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Seet A, Macapagal M, Ahmad A, Li G, Goh M, Ng M, Tan T, Tan D, Choo S, Lim W, Tai D. A phase I open-label, non-randomized study of recombinant super-compound interferon (rSIFN-co) in patients with advanced solid tumours. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz244.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Khanna S, Newman JM, Gan G, Bhat A, Chen H, Tan T. P4353Global longitudinal strain is a measure of subclinical left ventricular dysfunction in chronic inflammatory autoimmune conditions. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz745.0760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Myocardial deformation indices are proposed to be a more sensitive marker of subclinical dysfunction compared to standard measures of left ventricular (LV) systolic function. We hypothesize that subclinical myocardial dysfunction is present in chronic inflammatory autoimmune diseases such as Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA), despite both conditions being mediated by different pro-inflammatory modulators.
Purpose
Identify subclinical myocardial dysfunction through assessment of global longitudinal strain in two different chronic autoimmune conditions, SLE and RA.
Methods
Consecutive patients admitted to our institution with known history of SLE or RA (>1 year disease activity) were examined. Patients with preexisting cardiac disease, LVEF <50% and those without comprehensive transthoracic echocardiograms (TTE) were excluded. Mean longitudinal LV strain was performed offline using vendor-independent software (TomTec v4.6) and compared to age- and gender-matched controls with normal LV function and no history of cardiac disease.
Results
Of the 86 patients examined (mean age 53.01±21.74, 85.4% female), 51 (59.3%) had SLE and 35 (40.7%) had RA. No significant difference in BMI, hypertension, hypercholesterolemia, diabetes, obesity, obstructive sleep apnea and stroke was observed between controls and patients with SLE or RA. While there was no significant difference in LVEF between RA patients and matched controls, there was a significantly lower GLS in the RA cohort. Conversely, patients with SLE had significantly lower LVEF and GLS when compared to matched controls, despite LVEF being in the normal range. See Table 1. Receiver operator curve analysis revealed that mean GLS is a better discriminator for autoimmune disease with an area under the curve of 0.829 (95% CI, 0.77 to 0.89; p<0.01) compared to LVEF with an area under the curve of 0.632 (95% CI, 0.55 to 0.72; p<0.01).
Echocardiographic Parameters SLE (n=51) Controls (n=51) Sig (p value) RA (n=35) Controls (n=35) Sig (p value) LVEDV (mls) 102±30 85±20 <0.01 84±28 89±30 0.43 LVESV (mls) 36±17 29±9 0.02 26±14 30±12 0.24 Biplane LVEF % 59±6 63±4 <0.01 62±6 62±5 0.81 LV Mass (grams/m2) 96±34 72±20 <0.01 79±26 82±23 0.67 LV Mean GLS % 16.7±2.8 21.3±2 <0.01 17.8±1.7 19.1±2.5 0.02
Conclusions
Our results suggest that chronic inflammatory conditions (SLE and RA) are associated with subclinical cardiac dysfunction. Impaired GLS may reflect early myocardial damage and be used as a tool for screening of patients with inflammatory conditions.
Acknowledgement/Funding
None
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Zhang Z, Lian W, Lim E, Kumar R, Wong F, Tang T, Dent R, Tan T. Hepatitis B screening and incidence of flare among non-metastatic breast cancer patients treated with anthracyclines. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz240.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Bartko PE, Arfsten H, Frey M, Heitzinger G, Pavo N, Cho ANNA, Neuhold S, Tan T, Strunk G, Hengstenberg C, Huelsmann M, Goliasch G. 5937Natural history of functional tricuspid regurgitation: implications of quantitative doppler assessment. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Objectives
To establish the prognostic value of quantitative measures of functional tricuspid regurgitation (TR) severity i.e. effective regurgitant orifice area (EROA) and regurgitant volume.
Methods
382 patients with HFrEF on guideline-directed medical therapy were enrolled and TR EROA as well as regurgitant volume by Doppler/2D-echocardiography were assessed. All-cause mortality was defined as the primary study endpoint.
