Hung
- Department of Orthopaedic and Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
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Chu YW, Wong CH, Chu MY, Cheung CPF, Cheung TKM, Tse C, Luk WK, Lo JYC. Varibaculum cambriense infections in Hong Kong, China, 2006. Emerg Infect Dis 2009; 15:1137-9. [PMID: 19624944 PMCID: PMC2744223 DOI: 10.3201/eid1507.081291] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Abstract
Pyomyositis is a subacute infection of skeletal muscles. It can be life-threatening if diagnosis and treatment are delayed. Only 5 cases of isolated piriformis pyomyositis have been reported. We report signs and symptoms of piriformis pyomyositis in 3 women who were treated mainly with antibiotics. Computed tomography is useful in making the diagnosis. Early diagnosis and treatment may avoid surgical treatment and reduce mortality.
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Affiliation(s)
- C H Wong
- Department of Orthopaedics and Traumatology, Princess Margaret Hospital, Lai Chi Kok, Hong Kong.
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Chu YW, Cheung TK, Wong CH, Tsang GK, Lee K, Lau SS, Kam KM. Quinolone Resistance and Correlation to Other Antimicrobial Resistances in Faecal Isolates of Escherichia coli in Hong Kong. Chemotherapy 2008; 54:274-8. [DOI: 10.1159/000149718] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Accepted: 03/10/2008] [Indexed: 11/19/2022]
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Qua CS, Wong CH, Goh KL. Tumour seeding following percutaneous needle biopsy of hepatocellular carcinoma. Singapore Med J 2008; 49:e8-e11. [PMID: 18204759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report a hepatocellular carcinoma seeding following needle biopsy in a 57-year-old man who first presented with a focal hepatic lesion at another hospital. The patient had been a hepatitis B carrier for 20 years. Initial surveillance ultrasonography showed a lesion in segment IV, in the background of non-cirrhotic liver and normal serum alpha-foetoprotein level (8 ng/ml). A percutaneous needle biopsy was done and histopathology confirmed well-differentiated hepatocellular carcinoma. The patient had refused surgery and preferred to try traditional medicine. He presented to us four months after the initial biopsy with epigastric swelling. This was found to be due to a tumour seeding along the previous biopsy tract. He was given radiofrequency ablation (RFA) of tumour along the needle tract, in addition to the primary tumour. We conclude that the need for percutaneous needle biopsy should be critically evaluated in patients presenting with focal hepatic lesions and the role of RFA in treating tumour seeding needs further evaluation.
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Affiliation(s)
- C S Qua
- Division of Gastroenterology, Department of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur 50503, Malaysia.
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Chu YW, Wong CH, Tsang GKL, Kwok MSW, Wong RKO, Lo JYC, Kam KM. Authors' reply to ‘Controversial data on the association of Aeromonas with diarrhoea in a recent Hong Kong study’. J Med Microbiol 2007. [DOI: 10.1099/jmm.0.47225-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Yiu Wai Chu
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR
| | - Chi Ho Wong
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR
| | - Grand K. L. Tsang
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR
| | - Mike S. W. Kwok
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR
| | - Raymond K. O. Wong
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR
| | - Janice Y. C. Lo
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR
| | - Kai Man Kam
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR
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Abstract
BACKGROUND Gastro-oesophageal reflux is thought to cause chronic laryngitis through laryngopharyngeal reflux. Response of laryngitis to treatment with acid-suppressive therapy supports this causal link. AIM To determine the prevalence of gastro-oesophageal reflux disease in patients with chronic laryngitis and response to proton-pump inhibitor therapy. METHODS Patients with chronic laryngitis were recruited. The frequency and severity of reflux and laryngeal symptoms were scored and laryngitis graded by laryngoscopy. All patients underwent esophagogastroduodenoscopy and 24-h ambulatory pH monitoring before receiving lansoprazole 30 mg b.d. for 8 weeks. RESULTS The prevalence of gastro-oesophageal reflux disease was 65.6% (21 of 32). Based on positive pH test, the prevalence was 25% (eight of 32). The change in laryngeal symptom score and laryngitis grade was significantly higher in GERD compared with non-GERD patients (P = 0.010 for both). The proportion of patients with marked/moderate improvement in laryngeal symptoms were significantly higher in patients with reflux (14 of 21, 67%) compared to those without reflux (two of 11, 18%; P = 0.026). CONCLUSIONS The prevalence of gastro-oesophageal reflux disease amongst our patients with chronic laryngitis was high. The response to treatment with proton-pump inhibitors in patients with reflux disease compared to those without underlined the critical role of acid reflux in a subset of patients with chronic laryngitis.
