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Li KH, Zhu Y, Zhang PH, Alini M, Grad S, Li Z. Osteochondral explants for diarthrodial joint diseases: bridging the gap between bench and bedside. Eur Cell Mater 2022; 44:74-89. [PMID: 36161648 DOI: 10.22203/ecm.v044a05] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Diarthrodial joint diseases, affecting hundreds of millions of people worldwide, mainly include osteoarthritis and cartilage injuries. No consensus on joint disease models has been achieved so far owing to the complex aetiologies, pathophysiological mechanisms and heterogeneity of disorders. The disease models established using isolated chondrocytes or small animals have the weaknesses of lacking native extracellular matrix and inter-species differences in anatomical and biomechanical cartilage properties. Osteochondral explants (OCEs) from large-animal or human joints present characteristics of native articular cartilage, showing promising potential for application in research on joint diseases. The present review focuses on OCEs and highlights the OCE sources, harvesting techniques, culture systems, applications and future developments. The OCE-centred ex vivo system has the potential to develop into preclinical models mimicking human joint diseases to help elucidate disease mechanisms, prompt therapeutic strategies and facilitate the clinical translation of findings in basic research.
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Affiliation(s)
| | | | | | | | | | - Z Li
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos Platz,
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2
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Li KH, Leong PY, Tseng CF, Wang YH, Wei JCC. Influenza Vaccination Is Associated With Lower Incidental Asthma Risk in Patients With Atopic Dermatitis: A Nationwide Cohort Study. Front Immunol 2021; 12:729501. [PMID: 34721391 PMCID: PMC8548273 DOI: 10.3389/fimmu.2021.729501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/24/2021] [Indexed: 12/30/2022] Open
Abstract
Background Atopic march refers to the natural history of atopic dermatitis (AD) in infancy followed by subsequent allergic rhinitis and asthma in later life. Respiratory viruses interact with allergic sensitization to promote recurrent wheezing and the development of asthma. We aimed to evaluate whether influenza vaccination reduces asthma risk in people with AD. Methods This cohort study was conducted retrospectively from 2000 to 2013 by the National Health Insurance Research Database (NHIRD). Patients with newly diagnosed AD (International Classification of Diseases, Ninth Revision, Clinical Modification code 691) were enrolled as the AD cohort. We matched each vaccinated patient with one non-vaccinated patient according to age and sex. We observed each participant until their first asthma event, or the end of the study on December 31, 2013, whichever came first. Results Our analyses included 4,414 people with a mean age of 53 years. Of these, 43.8 were male. The incidence density of asthma was 12.6 per 1,000 person-years for vaccinated patients, and 15.1 per 1000 person-years for non-vaccinated patients. The adjusted hazard ratio (aHR) of asthma in the vaccinated cohort relative to the non-vaccinated cohort was 0.69 (95% CI = 0.55–0.87). Vaccinated patients had a lower cumulative incidence of asthma than unvaccinated patients. Vaccinated participants in all age and sex groups trended toward a lower risk of asthma. People will reduce more asthma risk when taking shots every year. Conclusion Influenza vaccination was associated with lower asthma risk in patients with AD.
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Affiliation(s)
- Kun Hong Li
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.,Department of Family Medicine, Changhua Christian Hospital, Changhua, Taiwan
| | - Pui-Ying Leong
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.,Department of Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan.,Division of Allergy, Immunology and Rheumatology, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Chung-Fang Tseng
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Yu Hsun Wang
- Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - James Cheng-Chung Wei
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.,Division of Allergy, Immunology and Rheumatology, Chung Shan Medical University Hospital, Taichung, Taiwan.,Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan
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3
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Wu P, Lin W, Li KH, Lai HC, Lee MT, Tsai KWK, Chiu PY, Chang WC, Wei CY, Taira T. Focused Ultrasound Thalamotomy for the Treatment of Essential Tremor: A 2-Year Outcome Study of Chinese People. Front Aging Neurosci 2021; 13:697029. [PMID: 34335232 PMCID: PMC8317688 DOI: 10.3389/fnagi.2021.697029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 06/15/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Essential tremor (ET) is a common movement disorder among elderly individuals worldwide and is occasionally associated with a high risk for mild cognitive impairment and dementia. This retrospective study aimed to determine the clinical outcome of unilateral magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy in Chinese patients with ET. Methods: In total, 31 male and 17 female patients with drug-refractory ET were enrolled in this research study from January 2017 to September 2019. The severity of tremor and disability were assessed using the Clinical Rating Scale for Tremor (CRST) within a 2-year follow-up period. Results: The mean age of the participants was 59.14 ± 13.5 years. The mean skull density ratio (SDR) was 0.5 ± 0.1. The mean highest temperature was 57.0 ± 2.4°C. The mean number of sonications was 10.0 ± 2.6. The average maximum energy was 19,710.5 ± 8,624.9 J. The total CRST scores and sub-scores after MRgFUS thalamotomy significantly reduced during each follow-up (p < 0.001). All but four (8.3%) of the patients had reversible adverse events (AEs) after the procedure. Conclusions: MRgFUS had sustained clinical efficacy 2 years after treatment for intractable ET. Only few patients presented with thalamotomy-related AEs including numbness, weakness, and ataxia for an extended period. Most Chinese patients were treated safely and effectively despite their low SDR.