Results
Quantitative metrics of TR severity were consistently associated with mortality with a HR of 1.27 (95% CI 1.13–1.42, P<0.001) for the EROA and of 1.29 (95% CI 1.14–1.45, P<0.001) for the regurgitant volume (Figure 1, Panels A and B). Results remained unchanged after bootstrap- or clinical confounder-based adjustment. A spline curve pattern illustrates the association with mortality with thresholds for the EROA≥0.2cm2, and the regurgitant volume≥20ml with sustained excess mortality thereafter (Figure 1 Panels C-D).
Figure 1. Panels A–D
Conclusions
This large-scale study demonstrates the prognostic value of quantitative measures of TR severity in HFrEF. Thresholds for EROA and TR regurgitant volume associated with mortality fall within current ranges defining non-severe TR. This may potentially impact therapeutic decision making particularly timing of intervention.
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Irwin R, Stanescu S, Buzaianu C, Rademan M, Roddy J, Gormley C, Tan T. Quadratus lumborum block for analgesia after caesarean section: a randomised controlled trial. Anaesthesia 2019; 75:89-95. [DOI: 10.1111/anae.14852] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2019] [Indexed: 12/13/2022]
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Boyd SC, O'Connor AD, Horan MA, Dicker P, Manning C, Lynch C, Regan C, Ryan K, Tan T, Byrne BM. Analgesia, anaesthesia and obstetric outcome in women with inherited bleeding disorders. Eur J Obstet Gynecol Reprod Biol 2019; 239:60-63. [PMID: 31185377 DOI: 10.1016/j.ejogrb.2019.05.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/28/2019] [Accepted: 05/30/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Vertebral canal haematoma (VCH) complicates 1 in 168,000 obstetric epidurals (Ruppen et al., 2006). This risk is increased in women with inherited bleeding disorders (IBD). The impact of a contraindication to regional anaesthesia on pain management and obstetric outcome in these women is unknown. The purpose of this study was to determine anaesthetic use and obstetric outcomes in a cohort of women with IBD. STUDY DESIGN 97 women with IBD that delivered 130 babies at the CWIUH from Jan 2011 to Dec 2016 were identified from a maternal medicine database. Multidisciplinary planning of peripartum care was communicated to labour ward staff using a simple checklist. The primary bleeding disorders were: Von Willebrands disease (VWD) Type 1 27 (27.8%); VWD Type 2A 3 (3.8%); Low VWF 3 (3.8%); Bleeding disorder of unknown aetiology (BDUA) 19 (19.6%); deficiency of Factors VII, VIII, IX, X, and XI 13 (13.4%); Carriers of Factor VIII, IX, X, XIII deficiency 17 (17.5%); 5 had combined deficiencies (5.2%) and there was one platelet function defect. 9 had a family history of a bleeding disorder (9.3%). Haemostatic support, analgesia, mode of delivery and maternal and fetal outcomes were compared between pregnancies where regional anaesthesia was permitted and those that were not using the Chi-squared test. RESULTS When pregnancies where regional anaesthesia was not recommended (49) were compared with pregnancies where regional anaesthesia was considered safe (81), the women were more likely to see an anaesthetist before labour 46 (94%) vs 46 (61%): p < 0.001; to require prophylactic haemostatic support for delivery 30 (61%) vs 1 (1%): p < 0.001; to use a remifentanil infusion 15 (31%) vs 0: p < 0.001, and have general anaesthesia for Caesarean Section (CS) 10 (20%) vs 1(1%): p < 0.001. Vaginal birth 35 (71%) vs 53(65%): p = 0.4 and CS rates 14 (29%) vs 26 (32%) p = 0.28 were similar. Postpartum haemorrhage (PPH) was more common 11 (24%) vs 9(12%) vs p = 0.07 but not statistically so. There were no cases of neonatal bleeding or VCH. CONCLUSION Contraindication to neuraxial blockade in labouring women with IBD does not influence mode of delivery. This information is reassuring to these women who may be anxious about delivery without regional anaesthesia.