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Affiliation(s)
- C S Qua
- Division of Gastroenterology, Facultu of Medicine, University of Malaysia, Kuala Lumpur, Malaysia
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Wong CH, Chua CJ, Liam CK, Goh KL. Gastro-oesophageal reflux disease in 'difficult-to-control' asthma: prevalence and response to treatment with acid suppressive therapy. Aliment Pharmacol Ther 2006; 23:1321-7. [PMID: 16629937 DOI: 10.1111/j.1365-2036.2006.02888.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND The causal association between gastro-oesophageal reflux disease (GERD) and difficult-to-control asthma is unclear. AIM To determine the prevalence of GERD and response to proton pump inhibitor therapy in patients with difficult-to-control asthma. METHODS Consecutive patients with difficult-to-control asthma as defined by persistent and recurrent symptoms despite on optimal asthmatic medications were recruited for the study. GERD was diagnosed by symptoms, gastroscopy and 24-h oesophageal pH monitoring. All patients were prescribed a course of lansoprazole 30 mg daily for 8 weeks. Improvement to treatment was assessed by a change in pulmonary symptom score and also by patient's subjective assessment of improvement. RESULTS Seventeen of 30 (56.7%) patients with difficult-to-control asthma were diagnosed with GERD. Pulmonary symptom score improved significantly only in patients with GERD (35.0 to 21.0; P = 0.002). Twelve of 16 (75%) patients with GERD reported an improvement in asthma symptoms; 1 of 11 (9.1%) without GERD reported mild symptom improvement. There was no significant change in peak expiratory flow rate and forced expiratory volume. CONCLUSIONS More than half of patients with difficult-to-control asthma were diagnosed with GERD. In these patients the severity of asthma improved significantly with potent acid suppression therapy. This underlines the critical role of acid reflux in this subset of patients with difficult-to-control asthma.
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Affiliation(s)
- C H Wong
- Division of Gastroenterology, Department of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Chu YW, Wong CH, Tsang GKL, Kwok MSW, Wong RKO, Lo JYC, Kam KM. Lack of association between presentation of diarrhoeal symptoms and faecal isolation of Aeromonas spp. amongst outpatients in Hong Kong. J Med Microbiol 2006; 55:349-351. [PMID: 16476802 DOI: 10.1099/jmm.0.46266-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Yiu Wai Chu
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR, PR China
| | - Chi Ho Wong
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR, PR China
| | - Grand K L Tsang
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR, PR China
| | - Mike S W Kwok
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR, PR China
| | - Raymond K O Wong
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR, PR China
| | - Janice Y C Lo
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR, PR China
| | - Kai Man Kam
- Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, 382 Nam Cheong Street, Kowloon, Hong Kong SAR, PR China
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Li SSL, So YC, Wong CH, Yiu SF, Chan KT. Treatment of long, diffuse in-stent restenosis with sirolimus-eluting stents. J Invasive Cardiol 2004; 16:81-3. [PMID: 14760198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Treatment of long, diffuse in-stent restenosis remains a therapeutic challenge. We report the successful use of multiple sirolimus-eluting stents (three 33-mm long stents) in a long, diffuse in-stent restenotic lesion. No major adverse cardiovascular events, including acute/subacute/delayed stent thrombosis, were noted at ten months. Angiography at six months showed widely patent stents with 19% restenosis only at the worst segment.
