Star-ECG: Visualization of Electrocardiograms for Arrhythmia and Heart Rate Variability.

Conventional electrocardiograms (ECG) are displayed in one dimension. Reading one-dimensional ECG waveform becomes challenging when one wants to visualize the heart rate variability with naked eye. Some ECG visualization techniques have been proposed. However, they rely on domain knowledge to comprehend the heart rate variability. To improve the readability for patients and non-experts, we introduce Star-ECG, a novel ECG visualization approach. Such approach projects ECG waveforms onto a two-dimensional plane in a circular form. We demonstrate that Star-ECG offers not only easily deciphered visualization of cardiac abnormalities and heart rate variability, but also the application of state-of-the-art arrhythmia classification with integrated deep neural networks. We also report positive user feedback from both experts and non-experts that Star-ECG can provide readable and helpful information to monitor cardiac activities.

An ultrasensitive sandwich type electrochemiluminescence immunosensor for triiodothyronine detection using silver nanoparticle-decorated graphene oxide as a nanocarrier.

An ultrasensitive electrochemiluminescence (ECL) immunosensor was constructed to detect 3,3',5-triiodothyronine (T3). The system employed T3-conjugated, silver nanoparticle-decorated carboxylic graphene oxide (Ag@fGO-T3) as a carrier and anti-T3 antibody-tris(2,2'-bipyridyl) ruthenium(II) (Ru(bpy)3(2+)) as a probe. The Ag@fGO-T3 and Ru(bpy)3(2+) complex could be mobilized rapidly to the anode in the reaction chamber through electrophoresis. The fGO is reduced electrochemically at the electrode, and the electrons could transfer from an anode to the Ru(bpy)3(2+). The complex is excited at the electrode and an ECL signal is produced upon reacting with tripropylamine (TPrA). Because of its large surface area and excellent conductivity, Ag@fGO could enhance ECL signal significantly in the system. Quantitative measurement of T3 could be achieved in the range from 0.1 pg/mL to 0.8 ng/mL with a detection limit of 0.05 pg/mL. In addition, the novel immunosensor showed good specificity in the presence of serum, indicating its high potential in clinical use.

Initial Experience of Modified Four-Branched Graft Technique and Antegrade TEVAR in Acute Type A Aortic Dissection.

BACKGROUND: We report the initial experience of modified four-branched graft technique for proximal aorta and arch repair, feasibly combined with antegrade thoracic endovascular aortic repair (TEVAR) to extend distal aortic reconstruction in acute type A aortic dissection. METHODS: From 2011 to 2013, 12 consecutive patients with acute type A aortic dissection were indicated for arch surgery and underwent surgical replacement of proximal aorta, arch replacement or debranching procedure, and concomitant TEVAR for distal aortic repair. RESULTS: A good surgical field was obtained in all patients. No major complications developed but two hospital deaths were attributed to end-organs damage preoperatively. Good and fast remodeling of thoracic descending aorta was demonstrated in 11 patients in postoperative CT imaging and no aneurysmal dilatation of visceral aorta had been observed in 10 patients during follow-up periods. CONCLUSION: Modified four-branched graft technique facilitated proximal aorta and arch repair, and provided excellent neurological outcome and favorable short-term results. Single-stage operation combined with antegrade TEVAR is feasible and effective to extend the repair down to the descending aorta, and thus achieved good remodeling of thoracic descending aorta.

High Mobility of Graphene-Based Flexible Transparent Field Effect Transistors Doped with TiO2 and Nitrogen-Doped TiO2.

Graphene with carbon atoms bonded in a honeycomb lattice can be tailored by doping various species to alter the electrical properties of the graphene for fabricating p-type or n-type field-effect transistors (FETs). In this study, large-area and single-layer graphene was grown on electropolished Cu foil using the thermal chemical vapor deposition method; the graphene was then transferred onto a poly(ethylene terephthalate) (PET) substrate to produce flexible, transparent FETs. TiO2 and nitrogen-doped TiO2 (N-TiO2) nanoparticles were doped on the graphene to alter its electrical properties, thereby enhancing the carrier mobility and enabling the transistors to sense UV and visible light optically. The results indicated that the electron mobility of the graphene was 1900 cm(2)/(V·s). Dopings of TiO2 and N-doped TiO2 (1.4 at. % N) lead to n-type doping effects demonstrating extremely high carrier mobilities of 53000 and 31000 cm(2)/(V·s), respectively. Through UV and visible light irradiation, TiO2 and N-TiO2 generated electrons and holes; the generated electrons transferred to graphene channels, causing the FETs to exhibit n-type electric behavior. In addition, the Dirac points of the graphene recovered to their original state within 5 min, confirming that the graphene-based FETs were photosensitive to UV and visible light. In a bending state with a radius of curvature greater than 2.0 cm, the carrier mobilities of the FETs did not substantially change, demonstrating the application possibility of the fabricated graphene-based FETs in photosensors.

Highly durable anodes of microbial fuel cells using a reduced graphene oxide/carbon nanotube-coated scaffold.

Melamine sponges coated with reduced graphene oxide/carbon nanotube (rGO-CNT sponges) through a dip-coating method were fabricated that provide a large electrical conductive surface for Escherichiacoli growth and electron transfer in microbial fuel cell. Four rGO-CNT sponges with different thicknesses and arrangements were tested as an anode in this study. The thinnest one (with a thickness of 1.5mm) exhibited the best performance, providing a maximum current density of 335 A m(-3) and a remarkably durable life time of 20 days at 37 °C. Analyses of bacterial colonisation on the rGO-CNT sponges using FE-SEM and the bacterial metabolic activity using the ß-galactosidase assay indicates that the rGO-CNT sponges provide excellent biocompatibility for E. coli proliferation and could help to maintain high bacterial metabolic activity, presumably due to the high mass transfer rate of the porous scaffold. In this regard, the rGO-CNT sponges showed higher durability and performed better electrochemical properties than traditional carbon-based and metal-based anodes.

Photothermal effects of multi-walled carbon nanotubes on the viability of BT-474 cancer cells.

Functionalized multi-walled carbon nanotubes (f-MWCNTs) were conjugated to an antibody of BT-474 cancer cells (f-MWCNTs-ab), and the photothermal effect of the f-MWCNTs-ab for BT-474 cancer cell destruction was demonstrated. After near-infrared irradiation, the f-MWCNTs-ab were more capable of killing cancer cells and possessed higher cell specificity than f-MWCNTs. Quantitative results showed that the viability of the cancer cells was affected by the concentration of the f-MWCNTs-ab solution, irradiation time, and settling time after irradiation. The membrane impermeable fluorescence dye ethidium bromide was used to detect cell viability after near-infrared irradiation, and the results agreed with those obtained from the Alamar Blue cell viability assay. The EtBr fluorescence results suggest that the cell membrane, attached to f-MWCNTs-ab, was damaged after irradiation, which led to cell death and necrosis. Using confocal microscopy, a few f-MWCNTs-ab were detected in the cell, indicating the endocytosis effect. The results not only explain the improved efficiency of thermotherapy but also indicate that necrosis may result from protein denaturation attributing to the heated f-MWCNTs-ab in the cell.

Quantum dot behavior in graphene nanoconstrictions.

Graphene nanoribbons display an imperfectly understood transport gap. We measure transport through nanoribbon devices of several lengths. In long (>/=250 nm) nanoribbons we observe transport through multiple quantum dots in series, while shorter (