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Affiliation(s)
- Peihan Wu
- Department of Neurology, Chang Bing Show Chwan Memorial Hospital, Changhua County, Taiwan
| | - Wei Lin
- Department of Neurology, Chang Bing Show Chwan Memorial Hospital, Changhua County, Taiwan
| | - Kun Hong Li
- MR-Guided Focused Ultrasound Center, Chang Bing Show Chwan Memorial Hospital, Changhua County, Taiwan
| | - Hui-Chin Lai
- MR-Guided Focused Ultrasound Center, Chang Bing Show Chwan Memorial Hospital, Changhua County, Taiwan
| | - Ming-Tsung Lee
- Research Assistant Center, Show Chwan Memorial Hospital, Changhua, Taiwan.,Department of Nursing, Hungkuang University, Taichung, Taiwan
| | | | - Pai-Yi Chiu
- Department of Neurology, Show Chwan Memorial Hospital, Changhua, Taiwan
| | - Wei-Chieh Chang
- Department of Neurosurgery, Chang Bing Show Chwan Memorial Hospital, Changhua County, Taiwan
| | - Cheng-Yu Wei
- Department of Neurology, Chang Bing Show Chwan Memorial Hospital, Changhua County, Taiwan.,Department of Exercise and Health Promotion, College of Kinesiology and Health, Chinese Culture University, Taipei, Taiwan
| | - Takaomi Taira
- Department of Neurosurgery, Tokyo Women's Medical University, Tokyo, Japan
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4
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Jin H, Chen L, Li J, An X, Wu YP, Zhu L, Yi H, Li KH. Vertically stacked RGB LEDs with optimized distributed Bragg reflectors. Opt Lett 2020; 45:6671-6674. [PMID: 33325867 DOI: 10.1364/ol.408416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/18/2020] [Indexed: 06/12/2023]
Abstract
The design and fabrication of a vertically stacked red-green-blue (RGB) light-emitting diode (LED) with novel, to the best of our knowledge, wavelength-selective distributed Bragg reflectors (DBRs) are demonstrated. The two DBRs are optimized to achieve selective reflectance in the RGB spectral region through theoretical calculations and simulation modeling. The insertion of optimal DBRs into the stack structure can effectively reflect downward emission from the upper chip without filtering the emission from the lower chips, thereby increasing the luminous efficiency for white emission with a color temperature range of 3000-8000 K by 1.6-7.4%. The optical performances of stacked devices with and without DBRs are thoroughly studied, verifying the effectiveness of the proposed wavelength-selective DBR structure.
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Abstract
Photo-plethysmography (PPG) making use of a monochromic light source and a photoelectric sensor is a non-invasive detection method to record blood volume changes in vessels and can be used to extract cardiac-related heart pulse information. Here, we demonstrated the fabrication of a monolithic photonic chip by integrating light-emitting diodes (LEDs) with photodetectors (PDs) on the same GaN-on-sapphire wafer containing InGaN/GaN multi-quantum wells (MQWs). The MQWs simultaneously act as light emitters in the LEDs and detectors in the PDs, and their mechanism has been studied. The fabricated chip operating in reflection mode is flip-chip bonded on a flexible polydimethylsiloxane (PDMS) strip, enabling the sapphire surface in close contact with the skin. The optical and electrical properties of the LED and PD have been thoroughly characterized, confirming that the PDs using identical MQWs can detect the reflected light from the LEDs. By attaching the chip to the wrist, PPG heart pulse signals from the arterial blood flow can be obtained, thereby verifying the feasibility of the proposed monolithic chip.
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Li KH, Ho J, Xu Z, Lakhani I, Bazoukis G, Liu T, Wong WT, Cheng SH, Chan MTV, Gin T, Wong MCS, Wong I, Wu WKK, Zhang Q, Tse G. P5014The NPAC score for predicting survival after incident acute myocardial infarction. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0192] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Risk stratification in acute myocardial infarction (AMI) is important for guiding clinical management. Current risk scores are mostly derived from clinical trials with stringent patient selection. We aimed to establish and evaluate a composite scoring system to predict short-term mortality after index episodes of AMI, independent of electrocardiography (ECG) pattern, in a large real-world cohort.
Methods
Using electronic health records, patients admitted to our regional teaching hospital (derivation cohort, n=2127) and an independent tertiary care center (validation cohort, n=1276) with index acute myocardial infarction between January 2013 and December 2017 as confirmed by principal diagnosis and laboratory findings, were identified retrospectively.
Results
Univariate logistic regression was used as the primary model to identify potential contributors to mortality. Stepwise forward likelihood ratio logistic regression revealed that neutrophil-to-lymphocyte ratio, peripheral vascular disease, age, and serum creatinine (NPAC) were significant predictors for 90-day mortality (Hosmer-Lemeshow test, P=0.21). Each component of the NPAC score was weighted by beta-coefficients in multivariate analysis. The C-statistic of the NPAC score was 0.75, which was higher than the conventional Charlson's score (C-statistic=0.63). Application of a deep learning model to our dataset improved the accuracy of classification with a C-statistic of 0.81.
Multivariate binary logistic regression Variable β Adjusted Odds ratio (95% CI) P-value Points Age ≥65 years 1.304 3.68 (2.63–5.17) <0.001 2 Peripheral vascular disease 1.109 3.03 (1.52–6.04) 0.002 2 NLRt ≥9.51 1.100 2.73 (2.12–3.51) <0.001 1 Creatinine≥109 μmol/L 1.003 3.00 (2.35–3.85) <0.001 2
NPAC deep learning model
Conclusions
The NPAC score comprised of four items from routine laboratory parameters and basic clinical information and can facilitate early identification of cases at risk of short-term mortality following index myocardial infarction. Deep learning model can serve as a gate-keeper to provide more accurate prediction to facilitate clinical decision making.