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Wang J, Wang G, Tan T, Zhu G, Sun C, Cao Z, Chen W, Gao X. Mid-infrared laser heterodyne radiometer (LHR) based on a 3.53 μm room-temperature interband cascade laser. OPTICS EXPRESS 2019; 27:9610-9619. [PMID: 31045110 DOI: 10.1364/oe.27.009610] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 03/14/2019] [Indexed: 06/09/2023]
Abstract
The performance of an interband cascade laser based laser heterodyne radiometer (LHR) is demonstrated in ground-based solar occultation mode. High-resolution (0.0033 cm-1) transmission spectra near 3.53 μm were obtained for simultaneous atmospheric observations of H2O and CH4. Combined with the preprocessed measurement data (acquired at Hefei, China, on June 21th 2016), an optimal estimation method based retrieval algorithm is developed for data retrieval and error analysis. By considering the corrected atmospheric parameters, vertical profiles of H2O and CH4 are retrieved. Finally, the measured total column abundance and XCH4 were calculated to be 1.87 ± 0.02 ppm and 1.88 ± 0.02 ppm, respectively. The interband cascade laser-based laser heterodyne radiometer that is demonstrated in this manuscript has high potential for use in the development of compact, robust, and unattended LHR for spacecraft, airborne or ground-based atmospheric sensing.
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Rubino P, Ruiz de Assin Alonso R, Dearden L, Guan L, Mazmanian K, Tapia L, Thiel A, Kolb B, Wilcox J, Nelson J, Norian J, Tan T. The blastocyst re-expansion status after thawing do not seem to affect the clinical outcomes in freeze all preimplantation genetic testing (PGT) cycles. Fertil Steril 2019. [DOI: 10.1016/j.fertnstert.2019.02.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Khanna S, Gan G, Gupta K, Khan W, Bhat A, Chen H, Tan T. Characterisation of Right Ventricular Size and Systolic Function in a Cohort of Myocarditis Patients with Normal LVEF. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.06.252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Khanna S, Gan G, Gupta K, Khan W, Tan W, Chen H, Bhat A, Tan T. Characterisation of Left Ventricular Shape Change as Defined by Sphericity Index in Patients with Acute Phase Takotsubo Cardiomyopathy and Anterior STEMI Patients. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.06.250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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86
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Chen H, Bhat A, Makarious D, Ng C, Khanna S, Gan G, Tan T. Characterisation of Right Heart Function in Patients with Non-Ischaemic Cardiomyopathy. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.06.251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Thangarajah M, Porter R, MacIntyre R, Tan T. Uptake of Influenza, Pneumococcal and Herpes Zoster Vaccination as a Preventative Strategy for Adverse Cardiovascular Outcomes in a High-Risk Cohort of Patients with Chronic Heart Failure. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.06.147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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88
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John S, Bhat A, Gan G, Tan T. Prospective Comparison of Semi-Automated 2-Dimensional Global Longitudinal Strain Measurements using three Different Software Programs in a Busy Clinical Setting. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.06.308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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89
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Chen H, Chiang B, Bhat A, Khanna S, Kayes T, Gan G, Tan T. Changes in Left Ventricular Structure and Function with Increasing Body Mass Index. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.06.248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Bhat A, Chen H, Rao A, Latumahina A, Tan T, Gan G, Sindone A. Target Heart Rate Versus Beta Blocker Dosage in Patients with Heart Failure with Reduced Ejection Fraction. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.06.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Black MH, Almabruk T, Albrecht MA, Chen NT, Lipp OV, Tan T, Bolte S, Girdler S. Altered Connectivity in Autistic Adults during Complex Facial Emotion Recognition: A Study of EEG Imaginary Coherence. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:2752-2755. [PMID: 30440971 DOI: 10.1109/embc.2018.8512802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Difficulties in Facial Emotion Recognition (FER) are commonly associated with individuals diagnosed with Autism Spectrum Disorder (ASD). However, the mechanisms underlying these impairments remain inconclusive. While atypical cortical connectivity has been observed in autistic individuals, there is a paucity of investigation during cognitive tasks such as FER. It is possible that atypical cortical connectivity may underlie FER impairments in this population. Electroencephalography (EEG) Imaginary Coherence was examined in 22 autistic adults and 23 typically developing (TD) matched controls during a complex, dynamic FER task. Autistic adults demonstrated reduced coherence between both short and long range inter-hemispheric electrodes. By contrast, short range intra-hemispheric connectivity was increased in frontal and occipital regions during FER. These findings suggest altered network functioning in ASD.
