1,264 research outputs found
Mutual pulse injection-seeding scheme by the use of two Fabry–Pérot laser diodes for tunable dual-wavelength optical short-pulse generation
2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
A totally laparoscopic associating liver partition and portal vein ligation for staged hepatectomy assisted with radiofrequency (radiofrequency assisted liver partition with portal vein ligation) for staged liver resection
In order to induce liver hypertrophy to enable liver resection in patients with a small future liver remnant, various methods have been proposed in addition to portal vein embolisation. Most recently, the ALPPS technique has gained significant international interest. This technique is limited by the high morbidity associated with an in-situ liver splitting and the patient undergoing two open operations. We present the case of a variant ALPPS technique performed entirely laparoscopically with no major morbidity or mortality. An increased liver volume of 57.9% was seen after 14 days. This technique is feasible to perform and compares favourably to other ALPPS methods whilst gaining the advantages of laparoscopic surgery
Negotiable Auction Based on Mixed Graph: A Novel Spectrum Sharing Framework
© 2015 IEEE. Auction-based spectrum sharing is a promising solution to improve the spectrum utilization in 5G networks. Along with the spatial reuse, we observe that the ability to adjust the coverage of a spectrum bidder can provide room to itself for further negotiation while auctioning. In this paper, we propose a novel economic tool, size-negotiable auction mechanism (SNAM), which provides a hybrid solution between auction and negotiation for multi-buyers sharing spectrum chunks from a common database. Unlike existing auction-based spectrum sharing models, each bidder of the SNAM submits its bid for using the spectrum per unit space and a set of coverage ranges over which the bidder is willing to pay for the spectrum. The auctioneer then coordinates the interference areas (or coverage negotiation) to ensure no two winners interfere with each other while aiming to maximize the auction's total coverage area or revenue. In this scenario, the undirected graph used by existing auction mechanisms fails to model the interference among bidders. Instead, we construct a mixed interference graph and prove that SNAM's auctioning on the mixed graph is truthful and individually rational. Simulation results show that, compared with existing auction approaches, the proposed SNAM dramatically improves the spatial efficiency, hence leads to significantly higher seller revenue and buyer satisfaction under various setups. Thanks to its low complexity and low overhead, SNAM can target fine timescale trading (in minutes or hours) with a large number of bidders and requested coverages
Local antiferromagnetic exchange and collaborative Fermi surface as key ingredients of high temperature superconductors
Cuprates, ferropnictides and ferrochalcogenides are three classes of
unconventional high-temperature superconductors, who share similar phase
diagrams in which superconductivity develops after a magnetic order is
suppressed, suggesting a strong interplay between superconductivity and
magnetism, although the exact picture of this interplay remains elusive. Here
we show that there is a direct bridge connecting antiferromagnetic exchange
interactions determined in the parent compounds of these materials to the
superconducting gap functions observed in the corresponding superconducting
materials. High superconducting transition temperature is achieved when the
Fermi surface topology matches the form factor of the pairing symmetry favored
by local magnetic exchange interactions. Our result offers a principle guide to
search for new high temperature superconductors.Comment: 12 pages, 5 figures, 1 table, 1 supplementary materia
Simple system for optical short-pulse generation in both active mode-locking and self-seeding schemes
Author name used in this publication: H. L. HoAuthor name used in this publication: H. L. Liu2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Photonic Analogue of Two-dimensional Topological Insulators and Helical One-Way Edge Transport in Bi-Anisotropic Metamaterials
Recent progress in understanding the topological properties of condensed
matter has led to the discovery of time-reversal invariant topological
insulators. Because of limitations imposed by nature, topologically non-trivial
electronic order seems to be uncommon except in small-band-gap semiconductors
with strong spin-orbit interactions. In this Article we show that artificial
electromagnetic structures, known as metamaterials, provide an attractive
platform for designing photonic analogues of topological insulators. We
demonstrate that a judicious choice of the metamaterial parameters can create
photonic phases that support a pair of helical edge states, and that these edge
states enable one-way photonic transport that is robust against disorder.Comment: 13 pages, 3 figure
In Vivo Regulation of Glycogen Synthase Kinase-3β (GSK3β) by Serotonergic Activity in Mouse Brain
The goal of this study was to determine if serotonergic activity, which is impaired in depression, regulates the phosphorylation of glycogen synthase kinase-3β (GSK3β) in mouse brain in vivo. GSK3β is inhibited by phosphorylation on serine-9 and is a target of the mood stabilizer lithium. Following administration to mice of d-fenfluramine to stimulate serotonin (5HT) release and reduce its reuptake, and clorgyline to inhibit 5HT catabolism, levels of phospho-Ser9-GSK3β were 300–400% of control levels in the prefrontal cortex, hippocampus, and striatum. Treatment with monoamine reuptake inhibitors fluoxetine and imipramine also increased the level of phospho-Ser9-GSK3β. Using receptor selective agonists and antagonists, 5HT1A receptors were found to mediate increases, and 5HT2 receptors decreases, in phospho-Ser9-GSK3β levels. This indicates that serotonergic regulation of the phosphorylation of GSK3β is achieved by a balance between the opposing actions of these 5HT receptor subtypes. These findings demonstrate for the first time that serotonergic activity regulates the phosphorylation of GSK3β and show that this regulation occurs in mammalian brain in vivo. These results raise the possibility that impaired inhibitory control of GSK3β may occur in conditions where serotonergic activity is dysregulated, such as in mood disorders
Nanoscale phase separation of antiferromagnetic order and superconductivity in KFeSe
We report an in-plane optical spectroscopy study on the iron-selenide
superconductor KFeSe. The measurement revealed the
development of a sharp reflectance edge below T at frequency much smaller
than the superconducting energy gap on a relatively incoherent electronic
background, a phenomenon which was not seen in any other Fe-based
superconductors so far investigated. Furthermore, the feature could be
noticeably suppressed and shifted to lower frequency by a moderate magnetic
field. Our analysis indicates that this edge structure arises from the
development of a Josephson-coupling plasmon in the superconducting condensate.
Together with the transmission electron microscopy analysis, our study yields
compelling evidence for the presence of nanoscale phase separation between
superconductivity and magnetism. The results also enable us to understand
various seemingly controversial experimental data probed from different
techniques.Comment: 6 figures, published versio
Panbacterial real-time PCR to evaluate bacterial burden in chronic wounds treated with Cutimed™ Sorbact™
The impact of polymicrobial bacterial infection on chronic wounds has been studied extensively, but standard bacteriological analysis is not always sensitive enough. Molecular approaches represent a promising alternative to the standard bacteriological analysis. This work aimed to assess the usefulness of a panbacterial quantitative real-time PCR reaction to quantitate the total bacterial load in chronic wounds treated with Cutimed™ Sorbact™, a novel therapeutic approach based on hydrophobic binding of bacteria to a membrane. The results obtained by panbacterial real-time PCR on conserved sequences of the bacterial 16S gene show that the bacterial burden significantly decreased in 10 out of 15 healing chronic wounds, and did not change in 5 out of 5 non-healing chronic wounds. On the contrary, classical culture for S. aureus and P. aeruginosa, and real-time PCR for Bacteroides and Fusobacterium did not show any correlation with the clinical outcome. Our study also shows that quantification of chronic wounds by panbacterial real-time PCR is to be performed on biopsies and not on swabs. These results show that panbacterial real-time PCR is a promising and quick method of determining the total bacterial load in chronic wounds, and suggest that it might be an important biomarker for the prognosis of chronic wounds under treatment
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