109 research outputs found
Investigating Amorphous Composition Mix Design Performance and Properties of Fly Ash-Based Geopolymer
Identifying viable replacement for Ordinary Portland Cement (OPC) is part of the effort to limit
CO2 emission during its production. Fly ash-based geopolymer composites have emerged as a sustainable and
promising replacement product with proven comparable binding properties, coupled with superior
characteristic in some area, when compared to OPC. However, fly ash being a by-product of coal combustion,
remains unfavourable in industry application due to its deferring composition dependent on the type of coal
feedstock, resulted in inconsistent mechanical and chemical properties produced. In order to overcome this
shortcoming, a unified method to evaluate fly ash at the amorphous composition level is required. This study
aims to tackle this challenge by establishing a framework to effectively identify relationship among the fly ash
amorphous content and identifying an optimum proportion of alkaline activator in order to optimise its full
potential in geopolymer concrete or mortar production. This is achieved by utilising XRF and Q-XRD analyses
on geopolymer specimen’s amorphous compositions and evaluate their respective compressive strength
through laboratory testing. A number of testing variants are carried out including curing regime, alkaline
activator concentrations, presence of mechanical activation and deferring water content are investigated
Concurrent extrahepatic autoimmunity in autoimmune hepatitis: implications for diagnosis, clinical course and long term outcome
Concurrent extrahepatic autoimmune disease (CEHAID) associated with autoimmune hepatitis (AIH) have been incorporated into the diagnostic criteria stipulated by the International Autoimmune Hepatitis Group (IAIHG). Large comprehensive cohort data on the extrahepatic autoimmunity in AIH remain scanty AIM: To systematically assess features and clinical impact of CEHAID on AIH METHODS: Clinical records of 562 patients with AIH from two tertiary centres in the United Kingdom were retrospectively reviewed RESULTS: Prevalence of CEHAID in patients with AIH were 42%. Autoimmune thyroid disease was the commonest CEHAID associated with AIH (101/562, 18%). Autoimmune skin diseases were more prevalent in AIH-2 than AIH-1 (21.9% vs.7%, p=0.009). Personal history of CEHAID was more commonly found in AIH patients with than without first degree family history of CEHAID [(48/86, 55.8% vs 169/446, 37.9%), p=0.002]. AIH patients with CEHAID were more often female [201/236 (85.2%), p=0.008], had higher post-treatment IAIHG score (22 vs. 20, p<0.001), less reactivity to smooth muscle antibodies (49.8% vs 65%, p<0.001), more likely to have mild fibrosis at diagnosis (20.9% vs. 6.5%, p<0.001), less often had ascites (6.3% vs. 13.6%, p=0.008) and coagulopathy (1.18 vs. 1.27, p=0.013) at presentation. Presence of CEHAID, however, did not significantly affect disease progression, prognosis and survival in AIH CONCLUSIONS: Our study confirms the strong association of CEHAID with AIH. Association between personal and familial extrahepatic autoimmunity especially among first degree relatives was evident. Presence of CEHAID may influence clinical phenotype of AIH at presentation but without notable impact on the long term clinical outcome
Adipokines, insulin resistance, metabolic syndrome, and breast cancer recurrence: a cohort study
Heterogeneity of tumour infiltrating lymphocytes (TILs) in breast cancer and its prognostic significance
Background: Tumour-infiltrating lymphocytes (TILs) in breast cancer (BC) confer prognostic and predictive information. This study aims to assess the spatial and temporal heterogeneity of TILs in BC and its relationship with immune cell subtypes.
Method: Immunohistochemically-defined immune cell subtypes; T-cell markers (CD3, CD8, and FOXP3), B-cell marker (CD20) and histiocytic marker (CD68) were evaluated in a large series (n=1,165) of invasive BC. A subset of full-face haematoxylin and eosin (H&E) stained slides were examined for TILs heterogeneity within primary tumours and the corresponding local recurrent carcinomas to report on spatial and temporal TILs heterogeneity. H&E stained sections from multiple tumour blocks (3-4 blocks per case) representing different tumour areas were evaluated to assess TILS inter-slide heterogeneity as well as intra-slide heterogeneity. Both average (AV-TILs) and hotspot (HS-TILs) stromal TILs were assessed.
Results: AV-TILs showed association with all immune cell subtypes however; the main component were CD3+ cells (mean number = 55) whereas CD20+cells comprised the least component (the mean number = 13). There was no significant statistical difference between TILs across tumour blocks of the same case (p=0.251 for AV-TILs and p=0.162 for HS-TILs). Triple negative breast cancer (TNBC) showed higher TILs compared with other BC subtypes (p<0.001). High AV-TILs, CD3+, CD8+, and CD20+ cells were associated with longer survival in TNBC (p<0.05). High AV-TILs in recurrent tumours showed significant association with shorter post-recurrence survival (p=0.004).