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Han X, Tan T, Sun J, Chen X, Cai X, Lin P, Tan Y, Wang B, Wang Y, Wang J, Yu Z, Wu X, Xu Q, Gu Y. Resistance to anti-PD-1 therapy is associated with the retention of CXCR3+ CD4+ CD8- T cells in blood. Ann Oncol 2018. [DOI: 10.1093/annonc/mdy288.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Rubino P, Dearden L, Ruiz de Assin Alonso R, Guan L, Mazmanian K, Thiel A, Hernandez L, Li X, Sinogaya P, Lew J, Nelson J, Norian J, Kolb B, Wilcox J, Tan T. Embryos classified as low-grade mosaic (<50%) after preimplantation genetic screening (PGS) can have the same competence of producing healthy newborns as euploid embryos. Fertil Steril 2018. [DOI: 10.1016/j.fertnstert.2018.07.1167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Wang R, Zeng Y, Qin H, Lu Y, Huang H, Lei M, Tan T, Huang Y, Luo H, Lan Y, Wei Y. Association of interleukin 22 gene polymorphisms and serum IL-22 level with risk of systemic lupus erythematosus in a Chinese population. Clin Exp Immunol 2018; 193:143-151. [PMID: 29603203 PMCID: PMC6046499 DOI: 10.1111/cei.13133] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2018] [Indexed: 01/12/2023] Open
Abstract
The aim of this study was to investigate the association between the single-nucleotide polymorphisms (SNPs) of the interleukin 22 (IL-22) gene and systemic lupus erythematosus (SLE) in a Chinese population. Three IL-22 SNPs (rs2227485, rs2227513 and rs2227491) were genotyped using SNaPshot SNP genotyping assays and identified by sequencing in 314 SLE patients and 411 healthy controls. The IL-22 level of serum was assessed by enzyme-linked immunosorbent assay (ELISA) kits. Data were analysed by spss version 17.0 software. We found that rs2227513 was associated with an increased risk of SLE [AG versus AA: adjusted odds ratio (aOR) = 2·24, 95% confidence interval (CI) = 1·22-4·12, P = 0·010; G versus· A: adjusted OR = 2·18, 95% CI = 1·20-3·97, P = 0·011]. Further analysis in patients with SLE showed that the AG genotype and G allele were associated with an increased risk of renal disorder in SLE (G versus A: aOR = 3·09, 95% CI = 1·30-7·33, P = 0·011; AG versus· AA: aOR = 3·25, 95% CI = 1·35-7·85, P = 0·009). In addition, the concentration of IL-22 was significantly lower in the rs2227513 AG genotype compared with AA genotype (P = 0·028). These results suggest that rs2227513 polymorphism might contribute to SLE susceptibility, probably by decreasing the expression of IL-22.