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Affiliation(s)
- K H Li
- Newcastle University, Newcastle upon Tyne, United Kingdom
| | - J Ho
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Z Xu
- The Chinese University of Hong Kong, Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, Hong Kong, Hong Kong
| | - I Lakhani
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - G Bazoukis
- Evangelismos General Hospital of Athens, Cardiology, Athens, Greece
| | - T Liu
- 2nd Hospital of Tianjin Medical University, Cardiology, Tianjin, China
| | - W T Wong
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - S H Cheng
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - M T V Chan
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - T Gin
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - M C S Wong
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - I Wong
- The University of Hong Kong, Hong Kong, Hong Kong
| | - W K K Wu
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Q Zhang
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - G Tse
- The Chinese University of Hong Kong, Shatin, Hong Kong
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Li KH, Sang T, Chan CP, Gong M, Li G, Liu T, Wu WKK, Chan M, Tse G, Xia Y, Ho J. P2838The impact of anesthesia depth on catheter ablation for atrial fibrillation: a systematic review and meta-analysis of observational studies. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.1148] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Objectives
This meta-analysis and systematic review seeks to compare both characteristic parameters and procedural outcomes of catheter ablation in patients under GA/deep sedation and mild/moderate sedation.
Background
Catheter ablation has become a widely applied intervention for treating symptomatic AF and arrhythmias that are refractory to medical therapy. It can be conducted through from mild sedation to general anesthesia.
Methods
PubMed and Embase were searched up to July 2018 for randomized controlled trials, cohort and observational studies that assessed the outcomes of catheter ablation under GA/deep sedation or mild/moderate sedation. 12 studies were included in this meta-analysis after screening with the inclusion and exclusion criteria. Heterogeneity between studies and publication bias was evaluated by I2 index and Egger's regression, respectively.
Results
Our meta-analysis found catheter AF ablation with GA/deep sedation to be associated with reduced risk of recurrence (RR: 0.79, 95% CI: 0.56 to 1.13, P=0.20) and complications (RR: 0.95, 95% CI: 0.64 to 1.42, P=0.82), though statistically insignificant. In terms of procedural parameters, there was non-significant difference between the two groups when both procedural time (SMD: −0.13, 95% CI: −0.90 to 0.63, P=0.74) and fluoroscopy time (SMD: −0.41, 95% CI: −1.40 to 0.58, P=0.41) were considered. Multivariate meta-regression demonstrated hypertension as an independent moderating factor for complication risk.
Complications Comparison
Conclusion
Apart from an increased likelihood of procedural success, ablation by GA/deep sedation was found to be non-significantly different from the mild/moderate sedation approach in both procedural parameters and outcome measures.
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Affiliation(s)
- K H Li
- Newcastle University, Newcastle upon Tyne, United Kingdom
| | - T Sang
- University of Toronto, Toronto, Canada
| | - C P Chan
- University of Manchester, Manchester, United Kingdom
| | - M Gong
- 2nd Hospital of Tianjin Medical University, Cardiology, Tianjin, China
| | - G Li
- 2nd Hospital of Tianjin Medical University, Cardiology, Tianjin, China
| | - T Liu
- 2nd Hospital of Tianjin Medical University, Cardiology, Tianjin, China
| | - W K K Wu
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - M Chan
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - G Tse
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Y Xia
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - J Ho
- The Chinese University of Hong Kong, Shatin, Hong Kong
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Park Y, Li KH, Fu WY, Cheung YF, Choi HW. Packaging of InGaN stripe-shaped light-emitting diodes. Appl Opt 2018; 57:2452-2458. [PMID: 29714220 DOI: 10.1364/ao.57.002452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate the fabrication of InGaN/GaN stripe-shaped light-emitting diodes (LEDs) in flip-chip packaging (FC-LED) and vertically mounted packaging (VM-LED). Compared to conventionally packaged LEDs, these packaging schemes enhance light output and emission divergence in ways favorable for general lighting applications. The FC-LED can sustain efficiency at high current operations due to effective heat sinking, while the VM-LED excels at light extraction efficiency due to the exposure of two large emission surfaces. Together with the properties of low luminous exitance and emission uniformity, the stripe-shaped LEDs are ideal for the assembly of luminaires. An LED light tube comprising a continuous linear array of 10 stripe-shaped LED chips has been assembled. The optical performance of the light tube is compared to another light tube assembled with conventional square-shaped LED chips (with and without external diffuser) by confocal microscopy. It is found that emission uniformity of the stripe-shaped LED tube is significantly improved, with a threefold increase in illumination area, without efficiency loss associated with diffusers.
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9
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Pang T, Guo XF, Zhou YH, Qiu XQ, Li S, Liang ZR, Qin XL, Li KH, Zeng XY. [Outcomes of pregnancy among women with alpha-thalassemia minor: A retrospective study of Pingguo county in Guangxi Zhuang Autonomous Region]. Zhonghua Liu Xing Bing Xue Za Zhi 2018; 38:1620-1623. [PMID: 29294574 DOI: 10.3760/cma.j.issn.0254-6450.2017.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the association between the value of α-thalassemia minor and the outcomes in pregnant women. Methods: A total of 445 pregnant women with α-thalassemia minor were selected as thalassemia group in the Pingguo County Maternal and Child Health Hospital of Guangxi from January 2011 to December 2015, with ratio of 1∶4 healthy pregnant women was randomly recruited as non-thalassemia group. Clinical characteristics and pregnancy outcomes of the two groups were retrospectively analyzed using methods including t test, χ(2) test, and logistic regression model and ROC curve. Results: There were no significant differences noticed in factors as age, BMI, gestational age and educational level of the two groups. Hemoglobin of the thalassemia group was significantly lower than that of the non-thalassemia group (P<0.001). Differences on parity, ethnicities or occupation were statistically significant. Results from univariate analysis showed that the proportions of low birth weight, small for date infant and 1 min Apgar score<7 were higher in the thalassemia group, but the ratio of adverse pregnancy outcomes was comparable on parameters as preterm birth, stillbirth, macrosomia. Findings from the unconditional logistic regression showed that pregnancy complicated with α-thalassemia minor appeared a risk for both newborns with low birth weight (aOR=2.29, 95%CI: 1.32-3.95) and small for date infant (aOR= 2.11, 95%CI: 1.16-3.84). The ROC curve showed that α-thalassemia minor combined with multiple indicators presented a certain predictive value on neonatal birth weight. Conclusion: Pregnancy complicated with α-thalassemia minor was likely to increase the risk of birth weight loss in newborns, suggesting that prenatal care for pregnant women with thalassemia be strengthened, in order to reduce the incidence of adverse pregnancy outcomes.
