Thermal interface materials (TIMs) are essential components to deplete the accumulated heat with efficient thermal management in the majority of power electronic systems such that the interfacial ...thermal resistance (ITR) should be significantly reduced. A reduced percolation threshold of hybrid fillers of ball-milled exfoliated graphite nanoplatelets and AgNWs are used for enhanced thermal interface materials via the assembly of high-quality ball-milled exfoliated graphite nanoplatelets (BMEGN) and AgNWs on a flexible Polydimethylsiloxane (PDMS) substrate. BMEGN modified surface with increased specific area and reduced percolation interface, together with the generation of effective 3D thermal conductive pathways between the 2D graphite and 1D AgNWs, which was experimentally measured to possess the significant improvement in thermal conductivity. The proposed method of thermally conductive film of AgNWs at the loading of 2.0 mg/mL can dramatically increase the in-plane thermal conductivity (K//) to 29.2 W/mK, while the through-plane thermal conductivity (K┴) shows the value of 4.94 W/mK by using the reduced percolation threshold. Anisotropy reaches up to K///K┴ = 5.9 with the proposed percolation, which is much larger than filler only BMEGN, indicating that the effective thermal conductive path (TCP) can be networked on a PDMS polymeric to thermally dissipate high power electronics with enhanced heat management capability. Both CPU and IGBT tests of the proposed TIMs with fillers of AgNWs loading 2.0 mg/mL can effectively minimize temperature rise to ~16 °C and ~17 °C as favorably compared with thermal grease alone. Furthermore, transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used for surface morphology, microstructure evolution, disorder evaluation, phase analysis and thermal stability of the composite material.
Peroxynitrite (ONOO–), the product of a radical combination reaction of nitric oxide and superoxide, is a potent biological oxidant involved in a broad spectrum of physiological and pathological ...processes. Herein we report the development, characterization, and biological applications of a new fluorescent probe, HKGreen-4, for peroxynitrite detection and imaging. HKGreen-4 utilizes a peroxynitrite-triggered oxidative N-dearylation reaction to achieve an exceptionally sensitive and selective fluorescence turn-on response toward peroxynitrite in chemical systems and biological samples. We have thoroughly evaluated the utility of HKGreen-4 for intracellular peroxynitrite imaging and, more importantly, demonstrated that HKGreen-4 can be efficiently employed to visualize endogenous peroxynitrite generated in Escherichia coli-challenged macrophages and in live tissues from a mouse model of atherosclerosis. This probe should serve as a powerful molecular imaging tool to explore peroxynitrite biology under a variety of physiological and pathological contexts.
Objective
With increasing prevalence of childhood obesity worldwide, the incidence of pediatric‐onset type 2 diabetes (T2D) is also increasing in many countries. We aim to analyze the time trend and ...incidence of T2D in children in Hong Kong from 2008 to 2017, and to characterize clinical characteristics at diagnosis.
Methods
Data were retrieved from the Hong Kong Childhood Diabetes Registry. All children with T2D diagnosed at the age of less than 18 years from January 1, 2008 to December 31, 2017 and managed in the public health care system were included in this study.
Results
In the incident years of 2008–2017 period, 391 children were diagnosed with T2D. The crude incidence rate was 3.42 per 100,000 persons/year 95% confidence interval (CI) 3.08–3.76, which was much higher than that in last registry of 1.27 per 100,000 persons/year in 1997–2007 (P < 0.001).Most children (76%) were asymptomatic and were diagnosed by routine screening. At presentation, a significant proportion presented with co‐morbidities including fatty liver (37.9%), dyslipidaemia (35.3%), hypertension (22.5%), and microalbuminuria (12.8%).
Conclusions
The incidence of T2D in children has increased significantly in Hong Kong. Most of them were asymptomatic and picked up on routine health screening. Yet, comorbidities were commonly identified at diagnosis.
People with type 2 diabetes (T2D) have increased cancer risk. Liver cancer (LC) has a high prevalence in East Asia and is one of the leading causes of cancer death globally. Diagnosis of LC at early ...stage carries good prognosis. We used stored serum from patients of Hong Kong Diabetes Register before cancer diagnosis to extract RNA to screen for microRNA markers for early detection of LC in T2D. After screening with Affymetrix GeneChip microarray with serum RNA from 19 incident T2D LC (T2D-LC), 20 T2D cancer free (T2D-CF) and 20 non-T2D non-cancer patients, top signals were validated in a 3-group comparison including 1888 T2D-CF, 127 T2D-LC, and 487 T2D patients with non-liver cancer patients using qPCR. We detected 2.55-fold increase in miR-122-5p and 9.21-fold increase in miR-455-3p in the T2D-LC group. Using ROC analysis, miR-122-5p and miR-455-3p jointly predicted LC with an area under the curve of 0.770. After adjustment for confounders, each unit increase of miR-455-3p increased the odds ratio for liver cancer by 1.022. Increased serum levels of miR-122-5p and miR-455-3p were independently associated with increased risk of incident LC in T2D and may serve as potential biomarkers for early detection of LC in T2D.