Conclusion: Despite the heterogeneity of immune cell type components, average TILs in one full-face H&E stained section reliably represent whole tumour TILs. TILs were associated with outcome in TNBC as well as provided prognostic significance in recurrent tumour
The trans-ancestral genomic architecture of glycemic traits
Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution. A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Peer reviewe
Si-Compatible Cleaning Process for Graphene Using Low-Density Inductively Coupled Plasma
We report a novel cleaning technique for few-layer graphene (FLG) by using inductively coupled plasma (ICP) of Ar with an extremely low plasma density of 3.5 × 10<sup>8</sup> cm<sup>–3</sup>. It is known that conventional capacitively coupled plasma (CCP) treatments destroy the planar symmetry of FLG, giving rise to the generation of defects. However, ICP treatment with extremely low plasma density is able to remove polymer resist residues from FLG within 3 min at a room temperature of 300 K while retaining the carbon sp<sup>2</sup>-bonding of FLG. It is found that the carrier mobility and charge neutrality point of FLG are restored to their pristine defect-free state after the ICP treatment. Considering the application of graphene to silicon-based electronic devices, such a cleaning method can replace thermal vacuum annealing, electrical current annealing, and wet-chemical treatment due to its advantages of being a low-temperature, large-area, high-throughput, and Si-compatible process
Direct Selective Laser Sintering and Melting of Ceramics: A review
Purpose: This paper aims to provide a review on the process of additive manufacturing of ceramic materials, focusing on partial and full melting of ceramic powder by a high-energy laser beam without the use of binders.
Design/methodology/approach: Selective laser sintering or melting (SLS/SLM) techniques are first introduced, followed by analysis of results from silica (SiO2), zirconia (ZrO2) and ceramic-reinforced metal matrix composites processed by direct laser sintering and melting.
Findings: At the current state of technology, it is still a challenge to fabricate dense ceramic components directly using SLS/SLM. Critical challenges encountered during direct laser melting of ceramic will be discussed, including deposition of ceramic powder layer, interaction between laser and powder particles, dynamic melting and consolidation mechanism of the process and the presence of residual stresses in ceramics processed via SLS/SLM.
Originality/value: Despite the challenges, SLS/SLM still has the potential in fabrication of ceramics. Additional research is needed to understand and establish the optimal interaction between the laser beam and ceramic powder bed for full density part fabrication. Looking into the future, other melting-based techniques for ceramic and composites are presented, along with their potential applications
An integrated, collaborative healthcare model for the early diagnosis and management of dementia: Preliminary audit results from the first transdisciplinary service integrating family medicine and geriatric psychiatry services to the heart of patients’ homes
Abstract Background The number of dementia cases is expected to rise exponentially over the years in many parts of the world. Collaborative healthcare partnerships are envisaged as a solution to this problem. Primary care physicians form the vanguard of early detection of dementia and influence clinical care that these patients receive. However, evidence suggests that they will benefit from closer support from specialist services in dementia care. An interdisciplinary, collaborative memory clinic was established in 2012 as a collaborative effort between a large family medicine based service and a specialist geriatric psychiatry service in Singapore. It is the first service in the world that integrates a family medicine based service with geriatric psychiatry expertise in conjunction with community-based partnerships in an effort to provide holistic, integrated care right into the heart of patients’ homes as well as training in dementia care for family medicine physicians. We describe our model of care and the preliminary findings of our audit on the results of this new model of care. Methods This was a retrospective audit done on the electronic medical records of all patients seen at the Memory Clinic in Choa Chu Kang Polyclinic from August 2013 to March 2016. The information collected included gender, referral source, patient trajectories, presence of behavioural and psychological symptoms of dementia and percentage of caregivers found to be in need of support. A detailed outline of the service workflow and processes were described. Results A majority (93.5%) of the patients had their memory problems managed at the memory clinic without escalation to other specialist services. 22.7% of patients presented with behavioural and psychological symptoms of dementia. When initially assessed, a majority (82.2%) of patients’ caregivers were found to be in need of support with 99.5% of such caregivers’ needs addressed with memory clinic services. Conclusion Our model of care has the potential to shape future dementia care in Singapore and other countries with a similar healthcare setting. Redesigning and evolving healthcare services to promote close collaboration between primary care practitioners and specialist services for dementia care can facilitate seamless delivery of care for the benefit of patients
Anti-diabetic effect of black ginseng extract by augmentation of AMPK protein activity and upregulation of GLUT2 and GLUT4 expression in db/db mice
Abstract Background Black ginseng (Panax ginseng C. A. Meyer), three to nine times-steamed and dried ginseng, has biological and pharmacological activities. In this study, the anti-diabetic effects of the black ginseng ethanol extract (GBG05-FF) in typical type 2 diabetic model db/db mice were investigated. Methods The effect of GBG05-FF in Type 2 diabetic mice was investigated by their blood analysis, biological mechanism analysis, and histological analysis. Results The mice group treated with GBG05-FF showed decreased fasting blood glucose and glucose tolerance compared to that of the nontreated GBG05-FF group. In the blood analysis, GBG05-FF decreased main plasma parameter such as HbA1c, triglyceride, and total-cholesterol levels related to diabetes and improved the expression of genes and protein related to glucose homeostasis and glucose uptake in the liver and muscle. The histological analysis result shows that GBG05-FF decreased lipid accumulation in the liver and damage in the muscle. Moreover, GBG05-FF increased the phosphorylation of the AMPK in the liver and upregulated the expression of GLUT2 in liver and GLUT4 in muscle. Therefore, the mechanisms of GBG05-FF may be related to suppressing gluconeogenesis by activating AMPK in the liver and affecting glucose uptake in surrounding tissues via the upregulation of GLUT2 and GLUT4 expression. Conclusion These findings provided a new insight into the anti-diabetic clinical applications of GBG05-FF and it might play an important role in the development of promising functional foods and drugs from the viewpoint of the chemical composition and biological activities
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