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Affiliation(s)
- T Pang
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - X F Guo
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Y H Zhou
- Department of Maternity, Pingguo County Child Health, Baise 531400, China
| | - X Q Qiu
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - S Li
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Z R Liang
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - X L Qin
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - K H Li
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - X Y Zeng
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
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Hao ZQ, Liu L, Shen M, Yang XY, Li KH, Guo LB, Li XY, Lu YF, Zeng XY. Investigation on self-absorption at reduced air pressure in quantitative analysis using laser-induced breakdown spectroscopy. Opt Express 2016; 24:26521-26528. [PMID: 27857385 DOI: 10.1364/oe.24.026521] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The self-absorption at reduced air pressure for quantitative analysis of Mn and Cu elements in steel using laser-induced breakdown spectroscopy was investigated. The calibration curves of Mn and Cu elements at the air pressures of 100, 80, 50, 20, and 1 kPa were studied. The results show that, the nonlinearity of calibration curves which caused by self-absorption effects at atmosphere could be significantly improved by reducing the air pressure to 1 kPa, and the coefficients of determination (R2) of linear calibration curves of Mn and Cu lines are all higher than 0.99. The further study explored that the reason for the improvement was that the induced plasma became low density and the self-absorption coefficient was close to 1 when the air pressure reduced to 1 kPa.
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Abstract
The majority of a GaN light-emitting diode (LED) is released from its sapphire substrate through selective-area laser lift-off to form a freely suspended light emitter. By virtue of being suspended in air without supporting substrates, the ultrathin crystalline and crack-free film possesses flexibility and bendability. The free-standing LEDs benefit from significant relaxation of strain, evident from red-shifting of the E2(high) phonon frequencies as measured by Raman spectroscopy toward those of strain-free free-standing GaN substrates. The phonon frequencies remain invariant upon bending of the film; this indicates that the properties of the flexible device will not be dependent on the bending curvatures. The observation of pronounced spectral blue-shifts from the photoluminescence (PL) spectrum from the flexible regions further confirms the occurrence of strain relaxation in the quantum wells. Being free-standing and thus lacking a direct heat-sinking pathway, emissions from the different regions of the suspended film can be affected by thermal effects to different extents, which are investigated by long-wave infrared thermometry. Heat accumulation is determined to be most severe at the far end of the flexible stripe at higher currents, leading to reduced efficiencies and electroluminescence (EL) spectral red-shifts. Based on this architecture, a monolithic 3 × 4 dot-matrix microdisplay prototype is demonstrated, comprising three adjacent flexible stripe emitters with four individually addressable pixels on each stripe. This proof-of-concept demonstration opens up new opportunities for GaN optoelectronics for a wide range of flexible display and visual applications.
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Affiliation(s)
- Y F Cheung
- Department of Electrical and Electronic Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong
| | - K H Li
- Department of Electrical and Electronic Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong
| | - H W Choi
- Department of Electrical and Electronic Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong
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Yang XY, Hao ZQ, Li CM, Li JM, Yi RX, Shen M, Li KH, Guo LB, Li XY, Lu YF, Zeng XY. Sensitive determinations of Cu, Pb, Cd, and Cr elements in aqueous solutions using chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy. Opt Express 2016; 24:13410-13417. [PMID: 27410358 DOI: 10.1364/oe.24.013410] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this study, chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy (CR-SENLIBS) was for the first time applied to improve the detection sensitivities of trace heavy metal elements in aqueous solutions. Utilizing chemical replacement effect, heavy metal ions in aqueous solution were enriched on the magnesium alloy surface as a solid replacement layer through reacting with the high chemical activity metallic magnesium (Mg) within 1 minute. Unitary and mixed solutions with Cu, Pb, Cd, and Cr elements were prepared to construct calibration curves, respectively. The CR-SENLIBS showed a much better detection sensitivity and accuracy for both unitary and mixed solutions. The coefficients of determination R2 of the calibration curves were above 0.96, and the LoDs were of the same order of magnitude, i.e., in the range of 0.016-0.386 μg/mL for the unitary solution, and in the range of 0.025-0.420 μg/mL for the mixed solution. These results show that CR-SENLIBS is a feasible method for improving the detection sensitivity of trace element in liquid sample, which definitely provides a way for wider application of LIBS in water quality monitoring.
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13
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Li KH, Cheung YF, Choi HW. Whispering gallery mode lasing in optically isolated III-nitride nanorings. Opt Lett 2015; 40:2564-2567. [PMID: 26030558 DOI: 10.1364/ol.40.002564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
III-nitride nanorings fabricated from a combination of hybrid-nanosphere-lithography and laser lift-off processes is demonstrated. Being formed on an interfacial metallic layer optically coupling between the optical ring and its substrate is eliminated, maximizing optical confinement of whispering gallery resonant mode within the ring cavity. The tapered cross-sectional profile also promotes coupling of emitted light into resonant modes. Optically pumped lasing with a dominant peak at 421.5 nm is observed at room temperature, with threshold energy density of ∼6.5 mJ/cm2. Etch-induced sidewall roughness causes scattering of light at the interface to diminish confinement, and is also responsible for the mode-splitting effect according to finite-difference time-domain simulations.