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Shohat N, Foltz C, Restrepo C, Goswami K, Tan T, Parvizi J. Increased postoperative glucose variability is associated with adverse outcomes following orthopaedic surgery. Bone Joint J 2018; 100-B:1125-1132. [DOI: 10.1302/0301-620x.100b8.bjj-2017-1283.r1] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Aims The aim of this study was to examine the association between postoperative glycaemic variability and adverse outcomes following orthopaedic surgery. Patients and Methods This retrospective study analyzed data on 12 978 patients (1361 with two operations) who underwent orthopaedic surgery at a single institution between 2001 and 2017. Patients with a minimum of either two postoperative measurements of blood glucose levels per day, or more than three measurements overall, were included in the study. Glycaemic variability was assessed using a coefficient of variation (CV). The length of stay (LOS), in-hospital complications, and 90-day readmission and mortality rates were examined. Data were analyzed with linear and generalized linear mixed models for linear and binary outcomes, adjusting for various covariates. Results The cohort included 14 339 admissions, of which 3302 (23.0%) involved diabetic patients. Patients with CV values in the upper tertile were twice as likely to have an in-hospital complication compared with patients in the lowest tertile (19.4% versus 9.0%, p < 0.001), and almost five times more likely to die compared with those in the lowest tertile (2.8% versus 0.6%, p < 0.001). Results of the adjusted analyses indicated that the mean LOS was 1.28 days longer in the highest versus the lowest CV tertile (p < 0.001), and the odds of an in-hospital complication and 90-day mortality in the highest CV tertile were respectively 1.91 (p < 0.001) and 2.10 (p = 0.001) times larger than the odds of these events in the lowest CV tertile. These associations were significant even for non-diabetic patients. After adjusting for hypoglycaemia, the relationships remained significant, except that the CV tertile no longer predicted mortality in diabetics. Conclusion These results indicate that higher glycaemic variability is associated with longer LOS and in-hospital complications. Glycaemic variability also predicted death, although that primarily held for non-diabetic patients in the highest CV tertile following orthopaedic surgery. Prospective studies should examine whether ensuring low postoperative glycaemic variability may reduce complication rates and mortality. Cite this article: Bone Joint J 2018;100-B:1125–32.
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Almabruk T, Tan T, Khan MM. EEG Based Network Connectivity Classification in 7 and 9 Years- Old Children. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:243-246. [PMID: 30440383 DOI: 10.1109/embc.2018.8512187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Investigating the brain neural pathways requires extensive knowledge of childrens' cognitive development. Significant variations in the cognitive process of a child, across ages, were assessed through the success in recognizing various stimuli. Longitudinal EEG data were gathered from 45 healthy children at the ages of seven and nine years. During the EEG data acquisition, children were asked to respond to the Flanker stimuli for investigating the development of the response conflict process. In each age group, the coherence and imaginary component of coherency were used to assess the network connectivity of each child. The congruent and incongruent stimuli were tried within delta, theta, alpha and beta bands. Following that, efficacies of various classification algorithms were tested in discriminating the coherency data of the two age groups. It was observed that brain connectivity was more helpful in distinguishing between two age groups using the incongruent Flanker stimuli. For the incongruent condition, the imaginary part of the coherency provides better features for classification. Using the features derived from the theta, alpha and beta bands, a classification accuracy of more than 94.31% could be achieved using the naïve Bayes classifier.
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Zhao Q, Wu Z, Zhang Z, Lin W, Li C, Guan X, Tan T, Yang C, Cheng H, Gan J, Feng Z, Peng M, Yang Z, Xu S. Stable actively Q-switched single-frequency fiber laser at 1.5 μm based on self-injecting polarization modulation. OPTICS EXPRESS 2018; 26:17000-17008. [PMID: 30119516 DOI: 10.1364/oe.26.017000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/13/2018] [Indexed: 06/08/2023]
Abstract
A new technique for the realization of a stable Q-switched operation in a single-frequency fiber laser based on self-injecting polarization modulation is demonstrated, for the first time to the best of our knowledge. A piezoelectric fiber stretcher was utilized to introduce periodic stress-induced polarization changes. Then the modulation of polarization state transformed into Q switching by virtue of a designed distributed Bragg reflector (DBR) resonant cavity with polarizations loss anisotropy. Finally, a stable actively Q-switched single-frequency fiber laser at 1.5 μm with Gaussian-shape pulse output was achieved. We experimentally found that, the repetition frequency (several hundred kHz) coincided with the working frequency of the polarization modulation, and the pulse width (several hundred ns) reduced with the increasing of the modulating frequency, the modulating amplitude, as well as the pump power. This stable Q-switched single-frequency fiber laser is promising for applications in optical time-domain reflectometry, coherent Doppler wind radar, and optical coherent detection. More importantly, this novel Q-switched technology may be applicable to other DBR single-frequency fiber lasers.
