On-Chip Integrated, Silicon-Graphene Plasmonic Schottky Photodetector with High Responsivity and Avalanche Photogain.

We report an on-chip integrated metal graphene-silicon plasmonic Schottky photodetector with 85 mA/W responsivity at 1.55 μm and 7% internal quantum efficiency. This is one order of magnitude higher than metal-silicon Schottky photodetectors operated in the same conditions. At a reverse bias of 3 V, we achieve avalanche multiplication, with 0.37A/W responsivity and avalanche photogain ∼2. This paves the way to graphene integrated silicon photonics.We acknowledge funding from EU Graphene Flagship (No. 604391), ERC Grant Hetero2D, and EPSRC Grant Nos. EP/ K01711X/1, EP/K017144/1, EP/N010345/1, EP/M507799/ 1, and EP/L016087/1.This is the final version of the article. It first appeared from the American Chemical Society via https://doi.org/10.1021/acs.nanolett.5b0521

Hybrid Copper-Nanowire–Reduced-Graphene-Oxide Coatings: A “Green Solution” Toward Highly Transparent, Highly Conductive, and Flexible Electrodes for (Opto)Electronics

This study reports a novel green chemistry approach to assemble copper-nanowires/reduced-graphene-oxide hybrid coatings onto inorganic and organic supports. Such films are robust and combine sheet resistances ( 70%) that are rivalling those of indium–tin oxide. These electrodes are suitable for flexible electronic applications as they show a sheet resistance change of <4% after 10 000 bending cycles at a bending radius of 1.0 cm, when supported on polyethylene terephthalate foils. Significantly, the wet-chemistry method involves the preparation of dispersions in environmentally friendly solvents and avoids the use of harmful reagents. Such inks are processed at room temperature on a wide variety of surfaces by spray coating. As a proof-of-concept, this study demonstrates the successful use of such coatings as electrodes in high-performance electrochromic devices. The robustness of the electrodes is demonstrated by performing several tens of thousands of cycles of device operation. These unique conducting coatings hold potential for being exploited as transparent electrodes in numerous optoelectronic applications such as solar cells, light-emitting diodes, and displays

The Role of Ultrasonography in the Evaluation of Abdominal Fat

RATIONALE AND OBJECTIVES: Ultrasonography (US) is becoming popular for the assessment of adiposity, but no one has studied this tool in the light of its potential limitations. Our purpose was to investigate the impact of technical conditions on the evaluation of abdominal fat by US. MATERIALS AND METHODS: Forty-five healthy males and 45 healthy females were consecutively enrolled in the study, randomly assigned to three groups equally distributed by sex, and examined accordingly to three technical points: fasting state (before and after meal [A]), breathing (expiration and inspiration [B]), and US equipment from different generations: 2003 and 1998 (C). Two blinded radiologists performed US in the these opposite conditions, acquiring five parameters representative of subcutaneous and visceral adiposity in two times. Student's t-test and Lin's correlation coefficient were used for statistical analysis to assess differences in the measures as well as in inter- and intra-observer agreements. RESULTS: The maximum and the only statistically significant changes were observed for intra-abdominal fat thickness regarding fasting state and breathing (\u394% = 24.1 \ub1 21.3 and \u394% = 9.2 \ub1 20.4, respectively; P < .0001). Reproducibility and repeatability, especially for visceral fat, were proved more stable in the following conditions: fasting state, expiration, and newer machine (2003). CONCLUSION: This article provides essential information and "range of confidence" for variations that can be expected from using different conditions in the measurement of abdominal adiposity by US to be carefully addressed as well as considered by US users and by researchers involving this technique in the field of body composition

New regions of interest in body composition analysis by dual energy X-ray absorptiometry: "liver adiposity".

Purpose: Hepatic steatosis is an increasing worldwide metabolic disease and the earliest biomarker for the liver fibrosis development. Thus, its detection and quantification during non-invasive examinations should be always considered as clinically relevant. Our aim was to test new designed regions of interest (ROIs) on whole body images acquired by dual energy x-ray absorptiometry (DXA) in comparison with DXA conventional ROIs and ultrasonography (US) in order to evaluate predictive values on liver steatosis detection and grading. Methods and Materials: Ninety-nine subjects directed to body composition assessment by DXA were prospectively enrolled. All patients were submitted to whole body DXA scan (Lunar iDXA, software enCORE 12.0) and underwent US evaluation on the same day to assess hepatic steatosis (mild-moderate-severe). On every DXA image three new liver-suited ROIs were manually created by a skilled radiologist. Fat mass (FM) and FM percentage (FMp) were investigated on whole body and regionally (android and new ROIs). FM and FMp results were correlated with US Results: Out of 99 patients, 70 (70.7%) resulted affected by liver steatosis on US evaluation (32/70&#8722;45.7% mild, 32/70&#8722;45.7% moderate and 6/70&#8722;8.6% severe). FM and FMp of all ROIs were significantly correlated with presence and grading of steatosis (p &lt; 0.001); however, they were able to predict and to distinguish steatosis absence from moderate and severe grade, but not mild. FMp of one among the new liver-suited ROIs showed the best predictive value for liver steatosis. Conclusion: New ROIs should be included in whole body DXA examinations to provide additional information and higher predictive value on liver steatosis

Proximal aortic dissection with coronary malperfusion: Presentation, management, and outcome