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14
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Hao ZQ, Li CM, Shen M, Yang XY, Li KH, Guo LB, Li XY, Lu YF, Zeng XY. Acidity measurement of iron ore powders using laser-induced breakdown spectroscopy with partial least squares regression. Opt Express 2015; 23:7795-7801. [PMID: 25837118 DOI: 10.1364/oe.23.007795] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Laser-induced breakdown spectroscopy (LIBS) with partial least squares regression (PLSR) has been applied to measuring the acidity of iron ore, which can be defined by the concentrations of oxides: CaO, MgO, Al₂O₃, and SiO₂. With the conventional internal standard calibration, it is difficult to establish the calibration curves of CaO, MgO, Al₂O₃, and SiO₂ in iron ore due to the serious matrix effects. PLSR is effective to address this problem due to its excellent performance in compensating the matrix effects. In this work, fifty samples were used to construct the PLSR calibration models for the above-mentioned oxides. These calibration models were validated by the 10-fold cross-validation method with the minimum root-mean-square errors (RMSE). Another ten samples were used as a test set. The acidities were calculated according to the estimated concentrations of CaO, MgO, Al₂O₃, and SiO₂ using the PLSR models. The average relative error (ARE) and RMSE of the acidity achieved 3.65% and 0.0048, respectively, for the test samples.
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15
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Li KH, Liu X, Wang Q, Zhao S, Mi Z. Ultralow-threshold electrically injected AlGaN nanowire ultraviolet lasers on Si operating at low temperature. Nat Nanotechnol 2015; 10:140-4. [PMID: 25599190 DOI: 10.1038/nnano.2014.308] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 11/19/2014] [Indexed: 05/22/2023]
Abstract
Ultraviolet laser radiation has been adopted in a wide range of applications as diverse as water purification, flexible displays, data storage, sterilization, diagnosis and bioagent detection. Success in developing semiconductor-based, compact ultraviolet laser sources, however, has been extremely limited. Here, we report that defect-free disordered AlGaN core-shell nanowire arrays, formed directly on a Si substrate, can be used to achieve highly stable, electrically pumped lasers across the entire ultraviolet AII (UV-AII) band (∼320-340 nm) at low temperatures. The laser threshold is in the range of tens of amps per centimetre squared, which is nearly three orders of magnitude lower than those of previously reported quantum-well lasers. This work also reports the first demonstration of electrically injected AlGaN-based ultraviolet lasers monolithically grown on a Si substrate, and offers a new avenue for achieving semiconductor lasers in the ultraviolet B (UV-B) (280-320 nm) and ultraviolet C (UV-C) (<280 nm) bands.
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Affiliation(s)
- K H Li
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - X Liu
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Q Wang
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - S Zhao
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Z Mi
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
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Wang Q, Liu X, Kibria MG, Zhao S, Nguyen HPT, Li KH, Mi Z, Gonzalez T, Andrews MP. p-Type dopant incorporation and surface charge properties of catalyst-free GaN nanowires revealed by micro-Raman scattering and X-ray photoelectron spectroscopy. Nanoscale 2014; 6:9970-9976. [PMID: 25074362 DOI: 10.1039/c4nr01608d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Micro-Raman scattering and X-ray photoelectron spectroscopy were employed to investigate Mg-doped GaN nanowires. With the increase of Mg doping level, pronounced Mg-induced local vibrational modes were observed. The evolution of longitudinal optical phonon-plasmon coupled mode, together with detailed X-ray photoelectron spectroscopy studies, show that the near-surface region of nanowires can be transformed from weakly n-type to p-type with the increase of Mg doping.
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Affiliation(s)
- Q Wang
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, QC H3A 0E9, Canada.
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Lee HL, Ho WY, Lam YL, Ng TP, Li KH, Shek T, Mak KL, Fong ST, So YC, Ngan RKC, Lau PPL, Chan ACL. Prognostic factors associated with clear cell sarcoma in 14 Chinese patients. J Orthop Surg (Hong Kong) 2014; 22:236-9. [PMID: 25163964 DOI: 10.1177/230949901402200226] [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] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
PURPOSE. To identify prognostic factors associated with clear cell sarcomas in 14 Chinese patients. METHODS. Medical records of 7 men and 7 women (mean age, 36 years) with histologically confirmed clear cell sarcoma of tendons and aponeuroses were reviewed. Patient demographics, tumour characteristics, and treatment modalities were retrieved. Prognostic factors associated with favourable 5-year survival were determined. RESULTS. The most affected sites were the thigh (n=5) and the foot (n=4); the mean time from symptom onset to diagnosis was 9.5 months. The tumour stage at diagnosis was IIA in 8 patients, IIB in 2, and III in 4. The mean tumour size was 4.5 cm in diameter. One patient was lost to follow-up. For the remaining 13 patients, the mean time to disease-related mortality was 2.5 years. Nine patients had distant metastases; the most common sites were lungs and pleura (n=7), followed by distant lymph nodes (n=4), bone (n=2), pericardium (n=2), and brain (n=1). All patients underwent surgical excision. Three women and one man (mean age, 27 years) attained 5-year disease-free survival. All had stage IIA tumours at diagnosis. Their mean tumour size was 1.75 cm in diameter, which was significantly smaller than that of all patients (4.5 cm). Tumour size of ≤ 2.5 cm in diameter (p=0.004) and stage IIA tumour at diagnosis (p=0.04) were significant prognostic factors for 5-year survival. CONCLUSION. Tumour size of ≤ 2.5 cm and early stage tumour are associated with 5-year disease-free survival. Early detection is crucial for the prognosis of clear cell sarcomas.