A simple and sustainable production of nanoplatelet graphite at low cost is presented using carbon-based materials, including the recycled lead-graphite pencils. In this work, exfoliated graphite ...nanoplatelets (EGNs), ball-milled exfoliated graphite nanoplatelets (BMEGNs) and recycled lead-graphite pencils (recycled 2B), as well as thermally cured polydimethylsiloxane (PDMS), are used to fabricate highly stretchable thermal-interface materials (TIMs) with good thermally conductive and mechanically robust properties. Several characterization techniques including scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) showed that recycled nanoplatelet graphite with lateral size of tens of micrometers can be reliably produced. Experimentally, the thermal conductivity was measured for EGNs, BMEGNs and recycled 2B fillers with/without the effect of ball milling. The in-plane thermal conductivities of 12.97 W/mK (EGN), 13.53 W/mK (recycled 2B) and 14.56 W/mK (BMEGN) and through-plane thermal conductivities of 0.76 W/mK (EGN), 0.84 W/mK (recycled 2B) and 0.95 W/mK (BMEGN) were experimentally measured. Anisotropies were calculated as 15.31, 15.98 and 16.95 for EGN, recycled 2B and BMEGN, respectively. In addition, the mechanical robustness of the developed TIMs is such that they are capable of repeatedly bending at 180 degrees with outstanding flexibility, including the low-cost renewable material of recycled lead-graphite pencils. For heat dissipating application in high-power electronics, the TIMs of recycled 2B are capable of effectively reducing temperatures to approximately 6.2 °C as favorably compared with thermal grease alone.
Atherosclerosis appears to have multifactorial causes - microbial component like lipopolysaccharides (LPS) and other pathogen associated molecular patterns may be plausible factors. The gut ...microbiota is an ample source of such stimulants, and its dependent metabolites and altered gut metagenome has been an established link to atherosclerosis. In this exploratory pilot study, we aimed to elucidate whether microbial intervention with probiotics L. rhamnosus GG (LGG) or pharmaceuticals telmisartan (TLM) could improve atherosclerosis in a gut microbiota associated manner.
Atherosclerotic phenotype was established by 12 weeks feeding of high fat (HF) diet as opposed to normal chow diet (ND) in apolipoprotein E knockout (ApoE
) mice. LGG or TLM supplementation to HF diet was studied.
Both LGG and TLM significantly reduced atherosclerotic plaque size and improved various biomarkers including endotoxin to different extents. Colonial microbiota analysis revealed that TLM restored HF diet induced increase in Firmicutes/Bacteroidetes ratio and decrease in alpha diversity; and led to a more distinct microbial clustering closer to ND in PCoA plot. Eubacteria, Anaeroplasma, Roseburia, Oscillospira and Dehalobacteria appeared to be protective against atherosclerosis and showed significant negative correlation with atherosclerotic plaque size and plasma adipocyte - fatty acid binding protein (A-FABP) and cholesterol.
LGG and TLM improved atherosclerosis with TLM having a more distinct alteration in the colonic gut microbiota. Altered bacteria genera and reduced alpha diversity had significant correlations to atherosclerotic plaque size, plasma A-FABP and cholesterol. Future studies on such bacterial functional influence in lipid metabolism will be warranted.
Objective
The incidence of childhood‐onset type 1 diabetes (T1D) has been reported to be rising but there is also evidence that it has been attenuated in recent years. We described the time trends ...and the incidence of T1D in children in Hong Kong from 2008 to 2017 and compared with the previous local registry in 1997 to 2007.
Methods
Data were extracted from the Hong Kong Childhood Diabetes Registry, which was established in 2016. It consists of a retrospective registry (including all childhood diabetes diagnosed in 2008 to 2015) and a prospective registry (including all T1D children diagnosed from 2016 onwards). All T1D children diagnosed at the age of less than 18 years from 1 January 2008 to 31 December 2017 and managed in the public system were included in this study.
Results
For the incident years in the 2008 to 2017 period, a total of 498 children with T1D was identified. The crude incidence rate was 4.3 per 100 000 person/year (95% confidence interval 3.96‐4.72), which was much higher than the last registry of 2.2 per 100 000 persons/year. Using general linear model, the increment is statistically significant (P = .02). When compared to the last registry, the rate of increment had attenuated, with annual increment in crude incidence in the two periods for T1D <15 years changing from 4.3% to 3.5% (P = .02).
Conclusions
The incidence of T1D children increased significantly in the past two decades in Hong Kong, but the rate of increase had attenuated in recent years.
Ovarian cancer is characterised by frequent recurrence due to persistent presence of residual cancer stem cells (CSCs). Here, we identify and characterise tumour subsets from ascites-derived tumour ...cells with stemness, metastasis and metabolic switch properties and to delineate the involvement of pyruvate dehydrogenase kinase 4 (PDK4) in such process.
Ovarian cancer cells/cell lines derived from ascites were used for tumourspheres/ALDH+CD44+ subset isolation. The functional roles and downstream signalling of PDK4 were explored. Its association with clinical outcome of ovarian cancer was analysed.
We demonstrated enhanced CSC characteristics of tumour cells derived from ovarian cancer ascites, concomitant with ALDH and CD44 subset enrichment and high PDK4 expression, compared to primary tumours. We further showed tumourspheres/ALDH+CD44+ subsets from ascites-derived tumour cells/cell lines with CSC properties and enhanced glycolysis. Clinically, PDK4 expression was correlated with aggressive features. Notably, blockade of PDK4 in tumourspheres/ALDH+CD44+ subsets led to inhibition of CSC characteristics, glycolysis and activation of STAT3/AKT/NF-κB/IL-8 (signal transducer and activator of transcription 3/protein kinases B/nuclear factor-κB/interleukin-8) signalling. Conversely, overexpression of PDK4 in ALDH-CD44- subsets exerted the opposite effects.
Ascites-derived ALDH+CD44+ tumour cell subsets endow stemness, metastatic and metabolic switch properties via PDK4-mediated STAT3/AKT/NF-κB/IL-8 signalling, suggesting PDK4 as a viable therapeutic molecular target for ovarian cancer management.
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