Background: Acute myocardial ischemia and infarction due to retrograde dissection of the aortic root reaching the coronary ostia is a potentially fatal condition. Surgical treatment of these patients relies on the re-establishment of an adequate coronary blood flow and on the rescue of jeopardized myocardium. This article reports the results of a selected group of 24 patients with type A acute aortic dissection and coronary artery dissection. We review our experience and illustrate our approach to this condition, which evolved over a 15-year period. Methods: Between July 1985 and March 2000, 24 patients from a total of 211 (11.3%) treated for acute type A aortic dissection had dissection of at least one of the coronary ostia. There were 14 men and 10 women. The mean age was 65.5 years (median 61.7; range 41-78 years). The right coronary artery was involved in 11 patients, the left in 4 patients, and both coronary arteries in 9 patients. At admission, 16 patients had Q waves (66%), inferior in 6 (25%) and anterior, lateral, septal, or posterior in 10 (41%). All procedures were done on an emergency basis within 10 hours (median 4 hours) after initial chest pain and within 2 hours after the patient's arrival. Results: Hospital mortality was 20% (5 patients); 3 patients could not be weaned from cardiopulmonary bypass and died intraoperatively, and 2 patients died postoperatively of low cardiac output. Conclusions: As illustrated in this study, direct coronary repair is a safe alternative to bypass grafting. Aggressive myocardial resuscitation together with early operation is a key factor in the management of these patients

High Responsivity, Large-Area Graphene/MoS2 flexible photodetectors

We present flexible photodetectors (PDs) for visible wavelengths fabricated by stacking centimeter-scale chemical vapor deposited (CVD) single layer graphene (SLG) and single layer CVD MoS2, both wet transferred onto a flexible polyethylene terephthalate substrate. The operation mechanism relies on injection of photoexcited electrons from MoS2 to the SLG channel. The external responsivity is 45.5A/W and the internal 570A/W at 642 nm. This is at least 2 orders of magnitude higher than bulk-semiconductor flexible membranes. The photoconductive gain is up to 4 x 10(5). The photocurrent is in the 0.1-100 mu A range. The devices are semitransparent, with 8% absorptance at 642 nm, and are stable upon bending to a curvature of 1.4 cm. These capabilities and the low-voltage operation (<1 V) make them attractive for wearable applications

Proximal aortic dissection with coronary malperfusion: Presentation, management, and outcome

Background: Acute myocardial ischemia and infarction due to retrograde dissection of the aortic root reaching the coronary ostia is a potentially fatal condition. Surgical treatment of these patients relies on the re-establishment of an adequate coronary blood flow and on the rescue of jeopardized myocardium. This article reports the results of a selected group of 24 patients with type A acute aortic dissection and coronary artery dissection. We review our experience and illustrate our approach to this condition, which evolved over a 15-year period. Methods: Between July 1985 and March 2000, 24 patients from a total of 211 (11.3%) treated for acute type A aortic dissection had dissection of at least one of the coronary ostia. There were 14 men and 10 women. The mean age was 65.5 years (median 61.7; range 41-78 years). The right coronary artery was involved in 11 patients, the left in 4 patients, and both coronary arteries in 9 patients. At admission, 16 patients had Q waves (66%), inferior in 6 (25%) and anterior, lateral, septal, or posterior in 10 (41%). All procedures were done on an emergency basis within 10 hours (median 4 hours) after initial chest pain and within 2 hours after the patient's arrival. Results: Hospital mortality was 20% (5 patients); 3 patients could not be weaned from cardiopulmonary bypass and died intraoperatively, and 2 patients died postoperatively of low cardiac output. Conclusions: As illustrated in this study, direct coronary repair is a safe alternative to bypass grafting. Aggressive myocardial resuscitation together with early operation is a key factor in the management of these patients

p-wave triggered superconductivity in single layer graphene on an electron-doped oxide superconductor

Electron pairing in the vast majority of superconductors follows the Bardeen–Cooper–Schrieffer theory of superconductivity, which describes the condensation of electrons into pairs with antiparallel spins in a singlet state with an s-wave symmetry. Unconventional superconductivity was predicted in single-layer graphene (SLG), with the electrons pairing with a p-wave or chiral d-wave symmetry, depending on the position of the Fermi energy with respect to the Dirac point. By placing SLG on an electron-doped (non-chiral) d-wave superconductor and performing local scanning tunnelling microscopy and spectroscopy, here we show evidence for a p-wave triggered superconducting density of states in SLG. The realization of unconventional superconductivity in SLG offers an exciting new route for the development of p-wave superconductivity using two-dimensional materials with transition temperatures above 4.2 K

p-wave triggered superconductivity in single-layer graphene on an electron-doped oxide superconductor

Electron pairing in the vast majority of superconductors follows the Bardeen-Cooper-Schrieffer theory of superconductivity, which describes the condensation of electrons into pairs with antiparallel spins in a singlet state with an s-wave symmetry. Unconventional superconductivity was predicted in single-layer graphene (SLG), with the electrons pairing with a p-wave or chiral d-wave symmetry, depending on the position of the Fermi energy with respect to the Dirac point. By placing SLG on an electron-doped (non-chiral) d-wave superconductor and performing local scanning tunnelling microscopy and spectroscopy, here we show evidence for a p-wave triggered superconducting density of states in SLG. The realization of unconventional superconductivity in SLG offers an exciting new route for the development of p-wave superconductivity using two-dimensional materials with transition temperatures above 4.2 K.publishe