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Affiliation(s)
- H L Lee
- Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong
| | - W Y Ho
- Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong
| | - Y L Lam
- Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong
| | - T P Ng
- Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong
| | - K H Li
- Department of Surgery, Queen Mary Hospital, Hong Kong
| | - T Shek
- Department of Pathology, Queen Mary Hospital, Hong Kong
| | - K L Mak
- Department of Orthopaedics and Traumatology, Queen Elizabeth Hospital, Hong Kong
| | - S T Fong
- Department of Orthopaedics and Traumatology, Queen Elizabeth Hospital, Hong Kong
| | - Y C So
- Department of Orthopaedics and Traumatology, Queen Elizabeth Hospital, Hong Kong
| | - R K C Ngan
- Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong
| | - P P L Lau
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong
| | - A C L Chan
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong
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18
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Yu Y, Guo LB, Hao ZQ, Li XY, Shen M, Zeng QD, Li KH, Zeng XY, Lu YF, Ren Z. Accuracy improvement on polymer identification using laser-induced breakdown spectroscopy with adjusting spectral weightings. Opt Express 2014; 22:3895-3901. [PMID: 24663709 DOI: 10.1364/oe.22.003895] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A new approach to polymer identification by laser-induced breakdown spectroscopy (LIBS) with adjusting spectral weightings (ASW) was developed in this work aiming at improving the identification accuracy. This approach has been achieved through increasing the intensities of specific characteristic spectral lines which are important to polymer identification but difficult to be excited. Using the ASW method, the identification accuracies of all 11 polymers were increased to nearly 100%, while the accuracies of PE, PU, PP and PC were only 98%, 74%, 90% and 98%, respectively, without using the ASW method.
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Li KH, Sun BH, Zhu Y, Long HT. Locked pubic symphysis into the obturator foramen: a rare case presentation and literature review. Orthop Traumatol Surg Res 2013; 99:106-10. [PMID: 23270720 DOI: 10.1016/j.otsr.2012.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 07/27/2012] [Accepted: 08/21/2012] [Indexed: 02/02/2023]
Abstract
Locked pubic symphysis is a rare form of pelvic injury. It occasionally occurs after a lateral compression injury of the pelvis. We described an overlapping pubic symphysis dislocation that was locked into the contralateral obturator foramen. To the best of our knowledge, there are about seventeen similar cases reported in the literature. The pubic symphysis was finally reduced by means of a superior pubic ramus osteotomy to unlock the incarcerated pubic body out of the contralateral obturator foramen. As the reduction was unstable, the pubic symphysis was fixed with a reconstruction plate. The patient recovered completely and returned to normal activities within 4months. At 1year's follow-up she reported no discomfort in the pubic symphysis region and was able to void urine normally.
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Affiliation(s)
- K H Li
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China
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Abstract
An ordered hexagonal closed-packed nanopillar array is fabricated on GaN. A metal coating is then applied to encapsulate the pillars for promoting optical confinement within the cylindrical cavity. Room-temperature lasing at 373 nm is observed under pulsed excitation, at a lasing threshold of 0.42 MW/cm2. With pillar diameters of around 980 nm, the number of modes overlapping the emission spectrum is reduced, giving rise to single-mode whispering gallery stimulated emission. Finite-difference time-domain simulations are carried out for the prediction of resonant frequencies and electric field patterns corresponding to the resonant modes.
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Affiliation(s)
- K H Li
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
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Gao SG, Li KH, Zeng KB, Tu M, Xu M, Lei GH. Elevated osteopontin level of synovial fluid and articular cartilage is associated with disease severity in knee osteoarthritis patients. Osteoarthritis Cartilage 2010; 18:82-7. [PMID: 19747583 DOI: 10.1016/j.joca.2009.07.009] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 07/27/2009] [Accepted: 07/31/2009] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate osteopontin (OPN) levels in both synovial fluid and articular cartilage of patients with primary knee osteoarthritis (OA) and their relationship with severity of the disease. METHOD Fifty patients aged 48-81 years with knee OA and 10 healthy controls were enrolled in this study. Anteroposterior knee radiographs or/and Mankin score were taken to determine the disease severity of the affected knee. The radiographic grading of OA in the knee was performed by using the Kellgren-Lawrence criteria. OPN levels in synovial fluid were measured using enzyme-linked immunosorbent assay. OPN levels in articular cartilage were assessed by immunohistochemical methods. RESULTS Compared to healthy controls, OA patients had higher OPN concentration in synovial fluid (4519.60+/-1830.37, 95%CI 3999.42-5039.79 vs 1179.70+/-303.39, 95%CI 1035.53-1438.74 pg/ml, P<0.001)and articular cartilage(0.6+/-0.06, 95%CI 0.59-0.62 vs 0.43+/-0.07, 95%CI 0.38-0.48, P<0.01). In addition, synovial fluid OPN levels showed a positive correlation with articular cartilage OPN levels (r=0.411, 95%CI 0.150-0.619, P=0.003). Subsequent analysis showed that synovial fluid OPN levels significantly correlated with severity of disease (Spearman's rho=0.581, 95%CI 0.335-0.726, P<0.001). Furthermore, the articular cartilage levels of OPN also correlated with disease severity (Spearman's rho=0.675, 95%CI 0.500-0.808, P<0.001). CONCLUSIONS OPN in synovial fluid and articular cartilage is associated with progressive joint damage and is likely to be a useful biomarker for determining disease severity and progression in knee OA.
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Affiliation(s)
- S G Gao
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China
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22
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Au WY, Ooi CGC, Li KH, Shek TW, Liang R. Challenges in oncology. Case 1. Oncology emergencies: a myeloma patient with stridor. J Clin Oncol 2002; 20:866-7. [PMID: 11821472 DOI: 10.1200/jco.2002.20.3.866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- W Y Au
- Queen Mary Hospital, University of Hong Kong, Hong Kong
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Abstract
AIMS Tumour vascularity is considered a prognostic indicator in breast carcinoma, but its utility in mammary phyllodes tumour has not been explored. The authors report the correlation between intratumoral microvessel density and the histological grade of phyllodes tumour. METHODS AND RESULTS Forty cases of phyllodes tumour were reviewed for stromal cellularity, overgrowth, cytological pleomorphism, mitotic count and margin pattern. Using established criteria, these were diagnosed as benign (n=28), borderline (n=10) and malignant (n=2). Microvessel density was counted on CD31-stained slides as the number of vessels per high power field. For benign phyllodes tumour, the range was 7-26.2 (mean 13.1); for borderline phyllodes tumour the range was 17.2-32.5 (mean 22.4); for malignant phyllodes tumour the range was 25.9-33.3 (mean 29.6). The difference between the benign and borderline groups was significant (P < 0.0001) but that between the borderline and malignant groups was not, due to the small number of malignant cases. CONCLUSIONS There is a significant difference in stromal microvessel density between benign and borderline phyllodes tumour. Although the small number of cases of malignant phyllodes tumour limits further interpretation, we believe that microvessel density can be used as an additional objective histological parameter in the evaluation of phyllodes tumour.