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Affiliation(s)
- Steven Siu-Lung Li
- Division of Cardiology, Department of Medicine, Queen Elizabeth Hospital, Kowloon, Hong Kong.
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Abstract
We report our early experience in using the PercuSurge GuardWire Plus system as a distal protection device in patients with acute coronary syndrome and acute myocardial infarction. Forty-three patients received percutaneous coronary intervention with the GuardWire Plus system. Thirteen had unstable angina, five had non-Q myocardial infarction and 25 had ST segment elevation myocardial infarction. Forty-one target lesions were in native coronary vessels and two were in saphenous vein grafts. Total occlusion occurred in 18 patients. The mean occlusion time by the distal protective balloon was 262.8 +/- 114.1 s. Preoperatively, TIMI 0 flow was present in 18, TIMI II flow in two and TIMI III flow in 23 patients. Post-operatively, TIMI II and TIMI III flow were established in two and 41 patients, respectively. All procedures were successful and the GuardWire Plus system was successfully deployed in all but two patients. There was no procedure-related major adverse clinical event. There was no major adverse clinical event at 30 days. There was no device-related complication. We believe that the GuardWire Plus system is safe and feasible in patients with acute coronary syndrome and acute myocardial infarction.
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Affiliation(s)
- Steven S L Li
- Division of Cardiology, Department of Medicine, Queen Elizabeth Hospital, Kowloon, Hong Kong.
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Wong CH, Wong SF, Shen L. Correlates of habitual walking and sports/leisure-time physical activity in older persons in Singapore: interaction effects between educational attainment and gender. Ann Acad Med Singap 2003; 32:801-6. [PMID: 14716950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
INTRODUCTION We examined for demographic and psychosocial correlates on the participation of habitual walking and sports/leisure-time physical activity (LTPA) among older persons in Singapore. MATERIALS AND METHODS In an observational study, 177 Chinese, community/urban-dwelling, ambulant, non-disabled participants > or = 50 years old were recruited from a health promotion programme. The main outcome measures were self-reported participation in habitual walking and sports/LTPA. Variables examined include highest educational attainment, demographic and health characteristics, social contact and health knowledge. Interaction between gender and educational attainment was also examined. RESULTS The mean age of participants was 62.5 +/- 7.8 years. The effects of educational level were significant on habitual walking (P = 0.02), while that of age, self-rated health and interaction between gender and educational level were significant for sports/LTPA (P = 0.012, P = 0.002 and P = 0.019, respectively). Men with higher education had a higher self-reported sport/LTPA, while in women; those with lower education attainment had a higher participation. CONCLUSION Unlike findings from Western developed nations, previous studies done in Japan and Singapore found that educational level and health behaviours may not be positively associated. In this study, there is a negative correlation between educational attainment and participation in habitual walking and sports/LTPA, especially among older Singaporean women.
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Affiliation(s)
- C H Wong
- Department of Geriatric Medicine, Alexandra Hospital, 378 Alexandra Road, Singapore 159964
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Abstract
Deliberate self-injection of metallic mercury into subcutaneous tissue is uncommon. A 41-year-old lady with a history of schizophrenia was admitted to our hospital after deliberate injection of metallic mercury into her right wrist and antecubital fossa. Physical examination was unremarkable except for the injection marks over right antecubital fossa and wrist. The presence of subcutaneous mercury deposits in her right elbow and wrist was confirmed by X-rays and ultrasound scan. Three days later, erythema, swelling, induration and tenderness were seen over the injection sites. At the operation on day 9, mercury streaks were seen within the brachialis muscle belly, surrounded by friable necrotic tissues along the tract. A similar picture was noted in her right wrist. The necrotic tissues and mercury streaks were removed. The patient had been unco-operative and she only received incomplete treatment with dimercaprol and 2,3-dimercaptosuccinic acid. Her total blood mercury level (normal < 50 nmol/L) decreased from 101-151 nmol/L in the first two weeks to 42 nmol/L 3 months later. Her 24-hour urinary mercury excretion (normal < 10 nmol) changed from 55.7-209.5 nmol in the first 7 weeks to 125.4 nmol 3 months later. This case illustrates that soft tissue metallic mercury can produce local necrosis and may allow continuous absorption with persistent elevations in blood and urinary mercury levels. Therefore, early surgical removal of subcutaneous mercury deposits is required to prevent local complications and minimize the risk of systemic absorption and toxicity.