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Scott R, Minnion J, Tan T, Bloom SR. Oxyntomodulin analogue increases energy expenditure via the glucagon receptor. Peptides 2018; 104:70-77. [PMID: 29680267 PMCID: PMC5958244 DOI: 10.1016/j.peptides.2018.04.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/03/2018] [Accepted: 04/10/2018] [Indexed: 01/12/2023]
Abstract
The gut hormone oxyntomodulin (OXM) causes weight loss by reducing appetite and increasing energy expenditure. Several analogues are being developed to treat obesity. Exactly how oxyntomodulin works, however, remains controversial. OXM can activate both glucagon and GLP-1 receptors but no specific receptor has been identified. It is thought that the anorectic effect occurs predominantly through GLP-1 receptor activation but, to date, it has not been formally confirmed which receptor is responsible for the increased energy expenditure. We developed OX-SR, a sustained-release OXM analogue. It produces a significant and sustained increase in energy expenditure in rats as measured by indirect calorimetry. We now show that this increase in energy expenditure occurs via activation of the glucagon receptor. Blockade of the GLP-1 receptor with Exendin 9-39 does not block the increase in oxygen consumption caused by OX-SR. However, when activity at the glucagon receptor is lost, there is no increase in energy expenditure. Glucagon receptor activity therefore appears to be essential for OX-SR's effects on energy expenditure. The development of future 'dual agonist' analogues will require careful balancing of GLP-1 and glucagon receptor activities to obtain optimal effects.
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Kozegar E, Soryani M, Behnam H, Salamati M, Tan T. Mass Segmentation in Automated 3-D Breast Ultrasound Using Adaptive Region Growing and Supervised Edge-Based Deformable Model. IEEE TRANSACTIONS ON MEDICAL IMAGING 2018; 37:918-928. [PMID: 29610071 DOI: 10.1109/tmi.2017.2787685] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Automated 3-D breast ultrasound has been proposed as a complementary modality to mammography for early detection of breast cancers. To facilitate the interpretation of these images, computer aided detection systems are being developed in which mass segmentation is an essential component for feature extraction and temporal comparisons. However, automated segmentation of masses is challenging because of the large variety in shape, size, and texture of these 3-D objects. In this paper, the authors aim to develop a computerized segmentation system, which uses a seed position as the only priori of the problem. A two-stage segmentation approach has been proposed incorporating shape information of training masses. At the first stage, a new adaptive region growing algorithm is used to give a rough estimation of the mass boundary. The similarity threshold of the proposed algorithm is determined using a Gaussian mixture model based on the volume and circularity of the training masses. In the second stage, a novel geometric edge-based deformable model is introduced using the result of the first stage as the initial contour. In a data set of 50 masses, including 38 malignant and 12 benign lesions, the proposed segmentation method achieved a mean Dice of 0.74 ± 0.19 which outperformed the adaptive region growing with a mean Dice of 0.65 ± 0.2 (p-value < 0.02). Moreover, the resulting mean Dice was significantly (p-value < 0.001) better than that of the distance regularized level set evolution method (0.52 ± 0.27). The supervised method presented in this paper achieved accurate mass segmentation results in terms of Dice measure. The suggested segmentation method can be utilized in two aspects: 1) to automatically measure the change in volume of breast lesions over time and 2) to extract features for a computer aided detection or diagnosis system.
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Liao X, Li J, Orlandini L, Xu P, Li C, Wang P, Chen Y, Xu J, Tan T, Zhang Y. EP-1921: Dosimetric study of neck skin dose for early-stage nasopharyngeal carcinoma. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32230-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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