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Affiliation(s)
- G M Tse
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Shatin, China.
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Xiao T, Fang JZ, Li KH. [Study on in vitro nitric oxide and interleukin-6 levels induced from peripheral mononuclear cells in patients with osteosarcoma]. Hunan Yi Ke Da Xue Xue Bao 2001; 26:139-40. [PMID: 12536647] [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: 02/28/2023]
Abstract
Peripheral blood mononuclear cells from 32 cases of osteosarcoma and 20 normal controls were separated and induced by lipopolysaccharide, followed by 48 hour incubation in vitro, then the supernatant were collected. The levels of IL-6 were measured by enzyme linked immunosorbent assays, the concentrations of NO were measured by Griess methods. The results were as follows: The concentrations of IL-6 and NO were significantly higher than those in normal controls (P < 0.01). There were positive correlation between the levels of IL-6 and NO in patients with osteosarcoma (r = 0.652, P < 0.01). The results suggest that the immune function of peripheral mononuclear cell in patients with osteosarcoma was disordered. It may activate peripheral mononuclear cells to produce high levels of IL-6 and NO, which may take part in the pathogenesis of osteosarcoma.
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Affiliation(s)
- T Xiao
- Department of Orthopaedics, Second Xiangya Hospital, Changsha 410011
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Wang XY, Li KH, Wang WG. [Experimental study of tendon allograft]. Hunan Yi Ke Da Xue Xue Bao 2000; 25:138-40. [PMID: 12212200] [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: 02/26/2023]
Abstract
A series of immunologic tests, including lymphocyte cell toxicity test, as well as lymphocyte transformation test, macrophage function test, histological examination, and biomechanical measurement were carried out in guinea pigs to compare the effect of deep freezing(Group I) with deep freeze drying(Group II) on tendon allografts. The results revealed that the lymphocyte mortality, lymphocytic-transformed rate and phagocytizing rate of the macrophages in Group I and Group II were lower than those in non-processed allograft group (Group III) and had no statistical difference among Group I, Group II and Group III. As compared with the non-processed allograft, the freezed and freeze-dried allografts showed ameliorated immunologic reactions, mild morphological lesion and better mechanical strength after transplantation. The results suggest that deep freezing and deep freeze-drying processing are valid measures in tendon allograft treatment.
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Affiliation(s)
- X Y Wang
- Department of Ortheopedics, Xiangya Hospital, Hunan Medical University, Changsha 410008
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Lei GH, Zhou JN, Li KH, Li J. [Myelopathy-hand and cervical spondylotic myelopathy]. Hunan Yi Ke Da Xue Xue Bao 2000; 25:179-80. [PMID: 12212216] [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: 02/26/2023]
Abstract
The clinical manifestations and MRI characteristics of 58 patients with cervical spondylotic myelopathy were analysed in this study. The results showed that there was myelopathy-hand in 49 patients and none in 9 patients. Two groups were not significantly different in gender, age, course and involved segment, side or level of spinal cord(P > 0.05), but were significantly different in the compression degree of spinal cord(P < 0.01). In the positive group, the degree of myelopathy-hand was positively related to the severity of spastic gait, pyramidal tract sign and spinal cord compression.
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Affiliation(s)
- G H Lei
- Department of Orthopaetics, Xiangya Hospital, Hunan Medical University, Changsha 410008
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Li KH, Sawamura D, Giudice GJ, Diaz LA, Mattei MG, Chu ML, Uitto J. Genomic organization of collagenous domains and chromosomal assignment of human 180-kDa bullous pemphigoid antigen-2, a novel collagen of stratified squamous epithelium. J Biol Chem 1991; 266:24064-9. [PMID: 1748679] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have recently isolated a 1.0-kilobase (kb) cDNA encoding 180-kDa bullous pemphigoid antigen (BPAG2), an autoantigen in blistering skin disease, bullous pemphigoid (Giudice, G. J., Squiquera, H. L., Elias, P. M., and Diaz, L. (1991) J. Clin. Invest. 87, 734-738). The deduced amino acid sequence identified two collagenous domains characterized by Gly-X-Y repeats. In this study we have elucidated the genomic organization of the corresponding segment in the human BPAG2 gene. Screening of a genomic lambda-phage DNA library yielded six overlapping clones, and the sequences corresponding to the 1.0-kb cDNA spanned approximately 12 kb of genomic DNA. The coding segment consisted of 19 separate exons varying in size from 27 to 222 base pairs. The organization of these exons and the splice sites at the intron-exon junctions were clearly different from other fibrillar and nonfibrillar collagen genes described to date. The BPAG2 gene was mapped by chromosomal in situ hybridization to the long arm of human chromosome 10, at locus 10q24.3; this location is distinct from any previously mapped collagens, and it also distinguishes BPAG2 from BPAG1, a 230-kDa bullous pemphigoid antigen, which has been mapped to chromosome 6p (Sawamura, D., Nomura, K., Sugita, Y., Mattei, M.-G., Chu, M.-L., Knowlton, R.G., and Uitto, J. (1990) Genomics 8, 722-726). These data suggest that BPAG2 is a novel collagen present in stratified squamous epithelia.