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Affiliation(s)
- Y O Y Soo
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, China
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Li SSL, Wong CH, Lam CWLW. Renal angioplasty under protection of the PercuSurge GuardWire Plus System. J Invasive Cardiol 2003; 15:148-50. [PMID: 12612389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Renal artery revascularization with angioplasty may preserve renal function and facilitate hypertension control. However, in a significant proportion of patients, renal function may deteriorate after the procedure. Distal microembolization has been implicated as a possible cause; it may be prevented with distal protection during the procedure. We report a case of successful renal angioplasty and stenting using the PercuSurge GuardWire Plus system.
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Affiliation(s)
- Steven S L Li
- Division of Cardiology, Department of Medicine, Queen Elizabeth Hospital, Kowloon, Hong Kong.
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Chen WS, Wong CH, Cillekens L. Dengue antibodies in a suburban community in Malaysia. Med J Malaysia 2003; 58:142-3. [PMID: 14556343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
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Bonser RS, Wong CH, Harrington D, Pagano D, Wilkes M, Clutton-Brock T, Faroqui M. Failure of retrograde cerebral perfusion to attenuate metabolic changes associated with hypothermic circulatory arrest. J Thorac Cardiovasc Surg 2002; 123:943-50. [PMID: 12019380 DOI: 10.1067/mtc.2002.120333] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES Although retrograde cerebral perfusion has become a popular adjunctive technique and may improve cerebral ischemic tolerance during hypothermic circulatory arrest, direct cerebral metabolic benefit has yet to be demonstrated in human subjects. We investigated the post-arrest metabolic phenomena with and without retrograde cerebral perfusion in patients. METHODS In a prospective randomized trial, 42 patients undergoing aortic surgery requiring hypothermic circulatory arrest were allocated to receive hypothermic circulatory arrest alone (n = 21) or hypothermic circulatory arrest with additional retrograde cerebral perfusion (n = 21). Circulatory arrest was commenced at 15 degrees C, and retrograde perfusion was instituted through the superior vena cava at a maximum jugular bulb pressure of 25 mm Hg. Transcranial, paired, repeated samples of the arterial and jugular bulb blood were analyzed for oxygen and glucose. Velocity in the right middle cerebral artery was also measured simultaneously. RESULTS There were 3 (7.1%) deaths and 3 (7.1%) episodes of neurologic deficit. Mean bypass and circulatory arrest duration (in minutes) were similar between groups (P =.4 and.14). The mean retrograde perfusion duration was 23 minutes. Post-arrest nasopharyngeal temperature was similar (15.3 degrees C vs. 15.3 degrees C). Retrograde perfusion did not affect post-arrest oxygen extraction, glucose extraction, or jugular bulb Po(2). There was no immediate lactate release immediately after hypothermic circulatory arrest. CONCLUSIONS Retrograde cerebral perfusion did not influence immediate post-arrest nasopharyngeal temperature or cerebral metabolic recovery. The low jugular bulb Po(2) suggests equivalent ischemia. These findings cast doubt on the effectiveness of retrograde cerebral perfusion as a metabolic adjunct to hypothermic circulatory arrest.
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Affiliation(s)
- R S Bonser
- Cardiothoracic Surgical Unit and Department of Anaesthesia and Intensive Care, University Hospital Birmingham Queen Elizabeth Medical Centre, Birmingham, United Kingdom.
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Affiliation(s)
- C H Wong
- The Canberra Hospital, Australian Capital Territory, Australia
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Abstract
Neuropeptide FF (NPFF) is an endogenous anti-opioid peptide. NPFF could potentiate the naloxone-precipitated morphine withdrawal syndromes in morphine-dependent rats, indicating the possible involvement of the endogenous NPFF system in opioid analgesia and dependence. The present study was performed to examine the effects of dansyl-PQRamide (dns-PQRa), a putative NPFF antagonist, on conditioned place preference (CPP), in addition, its interaction with the opioid system. Two CPP experiments were conducted. First, rats were treated with dns-PQRa (4-13 mg/kg, i.p.) and paired with the non-preferred compartment while the vehicle was paired with the preferred compartment. Second, similar to experiment 1 except naloxone (1 mg/kg, i.p.) was given 10 min prior to each dns-PQRa administration. The post-drug place preference was examined after 4 alternative pairings. Another group of animals after repetitive dns-PQRa treatments were analyzed for levels of neurotransmitters in discrete brain areas. Dns-PQRa (4-13 mg/kg, i.p.) induced a significant dose-dependent CPP. The dns-PQRa-induced CPP was completely blocked by pretreatment with 1 mg/kg i.p. naloxone, while naloxone alone did not induce any place aversion. The chronic dns-PQRa-treated (13 mg/kg, i.p., b.i.d.) rats caused a significant increase in 3,4-dihydroxyphenylacetic acid and 5-hydroxyindoleacetic acid in the olfactory tubercle compared to the vehicle-treated controls. There was also an increase in the turnover of serotonin in the olfactory tubercle, nucleus accumbens and medial prefrontal cortex. These results suggest that blockade of the NPFF system produces rewarding, possibly via an inhibition of the anti-opioid action of NPFF. These results also reveal a close relationship between NPFF, drug rewarding and the dopaminergic and serotoninergic neurons in the mesolimbic system.
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Affiliation(s)
- E Y K Huang
- Department of Pharmacology, National Defense Medical Center, Nei-Hu 114, Taipei, Taiwan, ROC.
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Affiliation(s)
- P Sears
- Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, USA
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Abstract
OBJECTIVES Paraplegia following coarctation repair occurs in 0.4% of infants. However, for older children, adults and re-operations, the incidence can be as high as 2.6%. Yet there is no consensus on the need for spinal cord protection or the optimal method. This paper reports our experience with left heart bypass (LHB) in adult and re-do coarctation. METHODS Between 1997 and 2000, nine patients underwent elective resection of coarctation (three re-dos, two balloons) with a mean age of 17.9 years (range, 8-44) and weight of 52 kg (range, 17.3-109). The mean trans-coarctation gradient was 29.6 mmHg (range, 20-45). Patients were placed on LHB using a centrifugal pump with full heparinization through a fourth-space thoracotomy. Patients were cooled to 31-34 degrees C for additional spinal cord protection. Repair was carried out with an inter-positional graft (5/9), a Gore-Tex patch (2/9) or end-to-end anastomosis (2/9). The mean cross-clamp and bypass times were 36.4 (range, 19-65) and 40.3 min (range, 22-70), respectively. RESULTS No patient developed transient or permanent paraplegia. The mean peak creatinine was 80 micromol/l (range, 51-123). CONCLUSIONS LHB is simple, easy and safe to implement, and is the only technique capable of maintaining independent upper and lower body perfusion pressure. Potentially, it provides the best spinal cord protection, and extends the margin of safety and time to execute an accurate repair.
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Affiliation(s)
- C H Wong
- Department of Cardiothoracic Surgery, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK.
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