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Affiliation(s)
- K H Li
- Department of Dermatology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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Ryynänen M, Knowlton RG, Kero M, Sawamura D, Li KH, Giudice GJ, Diaz LA, Uitto J. Bullous pemphigoid antigens (BPAGs): identification of RFLPs in human BPAG1 and BPAG2, and exclusion as candidate genes in a large kindred with dominant epidermolysis bullosa simplex. Genomics 1991; 11:1025-9. [PMID: 1686013 DOI: 10.1016/0888-7543(91)90028-d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Bullous pemphigoid antigens (BPAGs) are defined as autoantigens in a blistering skin disease, bullous pemphigoid. Two of the BPAGs, a 230-kD (BPAG1) and a 180-kD (BPAG2) protein, have been localized to hemidesmosomes, attachment structures at the basal keratinocyte-basement membrane interphase. We have recently cloned cDNAs corresponding to human BPAG1 and BPAG2, and mapped the corresponding genes to human chromosomes 6p and 10q, respectively. These cDNAs have now been used in a search for RFLPs in the corresponding genes. Southern hybridizations of genomic DNA from normal unrelated individuals with a BPAG1 cDNA detected an informative MspI RFLP, and similar hybridizations with a BPAG2 cDNA revealed an informative TaqI RFLP. These RFLPs were applied to a large kindred with epidermolysis bullosa simplex (EBS), generalized (Koebner) type, consisting of 14 affected and 12 unaffected individuals in three generations. Linkage analysis excluded the EBS locus in this pedigree approximately 9 cM and approximately 5 cM on either side of the BPAG1 and BPAG2 loci, respectively, when a lod score of -2.0 was taken as the limit of exclusion. This study demonstrates that mutations in the BPAG1 or BPAG2 genes are not the primary genetic defect in this family with EBS.
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Affiliation(s)
- M Ryynänen
- Department of Dermatology, Jefferson Medical College, Philadelphia, Pennsylvania
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Sawamura D, Li KH, Nomura K, Sugita Y, Christiano AM, Uitto J. Bullous pemphigoid antigen: cDNA cloning, cellular expression, and evidence for polymorphism of the human gene. J Invest Dermatol 1991; 96:908-15. [PMID: 2045679 DOI: 10.1111/1523-1747.ep12475433] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A human epidermal keratinocyte lambda gt11 recombinant cDNA library was screened with a 0.45-kb cDNA that was generated by polymerase chain reaction (PCR) amplification of a segment of human bullous pemphigoid (BP) antigen mRNA. The screen yielded five clones, the largest one, pcBPA-4, being 2.3 kb in size. The pcBPA-4 cDNA hybridized in Northern analyses with an approximately 9-kb mRNA from cultured keratinocytes, whereas no hybridization signal was detected with RNA from human skin fibroblast, fibrosarcoma HT-1080 cells, or amniotic epithelial WISH cell cultures. Nucleotide sequencing of pcBPA-4 revealed an open reading frame encoding a putative polypeptide of 447 amino acids. This polypeptide showed 88% homology with corresponding mouse BP antigen sequences, and a region of it was identical to a segment in previously published human BP antigen sequences. The 2.3-kb cDNA isolated here was different from a previously published human BP antigen cDNA, in that the open reading frame coded for 264 additional amino acids at the carboxyl end of the putative polypeptide. Known human BP antigen amino acid sequences, compared with mouse sequences, were predicted to be moderately divergent with a unit of evolutionary period (UEP) of 4.5 millions of years (MY). Southern hybridizations suggested that the BP antigen gene (BPAG1) is present as a single copy in the human genome. Southern analyses also revealed the presence of a StuI restriction fragment length polymorphism that can be used for linkage analyses to study the inheritance of a particular BPAG1 allele and a heritable cutaneous disorder affecting the basement membrane zone, such as epidermolysis bullosa.
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Affiliation(s)
- D Sawamura
- Department of Dermatology, Jefferson Medical College, Philadelphia, Pennsylvania
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Woo J, Or KH, Suen WM, Li KH, McGuire L. Pheochromocytoma masquerading as a hematological problem. Pathology 1990; 22:245-6. [PMID: 2091008 DOI: 10.3109/00313029009086674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Abstract
By comparing the theoretically expected results of photon emission from a chaotic (thermal) field and those of an ordered (fully coherent) field with the actual experimental data, one finds ample indications for the hypothesis that 'biophotons' originate from a coherent field occurring within living tissues. A direct proof may be seen in the hyperbolic relaxation dynamics of spectral delayed luminescence under ergodic conditions. A possible mechanism has to be founded on Einstein's balance equation and, under stationary conditions, on energy conservation including a photochemical potential. It is shown that the considered equations deliver, besides the thermal equilibrium, a conditionally stable region far away from equilibrium, which can help to describe both 'biophoton emission' and biological regulation.
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Affiliation(s)
- F A Popp
- Institute of Biophysical Cell Research, Technology Center, Kaiserslautern, Federal Republic of Germany
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Popp FA, Nagl W, Li KH, Scholz W, Weingärtner O, Wolf R. Biophoton emission. New evidence for coherence and DNA as source. Cell Biophys 1984; 6:33-52. [PMID: 6204761 DOI: 10.1007/bf02788579] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The phenomenon of ultraweak photon emission from living systems was further investigated in order to elucidate the physical properties of this radiation and its possible source. We obtained evidence that the light has a high degree of coherence because of (1) its photon count statistics, (2) its spectral distribution, (3) its decay behavior after exposure to light illumination, and (4) its transparency through optically thick materials. Moreover, DNA is apparently at least an important source, since conformational changes induced with ethidium bromide in vivo are clearly reflected by changes of the photon emission of cells. The physical properties of the radiation are described, taking DNA as an exciplex laser system, where a stable state can be reached far from thermal equilibrium at threshold.
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